Health promoting lifestyle behaviors of university employees in work-from-home arrangement during the COVID-19 pandemic

@#Since the COVID-19 emerged, a work-from-home (WFH) arrangement was implemented as an infection containment measure among employees. This lifestyle change is bound to affect health-promoting behaviors. The study aims to determine the health-promoting lifestyle behaviors of university employees in a WFH arrangement during the COVID-19 pandemic. This study utilized a quantitative descriptive research design. After consecutive sampling of employees of a state university in Manila, the response rate was 33.1% (395 out of 1, 195 eligible respondents), but only 31.8% or 380 respondents completed the validated online questionnaire through Google Forms™ from August to October 2021. The instrument was based on the Health Promoting Lifestyle Profile (HPLP) survey by Walker and Hill-Polerecky (1996). Descriptive data analysis was done via IBM® SPSS® Statistics v22. Majority were females (70.3%) and single (51.8%). Approximately 70% were staying at home with their family. The mean scores for the subscales of inner development, interpersonal relations, and stress management were 3.08 (SD±.24), 3.00 (SD±.30), and 2.70 (SD±.30), respectively. These were observed to be higher than other HPLP subsets. Subscales garnering the lowest mean scores were physical activity at 2.32 (SD±.21), nutrition at 2.68 (SD±.31), and health responsibility at 2.56 (SD±.12). The mean HPLP score of faculty members was the highest at 2.74 (SD±.36) as compared to administrative staff and research extension and professional staff (REPS) with mean scores of 2.73 (SD±.36) and 2.71 (SD±.39), respectively. Overall HPLPscores suggested that the majority (60.8%) practice “good” health-promoting lifestyle behaviors. These findings indicate that the WFH arrangement allows employees to develop social and coping skills while staying in their residences. Whereas limitations to opportunities for a more active lifestyle, availability of nutritious food, and access to health care also contribute to the low HPLP scores. Health promotion and protection strategies such as nurse-led health programs must be instituted to improve and develop the knowledge, skills, and attitude among employees working from home in the aspects of nutrition, physical activity, and health responsibility. Nurses must also use this opportunity to promote occupational health among employees through lifestyle programs in coordination with universities and colleges or other workplaces of similar nature. Health programs must capitalize on the increase in the utilization of social media and the Internet during the pandemic. There is a need for further research to examine associations between the variables in various institutions and settings.

Silicon level in skin tissues of normal female individuals

Objective To evaluate silicon level in normal skin tissue

Methods The silicon levels in skin samples were measured using an atomic absorbance spectrophotometer in 37 healthy normal females who had never received silicone injection and compared with those who had developed granuloma after silicone injection

Results Low silicon level [44.07+/-75.86 microgram/g] was found in skin tissues of normal individuals as compared to those who developed post-silicone granuloma [1709.21+/-1851.72 microgram/g]

Conclusion Silicon may be found in normal skin tissue due to daily use of cosmetic products; however the level is significantly low

Indoleamine 2, 3-dioxygenase [IDO] levels in leprosy patients with positive serology

Background: Seropositive leprosy individuals have a tendency to experience a change into leprosy lepromatous type. Previous studies have demonstrated that the activity of indoleamine 2, 3-dioxygenase [IDO] in patients with lepromatous type leprosy is higher than those with tuberculoid type leprosy. However, no study has been available showing how IDO level can be correlated to seropositive subjects

Methods: Our observational cross-sectional study was conducted in Brebes, Central Java, Indonesia. Leprosy seropositivity was determined by measuring the level of anti-phenolic glycolipid-1 IgM and IDO level using ELISA

Results: Result of The IDO level in seropositive leprosy subjects was higher compared to those who were seronegative [p = 0.048]

Conclusion: In the early stage of leprosy infection, a high level of IDO level can already be found; therefore, it can affect immune response and ultimately affecting further course of the disease

Sero-prevalence of Hepatitis B Infection and Its Risk Factors among Women Admitted for Delivery in Ucth, Calabar, Nigeria.

