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Biomedical subjects

G S Nelson

Publications and source records attributed to G S Nelson.

At least 91 records · Page 5Linked to original sources
PubMed1972

Studies on heterologous immunity in schistosomiasis. 5. Heterologous schistosome immunity in sheep.

Previous studies have shown that when cattle are exposed to cercariae of Schistosoma mansoni they develop considerable resistance to subsequent challenge with S. mattheei. The present study showed that when sheep are immunized with S. mansoni cercariae they too develop a marked resistance to subsequent challenge with S. mattheei. A small proportion of the immunizing cercariae reached maturity and a few viable S. mansoni eggs were found in the faeces of the sheep. The results of this experiment provide further evidence that heterologous immunity may be of significance in limiting the severity of schistosomiasis in both man and domestic animals in areas where animal and human schistosomes occur together.

Animals↗
PubMed1972

Studies on heterologous immunity in schistosomiasis. 6. Observations on cross-immunity to Ornithobilharzia turkestanicum, Schistosoma bovis, S. mansoni, and S. haematobium in mice, sheep, and cattle in Iran.

Experiments were carried out in mice, cattle, and sheep to investigate the possibility that heterologous immune reactions may occur between the schistosomes prevalent in man and domestic animals in Iran. Immunization with Ornithobilharzia turkestanicum from cattle produced a considerable degree of immunity in mice against challenge with Schistosoma bovis, S. haematobium, and S. mansoni. The results of immunizing cattle with O. turkestanicum, S. bovis, and S. haematobium were even more striking; there was a reduction of 30-40% in the number of adult worms and a proportionally greater reduction in the tissue egg counts. Sheep developed a less marked immunity. Supplementary experiments on homologous immunity showed that mice developed a considerable degree of immunity against S. bovis. The results of the heterologous immunity experiments with S. haematobium and S. bovis are of particular interest as both parasites often occur in the same area and are often transmitted by the same snail host, man and cattle being exposed to the cercariae of both species simultaneously. The reciprocal immunity produced by these infections may be mutually beneficial in limiting the severity of schistosomiasis in man and domestic animals in the endemic areas.

Animals↗
PubMed1971

Tanapox: a new disease caused by a pox virus.

Two epidemics of a new virus disease, tanapox, occurred in 1957 and 1962 among the Wapakomo tribe along the Tana River in Kenya. Several hundred people were affected by a short febrile illness with headache and prostration and the disease was characterized by a single pock-like lesion on the upper part of the body. A pox virus, unrelated to the vaccinia-variola group, has been incriminated as the causative agent. The virus has a limited host range and has been grown only in human and monkey tissue cultures, and so far the only animals that have proved susceptible in the laboratory have been monkeys. The characteristic lesions have been reproduced in a human volunteer. Histopathological and electron microscopic studies indicate that the virus belongs to the pox group, but serological tests show that it differs from other animal pox viruses, including yabapox virus of monkeys. A similar if not identical pox virus has caused epidemics in primate colonies in the U.S.A. It is suggested that tanapox is a zoonosis and that the disease is transmitted from monkeys to man in Kenya.

Animals↗
PubMed1971

The effect of metrifonate on Brugia pahangi infections in domestic cats.

Metrifonate, an organophosphorus compound, caused a decline in the number of microfilariae in domestic cats experimentally infected with Brugia pahangi. It was found that the drug was active against both microfilariae and macrofilariae, but probably its greatest effect was on the macrofilarial stages. It is suggested that the drug should be used in filarial infections of man on a trial basis.

Animals↗