Role of the placenta in the control of the ante-partum surge of prolactin in the rat

A nocturnal surge of prolactin secretion occurs in the dark period preceding parturition in the rat. The aim of this study was to examine the role of the placenta in the control of this prolactin surge. Plasma prolactin and progesterone were measured by radioimmunoassay in serial blood samples collected after surgical removal of conceptuses during late pregnancy, and after intracerebroventricular (i.c.v.) injection of placental lactogen (PL) before the prolactin surge. In intact control animals, prolactin secretion remained low until a nocturnal surge of secretion occurred in the dark period preceding parturition, peaking at 269 +/- 51 (S.E.M.) micrograms/l at 03.00 h on day 21. Progesterone levels fell from greater than 200 nmol/l on day 19 to less than 40 nmol/l by 12.00 h on day 20 of pregnancy. PL levels during late pregnancy were modified by partial or complete removal of conceptuses at 10.00 h on day 19 of pregnancy. Removal of all but one or two conceptuses did not change the normal pattern of prolactin or progesterone secretion. Removal of all conceptuses, however, induced a large nocturnal surge of prolactin secretion, peaking at 211.7 +/- 78 micrograms/l at 03.00 h on day 20, 24 h earlier than the surge in intact animals. Progesterone levels after removal of all conceptuses fell to less than 40 nmol/l by 23.00 h on day 19, approximately 12 h before the decline in intact animals. Maintenance of increased progesterone levels after conceptus removal using silicone tubing implants significantly (P less than 0.05) reduced the peak of the premature prolactin surge to 79.7 +/- 18 micrograms/l at 05.00 h on day 20.(ABSTRACT TRUNCATED AT 250 WORDS)     

On the Role of the Septal Area in the Development of Doca-Salt Hypertension in the Rat

The extensive destruction of forebrain noradrenergic nerve terminals by the intraventricular injection of 250 μg of 6-hydroxy-dopamine prevents the subsequent development of DOCA-salt experimental hypertension in rats while the lesser destruction of noradrenergic nerve terminals produced by 90 μg of 6-hydroxydopa does not. The greatest difference in brain part noradrenaline levels between these two neurotoxins was in the septal area where noradrenaline was less than 15% of controls after 6-hydroxydopamine but was the same as controls after 6-hydroxydopa. The non-specific destruction of the lateral septal area by radiofrequency lesions prevented the subsequent development of DOCA-salt hypertension. The relatively selective destruction of catecholamine nerve terminals in the lateral septal area by the injection of 1 μg 6-hydroxydopamine in 1 μl vehicle also prevented the development of DOCA-salt hypertension. These data suggest that the lateral septal area may be the location of the forebrain catecholaminergic neural activity that is necessary for the development of DOCA-salt experimental hypertension in rats.     

Oxprenolol in the treatment of hypertension in the elderly

Controversy continues to surround the value of drug treatment of hypertension in the elderly. Epidemiologic evidence implicates hypertension as a major risk factor in the precocious development of stroke and coronary heart disease in the elderly subject as clearly as it is implicated in the younger person. The hemodynamic and neuroendocrine profiles of the older patient with essential hypertension are similar to those of younger patients in the stable phase of the disease. However, the arterial ravages induced by many years of sustained hypertension render the circulation of the elderly subject more sensitive to pharmacologic intervention. The benefit-risk ratio of most antihypertensive drugs appears to be inversely related to age. Diuretics reduce the blood pressure at rest but have no influence on the increases in systolic pressure during normal activity; in addition, they carry potentially serious metabolic hazards in the elderly hypertensive patient. Centrally acting drugs likewise lower the blood pressure at rest without influencing the high systolic pressures induced by exercise. They also enhance the tendency to endogenous depression. Adrenergic-neurone blocking drugs and alpha-adrenoceptor antagonists are contraindicated because of the frequency of impaired cardiovascular reflexes in the elderly. The beta-blocking drugs can reduce the risk of coronary and cerebrovascular disease in the older patient with hypertension. They appear to be well tolerated, but because of their impaired metabolic handling in many elderly patients they should probably be used in smaller doses than those prescribed in younger patients. The influence of antihypertensive treatment on cardiovascular morbidity and mortality in the elderly hypertensive patient is not known.     

