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Biomedical subjects

J Schmidt

Publications and source records attributed to J Schmidt.

At least 757 records · Page 42Linked to original sources
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

Monoclonal antibody against a membrane antigen characterizing leukemic human B-lymphocytes.

In the diagnosis of non-Hodgkin's lymphomas, the ready characterization of the neoplastic cell lineage by analysis of cell surface markers is of great importance. We present evidence for the existence of a human B-leukemia-associated antigen recognized by a complement-fixing monoclonal antibody (anti-Y 29/55). A hybridoma was produced by fusing mouse myeloma cells and splenocytes of a mouse immunized against lymphoid cells of a patient with B-cell chronic lymphocytic leukemia. Characterization of anti-Y 29/55-reactive normal and malignant leukocytes was demonstrated by cytolysis and indirect immunofluorescence. This revealed reactivity with an antigen on B-lymphoma cells (11 patients), on leukemic lymphocytes in B-cell chronic lymphocytic leukemia (13 patients), and on malignant cells in hairy-cell leukemia (two patients) but not on leukemic cells of T-cell acute lymphoblastic leukemia (one patient), on T-lymphoma cells (one patient), on cells of acute myeloblastic leukemia (four patients), or of chronic myeloid leukemia (four patients). No specific cytolysis occurred with B- and T-peripheral blood lymphocytes from (a) healthy donors (16 individuals), (b) patient with reactive lymphocytosis (one patient), (c) nonleukemic multiple myeloma (six patients), or (d) Hodgkin's disease (three patients). Surface immunoglobulin-positive, sheep RBC-negative lymphocytes isolated from human spleen (three individuals), tonsils (seven individuals), and lymph nodes (one individual), however, were recognized. It is concluded that leukemic B-cells carry a marker characteristic of nonrecirculating sessile B-lymphocytes.

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

[Analysis of methods for optimizing lysozyme determination].

In order to optimize the detection of lysozyme in the clinic, studies on photometric and agar diffusion methods were performed with different preparations of micrococcus luteus (lysodeikticus). Living or living lyophilized preparations of micrococcus were suitable. The influence of temperature, test period and lysozyme concentration on the result was demonstrated. The lysoplate technique has several advantages in clinical routine tests, however an exact adjustment of the reagents and the test is necessary (living micrococcus, 3 hours incubation, 50 degrees C test temperature). The lysozyme measurements of different papers are transferable not without reserve and require a careful interpretation in respect of reproducibility and clinical relevance.

Animals↗
PubMed1982

Relation between Na+-K+-ATPase activity and dopamine release from rat striatum slices.

Ouabain inhibits potassium induced dopamine release in a competitive manner. On the other hand, amphetamine induced release is facilitated. In dependence on the stimulus power used, the electrically evoked release is reduced by ouabain. Thus, cardiac glycosides represent an appropriate tool for differentiating pools and processes involved in transmitter release, controlled by Na+-K+ ATPase activity.

Animals↗
PubMed1982

[Retrovirus activating potential of nuclear polyhedrosis viruses in mammalian cell cultures].

Activation of endogenous C-type retroviruses by nuclear polyhedrosis viruses (NPV) was investigated in "in vitro" cell culture systems of four mammalian species: mouse, rat, monkey and man. Cells were treated with NPV, (isolated from larvae and insect cell cultures), NPV-DNA, C-type virus-activating chemicals (halogenated pyrimidine analogue) and chemical insecticides alone and in combination. C-type retroviruses were activated only in mouse cells and transformed rat cells by the halogenated pyrimidine analogue. In NPV-treated cell cultures no C-type retrovirus activation was detectable. In simultaneous treatments of the cells with nuclear polyhedrosis viruses and chemicals no potentiating effects by the NPV could be detected. Virions of NPV in cell cultures showed unaltered morphology and upon reisolation were infectious in homologous insect cell cultures for a long time. No influence upon growth or morphology of the treated mammalian cells could be observed. From our experiments we conclude that the application of nuclear polyhedrosis viruses for pest control is uncritical with respect to their retrovirus activating potential in mammalian cells.

