Nutrition
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The hypothesis that antioxidant vitamins might reduce cardiovascular disease risk is based on a large body of both basic and human epidemiologic research. One of the most consistent findings in dietary research is that those who consume higher amounts of fruits and vegetables have lower rates of heart disease and stroke as well as cancer. Recent attention has focused on the antioxidant content of fruits and vegetables as a possible explanation for the apparent protective effects. ⋯ They do, however, raise the possibility that some of the benefits from observational epidemiology may have been overestimated and that there may be some adverse effects. At this point randomized trial data are not yet sufficient to fully assess the risk-to-benefit ratios for antioxidant supplements. More reliable data should be forthcoming in the near future which will better define the role of antioxidants in the primary and secondary prevention of atherosclerotic disease as well as cancer.
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Albumin and fibrinogen synthesis appear to account for the majority of protein exported by the liver and therefore make a substantial contribution to that of whole-body protein synthesis. However, data on the protein synthetic rates of albumin and fibrinogen in normal subjects are limited. Albumin and fibrinogen synthetic rates were measured simultaneously over a 120-min period in normal subjects (n = 6) by using a flooding dose of 2H5-phenylalanine. ⋯ In the context of the current interest in manipulating the inflammatory response of patients with various disease states, we introduce the concept of an acute phase protein quotient (APPQ). The APPQ is defined as the absolute rate of fibrinogen synthesis divided by that of albumin. In this group of normal subjects, the median APPQ was 0.14.
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Randomized Controlled Trial Comparative Study Clinical Trial
Hypermetabolism and increased peripheral release of amino acids after subarachnoidal hemorrhage and its operative treatment.
The metabolic response to surgery for acute subarachnoidal hemorrhage and its modification by amino acid infusions was studied. Thirty patients with acute subarachnoidal hemorrhage were randomly assigned to receive for 12 h either an infusion of glucose and a balanced amino acid solution (1.68 MJ = 400 kcal/d and 0.15 gN.kg-1.d-1; group AA) or a glucose and a solution containing 20% of total nitrogen as alanyl-glutamine (1.68 MJ = 400 kcal/d and 0.15 gN.kg-1.d-1; group ALAGLN). A separate control group received glucose alone (1.68 MJ = 400 kcal/d). ⋯ Also the release of alanine (ALAGLN: 35 +/- 24 mumol/min, AA: 34 +/- 24 mumol/min, and control: 30 +/- 18 mumol/min) and total amino acids (ALAGLN: 133 +/- 131 mumol/min, AA: 125 +/- 98 mumol/min, and control: 112 +/- 72 mumol/min) were similar in all groups. All groups were characterized by a pattern of preoperative hypermetabolism that persisted after the operation. The hypermetabolism was not related to increased peripheral oxygen consumption, since femoral oxygen consumption (VO2) represented only 3% of the whole body VO2-.
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The proportion of patients with total parenteral nutrition (TPN)-associated cholestasis (TPN-AC) who have necrotizing enterocolitis (NEC) has increased markedly in the past ten years. Little is known about how these diseases affect each other. We retrospectively studied 24 patients with NEC and bowel necrosis or perforation who required surgical intervention. ⋯ We conclude that NEC alone can cause functional cholestasis and histologic liver injury but does not cause the specific progressive damage caused by TPN. NEC may make the liver more susceptible to the effects of TPN. Partial enteral feeding does not halt or reverse this injury.
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Randomized Controlled Trial Clinical Trial
Effect of parenteral L-glutamine on muscle in the very severely ill.
Glutamine (Gln)-supplemented perioperative total parenteral nutrition (TPN) has been reported to reduce the loss of intramuscular glutamine following routine surgery. This study investigates whether glutamine-supplemented TPN can alter muscle biochemistry acutely in the very severely ill patient. Thirty-eight patients (age 19-77 yr; mean 55 yr), critically ill (APACHE II range 8-31; median 17) admitted to the intensive care unit (ICU) were recruited to receive either conventional TPN (CTPN) or an isonitrogenous, isoenergetic feed supplemented with 25 g crystalline L-glutamine per 24 h (GTPN) in a prospective, double blind, block-randomized study. ⋯ It also proved difficult in these very sick patients to correct a low plasma Gln with L-Gln-TPN during the initial phase of the severe illness. TPN supplementation with 25 g/24 h, L-glutamine appears inadequate in the acute period to counteract the muscle and plasma biochemical changes seen in these patients. It is unknown whether any larger dose could alter this state.