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Biomedical subjects

C A Wright

Publications and source records attributed to C A Wright.

61 records · Page 4Linked to original sources
PubMed1966

Electrophoretic studies on planorbid egg-proteins. The Bulinus africanus and B. forskalii species groups.

It is possible that physiological differences between populations of an intermediate snail host of schistosomes may be linked with differences in the pathogenicity of the parasite strains they harbour. With a view to differentiating between local populations of bulinid snails, a previous electrophoretic study of snail egg-proteins has been extended to cover all the recognized species of the Bulinus africanus group and most of those of the B. forskalii group.The results show that in general the level of variation between populations of the same morphological species is greater than the differences between species in the same group. However, at the specific level there are similarities suggesting close affinities between B. nasutus and B. abyssinicus, and the electrophoretic pattern for B. jousseaumei shows close relationships with West African populations of B. globosus. In the B. forskalii group the patterns for various populations of B. reticulatus differ from each other and from those of other members of the group.

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PubMed1965

Electrophoretic studies of some planorbid egg proteins.

Morphological characters alone have so far failed to provide adequate criteria for the identification of the molluscan intermediate hosts of African schistosomes. In the course of investigations into various other taxonomic approaches, it has been found that the egg proteins, when subjected to electrophoresis, are sensitive indicators of differences at the population level. About 80 populations of various species of African and Neotropical planorbids have been examined in this preliminary study. Differences at the population level have a considerable bearing on relationships between the snails and the larval schistosomes that parasitize them and help to explain the evolution of local races of schistosomes.

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PubMedDate not supplied

Safety and yield of ultrasound-assisted transthoracic biopsy performed by pulmonologists.

BACKGROUND: Transthoracic ultrasound (US) has gained popularity as a tool for visualizing pleural effusions and assisting thoracentesis or chest drain placement. In the absence of effusion, US just as well demonstrates solid masses involving or abutting the pleura, yet biopsy of such lesions is not widely performed by chest physicians. OBJECTIVE: To assess the feasibility and the safety of US-assisted cutting needle biopsy performed by chest physicians in routine practice. METHODS: Lesions involving or abutting the pleura > or =20 mm in diameter on US were sampled with a 14-gauge cutting needle under local anesthesia. Biopsy site, needle direction and depth of penetration were determined with US. The procedure was performed without direct US guidance in 'free-hand' technique. RESULTS: Ninety-one patients underwent 96 cutting-needle biopsies for suspected peripheral lung tumors (n = 44, 46%), pleural-based (n = 39, 41%), mediastinal (n = 10, 10%), or chest wall lesions (n = 3, 3%), which were single in 71%, multiple in 6% and diffuse in 23%. Sensitivity for malignant neoplasms (n = 65) was 85.5% and 100% for mesothelioma (n = 10). Pneumothorax occurred in 4%. CONCLUSIONS: US-assisted cutting-needle biopsy of lesions > or =20 mm in diameter is safe in the hands of pulmonologists. The yield for neoplastic disease including mesothelioma is high.

Adult↗
PubMedDate not supplied

Is Planorbarius metidjensis compatible with Schistosoma haematobium and S. bovis?

On the basis of laboratory snail infection experiments it is concluded that Planorbarius metidjensis is unimportant in the epidemiology of Schistosoma haematobium in North West Africa. 410 P. metidjensis Spain were exposed to 8 isolates of S. haematobium from Ghana, Kenya, Madagascar, Mauritius, Morocco, Tanzania, South Africa and Sudan. 50 P. metidjensis Morocco and 50 P. metidjensis Algarve were exposed to S. haematobium Morocco. All infections failed to develop to maturity. Serial sections of P. metidjensis Morocco infected with S. haematobium Morocco at 24 h, 48 h and 72 h post infection showed that 34% of the miracidia penetrated the snail epithelium, but young sporocysts were encapsulated and killed by an ameobocytic host response. Two hypotheses are postulated to explain the reports in the literature that P. metidjensis transmits S. haematobium. The dual infectivity of B. truncatus and B. africanus by S. haematobium from Guinea Bissau suggests that this isolate is probably an infraspecific hybrid with enhanced intermediate host infectivity. By analogy with work on Biomphalaria glabrata and S. mansoni, field observations of P. metidjensis transmitting S. haematobium could be explained if the snail had been previously infected with a compatible digenean, thus rendering a refractory snail into a susceptible snail. S. bovis Spain is compatible with P. metidjensis Morocco, Portugal and Spain with 14.3%, 29.2% and 73.3% of the snails respectively surviving the prepatent period becoming infected. P. metidjensis Spain is refractory to S. bovis Iran and Sudan. Thus, P. metidjensis may be important in the epidemiology of S. bovis in the Iberian Peninsula and North West Africa.

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