Animals↗
PubMed1982

[Effect of nootropic drugs on the dopamine release and dopamine uptake in structures of the rat striatum].

Nootropics increase the overflow of dopamine from rat striatum slices in a concentration dependent manner, but without relation to their clinical effectiveness. The influence of a nootropic drugs and of amphetamine on the stimulus induced dopamine release points to a relationship between nootropic and nooanaleptic activity, on the one hand, and transmitter release, on the other. Dopamine re-uptake is not altered by nootropics like piracetam.

Animals↗
PubMed1982

Sodium flux and lipid spectrum in the erythrocyte membrane in essential hypertension.

In the erythrocyte membranes of normotensive individuals and patients with essential hypertension, sodium flux behavior, cholesterol content, phospholipid spectrum, and the fatty acid composition of the phospholipids were measured. There was no difference between normotensives and hypertensives in sodium influx in the erythrocyte. In both groups, 1 microM norepinephrine resulted in a significantly equal increase of sodium influx after an incubation period of 15 min. Compared with normotensives, erythrocytes in essential hypertensive patients showed a decreased sodium efflux. The cholesterol/phospholipid quotient of the erythrocyte membrane of hypertensive subjects increased in comparison with that of normotensive individuals. No differences between the two groups were found in the phospholipid pattern and in the fatty acid composition of phosphatidylserine/-inositol, -choline, and sphingomyelin. However, in phosphatidylethanolamine of the erythrocyte membrane in essential hypertensives in contrast to normals, a decreased content of the fatty acid fraction 22:0/20:3 and in increased content of the fatty acid fraction of 20:5/22:2/22:3 was found. The dependence of the Na turnover on the lipid spectrum of the erythrocyte membrane is discussed. The altered lipid composition of the erythrocyte membrane in essential hypertensives does not seem to cause the altered Na efflux behavior.

Adult↗
PubMed1982

Inhibitory effects of hypoxia on dopamine release.

Behavioral and neurochemical results refer to an impairment of the dopaminergic system produced by hypoxia. On that account we determined the chemically (K+, amphetamine) and electrically stimulated release of dopamine from rat striatum slices which were preloaded with labeled dopamine following the animals' exposure to hypobaric hypoxia. The effect of hypoxia consists in a marked inhibition of dopamine release depending both on the degree of hypoxia and on the kind of stimuli used. Dopamine release inhibition reflects not only the direct effect of hypoxia, which seems to be connected especially with the vesicular compartment, but also adaption and restitution processes. Regarding the effects on rats at the age of two weeks the resistance of young animals against hypoxia may be founded also upon missing vesicular mechanisms of distinct vulnerability.

Animals↗
PubMed1982

The effect of piracetam on posthypoxic dopamine release inhibition.

Subsequently to a hypoxic exposure of adult rats the stimulus induced release of dopamine from striatum slices in inhibited for several days. Depending on the treatment with piracetam the restitution of this inhibition is accelerated manifold, though piracetam does not prevent the acute effect of hypoxia on dopamine release. The particular hypoxia related vulnerability of the potassium evoked dopamine release and the time course of piracetam effect obviously point to drug induced anabolic processes rebuilding vesicle storage sites.

Amphetamine↗
PubMed1982

[Type III shortrib-polydactyly syndrome (Verma-Naumoff) in concomitance with ectodermal dysplasia (author's transl)].

