Suplemento Especial: II PanAmerican Congress of Physiological Sciences

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EDITORIAL

Recientes avances en Fisiología
Jairo Lumpuy-Castillo
6 lecturas
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SHORT COMMUNICATIONS

Inflammation induced disruption in Circadian Rhythm in Pulmonary Endothelial cells is modulated via reactive oxygen species

Introduction: While the circadian clock has been characterized in systemic blood vessels and well established to contribute to various inflammatory pathologies associated with the endothelium, the mechanisms of circadian control of endothelial inflammation specifically in pulmonary inflammation is not known. We hypothesized that the pulmonary vasculature is under circadian control and that this rhythm is disrupted by inflammatory stimuli via redox mediated processes.

Objective:To determine the possible relationship between the inflammation induced disruption in Circadian Rhythm in pulmonary endothelial cells and reactive oxygen species.

Material and Methods: Circadian rhythms were monitored in pulmonary artery segments and endothelial cells isolated from mPer2luciferase transgenic mice in presence of an inflammatory stimuli (LPS). Reactive oxygen species (ROS) production in LPS treated cells was measured by fluorescence microscopy using the cell permeant dye CellROX Green.

Results: The circadian rhythm of the pulmonary endothelium was disrupted by LPS. To identify the mechanism of this disruption, ROS production in these cells was monitored. At 3 h post LPS treatment, we observed a >3 fold increase in ROS production which further increased to 6 fold by 36 h and returned to baseline values at 72 h. ROS was inhibited by pretreating the cells with the NADPH oxidase 2 (NOX2) inhibitor DPI. Addition of DPI, prior to LPS pretreatment also restored the circadian rhythmicity of the pulmonary endothelium.

Conclusions: Pro-inflammatory stimuli can disrupt circadian rhythms in the pulmonary endothelium via NOX2 regulated ROS signaling. We speculate that under inflammatory conditions disrupted circadian rhythms in the pulmonary vascular endothelium contributes to worsening outcomes.

Shampa Chatterjee, Yool Lee, Jian Qin Tao, Amita Sehgal, Shaon Sengputa
48 lecturas
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Nanoparticle Fate in Alveolar Epithelial Cells: Uptake, Distribution and Exocytosis

Introduction. Strategies for enhancement of nanoparticle-driven AEC gene/drug delivery and/or amelioration of AEC nanoparticle-related cellular toxicity is an important target in the next future.

Objective: To prove that autophagic processing of nanoparticular is essencial for maintenance of alveolar epithelial cells.

Material and Methods:  Utilizing confocal microscopy, we quantitatively assessed uptake, processing and egress of near infrared (NIR) fluorescence-labeled polystyrene nanoparticles (PNP) in live primary rat alveolar epithelial cell (AEC) monolayers (RAECM) after apical exposure. Intracellular PNP content was assessed by measuring the time courses of NIR fluorescence intensity for PNP of 20, 100 and 200 nm and for apical [PNP] (20 nm) of 40, 80 and 160 ng/mL. PNP content and colocalization with intracellular vesicles (including autophagosomes, lysosomes, Golgi and endoplasmic reticulum) in PNP-exposed AEC were determined over the entire cell volume via z-stacking. Involvement of endocytosis in PNP uptake was tested by pharmacologic inhibition of classical endocytotic pathways. Colocalization of early endosome marker Rab5-GFP with PNP in apically exposed AEC was investigated for up to 3 hr. The role of autophagy in intracellular processing of PNP or ambient pollution particles (APP, diameter ≤200 nm) was assessed using LC3 (microtubule-associated protein 1A/1B light chain 3B)-II immunolabeling and inhibitors of autophagosome formation (3-methyladenine (3-MA)) or autolysosome formation (bafilomycin or chloroquine). Mechanisms of PNP uptake into and egress from RAECM were further studied by inhibition of microtubule polymerization required for movement of PNP-filled intracellular vesicles (e.g., autophagosomes) and mobilization of intracellular [Ca2+] known to speed up exocytosis. Isotropic cuvette-based microfluorimetry was used to determine intracellular [PNP] from PNP content assessed by anisotropic confocal microscopy.

Results: Uptake rates and steady state intracellular content decreased as PNP size increased from 20 to 200 nm. Uptake rates and steady state intracellular content increased with increased apical [PNP] (20 nm) and were unaffected by inhibition of endocytic pathways. <3% of total intracellular PNP colocalized with Rab5 positive intracellular vesicles post-PNP exposure for up to 3 hr. Both PNP and APP exposure led to marked increases in LC3-II expression, and PNP increasingly co-localized with autophagosomes and/or lysosomes over time. PNP egress exhibited both fast [Ca2+]-dependent release and a slower diffusion-like process. Inhibition of microtubule polymerization curtailed initial rapid PNP egress, causing elevated vesicular and intracellular PNP content. Interference with autophagosome formation led to slower PNP uptake and markedly decreased steady state intracellular PNP content. At steady state, cytosolic [PNP] was higher than apical [PNP], and vesicular [PNP] (~80% of intracellular PNP content) exceeded both cytosolic [PNP] and intracellular [PNP].

Conclusions: These findings are consistent with the hypotheses that (1) autophagic processing of nanoparticles is essential for maintenance of AEC integrity, (2) altered autophagy and/or lysosomal exocytosis may lead to AEC injury and (3) intracellular [PNP] in AEC is regulable, suggesting strategies for enhancement of nanoparticle-driven AEC gene/drug delivery and/or amelioration of AEC nanoparticle-related cellular toxicity.

 

Edward Crandall, Arnold Sipos, Kim Kwang-Jin, Zea Borok, Ulf Per Flodby
30 lecturas
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Role Of Raphe In The Body Temperature Regulation Of Precocious Birds

Introduction: It is demonstrated in mammals that, at least in rats, caudal brain regions, such as raphe nuclei, are involved in the modulation of thermoeffectors for heat loss and heat production, such as peripheral vasodilation/vasoconstriction, nonshivering and shivering thermogenesis. If the same scenario occurs in the other group of endothermic vertebrates, i.e., birds, it is still completely unknown.

Objective: To verify the role of raphe in the regulation of body temperature (Tb) in chicken chicks at the first week of life after hatching.

Material and Methods: Specifically, in this first experimental approach, we verified the effect of the disinhibition of raphe on body temperature (Tb) of chicks. To this end, Tb was measured in chicks, implanted with a mini temperature sensor in the coelomatic cavity, before and each 10 min up to 2hs after intra-raphe microinjections of the GABA receptor antagonist bicuculline (0.05mM and 0.5mM) or saline (vehicle). Protocols were approved by the local Animal Care Committee (CEUA of FCAV/Unesp, nº 013907/17).

Results: Bicuculline (0.05 mM) significantly decreased (P <0.05) Tb of the animals when compared to the vehicle group (in °C. Vehicle: 40.8 ± 0.1, bicuculline 0.05 mM: 40.3 ± 0.2, bicuculline 0.5 mM: 40.8 ± 0.1).

Conclusions: Our preliminary results suggest that the disinhibition of Raphe neurons is able to modulate the Tb of chicks, and the thermoeffectors involved in this response is currently under investigation.

 

Caroline Cristina Silva, Welex Cândido Silva, Luciane Helena Gargaglioni, Kênia Cardoso Bícego
23 lecturas
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Role of the parafacial respiratory group in the recruitment of abdominal activity across sleep states

Introduction: In resting conditions, breathing is typically characterized by an active inspiratory phase and a passive expiratory phase. Expiration may become active through abdominal (ABD) muscle recruitment during periods of increased inspiratory requirements. This respiratory rhythm is thought to be controlled by three coupled oscillators: preBötzinger complex (preBötC) for generating inspiration, the parafacial respiratory group (pFRG) for generating active expiration, and the post-inspiratory complex (PiCo) which is thought to control the post-inspiratory phase. Research addressing the role of pFRG in ventilation and rhythm generation across sleep states is limited. Recent work in our laboratory reports the occurrence of ABD recruitment during REM sleep, despite the induction of muscle paralysis during this sleep state. This ABD recruitment was associated with a stabilization of breathing in healthy rats. Because pFRG generates active expiration through the engagement of ABD muscles, we hypothesize that the expiratory oscillator is also responsible for the ABD recruitment observed during REM sleep in healthy rats.

Objective: To demonstrate of the parafacial respiratory group in the recruitment of abdominal activity across sleep states.

Material and Methods: To test this hypothesis, we inhibited and activated the pFRG oscillator using a chemogenetic approach (DREADDs) while simultaneously recording EEG, airflow, DIA, ABD and neck EMG of transfected rats across sleep/wake cycles.

Results: Manipulation of pFRG activity does not affect the sleep architecture. However, activity of pFRG seems to have an effect in the occurrence of ABD recruitment events during REM sleep. Inhibition of pFRG (N=7) significantly reduced the number of REM events with ABD recruitment and the intensity of these events (described as the ABD to DIA ratio), whereas activation of this oscillator (N=8) resulted in an increase of the number of REM events in which ABD recruitment was observed and the intensity of those events. Interestingly, modulation of pFRG activity did not seem to affect the occurrence of ABD recruitment during NREM sleep.

Conclusions: The occurrence of ABD recruitment during sleep may be state dependent. Further research investigating the mechanisms behind the recruitment of ABD activity specifically during REM and NREM sleep will be necessary.

Annette Pisanski Hernandez-Abad, Nils Koch, Xiu Ding, Silvia Pagliardini
47 lecturas
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Insulin in the Carotid Sinus Increases Suprahepatic and Arterial Glucose Levels

Introduction: Insulin is a well-known enzyme but there are some relationships that remains not completely clear in rats.

Objective: To analyze the effects of this hormone infused into the isolated carotid sinus (ICS), on suprahepatic and arterial glucose levels.

Material and Methods: All procedures were carried out in accordance with the United States National Institutes of Health. Ten male Wistar rats 280-300 g anesthetized with sodium pentobarbital (5 mg /100 g i.p.) after 12 h fasting were randomly divided into control and experimental groups.  Saline (100µL) or insulin (15 mIU/rat in 100 μL saline) was injected into the ICS. To blood collection, the catheters in the suprahepatic vein (SHV), starting in the jugular vein and into the femoral artery (FA) were placed. Glucose levels were determined at -10 and -5 min before saline or insulin were injected in the ICS; and 1, 5, 10, 20, and 40 min after the above injection.  

Results: Insulin injection significantly increased glucose levels in the SHV from 128.8 ± 5.2 mg/dL to 207.4 ± 10.6 mg/dL (p = 0.00005), while in the FA they increase from 123.4 ± 6.7 mg/dL to 199.8 ± 9.6 mg/dL (p = 0.0008) at 40 min after insulin injection. Control group with saline did not show significant changes (p = 0.97 in FA) and (p = 0.34 in SHV). The comparison between both groups was significant on arterial (p = 0.007) and venous (p = 0.003) blood glucose levels. Conclusions: As other studies, report an overactivation of the carotid bodies and sympathetic activity increase after insulin injections in the carotid artery, we assume that insulin in the carotid bodies activates hepatic glycogenolysis to increase blood glucose levels (hyperglycemia)

José Luis Cadenas Freixas, Sergio A. Montero Cruz, Mónica Lemus Vidal, Héctor R. Tejeda Chávez, Edgar U. Mejía Chávez, Julián E. Martínez Sánchez, Claudia Z. Valle Rubio, Sergio A. Montero Villegas, Elena R oces Dorronsoro
31 lecturas
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Evaluation in the Monoamine Concentrations and Microglia Morphology in the Locus Coeruleus of Female Ovariectomized Rats Submitted to Hypercapnia

Introduction: Ovariectomy reduces the hypercapnic ventilatory response and Locus Coeruleus (LC) appears to be involved in this response. Sex hormones as well as CO 2 can act in neurons of LC and also in microglial cells, however what these stimuli promoted in LC monoamine concentrations and microglial morphology is still unknown.

Objective: To evaluate monoamine release in the LC, we measured the concentration of norepinephrine (NE), serotonin (5-HT) and dopamine (DA), and the metabolites 5-hydroxyindoleacetic acid (5HIAA; metabolite of 5-HT) and 5-hydroxyphenylacetic acid (DOPAC; metabolite of DA) in the LC, by HPCL method.

Material and Methods: Protocols were approved by the local Animal Care and Use Committee (protocol no 8.129/16). For LC microglial analysis, we used ionized calcium-binding adapter molecule-1 (Iba1) immunolabeling to compare the density and morphology of microglia in the LC of OVX and intact female rats during normocapnia or hypercapnia (5%CO2). Protocols were approved by Laval University Animal Care Committee (Permit Number: 2012-023).

Results: No significant differences were found in the quantification of the monoamines analyzed as well as their metabolites in OVX female rats compared to intact animals during normocapnia and hypercapnia. Regarding microglia cells in the LC, we observed an increase on morphological index, that indicates a reactive form of the cell, of OVX animals, and also an increase in the nearest neighbor distance (NND) caused by hypercapnia, which may indicate a higher motility of those cells.

Conclusions: OVX and hypercapnia can affect microglial cells of LC but not monoamine concentrations.

Danuzia A. Marques, Renato N. Soriano, Carlos C. Crestani, Kênia C. Bícego, Vincent Joseph, Richard Kinkead, Luciane H. Gargaglioni
34 lecturas
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The impact of prenatal inflammatory priming on the neuron-microglia proteines expression in young offspring brain: immunohistochemical study in neurodevelopmental model of schizophrenia

Introduction: A number of studies suggest that in brain microglia are held in a surveillant and quiescent state of activation through several inhibitory signaling dyads. Recently the fractalkine (CX3CL1) and its receptor (CX3CR1) as well as CD200 and CD200 receptor (CD200R) are particularly noteworthy, because disruption of these networks extended the duration of pro-inflammatory response, mainly via malfunction of a unique communication system between neuron-microglia cells.

Objective: To explore the possibility that maternal inflammatory priming based on the bacterial endotoxin (lipopolisaccharide, LPS) administration might serve as a  trigger to disturbances in CX3CL1-CX3CR1 and CD200-CD200R signaling in the brain of young offspring.

Material and Methods: Pregnant females were injected subcutaneously with LPS at a dose of 2 mg/kg every second day from the seventh day of pregnancy until the delivery. Control pregnant rats were left undisturbed in their homecages. At 7 days of age, control and prenatally LPS-treated rats were decapitaded and hippocampi and frontal cortices were dissected. Immunohistofluorescent staining was performed using primary antibodies: anti-CX3CL1, anti-OX2 and anti-CX3CR1 as well as anti-OX2R. Moreover proteins were co-stained with neuronal (anti-MAP2), astroglial (anti-GFAP) and  microglial markers (anti-Iba1), to clearly demonstrate the co-localization of CX3CL1, CD200, CD200R and CX3CR1 with brain cells in selected areas of hippocampus and frontal cortex of young offspring.

Results: First we demonstrated the localization of CX3CL1 and CD200 mainly on neuronal cells, while CX3CR1 and CD200R on microglial cells in hippocampus and frontal cortex of young offspring. Analyzing both ligands localization we observed that maternal LPS administration tender to increase the expression of neuronal CX3CL1 in hippocampus, while CD200 in both examined brain areas. On the other hand, maternal immune challenge in the opposite way affects the microglial expression of CX3CR1 and CD200R. Prenatal exposure to LPS have been found to increase the CX3CR1 expression in hippocampus regions, while decrease a staining of CD200R in hippocampus and also in the frontal cortex of young offspring.

Conclusions: These immunohistofluorescent data provide evidence that maternal exposure to immune challenges induce malfunction of neuron-microglia proteines staining in brain areas of young offspring. Thus phenomenon, termed prenatal neuroinflammatory priming, via disruption of homeostatic mechanisms regulating brain immune system, may be a key factor  leading to the occurrence of schizophrenia-like behavioral deficits observed in adult animals in commonly accepted neurodevelopmental  model of this disease.

Agnieszka Basta-Kaim, Katarzyna Chamera, Ewa Trojan, Natalia Bryniarska, Magdalena Szuster, Bogusława Budziszewska
45 lecturas
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Can Whole Body Blood Flow Autoregulation Lead to Hypertension? Testing Its Role by Computer Simulations

Introduction: Volume-loading hypertension is characterized by an initial increase in cardiac output (CO) followed by a secondary blood flow autoregulatory vasoconstriction due to the overperfusion of tissues, leading to chronic hypertension with a relatively normal CO, but a high total peripheral resistance (TPR). This concept of whole body blood flow autoregulation (WBFAR) has often been used to explain the increase in blood pressure (BP) in various models of salt-loading hypertension. Objective: To test the role of WBFAR in achieving salt balance and BP control during salt-loading since it is not possible to block WBFAR experimentally.

Material and Methods: Using Guyton’s large circulatory model, we tested, in the presence or absence of WBFAR, the hemodynamic and fluid volume changes that occur after a 10-fold increase in salt intake in three different situations: (A) normal neurohormonal modulation; (B) fixed circulating angiotensin II at a normal level; (C) full neurohormonal blockade (fixed angiotensin, aldosterone and ANP, and fixed autonomic output). In the presence of WBFAR, BP after salt-loading remained stable in situation A, but increased by ~10 mmHg in situation B, and by ~30 mmHg in situation C. We further tested the role of WBFAR in three classical models of volume-loading hypertension.

Results: Even then, changes in CO and blood volume (BV) were minimal (less than 4% and 2%, respectively). In the absence of WBFAR, the same simulations led to similar changes in BP. However, a nearly two-fold increase in CO and an increase in BV by more than 20% were required to achieve salt-balance in situation C. In the first model, hypertension was induced by reducing renal mass to 30% of normal and increasing salt intake by 6-fold. In the presence of WBFAR, the development of hypertension (+30 mmHg) was characterized by an initial increase in CO by ~30% followed by a secondary increase in TPR (+25%). In the absence of WBFAR, there was a similar long-term increase in BP. However, a nearly 2-fold increase in CO and an increase in extracellular fluid volume by more than 30% were observed whereas TPR decreased by 30% owing to the mechanical distension of blood vessels by the increased BP. Qualitatively similar results were obtained in two other models of volume-loading hypertension: aldosterone infusion and Goldblatt 1 kidney - 1 clip hypertension.

Conclusions: From the simulations one may conclude that autoregulation limits the amount of fluid retention required to increase BP in order to achieve salt balance, but does not affect the final level of BP.

Jean-Pierre Montani, Bruce N. Van Vliet
28 lecturas
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Sex differences in blood pressure response to continuous ang ii infusion: Involvement of sex hormones and sex chromosome complement

Introduction: Cardiovascular diseases are the leading cause of death in men and women. The renin angiotensin system (RAS) plays a major role in the regulation of blood pressure (BP), however a growing body of evidence demonstrate that the pressor response to Ang II is sexually dimorphic under physiological and pathophysiological circumstances. But why do male and female show differences in RAS blood pressure modulation? Sex steroids can induce organizational (long-lasting or permanent) effect during critical periods of development but can also impart (temporary or reversible) activational effects. Furthermore, males and females also carry different sex chromosome complements (SCC:XY/XX) and thus are influenced throughout life by different genomes. Previous evidence demonstrate a modulatory effect of SCC in RAS receptors expression (at brain and renal levels), as well as in the Ang II sexually dimorphic bradycardic barroreflex and hypertensive responses.

Objective: To evaluate the different factors involved in the sexual diferences on changes in mean arterial pressure (MAP) in a 30 min Ang II infusion protocol.

Material and Methods: We use mice of the "four core genotype" model, in which the effect of gonadal sex and SCC is dissociated, allowing comparisons of sexually dimorphic traits between XX and XY females as well as in XX and XY males. Comparing these genotypes, it is possible to segregate the role of a) SCC (comparing mice with the same gonadal type but different SCC, XX vs. XY) b) sex (females vs male) and c) the interaction of SCC and sex factors. To evaluate the modulatory action of SCC and the organizational hormonal effects on a 30 min-Ang II infusion protocol, mice of the four genotypes were gonadectomized (GDX) and 15 days later their BP was measured under urethane anesthesia (control group – CON). We also analized, in a separate group of mice, the activational effect of estradiol on blood pressure response during Ang II infusion; for hormonal replacement experiments GDX mice were daily injected with ß-estradiol (2ug/g) for a 4 day period ( ß-estradiol group – E2).

Results: The statistical analysis indicated an interaction of SCC and organizational-sex factors {F(1.25)=7.93;p<0.01}; XX-male/GDX-CON, XY-female/GDX-CON and XX-female/GDX-CON mice showed an increase in MAP due to Ang II infusion, while no changes were observed in XY-males/GDX-CON mice. Furthermore, this increase in MAP was reversed by the activational effect of ß-estradiol (CON vs. E2 {F(1,59)=23,03 p<0,01 }) in XX-male/GDX-E2, XY-female/GDX- E2 and XX-female/GDX-E2, while no effect on blood pressure was observed in XY-male/GDX- E2.

Conclusion: In absence of the activational hormonal effects an interaction between the CCS and the organizational effects of the sex hormones differently modulate changes in the arterial pressure during Ang II infusion. Furthermore, estrogen replacement exerts an important activational effect by preventing the increase in blood pressure observed in most groups, except in XY-male/GDX.

Florencia Dadam, Laura Vivas, Ximena E. Caeiro
19 lecturas
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Role of Cingulate Cortex Glucocorticoid Signaling in Alcohol Dependence

Introduction: Alcohol Use Disorder (AUD) is a chronic, relapsing disorder characterized by the development of negative motivational symptoms and emotional states, including escalation of alcohol intake, dysphoria, anxiety, and pain. We propose that the progression from recreational, limited alcohol consumption to uncontrolled, escalated intake involves a transition from positive to negative reinforcement mechanisms that drive excessive alcohol use and maintain AUD. Our lab models AUD in rats by utilizing a chronic intermittent ethanol vapor exposure (CIEV) procedure that produces both somatic and motivational symptoms of alcohol dependence.

Objective: To look for the role of cingulate cortex glucocorticoid signaling in alcohol dependence.

Material and Methods/Results: Using this model, we and others have shown that alcohol dependence is associated with dysregulated glucocorticoid signaling in brain regions that mediate stress and nociception, e.g., the central amygdala and anterior cingulate cortex (ACC). Specifically, we identified an increase in glucocorticoid receptor (GR) activation in the ACC of alcohol-dependent male rats. We tested the functional significance of this neuroadaptation on alcohol drinking. Alcohol-dependent and non-dependent male rats were trained to self-administer 10% alcohol and H2O in 30 minute operant sessions. Rats were then surgically implanted with guide cannulas aimed at the ACC. The GR antagonist mifepristone (MIF) was microinjected into the ACC 90 minutes prior to the drinking sessions. MIF decreased levels of alcohol-dependent drinking to that of the non-dependent rats. Given that GR is a transcription factor, we then sought to determine how potentiated GR activity in the ACC of alcohol-dependent animals alters gene expression, and if MIF prevents these changes. Male rats received a subcutaneous implant of either chronic release MIF or placebo pellet and half of each group underwent the CIEV alcohol dependence induction procedure. We then utilized a fluorescent bead-based multiplex assay to determine changes in mRNA levels of GR-regulated genes in the ACC.

Conclusions: Alcohol dependence increased mRNA of circadian regulatory genes Per1 and Per2, while MIF treatment attenuated this elevation. Circadian and glucocorticoid signaling directly regulate one another and both systems are known to be dysregulated in humans with AUD. The efficacy of MIF for the treatment of AUD may therefore involve a normalization of the ACC circadian rhythm.

Adrienne McGinn, Amanda R. Pahng, Kimberly N. Edwards, Scott Edwards
49 lecturas
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Angiotensin II Receptor Type 1 Blockade Prevents Arterial Remodeling and Stiffness in Iron Overloaded Rats

Introduction: Iron is an essential metal for cellular homeostasis participating in important physiological processes. Concentrations of this metal in the organism need to be rigorously regulated, because the deficiency and excess of this metal cause serious damage to health. Regarding iron overload, it has been suggested that the vasculature is damaged human and animal models, characterized by endothelial dysfunction and reduced compliance.

Objective: To prove that angiotensin II receptor type 1 blockade prevent arterial remodeling and stiffness in iron overloades rats.

Material and Methods: We previously demonstrated that in vitro blockade of the angiotensin II type 1 receptor (AT1R) reversed functional vascular changes induced by chronic iron overload. In this study the effect of chronic AT1R blocker on aorta stiffening was test in iron overloaded rats. Aortic mechanics, geometry, and composition was assessed in Wistar rats treated for 15 days with saline as control group, iron-dextran 200 mg/kg/day five days a week (iron overload group), losartan (20 mg/kg/day in drinking water), and iron-dextran plus losartan.

Results: There were no differences in aortic hemodynamics and vascular tone due to iron overload, but thoracoabdominal aortic pulse-wave velocity (PWV) increased significantly indicating a decrease in aortic compliance. Co-treatment with losartan prevented changes on PWV, β-index and elastic modulus from iron overloaded rats. This iron-related increase in PWV was not related to changes in aortic geometry and wall stress but increased elastic modulus/wall stress ratio suggesting that a change in the composition of the wall was responsible for the stiffness. Confirming, despite not changing circulating iron or vascular deposits, losartan also ameliorated the increase in aorta collagen content of the iron overload group.

Conclusions: Taking together, losartan prevented the structural and functional indices of aortic stiffness in the iron loading rats, suggesting a capacity for renin-angiotensin system inhibition to limit the vascular remodeling in chronic iron overload.

Renata Andrade Ávila, Helbert Gabriel Fidelis, Jandinay Alexandre Gonzaga, Susana Curry Evangelista Goes, Vinicius Bermond Marques, Leonardo dos Santos
22 lecturas
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High Frequency Spinal Cord Stimulation (HF-SCS) in a Sub-Acute Animal Model of Spinal Cord Injury (SCI)

Introduction: In previous studies, HF-SCS applied at the T2 spinal level was shown to result in physiologic activation of the both the diaphragm and inspiratory intercostal muscles in C2 spinal sectioned dogs. While the bulbo-spinal fibers were cut, they likely survived given the short duration of the day long acute experiments and that the mechanism of inspiratory muscle activation may have involved stimulation of these fibers. Since these fibers would not be viable in patients with chronic ventilator dependent SCI.