Background: Vertical transmission of hepatitis B virus infection during pregnancy and delivery remains the major route of transmission in low resource areas. The objectives of this study were to determine the sero-prevalence of hepatitis B infection (HBsAg) and the potential risk factors among pregnant women admitted for delivery. Materials and Methods: This cross-sectional study of 300 women admitted for delivery was conducted at University of Calabar Teaching Hospital, Calabar, Nigeria. A pretested questionnaire was used for the collection of socio-demographic data and possible risk factors. Blood sample was collected from each consented woman and the plasma tested for the presence of HBsAg using rapid ELISA test Kits in the laboratory of the hospital. All the data were analyzed using microsoft SPSS version 17 statistical program. Results: Out of the 300 women studied, positive HBsAg was detected in 14 women, giving a seroprevalence rate of 4.7%. The age of the women studied varied from 16 to 43 years with mean age of 27.9±4.6 years and mean parity of 1.1±1.5. Hepatitis B viral infection was significantly higher among pregnant women who did not attend any antenatal care (unbooked women) than pregnant women who attended antenatal care (booked women). There were statistically significant relationships between HBV infection and 2 or more sexual partners and previous history of induced abortion. Previous histories of blood transfusion, previous surgeries/dental manipulations, tribal marks/tattoos, previous contact with somebody with hepatitis B infection were not statistically significant. The data are related to 14 (4.7%) of HBV infected women in the study. Conclusion: An intermediate prevalence of hepatitis B virus infection was identified which justifies the need for routine screening in pregnancy especially among unbooked women in order to identify and treat the infection.

Espirometria de incentivo com pressão positiva expiratória é benéfica após revascularização miocardio / Espirometría incentivada con presión positiva espiratoria es beneficiosa después de revascularización de miocardio / Incentive spirometry with expiratory positive airway pressure brings benefits after myocardial revascularization

FUNDAMENTO: Pacientes que são submetidos à cirurgia de revascularização do miocárdio (CRM) apresentam risco maior para desenvolver complicações pulmonares, como atelectasias, pneumonia e derrame pleural. Estas complicações podem aumentar o tempo de internação hospitalar, a necessidade de recursos financeiros e também se associam com a redução da qualidade de vida e da capacidade funcional a longo prazo. OBJETIVO: Testar se o uso de espirometria de incentivo (EI) associada com pressão positiva expiratória na via aérea (EPAP), após CRM melhora a dispneia, a sensação de esforço percebido e a qualidade de vida 18 meses após a CRM. MÉTODOS: Dezesseis pacientes submetidos a CRM foram randomizados para o grupo controle (n=8) ou para o grupo EI+EPAP (n=8). O protocolo de EI+EPAP foi realizado no período pós-operatório imediato e durante mais 4 semanas no domicílio. Dezoito meses após a CRM foram avaliadas a força da musculatura respiratória, a capacidade funcional, a função pulmonar, a qualidade de vida e o nível de atividade física. RESULTADOS: Após o teste de caminhada de seis minutos (TC6), o escore para dispneia (1,6±0,6 vs 0,6±0,3, P<0,05) e a sensação de esforço (13,4±1,2 vs 9,1±0,7, P<0,05) foram maiores no grupo controle comparado com o grupo EI+EPAP. Na avaliação da qualidade de vida, o domínio relacionado às limitações nos aspectos físicos foi melhor no grupo EI+EPAP (93,7±4,1 vs 50±17, P<0,02). CONCLUSÃO: Pacientes que realizam EI+EPAP apresentam menos dispneia e menor sensação de esforço após o TC6 e também melhor qualidade de vida 18 meses após a CRM.