Reported in this paper is a case of shortrib-polydactyly syndrome in a stillborn male infant. The case was identified as Type III (Verma-Naumoff) on account of typical skeletal findings, such as very short ribs, micromelia, postaxial hexadactyly of all extremities, and shortened cranial base, with due consideration being also given, in that context, to characteristic radiographic and histological changes, including metaphysial spurs of long cylindrical bones. Malformations were recorded also from kidneys, ureters, small intestine, and pancreas.--Thin downy head-hair, missing eyebrows, precocious dentition, as well as partial hypoplasia and aplasia of nails were interpreted as signs of ectodermal dysplasia.--Shortrib-polydactyly syndrome is based on autosomal recessive inheritance. Early genetic advice should be offered to parents. Systematic prenatal diagnosis is necessary in case of another pregnancy.

Abnormalities, Multiple↗
PubMed1981

[Intravaginal treatment of colpitis maculosa with an oestriol-containing vaginal cream (author's transl)].

43 patients with colpitis maculosa (average age 60.2 years) were selected for an open control therapeutic study with Ortho-Gynest vaginal cream (Ortho-Cilag). The cream contains 0.5 mg of oestriol per single applicator filling. The treatment lasted from 3 to 4 weeks, success being evaluated by clinical documentation and cytological evaluation of vaginal smears before and after treatment. 10 patients (23.3%) were treated successfully, 29 (67.4%) showed a distinct improvement both clinically and cytologically, whilst the remaining 4 (9.3%) showed only moderate improvement. Hence, 39 patients (90.7%) were classified as having been successfully or partly successfully treated. Severe symptoms disappeared completely or were greatly alleviated in 91.4% cases. Moderate symptoms vanished in 59.7%. 58.1% showed a complete normalisation of the former atrophic vaginal skin. Blood spotting and reddening of the vaginal wall vanished completely. A change from dry to moist vagina occurred in 77.3% patients. Discharge vanished completely in 80.6% cases. No untoward side effects were recorded.

Administration, Topical↗
PubMed1981

Mechanistic studies on fatty acyl-CoA dehydrogenase.

It has previously been shown that the "partial" reaction between fatty acyl-CoA dehydrogenase and acyl-CoA substrate is pH-dependent (larger rate constants at basic pH) and shows a biphasic rate profile indicative of formation of an initial charge transfer complex between the C-2 anion of substrate and enzyme. The present investigation indicates that the complete reaction between acyl-CoA and electron transfer flavoprotein shows a pH profile dependent upon ionization of a single basic group with pKa = 7.7. these facts are consistent with electron transfer which occurs through an obligatory charge transfer complex between the C-2 anion of substrate and oxidized FAD at the enzyme active site. The anion of acetoacetyl-CoA forms a charge transfer complex with enzyme which serves as a model for the putative catalytically active complex mentioned above. Resonance Raman investigation of this acetoacetyl-CoA-enzyme complex indicates that the 1586 cm-1 band is coupled strongly to the charge transfer electronic transition. Since this vibrational band is associated with vC=N at N-5, C-4a of the flavin ring, we suggest that electron transfer takes place at this site.

Acyl Coenzyme A↗
PubMed1981

Phosphatidate as a molecular link between depolarization and neurotransmitter release in the brain.

Phosphatidate, a neuronal phospholipid, stimulated the uptake of calcium by nerve terminals isolated from the striatum of rat brain. This effect was not produced by other phospholipids or glycolipids. Phosphatidate, but not other phospholipids, evoked the release of [3H] dopamine from striatal synaptosomes. The magnitude of both effects was similar to that observed after chemical depolarization of the nerve terminals. These results show that phosphatidate is the only membrane lipid component that acts as a functionally competent ionophore and support the suggestion that phosphatidate may serve as a link between depolarization and neurotransmitter release in the brain.

Animals↗
PubMed1981

Production of hybridomas secreting monoclonal antibodies to the human leukocyte interferons.

Thirteen monoclonal antibodies to human leukocyte interferon have been obtained. They exhibit different patterns of binding to purified leukocyte interferon species that are consistent with the structural multiplicity of the human leukocyte interferons. These antibodies will be useful as probes into the structure of the human leukocyte interferons, for their purification, and for rapid assay of leukocyte interferon.

Animals↗