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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Until the 1960s, liver disease of the alcoholic patient was attributed exclusively to dietary deficiencies. Since then, however, our understanding of the impact of alcoholism on nutritional status has undergone a progressive evolution. Alcohol, because of its high energy content, was at first perceived to act exclusively as 'empty calories' displacing other nutrients in the diet, and causing primary malnutrition through decreased intake of essential nutrients. With improvement in the overall nutrition of the population, the role of primary malnutrition waned and secondary malnutrition was emphasized as a result of a better understanding of maldigestion and malabsorption caused by chronic alcohol consumption and various diseases associated with chronic alcoholism. At the same time, the concept of the direct toxicity of alcohol came to the forefront as an explanation for the widespread cellular injury. Some of the hepatotoxicity was found to result from the metabolic disturbances associated with the oxidation of ethanol via the liver alcohol dehydrogenase (ADH) pathway and the redox changes produced by the generated NADH, which in turn affects the metabolism of lipids, carbohydrates, proteins and purines. Exaggeration of the redox change by the relative hypoxia which prevails physiologically in the perivenular zone contributes to the exacerbation of the ethanol-induced lesions in zone 3. In addition to ADH, ethanol can be oxidized by liver microsomes: studies over the last twenty years have culminated in the molecular elucidation of the ethanol-inducible cytochrome P450IIE1 (CYP2E1) which contributes not only to ethanol metabolism and tolerance, but also to the selective hepatic perivenular toxicity of various xenobiotics. Their activation by CYP2E1 now provides an understanding for the increased susceptibility of the heavy drinker to the toxicity of industrial solvents, anaesthetic agents, commonly prescribed drugs, 'over the counter' analgesics, chemical carcinogens and even nutritional factors such as vitamin A. Ethanol causes not only vitamin A depletion but it also enhances its hepatotoxicity. Furthermore, induction of the microsomal pathway contributes to increased acetaldehyde generation, with formation of protein adducts, resulting in antibody production, enzyme inactivation and decreased DNA repair; it is also associated with a striking impairment of the capacity of the liver to utilize oxygen. Moreover, acetaldehyde promotes glutathione depletion, free-radical mediated toxicity and lipid peroxidation. In addition, acetaldehyde affects hepatic collagen synthesis: both in vivo and in vitro (in cultured myofibroblasts and lipocytes), ethanol and its metabolite acetaldehyde were found to increase collagen accumulation and mRNA levels for collagen. This new understanding of the pathogenesis of alcoholic liver disease may eventually improve therapy with drugs and nutrients.
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PMID:Aetiology and pathogenesis of alcoholic liver disease. 821 1

Alcohol causes primary malnutrition by displacing nutrients in the diet and secondary malnutrition via malabsorption and cellular injury through direct cytotoxicity. Hepatotoxicity results from metabolic disturbances associated with the oxidation of ethanol via liver alcohol dehydrogenase (ADH) and the redox changes produced by the generated NADH (the reduced form of nicotinamide adenine dinucleotide), which in turn affects the metabolism of lipids, carbohydrates, proteins, and purines. Ethanol is also oxidized in liver microsomes by an ethanol-inducible cytochrome P450, which contributes to the alcoholic's tolerance and his increased vulnerability to the toxicity of industrial solvents, anesthetics, commonly prescribed drugs, over-the-counter analgesics, chemical carcinogens, and retinoids. Increased acetaldehyde generation, with formation of protein adducts, results in antibody production, enzyme inactivation, decreased DNA repair, impaired utilization of oxygen, glutathione depletion, free radical-mediated toxicity, lipid peroxidation, and increased collagen synthesis. Therapy may eventually improve with the use of supernutrients such as S-adenosyl-L-methionine, which replenishes glutathione, restores methylation, and attenuates liver injury, as well as dilinoleoylphosphatidylcholine, which prevents cirrhosis.
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PMID:Herman Award Lecture, 1993: a personal perspective on alcohol, nutrition, and the liver. 823 56

Increased concentrations of reactive oxygen species in children with depleted antioxidant defences have been implicated in a cycle of malnutrition, malabsorption, and infection leading to protracted diarrhoea. A rat model of chronic vitamin E deficiency has been used to study the effects of antioxidant depletion on jejunal structure and function in vitro. Basal intestinal short circuit current (Isc), a measure of net electrogenic ion movement across the intestinal epithelium, was greater in chronically vitamin E deficient jejuna than controls, as was the electrogenic secretory response to aminophylline and Escherichia coli STa but not to bethanechol. The galactose stimulated current was also greater in vitamin E deficient jejuna. Indices of lipid peroxidation (concentrations of thiobarbituric acid reactive substances and malondialdehyde) were increased in the vitamin E deficient small bowel. Small intestinal brush border membranes from vitamin E deficient animals displayed changes in both static and dynamic components of membrane fluidity measured by steady state fluorescence polarography. The results of these studies support the hypothesis that oxidative stress in subjects with compromised antioxidant defences results in small intestinal hypersecretion, which could predispose to or perpetuate protracted diarrhoea.
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PMID:Lipid peroxidation and electrogenic ion transport in the jejunum of the vitamin E deficient rat. 830 46

