ISSN:0148-6071    

DOI:10.1177/0148607192016004301

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

The bidirectional transmembrane transport rates of leucine (Leu), valine (Val), phenylalanine (Phe), lysine (Lys), and alanine (Ala) were measured in vivo in the hindlimb muscle of five dogs and related to the rates of protein synthesis and degradation. The compartmental model was based on the systemic continuous infusion of stable isotopic tracers of the amino acids, and the measurement of the enrichment and concentration in the arterial and femoral vein plasma and the intracellular free water in muscle (obtained by biopsy). The transport rate from plasma to tissue (in micromoles per minute) was: Leu, 18.1 ± 1.8; Val, 26.9 ± 3.5; Phe, 10.5 ± 1.6 Lys; 12.2 ± 1.8; and Ala, 10.7 ± 3.4. The transport rate from tissue to plasma (in micromoles per minute) was: Leu, 25.5 ± 2.5; Val, 32.4 ± 2.8; Phe, 17.0 ± 2.8; Lys, 24.9 ± 3.4; Ala, 34.4 ± 9.0. When the transmembrane transport rate was normalized per unit of amino acid concentration in the source pool, we found that the transport of Leu, Val, and Phe was significantly faster (p<.05) than the transport of Lys and Ala. The calculated rates of incorporation into hindlimb muscle protein of Phe and Lys (in micromoles per minute) were 4.2 ± 1.3 and 19.4 ± 5.3, respectively, and the rates of intracellular appearance from breakdown were 10.7 ± 1.9 and 32.1 ± 6.6, respectively. We concluded, therefore, that (1) the transmembrane amino acid transport rate can be measured in vivo in muscle with a relatively noninvasive technique, (2) in the dog hindlimb the equilibration between tissue and plasma free amino acid pool is different for each amino acid depending on the kinetics of the transmembrane transport systems, and (3) the transport rates of amino acids and their rate of appearance from protein breakdown are roughly comparable, suggesting that variations in transport rates could play a role in controlling the rate of protein synthesis.(Journal of Parenteral and Enteral Nutrition16:305–315, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004305

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

The effect of dietary triglycerides varying in fatty acid composition on the tissue fatty acids and prostaglandin synthesis was studied in mice. The dietary fats were medium‐chain triglycerides (rich in C8:0 and C10:0), structured lipids (rich in 12:0), high oleic sunflower oil (rich in 18:1), corn oil (rich in n‐6 polyunsaturated fatty acids), and menhaden oil (rich in n‐3 polyunsaturated fatty acids) fed at 5% by weight in refined diets. The medium chain fatty acids C8 to C12 from medium‐chain triglycerides and structured lipids did not accumulate in liver phospholipids. However, long‐chain fatty acids from the dietary fats were incorporated into liver lipids, with n‐3 polyunsaturated fatty acids replacing arachidonic acid. The synthesis of 6‐keto‐prostaglandin F1αand prostaglandin E2 by peritoneal cells in response to intraperitoneal injection of zymosan decreased as the arachidonic acid levels were decreased. When the same dietary fats were added to the refined, fat‐free diets, at 7.5 wt% levels, together with 2.5 wt% of safflower oil to provide essential fatty acids, only the long‐chain fatty acids from the dietary fats were incorporated into the liver lipids. The arachidonic acid in liver lipids was enhanced after supplementation of diets with safflower oil. However, the reduction in prostaglandin synthesis by peritoneal cells in response to intraperitoneal injection of zymosan was similar to that observed when 5% fat was fed. The data suggest that dietary fats of defined composition, with or without added essential fatty acids, may be useful as alternate fat sources in parenteral nutrition in reducing inflammatory responses mediated via prostaglandins.(Journal of Parenteral and Enteral Nutrition16:316–321, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004316

