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Biomedical subjects

A McKellar

Publications and source records attributed to A McKellar.

5 recordsLinked to original sources
PubMed2000

Susceptibility of high and low producer dairy goats to single experimental infection with Trichostrongylus colubriformis.

Culled dry dairy goats, which differed in their level of production in previous lactations, received a single infection with Trichostrongylus colubriformis. The objectives of the study were twofold. First, the study aimed at examining the ability of dairy goats to develop an immune response to trichostrongyle infection and the associated cellular changes developing within the intestinal mucosa. Second, a comparison between animals differing in their level of production was assessed, in order to determine whether these differed in their susceptibility to infection. No difference occurred in egg excretion, worm burden and local inflammatory cell responses between high (HP) and low (LP) producer dairy goats, in contrast to observations in previous studies. Because their nutrition was controlled and milk production absent in the goats employed in the present study, these results suggest that any genetic component associated with the selection of HP and LP goats had little influence on the development of acquired resistance to T. colubriformis. The analysis of the relationship between different cell types in the mucosa and some characteristics of the worm population show that eosinophils are negatively related to worm burden. Also, a role is suggested for mast cells and globule leukocytes in the modulation of egg excretion.

Animals↗
PubMed1994

Hepatic recruitment of mast cells occurs in rats but not mice infected with Schistosoma mansoni.

The pathogenesis of infection with Schistosoma mansoni in rats is distinct from that in mice. Rats are non-permissive hosts and infection is terminated in the liver before egg laying commences whereas the parasites completes its life cycle in mice. Comparison of the mast cell responses in the two species reveals that a pronounced hepatic mastocytosis occurs in the rat and this is concomitant with the demise of the parasite. The majority of recruited hepatic mast cells contain the highly soluble granule chymase, rat mast cell protease-II, which is released systemically into blood during the period of parasite elimination. In contrast, very few mast cells are found in livers of parasitized mice and none contain the soluble granule chymase mouse mast cell protease-1. However, during egg deposition in the gut, an intraepithelial mastocytosis occurs in parasitized mice. These intraepithelial cells are typical mucosal mast cells as determined by their content of mouse mast cell protease-1. Recruitment of mucosal mast cells occurs in the intestinal lamina propria of infected rats soon after the parasites migrate to the liver. These findings suggest that mast cells of the mucosal phenotype are involved in the pathogenesis of the hepatic response to infection in the rat but that, in the mouse, mucosal mastocytosis is associated with intestinal sensitization by egg antigens.

Animals↗
PubMed1978

Request for sex change.

Five patients who presented at the Veterans Administration Mental Hygiene Clinic, Brentwood Hospital, Los Angeles, California, are described. All claimed to be transsexuals and requested estrogens and sex reassignment surgery on admission. They created great difficulty at the time of their admission and follow-up because of lack of precedents for such eventualities in government medicine. These veterans, displaying a mosaic of psychologic problems, were followed up for a period of three years. The federal social medicine system, particularly the VA, is not equipped psychologically or physically to deal with unusual requests.

Adult↗
PubMed1978

Depersonalization in a 16-year-old boy.

A prolonged period of depersonalization resolved in this 16-year-old boy with only supportive therapy. Reasons for the depersonalization and withholding of other treatment are discussed. Observations are shared of the very intriguing phenomenon of derealization and allied conditions, psychiatric syndromes which are appearing with increasing frequency among so-called "normal adolescents" who indulge in drugs or other experiences which alter the state of consciousness, and among adolescents who survive disasters or harrowing experiences.

Adult↗