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Biomedical subjects

W Hall

Publications and source records attributed to W Hall.

At least 163 records · Page 9Linked to original sources
PubMed1993

Methadone maintenance treatment in prisons: The New South Wales Experience.

This paper uses the New South Wales experience with methadone maintenance treatment in prison to address the question: should methadone maintenance treatment be provided in Australian prisons for opioid-dependent prisoners? First, it outlines three rationales for providing drug dependence treatment in prisons: as a way of giving prisoners access to community-based forms of drug treatment in the prison setting; as a measure to reduce recidivism in opioid-dependent prisoners; and as a measure to prevent the transmission of HIV and other infectious diseases within prisons, and to the sexual partners of prisoners on their release. Secondly, it reviews the kind of research evidence that supports the effectiveness of community-based methadone maintenance treatment in Australia. Thirdly, the effectiveness of the New South Wales Prison Methadone Programme, one of the few prison-based methadone programmes in the world, is evaluated in the light of the available research evidence.

Journal Article↗
PubMed1993

Molecular cloning, expression, and biological characterization of an HTLV-II envelope glycoprotein: HIV-1 expression is permissive for HTLV-II-induced cell fusion.

The human T cell leukemia virus II (HTLV-II) is a type C retrovirus closely related to the human transforming retrovirus HTLV-I. In contrast to HTLV-I, the role of HTLV-II in human disease is controversial. However, HTLV-II infection has been documented in several cases of a clinically benign hairy cell leukemia and has also been suggested as a cofactor for HIV-1 disease progression. We report that an HTLV-II isolate (designated FLW) derived from a serum-positive white male can induce cell fusion and significant cytopathic effects in tissue culture. This HTLV-II isolate induced syncytium formation with human T and B cell lines, several human fibroblast cell lines, and, interestingly, HIV-1- and HIV-2-infected cell lines. To elucidate the role in the FLW envelope in this phenomenon, we have cloned the envelope glycoproteins gp46 and gp21 of this isolate. The envelope glycoproteins expressed in the absence of the rest of the viral genome were sufficient to drive syncytium formation in vitro, and preserved the cellular tropism for syncytium formation observed with the native retroviral isolate. Amino acid (aa) sequence analysis demonstrated 88% overall similarity with other HTLV-II envelope glycoproteins. Interestingly, only cells infected by HIV-I, but not parental H9 cells, form syncytia with FLW env-transfected cells as well as with HTLV-II/FLW-infected BJAB-WH cells. Furthermore, antibodies directed at the CD4 receptor failed to inhibit the induction of giant cell formation, implying that the FLW envelope protein was responsible for driving syncytium formation in this system. These observations may be important for the understanding of the processes involved in human retroviral-mediated syncytium formation and may suggest a mechanism whereby HTLV-II could influence the disease process in individuals dually infected with HIV-1 and HTLV-II.

Amino Acid Sequence↗
PubMed1993

The structure and correlates of alcohol dependence: WHO collaborative project on the early detection of persons with harmful alcohol consumption--III.

The cross-cultural validity of the Alcohol Dependence Syndrome was tested on 13 symptoms of alcohol dependence which were assessed as part of a WHO collaborative study of the early detection of harmful drinking. The subjects were drinking patients in health care settings in Australia, Bulgaria, Kenya, Mexico, Norway, and the US. Principal Components Analyses were performed on the symptoms in each centre, and the degree of agreement between the results was assessed by calculating coefficients of congruence between the item loadings on the first principal component. In all six centres the first Principal Component accounted for at least half of the total variance and all symptoms had positive loadings greater than 0.40 on the first Principal Component. The coefficients of congruence were all 0.98 or more, and the 13 symptoms had internal consistency coefficients of 0.94 or more. An alcohol dependence score defined by the sum of positive responses to the 13 alcohol dependence symptoms was positively correlated with self-reported alcohol consumption, alcohol-related problems, serum gamma glutamyltransferase and a clinical examination assessment of alcoholism in all six samples.

Adolescent↗
PubMed1993

Patterns of drug use and risk-taking among injecting amphetamine and opioid drug users in Sydney, Australia.

