Hernán Lotero

Utilization of exogenous urea nitrogen in malnourished adults

Abstract The utilization of exogenous urea as a nitrogen source was studied in 10 malnourished adults. Urea administration induced a significant positive nitrogen balance in all cases. In three subjects increasing doses of urea nitrogen induced a corresponding rise in positive nitrogen balance. Neomycin administration produced a slight decrease in urea nitrogen retention, apparently due to an increased fecal nitrogen loss during neomycin induced diarrhea. An increased supply of dietary protein as well as an improved nutritional status were shown to abolish the need for utilization of urea nitrogen. Intravenous urea administration in two subjects demonstrated similar effects to those obtained through oral route of administration.

IgA heavy chain disease. A case detected in the western hemisphere.

IgA heavy chain disease (alpha chain disease) was detected in a 46 year old South American (Colombian) of mixed Spanish and Indian (Mestizo) descent. The clinical course was characterized by severe malabsorption, initially thought to be a variant of tropical sprue. Jejunal mucosal biopsy revealed marked villous atrophy with heavy infiltration of the lamina propria by a single monotonous cell type which, by light microscopy, had the appearance of either a large, abnormal plasma cell or a small histiocyte. Electron microscopy of the biopsy specimen demonstrated the presence of abnormal plasma cells, lymphatic distention and abnormalities of surface epithelial cells. At autopsy a 6 by 3 cm mass was found in the right para-aortic area along with many firm 2 cm mesenteric and para-aortic lymph nodes. Histologic examination revealed the presence of a monotonous cell type similar to that found in the jejunal mucosal biopsy specimen.