Objective: To determine if HF-SCS is effective following degeneration of these fibers.

Material and Methods: In 2 anesthetized, C2 paralyzed, intubated and mechanically ventilated dogs, an electrode lead was positioned on the ventral epidural surface of the spinal cord at the T2 level to activate the inspiratory muscles. Animal temperature, end-tidal PCO2 and oxygen saturation were continuously monitored. The effectiveness of HF-SCS in generating inspired volume (V) and negative airway pressures (P) was evaluated over a period of 5 days during which time the bulbo-spinal fibers would have degenerated. Since the effectiveness of HF-SCS may be adversely affected by deterioration in the condition of the animal, low frequency (50Hz) SCS (LF-SCS) was also performed and served as a control.

Results: All vital signs, oxygen saturation and end-tidal PCO2 remained stable over the 5-day period. V and P also remained stable over the study period. For example, V and P were 771±25ml and 64±1cmH2O with HF-SCS (3mA, 300Hz) during the initial and 674±59ml and 63±5cmH2O and final 6 hours on day 5. Comparable values during LF-SCS (8mA, 50Hz) were 467±12ml and 48±1cmH2O during the initial and 397±16ml and 40±1cmH2O final 6 hours on day 5.

Conclusions: Since V and P in response to HF-SCS remained stable over a 5-day period following which the bulbo-spinal fibers would have degenerated, the mechanism of HF-SCS does not depend upon the viability of these tracts. HF-SCS therefore may be a useful method to restore ventilation in ventilator dependent tetraplegics
Anthony F. DiMarco, Krzysztof E. Kowalski
19 lecturas
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Intra-uterine Exposure to Cannabinoid and its effects on the Ventilatory System of Newborn and Juvenile Rat’s Life

Introduction: The prenatal period is highly sensitive to pharmacological interventions. The psychoactive compounds of Cannabis act directly on the endocannabinoid system, and the deleterious effects of external cannabinoids during gestation may be related to negative interference in the central nervous system (CNS) formation, structuring and functioning of the respiratory system. Nevertheless, the influence of external cannabinoids on the ventilatory network development as well as in the chemosensitivity and the future consequences during neonatal and juvenile period is still unclear.

Objective: To evaluate the effects of exposure to cannabinoid during the whole gestational period on the respiratory control system at P0, P6-7, P12-13 and P27-28 male and female rats.

Material and Methods: Osmotic pumps were implanted subcutaneously in pregnant rats at embryonic day 0 and delivered vehicle (VEH) or CB1 receptor agonist (WIN 55212-2, 0.5 mg/Kg/day) for 21 days. Ventilation (VE) of animals was recorded by pressure-plethysmography (P0, P6-7 and P12-13) and whole body plethysmography (P27-28) during normoxia, hypercapnia (7% CO2) and hypoxia (10% O2), as well as the O2 consumption (VO2) was measured.

Results: At P0, WIN-treated male rats had a higher resting ventilation (~45%), hypercapnic (HCVR, ~41%) and hypoxic ventilatory response (HVR, ~35%) compared to vehicle group. At P6-7, WIN male group had a decreased HCVR (~19%) and also a lower HVR (~16%). For P12-13 animals, both male and female WIN-treated rats had an increase in the response to CO2 (male - 33% and female - 18%). For P27-28 rats, the HCVR was significantly higher for male (~21%) as well as for female (~25%) WIN-treated groups, no difference was observed for HVR. All the respiratory changes observed were not caused by metabolic issues since no difference was observed in the VO2.

Conclusions: A chronic and over activation of endocannabinoid system during gestation promotes alteration in the respiratory system development affecting the chemosensitivity to CO2 and O2 during neonatal and juvenile period. Financial support: FAPESP and CNPq
Luis Gustavo Alexandre Patrone, Kênia C. Bícego, Luciane Helena Gargaglioni
22 lecturas
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Exposure to Diazepam during Pregnancy Alters the Breathing Control in Post-Natal Life

Introduction: Breathing is an important motor behavior that contributes to the maintenance of homeostasis. This behavior depends on the proper development of respiratory network located in brainstem that generates and controls the respiratory rhythm during the embryonic and post-natal ages. The development of this network can be affected by the use of psychiatric medications prescribed to mothers to treat general anxiety or panic disorders. One of the most common drugs prescribed is Diazepam (DZP), a benzodiazepine that binds to gamma-aminobutyric acid (GABAA) receptors enhancing the permeability of chloride channels. However, it is still unknown if the administration of DZP during pregnancy could have deleterious effects on breathing control during post-natal life.

Objective: To understand the consequences of intrauterine exposure to DZP on the ventilatory responses of newborns rats,

Material and Methods: We administered DZP (1mg/Kg) or its vehicle, via osmotic pump, to pregnant rats during whole pregnancy (21 day). We used newborns rats (male and female) at post-natal day 0 (P0) and P12. Ventilation (VE), tidal volume (VT), respiratory frequency (fR) and oxygen consumption (VO2) were measured by using head-out plethysmograph during 20 minutes of normocapnia, hypercapnia (7% CO2) and hypoxia (10% O2).

Results: At P0, females treated with DZP had an attenuation of VT during hypoxia. At P12, males and females presented a decrease on VE during hypoxia and VE/VO2 was lower in DZP-treated animals. At this age, hypercapnic ventilatory response was also reduced in DZP groups due to an attenuation of VT.

Conclusions: DZP during pregnancy promotes a decrease in ventilatory responses to CO2 and O2 in males and females, and this disturbance occurs at P12 that is considered the critical period for breathing control.

Carlos Aparecido da Silva Junior, Vivian Biancardi, Luis Gustavo Alexandre Patrone, Luciane Helena Gargaglioni
14 lecturas
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Alteration in Glucose Metabolism and Adipose Tissue Induced by Zinc Restriction and High Fat Diet during Growth

Introduction: Metabolic diseases as obesity and diabetes lead to an increase in cardiovascular risk, morbidity and mortality. Zinc is an essential micronutrient for carbohydrates and lipids metabolism. In previous studies, we have demonstrated that zinc deficiency induces cardiovascular and renal alterations associated with an increase in blood pressure.

Objective: To evaluate in adult male rats if prenatal and postnatal zinc restriction aggravates the effects of a high-fat diet (HF) during post-weaning growth in systolic blood pressure (SBP), morphology and oxidative stress of retroperitoneal adipose tissue (RPAT) and glucose metabolism.

Methods: Female Wistar rats received control (C, 30ppm) or low-zinc diet (L, 8ppm) during pregnancy and lactation. At weaning (day 21) C pups were fed C (Cc) or C-HF diet (CcHF). L offspring received L (Ll) or L-HF diet (LlHF). 60% of total calories of HF hypercaloric diets correspond to fat. Oral glucose tolerance test (OGTT) was performed at day 74 (area under curve (AUC)). On day 81 SBP was evaluated, then rats were sacrificed to evaluate RPAT weight, morphology and oxidative stress (lipid peroxidation (TBARS), Catalase (CAT), superoxide dismutase activity (SOD)).

Results: Table. Two way ANOVA, test Bonferroni (n=6/group *p<0.01 vs Cc, †p<0.01 vs Ll, ‡p<0.01 vs CcHF) Zinc restriction induced RPAT adipocyte hypertrophy accompanied by an increase in lipid peroxidation. HF diet administration resulted in an increase in adipocyte size and a reduced cell density in RPAT of CcHF and LlHF. In addition, HF rats showed a reduced SOD activity that would affect RPAT redox state. Morphological and oxidative stress alterations observed in RPAT would affect carbohydrates metabolism.

Conclusions: Both HF and L diets contributed to a glucose intolerance state, considering the higher glycaemia at 180min of Ll and the increase in AUC in CcHF and LlHF. Moreover, HF only increased RPAT weight in zinc-deficient rats. Zinc restriction and HF diet induce changes in RPAT that would lead to a reduced glucose tolerance, contributing to metabolic and cardiovascular diseases development.

Cristina Arranz, Nicolás Ciancio, Facundo Mendes Garrido Abregú, Melisa Saravia, Joaquín Martínez Tambella, Valeria Zago, Carolina Caniffi, Laura Schreier, Rosana Elesgaray, Analía Tomat
39 lecturas
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Comparative Assessment of Electrocardiographic Parameters of Some Birds in Ilorin

Introduction: Cardiovascular disease is an important cause of death in commercial turkeys, meat-type chicken and other birds. Spontaneous turkey cardiomyopathy (STC; round heart), ruptured aorta and sudden death account for over 50% of the "normal" mortality in tom turkeys. Flip-over (sudden death syndrome) and pulmonary hypertension, leading to right ventricular failure, cause high losses in broiler and roaster chickens. In both chickens and turkeys these condition are related directly to growth rate. The diagnosis is usually based on history and gross examination. This work was designed to assess the electrocardiographic (ECG) parameters of various birds as alternative/additional means of clinical diagnosis.

Objective: To identify every aspect of the Lead II ECG wave form. The electrocardiogram is a useful tool in avian medicine as it can be utilized to measure heart rate and to detect arrhythmias, cardiac chamber enlargement, and electrical conductance abnormalities

Method: EDAN 10 Veterinary electrocardiographic equipment made in China; with a 200 mm/s paper speed and a sensitivity of 100 mm/mV was used to measure the ECG. The five alligator clip electrodes were fixed directly to the skin under the feather- on the forearms (muscular part of the wing), on the hind limbs above the stifle joint, and the heart as described earlier by Azeez et al, (2017). The EDAN was connected to the laptop and information about each bird was recorded and saved. Birds considered include Turkey, Chinese geese, Laying birds (chicken), point of lay birds and domestic ducks. They were all carefully restrained. 5 birds from each group was used

Results: The ECG exhibited positive P wave, inverted (Q) RS and positive T wave in all of them. S-S interval was regular in turkey and duck, irregular in chicken and Chinese geese. The PR interval in the Laying birds and Broilers were very longer with overlap by QRS. The (Q) RS was shorter (29-44ms) in the chicken with very short amplitude, longer (50-65ms) in turkey and duck with longer amplitude. No significant difference in the QRS within the groups. QT interval was longer in turkey, geese and duck (297-456ms) but shorter in chicken.

Conclusions: In birds, the mean electrical axis is negative (and thus the QRS wave is inverted in lead II); however, in many other respects the avian ECG is similar to mammals. We suspect that turkey geese and duck are heavier birds and require more calcium ion which have an effect on the heart compared with chicken. As expressed by their prolonged QT and higher heart rate.
O. M. Azeez, Afisu Basiru, A. S. Adah, F. H. Olaifa, A. S. Ameen, H. A. Ambali, M. Bolaji, R. B. Balogun
15 lecturas
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A Projection from the Hypothalamic Paraventricular Nucleus to the Nucleus Tractus Solitarii is Essential for Cardiorespiratory Responses to Hypoxia

Introduction: The hypothalamic paraventricular nucleus (PVN) is critical for cardiorespiratory responses to arterial chemoreflex activation. We recently reported that acute hypoxia (Hx) activates PVN neurons that project to the nucleus tractus solitarii (nTS) but the functional role of this projection has not been fully delineated. We hypothesized PVN inputs to the nTS facilitate cardiorespiratory responses to Hx. To test this, male SD rats received bilateral microinjections of retrograde AAV-pgk-Cre into the nTS. One week later, Cre-dependent AAV2-DIO-hSyn-mCherry expressing excitatory (Gq) or inhibitory (Gi) DREADD, or control virus (mCh) was bilaterally microinjected into the PVN, and 3-5 weeks allowed for expression in nTS-projecting PVN neurons.

Objective: To determine the contribution of the PVN to nTS pathway in chemoreflex function.

Method:  We assessed ventilatory responses (plethysmography) to progressive Hx (14-8% O2) in conscious rats before and after ip injection of saline or the synthetic selective DREADD ligand C21 (1mg/kg). We similarly evaluated the role of this pathway in Hx-induced nTS neuronal activation (Fos immunoreactivity, IR); 60 min after ip saline or C21, conscious mCh and Gi rats were exposed to Hx (2 hr, 10% O2) and Gq rats were exposed to 12% O2.

Results: Saline had no effect on either ventilatory responses or nTS neuronal activation to Hx in any group. In Gq rats (n=8), DREADD-mediated selective activation of nTS-projecting PVN neurons with C21 enhanced ventilatory responses to mild hypoxia (14 and 12% O2, p<0.05). This was associated with increased Hx-induced nTS neuronal activation (377±45 vs. 550±23 Fos-IR cells; saline vs. C21). Conversely, selective inhibition of the PVN to nTS pathway by C21 in Gi rats blunted hypoxic ventilatory responses to 10% and 8% O2 (n=8, p<0.05) and produced decreased Hx-induced nTS neuronal activation (581±33 vs. 375±150 Fos-IR cells; saline vs. C21). To confirm that altered cardiorespiratory chemoreflex responses were mediated by PVN terminals in the nTS, anesthetized rats were exposed to brief (45s) Hx episodes (10% O2, mCh and Gi rats; 12% O2, Gq rats) before and after bilateral nTS microinjection of C21 (0.1mM; 90nl/side). Mean arterial pressure (MAP), heart rate (HR), splanchnic sympathetic nerve activity (sSNA) and phrenic nerve activity (PhrNA) were measured. Under control conditions, Hx decreased MAP and increased HR, sSNA and PhrNA in all groups. Peak responses to 10% O2 were similar in mCh and Gi rats and greater than responses to 12% O2 in Gq rats. nTS microinjection of C21 had minor baseline effects, which were not different among groups. nTS C21 did not alter the Hx-induced increase in PhrNA in mCh rats. In Gq rats (n=3), DREADD-mediated activation of PVN terminals in the nTS enhanced both PhrNA (+51±36%) and sSNA (+166±41%) responses to Hx (12% O2). In contrast, inhibition of PVN terminals in the nTS blunted both PhrNA (-63±10%; p<0.05) and sSNA (-32±18%; p<0.05) responses to Hx (10% O2) in Gi rats (n=3).

Conclusions: Together, these results suggest that a PVN to nTS pathway directly enhances nTS neuronal activation and cardiorespiratory responses to hypoxia, and is required for responses to more severe hypoxia.

Eileen M. Hasser, Brian C. Ruyle, David D. Kline, Cheryl M. Heesch
26 lecturas
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Four days of Fructose Supplementation Affected the Vascular Function of Rats in a Sex-Dependent Manner without Changing Glucose Metabolism

Introduction: Fructose consumption has been increased in the last few decades, raising the concern about the effects of this sugar on the organism. It is already known that fructose induces metabolic disturbances as insulin resistance and lipid accumulation and it may affect cardiovascular function. In addition, it has been demonstrated that high fructose diet affected differently cardiovascular parameters in males and female rats, however the mechanisms involved in these alterations remain unclear.

Objective: To determinate how fructose dietary supplementation, in a non-insulin resistance stage, could affect the vascular function of male and female rats.

Material and Methods:  In order to stablish a fructose supplementation model with no changes on glucose metabolism, we provide 10% fructose solution (Fr Group) or tap water (Ct Group) to Wistar male and female rats during four days and performed glucose intraperitoneal tolerance test or insulin sensitivity test. The results confirmed that 4 days of fructose supplementation did not change neither the glucose tolerance nor insulin sensitivity comparing to the Ct Group. Once stablished the experimental model, we investigated whether fructose overload could alter the vascular function. For this, the animals were euthanized and thoracic aorta responses induced by phenylephrine (PE) were analyzed by iron myography. We observed that rats treated with high fructose showed a decreased response to PE when compared with those from Ct Group.

Results: To address the influence of the sex on the vascular dysfunction induced by high fructose diet, we analyzed separately the PE responses from female and male rats. Interestingly, on male rats, fructose did not alter the the contractility of aortic segments. However, female population preserved the vascular phenotype of decreased response to PE after fructose supplementation observed on the overall population. This lack os response to PE was accompanied by an exacerbated endothelial anti-contractile action not connect to NO bioavailability. Also in females treated with high fructose, the modulation of vascular contractility by superoxide anion was pronounced, which can be responsible for the reduced Na+K+ATPase activity observed in this group. Despite of male rats treated with fructose did not show increased vascular response to PE, it seems to reduce superoxide dismutase enzyme function. Consequently, less hydrogen peroxide resembles to be available reverberating in reduced potassium channel activity in that population.

Conclusions: Together, the results obtained in the present study demonstrated that fructose dietary supplementation, in an early stage as four days, affect the vascular function independently of the metabolic alterations. This effect seems to be sex-dependent and may involve alterations on redox signaling on smooth muscle cells.
Camila Almenara Cruz Pereira, Gilson Brás Broseghini-Filho, Kevin Mesquita Silva, Alessandra Peres Guimarães, Marcelo Perim Baldo, Alessandra Simão Padilha
37 lecturas
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Muscle Metaboreflex Activation via Post-Exercise Ischemia as a Tool for Teaching Cardiovascular Physiology for Undergraduate Students

Introduction: The cardiovascular responses to exercise is mediated by several interactive neural mechanisms including central command, arterial baroreflex and skeletal muscle mechano- and metaboreflex. In humans, muscle metaboreflex activation can be isolated via post-exercise ischemia (PEI) which increases sympathetic nerve activity and partially maintains the exercise-induced increase in arterial blood pressure (BP). Although skeletal muscle metaboreflex is considered one of the principal mediators of the cardiovascular response to exercise, PEI was widely used in scientific reports, but its use as a tool for teaching cardiovascular physiology has not been previously reported.

Objective: To describe a practical lesson methodology used in an undergraduate exercise physiology laboratory class that can guide teachers to demonstrate several aspects of cardiovascular regulation during exercise and report the perceptions of the students after the laboratory class.

Material and Methods:  We hypothesized that our practical laboratory class will improve the student’s perceptions of their understanding of the cardiovascular regulation during exercise. In an undergraduate exercise physiology class (n=47), a traditional 4-h lecture was conducted discussing the neural control mechanisms of cardiovascular regulation during exercise. Thereafter, eight students (4 men and 4 women) were selected to participate as a volunteer of a practical laboratory class. Each participant performed 90 s of isometric handgrip (IHG) exercise at 40% of maximal voluntary contraction followed by 3 min of PEI. Arterial BP and heart rate were measured by digital monitors at rest, during IHG, PEI and recovery. In addition, blood samples were collected from the tip of the exercising finger for blood lactate analyses. After the laboratory class, a survey was given to determine the perceptions of the students through a questionnaire consisting of 10 items on a 5-point Likert scale.

Results: The findings demonstrate that, before the laboratory class, some students were not confident of their understanding of cardiovascular regulation during exercise. Overall, the students self-related that the activity improved their level of understanding regarding 1) the cardiovascular responses to exercise; 2) the role of skeletal muscle metaboreflex as an important mediator of cardiovascular responses to exercise; 3) the role of blood lactate as a trigger of muscle metaboreflex activation; and 4) the sex-related differences in cardiovascular responses to exercise. In addition, the majority of students believed that the activity reinforced their appreciation for the importance of the subject matter, enhanced their desire to learn the subject matter, and improved their approach for studying the content for the course exam. In summary, this laboratory class has proved to be highly popular with students, who self-reported a significant improvement in their understanding of several aspects of cardiovascular regulation during exercise.

Conclusions: These findings could encourage exercise physiology teachers to incorporate the use of PEI as a tool for teaching cardiovascular physiology for undergraduate students.

André L. Teixeira, Milena Samora, Lauro C. Vianna
19 lecturas
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Use of Clinical Cases to Teach Endocrine Physiology by means of Peer Instruction and via the Socrative app

Introduction: The peer instruction methodology promotes the consolidation of concepts through discussions by the students when they are asked to solve clinical cases or to answer questions elaborated by the teacher. Another approach is to use the Socrative app, which allows to project slides together with questions from the teacher´s platform to the students ‘cell phones. The app has the advantage that immediately after the questions have been answered, a histogram is generated that allows to verify the percentage of correct answers in the classroom or for each student.

Objective: To analyse if the use of clinical cases in combination with peer instruction and the Socrative app would be well accepted by the students in substitution for the traditional theoretical expositive classes in an Endocrine Physiology discipline.

Material and Methods: Third year Dentistry Course students (n=80) received didactic material related to the Thyroid or Pancreas Physiology prior to the class and they were asked to study this. In classroom, after a brief review of 30-40 min about the subject, a clinical case on hyper- or hypothyroidism or on Diabetes Mellitus was displayed to the students, and they were oriented to answer the teacher’s questions by peer instruction and the Socrative app. The correct answers were revealed after the teacher explained the concepts underlying the correct or wrong answers. Subsequently, the students’ perceptions about the use of these methodology in their learning process were evaluated through a Likert Scale questionnaire. Results: The correct answers to the questions were 53.6% for the thyroid clinical cases and 83.1% for the Diabetes Mellitus case. Regarding the perception concerning the use of the Socrative app, the majority of the students (76-89%) answered that it is very good and interesting to use during class, and similar results were obtained for peer instruction, which was evaluated as very good and good by 58% and 86% of the students. Furthermore, 85% fully agreed that the two methods together (peer instruction and Socrative) helped them to learn better the class subject. However, the majority also answered that they prefer the conventional theoretical class style over peer instruction. Conclusions: The conventional theoretical class style should not be entirely substituted by active learning methods, like peer instruction and apps like Socrative, but that the passive and active learning methods should be combined, since all these have good acceptance in the teaching-learning process. Furthermore, the use of the cell phone Socrative app prevents the students from using the cell phone for other purposes, and thus help to maintain their attention during class.
Maria José Alves da Rocha, José Caetano de Souza
35 lecturas
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The intra-test reliability of spontaneous cardiac baroreflex sensitivity in healthy young men

Introduction: Spontaneous cardiac baroreflex sensitivity (cBRS) is a non-invasive and a valuable tool for assessing the baroreflex buffering of beat-to-beat changes in blood pressure. However, the impact of sampling duration is yet to be established. In addition, since body position interacts with cBRS, the necessity of intra-test reliability study is still warranty.

Objective: To examine the intra-test reliability within different time duration analyses and between body positions in cBRS measurements.

Material and Methods:  In 6 healthy men (21±3 years of age) beat-to beat measurements of blood pressure and heart rate were recorded for 10 min in both the supine and seated position. The cBRSall, cBRSup and cBRSdown were analyzed by sequence technique from a stable 10 minute resting baseline. Randomly, we separate the data analyses in different time durations (1-min, 3-min, 5-min and 7-min) and compared with the standard 10-minute data control. To calculate the relative and absolute reliability we analyzed the coefficients of variation (CV), the technical error of the measurement (TEM) and the intraclass correlation coefficients (ICC). Results: The cBRS was lower in the seated position than in the supine position (P < 0.05). All cBRS values were similar between each sampling duration compared to the 10-min control (P > 0.05). The ICC indicated moderate to excellent (cBRSall: 0.71-0.99; cBRSup: 0.79-0.99 and cBRSdown: 0.71-0.98) in supine position and good to excellent (cBRSall: 0.93-1.00; cBRSup: 0.87-1.00 and cBRSdown: 0.90-1.00) in seated position between each sampling duration and 10-min control. Additionally, the data reliability decreased progressively with the shortening of sampling duration. The CV and TEM increases for supine [(cBRSall: 7%, 6%, 12%, 16% and 8%, 8%, 12%, 21%); (cBRSup: 11%, 8%, 10% 11% and 13%, 9%, 15%, 15%) and (cBRSdown: 8%, 7%, 12%, 23% and 8%, 9%, 15%, 26%)] and for seated position [(cBRSall: 3%, 4%, 6%, 13% and 5%, 4%, 8%, 17%); (cBRSup: 6%, 4%, 11%, 25% and 8%, 3%, 20%, 36%) and (cBRSdown: 2%, 6%, 7%, 12% and 3%, 6%, 7%, 17%)].

Conclusions: A minimum of 3-min of data sampling duration in seated position provides more reliable measures of cBRS than all-time durations measures in supine position. The poorer reliability observed in supine position could be due to cardiopulmonary baroreceptor loading via elevations in central venous pressure and/or from significant reductions in the magnitude of spontaneous blood pressure fluctuations, which would induce a more tonic loading of the arterial baroreflex.

Jeann L. Sabino-Carvalho, André L. Teixeira, Milena Samora, Lauro C. Vianna
31 lecturas
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Effect of Electrical Stimulation of the Aortic Depressor Nerve on Inflammatory Response after Experimental Myocardial Infarction in Rats

Introduction: A marked or prolonged post-infarction inflammatory response leads to a pathologic remodeling, impairing the left ventricle function that is the most important predictor of heart failure development. Recent studies have investigated the modulation of inflammation by the autonomic system, mainly by electrical or drug vagal stimulation, making possible a new therapeutic approach for the modulation of the inflammation in the AMI. 

Objective: To evaluate the effect of the electrical stimulation of the aortic depressor nerve (ADN) on autonomic modulation and the possible effect on inflammatory response post AMI. Material and Methods: The animals were divided into 3 groups: Sham Group (SHAM) - 5 animals not infarcted without treatment; Infarcted group (AMI) - 10 infarcted animals without treatment; Infarcted and stimulated group (AMI+EST) - 10 infarcted animals treated with electrical stimulation of the ADN. Five sessions of 30 min of ADN stimulation were performed between days 1 and 3 post AMI.

