Long-term low intensity physical exercise attenuates heart failure development in aging spontaneously hypertensive rats.

BACKGROUND: Physical exercise is a strategy to control hypertension and attenuate pressure overload-induced cardiac remodeling. The influence of exercise on cardiac remodeling during uncontrolled hypertension is not established. We evaluated the effects of a long-term low intensity aerobic exercise protocol on heart failure (HF) development and cardiac remodeling in aging spontaneously hypertensive rats (SHR). METHODS: Sixteen month old SHR (n=50) and normotensive Wistar-Kyoto (WKY, n=35) rats were divided into sedentary (SED) and exercised (EX) groups. Rats exercised in treadmill at 12 m/min, 30 min/day, 5 days/week, for four months. The frequency of HF features was evaluated at euthanasia. STATISTICAL ANALYSES: ANOVA and Tukey or Mann-Whitney, and Goodman test. RESULTS: Despite slightly higher systolic blood pressure, SHR-EX had better functional capacity and lower HF frequency than SHR-SED. Echocardiography and tissue Doppler imaging showed no differences between SHR groups. In SHR-EX, however, left ventricular (LV) systolic diameter, larger in SHR-SED than WKY-SED, and endocardial fractional shortening, lower in SHR-SED than WKY-SED, had values between those in WKY-EX and SHR-SED not differing from either group. Myocardial function, assessed in LV papillary muscles, showed improvement in SHR-EX over SHR-SED and WKY-EX. LV myocardial collagen fraction and type I and III collagen gene expression were increased in SHR groups. Myocardial hydroxyproline concentration was lower in SHR-EX than SHR-SED. Lysyl oxidase gene expression was higher in SHR-SED than WKY-SED. CONCLUSION: Exercise improves functional capacity and reduces decompensated HF in aging SHR independent of elevated arterial pressure. Improvement in functional status is combined with attenuation of LV and myocardial dysfunction and fibrosis.

Aldosterone blockade reduces mortality without changing cardiac remodeling in spontaneously hypertensive rats.

BACKGROUND: The role of aldosterone blockers during transition from long-term compensated hypertrophy to dilated failure is not completely understood. In this study we evaluated the effects of early administration of spironolactone on cardiac remodeling, myocardial function, and mortality in spontaneously hypertensive rats (SHR). METHODS: Sixteen-month-old SHR received no treatment (SHR-C, n=72) or spironolactone (SHR-SPR, 20 mg/kg/day, n=34) for six months. Echocardiogram was performed before and after treatment. Myocardial function was analyzed in left ventricular (LV) papillary muscle preparations. Myocardial collagen and hydroxyproline concentration were evaluated by morphometry and spectrophotometry, respectively. LV gene expression was assessed by real time RT-PCR. STATISTICS: Student's t test; Log rank test (Kaplan Meyer). RESULTS: SHR-C and SHR-SPR presented mortality rates of 71 and 38%, respectively (p=0.004). Systolic arterial pressure did not differ between groups (SHR-C 199±43; SHR-SPR 200±35 mmHg). Initial and final echocardiograms did not show significant differences in cardiac structures or LV function between groups. Myocardial function was similar between groups at basal and after inotropic stimulation. Collagen fractional area, hydroxyproline concentration, gene expression for α- and ß-myosin heavy chain, atrial natriuretic peptide, and Serca2a were not different between groups. CONCLUSION: Early spironolactone administration reduces mortality without changing cardiac remodeling in spontaneous hypertensive rats.

Diabetes mellitus activates fetal gene program and intensifies cardiac remodeling and oxidative stress in aged spontaneously hypertensive rats.

