PubMed Health⌕ Search

Biomedical subjects

W Mayrink

Publications and source records attributed to W Mayrink.

At least 37 records · Page 2Linked to original sources
PubMed1986

Controlled field trials of a vaccine against New World cutaneous leishmaniasis.

Two controlled, double blind field trials of a non-living promastigote vaccine against New World Cutaneous Leishmaniasis (NWCL) were conducted in 1981 and 1983 in Brazil. Brazilian Army conscripts were randomly assigned to the vaccine or placebo groups and tested during their training in the Amazon jungle, a high risk area for NWCL. The results obtained showed: no significant differences between the vaccine and the placebo groups with respect to a number of characteristics (age, race, previous contact with the jungle, etc.); no significant differences between the participants who got and who did not get NWCL during the trial, with respect to length of exposure, contact with the jungle, etc. and a reduction of 67.3 and 85.7% in the annual incidence rate of NWCL, in 1981 and 1983 respectively (although the difference between incidence rates of the disease in vaccinated and control groups in the 1983 trial was not statistically significant), among those vaccinated who had converted to a positive leishmanin skin test as compared with the placebo groups.

Adolescent↗
PubMed1985

An experimental vaccine against American dermal leishmaniasis: experience in the State of Espírito Santo, Brazil.

A vaccine prepared from killed and sonicated promastigotes of five Brazilian strains of Leishmania was used during an epidemic of American dermal leishmaniasis that occurred in Viana county, State of Espírito Santo, Brazil. Initially, all of the participants in the vaccination programme had negative reactions to Montenegro antigen. Forty days after the last dose of vaccine had been given, 87.6% of the 216 vaccinated individuals had become Montenegro-positive whereas the 266 unvaccinated persons remained Montenegro-negative. The study area had an unstable population and details are given about the human population changes that occurred during the two-year study period. Taking into account population movements, 1.5% of those vaccinated and 6.4% of the unvaccinated group developed dermal leishmanial lesions by the end of the first year. At the end of the second year, 1.7% of those vaccinated and 8.9% of the unvaccinated group had become infected. The difference in infection rates of the two groups is statistically significant at both the end of the first and second years of observation. Diagnosis of the disease(s) was based on the clinical appearance of lesions combined with parasitological and/or immunological evidence and subsequent responses to treatment. The experience gained in Viana also provided information about the storage and administration of the experimental vaccine which have been used in mounting a randomized clinical trial.

Adolescent↗
PubMed1985

A new defined medium for cultivating Leishmania promastigotes.

A chemically defined medium to grow the promastigotes of 19 stocks of Leishmania is described. The medium was developed by making qualitative and quantitative modifications of the medium AR-103 devised for Trypanosoma cruzi. The new medium, designated as MD-29, can be used in studies on the nutritional requirements of promastigotes.

Animals↗
PubMed1979

A field trial of a vaccine against American dermal leishmaniasis.

A field trial was carried out in the eastern part of the State of Minas Gerais (Brazil) of a vaccine containing killed promastigotes of five stocks of Leishmania. Tests with Montenegro antigen showed that a high proportion of the vaccinated persons became positive within three months, but circulating antibodies were not detected. A proportion of those vaccinated continued to give positive Montenegro reactions for up to three years. Lymphocyte sensitivity tests carried out, on a small sample, three years after vaccination were positive and gave no evidence of immunological depression. No cases of cutaneous or mucocutaneous leishmaniasis occurred in the trial area during the three years of observations.

Adolescent↗
PubMed1979

Epidemiology of dermal leishmaniasis in the Rio Doce Valley, State of Minas Gerais, Brazil.

Dermal leishmaniasis is prevalent in the predominantly settled agricultural areas in the Rio Doce Valley in the eastern part of the State of Minas Gerais, Brazil. The disease has been recorded almost equally in both sexes. Cases have been confirmed in all age groups but youths aged ten to 14 years form the population segment at greatest risk to infection. Cases of single cutaneous lesions, multiple cutaneous lesions and muco-cutaneous lesions have been recorded in the area. Isolates of parasites include representatives of the Leishmania mexicana and L. braziliensis complexes and at least one parasite that does not fit into either category. Infections have not been detected in small mammals (mainly rodents) but about 3% of dogs are infected. The phlebotomine fauna includes no species (or close relatives of species) previously incriminated as vectors of mexicana and braziliensis infections in Brazil. In the complex and confusing epidemiological situation in the Rio Doce Valley it seems unwise to apply traditional specific names to Leishmania of the area.

Adolescent↗
PubMed1979

Wild reservoirs of Schistosoma mansoni from Caratinga, an endemic schistosomiasis area of Minas Gerais State, Brazil.

Among 472 small mammals trapped in the Caratinga area of Minas Gerais, Brazil, Schistosoma mansoni infection was demonstrated in 6 of 9 Procyon, 1 of 7 Didelphis, 1 of 1 Philander, 25 of 72 Nectomys, and 16 of 383 various other rodents representing 20 species. The role of Nectomys and Procyon in maintaining endemicity needs further investigation.

Animal Population Groups↗
PubMed1978

Mastomys natalensis as an experimental host for Leishmania mexicana mexicana.

Young multimammate rats (Mastomys natalensis) can be readily infected when inoculated intradermally with the amastigotes of Leishmania mexicana mexicana. Lesions appear at the site of inoculation in the second week of infection and continue to increase in size for the first month; amastigotes can be detected during this period. In the second month, lesions begin to decrease in size and it is more difficult to detect amastigotes. Three months after inoculation, the rats show no sign of infection. The results suggest that M. natalensis could be a useful laboratory host for immunological studies on dermatotropic Leishmania and for chemotherapeutic assays.

Animals↗