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Biomedical subjects

M Pfisterer

Publications and source records attributed to M Pfisterer.

At least 145 records · Page 8Linked to original sources
PubMed1987

Immunogenicity of a hepatitis A virus vaccine.

Hepatitis A virus (HAV) strain HAV/HFS/GBM was adapted to and grown in human diploid fibroblast cells. The HAV was concentrated by ammonium sulphate precipitation and high-speed centrifugation. The virus was inactivated by beta-propiolacton and purified by sedimentation through a 20% solution of sucrose and by CsCl gradient centrifugation. The immunogenicity of different preparations was tested in mice, guinea pigs, and goats. The immune response after vaccination was tested by determination of anti-HAV with RIA and of neutralizing antibodies with an appropriate test system. Results showed that anti-HAV titers of 1:1,000 and greater, as well as neutralizing antibody titers of 1:1,000 and greater, were found in sera of animals vaccinated with different preparations. It became evident that good anti-HAV titers persisted over a period of at least 1.5 years in goats and mice after immunization with a semipurified HAV vaccine, and titers up to 1:200 were present in mice 2 years after vaccination with a highly purified HAV vaccine.

Animals↗
PubMed1987

Acute hemodynamic effects of MDL 19205 in mild congestive heart failure.

MDL 19205 4-ethyl-1-,3-dihydro-5-(4-pyridinylcarbonyl)-2H-imidazol-2-one, a new cardioactive agent, has been shown to increase myocardial contractile force in animals. It is effective by both oral and intravenous routes. We studied 11 patients with congestive heart failure--in 10 cases owing to coronary artery disease, and in one to cardiomyopathy. All patients had symptoms of NYHA class II or III, left ventricular ejection fractions (LVEF) less than 55%, and left ventricular end-diastolic pressures (LVEDP) greater than 15 mm Hg. Following routine coronary angiography and ventriculography, 0.5 mg/kg MDL 19205 was administered intravenously over 5 min to six patients. Thirty minutes after injection, hemodynamic measurements and ventriculography were repeated. Mean LVEF increased from 42 to 49% (p less than 0.05 for baseline vs. 30 min). In five patients ventriculography was repeated 60 min after placebo administration: LVEF decreased from 45 to 40%. LVEDP decreased from 29 +/- 8 to 16 +/- 8 mm Hg after MDL 19205 administration (p less than 0.05) and remained constant at 24 mm Hg in the placebo group. The small although nonsignificant increase of LVdP/dt after MDL 19205 administration (10 +/- 33%), together with a considerable decrease in LVEDP, was consistent with a positive inotropic effect. LVdP/dt/total pressure developed (VPM), a measure of contractility relatively independent of changes in pre- and afterload, increased from 1.0 +/- 0.3 to 1.3 +/- 0.3 s-1 (p less than 0.05). Neither parameter of contractility (LVdP/dt and VPM) changed significantly in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiotonic Agents↗
PubMed1987

Properties of a hepatitis A virus candidate vaccine strain.

This paper describes the biophysical and biochemical properties as well as electron microscopical studies of a candidate hepatitis A vaccine strain propagated in human fibroblast cells. Our results indicated that, in CsCl, the density of hepatitis A virus (HAV) from cell culture supernatant and of HAV extracted from infected cells was influenced by the quantity of lipid material associated with HAV. Antigenicity of untreated HAV, therefore, was detected primarily in low density CsCl fractions (1.11 g/ml, 1.21 g/ml). After lipid reduction with NP40 detergent or chloroform/Genetron, antigenicity and infectivity were primarily detected in high density CsCl fractions (1.31 g/ml). Electron microscopy demonstrated a strong association between membranous material and virus particles of low density in CsCl as well as virus-like particles in ultrathin sections of HAV-infected human fibroblast cells. The uncovered virus particles banded in the 1.31 g/ml dense CsCl fraction lacked lipid material. The s value was 79 for 1.19 g/ml to 1.22 g/ml dense HAV and 147 for 1.29 g/ml to 1.33 g/ml HAV. Autoradiography of the radioiodinated dense HAV revealed some proteins with high Mr (120K to 67K) and others with low Mr (37K to 15K).

Fibroblasts↗
PubMed1986

[Physical performance with rate-responsive pacemakers].

