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Biomedical subjects

D Brandt

Publications and source records attributed to D Brandt.

At least 73 records · Page 4Linked to original sources
PubMed1977

[Cardiac pacing in tachycardiac arrhythmias].

Cardiac pacing may be useful in the management of supraventricular and ventricular tachycardias. Prophylactically, recurrent ectopic tachycardias may be prevented by atrial or ventricular pacing for a sustained period at a rate faster than the spontaneous rate, but slower than the rate of the tachycardia being suppressed. Moreover, the pacemaker permits the dosage of antiarrhythmic agents to be increased until the recurrent arrhythmias are completely controlled. Therapeutically, supraventricular tachycardias may be terminated by (1) overdrive suppression, (2) delivery of a single stimulus or two serial stimuli or repetitive stimulation at a rate slower than the tachycardia (competitive stimulation) and (3) orthorhythmic stimulation. Today, implantable units exist. Advantages and disadvantages as well as risks of pacing in patients with tachycardias, are discussed.

Electric Stimulation↗
PubMed1976

Studies on immunoglobulins of Xenopus borealis, Xenopus clivii and Xenopus muelleri.

Following immunization with human IgG three species of anuran amphibians, Xenopus borealis, Xenopus clivii and Xenopus muelleri, were found to synthesize two molecular populations of antibodies associated with 19S and 7S fractions of the sera. These antibodies, designated high (HMW) and low (LMW) molecular weight immunoglobulins, were isolated and their constituent heavy (H) and light (L) polypeptide chains separated following extensive reduction and alkylation in a relative yield of about 70% and 30% respectively. The molecular weights of H and L chains of the three species were determined by SDS-acrylamide gel electrophoresis. The L chains from both molecules in the three species had a molecular weight of about 26,000. The H chains of the HMW and LMW immunoglobulins had a molecular weight of about 73,000 and 63,000 respectively. The two populations of immunoglobulins were analysed in immunodiffusion plates using rabbit antisera to LMW immunoglobulins. The HMW immunoglobulins were found to be antigenically deficient with respect to LMW immunoglobulins. From these results it was judged that the two populations in each species belonged to distinct classes. The antigenicities of the LMW and HMW immunoglobulins of different species within the genus Xenopus were compared.

Animals↗
PubMed1976

[Hemodynamic long-term effects of a beta-receptor blockader (Pindolol) in primary essential hypertension].

1. Pindolol lowers blood pressure both, immediately after administration by a reduction of cardiac output and heart rate and after long-term administration by reducing peripheral resistance. Cardiac index, initially decreased, reached the control value after 8 weeks of treatment. 2. The persistent reduction in heart rate and increase of the cardiac index during exercise after prolonged treatment together with the increase of right and left heart filling pressures seems to be due to augmentation of the Starling mechanism. The increase of the stroke volume at rest and during exercise diminished the blood-pressure lowering effect of the drug. 4. The exercise-induced increase of noradrenalin was abolished by acute administration of pindolol. After long-term treatment, however, we found a consistent and significant elevation of the plasma-catecholamines. This may reflect the development of heart failure [1], a tyramin- or cocain-like action of pindolol [2] or an indirect sympathicomimetic effect of this drug at low doses (10--15 mg/day orally ) [3]. 5. The elevation of plasma-noradrenalin reflects increased sympathetic tone and may be responsible for the increase in stroke volume and plasma renin activity observed by several authors. 6. Since there was no evidence for a hemodynamic mode of action, the lowering of blood rpessure by pindolol may be a central effect.

Blood Pressure↗
PubMed1976

[Dynamics and metabolism in coronary heart disease before and after revascularization intervention].

In summary, rapid atrial pacing prior to surgery may be able to assess LVF and the degree of coronary insufficiency by measuring lactate production. Functional contraction abnormalities of the left ventricle are described by the anginal depression of the LVF, whereas a preanginal depression should be a sign of organic, fibrotic impairment of myocardial function. In cases of the former, after successful bypass surgery, a normal LVF may be observed. Moreover, myocardial metabolism is normalised. In the latter group, despite clinical improvement, functional abnormalities can persist.

Blood Pressure↗
PubMed1976

Removal of hepatitis B surface antigen (HBsAg) from plasma fractions.

Endogenous or deliberately added hepatitis B antigen was removed and concentrated for assay from albumin, and from coagulation factor II, VII, IX, and X concentrates as model plasma fractions. The concentrates carry considerable risk of causing hepatitis in transfused patients. The amount of antigen remaining in the fraction was estimated to be less than 1/10,000 of that detectable by the Ausria II radioimmunoassay and 1/100 of that found to be infectious when highly contaminated human sera were diluted and injected in chimpanzees. Batch fractionation methods with polyethylene glycol were used. The yield of albumin was 96 per cent and of the coagulation factors about 90 per cent.

Blood Proteins↗
PubMed1976

[Mitral valve function during frequency stimulation in coronary disease. Echocardiographic and hemodynamic comparative studies].

In 3 controls and 10 patients with coronary heart disease (CHD) and angina pectoris (AP) left ventricular enddiastolic pressure (LVEDP) and pulmonary artery diastolic pressure (PADP) are measured at rest (R) and during right atrial pacing with stepwise increments in heart rate. The values were compared to the simultaneously recorded DE-slope and EF-slope of the mitral valve echocardiogram. The following results could be obtained: 1. In the control group PADP increased sharply at a rate of aobut 120/min, while LVEDP further decreased. This "physiological dysfunction" of the mitral valve could not be detected by echocardiography. 2. In patients with CHD and AP both pressures rose concomitantly with the onset of the angina; moreover, the EF-slope showed a significant reduction. 3. This decrease of the EF-slope is due to an increment of LVEDP during angina and may be used as a diastolic tool, if the exercise electrocardiogram is negative. 4. LVEDP and EF-slope are correlated weil in most patients with CHD. However, there was a lack of correlation between the reduction of the EF-slope and left ventricular function.

Arteriosclerosis↗
PubMed1975

Furuncular myiasis.

We saw two cases of cutaneous myiasis from the larvae of the botfly, Dermatobia hominis. The first patient acquired the disease in Brazil, the second in Guatemala. The appearance is quite similar to furunculosis, but is not responsive to antibiotic therapy. Surgical excision is the treatment of choice.

Adult↗
PubMed1975

[Evaluation of the left ventricular function in patients with coronary disease by means of atrial pacing].

In 18 patients with coronary artery disease and in 12 control subjects, left ventricular function was studied by means of rapid artial pacing. The results were compared with the cardiac dynamics, as determined by left ventricular dysfunction although the angiograms portrayed normal contractility at rest. It has to be assumed, that abnormal myocardial function was only evident during the pacing stress. On the other hand, if the angiogram showed local hypokinesis, the hemodynamic effect of this slightly abnormal contraction could be determined by atrial pacing. Moreover, rapid atrial pacing often produced myocardial ischemia and anginal pain in patients with coronary heart disease. In these cases the transient "anginal" depression of left ventricular function could be separated from the chronic hypoxic "preanginal" dysfunction. This may be of vale in terms of surgical revascularisation.

Adult↗