Nutrition
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Comparative Study
Increased contribution by myofibrillar protein to whole-body protein breakdown according to severity of surgical stress.
A study was conducted to clarify the contribution by myofibrillar protein to whole-body protein breakdown in surgically stressed patients. Thirteen patients who underwent esophagectomy (group E) and 22 who underwent gastric or colorectal operation (group GC) were studied. Patients were all male and younger than 65 y old. ⋯ On the other hand, femoral-arteriovenous differences of BCAA, Ala, Gln, Tyr, and Phe correlated significantly with the urinary excretion of 3-MH. These data suggest that skeletal muscle protein degradation is proportional to the breakdown of total myofibrillar proteins and both correlate with the severity of stress. From these data, it may be suggested that the contribution of skeletal muscle to whole-body protein catabolism is increased postoperatively, and that the increase is correlated with the severity of surgical stress.
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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-.