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Dietary nucleotides seem to play a number of physiologic roles during early life. They are improved in the maintenance of the immune system, intestinal maturation, and lipid metabolism. Nucleotides affect the conversion of essential fatty acids into their long‐chain polyunsaturated (PUFA) derivatives in both preterm and at‐term newborn infants. This work examines the effect of postnatal age and dietary nucleotides on the fatty acid composition of total plasma lipids and lipid fractions in the rat. Weanling rats (21 days old) were divided into three groups. The first group was killed, and the other two groups were fed a standard semipurified diet, and the same diet supplemented with 250 mg each of CMP, UMP, AMP, GMP, and IMP per 100 g of diet for 4 weeks. Advancing postnatal age led to an increase of total plasma fatty acids, especially saturated, and PUFA of the n‐6 series, whereas PUFA of the n‐3 series decreased. The fatty acid profile of plasma phospholipids (PL) exhibited minor changes, although there was a tendency to show lower levels of saturates and PUFA of the n‐3 series and increased levels of PUFA of the n‐6 series. Cholesteryl esters showed a response similar to that of PL, although the increase in arachidonic acid (20:4n‐6) was significant. For triglycerides, linoleic acid (18:2n‐6) and mono‐unsaturates increased their levels, whereas saturates decreased. Dietary nucleotides mediated a significant increase in total plasma fatty acids, namely monounsaturated fatty acids and PUFA of both n‐6 and n‐3 series as compared with the control group. The relative fatty acid composition of PL and cholesteryl esters was mostly unaffected. Only increased levels of MUFA were found for PL. For triglycerides, a relative increase of palmitic acid (16:0) and oleic acid (18:1) was observed in the group fed the supplemented diet, whereas 20:4n‐6 decreased. These data suggest that dietary nucleotides are important modulators of PUFA synthesis and that the weanling rat may be a relatively valid experimental model to ascertain the biochemical mechanisms by which nucleotides affect the lipid metabolism in early life.(Journal of Parenteral and Enteral Nutrition16:322–326, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004322

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

We report a 3‐year analysis (1986 to 1989) of the management of 63 home parenteral nutrition patients, 40 with short‐bowel syndrome and 23 with chronic intestinal obstruction with or without intestinal resection. Intravenous fluid requirements varied from 0.9 to 6 L/day, and the content of glucose varied between 46 and 531 g/day, protein varied from.0 to 85 g/day, fat from.0 to 100 g/day, sodium from 37 to 695 mEq/day, potassium from 30 to 220 mEq/day, chloride from 60 to 760 mEq/day, and acetate from 0 to 200 mEq/day. Body weight was normalized and well maintained in the majority of patients, but using the strict definition of deficiency as the presence of one abnormal value during 3 years, more than half had abnormal plasma chloride, glucose, alkaline phosphatase, serum glutamic oxaloacetic transaminase, total protein, albumin, selenium, and iron concentrations, and more than a third had low calcium, magnesium, vitamin D, and vitamin C levels. Normochromic anemia was seen in 73% and high blood creatinine associated with low urine volumes in 42%. Most (78%) returned to relatively normal lifestyles, but employability was occasionally impaired by loss of third‐party insurance coverage resulting from a therapy that may cost $100,000 per year. Overall mortality was low (5% per year), but 73% needed readmission to hospital, mainly for suspected catheter sepsis. The results indicate that home parenteral nutrition has allowed many patients to survive gut failure and return to work but problems with chronic fluid, electrolyte and micronutrient deficiencies, catheter sepsis, and insurance coverage often restrict optimal rehabilitation.(Journal of Parenteral and Enteral Nutrition16:327–332, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004327

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

This study was designed to assess the effect of operative stress on resting energy expenditure (REE) in the newborn infant. In 13 neonates who had an uncomplicated abdominal, thoracic, or spinal operation, REE was measured both preoperatively and on the third postoperative day. The mean preoperative REE of 43.19 ± 7.95 kcal/kg per day was not significantly different from the mean postoperative REE of 41.70 ± 7.94 kcal/kg per day. Sixteen neonates had REE measured on the first, second, and seventh postoperative days. The mean postoperative REE values of 43.12 ± 6.92, 42.41 ± 7.58, and 46.33 ± 6.89 kcal/kg per day at 1, 2, and 7 days, respectively, were not significantly different from the preoperative REE. There was no significant difference in oxygen consumption, carbon dioxide production, and respiratory quotient between the preoperative and postoperative groups. In this study, an uncomplicated operation did not increase REE in the neonate.(Journal of Parenteral and Enteral Nutrition16:333–336, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004333

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Clinical nutrition assessment has identified two types of protein‐calorie malnutrition (PCM), a stress‐induced hypoalbuminemic form (HAF‐PCM) and a marasmic form (MF‐PCM) generated by adaptation to starvation. This study evaluated the differences between these two patterns of PCM with regard to precipitating factors and the clinical sequelae of mortality, cost of total parenteral nutrition, length of hospitalization, and rate of sepsis and nosocomial infection. Of 220 patients receiving total parenteral nutrition over a 12‐month period (0.7% of 30, 127 admissions), 180 were included in this study. HAF‐PCM was diagnosed in 45% and MF‐PCM in 25% of study patients. HAF‐PCM was more common in older age groups. Women had PCM less often than did men (57% vs 83%), but whereas men developed both forms of PCM equally, women were more likely to develop HAF‐PCM. Prolonged mechanical ventilation increased the likelihood of both patterns, whereas the presence of malignancy, concomitant organ failure, trauma, burns, or surgery did not increase the likelihood of developing either pattern of PCM. HAF‐PCM increased the length of hospitalization by 29% and the cost of total parenteral nutrition by 42%. The presence of HAF‐PCM increased fourfold the odds of dying, and the odds of developing nosocomial infection and sepsis almost 2.5 times above that seen in its absence. MF‐PCM had no clinical effect of its own on any of the outcome parameters, but instead exerted only an interactive synergistic effect with HAF‐PCM on length of hospitalization and cost of total parenteral nutrition.(Journal of Parenteral and Enteral Nutrition16:337–342, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004337

