Gastroenterology
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Increased intake of dietary fiber has been proposed to reduce the risk of inflammatory bowel disease (Crohn's disease [CD] and ulcerative colitis [UC]). However, few prospective studies have examined associations between long-term intake of dietary fiber and risk of incident CD or UC. ⋯ Based on data from the Nurses' Health Study, long-term intake of dietary fiber, particularly from fruit, is associated with lower risk of CD but not UC. Further studies are needed to determine the mechanisms that mediate this association.
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Splanchnic vascular hypocontractility with subsequent increased portal venous inflow leads to portal hypertension. Although the renin-angiotensin system contributes to fibrogenesis and increased hepatic resistance in patients with cirrhosis, little is known about its effects in the splanchnic vasculature, particularly those of the alternate system in which angiotensin (Ang) II is cleaved by the Ang-converting enzyme-2 (ACE2) to Ang-(1-7), which activates the G-protein-coupled Mas receptor (MasR). We investigated whether this system contributes to splanchnic vasodilatation and portal hypertension in cirrhosis. ⋯ In the splanchnic vessels of patients and rats with cirrhosis, increased levels of ACE2 appear to increase production of Ang-(1-7), which leads to activation of MasR and splanchnic vasodilatation in rats. This mechanism could cause vascular hypocontractility in patients with cirrhosis, and might be a therapeutic target for portal hypertension.