Results: The electric current was able to reduce the median arterial pressure during the stimulation period by more than 30 mmHg in all sessions. The LF/HF ratio, which reflects the global sympathetic-vagal balance, was elevated in the AMI group (0.36±0.066) when compared to SHAM (0.18±0.015) and AMI+EST (0.16±0.022). Thus, it was possible to observe that the HF and LF parameters, important indicators of autonomic function, were similar between the SHAM and AMI+EST groups, demonstrating the beneficial effect of ADN electrical stimulation on the maintenance of autonomic modulation. The baroreflex sensitivity (BPM/mmHg) was reduced in the IAM group (ITR=1.44±0.20; IBR=-0.82±0.15) when compared to the SHAM group (TRI=2.79±0.58; BRI=1.10±0.43). The IAM+EST group presented higher induced baroreflex sensitivity (TRI=3.40±0.18; BRI=-3.32±0.43) and spontaneous compared to the AMI group, being similar or higher when compared to the SHAM group. Cardiac function assessed by echocardiography revealed a better systolic function in the AMI+EST group (Ejection Fraction %=53±3.8) when compared to the AMI group (Ejection Fraction %=43±2.0). Regarding collagen deposition in the lesion (% of collagen), the AMI group presented significantly higher values (14.24±1.75) when compared to SHAM (0.85±0.04) and AMI+EST (5.35±0, 46). Immunohistochemical analysis showed a higher concentration (cells per field) of M1 macrophages in the AMI group (131.13±11.75) in comparison to the AMI+EST group (95.46±16.27) and a higher number of M2 macrophages in the AMI+EST group (143.69±15.23) when compared to the AMI group (96.38±22.35). Oxidative stress markers indicated a higher carbonyl content of proteins (nmol/mg) in the AMI group (2.24±0.09) in comparison to the AMI+EST group (1.96±0.07). The IAM+EST group had a higher activity of the superoxide dismutase enzyme (USOD/mg) (5.55±0.04) when compared to the AMI group (5.16±0.06).

Conclusions: These findings suggest that the electrical stimulation of the ADN was able to modulate the inflammatory response post AMI, leading to a less pathological remodeling and improving the indexes of the cardiac function evaluated by echocardiography, presenting as a new therapeutic approach in the prevention of heart failure development after AMI.

Rodrigo SCHMIDT, Mariana MORRIS, Kelen H. SCHMIDT, Katia DE ANGELIS, Camila P. DOS SANTOS, Maria C. IRIGOYEN
16 lecturas
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Iván Delgado Suárez, Arquímedes Montoya Pedrón, Lianne Alicia Chang Arraño
12 lecturas
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Relation of polymorphisms VEGF (+405G>C) and TNFα (-308A>G) with the embryo implantation in Cubans patient undergoing in vitro fertilizationIntroduction. A cohort study was carried out at the National Center for Medical Genetics, from July 2017 to June 2018, in 27 patients evaluated in the consultation for the infertile couple at the Hermanos Ameijeiras Hospital. Objective. To establish the relationship of the individual and combined expression of the genotypes of the polymorphisms VEGF (+405 G> C) and TNFα (-308A> G), with the rates of embryo implantation in Cuban patients receiving treatment with in vitro fertilization. Materials and Methods.The identification of the genotypes was carried out using an ARMS PCR. The Hardy-Weinberg equilibrium was determined by applying the Chi square test of goodness of fit from a reference population, and a Principal Component Analysis (PCA) was carried out to evaluate the genotypic population structure with respect to the variables studied. Results. Individuals with combined genotype variant VEGF.CC / TNFα.GG were grouped homogeneously in the PCA model with respect to axis 2, where there was a higher frequency of women with a low implantation rate. In contrast, patients with a genotypic TNFα.AG variant were grouped according to the highest implantation rates. Conclusions. It was concluded that there is a relationship between genotype variants VEGF.CC and TNFα.GG with a low implantation rate, when they are expressed individually or in combination in patients treated with the in vitro fertilization technique, while the individual genotypic variant TNFα. AG is associated with a higher implantation rate.
Francisco Sotomayor Lugo, Beatriz Marcheco Teruel, Kenia Rodríguez Martínez, Alejandro Esperón Álvarez, Ahmed Menocal Alayón, José Alberto Almaguer Almaguer, Ixchel López Reyes, Rosa María Flores Sánchez, Yoandra Crespo Ferrán, Vivian Veiga Loyola
20 lecturas
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Lianne Alicia Chang Arraño, Iván Delgado Suárez, Odalis Querts Méndez, Nelsa Sagaró del Campo
20 lecturas
Aquaglyceroporins Expression and Glycerol Permeability are modulated by Estradiol in Mouse Sertoli cells

Introduction: Metabolic diseases are related with severe fertility problems, partly due to increased aromatization of androgens to estrogens. Elevated levels of 17β-Estradiol (E2) are known to cause alterations on normal development of germ cells, compromising spermatogenesis. Spermatogenesis is dependent on Sertoli cells (SCs) function, since these cells ensure an adequate environment inside the seminiferous tubule.

Objective: To determine the impact of elevated levels of E2 on aquaglyceroporins (AQPs) expression and glycerol permeability in mouse SCs (mSCs, TM4 cell line).

Material and Methods: The expression of AQP3, AQP7, AQP9, and AQP11 were identified by RT-PCR and immunofluorescence techniques. Then, the expression was evaluated by qRT-PCR. Glycerol permeability was evaluated by stopped flow light-scattering.

Results: We were able to identify for the first time the expression of AQP3, AQP9 and AQP11 in mouse testis and mSCs. AQP9 was about six times more expressed than AQP3 and sixty-four times more expressed than AQP11 in these cells. High E2 levels caused a decrease of AQP9 mRNA levels and had no influence on AQP3 expression. On the other hand, high E2 levels led to an increase in AQP11 mRNA levels. AQPs are the main transporters of glycerol in physiological conditions, where AQP9 and AQP3 are responsible for transmembrane transport and AQP11 for endoplasmic reticulum and lipid droplets transport. In addition to downregulating the expression of AQP9, E2 also decreased cellular glycerol permeability.

Conclusions: E2 is a regulator of mSCs physiology by modulating AQP9 expression and the permeability to glycerol, which has been referred as crucial player for the homeodynamics of these testicular cells and for spermatogenesis. In addition, as glycerol is essential for spermatogenesis by control of blood-testis barrier, it is evident that alterations caused by E2 in glycerol permeability can be related to infertility problems.

 

Keywords: Aquaglyceroporins, glycerol permeability, estradiol, mouse sertoli cells

David F. Carrageta, Raquel L Bernardino, Ana M. Silva, Marco G Alves, Graça Soveral, Pedro F. Oliveira
19 lecturas
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Thermal and Metabolic Biphasic Response to LPS in Chicks

Introduction: Severe inflammation may induce body temperature (Tb) reduction instead of fever. In this situation, morbidity and mortality is generally higher. In mammals, based on experimental models of rats injected with endotoxin (LPS), a biphasic thermal response is suggested to be a regulated process. The initial Tb reduction, which avoids tissue hypoxia and damage because of reduction in O2 demands, is followed by fever, which is considered to be a beneficial response when the LPS concentrations become lower throughout the time. In fact, different humoral pathways are involved in each thermal response, as for example, cyclooxygenase (COX)-1 in the Tb reduction and COX-2 during fever. The demonstration of such phenomenon in other species is important for supporting the adaptive nature of thermal responses to systemic inflammation. In this context, birds are the other endothermic vertebrate group besides mammals, which deserve investigation.

Objective: To use a precocious bird as animal model for investigating: 1) the effect of COX-2 and COX-1 inhibition on Tb changes induced by LPS; 2) the metabolic response to LPS under other two challenging conditions for O2 demand such as food deprivation and cold.

Material and Methods: Five-day old chicks (Gallus gallus; ~100 g) injected with LPS (100 μg/kg, IM) decreased (-1.0±0.0oC) and increased Tb (+0.9±0.2oC) 1h and 4h after injection, respectively.

Results: The selective COX-2 inhibitor (SC-236, 1.25 mg/kg) caused no change in the initial Tb fall but attenuated the subsequent fever. In contrast, SC560 (selective COX-1 inhibitor; 1, 2.5, 5 mg/kg) did not affect the Tb reduction, but the lower doses induced a faster increase of Tb after 2h of LPS injection. Regardless the feed (food deprived or not) and thermal (cold-25oC or neutral-30oC) conditions, O2 consumption was reduced 40-60 min after LPS injection, coinciding with Tb falling. The febrile response, however, was affected by cold and fasting as Tb increase was inhibited despite of no change in O2 consumption. Conclusions: Thus, our preliminary results suggest that, similarly to rats, the febrile response to LPS is affected by other O2 demands and may be modulated by COX-2 dependent pathways. In contrast, the initial thermal and metabolic decreases of Tb seem not to be affected by competing O2 demands and is independent of COX-2 activity.

 

Keywords:   Thermal, Metabolic Biphasic Response, inflammation, chikens,  rats, Temperature, febrile response

Kênia C Bícego, Lara Amaral-Silva, Alexandre Steiner, Welex Cândido, Luciane H. Gargaglioni
14 lecturas
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Fibroblast growth factor 21 promotes glucose uptake by a GLUT4-dependent and Akt-independent mechanism in isolated fibers of skeletal muscle

Introduction: Fibroblast growth factor 21 (FGF21) is a pleiotropic peptide hormone that induces glucose uptake in both primary myotubes and C2C12 myoblasts. However, the cellular mechanism involved and its role in adult skeletal muscle fibers is poorly understood.

Material and Methods: Male mice were used at 6-8 weeks of age. The glucose uptake was evaluated in single living fibers from flexor digitorum brevis muscle. To determine glucose uptake, we used the phosphorylable, non-metabolizable fluorescent glucose analog 2-NBDG (300 µM) that has been used to monitor glucose uptake in single living cells.

Results: FGF21 induces a dose-response effect, increasing glucose uptake in isolated skeletal muscle fibers. This effect is prevented by the use of either Cytochalasin B (5 µM) or Indinavir (100 µM), both antagonists of GLUT4 activity. The use of PI3K inhibitors such as Wortmannin (100 nM) and LY294002 (50 µM) prevents the FGF21-dependent glucose uptake. In fibers electroporated with the construct encoding GLUT4myc-eGFP chimera and stimulated with FGF21 (100 ng/mL) for 20 min, a strong sarcolemmal GLUT4 presence was detected. This effect, promoted by FGF21, is independent of Akt phosphorylation and is partially prevented by the inhibition of PKCs.

Conclusions: These results suggest that FGF21 regulates glucose uptake by a mechanism dependent on PI3K activity and independent of Akt phosphorylation.

Keywords: Fibroblast growth factor 21, glucose uptake, GLUT4-dependent and Akt-independent mechanism, isolated fibers, skeletal muscle

 

Financed by FONDECYT (1151293, 11130267, and 11150243)

Giovanni Rosales-Soto, Alexis Díaz-Vegas, Paola Llanos, Mariana Casas, Enrique Jaimovich, Ariel Contreras-Ferrat
18 lecturas
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The effect of titanium alloy and stainless steel implants on immunological responses by analysis of NF-κB/ p65, NF-κB1/p50 profiles and the Tregs

Introduction: A comprehensive understanding of the tissue-biomaterial interactions at a cellular level is required to explain the immune responses of numerous implant mediated complications and help to improve biomaterial design and use.

Objectives: To research the effect of titanium alloy and stainless steel implants on immunological responses in rats by analysis of NF-κB/ p65, NF-κB1/p50 profiles in the activation of inflammatory signaling pathways and the role of Tregs. To minimize the inflammatory response of host-formed bio-material implants is our main goal.

Materials and Methods: In this study, 39 Wistar albino male rats were divided into three groups with 13 rats each resulting in Group I (n: 13, sham), Group II (n: 13, Ti alloy rods), and Group III (n: 13, SS alloy rods). The NF-κB/ p65, NF-κB1/p50 and CD4+CD25+Foxp3+ (Tregs) in the blood were analyzed on days 7, 14 and 28 using ELISA and Flow cytometry.

Results: Tregs level were lower in the stainless steel (SS) alloy compared to the sham and Titanium (Ti) alloy. NF-κB/ p65 (RelA) levels in the SS alloy showed a significant increase on all days in comparison with the sham and Ti alloy. NF-κB1 (p50) in the SS alloy was a significant increase on the 14th and 28th day. When the Ti alloy was compared with the SS alloy, NF-κB/ p65 (RelA) and NF-κB1 (p50) levels were significantly lower levels.

Conclusions: Both the Ti alloy and SS alloy group implantation effects CD4+CD25+Treg cells in different ways. This work suggests that NF-κB/ p65, NF-κB1/p50 have excellent potential as a therapeutic target in the prevention of adverse reactions to metal, especially for controlling the inflammation after the implantation. In this application target can be NF-kB and for this IKK molecule inhibitors can be used or it can be done by the stabilization of IkB proteins.

 

Keywords: Titanium alloy implants, stainless steel implants, immunological response,  NF-κB/ p65, NF-κB1/p50, Tregs

 

 

Sibel Akyol, Murat Hanci, Besim Ben-Nissan
31 lecturas
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Prenatal and Postnatal Malnutrition: Relationship with AQP2 and GLUT4 Expression in Male Adult Rats

Introduction: The physiology of the urinary tract achieves the elimination of toxic substances from the organism, particularly in the kidneys. There are several molecules and proteins wich participate in the kidney function. Among others, this organ has to transport water and glucose and it have specific proteins that make it possible. Fourteen aquaporins (AQPs) have been described until now, distributed in different parts of the organism. Some of them (1,2,3,4,6,7 and 11 AQPs) are differentially expressed along the kidney and are highly relevant for the water transport across the renal tubules. Particularly, AQP2 is located on the collecting duct where the urine will be diluted or concentrated because of the function of Antidiuretic hormone (ADH). The ADH link up with its specific receptor in principal cells, triggers the trafficking of AQP2 to the apical membrane to permit the water passage.  Also, in this tubs there is glucose exchange, to do that there are glucose transporters (GLUTs). Specifically, GLUT4 have been determinate in glomerulus, proximal and collector tubule. This kind of transporter have been studied in insulin sensitive organs but is not clear how it is working in kidney. The high consumption of sugared drinks have been associated with metabolic diseases, including type 2 diabetes mellitus that is linked to renal failure.

Objective: To determine whether the consumption of sugared water during pregnancy and lactation, alters the expression of AQP2 and GLUT4 in the kidney of adult male offspring.

Material and Methods: We used female rats that were mated and divided in a control group fed with standard diet and tap water, and the experimental group fed with standard diet and 5% sucrose diluted in tap water (sugared water). At weaning, two male rats were randomly selected per litter; one of them had free access to simple water while the other had free access to the sugared water. The male rats were sacrificed at four months old and the expression of AQP2 and GLUT4 in the left kidney was analyzed by Immunohistochemistry and Western blot.

Results: Opposite the group that consumed plain water during the experiment with the group that consumed sugared water during pregnancy, lactation and postnatal life, preliminary results show an overexpression of AQP2 and GLUT4 in the last group. It seems that the consumption of sugared water, even in low concentration, modifies the renal expression of AQP2 and GLUT4.

Conclusions: Present finding encourage to a further regionalization of the AQP2 and GLUT4 expression in kidneys. In doing this, we advanced in the knowledge of renal outcomes associated to the intake of sugared beverages.

 

Keywords: Prenatal malnutrition, postnatal malnutrition,  AQP2 and GLUT4 expression, male adult rats

 

Verónica Velázquez-Orozco, Ricardo Pérez-Fuentes, Ricardo Pérez-Fuentes, Leticia Nicolás-Toledo, Leticia Nicolás-Toledo, Estela Cuevas, Estela Cuevas, Francisco Castelán, Francisco Castelán, Jorge Rodríguez-Antolín, Jorge Rodríguez-Antolín
18 lecturas
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ROS-dependent PRR Expression in Immune Cells in a Diabetes Mellitus Rat Model

Introduction: Diabetes Mellitus (DM) is a major public health problem. Either diabetes mellitus type 1, type 2, gestational or other, is a complex syndrome characterized by hyperglycemia, polydipsia, polyphagia, polyuria, and loss weight. DM can lead to complications in which oxidative stress has been related. There is a bulk of evidence suggesting that glucose can stimulate by itself or by several enzymatic cascades the overproduction of reactive oxygen species (ROS), as well as the imbalance in the antioxidant defense mechanisms. Numerous studies have proposed the administration of antioxidants such as vitamins C and E to prevent or avoid progression of complications derived from DM. It has been reported that activation of the renin-angiotensin system (RAS) plays a significant role in the pathophysiology of DM. A new component appears important: the Prorrenin / Renin Receptor (PRR), initially found in the kidney, but more recently detected in cells of the immune system. There is evidence showing the PRR as an inflammatory component in DM models because besides being constitutively expressed in T cells, NK and macrophages, it regulates cytokine levels. However it is unknown, if oxidative state in diabetes is responsible for the PRR-expression elevation. Objective: To evaluate, in a rat DM model, ROS effect on the expression of PRR in cells of the immune system.

Material and Methods: Wistar male rats, 250-300 g weight, were used in four groups: DM rats with antioxidants (H + A), DM rats without antioxidants (H + 0), normoglycemic rats with antioxidants (Sh + A) and normoglycemic rats without antioxidants (Sh + 0). This investigation was conducted in conformance with ethical and animal care principles under mexican norm (NOM-062-ZOO-1999). Hyperglycemia was induced by streptozotocin (STZ) IV injection, at a dose of 65mg / kg using citrate buffer, pH 4.2 as vehicle. After measurement of glucose level, 500mg / kg of vitamin C and 700mg / kg of vitamin E were administered daily for 8 or 15 days, p.o. At the end of the 8 or 15 days treatment, spleen and blood were obtained. SOD, CAT and GPX activity was determined in the spleen, as well as the total antioxidant activity by ELISA and lipid peroxidation by MDA-TBARS; total ROS were quantified by flow cytometry. In blood, the expression of TNF-α, IL-6, IL-10 and TGF-β was measured by qRT-PCR. The expression of PRR in T cells, NK and macrophages was performed by cytometry.

Results: Hyperglycemia presented an average value of 400 mg/dL in diabetic rats. There was a significant decrease of the enzymatic activity in the H+0 group compared to the control (Sh+0), while in the H+A group augmented. Lipid peroxidation was risen in the H+0 groups, but disappeared with vitamins administration at both times. ROS level were significantly high in H groups, but did not increase in H+A group. Pro inflammatory cytokines were elevated in DM rats. In all cell populations, ROS had different effects on PRR expression.

Conclusions: These results suggest that ROS play a significant role in DM controlling PRR expression and possibly in the onset of complications derived from this disease.

Keywords: Reactive oxigen species, rat model, diabetes mellitus, dependent   ,Prorrenin / Renin Receptor, immune response

Ariadna Velázquez Mata, María Elena Hernández Campos, Pedro López Sánchez
11 lecturas
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Effect of inhibition of the prorenin receptor (prr) on the production of cytokines in cells of the immune system in a model of hypertension by nephrectomy 5/6

Introduction: Hypertension is a condition where blood pressure is persistently high; this pathology affects 1.13 billion people worldwide and 95% of cases do not have an identifiable cause. Several systems are involved in blood pressure regulation. Among them, the renin-angiotensin-aldosterone system (SRAA) and the immune system (SI) stand out, which seem to participate in the onset and permanence of the disease. It has been documented that Angiotensin II (Ang II) induces cytokine production and a proinflammatory state; on the other hand, a new component of RAAS, the prorenin/renin receptor (PRR), seems to have participation in several processes where the system has relevance, such as hypertension itself, diabetes mellitus and some forms of glomerulonephritis. The presence of PRR in several SI cells has also been reported. The role of PRR in the production of cytokines, however, is unknown.

Objective: To evaluate the effect of PRR inhibition, by use of handle peptide, upon secretion of TNFα, IL-6, TGFβ, and IL-10 on immune system cells in a renal-origin hypertension model.

Material and Methods: We used a 5/6 nephrectomy model and two experiment times, 7 and 15 days. The model was characterized by measuring blood pressure, quantification of urinary volume, water and food intake, proteinuria and serum and urine creatinine. At 7 and 15 days after nephrectomy and sham surgery, rats were sacrificed with an overdose of sodium pentobarbital, the spleen was removed, and the immune cells were isolated. These were incubated with or without the peptide (1 μM) for 30 minutes, 1 hour, 6 and 12 hours, and then the mRNA quantification of TNFα, IL-6, TGFβ and IL-10 was determined by RT-PCR. All procedures in animals complied with NOM-062-ZOO-1999 and institutional animal care committee.

Results: We found that 5/6 nephrectomy groups had an increase in blood pressure (169/95 mmHg), a decrease in the feed intake, an increase in water consumption and urine volume. In the biochemical parameters, an increase in serum creatinine, a decrease in urine creatinine and as a consequence a decrease creatinine clearance, compared to the Sham group. Quantification of mRNA for the mentioned cytokines, a significant decrease of their expression was observed in hypertensive groups exposed to the peptide compared with the Sham groups.  

Conclusions: With 5/6 nephrectomy surgery, it is possible to induce hypertension and renal failure. Blockade of prorenin receptor (PRR), significantly decreases TNFα, IL-6, IL-10 and TGFβ expression in hypertensive rats.

 

Keywords: Hypertension, rats, renal failure, experimental nephrectomy

Blanca Rubí Vélez Godínez, Pedro López Sánchez, María Elena Hernández Campos
4 lecturas
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Brain Areas Involved in Self-Body Image Reconstruction

Introduction: The concept of self-face/body image is very complex because it combines the interaction of multiple factors of body experience and perception. When this self-face/body image concept is altered by the loss of an eye, neurobiological and psychological brain reorganization occurs. A missing eye can be replaced by a prosthetic eye, which gives the person an opportunity to build a new self-face/body image. Even though, it is known that neurobiological changes occur, brain areas involved in constructing a new self-face/body image are not known.

Objective: To identify brain areas involved in the reconstruction of the new self-face/body image.

Material and Methods: blood oxygenation-level dependent signal was obtained through functional magnetic resonance imaging of three individuals who had lost their left eye under different circumstances and were experiencing for the first time the use of a new a prosthetic eye. Individuals agreed to take part in this study and signed a voluntary consent form at the School of Dentistry of the Universidad Nacional Autónoma de México that follows the Basic Principles of the Declaration of Helsinki and also assented in accordance with the Universidad Autónoma Metropolitana scientific review board. Psychological interviews were also performed to obtain a verbal description of how these individuals felt using their new prosthetic eye and how the prosthesis had changed their self-face/body image.

Results: We found that the first impression of observing themselves with the new prosthetic eye resulted in activation of two brain areas, the calcarine and the central sulcus. From psychological data it was also determined that wearing a prosthetic eye helps these patients to construct a new self-face/body image.

Conclusions: Thus, the calcarine and the central sulcus participate in the initial steps of the reconstruction a new self-face/body image.

 

Keywords: brain, calcarine, central sulcus, self-face image, sefl body image

Eileen Uribe-Querol, René Jiménez
12 lecturas
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Improving Knowledge Retention and Clinical Reasoning Skills in Second-Year Medical Students with Physiology Review Videos

Introduction: Teaching students how to think logically about disease processes is essential to increasing retention of their physiology knowledge base and developing effective clinical reasoning skills. At the University Of South Florida Morsani College Of Medicine, students are taught normal structure and function of the human body in four integrated organ system-based courses during the first year. In the second year, students learn about abnormal structure and function in three integrated organ system-based courses. We found that many second-year medical students were either not retaining physiology knowledge or were not able to apply it in a clinical context when learning about diseases. Consequently, these students were relying on rote memorization of signs/symptoms of disease and the relevant pharmacological treatments, were not performing well on the Step 1 USMLE, and did not have effective clinical reasoning skills as they entered clerkships.

Objective: To design a series of eight physiology review videos that were directly related to pathophysiology content being taught in the second-year courses.

Material and Methods: The videos were not meant to teach any new material or serve as a complete review of physiology; instead, the focus was on i) emphasizing key points about normal physiology and reminding students to review Year 1 content, ii) teaching students how to use their knowledge base in physiology to analyze and synthesize information as it relates to a patient case, and iii) teaching students how to develop an effective diagnosis and treatment plan based on the disordered physiology. The videos were implemented into Year 2 courses during academic year 2017-2018.

Results: Students who chose to watch the videos (n=72) scored an average of 2.2 percentage points higher on internal course exams and 1.6 percentage points higher on faculty-selected NBME shelf exams reflective of the course content compared to students that did not watch the videos (n=96). Students who watched the videos also scored higher on their first attempt at the Step 1 USMLE compared to those that did not (237.0 vs 233.1, respectively). To assess if students who chose to watch the videos were stronger students in general, we looked at scores from a required comprehensive exam given at the end of Year 1. We found minimal differences between groups (85.7% vs 85.2%), suggesting that the improvement in test and Step 1 scores was more likely, at least in part, a result of knowledge and skills gained by watching the videos. Feedback from students who watched the videos has been very positive and many commented on the fact that they feel more confident in thinking through patient cases.

Conclusions: The physiology review videos were effective at helping students retain physiology knowledge, apply it in clinical context, and develop effective clinical reasoning skills that not only allowed them to score higher on the Step 1 USMLE, but will ultimately better prepare them for the clerkship years.

 

Keywords: Teaching, video, knowledge, student, teaching methods

Jessica A Dominguez Rieg,
10 lecturas
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Hypoventilation and autonomic dysfunction in infant rats following orexin receptor blockade

Introduction: Orexin (hypocretin) is a neuropeptide expressed by neurons in the lateral and perifornical hypothalamus that project widely to respiratory and autonomic regions of the brainstem. The activity of orexin neurons depends on vigilance state; they are most active in wakefulness, less active in quiet sleep, and silent during active sleep. Although there are well-described facilitatory effects of orexin in adult animals on the control of breathing and autonomic response to stress, its role in infancy has not been studied. This is an important issue because there is accumulating pathological evidence of orexinergic dysfunction in some cases of the Sudden Infant Death Syndrome (SIDS), a leading cause of death in infancy that is highly associated with abnormal respiratory and autonomic control during periods of sleep. We hypothesized that in infant (~2 week old) rat pups, orexin receptor blockade would: 1) lead to respiratory dysfunction, more so in wakefulness and quiet sleep than in active sleep, and 2) compromise the thermogenic response to mild environmental cooling.

