Ouabain amplifies contractile responses to phenylephrine in rat tail arteries in hypertension.

Ouabain, a cardiac glycoside, binds to the alpha-subunits of Na+, K(+)-ATPase and inhibits Na+ pump activity. It has been proposed that endogenous ouabain, by inhibiting vascular Na+, K(+)-ATPase, can increase vascular resistance and thus may contribute to hypertension. One of the consequences of inhibition of the membrane Na+ pump is enhanced responsiveness of vascular smooth muscle to vasopressor substances.

Changes in collagen content in the residual myocardium surviving after infarction in rats. Influence of propranolol or hydralazine therapy.

The changes occurring in the collagen content in the residual myocardium after infarction have been poorly studied. The aim of this study was to determine the changes in the collagen content in the right and left ventricular muscle of chronically infarcted hearts. Male albino rats were submitted to ligature of the left coronary artery to produce infarction (Inf).

Analysis of right and left ventricular performance of the rat heart with chronic myocardial infarction.

1. The rat heart develops a compensatory hypertrophy after infarction which is secondary to volume overload in the left ventricle (LV) and to pressure overload in the right ventricle (RV). This study was undertaken to determine whether the reduced inotropic response to Ca2+ presented by the LV of infarcted rats extends to the RV and whether this hemodynamic profile in vivo affects the contractile performance of the ventricles assessed in vitro.

The International Red Cross and Red Crescent Movement and lessons from its experience of war surgery.

This article describes the evolution, motivation and structure of the International Red Cross and Red Crescent Movement, and its contribution to international humanitarian law. It explains the respective roles of its three components: the National Societies, the International Federation of Red Cross and Red Crescent Societies, and the International Committee of the Red Cross (ICRC). It highlights the ICRC's experience of war surgery and emphasises the relevance of this for the military medical services, especially for the training of military surgeons and anaesthetists.

Mercury effects on the contractile activity of isolated heart muscle.

The toxic effects of HgCl2 (1, 2.5, 5, and 10 microM) were studied in isolated, isometrically contracting rat papillary muscles and frog ventricular strips. In rat papillary muscles 1 microM Hg2+ produced a small increase in the force of contraction.

Antibiotic irrigation and conservative surgery for major aortic graft infection.

Purpose: Traditional surgical treatment for panprosthetic aortic graft infection entails radical excision of the graft, aortic stump closure, and extraanatomic revascularization of the lower limbs. This carries an early mortality rate of 24% to 45%. Amputation rates range from 11% to 37%.

Influence of the sarcoplasmic reticulum on the inotropic responses of the rat myocardium resulting from changes in rate and rhythm.

1. The role of the sarcoplasmic reticulum (SR) in the inotropic responses produced by changes in stimulation rate and rhythm and resting tension was investigated in the rat myocardium. 2.

Effects of isoproterenol on the mechanical activity of isolated papillary muscles and perfused rat hearts in various calcium concentrations.

The aim of the study was to examine, in papillary muscles and in a whole heart preparation, the effects of isoproterenol on the myocardial mechanical activity at different extracellular Ca2+ concentrations. Papillary muscles from left ventricles, contracting isometrically, and rat hearts perfused by the Langendorff technique developing isovolumetric pressure at a fixed rate (200 bpm) and diastolic pressure of 5 mmHg were studied at different Ca2+ concentrations for analysis of the effects of increasing doses of isoproterenol. Papillary muscles were treated with isoproterenol (0.

Time-dependent changes of left ventricular contractility in Langendorff perfused hearts from renovascular hypertensive rats.

1. The contractile activity of the hypertrophied myocardium was investigated in Langendorff perfused hearts from one-kidney one-clip (1K1C) renovascular hypertensive rats. 2.

Influence of chronic captopril therapy on the mechanical performance of the infarcted rat heart.

The influence of angiotensin converting enzyme inhibition of hemodynamic changes, development of postinfarction myocardial hypertrophy and left ventricular performance was studied in rats. Infarction was produced under ether anaesthesia by ligature of the descending anterior branches of the left coronary artery. Control rats were submitted to a sham surgery.

Effects of aluminum on the mechanical and electrical activity of the Langendorff-perfused rat heart.

The effect of aluminum (Al3+) chloride (1, 5, 10, 50 and 100 microM) on myocardial electromechanical activity was studied in 10 Langendorff-perfused hearts from adult female Wistar rats. Al3+ decreased the development of isovolumic systolic pressure from 34.3 +/- 2.

Necrotising fasciitis of the leg as a complication of ischiorectal abscess.

This case report describes the rare complication of necrotising fasciitis of the right thigh and calf after drainage of an ischiorectal abscess. The important early symptoms and signs of this life threatening infection, and the need for urgent treatment with aggressive surgical debridement and broad spectrum antibiotics, are emphasised in order to facilitate early recognition and prompt initiation of the appropriate therapy in future cases.

