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Biomedical subjects

J Stefanovic

Publications and source records attributed to J Stefanovic.

At least 37 records · Page 2Linked to original sources
PubMed1987

Deficiency of C2, the second complement component, in the family of a patient with SLE-like syndrome: the first case of hereditary C2 deficiency in Czechoslovakia.

A family with hereditary C2 deficiency was discovered in Czechoslovakia. The proband is a 47-year-old female with a SLE-like syndrome and zero activity of the classical complement pathway. Functional CH50, C1, C2, and C4 estimations for all family members revealed a homozygous C2 deficiency in both the proband and her elder sister, and several heterozygotic C2-deficient individuals. The defect segregates with haplo-type HLA A25, B18, DR2.

Adult↗
PubMed1987

In vitro effects of organic solvents on immunity indicators in serum.

Serum treatment in vitro with organic solvents (chloroform, ether, toluene) failed to produce an effect on immunoglobulin levels and activity. After chloroform and ether treatment, no complement activity could be determined, with chloroform-treated serum beginning to express anticomplement activity against autologous, allogenic and xenogenic sera. The classical pathway of complement activation (C1, C4, C2, C3) was primarily inhibited, whereas the alternative pathway remained unaffected. Chloroform-treated sera exhibited significantly declined levels of C1-INH, C3 and C4 as well as of circulating immune complexes. Toluene did not influence any of the parameters tested, while ether blocked complement activity without affecting either the concentration or activity of the other components under investigation. The obtained findings are discussed from the aspect of organic solvent applications in preparing immune products and determining immunity indicators in the serum or other biological fluids.

Antibodies↗
PubMed1986

A standard microcytotoxicity technique for quantitative analysis of lymphocyte subsets. A comparison with indirect immunofluorescence, evaluated by microscopy or flow cytometry.

A standard complement-dependent microcytotoxicity (CDC) technique was used for quantitative analysis of T-lymphocyte subsets in human peripheral blood and the results compared to those obtained by indirect immunofluorescence microscopy and flow cytometry. The monoclonal antibodies OKT3, OKT4 and OKT8 were used in the CDC method for detection of total-T cells, T-helper and T-suppressor cells respectively. The CDC technique provided reproducible results (CV, 3-7%) correlating well with both immunofluorescence techniques. This observation was valid both for healthy persons (n = 21) and for patients (n = 10) with immunological disorders. The correct antibody dilution, correction for background and the use of eosin staining are considered critical for the usefulness of this technique. The method has several advantages: it is widely used for histocompatibility testing, only simple equipment is necessary, and the amount of monoclonal antibody required per test is small.

Antibodies, Monoclonal↗
PubMed1986

The characteristics of the HLA antigens determined by cellular techniques.

The complexity of the D region of the HLA complex is rather great. Three loci--HLA-DP, DQ, DR are very well established in this time. However, the question about the independence of the first known locus of this region--HLA-D--remains elusive--it is still not known if HLA-D antigens are really independent or they rather represent some epitopes of HLA-DR/DQ antigens. The HLA-DP antigens represent the additional series of specificities of the HLA complex recognized by PLT technique. On the other hand HLA-PL antigens, detected by PLT too, correlate as to HLA-D as to HLA-DR antigens and with a great probability they do not form an independent group of HLA antigens.

Antibodies, Monoclonal↗
PubMed1986

Modulatory effect of glucans on the functional and biochemical activities of guinea-pig macrophages.

The particulate and soluble glucan preparations isolated from Saccharomyces cerevisiae and Candida albicans affected various activities of guinea-pig macrophages. The stimulation of INT reduction and superoxide production were observed in the presence of all insoluble and some soluble glucans in vitro, but most of the preparations under study had an inhibitory effect on phagocytic activity. On the other hand, the stimulation of both metabolic and functional activities was obtained in vivo. Macrophages from guinea-pigs treated with glucans exerted an increased ability to reduce INT and to produce superoxide. Their candidacidal capacity was rapidly elevated, and peritoneal macrophages had raised phagocytic activity as well. A more pronounced stimulatory effect was observed in the presence of insoluble rather than soluble glucans, and this was more expressive in vitro than in vivo.

