Young adults' trajectories of Ecstasy use: A population based study

Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19–23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1–2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (> 70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns.     

INFANT MORTALITY IN SOCIOECONOMICALLY ADVANTAGED AND DISADVANTAGED AREAS OF BRISBANE

Problems in defining social class and its relationship to health are discussed and the results of a study of infant mortality from 1976 to 1979 in socioeconomically ranked suburbs of Brisbane are presented. The ranking is according to a score developed from aggregate suburb data gathered at the 1976 and 1981 censuses; the population at risk was ascertained from published annual suburb birth figures, and numbers of death by suburb, age and cause, from computerised mortality files. Significantly higher mortality rates in lower ranking suburbs were observed. Possible explanations for, and implications of, the findings are discussed.     

Social class, religion and contraceptive failure in a sample of pregnant women in Brisbane

4000 pregnant women were specifically asked about the method of contraception they last used and whether their pregnancy was a consequence of a failure of contraception. Social, economic, and religious variables were examined to assess the extent to which these were associated with differing rates of contraceptive failure. As part of a longtitudinal study of the outcomes of pregnancy, all women seeking antenatal care at a large public hospital in Brisbane (Australia) were enrolled at their 1st visit. The direct method of standardization was used to examine the contraceptive failure rate for the demographic variables of interest. This allowed adjustment for any effect of associated variables by calculating a weighted average of the specific rates within each category. Variation in the standardized rates of contraceptive failure was examined by a chi-squared test and, where appropriate, supplementary stepwise chi-squared tests were used to detect an upward or downward trend in rates for an ordinal demographic variable. While the rate of unwanted/unplanned pregnancies differed according to the criterion chosen, the variation was between 22% who believed their pregnancy was attributable to a contraceptive failure and 58% who stated that they did not plan their pregnancy or were unsure about whether it was planned or not. Altogether 29% of women acknowledged the possibility or probability of contraceptive failure. Single women were about twice as likely as married women to report contraceptive failure. These differences were independent of age differences between the marital status group. Single women and those "living together" reported the highest failure rates regardless of the most recent method of contraception used. The standardized rate at which a particular method was reported to fail did not relate significantly to the mother's educational or occupational status. More educated women had higher contraceptive failure rates because they were more frequent users of the "rhythm" method and this method fails about half the time. Lower income women reported higher rates of contraceptive failure because they tended to be less successful users of oral contraceptives (OCs. Reported contraceptive failure rates appeared relatively consistent for the method of contraception reported. Women who were more frequent church attenders reported somewhat higher rates of contraceptive failure.     

Regulation of human peripheral blood BFU-E growth in vitro by leukaemic B-lymphocytes

We report a stimulating effect of leukaemic B-lymphocytes from anaemic and non-anaemic patients with CLL on the proliferation of normal peripheral blood BFU-E. Coculture of leukaemic B-cells at various concentrations (2.5 X 10(3)-10(6)) with 2.5 X 10(5) mononuclear cells from normal peripheral blood increased the number of BFU-E derived erythroid colonies. The same effect was observed when the number of target cells was varied in the presence of a fixed number of B-lymphocytes, with a clear linear relationship. B-cell conditioned medium gave a similar increase when added to the culture instead of B-cells. At high concentration of B-cells from anaemic patients, the size of the colonies was increased and a large number of macroscopic colonies was seen. The place of the B-cells in the regulation of erythroid progenitors in relation to monocytes and T-lymphocytes has still to be established.     

The properties of the International Classification of the External Cause of Injury when used as an instrument for injury prevention research.

OBJECTIVE: To demonstrate properties of the International Classification of the External Cause of Injury (ICECI) as a tool for use in injury prevention research. METHODS: The Childhood Injury Prevention Study (CHIPS) is a prospective longitudinal follow up study of a cohort of 871 children 5-12 years of age, with a nested case crossover component. The ICECI is the latest tool in the International Classification of Diseases (ICD) family and has been designed to improve the precision of coding injury events. The details of all injury events recorded in the study, as well as all measured injury related exposures, were coded using the ICECI. This paper reports a substudy on the utility and practicability of using the ICECI in the CHIPS to record exposures. Interrater reliability was quantified for a sample of injured participants using the Kappa statistic to measure concordance between codes independently coded by two research staff. RESULTS: There were 767 diaries collected at baseline and event details from 563 injuries and exposure details from injury crossover periods. There were no event, location, or activity details which could not be coded using the ICECI. Kappa statistics for concordance between raters within each of the dimensions ranged from 0.31 to 0.93 for the injury events and 0.94 and 0.97 for activity and location in the control periods. DISCUSSION: This study represents the first detailed account of the properties of the ICECI revealed by its use in a primary analytic epidemiological study of injury prevention. The results of this study provide considerable support for the ICECI and its further use.     

The tetrapeptide AcSDKP, an inhibitor of the cell-cycle status for normal human hematopoietic progenitors, has no effect on leukemic cells.

The tetrapeptide acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) inhibits the entry into DNA synthesis of murine spleen colony-forming units (CFU-S) and protects these cells during chemotherapy. This synthetic peptide also inhibits the growth of normal human marrow progenitors granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E) and decreases their percentage in DNA synthesis at nanomolar concentration. In view of its clinical application as a marrow protector, we have investigated its effects on malignant cells. Studies were carried out on HL-60 cells and on fresh leukemic cells from patients with either chronic myeloid leukemia (CML) or acute myeloid leukemia (AML). Results showed that AcSDKP, whatever the doses used, did not modify the proliferation of both HL-60 cells and AML cells even when enhanced by stimulating factors such as interleukin 3 or granulocyte-macrophage colony-stimulating factor (GM-CSF). In addition, no change in the number and the percentage in S-phase of both HL-60 clonogenic cells and CML progenitors was observed. Our data clearly demonstrate that the tetrapeptide AcSDKP was ineffective on leukemic cells and therefore by acting selectively on normal progenitors represents a potent therapeutical agent for the protection of normal bone marrow progenitors during chemotherapy.