The effects of the new rate-responsive pacemaker Medtronic Activitrax on maximal exercise heart rate and physical work capacity were studied acutely and after two weeks in 10 patients. Compared to the VVI-mode, heart rate increased in activity mode during exercise from 102.1 +/- 29.0 to 115.8 +/- 13.5/min (p less than 0.05). Similarly, physical work capacity increased from 343 +/- 260 to 528 +/- 354 watts X min (p less than 0.02). This effect persisted over 2 weeks. Thus, using rate-responsive pacing a significant improvement in working capacity could be shown in patients with inadequate exercise heart rate.

Aged↗
PubMed1986

Prognostic significance of right ventricular ejection fraction for persistent complex ventricular arrhythmias and/or sudden cardiac death after first myocardial infarction: relation to infarct location, size and left ventricular function.

To assess the prognostic significance of right ventricular dysfunction after a first myocardial infarction for complex ventricular arrhythmias and or sudden cardiac death in relation to infarct location, size and left ventricular function, a series of 127 consecutive patients was prospectively studied and followed up for one year. Prior to hospital discharge, a 24-hour electrocardiographic recording and radionuclide angiocardiography were performed. Right ventricular ejection fraction was related to inferior infarct location and size (r = 0.45, P less than 0.01): similarly left ventricular ejection fraction was related to anterior infarct location and size (r = 0.76, P less than 0.001). The incidence of severe ventricular arrhythmias was significantly higher in patients with isolated right or left ventricular dysfunction compared to patients with normal function; it was highest in patients with severe depression of both ventricles. Patients with complex ventricular arrhythmia and/or sudden cardiac death had significantly reduced left and right ventricular ejection fractions. Detailed analysis in patients with left ventricular ejection fraction greater than 0.40 vs. less than or equal to 0.40 showed that presence of complex ventricular ectopic activity and/or sudden cardiac death after myocardial infarction was related not only to left, but also independently to right ventricular dysfunction. These results imply a significant prognostic contribution of right ventricular dysfunction to the occurrence of severe ventricular arrhythmias and/or sudden cardiac death after myocardial infarction independent of and additive to left ventricular dysfunction.

Adult↗
PubMed1986

Effects of bisoprolol in relation to metoprolol and bufuralol on left ventricular hemodynamics at rest and during exercise in chronic ischemic heart disease.

To assess acute hemodynamic effects of bisoprolol on left ventricular hemodynamics at rest and during exercise, 16 patients with documented chronic ischemic heart disease were studied and compared with patients after administration of metoprolol and bufuralol. Simultaneous right heart catheterization and radionuclide angiocardiography were performed at rest and during exercise before and after drug administration. Bisoprolol was given orally to 16 patients, six receiving 5 mg, and 10 patients receiving 20 mg. Metoprolol was injected intravenously in a dose of 0.15 mg/kg to another 16 patients, and 30 mg bufuralol were given orally to 10 patients. The hemodynamic profiles of all three compounds were similar to that previously described after acute beta-blockade. All three drugs tested and compared showed a marked negative chronotropic effect, while there were slight differences in the negative inotropic and blood pressure lowering effect. Bisoprolol induced only mild negative inotropic changes, which were barely detectable after the 5 mg dose. The negative inotropic changes were more pronounced after metoprolol, and were partly balanced by the vasodilating properties of bufuralol. Thus, bisoprolol showed a significantly reduced rate pressure product with only a relatively mild negative inotropic effect. Based on these observations, even the higher dose of 20 mg bisoprolol seems to be hemodynamically safe for clinical application.

Adrenergic beta-Antagonists↗
PubMed1986

Non-invasive grading of aortic regurgitation by Doppler ultrasonography.

Doppler ultrasound without concomitant echocardiographic imaging was used to grade isolated aortic regurgitation in 21 patients. The severity of aortic regurgitation was subsequently graded (from 0 to IV) angiographically. A 2 MHz continuous wave Doppler transducer was placed over the apex of the heart and the beam was aimed parallel to the mitral flow by means of acoustic guidance. Mitral pressure half time was calculated from the analogue maximum velocity tracing and it was less than or equal to 60 ms in 10 controls; 50-120 ms in five patients with grade II, 120-160 ms in nine patients with grade III, and greater than or equal to 160 ms in seven patients with grade IV aortic regurgitation. These results indicate that a semi-quantitative grading of aortic regurgitation may be obtained non-invasively with non-imaging Doppler ultrasonography in patients without concomitant mitral valve disease.

