Search PubMed⌕ Search

Biomedical subjects

D G Gall

Publications and source records attributed to D G Gall.

135 records · Page 8Linked to original sources
PubMed1974

Transmissible gastroenteritis. Mechanisms responsible for diarrhea in an acute viral enteritis in piglets.

We studied 3-wk-old piglets 40 h after experimental infection with transmissible gastroenteritis (TGE) virus to identify the mechanisms of diarrhea in this disease and to better understand infectious diarrhea in humans. Using continuous segmental marker perfusion in four regions along the gut, we found significant increases in net intraluminal accumulation of water and electrolytes only in the proximal jejunum, the region infected by the virus. In this jejunal segment studied in vivo, unidirectional sodium flux, extracellular fluid (ECF) to lumen, significantly increased, lumen to ECF significantly decreased, compared with matchfed littermates. The standard perfusate rendered hypertonic by adding mannitol (450 mosmol/kg), in the same segment of normal pigs, caused only an increase in ECF to lumen flux of sodium. TGE did not alter gross villous structure or intraluminal bacteria, bile salts, lactate, pH, or osmolality. Epithelial cell migration was accelerated in the jejunum of infected pigs. Isolated in suspension, these cells from TGE pigs exhibited increased active and passive sodium efflux, cells from mannitol-perfused pigs exhibited only increased active sodium efflux. In this viral enteritis, altered sodium transport occurring in the jejunum, the region of the intestine infected appears to be associated with defective epithelial cell function. The precise nature of the abnormalities in sodium transport, their relationship to disturbances of transport of other solutes, and to virus epithelial cell interaction remain to be defined.

Animals↗
PubMedDate not supplied

Gastrointestinal uptake of macromolecules.

Although the majority of dietary proteins undergo extensive digestion, small, nutritionally insignificant amounts of food proteins appear to cross the gastrointestinal mucosa intact. Experiments in a variety of allergic models has demonstrated that exposure of the gastrointestinal mucosa to the intact allergen leads to an anaphylactoid reaction. To examine the uptake of immunologically intact protein across the gastrointestinal epithelium, the mucosal to serosal movement of bovine serum albumin was measured in stripped gastric and intestinal mucosa mounted in modified Ussing-type chambers. Studies demonstrated that both gastric and intestinal mucosa are capable of actively transporting intact dietary proteins. In the intestine, the transport of intact molecules across the epithelium is a saturable, energy dependent process which utilizes the microtubular network and is regulated by the enteric nervous system. Transport across gastric mucosa is also dependent upon the microtubular network and is energy dependent.

Anaphylaxis↗