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Biomedical subjects

H Seidel

Publications and source records attributed to H Seidel.

At least 91 records · Page 5Linked to original sources
PubMed1986

Investigations of the time series structure of the EMG during sustained isometric contractions of back muscles.

The experiment aimed at elucidating electromyographic signs of fatigue of lumbar muscles. On two days, 4 subjects had to hold 4 different target forces to fatigue. Bipolar surface EMG's were derived at the L3 level. The time series structure of the EMG's was characterized by means of autoregressive models. The r.m.s.- value did not reveal uniform time-dependent changes, except for an increase during the highest force level. The variance explained by a linear stochastic process systematically increased during the sustained contractions. The mean power frequencies exhibited similar changes.

Adult↗
PubMed1985

[Biometric analysis of hybrid fishes from experimental populations. I. Interpretation of morphological characteristics and quantification of their variability].

Variability of 8 meristic and 27 morphometric characters in 4 groups of laboratory-reared fishes have been studied. There were 2 parental groups of Barbus conchonius and Barbus sp. respectively and 2 groups of their hybrids from reciprocal crossings. Evaluation of individual characters' variability was made by using of univariate statistics including the coefficient of variation, in each group. Relation between hybrids and parental species based on hybridity quotient showed that there was no form of hybrids accurately intermediate in any evaluated character. There were found some differences between reciprocal crosses in number and configuration of the characters. By these differences, they are more related to one parental species or to the second one, respectively.

Animals↗
PubMed1983

[Comparative circulatory studies during implantation of total endoprostheses using methylmethacrylate and BDF cement].

In every ten patients undergoing elective surgery for total hip prosthesis methylmethacrylate and BDF cement respectively were used for the implantation of the prosthesis. The results of the haemodynamic investigation demonstrate that improvement of the surgical procedure may reduce the incidence of haemodynamic parameters: After implantation of methylmethacrylate into the femoral shaft the arterial pressure decreased from 95.9 +/- 13 to 86 +/- 11 torr (P less than 0.05); the left ventricular stroke work index dropped from 49.9 +/- 5 to 42.1 +/- 7 g.m/m2 (P less than 0.01). While total peripheral resistance decreased slightly in the methylmethacrylate group, there was a small increase after implantation of BDF cement into the femoral shaft. In both groups, however we found a slight elevation of pulmonary vascular resistance after cement implantation into the femur. The determination of the serum concentration of the cement monomer did not yield any measurable serum concentrations. Heat production by polymerisation of BDF cement (maximum 45.8 +/- 6.5 Centigrade) was much less compared with the temperature which developed during the polymerisation of methylmethacrylate (maximum 63 +/- 16.4 Centigrade); therefore, the safety of clinical application seems to be greater with the new BDF cement.

Aged↗
PubMed1983

[Immunomodulation with symptomatically effective antirheumatic agents].

As antigen-presenting and/or monokine-secreting cells, macrophages play a major role in immunoregulation. Proteases of macrophage origin (cathepsin G, elestase , thrypsin and pronase) act on cell surfaces of different cell lines, inducing cell activation, e.g. of B-lymphocytes. T-lymphocytes might be stimulated by the activating factor LAF. Other macrophage products (CSF, FIM ) control monocyte production in bone marrow. While lymphocytes are the target cell lines for classical immunosuppressive agents, mononuclear phagocytes are kept for the major cell population affected by antiinflammatory drugs. The presented study outlines the significance of the mononuclear-phagocyte-system in antiinflammatory drug research. The inhibiting potency of antiinflammatory drugs on the monocyte-macrophage cell line as an additional immunoregulatory principle should be discussed.

Animals↗
PubMed1983

[Immunomodulation by symptomaticly active antirheumatic agents].

As antigen-presenting and/or monokine-secreting cells, macrophages play a major role in immunoregulation. Proteases of macrophage origin (cathepsin G, elestase, thrypsin and pronase) act on cell surfaces of different cell lines, inducing cell activation, e.g. of B-lymphocytes. T-lymphocytes might be stimulated by the activating factor LAF. Other macrophage products (CSF, FIM) control monocyte production in bone marrow. While lymphocytes are the target cell lines for classical immunosuppressive agents, mononuclear phagocytes are kept for the major cell population affected by antiinflammatory drugs. The presented study outlines the significance of the mononuclear-phagocytesystem in antiinflammatory drug research. The inhibiting potency of antiinflammatory drugs on the monocyte-macrophage cell line as an additional immunoregulatory principle should be discussed.

