Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0235394 (wasting)
 8,040 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

General anesthesia in combination with surgery is known to result in negative nitrogen balance. To determine whether general anesthesia without concomitant surgery decreases whole body protein synthesis and/or increases whole body protein breakdown, two groups of dogs were studied: Group 1 (n = 6) in the conscious state and Group 2 (n = 8) during general anesthesia employing halothane (1.5 MAC) in 50% nitrous oxide and oxygen. Changes in protein metabolism were estimated by isotope dilution techniques employing simultaneous infusions of [4,53H]leucine and alpha-[1-14C]-ketoisocaproate (KIC). Total leucine carbon flux was unchanged or slightly increased in the anesthetized animals when compared to the conscious controls, indicating only a slight increase in the rate of proteolysis. However, leucine oxidation was increased (P less than 0.001) by more than 80% in the anesthetized animals when compared with their conscious controls, whereas whole body nonoxidative leucine disappearance, an indicator of whole body protein synthesis, was decreased. The ratio of leucine oxidation to the nonoxidative rate of leucine disappearance, which provides an index of the catabolism of at least one essential amino acid in the postabsorptive state, was more than twofold increased (P less than 0.001) in the anesthetized animals regardless of the tracer employed. These studies suggest that the administration of anesthesia alone, without concomitant surgery, is associated with a decreased rate of whole body protein synthesis and increased leucine oxidation, resulting in increased leucine and protein catabolism, which may be underlying or initiating some of the protein wasting known to occur in patients undergoing surgery.
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PMID:Anesthesia with halothane and nitrous oxide alters protein and amino acid metabolism in dogs. 304 37

Wasting of muscle and a negative nitrogen balance are obvious effects of malnutrition, and have led to the use of anthropometric measurements and nitrogen balance for its assessment. A positive nitrogen balance and an increase in limb muscle circumference are believed to be solid indices of the beneficial effects of nutritional support. In experiments with growing rats and in young children, nitrogen retention and growth are recognized to be the desirable effects of optimal nutritional intake. This concept has been applied to malnourished adult humans (nongrowing) who have been considered potentially able to "regrow" the lost tissue. Although it is true that patients receiving long-term (greater than 6 months) home total parenteral nutrition (TPN), gain body weight and nitrogen over many months and years of observation, these processes are not seen during shorter (less than 40 days) periods of nutritional intervention given in hospital. Despite adequate intakes of nitrogen and calories, little or no significant increase in total body nitrogen is seen in a variety of patients receiving TPN in hospital over several weeks, but nutritional support does appear to improve outcome in the form of reduced complications after a period of support so short that body composition is barely altered. For example, Young and Hill showed that although amino acids and amino acids plus calories both resulted in equivalent sparing of body nitrogen, the latter was associated with quicker wound healing and fewer complications. Thus, the outcome and body composition data suggest that reversal of the adverse effects of malnutrition is not based on improvement of the traditional parameters of nutrition, such as gain in body nitrogen, or a demonstrable increase in muscle mass, or in plasma proteins. On the basis of the foregoing evidence, there are grounds for suspecting that functional abnormalities in adult humans may not be the result of simple loss of lean tissue and therefore may recover before such lean tissue is regained. This hypothesis is supported by the observation of Klidjian et al who showed that muscle force is a good measure of outcome. One of the major organ systems of the human body is the musculoskeletal system, and therefore it would seem important to determine the effect of malnutrition on that system. Previous studies of muscle function have been largely related to the examination of fatigue, myopathy, and endocrine-metabolic abnormalities. Subsequently we undertook initial studies of muscle function in very malnourished patients as outlined below.
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PMID:Rhoads lecture--1988. Bulk or bounce--the object of nutritional support. 306 74

Liver transplantation now provides a viable alternative to patients with end-stage hepatic failure. Because of the damaging effects of liver failure on other organ systems, transplant candidates frequently suffer from moderate to severe malnutrition. Chronic hepatic failure can result in deranged metabolism of not only macronutrients and micronutrients but also various hormones. Patients are frequently in a catabolic state. Wasting of the skeletal muscle mass occurs and synthesis of secretory proteins and clotting factors decreases. Hepatic encephalopathy and fluid/electrolyte imbalances often complicate the provision of appropriate nutrition support. Nutrition support may be provided by the oral route, tube feeding, parenteral nutrition, or a combination of those routes. A multidisciplinary approach to determine the appropriate nutrition support regimen is most optimal. To assess the efficacy of the support, monitoring of the nutritional/metabolic status is necessary on an ongoing basis. An aggressive nutrition support regimen can induce positive nitrogen balance, promote hepatic protein synthesis, and expand lean body mass, controlling the symptoms of malnutrition in end-stage liver disease.
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PMID:Nutrition support of the adult liver transplant candidate. 310 37

