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Biomedical subjects

K Bachmann

Publications and source records attributed to K Bachmann.

At least 181 records · Page 10Linked to original sources
PubMed1982

Warfarin binding to plasma of workers exposed to toluene diisocyanate.

The extent of [14]C-warfarin binding to plasma proteins was evaluated in a group of normal, healthy volunteers and in two groups of individuals occupationally exposed to toluene diisocyanate (TDI). Plasma binding was assessed by ultrafiltration after the addition of racemic [14]C-warfarin to a final concentration of 0.8 microgram/ml. Chronic occupational exposure to TDI did not affect the extent of warfarin binding since warfarin free fractions (normalized to an albumin concentration of 4.5 g/dl) were 1.09 +/- 0.23 (mean +/- SD), 0.98 +/- 0.19, and 0.97 +/- 0.15 for controls and the two groups of TDI-exposed individuals, respectively.

Adult↗
PubMed1981

A frog with highly evolved sex chromosomes.

Highly differentiated ZZ/ZW sex chromosomes and an exceptionally low genome size were found in the karyotypes of Pyxicephalus adspersus (Anura, Ranidae). The W-chromosome is considerably smaller than the Z-chromosome and consists to a very great proportion of constitutive heterochromatin. The DNA content of this species and the chromosome length have the lowest values determined in the Ranidae to date.

Animals↗
PubMed1981

Radiotelemetry of direct blood pressure measurements in the arterial and pulmonary circulation.

Radiotelemetry of direct blood pressure measurements in the arterial and pulmonary circulation is assessed in most practical situations of everyday life and sport activities. Comparison of radiotelemetric data with values estimated by practitioners, students and doctors of internal medicine demonstrates a general underestimation of everyday physical and emotional stress, whereas car driving is heavily overestimated. A wide difference is also found in swimming, isometric exercise and the cold phase of the sauna bath.

Aerospace Medicine↗
PubMed1981

Ambulatory monitoring of arterial blood pressure. Comparison between blood pressure measurements obtained with the Remler M 2000 portable recorder and by radiotelemetry under laboratory conditions and during everyday activities.

Simultaneous indirect and direct arterial blood pressure measurements were performed with a Remler M 2000 (RM) portable recorder and by radiotelemetry (RT) in 21 subjects under various conditions such as rest in the supine position and in an 80 degree upright position on a tilting table, during bicycle ergometry, physical exercise on the terrain and under the emotional stress of driving a car. There is a good correlation between semiautomatic pressure measurements carried out with the RM portable recorder and radiotelemetric data. The differences observed are basically due to the auscultation method. But the RM has an advantage over the auscultation method in that it objectively registers the Korotkov sounds and records them on a tape, not only under laboratory conditions but also during everyday activities.

Activities of Daily Living↗
PubMed1981

Radiotelemetry of direct blood pressure.

With radiotelemetry either systemic arterial pressure or pulmonary artery pressure or both simultaneously can be measured, which allows testing of all groups of patients with cardiovascular diseases. The telemetry system also allows simultaneous assessment of ECG, which in patients with arrhythmias reveals the hemodynamic effects of ectopic beats. For radiotelemetry of blood pressure the microcatheter (Leadercath system) is introduced by a modified Seldinger technique into the brachial or femoral artery. The pressure transducer (Statham type P 23 and SP 37) is mounted extracorporeally as close as possible to the right atrium.

Blood Pressure↗
PubMed1981

Comparison of radiotelemetry of blood pressure and standard exercise tests.

The response of blood pressure, heart rate and systolic rate-pressure-product was investigated in healthy subjects during normal everyday and sports activities. In patients with coronary heart diseases the validity of different types of exercise tests was investigated during cross-country walking. The results are described in detail, leading to a number of clinically useful conclusions, e.g., that the body position and type of muscle work play an important role in the hemodynamic response, both in healthy persons and coronary patients.

Adult↗
PubMed1980

[Surgical treatment of aneurysm of the left ventricle. Prognostic considerations].

174 cardiac aneurysms were resected between 1970 and 1977. In 49 patients the remaining contractile segment was revascularised at the same time. The hospital mortality was 10.3%, the late mortality was 14%. The uncorrected cumulative survival rate calculated by the actuarial method was 90% at 3 years (84--96), and 80% at 5 years (74--85). Results were excellent or good in two thirds of the survivors; 44% were free of angina pectoris, 40% were improved, 73% had no disturbances of cardiac rhythm, and in 15% they were improved. Comparison of the pre- and post-operative ejection fraction showed that the indication for surgery of a cardiac aneurysm exists when more than 20% of the musculature of the left ventricle is affected, when the total ejection fraction is larger than 10% when one vessel is affected, and more than 30% when more than one vessel is affected. Contraindications are diffuse coronary heart disease, when ejection fraction of the contractile segment is less than 30%, reduction in contractility of the ventricular septum, and the generally applicable surgical contraindications.

