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)

Fermentation, the process whereby anaerobic bacteria break down carbohydrates to short-chain (C2-C6) fatty acids (SCFAs), is an important function of the large bowel. SCFAs constitute approximately two-thirds of the colonic anion concentration (70-130 mmol/l), mainly as acetate, propionate, and butyrate. Gastroenterologists have, in spite of these facts, addressed this scientific field surprisingly late, in contrast to veterinarians, for whom the fermentative production of SCFAs has been acknowledged as a principal mechanism of intestinal digestion in plant-eating animals for decades. Interest in the effects of SCFA production on the human organism has been growing rapidly in the last 10 years, because gastrointestinal functions and beneficial effects are associated with these acids. SCFAs are of major importance in the understanding of the physiological function of dietary fibre and their possible role for colonic neoplasia. SCFA production and absorption are closely related to the nourishment of the colonic mucosa and sodium and water absorption, and mechanisms of diarrhoea. Patients with severe malabsorption compensate by the fermentation of otherwise osmotic active saccharides to SCFAs, which are readily absorbed and used as energy fuels in the organism. SCFA production from dietary carbohydrates is a mechanism whereby considerable amounts of calories can be salvaged in short-bowel patients with remaining colonic function if dietary treatment is adjusted. SCFA enemas are a new and promising treatment modality for patients with ulcerative colitis. The effect has been attributed to the oxidation of SCFAs in the colonocytes. An impressive number of papers have described the effects of butyrate on various cell functions, the significance of which is still unknown. Up until now, attention has been related especially to cancer prophylaxis and treatment. Diminished production of SCFAs appears to be involved in antibiotic-associated diarrhoea, diversion colitis, and possibly in pouchitis. The interaction between bacterial fermentation, ammonia metabolism, and bacterial growth and protein synthesis appears to be the main mechanism of action of lactulose treatment in hepatic coma. Pathological and extremely high rates of saccharide fermentation explain the severe deterioration in patients with D-lactate acidosis. Hence, this scientific field has come late to clinical working gastroenterologists, but as work is progressing the production of SCFAs in the large bowel becomes involved in several well-known intestinal disorders.
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PMID:Short-chain fatty acids in the human colon: relation to gastrointestinal health and disease. 872 86

With estimates that about 14% of the U.S. population will be over 65 years old by the end of this century, scientific research has attempted to achieve a better understanding of the aging process and of diseases that are expressed in higher incidence with advancing age. Because of its high rate of cell turnover and continual renewal, the mucosa of the gastrointestinal (GI) tract appears particularly susceptible to age-related disruptions in the normal cell proliferative process. This may translate into altered function that may result in the induction of malnutrition or malabsorption of particular nutrients, or a greater incidence of GI diseases, such as neoplasia. This review will examine the evidence for age-related alterations in the structural and functional properties of different regions of the GI tract and the pancreas, and how they may relate to malnutrition or disease processes.
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PMID:Effect of aging on the gastrointestinal tract and the pancreas. 916 41

Cryptosporidium parvum infection of the small epithelial intestine causes unremitting diarrhea and malabsorption that can lead to chronic and sometimes fatal illness in patients with AIDS. The illness may be ameliorated by passive oral immunoglobulin therapy. The objective of this study was to produce anti-Cryptosporidium human monoclonal antibodies for evaluation as potential therapy. All human monoclonal cell lines that produced C. parvum antibodies were originally generated from the peripheral blood lymphocytes of a human immunodeficiency virus-seronegative woman. She had recovered from C. parvum infection and had a high specific antibody titer. Hybridization of these lymphocytes with a tumor cell line was accomplished by hypo-osmolar electrofusion. Twelve clones were identified by enzyme-linked immunosorbent assay (ELISA) as secreting anti-Cryptosporidium antibodies after the initial hybridization. From the 12 positive clones, two high antibody-secreting clones, 17A and 17B, were maintained in long-term culture. A second hybridization produced two other human monoclonal cell lines, EC5 and BB2. Human monoclonal antibody from the first two cell lines bound to C. parvum sporozoites and oocysts by immunofluorescence. The ability of human monoclonal antibodies to inhibit C. parvum infection in vitro was assessed by using a human enterocyte cell line, HT29.74. The antibodies of the four different human hybridomas inhibited infection by 35 to 68% (P < 0.05) compared to a control irrelevant human monoclonal antibody derived in a similar fashion. Human monoclonal antibodies are candidate molecules for immunotherapy of C. parvum infection.
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PMID:In vitro inhibition of Cryptosporidium parvum infection by human monoclonal antibodies. 928 73

