The association of substance use disorders with trauma exposure and PTSD among African American drug users.

This study examines the association of traumatic exposure, PTSD and substance use among 1098 out-of-treatment African American drug users. Over 40% of the respondents experienced a DSM-III-R qualifying traumatic event with 44% of those developing PTSD. Early onsets of marijuana and heroin use, alcohol dependence and opiate dependence were each associated with exposure to a traumatic event for males and early onset alcohol use and alcohol dependence were associated with females' exposure to a traumatic event.

High-affinity vanadate transport system in the cyanobacterium Anabaena variabilis ATCC 29413.

High-affinity vanadate transport systems have not heretofore been identified in any organism. Anabaena variabilis, which can fix nitrogen by using an alternative V-dependent nitrogenase, transported vanadate well. The concentration of vanadate giving half-maximum V-nitrogenase activity when added to V-starved cells was about 3 x 10(-9) M.