Prevention of the manifestation of diabetes in the elderly in the presymptomatic stage

Diabetes Mellitus is thought as the presymptomatic stage to cause various vascular diseases. From the point of view that diabetes is already a disease, this paper discusses the prevention of the manifestation of diabetes in the elderly. STOP-NIDDM study demonstrated that acarbose, an alpha-glucosidase inhibitor, reduced the onset of diabetes in impaired glucose tolerance (IGT) subjects by 24%. On the other hand, the Diabetes Prevention Program (DPP) study for IGT subjects revealed that intensive life style intervention prevented diabetes most powerfully by 58% and metformin treatment also reduced by 31%. Furthermore, HOPE, LIFE, and SCOPE studies against hypertension showed that ACI or ARB reduced diabetes by 20-32%, and the WOSCOT study that pravastatin, a HMG-CoA reductase inhibitor, reduced diabetes by 30%. These accumulated results suggest that the most suitable strategy to prevent diabetes in the elderly is intensive life style intervention, and in cases incapable of exercise and diet therapy, acarbose or metformin are recommended for IGT. When associated with hypertension and/or hyperlipidemia, the subjects have to receive ACI or ARB and statins to prevent diabetes.     

Tissue Oxygen Demand in Regulation of the Behavior of the Cells in the Vasculature

The control of arteriolar diameters in microvasculature has been in the focus of studies on mechanisms matching oxygen demand and supply at the tissue level. Functionally, important vascular elements include EC, VSMC, and RBC. Integration of these different cell types into functional units aimed at matching tissue oxygen supply with tissue oxygen demand is only achieved when all these cells can respond to the signals of tissue oxygen demand. Many vasoactive agents that serve as signals of tissue oxygen demand have their receptors on all these types of cells (VSMC, EC, and RBC) implying that there can be a coordinated regulation of their behavior by the tissue oxygen demand. Such functions of RBC as oxygen carrying by Hb, rheology, and release of vasoactive agents are considered. Several common extra‐ and intracellular signaling pathways that link tissue oxygen demand with control of VSMC contractility, EC permeability, and RBC functioning are discussed.     

社区老年高血压自我管理模式效果分析

目的评估社区老年高血压自我管理模式的效果。方法在浦东新区23个街镇中每个街镇各抽取1个老年高血压自我管理小组,对所有组员进行参加课程前后的效果进行问卷调查和血压测量。结果参与课程后,组员自评健康状况明显改善（P〈0．05）,体力活动、对控盐勺、控油壶的使用率、每周测量1次血压的比例均较参与课程前明显增加（P〈0．05）,每天摄入水果蔬菜、口味变清淡的比例较参与课程前增多。自我效能明显提高,收缩压下降了17mmHg,舒张压下降了10mmHg（P〈0．05）。结论对社区老年高血压患者以自我管理的方式进行管理,并针对性地进行行为干预,是控制老年高血压的有效手段。     

孟德尔随机化法在常见老年病病因探索中的应用进展

孟德尔随机化法是在横断面研究数据中通过引入基因型作为暴露因素的工具变量而进行混杂校正的遗传流行病学方法,对无法测量、未知的混杂因素的校正有独特的优势。近年来该方法在老年常见病的病因研究中得到广泛应用且进展较快。本文就此方法原理及其在心血管疾病、2型糖尿病、骨质疏松症、阿尔茨海默病、恶性肿瘤等老年常见病中的应用进展进行综述。     

Chinks in the armor: the role of the nonclinical environment in the transmission of Staphylococcus bacteria

The staphylococci include bacteria species and strains that are capable of causing significant infections in humans. During the past decades, staphylococci, such as methicillin-resistant S aureus (MRSA), have emerged outside the nosocomial settings, spreading in the community and raising public health concerns. However, the full contribution of potential community reservoirs to the changing epidemiology of these pathogens remains largely uncharacterized. Here, it is suggested that the role of animals (pets and livestock) and inanimate surfaces in the dissemination of staphylococci in the community is worthy of investigation and might potentially enhance efforts for controlling Staphylococcus-associated infections in susceptible individuals.     

Problems in the Diagnosis of Diverticulitis in the Young

Five cases of sigmoid diverticulitis in young patients are reported. The difficulty in obtaining preoperative diagnosis in these cases was due primarily to the fact that the diagnosis was not suspected because of their young age. Although diverticula were seen on barium enema in all cases, the "classical radiological pictures of diverticulitis" were not seen in three of the five cases, presumably because of a short duration of the illness. Diverticular disease of the colon in young patients appears to require more aggressive surgical approach in view of the fact that the disease is characterized by recurrent inflammations. These patients are presently followed up carefully with particular reference to recurrence of the disease in the rest of the bowel as they progress into "older age groups". There being no definite measures at present which are known to protect against the development of diverticulitis in the unaffected population, the question naturally arises, "will this group be even more susceptible?".     

美托洛乐治疗老年人高血压

疾病 高血压病。目的 评估美托洛尔治疗高血压的短期疗效和安全性，病人年龄在50—75岁。