Past, present, and future of nutritional support.
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Amino Acids↗
Biomedical subjects
M M Meguid
Publications and source records attributed to M M Meguid.
Cytokines, tryptophan and anorexia in cancer patients before and after surgical tumor ablation.
Serotoninergic system activity and cytokine production have been both implicated in the pathogenesis of cancer anorexia. To verify the existence of relationships between tryptophan, cytokines and anorexia, twenty cancer and six non-neoplastic patients were studied. Plasma amino acid concentration, including tryptophan, and spontaneous and LPS stimulated tumor necrosis factor and interleukin-1 release from peripheral blood mononuclear cells were determined before and after surgery in both groups of patients. A close relationship between plasma free tryptophan concentration and anorexia was observed, whereas no relationship between cytokine production and either anorexia or plasma tryptophan was found in cancer patients.
Adult↗
Taurine-supplemented total parenteral nutrition and taurine status of malnourished cancer patients.
The status of plasma taurine and whether its concentration can be influenced by total parenteral nutrition (TPN) was determined in 51 malnourished fasting cancer patients after surgery and 7-14 days after starting TPN providing 41 +/- 2 kcal, 0.30 +/- 0.02 g N kg-1.day-1 and 40 mg pyridoxine. Plasma taurine was 50% lower in patients than in control subjects. Plasma taurine was significantly greater than baseline only after 14 days of TPN. We also studied the effects of surgery and taurine supplementation (8.6 mg.kg-1.day-1) on plasma and urine taurine concentrations in 12 malnourished patients. Preoperatively, all patients had normal plasma taurine concentrations; postoperatively, it was in the deficient range in 4 patients. Taurine-supplemented patients initially had higher than baseline concentrations; by day 10, none had subnormal levels. Subnormal taurine concentrations commonly occur in malnourished postoperative cancer patients; surgery further precipitates their fall. Plasma concentrations were maintained only with taurine-supplemented TPN.
Adult↗
Densitometry-based equations for estimating body composition in Fischer rats.
Male Fischer rats are widely used to evaluate the effects of nutritional repletion or deprivation on the rat's nutritional status. Practical methods are needed to evaluate changes in body composition. Chemical analysis is expensive, time consuming, and often not available; bioelectrical impedance analysis in laboratory animals lacks standardization. Postulating that the measurement of densitometry would allow reliable estimation of body composition in the male Fischer rat, we studied 27 male Fischer rats. Densitometric measurements of the carcasses and their chemical analysis were performed to obtain reference values. Initial estimation of the fraction of body fat based on densitometry was attempted with the Siri equation intended for use in humans. We found that this equation was not suitable for use in the male Fischer rat because it underestimated fat mass at high carcass weights and overestimated fat mass at low carcass weights. Therefore, the Siri equation was modified to more accurately predict carcass composition in the male Fischer rat. Three different predictive equations based on simple densitometric measurements were developed that allow separate estimation of carcass fat, carcass water, and carcass protein in the male Fischer rat. These equations were found to be accurate to within 2-5-3% of carcass weight.
Adipose Tissue↗
Acute nutrition management in insulin-dependent diabetes: presentation of an index case.
Diabetic patients unable to ingest nutrients orally but who have functioning gastrointestinal tracts should be nutritionally supported via enteral feeding. Provision of enteral nutrition can be problematic in terms of glycemic control. Diabetes compounded with kidney failure further complicates calorie delivery and distribution. Enteral-nutrition formulas should be carefully selected with attention to macronutrient profile, specific carbohydrate constituents, and presence or absence of dietary fiber. Modular components can be added to standard enteral feedings to alter calorie distribution while enhancing calorie provision. Selecting the method of insulin infusion (i.e., intermittent subcutaneous insulin therapy versus continuous intravenous or continuous subcutaneous infusion) for maximizing glucose control is an important step in the acute nutrition management of insulin-dependent diabetic patients. Attention to nutrition indices, fingersticks, and parameters of enteral-feeding intolerance is of utmost importance. The transition from enteral to oral nutrition will depend on adequacy of oral intake as determined by calorie counts.
