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Biomedical subjects

W Hartmann

Publications and source records attributed to W Hartmann.

At least 55 records · Page 3Linked to original sources
PubMed1989

Evaluation of "major genes" affecting disease resistance in poultry in respect to their potential for commercial breeding.

The evaluation of "major genes" is an essential step before their commercial utilization and transfer into a breeding population is considered. Of particular importance is, whether the effects of a "major gene" are independent of the genetic background into which it is introduced. This aspect has been investigated in respect to "major genes" affecting disease resistance in poultry. One of these controls genetic resistance to Leukosis virus (ALV) infection. Such infections have a negative effect on egg production and can result in increased mortality from causes other than Leukosis. The other "major gene" concerns B blood groups - genetic markers of the major histocompatibility complex (MHC) of the fowl - which influence resistance to Marek's disease. The effects of these major genes on egg production and/or viability were studied in three Leghorn lines of different origin and in crossbred combinations of these lines. For either of the "major genes", significant interactions with genetic characteristics of lines have been found which might induce changes of their effects on performance traits in different purebred and crossbred populations. To ignore this, could lead to false decisions when evaluating the potential benefit of known "major genes" for genetic improvement of economic merit. From the point of view of practical poultry breeding, "major genes" need to be evaluated on the basis of the effects achieved in crossbreds of the particular breeding lines, before making decisions about their utilization.

Animals↗
PubMed1988

Heterogeneity of insulin and insulin-like growth factor I binding in a human Burkitt type ALL cell line during the cell cycle and in three Burkitt type ALL sublines.

The expression of hormonal and growth factor receptors in leukemic cell lines might be heterogeneous due to the admixture of different cell cycle phases and the presence of yet unidentified sublines. Therefore, cell cycle-specific separation of Burkitt type ALL cells was performed by counterflow elutriation, and by limited dilution procedure three sublines of this cell line were obtained. Counterflow elutriation enriched to 60-80% purity for G1-, S-, and G2-phase which was shown by DNA flow cytometry. Insulin and insulin-like growth factor I (IGF-I) binding was investigated in the G1, S, and G2 phase. Insulin binding sites decreased from 10 to 15,000 per cell in G1 to 1,000-5,000 in S and increased to 40-50,000 in G2. The affinity of insulin binding remained constant during the cell cycle. IGF-I binding sites increased from 2,000 per cell in G1 to 5,000 in S and 15,000 in G2. The affinity of IGF-I binding decreased from G1 toward S and then remained constant in G2. The three isolated clonal sublines differed in numbers of insulin and IGF-I binding sites/cell without differences in affinity. The fact that IGF-I shows higher affinity binding during G1 than during S and G2 Burkitt type ALL cells suggests that IGF-I might be important for initiation of proliferation. The reduction in insulin binding sites during S-phase may indicate refractoriness of the cell to insulin during DNA replication.

Binding Sites↗
PubMed1987

[Neurochemical knowledge in electroconvulsive therapy (ECT)].

The paper is concerned with an attempt to generalize and categorize current hypotheses on the biochemical basis of ECT. The hypotheses are critically evaluated with respect to the relevance of their experimental fundamentals. Thus, certain hypotheses are valid only in a qualified sense. Particular interest is focussed on those conceptions which try to correlate ECT-induced changes in synaptic receptor sensitivities (up-/down-regulation) with super- resp. subsensitivity hypotheses of psychoses. In this connection, noradrenergic and opioid systems on the one hand, and the axis hypothalamus-hypophysis on the other hand seem to play a dominant role.

Brain↗
PubMed1987

[Assessment of prealbumin in cerebrospinal fluid].

The paper describes statistical relationship between prealbumin and total protein in lumbal CSF of a control group and a total group of patients with neurological diseases. The equations of the regression lines and the boundary lines of the distribution areas did not significantly differ between both groups. Therefore, prealbumin seems to be not qualified for differential diagnosis. On the other hand, its application to characterize functional states of blood-brain-CSF barrier systems is discussed.

Blood-Brain Barrier↗
PubMed1986

Correlation between protein data in normal lumbar CSF and morphological findings of choroid plexus epithelium: a biochemical corroboration of barrier transport via tight junction pores.

