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Biomedical subjects

I Lang

Publications and source records attributed to I Lang.

87 records · Page 5Linked to original sources
PubMed1983

Functional evaluation of murine allogeneic T lymphoblasts separated by Vicia villosa lectin positivity.

Mixed-lymphocyte culture-stimulated cells have been fractionated by their ability to bind the lectin Vicia villosa (Vv) and assessed for their cytolytic and suppressor activity in vitro. Vv positive and negative cells were separated either by cell affinity chromatography using Vv-Sepharose 6MB chromatography or by electronic cell sorting with FITC-Vv. Both populations expressed marked cytolytic and suppressor cell activity. Thus this lectin cannot be used to discriminate between these and other functional lymphoid cell population of blastoid cells binding the FITC-Vv appears following allogeneic stimulation; treatment with the immunosuppressive drug cyclosporin A, which affects cytotoxic cells preferentially, results in a considerable reduction of the Vv positive blastoid cells.

Animals↗
PubMed1983

Effect of in vitro cyclosporin. A treatment on human natural and antibody-dependent cell-mediated cytotoxicity.

Concentrations of 0.1 to 10.0 micrograms of cyclosporin A (Cy A) per ml do not directly inhibit the lysis of 51Cr-labeled K562 target cells by human peripheral blood natural killer (NK) cells nor of antibody-coated chicken red blood cells by antibody-dependent cellular cytotoxicity (ADCC) effector cells. Pretreatment of effector cells with Cy A for 18 hr still failed to affect NK or ADCC effector function. However, induction of NK cell activity by overnight pretreatment of effector cells by polyinosinate-polycytidylate (PolyIC) is inhibited by as little as 1 micrograms of Cy A per ml. The mechanism of inhibition may involve a direct effect of Cy A on "induced" or "activated" NK cells or inhibition of the release of Poly IC-induced interferon from lymphocytes.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1982

Direct staining of mouse T lymphoblasts with fluoresceinated Vicia villosa lectin.

Fluorescein conjugated Vicia villosa (Vv) lectin was used for direct staining of the surface of viable cells of various mouse lymphocyte populations. A varying proportion of polyclonally-activated T cells expressed Vv receptor although less strongly than cells of an influenza virus-specific cytotoxic T lymphocyte (CTL) clone and blasts generated in the mixed lymphocyte reaction. Cyclosporin A (CyA) treatment markedly reduced the expression of Vv receptor following concanavalin A (Con A) stimulation by between 66% and 93% with a concurrent inhibition of blastogenesis and complete abrogation of cytolytic function. Resting mouse lymphocytes and B-cell blasts were always Vv-negative. However, non-specific suppressor factor producing non-cytotoxic T-cell lines also expressed Vv receptor as shown by the weak, but specific, surface fluorescence of EL4 and BW5147 cells stained with Vv. Vv-positive cells were not restricted to a particular Ly phenotype, Vv-positive cells being found among both Lyt 1+ and Lyt2+ MLC stimulated lymphocytes. Our data suggest that the receptor for Vv lectin cannot be regarded as an exclusive differential marker for CTL.

Animals↗
PubMed1981

[Changes in cellular immunity during peritoneal dialysis].

In 8 patients with chronic peritoneal dialysis before and after 24-hour peritoneal dialysis examinations on the cellular immunity were performed (lymphocyte blast transformation with PHA and Con A, ADCC). There was no difference to the normal findings in healthy control persons. Blast transformation decreased during peritoneal dialysis, no changes were visible with ADCC. Compared with reports in literature concerning regular hemodialysis therapy the state of cellular immunity in chronic peritoneal dialysis seemed to be superior.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1981

Electron microscopic and histochemical investigations of the atretic oocyte of Perca fluviatilis L. (Teleostei).

The regression of atretic oocytes in Perca fluviatilis was studied by histochemical, light and electron microscopic methods. The course of regression can be divided into three stages, the first two comprising the dissolution of the atretic oocyte and its phagocytosis by the granulosa cells of the follicular epithelium, and the third stage consisting of the dissolution of the granulosa cells themselves. The ultrastructure in all three stages shows only features related to phagocytosis and lysosome formation. In particular, there is no agranular endoplasmic reticulum formed within the phagocytically active granulosa cells, nor is there any 3 beta-hydroxysteroid dehydrogenase activity (3 beta-HSD). Large yellow-orange pigments, formed during the third stage of regression, are ascribed to a relative deficiency of lysosomes in lipid digestion, and do not result from a preceeding steroid-synthesising phase in mammalian corpora lutea. Thus, the atretic oocyte of P. fluviatilis is considered not to give rise to a corpus luteum formation with endocrine function, but merely represents a degenerative structure.

Animals↗
PubMedDate not supplied

Four year follow-up of the Duromedics Edwards bileaflet valve prostheses.

The Duromedics Edwards (DE) bileaflet valve prosthesis was withdrawn from the market after 12 leaflet escapes had been reported in 20,000 implants. Effort is necessary to identify the failure mode to improve valve design or production, but the rate of other valve related complications will tell if it is worthwhile reintroducing this prosthesis. Five-hundred and sixty-four DE valves have been implanted in 508 patients between September 1983 and May 1988. Two-hundred and sixty-eight had aortic valve replacement (AVR), 183 mitral valve replacement (MVR) and 56 double valve replacement (DVR); the perioperative mortality was 6.9%. Follow-up has been 98.7% complete for a total of 1064 patient years and a mean follow-up of 26 months (range 3 to 54 months). Late mortality was 3.7%/yr and actuarial survival was 85 +/- 3% without and 78 +/- 3% including operative mortality after 54 months. Event free actuarial rates (linearized rates in parenthesis) were 93 +/- 2% (1.5%/yr) for thromboembolism, 91.7 +/- 1.9% (2.3%/yr) for anticoagulant related hemorrhage, 89 +/- 4.8% (2.3%/yr) for valve failure, 93 +/- 2% (1.8%/yr) for valve related mortality, 72 +/- 4.8% (6.3%/yr) for all valve related morbidity and mortality and 83 +/- 4.4% (3%/yr) for treatment failure. Two leaflet escapes occurred in the study group (0.18%/yr), both patients survived reoperation. The concept of reducing thrombus formation by a specially designed irrigating hinge mechanism was proven by a low rate of thromboembolism in our clinical follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMedDate not supplied

Elevated nascent DNA content of peripheral blood mononuclear cell compartment in lymphoma patients.

The kinetics of DNA synthesis and the DNA pattern of isolated peripheral blood mononuclear cells from control subjects and lymphoma patients prior to drug treatment were studied as a possible tool in the early diagnosis of lymphoma. Thymidine and [H3]-dTTP incorporation represented the measure of replicative DNA synthesis in permeable murine thymocytes and HT-168 human melanoma cells as described earlier. The kinetic parameters of nucleotide incorporation were compared with the ploidity parameters of the Feulgen-stained smears examined by the DNASK TV-cytophotometric system. For better evaluation and visualization of the S-phase population, the method of silver impregnation of the Nucleolar-Organizer-Region in combination with the Feulgen technique was used. Significant differences were observed among the five determined parameters of healthy and lymphoma patients. Our results allow to explain some of the facts related to T-cell function deficiency in lymphoma.

Adolescent↗