Whole body nitrogen can be measured by neutron activation analysis with an acceptable radiation dose; it is an index of body protein which, in normal subjects, is 65% cellular protein and 35% extracellular connective collagen. Whole body potassium can be measured by whole body counting without irradiating the subject; it is an index of body cell mass. We measured whole body nitrogen, potassium, extracellular water, intracellular water, and fat-folds. The differences between 37 malnourished patients and five normal subjects suggested that the patients had 9 kg less cell mass than normal, but no difference in extracellular mass. Measurements were made on eight patients before and after 14 days of total parenteral nutrition; balance of nitrogen intake and excretion also was measured. The changes were consistent with mean increases of 3 kg of cellular mass and 3 kg of fat with no change of extracellular mass. The accuracy and sensitivity of the whole body measurements need further confirmation for use in patients with changing body composition. Where tissue wasting is largely from the cellular compartment, potassium could be a more sensitive index of wasting than nitrogen. Multielement analysis of nitrogen, potassium, chlorine, and carbon will probably be valuable in elucidating body composition in malnutrition.
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PMID:Measurement of whole body cellular and collagen nitrogen, potassium, and other elements by neutron activation and whole body counting. 311 69

The peripheral nitrogen wasting and loss of functional capacity caused by the malnutrition of disease and the immobilization of hospitalization may not be readily reversed by refeeding alone. In order to examine submaximal exercise as an adjunctive anabolic stimulus to intravenous refeeding (IVF) in depleted subjects, 14 volunteers were studied in the postabsorptive (PA) state, after 10 days of total starvation, and again after 10 days of nutritional repletion with I.V. feedings. The subjects were randomized to one group that received IVF alone and one group that performed 1 hour of submaximal (51% of VO2max) stationary bicycle exercise daily during IVF. The exercised group was not significantly different from the nonexercised group in urinary nitrogen balance, resting energy expenditure, extremity amino acid flux, or maximal oxygen consumption. Acute exercise did not induce significant derangements in electrolytes or counter-regulatory hormone concentrations. Ten days of submaximal exercise does not appear to be detrimental in this population recovering from moderate hospitalized malnutrition, but additional anabolic stimulae may be needed for improvements in protein accrual or functional capacity.
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PMID:Submaximal exercise during intravenous hyperalimentation of depleted subjects. 312

A knowledge of the relationship between nutrition and the respiratory system applied in chronic airflow obstruction (BCO) enables a better understanding of the increased frequency (30 to 50%) of protein-energy malnutrition (MEP) in this population. The physiology of the wasting in chronic airflow obstruction seems to relate to hypermetabolism (HMB) which is not compensated by an increased alimentary intake. The HMB is linked to a rise in the work of the respiratory muscles whose efficiency is altered by intrathoracic hyperinfiltration and also the consequences of MEP on the mass and function of the respiratory muscles. In the animal MEP induced by alimentary restrictions leads to a model of pulmonary emphysema and to the diminution of the synthesis of surfactant. This emphysema seems to be principally due to an alteration of the process of protein synthesis and to a diminution of lysyl-oxydase activity. The nutrients (utilised notably by the venous route) have their own pharmacological role, and in addition they have an effect on the natural equilibrium of the energy and nitrogen balance. Lipids (rich in polyunsaturated fatty acids) intervene in the synthesis of prostaglandins, and exercise some effects on the inflammatory process and the activity in the bronchial and vascular smooth muscles. Based on this fact they have been used for their anti-inflammatory role at the pulmonary level in the treatment of mucoviscidosis. The administration of amino acids changes ventilation by acting on the central neuro-muscular command mechanism (VT/TI). The perfusion of amino acids enables a restoration of the chemo-sensitivity to oxygen and to CO2 abolished by the prolonged restricted diet. Finally the partial pressure of oxygen ought to be interpreted with respect to meal times because an oral dose of glucose can provoke an increase in the PaO2 of around 10 mmHg for healthy subjects and those with BCO. A preventive and therapeutic attitude vis a vis BCO should take account of the relationship between nutrition and the respiratory system in parallel with a correction of hypoxaemia in order to avoid the development of wasting.
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PMID:[Malnutrition and chronic obstructive bronchopathies]. 314 Mar 15

Previous studies have shown that the polychlorinated biphenyl mixture, Aroclor 1254 (ARO), -induced wasting in male rats is associated with increased permeability of hepatic mitochondria. This was correlated with hyperuremia and stimulated urea synthesis, hypoglycemia and suppressed glucogenesis after an ammonium acetate injection, and decreased retention of assimilated nitrogen and food intake. For ARO-toxic rats (100 mg/kg, ip, for 1, 2, and 4 days) versus Tween 80-treated, ad libitum-fed controls, mitochondrial carbamoyl phosphate (CP) formation (the initial step in urea synthesis from NH4+) was progressively stimulated for the duration of treatment from NH4+ and ATP but not from NH4+ and ADP. ARO maximal stimulation of CP formation also correlated with significant loss in body weight. Mitochondrial ornithine transcarbamoylase synthesis of citrulline from ornithine and carbamoyl phosphate was also stimulated. In comparison to fasted rats (24 hr), mitochondrial CP synthesis from NH4+ was enhanced with ADP but not with ATP. This ARO uncoupling of mitochondrial NH4+ metabolism and stimulation of CP formation with exogenous ATP and citrulline synthesis may have resulted from increased availability of substrates and cofactors in the matrix space, leakage of enzymes from the matrix, or a combination of these effects. These results are consistent with an increased inner membrane permeability and fragility during isolation and assays. In agreement with our previous studies, the data show that ARO exposure poises hepatic mitochondria toward the synthesis of urea intermediates.
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PMID:Aroclor 1254 treatment and fasting influences on rat liver mitochondrial carbamoyl phosphate synthesis with ADP and ATP. 314 1

