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Biomedical subjects

Y Kodera

Publications and source records attributed to Y Kodera.

At least 325 records · Page 18Linked to original sources

Inactivation of the mitogenic property of pokeweed mitogen by erythrocytes.

In whole blood culture, pokeweed mitogen (PWM) is unable to stimulate human lymphocytes. This is because the mitogenic property of PWM is inactivated by erythrocytes, presumably due to absorption. The inactivation was observed with as few as 5 x 10(6)/ml of human erythrocytes. Therefore, when PWM is used to study the functions of human lymphocytes, especially of suppressor T lymphocytes, erythrocytes should be removed from lymphocyte preparations for accurate analysis.

Absorption↗

Human blood T lymphocytes that suppress the mixed leukocyte culture reactivity of lymphocytes from HLA-B14 bearing individuals.

A nontransfused male patient with recurrent bladder carcinomata has been demonstrated to have blood T lymphocytes that suppress the MLC responsiveness of lymphocytes only from normal individuals positive for HLA-B14. Unexpectedly, this T-suppressor cell differs from three other reported blood T-suppressor cells arising in man in that it apparently does not require HLA-D locus compatibility between the suppressor cell and the lymphocyte being suppressed.

Epitopes↗

In vitro immune parameters in relation to clinical course in transitional cell carcinoma.

Longitudinal experiments were performed in which lymphocytes from patients were compared with simultaneously studied normals. Patient lymphocytes were examined for their ability to function as stimulator and responder cells in a one-way MLC. Additionally, lymphocyte mitogenic response to PHA and Con A were examined. We observed changes in these parameters that could be correlated with the clinical course of the patients.

Carcinoma, Transitional Cell↗

Factors that affect the results of microcytotoxicity testing in man.

A great number of variables affect the pattern of test results obtained in studies of cell-mediated cytotoxicity of blood lymphocytes for tumor cells in vitro. The classic microcytotoxicity test measures both cell destruction and effects on cell growth. Microcytotoxicity tests in which isotopically prelabeled target cells are used measure primarily cell destruction. The method of preparation of effector cells from human blood can greatly influence results of such tests. Perhaps the most clear-cut example of this influence is the effect of Tris--NH4Cl treatment of effector cells to lyse contaminating red blood cells. This treatment inactivates the lytic function of certain effector cell types. In addition, a major consideration that must be kept in mind is the difference in patients under study by different groups of investigators.

Cell Separation↗

Function of cryopreserved human effector cells in antibody-dependent, cell-mediated cytotoxicity.

Cells active in an ADCC model were studied for their ability to withstand cryopreservation. For this model, we used the [3H]proline microcytotoxicity assay with fibroblast target cells and a serum containing lymphocyte-dependent antibody reactive with the alloantigens on those target cells. Human blood effector cells active in this system can be successfully cryopreserved with minor dimunition in function with standard techniques and concentrations between 9 and 12% DMSO.

Antibody-Dependent Cell Cytotoxicity↗

Occurrence of restricted suppressor T-cell activity in man.

Blood leukocytes from an immunologically hyporesponsive patient with urinary bladder carcinoma were found to be deficient in their ability to stimulate 3 of 27 responder leukocyte preparations from normal individuals in one-way mixed leukocyte culture (MLC). The patient's T-depleted leukocytes, however, functioned adequately as stimulator cells. T-enriched lymphocytes from this patient suppressed the MLC responsiveness of those three normals but not the responsiveness of other normals. The patient's cells suppressed the MLC responsiveness of only one of each of the parents of two of the normals who could be suppressed by the patient's leukocytes suggesting a possible genetic restriction to this suppressor cell activity.

HLA Antigens↗

Antibody-dependent cell-mediated cytotoxicity for human monolayer target cells bearing blood group and transplantation antigens and for melanoma cells.

A sensitive assay for antibody-dependent cell-mediated cytotoxicity (ADCMC) was developed utilizing serum from a patient with gestational choriocarcinoma and the 3H-proline microcytotoxicity test for detection fo destruction of monolayer target cells. Conditions for optimal expression of ADCMC were investigated using serum from this patient and skin fibroblasts from her husband and daugther as target cells with semi-purified blood leukocytes from normal donors as effector cells. Factors critical for optimal expression of ADCMC in this assay are the selection of effector cell donors possessing high levels of activity in the presence of serum with known lymphocyte-dependent antibody. (LDA), the effector cell preparative technique, and incubation for up to 40 h. Tris-NH4Cl lysis of red blood cells was found significantly to reduce effector cell activity. Under optimal conditions, the LDA titer of this patient's serum was greater than 10(-4). The sensitivity of the assay was confirmed by the detection of LDA activity of an anti-blood-group antibody at dilutions not demonstrating hemagglutination, and by the induction of ADCMC for blood group A antigen-bearing target cells by normal sera of B and O blood groups. In a preliminary study of sera from 16 melanoma patients on the corresponding antologous tumor target cells, four had significant LDA. Further studies are under way to determine specificty, incidence, and relationship of LDA-positive autologous sera to course of disease.

Antibodies, Anti-Idiotypic↗