Adult↗
PubMed1980

Effects of urea on hexobarbital and antipyrine disposition in rats.

Hexobarbital sleep times, antipyrine-induced temperature depression, in vitro hexobarbital metabolism, and antipyrine half-life were measured in rats receiving either saline or urea pretreatments. Urea pretreatment slows hexobarbital metabolsim and prolongs hexobarbital sleep times. Urea pretreatment als shortens the duration of antipyrine-induced temperature depression as well as the half-life of antipyrine. Urea appears to contribute to the changes in drug metabolism which have been reported for nephrectomized rats, and may also contribute to aberrations of drug metabolism accompanying uremia in man.

Animals↗
PubMed1979

[Surgical treatment of left ventricular aneurysm (author's transl)].

174 cardiac aneurysms were resected between 1970 and 1977. In 49 patients the remaining contractile segment was revascularised at the same time. The hospital mortality was 10.3%, the late mortality was 14%. The uncorrected cumulative survival rate calculated by the acturial method was 90% at 3 years (84--96), and 80% at 5 years (74--85). Results were excellent or good in two thirds of the survivors; 44% were free of angina pectoris, 40% were improved, 73% had no disturbances of cardiac rhythm, and in 15% they were improved. Comparison of the pre- and postoperative ejection fraction showed that the indication for surgery of a cardiac aneurysm exists when more than 20% of the musculature of the left ventricle is affected, when the total ejection fraction is larger than 10% when one vessel is affected, and more than 30% when more than one vessel is affected. Contraindications are diffuse coronary heart disease, when ejection fraction of the contractile segment is less than 30% reduction in contractility of the ventricular septum, and the generally applicable surgical contraindications.

Adult↗
PubMed1979

Computer analysis of Feulgen hydrolysis kinetics.

A least squares fit of Feulgen hydrolysis time curves to the Bateman function is performed using an especially adapted parameter transformation together with a standard conjugate gradients iteration procedure. The method has been applied to a large number of measured data, and the use and limits of the computer evaluation are discussed.

Animals↗
PubMed1979

Smoking and warfarin disposition.

Nine cigarette smokers ingested an average daily 0.032 mg/kg dose of sodium warfarin for 2 wk while continuing to smoke and for an additional 2 wk after having abstained from cigarette smoking for a month washout phase. Steady-state plasma levels of warfarin, clearances, t 1/2, apparent volumes of distribution, steady-state prothrombin times, and plasma thiocyanate levels were measured during both the smoking and nonsmoking phases. During the nonsmoking phase there was a 13% increase in average steady-state warfarin level and a 13% decrease in warfarin clearance rate. There also was a 23% increase in warfarin t 1/2 and an 11% increase in the apparent volume of distribution. Prothrombin time did not change. Thiocyanate levels were 3 to 4 times as high during the smoking than the nonsmoking phase. It appears that cigarette smoking does affect warfarin clearance, t 1/2, and apparent volume of distribution, though the net effect on warfarin's pharmacodynamic activity is negligible, at least at doses which are ineffective therapeutically.

Adult↗
PubMed1979

Tissue binding of warfarin.

The binding of C-14 warfarin to liver, kidney, and skeletal muscle was evaluated among rats ranging in age from 29 to 832 days. Binding extensiveness was greatest for liver and least for skeletal muscle. The mean fraction bound remained relatively constant for each tissue among animals of all but the oldest age group. The oldest animals exhibited a lower fraction bound in each tissue. The influence of decreased tissue binding on its temporal profile in the blood is discussed.

Aging↗
PubMed1979

Repetitive DNA and Feulgen hydrolysis kinetics in three species of Bufo.

Two North American species of the genus Bufo (Bufo cognatus and Bufo boreas, 2n = 22) and one African species (Bufo regularis, 2n = 20) were analyzed with respect to their repetitive DNA fractions and the behaviour of their chromatin to the acid hydrolysis at different times. The mean melting point of the total isolated DNA decreased from 89 degrees C to 87 degrees C with a genome size increase from 4.4 to 7.5 pg. The differences in genome size can only partly be explained on the basis of repetitive DNA fractions (renaturing up to Cot 10 in 0.12 M phosphate buffer). Several fractions in this repetitive range behave independently in the three species and the spectrum of repetitive fractions in the African Bufo regularis differs distinctly from those of the American toads. When fixed chromatin of these species in histochemical preparations is hydrolyzed with 5N HCl during the Feulgen reaction, the kinetics of depurination are equal in all species, while hydrolytic DNA breakdown proceeds distinctly more slowly in Bufo reularis as compared to the other species.

Animals↗