BACKGROUND: The combination of systemic arterial hypertension and diabetes mellitus (DM) induces greater cardiac remodeling than either condition alone. However, this association has been poorly addressed in senescent rats. Therefore, this study aimed to analyze the influence of streptozotocin-induced DM on ventricular remodeling and oxidative stress in aged spontaneously hypertensive rats (SHR). METHODS: Fifty 18 month old male SHR were divided into two groups: control (SHR, n = 25) and diabetic (SHR-DM, n = 25). DM was induced by streptozotocin (40 mg/kg, i.p.). After nine weeks, the rats underwent echocardiography and myocardial functional study in left ventricular (LV) isolated papillary muscle preparations. LV samples were obtained to measure myocyte diameters, interstitial collagen fraction, and hydroxyproline concentration. Gene expression of atrial natriuretic peptide (ANP) and α- and ß-myosin heavy chain (MyHC) isoforms was evaluated by RT-PCR. Serum oxidative stress was assessed by measuring lipid hydroperoxide concentration and superoxide dismutase and glutathione peroxidase activities. STATISTICS: Student's t test or Mann-Whitney test, p < 0.05. RESULTS: SHR-DM presented higher blood glucose (487 ± 29 vs. 89.1 ± 21.1 mg/dL) and lower body weight (277 ± 26 vs. 339 ± 38 g). Systolic blood pressure did not differ between groups. Echocardiography showed LV and left atrial dilation, LV diastolic and relative wall thickness decrease, and LV systolic and diastolic function impairment in SHR-DM. Papillary muscle study showed decreased myocardial contractility and contractile reserve in SHR-DM. Myocyte diameters and myocardial interstitial collagen fraction and hydroxyproline concentration did not differ between groups. Increased serum pro-oxidant activity and gene expression of ANP and ß/α-MyHC ratio were observed in DM. CONCLUSION: Diabetes mellitus induces cardiac dilation and functional impairment, increases oxidative stress and activates fetal gene program in aged spontaneously hypertensive rats.

Respiratory pressures and expiratory peak flow rate of patients undergoing coronary artery bypass graft surgery.

BACKGROUND: To evaluate clinical and laboratorial parameters that predict decreased respiratory function in patients subjected to coronary artery bypass graft surgery (CABG). MATERIAL/METHODS: This was a prospective study evaluating 61 patients subjected to CABG with cardiopulmonary bypass, median sternotomy, and under mechanical ventilation for up to 24 h. One day before surgery, clinical information was recorded. Maximal inspiratory (MIP) and expiratory (MEP) pressures, and expiratory peak flow rate (EPFR) values were assessed 1 day before surgery and on the fifth postoperative day. Student's t test, 2-way ANOVA, Pearson's linear correlation, and logistic regression were used for statistical analysis. RESULTS: Patients were 63±10 years old, 67% males. Arterial hypertension was found in 75.4% of the patients, diabetes in 31.2%, dyslipidemia in 63.9%, tabagism in 25%, and chronic obstructive pulmonary disease (COPD) in 16.4%. Previous myocardial infarction was found in 67%. Preoperative hemoglobin levels were 12.8±1.71 g/dL. Older individuals had lower preoperative MEP and EPFR values. Preoperatively, positive association was found between hemoglobin levels and maximal respiratory pressures and EPFR values. Patients with both class III angina and COPD presented higher reductions in pulmonary pressures between the preoperative period and the 5th postoperative day. CONCLUSIONS: Older age and low hemoglobin levels are associated with preoperative low maximal respiratory pressures and EPFR. The combination of severe angina and COPD results in higher postoperative reduction of maximal respiratory pressures for patients who underwent CABG.

Association of pre and intraoperative variables with postoperative complications in coronary artery bypass graft surgery.

OBJECTIVE: To associate the pre- and intraoperative variables with postoperative complications of patients undergoing coronary artery bypass graft surgery. METHODS: The pre- and intraoperative risk factors of individuals of both genders with diagnosis of coronary insufficiency undergoing coronary artery bypass graft have been studied. RESULTS: Fifty-eight individuals with median age 62 ± 10 year-old were included in the study, 67% of whom were male. Fourteen (24.1%) patients were smokers, 39 (67.2%) had previous myocardial infarction history, 11 (19%) had undergone coronary angioplasty, 74% had hypertension, 27% had diabetes mellitus, 64% had dyslipidemia and 15.5% had chronic obstructive pulmonary disease. Eighteen (31%) patients presented postoperative complications, most frequent being: infection in surgical incision, difficulties in deambulation, dyspnea, urinary infection and generalized weakness. Male patients had fewer complications than females (P=0.005). Patients with chronic obstructive pulmonary disease remained hospitalized for longer time periods (P=0.019). Postoperative complications occurred in 50% of the patients with creatinine increased, while only 27.1% of the patients with normal value of creatinine had complications (P=0.049). In addition, complications occurred in 50% of the patients with diabetes mellitus, while only 23.8% of patients without diabetes mellitus had complications (P=0.032). The intraoperative factors showed no statistically significant differences. CONCLUSION: The preoperative factors are associated with postoperative complications in patients undergoing coronary artery bypass graft surgery.

