Diagnosis of tricuspid regurgitation. Current status

The most accepted diagnostic methods of tricuspid regurgitation (TR) are the physical examinations and the evaluation of right atrial pressure. However, these methods are not consistently diagnostic, and a "silent" form of TR has been recognized. The current status of noninvasive and invasive diagnostic techniques is reviewed.     

冠状动脉生物可降解支架的研究现状

【】随着老年化的进展,冠心病成为威胁人类生命的重要杀手。随着血管介入的不断发展,冠心病的诊治水平达到新的突破。但是金属裸支架长期存留会导致血管内再狭窄的发生。生物可降解支架的出现是必然的趋势,本文通过概述生物可降解支架的目前临床试验、发展历程,指出当前各种支架所面临的问题,并对其未来进行展望。     

Current hepatitis A status in Canada.

Hepatitis A, caused by the hepatitis A virus, occurs most frequently in developing countries, but also causes sporadic cases or outbreaks in industrialized countries. The most common route of transmission is fecal-oral. The incidence of hepatitis A varies with geography, and economic and environmental conditions. The epidemiological pattern of the disease has changed with improvements in hygiene and economic conditions. The incidence and prevalence of hepatitis A has decreased, while the average age of exposure and subsequent infection has increased. The present report describes the current status of hepatitis A in Canada. The incidence rate of reported cases in Canada varies from over 10/100,000 (1991) to 3.6/100,000 (1998), and is higher in males, 4.7/100,000 (1998), than in females, 2.5/100,000 (1998). The highest reported hepatitis A rates are in age groups 30 to 39 years and 40 to 59 years, and in British Columbia. Such information is important for assessing current immunization approaches and for decision-making about new preventive strategies against hepatitis A in Canada.     

Labetalol. Current research and therapeutic status

Labetalol hydrochloride is the prototype drug of a new class of antihypertensive agents that competitively and peripherally blocks both beta- and alpha-adrenergic receptors. It possesses approximately one fourth of the beta-blocking activity of propranolol hydrochloride and one half of the alpha-blocking activity of phentolamine. In humans, the effective beta- to alpha-blocking activity is approximately 7:1. It has been used successfully in oral form to treat patients with mild, moderate, and severe hypertension and in intravenous form to manage hypertensive emergencies. Prominent side effects include orthostatic hypotension and gastrointestinal disturbances. Overall, the drug appears to offer several advantages over pure beta-blocking drugs in some patients and should expand the armamentarium of the practicing physician in the management of the difficult hypertensive patient.     

老年医学的现状和展望

人口老龄化是一个普遍的、前所未有的全球现象,这种趋势在21世纪还会持续。中国的人口老龄化状态将对中国社会、经济发展产生重大影响。文章介绍了老年医学的定义、目的和主要任务,同时回顾了中国老年医学的发展历程,阐述了老年医学的范畴;展望了老年医学工作者在未来应对中国的人口老龄化巨大挑战措施和策略。     

Current status of non-digitalis positive inotropic drugs.

Considerable effort and resources have been directed at the development and study of positive inotropic drugs over the past 10-15 years. Much has been learned about the physiology and pharmacology of myocardial contraction, the application of agents to augment contractility, and, importantly, the general and specific limitations of positive inotropic therapy. Studies on acute inotropic intervention have now shown that a drug's ability to augment overall cardiac performance is heavily dependent on its effects on vasculature, vascular control, and ventricular-vascular coupling. The clinical research on new agents has served to remind us how difficult it is to formulate the "ideal" positive inotropic or cardiovascular support drug for the critical care setting. The vast effort to develop a chronically and orally administrable drug to replace or even supplement digitalis has generally been disappointing. The dopaminergic agents (e.g., ibopamine, levodopa) act primarily via vasodilation and their effectiveness and role in managing heart failure remain unresolved. The initial excitement about the phosphodiesterase III inhibitors (e.g., amrinone, milrinone, enoximone) has been tempered by the results of large well-designed trials indicating variable effectiveness and a prominent adverse effect profile. During long-term oral administration none of these agents has been shown to improve clinical status or exercise capacity beyond that achieved by digoxin, when administered either separately or in combination with digoxin. The Prospective Randomized Milrinone Survival Evaluation (PROMISE) trial, showing that repeated oral administration of milrinone can increase mortality in heart failure, is having a devastating effect on the further development of this class of drugs.(ABSTRACT TRUNCATED AT 250 WORDS)