Biological significance of exocrine gamma-A-immunoglobulin

IgA deficiency and severe post-vagotomy diarrhoea

Between January, 1969, and December, 1973, 2058 truncal vagotomies were performed in the Merseyside Regional Health Authority area. 14 of these patients subsequently developed severe post-vagotomy diarrhoea and were extensively investigated. 6 were found to have IgA deficiency. It is suggested that antecedent IgA deficiency may account for the varied reported incidence of severe post-vagotomy diarrhoea and that preoperative screening could reduce the incidence of this complication.

Methods for detecting food-borne enteroviruses

A method previously reported for detecting virus in a model system composed of cottage cheese contaminated with coxsackievirus type A9 has been adapted to detecting selected strains of enteroviruses in a variety of foods. Bentonite is omitted and serum is added for extracting virus from low-protein foods. Samples of foods, usually 25 g, must contain at least 3 to 4 plaque-forming units for a 50% probability of detecting virus. Sensitivity in detecting echovirus type 6 was lower than that for the other viruses used. After extraction from potato salad, poliovirus type 2 was completely reactivated if it had been neutralized with coproantibody, but it was only partially reactivated if neutralized with hyperimmune rabbit serum.

Adsorption of immunolgobulin A onto oral bacteria in vivo

Oral bacteria become coated with immunoglobulin A in human saliva in vivo. This may indicate that the salivary immunoglobulin A possesses antibacterial activity. Some of the immunoglobulin-coated cocci grow in extremely long chains and exhibit synchronous cell division. The long chain phenomenon may result from growth in the presence of salivary antibody specific to antigenic determinants of the bacterial cell walls.