PubMed HealthSearch

Biomedical subjects

J Stefanovic

Publications and source records attributed to J Stefanovic.

At least 19 recordsLinked to original sources

[Inflammation, immunity and surgery].

The activation of endothelial and phagocytic cells, with concomitant formation of a range of adhesive molecules and inflammatory mediators, are integral parts of the host response to injurious agents (trauma, infection, altered antigens, toxins, chemicals etc.). The excessive mediator responses are associated with increased morbidity and lethality. Cytokines, soluble mediators secreted by cells, play an integral role in the metabolic and immune responses to the injurious agents. Widespread tissue damage, when associated with fulminant sepsis may induce massive release of cytokines (TNF, IL-1, IL-6), triggering certain steps of reactions involving multiple organs and culminating in the systemic inflammatory response syndrome, sepsis syndrome or multiple organ failure syndrome. (Fig. 2, Ref. 21.)

Animals

[Antiphagocytic activity of sera treated with organic solvents (chloroform, ether)].

The opsonization of C. albicans by means of sera treated with chloroform and ethyl ether resulted in significantly decreased values of PMN leucocyte phagocytic activity. In contrast to ethyl ether treated sera (decrease of phagocytic activity about 45%), chloroform processed sera possessed increased antiphagocytic activity (decrease of phagocytic activity about 63%). Significant changes were observed in the candidacidal capacity to C. albicans (decrease about 50%) and in the capacity of NBT (INT) reduction measured spectrophotometrically (decrease about 66% in chloroform treated sera and about 42% in ethyl ether treated sera). (Fig. 1, Ref. 22.)

Candida albicans

Vaginal leukocyte characteristics in urogenital trichomoniasis.

Morphological and functional characteristics of vaginal exudate leukocytes were examined in 47 patients with urogenital trichomoniasis. Electron microscopic morphology, viability, phagocytosis of Candida albicans blastospores and ability to undergo respiratory burst in the iodonitrotetrazolium reductase test were evaluated in these cells. Vaginal inflammatory leukocytes were almost exclusively polymorphonuclear neutrophils, and their concentration was positively correlated (r = 0.58; p less than 0.001) with the number of trichomonads in the exudate. Median leukocyte viability reached 39% and both phagocytic and tetrazolium reductase activities of these cells were significantly reduced in comparison with those of circulating polymorphonuclear leukocytes. Patients with a clinical picture of severe mucosal inflammation had significantly higher vaginal exudate leukocyte concentrations and viability than those without inflammatory signs. The possible role of vaginal leukocytes in the pathogenesis of urogenital trichomoniasis is discussed.

Adolescent

Quantification of proliferative and suppressive responses of human T lymphocytes following ConA stimulation.

The mitogenic response of human T lymphocytes to graded doses of concanavalin A (ConA) has been measured by means of an MTT tetrazolium dye metabolic assay. Three groups of healthy subjects, representing children, younger adults and elderly persons, were investigated. It was shown that a typical bell-shaped course of the ConA dose-response curve is the result of a proliferative response to suboptimal concentrations of ConA and a toxic action of ConA at supraoptimal concentrations. The ascending part of the response curve reflects in its shape the regulatory interaction of responding cells. A decrease in suppressive functions is accompanied by a shift of this part of the curve to lower concentrations of ConA. By means of a mathematical model derived from enzyme kinetics, an attempt was made to quantify the suppressive functions from the course of the individual dose-response curve. It was found that after suitable data processing, suppression-related shape changes can be assigned to a single parameter. The value of this parameter as a diagnostic tool was tested in a study of the age dependence of human T lymphocyte responses to ConA. While the proliferative response decreased with age, the suppressive functions exhibited their maximum effect in the group of adults. Thus it could be demonstrated that ConA induced proliferative and suppressive responses are due to two different pathways which can be independently extracted from the dose-response curve.

Aging

Proteolytic activity in Tritrichomonas mobilensis.

Cell extracts of an entero-invasive protozoon of squirrel monkeys, Tritrichomonas mobilensis, contained relatively high proteolytic activity, measured on hide powder azure (HPA). Multiple proteinase forms, optimally active at pH 5-7, were detected by electrophoretic analysis in gelatin-containing polyacrylamide gels. Three major proteinase bands of apparent low molecular weights, Mr 18, 23 and 30 kDa, were seen on gels. Inhibition-activation studies suggest that only cysteine proteinases were involved in HPAase and gelatinolytic activities of T. mobilensis cell extracts.

Animals

[Trichomonas in girls during the period of hormonal inactivity].

Trichomoniasis occurs also in childhood in the period of hormonal inactivity, though its rate is not so high as in women of childbearing age and full sexual activity. In our series of children in the period of sexual inactivity, established by functional cytology, trichomoniasis was diagnosed in 3.8% of the total number of 1,562 children. Preparations of imidazol proved to be fully effective in the treatment of trichomoniasis in girls. In diagnosis the semisolid Szenes's culture medium in Valent's modification was used to advantage. Its standard use provides a basic precondition for good recovery of the protozoon. Trichomoniasis as such does not present so serious a problem as do the consequences of the unrecognized and untreated disease when the proliferated secondary flora potentiates the severity of the infection. This condition may lead to salpingitis and peritonitis causing sterility, and it may also spread into the uropoietic system.

Child

Family study of natural killer cell activity in C1q-deficient patients with systemic lupus erythematosus-like syndrome: association between impaired natural killer cell function and C1q deficiency.

