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Biomedical subjects

W Greil

Publications and source records attributed to W Greil.

80 records · Page 5Linked to original sources
PubMed1976

Nuclease digestion in between and within nucleosomes.

In the course of digestions of rat liver nuclei with micrococcal nuclease the size of the nucleosomal DNA is shortened by 50-60 nucleotide pairs from starting lengths of about 200, 400, 600, 800, etc. nucleotide pairs in the monomeric and oligomeric nucleosomes, respectively. Acid soluble DNA material is created relatively slowly as compared to the rate of formation of subnucleosomal material. More DNA with lengths in between the 200, 400, etc. nucleotide pairs of nucleosomal DNA is formed when digestions with micrococcal nuclease are carried out at 0 to 10 degrees C compared to 40 degrees C. With DNAase II, on the other hand, formation of a 200 nucleotide pair pattern is favoured at the low temperatures. Apparently, the accessibility of potential cleavage sites in between and within nucleosomes depends strongly on the conditions of digestion. Possible reasons for this dependence are discussed.

Animals↗
PubMed1976

[Direct quantitative measurement of tremor: first results of a new mesuring procedure in patients under lithium therapy].

The use of a new piezoresistive minature accelerometer as part of an electronic measurement system for the direct quantification of human finger tremor in physical units is described. The system was designed to yield digital values for the mean tremor amplitude in a given period of time. Reliability coefficients were computed for a smaple of 34 patients under lithium therapy. Coefficients ranged between 0.75 and 0.94 for test-retest intervals between 30 min and several days. Some of the usual indirect methods for the assessment of tremor showed very low correlations to the true tremor amplitude and seemed to be only of limited usefulness. It was further demonstrated that situational factors play a dominant role independently of the particular method of measurement.

Fingers↗
PubMed1976

[The distribution of lithium between erythrocytes and plasma: in vitro studies on the transport of lithium in human erythrocytes].

Distribution ratiors of intracellular lithium (Lii) and extracellular Li (Lie) were determined in vitro after incubation of Li-free or Li-loaded red cells in media containing varying Li-concentrations (37 degrees C, pH 7.4). The distribution ratios Lii/Lie obtained in vitro after 24 h of incubation corresponded to those found in vivo. The results indicate that Li can be extruded from red cells against an electrochemical gradient. This Li extrusion is inhibited by replacing extracellular Na+ with K+ or choline+, but is not affected by ouabain or by glucose depletion.

Biological Transport, Active↗
PubMed1975

[Biochemical action mechanisms and pharmacokinetics of psychoactive drugs].

A short review is given on the effects of antidepressant drugs (tricyclic thymoleptics and MAO inhibitors), neuroleptics and lithium salts on catecholamine and serotonin metabolisms in brain. The second part deals with some pharmacokinetic investigations with these psychotropic drugs. In connection with tricyclic thymoleptics some factors influencing steady-state plasma concentration and their relation to the therapeutic effect are discussed. Furthermore, recent investigations into the pharmacokinetics of lithium salts are dealt with.

Animals↗
PubMedDate not supplied

Effects of the beta-adrenoceptor blocking agent sotalol on CNS: sleep, EEG, and psychophysiological parameters.

Sotalol (Sotalex), 320 or 960 mg, was administered to 12 healthy subjects daily for a period of four days in a double-blind trial over 11 days. The effects of sotalol on heart rate, blood pressure, EEG, subjective quality of sleep, polygraphically determined sleep pattern, and psychophysiological parameters such as psychomotor performance, memory, perception, vigilance, and general condition were studied and were related to dosage and plasma levels. Steady-state plasma levels of sotalol were reached within 24 hours after a single dose; 960 mg resulted in plasma levels three times higher than those reached with 320 mg, which indicates first-order linear absorption. The effects of sotalol on EEG, sleep, and performance in psychological tests were equivocal and do not yield evidence for CNS activity of sotalol.

Adolescent↗