Association of pre and intraoperative variables with postoperative complications in coronary artery bypass graft surgery / Associação de variáveis pré e intraoperatórias com complicações pós-operatórias em cirurgia de revascularização do miocárdio

OBJECTIVE: To associate the pre- and intraoperative variables with postoperative complications of patients undergoing coronary artery bypass graft surgery. METHODS: The pre- and intraoperative risk factors of individuals of both genders with diagnosis of coronary insufficiency undergoing coronary artery bypass graft have been studied. RESULTS: Fifty-eight individuals with median age 62 ± 10 year-old were included in the study, 67% of whom were male. Fourteen (24.1%) patients were smokers, 39 (67.2%) had previous myocardial infarction history, 11 (19%) had undergone coronary angioplasty, 74% had hypertension, 27% had diabetes mellitus, 64% had dyslipidemia and 15.5% had chronic obstructive pulmonary disease. Eighteen (31%) patients presented postoperative complications, most frequent being: infection in surgical incision, difficulties in deambulation, dyspnea, urinary infection and generalized weakness. Male patients had fewer complications than females (P=0.005). Patients with chronic obstructive pulmonary disease remained hospitalized for longer time periods (P=0.019). Postoperative complications occurred in 50% of the patients with creatinine increased, while only 27.1% of the patients with normal value of creatinine had complications (P=0.049). In addition, complications occurred in 50% of the patients with diabetes mellitus, while only 23.8% of patients without diabetes mellitus had complications (P=0.032). The intraoperative factors showed no statistically significant differences. CONCLUSION: The preoperative factors are associated with postoperative complications in patients undergoing coronary artery bypass graft surgery.

OBJETIVO: Associar variáveis pré e intraoperatórias com as complicações pós-operatórias de pacientes submetidos à cirurgia de revascularização miocárdica. MÉTODOS: Foram estudados os fatores de risco pré e intraoperatórios de indivíduos de ambos os sexos, com diagnóstico de insuficiência coronariana, submetidos à cirurgia de revascularização do miocárdio. RESULTADOS: Participaram do estudo 58 indivíduos, com idade média de 62 ± 10 anos e 67% eram do sexo masculino. Catorze (24,1%) pacientes eram fumantes, 39 (67,2%) apresentavam história de infarto do miocárdio prévia, 11 (19%) tinham realizado angioplastia coronariana, 74% apresentavam hipertensão arterial, 27% diabetes mellitus, 64% dislipidemia e 15,5% doença pulmonar obstrutiva crônica. Dezoito (31%) pacientes apresentaram complicações no pós-operatório e as mais frequentes foram infecção na incisão cirúrgica, dificuldades na deambulação, dispneia, infecção urinária e fraqueza generalizada. Pacientes do sexo masculino apresentaram menos complicações que os do sexo feminino (P=0,005). Pacientes com diagnóstico de doença pulmonar obstrutiva crônica permaneceram maior tempo hospitalizados (P=0,019). Complicações pós-operatórias ocorreram em 50% dos pacientes com creatinina aumentada, enquanto que apenas 27,1% dos pacientes com valor normal de creatinina apresentaram complicações (P=0,049). Ocorreram também complicações em 50% dos pacientes com diabetes mellitus, enquanto que apenas 23,8% dos pacientes sem diabetes mellitus tiveram complicações (P=0,032). Os fatores intraoperatórios não apresentaram diferenças significativas estatisticamente. CONCLUSÃO: Os fatores pré-operatórios estão associados com complicações pós-operatórias em pacientes submetidos à cirurgia de revascularização miocárdica.