We describe here an experience of successful treatment of systemic sclerosis (SSc) complicated with various gastrointestinal (GI) problems including pneumoperitoneum, pneumatosis cystoides intestinalis and malabsorption syndrome. A 35-year-old female had developed selerodactyly since February, 1990. She had been treated under the diagnosis of SSc at other hospital. She had required several hospitalizations because of nausea, vomitting and abdominal distension, but her GI symptoms had gradually deteriorated. In April 1993, she was referred to our hospital and admitted for the treatment of her GI problems. On admission, she had systemic cutaneous sclerosis and marked abdominal distension without peritoneal signs was recognized. Chest and abdominal roentgenograms demonstrated massive free air under the diaphragm, marked dilation of small and large bowels, and multiple intestinal cysts (pneumatosis cystoides intestinalis ; PCI). We treated her GI problems with various modalities combined with medications, oxygen breathing, intravenous hyperalimentation and hyperbaric oxygen therapy. Pneumoperitoneum and PCI had disappeared after 8 courses of hyperbaric oxygen therapy and her GI symptoms had been well controled by intravenous hyper alimentation. Thereafter, she has been on intermittent parenteral nutrition through subcutaneous port inplantation. During the courses of this treatment, she developed an episode of Wernicke-Kolsakoff (W-K) syndrome which was considered to associate with malabsorption syndrome. The W-K syndrome had recovered by intravenous administration of vitamin B1.
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PMID:[Systemic sclerosis with various gastrointestinal problems including pneumoperitoneum, pneumatosis cystoides intestinalis and malabsorption syndrome]. 872 Feb 72

Oxygen free radicals have been implicated as mediators of tissue injury in a variety of diseases. We investigated the role of oxidative injury and oxygen free radical scavengers in liver cell injury associated with obstructive jaundice in Wistar rats. Bile duct ligation for 4 or 7 days led to a decrease in both vitamin E and A in the plasma and liver of male Wistar rats, indicating the malabsorption of lipid-soluble vitamins. Serum bilirubin, alkaline phosphatase and gamma-glutamyl transpeptidase activities were increased in the bile-duct-ligated rats. Furthermore, marked increases in lipid peroxide and oxidized glutathione levels indicated cholestatic liver injury. The antioxidant defense system was impaired, as shown by decreases in reduced glutathione and in the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase. Moreover, these high lipid peroxide levels and low levels of antioxidants correlated with the severity of jaundice. After releasing the bile duct ligation, levels of bilirubin, lipid peroxide and oxidized glutathione declined, while the levels of vitamin E and A, reduced glutathione, and the activities of GSH-Px increased, indicating an improvement in liver function. These findings suggest that lipid peroxidation is associated with the pathogenesis of liver damage in animals with bile duct ligation. Meanwhile, free oxygen radical scavengers are reduced in the bile-duct-ligated rats, thereby increasing the susceptibility of the liver to injury by oxygen-derived free radicals.
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PMID:Biochemical events associated with ligation of the common bile duct in Wistar rats. 903 77

Piglet cryptosporidiosis is characterized by intestinal villous damage and malabsorption, and by reduced NaCl absorption in response to prostaglandins (PGs), which act directly on the epithelium and indirectly through enteric nerves. We hypothesized that phagocyte-derived reactive oxygen metabolite (ROM) production contributed to PG synthesis and altered transport in inflamed ileum. Ileal mucosa from control and infected piglets was analyzed for villous height, PGE2, catalase (an endogenous antioxidant), and malondialdehyde (MDA, a by-product of lipid peroxidation) from d 2-8 after infection. The response of control ileal mucosa to exogenous ROM and infected mucosa to antioxidant treatment was also studied in tissues mounted in Ussing chambers. Increased levels of MDA on d 2 preceded increased PGE2 on d 3-4, which correlated with the acute diarrheal phase; however the most severe villous atrophy (d 8) correlated with the highest levels of catalase and MDA but low levels of PGE2. Control mucosa responded to H2O2 with indomethacin- and tetrodotoxin-sensitive transient increases in short circuit current (Isc), which were accompanied by increased tissue production of 6-keto-PGF1a, the stable metabolite of PGI2; however, no increased PGE2 production was detectable. A stable analog of PGI2, carbacyclin, mimicked the transient Isc response to H2O2; however, several antioxidants failed to alter the abnormal Isc of infected tissue. These results suggest that there is evidence of increased ROM production in cryptosporidial infection and that intestinal PG synthesis and inhibited NaCl absorption may be mediated partially by ROM in this model. Additional, cooperative factors, such as PGE2 production, however, are likely needed to induce the alterations in ion transport seen in this infection.
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PMID:Reactive oxygen metabolites in piglet cryptosporidiosis. 909 54

