Human milk obtained from 21 American nursing mothers was studied for the presence of secretory immunoglobulin A antibody to rotavirus, the most common etiological agent of infantile gastroenteritis. Antibody was quantitated by adaptation of a recently described solid-phase radioimmunoassay technique that employs simian rotavirus as a convenient substitute antigen for human rotavirus. Of the mot...

The insulin radioimmunoassay technique used for human insulin has been modified for measuring rabbit insulin (i) at lower concentrations of insulin in plasma, and (ii) more precisely. Eleven algebraic functions were fitted in turn to fifty-three data sets. The goodness-of-fit was assessed in each case. It was concluded that a quadratic equation was the best function for the standard curve of th...

A rapid, sensitive, and precise method for measuring the plasma digoxin concentration has been developed with the radioimmunoassay technique. Seventy patients receiving digoxin were shown to have plasma digoxin concentrations between 0.4 and 5 ng./ml. Preliminary studies show that though there is a positive correlation between total daily dose and the plasma digoxin concentration, the relations...