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M Halperin

Publications and source records attributed to M Halperin.

61 records · Page 4Linked to original sources

On the use of the logistic model in prospective studies.

We describe the usual statistical concepts and consequent appropriate simulations of a prospective study for the simple case of a single risk variable and an assumed logistic model. We examine the simulations of Lilienfeld and Pyne, and show that they are seriously flawed. Contrary to those authors' claims, the estimates of parameters by the Walker-Duncan technique are both accurate and reliable.

Biometry↗

Effect of mycobacterial lipids on membrane fluidity and natural killer cell-mediated cytotoxicity.

A total lipid fraction was extracted from BCG and used for the lipid modulation of effector and target cells in relation to the effect of mycobacterial lipid on human natural-killer(NK)-cell-mediated cytotoxicity. Treatment of the cells with the lipid fraction resulted in decreased membrane fluidity and inhibition of NK-cell-mediated cytotoxicity irrespective of whether the targets or the effectors were treated. These results were obtained in the chromium release assay and the single cell assay. Pretreatment of target cells did not affect binding between target and effector cells, whereas pretreatment of effectors resulted in inhibition of conjugation. These results are discussed with respect to known effects of lipid modulation of target and effector cells on NK-cell-mediated cytotoxicity and of mycobacterial lipids on immune responses.

Antibody-Dependent Cell Cytotoxicity↗