Rats immunized with Escherichia coli heat-labile (LT) enterotoxin, either in the form of the holotoxin derived from a transformed K-12 strain or the polymyxin-release form obtained from human strains which produce LT toxin alone (LT+/ST- [ST is heat-stable toxin)] or together with ST toxin (LT+/ST+), were challenged with viable organisms of 10 different serotypes, 5 LT+/ST- and 5 LT+/ST+. The s...

BACKGROUND Cholera toxin, and Escherichia coli heat labile (LT) and heat stable (STa) enterotoxins induce small intestinal secretion in part by activating enteric nerves. Igmesine is a novel sigma receptor ligand that inhibits neurally mediated secretion. AIMS To assess the antisecretory potential of igmesine in cholera toxin, LT, and STa induced water and electrolyte secretion using an in vi...

Chapter 1: Literature Review I. Allergic Responses II. Animal Allergy Models III. Cholera Toxin and Heat Labile Toxin Chapter 2: Cholera Toxin or Escherichia coli Heat Labile Toxin Subunit B and Mouse Peanut Allergy Model I. Abstract I

Guanylate cyclase is regulated by adenine nucleotides in membranes of intestinal mucosal cells. Basal guanylate cyclase was activated about twofold by adenine nucleotides. Activation was specific for adenine, as compared with the pyrimidine nucleotides UTP and CTP. In addition, enzyme activation was obtained in the presence of saturating concentrations of GTP, the substrate for guanylate cyclas...

The genes for a new enterotoxin were cloned from Escherichia coli SA53. The new toxin was heat labile and activated adenylate cyclase but was not neutralized by antisera against cholera toxin or E. coli heat-labile enterotoxin. Subcloning and minicell experiments indicated that the toxin is composed of two polypeptide subunits that are encoded by two genes. The two toxin subunits exhibited mobi...

Hot phenol-water extraction of smooth Brucella abortus and B. melitensis cells yielded a toxic fraction which was recovered from the phenol phase (fraction 5). Chemically, fractions 5 from both Brucella species were lipid-carbohydrate-protein-2 keto-3-deoxyoctulosonic acid complexes which were stable to heat and resistant to Pronase digestion. Electron micrographs of the Brucella toxins were mo...

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...