BACKGROUND: Patients undergoing coronary artery bypass graft (CABG) surgery have higher risk to develop pulmonary complications (PCs) such as atelectasis, pneumonia and pleural effusion. These complications could increase the length of hospital stay, resources utilization and also are associated with reduced quality of life and functional capacity a long term. OBJECTIVE: To test if the use of incentive spirometry (IS) associated with expiratory positive airway pressure (EPAP), after CABG surgery improves dyspnea, effort perceived and quality of life 18 months after CABG. METHODS: Sixteen patients submitted to a CABG, were randomized to a control group (n=8) or IS+EPAP group (n=8). The protocol of IS+EPAP was applied in the immediate postoperative period and following for more 4 weeks in the patient's home. Eighteen months after CABG, the strength of the respiratory muscle, the functional capacity, the lung function, the quality of life and the level of physical activity were evaluated. RESULTS: After six minute walk test (6-MWT), the score of the dyspnea (1.6±0.6 vs 0.6±0.3, P<0.05) and the perceived effort (13.4±1.2 vs 9.1±0.7, P<0.05) were higher in the control group, when compared with the IS+EPAP group. In quality of life evaluation, the domain related to the physical aspects limitations was better in IS+EPAP group (93.7±4.1 vs 50±17, P<0.02). CONCLUSION: Patients that were submitted to IS+EPAP present reduction of dyspnea and lower effort sensation after the 6-MWT, and also a better quality of life 18 months after CABG.

FUNDAMENTO: Pacientes que son sometidos a cirugía de revascularización del miocardio (CRM) presenta mayor riesgo de desarrollar complicaciones pulmonares, como atelectasias, neumonía y derrame pleural. Estas complicaciones pueden aumentar el tiempo de internación hospitalaria, la necesidad de recursos financieros y también se asocian con la reducción de la calidad de vida y de la capacidad funcional a largo plazo. OBJETIVO: Probar si el uso de espirometría incentivada (EI) asociada con presión positiva espiratoria en la vía aérea (EPAP), después de la CRM mejora la disnea, la sensación de esfuerzo percibido y la calidad de vida 18 meses después de la CRM. MÉTODOS: Dieciocho pacientes sometidos a CRM fueron aleatorizados para el grupo control (n=8) o para el grupo EI+EPAP (n=8). El protocolo de EI+EPAP se realizó en el período postoperatorio inmediato y durante 4 semanas más en domicilio. Dieciocho meses después de la CRM se evaluaron la fuerza de la musculatura respiratoria, la capacidad funcional, la función pulmonar, la calidad de vida y el nivel de actividad física. RESULTADOS: Después del test de caminata de seis minutos (TC6), el score para disnea (1,6 ± 0,6 vs 0,6 ± 0,3, P < 0,05) y la sensación de esfuerzo (13,4 ± 1,2 vs 9,1 ± 0,7, P < 0,05) fueron mayores en el grupo control comparado con el grupo EI+EPAP. En la evaluación de la calidad de vida, el dominio relacionado con las limitaciones en los aspectos físicos fue mejor en el grupo EI+EPAP (93,7 ± 4,1 vs 50 ± 17, P < 0,02). CONCLUSIÓN: Pacientes que realizan EI+EPAP presentan menos disnea y menor sensación de esfuerzo después del TC6 y también mejor calidad de vida 18 meses después de la CRM.

Repercussões respiratórias da ventilação por cinta abdominal pneumática em ratos normais / Respiratory repercussions of the ventilation with abdominal pneumatic belt in normal rats

A Cinta Abdominal Pneumática (CAP) é um aparelho utilizado no mercado internacional com o objetivo de melhorar a função pulmonar de pacientes com seqüelas de poliomielite, doenças neuromusculares e lesão raquiomedular. O objetivo desta pesquisa foi avaliar os parâmetros respiratórios durante o uso da CAP através de um experimento com sete ratos normais. A variação da pressão intrapleural (Ppl), o tempo inspiratório (Ti), o tempo expiratório (Te), o tempo total do ciclo (Ttot), a freqüência respiratória (FR), a relação Ti/Ttot e o produto pressão tempo (PTP) foram mensurados com um transdutor de pressão no espaço pleural dos ratos, sem e com a CAP; a fim de se verificar seus reais efeitos fisiológicos. Os resultados mostraram que a CAP determina variação significativa na pressão pleural (p = 0,0489) o que melhora os volumes pulmonares e conseqüentemente a ventilação. A FR, Ti, Te, Ttot não sofreram alterações significativas. A variação da relação Ti/Ttot e do PTP não foi significativamente diferente, o que é vantajoso, uma vez que refletem aumento do gasto energético da respiração. Observou-se também assincronia durante seu uso, funcionando como estímulo inspiratório e não como auxílio expiratório.