Qualidade microbiológica e físico-química de leite humano, processado no banco de leite humano de Bauru, SP / Microbiological and physico-chemistry of human milk, processed human milk bank in Bauru, SP

O leite humano é o alimento mais adequado para as crianças nos primeiros meses de vida, principalmente para bebês prematuros, com deficiências metabólicas ou alérgicas a outros tipos de leite, devido aos fatores nutricionais e imunológicos que o constitui. Os Bancos de Leite Humano desempenham papel importante na coleta, processamento e distribuição desse leite. O objetivo deste estudo foi avaliar a qualidade de leite humano processado no Banco de Leite de Bauru/SP.

Influência da inibição da NADPH oxidase sobre o remodelamento cardíaco de ratos com diabetes mellitus / Influence of NADPH oxidase inhibition by apocynin on cardiac remodeling in rats with diabetes mellitus

O diabetes mellitus (DM) está associado a diversas doenças vasculares e cardíacas. Nos últimos anos, aumentaram as evidências de que pacientes diabéticos são acometidos por uma forma de doença miocárdica denominada miocardiopatia diabética. O aumento na produção de espécies reativas de oxigênio (EROs), causado por alterações metabólicas induzidas pelo DM, é um dos principais mecanismos desencadeadores de alterações miocárdicas. A maior fonte de EROs no sistema cardiovascular está relacionada a atividade da família de enzimas da NADPH oxidase. Em relação ao DM, há evidências de que a elevação da glicose sérica, induzida por estreptozotocina em camundongos ou em pacientes diabéticos, causa aumento na atividade da NADPH oxidase nos vasos. Sendo o sistema NADPH oxidase o principal responsável por desequilíbrio no sistema de produção e eliminação de EROs, e também por estar envolvido em muitas patologias cardíacas, estudos à respeito de seu bloqueio têm aumentado nos últimos anos. O objetivo do presente trabalho foi analisar a influência da inibição da NADPH oxidase por apocinina sobre o remodelamento cardíaco de ratos com DM. Foram utilizados ratos Wistar machos com 6 meses de idade, divididos em 4 grupos: controle (CTL, n=15), controle+apocinina (CTL+APO, n=20), diabético (DM, n=20) e diabético+apocinina (DM+APO, n=20). O diabetes foi induzido por estreptozotocina. Após 7 dias, foi iniciado tratamento com apocinina e mantido por 8 semanas. A avaliação estrutural e funcional in vivo do coração foi realizada por ecocardiograma. O estudo funcional in vitro foi realizado em músculo papilar isolado do ventrículo esquerdo (VE) em condições basal e após estimulação com manobras inotrópicas (contração pós-pausa, aumento da concentração extracelular de cálcio e adição de isoproterenol à solução nutriente)...

Diabetes mellitus (DM) is associated with cardiac and vascular diseases. In recent years, there has been increased evidence that diabetic patients are affected by a form of myocardial disease known as diabetic cardiomyopathy. High production of reactive oxygen species (ROS), caused by diabetes-induced metabolic changes, is one of the main mechanisms leading to myocardial damage. A major source of ROS in the cardiovascular system is related to the activity of NADPH oxidase enzymes family. In streptozotocin-induced diabetic mice or in diabetic patients, serum glucose elevation increases NADPH oxidase activity in vessels. As NADPH oxidase is involved in imbalance of ROS production and elimination systems, and in pathophysiology of cardiac diseases, research on its blockade has increased in recent years. The purpose of this study was to analyze the influence of NADPH oxidase inhibition by apocynin on cardiac remodeling in rats with DM. Six month old male Wistar rats were assigned into 4 groups: control (CTL, n=15), control+apocynin (CTL+APO, n=20), diabetic (DM, n=20) and diabetic+apocynin (DM+APO, n=20). Diabetes was induced by streptozotocin. Seven days later, apocynin was initiated and maintained for 8 weeks. In vivo cardiac structures and functions were assessed by echocardiography. In vitro left ventricular (LV) functional study was performed in isolated papillary muscle preparation at basal condition and after inotropic stimulation with post-rest contraction, increase of extracellular calcium concentration, and addition of isoproterenol to the nutrient solution. Wet and dry weights of LV, right ventricle (RV), atria, lung, and liver sample were measured. LV histological sections were used to analyze interstitial collagen fraction. Antioxidant enzymes glutathione peroxidase (GSH-Px), catalase, and superoxide dismutase (SOD) were measured in serum...