Risk of human immunodeficiency virus infection among pregnant crack cocaine users in a rural community

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.     

Book reviews

Shelter Is Not Enough: Transforming Multi-Storey Housing. Graham Towers. Policy, Bristol, 2000. ISBN 1861341563. 259 pp. RRP £19.99.

Social Policy in Aotearoa New Zealand: A Critical Introduction. Christine Cheyne, Mike O'Brien and Michael Belgrave. Oxford University Press, Auckland, 2000. ISBN 0195584422 (paperback). 275 pp.; bibliography and index. RRP NZ$37.95, A$28.95.

Citizenship and Migration: Globalization and the Politics of Belonging. Stephen Castles and Alastair Davidson. Macmillan, London, 2000. ISBN 0333643100. vii + 258 pp.; RRP $47.00.

Queer City: Gay and Lesbian Politics in Sydney. Craig Johnston and Paul van Reyk (eds). Pluto, Sydney, 2001. ISBN 1864031921. 322 pp. RRP $32.95.

Environmental Planning and Management in New Zealand. P. Ali Memon and Harvey C. Perkins (eds). Dunmore, Palmerston North, rev. edn, 2000. ISBN 086469363X (paperback). 401 pp.; bibliography and index. RRP NZ$66.00.

Resetting the Compass: Australia's Journey Towards Sustainability. David Yencken and Debra Wilkinson. CSIRO Publishing, Melbourne, 2000. ISBN 0643063854 (paperback). 416 pp.; endnotes and index. RRP $39.95.     

Structure and properties of (1 − x)BiFeO3 · xPbFe2/3W1/3O3 (0 ≤ x ≤ 1) solid solutions

(1 ? x)BiFeO₃ · xPbFe_2/3W_1/3O₃ ((1 ? x)BFO · xPFWO) samples with 0 ≤ x ≤ 1 have been prepared by a standard ceramic processing technique and characterized by X-ray diffraction, dielectric measurements, and Mössbauer spectroscopy. The system has been shown to contain a continuous series of perovskite solid solutions. The solid solutions in the range 0 ≤ x < 0.32 have a rhombohedral structure and those with 0.32 ≤ x ≤ 1 have a cubic structure. Increasing the BFO content from 0 to 40% leads to rapid degradation of the dielectric permittivity peak that occurs at 180 K in PFWO and is due to the relaxor behavior of this component. At higher BFO concentrations, the electrical conductivity of the solid solutions increases by about two orders of magnitude. The temperature dependences of permittivity for the samples containing ～80% BFO have prominent maxima around 430 and 520 K, whose position is frequency-independent. The solid solutions exhibited no piezoelectric or pyroelectric effect, probably because they were insufficiently poled in a field of 10 kV/cm at 300 K. At higher electric field intensities, the samples experienced breakdown.     

Preparation of Gd_(0.3)Ce_(0.7)O_(1.85-x) Single Buffer Layer for Coated Conductor Using a Novel-PACSD Method

To increase the critical thickness of CeO2 single buffer layer, the polymer assisted chemical solution deposition (PACSD) approach has been adopted to prepare a single buffer layer of Gd0.3Ce0.7O1.85-x (GCO) on bi-axially textured Ni-5%W alloy substrate, and the influences of different annealing temperatures on texture and microstructure of the buffer layer has also been studied in this paper. The results demonstrate that a well textured, dense and smooth GCO single buffer layer with thickness of 180 nm has...     

Comparison of two-dimensional MR digital subtraction angiography of the lower extremity with x-ray angiography

PURPOSE: To perform a preliminary evaluation of the diagnostic accuracy of contrast-enhanced, two-dimensional (2D) magnetic resonance (MR) digital subtraction angiography (DSA) of the lower extremity by comparison with x-ray angiography (XRA). MATERIALS AND METHODS: Forty lower extremities in 22 patients were imaged at multiple levels with both XRA and 2D MR DSA. Images were retrospectively analyzed by three radiologists in a randomized blinded manner. Seventeen vascular segments were graded as an insignificant lesion, a significant lesion, or as an occlusion. With the use of segments well depicted with XRA as the gold standard, the sensitivity, specificity, and accuracy of 2D MR DSA, as compared with XRA, were evaluated. The McNemar-Stuart-Maxwell test was performed to determine the significance of any differences found. RESULTS: Three hundred eighty-three arterial segments were evaluated with both techniques. Three hundred one segments were well depicted with XRA. There was no significant difference between 2D MR DSA and XRA for assessing the degree of occlusive disease in these 301 segments (.25 < P < .5). The sensitivity, specificity, and diagnostic accuracy of 2D MR DSA were found to be 90%, 98%, and 93%, respectively. CONCLUSION: Two-dimensional MR DSA is an accurate method for assessing arterial lesions in the lower extremity.     

