Antihypertensive effects of captopril and saralasin in essential and renal hypertension

The antihypertensive effect of captopril and its mechanism of action were studied in patients with essential and renal hypertension. In mild essential hypertension (n = 12), during monotherapy with captopril (50 to 450 mg, 4 to 12 weeks) blood pressure was normalized in seven, improved in two and remained unchanged in three patients, plasma levels of active and acid-activatable inactive renin significantly increased and angiotensin II decreased, whereas no consistent changes in urinary kallikrein excretion occurred. In severe renal (n = 14) and essential (n = 9) hypertension, blood pressure was normalized in eight (seven with renal hypertension), improved in seven and unchanged in eight patients, when captopril (50 to 450 mg, 3 to 15 months) was added to the antihypertensive medication. In one patient with stenosis in a transplanted renal artery reversible renal failure occurred during captopril therapy possibly because of a steep initial decrease in blood pressure, although a toxic effect of the drug cannot be excluded. In another series of 12 renal and 8 essential hypertensive patients, a significant correlation between the acute effect of captopril (within 90 minutes) and saralasin on blood pressure was demonstrated (r = 0.71, p < 0.001). The change in blood pressure after either drug was significantly related to the initial plasma renin concentration.In conclusion, captopril sems to be an effective antihypertensive agent in essential and renal hypertension. Renal function should be monitored during captopril therapy. Our studies suggest that captopril decreases blood pressure by inhibiting the vasopressor action of the renin-angiotensin system.     

The clinical pharmacology and antiarrhythmic efficacy of acetylprocainamide in patients with arrhythmias

The actions of acetylprocainamide, the major metabolite of procainamide in man, were studied in a placebo-controlled oral-dose-ranging trial in 16 persons with arrhythmias. The occurrences of arrhythmias decreased in 15 patients receiving acetylprocainamide and increased subsequently in 10 of 13 patients given placebo. The frequency of arrhythmias was reduced by more than 75 percent in nine patients. Antiarrhythmic effects were dependent on dose and serum drug concentrations, with levels of 10 to 24 μg/ml observed in patients with a reduction of more than 70 percent in premature ventricular complexes. The ratio of preejection period to left ventricular ejection time decreased during therapy. Side effects of light-headedness, insomnia, nausea and diarrhea occurred in six patients at serum levels ranging from 11 to 22 μg/ml. The serum half-life of acetylprocainamide lengthened from 7 to 21 hours as the creatinine clearance decreased from 105 to 35 ml/min. Acetylprocainamide has antiarrhythmic efficacy, but causes side effects in human beings. This compound appears to contribute to the effects of procainamide therapy and may be useful as an antiarrhythmic drug.     

Changes in cathepsin C activity during spontaneous and induced metamorphoses of the bullfrog

The specific activity of cathepsin C and other tissue parameters have been studied in five tadpole tissues during spontaneous and triiodothyronine (T₃)-induced metamorphosis. During spontaneous metamorphosis, all these tissues showed an increase in cathepsin C activity at some point in the metamorphic climax. The effect is especially pronounced in the tadpole tail in which cathepsin C activity increases at least 100-fold from an almost undetectable level to the highest activity in any tissue tested. Cathepsin C activity also increased 3- to 4-fold in the gills, but from a much higher initial premetamorphic level. An increase in enzyme activity in kidney, liver, and lungs was also observed during spontaneous metamorphosis. However, only in tail tissue was there a decisive increase in cathepsin C activity up to 14 days after an injection of an effective dose of T₃. The implications of these data have been discussed in relation to the mechanism of tissue resorption and the possibility of additional factors being involved in certain metamorphic processes.     

Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring

Clinical and angiographic or autopsy data, or both, on three children with a subdivided left atrium (cor triatriatum) and an associated endocardial cushion defect are reviewed. (One child had ostium primum defect, and two had complete atrioventricular [A-V] canal.) A fourth patient demonstrates the difficulties in differentiating subdivided left atrium from supravalve mitral stenosis in the presence of an endocardial cushion defect. The clinical findings are greatly influenced by the endocardial cushion defect. A pressure gradient between the pulmonary wedge and (left or right) ventricular end-diastolic pressures in patients with an endocardial cushion defect indicates pulmonary venous obstruction and should alert one to the possibility of these combined lesions. The exact diagnosis is made with injections of angiographic contrast medium into the proximal and distal left atrial chambers, to document the respective relations of the pulmonary veins, left atrial appendage and A-V valves to these atrial chambers. All three patients with an endocardial cushion defect and a subdivided left atrium had an associated patent ductus arteriosus. The common association of subdivided left atrium with intracardiac, pulmonary venous and aortic anomalies is again demonstrated.     