Animals↗
PubMed1986

The HLA class II antigens determined by cellular techniques. A review.

The D region of the HLA system is very complex. Three loci, HLA-DR, DQ and DP, are now very well established. However, the question of the independence of the first known locus of this region remains elusive--it is not yet known if HLA-D antigens are really independent or if they represent some epitopes on the molecules of HLA-DR/DQ antigens. The HLA-DP antigens represent an independent series in the HLA system recognized by the PLT technique. On the other hand, the HLA-PL antigens also detected by PLT correlate with both HLA-D and HLA-DR antigens, and it seems that they do not constitute an independent group of HLA antigens.

Genes, MHC Class II↗
PubMed1985

Lysosomal enzyme activities in polymorphonuclear leukocytes, macrophages, serum, and spleen of conventional, germ-free, and antigen-free Minnesota miniature swine.

The activities of lysozyme, myeloperoxidase, and elastase were lower in PMNs and AMs from GF and AF Minnesota miniature piglets than in the leukocytes from their CONV counterparts. In the spleen and serum of gnotobiotic piglets only the levels of lysozyme were slightly reduced. Substantially depressed activities of these LEs were found also in PMNs from precolostral piglets in comparison with PMNs from their CONV mother. The bisassociation of GF piglets with Enterococcus liquefaciens and Escherichia coli caused an increase of LE activities in their AMs, spleens, and sera. Fewer LEs were released after phygocytic stimulation with zymosan from PMNs of GF, AF, and precolostral piglets than from PMNs of CONV animals of the same age. These data suggest that the antigenic-microbial stimulation is important for the development of normal lysosomal enzyme activities in PMNs and AMs from gnotobiotic animals.

Animals↗
PubMed1984

Effect of Coxiella burnetii on the stimulation of hexose monophosphate shunt and on superoxide anion production in human polymorphonuclear leukocytes.

Killed Coxiella burnetii (C.b.) cells in phase II but not in phase I had a mild stimulatory effect on hexose monophosphate shunt (HMPS) and superoxide anion production by human polymorphonuclear (PMN) leukocytes. Preincubation of C.b. cells of either phase with serum of a leukocyte donor lacking detectable antibodies to C.b. did not affect the studied activities of PMN leukocytes. In contrast, both HMPS stimulation and superoxide production were enhanced by specific opsonization of C.b. cells with rabbit immune sera containing corresponding phase I and/or phase II antibodies. Stimulatory effect was observed also with lipopolysaccharide-protein-phospholipid (LPS-Pr-Pl) complex but not with lipopolysaccharide-protein (LPS-Pr) complex and with purified lipopolysaccharide (LPS) isolated from phase I C.b. cells. Possible consequences of these findings for explanation of C.b. resistance to intracellular killing by professional phagocytes are discussed.

Coxiella↗
PubMed1983

Phagocytic capacity of human leukocytes preincubated with Imuran and prednisone.

The phagocytic and microbicidal activities of human polymorphonuclear leukocytes (PMNL) were tested after a short-term preincubation of phagocytic cells with Imuran or Prednisone, using C. albicans strains as a test organism. The tests showed that both immunosuppressive agents reduced significantly the microbicidal activity of PMNL cells by 35-40%. Detectable differences in the phagocytic activity and phagocytic index values were not statistically significant. The decreased ability of PMNLs to kill ingested C. albicans strains appears thus to sensitively reflect the altered PMNL function and can be utilized in the biologic monitoring of immunosuppression. The reduced microbicidal potential of phagocytic cells may be also one of the causes of recurrent microbial infections that are so frequent in immunosuppressant-treated patients.

Azathioprine↗