Fundamental cryobiology of selected African mammalian spermatozoa and its role in biodiversity preservation through the development of genome resource banking

Fundamental cryobiological characteristics of spermatozoa from threatened or endangered species must be determined for successful cryopreservation techniques to be established. In this study, spermatozoa from four diverse species, impala (Aepyceros melampus), wart hog (Phacochoerus aethiopicus), elephant (Loxodonta africana), and lion (Panthera leo), were collected by electroejaculation or epididymal aspiration. Spermatozoal plasma membrane permeability to water (hydraulic conductivity, Lp) and the osmotically inactive fraction of the sperm cell (Vb) were determined from each species. Changes in cell volume were measured over time using an electronic particle counter. A Kedem-Katchalsky membrane transport model was used to theoretically characterize the data to determine Lp and Vb for each species. In addition to determining plasma membrane characteristics, spermatozoa were also studied to determine their sensitivity to low temperatures and to permeating cryoprotectant solutes. Cells maintained at room temperature (20-22 degrees C) were slowly or rapidly exposed to cold temperatures (1-4 degrees C), and percent motility was estimated to determine the sensitivity of the cells to cooling. Spermatozoa were also in media containing 1 M glycerol, dimethyl sulfoxide or ethylene glycol, and percent motility was measured at 15, 30 and 60 min intervals to determine the sensitivity of the cells to the cryoprotectant agent over time. Results indicate that sperm motility is significantly effected by decreased temperatures and the presence of cryoprotectant agents.     

The association between cigarette smoking and selected HIV-related medical conditions

OBJECTIVE: To clarify the effect of cigarette smoking on the development of conditions associated with HIV infection. DESIGN: Prospective and retrospective cohort study, with interview and examination twice a year since 1988. METHODS: Data on 516 HIV-infected men from cohorts of homosexual and bisexual men in San Francisco, Denver and Chicago, who were repeatedly interviewed and examined between 1988 and 1992, were analysed. After excluding men who did not have well-defined dates of seroconversion and those who were classified as ex- or intermittent smokers, 232 men remained for analysis: 106 were smokers and 126 were non-smokers. Univariate and Kaplan-Meier survival analyses were performed to assess the relationship between cigarette smoking and loss of CD4+ T-lymphocytes, diagnosis of any AIDS-defining illness, and specific diagnosis of Kaposi's sarcoma, Pneumocystis carinii pneumonia (PCP), oral candidiasis, hairy leukoplakia, and community-acquired pneumonia. RESULTS: By univariate analyses, cigarette smoking was not associated with clinical AIDS, loss of CD4+ cells, Kaposi's sarcoma or PCP, but was significantly associated with oral candidiasis [relative risk (RR), 1.32; 95% confidence interval (CI), 1.02-1.70], hairy leukoplakia (RR, 1.51; 95% CI, 1.15-1.99), and community-acquired pneumonia (RR, 2.62; 95% CI, 1.30-5.27). Dose-response effect was also evident for these three conditions (all P < 0.01). Kaplan-Meier survival analysis indicated no association between cigarette smoking and time of progression to clinical AIDS, Kaposi's sarcoma (KS), or PCP (P = 0.62, 0.54 and 0.11, respectively) but showed that cigarette smokers developed oral candidiasis, hairy leukoplakia, and pneumonia more quickly than non-smokers (P = 0.031, 0.006 and 0.009, respectively). CONCLUSIONS: Cigarette smoking was not associated with an increased likelihood or rate of developing KS, PCP or AIDS, but was associated with developing community-acquired pneumonia, oral candidiasis, and hairy leukoplakia in these HIV-infected men.     

Collaboration between pharmacy and laboratory: defining total allowable error limits for therapeutically monitored drugs

The incidence of serious breast pathology in children and adolescents is low. Despite this, children, adolescents, and their parents come to the primary care provider with many breast-related concerns. Tanner staging is a good predictor of ensuing physical sexual development and can be used as a tool to reassure the pubertal girl that she is normal. Variations such as polythelia, premature thelarche, gynecomastia, nipple irritation from exercise, and nipple piercing and tattooing can be managed with education and reassurance. Whereas breast cancer is extremely rare in adolescents, evaluation with ultrasonography may be indicated. The primary care provider plays a central role in educating young girls and adolescents about healthy breast practices such as avoidance of alcohol and cigarette smoking, exercise, low-fat diet, breast self-examination, and avoidance of piercing and tattooing.