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Biomedical subjects

J R Robertson

Publications and source records attributed to J R Robertson.

At least 37 records · Page 2Linked to original sources
PubMed1995

Heterosexual transmission of HIV analysed by generalized estimating equations.

A longitudinal analysis of a partner study is compared with a cross-sectional analysis which identify behavioural and biological risk factors for heterosexual transmission of HIV. Using generalized estimating equations (GEEs) a random effects logistic model is used for the longitudinal analysis. These approaches are illustrated by the Edinburgh heterosexual partner study. The longitudinal analysis finds that 'high-risk' sexual practices, unprotected intercourse for HIV and a low CD4 count in the index case significantly increase the risk of HIV transmission. The cross-sectional analysis, however, only indicates 'high-risk' sexual practices as favourable for HIV transmission.

Adolescent↗
PubMed1995

Schizophrenia with karyotype mosaic 47,XXY/48,XXY + 8.

A case of severe schizophrenia is described in a patient with chromosomal mosaicism of Klinefelter's syndrome (XXY) and trisomy 8. The literature of both syndromes is reviewed and the aetiological implications discussed.

Abnormalities, Multiple↗
PubMed1994

Deaths, HIV infection, abstinence, and other outcomes in a cohort of injecting drug users followed up for 10 years.

OBJECTIVE: To trace, follow up, and interview a group of patients known to be injecting drug users in order to establish current drug taking and other features related to drug use over 10 years. DESIGN: Descriptive follow up study of a cohort of injecting drug users established between 1982 and 1985. SETTING: General practice based patient population study initially, with later tracing of subjects throughout the United Kingdom through NHS Central Registries and current general practitioners. SUBJECTS: 203 injecting drug users recruited up to December 1985. MAIN OUTCOME MEASURES: Survival, cause of death, abstinence, or continued drug use; HIV status; and demographic variables. RESULTS: Of the 203 injecting drug users recruited into the study, over half were known to be HIV positive and 42 died of various causes (increasingly AIDS). From the start of follow up in 1990, 163 (91%) of the 180 survivors were traced, of whom 116 (71%) were interviewed. Dramatic changes had occurred in drug taking, with a move away from injecting towards oral drug use. A few patients, however, continued to inject. 90 (78%) of those interviewed had been in prison, of whom 37 (41%) had injected drugs while in prison. CONCLUSIONS: The pattern of deaths had changed from being largely due to overdose in the early 1980s to predominantly AIDS related in later years. The reduction in deaths due to overdose may have been connected with but was not always causally related to a new approach by legal, social, and medical services. Drug use continues in a modified form in a large proportion of patients followed up. As a group, drug users require long term support for a multiplicity of problems.

Adult↗
PubMed1994

Redistribution of HIV outside the lymphoid system with onset of AIDS.

The basis for many of the symptoms and pathological changes found in patients with the acquired immunodeficiency syndrome (AIDS) remains poorly understood. We have used a quantitative polymerase chain reaction technique to investigate the extent to which direct infection with human immunodeficiency virus (HIV) produces the disease manifestations of AIDS. In five patients who died with AIDS-defining illnesses (Centers for Disease Control and Prevention class IV), we found variable, but in many cases extensive, infection by HIV at various sites, including brain, lung, colon, and liver. By contrast, in three HIV-positive subjects who died without HIV-related disease (CDC class II), we found no evidence of significant infection of any non-lymphoid organ. In both groups of patients there were high levels of infection in cells of the spleen, lymph nodes, and peripheral blood. Pathological examination of tissues from the AIDS patients revealed many abnormalities, of which some, such as giant-cell encephalitis in the brain, were specifically associated with the presence of high levels of HIV infection. These findings suggest that spread of HIV outside cells of the immune system is a late event in HIV infection and is extremely sensitive to the degree of immunosuppression in the patient.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Continued drug use and other cofactors for progression to AIDS among injecting drug users.

OBJECTIVE: To evaluate the effects of continued drug use and other cofactors on progression to AIDS among HIV-infected injecting drug users. DESIGN: A prospective study. SETTING: The Muirhouse Medical Group in Edinburgh, Scotland, UK. SUBJECTS: A total of 156 HIV-infected injecting drug users. MAIN OUTCOME MEASURES: Progression to AIDS and low absolute CD4 counts. RESULTS: Of this group, 48% will have progressed to AIDS 10 years after seroconversion. Age and low absolute T4 counts had a significant effect on progression to AIDS, with older patients progressing more rapidly. Sex had no significant effects on progression. Absolute CD4+ counts and the CD4:CD8 ratio were significant predictors of progression among the group. Concurrent heroin injecting increased the risk of progression to AIDS. No significant effects were observed for use of other drugs. CONCLUSIONS: Our findings suggest that continued drug use may have an accelerating effect on progression to AIDS. Age also had an accelerating effect on progression, but sex had no significant effects. In general, the study group did not appear to progress at a different rate from other similar groups of HIV-infected individuals, despite the fact that this was a relatively young cohort. These data were based on accurate estimates of seroconversion dates.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Initial and current drug use: how are they related?

