Determination of purity and identification of animal sources of insulin in various insulin preparations

Prolonged administration of insulin leads to the formation of insulin-binding antibodies due to contaminant peptides and the animal source of the insulin. It follows that quantitation and identification of these factors are of significant importance in pharmaceutical insulin preparations. The assay and test procedures stipulated in the current pharmacopoeia of various countries, nevertheless, cannot determine either of these effects. In the present study, the content of impurities in insulin preparations was measured by polyacrylamide gel disc electrophoresis and the animal source of insulin identified by amino acid analysis. Assays of 17 commercial insulin preparations by these techniques revealed diversity in purity and animal sources of insulin. The present results suggest potential usefulness of these assay methods and advisability of their adoption not only by the manufacturers but also by the official pharmacopoeia as well.

Dirofilaria in the abdominal cavity of a man in Japan

A case of human dirofilariasis of the abdominal cavity is reported from Japan. The patient, a 74-year-old man, died of liver cancer; postmortem examination revealed a granulomatous mass on the mesentery. In histologic sections there were cross-sections of a mature female nematode identified as a Dirofilaria. The cuticle had a smooth surface and consisted of four distinct layers. The inner cuticular layer had internal lateral longitudinal ridges, and the musculature of the body wall was of the high polymyarian type. On the basis of morphology of the worm, it is suggested that this may represent the first human case of Dirofilaria immitis occurring in the abdominal cavity.