Seed germination performances of Styrax species help understand their distribution in Cerrado areas in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Participation of the dorsal periaqueductal grey matter in the hypoxic ventilatory response in unanaesthetized rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Carbohydrate and glutamine supplementation modulates the Th1/Th2 balance after exercise performed at a simulated altitude of 4500 m

Objective: The aim of this study was to evaluate the effect of carbohydrate or glutamine supplementation, or a combination of the two, on the immune system and inflammatory parameters after exercise in simulated hypoxic conditions at 4500 m.Methods: Nine men underwent three sessions of exercise at 70% VO2(peak) until exhaustion as follows: 1) hypoxia with a placebo; 2) hypoxia with 8% maltodextrin (200 mL/20 min) during exercise and for 2 h after; and 3) hypoxia after 6 d of glutamine supplementation (20 g/d) and supplementation with 8% maltodextrin (200 mL/20 min) during exercise and for 2 h after. All procedures were randomized and double blind. Blood was collected at rest, immediately before exercise, after the completion of exercise, and 2 h after recovery. Glutamine, cortisol, cytokines, glucose, heat shock protein-70, and erythropoietin were measured in serum, and the cytokine production from lymphocytes was measured.Results: Erythropoietin and interleukin (IL)-6 increased after exercise in the hypoxia group compared with baseline. IL-6 was higher in the hypoxia group than pre-exercise after exercise and after 2 h recovery. Cortisol did not change, whereas glucose was elevated post-exercise in the three groups compared with baseline and pre-exercise. Glutamine increased in the hypoxia + carbohydrate + glutamine group after exercise compared with baseline. Heat shock protein-70 increased post-exercise compared with baseline and pre-exercise and after recovery compared with pre-exercise, in the hypoxia carbohydrate group. No difference was observed in IL-2 and IL-6 production from lymphocytes. IL-4 was reduced in the supplemented groups.Conclusion: Carbohydrate or glutamine supplementation shifts the T helper (Th)1/Th2 balance toward Th1 responses after exercise at a simulated altitude of 4500 m. The nutritional strategies increased in IL-6, suggesting an important anti-inflammatory effect. (C) 2014 Elsevier Inc. All rights reserved.

Phenotypic and functional evaluations of peripheral blood monocytes from chronic-form paracoccidioidomycosis patients before and after treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular markers of angiogenesis and metastasis in lines of oral carcinoma after treatment with melatonin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de hipercabia no desenvolvimento de ovos de Trachemys scripta

Females of the painted turtle, Trachemys scripta, have an annual reproductive cycle. Their nest periods in Brazil starts around September and they lay about 7 - 10 eggs in nests dug in the soil. The eggs hatch in December. It is possible that the nest cover cause problems for the gas diffusion, also, the rain can wet or compact the soil covering the nest, or even soaked the whole area. Those problems may change the nests intern atmosphere decreasing O2 partial pressure (hypoxia) and increasing CO2 partial pressure (hypercarbia). The main objective of this study was to determine if and how hypercarbia (3% and 6%CO2), could influence the eggs and early posthatching development of the Trachemys scripta. We used three experimental groups of eggs incubated in: normal atmosphere (Control group CG, n = 14), hypercarbia with 3% of CO2 (G3%, n = 16) and with 6% of CO2 (G6%, n = 15). The profile of the mass increment during the egg development were not different among the groups, GC = 9.89±0.81g; G3% = 10.11±0.60g and G6% = 10.58±0.36g. In addition, the mass of the post-hatching turtles were the not different. There were not differences between the duration of the incubation period among the experimental groups, GC = 60.12±0.97days, G3% = 59.00±0.98days and G6% = 60.80±1.14days. The mortality rates were not affected by the hypercarbia, GC = 0.43 (43%), G3% = 0.27 (27%) and G6% = 0.37 (37%). Furthermore, the mass increment and the metabolic rate were the same among the early development of the turtles until 3 month after hatching. We conclude that hypercarbia (up to 6% of CO2) does not cause any alteration on the eggs or post-hatching normal development. It is possible that the combination of hypercarbia and hypoxia change those results

Choque

The shock, now known as a clinical syndrome due to a systemic breakdown in tissue perfusion leading to cellular hypoxia, metabolic changes and consequently organ dysfunction, is a condition that affects both humans and animals and should be classified as an emergency. For its dynamic course the therapy becomes a challenge, all the time time spared in diagnosis and treatment is essential to save the patient's life, so knowledge of its physiopathology can become of great value, and in order to clarify it better, shock has been divided didactically into: cardiogenic, hypovolemic, distributive, and obstructive, so the best approach may be chosen to this situation, noting that the therapy in general is the sum of several procedures that aims to compensate for the animal so that the underlying cause of shock may be treated

Alterações metabólicas e morfométricas induzidas por hipóxia em Gallus gallus

Pós-graduação em Zootecnia - FCAV

Função pulmonar em indivíduos com SAOS antes e após o uso do CPAP: estudo randomizado duplo cego

Pós-graduação em Bases Gerais da Cirurgia - FMB

Peripheral chemoreceptors and cardiorespiratory coupling: a link to sympatho-excitation

Chronic intermittent hypoxia (CIH) has been identified as a relevant risk factor for the development of enhanced sympathetic outflow and arterial hypertension. Several studies have highlighted the importance of peripheral chemoreceptors for the cardiovascular changes elicited by CIH. However, the effects of CIH on the central mechanisms regulating sympathetic outflow are not fully elucidated. Our research group has explored the hypothesis that the enhanced sympathetic drive following CIH exposure is, at least in part, dependent on alterations in the respiratory network and its interaction with the sympathetic nervous system. In this report, I discuss the changes in the discharge profile of baseline sympathetic activity in rats exposed to CIH, their association with the generation of active expiration and the interactions between expiratory and sympathetic neurones after CIH conditioning. Together, these findings are consistent with the theory that mechanisms of central respiratory–sympathetic coupling are a novel factor in the development of neurogenic hypertension.

