Inhibition of Lymphocyte Stimulation by Measles Virus

The effect of measles virus on phytohemagglutinin-(PHA) induced stimulation of human peripheral blood mononuclear cells was investigated to delineate possible mechanisms for viral suppression of cell-mediated immunity (CMI). It was noted that medium which had several days contact with uninfected monolayers as well as unpurified measles virus preparations produced significant inhibition of 3H-thymidine incorporation by PHA-stimulated lymphocytes. When partially purified measles virus preparations were used, however, marked inhibition was observed and the inhibitory effect of cell-derived factors could be separated easily from the virus-induced inhibition.

Experiments to determine the mechanisms of this virus-induced inhibition of 3H-thymidine incorporation showed the following: 1) live measles virus and not UV-irradiated or heat-inactivated virus produced inhibition; 2) the inhibitory effect observed was not the result of a viral-induced inhibitor being released from measles-infected lymphocytes; and 3) monocyte depletion had no effect on the ability of measles virus to inhibit 3H-thymidine incorporation by PHA-stimulated lymphocytes.

Since it was found that measles virus-infected lymphocytes display an impaired response to in vitro PHA stimulation, perhaps this dysfunction may be extended to mediator release and other functions associated with delayed cutaneous hypersensitivity (DCH) in vivo.

Increased viability of a strain of Neurospora crassa after treatment with ultraviolet radiation or other agents

A strain of Neurospora crassa with low viability but near normal germination shows a two- to sixfold increase in the number of colonies formed after treatment with ultraviolet radiation, X radiation, nitrous acid, or heat (50 C). Effective dosages of these agents produce moderate killing of the wild type.

Some observations of ascospores of Neurospora crassa made with a scanning electron microscope

Scanning electron micrographs of ascospores of Neurospora crassa reveal two of the structures which develop during germination and outgrowth: (i) a germination pore and (ii) the probable site of initiation of hyphal cell wall synthesis.

Effects of long-term reserpine treatment on brain tyrosine hydroxylase and behavioral activity

Treatment of rats with reserpine (for 8 or 9 days) produced a temporally related increase in behavioral activity and in tyrosine hydroxylase activity in the midbrain. Weight loss resulting from such treatment was not sufficient, by itself, to account for either the behavioral or enzymatic changes. The results support the role of catecholamines in behavioral arousal.