Adult↗
Nutrition management in acute renal failure.
A case report is presented in which a man developed acute renal failure after a surgical misadventure. The initial management, postoperative course with the manifestation of acute tubular necrosis with oliguria and its physiological sequelae, nutrition management in the context of the overall treatment, hospital course, and patient's disease are discussed in detail. The rationale for giving nutrition support, the general considerations for providing nutrients, and the specific nutrition considerations as they pertain to the patient under discussion are outlined to provide a comprehensive guide and overview of the nutrition management of a patient with acute renal failure.
Acute Kidney Injury↗
Correlation between food intake and cerebrospinal fluid interleukin 1 alpha in anorectic tumor-bearing rats.
Anorexia is observed in 50% of cancer patients; however, the pathogenesis for cancer anorexia is unclear. We postulate that centrally acting cytokines play a role in the pathogenesis of cancer anorexia. To test our hypothesis we determined whether central interleukin 1 alpha (IL-1 alpha) was related to anorexia in tumor-bearing (TB) rats. Fischer 344 rats were inoculated with either 1 ml of 1 x 10(6) trypan blue viable methylcholanthrene-induced sarcoma cells (TB rats) or normal saline (non-tumor-bearing [NTB] rats). Rats were placed into individual metabolic cages equipped with an Automated Computerized Rat Eater Meter that continuously measured food intake. When TB rats became anorectic, TB and NTB rats were anesthetized and cerebrospinal fluid (CSF) was collected. IL-1 alpha was measured. Food intake in TB was 7.1 +/- 1.1 g, whereas that in NTB was 12 +/- 1.1 g (p < 0.05). Eight of the 13 TB rats had detectable concentrations of CSF IL-1 alpha; the mean CSF IL-1 alpha concentration for TB rats was 73.2 +/- 17.3 pg/ml. In contrast, none of the NTB rats (n = 11) had detectable concentrations of CSF IL-1 alpha. CSF IL-1 alpha concentrations correlated inversely with food intake. Data suggest a link between CSF IL-1 alpha and food intake in anorectic TB rats.
Animals↗
Relationship between interleukin-1 and cancer anorexia.
Interleukin-1 (IL-1) induces anorexia via direct action in the brain, and its participation in the pathogenesis of cancer-associated anorexia has been hypothesized. Because the functional ablation of the ventromedial nucleus of hypothalamus (VMH), where IL-1 receptors have been detected, reverses cancer-associated anorexia in tumor-bearing (TB) rats, we hypothesize that cancer anorexia involves the direct effect of IL-1 on the VMH. To test this hypothesis, we investigated whether the intra-VMH injection of the IL-1 receptor antagonist (IL-1ra) improves food intake in anorectic TB rats. Sixteen Fischer rats (approximately 300 g/BW) were injected s.c. with 10(6) trypan-blue viable methylcholanthrene sarcoma cells, and then individually caged. Chow and water were freely available, and food intake was recorded throughout the study. Normal food intake was measured in 8 more rats, injected s.c. with normal saline. Tumor developed in all rats. When TB rats became anorectic, they were randomly assigned to either treatment or control groups. Using stereotaxic techniques, 25 ng of IL-1ra dissolved in normal saline (TB-IL-1ra; n = 8), or an equal volume of normal saline (TB-NS; n = 8) was injected bilaterally into the VMH. After surgery, rats were caged and changes in food intake recorded. At study's end, rats were sacrificed and brains removed for histological confirmation of injection sites. In the TB-NS group, food intake decreased with the occurrence of anorexia. In contrast, the intra-VMH injection of IL-1ra reduced the severity of cancer anorexia, significantly improving food intake in TB-IL-1ra rats. Data indicate that centrally acting IL-1 plays a significant role in the development of cancer anorexia.
Animals↗