Data are presented on the patterns of drug use and HIV risk-taking of daily amphetamine and opioid injectors among 1245 injecting drug users who were interviewed in Sydney in 1989. About one-third of the sample had injected amphetamines during a typical month of injecting, and 12% were using amphetamines on a daily basis. Daily amphetamine injectors were younger, less well educated, and less likely to have engaged in drug treatment, but they were no more likely than daily opioid users to have shared injection equipment or to have engaged in other behaviour likely to transmit HIV. Although there seemed to be no special cause for concern about HIV risk-taking among amphetamine injectors, there was nonetheless a high prevalence of sharing injecting equipment, with over half of daily amphetamine and heroin injectors having shared in the past several months. In addition, approximately a third of amphetamine injectors were injecting on a daily basis, a pattern of use which increases the risk of developing a severe dependence syndrome, and of experiencing an amphetamine-induced psychosis.

Adolescent↗
PubMed1993

Alcohol-related problems among Aboriginal drinkers in the Kimberley region of Western Australia.

The paper reports on the prevalence of alcohol-related problems among drinkers in a stratified random sample of the adult Aboriginal population of the Kimberley region of Western Australia. Subjects were 265 current drinkers who were identified in the total sample of 516 Kimberley Aboriginal men and women over the age of 15 years. Participants' reports were obtained on their frequency and quantity of alcohol consumption, and their lifetime experience of 16 alcohol-related problems. The majority of Aboriginal drinkers in the Kimberley consumed harmful amounts of alcohol, and there was a high prevalence of the 16 alcohol-related problems which showed a high degree of internal coherence, with the first principal component accounting for 45% of the total variance. The number of alcohol-related problems which respondents reported was strongly related to the quantity and frequency of self-reported alcohol consumption.

Adult↗
PubMed1993

Serial phenotypic, cytogenetic and molecular genetic studies in Richter's syndrome: demonstration of lymphoma development from the chronic lymphocytic leukaemia cells.

In this report we describe a unique longitudinal study on the clinical, phenotypic, cytogenetic and molecular genetic features of malignant cells from diagnosis of chronic lymphocytic leukaemia (CLL) to the development of lymphoma and lymphomatous meningitis. CLL cells at diagnosis were CD5+, CD19+, surface IgG+, kappa+, were karyotypically abnormal and showed clonal rearrangements in the immunoglobulin heavy (IgH) and kappa light chain genes. Phenotypically leukaemic cells and lymphoma cells at RS resembled CLL at diagnosis, but showed cytogenetic evolution. Geometrically leukaemic cells and lymphoma cells retained the initial clonal rearrangements in IGH and kappa genes, but showed additional supervening clonal rearrangements in both of these genes as the disease progressed to RS. Furthermore, the c-lambda DNA showed clonal rearrangements in the leukaemic cells and lymphoma cells at RS. This complete phenotypic and genotypic analysis of tumour cells during the course of the disease demonstrates the origin of lymphoma from CLL cells through progressive cytogenetic and molecular genetic changes in CLL cells.

Blotting, Southern↗
PubMed1992

Murine B7 antigen provides a sufficient costimulatory signal for antigen-specific and MHC-restricted T cell activation.

We have previously shown that the murine B7 (mB7) molecule, when expressed in Chinese hamster ovary cells in stable fashion, can costimulate with anti-CD3 mAb or Con A to induce T cell activation. We have now derived, by gene transfection, Chinese hamster ovary cell lines that express the I-Ad molecule, either alone or in context with mB7. We have analyzed these transfectants for their capacity to present Ag to murine CD4+ T lymphocytes. I-Ad/mB7-double transfectants were able to stimulate mixed lymphocyte reactions and to present peptide Ag to specific T cells. Chinese hamster ovary cells that expressed only the I-Ad molecule were not able to stimulate T cell proliferation in these systems. Thus, the mB7 protein is a sufficient costimulatory molecule for the physiologic, Ag-dependent/MHC-restricted activation of murine CD4+ T cells. Stimulation of T cell bulk cultures resulted predominantly in the production of IL-2 and not of IL-4. The costimulatory activity of mB7 is not, however, restricted to the IL-2-secreting subset. We have identified one IL-4-secreting T cell clone, CDC35, which is responsive to mB7 triggering. Finally, we present experiments that suggest that mB7 and peptide/MHC complexes need to be expressed on the same cell for optimal induction of T cell activation.

Animals↗
PubMed1992

Relationship of anxiety and depression.