Common variable immune deficiency (CVID) is characterized by low immunoglobulin levels and recurrent infections in patients with a period of normal immune function several years after birth. It is associated with diarrhea, malabsorption, bronchiectasis, and lymphoreticular malignancies. Radiation-induced chromosome instability may contribute to the high degree of susceptibility to neoplasia. Peripheral blood lymphocyte cultures were obtained from six patients with CVID and the healthy control group matched by age and sex. The groups did not differ in the frequency of spontaneous chromosome aberrations. After exposure to X-ray radiation, mitotic indices were found to be significantly low and incidence of chromosomal alterations were high in the CVID group. We conclude that chromosomes of cells from patients with CVID are significantly more radiosensitive than those of controls. Thus these patients must be protected from unnecessary X-ray examinations and in case of radiosensitive tumour, the dose of irradiation should be carefully monitored.
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PMID:In vitro chromosomal radiosensitivity in common variable immune deficiency. 947 80

Necrolytic migratory erythema is characterized by waves of irregular erythema in which a central bulla develops, and subsequently erodes and becomes crusted. It usually occurs in patients with an alpha-islet cell tumor of the pancreas. However, necrolytic migratory erythema has also been observed in patients without an associated glucagonoma. We describe a woman with iatrogenic necrolytic migratory erythema. She received intravenous glucagon for hypoglycemia associated with an insulin-like growth factor II-secreting hemangiopericytoma. After chemotherapy, she developed necrolytic migratory erythema. The characteristics of the previously reported patients with nonglucagonoma-associated necrolytic migratory erythema are reviewed. In patients with nonglucagonoma-associated necrolytic migratory erythema, the dermatosis-related conditions most commonly observed were celiac disease or malabsorption, cirrhosis, malignancy, and pancreatitis; less common conditions included hepatitis, inflammatory bowel disease, heroin abuse, and odontogenic abscess. Although the pathogenesis of necrolytic migratory erythema remains unknown, hyperglucagonemia appears to have had a causative role in the development of this dermatosis in our patient. Patients who develop necrolytic migratory erythema should be evaluated for the presence of a glucagonoma; if a glucagonoma is ruled out, evaluation for other conditions known to occur with necrolytic migratory erythema, such as liver disease, malabsorptive disorders, and nonislet-cell tumors is warranted.
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PMID:Iatrogenic necrolytic migratory erythema: a case report and review of nonglucagonoma-associated necrolytic migratory erythema. 959 6

Wernicke's encephalopathy is an uncommon disorder caused by a thiamine deficiency which is clinically characterized by the triad of ophthalmoplegia, ataxia and disturbances of consciousness, each finding being variably present. The disease is caused by malnutrition or malabsorption, and is often associated with prolonged alcohol intake, neoplasm and extensive inflammatory processes of the digestive tract and parenteral hyperalimentation-induced gastrointestinal mucosal atrophy. Clinical diagnosis can be elusive and MRI may be the only imaging technique able to detect the cerebral lesions, whose type and distribution are characteristic of the Wernicke's encephalopathy, whereas CT is positive only in exceptional cases. We report a case of a 56-year-old woman who developed a Wernicke's encephalopathy 1 month after a colonic resection with signal intensity changes located in the mammillary bodies and in the medial thalamic nuclei.
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PMID:Magnetic resonance imaging in a case of Wernicke's encephalopathy. 968 4

We report a case of enteropathy-associated T-cell lymphoma (EATL), diagnosed by small intestine and gastric biopsies, who presented with manifestations of hypocalcemia and malabsorption. Immunological assessment revealed increased expression levels of tumor necrosis factor system components and eotaxin, an observation that is consistent with the cytotoxic T-cell phenotype characteristic of EATL, and decreased numbers of circulating activated (CD8+CD38+ and CD4+CD25+) and suppressor (CD11b+) T cells, a feature which can contribute to lymphomagenesis in patients with celiac disease. The acute clinical presentation of the patient resolved with mineral and vitamin supplementation and a gluten-free diet. The novel immunological findings described are discussed in the context of a review of our current knowledge of the immunopathogenesis of celiac disease and associated intestinal neoplasia.
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PMID:Enteropathy-associated T-cell lymphoma and its immunocarcinogenic correlates: case report and review of the literature. 975 48