Animals↗
PubMed1983

[Variability of quantitative markers of irradiated and non-irradiated fish from experimental populations. II. Changes in the values of some quantitative markers in relation to body length].

The influences of a single rtg irradiation dose (14 mGy) on some quantitative signs in dependence on the body length was studied in the experimental fishes Barbus conchonius and B. tetrazona. The values of all followed signs increased positively due to the body length growth. The irradiation with the abovementioned dose in the given conditions had relative small influence on the growth course of the chosen quantitative sign values in the control and irradiated fishes of both species is the same (the regression lines are in good agreement, resp. they are parallel). The statistically significant difference was stated only between the irradiated the non-irradiated groups of B. tetrazona due to the head height (the regression lines are divergent).

Animals↗
PubMed1983

The quinidine-digoxin interaction in patients with impaired renal function.

Quinidine has been reported to reduce clearance and the distribution volume of digoxin. Data are presented indicating that serum digoxin concentration (SDC) is increased throughout the coadministration of quinidine. This strongly suggests that the quinidine-induced reduction of digoxin clearance is the main mechanism underlying this drug interaction. It has been suggested that beside renal clearance quinidine also reduces non-renal clearance of digoxin. Direct evidence is provided by a study in patients with impaired renal function. Irrespective of the degree of renal impairment, quinidine increases SDC to about the same amount as found in patients with normal renal function. Since quinidine does not interfere with plasma protein binding of digoxin, this implies a decrease in non-renal clearance. In all patient groups the incidence of this drug interaction is rather high; however, pronounced interindividual differences occur as regards the extent of the increase in SDC. Regardless of the state of renal function careful monitoring of digitalized patients is mandatory once quinidine therapy is initiated. Since it may take a week or more until a new steady state is established in patients with impaired renal function, this period of close monitoring should be extended correspondingly.

Blood Proteins↗
PubMed1982

[Experiences with the Rostock artificial heart].

A totally artificial heart--the Rostock totally artificial heart (Rostock TAH) was implanted in calves. We can give the following deductions after 27 examinations: -- The Rostock TAH was tested successfully in endurance test about 7 months; it show no sign of wear. -- The surgical technique of the implantation was standardised and a successful experimentation is possible. -- The longest survival time was 15 days. The hemodynamic early results were very good in 3 other animals. -- Modifications of the Rostock TAH were taken up relating to the dimensions of the artificial ventriculi and by mounting a screw cap for avoiding an air embolism. -- Adaption tests in the corpse show that the present form of the artificial heart is not ideal for a possible application in man. -- The problem is still existing in developing a suitable drive system locates intrathoracically. The present drive and control system on a pneumatic base is qualified only for the animal experiment but not for a possible application in man.

Anesthesia, General↗
PubMed1982

[Variability of the quantitative characteristics in irradiated and non-irradiated fishes from experimental populations. I. Biometric basic characteristics and a comparison of irradiated and non-irradiated groups].

The variability of 35 morphological singns in fishes Barbus conchonius and B. tetrazona from experimental breeding under defined conditions was studied. The experimental groups were irradiated with a single rtg-dose 14.355 mGy. chi 2-test and t-test were used for the statistical evaluation. Statistically significant differences between the irradiated and non-irradiated groups were stated at B. conchonius to be only in the head height, the scale number under the side line, and in almost all plastic signs (with exception of the tail fin and the distance between the nostrils). The differences of most signs were determined on the 1-%-significance level.

Animals↗
PubMed1981

[The penetration of moxalactam into bone (author's transl)].

After injection of 2 g of moxalactam over 5 minutes in 8 patients with mean age of 71,5 years, serum halflife was found to be T 50% beta = 184 min and the volume of distribution at steady state VDSS = 17,45l, whereas these figures in volunteers with mean age of 22.8 years were T 50% beta = 134 min and VDSS 16,80l respectively. The concentrations in organic bone were 30 to 60 min after injection of 2 g of Moxalactam 19,40 mg/l with a deviation factor of 1,43 and 61 to 120 min after injection 19,08 mg/l with a deviation factor of 1,16. The problems of penetration of antibiotics into bone are discussed. Moxalactam does not penetrate into anorganic bone (hydroxylapatite).

Aged↗