A negative feedback regulation of pancreatic exocrine secretion has been observed in fasting rats, pigs, and humans, but this phenomenon could not be found in fasting dogs. The aims of the present study were to investigate whether or not postprandial pancreatic secretion is regulated by a negative feedback mechanism and to determine if the mechanism is mediated by secretion and/or cholecystokinin (CCK) in dogs.

The transforming growth factor beta (TGF-beta) proteins are key regulators of cellular growth and differentiation. Previous studies have shown that TGF-beta 1 is a potent growth inhibitor of cultured jejunal epithelial cells. The reported distribution of TGF-beta 1 messenger RNA (mRNA) expression along the intestinal villus has been controversial. The purpose of the current study is to determine the loci of TGF-beta protein expression in the normal small intestine and colon.

Peptide YY (PYY) given intravenously was shown to inhibit pancreatic exocrine secretion both in the dog and the rat. However, a possible physiological role of PYY on the pancreatic secretion has not been clarified. The present study was undertaken to investigate its physiological role on the exocrine pancreas.

Mucin, a population of polymeric glycoproteins, constitutes the primary component of the mucus layer that overlies the gastrointestinal tract. These studies aimed to determine whether murine intestinal mucins inhibit rotavirus infection.

The composition of the extracellular matrix (ECM) as well as insulinlike growth factor I (IGF-I) receptor density vary along the crypt-villus axis. We determined whether components of the ECM influence IGF-I receptor expression in IEC-18 rat small intestine crypt cells.

The locally acting vasodilator nitric oxide has recently been implicated as a possible mediator in the vasodilatation observed in prehepatic portal hypertension. The aim of this study was to assess if nitric oxide could also be implicated in the vasodilation observed in experimental cirrhosis.

Increased knowledge has been gained into the aetiology and pathogenesis of viral gastroenteritis during the past two decades. There are now thought to be four major subclassifications of gastroenteritis-causing viruses; these include rotavirus, enteric adenovirus, calicivirus, including Norwalk and Norwalk-like viruses, and astrovirus. The association of these agents with gastroenteritis has been made by their electron microscopic detection in stool and intestinal biopsy specimens from affected patients, the inability to detect the viruses after recovery from disease, and the subsequent development of immunoglobulin responses after infection; in some instances disease transmission was achieved in human volunteers. The association of these viral agents with gastroenteritis has facilitated the study of classification, epidemiology, immunity, diagnostic tests, methods of treatment and, most importantly, disease prevention strategies such as vaccine development for rotavirus. This chapter highlights the major features of these agents, with special attention being given to the pertinent molecular biology as well as current and future prospects for vaccination. Enteric viral infections of the gastrointestinal tract in patients with AIDS are also discussed.

Saccharomyces boulardii is a nonpathogenic yeast used for the prevention and treatment of Clostridium difficile-associated diarrhea and colitis. However, the mechanism by which S. boulardii exerts its protective effects remains unclear.

Over a period of 33 years, it has become possible to successfully transplant individual intra-abdominal viscera or combinations of these organs. The consequences have been, first, new information about the metabolic interrelations that the visceral organs have in disease or health; second, the addition of several procedures to the treatment armamentarium of gastrointestinal diseases; and third, a more profound understanding of the means by which all whole organ grafts are accepted.

Tauroursodeoxycholic acid (TUDCA) is of potential benefit in cholestatic disorders. However, the effects of TUDCA on cytosolic free calcium [(Ca2+)i], which regulates hepatocyte secretion, are unknown.

Hepatic histological responses described in hepatitis C virus (HCV) infection include bile duct damage, lymphoid follicles and/or aggregates in portal tracts, large- and small-droplet fat, Mallory body-like material in hepatocytes, liver cell dysplasia and multinucleation, and activation of sinusoidal inflammatory cells. The specificity of these lesions for HCV infection is uncertain.

Whether long-term octreotide treatment given to portal hypertensive rats could prevent or ameliorate peripheral vasodilatation and thereby modify sodium retention was investigated.

The muscularis mucosae is the muscle layer closet to the site of elevated inflammatory mediator production in inflammatory bowel disease. Thus, it is the first muscle layer subject to their influence.