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Biomedical subjects

S Schmidt

Publications and source records attributed to S Schmidt.

At least 469 records · Page 26Linked to original sources
PubMed1983

Changes in activities of fucokinase and fucosyltransferase in rat hippocampus after acquisition of a brightness discrimination reaction.

Activities of enzymes involved in utilization of the glycoprotein precursor L-fucose (fucokinase and fucosyltransferase) were studied in rat hippocampal tissue after acquisition of a brightness discrimination reaction. Fucokinase activity was increased immediately after training, while fucosyltransferase revealed decreased values. However, 7 hr after training fucokinase activity showed normal values, while fucosyltransferase activity rose in trained animals over active and passive controls. The results are discussed in the light of a regulatory role that fucokinase and fucosyltransferase may play in fucose utilization under altered functional conditions.

Animals↗
PubMed1983

[Transcutaneously measured carbon dioxide partial pressure in non-hypoxic fetuses during labor].

Using the newly developed Severinghaus electrode we performed measurements of the transcutaneous carbon dioxide partial pressure (tcPco2) in 81 non-hypoxic fetuses during labor. The calibration and measuring temperature was 39 degrees C. After a correction with a factor of 13% the transcutaneous Pco2 values corresponded well with the blood values of the Pco2 from FBA respectively the umbilical artery. While during the first stage of labor we found only a gradual rise in the tcPco2 level, we observed a rapid rise at the end of the second stage. Analysing the influence of clinical factors on the fetal tcPco2 level we found statistically significant higher levels during the first stage of labor in primipara compared with multipara. However there was no significant difference dependent on gestational age, the age of the mother and the birthweight.

Birth Weight↗
PubMed1983

Renal functional and metabolic studies on the role of preventive measures in experimental acute ischemic renal failure.

In the present study 1 h of total occlusion of the left renal artery in conscious rats was chosen as experimental model of ischemic acute renal failure (ARF), while the contralateral kidney was left intact. Chronic high dietary sodium intake, acute isotonic saline infusion, or administration of saralasin did not protect from ARF. Furosemide, mannitol, and verapamil converted oliguric into non-oliguric ARF in 100%, 75%, and 60% of the animals, resp. Protection from oliguria and preservation of GFR inversely correlated with the depression of cortical ATP-concentration (control: 1.32 +/- 0.07 mumoles/g wet weight) 6 h after ischemia by 16%, 41%, and 58% in mannitol- and verapamil- treated rats and in untreated rats, resp. At this time, Na-K-ATPase enzyme activities in renal cortex and papilla were unaffected, while enzyme activity in outer medulla was suppressed from 15.4 +/- 1.4 to 9.4 +/- 1.0 mumoles Pi/mg protein h in all groups of animals. The results suggest that in this model of ARF renal ischemia not only affects cellular energy supply in renal cortex but also causes severe structural and functional impairment in the outer medulla, probably leading to tubular obstruction and depression of glomerular function. Pharmacological protection from ischemic oliguric ARF cannot be achieved by prior induction of high urine flow rates alone but depends on the degree of metabolic and functional reserve of the injured tubular epithelium.

Acute Kidney Injury↗
PubMed1982

Mechanisms of dopamine induced changes in hippocampal glycoprotein metabolism.

In rat hippocampal slices incubated in the presence of dopamine, a relatively strong correlation was observed between changes in the incorporation of 3H-fucose into total proteins and the formation of GDP-3H-fucose. However, in hippocampal homogenate the incorporation of 14C-fucose from GDP-14C-fucose was not stimulated by dopamine. In contrast, the incorporation of 3H-fucose was stimulated by dopamine to a similar extent observed in hippocampal slices. Furthermore, in hippocampal slices dopamine did not increase the activity of fucosyltransferase. These results, together with our previous findings, suggest that the increased incorporation of fucose induced by dopamine in the hippocampal slices may be due to a receptor-mediated cAMP-dependent regulation, which controls the rate of fucosylation of acceptor-glycoproteins either at the level of fucose phosphorylation or of formation of GDP-fucose rather than the activity of fucosyltransferase.

Animals↗
PubMed1982

E-rosette forming cells and humoral antibody titres in humans after vaccination with three different inactivated influenza virus vaccines A/USSR/92/77 (H1N1).

The number of E-rosette forming cells and the serum haemagglutination inhibition (HI) antibody titres were examined in 37 volunteers immediately before and 14, 28, 35 and 63 days after immunization with three inactivated influenza virus vaccines A/USSR/92/77 (H1N1)--NIB 6 and in 11 non-vaccinated controls. From the former, 10 volunteers were immunized with 1000 haemagglutinin (HA) IU per dose, 11 volunteers with the NIB 6 adsorbate vaccine (340 HA IU/dose) and 16 volunteers with a bivalent vaccine composed of 180 HA IU/dose NIB 6 and 180 HA IU/dose of influenza virus A/Bangkok X-73 (H3N2). The percentage of E-rosette forming cells was decreased in all vaccinated volunteers 14 days after vaccination; later on the values reached normal level of non-vaccinated controls or of subjects before vaccination. The number of E-rosette forming cells was in correlation with the applied virus vaccine dose, i.e. for the 1000 HA IU/dose: 29.95 +/- 11.74%, p less than 0.001 and for the 340 HA IU/dose: 47.75 +/- 11.15%, p less than 0.005; however, after administration of 180 HA IU/dose of NIB 6 in the bivalent vaccine, the value 58.65 +/- 11.5% was not significantly decreased in comparison to non-vaccinated donors. The serum HI antibody titres reached the highest level 14 days after vaccination and remained constant during the next 6 weeks. There was a correlation between decreased E-rosette values and increased serum antibody titres (p less than 0.05). The current study indicates that the number of E-rosette forming cells may serve as a further laboratory criterion for controlling the effect of inactivated influenza virus vaccines on the immune system of man.

