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Biomedical subjects

D G Godfrey

Publications and source records attributed to D G Godfrey.

At least 37 records · Page 2Linked to original sources
PubMed1980

Epidemiological aspects of three Trypanosoma cruzi zymodemes in Bahia State, Brazil.

Culture forms of 104 stocks of Trypanosoma cruzi isolated in different regions of the State of Bahia were compared by electrophoresis of six enzymes. The three distinct combinations of isoenzyme patterns seen were designated ZI, Z2 and Z3. In an area of endemic Chagas's disease in eastern Bahia, T. cruzi Z1 was associated with sylvatic mammals and sylvatic triatomines, whereas T. cruzi Z2 was associated with a separate domestic cycleof transmission. T. cruzi Z1 was also found in sylvatic triatomines from other parts of the State. In contrast, in an area of the São Francisco Valley region of western Bahia, both T. cruzi Z1 and Z2 were isolated from man, domestic animals, and peridomestic rats. T. cruzi Z3 was isolated from an armadillo and from Panstrongylus geniculatus, a triatomine commonly found in armadillo burrows. Both T. cruzi Z1 and Z2 appeared to be pathogenic in man: T. cruzi Z1 was isolated from patients with acute Chagas's disease and from a single patient with chronic cardiac manifestations. T. cruzi Z2 was isolated from some asymptomatic individuals but was also associated with acute disease and chronic cardiac and digestive syndromes.

Adult↗
PubMed1978

Identification of economically important parasites.

The taxonomy of a parasite can be an important guide to its pathogenic characteristics. A wide range of anatomical, biochemical and behavioural tests is now being developed to define different strains and subspecies of the main tropical parasites.

Amebiasis↗
PubMed1978

The influence of lorry transport on the Trypanosoma vivax infection rate in Nigerian trade cattle.

In Nigeria in 1974 and 1975 there was an apparent sharp reduction in the prevalence of trypanosomiasis of cattle at several markets and control points. Some of the decrease appears to be due to the tsetse eradication programmes and Sahelian drought, but the change to lory transport as the principal means of moving cattle from the northern grazing areas to the south-western markets, which replaced a trek of at least three weeks, was probably an important factor.

Animals↗
PubMed1978

Biochemical characterization of some species of Trypansoma (Schizotrypanum) from bats (Microchiroptera).

Trypanosoma (Schizotryanum) species isolated from bats (Microchirotera) in Europe and Latin America were examined by determining the buoyant densities of their nuclear and kinetoplastic deoxyribonucleic acid (DNA) and the electrophoretic patterns of six isoenzymes. By these criteria they were separated into three distinct groups -- two from Europe (T. dionisii and T. vespertilionis) and one from America. T. dionisii was also separable by its morphology in vitro. Geographical location and DNA buoyant densities suggested that the American stocks were more closely related to T. cruzi than to the European species, though they differed from it marginally in kinetoplastic DNA density and in being noninfective to mice. Similar stocks studied by other workers have been shown to differ from T. cruzi also in reduced infectivity to, and lack of natural association with, Triatominae, and in antigenic composition. It is therefore proposed that trypanosomes of the subgenus Schizotryanum occuring naturally in Microchiroptera and differing from T. cruzi sensu stricto as outlined above should be treated as a distinct subspecies, T. cruzi marinkellei ssp. nov. T. cruzi sensu stricto thus becomes the nominate subspecies T. cruzi cruze Chagas 1909.

Alanine Transaminase↗
PubMed1978

The identification of Trypanosoma brucei gambiense in Liberian pigs and dogs by isoenzymes and by resistance to human plasma.

29 Trypanozoon stocks from Liberian pigs and dogs were screened for human plasma resistance and electrophoretic isoenzyme patterns of eleven enzymes. Two stocks from pigs were found both to be resistant to human plasma and to have an isoenzyme marker, a slow alanine aminotransferase (ALAT) pattern, previously found only in Trypanosoma brucei gambiense from man. This constitutes evidence that the pig is a reservoir of human trypanosomiasis in West Africa. The T.b.gambiense ALAT was also found in stocks from 5 other pigs and a dog, but none of these stocks was resistant to human plasma; conversely, 9 further isolations from pigs and 2 from dogs were plasma resistant but did not have the T.b.gambiense ALAT. The lack of correspondence between the two characteristics is discussed. A T.b.gambiense stock from man in Zaire had the ALAT pattern characteristic of T.b.gambiense from Senegal and Nigeria, together with the ASAT triplet found in most T.b.gambiense stocks. Peptidase polymorphism was shown in trypanosomes for the first time.

Alanine Transaminase↗
PubMed1977

The identification by isoenzyme patterns of two distinct strain-groups of Trypanosoma cruzi, circulating independently in a rural area of Brazil.

Culture forms of 17 Trypanosoma cruzi stocks, primarily isolated from a rural area of endemic Chagas disease at São Felipe, Bahia, Brazil, were compared by the electrophoretic patterns of six enzymes: aspartate aminotransferase, alanine aminotransferase, glucose-6-phosphate dehydrogenase, malate dehydrogenase (decarb-oxylating) (NADP+), glucosephosphate isomerase and phosphoglucomutase. Two markedly distinct combinations of isoenzyme patterns were seen, justifying the arrangement of the 17 stocks into two strain-groups, each of which was enzymically homogeneous. One combination was characteristic of the 11 domestic stocks of T. cruzi derived from both human infections and domiciliated animals; the second was characteristic of the six sylvatic stocks derived from opossums and a sylvatic triatomine species. The enzyme patterns were independent of the original host and the type of culture medium used. Distinction of the two strain-groups accords with epidemiological evidence that the domestic and sylvatic transmission cycles in São Felipe do not overlap. It is suggested that the diverse enzyme characters of the two strain-groups circulating in São Felipe reflect diverse origins; the domestic form of T. cruzi probably invaded the area from the south of Brazil with the domestic triatomine vector, Panstrongylus megistus.

Animals↗
PubMed1976

Enzyme electrophoresis in characterizing the causative organism of Gambian trypanosomiasis.

Trypanosoma (Trypanozoon) brucei includes three morphologically identical subspecies which are poorly defined by clinical behaviour; T. b. brucei does not infect man, whereas T. b. rhodesiense causes an acute, and T. b gambiense a chronic, disease. Thirty-three isolates of the complex, each of which had previously been identified on clinical or other criteria, were compared by the electrophoretic patterns of two trypanosomal enzymes, alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT). One particular ALAT pattern clearly segregated a group of human pathogens of which all except one were labelled T. b. gambiense. The exception was labelled T. b. rhodesiense, and in addition three putative T. b. gambiense isolates did not have this pattern; it is suggested that only one presents a serious anomaly. The T. b. gambiense group could also be subdivided by three ASAT patterns which coincided with known groupings based on serological criteria.

Alanine Transaminase↗
PubMed1975

Isoenzymes of two aminotransferases among Trypanosoma vivax in Nigerian cattle.

During a period of three months, thin-layer starch-gel electrophoresis was used to examine the isoenzymes of alanine and asparate aminotransferases from samples of T. vivax collected from naturally infected Nigerian cattle. Experimentally infected cattle sheep and goats were also studied. Three patterns, termed Sets 1,2 and 3, differed in both enzymes. The stability of the enzyme patterns was generally confirmed in experimental animals. The results are discussed in relation to subspeciation in T. vivax.

Alanine Transaminase↗