The reduction in arterial pH with increased temperature is not affected by hyperoxia in toads (Rhinella marina) and pythons (Python molurus).

It is well established that arterial pH decreases with increased temperature in amphibians and reptiles through an elevation of arterial PCO2, but the underlying regulation remains controversial. The alphastat hypothesis ascribes the pH fall to a ventilatory regulation of protein ionisation, but the pH reduction with temperature is lower than predicted by the pKa change of the imidazole group on histidine. We hypothesised that arterial pH decreases at high, but not at low, temperatures when toads (Rhinella marina) and snakes (Python molurus) are exposed to hyperoxia. In toads, hyperoxia caused similar elevations of arterial PCO2 at 20 and 30°C, indicative of a temperature-independent oxygen-mediated drive to breathing, whereas PCO2 was unaffected by hyperoxia in snakes at 25 and 35°C. These findings do not support our hypothesis of an increased oxygen-mediated drive to breathing as body temperature increases.

Adrenergic control of functional characteristics of the cardiovascular system in the South American rattlesnake, Crotalus durissus.

In squamate reptiles, extensive innervation of the heart and vascular beds allows for continuous modulation of the cardiovascular system by the autonomic nervous system. The systemic vasculature is the main target of excitatory sympathetic adrenergic fibers, while the pulmonary circulation has been described as less responsive to both nervous and humoral modulators. However, histochemical evidence has demonstrated the presence of adrenergic fibers in pulmonary circulation. Besides, reduced responsiveness is intriguing since the balance of regulation between systemic and pulmonary vascular circuits has critical hemodynamic implications in animals with an undivided ventricle and consequent cardiovascular shunts. The present study investigated the role and functional relevance of α and ß-adrenergic stimulation in regulating systemic and mainly the pulmonary circulations in a decerebrate, autonomically responsive rattlesnake preparation. The use of the decerebrate preparation allowed us to observe a new diverse functional modulation of vascular beds and the heart. In resting snakes, the pulmonary vasculature is less reactive to adrenergic agonists at 25 °C. However, the ß-adrenergic tone is relevant for modulating resting peripheral pulmonary conductance, while both α- and ß-adrenergic tones are relevant for the systemic circuit. Active dynamic modulation of both pulmonary compliance and conductance effectively counterbalances alterations in the systemic circulation to maintain the R-L shunt pattern. Furthermore, we suggest that despite the great attention given to cardiac adjustments, vascular modulation is sufficient to support the hemodynamic adjustments needed to control blood pressure.

Baroreflex responses of decerebrate rattlesnakes (Crotalus durissus) are comparable to awake animals.

A decerebrate rattlesnake, Crotalus durissus, has previously been used as a model Squamate for cardiovascular studies. It enabled instrumentation for concomitant recordings of diverse variables that showed autonomic responses. However, to validate the preparation and its scope for use, it is necessary to assess how close its cardiovascular variables are to non-decerebrate snakes and the effectiveness of its autonomic responses. Similarly, it is important to analyze its recovery profile after instrumentation and observe if it maintains stability throughout the duration of experimental protocol. Here we have objectively assessed these points by comparing decerebrate preparations and non-decerebrate snakes, after the occlusive cannulation of the vertebral artery. We have assessed cardiovascular variables and the baroreflex to analyze the presence, magnitude and stability of complex autonomic-controlled parameters as indicators of autonomic nervous system (ANS) functionality. After instrumentation, mean heart rates were high but recovered to stable values within 24 h. Mean arterial pressure stabilized within 24 h in control snakes and 48 h in decerebrate preparations. After that, both parameters remained stable. The operational gain and effectiveness index of the baroreflex recovered within the first 6 h after instrumentation in both experimental groups. In addition, the baroreflex capacities and its limits were also equivalent between the groups. These experiments demonstrated that decerebrate preparations and inactive, non-decerebrate snakes showed comparable recovery profiles following anesthesia and cannulation, maintained similar values of cardiovascular variables during experimental manipulation and exhibited functional, ANS modulated reflexes. Accordingly, the present results attest the relevance of this decerebrate preparation for studies on cardiovascular modulation.

Role of Nitric Oxide in the Cardiovascular System of South American Rattlesnakes (Crotalus durissus).

