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Biomedical subjects

T J Stewart

Publications and source records attributed to T J Stewart.

25 records · Page 2Linked to original sources
PubMed1975

Occult schwannomas of the vestibular nerve.

Five small occult schwannomas of the vestibular nerve were discovered on routine examination of 893 serially sectioned temporal bones of 517 individuals. Three arose from the superior division, one from the inferior division, and the other had a multicentric origin from both divisions of the nerve. Location and size of these tumors indicate that clinical diagnosis would have been difficult or impossible by any method of study. The finding of vestibular schwannomas in 0.9% of individuals in this series, indicates the high incidence of this tumor in the general population. The much lower incidence of diagnosed symptomatic tumors in the general population can only be explained by the conclusion that this neoplasm exhibits considerable variation in growth characteristics. Usually the tumor enlarges so slowly as to be of no health importance, but occasionally it grows more rapidly to become symptomatic and require surgical removal.

Aged↗
PubMedDate not supplied

Infection with Pneumocystis carinii is prevalent in healthy Gambian children.

Pneumocystis pneumonia is rarely identified in the many immunosuppressed individuals with acquired immune deficiency syndrome (AIDS) and malnutrition in Africa. To test whether infection with Pneumocystis carinii occurs in the continent we conducted a comparative serological study, measuring by enzyme-linked immunosorbent assay antibodies to the parasite in 150 healthy young individuals from both Britain and the Gambian savanna. The prevalence of significant titres of antibody to P. carinii steadily increased with age and included more than 70% of both populations by 8 years of age. Infection with P. carinii is, therefore, common in the Gambia. Thus opportunistic pneumocystis pneumonia may be an important but largely unrecognized disease in the continent, though its impact is probably diminished by the prevalence of fatal tuberculous infection, particularly in the AIDS population.

Adolescent↗
PubMedDate not supplied

Human IgE response to the Schistosoma haematobium 22.6 kDa antigen.

In Schistosoma mansoni and S. japonicum infection, the 22.6 kDa tegumental antigens Sm22.6 and Sj22.6 are principal targets for the human IgE response, and levels of IgE to Sm22.6 have been correlated with resistance to re-infection after chemotherapy. S. haematobium is arguably a more important species in terms of human infection, and in this report we describe for the first time the molecular characterization of a cDNA from S. haematobium (Sh22.6) that is closely homologous to Sm22.6 and Sj22.6. As a member of the tegument-associated antigen family, Sh22.6 possesses EF-hand domains and regions homologous to the dynein light chain domains. We have expressed recombinant Sh22.6 and studied the IgE responses to the antigen in a group of 99 infected individuals (68 children and 31 adults) from an endemic area of Gabon who donated blood before and 5 weeks after praziquantel treatment. IgE to Sh22.6 was detected by ELISA in 18 subjects (18%), and in the majority of responders levels rose between pre- and post-treatment. Interestingly, the proportion of adults expressing IgE to Sh22.6 was 35.5%, significantly higher than the 10.3% seen in children. IgE from at least 10 of the 18 ELISA responders recognized Sh22.6 on Western blots of adult worm extract and recombinant antigen. These results demonstrate that like related molecules in other species, Sh22.6 is a target for the human IgE response. The data also indicate that changes in the IgE response occur with age or with progressive exposure to key antigens.

Adolescent↗