A detailed physical and genetic map of two R.ColBM IncFIII plasmids.

The cleavage and genetic maps of two closely related R.ColBM IncFIII plasmids, designated pSAS1201 and pSAS1203, are presented. Restriction analysis of both plasmids with SstI, EcoRI, Bg/II, XhoI, HindIII, and Sa/I indicated that the maps of these two plasmids are superimposable with the exception of a 1.

Myocardial hypertrophy and cardiac failure: a complex interrelationship.

The interrelationship between myocardial hypertrophy and myocardial function is a complex one. In patients with essential hypertension, the appearance of left ventricular hypertrophy may be an ominous sign, often presaging the evolution of congestive heart failure. In other settings, such as valvular heart disease, congestive cardiomyopathy, and ischemic heart disease, myocardial hypertrophy serves as a compensatory mechanism in response to excessive loading conditions.

Hemodynamic responses to combined therapy with captopril and hydralazine in patients with severe heart failure.

The hemodynamic benefits and safety of combined therapy with captopril and hydralazine were studied during invasive hemodynamic monitoring in 14 patients with severe heart failure. In eight patients, the individual effects of both drugs were evaluated before the administration of combined therapy, whereas hydralazine was added to maintenance captopril therapy in the other six patients. In the first group, captopril alone produced a marked decrease in pulmonary wedge pressure (28 +/- 4 to 18 +/- 5 mm Hg) and mean arterial pressure (85 +/- 20 to 69 +/- 13 mm Hg) (both p less than 0.

Converting-enzyme inhibitor therapy for chronic heart failure.

In congestive heart failure, acute administration of the converting enzyme inhibitor captopril leads to a decrease in arterial pressure, systemic vascular resistance, left ventricular filling pressure, and the end-diastolic volumes of both ventricles, as well as to an increase in cardiac index, stroke volume index, right and left ventricular ejection fractions. The mechanism of action appears not only attributable to a decrease in angiotensin II but, possibly, may also be accounted for by central and peripheral sympathicolytic effects diminished degradation of bradykinin and an increase in synthesis of vasoactive prostaglandins. During continued treatment with captopril over three months a further decrease in left ventricular filling pressure and an increase in cardiac output can be observed.

Acute and long-term effects of captopril on left and right ventricular volumes and function in chronic heart failure.

To more fully delineate the effects of captopril (CPT) on cardiac size and function in patients with chronic congestive heart failure (CHF), we performed blood pool scintigraphy in conjunction with hemodynamic measurements during the initiation of vasodilator therapy and repeat scintigraphy after 2 and 12 weeks. Measurements of both right and left ventricular volumes and ejection fraction were made before and 90 minutes after the first 25 mg dose of CPT in 14 patients. Overall, heart rate fell modestly, from 82 +/- 10 to 77 +/- 11 bpm (p less than 0.

Acute and long-term effects of captopril on exercise cardiac performance and exercise capacity in congestive heart failure.

Although many studies have shown that captopril (CPT) provides acute hemodynamic improvement in patients with severe congestive heart failure (CHF) at rest, little information is available concerning exercise hemodynamic responses to CPT or the effect of this drug on exercise tolerance in CHF. Therefore, we evaluated the hemodynamic effects of CPT at rest and during upright bicycle exercise in 15 patients with stable CHF. CPT (25 to 50 mg) reduces both resting heart rate and mean arterial pressure (84 +/- 11 to 78 +/- 7 bpm, p less than 0.

Hemodynamic differences between supine and upright exercise in patients with congestive heart failure.

Although the differences in hemodynamic responses to supine and upright exercise have been studied in normal subjects and in patients with angina pectoris, no such comparison has been made in patients with congestive heart failure. Many investigators measure exercise hemodynamics in heart failure patients to assess the effect of vasodilator and inotropic drugs. Both modes of exercise have been used and have often yielded differing results.

Beneficial hemodynamic effects of intravenous diazoxide in refractory congestive heart failure.

Despite the growing popularity of vasodilator therapy for acute and chronic congestive heart failure (CHF), no single agent has been uniformly effective and well tolerated. Therefore, we investigated the acute hemodynamic response to diazoxide, a potent and long-acting arteriolar dilator, in nine patients with severe CHF refractory to conventional treatment and, in seven of nine, other vasodilators. Diazoxide was administered intravenously in successive 300 mg infusions, each over 10 minutes, until a satisfactory response in cardiac and output occurred or a fall in arterial blood pressure or increase in heart rate was noted.

Deleterious effects of hydralazine in patients with pulmonary hypertension.

Thirteen consecutive patients with primary and secondary pulmonary hypertension who had normal left ventricular function were treated with hydralazine in an effort to reduce pulmonary vascular resistance and clinical symptoms. Despite marked decreases in systemic vascular resistance (40 per cent; P less than 0.001), hydralazine produced only moderate decreases in pulmonary arteriolar resistance (21 per cent), without improving stroke volume or pulmonary-artery pressure.

Hemodynamic and radionuclide effects of acute captopril therapy for heart failure: changes in left and right ventricular volumes and function at rest and during exercise.

Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg or oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril.

Comparison of myocardial thallium-201 clearance after maximal and submaximal exercise: implications for diagnosis of coronary disease: concise communication.