Specific "reference areas" were derived from relationships between the proteins prealbumin, albumin, alpha 1-acid glycoprotein, alpha 2-macroglobulin, total transferrin, IgG, IgA, IgM, and the corresponding total protein in normal lumbar CSF samples. The procedure for calculating the boundary lines of these reference areas was carried out on the basis of double standard deviations in subgroups with total protein differences of 50 ml/l within the whole range of 150-400 ml/l CSF. The resulting biochemical data, hydrodynamic radii of the individual proteins investigated, and van Deurs' and Koehler's morphological findings on the existence of pores in the barrier-forming tight junctions of the choroid plexus epithelium could be surprisingly well correlated with one another, although these morphological findings were obtained in choroid plexus of the rat brain. The correlation allowed the conclusion that proteins undergo ultrafiltration via a pattern of tight junction pores with various diameters. However, the molecular mechanism seems to include an additional facilitating component.

Adult↗
PubMed1986

Human leukemic cells: receptor binding and biological effects of insulin and insulin-like growth factors.

Receptor binding and biological effects of insulin and insulin-like growth factors I and II (IGF I/II) were assessed in three human malignant cell lines: a Burkitt-type ALL-cell line, a ANLL-cell line and a Hodgkin's disease-cell line. Insulin receptor binding could be demonstrated in Burkitt-type ALL cells and ANLL cells, whereas no insulin receptor binding was detectable in Hodgkin cells. IGF I and IGF II binding could be demonstrated in all leukemic cells. Insulin stimulated glycogen synthesis in the insulin receptor bearing cell lines. DNA synthesis was stimulated by insulin, IGF I and II. IGF I was more active in stimulating DNA synthesis than IGF II.

Cell Line↗
PubMed1985

T-cell phenotypes in chemically induced leukemia in mice.

T-cell leukemias were induced in adult BDF mice by a single i.v. injection of 50 mg kg-1 of methylnitrosourea (MNU). Leukemic cells from the thymus and other organ sites showed the theta antigen and were peanut-negative, but were heterogeneous with respect to Lyt-1 and Lyt-2. The acute cytotoxic effect of the MNU showed no preferential toxicity to a special T-cell subset in the thymus. During the latency period of leukemogenesis a continuous fall in peanut-positive cells in the thymus was found.

Animals↗
PubMed1984

Genetic resistance to Leukosis virus infection: effects on mortality and egg production in Leghorn hens.

The influence of genotypic differences in resistance to infection from Lymphoid Leukosis (LL) on mortality and egg production was studied in three pairs of sublines. One subline of each pair had been selected for resistance and the other for susceptibility to infection. At 10 months of age, almost no hens with neutralising antibodies against LL were found in the resistant sublines, while in each susceptible subline more than 40% of the hens had LL antibodies. At 21 months of age, very few hens of the resistant sublines had group-specific (gs) antigen in their eggs. Susceptible sublines differed considerably in this respect, from 81% gs antigen-positive hens in one subline to 9% or no positive hens in the others. On the whole, the susceptible sublines had 6% higher mortality during the laying period (8 months) but the size of the difference was influenced by vaccination against Marek's disease (MD) and varied considerably between pairs of sublines. Significant interactions between strain and genotype of resistance to LL infection were observed for mortality from "other causes" in hens vaccinated against MD, as well as for mortality from "Leukosis" and from "MD" in non-vaccinated hens. The average rate of lay from 1 to 8 months was 8% lower in susceptible hens. In the subline with the highest frequency of eggs containing LL group-specific antigen in the albumen, the reduction of laying rate was twice as large as in the other susceptible sublines.

Animals↗
PubMed1983

[Magnesium oxide as cause of metal fume fever].

Seven foundry workers are described who all developed pulmonary symptoms and in the majority of cases recurrent occupational fever; the onset of these episodes coincided with the introduction of a new founding technique resulting in exposure to magnesium oxide fumes. The foreman - most exposed because responsible for vaccination of the melted iron with metallic magnesium - developed disabling pneumopathy. The feverish episodes are interpreted as metal fume fever and in 6 patients the pneumopathy is considered to be due to alkalitoxic damage to the small airways and alveoli caused by the magnesium oxide fumes. The seventh patient suffered from allergic asthma bronchiale. Differentiation from hypersensitivity pneumonitis and from humidifier fever of nonallergic etiology is discussed.

Adult↗
PubMed1983

The flow cytometry for diagnosis of male fertility.

The patient came with a severe testicular disturbance (oligoasthenoteratozoospermia) into the department of andrology. After antiphlogistic- and antiestrogen therapy the clinical spermatological findings (spermiograms) were compared with the corresponding histograms of the flow cytometry analysis and interpreted as according with them.

Adult↗