Biomedical subjects
Publications and source records attributed to P E Harrington.
The enantiospecific total synthesis of natural roseophilin has been completed in 7.0% overall yield over 15 steps by means of an asymmetric cyclopentannelation. This establishes the absolute configuration of the natural product as 22R,23R. Cyclopentenone (+)-12 was prepared in 78% yield and 86% ee in the key step.
An effective synthesis of tricyclic, nonclassical cannabinoids has been developed on the basis of a cation-olefin cyclization that forms the two nonaromatic rings with the desired stereochemistry in a single step.
An enantioselective variant of the synthesis of cross-conjugated cyclopentenones, based on D-glucose-derived chiral auxiliaries, is described. Minor modification of the method makes it applicable to the preparation of both enantiomeric series of products. Both enantiomers of the key intermediate in our roseophilin synthesis have been prepared.
[formula: see text] The formal total synthesis of the macrocyclic core of roseophilin 4 has been accomplished in 12 steps from 5-hexenal 8. The cyclopentannelation reaction was used to form the aliphatic five-membered ring of 3. Diene 2 was assembled by means of a Stetter reaction. Ring-closing metathesis of 2, reduction, and Knorr reaction of the 1,4-diketone 5 gave the ketopyrrole 3.
OBJECTIVE: To investigate why women who use crack cocaine are at increased risk of human immunodeficiency virus (HIV) infection. METHODS: One thousand one hundred fifty-two (99.7%) of 1155 consecutive prenatal patients attending a rural public health clinic were interviewed about drug use and sexual practices and tested for HIV infection and other sexually transmitted diseases. RESULTS: Fifty-one (4.7%) of 1096 pregnant women reported ever using crack cocaine, but only five (10%) of the crack cocaine users had ever injected drugs. Eighteen (35%) of the crack users were HIV infected compared with 22 (2%) of the 1045 women who reported never using crack (odds ratio 25, 95% confidence interval 12-52; P < .001). Crack users were more likely to have had a known HIV-infected sex partner, exchanged sex for money or drugs, and tested positive for syphilis than were non-crack users (for each comparison, P < .001). Before using crack, 18% of crack users had exchanged sex for money or drugs and 8% had averaged three or more sex partners per month; in contrast, after beginning to use crack, 76% of crack users exchanged sex for money or drugs and 63% averaged three or more sex partners per month (for both comparisons, P < .001). Crack users who were not HIV infected were more likely to have almost always used condoms and/or had fewer than three sex partners per month than were HIV-infected crack users (P < .01). CONCLUSION: Women who reported using crack cocaine were at an increased risk of HIV infection because crack use was associated with a significant increase in unprotected sexual contact.
BACKGROUND: In the United States, an increasing proportion of women infected with the human immunodeficiency virus (HIV) live in nonmetropolitan areas. Little is known, however, about the risk factors for HIV transmission in women outside large cities. METHODS: We interviewed and tested 1082 (99.8 percent) of 1084 consecutive pregnant women who registered for prenatal care at a public health clinic in western Palm Beach County, Florida. This rural agricultural area of about 36,000 people is known to have a high prevalence of HIV infection. RESULTS: The seroprevalence of HIV was 5.1 percent (52 of 1011 women). Black women who were neither Haitian nor Hispanic had the highest rate of infection (8.3 percent [48 of 575]). Only 4 of 1009 women (0.4 percent) reported ever injecting drugs, and the 4 were HIV-seronegative; however, 14 of 43 users of "crack" cocaine (33 percent) had HIV infection. At prenatal registration, 131 of 983 women (13 percent) tested positive for gonorrhea, chlamydial infection, or syphilis. By multivariate logistic-regression analysis, HIV infection was found to be independently associated with having used crack cocaine (odds ratio, 3.3; P < 0.001), having had more than two sexual partners (odds ratio, 4.6; P < 0.001), being black but neither Hispanic nor Haitian (odds ratio, 11; P < 0.001), having had sexual intercourse with a high-risk partner (odds ratio, 5.6; P < 0.001), and testing positive for syphilis (odds ratio, 3.1; P = 0.015). Nevertheless, 11 of the 52 HIV-infected women (21 percent) reported a total of only two to five sexual partners and no known high-risk partners, had never used crack cocaine, and had no positive tests for sexually transmitted disease. CONCLUSIONS: In the rural community we studied, most of the women with HIV infection acquired it through heterosexual contact. The increasing seroprevalence of HIV and the increasing incidence of syphilis and use of crack cocaine mean that other women may be at similar risk of acquiring heterosexually transmitted HIV infection.