Abstract: By isolation and purification from the urine of patients treated with niridazole there is obtained substantially pure 1-(thiocarbamoyl)-2-imidazolidinone which exhibits marked immunosuppressive activity.

Abstract: Eggs of Schistosoma species in urine are reliably counted in a simple field test involving passing a urine sample of 10 ml or less through a thin transparent microporous membrane having pores of less than about 30 .mu.m, drying the membrane until ready for counting, wetting the membrane with a drop of saline solution, scanning the membrane at about 40X magnification and counting the eggs. Workers of limited skill can run a test in about 1 minute.

Abstract: Schistosoma mansoni eggs are ground to liberate soluble egg antigens which are fractionated and purified by absorption, gel filtration and/or ion exchange chromatography, and then radioactively labelled with .sup.125 I. A fraction, identified as MSA.sub.1, is specific to the mature egg stage of Schistosoma mansoni and thus can be used to detect the presence of antibody to mature Schistosoma mansoni eggs in a patient's serum even as compared with mature eggs of different Schistosoma (species specific) or of Schistosoma mansoni worms but not mature eggs (stage specific).