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M B Epstein

Publications and source records attributed to M B Epstein.

7 recordsLinked to original sources

Monocyte subsets in neonates and children.

Volumetrically distinct subpopulations of peripheral blood monocytes, termed M1, M2, and M3, were identified in healthy normal adults and children. Because normal neonates have abnormal monocyte chemotaxis, it was determined whether monocyte subpopulations have different chemotactic capabilities and, if so, whether chemotactically active subpopulations were quantitatively deficient in neonates. Chemotaxis tests with zymosan-activated normal human serum as the chemoattractant and purified monocyte subpopulations revealed that large M3 monocytes were capable of significantly more directed migration than were small M1 and M2 monocytes. Volumetric analysis of monocytes from normal newborns rather than demonstrating an absence of M3 cells revealed that these cells were the predominant monocyte subpopulation. Therefore, we conclude that the impaired chemotactic ability of newborn monocytes is due to a functional rather than quantitative deficiency of M3 cells.

Adult

Studies on human monocytes with a multiparameter cell sorter.

Suspensions of human lymphocytes and monocytes separated by the Ficoll-hypaque method from the peripheral blood show a Coulter volume distribution, measured with a multiparameter cell sorter, characterized by a minor peak at 500 mu3, containing 5-15% of the cells, and a major peak at 200 mu3. Using fluorescent latex particles we have found that the monocytes, the cells that ingest the latex particles, all lie in the 500 mu3 peak; conversely, all of the cells in the 500 mu3 peak are monocytes. When the cell suspensions are incubated, the monocytes increase both the average volume and in absolute numbers. The number of monocytes approximately doubles during 3 days of incubation, when it reaches its maximum value. At that time we have found that all of the monocytes lack receptors for sheep red blood cells and all possess receptors for human gamma-globulin. The increase in monocyte number appears, therefore, to arise from the enlargement of "monocyte presursors" that resemble lymphocytes in volume and resemble both the monocytes and the B lyphocytes with respect to surface sheep red blood cell and human gamma-globulin receptors.

Animals