AbstractUnderstanding the basis of vascular tonus regulation is fundamental to comprehending cardiovascular physiology. In the present study, we used the recently developed decerebrate rattlesnake preparation to investigate the role of nitric oxide (NO) in the control of vascular tonus in a squamate reptile. This preparation allowed multiple concomitant cardiovascular parameters to be monitored, while avoiding the deleterious effect of anesthetic drugs on autonomic modulation. We observed that both systemic and pulmonary circuits were clearly responsive to NO signaling. NO increased vascular conductance in the systemic and pulmonary systems. Vasodilation by NO of the systemic circulation was compensated by cardiovascular alterations involving venous return, cardiac output, and cardiac shunt adjustments. The cardiac shunt seemed to be actively used for hemodynamic adjustments via modulation of the pulmonary artery constriction. N(ω)-nitro-L-arginine methyl ester injection demonstrated that NO contributes to modulating resting vasodilation in the systemic circuit. In contrast, NO-mediated vasodilation did not have an important role in the pulmonary circulation in inactive decerebrated snakes at 25°C. These responses vary importantly from those described for anesthetized snakes.

A Decerebrate Preparation of the Rattlesnake, Crotalus durissus, Provides an Experimental Model for Study of Autonomic Modulation of the Cardiovascular System in Reptiles.

AbstractThe South American rattlesnake, Crotalus durissus, has been successfully used as an experimental model to study control of the cardiovascular system in squamate reptiles. Recent technical advances, including equipment miniaturization, have lessened the impact of instrumentation on in vivo recordings, and an increased range of anesthetic drugs has improved recording conditions for in situ preparations. Nevertheless, any animal-based experimental approach has to manage limitations regarding the avoidance of pain and stress the stability of the preparation and duration of experiments and the potentially overriding effects of anesthesia. To address such aspects, we tested a new experimental preparation, the decerebrate rattlesnake, in a study of the autonomic control of cardiovascular responses following the removal of general anesthesia. The preparation exhibited complex cardiovascular adjustments to deal with acute increases in venous return (caused by tail lifting), to compensate for blood flow reduction in the cephalic region (caused by head lifting), for body temperature control (triggered by an external heating source), and in response to stimulation of chemoreceptors (triggered by intravenous injection of NaCN). The decerebrate preparation retained extensive functional integrity of autonomic centers, and it was suitable for monitoring diverse cardiac and vascular variables. Furthermore, reanesthetizing the preparation markedly blunted cardiovascular performance. Isoflurane limited the maintenance of recovered cardiovascular variables in the prepared animal and reduced or abolished the observed cardiovascular reflexes. This preparation enables the recording of multiple concomitant cardiovascular variables for the study of mechanistic questions regarding the central integration of autonomic reflex responses in the absence of anesthesia.

Hypotensive effect of Eugenia dysenterica leaf extract is primarily related to its vascular action: The possible underlying mechanisms.

ETHNOPHARMACOLOGICAL RELEVANCE: Eugenia dysenterica (ED) leaves are used in Brazil to treat cardiac diseases; however, there are no scientific data describing the effects of this species on cardiac activity. AIM OF THE STUDY: To investigate the effect of ED aqueous leaf extract (EDLE) on hear rate (HR) and mean arterial pressure (MAP) of anaesthetised rats and its underlying mechanism of action. MATERIAL AND METHODS: EDLE was analysed, and its proanthocyanidin composition was determined. After performing dose-effect curves for EDLE on HR and MAP, EDLE-induced hypotension was evaluated before and after atropine (AT), L-N(ω)-nitro-L-arginine methyl ester (L-NAME), hexamethonium (HXT), indomethacin (IND), carbenoxolone (CBX), or nifedipine (NFD) administration. The effect of proanthocyanidin-depleted extract (EDLE/P-) was also determined and compared to that of the EDLE with proanthocyanidins. RESULTS: EDLE decreased the MAP in a dose-dependent manner; HR was decreased only with the highest and most toxic dose. Only CBX and NFD decreased EDLE-induced hypotension. Five polymeric series of proanthocyanidins were identified, which were mainly constituted by procyanidin and prodelphinidin units with B-type linkage and up to 12 flavan-3-ol units. EDLE/P- induced hypotension did not differ from that induced by EDLE. CONCLUSIONS: The cardiovascular effects of EDLE were primarily related to its vascular action. EDLE-induced hypotensive effect appeared to involve L-type calcium channel blockage as well as myoendothelial gap junction signalling. The higher molecular weight proanthocyanidins from EDLE are unlikely to contribute to its cardiovascular effect.

Evaluation of the sequence method as a tool to assess spontaneous baroreflex in reptiles.

The sequence method is an alternative to the traditional pharmacological approach (i.e., the Oxford technique) used to calculate baroreflex gain (G) in mammals. Although the sequence method assesses baroreflex by measuring spontaneous events of blood pressure regulation, the pharmacological method relies on the injection of vasoactive drugs that impact the baroreflex mechanism itself. The sequence method might be relevant for dynamic measurement of baroreflex modulation but it was never validated for vertebrates with low heart rate. Hence, we tested the sequence method in three species of reptiles and compared the results with those provided by the classic pharmacological method. G was similar between both methods and values correlated when parameters for the sequence method were set at delay 0 or 1 (i.e., the baroreflex system responds immediately to blood pressure changes or after 1 heartbeat). Calculation of the baroreflex effectiveness index was adequate at a minimum of 300 cycles and a delay of 1 for the three species. Therefore, the sequence method has been validated to investigate baroreflex regulation in reptiles, enabling studies during dynamic alterations in homeostasis.

