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)

Bicarbonate reabsorption by the immature kidney in response to acute acid-base changes was assessed in 50 anesthetized newborn rabbits before the end of nephrogenesis. The normal newborn rabbit (age 5-12 days) is in a state of hypochloremic metabolic alkalosis (PHCO3-, 31.9 +/- 0.6 mmol/l; PCl-, 83.1 +/- 1.0) and excretes a hypertonic (Uosmol = 578 +/- 41 mosmol/kgH2O), alkaline (UpH = 7.40 +/- 0.15) urine containing 50 +/- 9 mmol/l Cl- and 13 +/- 4 mmol/l Na+. The alkalosis is probably generated by an alkaline load contained in the mother's milk and maintained by a state of chloride wasting and volume contraction. In this alkalotic model, bicarbonate reabsorption, expressed per milliliter glomerular filtration rate (GFR), correlates positively with arterial CO2 pressure (PaCO2). The ability of the immature kidney to reclaim filtered bicarbonate in response to an elevation of the plasma carbon dioxide tension remains unlimited up to PaCO2 of 110 mmHg (y = 20.7 + 0.15 x, r = 0.82, P less than 0.001). Hypercapnia is associated with a marked fall in GFR, so that the positive correlation between bicarbonate reabsorption and PaCO2 vanishes when the bicarbonate reabsorption rate is expressed in absolute terms. Bicarbonate reabsorption is strongly dependent on the filtered load during both acutely induced metabolic acidosis and alkalosis. The acid-base state of the newborn rabbit is in sharp contrast with that of most animal species, and the renal handling of bicarbonate as a function of GFR does not show signs of tubular immaturity.
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PMID:Bicarbonate reabsorption by the kidney of the newborn rabbit. 291 64

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

The cytokine cachectin/TNF induces a rapid increase in lactate production and in glucose metabolism in L6 myocytes in culture; glucose uptake was maximal after 17 h, while elevated glucose utilization and lactate production persisted for up to 32 h. These increases are suggestive of increased glycolytic activity, and were associated with a 10% decrease in cellular oxygen consumption and a comparable decrease in the production of 14C-labelled CO2 from 14C-labelled glucose. This decrease in aerobic metabolism, however, could account for only a small fraction of the energetic requirement for increased glycolytic activity. Furthermore, maximal stimulation of pyruvate dehydrogenase (PDH) by dichloroacetate (DCA) treatment in conjunction with cachectin/TNF abolished lactate production, but increased glucose uptake persisted. Taken together, this suggests that the primary effect of cachectin/TNF on myocyte carbohydrate metabolism is to increase glycolysis. Correspondingly, we postulated that cachectin/TNF must activate one or more ATP-depleting cellular processes to account for the lack of feed-back inhibition on glycolysis by the ATP produced. This led to the identification of a futile substrate cycle between fructose 6-phosphate and fructose 1,6-bisphosphate as a novel energy sink that is activated by cachectin/TNF. Cachectin/TNF treatment led to increased activity of both phosphofructokinase (PFK) and fructose bisphosphate phosphatase (FBP) in myocytes in culture, detectable after 1 h of incubation and persisting for up to 16 h. The possible role of cachectin/TNF-mediated futile substrate cycling in increased glycolytic activity, increased energy expenditure, heat production and tissue wasting during bacterial infections is discussed.
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PMID:Cachectin/TNF-mediated lactate production in cultured myocytes is linked to activation of a futile substrate cycle. 814 98

1. Differing patterns of protein metabolism are seen in wasting due to undernutrition and wasting due to chronic infection. 2. We investigated whole body energy and protein metabolism in nine subjects with pulmonary tuberculosis, six undernourished subjects (body mass index < 18.5 kg/m2) and seven control subjects from an Indian population. Fasting subjects were infused with L-[1-13C]leucine (2.3 mumol.h-1.kg-1) for 8 h, 4 h fasted then 4 h fed. Leucine kinetics were derived from 13C-enrichment of leucine and alpha-ketoisocaproic acid in plasma and CO2 in breath. 3. Undernourished subjects, but not tuberculosis subjects, had higher rates of whole body protein turnover per unit lean body mass than controls [163.1 +/- 9.4 and 148.6 +/- 14.6 mumol compared with 142.8 +/- 14.7 mumol leucine/h per kg, based on alpha-ketoisocaproic acid enrichment (P = 0.039)]. 4. In response to feeding, protein oxidation increased in all groups. Tuberculosis subjects had the highest fed rates of oxidation (47.0 +/- 10.5 compared with 37.1 +/- 5.4 mumol.h-1.kg-1 in controls), resulting in a less positive net protein balance in the fed phase (controls, 39.7 +/- 6.2; undernourished subjects, 29.2 +/- 10.6; tuberculosis subjects, 24.5 +/- 9.3; P = 0.010). Thus fed-phase tuberculosis subjects oxidized a greater proportion of leucine flux (33.2%) than either of the other groups (controls, 24.0%; undernourished subjects, 24.0%; P = 0.017). 5. Tuberculosis did not increase fasting whole body protein turnover but impaired the anabolic response to feeding compared with control and undernourished subjects. Such 'anabolic block' may contribute to wasting in tuberculosis and may represent the mechanism by which some inflammatory states remain refractory to nutrition support.
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PMID:Whole body protein metabolism in human pulmonary tuberculosis and undernutrition: evidence for anabolic block in tuberculosis. 961 67

