Characterization of human lymphocytes which proliferate "spontaneously" in vitro

Bromodeoxyuridine: a diagnostic tool in biology and medicine, Part III. Proliferation in normal, injured and diseased tissue, growth factors, differentiation, DNA replication sites and in situ hybridization

This paper is a continuation of parts I (history, methods and cell kinetics) and II (clinical applications and carcinogenesis) published previously (Dolbeare, 1995 Histochem. J. 27, 339, 923). Incorporation of bromodeoxyuridine (BrdUrd) into DNA is used to measure proliferation in normal, diseased and injured tissue and to follow the effect of growth factors. Immunochemical detection of BrdUrd can be used to determine proliferative characteristics of differentiating tissues and to obtain birth dates for actual differentiation events. Studies are also described in which BrdUrd is used to follow the order of DNA replication in specific chromosomes, DNA replication sites in the nucleus and to monitor DNA repair. BrdUrd incorporation has been used as a tool for in situ hybridization experiments.

Lymphocyte subpopulations in multiple sclerosis: spontaneous and mitogen-induced activity

Lymphocytes of chronic progressive multiple sclerosis (MS) patients and healthy persons were isolated by nylon-wool column filtration followed by density centrifugation. Incubating part of these lymphocytes with 2- aminoethyliso thiouronium bromide hydrobromide-treated sheep erythrocytes resulted in two other subfractions, the rosette-forming (E+) lymphocytes and the nonrosette -forming (E-) lymphocytes. Increased spontaneous activity was observed with the nonfractionated lymphocyte populations and with the E+- and E- -cell fractions of MS patients compared to the corresponding cell populations of controls following a culture period of one or several days. Phytohemagglutinin- and pokeweed mitogen-induced stimulation of these different lymphocyte fractions was the same in MS patients and controls. No influence of disease activity could be found on the immune parameters. Characterization of the different lymphocyte populations with monoclonal anti-human T-cell antibodies demonstrated a prevalence for helper T cells in forming rosettes.

Opiate receptors on lymphocytes and platelets in man

Receptors for opiates, opiate-like substances, and their antagonists, such as naloxone (a close chemical and conformational congener of morphine), on brain cell homogenates and neuroblastoma X glioma hybrid cells in tissue culture have been reported. The present study on the binding of [3H]naloxone to lymphocytes and platelets freshly isolated from the peripheral blood of 39 healthy adult human volunteers showed that (1) [3H]naloxone bound to lymphocytes and platelets at 4 degrees C, reaching equilibrium in 30 min, and was not removed by washing (three times) with the suspending medium; (2) the binding of [3H]naloxone to cells decreased in the presence of increasing amounts of unlabeled naloxone, approaching a plateau; (3) significant amounts of the radioligand remained bound in the presence of micromolar quantities of the unlabeled ligand; and (4) in the absence of Na+ ions, 1 to 10 nmol of morphine hydrochloride for 10(6) lymphocytes, and 1 to 25 nmol of morphine hydrochloride for 10(8) platelets, decreased the binding of [3H]naloxone by 43 to 57%. It is concluded that at least some of the [3H]naloxone binding sites on human lymphocytes and platelets are specific opioid receptor sites of the mu type (Enkephalins define the delta sites.) The observations on the binding of naloxone to cells do not appear to be artifacts. Opioid receptor sites on lymphocyte and platelet membranes may have properties similar to those on nerve cell membranes.