Canine electrophysiology of encainide, a new antiarrhythmic drug

Encainide, a new benzanillide derivative with high potency and a good therapeutic/toxic ratio, was evaluated with the use of standard His bundle recording techniques to determine its effects on the cardiac conduction system in closed chest animals. Twenty mongrel dogs weighing 18 to 29 kg were anesthetized with 4 percent chloralose and classified into groups: group 1, a control group and groups 2,3, and 4, which were given 0.3, 0.9 and 2.7 mg/kg body weight, respectively, of encalnide In an intravenous infusion over a 15 minute period. Plasma concentration, blood pressure, surface electrocardiogram and atrlal and His bundle electrograms were recorded before, during and after drug infusion for a total of 120 minutes. Heart rate, A-H and H-V intervals, the QRS complex and Q-Tc interval were measured every 5 minutes during sinus rhythm and with constant atrial pacing. In addition, sinus nodal recovery time and atrial, atrioventrlcular (A-V) nodal and left ventricular refractory periods were measured before and immediately after infusion and every 30 minutes for 2 hours. Peak plasma concentration averaged 450 ng/ml in group 2,1,300 ng/ml in group 3 and 4,000 ng/ml in group 4. Blood pressure was not altered at any dose level throughout the study. The QRS complex and H-V interval were significantly prolonged (P < 0.005) at doses of 0.9 mg/kg and greater. These effects correlated well with plasma concentration. There was no significant change in heart rate, corrected sinus nodal recovery time, A-H interval, Q-Tc Interval atrial, A-V nodal or left ventricular refractory period. It is concluded that, unlike other antiarrhythmic agents, encainide prolongs His-Purkinje system conduction without significantly affecting conduction or refractoriness of other parts of the cardiac conduction system in animals.     

Effect of changes in plasma levels of free fatty acids on plasma glucagon,insulin, and growth hormone in man

A regulatory role of acute changes in plasma concentration of free fatty acids on glucagon secretion has been suggested. We have studied the effect of such changes on plasma levels of glucagon, insulin, and growth hormone in man. Basal plasma levels of immunoreactive glucagon (IRG) were only slightly raised in 11 healthy subjects when the mean concentration of free fatty acids (FFA) was depressed to levels as low as 0.315 ± 0.043 (SEM) mM by infusion of nicotinic acid. Basal levels were increased modestly when the mean FFA level was elevated to 3.027 ± 0.184 mM by infusion of a triglyceride emulsion (Intralipid) with heparin. The plasma IRG response to intravenous arginine was unaffected by high or low levels of plasma FFA. These findings contrasted with the effects upon plasma levels of immunoreactive insulin (IRI) and growth hormone (IGH). During elevation of FFA levels, the mean basal level of plasma IRI increased by 100%, and the IRI response to arginine increased by 50%. Concomitantly, basal IGH levels and the plasma IGH response to arginine were suppressed markedly by elevation of FFA levels. The results of these studies do not offer support for a significant role of variation in plasma level of FFA as a regulator of acute changes in plasma IRG in man. An influence of changing levels of FFA on insulin secretion was found, and an effect on levels of growth hormone was confirmed.     

上海大学生非酒精性脂肪肝与载脂蛋白E基因多态性的关系

目的 探讨上海大学生非酒精性脂肪肝(NAFLD)的患病率及与载脂蛋白E(ApoE)基因多态性的相关性.方法 对上海同济大学4 148名在校学生进行问卷调查;采用肝脏超声以及血肝功能、脂蛋白等生化指标检测,将确诊的NAFLD患者与正常者200例,进行外周血PCR-RFLP检测ApoE基因多态性.结果 (1)4 148名大学生中NAFLD检出398例(9.6%),NAFLD患者的体重指数、腰臀比、甘油三酯、总胆固醇、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、谷氨酰转移酶均高于对照组(P＜0.01),且随NAFLD程度加重,有递增趋势.(2)NAFLD组和对照组ApoE基因型分布比较差异显著(,P＜0.01).NAFLD E4/4基因型分布频率(5.5%)明显升高,E3/3分布频率(61.8%)明显减低(均P＜0.01).(3)非条件logistic回归分析显示总胆固醇、低密度脂蛋白胆固醇、腰臀比、AST、ALT、GGT与E4/4基因型密切相关.结论 ApoE基因112位和158位的氨基酸残基发生相应的变化可引起不同程度的脂质代谢障碍,E4/4可能是导致NAFLD发生的遗传因素之一.     

Quality of life in Palestinian patients with end-stage renal disease receiving treatment by haemodialysis: a cross-sectional study

Background

Haemodialysis is a life-saving but burdensome therapy for patients with end-stage renal disease, which can substantially impair health-related quality of life (HRQOL) and outcomes. The aim of this study was to determine the patterns of HRQOL and to identify the risk factors for reduced HRQOL in Palestinian patients receiving treatment by haemodialysis.

Maternal Physical Activity Is Associated With Improved Blood Pressure Regulation During Late Pregnancy

Background

Cardiovagal baroreflex gain (cBRG) reflects an individual's ability to buffer swings in blood pressure. It is not well understood how this mechanism is influenced by physical activity in pregnancy. Because pregnant women tend to engage in low levels of moderate-to-vigorous physical activity (MVPA) and high levels of sedentary behaviour, we sought to determine the influence of MVPA and sedentary behaviour on cBRG and mean arterial pressure (MAP) in pregnancy.