The nucleus of the solitary tract and the coordination of respiratory and sympathetic activities

It is well known that breathing introduces rhythmical oscillations in the heart rate and arterial pressure levels. Sympathetic oscillations coupled to the respiratory activity have been suggested as an important homeostatic mechanism optimizing tissue perfusion and blood gas uptake/delivery. This respiratory-sympathetic coupling is strengthened in conditions of blood gas challenges (hypoxia and hypercapnia) as a result of the synchronized activation of brainstem respiratory and sympathetic neurons, culminating with the emergence of entrained cardiovascular and respiratory reflex responses. Studies have proposed that the ventrolateral region of the medulla oblongata is a major site of synaptic interaction between respiratory and sympathetic neurons. However, other brainstem regions also play a relevant role in the patterning of respiratory and sympathetic motor outputs. Recent findings suggest that the neurons of the nucleus of the solitary tract (NTS), in the dorsal medulla, are essential for the processing and coordination of respiratory and sympathetic responses to hypoxia. The NTS is the first synaptic station of the cardiorespiratory afferent inputs, including peripheral chemoreceptors, baroreceptors and pulmonary stretch receptors. The synaptic profile of the NTS neurons receiving the excitatory drive from afferent inputs is complex and involves distinct neurotransmitters, including glutamate, ATP and acetylcholine. In the present review we discuss the role of the NTS circuitry in coordinating sympathetic and respiratory reflex responses. We also analyze the neuroplasticity of NTS neurons and their contribution for the development of cardiorespiratory dysfunctions, as observed in neurogenic hypertension, obstructive sleep apnea and metabolic disorders.

Contribution of retrotrapezoid/parafacial respiratory region to the expiratory-sympathetic coupling in response to peripheral chemoreflex in rats

Central mechanisms of coupling between respiratory and sympathetic systems are essential for the entrainment between the enhanced respiratory drive and sympathoexcitation in response to hypoxia. However, the brainstem nuclei and neuronal network involved in these respiratory-sympathetic interactions remain unclear. Here, we evaluated whether the increase in expiratory activity and expiratory-modulated sympathoexcitation produced by the peripheral chemoreflex activation involves the retrotrapezoid nucleus/parafacial respiratory region (RTN/pFRG). Using decerebrated arterially perfused in situ rat preparations (60–80 g), we recorded the activities of thoracic sympathetic (tSN), phrenic (PN), and abdominal nerves (AbN) as well as the extracellular activity of RTN/pFRG expiratory neurons, and reflex responses to chemoreflex activation were evaluated before and after inactivation of the RTN/pFRG region with muscimol (1 mM). In the RTN/pFRG, we identified late-expiratory (late-E) neurons (n = 5) that were silent at resting but fired coincidently with the emergence of late-E bursts in AbN after peripheral chemoreceptor activation. Bilateral muscimol microinjections into the RTN/pFRG region (n = 6) significantly reduced basal PN frequency, mean AbN activity, and the amplitude of respiratory modulation of tSN (P < 0.05). With respect to peripheral chemoreflex responses, muscimol microinjections in the RTN/pFRG enhanced the PN inspiratory response, abolished the evoked late-E activity of AbN, but did not alter either the magnitude or pattern of the tSN reflex response. These findings indicate that the RTN/pFRG region is critically involved in the processing of the active expiratory response but not of the expiratory-modulated sympathetic response to peripheral chemoreflex activation of rat in situ preparations.

Electrophysiological properties of rostral ventrolateral medulla presympathetic neurons modulated by the respiratory network in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Maternal protein restriction increases respiratory and sympathetic activities and sensitizes peripheral chemoreflex in male rat offspring

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Autonomic control of post-air-breathing tachycardia in Clarias gariepinus

The African catfish (Clarias gariepinus) is a teleost with bimodal respiration that utilizes a paired suprabranchial chamber located in the gill cavity as an air-breathing organ. Like all air-breathing fishes studied to date, the African catfish exhibits pronounced changes in heart rate (f H) that are associated with air-breathing events. We acquired f H, gill-breathing frequency (f G) and air-breathing frequency (f AB) in situations that require or do not require air breathing (during normoxia and hypoxia), and we assessed the autonomic control of post-air-breathing tachycardia using an infusion of the β-adrenergic antagonist propranolol and the muscarinic cholinergic antagonist atropine. During normoxia, C. gariepinus presented low f AB (1.85 ± 0.73 AB h−1) and a constant f G (43.16 ± 1.74 breaths min−1). During non-critical hypoxia (PO2 = 60 mmHg), f AB in the African catfish increased to 5.42 ± 1.19 AB h−1 and f G decreased to 39.12 ± 1.58 breaths min−1. During critical hypoxia (PO2 = 20 mmHg), f AB increased to 7.4 ± 1.39 AB h−1 and f G decreased to 34.97 ± 1.78 breaths min−1. These results were expected for a facultative air breather. Each air breath (AB) was followed by a brief but significant tachycardia, which in the critical hypoxia trials, reached a maximum of 143 % of the pre-AB f H values of untreated animals. Pharmacological blockade allowed the calculation of cardiac autonomic tones, which showed that post-AB tachycardia is predominantly regulated by the parasympathetic subdivision of the autonomic nervous system.