There has been considerable controversy regarding the relationship between depression and anxiety. We review briefly the descriptive, longitudinal, genetic, biological, and treatment response data indicating that there is overlap between depression and anxiety. Several possible models are explored that provide different conceptions of how this relationship may best be understood: (1) that there are a variety of more or less discrete, but sometimes coexisting, syndromes within the spectrum of anxiety and depression; (2) that symptoms of depression and anxiety represent different external manifestations of a more basic underlying cause; (3) that one condition may predispose to the other; (4) that the association may be due to artifactual definitional overlap, particularly since the instruments used to measure depression and anxiety share so many items. All these propositions are supported. An important, practical question is discussed--should the mixed anxiety/depressive disorder that has been suggested by ICD-10 be included in DSM-IV?

Anxiety↗
PubMed1992

Benzodiazepine use and HIV risk-taking behaviour among injecting drug users.

This paper examines the prevalence of benzodiazepine use, and its relationship to other drug use and HIV risk-taking among a sample of 1245 injecting drug users (IDU). Approximately a third (36.6%) of the sample had used benzodiazepines during their last typical month of injecting. Benzodiazepine users had injected more frequently, injected more heroin and amphetamines, and had more poly-drug use than other IDU. They also had higher levels of HIV risk-taking, having shared injecting equipment more frequently and with more people. There were no differences between groups in number of sexual partners or condom use, although benzodiazepine users were more likely to have been paid for sex. The demographic and drug use variables indicate that benzodiazepine users are a more dysfunctional subgroup of IDU who require particular attention in HIV interventions.

Adult↗
PubMed1992

Alcohol and recreational drug use by HIV-seropositive homosexual men.

The objectives of this study were to describe the patterns of alcohol and recreational drug use of HIV-seropositive homosexual men and to determine the effect of alcohol use on HIV risk-taking behaviour. Of particular interest was the effect of knowledge of HIV status on these behaviours. Information on alcohol and drug use was obtained from 485 HIV-seropositive homosexual and bisexual men presenting to a HIV-antibody testing and medical management clinic. Heavy alcohol use was common, with 46.2% reporting consumption of six or more standard drinks on one day recently. Men who knew that they were HIV infected drank significantly more than those men who had yet to learn of their HIV status at the time of interview. There was clear evidence in this study for a role of alcohol use in HIV risk-taking behaviour. Almost one-third (27%) of the HIV-seropositive men reported unprotected anal intercourse during the previous 3 months with approximately one-third of these (27/76, 35.5%) nominating alcohol as contributing to their high HIV-risk behaviour.

Journal Article↗
PubMed1992

Liver carcinogenesis by methyl carbamate in F344 rats and not in B6C3F1 mice.

Short-term and long-term carcinogenicity of methyl carbamate (MCB) was evaluated in F344 rats and B6C3F1 mice. In experiments lasting 6, 12, and 18 months, MCB was given in water by gavage to groups of 10 male and 10 female rats at 0 or 400 mg/kg body weight, 5 days per week, and to similar groups of mice at 0 or 1,000 mg/kg. At 6 months, MCB induced atypical mitoses, cytologic alterations, cytomegaly, pigmentation, necrosis, and neoplastic nodules of the liver in rats. At 12 and 18 months, carcinomas of the liver were induced by MCB in 80-90% of male rats and in 60-80% of female rats. None was observed in control rats or in mice. In the 2-year studies, MCB was given to groups of 50 male and 50 female rats at 0, 100, or 200 mg/kg and to similar groups of mice at 0, 500, or 1,000 mg/kg, 5 days/week. Chronic focal inflammation, cytologic alteration, hyperplasia, and neoplastic nodules and carcinomas (200 mg/kg groups only) of the liver were induced by MCB in rats. Liver tumor incidence data for combined experiments in rats were: males--5% in controls, 0% in 100 mg/kg group, 14% in 200 mg/kg group, and 77% in 400 mg/kg group; females--5% in controls, 0% in controls, 0% in 100 mg/kg group, 12% in 200 mg/kg group, and 63% in 400 mg/kg group. MCB was not shown to be carcinogenic in mice.

Animals↗
PubMed1992

Methadone maintenance and the human immunodeficiency virus: current issues in treatment and research.

This paper examines the changes that have occurred in methadone maintenance programmes in response to the advent of HIV and the adoption of harm minimization policies, and the implications of these changes for research. A need for the use of more rigorous research methods is identified and recommendations are made that take into account both the ethical and practical difficulties of conducting research in this area. Both old, unanswered questions that have resurfaced with the recent massive growth in methadone programmes in some countries, and new questions that need to be answered in order to improve the effectiveness of methadone maintenance in the fight against HIV infection are identified as future areas in need of research.

