This study aimed to evaluate the distribution of mercury in rats after controlled chronic exposure to three different doses of HgCl2 for 30 days. Samples of blood, brain, liver, testis, heart, and kidneys were collected for mercury determination. Although the rats were exposed to different doses, the Hg levels in blood were similar among the groups under study. However, the distribution of mercury in the organs have substantially differed between low and high doses. There was a significant tendency to high deposition in the liver and kidney. The deposition profile in the tissues suggests that the level of mercury remains relatively low in blood while it is deposited at preferential sites such as liver and kidney, demonstrating that, at least at the doses studied, the screening for Hg exposure is unreliable by blood sample analysis.

FUNDAMENTO: A Contração Pós-Repouso (CPR) do músculo cardíaco fornece informações indiretas sobre a manipulação de cálcio intracelular. OBJETIVO: Nosso objetivo foi estudar o comportamento da CPR e seus mecanismos subjacentes em camundongos com infarto do miocárdio. MÉTODOS: Seis semanas após a oclusão coronariana, a contratilidade dos Músculos Papilares (MP) obtidos a partir de camundongos submetidos à cirurgia sham (C, n = 17), com infarto moderado (MMI, n = 10) e grande infarto (LMI, n = 14), foi avaliada após intervalos de repouso de 10 a 60 segundos antes e depois da incubação com cloreto de lítio (Li+) em substituição ao cloreto de sódio ou rianodina (Ry). A expressão proteica de SR Ca(2+)-ATPase (SERCA2), trocador Na+/Ca2+ (NCX), fosfolambam (PLB) e fosfo-Ser (16)-PLB foi analisada por Western blotting. RESULTADOS: Os camundongos MMI apresentaram potenciação de CPR reduzida em comparação aos camundongos C. Em oposição à potenciação normal para camundongos C, foram observadas degradações de força pós-repouso nos músculos de camundongos LMI. Além disso, a Ry bloqueou a degradação ou potenciação de PRC observada em camundongos LMI e C; o Li+ inibiu o NCX e converteu a degradação em potenciação de CPR em camundongos LMI. Embora os camundongos MMI e LMI tenham apresentado diminuição no SERCA2 (72 ± 7% e 47 ± 9% de camundongos controle, respectivamente) e expressão protéica de fosfo-Ser16-PLB (75 ± 5% e 46 ± 11%, respectivamente), a superexpressão do NCX (175 ± 20%) só foi observada nos músculos de camundongos LMI. CONCLUSÃO: Nossos resultados mostraram, pela primeira vez, que a remodelação miocárdica pós-IAM em camundongos pode mudar a potenciação regular para degradação pós-repouso, afetando as proteínas de manipulação de Ca(2+) em miócitos.

BACKGROUND: Post-rest contraction (PRC) of cardiac muscle provides indirect information about the intracellular calcium handling. OBJECTIVE: Our aim was to study the behavior of PRC, and its underlying mechanisms, in rats with myocardial infarction. METHODS: Six weeks after coronary occlusion, the contractility of papillary muscles (PM) obtained from sham-operated (C, n=17), moderate infarcted (MMI, n=10) and large infarcted (LMI, n=14) rats was evaluated, following rest intervals of 10 to 60 seconds before and after incubation with lithium chloride (Li+) substituting sodium chloride or ryanodine (Ry). Protein expression of SR Ca(2+)-ATPase (SERCA2), Na+/Ca2+ exchanger (NCX), phospholamban (PLB) and phospho-Ser(16)-PLB were analyzed by Western blotting. RESULTS: MMI exhibited reduced PRC potentiation when compared to C. Opposing the normal potentiation for C, post-rest decays of force were observed in LMI muscles. In addition, Ry blocked PRC decay or potentiation observed in LMI and C; Li+ inhibited NCX and converted PRC decay to potentiation in LMI. Although MMI and LMI presented decreased SERCA2 (72±7% and 47±9% of Control, respectively) and phospho-Ser16-PLB (75±5% and 46±11%, respectively) protein expression, overexpression of NCX (175±20%) was only observed in LMI muscles. CONCLUSION: Our results showed, for the first time ever, that myocardial remodeling after MI in rats may change the regular potentiation to post-rest decay by affecting myocyte Ca(2+) handling proteins.

