Three variants of the chloramine-T radioiodination method were used to iodinate staphylococcal enterotoxin A with 125I. Only one method consistently produced usable labels for radioimmunoassay. The iodine incorporation was 55 to 76%; the specific activity was 3.5 to 5.5 muCi/microgram of enterotoxin, and the label was extremely stable on storage at -20 degrees C. Determinations of the enterotox...

The effect of Escherichia coli heat-stable (ST) enterotoxin on calcium and cyclic nucleotide metabolism in rat basophilic leukemia cell cultures was investigated. Addition of ST enterotoxin to rat basophilic leukemia cell cultures resulted in dose- and time-dependent stimulation of calcium uptake and elevation of the intracellular cyclic GMP (cGMP) concentration. The effect of ST enterotoxin on...

Natural cholera toxoid appears to act as a competitive inhibitor of cholera enterotoxin and is thus a useful tool for studying the interaction of cholera enterotoxin with cell membranes. Cholera enterotoxin binds to gut mucosa more rapidly than does its natural toxoid. Once binding occurs, however, it appears to be prolonged for both materials. Formalinized cholera toxoid has no inhibitory effe...

since the heat-stable enterotoxin (st) produced by yersinia enterocolitica is similar to enterotoxin production by e. coli, it is probably classified among toxinogenic bacteria. the culture filtrate of st-producing strains of y. enterocolitica is able to activate guanylate cyclase and to increase fluid accumulation action of cylic guanosin 3', 5' - monophosphate (cgmp) in sucking mous...

The astA gene responsible for production of enteroaggregative Escherichia coli heatstable enterotoxin 1 (EAST1) was identified in E. coli strains isolated from pigs with postweaning diarrhea. Two hundred and twenty-six isolates were tested using PCR for the astA marker as well as for heat-labile I (LTI), heat-stable I (STI), and heat-stable II (STII) enterotoxin genes characteristic for enterot...

One half million patients suffer from colorectal cancer in industrialized nations, yet this disease exhibits a low incidence in under-developed countries. This geographic imbalance suggests an environmental contribution to the resistance of endemic populations to intestinal neoplasia. A common epidemiological characteristic of these colon cancer-spared regions is the prevalence of enterotoxigen...

E. coli heat stable enterotoxin STa is an agonist of the membrane guanylate cyclase C whose endogenous ligands are the peptide hormones guanylin and uroguanylin. Whereas these peptides contain only two disulfide bonds, STa is stabilized by one additional disulfide bridge. We chemically synthesized the enterotoxin STh that originates from the E. coli strain found in humans, and we determined its...

The plasmid mediation and transmissibility of heat-stable enterotoxin production and multiple antibiotic resistance have been demonstrated for Escherichia coli O78:K80:H12 epidemiologically incriminated in a hospital outbreak of infantile diarrhea. The conjugal transfer of a 67 X 10(6) - and a 30 X 10(6)-dalton plasmid was associated with the transfer of resistances and enterotoxin production, ...

A total of 88 isolates of Yersinia enterocolitica was examined for heat-stable enterotoxin production and ability to penetrate HeLa cells and evoke keratoconjunctivitis in guinea pigs (Séreny test) as potential pathogenic properties. All 49 isolates belonging to serotypes O:3, O:8, O:9, and O:5,27 and only 5 of 39 strains of other serotypes were HeLa positive. Séreny-positive strains were found...

Macromolecular absorption of gliadin, a wheat protein and alpha lactalbumin, a milk protein was evaluated in control and Escherichia coli enterotoxin (heat-stable, heat-labile, and both heat-stable and heat-labile enterotoxin) treated mice. The peak concentration of gliadin and lactalbumin was two hours and three hours after their ingestion, respectively. There was also a significant increase (...