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Biomedical subjects

A F Castro

Publications and source records attributed to A F Castro.

11 recordsLinked to original sources
PubMed1992

Gangliosides inhibit serological reactions for the detection of cholera and heat-labile enterotoxins of Escherichia coli.

GM1 ganglioside has been identified as the receptor for cholera toxin (CT) and heat-labile (LT) enterotoxin of Escherichia coli in many cell types. Using the radial immune hemolysis (RIH) and indirect hemagglutination (IH) tests described for the detection of these enterotoxins, a study was conducted on the 100% inhibition of these reactions by pre-incubating these enterotoxins with GM1, GD1a and GT1 gangliosides. GM1 was found to be much more efficient than the other two. With respect to the RIH test, GT1 was more efficient than GD1a as an inhibitor of enterotoxin binding. Similar results were obtained with the IH test. These data also showed that sheep red blood cells provide a good model system for the study of receptors for CT, LT and probably other enterotoxins which bind to gangliosides.

Animals↗
PubMed1979

Sigmoidoscopic examinations with rigid and flexible fiberoptic sigmoidoscopes in the surgeon's office: a comparative prospective study of effectiveness in 1,012 cases.

The results obtained from 1,012 examinations in an on-going, cooperative study indicate that the overall yield provided by use of the flexible fiberoptic sigmoidoscope is 3.2 times greater than that of examinations with the rigid sigmoidoscope. More than twice (2.4 times) the number of polyps and more than three times the number of cancers were detected with the flexible fiberoptic sigmoidoscope. Experienced endoscopists can perform an examination with the flexible fiberoptic sigmoidoscope expeditiously in the office with minimal patient preparation, a high level of patient and physician acceptance, and relative safety when the usual mandatory colonoscopic precautions and guidelines are obeyed. The extraordinary advantages demonstrated by this study warrant wide clinical application of the flexible fiberoptic sigmoidoscope. We strongly recommend provision be made for appropriate training of physicians in the use of the instrument.

Colon, Sigmoid↗