Search PubMed⌕ Search

Biomedical subjects

J C Skinner

Publications and source records attributed to J C Skinner.

At least 91 records · Page 5Linked to original sources

Studies on human malaria in Aotus monkey. VII. Comparative infectivity of two strains of Plasmodium vivax to to Anopheles freeborni, A. maculatus, and for strains of A. albimanus.

A strain of Plasmodium vivax from El Salvador was shown to be more infectious to the Apastepeque strain of Anopheles albimanus from El Salvador than was a strain of P. vivax from Colombia, S. A. The Apastepeque mosquito strain was also more susceptible to the Savadoran strain of P. vivax than were 2 other strains of this mosquito from El Salvador. A strain of A. albimanus from Panama was more susceptible to both of the parasite than were any of the Salvadoran strains of A. albimanus.

Animals↗

Development of antibodies to Plasmodium vivax as measured by two different serologic techniques.

Sera from individuals infected with Plasmodium vivax were tested for the presence of malarial antibodies using the indirect fluorescent antibody (IFA) and the indirect hemagglutination (IGA) tests. The primary infection resulted in the conversion of all sera to a positive response in the IFA test, whereas only 50% gave a positive IGA response. There was a direct relationship between the duration of the primary parasitemia and percentage giving positive IGA response. Relapse resulted in high level positive IFA and IGA responses.

Antibodies↗

The seroepidemiology of malaria in Middle America. I. Longitudinal studies on populations in a low incidence area of El Salvador.

Serologic profiles were established using the indirect fluorescent antibody test in a longitudinal study of six villages in an interior area of El Salvador. Positive serologic responses as well as active cases found through the voluntary collaborator posts occurred primarily in adult males, suggesting that much of the malaria experience in the study area resulted from exposure of this segment of the population in more malarious areas where they traveled to engage in temporary agricultural labor. Malaria incidence was generally low but transmission potential apparently varied markedly even over relatively small distances. Serologic profiles reflected the malaria experience in the population sampled, but many localities were widely dispersed and samples taken from village centers were found in some cases not to be representative of the entire locality population in terms of malaria exposure. The indirect fluorescent antibody technique was found to reflect the malaria experience in the population segments examined. When these data were correlated with the surveillance data from the voluntary collaborator posts, the epidemiology of malaria in the study area was more thoroughly understood.

Adolescent↗

The seroepidemiology of malaria in Middle America. II. Studies on the Pacific coast of Costa Rica.

Serologic studies for malaria using the indirect fluorescent antibody technique suggest that active transmission is either absent or very low in 6 villages on the Pacific side of Costa Rica. Positive titers (1:20 or higher) were seen in the under-15-year age group in three of the study localities, but only 5 such responses were encountered among 249 people examined in this age range. In the adults (15 years and over) from the same 3 villages there were 68 positive titers among 161 examined. There were 43 positive responses in 189 adults from the remaining 3 villages where none of 307 persons under 15 years of age showed a titer of 1:20 or higher to any of the 3 malaria antigens tested (Plasmodium falciparum, P. vivax and P. malariae). These data suggest that the positive responses in the latter villages are more likely to be associated with old or imported cases than with current local transmission. Serologic responses of 1:80 or higher to the P. falciparum antigen suggested the continued presence of this parasite in the population in spite of the paucity of positive blood smears with this species in recent years. Positive titers with the P. malariae antigen suggest that this parasite is probably still present in the area. Such serologic studies help to indicate areas where malaria transmission is active and provide information on parasite reservoirs in particular populations.

Adolescent↗

Studies on the transmission of simian malaria. VI. Mosquito infection and sporozoite transmission of Plasmodium fragile.

Anopheles b. balabacensis mosquitoes were infected with Plasmodium fragile when fed upon splenectomized Macaca mulatta monkeys. Highest level mosquito infections were obtained when feedings were made from 2 to 4 days prior to the peak in the parasitemia. Transmission to M. mulatta monkeys was obtained via mosquito bite on 2 occasions and via intrahepatic and intravenous inoculation of dissected infected salivary glands on 9 occasions. The prepatent periods ranged from 12 to 17 days with a median of 15 days.

Animals↗