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Biomedical subjects

A Govaerts

Publications and source records attributed to A Govaerts.

At least 19 recordsLinked to original sources
PubMed1991

[Integration of carcinogenic viruses in the genome of in-vitro cultured human fibroblasts].

Avian sarcoma viruses are known for inducing no transformation of human diploid fibroblasts. Nevertheless, we show that the Rous sarcoma virus can infect and transform some human fibroblastic cell lines, replicate and express viral proteins, integrate into the host genome and prevent expression of MHC class I antigens on cell membranes. Cell transformation happens together with important and significant abnormalities of the cell karyotype and proviral integration is most often close to the c-src oncogene on chromosomes 1 and 20.

Avian Sarcoma Viruses↗
PubMed1979

Suggestive evidence for receptors for morphine and methionine-enkephalin on normal human blood T lymphocytes.

This study reports the in vitro influence of morphine, dextromoramide, levomoramide, and methionine-enkephalin upon normal human T blood lymphocytes by using the active and total rosette tests. Morphine and dextromoramide inhibited the percentage of active T rosettes. This effect was completely reversed in the presence of naloxone, their specific antagonist. The specificity was further demonstrated by the absence of the effect of levomoramide, the inactive enantiomere, upon the rosette system. Methionine-enkephalin increased the percentage of active T rosettes. This effect was specifically inhibited by naloxone. These observations suggest that normal human blood T lymphocytes bear surface receptor-like structures for morphine, dextromoramide, and methionine-enkephalin. Such findings may provide a link between the central nervous system and the immune system.

Binding Sites↗
PubMed1978

Leucocyte adherence inhibition test in arthritis.

Peripheral leucocytes from healthy blood-donors were preincubated in polyarthritic serum or normal serum and their adherence to glass tubes in the presence of synovial extract of control extract was measured. Serum from patients with inflammatory polyarthritis significantly reduced the proportion of leucocytes which adhered in the presence of synovial extract, but not control extract. Serum from patients with polyarthritis with visceral manifestations, patients with degenerative or metabolic polyarthritis or rheumatic fever, and controls did not have this effect. The leucocyte sensitising activity was eluted in the IgG fraction of serum, and could be absorbed by both synovial extract and IgG. It is thus probably IgG rheumatoid factor. In vivo, armed leucocytes in polyarthritic patients may bind to synovial tissue initiating or perpetuating the articular inflammatory process.

Adult↗
PubMed1978

[Integration othe MG 50 into the routine of a hospital transfusion center].

Groupamatic MG 50 equipment looks to be quite well adapted to suit the needs of small or medium size blood transfusion centers, in which the number of blood grouping determinations daily processed is in the range of 100 to 500. In its present configuration (after some modifications have been brought in), the MG 50 offers significant advantages which will be discussed in detail. For a batch of 58 samples tested in one hour on twelve channels a single technician is required instead of 3 to 4; sample supply of equipment is therefore made in a more regular way. In case of run interrupt a single series of 12 determinations is implicated and can be immediately checked. The whole analysis process is limited to twice 11 minutes due to the continuous agitation of discs. The tubing pump priming is automatically performed and the reagent homogeneity is better insured; the presence of dilution tubes is easily controlled. Different programs are easily interchangeable and make the use of equipment smooth. We do think that MG 50 allows a better distribution of work throughout the day and accepts emergency blood grouping requests without any special difficulty.

Autoanalysis↗
PubMed1978

[Humoral immunity].

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Antibody Formation↗
PubMed1978

[Autoimmunity].

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Autoimmune Diseases↗
PubMed1978

Inosiplex, a stimulating agent for normal human T cells and human leukocytes.

The influence of inosiplex upon various in vitro leucocyte assays was studied in normal individuals. It was found that the drug increases the response of bidirectional and unidirectional mixed lymphocyte cultures at concentrations of 200, 300, and 500 microgram/ml. It also significantly increases the percentage of active T rosettes (concentration range: 50 to 500 microgram/ml) and the percentage of autologous red cell T rosettes (concentration: 100 microgram/ml). In contrast, inosiplex did not modify the percentage of total T rosettes and EAC rosettes. Inosiplex increases the number of nonadherent leucocytes in the leucocyte adherence inhibition test at a concentration range between 100 and 300 microgram/ml. Finally, inosiplex also increases the percentage of monocytes phagocytizing yeast at a concentration between 50 and 500 microgram/ml. These data indicate that inosiplex enhances the function of normal human T cells, monocytes, and possibly neutrophils. Therefore inosiplex appears to have immunostimulant properties.

Dose-Response Relationship, Drug↗
PubMed1977

Lynestrenol, an amplifier of lymphocyte stimulation.

Lynestrenol, a synthetic steroid progesterone-like substance, has been found to enhance the stimulation of normal human lymphocytes. It increases the phytohemagglutinin response and the mixed-lymphocyte cultures. This augmentation can, in some cases, be higher than 100% of the phytohemagglutinin or mixed lymphocyte reaction baseline. There is no significant effect on the pokeweed mitogen stimulation. It is concluded that lynestrenol can modulate, "in vitro", some T cell functions.

Cells, Cultured↗
PubMed1977

Human autologous and allogeneic rosettes.

Human red blood cells can bind to human peripheral blood lymphocytes. The percentage of these rosette-forming cells (TEh) depends on various conditions including temperature and the use of selected foetal calf serum. It is improved by toluidine blue. Prior incubation at 37 degrees C is not necessary. ABO and rhesus antigen D have no influence on rosette formation. Analysis of human rosettes in T and B cell rich populations, in patients with chronic lymphatic leukaemia or T cell lymphoma provides further evidence that human autologous and allogeneic rosette-forming cells belong to a T cell subpopulation.

ABO Blood-Group System↗
PubMed1977

IgE mediated hypersensitivity in ageing.

The serum IgE concentration is significantly lower in aged as compared with young people. This is more pronounced in males than in females (P less than 0-05). In fifteen aged (greater than 70 years) compared with fifteen young subjects (less than 40) the specific IgE antibody response to an injection of diphtheria toxoid was significantly reduced (P less than 0-01). The minimum concentration of anti-IgE antibody able to induce a weal and flare reaction when injected intradermally, was comparable in the two age groups. However, the diameter of the weal reaction was significantly reduced in the aged. It is concluded that the reduced incidence of atopic symptoms in old people might be secondary to an anomaly of both the immune system and the mast cells.

Adult↗
PubMed1977

Influence of levamisole on the immune response of old people.

Fifteen healthy people, over 70 years old, have been treated during 1 month with Levamisole at the dose of 150 mg a day, twice a week. They have been compared to 15 controls matched for age and sex. At the start of the study, each subject was injected with 0.2 ml of a diphtheria-tetanus vaccine. Levamisole had no effect on the following immune parameters known to be altered in old age: serum IgE concentration, specific IgE and IgG antibody response to diphtheria toxin, lymphocyte response to phytohemagglutinin (PHA). There was a slight and transitory effect of Levamisole on the isohemagglutinin titer. In vitro, Levamisole was weakly mitogenic for the peripheral blood lymphocytes from old and young control subjects but there was no influence on the response to PHA.

Aged↗
PubMed1977

Differential effect of vinblastine and colchicine on human active and total T rosettes.

The effect of vinblastine and colchicine on human blood T cell rosette formation with sheep erythrocytes was assessed. For some concentrations, both drugs increased the percentage of active T rosettes. In contrast, the total T rosette percentage was decreased by the same drugs. These experiments further confirm the heterogeneity of T cell rosettes and suggest the existence of three types of sheep red blood cell receptors on human blood T lymphocytes.

Colchicine↗