Over the past 18 years, our laboratory has been interested in the pathogenesis of energy imbalance caused by a variety of diseases. Our view is that a clear understanding of the various factors causing negative energy balance, which in turn results in malnutrition, is the most effective way of designing preventive and therapeutic nutritional strategies. Thus, in cancer, one of the common factors is anorexia, due either to the primary tumor or to the effects of cancer therapy. Currently there is little evidence of increased resting energy expenditure in children with cancer, except in cases with very high tumor burden. Conversely, there are suggestions of a failure to down-regulate resting energy expenditure in the presence of reduced food intake in patients with cancer. Damage to the gastrointestinal tract, due to the effects either of the tumor or of tumor therapy, may result in maldigestion and/or malabsorption. Thus, as a result of a combination of reduced intake, reduced absorption and increased needs, the child with cancer may become malnourished. Prevention and treatment are dependent on the type of cancer and the pathogenesis of the negative energy balance. In broad terms, we try as far as possible to use external routes. With the advent of percutaneously placed gastrostomies and gastrojejunal tubes, we use these methods increasingly to provide nutritional support. Only in patients whose gastrointestinal tract cannot be used do we turn to i.v. feeding. In these patients, the placement of a central venous line is required, but great care must be taken to avoid infection. Whatever form of nutritional support is used, whether enteral or parenteral, we measure the body composition and energy expenditure in the patient, so that the nutritional therapy can be tailored to the child's specific needs. Using these approaches, we are having significant success in preventing and reversing malnutrition in children with cancer and those undergoing bone-marrow transplantation.
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PMID:Aggressive oral, enteral or parenteral nutrition: prescriptive decisions in children with cancer. 987 84

Folate plays a key role in nucleic acid synthesis. As a consequence, the most conspicuous complication of folate deficiency or of derangements of folate metabolism is megaloblastic macrocytic anemia caused by interdiction of normal proliferation of rapidly dividing bone marrow cells. Other rapidly dividing cells, including those in the gastrointestinal tract, may also be affected by the megaloblastic process. This may result in malabsorption. However, there is mounting evidence to indicate that there are other earlier manifestations of folate deficiency or of longstanding suboptimal folate nutrition. Chief among these manifestations of folate deficiency are an increased predisposition to occlusive vascular disease and thrombosis, which have been linked to increased levels of homocysteine found in folate deficiency and abnormal states of folate metabolism. In addition, folate deficiency, previously considered free of neurological consequences, is now known to be associated with disturbances of mood, and even spinal cord syndromes similar to those seen in vitamin B12 deficiency. Finally, there is both experimental and clinical evidence to suggest that folate deficiency may interfere with immunologic status and may be associated with an increased predisposition to neoplasia. Nutritional as well as genetic factors may contribute to these various nonhematological manifestations of folate insufficiency.
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PMID:Folate deficiency beyond megaloblastic anemia: hyperhomocysteinemia and other manifestations of dysfunctional folate status. 993 May 68

Gastrointestinal lymphomas are almost exclusively of a non-Hodgkin's type. The Western form is characterized by a higher incidence of stomach location (50%), a MALT type (mucosa associated lymphoid tissue) (40%), a B-cell type (90%), and a high grade (55%). Chronic infection with Helicobacter pylori is an important risk factor. Mediterranean lymphomas form a particular clinical and pathological entity with diffuse involvement of the small bowel and are frequently being associated with a chronic malabsorption disorder. Eradication of Helicobacter pylori in early gastric lymphomas, and the use of tetracyclines in early Mediterranean lymphomas, have been shown to induce durable remissions. For more advanced gastric lymphomas, treatment usually consists of anthracyclin-based chemotherapy followed by involved field radiotherapy. Surgery is usually reserved for complications such as perforation or bleeding, or in some selected cases for salvage after failure of non-surgical therapy. For intestinal lymphomas, surgical resection whenever feasible, followed by anthracyclin-based chemotherapy is the most common treatment. Radiotherapy is usually reserved for consolidation in some clinical situations. The most commonly found prognostic factors are stage, grade, and tumor bulk. Treatment results vary with the presence of adverse prognostic factors and the used treatment combination. In general, patients with favorable disease receiving combined therapy have a 5-year relapse free survival (RFS) approaching 90%, whereas those with unfavorable disease have a RFS of 40-50%.
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PMID:[Radiotherapy for gastrointestinal lymphomas: indications and techniques]. 1023 Mar 73


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