Background-The pathogenesis of pancreatic fibrosis is unknown. In the liver, stellate cells (vitamin A storing cells) play a significant role in the development of fibrosis. Aims-To determine whether cells resembling hepatic stellate cells are present in rat pancreas, and if so, to compare their number with the number of stellate cells in the liver, and isolate and culture these cells from rat pancreas. Methods-Liver and pancreatic sections from chow fed rats were immunostained for desmin, glial fibrillary acidic protein (GFAP), and smooth muscle actin ( -SMA). Pancreatic stellate shaped cells were isolated using a Nycodenz gradient, cultured on plastic, and examined by phase contrast and fluorescence microscopy, and by immunostaining for desmin, GFAP, and -SMA. Results-In both liver and pancreatic sections, stellate shaped cells were observed; these were positive for desmin and GFAP and negative for -SMA. Pancreatic stellate shaped cells had a periacinar distribution. They comprised 3.99% of all pancreatic cells; hepatic stellate cells comprised 7.94% of all hepatic cells. The stellate shaped cells from rat pancreas grew readily in culture. Cells cultured for 24 hours had an angular appearance, contained lipid droplets manifesting positive vitamin A autofluorescence, and stained positively for desmin but negatively for -SMA. At 48 hours, cells were positive for -SMA. Conclusions-Cells resembling hepatic stellate cells are present in rat pancreas in a number comparable with that of stellate cells in the liver. These stellate shaped pancreatic cells can be isolated and cultured in vitro. (Gut 1998;43:128-133)

The term ''ectopic varices'' is sometimes reserved for abnormally dilated veins associated with gastrointestinal mucosa and, therefore, with the potential for gastrointestinal hemorrhage. However, the term has also been used loosely to describe portosystemic collateral veins in the abdominal wall and retroperitoneum. The distinction between ''ectopic varices'' and collaterals that are commonly found on the abdominal wall and retroperitoneum of patients with portal hypertension is one of semantics. Thus, ectopic varices may be best defined as large portosystemic venous collaterals occurring anywhere in the abdomen except in the cardioesophageal region.Ectopic varices are an unusual cause of gastrointestinal hemorrhage, but account for up to 5% of all variceal bleeding. 1 The clinician caring for patients with gastrointestinal bleeding must be aware of this entity, because diagnosis and management of ectopic varices differ from that of esophagogastric varices. Furthermore, the prognosis from bleeding ectopic varices may be poor, with one study quoting 40% mortality at initial bleed from duodenal varices. 2 The literature on this subject consists mainly of small series and case reports with no randomized trials of therapeutic modalities. However, a review of the literature does provide sufficient information from which rational management decisions can be made. PREVALENCEEctopic varices account for between 1% and 5% of all variceal bleeding. 1,3 Ectopic varices are a relatively common finding at endoscopy in patients with portal hypertension. The prevalence seems to be related to the cause of the portal hypertension and the technique used to show the varices. In patients with intrahepatic portal hypertension, duodenal varices are seen in 40% of patients undergoing angiography, 3 whereas anorectal varices have been reported in between 10% and 40% of cirrhotic patients undergoing colonoscopy. 4,5 It is important to differentiate anal varices from hemorrhoids: Anal varices collapse with digital pressure, whereas hemorrhoids do not. 4 In patients with portal hypertension caused by obstruction of the portal or splenic veins, duodenal varices are more prevalent than in patients with intrahepatic portal hypertension. The prevalence is higher if angiography is used to show varices. In fact, most patients with portal or splenic vein thrombosis are likely to have duodenal varices shown on angiography. 6,7 The majority of patients with duodenal varices visualized on endoscopy have extrahepatic portal hypertension. In contrast to duodenal varices, it appears that most cases of varices in other portions of the small intestine and colonic varices are seen in patients with intrahepatic portal hypertension who have previously undergone abdominal surgery. 6 In the west, because the prevalence of extrahepatic portal hypertension is low, most bleeding from ectopic varices is usually associated with intrahepatic portal hypertension. 6,8 Stomal varices are a particularly common cause of ectopic varices and occur in patients with intrah...

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