The present study examines how initial and current patterns of drug use are related among a group of drug users in Edinburgh. The study categorised individuals according to the year in which they first used illicit drugs. 1984 has been shown to be the year when patterns of drug use in this group began to change after high levels of heroin use in the late 1970s and early 1980s. Thus 1984 was used as the intercept point to create two groups: the epidemic group, comprising individuals who began using illicit drugs before 1984, and, the post epidemic group, who began using during or after 1984. Data from individuals were gathered from interviews and medical records. Statistical analysis revealed interesting differences between the groups, for example, the groups did not differ significantly in their use of methadone but the epidemic group used more methadone obtained on prescription. The post epidemic group was found to inject more often, but, did not share injecting equipment more than the epidemic drug users. A greater number of the epidemic group began using drugs by injecting and a greater number of the post epidemic group began by taking drugs orally. The issues raised by the results are discussed, and, it is suggested that the characteristics of the drug using community within which an individual begins using drugs may exert influence on patterns of drug use in later years.

Adult↗
PubMed1992

Risk-taking behaviour on the decline in intravenous drug users.

In order to assess behaviour changes among intravenous drug users we interviewed 51 IVDUs attending a general practice in Edinburgh. The data obtained was compared with equivalent data gathered in 1986. We were able to show that significant changes in injecting behaviour have occurred and have been maintained over time. A decrease in HIV seroprevalence in this group was also found. The primary drugs of abuse are benzodiazepines and pharmacological opiates, a fact which has important implications for the medical authorities.

Attitude to Health↗
PubMed1992

Problems of drug abuse, HIV and AIDS: the burden of care in one general practice.

Responsibility for many of the problems of intravenous drug abuse and human immunodeficiency virus (HIV) infection lies with community care agencies, such as general practitioners, community psychiatric and district nurses and drug agencies. It is in general practice that this burden is most clearly observed, given that general practitioners are in charge of the day-to-day care of patients. In an attempt to quantify this workload in an inner city practice with 11,200 patients, data were gathered from several sources relating to drug use and HIV infection. The study identified 432 patients who had consulted with problems of drug abuse and/or HIV infection over the period 1981-90. Among this group of patients 161 (37%) were HIV antibody positive. Among 191 drug abusers who were still registered with the practice in 1990 dihydrocodeine was the most commonly prescribed substitute treatment (130 patients) and only nine patients were prescribed methadone. Forty seven per cent of drug users continued to inject drugs occasionally. However, analysis of urine samples revealed that there was a shift away from injecting mainly heroin to multiple drug use, including benzodiazepines, usually originating from prescribed sources. Drug abusers who were HIV positive consulted their general practitioner significantly more often over one year than those who were not (mean 24.9 versus 15.8 consultations, P < 0.01). However, there was no significant difference between these two groups in terms of days spent in hospital. A total of 61 patients were referred to a community psychiatric nurse over an eight month period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Beta 2-microglobulin levels in drug users: the influence of risk behaviour.

beta 2-microglobulin (beta 2M) levels were measured in 217 Edinburgh drug users to assess their usefulness as a marker for HIV-related disease. Eighty HIV-seronegative drug injectors had significantly higher levels than 100 HIV-seronegative blood-donor controls. Amongst 137 asymptomatic HIV-seropositive drug users, those who were defined as continued drug users had significantly higher beta 2M levels and percentages of CD3+ T lymphocytes with DR Class II expression than non-injecting drug users. beta 2M levels correlated with the percentage of activated DR+ CD3+ T lymphocytes. These findings indicate that changes in beta 2M levels may reflect differences in drug-injecting behaviour and are not influenced solely by HIV status or progression. These changes in beta 2M probably represent differing degrees of immunostimulation resulting from the antigenic challenges afforded by continued or frequent drug injection. It is important to establish normal ranges for beta 2M from HIV-seronegative controls who are matched with respect to risk group and behaviour. All these factors should be taken into account if beta 2M is to be used as a marker of HIV progression.

Adult↗