Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diarrhea and malabsorption due to intestinal dysfunction are common symptoms in HIV infection. The pathophysiologic mechanisms of these alterations are often not known, and the role of HIV per se is still controversially discussed. We measured the epithelial transport and barrier function by means of a miniaturized Ussing chamber system in the duodenum of HIV-infected patients in different disease stages, determined by the CD4 cell count in the serum as well as symptoms in patients with and without diarrhea. We could show that diarrhea induced by HIV per se is caused by a leak flux mechanism due to impaired epithelial barrier function. Antisecretory therapy does not seem to be useful in these patients, because we did not find increased active ion secretion. Along the course of the HIV infection, the epithelial transport and barrier function varies with HIV disease stage (expressed by CD4 cell status). In addition, an in vitro model was studied to characterize the effect of HIV-infected human immune cells on the epithelial barrier function using the human colonic epithelial cell line HT-29/B6. HIV infection of human immune cells induced an increase in cytokine release--for example, TNF-alpha, IL-1 beta, IFN-alpha, and IFN-gamma--downregulating the epithelial barrier function of the human colonic epithelial cell line HT-29/B6. Taken together we postulate a specific stage-dependent cytokine pattern released from HIV-infected immune cells in the mucosa, which, corresponding to the HIV disease stage, is responsible for the variation in epithelial function.
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PMID:Mechanisms of epithelial barrier impairment in HIV infection. 1119 91

Celiac disease (nontropical sprue) is autoimmune disorder of the intestinal mucose, which usually develops in humans hypersensitive to gluten. The disease can occur at any age, with the greatest occurrence in early adulthood. Besides intestinal symptomatology--abdominal pain, diarrhoea and weight loss--celiac disease is often accompanied by extra-intestinal complications including osteopenia or osteoporosis and osteomalacia. Overproduction of cytokines IL-1 alpha, IL-1 beta and TNF-alpha increases bone resorption, which is further accelerated by hyperparathyroidism connected with malabsorption of calcium and vitamin D. Interaction of both these mechanisms activated bone loss. Similarly as the classic (symptomatic) celiac disease, the occult form, commonly seen in the elderly, may be associated with a risk of osteoporosis or osteomalacia related fractures. Diagnosis is based on positivity of IgA and IgG antigliadin and endomysial antibodies and characteristic endoscopic detection of inflammation and atrophy of duodenal mucose. Areal screening of celiac disease in osteoporotic patients is very dubious. However, a methodical examination should be performed in all patients with unexplainable hyperparathyroidism or in those with various autoimmune diseases (type 1 diabetes, thyroiditis chronica), or in premenopausal women and men, who did not reach the appropriate peak bone mass. On the other hand, detailed analysis of calcium metabolism, including markers of bone remodlling and X-ray densitometry (DXA), are recommended in all patients with verified celiac disease. The effectiveness of a gluten-free diet and substitution with vitamin D and calcium, or treatment with bisphosphonates are discussed. The promising therapy appears to be new molecules with reparative effect on intestinal mucose such as AT-1001.
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PMID:[Celiac disease and its relation to bone metabolism]. 1964 5