To test the hypothesis that cognitive impairment may be present early in the course of HTLV-III/LAV infection, intravenous drug abusers (IDVAs) without overt symptoms of AIDS related illness were tested with standard neuropsychological and psychosocial measures. This study is the baseline for a prospective longitudinal study of the natural history of… (More)
We consider a regression to the mean problem with a very large sample for the first measurement and relatively small subsample for the second measurement, selected on the basis of the initial measurement. This is a situation that often occurs in screening trials. We propose to estimate the unselected population mean and variance from the first measurement… (More)
Platelet-activating factor (PAF), a potent endogenous phospholipid released by a variety of mammalian cells, induces platelet activation in vivo and in vitro. Little is known, however, about the physiological modulation of its actions. We have examined the ability of two naturally occurring compounds which stimulate cAMP production, vasoactive intestinal… (More)
A procedure is given for estimating the ratio of the means of two populations using the data from two independent random samples when the observations are normally distributed with population variances that are related to the population means.