The Abdominal Pneumatic Belt (APB) is a device used in the international market with the objective to improve the pulmonary function of patients with polio sequels, neuromuscular disorders and injury of spinal cord. This research considered an evaluation of the respiratory parameters during the use of the APB through an experiment with seven normal rats. The variation of the pleural pressure (Ppl), the inspiratory time (Ti), the expiratory time (Te), the total time of the cycle (Ttot), the respiratory frequency (FR), the Ti/Ttot relation and the pressure-time product (PTP) had been measure, through a transducer of pressure in the pleural space, without and with such equipment; in order to analyze its real physiological effect. The results had shown that the APB determines significant variation in the pleural pressure (p = 0,0489) what probably determines better pulmonary volumes and consequently better ventilation. The FR, Ti, Te and Ttot had not suffered significant alterations. The variation of the Ti/Ttot relation and the PTP is not significant too, what it would be advantageous, because it reflects increase of energy expense of the breath. It was observed an antagonism during the use, functioning as inspiratory stimulation and not as expiratory aid.

Anastomose colônica com adesivo de fibrina em ratos diabéticos / Colonic anastomosis with fibrin glue in diabetic rats

OBJETIVO: Estudar aspectos da cicatrização na anastomose colônica com adesivo de fibrina em ratos normais e diabéticos. MÉTODO: Foram utilizados 160 ratos Wistar (Rattus novergicus albinus), machos, com peso variando de 250 a 300g, sendo que oitenta destes animais eram não diabéticos e os outros oitenta animais apresentavam diabetes mellitus induzido pela aloxana, Os animais foram submetidos a procedimento operatório padronizado que consistiu em colectomia parcial esquerda e anastomose primária por sutura manual ou com adesivo de fibrina. Foram reavaliados no quarto ou sétimo dia de pós-operatório quando se observou a presença de coleção líquida ou purulenta na tela subcutânea; integridade da sutura; presença de aderências; presença de deiscência; resistência da anastomose (pressão máxima de insuflação) em mmHg, e a concentração tecidual de hidroxiprolina. RESULTADOS: Em relação à presença de deiscência de anastomose e mortalidade ocorreram piores resultados nos animais diabéticos no quarto e sétimo dias de observação em comparação ao controle. Nos grupos e subgrupos estudados os resultados com o uso do adesivo de fibrina não foram melhores que os da sutura manual. Em relação à concentração tecidual de hidroxiprolina não houve diferença significativa entre os grupos. CONCLUSÃO: O diabetes mellitus induzido pela aloxana impede a reparação normal da anastomose colônica em ratos e o uso adesivo de fibrina na anastomose colônica em ratos normais e diabéticos não trouxe benefícios na evolução pós-operatória.

BACKGROUND: The aim of this experimental study was to assess healing in colonic anastomosis with fibrin glue in normal and diabetics rats. METHODS: One hundred and sixty Wistar rats were randomly assigned for two groups (normal and diabetics). The animals underwent a partial left colectomy and after an end-to-end anastomosis or a fibrin glue anastomosis. The rats were submitted to a new operative procedure on the 4th or 7th postoperative day, when the anastomosis were observed. The bursting pressure measurements were recorded. RESULTS: Mortality and anastomosis dehiscence were greater in diabetic animals on 4th and 7th days of observation when compared to controlled rats. There have been no differences between groups and sub-groups regarding the use of fibrine patch or handmade suture. There were no significant differences on hidroxiproline tissue concentration. CONCLUSIONS: Aloxane-induced Diabetes mellitus impairs normal healing in colonic anastomosis in rats, and there were no benefits in normal or diabetic groups with the use of fibrin glue.

