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Biomedical subjects

Ingrid van Beek

Publications and source records attributed to Ingrid van Beek.

6 recordsLinked to original sources
PubMed2006

Some characteristics of early-onset injection drug users prior to and at the time of their first injection.

AIMS: This paper examines differences between early- and late-onset injection drug users (12-16 years versus 17-24 years) in terms of the antecedents and circumstances of first injection. DESIGN: Cross-sectional retrospective design, using logistic regression. Setting Australia: Sydney, Brisbane, rural New South Wales. PARTICIPANTS: A total of 336 injection drug users aged 16-25 years at the time of interview. MEASUREMENTS: Independent variables included family injection drug use, homelessness and other demographic variables, drugs used prior to the first injection, length of pre-injection drug career, behaviours at time of first injection (e.g. drug injected, reasons/motives for the first injection, risk behaviours). FINDINGS: Early-onset injection was associated independently with: having a family who injected drugs, having left school early, an unreliable source of income, a short pre-injection drug career, planning of the first injection, reliance on others for administration of the first injection and denial that experimentation was the motive for the first injection. In bivariate analysis, early-onset injection was associated further with: homelessness, being an Indigenous Australian, omission of use of certain pre-injection drugs, group presence at first injection, reliance on others for acquisition of the first needle and syringe and having injected the first time because an injection was offered. CONCLUSIONS: The research shows that early-onset, compared with late-onset injectors, are more likely to have an immediate family who inject drugs and other problematic beginnings in early life. They have an accelerated transition to injection, and differences in autonomy and motivation at first injection. These characteristics may make them more vulnerable to risk taking.

Adolescent↗
PubMed2004

Clearance of hepatitis C virus after newly acquired infection in injection drug users.

A retrospective cohort of injection drug users with newly acquired hepatitis C virus (HCV) infection was established to examine viral clearance. Newly acquired HCV infection was defined by anti-HCV antibody seroconversion within a 2-year interval. Stored serum samples were tested for HCV RNA, with viral clearance defined as >/=2 consecutive negative HCV RNA test results after infection. Ninety-nine cases of HCV infection were identified; 57 had >/=2 HCV RNA test results after infection. Viral clearance occurred in 24 (42%) cases, with Kaplan-Meier estimated probabilities of 23%, 38%, and 40% at 6, 12, and 24 months, respectively.

Adolescent↗
PubMed2004

Prevalence of production of virus-specific interferon-gamma among seronegative hepatitis C-resistant subjects reporting injection drug use.

This report describes subjects who were highly likely to have been repeatedly exposed to hepatitis C virus (HCV) through injection drug use and who remained negative for anti-HCV antibody. Production of virus-specific interferon- gamma by peripheral blood mononuclear cells was seen in the majority of subjects (72%) and was associated with higher-risk behavior. For 92% of the subjects, results of recombinant immunoblot assays demonstrated faint bands against nonstructural proteins. The immune responses described are likely to have been primed and maintained by episodes of subclinical infection without classic seroconversion and may indicate a hepatitis C-resistant phenotype. Vaccine strategies to mimic this response may provide protection against persistent HCV infection.

Adolescent↗
PubMed2003

Pilot randomized double blind placebo-controlled study of dexamphetamine for cocaine dependence.

AIMS: To establish the feasibility of conducting a placebo-controlled clinical trial of dexamphetamine replacement therapy for cocaine dependence and to obtain preliminary data. DESIGN: Double-blind randomized placebo-controlled trial. PARTICIPANTS: Thirty cocaine-dependent injecting drug users. INTERVENTION: Subjects were assigned randomly to receive 60 mg/day dexamphetamine (n = 16) or placebo (n = 14) for 14 weeks. MEASUREMENTS: Immunoassay and mass spectrometric techniques were used to identify cocaine metabolites in urine. Subjects were screened using the Composite International Diagnostic Interview and DSM-IV. The Opiate Treatment Index, Brief Symptom Inventory, Severity of Dependence Scale and visual analogue craving scales were used to collect pre- and post-self-report data. FINDINGS: Treatment retention was equivalent between groups; however, outcomes favoured the treatment group with no improvements observed in the placebo control group. The proportion of cocaine-positive urine samples detected in the treatment group declined from 94% to 56% compared to no change in the placebo group (79% positive). While the improvements were not significant between groups, within-group analysis revealed that the treatment group reduced self-reported cocaine use (P = 0.02), reduced criminal activity (P = 0.04), reduced cravings (P < 0.01) and reduced severity of cocaine dependence (P < 0.01) with no within-group improvements found in the placebo group. CONCLUSIONS: A definitive evaluation of the utility of dexamphetamine in the management of cocaine dependence is feasible and warranted.

Adult↗