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Biomedical subjects

D H Joynson

Publications and source records attributed to D H Joynson.

13 recordsLinked to original sources
PubMed1992

Epidemiology of toxoplasmosis in the U.K.

The overall rate of toxoplasma infection in the U.K. is between 23-33% though there is evidence of regional variation. Seropositivity increases by 0.5-1.0% per annum to reach about 50% at the age of 60 years. The incidence of acute infection in pregnant women is about 2-2.6% per thousand pregnancies while the transplacental transmission rate is reported to range from 0% to 40%. As there is no official notification of congenital toxoplasma infections within U.K. the true number of cases is not known. However, information relating to the prevalence of infection in the general population in the U.K. is outdated and new studies are urgently required.

Adult↗
PubMed1992

The prevalence of Toxoplasma infection among pregnant women in Ibadan, Nigeria.

The seroprevalence of toxoplasmosis in pregnant women from the inner area of Ibadan was determined by the dye test. Two hundred and seventy-three of the 352 women (78%) had dye test titres of 1/16 or greater with 165 (47%) having titres of 1/128 or greater. In contrast, 42 of 192 pregnant women (22%) from the Swansea area of the UK were dye test positive with only six (3%) having titres of 1/128. The possibility that reinfection or recrudescence is responsible for maintaining high antibody levels in African women and the consequence of this high level of infection in relation to potential human immune deficiency virus (HIV) infections are discussed. Social and environmental conditions indicate that the source of infection is contact with cat faeces.

Animals↗
PubMed1990

Potential role of IgG avidity for diagnosing toxoplasmosis.

Sera from 20 cases of toxoplasmic lymphadenopathy were examined by an enzyme linked immunosorbent assay toxoplasma IgG avidity (ELISA) at two laboratories. The results obtained were largely in agreement and showed that sera from patients with acute infection had low avidity IgG (30% or less), whereas sera from patients with chronic infection had high avidity IgG (40% or more). It is suggested that this type of assay could have a useful complementary role in antenatal testing for toxoplasmosis.

Acute Disease↗
PubMed1989

Five commercial enzyme linked immunosorbent assay kits for toxoplasma specific IgM antibody.

Five commercially available enzyme linked immunosorbent assay (ELISA) kits for the detection of specific IgM against Toxoplasma gondii were evaluated in a three centre study and results compared with those of the Public Health Laboratory Service ELISA for Toxoplasma IgM (PHL IgM ELISA). Fifty selected sera were tested by all the methods (Toxo-M, Captia Toxo-M EIA, Toxo Enz M EIA, Toxonostika IgM EIA, Sopazyme Toxo IgM EIA) at the three reference centres in England and Wales and 177 routine sera by all the methods in one or other of the centres. Ten of the 50 selected sera contained autoimmune antibodies but no specific IgM and 29 had toxoplasma specific IgM detectable by the PHL IgM ELISA. The kits were assessed for their specificity and sensitivity compared with the PHL IgM ELISA, and the percentage coefficient of variation for binding to the solid phases was determined. They were also rated subjectively by the staff performing the assays and an overall impression of each kit was gained by allocating scores of several criteria. There was quite close agreement among the results obtained with all five commercial assays and the PHL IgM ELISA, although some of the sera pre-selected as being potentially problematic showed the limitations of some of the assays.

Animals↗
PubMed1979

Water: the natural habitat of Mycobacterium kansasii?

It has been demonstrated that, after inoculation, Mycobacterium kansasii will survive in water up to 12 months without any change in cultural or lipid characteristics. The organism failed to survive in soil. It is suggested that the natural habitat of M. kansasii is water.

Mycobacterium↗
PubMed1979

Salmonella isolation from hospital areas.

Evidence of the presence of salmonellas in a paediatric ward, a special care baby unit, a maternity unit and a hospital kitchen was obtained by culture of sewer swabs, faeces and food samples. The survey was designed to cause as little administrative interference as possible. The technical aspects of the survey did not strain laboratory facilities. Minimal secondary spread of salmonella infection was experienced.

Bacteriological Techniques↗
PubMed1978

Bowls and bacteria.

An episode of nosocomial infection with Klebsiella aerogenes in a surgical ward, in which six patients were infected, is described. The cause of the outbreak was identified as being contaminated washing-bowls. It is recommended that each patient should have his own bowl, which should be disinfected after use, dried and stored upside-down.

Adult↗
PubMed1977

Role of in vitro and in vivo tests of hypersensitivity in beryllium workers.

The value of the beryllium macrophage migration inhibition (Be MIF) and Mantoux tests in the diagnosis of chronic beryllium disease and in the detection of hypersensitivity in healthy beryllium workers is demonstrated. In the absence of steroid treatment the Be MIF test is positive in chronic beryllium disease patients. Seven of 50 (14%) helathy beryllium workers were Be MIF positive, while all the control subjects, normal and sarcoidosis patients, were negative. Healthy beryllium workers tend to be more often Mantoux negative than a comparable group of non-exposed workers, and although not conclusive this finding correlates with a positive Be MIF test. Although the detection of hypersensitivity is not diagnostic of disease, the Be MIF test can be used as an additional method for monitoring the health of beryllium workers. The full significance of our results should be assessed by a long-term study.

Adult↗
PubMed1976

Observations on environmental contamination in a microbiological laboratory.

Contamination of a laboratory environment with pathogenic or non-pathogenic micro-organisms may be relevant to safety of technicians and quality of technical performance. Two widely separated incidents in 1968 and 1974 initiated a study of aspects of the laboratory environment. Water-baths, water of syneresis and portions of salmonella cultures spurting out of the sterilizing flame were examined. The water of water-baths was shown to be contaminated from the fluid cultures incubated in them. This raised questions of potential cross-contamination and reporting of false positives. Water of syneresis was sometimes contaminated with salmonellas. A few quantitative counts were made. The range of counts varied between 16 salmonellas per ml. and 13,000,000 salmonellas per ml. Five hundred portions of salmonella cultures and 571 portions of Shigella sonnei cultures which had spurted from the sterilizing flame were examined. All these samples failed to grow salmonellas or shigellas. Precautions necessary to avoid environmental contamination are briefly discussed.

Bacteria↗
PubMed1975

Contamination of fluids from a hospital pharmacy.

An investigation into the cause of bacterial contamination of bottles of noninjectable water has been reported. A method of monitoring such bottles has also been described. The roles played by autoclave spray-cooling water and inadequate bottle seals in the contamination of fluids have been examined. Possible methods of reducing the risk of contamination are discussed and the design of an improved method of closure of sterile bottled fluids is stressed. Bacteriological examination is shown to be a more accurate index of the true rate of contamination than measurement of dye concentrations of bottle contents.

Coloring Agents↗