Objective: To study the effects of orexin in infant rats on the control of breathing and autonomic response to stress.

Material and Methods: To test these hypotheses we used whole-body plethysmography to monitor breathing and metabolic O2 consumption in rat pups treated with suvorexant, a selective orexin 1 and 2 receptor antagonist. Vigilance state was determined using high-definition video to monitor and confirm standard behavioral criteria associated with quiet sleep, active sleep, and arousal in infant rat pups. Experiment 1: Pups cycled through wakefulness, quiet and active sleep for 1hr at thermoneutral ambient temperature (TA=31°C), at which point suvorexant (1mg/kg in 50% DMSO; n=3) or vehicle alone (n=2) was injected via an intra-abdominal cannula, and pups cycled between wakefulness and sleep for another 1 hr. The two groups were compared with respect to respiratory frequency (f), tidal volume (VT), ventilation (VE) and metabolic O2 consumption (VO2). Experiment 2: Pups were kept at thermoneutral TA for 1 hr, then exposed to a ~2°C drop in TA over the following 15 min, and then returned to baseline TA. Pups were then injected with either suvorexant (1mg/kg; n=8) or vehicle alone (n=8), and after another 1 hr, the TA challenge was repeated. In each animal, the change in metabolic O2 consumption in response to cooling was measured before and after drug or vehicle injection.

Results: In wakefulness and quiet sleep, suvorexant reduced respiratory frequency by 48 ± 4 breaths/min (~30%; p=0.01), and VE by 770 ± 254 ml/min/kg (~40%; p<0.001), with no effect on VO2.  These effects were not consistently observed during active sleep, and were absent in pups given vehicle alone. Suvorexant nearly abolished the metabolic response to cooling (p=0.01).

Conclusions: These data suggest that orexin dysfunction can severely compromise breathing and autonomic function in infancy during wakefulness and quiet sleep.  

 

Keywords:  orexin, infant rats, control  breathing, autonomic response, stress

Jane R Kielhofner, Kevin J. Cummings
3 lecturas
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Hypercaloric Feeding Differentially Affects the Neuron Populations of the Hippocampus

Introduction: The generation of obesity through hypercaloric dieting is accompanied by a reduction of some indexes of cognitive performance such as spatial learning and memory in animal models. This suggests that hypercaloric feeding interferes in the dynamics of the neuron populations of the hippocampus. It is known that feeding hypercaloric diets implies a calorie-based regulation of food intake that results in a reduction of the protein and micronutrient supply, which in itself could affect metabolic and cognitive variables in addition to obesity.

Objective: In this study we discriminate the effects of obesity and undernutrition on the structure of the neuron populations of the Ammon Horn (CA) and the dentate gyrus (GD) of the rat hippocampus.

Material and Methods: A group of rats was maintained on a hypercaloric diet or on a hypercaloric diet supplemented with proteins and micronutrients, for 25 weeks. At the end of the treatment, the animals were tested for spatial learning performance and then sacrificed to obtain the brains. Samples were processed and analyzed by conventional histological technique to evaluate the integrity of the pyramidal neurons of each hippocampal region.

Results: The hypercaloric feeding raised metabolic markers of obesity and insulin resistance, and caused an increase in the number of atrophic neurons in all fields of CA but not in GD. Dietary restitution did not modify the development of obesity; however, it prevented the neuronal damage specifically in CA1 but not in CA 2 to 4. The DG was not affected in any condition. The reduction of neuronal damage in CA1 coincided with an improvement in performance in memory tests.

Conclusions: These results suggest that the hypercaloric diet exerts differential effects on the different neuron populations of the hippocampus, which in some cases are due to nutritional deficiency and in others to obesity itself.

 

Keywords: hypercaloric diet, rats, neuron population, hypocampus, obesity, insulin resistance

Claudia Alva-Sánchez, Laura Cruz-Corona, Iván Villanueva
5 lecturas
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Alcohol Intoxication Modifies the Phase and Coupling of Circadian Rhythms

Introduction: In mammals, the circadian rhythms of the diverse physiological variables are maintained by local tissue oscillators. These secondary oscillators are coordinated by central oscillators and are kept functionally coupled by nervous and hormonal signals. The impairment of the communication between oscillators causes the rhythms of different tissues to desynchronize form each other. Ethanol affects the neuronal GABAergic activity, so that it has a general inhibitory effect on the nervous functions. We propose that intoxication with ethanol affects the communication and integration between oscillators, thus modifying the general circadian rhythmicity and the coupling of local rhythms.

Objective: This work evaluates the effects of acute alcohol intoxication on circadian rhythmicity in rats.

Material and Methods: Ethanol (200 mg/dL) was administered at two moments of the circadian cycle (ZT 11 and ZT 23) to a group of Wistar rats maintained in a 12:12 h light/dark cycle, and the circadian rhythms of activity and food consumption were analyzed for the following three cycles under constant darkness.

Results: Alcohol produced a significant shortening of the period along with a delay of the acrophase of the activity rhythm when applied at the beginning of the active phase but not at the beginning of the rest phase. The rhythm of food intake was affected similarly but to a lesser extent.

Conclusions: These results indicate that alcohol intoxication has the potential to alter the endogenous circadian rhythmicity, and that the intensity of this effect varies according to the moment of the endogenous cycle in which it occurs.

 

Keywords: alcohol intoxication, circadian rhythm, wistar rats,

Noemi Méndez-Díaz, Rosa Elvira Núñez-Anita, Iván Villanueva
8 lecturas
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Mechanism of Alcohol Induced Mesenteric Lymphatic Vessel Leakage

Introduction: Lymphatic vessels are involved in the trafficking of immune cells and play a role in antigen transport and immune cell regulatory functions. Lymphatic endothelial tight junctions (TJ) form a seal between endothelial cells and help to control diffusion of molecules across the endothelium, regulating the permeability of the lymphatic barrier. Our previous studies have shown that alcohol consumption can disrupt lymphatic permeability, leading to increased leakage of molecules from the lymphatic system into perilymphatic adipose tissue (PLAT). As a consequence, metabolic dysregulation in PLAT was found, characterized by PLAT inflammation and impairment of insulin-dependent responses. Although the mechanisms underlying alcohol-induced lymphatic vessel leakage are unknown, in blood vessels, alcohol-induced barrier dysfunction involves MAP Kinases (MAPK- Erk ½ and p38) activation and TJ impairment. Thus, we hypothesized that alcohol induces lymphatic leakage via disruption of lymphatic endothelial tight junctions via MAPK activation.

Objective: To prove that alcohol may induce lymphatic leakage via disruption of lymphatic endothelial tight junctions via MAPK activation.

Material and Methods: To test our hypothesis we used commercially available lymphatic endothelial cells and investigated MAPK and TJ (Claudin-5, ZO-1, and Occludin) expressions. The cells were incubated in 0, 25, and 50 mM of alcohol-supplemented cell culture media for 48 hours. Following alcohol treatment, total protein was extracted and analyzed via western blotting or the cells were fixed for immunohistochemistry.

Results: We found that alcohol increased Erk ½ phosphorylation compared to controls but didn’t change p38 phosphorylation. Alcohol also decreased TJ expression compared with controls.

Conclusions: These Overall, alcohol-induced lymphatic leakage might be due to MAPK activation, leading to TJ protein phosphorylation and lymphatic endothelial barrier loss.

 

Keywords: alcohol, lymphatic leakage, tight junction, MAP kinases

Flavia Souza-Smith, Matthew Herrera, Liz Simon, Patricia Molina
14 lecturas
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Neurohypophysial Secretion Alterations in Sepsis Survivor Animals Challenged with Immune Stimulus

Introduction: Previous work in our laboratory showed that inflammatory mediators released during sepsis contribute to the impairment of vasopressin and oxytocin secretion that persist in survivors challenged with osmotic stimulus. However, it is unclear whether these changes persist when the animals are submitted to immune stimulus.

Objective: To study the neuroendocrine alterations in sepsis survivor animals following immune challenge with LPS. Sepsis was induced by the cecal ligation and perforation (CLP) method and the animals (perforated once with a 14G needle) were observed for five or ten days. Naive or sepsis survivors were submitted to intravenous injection of LPS (1.5 mg/kg). After 60 minutes the animals were decapitated for collection of blood and the hypothalamus. Blood was collected for the determination of nitrate, cytokines and hormones (vasopressin, oxytocin) and the hypothalamus for cytokine, synaptophysin and beta-amyloid contents analyses.

Material and Methods: Following the immune challenge, we observed a peripheral increase of nitrate, IL-1 and IL-6 in both group naïve and survivor with an attenuated response in the 10 days survivor. An hypothalamic IL-1 increase was seen in the naïve and survivors, however no such change was seen for IL-6. An exacerbated secretion of vasopressin and oxytocin was observed in either 5 or 10 days survivors animals submitted to the immune stimulus. We also found a decrease in the hypothalamic content of synaptophysin, and no signal of beta amyloid accumulation in the survivors before or after the LPS injection.

Conclusions: We conclude that alterations in vasopressin and oxytocin secretion may be associated with sustained neuroinflammation and synaptic dysfunction. This model of sepsis may provide important information for understanding neuroendocrine alterations in the disease.

 

Keywords: vasopressin, oxytocin secretion, neuroinflammation, synaptic dysfunctionn neuroendocrine, hyphothalamus

Maria José A. Rocha, Nilton N. Santos-Júnior
6 lecturas
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CO2 Decreases the Activity of Locus Coeruleus Neurons in the Streptozotocin-Induced model for Alzheimer's Disease

Introduction: Locus Coeruleus (LC) is an important chemosensitive nucleus and affected by neurodegenerative diseases like Alzheimer's disease (AD). LC dysfunction in AD may account for the respiratory problems observed in patients.

Objective: To test the electrophysiological properties of LC neurons in a model for sporadic AD.

Material and Methods: AD was induced in rats (6-7 weeks) by intracerebroventricular injection of streptozotocin (STZ; 2 mg/kg). 14 days following injection, LC neurons were recorded using the patch clamp technique and tested for CO2 chemosensitivity (10% CO2, pH = 7.0).

Results: When exposure hypercapnic condition, most LC neurons (~60%) exhibited a blunted spike discharge to current injections in comparison to baseline responses. The minority of cells either increased spiking (~20%) or did not respond (~20%) to CO2. Within cells that were inhibited by CO2, current-evoked spike discharge at baseline condition had the same magnitude in control and STZ rats. Responses in both groups decreased significantly when exposed to 10% CO2 (bsl vs. 10% CO2: CTL, p=0.003, n=8 and STZ, p=0.001, n=9). In the STZ group, this CO2-induced decrease in spike discharge was more pronounced when compared to control (CTL vs. STZ, p=0.038), suggesting greater sensitivity to hypercapnia. There was no difference in resting membrane potential and input resistance (Ri, cell membrane resistance) between groups at baseline and CO2. However, although there was no difference between groups values, we found a significant decrease of Ri within the STZ group when exposed to hypercapnia (bsl, 126.5 ± 14.9 MΩ vs. 10% CO2, 98.4 ± 8.2 MΩ; p=0.01), indicating opening of ion channels. The current-voltage relationship of the cell membrane showed a significant CO2-induced decrease of the steady state current (bsl vs. 10% CO2: CTL, p=0.002, and STZ, p=0.001). The magnitude was similar in both groups. This result would paradoxically favor increased excitability in neurons. Analysis of action potential (AP) parameters (AP threshold, AP peak, upstroke slope, peak to anti-peak) also showed no difference between groups. However, within the STZ group spike threshold was significantly shifted to more positive potentials under increased CO2 (-39.6 ± 1.9 mV vs -34.8 ± 2.2 mV, p=0.01). This shift in spike threshold would explain the blunted spike discharge of LC neurons in the STZ group during hypercapnic conditions.

Conclusions: In summary, our data suggest that the majority of LC neurons in adult rats are inhibitedunder CO2 exposure. Further, the STZ-treated group exhibits a greater sensitivity to CO2, likely due to an increased spike threshold and opening of additional, yet unidentified membrane channels. Decreased excitability of LC neurons may be an underlying mechanism for the breathing disturbances observed in patients with AD.

 

Keywords: CO2,neurons,adult rats,  locus coeruleus Neurons, streptozotocin-Induced model, Alzheimer's Disease

Mariane C Vicente, Luciane H Gargaglioni, Tim D. Ostrowski
18 lecturas
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Respiratory variability modulated by vagal and spinal pulmonary afferents

Introduction: Respiratory variability is important in order to respond to internal and external perturbations. While vagal afferents have been shown to be important for feedback during breathing, the influence of spinal afferents has not been as well described. We hypothesized that disruption of vagal and spinal afferents reduces respiratory variability during eupnea and alters respiratory response during thoracic mechanical restriction (banding).

Objective: To prove that disruption of vagal and spinal afferents reduces respiratory variability during eupnea and alters respiratory response during thoracic mechanical restriction

Material and Methods: We measured costal diaphragm and thyroarytenoid electromyography (EMG) activity in sodium pentobarbital anesthetized spontaneously breathing male and female Sprague Dawley rats. We conducted three sets of experiments to elucidate contributions of vagal, and spinal afferents: A) inhalation of 10% nebulized lidocaine to attenuate pulmonary vagal afferents B) bilateral injections of 10% lidocaine into the pleural space to attenuate thoracic afferent feedback; C) bilateral tracheal vagotomy caudal to the larynx. Solutions of 10% lidocaine were mixed with saline and 2% Evans Blue dye to confirm the distribution of lidocaine following nebulization and injection. Additionally, banding was performed before and after each experimental protocol.

Results: Banding significantly increased costal diaphragm amplitude which was further increased with each intervention, however there was a gender specific increase in thyroarytenoid activity with only ~50% of males demonstrating this phenomenon. Both lidocaine protocols demonstrated features of vagotomy including reduction of each eupneic phase duration coefficient of variance as well as alterations in EMG amplitude. Conclusions: These results demonstrate gender-specific effects of the respiratory system to challenges, and provide preliminary evidence of the importance of non-vagal pulmonary feedback. Moreover, this present study could have broad clinical implications in disorders such as spinal cord injury.

 

Keywords: vagal, spinal injury, respiratory variability, eupnea, respiratory response, thoracic mechanical restriction, gender

Alyssa Huff, Mitchell Reed, Seema Mian, Kimberly Iceman, Teresa Pitts
16 lecturas
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Subclinical Carotid Disease in Elderly Women is Associated with Cardiac Hypertrophy and Ageing

Introduction: Women have a higher risk of stroke and poorer functional outcomes after stroke than men. Moreover, with the increase in the aging population, prevalence of stroke survivors among elderly women is projected to increase.

Objective: The aim of this study was to investigate sex differences between the carotid, cardiac and vascular imaging markers of risk in elderly with subclinical carotid disease.

Material and Methods: This was a cross-sectional observational study on a cohort of 100 subjects aged more than 50 years. Carotid intima-media thickness (CIMT), plaque score and resistive index, left ventricular (LV) wall thickness and ascending aorta diameter were determined by echography.

Results: The right CIMT had a significantly positive correlation with the LV wall thickness and the ascending aorta diameter in women (Spearman's r = 0.31 and 0.31, p < 0.05) but not in men. The right CIMT, LV thickness and aortic diameter were positively correlated with age only in women (Spearman's r = 0.33, 0.40 and 0.26 respectively, p < 0.05). Right CIMT correlated with the plaque score at both sexes (Spearman's r = 0.36 in women and 0.37 in men, p = 0.01).

Conclusions: The association of carotid, cardiac and vascular risk factors may contribute to a worse subclinical carotid disease deterioration in elderly women. In this selected age group by sex, the combined assessment of more than one cardiovascular risk imaging biomarker may be required.

 

Keywords: carotid disease; elderly women; cardiac hypertrophy; ageing; sex-differences; ultrasonography

Ovidiu Constantin Baltatu, Valter Luis Pereira, Sandra Gomes dos Santos, Juliana Stefanin Fuzatti, Luciana Aparecida Campos
13 lecturas
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Neurophypophysial Secretion Alterations in Sepsis Survivor Animals Challenged with Immune Stimulus

Introduction: Previous work in our laboratory showed that inflammatory mediators released during sepsis contribute to the impairment of vasopressin and oxytocin secretion that persist in survivors challenged with osmotic stimulus. However, it is unclear whether these changes persist when the animals are submitted to immune stimulus.

Objective: To study the neuroendocrine alterations in sepsis survivor animals following immune challenge with LPS.

Material and Methods: Sepsis was induced by the cecal ligation and perforation (CLP) method and the animals (perforated once with a 14G needle) were observed for five or ten days. Naive or sepsis survivors were submitted to intravenous injection of LPS (1.5 mg/kg). After 60 minutes the animals were decapitated for collection of blood and the hypothalamus. Blood was collected for the determination of nitrate, cytokines and hormones (vasopressin, oxytocin) and the hypothalamus for cytokine, synaptophysin and beta-amyloid contents analyses.

Results: Following the immune challenge, we observed a peripheral increase of nitrate, IL-1 and IL-6 in both group naïve and survivor with an attenuated response in the 10 days survivor. A hypothalamic IL-1 increase was seen in the naïve and survivors, however no such change was seen for IL-6. An exacerbated secretion of vasopressin and oxytocin was observed in either 5 or 10 days survivors animals submitted to the immune stimulus. We also found a decrease in the hypothalamic content of synaptophysin, and no signal of beta amyloid accumulation in the survivors before or after the LPS injection.

Conclusions: We conclude that alterations in vasopressin and oxytocin secretion may be associated with sustained neuroinflammation and synaptic dysfunction. This model of sepsis may provide important information for understanding neuroendocrine alterations in the disease.

 

Keywords: Neurophypophysia, sepsis survivor animals, immune stimulus

Maria José A. Rocha, Nilton N. Santos-Júnior
8 lecturas
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Dam Early Free Access to Hypertonic NaCl Solution Induces a Long-Term Effect on Offspring Basal Chronic Brain Cell Activity

Introduction: Exposure to an altered osmotic environment during a pre/postnatal period can differentially program the fluid intake and excretion pattern profile in a way that persists until adulthood. Our recent results indicate that maternal voluntary ingestion of hypertonic NaCl solution during pregnancy and lactation until one week post-weaning alters the offspring’s central osmoregulatory mechanisms. Offspring water and sodium intake induced by different osmotic manipulations (sodium depletion or sodium overload) is changed during adulthood. However, the analysis of the programing effects on basal pattern of neuronal activity along brain nuclei involved in the control of hydroelectrolyte balance is limited.

Objective: To evaluate the impact of maternal voluntary ingestion of hypertonic NaCl solution (as previously detailed) in the basal brain chronic neuronal activity of adult’s offspring.

Material and Methods: Animal handling and experimental procedures were approved by the Animal Care and Use Committee of our institute, and the National Institutes of Health (NIH) Guidelines were followed. We analyzed the immunohistochemical detection of brain Fra like protein (Fra-LI), alone or combined with vasopressin (AVP) in control (M-Ctrol group) and imprinted (M-Na group) rats, at 70 postnatal day.

Results: The M-Na group showed increased Fra-Li immunoreactivity (ir) along the organum vasculosum of the lamina terminalis (OLVT) (M-Ctrol= 105.75± 21.77 vs M-Na= 308.5 ±59.01; p=0.018; t=-3.22).  However, double Fra-AVP ir neurons or Fra-Li ir along the subfornical organ, hypothalamic paraventricular nucleus (PVN, lateral mangocellular and medial parvocellular subnuclei) and supraoptic nucleus (anterior and medial sections) did not show any significant differences between the maternal treatments.

Conclusions: Taking into account our previous evidence and the present results indicate that the availability of a rich source of sodium during the pre/postnatal period induces a long-term effect on drinking and the basal neural activity along the OVLT implicated in the control of hydroelectrolyte balance.

 

Keywords: hypertonic environment, pre/post natal, basal chronic brain cell activity, long-term effect.

 

A Godino, A Macagno, C Porcari, F Macchione, X Caeiro, L Vivas
7 lecturas
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The Effect of Titanium (Ti) and Titanium 500 (Ti 500) Implantation on the Activation of Rat Macrophage Subgroups

Introduction: Nowadays it is necessary to make new researches in order to solve the problems related to the prolongation of life and related health problems, especially fractures and spinal degeneration. The biocompatibility, mechanical compatibility, morphological compatibility and osseointegration properties of the implant material are very important. In order to prevent unwanted side effects in the use of biomaterials, new strategies need to be developed. Implants, where they will be implanted and their functions will vary according to the characteristics of the material used. The most commonly used metallic materials are 316L stainless steel, Co-Cr alloys and Ti alloys.

Objective: To demostrate the effect of Titanium and Titanium 500 on activation of macropages

Material and Methods: Our research was performed in the Laboratory of Cytokines and Receptors in the Department of Physiology of Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa. Our research has been approved by the Animal Experiments Local Ethics Committee of Bezmialem Vakıf University (Approval Number:2017/218).

In order to control the rejection of the patient with specific inflammation caused by titanium implantation, we analyzed the first triggered cells of the innate immun system, especially macrophages and sub-groups (M1, M2a, M2b, M2c), by implanting Titanium and Titanium 500 into the spinal region in Wistar albino male rats. According to the Power Analysis statistic program, 3 different groups of Wistar albino species male rats with a weight of 250 - 300 grams and 10-12 weeks of age were formed. Group I (n: 8, Sham group (Control)), Group II (n: 8, Titanium alloy), Group III (n: 8, Titanium 500). No implant was used in Group I (sham group). Only surgical stress was applied to the rats and they were closed again. In Group II and Group III, the rods were placed on the lamina. Peripheral blood samples were collected on the 1st, 3rd, 5th and 7th days following the implantation phase. M1 macrophages (CCL3, CCL4, CXCL9, IL-23), M2a macrophages (CD163, CD206), M2b macrophages (CCL1), M2c macrophage (SLAM) markers were examined by ELISA (Enzyme-Linked ImmunoSorbent Assay) method. Groups were compared with one-way analysis of variance (ANOVA). For the paired comparison of significant variables, a statistically significant difference (HSD) test was used for Tukey's homogeneous variance variables. Statistical significance was set at p <0.05.

Results and Conclusions: We believe that our analysis results will be helpful in the control, prevention, immunological and therapeutic methods of the reactions (inflammation, rejection, etc.) that may occur in patients who are implanted with Titanium (Ti) and Titanium 500 (Ti 500) implants (spinal, orthopedic, dental etc.).

 

Keywords: Titanium, Titanium 500, Implantation, rat,  macrophage

Sibel AKYOL, Yagmur ORUC, Besim BEN NISSAN
21 lecturas
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Measuring Cardiorespiratory Variables on Small Tadpoles Using a Non-invasive Methodology

Introduction: Cardiorespiratory studies in tadpols species are scarce, reflecting challenges of using invasive tools, for measuring heart rate (fH) and breathing frequency (fB) by means of implanting   electrodes, cannulae, and others, especially in the case of long-term measurements. This study attempted to improve techniques previously used by Longhini and coworkers (2017) on measuring cardiorespiratory parameters non-invasively in bullfrog tadpoles  in a much smaller anuran tadpole specie, Boana albopunctaca (Anura: Hylidae) from the Savannah-like Cerrado. This specie occurs in the central, southern and southeastern regions of Brazil in an area where deforestation levels are high.

Objective: To determine the resting values for fH and fB of tadpoles (stage 26 from Gosner, 1960) B. albopunctata at 25°C using a non-invasive methodology. Additionally, we determined the Maximum Critical Temperature (CTmax) by exposing tadpoles to a heating ramp (1°C/4min).

Material and Methods: Pre-metamorphic tadpoles (N=11) of Boana albopunctata were collected (SISBIO: 621361) in the Cerrado biome, in Minas Gerais state (20º 14' 43" S; 46º 21' 57" O), and maintained in the lab in aquariums at 25°C. The cardiorespiratory parameters, fH and fB, were obtained by a non-invasive electrocardiogram (ECG) and surface electromyogram (EMG) method, respectively. After baseline measurement, animals were handled in order to administer an intraperitoneal injection of Ringer solution (vehicle) to verify the influence of the injections on the basal cardiorespiratory parameters, which were recorded for an additional hour. For that, we used a thin dental needle (30 gauge) connected by a polyethylene tube (PE10, Clay Adams) to a Hamilton syringe (5 μl). The CTmax, the temperature at which animals lose the ability to escape from conditions that may ultimately lead to death, was determined by exposing tadpoles acclimatized at two different temperatures (15 and 25°C) to a constant heating rate of 1°C/4min. When the animals began to present loss of equilibrium, we stimulated them with a glass rod, and considered the CTmax when tadpoles were motionless after five consecutive taps. Immediately after assessing CTmax, we transferred tadpoles to plastic cups with water at ambient temperature (25°C). We validated the CTmax for individuals that remained alive for at least 24 h after the test. The data obtained were expressed as mean ± s. e. m.     
Results:   At 25°C, baseline values for fH and fB were 104.6 ± 20.0 and 85.94 ± 18.9, respectively. Cardiorespiratory parameters were not significantly affected by the intraperitoneal Ringer solution injection: fH (beats.min−1): 103.2 ± 15.6 and fB (movements.min−1): 85.3 ± 16.1. Animals’ acclimatized at 20°C exhibited CTmax of 35.88 ± 1.58°C  compared to those acclimatized at 30°C, with a CTmax of 39.57 ± 0.49°C.

Conclusion:  According to our preliminary results, we confirm that the non-invasive methodology adapted for larger tadpoles (e.g Bullfrog; size: ~9 cm) can be improved for measuring cardiorespiratory parameters non-invasively in small tadpoles (size: ~4 cm).After one hour from intraperitoneal ringer injection, fH and fB returned to their baseline values. Furthermore, animals acclimated to the higher temperature (30°C) showed greater thermal tolerance during a heating rate protocol.

 

Keywords: Boana albopunctaca, Heart rate, bucal movements frequency, Savannah-like Cerrado.