In many patients with neuromuscular diseases, respiratory failure is mainly caused by alveolar hypoventilation in their terminal stages. Malnutrition is one of the common and serious problems in patients with chronic respiratory failure. Energy consumption for breathing is remarkably high in respiratory compromised patients, causing subsequent increase of total energy expenditure. However, most patients have limited capacity of oral intake. Nutritional depletion is associated with wasting of respiratory muscles, impairment of respiratory drive, alteration of respiratory pattern, and pathological change of pulmonary parenchyma. These indicate that nutritional and ventilatory support is very important in these patients. However, overfeeding also may have detrimental influence on respiratory failure. We experienced a Duchenne muscular dystrophy (DMD) patient on noninvasive positive pressure ventilation (NIPPV) who developed hypercapnia after total parenteral nutrition (TPN). Analysis of clinical course of this patient revealed that there is a significant correlation between PaCO2 and caloric intake. Excess carbohydrate intake can precipitate fat synthesis which induces over-production of carbon dioxide (CO2). Since NIPPV doesn't have a closed circuit, there are some difficulties in respiratory management, such as air leakage to stomach and mouth, and airway obstruction. Failure to optimize NIPPV setting against increased CO2 load might cause hypercapnia in this patient. These suggest that evaluation of energy expenditure and design of nutritional program are essential to avoid hypercapnia due to nutritional support.
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PMID:[Excess caloric intake induced severe hypercapnia in a patient with Duchenne muscular dystrophy on noninvansive positive pressure ventilation]. 1007 34

To determine (1) whether protein restriction, combined with glucocorticosteroid treatment, can be used as a hypercatabolic model and (2) if so, whether glutamine attenuates protein wasting in this model, the effects of protein restriction, dexamethasone, and glutamine on leucine metabolism were assessed in dogs. A control group (n = 8) received a maintenance diet; another group (n = 8) received a protein-restricted diet either (1) alone; (2) along with a 7-day corticoid treatment; or (3) along with a 7-day corticoid treatment and a 7-hour intravenous (IV) glutamine infusion. The last day of each regimen, dogs underwent an IV isotope infusion in the fasting state, with a 3-hour NaH(13)CO3 infusion to assess CO2 production, and immediately thereafter, a 3-hour (13)C-leucine infusion to assess leucine appearance rate (Ra), oxidation (Ox), and nonoxidative leucine disposal (NOLD), expressed as micromol x kg(-1) x h(-1). Protein restriction was associated with a 24% decline in leucine Ra (223 +/- 16 v 298 +/- 17; P <.01), an index of whole body proteolysis, and a 29% decline in NOLD (180 +/- 15 v 223 +/- 13; P <.01), an index of whole body protein synthesis. In the protein-restricted group, dexamethasone treatment was associated with a 32% increase in Ra, (295 +/- 28 v 223 +/- 16; P <.05), a 186% increase in Ox (120 +/- 14 v 43 +/- 4; P <.001), with no change in NOLD, when compared with the protein-restricted alone. After protein restriction + dexamethasone, glutamine infusion induced a 40% increase in plasma glutamine (1,090 +/- 70 v 780 +/- 29 micromol x L(-1); P <.01), but failed to alter Ra, Ox, or NOLD. These results suggest that (1) in dogs, protein restriction combined with a 7-day course of dexamethasone results in alterations in leucine kinetics similar to those observed in stress-induced protein wasting in humans, and (2) in that model, a 7-hour IV glutamine infusion in the fasting state does not significantly attenuate protein wasting.
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PMID:Protein restriction and dexamethasone as a model of protein hypercatabolism in dogs: effect of glutamine on leucine turnover. 1123 Jul 81

Incineration of sludge is occasionally accused of pollution. This paper shows that if it is correctly designed and implemented, it can be environmentally friendly. For this purpose, sludge incineration is compared to agricultural spreading of limed sludge with respect to toxicity criteria, greenhouse effect gases (GEG) release, energy wasting and other environmental parameters. Landfilling is also considered but as a standby route. Since present regulations on agricultural use and gas emission release from incinerators are stringent, incineration cannot be suspected to release more noxious substances in the environment than agriculture. A distinction is made between biogenic CO2 and fossil CO2. Nevertheless case studies show that incineration produces more GEG and wastes more energy than agricultural spreading if no energy is recovered from hot flue gas. In the case of thermal power or electrical power generation, the environmental balance becomes dramatically more favorable for incineration.
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PMID:Sustainability of thermal oxidation processes: strengths for the new millennium. 1247 80

The efficiency with which developing sunflower embryos convert substrates into seed storage reserves was determined by labeling embryos with [U-(14)C6]glucose or [U-(14)C5]glutamine and measuring their conversion to CO2, oil, protein and other biomass compounds. The average carbon conversion efficiency was 50%, which contrasts with a value of over 80% previously observed in Brassica napus embryos (Goffman et al., 2005), in which light and the RuBisCO bypass pathway allow more efficient conversion of hexose to oil. Labeling levels after incubating sunflower embryos with [U-(14)C4]malate indicated that some carbon from malate enters the plastidic compartment and contributes to oil synthesis. To test this and to map the underlying pattern of metabolic fluxes, separate experiments were carried out in which embryos were labeled to isotopic steady state using [1-(13)C1]glucose, [2-(13)C1]glucose, or [U-(13)C5]glutamine. The resultant labeling in sugars, starch, fatty acids and amino acids was analyzed by NMR and GC-MS. The fluxes through intermediary metabolism were then quantified by computer-aided modeling. The resulting flux map accounted well for the labeling data, was in good agreement with the observed carbon efficiency, and was further validated by testing for agreement with gas exchange measurements. The map shows that the influx of malate into oil is low and that flux through futile cycles (wasting ATP) is low, which contrasts with the high rates previously determined for growing root tips and heterotrophic cell cultures.
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PMID:Carbon conversion efficiency and central metabolic fluxes in developing sunflower (Helianthus annuus L.) embryos. 1768 73