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Biomedical subjects

K Steinbach

Publications and source records attributed to K Steinbach.

At least 91 records · Page 5Linked to original sources
PubMed1976

[The effect of dihydroegotamine and propanolol on acute orthostasis (author's transl)].

10 Patients with positive orthostatic dysregulation were investigated with regard to venous capacity, heart frequency and arterial blood pressure both lying down and sitting up. The venous capacity was reduced by 14% after dehydroergotamine (DHE) in the lying position, which is an expression of increased venous tone. There is no change in venous capacity following the administration of beta blockers in the lying position. Under orthostatic conditions beta blockers bring about an approximate normalization of the venous capacity reaction, whereas the abnormal response following placebo administration is only slightly altered by DHE.

Adult↗
PubMed1976

Studies on the toxicology of hexachlorobenzene. II. Identification and determination of metabolites.

Female rats were dosed intraperitoneally with 14C-hexaxhlorobenzene. The drug was administered on 2 or 3 occasions. The total doses amounted to 260 and 390 mg/kg 14C-hexachlorobenzene, respectively. Urine and feces from the animals were collected over a period of 4 weeks after the first injection. Both excreta and some tissues of the animals were examined for their content of radioactivity and for hexachlorobenzene and its metabolites. Gas chromatography, isotope dilution analysis, and combined gas chromatography-mass spectrometry were used to identify the metabolites of hexachlorobenzene. In urine pentachlorophenol, tetrachlorohydroquinone, and pentachlorothiophenol were present as major metabolites. One of the isomers of tetrachlorothiophenol was present as a minor metabolite. In the feces pentachlorophenol and pentachlorothiophenol only were identified. At the end of the experiment, carbon-14 excreted with urine and feces amounted to 7% and 27%, respectively, of the radioactivity administered. More than 90% of carbon-14 excreted in urine was contained in the major metabolites. In the feces about 30% of the excreted radioactivity was bound to metabolites and about 70% was contained in the unchanged drug, while in the tissues of the animals only pentachlorophenol was detected in measurable amounts, accounting for 10% of label in blood and less than 0.1% of carbon-14 determined in body fat. Total radioactivity contained in the metabolites detected in the animal body and in the excreta at the end of the experiment accounted for about 16% of the administered radioactivity.

Animals↗
PubMed1976

[Reduction of impulse duration for saving energy in pacemaker therapy].

The application of pacemakers with a impulse duration of 0.5 msec depends on the knowledge of the upper limit of the threshold, expressed in terms of current (rheobase). Follow-up studies in patients, where the implantation of the system was performed in two sessions, revealed a rheobase of 3.6 mA as the upper limit with the specified electrode system. Pacemakers with a impulse duration of 0.5 msec primarily offer themselves for the first implantation in connection with low surface electrodes, or for pacemaker replacement.

Aged↗
PubMed1975

[Follow-up study of patients implanted with a pulse width controlled pacemaker (author's transl)].

The output of a pacemaker system can be adapted to the individual need of the patient by means of a pulse width controlled pacemaker. The achievement of an optimum pacemaker impulse reduces the energy drain, therby allowing a prolongation of adequate functioning of the implanted pacemaker for up to 5 years. Follow-up studies demonstrate the reliability of a pulse width controlled system. The energy drain, measured in microcoulombs, is lower in all patients implanted with impulse width controlled pacer system as compared with output controlled pacer system.

Aged↗
PubMed1975

[Long-term results in pacemaker therapy].

The range of age, life expectancy and problems of functional control in pacemaker patients, are reported. The results demonstrate the dependability of pacemaker treatment, provided that there is an adequate functional control. The life expectancy, in comparison with total population, was found to be similar.

Adolescent↗