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G Cohnen

Publications and source records attributed to G Cohnen.

23 records · Page 2Linked to original sources
PubMed1975

Peripheral blood T and B lymphocytes in men in different age groups.

Peripheral blood T and B lymphocytes were determined in normal humans at different ages. Spontaneous rosette formation with sheep red blood cells (SRBC) was used as a marker for T cells. B cells were detected by immunofluorescent staining of membrane-bound immunoglobulins. Blood samples from old individuals contained significantly lower T lymphocyte numbers than those from children. This diminution of circulating T cells caused a reduction of the total lymphocyte count in the elderly persons. No significant differences were between the T cell values of young and old adults. Whereas the percentages of B cells indicated an increase of this lymphocyte population in old humans, the absolute numbers of B lymphocytes remained almost unchanged during aging.

Adult↗
PubMed1975

[T and B lymphocytes in chronic lymphocytic leukemia and Hodgkin's disease. Electron microscopic and immunologic studies].

The number of lymphocytes forming spontaneous rosettes with sheep erythrocytes, a property of thymus-dependent (T) cells, and the number of lymphocytes bearing surface immunoglobulins, a characteristic feature of bone marrow-dependent (B) cells, were determined in the peripheral blood of normals and of patients with chronic lymphocytic leukemia (CLL) and Hodgkin's disease. As compared with normal individuals CLL patients had an increased percentage of lymphocytes with membrane-bound immunoglobulins, whereas the proportion of rosette-forming lymphocytes was reduced. In Hodgkin's disease either normal, diminished, or increased B cell values were obtained; the percentage of T cells was decreased or within the lower range of normals. Lymphocyte transformation by various mitogenic agents in vitro may be regarded as a model of lymphocyte reactivity during immunologic processes in vivo. In order to study the functional capacity of lymphocytes in CLL and Hodgkin's disease in comparison with normal cells, purified peripheral blood lymphocytes from normals and patients with these diseases were incubated in vitro with phytohemagglutinin (PHA) and pokeweed mitogen (PWM) over 7 to 11 days. DNA synthesis was determined by incorporation of 3-H-thymidine. The cyto-architectural features of the cells before and during incubation with these phytomitogens were studied by electron microscopy. Planimetric measurements were performed on micrographs of comparable cell sections (through nucleus and Golgi zone) for the determiniation of cell, nuclear, cytoplasmic, and mitochondrial area. Furthermore, the number of mitochondria and of membrane-bounded acid phosphatase-positive lysosome-like organelles was determined in comparable sections of unstimulated and mitogen transformed lymphocytes.

Antibody Formation↗