Juan Ramón Malagelada

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BACKGROUND Increased numbers of mast cells and mast cell activation in distal gut segments are associated with symptom onset and severity in irritable bowel syndrome (IBS). Although upper gut symptoms are common, mast cells have not been thoroughly evaluated in proximal gut in IBS patients. METHODS Jejunal biopsies obtained by Watson's capsule, aspiration(More)
OBJECTIVES Rectal compliance may influence rectal perception, but their functional implications remain incompletely understood. Our aim was to determine whether rectal function is related to bowel habit in the irritable bowel syndrome. METHODS The responses to fixed tension rectal distension applied by means of a tensostat were compared among(More)
The localization of rat intestinal alkaline phosphatase has been studied in relation to fat absorption. The observations support a theory of conversion, within the intestinal mucosa, of intestinal type to liver type alkaline phosphatase when the criterion of differential sensitivity to two amino acid inhibitors, l-phenylalanine, and l-homoarginine, is(More)
BACKGROUND & AIMS Irritable bowel syndrome (IBS), a highly prevalent disorder among women, has been associated with life stress, but the peripheral mechanisms involved remain largely unexplored. METHODS A 20-cm jejunal segment perfusion was performed in 2 groups of young healthy women, equilibrated by menstrual phase, experiencing either low (LS; n = 13)(More)
The association between psychological and environmental stress with functional gastrointestinal disorders, especially irritable bowel syndrome (IBS), is well established. However, the underlying pathogenic mechanisms remain unknown. We aimed to probe chronic psychosocial stress as a primary inducer of intestinal dysfunction and investigate(More)
After cholecystectomy, bile secretion is continuous and 24-hour bile acid output exceeds that in health. Cholecystokinin-pancreozymin (CCK-PZ) influences neither bile acid secretion nor the bile acid composition of bile after the operation. It is proposed that the absence of the gallbladder causes more rapid enterohepatic recycling of bile acids and(More)
Enhanced knowledge of the pathophysiological basis of functional gastrointestinal disorders indicates that low-grade mucosal inflammation and mast cell hyperplasia are common findings. Mast cells are multipotent and mucosa-dwelling residents are uniquely located to communicate with host immune and nervous supersystems and with the gut microflora to provide(More)
A method has been developed and validated that simultaneously quantifies gastric secretion and the emptying of solids and liquids after an ordinary mixed meal. Using this technique in healthy persons, it is possible to: (1) measure the transformation of the meal in the stomach, where partial digestion and solubilization reduced the volume of the solids by(More)