O estresse oxidativo e o exercício físico em indivíduos HIV positivo / Oxidative stress and physical exercise in HIV positive individuals

A infecção pelo vírus da imunodeficiência humana (HIV) é acompanhada por alterações estruturais e funcionais relacionadas ao sistema imunológico. Além disso, o aumento do estresse oxidativo (EO) nos portadores do HIV, caracterizado por diminuição nos níveis de glutationa (GSH), aumentos na glutationa oxidada (GSSG), na razão GSSG/GSH e lipoperoxidação, bem como redução da atividade de enzimas antioxidantes - catalase, superóxido dismutase (SOD) e glutationa peroxidase (GPx) - é uma conseqüência da evolução dos pacientes infectados com HIV. As células do sistema imunológico necessitam de altas concentrações de antioxidantes para manter o balanço redox e preservar a sua integridade e função. Quando ocorre a depleção dos antioxidantes, há diminuição da resposta imunológica e aumento na replicação do HIV. O uso da terapia anti-retroviral combinada (TARV) melhorou significativamente a evolução clínica dos pacientes, porém, mesmo assim, alguns continuam apresentando EO aumentado e outros efeitos da TARV, como alterações no metabolismo lipídico e muscular. O treinamento físico é utilizado como intervenção não farmacológica nos pacientes infectados pelo HIV para proporcionar melhoria nos parâmetros antropométricos, aeróbios, musculares e psicológicos, porém, há carência de estudos sobre a sua utilização em relação ao estresse oxidativo. Nesta revisão, foram analisados os tópicos referentes ao estresse oxidativo nos pacientes HIV positivos e os possíveis benefícios do exercício físico na capacidade antioxidante. O treinamento físico é uma estratégia auxiliar para os pacientes, com ou sem uso da TARV, uma vez que melhora os aspectos cardiorrespiratórios, musculares, antropométricos e psicológicos sem induzir a imunossupressão. Referindo-se ao estresse oxidativo, infere-se, a partir dos dados em indivíduos HIV negativos, que o treinamento físico pode gerar adaptações que minimizam os efeitos deletérios provocados pelo EO através de melhorias nos ...

Human immunodeficiency virus (HIV) infection is characterized by functional and structural changes related to the immunological system. Moreover, increase in oxidative stress (OS) in HIV patients, characterized by a reduction in the glutathione (GSH) levels, increases in glutathione disulfide (GSSG), in the ratio GSSG/GSH and in lipid peroxidation, as well as a reduction in antioxidant enzymes - catalase, superoxid dismutase (SOD) and gluthatione peroxidase (GPx) - is a consequence of the evolution in HIV-infected patients. Higher levels of antioxidant activity are necessary to maintain the immunological system cells redox balance and preserve their function. In an antioxidant depleted state, there is a reduction in the immunological response and an increase in HIV replication. The use of highly active antiretroviral therapy (HAART) has improved the clinical evolution of these patients. However, some patients remain showing higher OS and other effects of HAART, such as changes in lipidic and muscle metabolism. Exercise training has been used as a non pharmacological treatment in HIV-infected patients to promote improvements in anthropometrics, aerobic, muscle and psychological outcomes; however, there are insufficient data about the effects of exercise training in OS. This review analyzes the topics related to the oxidative stress in HIV-infected patients and the possible benefits of the physical exercise in the antioxidant capacity. Physical training is a complementary procedure for the patients, with or without use of the HAART, since it improves the cardiorespiratory, muscle, anthropometrics and psychological performance without inducing immunodepression. In relation to oxidative stress, it is inferred, from the data obtained in non-HIV individuals, that the physical training could promote adaptations that minimize the deleterious effect induced by OS through improvements in the activity of the enzymatic and non-enzymatic antioxidant defenses.