Adult↗
PubMed1985

[Relation between intraoperative blood flow measurements and graft patency afer aortocoronary bypass surgery].

During aorto-coronary bypass surgery, electromagnetic flow measurements of venous grafts were performed in 50 consecutive patients at rest and after stimulation with papaverine (2 mg) to assess whether early postoperative patency was predictable. The overall patency rate at day 9-11 was 95.4% (145/152 distal grafts; 118 proximal grafts). Flow in all bypass grafts averaged 52.5 +/- 31.4 ml/min and increased after papaverine stimulation by 46.9 +/- 32.2 ml/min (p less than 0.01). 5 of 6 grafts with a flow of less than 30 ml/min and without adequate flow increase after papaverine (less than 80%) were occluded. Grafts with a flow of greater than or equal to 30 ml/min or an increase of greater than or equal to 80% after papaverine, had a high short-time patency rate (98%). Thus, perioperative flow measurements combined with papaverine stimulation predicted early patency of single grafts with an accuracy of 95%.

Coronary Artery Bypass↗
PubMed1985

[Reevaluation of pacemaker-induced reentry tachycardias: incidence, mechanisms and therapy].

To reassess incidence, mechanisms and therapeutic possibilities in the treatment of pacemaker-induced reentry tachycardias (RT) in patients with the second generation of DDD-pacemakers, 35 consecutive patients were studied prospectively by measuring VA conduction at implant and searching for RT clinically and by repeat 24-hour ECG monitoring. Reprogramming to the VVI mode because of atrial flutter and to the AAI mode because of lead displacement was necessary in 2 and 1 of the patients respectively. RT were detected in 7/32 patients (22%), 4 of whom were symptomatic. The triggering mechanism of RT was premature ventricular contraction in 4 patients, premature atrial contractions in 1, loss of atrial sensing in 1, and remained unclear in 1. Unlike the 30% of patients of an earlier consecutive series with first generation of physiologic PM who had RT and required permanent reprogramming to VVI stimulation in 10% of cases, RT was abolished in all patients maintaining physiologic pacing by prolonging the atrial refractory period, shortening the av delay, adjusting atrial output or atrial sensing, or by antiarrhythmic therapy.

Aged↗
PubMed1985

[Risk profile and prognosis after myocardial infarct complicated by ventricular fibrillation].

In a prospective series of 190 patients under the age of 70 with a first myocardial infarction, the risk profile for ischemia, heart function and arrhythmias was investigated at the time of hospital discharge. Fifteen of these 190 patients had had ventricular fibrillation within 24 hours after admission which could be converted into sinus rhythm. In comparison, patients with ventricular fibrillation had a significantly larger infarct as estimated with the thallium-defect score (11.0 +/- 5.8 vs. 7.3 +/- 5.4; p less than 0.02)). In addition, left ventricular ejection fraction at rest was lower, at 42.7 +/- 17.4% compared to 50.0 +/- 14.0, but the p-value reached only 0.07. Persistent arrhythmias and ischemia were not significantly different in the two groups. In the first year after infarction none of these 15 patients died, compared to 8/175 patients.

Adult↗
PubMed1985

Important differences between short- and long-term hemodynamic effects of amiodarone in patients with chronic ischemic heart disease at rest and during ischemia-induced left ventricular dysfunction.

To assess and compare the hemodynamic profile of short-and long-term amiodarone administration in the same set of patients and to investigate hemodynamic mechanisms responsible for the antianginal effect of this drug, 10 patients with documented coronary artery disease and stable angina pectoris were studied. Simultaneous right heart catheterization and equilibrium radionuclide angiocardiography were performed at rest and during exercise before therapy (control), after a 5 minute intravenous infusion of 7.5 mg/kg of amiodarone and after 21.0 +/- 4.3 days of peroral therapy (10 days 800 mg/day, 7 days 400 mg/day and then 200 mg/day). After acute drug administration, ejection fraction, stroke index and systolic blood pressure decreased, whereas heart rate, left and right ventricular filling pressures and systemic vascular resistance increased. These effects were reversed after long-term therapy; all measured values returned to control levels except for heart rate, which decreased below the control value, and right atrial pressure, which remained slightly elevated. Amiodarone drug levels decreased from 4.8 +/- 1.8 after intravenous infusion to 1.2 +/- 0.6 mg/liter after long-term therapy. After adjustment for hemodynamic changes at rest, there were still significant reductions in heart rate, mean arterial pressure and rate-pressure product during exercise. It is concluded that the marked negative inotropic effect of amiodarone administered acutely in the dose applied calls for cautious use of this drug when administered intravenously. In contrast, long-term oral amiodarone therapy seems hemodynamically safe, even in patients with moderately depressed left ventricular function.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1985

Effect of short and long term administration of amiodarone on ischaemia-induced left ventricular dysfunction. Implications for combined antianginal drug therapy.

