Biomedical subjects

D Char

Publications and source records attributed to D Char.

4 recordsLinked to original sources

PubMed1991

Transformation of T-lymphocyte subsets by Marek's disease herpesvirus.

Marek's disease herpesvirus (MDV)-transformed lymphoblastoid tumor cell lines were characterized for the presence of the surface markers. Monoclonal antibodies were used for CD3 (T-cell receptor [TCR] complex), TCR1, TCR2, and TCR3, CD4, CD8, and Ia antigen by indirect fluorescence staining followed by microscopic examination or flow cytometry. The lymphoblastoid cell lines were obtained from tumors from chickens infected with MDV (n = 44) or from local lesions induced by inoculation of allogeneic, MDV-infected chick kidney cells (n = 56). Lymphocytes were harvested from these lesions between 4 and 16 days postinoculation and cultured in vitro to establish cell lines. All cell lines expressed Ia antigen and CD3 and/or TCR and thus are activated T cells. Most of the cell lines developed from tumors were CD4+ CD8-; only one cell line was negative for both markers. Sixteen percent of the cell lines were TCR3+, while the remainder were TCR2+. The cell lines developed from local lesions were much more heterogeneous: 45% were CD4- CD8+, 34% were CD4- CD8-, and only 21% were CD4+ CD8-. The number of TCR3+ cell lines was larger than expected for the CD4- CD8+ and CD4- CD8- cell lines, as judged from the presence of these cells in the blood. These results indicate that several subsets of T lymphocytes can be transformed by MDV, depending on the pathogenesis of infection. Activation of T cells as a consequence of the normal pathogenesis or by allogeneic stimulation seem to be a first important step in the process of transformation.

Animals↗

PubMed1975

Rubella vaccination: fertility control in a large-scale vaccination program for postpubertal women.

Despite nationwide immunization programs, rubella infections during pregnancy continue. To solve this serious health problem direct immunization of women of reproductive age may be required. On a clinic basis, using nonphysician personnel, we vaccinated 404 susceptible women, ages 18 to 33; half were sexually active. Since pregnancy is proscribed for 2 to 3 months following rubella vaccination, a full range of family-planning services and a variety of contraceptive methods were used to ensure sustained fertility control. Sixteen vaccinees presented with possible conceptions in a 3 month follow-up. Of these, only five required treatment: two received diethylstilbestrol, two had menstrual inductions, and one an abortion. Administration of vaccine during a menstrual period was effective in preventing inadvertent vaccination of pregnant women. It was concluded that contraceptive counseling with adequate pregnancy termination backup makes it feasible to give rubella vaccine to highly motivated women.

Contraception↗

PubMed1975

Cell-mediated immunity in human acute leukemia.

The general cell-mediated immunological reactivity of patients with acute leukemia has been found to be intact, although it may be depressed by extensive disease or by chemotherapy. Patients with acute leukemia also have cellular immune reactivity against tumor associated antigens, as measured by skin tests for delayed hypersensitivity, lymphocyte stimulation, and 51Cr release cytotoxicity. Skin reactions to autologous and allogeneic crude membrane extracts of blast cells correlated with disease state, positive in many patients in remission and negative in most patients in relapse. Extracts of human lymphoid tissue culture cell lines derived from lymphomas or leukemia also gave positive reactions in patients with acute leukemia, and also in patients with lymphoma and nasopharyngeal carcinoma. The antigens detected in the skin tests with the lymphoid cell lines appear to be different from those associated with Epstein-Barr virus (EBV) and from those detected in the 51Cr release assay. Evidence is presented which suggests a complex variety of antigens on blast cells and on the cell lines. Although leukemia associated antigens were also detected by lymphocyte stimulation and by cytotoxicity assays, the results did not correlate with the skin tests nor with each other. The possible use of these assays for monitoring the chemotherapy and immunotherapy of acute leukemia patients is discussed.

Acute Disease↗

PubMedDate not supplied

Microscope sterility system.

The problem of microscope sterility during ophthalmic microsurgery has generally been managed by using sterilizable handle protectors, or by using some form of plastic sterilizable drape for the entire microscope. Both of these systems have disadvantages. A simple and effective alternative which has been designed for Zeiss operating microscopes and can be modified for other types of instruments is presented. No modification of the microscope is required. The instrument consists of two pieces: a metal bracket which mounts in the accessory shoe of the operating microscope, and a rigid plastic sterilizable portion which is readily attached on the microscope from below with three sterilizable screws. The entire assembly can be attached within 15 seconds. It affords complete sterility protection of the operative field; it provides a sterile surface for handling and moving the microscope; it does not interfere with accessory lighting systerms; and it allows open access to external accessories such as cameras and observer tubes.

Methods↗