Relationship between cardiovascular dysfunction and hyperglycemia in streptozotocin-induced diabetes in rats

Streptozotocin (STZ)-induced diabetes in rats is characterized by cardiovascular dysfunction beginning 5 days after STZ injection, which may reflect functional or structural autonomic nervous system damage. We investigated cardiovascular and autonomic function, in rats weighing 166 ± 4 g, 5-7, 14, 30, 45, and 90 days after STZ injection (N = 24, 33, 27, 14, and 13, respectively). Arterial pressure (AP), mean AP (MAP) variability (standard deviation of the mean of MAP, SDMMAP), heart rate (HR), HR variability (standard deviation of the normal pulse intervals, SDNN), and root mean square of successive difference of pulse intervals (RMSSD) were measured. STZ induced increased glycemia in diabetic rats vs control rats. Diabetes reduced resting HR from 363 ± 12 to 332 ± 5 bpm (P < 0.05) 5 to 7 days after STZ and reduced MAP from 121 ± 2 to 104 ± 5 mmHg (P = 0.007) 14 days after STZ. HR and MAP variability were lower in diabetic vs control rats 30-45 days after STZ injection (RMSSD decreased from 5.6 ± 0.9 to 3.4 ± 0.4 ms, P = 0.04 and SDMMAP from 6.6 ± 0.6 to 4.2 ± 0.6 mmHg, P = 0.005). Glycemia was negatively correlated with resting AP and HR (r = -0.41 and -0.40, P < 0.001) and with SDNN and SDMMAP indices (r = -0.34 and -0.49, P < 0.01). Even though STZ-diabetic rats presented bradycardia and hypotension early in the course of diabetes, their autonomic function was reduced only 30-45 days after STZ injection and these changes were negatively correlated with plasma glucose, suggesting a metabolic origin.

Cardiovascular control in experimental diabetes

Several studies have reported impairment in cardiovascular function and control in diabetes. The studies cited in this review were carried out from a few days up to 3 months after streptozotocin administration and were concerned with the control of the circulation. We observed that early changes (5 days) in blood pressure control by different peripheral receptors were maintained for several months. Moreover, the impairment of reflex responses observed after baroreceptor and chemoreceptor stimulation was probably related to changes in the efferent limb of the reflex arc (sympathetic and parasympathetic), but changes also in the central nervous system could not be excluded. Changes in renal sympathetic nerve activity during volume expansion were blunted in streptozotocin-treated rats, indicating an adaptive natriuretic and diuretic response in the diabetic state. The improvement of diabetic cardiovascular dysfunction induced by exercise training seems to be related to changes in the autonomic nervous system. Complementary studies about the complex interaction between circulation control systems are clearly needed to adequately address the management of pathophysiological changes associated with diabetes

Reflex control of arterial pressure and heart rate in short-term streptozotocin diabetic rats

Impaired baroreflex sensitivity in diabetes is well described and has been attributed to autonomic diabetic neuropathy. In the present study conducted on acute (10-20 days) streptozotocin (STZ)-induced diabetic rats we examined: 1) cardiac baroreflex sensitivity, assessed by the slope of the linear regression between phenylephrine- or sodium nitroprusside-induced changes in arterial pressure and reflex changes in heart rate (HR) in conscious rats; 2) aortic baroreceptor function by means of the relationship between systolic arterial pressure and aortic depressor nerve (ADN) activity, in anesthetized rats, and 3) bradycardia produced by electrical stimulation of the vagus nerve or by the iv injection of methacholine in anesthetized animals. Reflex bradycardia (-1.4 ± 0.1 vs -1.7 ± 0.1 bpm/mmHg) and tachycardia (-2.1 ± 0.3 vs -3.0 ± 0.2 bpm/mmHg) were reduced in the diabetic group. The gain of the ADN activity relationship was similar in control (1.7 ± 0.1 percent max/mmHg) and diabetic (1.5 ± 0.1 percent max/mmHg) animals. The HR response to vagal nerve stimulation with 16, 32 and 64 Hz was 13, 16 and 14 percent higher, respectively, than the response of STZ-treated rats. The HR response to increasing doses of methacholine was also higher in the diabetic group compared to control animals. Our results confirm the baroreflex dysfunction detected in previous studies on short-term diabetic rats. Moreover, the normal baroreceptor function and the altered HR responses to vagal stimulation or methacholine injection suggest that the efferent limb of the baroreflex is mainly responsible for baroreflex dysfunction in this model of diabetes