 

Leonardo Sambini Longhini, Cynthia Prado P. De Almeida, Kênia C. Bícego, Lucas A. Zena, Luciane H. Gargaglioni
17 lecturas
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Diaphragm Muscle Fatigue Resistance Does Not Increase With Age

Introduction: The diaphragm muscle (DIAm) contains a mixed motor units population, with FInt and FF units (comprising type IIx and/or IIb muscle fibers) vulnerable to sarcopenia - age-associated reductions of specific force and cross-sectional area (CSA). Fatigue-resistant S and FR units (comprising type I and IIa fibers) are relatively spared. There is controversy as to whether aging confers an enhanced resistance to DIAm fatigue, with interpretations relying on relative measurements of force.

Objective: To quantify differences in fatigue resistance between young (6-months) and old (24 months) Fischer 344 rats, taking into account maximum specific forces.

Material and Methods: We assessed the loss of DIAm force in young and old Fischer 344 rats of both sexes at 10, 40 and 75 Hz stimulation in 330 ms duration trains repeated each s (33% duty cycle) across a 2 min period.

Results: Although the initial specific force of the DIAm was lower in older rats across all stimulation frequencies, the final residual DIAm specific force after 2 min of stimulation was the same (~5 N/cm2) at all ages. These relative values gave the misconception of an improved fatigue resistance, especially at 40 and 75 Hz. We also found that aging is associated with an increase in the relative contributions of type I and IIa fiber CSA to DIAm mass with decreased contributions of type IIx and/or IIb fibers. When these changing contributions are factored into a fiber type-specific model of DIAm force generation, we found that ventilatory behaviors require activation of only type I and IIa fibers, regardless of age or fatigue. By contrast, the model predicts that aging impairs the ability of the DIAm to effectively perform expulsive manoeuvres, even in the non-fatigued condition.

Conclusions: Relative fatigue measurements are not indicative of improved fatigue resistance in aging and are an artifact of reduced initial specific force contributions from FInt and FF units. These results are consistent with previous studies showing the relative vulnerability of FInt and FF units and conserved ventilatory behaviors in aging DIAm.

 

Keywords: Diaphragm muscle, muscle fatigue resistance, age. rats, ventilatory behaviors,

Matthew J Fogarty, Carlos B Mantilla, Gary C Sieck
12 lecturas
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Hypoxia-induced Sighs Correlate with High Amplitude Bursts in Splanchnic Sympathetic Nerve Activity (SSNA): Role of Bombesin-Like Peptides in the PreBotzinger Complex

Introduction: Hypoxia-induced sighs are widely studied and the actual research are trying to correlate the role of the inhibition of the paraventricular nucleus of the hyphothalamus.among other approaches.

Objective: To demonstrate that hypoxia-induced sighs correlate with high amplitude bursts in splanchnic sympathetic nerve activity and the role of bombesin-like peptides in the preBotzinger complex.

Results: Previous experiments in inactin anesthetized (100 mg/kg, i.v.) spontaneously breathing male SD rats found that hypoxia (HX, O2 saturation ~ 50%) increased frequency(F) and amplitude (amp) of phrenic (Ph) nerve activity (NA) during eupnea, but distribution of SSNA across eupneic Ph cycles was similar for normoxia and HX [inspiration (I1, I2) > expiration (E1, E2)].  HX produced high amp bursts in PhNA (~ 4 to 6/min), followed by brief apnea (sighs). Correlation analysis during sighs revealed that SSNA redistributed such that high amplitude bursts in SSNA occurred in late inspiration (I2 > I1, E1, E2). In the PreBotzinger Complex (PreBot) 2 bombesin-like peptides (Bom), neuromedin B (NMB) and gastrin-releasing peptide (GRP), generate sighs (Li et.al., 2016). Current experiments evaluated the role of NMB and GRP in the Pre-Bot in redistribution of SSNA during sighs.  PhNA and SSNA were correlated before and after bilateral microinjections (100 nl) into the PreBot of a Bom receptor agonist cocktail [Bom-agonists) in rats breathing 100% O2 (n = 3). Bom-agonists increased Ph amp and F during eupnea, but the distribution of SSNA across the eupneic Ph cycle was similar before and after PreBot Bom-agonists (I1, I2 > E1, E2).  Bom-agonists in the PreBot produced high amp bursts in PhNA (131% of eupneic; 4.6 ± 0.5/min) with prolonged expiration (0.90 ± 0.08 vs 0.74 ± 0.07 sec), indicative of sighs.  However, unlike sighs due to HX, with PreBot Bom-agonists while  rats breathed 100% O2, the distribution of SSNA across the Ph cycle was similar for sighs and eupnea (I1, I2 > E1, E2). In 3 rats, sighs were evaluated during graded HX (18, 15 and 13% inspired O2, 2 min ea) before and after a cocktail of Bom-antagonists was injected bilaterally (100 nl) into the PreBot (PreBot-bX). Both the number and amp of sighs tended to be less after PreBot-bX (P = 0.07), but the brief duration of action of the antagonists precluded evaluation of SSNA correlations using this protocol. In separate rats (n = 4), PreBot-bX was performed during HX after regularly occurring sighs were evident (13% O2). PreBot-bX tended (P = 0.08) to decrease the number (2.6 ± 0.3 vs 1.4 ± 0.4/min) and amplitude of PhNA sighs. Correlation of SSNA across the Ph cycle was not changed by preBot-bX during eupnea (I1, I2 > E1, E2), but HX-induced redistribution of SSNA during sighs (I2 > E1, E2) was eliminated by PreBot-bX. Thus, Bom-like peptides in the PreBot contribute to sighs, but correlation of sighs with high amp bursts in SSNA was evident only with HX-induced sighs.

Conclusions: Based on these results and our previous finding that inhibition of the paraventricular nucleus of the hypothalamus (PVN) resulted in uncoupling of SSNA with inspiratory sighs, we speculate that HX activates descending projections from the PVN which modulate cardiorespiratory coupling in the medulla during sighs (Heesch et al., 2018).

 

Keywords: Hypoxia, rats, hypothalamus, inspiratory sighs, splanchnic sympathetic nerve activity, bombesin-like peptides, preBotzinger complex

Cheryl M Heesch, Eileen M Hasser, J. Glenn Phaup
12 lecturas
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PRR analysis in rat retina tissue with complicated pregnancy with Preeclampsia

Introduction: In pregnancy, women experience profound physical, morphological and metabolic changes. Alterations in these changes cause complications such as preeclampsia (PE). This is characterized by proteinuria, increased blood pressure levels and changes in vascular beds. Its etiology is unknown, but it is attributed an important role in its appearance in the Renin Angiotensin Aldosterone System (RAAS), a key system for the regulation of blood pressure, expressed locally in different tissues (including the retina), and whose components they could be involved in the appearance of ocular complications related to the increase in blood pressure, such as Hypertensive Retinopathy (HR). The retina is a sensory layer that, under high blood pressure, has a set of signs that affect it (HR) and that in advanced phases can reduce vision. The HR is presented in four stages according to Keith and Wagener. While in a pregnant woman the retina does not present changes, in women with PE it is possible to see moderate narrowing or sclerosis of the arteries, which corresponds to stage I according to these authors. Moreover, if a woman who has had previous PE develops later hypertension, the retinal changes develop much faster. In HR, there is an increase in vascular permeability and the production of proteins that are activated under hypoxic conditions such as VEGF and PEDF, which seem to play a central role in the development of HR.

Objective: To determine if the components of the RAAS present in the retina could be modified during PE and during arterial hypertension of rats with a history of PE, and induce the changes of the HR through VEGF and PEDF.

Material and Methods:  We used adult female Wistar rats to whom PE was induced by subrenal aortic coarctation. A group of these rats was allowed to give birth and, 30 days later, HTA was induced by the administration of L-NAME, 30 mg / Kg, VO for 30 days. The animals were managed according to the Official Norm for the handling of laboratory animals 062-ZOO-1999. The fundus was assessed and the retina was removed to measure the permeability markers, VEGF and PEDF, and the components of the RAAS AT1R and PRR by the immunoblot method.

Results: In rats with PE, VEGF, PEDF, AT1R and PRR were significantly increased compared to a healthy pregnancy. No changes were observed in the fundus of the PE groups compared with those of healthy pregnancy. In rats with hypertension and with a history of PE, there was no change in the expression of VEGF and PEDF with respect to the group with a history of healthy pregnancy. The proteins AT1 and PRR showed a significant increase in their expression in hypertensive rats with a history of PE compared to the group of hypertensive rats with a history of healthy pregnancy. Conclusions: Our results suggest that there is an incipient process of RH in PE due to the increase in vascular permeability and release of VEGF and PEDF, but without macroscopic changes in the retina. The increase of RAAS components in the retina of rats with PE could suggest their participation in the increase of vascular permeability during PE. In rats with HBP and with a history of PE we did not find an increase in vascular permeability, so the changes found could be due to the increase in the components of the RAAS.

 

Keywords: retina, pregnancy, preeclampsia, rats, renin angiotensin aldosterone system

Claudia Ramírez–Montero, Pedro López-Sánchez, Liliana Anguiano–Robledo, Virgilio Lima –Gómez
22 lecturas
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Effect of Exercise Modality on Cutaneous Blood Flow during Recovery in Normal Subjects

Introduction: During the exercise there is a decrease in cutaneous blood flow (CBF) that tends to increase during recovery; however, the postexercise response depends on the modality and intensity of the exercise.

Objective: To assess the effect of a session of aerobic exercise (AER) and anaerobic (AN) on cutaneous blood flow, assessed with infrared thermography, during post-exercise recovery (RPE) in normal subjects.

Material and Methods: A prospective quasi-experimental study was conducted with 39 normal second-year students of the health faculty, with an average age of 21.7 ± 2.28 years, body weight of 68.34 ± 10.78 kg, height of 171 ± 5.05 cm, body surface area of 1.79 ± 0.15 and BMI of 23.38 ± 3.4. After determining the maximum aerobic capacity (MAC) and the maximum anaerobic power PAM with the Wingate test, two groups were randomly assigned: Aerobic (AER) that exercised 70% of VO2Max, and anaerobic (AN) with exercise 80% of the maximum power. Before the exercise and at the end in minutes 10, 20, 30, 40, 50 and 60, the temperature of the skin of the forehead (T ° fr), of the anterior thorax (T ° ta) and of the anterior part was measured. Of the forearm (T ° ab) using a camera for infrared thermography. Additionally, axillary T ° ax (T ° ax), systolic blood pressure (SBP), diastolic (DBP), mean (MAP), heart rate (HR) and respiratory (FR) were recorded at the same time.

Results: Statistically significant differences were accepted with p <0.05 and thus are reported in all statistical tests. There are statistically significant differences (p <0.05) due to the effect of the main time factor in T ° ab, T ° ta, T ° fr, PD, PS and FC; by effect of the exercise modality in T ° ab, T ° pa, T ° ax and FC and by effect of the interaction in T ° ab, T ° pa, T ° fr, Tax and FC, according to the ANOVA with repeated measures. The AN exercise caused a greater decrease in T ° ab and T ° pa compared to the AER in minutes 20, 30 and 40 of recovery; while the answer was similar in T ° ax and T ° fr but this time in all the moments of post-exercise recovery. The AN exercise presented higher FC values in all the moments analyzed with respect to the AER exercise. The HR values were higher than the rest in both exercise modalities. Multiple pairwise comparisons with Bonferroni adjustment show statistically significant intragroup differences in T ° ab with respect to rest with lower values in minutes 20, 30, 40, 50 and 60 of the recovery when performing AN exercise. There are no differences in T ° ab when performing AER exercise. There are intra-group differences with rest in the T ° pa in the AN exercise in minutes 10 to 50; and in minutes 20, 30, 50 and 60 when performing AER exercise. In the case of the T ° fr, the significant differences with respect to rest, are presented when performing AN exercise in minutes 10, 20, 30 and 40, and do not occur in the AER exercise. In the three regions of interest (ROI) mentioned, the temperature values of the AN group were always below the AER group. In the case of T ° ax, there are statistically significant differences in the AN group in minutes 20, 30 and 40 of the recovery with lower values with respect to rest, while there are no differences in the AER exercise. The values of T ° ax of group AE were always above the resting value, although they were not statistically significant. For both treatments, the PS, PD and PAM values in the RPE were below the resting value while the FC remained above the resting values in the two modalities.

Conclusions: The anaerobic exercise produces a more intense decrease in the FSC in the three regions of interest (ROIs) evaluated compared to the changes produced by aerobic exercise, during the hour following the performance exercise. The infrared thermal images are useful to detect differences in the FSC and in the physiological evaluation of normal subjects in post-exercise.

 

Keywords: regional blood flow, infrared rays, aerobic exercise, high intensity interval training.

 

Flavio Guillermo Muñoz Bolaños, Rubiel Vargas Cañas, Mario Patiño Velasco, Jairo Vásquez
16 lecturas
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Manganese-enhanced MRI (MEMRI) imaging reveals elevated sodium intake induced by deoxycorticosterone acetate (DOCA) modulates activity in select brain regions in male SD rats

Introduction: Excessive intake of sodium is linked to cardiovascular disease. Activation of the renin-angiotensin-aldosterone system is the most common mechanism underlying an increase in sodium seeking or sodium appetite. Numerous brain regions are known to be excited or inhibited during the activation of sodium appetite.

Objective: To determine whether new brain regions linked to chronically elevated sodium intake could be uncovered using novel brain imaging techniques.

Material and Methods: Male SD rats received either a subcutaneous pellet of the aldosterone precursor deoxycorticosterone acetate (DOCA, 150 mg/60 day release) or sham surgery (n=6-8/group). Following surgery, all animals had access to both normal water and a 1% NaCl, 0.2% KCl solution. Between 11-13 days post-surgery the average daily sodium intake in the DOCA group was 196±21 versus 21±4 ml in the control group. On day 14 post-surgery all animals were given an intraperitoneal injection of manganese chloride (25 mg/kg). Following 24 hrs of recovery, while lightly anesthetized, the brain of each animal was imaged on a 4.7 Tesla MRI using a multi-slice spin echo sequence: TE=15ms, TR=350ms, 22 slices, 256x256 resolution. MEMRI enabled mapping of signal enhancement or depression in the brain associated with neuronal activity marked by paramagnetic Mn2+ accumulation.

Results: Preliminary results suggest an overall decrease in activity within many brain regions of interest in the DOCA/salt animals versus controls. Regions with significantly reduced activity following DOCA/salt treatment (P<0.05) included the shell of nucleus accumbens, the hypothalamic dorsomedial nucleus, and dorsal raphe.  There was also a strong trend for a reduction in activity in both the ventral tegmental area and the ventral posteromedial thalamic nucleus (P<0.07).  Many of these areas are linked multiple facets of sodium appetite/intake, including autonomic and defensive behavior control (dorsomedial hypothalamus), foraging (ventral tegmental area, nucleus accumbens), orofacial control (ventral posteromedial nucleus of the thalamus) and behavioral state (dorsal raphe).

Conclusions: These findings suggest that free sodium access during elevated sodium-appetite suppresses activity in multiple brain regions. These preliminary results also identify potential new targets for therapeutic intervention to control sodium intake.

 

Keywords: Manganese-enhanced MRI,  sodium intake, deoxycorticosterone acetate, brain activity, rats

Linda Hayward, Jacqueline Watkins, Marjory Pompilus,, Marcelo Febo
9 lecturas
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Making a Case for Using Simple, Non-technical Language and Analogies When Using Technology to Teach Physiologic Concepts

Introduction: The use of technological innovations in teaching physiology has increased dramatically in the past few decades, and many of the same technologies used for physiology teaching are a part of the clinical standard of care. For this reason, pre-health students in physiology programs need a comprehensive understanding of the technology, the physiological principles behind it, and its clinical relevance. However many students, especially at the undergraduate level, might not have had the courses necessary to understand the underlying principles of the technology prior to being introduced to it. This is especially true in cardiovascular physiology in relation to the electrocardiogram (ECG). Students are often tasked with reading ECG’s and diagnosing a clinical condition without having a baseline understanding of electrical theory necessary to truly understand the ECG. Providing a non-technical analogy to improve understanding of the underlying principles could help students grasp the necessary concepts.

Objective: To determine if the use of a simple, non-technical lesson related to the concepts underlying ECG technology, instead of a lesson using the technical jargon and specifics of the ECG, would improve undergraduate student understanding of its clinical use.

Material and Methods: Three separate anatomy and physiology laboratory sections were taught the basics of cardiovascular physiology. The individual lab sections were then taught by an instructor who introduced the concepts of the ECG using one of three conditions; non-technical, simple analogies about photography and baseball to teach principles of ECG (n = 17); technical aspects of electrical theory underlying ECG (n = 19),  or textbook provided lecture material (n = 17). Following these ECG introductions, the students partook in standard ECG laboratory activities including electrode placement and identification of basic waveforms. Following the laboratory, students were given a written quiz on their understanding of ECG theory.

Results: Results of the quiz suggested that the students who were first introduced to analogies about baseball and photography that were seemingly unrelated to ECGs, understood ECG theory and could identify waveforms and basic ECG concepts equally as well as students who had learned the technical aspects of electrical theory relating to ECG. Interestingly however, post laboratory follow-up indicated that students who had been taught using the non-technical language indicated that they enjoyed the laboratory more and felt they better understood ECG theory than those who had learned the technical aspects prior to the lab.

Conclusions: These results suggest that well-crafted, non-technical teaching styles that students enjoy can be equally effective in teaching complex technological concepts in physiology.

 

Keywords: teaching, physiological techniques, ECG, students

Edward Merritt, Erin Hobbs
7 lecturas
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In vivo effects of renal Npt2a inhibition

Introduction: Hyperphosphatemia is common in patients with chronic kidney disease and associated with increased mortality. Oral phosphate binders and dietary phosphate restriction are the current management protocols for patients with hyperphosphatemia; however, their effectiveness is insufficient. In the kidney, the sodium-phosphate cotransporter Npt2a is responsible for bulk uptake of phosphate in the proximal tubule. Recently, an orally bioavailable selective Npt2a inhibitor (Npt2a-I, PF-06869206) has been described to reduce phosphate uptake in HEK cells transfected with mouse or rat Npt2a. So far, its physiological in vivo function has not been tested.

Objective: To describe the in vivo effect of renal NPt2a inhibition in C57BL/6J mice

Material and Methods: Based on in vitro IC 50 concentrations, we chose to study 30 mg/kg (oral gavage, 1% of body weight) in short-term (3 hours) metabolic cage experiments in C57BL/6J mice.

Results: Compared to vehicle (n=14), bolus administration of Npt2a-I (n=12) caused significantly higher (~4-fold) urinary phosphate excretion (104±8 vs 27 ±6 µmol*min -1, P<0.05). Similarly, urinary phosphate/creatinine ratios were also significantly higher (32±2 vs 8±2 mmol*mmol -1, P<0.05). In addition, Npt2a-I caused higher urinary excretion of calcium (9±1 vs 3±1 µmol*min -1, P<0.05), sodium (316±37 vs 113±24 µmol*min -1, P<0.05), and chloride (277±31 vs 91±24 µmol*min -1, P<0.05), as well as their respective creatinine ratios (Ca 2+ : 2.5±0.2 vs 0.8±0.1; Na + : 92±9 vs 31±6; Cl - : 81±8 vs 25±6 mmol*mmol -1 ; all P<0.05). In contrast, urinary flow rate, urinary potassium excretion, potassium/creatinine ratio, and urinary pH were not significantly different between vehicle and Npt2a-I. In a different set of mice, we studied the effect of Npt2a-I on plasma phosphate and calcium. Under baseline conditions, plasma phosphate and calcium levels were not significantly different between the vehicle and Npt2a-I groups. Oral bolus administration of vehicle did not significantly change plasma phosphate (Δ 0.06±0.08 mmol/L, NS) or calcium (Δ -0.04±0.02 mmol/L, NS) 3 hours after application. In contrast, administration of Npt2a-I caused a significant decrease in plasma phosphate (Δ -0.5±0.05 mmol/L, P<0.05) without affecting plasma calcium (Δ 0.01±0.03 mmol/L, NS).

Conclusions: In summary, our study demonstrates for the first time that in vivo application of a novel Npt2a inhibitor efficiently increases urinary phosphate excretion leading to a decrease in plasma phosphate levels. Thus, inhibiting Npt2a might be a useful treatment strategy for hyperphosphatemia.

 

Keywords: Npt2a inhibitor, mice, urinary phosphate excretion, animal model, mice

Timo Rieg, Linto Thomas, Jianxiang Xue, Jessica Ann Dominguez Rieg
7 lecturas
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The Circadian Rhythm of Intestinal Melatonin-Synthesizing Enzymes

Introduction: Melatonin is a hormone tightly related to circadian synchronization. Blood levels of melatonin oscillate in 24-h cycles in close accordance with the external illumination. Most circulating melatonin is assumed to be secreted by the pineal gland, whose activity is subordinated to the central circadian clock in the suprachiasmatic nucleus. Pineal melatonin is produced during the dark phase of the endogenous circadian cycle, and acts as a synchronizing signal for secondary oscillators in peripheral tissues. It is recognized that tissues other than the pineal gland synthesize melatonin, but the role of these alternative sources in the circadian melatonin circulation is not clear. The intestine has been shown to contain great amounts of melatonin, estimated to be several-fold larger than that of pineal. However, the origin of intestinal melatonin is debated, for there seem to be several sources besides local synthesis from which melatonin could be incorporated into the intestinal mucosa. Moreover, the relationship of this local melatonin with the pineal circadian activity is obscure.

Objective: To describe the relationship between the circadian rhythm with the intestinal melatonin-synthesizing enzymes

Material and Methods: In this work we analyzed the presence of the main protein controlling melatonin synthesis, the enzyme aralkylamine N-acetyltransferase (AANAT) in the main different portions of intestine and the changes in its relative concentration along a 24-h cycle.

Results: We found that AANAT is present along the intestine with higher levels in the proximal portions. The concentration of AANAT in tissue lysates shows circadian oscillation that roughly parallels that of the pineal with a phase delay of around 4 h.

Conclusions: These results indicate that the intestinal wall produces melatonin with a circadian pattern and suggest that this activity is not related with central melatonin signaling but with local timing.

 

Keywords: circadian rhythm, aralkylamine N-acetyltransferase, melatonin, experimental animal

Dulce Andrade-Pavón, Claudia Alva-Sánchez, Noemi Méndez-Díaz, Iván Villanueva
8 lecturas
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Involvement of Protein Kinase B (Akt) in Cardioprotection Carried out by Oral Administration of Stevioside

Introduction: Stevia rebaudiana bertoni is an herbaceous plant widely distributed and used in Paraguay and Brazil, known for its sweetener character. Stevioside (E), a diterpenoid glycoside, is the main non-caloric sweetener extracted from Stevia leaves. Several papers have been published about stevia and its properties as antihypertensive, insulinotropic, antihyperglycemic and antitumor.  However, there are few documented findings on cardiovascular effects mediated by stevioside. In previous studies carried out in our laboratory, we demonstrated that oral administration of E improved the recovery of contractile activity in hearts subjected to I-R and decreased the infarct size. These effects were, at least in part, reverted by the administration of Wortmannin (W), an upstream inhibitor of Akt.

Objective: The aim of the present study was to investigate the mitochondrial morphology and the rate of ATP synthesis after oral administration of E (168 mg/kg for 15 days) and its relation with the activation profile of Akt and GSK3β, in Langendorff perfused rat hearts subjected to I-R.

Material and Methods: Hearts from female Wistar rats (200-250g) fed ad libitum were used. W (100nM) was added 15 min before I. Mitochondrial ultrastructure was analyzed by electron microscopy, the measurement of mitochondrial ATP synthesis was made by the luciferin-luciferase method and the activation profile of Akt and GSK3b were studied by western blot considering Akt-P/Akt-T and GSK3b-P/GSK3b-T, respectively. ANOVA, n=8/group.

Results: At the end of reperfusion, results showed an increase in mitochondrial ATP synthesis rate of hearts treated with E that was partly canceled by the administration of W (C: 66.3±6.5, W: 59.5±6.1, E: 87.3±3.7*, E+W: 64.6±6.9 nmol/min/mg mitochondrial protein; *p<0.05 vs all groups) Likewise, electron micrographs showed better mitochondrial conservation in the group treated with E. Akt presented higher phosphorylation with E treatment (C: 1.26±0.19, W: 1.16±0.07, E: 1.80±0.16*, E+W: 0.86±0.16 AU; *p<0.05 vs all groups). Moreover, GSK3b phosphorylation was higher in the E group with respect to the control group, being partially reverted with W (C: 1.03±0.11, W: 1.04±0.15, E: 1.88±0.05*, E+W: 1.63±0.18 AU; *p<0.05 vs C and W).

Conclusions: These findings suggest that oral administration of E presents cardioprotective effects which includes greater preservation of mitochondrial function and morphology and could be partly mediated by Akt activation.

 

Keywords: Wistar rats, electron microscopy, cardioprotection, protein kinase B, stevioside

Victoria Mestre Cordero, Débora Vélez, Sofia Harriet,, Rodrigo Tsacalian,, Romina Hermann, Marina Prendes, María Gabriela
32 lecturas
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Triiodothyronine improves post-ischemic myocardium recovery: A response associated with enhanced AMP-activated protein kinase activation

Introduction: Low triiodothyronine (T3) syndrome is the most frequent alteration of thyroid hormone metabolism in acute myocardial infarction, which occurs immediately after the onset of symptoms. Although low T3 state has been interpreted as a merely adaptive mechanism, the experimental and clinical data have rebutted this hypothesis, suggesting that T3 might play an effective role in the cardioprotection against ischemia-reperfusion injury. Recent studies have provided evidence that T3 could enhance the recovery of ischemic myocardium through the preservation of mitochondrial function and the improvement of energy substrate metabolism. To this respect, it has been suggested that T3 could activate AMP-activated protein kinase (AMPK), the cellular “fuel gauge” enzyme, which in previous studies carried out in our laboratory exerted protective effects for the recovery of ischemic-reperfused myocardium.

