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Biomedical subjects

G Widmer

Publications and source records attributed to G Widmer.

43 records · Page 3Linked to original sources
PubMed1987

Epidemiology of Chagas' disease in northern Chile: isozyme profiles of Trypanosoma cruzi from domestic and sylvatic transmission cycles and their association with cardiopathy.

Trypanosoma cruzi was isolated from 98 patients, 59 Triatoma infestans, 51 Triatoma spinolai, and 1 Octodon degus from northern Chile. With few exceptions, stocks originating from domestic hosts were classified, based on their isozyme profile, as principal zymodeme (Z)2, while sylvatic stocks from T. spinolai and the rodent O. degus showed Z1 profiles. These results indicate the existence of separate domestic and sylvatic transmission cycles. Clinical data and T. cruzi isozyme profiles from 107 chronic Chagas' disease patients showed no association between infecting T. cruzi zymodeme and the prevalence of chagasic cardiopathy. However, the age distributions of two groups of patients carrying different zymodemes were significantly different.

Adolescent↗
PubMed1986

A biochemical comparison of glucosephosphate isomerase isozymes from Trypanosoma cruzi.

The glucosephosphate isomerase (D-glucose-6-phosphate Ketol-isomerase, EC 5.3.1.9) isozymes of Trypanosoma cruzi were characterized with respect to their native and subunit molecular size, isoelectric point and in vitro thermostability. The molecular weight data are consistent with a dimeric enzyme structure. The apparent native and subunit size homogeneity and differences in pI values imply that the electrophoretic mobility differences of isozymes in native gels are determined by their molecular charge. Minor differences in peptide maps indicate the existence of some heterogeneity in the primary structure of the isozymes. The stability of triple-banded glucosephosphate isomerase electrophoretic profiles was confirmed, supporting the view that these phenotypes represent non-interconvertible enzyme species.

Animals↗
PubMed1985

Isozyme profiles of Trypanosoma cruzi stocks from Colombia and Ecuador.

A total of 74 of 82 domestic Rhodnius prolixus from the same locality in eastern Colombia were found to be infected with Trypanosoma cruzi or T. rangeli. One of three domestic Triatoma dimidiata from Ecuador also showed T. cruzi infection. A total of 59 T. cruzi stocks from these and five other localities in Colombia were isolated from man, marsupials and triatomine bugs. Cellulose-acetate electrophoresis of nine or ten enzymes characterized all T. cruzi stocks as zymodeme 1 (reference clone Silvio X10/1). Differences in electrophoretic patterns between the newly isolated stocks and the zymodeme 1 standard were seen with the enzymes G6PD and HK. These results are in agreement with the previously described geographical distribution of T. cruzi zymodemes. Stocks were isolated from both low and high altitudes and there was no evidence of adaptative significance of T. cruzi enzyme polymorphism.

Animals↗
PubMed1984

Isozyme heterogeneity and numerical taxonomy of Trypanosoma cruzi stocks from Chile.

Fifty-three stocks of Trypanosoma cruzi were isolated in Chile, 13 from patients, 32 from the domestic triatomine vector Triatoma infestans, and 8 from the silvatic and peridomestic vector T. spinolai. The majority of isolates from triatomine bugs were made by the direct culture of infected faeces. The 53 stocks and a single clone were characterized by a combination of starch-gel and cellulose acetate enzyme electrophoresis. Three groups of T. cruzi stocks were apparent from either simple visual comparisons of isozyme profiles or numerical taxonomy. The groups were designated Chilean zymodeme (Z) 1, which was similar to Brazilian Z1, Chilean Z2a, similar to Brazilian Z2 and Chilean Z2b, similar to Bolivian Z2 and with prominent heterozygous isozyme profiles. Chilean Z1 was isolated only from T. spinolai colonizing farm walls inhabited by the rodent Octodon degus. Chilean Z2a and Z2b were both isolated from domestic T. infestans T. infestans and man, in some cases within the same household. Hardy-Weinberg equilibria were not found amongst a group of 22 stocks from a single locality and deviations from theoretical Hardy-Weinberg distributions were compatible with the absence of genetic exchange in the sampled population of T. cruzi.

Alanine Transaminase↗
PubMedDate not supplied

A study of Cryptosporidium parvum genotypes and population structure.

Genetic evidence for the occurrence of two Cryptosporidium parvum subgroups is presented. This evidence is based on restriction fragment length polymorphism analysis of several independent loci. Sequence analysis of the beta-tubulin intron revealed additional polymorphism. The stability of the genetic profiles following passage of C. parvum isolates between different hosts was investigated.

Animals↗