Impaired natural killer (NK) cell activity has been found in patients with systemic lupus erythematosus (SLE)-like syndrome. The mechanism by which NK cell function is impaired in SLE patients is not quite clear. We report here a family study of NK cell activity in C1q-deficient patients with SLE-like syndrome. In both SLE-active and SLE-inactive stages of the disease, NK cell function was significantly impaired when compared with the healthy controls (10.6 +/- 2.3% and 16.9 +/- 4.8% to 34.7 +/- 9.6%, p less than 0.025). On the other hand, differences in NK cell cytotoxicity between SLE-active and SLE-inactive members of the family were not statistically relevant (p less than 0.1). Further, we found no correlation between NK cell activity and clinical or laboratory values, except for a positive correlation between function of NK cells and C1q and CH50 values, respectively (rs = 0.93, 0.01 less than p less than 0.02). To our knowledge, this is the first report on a notable association between impaired NK cell activity and C1q deficiency. The type of inheritance of C1q deficiency in this family is also discussed.

Adult

HLA-D/DR identity results in a positive CML reaction.

Investigating HLA-A, HLA-B, HLA-C, and HLA-DR antigens, MLR, CML, and PLT reactivity in two unrelated persons it was found that despite their HLA-D/DR identity cytotoxic T lymphocytes (CTL) could be induced in the CML assay. The HLA-DP antigens proved to provide the necessary proliferative impetus for the generation of CTL.

Cytotoxicity, Immunologic

A review: HLA and diseases--current status.

Since the discovery of polymorphism of the HLA complex the relationship between HLA antigens and various diseases has been followed. A number of HLA disease associations have been found. A review of the most important ones is given in this article. Explanation of the relations: "HLA and diseases" remains obscure till now what however does not hinder to take profit from them in practical medicine at diagnosis, differential diagnosis, therapy, prevention and also in genetic advisory service.

Endocrine System Diseases

[The development of cytotoxic T lymphocytes in HLA-D/DR identity].

The development of cytotoxic T-lymphocytes is controlled by genes of the HLA complex and occurs, in the majority of cases, when the responding and stimulating subjects differ both in HLA-A, -B and HLA-D/DR antigens. We examined a married couple for kidney transplantation and found that they differed in HLA-A, -B antigens and were identical in HLA-DR antigens. The negative results of the MLC test confirmed the serological findings. Nevertheless, cytotoxic T-lymphocytes developed despite HLA-D/DR identity. The presented case is one of the few published exceptions to the rule governing the development of cytotoxic T-lymphocytes.

Cytotoxicity Tests, Immunologic

Effect of cyclophosphamide on the candidacidal activity of rabbit peritoneal macrophages.

Single and repeated intravenous administration of cyclophosphamide significantly decreased the candidacidal activity of rabbit peritoneal macrophages. Using higher doses of the drug, a more pronounced decrease, persisting up to 10 d, was observed. The phagocytic index has not changed significantly 10 d after cyclophosphamide injection as compared with controls. No changes in the phagocytic activity were recorded. The decreased candidacidal activity may be one of the causes of serious microbial infections in cyclophosphamide-treated patients.

Animals

Specific parasitism of purified vaginal epithelial cells by Trichomonas vaginalis.

Human vaginal epithelial cells (VECs) from vaginal swabs obtained from normal women or from patients with trichomoniasis were purified, and VEC parasitism by Trichomonas vaginalis was examined. Trichomonads bound equally well to live or dead VECs, and up to 20% of VECs were parasitized. Trichomonal cytadherence of human VECs was time, temperature, and pH dependent. Saturation binding levels of live trichomonads to VECs gave approximately 2 organisms adherent to parasitized VEC. No differences in cytadherence levels were detected by different isolates to VECs from the same patient compared with adherence to VECs from normal individuals. Trypsinized, live T. vaginalis organisms failed to recognize VECs. A ligand assay identified four adhesin candidates, and only organisms without a prominent immunogen on the surface (negative phenotype) cytadhered to VECs and synthesized the adhesins, confirming the results of a recently published report by us on adherence to HeLa cell monolayers (J. F. Alderete and G. E. Garza, Infect. Immun. 56:28-33, 1988). These data show the ability of T. vaginalis to parasitize human vaginal epithelial cells in a specific receptor-ligand manner.

Animals

Genetic determination of phagocytic activity of polymorphonuclear leucocytes.

Sixty-three persons with the known HLA-A, -B, -C, -DR and -Dw antigens were investigated for phagocytic ability, candidacidal activity, respiratory burst values, and the levels of circulating immune complexes, C2, C4, IgG, IgM, and IgA. The investigated persons were divided into the HLA-DR2/Dw2, the HLA-DR3/Dw3 and a control group, members of which possessed neither antigen in question. The phagocytic activity of polymorphonuclear leucocytes ingesting dead cells of C. albicans and the candidacidal activity were found to be significantly lower (P less than 0.02) in the HLA-DR3/Dw3 compared to the control group. The respiratory burst values did not considerably differ in all three groups under study. The levels of circulating immune complexes were higher in both the HLA-DR2/Dw2 and HLA-DR3/Dw3 in comparison with the control group.

Antigen-Antibody Complex

Hereditary angioedema in Czechoslovakia. Clinical, immunological, genetic and therapeutic studies of 16 families.

The analysis of the findings in 16 families with hereditary angioedema detected in Czechoslovakia over the years 1975-1986 is being presented. In 14 families C1-inhibitor deficiency and in two families afunction of C1-inhibitor was established. Of the total number of 175 examined family members C1-inhibitor defect was registered in 66 subjects (60 with deficiency and 6 with afunction), and of these 48 suffered from clinical symptoms of edematous attacks affecting the skin, larynx, intestine and urinary tract, whereas 18 subjects were asymptomatic. Genealogical studies confirmed that the defect is inherited as an autosomal dominant trait. In 16 patients long-term prophylactic treatment with Danol was introduced. The effective minimum dosage was tested individually for each patient.

Angioedema