Objective: The aim of the present study was to investigate the effects produced by the acute treatment with T3 and the pharmacological inhibition of AMPK by Compound C (CC), on isolated rat left atria subjected to 75 min simulated ischemia- 75 min reperfusion (Is-Rs).

Material and Methods: Atria were incubated in Krebs–Ringer containing 10 mM glucose, 95% O2–5% CO2, pH 7,4. For Is, the incubation medium contained 10 mM 2-deoxy-D-glucose, 95% N2–5% CO2, pH 6.8. T3 (60 nM) and CC (10 mM) were added to the bathing medium at the onset of Is and maintained throughout the experiment. ANOVA, followed by Tukey’s test, was used, n=8/group.

Results: T3 increased AMPK activation during Is, which was prevented by CC (End stabilization period (ESP): 1.33 ± 0.02, Is-Rs: 2.20 ± 0.11*, Is-Rs+T3: 2.79 ± 0.10*#, Is-Rs+CC: 1.08 ± 0.19, Is-Rs+T3+CC: 1.17 ± 0.10 AU; *p<0.05 vs ESP, Is-Rs+CC, Is-Rs+T3+CC; #p<0,05 vs Is-Rs). During Rs T3 increased contractile function recovery, which was prevented by CC (Peak force (%) Is-Rs: 36.1 ± 3.3, Is-Rs+T3: 51.2 ± 1.6*, Is-Rs+CC: 37.8 ± 2.1, Is-Rs+T3+CC: 39.5 ± 4.0; *p<0.05 vs all groups). Mitochondrial ATP production rate and tissue ATP content was enhanced by T3 at the end of Rs, effect that was reverted by CC (Is-Rs: 24.2 ± 1.1, Is-Rs+T3: 58.9 ± 5.7*, Is-Rs+CC: 28.3 ± 3.8, Is-Rs+T3+CC: 39.7 ± 2.4 nmol/min/mg mitochondrial protein; Is-Rs: 420 ± 52, Is-Rs+T3: 608 ± 94*, Is-Rs+CC: 285 ± 86, Is-Rs+T3+CC: 266 ± 46 pmol/mg protein; *p<0.05 vs all groups). Cellular viability was enhanced by T3, effect prevented by CC (Is-Rs: 66 ± 4, Is-Rs+T3: 79 ± 3*, Is-Rs+CC: 57 ± 2, Is-Rs+T3+CC: 54 ± 3; *p<0.05 vs all groups).

Conclusions: The results support that acute treatment with T3 improves the recovery of ischemic-reperfused myocardium. The present study provided evidence that T3 enhances intrinsic activation of AMPK during Is, remaining its activation increased during Rs. The results showed that AMPK is involved, at least in part, in the protective effects exerted by T3, contributing to mitochondrial function preservation and thus to tissue ATP content recovery, improvement of post-ischemic contractile recovery and conservation cellular viability. 

 

Keywords: Triiodothyronine, post-ischemic myocardium recovery, AMP, protein kinase, enzyme activation

 

 

Romina Hermann, María de las Mercedes Fernández Pazos, Federico Reznik, Mailen Córdoba, Victoria Mestre Cordero, Débora Vélez, María Gabriela Marina P
8 lecturas
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Hypothyroidism: how it affects cardiac function

Introduction: A close relationship between thyroid status and cardiac function has been well established in adult mammals and humans. Several studies have been carried out to pinpoint those important variables whose manipulation in early postnatal life result in long-lasting effects upon cardiovascular function. In this context, induction of hypothyroidism in rats during the perinatal period leads to hormonal, neuronal, and metabolic disturbances that may influence heart function in adult life. The mechanisms underlying the repercussions of early events during the postnatal period on adult life are not fully known.

Objective: The aim of the present study was to examine: (1) whether postnatal hypothyroidism affects cardiac function during the second month of life in rats and (2) whether postnatal hypothyroidism alters cardiac calcium handling.

Material and Methods: Male Sprague–Dawley rats weighing approximately 50 g were used in this study and were randomly assigned to one of the two experimental groups: (1) euthyroid rats (received SC injections of 0.9 NaCl (0.1 ml/100 g body weight) or (2) hipothyroid rats (received 0.02% methimazole in drinking water during 60 days. Animals were sacrificed by cervical dislocation and hearts were rapidly excised. Cardiac myocytes were isolated by collagenase-based enzymatic digestion. Ca2+ transient and cardiomyocyte shortening measurements were performed.

Results: Perinatal hypothyroidism showed a reduced cardiac contractillity measuring by cell shortening and a reduced Ca2+ transient amplitude in isolated cardiomyocytes. Sarcoplasmic-reticulum Ca2+ content was reduced in hypothyroid animals. Hormonal deficit did not change its time to 50% Ca2+ decay. This negative inotropic effect was associated with an increase cardiomyocyte relaxation as revealed by a reduction in the time to 50% relengthening.

Conclusions: The number of spontaneous releases per minute was significantly increased in the cardiomyocytes of the hypo rats.

 

Keywords: Hypothyroidism, cardiac function, hypothyroid rats, inotropic effect, hormonal defficiency

Fellet Andrea, Florencia Vazquez, Juan Ignacio Burgos, Ariel Abramovici, Fiorella Lista, Natalia Ogonowski, Ana Balaszczuk, Petroff M Vila
14 lecturas
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The Non-transcriptional Function of IRF3 Dynamically Regulates Immune Cell Populations in Acute on Chronic Ethanol in Mice

Introduction: Interferon regulatory factor 3 (IRF3) is a transcription factor mediating anti-viral responses, yet recent evidence indicates that IRF3 also has critical non-transcriptional functions, including activating RIG-I-like receptors-induced IRF-3-mediated pathway of apoptosis (RIPA) and restricting activity of NFκB.  Using a novel murine model expressing only non-transcriptional IRF3 activity (Irf3S1/S1), we tested the hypothesis that non-transcriptional functions of IRF3 modulate innate immune responses in the Gao-binge (acute on chronic) model of alcohol-related liver disease.

Objective:  To prove that non-transcriptional functions of IRF3 modulate innate immune responses in the Gao-binge (acute on chronic) model of alcohol-related liver disease.

Material and Methods: C57BL/6, Irf3-/- and Irf3S1/S1 were exposed to Gao-binge ethanol-induced liver injury.  IRF3-mediated RIPA was investigated in cultured macrophages. 

Results: Phospho-IRF3 and IRF3-mediated signals were elevated in livers of patients with alcoholic hepatitis.  In C57BL/6 mice, Gao-binge ethanol exposure activated IRF3 signaling and resulted in hepatocellular injury.  Indicators of liver injury were differentially impacted by Irf3genotype.  Irf3-/-, but not Irf3S1/S1, mice were protected from steatosis, ALT/AST and inflammatory cytokine expression.  In contrast, neutrophil accumulation and ER stress were independent of genotype.  Protection from Gao-binge injury in Irf3-/- mice was associated with an increased ratio of Ly6Clow (restorative) to Ly6Chigh (inflammatory) cells compared to C57BL/6 and Irf3S1/S1 mice.  Reduced ratios of Ly6Clow/Ly6Chigh in C57BL/6 and Irf3S1/S1 mice were associated with an increased apoptosis in the Ly6Clow population in response to Gao-binge.  Activation of primary cultures of macrophages with Poly (I:C) induced translocation of IRF3 to mitochondria, association with Bax and activation of Caspases 3 and 9, processes indicative of activation of the RIPA pathway.

Conclusions: Taken together, these data identify important contributions of the non-transcriptional function of IRF3 in modulating the innate immune environment in response to Gao-binge ethanol exposure via regulation of immune cell apoptosis.   

 

Keywords: etanol, IRF3, innate immune responses, Gao-binge model, alcohol-related liver disease.

Laura E. Nagy, Carlos Garcia Sanz, Kyle Poulsen, Megan R McMullen, Saurabh Chattopadhahay, Ganes Sen
6 lecturas
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Gut microbiota-derived Hydrogen Sulfide is reduced in Spontaneously Hypertensive Rats

Introduction: Gut bacteria play a significant role in host homeostasis, and gut dysbiosis has been associated with many conditions including hypertension (HTN). In circulation, endogenously produced hydrogen sulfide (H2S) is an important freely-diffusing molecule that plays a role in modulation of neural, cardiovascular and immune systems. In view of this, reduced circulating levels of H2S have been shown in animal and human HTN. However, research to date has mainly focused on the H₂S endogenously produced by the host, while scarce evidence suggests that gut bacteria may also contribute to the overall levels of H₂S in host circulation. However, the role of gut bacteria-derived H2S in HTN has not been determined.

Objective: To investigate whether spontaneously hypertensive rat (SHR), an established model of HTN, has a disruption in the gut bacteria-derived H2S production.

Material and Methods: Bacterial DNA from fecal samples of adult male normotensive Wistar–Kyoto (WKY) and SHR was isolated for 16s bacterial genomic sequencing. WKY and SHR fecal and plasma samples were analyzed for H2S levels using modified methylene blue assay. Blood pressures were determined in all rats at several time points using tail cuff to confirm established HTN in the SHR. Data were expressed as mean±SEM. P<0.05 was considered statistically significant.

Results: We observed a significant reduction in the abundance of two H2S-producing gut bacteria in the SHR compared to WKY (Enterobacteriaceae: 1.423e-005±1.056e-005 vs. 0.0002329±7.853e-005, n=6, P<0.05; Clostridiaceae: 0.01134±0.00431 vs. 0.06408±0.01416, n=6, P<0.01). This decrease in the H2S-producing gut bacteria also reflected in a significant reduction in fecal H2S levels (SHR: 0±0.01703 AU vs. WKY: 0.094±0.03385 AU, n=5; P<0.05) and lower plasma H2S levels (SHR: 0.3265±0.07817 AU vs. WKY: 0.6850±0.1790 AU, n=2) in the SHR compared to the WKY.  

Conclusions: These results suggest that diminished gut bacterial production of H2S may contribute to the reduced H2S observed in host circulation in established HTN.

 

Keywords: Hydrogen sulfide; Hypertension; Gut

 

Basak Donertas, Wendi L Malphurs, David M. Baekey, David Julian, Jasenka Zubcevic
21 lecturas
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Central Neural Pathways Controlling Skeletal Muscle Shivering

Introduction: Skeletal muscle shivering is the most important source of thermogenesis in the human cold-defensive maintenance of core body temperature (Tcore) and the elevated Tcore during fever. The thermoregulatory reflex pathway through which skin and core cooling, or injection of prostaglandin E2 into the preoptic area of the hypothalamus, leads to activation of skeletal muscle shivering is only partly understood. On the other hand, other neural circuits provide a potent inhibitory regulation of shivering.

Objective: To demonstrate the tonic inhibitory influence of neurons in the vLPO on skeletal muscle shivering

Material and Methods: EMG activities in masseter, neck and gastrocnemius muscles were recorded in Inactin-anesthetized rats during cold exposure or injection of PGE2 into the preoptic hypothalamus.

Results Cold-evoked and febrile shivering EMGs were eliminated by activation of neurons in the ventral part of the lateral preoptic nucleus (vLPO), or by increasing the discharge of neurons in the paraventricular hypothalamus, in the nucleus of the tractus solitarii, or in the ventrolateral medulla. Inhibiting neuronal discharge or blocking glutamate receptors in the vLPO elicited a sustained increase in shivering EMGs in warm rats.

Conclusions: These results indicate the strong, tonic inhibitory influence of neurons in the vLPO on skeletal muscle shivering, likely through a GABAergic input to shivering premotor neurons in the rostral raphe pallidus. The discovery of the vLPO and other neuronal populations capable of inhibiting shivering supports the potential for the therapeutic control of shivering in the settings of neurogenic fever, brain injury, or induction of hypothermia.

 

Keywords: Central neural pathways,  skeletal muscle shivering, neuron activation,rats

Shaun F. Morrison, Ellen Paula Santos da Conceição
10 lecturas
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A Program of Professional Postgraduate Education in Transfusion Medicine for the Specialty of Anesthesiology and ReanimationIntroduction: The higher medical education identifies different learning needs to develop professional postgraduate courses. Objective: The research objective was to propose a program of professional postgraduate education for the development of the competency in transfusion medicine for the specialty Anesthesiology and Reanimation in Camagüey. Materials and Methods: An educational study at the Camagüey University of Medical Sciences from March 2016 to December 2017 was carried out, in which both quantitative and qualitative methods were employed. The elements of the competency in transfusion medicine within the context of Anesthesiology and Reanimation specialty in Cuba were outlined. Results: A program of a diploma course was designed, based on curricular development of medical education and the identified learning needs. It was characterized by flexibility, systematic teaching and a learner’s centered approach. More than half the specialists who validated the proposal through the variables that characterize the program coincided, according to the non-parametric Kendal test, in giving out an evaluation of excellent. Specialists and residents of Anesthesiology and Reanimation, as well as technicians of transfusion medicine participated in the first version of the diploma course, considered as a pre experiment, which was taught by professors with experience in transfusion, experts of blood banking, as well as basic biomedical and clinical sciences professors. A progressive, systematic and comprehensive approach to the optimal use of blood components was encouraged. Conclusions: Learners unanimously evaluated the diploma course as positive in order to enhance professional skills, and to update their knowledge of transfusion medicine, also considered as very good the teachers’ preparation and the availability of up-to-date literature. Technicians expressed their satisfaction for the opportunity of scientific exchange with professionals of anesthesiology and reanimation.
Ubaldo Roberto Torres Romo, Neyda Fernández Franch, Arturo Teodoro Menéndez Cabezas, Sarah Estrella López Lazo
7 lecturas
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Alexander Ariel Padrón-González, Jairo Lumpuy-Castillo, José Alejandro Rodríguez-Pérez, Vanesa Pérez-Vallín, Alejandro Mirabal-Viel, Cristóbal González-Losada, William Castillo-González, Alberto Juan Dorta-Contreras
22 lecturas
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Oxidative stress in the pathophysiology of cardiovascular disease. New approaches of Aneurysmatic diseases. State of Art

Introduction: Cardiovascular diseases are still the main cause of mortality all over the world.  Ischemic heart conditions are very well know, but aneurysmatic diseases. Endothelial damage seems to be the key in this illness. Objective. According to its importance, new risk factors and specifically biomarkers are needed. Methods: After looking for information in several databases such us: Medline- PubMed, Cochrane and Scielo, a review was done. Results: According literature, arterie’s conditions remain at the top ten cause of death of many countries such as Cuba were 2938 defunctions were registered during 2016. This condition importance is due to asymptomatic featuring so, when pain appears usually fatal complications just like dissection or rupture are presented. Through de major factors involved in this pathology aging, male sex, hypertension and left ventricular mass index ere described. Many biochemical parameters seem to be also coinvolved:  uric acid concentration, total reductive antioxidant capacity are some of them. Another proposed biomarkers are thioredoxin 1, peroxiredoxin 1 and iron. There is not still strong information about NOX4 or ROS, even though its role as a main actor in endothelial lesion through oxidative stress is very well known. Conclusion: Scientific community has realized about oxidative stress role according aneurysmatic diseases. Therefore, antioxidants could be an appropriate method for early diagnosis, follow-up evaluation and target therapy, but molecular studies are not still enough.

Roger Rodríguez Guzmán, Maria Giovanna Scioli, Federico D’Amico, Ela María Céspedes Miranda, Niurelkis Suárez Castillo, Pilar Guzmán Díaz
21 lecturas
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Alexander Ariel Padrón-González, Edel Jiménez-Hernández, Oliver Pérez, Miriam Lastre
43 lecturas
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Juan Carlos Piña Napal, Gustavo Crespo Campos, Rafael Fando Calzado, Yaimara Valdés Silva
13 lecturas
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Transfusion medicine competency andthe fundaments for its implementation in Anesthesiology and Reanimation

Introduction: A way to overcome the blood transfusion disadvantages is determining and developing transfusion competencies. Objective:The research aims were to identify the elements of transfusion medicine competencyand todescribe the fundaments for its implementation inthe specialty of Anesthesiology and Reanimation.Materials and Methods:Transfusion competencies include, among others, knowledge of the risks of blood-borne infections, safe prescription of blood products, identification of transfusion reactions, and competently perform and teach undergraduates the procedure of intravenous infusion of blood and blood products. It alsoincludesknowing and updating on ethical, scientific and legal issuesof blood components transfusion. Results:In Anesthesiology and Reanimation, transfusion medicine competency also involves demonstration of knowledge, abilities and values for the preoperative preparation of the patients with anemia, bleeding risk and other hematological illnesses, for the use of pharmacological and non pharmacological alternatives, as well as for blood components’ economy. Conclusions:Being competent in transfusional medicine in this specialty impliesan important and substantial reduction of the general morbidity-mortality andparticularly thatassociated with transfusion complications, and requires the capacity of mobilizethe set of knowledge, skills, attitudes and values in a comprehensiveand pertinent way in order to transfuse less and better, with more safety and lessexpenditures.

Neyda Fernández Franch, Ubaldo Roberto Torres Romo, Arturo Teodoro Menéndez Cabezas, Sarah Estrella López Lazo, Oscar Liza Hernández
21 lecturas
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Maria Elena de la Torre Santos, Manuela Herrera Martínez, Ana Esther Algora Hernández, Gisela Noche Gonzalez, Arlan Machado Rojas, Madeivy Paz Garcia, Diley Rodríguez Conde, Estrella Reyes Hernández, Carolina Machado de la Torre, Daniel González Benítez
4 lecturas
Circadian Typology and its Sleep - Wake Cycle Temporal Pattern Related in University Students

Introduction: Circadian typology is related to the sleep-wake timing. Objective:To determine the circadian typology and to assess the sleep-wake timing associated with it in a sample of university students. Methodology:273 university students were evaluated by the Morningness Eveningness Questionnaire (MEQ) and the Munich Chronotype Questionnaire (MCTQ). The MEQ established the independent circadian typology  variable and allowed the creation of three work groups: morning type (MT), indeterminate type (IT) and evening type (ET). The dependent variables were calculated from the MCTQ, we used sleep onset and sleep duration on days with classes and days free (SOW, SOF, SDW and SDF respectively), we also calculated the average weekly sleep duration (SDweek), the sleep debt (Sloss) and the social jetlag (SJL).In order to evaluate the phase of entrainment of sleep wake cycle (SWC)we determined two   variables: midpoint sleep on free days (MSF) and midpoint of with sleep corrections (MSFsc).Results:183 subjects (67%) were classified as IT, 65 subjects (23.8%) as MT and 25 subjects (9.2%) as ET. The means of  SOW, SOF and SJL were significantly different (p <.001) among the three groups, the MT were the first to initiate sleep and had less social jetlag, a behavior exactly opposite wereshowed byET. Likewise, to theaveragedifference of SLoss and SDW between groups corresponded values of p =.013 and p =.010 respectively, were the MT those who slept more on the days with classes and conversely less SLoss developed and once again the ET were the opposite. There were no significant differences concerning groups by SDF (p = .454) and SD week (p = .231). Phase of entrainment of SWCdisclosed significant differences (p <.001) between the threegroups and was manifested by earlier values of the MSF and MSFsc in MTand later values in ET.Conclusions:The ITpredominates and the ETisthe least frequent. The CT established by the MEQ corresponds to well-differentiated temporal behavioral patterns of the SWC, it is remarkable in the sleep initiation schedules and in the social jetlag, to a lesser extent it affects the sleepdurations on days with classes and sleep debt. The three CT are alsoclearly differentiated by the phaseof entrainment of the SWC.

Arlan Machado Rojas, Yunier Broche Pérez, Osvaldo Norman Montenegro, María Elena de la Torre Santos, Daniel Tirado Saura, Carolina Machado de la Torre
25 lecturas
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Ela Céspedes Miranda, Gretel Riverón Forment, Celia Alonso Rodríguez, Niurelkis Suárez Castillo, Kenia Rodríguez Oropesa
15 lecturas
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Molecular and Epidemiological Characterization of SMN Genes in Cuban Patients with Spinal Muscular Atrophy

Introduction: Spinal Muscular Atrophy (AME) is a neuromuscular disease of autosomal recessive inheritance with variable expressivity, characterized by degeneration and loss of the anterior horn neurons of the spinal cord and brainstem, resulting in progressive symmetric muscle weakness. The main cause of this disease is due to homozygous mutations in the SMN1 gene. Objective: The aim of the current study was to characterize molecularly the SMN genotypes in Cuban patients affected with Spinal Muscular Atrophy by PCR of Restriction Fragment Length Polymorphism (RFLP), establishing their association with molecular and biostatistical techniques, with gender, age and skin color. This study has two main lines of work: the genotypic characterization by the detection of homozygous deletions of SMN1 and SMN2 by PCR-RFLP and the establishment of the relationship with the clinical phenotype, demographic or ethnic characteristics using statistical tests.The proportion of patients by provinces, type of SMA, sex and skin color was calculated. Results:74% of the patients presented homozygous deletion of SMN1 and 2, 56% had deletion of SMN2. In this study, cases with SMA were confirmed by molecular study, finding that the clinical and electrophysiological characteristics coincided with the data reported in the medical literature. 74% of the patients who fulfilled the clinical and electrophysiological criteria presented homozygous deletion of exon 7 of the SMN1 gene, which represents the mutation most frequently observed in patients with SMA. The distribution showed that the highest percentage of patients are concentrated in the western provinces of Cuba, especially in Havana, where the greatest number of specialized medical services are found where AME patients are treated and the diagnosis is made. Conclusions: The results of this research seek to improve the genetic counseling of individuals carrying mutant SMN genes in order to improve quality of life by optimizing the diagnosis, prognosis and clinical management of these patients.

Fabián Lombillo-Alfonso, Mariana Pita-Rodríguez
4 lecturas
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Inflammation Modulation with Methanol Zea Mays Cob Husk on an Experimental Model in Albino Rats

Introduction: The anti-inflammatory effect of Zea mays cob husk extract may be attributed to the presence of saponins, tannins and polyphenols. Objective: to evaluate the modulatory effect on carrageenan induced inflammation of the methanolic extract of Zea mays cob husk in Albino rats. Methods: The carrageenan-induced paw edema model of acute inflammation was carried out to 30 Albino rats which were divided into five groups, two controls (negative and positive) and three experimental. 9.45% maize cob husks methanol extract was previously obtained by soxhlet extraction and the phytochemical screening was done. Acute toxicity studies were conducted in 12 rats. A single oral methanol plant extract (100mg/Kg, 200mg/Kg or 400mg/Kg) were administered to the experimental groups. Indomethacin 10mg/Kg was used as positive control. The paw volume up to the tribiotural articulation was measured at 0, 1, 3, and 6th hours. Inflammation was expressed as an increase in paw volume due to carrageenan injection and the percentage inhibition produced by the extracts was calculated to assess the anti-inflammatory activity. ANOVA was used to determine the statistical differences between the treatment groups considering a P value less than 0.05 significant. The research was conducted in conformance with the Ethical Principles for the use of animals in research with approval by the Ethical Research Committee of the Institution. Results: saponins, reducing sugars, steroids, tannins and polyphenols were present in the methanol Zea mays cob husk extract. Doses below 5000mg/Kg were considered safe. Significant anti-inflammatory activity was shown at 400mg/Kg after the sixth hour. Conclusions: The anti-inflammatory effect of Zea mays cob husk extract may be attributed to the presence of saponins, tannins and polyphenols. Percentage inhibition of inflammation by the extracts showed dose and time dependence. The antinflammatory activity was found significant for safe concentrations of the plant extract.

Genny Dominguez Montero, Mpewo Judah Thadeus, Miriela Betancourt Valladares, José Luis Cadenas Freixas
5 lecturas
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Redox State Biomarkers in Pregnant Anemic Women and its Relation to the Birthweight

Introduction: In pregnant anemic women redox biomarkers values are similar with the values of non anemic patients. But inter-correlations of redox parameters in the anemic group can increase the lipid peroxidation products and decrease some importantly antioxidants componentes. Objective: The present study was aimed to investigate the oxidant–antioxidant status of pregnant anemic women by iron deficiency in the third trimester of gestation and its relation to the birthweight. Materials and Methods: The present study comprised of 32 pregnant anemic women aged between 18–42 years and 33 pregnant healthy women as control with a haemoglobin (Hb) >110 g/L ranging in same age. Blood haemoglobin, haematocrit (Hct) and mean corpuscular haemoglobin concentration (MCHC) were determined as haematological parameters. The concentration of iron in plasma was also measured. Ferric reducing potential, albumin, vitamins C, E, A, erythrocyte reduced glutathione concentrations, total extracellular superoxide dismutase and catalase activity were measured as antioxidant indicators, and serum malondialdehyde plus 4-hydroxynonenal concentration as a lipoperoxidation biomarker. Results: The levels of haematological parameters were significantly reduced in the anemic group, but not iron plasma concentration, however, median was reduced in the anemic group.  Except of vitamin E levels, no significant differences between the values of the indicators of redox status between the two groups of pregnant women were found. Vitamin E levels were decreased significantly in pregnant non anemic women. The correlations between haematological parameters showed significant correlation with each other except MCHC which did not correlate significantly with Hct. The levels of Hct showed significant and positive correlation with vitamin C levels, but negative with MCHC levels, that correlates significantly and positively with vitamin A concentrations, so, the levels of this vitamin significantly and positively correlate with vitamin E concentrations. The levels of vitamin A also correlate with serum catalase activity. This study showed that Extracellular Superoxide dismutase activity significantly decreased with increased of plasma lipid peroxidation products, and significantly increased with increased of erythrocytes reduced glutathione concentrations. Malondialdehyde plus 4-hydroxy-nonenal concentrations correlated significantly and inversely with birthweight, while erythrocyte reduced glutathione and total extracellular superoxide dismutase activity correlated significantly and directly. Conclusions:  On the basis of our results, it may be concluded that in pregnant anemic women redox biomarkers values were similar with the values of non anemic patients, however inter-correlations of redox parameters in the anemic group showed that with an increase of lipid peroxidation products tends to decrease some importantly antioxidants components, which may result in various complications including peroxidation of vital body molecules resulting in increased risk for pregnant women as well as the fetus.

