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R W Thorp

Publications and source records attributed to R W Thorp.

5 recordsLinked to original sources
PubMed1992

Is the IEMA combined incubator/shaker device preferable to a waterbath for incubating enzyme immunoassays?

An incubator/shaker device proved to be a convenient alternative to a waterbath for the incubation of enzyme immunoassays (EIA). The device achieved effective and even heat transfer. In two of five EIAs it increased reactivity and in three of five EIAs it slightly increased the discrimination between seronegative and seropositive specimens though, for the samples investigated, extra sensitivity was not thereby achieved. At a high shaking frequency (1400 rpm) there was cross-contamination between wells, but this did not occur at 900 rpm. The relative contributions of heating and of shaking to the incubation of EIAs deserve further investigation.

AIDS Serodiagnosis↗
PubMed1989

Trends in sexual behaviour and risk factors for HIV infection among homosexual men, 1984-7.

To assess whether the spread of infection with HIV can be reduced by changes in behaviour among groups most at risk because of their sexual practices sexual behaviour was monitored among 1050 homosexual men tested for HIV infection at a genitourinary medicine clinic in west London from November 1984 to September 1987. Four cohorts, defined by date of presentation, were studied by questionnaire at their presentation, and blood samples were analysed. Between the first and last cohorts there was a considerable fall in the proportion reporting casual relationships (291/329 (88%) v 107/213 (50%] and high risk activities, such as anoreceptive intercourse with casual partners (262/291 (90%) v 74/106 (70%], with the greatest changes occurring before the government information campaign began in 1986. Nevertheless, half of the men in the last cohort studied reported having casual partners. Multiple logistic regression showed that behavioural risk factors for HIV infection most closely resembled those for hepatitis B and that previous sexually transmitted diseases (syphilis, hepatitis B, and anogenital herpes) were themselves independent risk factors. A history of syphilis ranked above anoreceptive intercourse as the strongest predictor of HIV infection. Actively bisexual men showed a much lower prevalence of HIV infection (3/57, 5%) than exclusively homosexual men (113/375, 30%). Sexual behaviour among homosexual men changed during the period studied, and the incidence of HIV infection fell, although more education programmes directed at homosexual men are needed to re-emphasise the dangers of infection.

AIDS Serodiagnosis↗
PubMed1988

Human immunodeficiency virus infection, hepatitis B virus infection, and sexual behaviour of women attending a genitourinary medicine clinic.

During the six months immediately after a public information campaign about the acquired immune deficiency syndrome 1115 women who attended a genitourinary medicine clinic in west London were tested for antibodies to the human immunodeficiency virus (HIV). Three women (0.27%) were positive, and all three were regular sexual partners of men with high risk lifestyles--two intravenous drug users and one bisexual. A consecutive series of 647 women from the cohort was tested for antibodies for hepatitis B core antigen: 27 were positive, of whom six had been born in the United Kingdom and were not known to have been at risk. The two women who were seropositive for HIV who completed a questionnaire on their sexual behaviour before they were tested reported both anal and oral receipt of semen and were in the upper fifth percentile for lifetime sexual partners. More than half (53%) of 424 women who reported that they had non-regular sexual partners never used a condom. It is concluded that heterosexual women in London are at a low risk of becoming infected with HIV.

Acquired Immunodeficiency Syndrome↗
PubMed1978

Serum alphafetoprotein in multiple pregnancy.

The concentration of alpha-fetoprotein (AFP) was determined in paired umbilical cord and maternal sera in 42 multiple pregnancies. No concentrations above 1.4 microgram/ml were detected in maternal sera. Although there was a significant inverse correlation between cord AFP levels and gestational age, large intrapair discrepancies were common and these were not influenced by birth order, weight, or malformations. Intrapair AFP ratios were higher amongst dizygotic (DZ) than monozygotic (MZ) twins. In a pair discordant for neonatal hepatitis, the affected twin had the lower level of AFP in cord serum, but AFP was still detectable at 55 days.

Amniotic Fluid↗