To asses haemodynamic effects of short and long term amiodarone on ischaemia-induced left ventricular dysfunction and to compare them with those of glyceryl trinitrate (nitroglycerin), beta-blocking and calcium antagonist drugs, 19 patients with chronic ischaemic heart disease were studied. All patients underwent simultaneous right heart catheterisation and equilibrium radionuclide angiocardiography at rest and during symptom-limited supine bicycle exercise. After control measurements without antianginal therapy, 10 patients received 7.5 mg/kg amiodarone intravenously over 5 minutes (short term study) followed by oral administration of amiodarone for 3 weeks (long term study). The remaining 9 patients were studied following the randomised administration of glyceryl trinitrate (0.8 mg sublingually), metoprolol (0.15 mg/kg intravenously) and nifedipine (5 ng/kg/min). During exercise known to provoke angina pectoris without therapy (control study), amiodarone improved myocardial oxygen consumption by reducing heart rate and systolic blood pressure without the negative inotropic effects seen after acute beta-adrenoceptor blockade. Comparisons with the haemodynamic profiles of other antianginal drugs suggest that amiodarone may be most effective when combined with glyceryl trinitrate or nifedipine for the treatment of ischaemic left ventricular dysfunction.

Adult↗
PubMed1985

[Aortocoronary bypass operation in the elderly patient: favorable long-term course].

Age has been identified as an independent risk factor for coronary artery bypass grafting (CABG). We evaluated, therefore, the perioperative phase and long-term prognosis of all patients over the age of 64 (n = 80), who had been operated on for coronary heart disease at the University Hospital of Basel/Switzerland between 1979 and 1983. These elderly subjects were compared to 80 patients, 50 to 60 years old at the time of CABG, who were matched for degree of angina pectoris, coronary artery disease, left ventricular ejection fraction, sex and year of operation (matched-pairs analysis). Evaluation of long-term prognosis was based on regular clinical controls and on a questionnaire, sent to the patients in June 1984. During the perioperative phase 3 patients over 64 died versus 0 in the group of patients 50-60 years old. There were more complications in the older group (perioperative myocardial infarction 10 vs. 4, pulmonary embolism 2 vs. 0, cerebro-vascular insult 4 vs. 0). Three vs. one permanent pacemaker had to be implanted for irreversible AV-block. The difference in hospital stay, 21 vs. 19 days, was not significant. The cumulative survival rate was in both groups 95% after one year and 86 vs. 92% 5 years after CABG (difference not significant), despite the fact that significantly more elderly patients have had myocardial infarction prior to CABG. After an average follow-up of 28 months, 72% vs. 60% were without thoracic pain; 63 vs. 49% considered themselves in a good overall condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1984

[Prosthesis endocarditis--a surgical indication!].

The authors summarize their experience of the management of 26 patients with prosthetic valve endocarditis. Out of 11 patients who did not undergo surgery, 8 were treated medically, with 9 early deaths (mortality 75%). 15 patients were treated surgically with 3 deaths caused by resistant infection (mortality 20%). Prosthetic valve endocarditis remains a dangerous complication of valve replacement, and the authors recommend immediate valve replacement in all patients with infected mechanical valves.

Adolescent↗
PubMed1984

[Incidence and course of complex ventricular arrhythmias in myocardial infarct as a function of infarct size, heart function and persistent ischemia].

Incidence and course of complex ventricular ectopic activity (VEA) after myocardial infarction was prospectively evaluated in 217 patients in relation to infarct size, location, ventricular function and signs of persistent ischemia. Complex VEA (Lown greater than III) was found acutely in 138 patients (63.6%) and at hospital discharge in 42 (19.3%). Of 79 patients with VEA Lown less than or equal to III in the first 24 hours, 93.7% remained VEA-free at follow-up. Patients with persistent complex VEA differed from those who became VEA-free only in left and right ventricular ejection fraction, whereas all the other infarct related factors had no influence on the course of VEA.

Aged↗