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A cell line model to detect enterotoxic effect was used to test fecal specimens of patients with enteric cryptosporidiosis. Fecal samples were obtained from 11 patients with Cryptosporidium diarrhea, and osmotic gap was determined. Caco-2 cell monolayers grown on filters were mounted in Ussing chambers, and electrical parameters were measured before and after the addition of fecal supernatant. A significant increase in short-circuit current was seen in 9 of 11 specimens. The enterotoxic effect was time- and dose-dependent, saturable, and Cl(-)- and Ca(2+)-dependent. Fecal osmotic gap was consistent with secretory diarrhea in the 9 enterotoxin-positive but not in the 2 enterotoxin-negative samples. In conclusion, a cell line model for studying the pathophysiology of enteric cryptosporidiosis was established. Enterotoxic activity was observed in most patients with enteric cryptosporidiosis and was strictly associated with secretory diarrhea.

Numerous studies have shown pancreatic disease in adult human immunodeficiency virus (HIV)-infected patients, but there are very few reports on pediatric patients. Our aim was to determine the prevalence of increased serum pancreatic enzyme levels and their relationship to clinical manifestations of acute pancreatitis in HIV-infected children.Forty-seven consecutive, symptomatic HIV-infected children (24 male; median age, 7.3 years; range, 1-17 years) and 45 sex- and age-matched controls without gastroenterologic disease were enrolled. In all subjects serum total amylase, pancreatic amylase, and lipase were assayed with commercial kits. The following were recorded: disease progression (CDC class), nutritional status (weight Z-score), CD4 lymphocyte count, drug treatment during the previous 12 months, presence of opportunistic infections, clinical evidence of acute pancreatitis (increased serum pancreatic enzymes associated with vomiting, abdominal distention, and intolerance when eating).Ten of 47 HIV patients had increased serum total amylase values; however fewer patients had increased specific pancreatic enzymes: 6 of 47 for pancreatic amylase (range, 1.8- to 19.8-fold normal limit) and 7 of 47 for lipase (range, 1.4- to 4-fold normal limit). Values were normal in all controls. Two HIV patients with increased total amylase had clinically evident parotid inflammation. None of the patients with increased serum pancreatic amylase and/or lipase had clinical symptoms of acute pancreatitis. Regression analysis showed no correlation between increased serum pancreatic enzyme levels and disease progression (CDC class), immunologic status (CD4 count), nutritional status, drug administration, or opportunistic infections.Fifteen per cent of HIV-infected children had biochemical evidence of pancreatic involvement; however, this condition was unrelated to clinical signs of pancreatitis. Neither drug administration nor opportunistic infections seem to determine the increased serum pancreatic enzyme levels.

It has been reported that: 1) ovine growth hormone stimulates intestinal water, sodium, and chloride absorption and 2) specific growth hormone receptors are present in the rat intestine. Aims of this work were to investigate the effects of acute administration of hGH on water and ion transport in the rat ileum in vivo and in vitro. In vivo, the absorption rates of water, sodium, chloride, and potassium were determined in the rat perfused ileum, during a basal period and after i.v. administration of 6 μg/kg recombinant DNA-derived hGH. In vitro, electrical parameters were measured before and after the hormone addition to the mucosal or the serosal side of rat ileal mucosa mounted in Ussing chambers. In vivo, growth hormone induced a rapid increase in the absorption rates of water, sodium, chloride, and potassium. In vitro, the serosal, but not the mucosal, addition of growth hormone induced a rapid decrease of transepithelial potential difference and of short-circuit current. The effect was time- and dose-dependent, saturable, but not reversible in the short time. The electrical effect was abolished in the absence of chloride, indicating that it was related, at least in part, to inhibition of basal active chloride secretion. Growth hormone also reduced the short-circuit current increase induced by the secretagogues Escherichia coli heat-stable enterotoxin, theophylline, and calcium ionophore A23187. These results indicate that hGH has a rapid absorptive effect that is related, at least in part, to a direct intestinal antisecretory mechanism. It also reduces active intestinal secretion induced by various secretagogues.