Ultrastructural Features of Phytohemagglutinin and Concanavalin A – Responsive Lymphocytes in Chronic Lymphocytic Leukemia

Abstract

Peripheral blood lymphocytes from patients with chronic lymphocytic leukemia (CLL) had diminished and/or delayed in vitro responses to both phytohemagglutinin (PHA) and concanavalin A (Con A) as determined by thymidine incorporation into DNA, over a 9-day incubation period. The cytoarchitectural features of CLL lymphocytes stimulated by each of the mitogens were similar to those observed in transformed normal cells. However, as shown by planimetric measurements, the mean cell area and the nuclear, cytoplasmic, and mitochondrial areas were diminished in comparison to PHA-stimulated normal cells. The data suggest that some CLL lymphocytes which transform with PHA or Con A are residual normal thymus-dependent (T) lymphocytes, and others may be derived from the metabolically defective leukemic cell population

<i>In vivo </i>Stimulation of Nerve Cells by Phytohemagglutinin

“…The increase of cell section area was determined by electron-microscopic morphometric methods {Douglas et al, 1973). One can calculate from the data of Douglas et al (1973) that the volume increase is about 13-fold during 72 h for normal lymphocytes, i.e. the cell volume increases by a factor of about 3.6 by the 20th hour after PHA addition, when Quastel and Kaplan (1970b) found 2.5 times increased 42K uptake.…”