FUNDAMENTO: La Contracción pos pausa (CPP) del músculo cardíaco provee informaciones indirectas sobre la manejo del calcio intracelular. OBJETIVO: Nuestro objetivo fue estudiar el comportamiento de la CPP y sus mecanismos subyacentes en Ratas con infarto de miocardio. MÉTODOS: Seis semanas después de la oclusión coronaria, la contractilidad de los Músculos Papilares (MP) obtenidos a partir de Ratas sometidos a falsa cirurgia (C, n = 17), con infarto moderado (MMI, n = 10) y gran infarto (LMI, n = 14), fue evaluada después de pausas de estímulos de 10 a 60 segundos antes y después de la incubación con cloruro de litio (Li+) en substitución del cloruro de sodio o rianodina (Ry). La expresión proteica de SR Ca(2+)-ATPasa (SERCA2), intercambiador Na+/Ca2+ (NCX), fosfolamban (PLB) y fosfo-Ser (16)-PLB fue analizada por Western blotting. RESULTADOS: Los Ratas MMI presentaron potenciación de CPP reducida en comparación a los Ratas C. En oposición a la potenciación normal para Ratas C, fueron observadas decaimientos de fuerza post-reposo en los músculos de Ratas LMI. Además de eso, la Ry bloqueó la decaimiento o potenciación de PRC observada en Ratas LMI y C; el Li+ inhibió el NCX y convirtió la decaimiento en potenciación de CPP en Ratas LMI. Aunque los Ratas MMI y LMI hayan presentado disminución en el SERCA2 (72 ± 7% y 47 ± 9% de Ratas control, respectivamente) y expresión proteica de fosfo-Ser16-PLB (75 ± 5% y 46 ± 11%, respectivamente), la superexpresión del NCX (175 ± 20%) sólo fue observada en los músculos de Ratas LMI. CONCLUSIÓN: Nuestros resultados mostraron, por primera vez, que el remodelado miocárdico post-IAM en Ratas puede cambiar la potenciación regular para decaimiento post-reposo, afectando las proteínas de manejo del Ca(2+) en miocitos.

OBJECTIVE: To evaluate the effects of short-term exercise detraining on the functional fitness of older women after a 12-week water-based exercise (WE) program. METHODS: Healthy older women (trained (TR) group) were submitted to 12 weeks WE (three 45 min sessions per week) followed by a 6-week detraining period. A group of aged-matched women without any exercise training (UN group) were evaluated during the same period. The aerobic power, measured by VO2max and 800 meters performance, and the neuromuscular fitness and quality of life were evaluated. All assessments were made at baseline, after 12 weeks of training and after 4 and 6 weeks of detraining. RESULTS: No changes were found for the UN group during the follow-up study, but WE induced significant improvement in aerobic capacity, neuromuscular fitness and quality of life score. However, the upper and lower body strength, agility, flexibility, and body balance returned to UN levels (p>0.05) after 6 weeks of detraining. CONCLUSIONS: The results confirmed that 12 weeks of WE improves the functional fitness parameters and quality of life of older women. However, after a short detraining period of 4-6 weeks, the neuromuscular parameters and the quality of life score returns to baseline or untrained subject levels.

OBJECTIVE: The purpose of this study was to investigate the effects of physical exercise on the functional capacity and quality of life in heart failure patients. METHODS: Forty-two patients of both sexes with heart failure of NYHA class II and III with different etiologies were randomly divided into untrained or trained groups. The six-month exercise program consisted of aerobic training, muscle strength training, agility and joint flexibility activities. Physical fitness was evaluated by testing the performance on these trained components. Quality of life was evaluated by scored answers to a standardized questionnaire involving multiple domains. RESULTS: Baseline values did not differ between groups. Improvement in the trained group was identified in all components of functional capacity when compared to the untrained group (p < 0.001). Quality of life improved in the trained patients concerning physical, psychological, social and environmental domains (p < 0.001), whereas no significant change was found in the untrained patients. CONCLUSIONS: Guided and monitored physical exercise is safe and has the potential to improve functional capacity and quality of life in heart failure patients with multiple etiologies.

A análise do efeito da profundidade de semeadura e carga vertical visando a melhorar o aproveitamento, e a integração entre o solo e a cultura é muito difícil. O objetivo do presente trabalho foi avaliar cargas verticais (0; 98; 196 e 294 N) sobre as rodas compactadoras das semeadoras, combinando com profundidades de semeadura (0,03; 0,05 e 0,07 m) para a cultura da soja. O trabalho foi realizado no DER/UNESP - Jaboticabal, na pista de ensaio do Laboratório de Máquinas e Mecanização Agrícola (LAMMA), utilizando o delineamento experimental em blocos casualizados, no esquema fatorial (4 x 3), com 12 tratamentos e três repetições, totalizando 36 observações. Foram analisados: emergência de plântulas, estandes inicial e final, índice de sobrevivência, área mobilizada e rendimento de grãos. Os resultados evidenciaram que, com exceção da área mobilizada em relação à profundidade de semeadura, todas as demais variáveis não foram influenciadas pelos tratamentos.

The choice of a soil tillage system, aiming the best use and integration between soil and crop, is very difficult. The objective of the present work was to evaluate vertical loads (0; 98; 196 and 294 N) on the press wheels of the seeders working at sowing depths (0.03; 0.05 and 0.07 m) for the soybean. The work was carried out at Rural Engineering Department of UNESP - São Paulo State University, Jaboticabal, Brazil, in the Machines and Mechanization Laboratory’s area. The experiment design was 4x3 factorial in randomized blocks with three replications, totalling 12 treatments and 36 observations. The emergence, initial and final population of cultivation, index of surving plants, immobilized area in sowing and the yield grain were analyzed. The results showed that, except for mobilized area concerning the working depth of sowing shaft, all the other variables were not influenced by the treatments.