Linear mapping of tryptophan residues in Vesiculovirus M and N proteins by partial chemical cleavage.

Nonlimit chemical cleavage at tryptophan residues of protein labeled at the amino terminus afforded a simple procedure for generating specific fragments and for mapping tryptophan positions. A comparison of the matrix (M) and nucleocapsid (N) proteins of four members of the Vesiculovirus group by this procedure suggests considerable conservation of tryptophan number and location in the four serotypes examined.     

In vitro heterologous cytotoxicity by T effector cells from mice immunized with Sindbis virus.

An in vitro correlate of cell-mediated cross-protection among alpha-viruses was demonstrated by cytotoxicity of Sindbis-immune spleen cells from mice to both Sindbis and Semliki Forest virus (SFV)-infected target cells. This cytotoxicity was shown to be mediated by the T cell population of the spleen and was independent of the presence of macrophages or B cells. The time when the level of the lymphocyte-mediated cytotoxicity (LMC) to SFV-infected cells was maximal coincides with the time when immunity to SFV is maximal in vivo, as reported previously, and when adoptive immunity to SFV can be transferred. After one i.p. injection of Sindbis virus, the level of homologous LMC was higher than the level of heterologous LMC. However, following a second injection of Sindbis virus as immunogen, at a time when the mice are cross-protected to SFV, the heterologous LMC was considerably higher than homologous LMC. We propose that there is suppression of the effector T cells specific for Sindbis-infected cells after the second immunizing injection, probably by homologous antibody. In contrast, there appears to be an anamnestic cell-mediated response to SFV.     

Sézary's syndrome and generalized plane xanthoma.

The first case of Sézary''s syndrome associated with generalized plane xanthoma is reported, thereby extending the association of lymphoreticular proliferative disorders with plane xanthomatosis. The association of Sézary''s syndrome with plane xanthomatosis may be an in vivo example of defective cell regulation involving the major cellular components of the immune response.     

Chemical composition and ultrastructure of the epicuticular wax in three lines of Brassica napus (L)

The epicuticular wax in three lines of Brassica napus (rape) has been investigated and the detailed chemistry and ultrastructure of the waxes examined. A distinct chemical make-up has been found for all three waxes which is correlated with three distinct crystallite structures. A tentative scheme for classification of Brassica wax mutants is described in which the two newly analysed rape mutants can be placed. Mass spectral analysis of all wax components confirms and extends previous ideas about the chemistry of Brassica waxes.     

Cardiovascular hemodynamics with increasing exercise intensities in postmenopausal women.

We sought to determine the cardiovascular responses to increasing exercise intensities in postmenopausal women with different physical activity levels and hormone replacement therapy (HRT) status. Forty-four women (11 sedentary, 19 physically active, 14 master athletes; 24 not on HRT, 20 on HRT) completed treadmill exercise at 40, 60, 80, and 100% of maximal oxygen consumption. Oxygen consumption, heart rate, blood pressure, and cardiac output, determined via acetylene rebreathing, were measured at each exercise intensity. HRT did not affect cardiovascular hemodynamics. Stroke volume (SV) decreased significantly between 40 and 100% of maximal oxygen consumption in all groups, and the decrease did not differ among groups. The greater oxygen consumption of the athletes at each intensity was due to their significantly greater cardiac output, which was the result of a significantly greater SV, compared with both of the less active groups. The athletes had significantly lower total peripheral resistance at each exercise intensity than did the two less active groups. There were no consistent significant hemodynamic differences between the physically active and sedentary women. These results indicate that SV decreases in postmenopausal women as exercise intensity increases to maximum, regardless of their habitual physical activity levels or HRT status.