Recently the quantitation of regional thallium-201 clearance has been shown to increase the sensitivity of the scintigraphic detection of coronary disease. Although TI-201 clearance rates might be expected to vary with the degree of exercise, this relationship has not been explored. We therefore evaluated the rate of decrease in myocardial TI-201 activity following maximal and submaximal stress in seven normal subjects and 21 patients with chest pain, using the seven-pinhole tomographic reconstruction technique.

Radionuclide measurement of left ventricular volume: comparison of geometric and counts-based methods.

Radionuclide measurements of left ventricular volume were determined in 20 patients by geometric and nongeometric, counts-based techniques using data from first-pass and equilibrium blood pool scintigraphy. Two geometric analytic approaches were used: directly measured long and short axes and the area-length method. Each approach was applied to the single-plane right anterior oblique images obtained by the first-pass technique and to biplane data, using the right anterior oblique first-pass and left anterior oblique blood pool data together.

Acute and long-term effects of captopril on exercise cardiac performance and exercise capacity in congestive heart failure.

Although in many studies patients in heart failure treated with captopril have shown acute haemodynamic improvement at rest, little information is available about the haemodynamic response to captopril during exercise or about its effect on exercise tolerance. Haemodynamic measurements were taken at rest and during upright bicycle exercise before and during the first two days of captopril treatment in 15 patients with stable congestive heart failure. At rest, the heart rate and mean arterial pressure both declined (84 ± 11 to 78 ± 7 beats/min ( < 0.

Antihypertensive therapy with prazosin in patients with left ventricular dysfunction. Improvement in cardiac performance and exercise tolerance.

Although the relationship between blood pressure and cardiac performance has been widely recognized, there are few published clinical observations concerning the effect of blood pressure control on cardiac function. We evaluated the effect of prazosin, an antihypertensive agent which also improves hemodynamic measurements in normotensive patients with heart failure, in 16 patients with moderate hypertension and reduced ejection fractions. Therapy with digoxin and diuretics was continued throughout the study, but other antihypertensive agents were withdrawn at least one week prior to the initiation of the study.

Acute and long-term effects of vasodilator therapy on resting and exercise hemodynamics and exercise tolerance.

The acute hemodynamic response to vasodilators in patients with chronic heart failure has been well characterized, but less is known about the long-term hemodynamic effects of vasodilator therapy. We measured hemodynamic variables at rest and during upright exercise in 11 patients during the initiation of therapy with oral hydralazine and sublingual isosorbide dinitrate and, in eight of these, after 3 months of continuous treatment. Marked initial increases in resting cardiac output and stroke volume and reductions in wedge pressure were sustained during chronic therapy.

Suspected epidemiological relationships among strains of Escherichia coli O55:B5 confirmed by restriction pattern analysis of the carried plasmid (RColBM IncFIII).

Seven strains of Escherichia coli O55:B5g, isolated from independent cases of infantile diarrhoea, contained similar RColBM plasmids beloning to incompatibility group IncFIII. Suspecting an epidemiological link among all these cases we compared the restriction pattern of the corresponding RColBM plasmids after digestion with endonucleases EcoRI and BglII. These patterns were similar, confirming the suspected relationships among the seven cases of infantile diarrhoea.

Primary oxalosis with pan-conduction cardiac disease: electrophysiologic and anatomic correlation.

A 27-year-old man with primary oxalosis and extensive visceral involvement was maintained on long-term chronic hemodialysis. He had an episode of presyncope associated with electrocardiographic findings of an erratic atrial rhythm, atrioventricular dissociation due to an accelerated junctional rhythm and right bundle branch block. Electrophysiologic studies showed irregular atrial depolarizations probably associated with multiple atrial pacemakers, atrial inexcitability, atrioventricular dissociation and infranodal conduction delay.

Contrast enhancement of thallium-201 myocardial scintigrams: improved sensitivity with diminished specificity in coronary disease detection.

Thallium-201 myocardial scintigraphy (TMS) has become an increasingly popular noninvasive technique with a high diagnostic specificity, but a somewhat lower sensitivity for coronary disease (CAD) detection. Many centers now routinely employ computer techniques to contrast enhance scintigrams, but the resulting changes in sensitivity and specificity have not been carefully evaluated. In the present study, three observers with different levels of experience blindly interpreted both unprocessed and enhanced exercise TMS from 40 patients with CAD and from 15 without significant obstructions.

Electrophysiologic effects on combined autonomic blockade in patients with sinus node disease.

Thirty-two patients were studied before and after i.v. administration of 0.

Vasodilator treatment with isosorbide dinitrate and hydralazine in chronic heart failure.

Several reports have suggested that because isosorbide dinitrate and hydralazine have different and additive haemodynamic effects at rest in patients with chronic heart failure, these agents should be administered in combination. Some studies, however, indicate thay they are effective individually as well. Since most patients with heart failure are symptomatic only with activity, we examined the haemodynamic effects of these drugs given individually and in combination, at rest and during upright bicycle exercise.

Postural hypotension and tachycardia during hydralazine--isosorbide dinitrate therapy for chronic heart failure.

Supine and upright hemodynamic measurements were performed in 10 patients with chronic congestive heart failure, before and during vasodilator therapy with hydralazine and isosorbide dinitrate. This combination of drugs produced significant improvement in supine hemodynamic measurements, with the pulmonary capillary wedge pressure decreasing from 26 +/- 5 to 18 +/- 5 mm Hg (mean +/- SD, p less than 0.01) and stroke volume index increasing from 25 +/- 6 to 39 +/- 6 ml/m2 (p less than 0.