Elio Cruz Manzano, Osmany Elías Postigo, Maria Rosario Milanés Ojea, Gonzalo Mompié Gómez, Loida Sanfiel Vasseur, Ariel Sarduy Rodríguez
11 lecturas
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Reproductive Parameters in a Model of Visceral Obesity

Introduction: monosodium glutamate can induce obesity and influence negatively inthe rat reproductive function. Objective: To evaluate the influence of the visceral obesity on the reproductive function. Methods: Newborn female Wistar rats were divided into 2 groups to receive MSG (4 mg/g of body weight)or NaCl 0.9%, subcutaneously, on days 2, 4, 6, 8, and 10 of life.At 90 days the animals injected with monosodium glutamate were determined the corporal weight (g) and the corporal length (cm) for the calculation of the Lee index (cube root of the body weight/corporal length). With values higher than 0,300 obesity was confirmed. From this day and to the day 105of life vaginal smears were collected every morning that were observed under light microscope for determination of the estrous cycle duration (days). Rats were then mated overnight with healthy males of the same substrain, starting from 120 days of age.Gestational day 0 was defined when sperms were found in vaginal smear.To a group of obese (n=15) and controls (n=13) practiced them euthanasia the day 11 of gestation. To the rest of the animals practiced them euthanasia the day 20 of gestation (Controls: n=10, Obese: n=11). The uterus was dissected out. The ovaries and uterine contents were examined to determine the number of corpora lutea, implantation sites, resorptions and number of embryos and live and dead fetuses. Reproductive parameters were determinated: fertility index (number of pregnant females x 100 /number of mated females); pregnancy index (number of dams with live pups x 100 / number of pregnant females); preimplantation loss rate (number of corpora lutea−number of implantations × 100/ number of corpora lutea). The postimplantation loss rate (number of implantations−number of living fetuses and embryos × 100/number of implantations). InfoStat program and Statistic package (version 10.0) were utilized. To compare continuous nonparametric variables between groups, the Mann-Whitney U test was used. Fisher exact test was used to compare proportions.A P value < 0,05 was considered significant. Results: the estrous cycle duration was significant increase in obese rats compared to controls. The obese rats had a significant reduced number of corporalutea, implantationsand number of embryos and fetuses. There were no significant differences in fertility and pregnancy indexes, preimplantation and postimplantation loss rates. Conclusion: monosodium glutamate-induced obesity had influence negatively the rat reproductive function, that can be due to the combined effect of the hypothalamic lesion induced by monosodium glutamate and the metabolic own alterations of obesity.

Gipsis Suárez Román, Catherina Capote Guitian, Sonia Clapés Hernández, Tammy Fernández Romero, Gregorio Belo, Manuel Fransisco Da Costa
20 lecturas
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Blood pressure in obese pregnant rats

Introduction: Monosodium glutamate-induced obesity canmodify blood pressure values. Objective: To evaluate the influence of pregestational obesity on the blood presure. Methods: Newborn female Wistar rats were divided into 2 groups to receive MSG (4 mg/g of body weight) or NaCl 0.9%, subcutaneously, on days 2, 4, 6, 8, and 10 of life.At 90 days the animals injected with monosodium glutamate were determined the corporal weight (g) and the corporal length (cm) for the calculation of the Lee index (cube root of the body weight/corporal length). With values higher than 0,300 obesity was confirmed. Rats were then mated overnight with healthy males of the same substrain, starting from 120 days of age.Gestational day 0 was defined when sperms were found in vaginal smear.Systolic (SAP) and diastolic (DAP)arterial pressuresand heart ratewere measured on the rat tail at 18 days of gestation. For itit was used non-invasive blood pressure system(CODA TM, Kent Scientific corporation). The mean arterial pressure(MAP) was calculedby the following formula: DAP + [(SAP- DAP)/3]. These investigation have been conducted in conformance with the Ethical Principles for the use of animals in research. InfoStat program and Statistic package (version 10.0) were utilized. To compare continuous nonparametric variables between groups, the Mann-Whitney U test was used. A P value < 0,05 was considered significant. Results: SAP, DAP and MAP were significant decrease in obese pregnat rats compared to control. There was no significant difference in heart rate between groups. Conclusion: monosodium glutamate-induced obesity affect blood pressure values, probably due to parasympathetic system hyperactivation.

Catherina Capote Guitian, Gipsis Suárez Román, Sonia Clapés Hernández, Gregorio Belo, Manuel Fransisco Da Costa
24 lecturas
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Jorge Ramón Blanco-Carmona, William Quintero-Pérez, Alexander Ariel Padrón-González, Maricarmen González-Costa, Meralys Iglesias del Valle
3 lecturas
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Kinetics-like equation for cerebrospinal fluid-blood diffusion models

Introduction: The diffusion of proteins from the blood to the cerebrospinal fluid is influenced by its molecular weight and by the intrinsic properties and biological properties of the protein. Objective: Determinate the diffusion of new proteins as they pass from the blood to the cerebrospinal fluid. Materials and methods: Paired samples of serum and cerebrospinal fluid were taken from normal subjects to quantify albumin and proteins of the lectin pathway of the complement system. The distribution of these with regard to the value of QAlbúmina = (Albumin in serum / albumin in cerebrospinal fluid) was evaluated because this protein is used as a marker of the passage of the barrier. Results: It was observed that some of these describe a saturation pattern which resembles the curves that describe the Michalis-Menten reaction of enzymatic activity. This led to the consideration of two constants that will help to characterize the behavior of these proteins by spreading to the cerebrospinal fluid: the maximum Q of the protein, which is the maximum proportion found empirically between the concentrations in blood and cerebrospinal fluid and the value Kcdw which is the value of the average diffusion speed of Q albumin when the semi-maximal value of the Q of the protein under study is obtained. Conclusions: Empirically obtained constants will help the characterization and differentiation of the diffusion of these new proteins as they pass from the blood to the cerebrospinal fluid.

José Alejandro Rodríguez-Pérez, Alejandro Mirabal-Viel, Vanessa Pérez-del-Vallín, Christian Meijides-Mejías, William Castillo-González, Jairo Lumpuy-Castillo, Alberto Juan Dorta-Contreras
9 lecturas
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Use of the ROC curves for the evaluation of the Guillain-Barré diagnostic methods

Introduction: The ROC (Receiver Operating Characteristic) curves are widely used to compare methods in search of greater specificity and sensitivity in which they are selected. Objective:  Use the latex agglutination test in the rapid diagnosis of Guillain-Barré Syndrome. Materials and methods: For the diagnosis of Guillain-Barré, different methods were used, such as the clinical one, which is performed in routine or basic clinical laboratories, radial immunodiffusion and neurophysiological, which are not mutually exclusive. The total number of patients studied was 347 divided into two groups: a probable group formed by 31 patients and not probable formed by 316 patients. For the quantification of albumin by radial immunodiffusion in serum and cerebrospinal fluid NOR and LC Partigen® plates were used by Siemens (Marburg, Germany) and by agglutination with modified particles of HELFA latex (CIE, BioCubaFarma, Havana). Results: The Guillain-Barré Syndrome rapid diagnostic latex agglutination test showed little difference between the areas under the curve contrasted with the method considered as reference. As the other tests were incorporated into the diagnosis by latex agglutination, the area under the curve was increased. The area under the curve of the latex agglutination method was 0.742, showing that the technique of agglutination in albumin latex in cerebrospinal fluid does not replace the simple radial immunodiffusion for the immunological diagnosis of Guillain-Barré Syndrome, but it does allow a diagnostic orientation as screening. Conclusions: The latex agglutination test showed that it can be used for the rapid diagnosis of Guillain-Barré Syndrome.

Alejandro Mirabal-Viel, Vanessa Pérez-del-Vallín, José Alejandro Rodríguez-Pérez, William Castillo-González, Christian Meijides-Mejías, Jairo Lumpuy-Castillo, Alberto Juan Dorta-Contreras
14 lecturas
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Christian Meijides-Mejías, William Castillo-González, José Alejandro Rodríguez-Pérez, Fabián Lombillo-Alfonso, Alejandro Mirabal-Viel, Vanessa Pérez-del-Vallín, Alberto Juan Dorta-Contreras
14 lecturas
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Comparison of methods for the quantification of albumin in serum and cerebrospinal fluid

Introduction: Albumin is the protein that marks the passage of cerebrospinal fluid proteins into the serum. Objective:  Determinate if the modified ELISA method is better than the bromocresol green method for serum in terms of specificity and sensitivity and in methods for quantifying cerebrospinal fluid. Materials and methods: Serum albumin was quantified by bromocresol green dye technique and by using the modified microalbuminuria method and for albumin in cerebrospinal fluid, the pyrogallol molybdate red complex  technique and the bromocresol green method were used. Results: Compared methods in serum, the modified ELISA method had a sensitivity of 100%, a specificity of 80% and the cut-off point was less than or equal to 58 g / L. In both fluids the bromocresol green method had a sensitivity of 72.7%, specificity of 60% and the cut-off point was greater than 34g / L. The areas under the ROC curves of the two methods did not show significant differences for p = 0.074. In the methods for cerebrospinal fluid the pyrogallol molybdate red complex had a sensitivity of 88.9% and a specificity of 90.5 and the cut-off point was less than or equal to 960mg / L and the bromocresol green method had a sensitivity of 66.7, a specificity of 85.7 and a cut-off point less than or equal to 700mg / L. The comparison between the ROC curves of the two methods studied was significant with p=0.138. Conclusions: The modified ELISA method is better than the bromocresol green method for serum in terms of specificity and sensitivity and in methods for quantifying cerebrospinal fluid albumin both methods do not show significant differences and have lower specificity and sensitivity than methods for quantifying albumin.

Vanessa Pérez-del-Vallín, José Alejandro Rodríguez-Pérez, Alejandro Mirabal-Viel, Christian Meijides-Mejías, Jairo Lumpuy-Castillo, William Castillo-González, Alberto Juan Dorta-Contreras
11 lecturas
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Electrocardiographic modifications in hypertensive patients without associated diseases

Introduction: Electrocardiographic changes are present in hypertensive patients without other associated diseases. Objective: To identify the electrocardiographic changes present in hypertensive patients without associated diseases. Methods: An analytical study comparing two groups (28 Hypertensive patientswithout associated diseases vs 14 healthy patients), 12 lead surface electrocardiograms were practiced to both group, blood pressure was measured also. P and QRS waves were measured and calculated their dispersions. QT and JT interval were measured and calculated their dispersion too. Results: Comparing the maximum P-wave means in both groups were significantly higher in the cases group, behaving similarly when P wave dispersion was compared in both groups. Maximum corrected QT interval (471,75 ±32,04  vs 448,36 ±40,84;p=0,020)and their dispersion (97,86 ±31,73 vs96,36 ±53,07;p=0,522) were realated too,  but only the first one showed significant differences between both groups. Maximum QRS wave and it dispersion showed significant differences when both groups were compared; hypertensive group showed higher value of QRS duration (116,07 ± 16,41 vs 101,43 ± 5,35; p= 0.003) and dispersion (44,64 ± 19,72 vs 30,71 ± 6,16; p=0.033). It is the first time that this variables were studied in hypertensive patients.The maximum JT segment and it dispersion did not show to be significantly different when comparing both groups. Conclusions: Maximum P and QRS waves and their dispersions showed significant differences between both groups. QRS duration and it dispersion were higher in hypertensive people, perhaps it could be related with some conduction disturbances through the conduction system or myocardial muscle.

Lissett Ferrer-Orozco, Yoandri Orozco-Martínez, Jesús Ignacio Medina-Morales, Beatriz Orozco Pérez de Prado, Calixto Orozco Pérez de Prado, Rosa María Hernández Maldonado, Elibet Chávez-González
6 lecturas
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Modifications of the non-linear parameters of the heart rate variability related to the systematic practice of physical exercise

Introduction: In recent years the relationship between the systematic practice of physical exercise, cardiovascular dynamics and the functioning of the autonomic nervous system has been recognized. Objective: To determine the modifications that nonlinear parameters undergo in the autonomic cardiovascular regulation of the heart rate variability with the systematic practice of physical exercise. Methodological Design: Retrospective cohort analytical study in the period from February 2016 to August 2018. Universe and sample of 36 individuals (Group 1: 18 high performance baseball athletes, Group 2: 18 students from the University of Medical Sciences of Santiago de Cuba). The data were collected in the Biomedical Basic Sciences Laboratory of the University's Faculty 1, through the 8-channel PowerLab polygraph, and stored using the Kubios Software version 3.0.4 Premium.
Results: Statistically significant differences were found in heart rate values (p = 0.000); SD1 (p = 0.025); SD2 / SD1 ratio (p = 0.007); sample entropy (p = 0.011); short-term fluctuations alpha 1 (p = 0.019); linear average length (p = 0.016); linear maximum length (p = 0.001); recurrence rate (p = 0.034); determinism (p = 0.010) and Shannon entropy (p = 0.015). The parameters of SD1 (C = 906) and sample entropy (C = 712) were significantly associated with a heart rate ≤ 70 beats / min. Conclusions: With the systematic practice of physical exercise, the non-linear dynamics of the autonomic cardiovascular regulation of the heart rate variability undergoes modifications that respond to a better adaptability of the autonomic nervous system, and to a greater capacity to regulate cardiovascular function.

Víctor Ernesto González-Velázquez, Roxana María Rebustillo-Escobar, Walfrido Semanat-Gabely, Lázaro Cobiellas-Carballo, Miguel Enrique Sánchez-Hechavarría
5 lecturas
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Sequential Variations of Renal Function Parameters and Oxidative Status after Surgical Ablation of 5/6 of Renal Mass in Wistar Rats

Introduction: In rats with subtotal nephrectomy occurs progressive changes on renal function, oxidative damage to lipids and proteins and antioxidant defenses. Objective: to evaluate the progressive changes on renal function, oxidative damage to lipids and proteins and antioxidant defenses in renal tissue after subtotal nephrectomy in rats.  Methods: The surgical ablation of 5/6 of the renal mass was performed by tying two branches of the left renal artery and removing the right kidney to 30 Wistar rats which were divided into three study groups and followed over a period of two, four, and six weeks. The remaining group of 10 rats was used as control. Functional remainder state of the renal mass was evaluated by measurement of the Glomerular Filtration Rate (GFR) and effective Renal Plasmatic Flow (RPF) through renal plasmatic clearance methods. Weekly measurements of plasma creatinine and excretion of proteins, sodium, and potassium and urine osmolality were performed.  Oxidative status was assessed based on four markers in renal tissue homogenate. Malonildialdehyde (MDA) and Advanced oxidation protein products (AOPP) were determined to assess oxidative damage to lipids and proteins respectively and measurement of reduced glutathione (GSH) and superoxide dismutase activity (SOD) were used as indicators of antioxidant defense. One way ANOVA was conducted to analyze the sequential changes of the study variables and lineal correlation was used to analyze correlations between progressive functional changes and oxidative markers; considering a P value lower than 0.05 significant. The research was conducted in conformance with the Ethical Principles for the use of animals in research with approval by the Ethical Research Committee of the Institution. Results: Significant reduction of GFR was found two weeks after nephrectomy and continue reducing together with RPF up to week 6; when FF was also significantly low compared to control group. Plasma creatinine increased over threefold by week four in the experimental groups while significant increase of proteins excretion was noted by week two to continue rising  slightly up to week six. Sequential changes on sodium and potassium excretion were observed. Lipid peroxidation significantly increased at 4th week and continues this trend throughout the time.  Oxidized proteins were higher over the nephrectomized rats and significant change of AOPP was found by week two. SOD activity diminished initially, followed by a super induction at 6th week and GSH levels started to decrease markedly at 4th week after nephrectomy. Conclusions: the sequential increase of lipids and proteins oxidation together with the variations of antioxidant defenses on renal tissue suggest that oxidative stress increases in the remainder kidney as the renal function is progressively reducing.

Miriela Betancourt Valladares, José Luis Cadenas Freixas, Genny Dominguez Montero, María Josefina Méndez, Odalys Rodríguez Martín
3 lecturas
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A Curriculum for Master of Science in Physiology of Mbarara University of Science and Technology in Uganda

Introduction: There are differets ways to design a Curriculum for Master of Science in Physiology to train postgraduate students. Objective: to design a Curriculum for Master of Science in Physiology to train postgraduate students in Mbarara University of Science and Technology (MUST) of Uganda. Methods: MUST was founded in 1989 and its Academic programmes are intended to be tailored towards the Government effort of solving Uganda’s economic problems by producing the skilled manpower in all relevant areas. There are 7 Degree programmes and 12 Master’s Degree Programmes, one of which was Physiology. The Department of Physiology was a pioneer in the Faculty of Medicine and had been training postgraduate students for some time without a proper curriculum. New regulations and guidelines together with the development of science and teaching demanded to generate a new Curriculum for Master in Physiology in order to resume the training at MUST according to the current needs and standards. During one year and under the guidance of the Curriculum Committee Faculty of Medicine, different steps were followed to come up with a product able to satisfy the requirements. Accomplished tasks included: identification of mandatory courses based on the need of a physiologist with knowledge in all areas to be able to train undergraduates through Physiology with research and teaching skills; a large search of curricula followed by several universities in Uganda and abroad; several meetings, discussions, workshops to review contents, objectives, skills and the overall structure according to the guidelines, and review after submissions. 

Results: The curriculum was designed, presented, reviewed at the different established levels and approved to resume the training of postgraduate students in the area of Physiology by the Department of Physiology, Faculty of Medicine, MUST. The first group of postgraduates started their training following this curriculum in August 2016.

Conclusions: As a result of the request by the Dean, Faculty of Medicine, MUST; the efforts made by the Physiology staff members who directly participated in designing the curriculum, under the leadership of the Head of Department who spent 4 years working as staff of the University; with the invaluable guidance of the Curriculum Committee, MUST; and the support and mentorship from experienced colleagues; was possible to come up with a curriculum in less than one year. Without this curriculum, the training of Physiologists at MUST was not going to be possible despite the urgent needs of the country.

Miriela Betancourt Valladares, Kasiisi Balaam, Namayanja Rosemary, Kiguli James Mukasa, José Luis Cadenas-Freizas, Genny Domínguez Montero
6 lecturas
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Sex Differences in QEEG in psychopath offenders

Introduction: Functional brain differences related to sex in psychopathic behaviour represent an important field of neuroscience research; there are few studies on this area, mainly in offender samples. Objective: The aim of this study was to investigate the presence of electrophysiological differences between male and female psychopath offenders, specifically we wanted to assess whether the results in QEEG, LORETA and changes in synchronous brain activity could be related to sex influence. Sample and Methods: The study included 31 male and 12 female psychopath offenders, according to the PCL-R criteria fromtwo prisons located in Havana City. The EEG visual inspection characteristics and the use of frequency domain quantitative analysis techniques are described. Results: The resting EEG visual analyses revealed a high percentage of EEG abnormalities in both studied groups. Significant statistical differences between the mean parameters of cross spectral measures between psychopathic offender groups were found in the beta band at bilateral frontal derivation and centro-parietal areas. LORETA showed differences especially in the paralimbic and parieto-occipital areasSynchronization likelihood revealed a significant group effect in the beta band (26-30 Hz). Conclusions: These results indicate that combining QEEG, LORETA analysis and Synchronization likelihood, may improve the neuro-functional differentiation between psychopath offenders of both sexes.

Ana Calzada-Reyes, Alfredo Alvarez-Amador, Lidice Galán-García, Mitchell Valdés-Sosa
2 lecturas
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Serum Copper, Zinc, Calcium and Magnesium Levels in Mothers with Offspring Affected by Neural Tube Defects: A Case-Control Study

Introduction: Neural tube defects is a health problem in Cuban population. Objective: To measure the maternal serum levels of copper, zinc, calcium and magnesium in mothers with offspring affected by neural tube defects (NTD) and to examine a possible relationship between the serum concentrations of these micronutrients and occurrence of NTD. Methods: Maternal serum blood samples were obtained at delivery from 56 healthy pregnant women and 56 mothers who had NTD affected offspring, including those alive, stillbirths and elective pregnancy termination. Copper, zinc, calcium and magnesium levels in serum were measuredby flame atomic absorption spectrometry and were compared between the two groups of mothers. The research was conducted in accordance with the basic principles of the Helsinki´s declaration. Results: Serum zinc levels were determined to be significantly lower in the study group compared with the control group, while copper levels were significant elevated in the study group (all p values < .05).There was a negative correlation between serum zinc levels and serum copper levels. However, no association between calcium and magnesiumserum levels and increased risk for the development of NTD was observed. Conclusions: High maternal serum levels of copper and lower level of zinc during pregnancy were associated with NTD in offspring. If folic acid supplementation is given, additional zinc supplementation should be considered for the further decrease in the recurrence risk of NTD.

Noel Taboada Lugo, Ángel Mollineda Trujillo, Manuela Herrera Martínez
6 lecturas
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Tammy Fernández Romero, Gipsis Suárez Román, Sonia Clapés Hernández
10 lecturas
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Modifications of the non-linear parameters of heart rate variability in relation to the arithmetic calculation test

Introduction: The nervous system is divided into voluntary nervous system and autonomic nervous system. The latter has been related to situations of stress and struggle usually results in an increase in heart rate, blood pressure and cardiac output. Objective: To determine the modifications that the non-linear parameters undergo in the autonomic cardiovascular regulation of the heart rate variability subjected to mental stress through the arithmetic calculation test. Material and Method: A non-observational quasi-experimental study was performed without control group before and after; the population constituted by 10 patients and the sample occupied the total of the population, in the Laboratory of Basic Sciences of the University of Medical Sciences of Santiago de Cuba Faculty No. 1 (March 2016-August 2018. The statistical analysis was performed by means of a set of statisticians contained in the SSPS version 21 package. Nonparametrictechniques are used when checking the small size of the sample. Results: Within the non-linear parameters that were modified with the stressor were SD1 (26.64 ± 15.33), SD2 / SD1 ratio (2.53 ± 0.68), Sample entropy (1.43±0) , 25), short-term fluctuation (1.28 ± 0.16), CorrelationDimension (2.41±1.52), maximum linear length (190.10 ± 120.12), recurrent frequency (27,10 ± 5,26), determinism (97.61 ± 1.28), multiscale entropy, minimum value (1.41 ± 0.65) and multiscale entropy, maximum value (2.08 ± 0.30). Conclusions: The nonlinear parameters in the autonomic cardiovascular regulation of the SD2 / SD1 relationship, short-term fluctuation, maximum linear length, recurrent frequency, determinism and multiscale entropy experienced an increase in patients subjected to mental stress through the arithmetic calculation test. . The SD1, Correlationdimension and Simple Entropy parameters experienced a decrease in patients subjected to mental stress through the arithmetic calculation test.

Elys María Pedraza Rodríguez, Carlos Almira Gómez, Sergio Cortina Reyna, Miguel Enrique Sánchez Hechavarria
5 lecturas
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Brain electrical activity in apparently healthy young people in a state of hypnosis

Introduction: There are many ways to distinguish hypnosis from wakefulness.  Materials and methods: A quasi-experimental study was conducted in 21 young adults with 20 years apparently healthy in a state of hypnosis at the "Juan Bruno Zayas" hospital in Santiago de Cuba, during the period from September 2014 to June 2015 Objective: evaluate if the narrow band quantitative analysis allows to distinguish hypnosis from wakefulness. Results: In order to validate the statistical information, the Manova multivariate analysis of variance was used as a technique and, through the Nest statistical system, the difference between hypnosis and wakefulness was validated through the student's t 'test. Validation of the difference between the different levels of hypnotic depth was carried out through the Nest statistical system using the False Discovery Rate (FDR) statistic. For all hypothesis tests, a statistical significance level of 0.05 was considered. Conclusions: The narrow band quantitative analysis allows to differentiate the wakefulness of the hypnosis state, the multivariate analysis of the hypnotic depth level by derivation for each of the narrow band frequencies allows to identify the hypnotic depth level, in the quantitative analysis of The narrow band spectral parameters are concentrated in the largest frequency range with statistical significance in the theta band, the leads that obtain a greater range of frequencies with significant responses are located in the frontocentral region of the right hemisphere and central midline.

Elizabeth María de la Paz Reyes, Elizabeth Salvador Peacok, Ileana Cutiño Clavel, Cesar Brook Lageire, Arquímedes Montoya Pedrón, Ricardo Javier Laborí de la Paz
16 lecturas
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Jennifer Salgado Rodríguez, José Alcides Reytor Vega
4 lecturas
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Protecting Embryonic Development in Diabetic Pregnant Rats

Introduction: Recently Erythropoietin (EPO) has been found to regulate survival and cyto-protection of different cells types. Objective: Evaluate the effect of low sialic EPO (lsEPO) in embryonic development, genetic expression and glucose homeostasis in diabetic pregnant rats. Materials and methods: Female rats were injected with Streptozotocin (60 mg/Kg B.W.) to induce diabetes. Two weeks after diabetes diagnosis, rats were paired with healthy males. Diabetic pregnant rats were included in three groups. Group A with diabetic, non-treated pregnant rats, group B and C treated with two different doses of isEPO by sub- cutaneous way; 0,5 and 1,0 mg/kg of body weight. The schedule was repeated in alternated days from the beginning of pregnant until 12 gestational days. In these day the dams was killed and their embryos was separated from decidua for morphologic studies. The decidua tissue was used for genetic studies. Specifically we studied the expression of genes that are very active in the  early stages of placental implantation and development. The genes expression studied were NFE2L2, HIF1A, VEGFA, BAX, INOS and BCL2. Ethics aspect was carefully considered. Results: Our result show a significant increase of reabsorption and early pregnancy loss (1.37 fold higher) in diabetic rat treated with placebo when compared to control. On the other hand, the diabetic rats treated with lsEPO show a decrease of reabsorption and early pregnancy loss when compared with those treated with placebo, with a risk of 0.8 fold lower. The glycaemia was lower in diabetic rats treated than in rats treated with placebo. The decrease was detected as early as day 6 of treatment and was higher at day 12 when diabetic rats with placebo show a glycaemia of 24.14 mM while those treated with lsEPO had 17.92mM/L. Relative expression of BCL2 gen was positively regulated and no other genes were modified in those tissues.  It is know that Epo should act on apoptosis way and control crucial process in right moment of development. The placental formation is an challenger on diabetic pregnant rats. The implication that these changes could have in the development of the embryo is yet to demonstrate. Conclusions: In conclusion, these results show that ls EPO ameliorate glucose homeostasis in diabetic pregnant rats and it is the first report of the protection of embryonic development in diabetic pregnant rats.

