A new human leukemia cell line, designated as ME-1, was established from the peripheral blood leukemia cells of a patient with acute myelomonocytic leukemia with eosinophilia (M,E,). This cell line has the characteristic chromosome abnormality of M,E,, inv(l6) (p13q22). When cultured in RPMI 1640 medium containing 10% fetal calf serum, ME-1 cells were monoblastoid, but with the addition of cyto...

The response of lymphocytes from patients with syphilis and normal subjects was studied in vitro by using phytohemagglutinin (PHA), pokeweed mitogen (PWM), streptolysin O (SLO), and a preparation of Treponema refringens. Normal lymphocytes exhibited a dose-response curve to treponemes. Although lymphocytes from patients with primary and secondary syphilis responded normally to PHA and PWM, thei...

Inosine pranobex (inosine dimepranol acedoben, isoprinosine) (Inos) is an immunomodulatory and antiviral drug used in some viral infections, especially in patients with weakened immunity. In the present study, effects of Inos on the production of cytokines attributable to Th1 (IL-2, IFN-g, and TNF-a) or Th2 cells (IL-4, IL-5, and IL-10) were tested in human peripheral blood lymphocyte cultures ...

Uncultured human leukocytes contain no detectable cystathionine synthase activity. A method is described in which the addition of phytohemagglutinin (PHA) to short-term lymphocyte cultures results in a significant induction of enzymatic activity. This PHA-stimulated activity has characteristics that resemble those previously described for cystathionine synthase of normal liver and cultured fibr...

Concanavalin A (Con A) and phytohemagglutinin (PHA) released histamine from hamster mast cells incubated in a serum-free medium. Concentrations of Con A and PHA approximating those optimal for transforming lymphocytes also released maximal amounts of histamine without apparent cytotoxicity. Higher concentrations of mitogen inhibited both lymphocyte transformation and histamine release. Incubati...

A new human leukemia cell line, designated as ME-1, was established from the peripheral blood leukemia cells of a patient with acute myelomonocytic leukemia with eosinophilia (M,E,). This cell line has the characteristic chromosome abnormality of M,E,, inv(l6) (p13q22). When cultured in RPMI 1640 medium containing 10% fetal calf serum, ME-1 cells were monoblastoid, but with the addition of cyto...

Nigericin, an ionophore that exchanges K+ for H+ across most biologic membranes, reversibly inhibited the proliferative response of human lymphocytes to phytohemagglutinin (PHA). Inhibition occurred at nigericin concentrations of 10(-8) M or greater, and only during the early event of mitogenesis. There was no effect if nigericin was added 24 h or later after the initiation of PHA-stimulated cu...

In vitro rubella virus infections of lymphocytes from normal adult humans impaired their responsiveness to phytohemagglutinin (PHA) stimulations; a situation which seemed analogous to the PHA unresponsiveness of peripheral lymphocytes from babies with the congenital rubella syndrome. Such in vitro viral infection of normal cells also decreased the synthesis of normal nucleic acids and structura...

The need for agents designed to modify immune response in the treatment of patients with viral infection, immunodeficiency, or cancer prompted the present study on the mechanisms of action of isoprinosine, a compound developed for antiviral use and whose therapeutic activity may involve the immune system. The effect of isoprinosine on in vitro proliferation of human peripheral blood lymphocytes...

A suspension culture technique for the study of peripheral blood cells from patients with leukemia is described. Cells from patients in relapse were preserved by freezing with dimethylsulfoxide at -70#{176}C to ensure the availability of the same population of cells for repeated experiments of varying designs. Cells from one AML patient proliferated only in the presence of phytohemagglutinin (P...