Oxidative stress in the latissimus dorsi muscle of diabetic rats

The purpose of the present study was to investigate the effects of experimental diabetes on the oxidant and antioxidant status of latissimus dorsi (LD) muscles of male Wistar rats (220 +/- 5 g, N = 11). Short-term (5 days) diabetes was induced by a single injection of streptozotocin (STZ, 50 mg/kg, iv; glycemia >300 mg/dl). LD muscle of STZ-diabetic rats presented higher levels of thiobarbituric acid reactive substances (TBARS) and chemiluminescence (0.36 +/- 0.02 nmol/mg protein and 14706 +/- 1581 cps/mg protein) than LD muscle of normal rats (0.23 +/- 0.04 nmol/mg protein and 7389 +/- 1355 cps/mg protein). Diabetes induced a 92 percent increase in catalase and a 27 percent increase in glutathione S-transferase activities in LD muscle. Glutathione peroxidase activity was reduced (58 percent) in STZ-diabetic rats and superoxide dismutase activity was similar in LD muscle of both groups. A positive correlation was obtained between catalase activity and the oxidative stress of LD, as evaluated in terms of TBARS (r = 0.78) and by chemiluminescence (r = 0.89). Catalase activity also correlated inversely with glutathione peroxidase activity (r = 0.79). These data suggest that an increased oxidative stress in LD muscle of diabetic rats may be related to skeletal muscle myopathy

Effects of exercise training on autonomic and myocardial dysfunction in streptozotocin-diabetic rats

Several investigators have demonstrated that diabetes is associated with autonomic and myocardial dysfunction. Exercise training is an efficient non-pharmacological treatment for cardiac and metabolic diseases. The aim of the present study was to investigate the effects of exercise training on hemodynamic and autonomic diabetic dysfunction. After 1 week of diabetes induction (streptozotocin, 50 mg/kg, iv), male Wistar rats (222 +/- 5 g, N = 18) were submitted to exercise training for 10 weeks on a treadmill. Arterial pressure signals were obtained and processed with a data acquisition system. Autonomic function and intrinsic heart rate were studied by injecting methylatropine and propranolol. Left ventricular function was assessed in hearts perfused in vitro by the Langendorff technique. Diabetes (D) bradycardia and hypotension (D: 279 +/- 9 bpm and 91 +/- 4 mmHg vs 315 +/- 11 bpm and 111 +/- 4 mmHg in controls, C) were attenuated by training (TD: 305 +/- 7 bpm and 100 +/- 4 mmHg). Vagal tonus was decreased in the diabetic groups and sympathetic tonus was similar in all animals. Intrinsic heart rate was lower in D (284 +/- 11 bpm) compared to C and TD (390 +/- 8 and 342 +/- 14 bpm, respectively). Peak systolic pressure developed at different pressures was similar for all groups, but +dP/dt max was decreased and -dP/dt max was increased in D. In conclusion, exercise training reversed hypotension and bradycardia and improved myocardial function in diabetic rats. These changes represent an adaptive response to the demands of training, supporting a positive role of physical activity in the management of diabetes.