HIV Infections↗
PubMed1992

A comparison of predictors of treatment drop-out of women seeking drug and alcohol treatment in a specialist women's and two traditional mixed-sex treatment services.

The problem of high levels of client drop-out in drug and alcohol treatment is frequently reported in the literature. In the course of conducting an evaluation of a specialist women's treatment service, the inadequacy of the data on women-specific predictors of treatment drop-out was highlighted. Using a retrospective design, the characteristics of 160 women who left treatment less than 5 days after admission were compared to the 160 women who stayed longer than 5 days and were enrolled in the evaluation study. The findings of this study suggested that women who were employed, had a history of sexual assault (especially in adulthood), nominated alcohol as their drug of choice, were not married, older than 25 years of age and had demonstrated a sympathy with the agency's treatment philosophy were less likely to drop-out of treatment. In addition, for lesbian women, women with a history of sexual assault in childhood, and those with dependent children, attendance at a specialist women's service reduced the incidence of treatment drop-out.

Adolescent↗
PubMed1992

Recreational MDMA use in Sydney: a profile of 'Ecstacy' users and their experiences with the drug.

'Ecstasy' (3,4-methylenedioxymethamphetamine or MDMA) is a recreational drug that is gaining popularity world wide. There is a paucity of research regarding the ways in which Ecstasy is used and the nature of its effects. A 'snowball' peer network technique was used to recruit 100 users who completed anonymous questionnaires. The research revealed that Ecstasy is primarily used by infrequent recreational drug users for 'fun' at dance parties and social gatherings. The primary reported effects of Ecstasy were a 'positive mood state' and feelings of intimacy and closeness to others. The secondary effects of Ecstasy were the stimulant effects of energy and activation, and the psychedelic effects of insight and perceptual and sensual enhancement. Ecstasy was reported to share the properties of both amphetamines and hallucinogens in the nature of its side effects and residual effects which were no more severe than those of the latter two classes of drug. It appeared Ecstasy was not conductive to regular and frequent use, because tolerance was reported to develop to the positive effects of Ecstasy, while negative effects increased with use. Although few problems associated with the recreational use of Ecstasy have surfaced to date, animal research has shown it to be neurotoxic to serotonergic nerve terminals. Caution must be observed until further research can determine the level of hazard in humans.

3,4-Methylenedioxyamphetamine↗
PubMed1992

Changes in criminal activity after entering methadone maintenance.

The impact of different approaches to methadone maintenance on the level of crime committed by heroin addicts was examined in a cohort of addicts entering methadone treatment. The cohort comprises three groups: 72 subjects (group 1) who were approved for treatment and referred to a long-term programme which tolerated continued illicit drug use in treatment; 159 subjects (group 2) who were referred to an abstinence orientated programme from which clients who continued to use heroin were expelled; and 84 subjects who were rejected as unsuitable or failed to complete the assessment process. Official records of convictions were used to calculate conviction rates in the pre- and post-assessment periods. Differences between groups in conviction rates for drug and property crimes were analysed using Poisson regression. Three variables--age, sex and age of first criminal conviction--were significant predictors of conviction rates and all analyses controlled for these variables. Most of the rejected subjects entered treatment during the study period and it was, therefore, not possible to interpret differences between treated and untreated subjects. Among those who entered treatment, property offence rates actually rose, due to a significant increase in conviction rates in group 2. Subjects in group 1 were retained significantly longer in treatment than those in group 2. Among those who remained in treatment less than 12 months, most offences occurred after leaving treatment. When conviction rates were adjusted for time spent in treatment, the differences between the clinics disappeared.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Development and validation of a multi-dimensional instrument for assessing outcome of treatment among opiate users: the Opiate Treatment Index.

This article presents a new instrument with which to assess the effects of opiate treatment. The Opiate Treatment Index (OTI) is multi-dimensional in structure, with scales measuring six independently measured outcome domains: drug use; HIV risk-taking behaviour; social functioning; criminality; health; and psychological adjustment. Psychometric properties of the Index are excellent, suggesting that the OTI is a relatively quick, efficient means of obtaining reliable and valid data on opiate users undergoing treatment over a range of relevant outcome domains.

Adolescent↗