Adolescent↗
PubMed1982

[Reaction of influenza viruses with thymus-dependent lymphocytes].

Apart from the humoral immune response against influenza viruses recent years much attention has focussed on problems of cell-mediated immunity. The most important cell-mediated immune reactions of humans and experimental animals against influenza viruses and the most used in-vitro-assays were reviewed in the present paper. Especially the specificity of these reactions against the surface antigens of influenza viruses, hemagglutinin and neuraminidase was presented. A lot of open questions in the field of the cellular immune defense against influenza viruses were also shown.

Animals↗
PubMed1982

[Morphologic and biochemical characterization of the Islets of Langerhans of C57BL/KsJ-mice treated with glibenclamid and glucose].

From the findings of our investigations can be concluded that after long-lasting in vivo gifts of glibenclamid and glucose a decrease of the glucose-induced secretion of insulin in the B-cells of the islets of Langerhans is resulting. After strong experimental stimulation during the existence of an abnormal metabolic situation the synthesis of insulin had not been disturbed and there were also no clear signs of exhaustion of the activity in the islets. Probably, biosynthesis of insulin is coming off only more quickly and is inducing a reduction of insulin already in the cell itself (according to the increased occurrence of lysosomes). The changed production of insulin which can be detected biochemically is, in some conditions, resulting from a temporally disturbance of the mechanism of secretion in the B-cells.

Animals↗
PubMed1982

[A new ECG electrode concept for the conduction of fetal heart action potentials without penetration of the skin].

Internal cardiotocography is an important method for reliable supervision of the fetus during labor. The main task is the prevention of fetal hypoxia. However, there is a considerable disadvantage as the electrodes used penetrate the fetal skin, creating a possible entry point for organisms. The concept we have developed forms a new way of decreasing the risk of infection during labor by conducting the fetal heart rate potentials without penetrating the skin. The electrode is fixed to the skin of the presenting part by tissue adhesive and electrical contact between the fetal skin and the wire of the electrode is established through using electrolyte fluid.

Electrocardiography↗
PubMed1982

Health Maintenance Organizations and the McCarran-Ferguson Act.

In the past, Health Maintenance Organizations (HMOs) were victims of anticompetitive practices, but the growth of HMOs casts them as potential growth encouraged by both the federal and state governments. This Note discusses a solution to the potential antitrust problems. HMOs can be exempt partially from antitrust regulation by the McCarran-Ferguson Act. To secure immunity under McCarran-Ferguson, the entity must function in the business of insurance, be regulated by the state, but not be engaged in acts of boycott, coercion, or intimidation. This Note sets forth potential antitrust violations by HMOs, examining the possible application of the McCarran-Ferguson exemption to them. Each of the elements required to satisfy McCarran is discussed in general and applied to HMOs. This Note concludes that the exemption can be applied to HMOs so long as their conduct fulfills the requirements of the McCarran Act.

Economic Competition↗
PubMed1981

Biosynthesis of somatostatin in pancreatic islets of Wistar rats and its regulation by glucose.

Pancreatic islets of Wistar rats incorporate L-[3H]-phenylalanine into proteins which react after gentle trypsination with a specific somatostatin antiserum. These somatostatin-like peptides were separated by gel chromatography and found to be a 3.5 kilodalton peptide, a peptide co-eluating with somatostatin (1.7 kd) and a low molecular weight peptide (1.0 kd). The biosynthesis of somatostatin may be regulated by glucose. The highest incorporation rate was measured in islets isolated from fasted rats and incubated in low glucose concentration.

Animals↗
PubMed1981

Secretion and biosynthesis of (pro)insulin by pancreatic islets isolated from fetuses of normal and diabetic women.

Insulin secretion, biosynthesis and content of isolated pancreatic islets prepared for fetuses of nondiabetic or insulin-dependent diabetic women were investigated in vitro. Glucose failed to stimulate the hormone release during an incubation period of 60 min in islets of fetuses from non-diabetic women. Prolongation of the glucose exposure or the addition of theophylline resulted in a significantly enhanced insulin release. The islets isolated from fetuses of insulin-dependent mothers are glucose-sensitive with respect to hormone release and biosynthesis. The results demonstrated that the human fetal B-cell is glucose-sensitive after glucose exposure. The differences between the islets of fetuses of nondiabetic and diabetic women are discussed as a response to the fetal plasma glucose levels.

Diabetes Mellitus↗
PubMed1981

[External version of fetus from breech to vertex presentation near term under tocolysis (author's transl)].

Between 10th May 1974 and 31st June 1980, 12960 births were registered at the Maternity Hospital, Neukölln; in 508 patients 536 (3,9%) external versions of the fetus from breech to vertex presentation near term were performed under tocolysis; of these 53% were successful. The incidence of births with breech presentation and/or transverse presentation could be reduced from 5.4% to 3.7% after the introduction of external version. Whilst the localization of the placenta did not influence the success to a great extent, the number of successful versions increased with advancing parity. No fetal death was caused by the version in 508 patients (536 attempted versions). In 11 attempted versions complications occurred in the form of early partial separation of the placenta and/or umbilical cord presentation. Experience and a more circumspect approach led to a definite decrease in the number of complications. As a result of our findings - and bearing in mind the contraindications and observance of safety measures - the external version can be recommended as a simple method of reducing the risk to infant and mother in the treatment of breech presentations.

Breech Presentation↗