Controle reflexo da pressão arterial no diabetes experimental / Reflex control of arterial pressure in experimental diabetes

Muitos dos mecanismos envolvidos nas alterações cardiovasculares do diabetes parecem representar adaptações funcionais e estruturais relacionadas à duração e à gravidade da doença. O controle da pressão arterial exercido por diferentes receptores periféricos está modificado precocemente e algumas modificações podem permanecer, independentemente do tratamento com insulina. O tamponamento das variações momento a momento da pressão arterial comandado pelos pressorreceptores arteriais está reduzido, assim como as respostas produzidas pela estimulação dos quimiorreceptores periféricos. Essas alterações representam comprometimento do ramo eferente (simpático e parassimpático), sem que se possa excluir mudanças no sistema nervoso central. As respostas do simpático renal às variações de volume estão bloqueadas e, no diabetes experimental, essa alteração pode caracterizar uma adaptação das respostas natriurética e diurética a essa condição. O endotélio parece ter papel relevante nas respostas hemodinâmicas sistêmica ou renal no diabetes. Algumas das alterações observadas no controle da pressão arterial em animais diabéticos podem ser revertidas pelo treinamento físico.

Baroreflex and chemoreflex dysfunction in streptozotocin-diabetic rats

Several investigators have demonstrated that streptozotocin (STZ) diabetes induces changes in the autonomic control of the cardiovascular system. Changes in cardiovascular function may be related to peripheral neuropathy. The aim of the present study was to a changes in heart rate (HR) and arterial pressure (AP) as well as baroreflex and chemoreflex sensitivity in STZ-induced diabetic male Wistar rats (STZ, 50 mg/kg, iv, 15 days). Intra-arterial blood pressure signals were obtained for control and diabetic rats (N = 9, each group). Data were processed in a data acquisition system (CODAS, 1 kHz). Baroreflex sensitivity was evaluated by measuring heart rate changes induced by arterial pressure varíation produced by phenyiephrine and sodium nitroprusside injection. Increasing doses of potassium cyanide (KCN) were used to evaluate bradycardic and pressor responses evoked by chemoreflex activation. STZ induced hyperglycemia (447 ñ 49 vs 126 ñ 3 mg/dl), and a reduction in AP (99 + 3 vs 118 + 2mmHg), resting HR (296 ñ 11 vs 355 ñ 16 bpm) and plasma insulin levels (16 ñ 1 vs 57 + 11 muU/ml). We also observed that the reflex bradycardia (-1.68 ñ 0.1 vs -1.25 ñ 0.1 bpm/mmHg, in the diabetic group) and tachycardia (-3.68 ñ 0.5 vs -1.75 ñ 0.3 bpm/mmHg, in the diabetic group) produced by vasopressor and depressor agents were impaired in the diabetic group. Bradycardia evoked by chemoreflex activation was attenuated in diabetic rats (control: -l7 + 1,-86 + 19,-l85 ñ 18, -208 + 17 vs diabetic: -7 + 1,-23 ñ 5,-95 ñ 13, - 140 + 13 bpm), as also was the pressor response (control: 6 ñ 1,30 ñ 7,54 + 59 ñ 5 vs diabetic: 6 ñ 1,8 ñ 2,33 ñ 4,42 ñ 5 mmhg). In conclusion the cardiovascular responses evoked by baroreflex and chemoreflex activation are impaired in diabetic rats. The alterations of caradiovascular responses may be secondary to the autonomic dysfunction of cardiovascular control.

Fluidity of detergent micelles plays an important role in muscarinic receptor solubilization.

In order to find a suitable reagent for extracting the muscarinic receptor from rat brain membranes 14 different detergents were tested. Only the plant glycoside digitonin efficiently solubilized the receptor protein in its native form. At the same time microviscosity of detergent micelles was determined by measuring the fluorescence polarization of a hydrophobic fluorescent probe diphenylhexatriene incorporated into the micelles. In the case of digitonin the polarization value was close to the corresponding value obtained for rat brain membrane fragments, while for the other detergents studied it remained considerably lower. The results obtained indicate that the fluidity of detergent micelles may play an important role in retaining the active conformation of the solubilized muscarinic receptor.