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Biomedical subjects

J Wybran

Publications and source records attributed to J Wybran.

At least 91 records · Page 5Linked to original sources
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

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↗
PubMed1977

Levamisole and human lymphocyte surface markers.

The action of various concentrations of levamisole on normal human lymphocytes was investigated in vitro. The action of levamisole (10(-1) mg-10(-8) mg%) upon rosette formation was studied using two rosette assays with SRBC (the active and the total T-rosette tests) to quantify T cells and the EAC assay to quantify B cells. Levamisole at only 10(-3) mg% significantly increased the percentage of both active and total T cells. In sharp contrast, levamisole between 10(-2) and 10(-7) mg% significantly decreased the EAC percentage. It is concluded that levamisole promotes a better expressivity of T-cell receptor and decreases the expressivity of C3 receptor.

Adult↗
PubMed1975

The immunologic and histopathologic changes of BCG-mediated tumor regression in patients with malignant melanoma.

Six patients with intradermal metastases of malignant melanoma were treated with intralesional bacile Calmette-Guérin (BCG). Four patients showed a good response with regression of injected, and in some cases, uninjected lesions, whereas two developed metastatic viscereal disease and died. Three of the six patients had complete regression of all lesions, and one exhibited complete regression of untreated lesions. All remain free of disease. The fourth patient had complete regression of injected and of some untreated lesions, but developed widespread dissemination and died. Preliminary experiments suggest the presence of a blocking factor in his sera which abrogates the lymphocyte stimulation in response to melanoma antigens. Three of four responders (i.e. those patients in whom treated lesions decreased in size by more than 50% for more than 1 month) showed a dramatic increase in lymphocyte stimulation to melanoma antigens. All responders (four out of four) had a marked increase to phytohemagglutinin (PHA), whereas non responders had no increase in lymphocyte stimulation either to melanoma antigens or PHA. Two of four responders showed inhibition of leukocyte migration to melanoma antigens before BCG, and two of four responders were positive after BCG. Of the nonresponders, one was positive and one negative before BCG; this remained the same after. There was a marked increase in active rosette forming cells in all responders and in one of the two nonresponders. Histopathologic studies at 3 hours, 6 hours, 24 hours, 14 days, and 4 weeks after BCG showed a definite sequence of events occurred, progressing from 1) inflammatory cell response at the periphery of the lesion, disruption of melanogenesis, extensive dumping of pigment from melanoma cells, proceeding to actual cell death at 24 hours, to 2) macrophages containing melanin and granulomas replacing tumor by 2 weeks. These studies suggest that BCG activates both specific and nonspecific immune responses. Thus, in vitro parameters of cellular immunity, including migration inhibitory factor production and inhibition of leukocyte migration, are affected by intralesional BCG, and some, particularly the lymphocyte stimulation and rosette test, seem to correlate with the clinical response of the patients.

Aged↗
PubMed1975

Osteogenic sarcoma. Immunologic parameters before and during immunotherapy with tumor-specific transfer factor.

18 patients with osteogenic sarcoma were followed by serial measurements in vitro of tumor-specific cell-mediated cytotoxicity and of "active" and total rosette-forming T-cells. 13 of these patients have had or are currently receiving injections of osteogenic sarcoma-specific dialyzable transfer factor derived from healthy donors. In three patients with very small lesions, cytotoxicity was high before amputation and decreased within 2 mo after removal of tumor. Cytotoxicity was low at time of diagnosis in all patients with large tumor masses. The cytotoxicity of the patients' lymphocytes increased after administration of tumor-specific transfer factor in all patients so treated. Patients receiving nonspecific transfer factor showed evidence of declining cell-mediated cytotoxicity. Tumor-specific transfer factor may produce an increase in cell-mediated cytotoxicity to the tumor in patients with osteogenic sarcoma. This possibility is suggested by the pain and edema that occurred in the area of the tumor in patients who had metastatic disease when therapy was started and by lymphocytic infiltrates in the tumor, as well as by the increase in cell-mediated cytotoxicity and the increase in percentage of active rosette-forming cells from subnormal to normal. Serial measurements of cell-mediated cytotoxicity are helpful in monitoring the efficacy of transfer factor and other modes of therapy in these patients, and these measurements are the best available criteria for selection of donors of tumor-specific transfer factor.

Adenocarcinoma↗
PubMed1975

Human thymus-derived rosette-forming cells and immunologic diseases.

This paper describes some studies done on the human lymphocytes that bind to normal sheep red blood cells in a rosette formation. On the basis of human fetal studies and investigations of markers for B cells, it is demonstrated that rosette-forming cells are valid markers for T cells. These cells were looked at in various immunologic diseases. A modification of the basic technic, one that detects subpopulations of lymphocytes, was mainly used. Results correlate closely with the cellular immune status of the patient.

Agammaglobulinemia↗