The centenary of the sinking of the Mediterranean Fleet flagship, HMS Victoria. What was the role of Malta fever?

This article commemorates the centenary of the tragic loss of the battleship HMS Victoria and 358 of her crew, together with the Commander-in-Chief of the Mediterranean Fleet, Vice-Admiral Sir George Tryon, as a result of an enigmatic order by Tryon himself. It also investigates the medical aspects and explores the contention that Tryon was suffering from Malta or Mediterranean fever (Brucellosis).

Introduction of a partial shift system for house officers in a teaching hospital.

Objectives: (1) To introduce a partial shift system to reduce the hours of work of preregistration house surgeons to an average of 64 a week to comply with the New Deal for junior doctors; (2) to test linking the partial shift concept to an existing structure of "on call" firms.

Design: Formal assessment after three months of a pilot partial shift system for eight house surgeons on three firms instituted on 1 November 1991, followed by questionnaire and interview evaluation at three and six months of a revised system implemented on 1 February 1992.

Setting: Department of general surgery at St Bartholomew's Hospital, London.

The corps disease: brucellosis and its historical association with the Royal Army Medical Corps.

Brucellosis (also known as Malta, Mediterranean or Undulant Fever) has aptly been nicknamed the Corps Disease because of the major role played by the Royal Army Medical Corps in elucidating its nature and discovering its mode of spread, thus leading to its prevention and eradication. This history of brucellosis, incorporating a complete bibliography of all references to the disease in the Journal of the Royal Army Medical Corps from 1903 to 1992, documents the fascinating story of this association.

Activation of the Langendorff perfused rat heart depolarized by increased external potassium concentration.

Myocardial activation under depolarized conditions was studied in spontaneously beating Langendorff perfused hearts from albino rats. Depolarization was obtained by increasing external potassium concentration in steps (5.4, 7.

Effects of mercury on the contractility of isolated rat cardiac muscle.

The effects of increasing concentrations of mercury (Hg2+) chloride (1, 2.5, 5 and 10 microM) were studied on isometrically contracting papillary muscles from female rats (Wistar, EPM strain) weighing 150 to 180 g. Hg2+ promoted an increase of 12.

Propranolol reduces myocardial hypertrophy in the right cardiac chambers after infarction in rats.

The effects of chronic propranolol (Prop) therapy on the postinfarction myocardial hypertrophy of infarcted rats were studied by histological techniques. Male albino rats were submitted to left coronary artery ligation to produce infarction or to sham surgery (Con, N = 6). Infarcted rats (Inf) were divided into 2 groups receiving Prop (2.

Effects of mercury on the mechanical and electrical activity of the Langendorff-perfused rat heart.

The effects of increasing concentrations of mercury (Hg2+) chloride (0.5, 1, 2 and 10 microM) on the myocardial electromechanical activity were studied on 10 Langendorff-perfused rat hearts. Hg2+ decreased the development of isovolumic systolic pressure from 20.

Electromechanical effects of urea on the isolated rat heart.

1. Langendorff-perfused isolated hearts and left ventricle papillary muscles from 3-month-old albino rats of both sexes were studied before and after a 30-min treatment with 17 mM urea added to the medium, a concentration equivalent to a plasma level of 100 mg/dl. To determine whether the effects observed after the addition of urea were produced by an increase in tonicity, the study was repeated using 17 mM sucrose.

Mechanisms underlying the genesis of post-rest contractions in cardiac muscle.

1. Post-rest potentiation reflects basic cellular mechanisms that control cardiac muscle contraction. Transmembrane calcium influx, the Na+/Ca2+ exchange and the function of intracellular stores that liberate activator calcium upon activation are some of the mechanisms involved.

Cardiovascular effects on conscious rats of pretreatment with isoproterenol for 3 days.

The cardiovascular effect of isoproterenol pretreatment (ISO) mimicking short duration sympathetic hyperactivity was studied in conscious adult male albino rats. Cardiac hypertrophy of right and left ventricles was observed after pretreatment with isoproterenol for 3 days (0.1 mg/kg, 3 times a day), when compared to saline-treated rats.

[Effects of sympathetic block on post-infarction cardiac hypertrophy and their impact on myocardial contractility].

Purpose: To investigate the effects of chronic subcutaneous administration of reserpine (Res) or propranolol (Prop) on the postinfarction myocardial hypertrophy and the effects of Prop treatment on myocardial contractility in rats.

Methods: Male albino rats (3-month-old) were submitted to left coronary artery ligation to produce myocardial infarction. Rats submitted to a sham-operation were used as controls.

Time-course effects of sinoaortic denervation on contractile state of the rat myocardium.

Sinoaortic baroreceptor denervation (SAD) in the rat immediately produces hypertension and tachycardia, as the result of an increased sympathetic tone to the heart and resistance vessels. Adaptive processes are then installed, changing according to the duration of the SAD. In this work we studied the time course of adaptive changes occurring in the rat heart within a 30-day period.