Sonia Clapés Hernandez, Carlos Luis Pérez Hernández, Tammy Fernández Romero, Hamlet Camacho Rodriguez, Gisell Pentón Rol, Gipsis Suárez Román
8 lecturas
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Causality: autoimmunity and cancerIntroduction: The effectors of autoimmune diseases are the mechanisms of hypersensitivity. These processes also appear in cancer, which can give rise to autoinflammation. Objective: To describe the causality between autoimmune diseases and cancer. Material and Methods: A bibliographic review was made using the Google Scholar and articles of free access in the Pubmed and Scielo database from January 2014 to February 2019. The search terms were used according to the DeCS and MeSH descriptors.
Development: Autoimmune diseases are chronic inflammatory processes caused by failures in tolerance. The mechanisms and specific processes that initiate the damage are still unknown. The activity of inflammatory cells and soluble pro-inflammatory mediators leads to a greater recruitment of endothelial cells and promotes angiogenesis. Persistent inflammation (chronic or low grade) can often promote tumor development, tumor progression and invasion. In the tumor environment there is release of molecular patterns associated with damage (DAMPs), which mimic a sterile lesion and recruit cells of innate immunity, which can promote an inflammatory environment and cause an autoimmune phenomenon. Conclusions: Inflammatory responses can improve tumor growth and progression. Cancer can develop self-immunity or arise secondary to the genetic and epigenetic changes of autoinflammation. The causality between cancer and autoimmunity is bi-directional due to inflammatory processes.
Maricarmen González-Costa, Alexander Ariel Padrón-González
5 lecturas
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Hormones, feeding, stress and low grade inflammation: its role in the etiology of autoimmune diseases

Introduction: The etiology of autoimmune diseases is still unknown but different causes arise. Objective: To describe the role of factors such as hormones, feeding, stress and low grade inflammation in the etiology of autoimmune diseases. Materials and Methods: A bibliographic review was made using the Google Scholar and articles of free access in the Pubmed and Scielo database from 2015 to February 2019. The search terms were used according to the DeCS and MeSH descriptors. Development: It is well known that female hormones increase the risk of autoimmune diseases. Recently it has been observed that an imbalance in the neurohormone melatonin can generate autoreactive lymphocytes. Stress can maintain low-grade chronic inflammatory responses that cause tissue damage, initiating or aggravating the clinical manifestations of autoimmunity. An adequate diet allows the guests of the intestinal microbiota to maintain the homeostasis of the immune system. Today, glutamate is used as a flavor enhancer, especially in developed countries. Perhaps it is one of the causes of the higher incidence of autoimmune diseases in these regions. Conclusions: Autoimmune diseases are more frequent in women. Adequate nutrition allows the gut microbiota not to be altered and to maintain immunological homeostasis. Situations of stress and low-grade inflammatory processes can trigger or exacerbate the clinical manifestations of autoimmunity.

Amanda Rodríguez-Manso, Maricarmen González-Costa, Alexander Ariel Padrón-González
15 lecturas
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The basal autonomic balance and during isometric exercise in young people with different cardiovascular reactivity

Introduction: the autonomic nervous system plays an important role in cardiovascular readjustments to exercise. In cardiovascular hyperreactivity there is a greater sensitivity of the sympathetic system to different stressors.  Objective: to determine the characteristics of cardiac autonomic control in young adults with different degrees of cardiovascular reactivity at rest and during isometric exercise. Material and Methods: the sample consisted of 97 individuals of both sexes, it was divided into three groups; normorreactives, hyperreactive and with hypertensive response according to the pressor response to the sustained weight test. All individuals underwent a variability study of heart rate at rest and during the isometric test. Variables in the frequency domain were studied: HF, LF, resting LF/HF ratio and the parameters of the Poincaré diagram SD1, SD2 and the SD1/SD2 ratio at rest and during exercise.  Results: At the basal state, hyperreactive individuals and with a hypertensive response had a sympathetic predominance over cardiac function and a lower variability of heart rate. During isometric exercise the values of the SD1 and SD2 axes decreased in all groups and the SD1/SD2 ratio decreased in normorreactive individuals and with hypertensive response, but it was only significantly in the hyperreactive ones. Conclusions: In individuals with cardiovascular hyperreactivity, an autonomic imbalance is already present in the basal state and there is a reduction in autonomic vagal modulation during exercise that may contribute to the development of hypertension.

Alexis Rodríguez Pena, Otmara Guirado Blanco, Héctor Jesús González Paz, José CArlos Casas Blanco
8 lecturas
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Kenia María Rodríguez Oropesa, Yanín Bebelagua Cid, Ana María Vázquez
9 lecturas
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Myeloperoxidase Activity, Lipid Profile and Thyroid Function in Patients Who Suffer from Alzheimer´s DiseaseIntroduction: Alzheimer´s disease increases its global incidence and prevalence, the WHO includes the disease among the main problems in public health today. Cuba is not apart from this reality.  Biochemical markers pretend to enhance its early diagnosis. Objective: to determine myeloperoxidase activity, lipid profile and thyroid function, in patients who suffer from Alzheimer´s disease.  Materials and methods: a case and control analytic observational study was done, in patients from the Santa Clara polyclinic. The MPO activity, total cholesterol, LDL-c, HDL-c, total triglycerides, VLDL, total T3 and T4, and TSH were determined in serum of both groups. Results: no association was found between myeloperoxidase activity and the presence of the disease (p = 0.348). There was an almost absolute predominance of low levels of HDL-c, more evident in cases (0.43 mmol/L), the levels of T3 tended to be close to the lower limit of  the physiological range (1.46 nmol/L), a relevant finding was a general presence of subclinical hypothyroidism (23.75 %), with no significant differences between groups.  Conclusions: The Alzheimer´s disease keeps showing its increasing with age and it is more common in females. High levels of LDL-c and low of HDL-c are frequent in the elderly. Higher levels of HDL-c and T3, this last one into the physiological range, act as protectors against the disease. The subclinical hypothyroidism is present and remains hidden in many of the elder with Alzheimer or not. In a high number of patients coexisted Alzheimer´s disease and some diseases from the metabolic syndrome, as dyslipidemias.
Rafael Marcel Ranzola, Yania Ramos Rodríguez, Julio Junco Cuesta, Ariel Pérez Trufin, Jorge Cabrera Llano, Vielka González Ferrer
4 lecturas
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Study of Antiulcer and Gastroprotective Effect of Musa Pulp ABB spp

Introduction: In previous studies we have demonstrated experimentally that the green fruit of the Musa spp ABB, variety Burro CEMSA, is effective as a gastroprotective agent in a model of induction of ulcers by absolute alcohol and indomethacin. Objective: To evaluate in a model of chronic ulcer the antiulcer effect and the possible mechanisms by which the pulp of this fruit produces gastroprotection.  Materials and methods: Male Wistar rats of 190 ± 10 g were used. The pulp of the green fruit was sliced, dried at 50 oC for 72 hours, ground and sieved. The antiulcer effect of pulp suspensions was performed with the model of chronic ulcer by acetic acid, used 5 experimental groups of 8 rats each, group 1 negative control, group 2 positive control (ranitidine 50 mg / kg, weight alive), group 3. 4 and 5 that was given the suspension of the pulp at 125; 250; 500 mg / kg live weight. The substances to be tested were applied 72 hours after inducing the ulcer for a period of 7 days. For the determination of the mechanisms, five experimental groups of 10 animals each were formed: the negative control, the positive control and three groups to which the banana pulp was supplied in a dose of 125, 250 and 500 mg / kg of live weight, for three days, before inducing the ulcers with indomethacin: at 40 mg / kg of live weight, the activity of the myeloperoxidase, the superoxide dismutase and the levels of prostaglandins in the gastric mucosa were determined. Results: Treatment with the suspensions of the pulp in the chronic ulcer model reduced in a very highly significant way the damaged area in all the treated groups and this reduction was greater than that produced by ranitidine. A highly significant decrease in lesion intensity was obtained with the use of all preparations of the banana pulp in the indomethacin ulcer induction model; there was a significant decrease in myeloperoxidase only with the highest dose tested and a significant increase of superoxide dismutase and prostaglandins content in the gastric mucosa with all the doses used.  Conclusions: We conclude that the pulp preparations provoked an intense anti-ulcer and gastroprotective action. The mechanism of action is mediated by an antioxidant effect and mucosal protection, caused by the increase of prostaglandin levels. The study has been conducted in conformance with the Ethical Principles for the use of animals in research and education.

María de los Ángeles Boffill Cárdenas, María José Martín Calero, Carmen Garrido Arce
5 lecturas
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Studies of genetic epidemiology about phenotype with complex determination in the context of biomedical basic sciences doctoral program

Introduction: The teaching process conducted studies in the doctoral program in Cuba is important in the context of biomedical basic sciences. Objective: To identify the general and specific basis for the teaching in relation of investigations procedure in genetic epidemiology that guarantee to obtain of scientific degree for the physicians and other professional in relation with biomedical basic science. Materials and Methods: In the paper we shown the results of six research project in this area in the doctoral program of Medical University of Villa Clara. For shown evidence that the six different phenotype has a genetic basis were analyzed the presence of higher prevalence in relatives compared with general population, higher risk among first-degree relatives of affected individuals, segregation mode of phenotype and different studies of association from DNA polymorphism (SNP), chromosome variants and echography biomarkers. For find evidence the intervention of environment factors in the pathogenesis of disorders we applied the interview with questions about specific risk factors, and analysis of gene - environment interactions in the pathogenesis with different model for demonstration the type of interactions suggests. Results: We found that the research studies conducted by mainstream epidemiological theme may be divided into three broad categories: (1) those that aim to describe the distribution of a disease or a determinant at the level of a population of interest (familiar hereditary angioedema); (2) those that attempt to investigate a potential etiological link between one or more specific determinants and a disease of interest (congenital birth defects, cervix cancer, reproductive failure, and longevity) and (3) those aimed at formally evaluating the effectiveness of an intervention applied to individuals or groups of individuals in the general population (hypoplasia fetal thymus). Conclusions: The teaching process which conducted studies in the doctoral program en Villa Clara, Cuba over the last 5 years indicate that both genetic and environmental factors play a critical role in the pathogenesis of theses disease, the high prevalence of these in the relative and the familiarity of the disease and its endophenotype, strongly suggest a substantial genetic basis.

Manuela Herrera-Martínez, Douglas Fernández-Caraballo, Danay Heredia-Ruiz, María Elena de la Torre-Santos, Noel Taboada–Lugo, Lay Salazar–Torres, Lorna González- Herrera
9 lecturas
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Hemodynamics patterns and response to isometric sustained weight test in normorreactive, hyperreactive and hypertensive young people: gender differences

Introduction: a number of adjustments of the cardiovascular system are required during isometric exercise; variations in the components involved in young people blood pressure response result controversial. Objective: to determine the difference between gender at baseline hemodynamic parameters and response to Sustained Weight Test in normorreactive, hyperreactive and hypertensive young people. Methods: sample was constituted by 97 young people of both genders, 41 males and 56 females, with an average age of 19±1,40 years, whom was applied hemodynamic monitoring in supine decubitus position with non- invasive by impedance cardiography at rest and while the sustained weight test was performed. Results: significantly superior values of heart rate and cardiac index were obtained in normorreactive women in basal conditions, and at the exercise. Normorreactive male had significantly higher Resistance index than females in both conditions and hypertensive response group had differences only in the exercise. Women achieved higher heart rate increments than men during isometric exercise. Systemic vascular resistance and resistance index were increased in all groups of both genders, mainly in normorreactive men. Conclusions: at baseline, women had higher values of hemodynamic variables related to cardiac activity and men related to vascular tone. Differences between both genders remained during isometric exercise, and the increased blood pressure was mainly due to the increase of systemic vascular resistance.

Alexis Rodríguez Pena, Omara Guirado Blanco, Héctor Jesús González Paz, Marianela Ballesteros Hernández
7 lecturas
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Endogenous antioxidant markers, oligo- and macro-elements in hypertensive, prehypertensive and normotensive school- age children

Introduction: nowadays, hypertension is a health problem worldwide and our country is not excluded from this disease. In recent years, this situation has increased in childhood. It states that there is presence of reactive oxygen species in hypertension, as well as, oxidative damage and affectation of antioxidant defenses. Objective: to evaluate the manifestation of oxidative stress markers through some of the components of the endogenous antioxidant system and oligo- and macro-elements in hypertensive, pre-hypertensive and normotensive school - age children. Materials and Methods: 628 children aged 8-11 years constituted the universe. They were classified according to their blood pressure. Superoxide dismutase was determined by means of Marklund's method, catalase by Aebi's method and reduced glutathione by Sedlak's one. Determinations of zinc, cooper, potassium and magnesium were made using flame atomic absorption spectrometry. The Mann-Whitney, Kruskal-Wallis and Student's Tests were used with a significance level of p˂ 0.05. Results: superoxide dismutase and catalase activity decreased in the total group of hypertensive children while superoxide dismutase activity and zinc concentrations only decrease in pre-hypertensive children. Superoxide dismutase and catalase activity and magnesium concentrations decreased in female hypertensive and pre-hypertensive children; male hypertensive only had affectations in superoxide dismutase and magnesium concentrations. Hypertensive children aged 8 years showed a decrease in the activity of the studied enzymes and the concentration of reduced glutathione. Magnesium concentrations decreased in hypertensive children aged 9 years. Conclusion: affectations of the endogenous antioxidant system were found, as well as zinc and magnesium concentrations in hypertensive and pre-hypertensive children.

Jesús Isaías Alfonso Rodríguez, Danay Heredia Ruiz, Douglas Fernández Caraballo, Marianela Ballestero Hernández, Carmen Patricia Alfonso González
6 lecturas
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Oxidative Imbalance and Risk Factors Involved in Premalignant and Malignant Lesions of the Uterine Cervix

Introduction: There is an oxidative imbalance in the cases due to the decrease of the antioxidant enzymatic system where glutathione levels contribute to the increase of lipid peroxidation. Objective: To determine indicators of oxidative stress and risk factors in patients with premalignant and malignant lesions of the uterine cervix. Materials and methods: A total of 120 women were studied: 30 with Cervical Intraepithelial Neoplasia (CIN) I, 30 with CIN III, 30 with stage IIB epidermoid carcinoma and 30 with negative cytology taken as control, from the gynecology out patients service of "Chiqui Gómez" Polyclinic and the Oncology Service of "Celestino Hernández" Hospital of Santa Clara, with ages between 19 and 65 years. Information on the risk factors was obtained through an individualized interview, and the levels of enzymes superoxide dismutase and catalase as well as reduced glutathione and malonidialdehyde concentrations as indicators of oxidative stress were determined by spectrophotometric techniques. The comparison and association between groups was carried out with the support of the statistical program SPSS. Results: The levels of antioxidant enzymes showed a non-significant decrease in three groups of cases, reduced glutathione decreased significantly in CIN III (p=0,043) and epidermoid carcinoma (p=0,036) groups, while malonildialdehyde increased significantly in the same groups (p<0,01) with respect to the controls. Risk factors with greater incidence in affected women were the exposure to the papilloma virus due to the early sexual contact, the number of sexual partners, the use of oral contraceptives and the habit of smoking. Conclusions: There is an oxidative imbalance in the cases due to the decrease of the antioxidant enzymatic system where glutathione levels contribute to the increase of lipid peroxidation. It also confirms the association between risk factors and the development of premalignant and malignant lesions in the uterine cervix.

Danay Heredia Ruiz, Manuela Herrera Martínez, Douglas Fernández Caraballo, Lázara Gladys López Ocampo, Luis Alfredo Estévez Cobo, Sergio Santana Rodríguez, Emilio González Rodríguez
15 lecturas
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Oxidative Stress Indicators in Long-Lived Individuals Belonging to The Municipality of Santa Clara

Introduction: There are many oxidative stress indicators in long-lived individuals. Objective: To determine oxidative stress indicators in long-lived individuals. Materials and methods: 120 subjects were studied and two groups were formed: 50 individuals older than 85 years from nuclear families belonging to the municipality of Santa Clara and 70 adults under 50 years belonging to the same area taken as a control group. Were determined the antioxidant activity of the enzyme Superoxide Dismutase (SOD) and Catalase (CAT) as well as the serum concentrations of Reduced Glutathione (GSH) and Malonildialdehyde (MDA), as indicators of the state of the antioxidant defense and the existence of oxidative damage to lipids. Determinations were made with the use of spectrophotometric techniques establishing comparisons between groups through the statistical program SPSS for a level of significance of 95%. Results: The activity of the antioxidant enzyme SOD and the serum levels of MDA showed significant differences when comparing both study groups. In case of the SOD enzyme, the group of long-lived individuals showed a significant reduction in their activity when compared to the controls, while the serum levels of MDA were higher. The enzymatic activity CAT and the serum levels of GSH did not show significant differences between both groups of study. Conclusions: The decrease in the activity of the main antioxidant enzyme SOD accompanied by an increase in MDA levels may constitute evidence of an oxidative imbalance in individuals older than 85 years accompanied by an increase in damage to lipids.

Douglas Fernández Caraballo, Manuela Herrera Martínez, Danay Heredia-Ruiz, Sonia Chaviano Machado, Emilio González Rodríguez
7 lecturas
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William Castillo-González, Jairo Lumpuy-Castillo, José Alejandro Rodríguez-Pérez, Vanessa Pérez-del-Vallín, Alejandro Mirabal-Viel, Christian Meijides-Mejías, Alberto Juan Dorta-Contreras
11 lecturas
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Giovet Aldama Paz, Elsa Pimienta Rodríguez, Karen Marrero Domínguez, Sandra Rodríguez Salgueiro, Yunier Serrano Rivero, Alina Falero Morejón, Susana Brito Molina
15 lecturas
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Programme of Studies of the Specialty of Normal and Pathological Physiology. Achievements and Challenges in the Current Context

Introduction: The programs of residences sometimes are extensives and there are deficiencies in the general strategy of teaching. Objective: identifying the susceptible of modification aspects in the effective Programme of Studies of the Specialty of Normal and Pathological Physiology, keeping in mind the current necessities, with a view to the future redraws of this Programme. Materials and methods: It was carried out a descriptive exploratory study. Three surveys were elaborated and applied about the Programme of Studies from the Specialty of Physiology to residents and specialists, to professors that have taught with this Programme of Studies and to professors that have worked with specialists graduated by this Programme of Studies. Results: In general, the results showed that the residence is extensive, there are deficiencies in the general strategy of teaching, it is necessary to review the pertinency and the programs of subjects and modules, as well as to elevate the quality of the education in the work and to carry out actions to perfect the resident's preparation to do the investigative and administrative functions. Conclusions: It would bear it to carry out modifications in the Programme of Studies of the Specialty of Normal and Pathological Physiology of the year 2000 as for: professional profile, organization strategies and development of the Programme of Studies, contents of the areas of knowledge, bibliography and evaluation system.

Zulema Adorna Carmenate
8 lecturas
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Activation of the expiratory muscles via lower thoracic high frequency spinal cord stimulation (HF-SCS) in intact non-anesthetized animals

Introduction: Lower thoracic SCS been shown to restore an effective cough mechanism in subjects with complete spinal cord injury. Unfortunately, the high stimulus amplitude requirements and potential activation of pain fibers significantly limits this application in subjects with intact sensation. Recent studies have shown that the expiratory muscles can also be effectively activated via low stimulus currents (1mA) but with high stimulus frequencies (500Hz) in anesthetized animals. Objective: To assess the response to HF-SCS, in intact, non-anesthetized animals (pigs). Material and Methods: During an initial surgical procedure performed under sterile conditions, a stimulating disc electrode was placed on the dorsal surface of the spinal cord at the T9 level. 10-14 days post-operatively, electrical stimulation was applied 2-3 times a day to activate the expiratory muscles. While awake, expiratory muscle contraction was assessed during HF-SCS via abdominal muscle EMG and inductance plethysmography (IP) via bands positioned over the abdominal wall. Electrocardiogram and heart rate were also monitored. While anesthetized during a terminal procedure, airway pressure generation and abdominal movement were assessed. Results: During HF-SCS in the awake state, there was marked movement of the abdominal wall as assessed by IP and electrical activation of the external oblique muscles, which was positively correlated with stimulus amplitude (correlation coefficients greater than 0.95 for both). HF-SCS was not associated with any changes in heart rate or vocalization. During a terminal procedure under general anesthesia, mean airway pressure generation during HF-SCS at 0.8, 1 and 1.5mA were 31±6, 46±2 and 65±2 cmH2O respectively. The positive correlation between stimulus amplitude and excursion of the abdominal wall was not significantly different compared to the awake state. Conclusions: HF-SCS applied to awake, non-anesthetized animals results in contraction of the abdominal muscles similar to that observed in anesthetized animals. The lack of changes in heart rate and vocalization suggests that HF-SCS was well tolerated and not painful. Lower thoracic HF-SCS may be a useful method to restore an effective cough in patients with intact sensation.

Anthony F. Di Marco, Krzysztof E. Kowalski
19 lecturas
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Effects of High Frequency Spinal Cord Stimulation (HF-SCS) Applied to the Ventral Surface of the Spinal Cord

Introduction: HF-SCS applied to the ventral surface of the upper thoracic spinal cord (T2 level) results in physiologic activation of both the diaphragm and inspiratory intercostal muscles. Objective: To evaluate the effects of HF-SCS (500Hz, 1mA) applied to the ventral surface of the entire thoracic spinal cord. Material and Methods: In 4 anesthetized dogs, three eight plate stimulation leads, were inserted epidurally and positioned on the ventral surface of the spinal cord via laminectomies at the T6 and T10 levels. Changes in airway pressure (P) were assessed over different regions of the thoracic spinal cord following electrical stimulation (HFSCS: 500 Hz, 1 mA, 0.2ms) at each electrode lead in separate trials, under conditions of airway occlusion and hyperventilation induced apnea. Results: HF-SCS (500Hz, 1mA) resulted in negative P generation over the ventral surface of the entire thoracic spinal cord. Negative P generation was most pronounced at the T2 level (60±2 cmH2O) and T9 levels (46±8 cmH2O). Further examination of HFSCS at the T9 level demonstrated that maximum negative P was dependent upon low stimulus currents (1-3 mA) and high stimulus frequencies (>300 Hz). Both the diaphragm and inspiratory intercostal muscles contributed to negative P generation. Conclusions: The unique findings of the present investigation include the demonstration that spinal circuits which have connections to the inspiratory motoneuron pools exist over the ventral surface of the entire thoracic spinal cord. We postulate that responses are mediated, in part, by stimulation of the previously described intercostal to phrenic excitatory reflex. The large negative P generated at the T9 level suggests that HF-SCS in this region of the spinal cord may be a useful method to restore breathing in ventilator dependent tetraplegics.

K. E. Kowalski, J. R. Romaniuk, P. A. Kirkwood, A. F. DiMarco
17 lecturas
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Excitatory amino acid transporters (EAATs) restrain nucleus tractus solitarii (nTS) activity induced by ionotropic and metabotropic glutamate receptor activation

Introduction: Glutamate (Glu) is the primary excitatory amino acid neurotransmitter released from visceral afferents in the nTS. Glu binds to postsynaptic ionotropic glutamate receptors (iGluRs, AMPA or NMDA) to induce rapid phasic synaptic currents and depolarization. Glu also binds to metabotropic glutamate receptors (mGluRs), including postsynaptic Grp I receptors to induce a slower depolarization, or alternatively presynaptic Grp II or III receptors to limit terminal activity and attenuate release of Glu via autoreceptor mechanisms. The timing and effect of iGluR and/or mGluR activation is guided not only by the concentration and spatial distribution of these receptors in the synaptic and extrasynaptic space, but also their position relative to uptake transporters that remove extracellular Glu and thus limit receptor activation. Thus excitatory amino acid transporters (EAATs) are critical to preventing over-excitation and maintaining synaptic efficacy. Objective: To examine the contribution of EAATs on nTS activity induced by iGluRs and mGluRs. Methods: We recorded synaptic currents and membrane activity in rat nTS slices before and after antagonism of iGluRs and mGluRs. Results: We showed that EAAT1 and EAAT2 are localized to nTS astrocytes. EAAT block with TBOA increases the static and afferent-induced, phasic release of nTS Glu. The increase in Glu depolarized neuronal membrane potential, induced inward currents and enhanced action potential discharge that are dependent on AMPARs and NMDARs, with a moderate contribution of Grp I mGluRs. Enhanced nTS discharge amplified network-induced spontaneous excitatory synaptic currents (EPSCs). Conversely, antagonism of EAAT and resulting Glu attenuated the amplitude of afferent (TS)-driven EPSCs. The latter reduction was due to activation of mGluR II/III and reduction in presynaptic calcium. Conclusion: Taken together, our data demonstrate EAATs critically limit activation of ionotropic and metabotropic GluRs, and thus neuronal and synaptic activity. These effects likely influence cardiorespiratory homeostasis and reflex responses to a variety of stimuli.

David D. Kline, Michael P. Matott, Diana Martinez
13 lecturas
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