PubMed Health⌕ Search

Biomedical subjects

S Arrenbrecht

Publications and source records attributed to S Arrenbrecht.

29 records · Page 2Linked to original sources
PubMed1981

Circulating immune complexes, complement factors C3, C4, C1-inhibitor, alpha-1-antitrypsin and immunoglobulins in asthmatic patients.

Sera from 159 adult asthmatic outpatients (extrinsic, n = 82, intrinsic, n = 65 and acetylosalicylic acid (ASA)-sensitive, n = 12) and from 100 controls were tested for total levels of IgG, IgM, IgA, IgE, complement factors C3, C4, C1-inhibitor, alpha 1-antitrypsin and circulating immune complexes. The following results were observed: (1) a marked increase of IgE in extrinsic asthma; (2) a slight increase of IgM, and (3) an equal increase of complement C4 levels in all three asthma groups; (4) normal mean values of C3 levels with a significantly larger standard deviation of the mean in all three asthma groups; (5) an equally slight decrease of protease inhibitors, such as C1-inhibitor and alpha 1-antitrypsin, and (6) the presence of circulating immune complexes in 22% of extrinsic, in 8% of intrinsic and 13% of ASA-sensitive asthmatics. Circulating immune complexes can be found in all three asthma groups and may correlate with complement deviation.

Adult↗
PubMed1980

In vitro stimulation of glia cells by a lymphocyte-produced factor.

The factors responsible for the activation of astrocytes surrounding inflammatory brain tissues are unknown. The present study was designed to examine the ability of lymphocytes to produce astrocyte stimulating activity in cell culture. Normal rat lymphocytes stimulated with Concanavalin A, or sensitized lymphocytes, challenged with antigen in vitro, activate cultured rat glia cells by a soluble mediator which we have termed glia stimulating factor (GSF). In undifferentiated glioblasts both RNA synthesis, as measured by [5-3H]uridine uptake, and DNA synthesis, as measured by [6-3H]thymidine uptake, were stimulated by the presence of GSF. Preliminary characterisation showed the GSF to be non-dialysable and heat stable at 56 degrees C for 30 min, but not stable at 80 degrees C for 30 min. To study the effect of this factor on differentiated glia cells, brain cell cultures were treated with dibutyryl cyclic AMP (db-cAMP) which induces a morphologic transformation of glioblasts to multipolar cells that have a characteristic astrocytic appearance. After addition of GSF to db-cAMP treated astrocytes only an increase in RNA synthesis was observed. The significance of this in vitro phenomenon, mediated by a glia stimulating factor, to activation of astrocytes and astrocytic gliosis in human brain diseases is discussed.

Animals↗
PubMed1975

T cell-dependent helper and suppressive influences in an adoptive IgG antibody response.

When immune spleen cells of mice immunized to a hapten carrier preparation 4 days previously were transferred to normal syngeneic hosts, they began to produce 7S antibody (presumably of the IgG class), provided that relatively small numbers of cells (about 1/10 spleen equivalent) were transferred. Increasing the number of transferred cells resulted in less IgG antibody formed. Depletion of the immune spleen cells of T cells by treatment with anti-theta serum and complement prevented IgG antibody formation. IgG antibody production by untreated and anti-therta serum-treated immune spleen cells could be enhanced (reinduced) by addition of small numbers of cells enriched for carrier-activated T cells. These suggest that T cells are necessary to stimulate antigen-activated B cells into IgG antibody production. Larger numbers of 'carrier-activated T cells' depressed IgG antibody production. Both enhancement and depression could be demonstrated to be antigen-specific. IgG antibody production high numbers of transferred immune spleen cells could be induced by treating the cells prior to transfer with suboptimal amounts of anti-theta serum and complement. It is argued that this results from the elimination of a T cell-dependent suppressor influence arising during a normal immune response.

Animals↗
PubMedDate not supplied

Pneumococcal vaccination: the response of patients with alcoholic liver cirrhosis.

Patients with cirrhosis have an increased risk of dying from pneumococcal pneumonia. Their immunological response to pneumococcal vaccination is not known. We compared the antibody response to challenge with a 14-valent purified pneumococcal polysaccharide vaccine in 15 patients with biopsy-proven alcoholic liver cirrhosis, 10 healthy volunteers and 10 patients with chronic obstructive pulmonary disease. Preimmunization levels for Danish type 1 pneumococcal polysaccharide were lower among cirrhotics than patients with chronic obstructive pulmonary disease. Four and 12 weeks after immunization, no significant differences were found in antibody concentrations between the three groups. We conclude that patients with alcoholic cirrhosis can produce an adequate antibody response to pneumococcal polysaccharide antigen.

Adult↗
PubMedDate not supplied

The effects of interferon on granulopoiesis in vitro.

Colony formation by myeloid progenitor cells (CFU-c) in agar was inhibited to the same extent by heterogeneous human leucocyte IFN (IFN-Le) and 2 different cloned IFN-alpha 2 preparations, but approximately 10 times less by cloned IFN-alpha 1; cluster formation remained unaffected by any of the interferons. An anti-proliferative effect is suggested by both lower cell yield and DNA synthesis in IFN containing liquid cultures. Incubation of cells with IFN for 18 h prior to plating with colony stimulating factor (CSF) reduced colony formation, indicating an altered responsiveness of CFU-c to CSF. In IFN treated cultures no consistent block of morphological differentiation occurred, but granulocyte alkaline phosphatase activity was reduced. Thus, IFN may play a modulatory role on functional markers. Our results indicate that the effects observed with heterogeneous preparations are due to IFN and not to impurities and that various differentiation parameters are unequally affected by IFN.

Alkaline Phosphatase↗
PubMedDate not supplied

DNA-abnormality in hairy cell leukemia.

Spleen and light density peripheral blood leukocytes of 10 hairy cell leukemia (HCL) patients and total leukocytes of one patient and blood donor cells were stained quantitatively for cellular DNA. The DNA content of single cells was measured by flow cytometry (FC) and compared to the DNA content of sheep cells admixed as an internal control. Eight of eleven patients (72 per cent) showed deviations from blood donor DNA content. Two female patients showed increased cellular DNA content, the six male patients had hypodiploid cells. Chromosomal aberrations are therefore likely to exist in the majority of HCL patients. Separation of HCL cells into sheep erythrocyte rosette and non rosette forming cells revealed similar DNA abnormalities in both cell populations, suggesting that the leukemia encompasses cells with B and with T markers.

DNA, Neoplasm↗