A continuously increasing production level in poultry breeding has resulted in changes in metabolism. Selection procedures in breeding programmes are focused on an increase in growth rate and on a decrease in feed conversion ratio (less feed intake per unit of deposited tissue). These procedures do not pay attention to the maintenance requirements of birds. Imbalances between production (protein and fat deposition) and supply of energy for maintenance requirements lead to homeostatic dysregulation and to diseases of organs which supply the energy for production and maintenance. The alarming increase in metabolic diseases, such as heart failure syndrome, ascites, and oedema in the lungs and heart, can be directly related to an insufficient oxygen supply. A low oxygen consumption and heat production is one of the mechanisms by which a low feed conversion ratio can be achieved, as is induced hypothyroidism by which physical activity and thus heat production is reduced. Other diseases, such as liver cirrhosis, malabsorption syndrome, sudden death syndrome in broilers, and fatty liver-hemorrhage syndrome, which is nowadays the most important disease in laying hens in the Netherlands, can be related to an imbalance between the production rate and maintenance requirements. A continued selection on the basis of retained energy (in protein and fat) without paying attention to the maintenance requirements of birds will be detrimental for the health and welfare of poultry. These undesirable developments in poultry husbandry should be a challenge for sciences focused on welfare and stress in animals. Such a scientific approach to animals suffering from dysgenic changes in metabolism is needed to solve serious problems in poultry breeding.
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PMID:Pathological changes in metabolism of poultry related to increasing production levels. 932 54

A major hemorrhagic insult may require massive transfusions to maintain oxygen transport and hemostasis. Thus an adequate transfusion budget must consider losses, patient's blood volume, critical levels of laboratory parameters, replacement rates of coagulation factors from the extravascular space, and the efficacy of blood products. The substitution of large quantities of blood or red cell concentrates can induce and aggravate a complex haemostatic disorder. Some patients develop generalized microvascular bleeding. A transfusion regimen is described, which in our hands can reduce complications of massive transfusion. For hemostatic support, platelet concentrates and fresh frozen plasma are the treatment of choice. Localization and persistence of bleeding, hepatic disease, and vitamin K deficiency due to medication or intestinal malabsorption may require the supplementary use of prothrombin complex concentrates. Furthermore, antithrombin and fibrinogen concentrates may be indispensable.
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PMID:Indications for prothrombin complex concentrates in massive transfusions. 1049 11

Twelve patients (weight 107-178 kg and age range 19-43 years) were investigated following ileo-gastrostomy for morbid obesity. A number of variables were studied prospectively, pre- and postoperatively, to determine the cause of weight loss-previously attributed to malabsorption or decreased caloric intake. Weight loss of 10.9-36.5 kg, mean 22.9 kg, occurred. Three-day calorie counts demonstrated a postoperative decrease in daily caloric consumption of 320-3870, mean 1975 cal. Analysis of body compartment composition after derivation of lean body mass (from calculation of total body water with tritiated water) showed a mean decrease in adipose tissue of 17.7 kg. Postoperative weight loss, mainly fat, could not all be accounted for by decreased caloric consumption or steatorrhea (72-h stool fat increased by a mean of 30 g). Pulmonary studies showed no significant change in respiratory quotient, but a large decrease in both postoperative utilization of oxygen and the production of carbon dioxide. This may indicate an alternate, anaerobic, energy cycle utilization. Other statistically significant variables included a large fall in cholesterol, LDH cholesterol and triglycerides, and smaller decrease in HDL cholesterol. Changes in gastro-intestinal (GI) hormones and cell counts in stomach and small intestine were also measured and will be reported later.
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PMID:The Mechanism of Weight Loss after Ileo-gastrostomy for Morbid Obesity. 1077 23

Increased concentrations of reactive oxygen species (ROS) and depleted antioxidant defences have been implicated in a cycle of infection, malabsorption and malnutrition, leading to persistent diarrhea. In order to determine whether in non-malnourished children oxidative stress predisposes to the development of persistent diarrhea, infants with acute diarrhea (< 7 days) (n = 39) were compared to infants with persistent diarrhea (> 14 days) (n = 38). Lipid peroxidation was assessed by the TBARs assay and expressed as malondialdehyde equivalent content (nmol MDA/ml plasma), and levels of plasma antioxidants vitamin A and vitamin E were determined. In infants with acute and persistent diarrhea nutritional status, as assessed by weight/height and height-for-age, hemoglobin levels, serum albumin and immunoglobulin levels, did not differ between groups. Serum vitamin A and vitamin E levels did not differ in infants with acute or persistent diarrhea. TBARs, expressed as nmol MDA/ml plasma did not differ between infants with acute or persistent diarrhea and furthermore did not differ from levels in a healthy, similar age, control group. Non-malnourished infants with persistent diarrhea do not exhibit plasma antioxidant depletion or enhanced lipid peroxidation. In these infants, oxidative stress, as reflected in plasma, does not play a role in the pathogenesis of persistent diarrhea.
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PMID:Oxidative stress is not enhanced in non-malnourished infants with persistent diarrhea. 1169 27


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