This study investigated the possibility of preventing prednisone-induced protein wasting by regular physical activity. Eight healthy untrained volunteers took prednisone (30 mg/d for nine days), once after a 4-week exercise program that consisted of jogging 2.5 miles four times a week, and once without exercise. Whole body protein turnover was measured from the 15N enrichment plateau of urinary ammonia during ingestion of 15N glycine at hourly intervals. Whole-body protein synthesis and breakdown were derived from nitrogen flux, nitrogen intake, and urinary nitrogen elimination. Muscle myofibrillar protein breakdown was explored by measuring urinary 3-methylhistidine excretion. Bone protein metabolism was studied by measuring serum bone GLA protein (BGP), a specific marker of bone protein synthesis, and urinary elimination of hydroxyproline, an index of bone resorption. Whole-body protein turnover was significantly increased by exercise and prednisone (+19% and +17%, respectively); this effect was related to increased protein synthesis during exercise training (+27%, P less than .01) and to increased protein breakdown during prednisone administration without exercise (+21%, P less than .05). In contrast, values of protein turnover, synthesis, and breakdown were not different from control when the subjects took prednisone after training. Urinary excretion of 3-methylhistidine was decreased (-15%, P less than .05) at the end of the prednisone administration period but was identical to the control value when the subjects took prednisone in association with exercise. In contrast, serum BGP was significantly decreased by prednisone, with or without exercise (-35%, P less than .001). These data suggest that moderate exercise training can prevent, at least in part, the protein loss induced by prednisone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of moderate physical training on prednisone-induced protein wasting: a study of whole-body and bone protein metabolism. 325 6

This study evaluated whether altered insulin metabolism is a key factor behind weight loss during sarcoma growth in nongrowing mice (C57BL/6J). Fasted sarcoma-bearing mice had decreased blood glucose concentrations but unchanged levels of insulin, compared with those in pair-weighed and freely fed controls. During refeeding, insulin levels were inappropriately low for the degree of glycemia in sarcoma-bearing mice compared with those of pair-weighed and freely fed controls. Injections ip of glucose to tumor-bearing animals resulted in insulin levels comparable to postabsorptive values in healthy control animals, indicating that hypoinsulinemia in freely eating tumor-bearing animals was due to a reduced glycemic sensitivity for pancreatic insulin release. Insulin supplementation at doses [4 IU/100 g (body wt)] that increase body fat in normal animals could not protect the tumor-bearing host from progressive loss of body fat or lean tissues. Exogenous insulin in excess of endogenous insulin production did not stimulate tumor growth. Nitrogen and RNA-DNA content were significantly decreased in the quadriceps muscle of tumor-bearing mice. This reduction was independent of altered insulin levels and could not be prevented by exogenous insulin. The depressed capacity of protein synthesis in extensor digitorum longus (EDL) muscle could be entirely attributed to the state of malnutrition in tumor-bearing animals. The sensitivity and responsiveness of protein synthesis in EDL muscles to insulin were normal in tumor-bearing mice, regardless of whether exogenous insulin exerted its effect in vivo or in vitro. This study confirms insulin resistance for glucose metabolism in an experimental sarcoma animal model. Such changes are concluded to be secondary to anorexia and necessary to counteract hypoglycemia. In non-growing sarcoma-bearing mice, malnutrition and anorexia account entirely for depressed muscle protein synthesis, which is not explained by insulin resistance at the translational level. Insulin metabolism is not a key factor behind progression of wasting in sarcoma-bearing mice, but anorexia is.
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PMID:Role of insulin in development of cancer cachexia in nongrowing sarcoma-bearing mice: special reference to muscle wasting. 355 91

We studied the sodium balance and changes in plasma volume by an isotope dilution technique in the first week after an aneurysmal subarachnoid hemorrhage in 21 patients. In 11 of the patients, the plasma volume decreased by more than 10%. This was accompanied by a negative sodium balance and hyponatremia in 6 patients, a negative sodium balance without hyponatremia in 4 patients, and a positive sodium balance in 1 patient. Together with a decrease in plasma volume, blood urea nitrogen content increased and body weight decreased. Three patients developed hyponatremia without a decrease in plasma volume. Serum vasopressin was measured in 14 of the 21 patients. The values were elevated on admission and declined in the first week, regardless of the presence of hyponatremia. These findings indicate that natriuresis and hyponatremia in aneurysmal subarachnoid hemorrhage reflect salt wasting and not inappropriate secretion of antidiuretic hormone and that these changes should be corrected by fluid replacement rather than by fluid restriction.
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PMID:Volume depletion and natriuresis in patients with a ruptured intracranial aneurysm. 403 61


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