Primary umbilical endometriosis.

OBJECTIVE: to report the characteristics, evolution and outcome of patients with primary umbilical endometriosis. METHODS: an observational and descriptive study of patients with primary umbilical endometriosis diagnosed between 2014 and 2017. The clinical variables evaluated were age, clinical picture, lesion characteristics, diagnostic methods, treatment and recurrence. RESULTS: six patients diagnosed with primary umbilical endometriosis aged 28 to 45 years were operated on during the study period. They had lesions ranging from one to 2.5cm in diameter, violet in five patients and erythematous-violaceous in one. The duration of the symptoms until diagnosis ranged from one to three years and in all the cases studied the diagnosis was made through the clinical manifestations and confirmed by histopathological analysis. No case was associated with neoplastic alterations. All patients evaluated had pain and umbilical bleeding in the menstrual period. CONCLUSION: umbilical endometriosis is an uncommon disease and should be included in the differential diagnosis of women as umbilical nodules. The treatment of choice is the total exeresis of the lesion.

Primary umbilical endometriosis / Endometriose umbilical primária

ABSTRACT Objective: to report the characteristics, evolution and outcome of patients with primary umbilical endometriosis. Methods: an observational and descriptive study of patients with primary umbilical endometriosis diagnosed between 2014 and 2017. The clinical variables evaluated were age, clinical picture, lesion characteristics, diagnostic methods, treatment and recurrence. Results: six patients diagnosed with primary umbilical endometriosis aged 28 to 45 years were operated on during the study period. They had lesions ranging from one to 2.5cm in diameter, violet in five patients and erythematous-violaceous in one. The duration of the symptoms until diagnosis ranged from one to three years and in all the cases studied the diagnosis was made through the clinical manifestations and confirmed by histopathological analysis. No case was associated with neoplastic alterations. All patients evaluated had pain and umbilical bleeding in the menstrual period. Conclusion: umbilical endometriosis is an uncommon disease and should be included in the differential diagnosis of women as umbilical nodules. The treatment of choice is the total exeresis of the lesion.

RESUMO Objetivo: relatar as características, evolução e desfecho de pacientes portadoras de endometriose umbilical primária. Métodos: estudo observacional e descritivo de pacientes portadoras de endometriose umbilical primária diagnosticada entre 2014 e 2017. As variáveis clínicas avaliadas foram: idade, quadro clínico, características das lesões, métodos diagnósticos, tratamento e recidiva. Resultados: seis pacientes com diagnóstico de endometriose umbilical primária, com idades entre 28 e 45 anos foram operadas no período do estudo. Elas apresentavam lesões que variavam de 1,0cm a 2,5cm de diâmetro, de cor violácea em cinco pacientes e eritemato-violácea em uma. O tempo de duração dos sintomas até o diagnóstico variou de um a três anos e em todos os casos estudados o diagnóstico foi feito por meio das manifestações clínicas e confirmado por meio da análise histopatológica. Nenhum caso foi associado com alterações neoplásicas. Todas as pacientes avaliadas apresentavam como manifestação clínica dor e sangramento umbilical no período menstrual. Conclusão: a endometriose umbilical é uma doença pouco frequente e deve ser incluída no diagnostico diferencial de mulheres como nódulo umbilical. O tratamento de eleição é a exérese total da lesão.

Estudio sobre TIC y salud pública en América Latina: la perspectiva de e-salud y m-salud / Study on TIC and public health in Latin America: the perspective of e-health and m-health

El presente estudio profundiza en el trabajo de 2014 "Mejores prácticas de liderazgo, innovación y gestión pública en e­salud: los casos de Brasil, México y Perú" elaborado para la Unión Internacional de Telecomunicaciones. El estudio anterior tenía como objetivo documentar experiencias que ocurrían en un contexto de e-salud incipiente y que tuvieron éxito porque usaban tecnologías asequibles y tenían mecanismos de gestión sólidos. Puesto que actualmente una de estas iniciativas, el caso de Wawared en Perú, se ha convertido en política pública y que, además, otros procesos políticos ya son visibles en estos países y en la región, el alcance de esta investigación es más amplio y se centra en la comprensión de las políticas y los planes nacionales de e-salud y m-salud, sus procesos y contextos en Brasil, México, Perú, Argentina y Panamá