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Dietary lipid manipulation has been shown to have various effects on the immune system, depending on the amount of fat, degree of saturation, and type of fat used. In this study we investigated the role of different sources of fat at different levels on the survival of mice in two models of peritonitis, one withPseudomonas aeruginosaand the other withSalmonella typhimurium.CF1 mice were pair‐fed diets with 5% or 40% of total calories as fat. The source of fat used was coconut oil, oleic acid, safflower oil, or fish oil. Three other diets were tested as well, one with no fat, one with only 0.5% of total calories linoleic acid as the only source of fat, and a control diet that had 12% of total calories as corn oil. At the end of 2 weeks of feeding the experimental diets, mice were challenged withPs aeruginosaintraperitoneally and mortality was recorded over 1 week. After 3 weeks of feeding the experimental diets, mice were challenged with S typhimurium and mortality was recorded over 2 weeks. No significant differences were seen on survival among groups fed different levels of fat, as well as different sources of fat. We conclude that, overall, 2‐and 3‐week manipulation of dietary fat does not affect outcome from infection in these models.(Journal of Parenteral and Enteral Nutrition16:343–347, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004343

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Liver test abnormalities are a well‐recognized complication in the parenterally fed population. Numerous etiologies for the development of elevated liver tests have been suggested. However, the etiology and clinical significance remain unclear. The aim of this retrospective study was to determine the extent of liver‐associated test (LAT) abnormalities in patients receiving total parenteral nutrition (TPN) and to investigate whether the composition of TPN solutions and the magnitude of malnutrition could be used to predict subsequent LAT abnormalities. Medical records of 78 adult patients who received TPN for at least 2 weeks were reviewed. All subjects had normal LAT results before TPN, were not receiving hepatotoxic drugs, and had no underlying liver disease. Aspartate aminotransferase peaked transiently during week 2 and returned to normal during week 4. Alkaline phosphatase and total bilirubin peaked during weeks 4 and 3, respectively. The average nonprotein kilocalorie distribution was approximately 80% dextrose and 20% lipid. Caloric intake ranged from 7% to 23% above estimated needs. The mean nutritional status score was 22 ± 15, with a possible range of 0 to 75 (0 indicates no malnutrition). The composition of TPN solutions was not significantly associated with the changes in the three LATs during any week of the 4‐week study. The nutritional status score was significantly associated (p<.05) with the change in alkaline phosphatase during week 1. This study confirms that LAT abnormalities occur during TPN, but the composition of the solution has no significant ability to predict subsequent LAT abnormalities. Factors associated with cholestasis may have contributed to the LAT abnormalities in this group of subjects because the pattern of LAT elevations suggested cholestasis more than hepatocellular damage. The magnitude of malnutrition before TPN may identify patients likely to develop early alkaline phosphatase abnormalities.(Journal of Parenteral and Enteral Nutrition16:348–352, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004348

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Hypertriglyceridemia and fatty liver are common lipid abnormalities associated with Gram‐negative sepsis. Fish oils have been shown to have beneficial effects in reducing plasma triglycerides (TG). This study was designed to investigate whether fish oils would prevent the elevation of plasma TG and the accumulation of liver lipids during sepsis. One group of rats was fed a 10% menhaden oil diet and the other group was fed a 10% corn oil diet for 14 days. On the 14th day, sepsis was induced by injecting the rats with 8 x 107live Escherichia coli colonies/100 g of body weight and the rats were fasted for 22 hours. The liver composition of total lipids and TG in the septic rats prefed the fish oil was lower than in the septic rats prefed the corn oil. In the rats adapted to the corn oil diet, lipids accumulated in the livers of the septic rats in comparison with the control rats. Hepatocytes isolated from the septic rats adapted to the corn oil diet showed an increased esterification of [1‐14C]palmitate into TG and phospholipids than hepatocytes from the control rats. Feeding the fish oil diet instead of the corn oil diet before inducing sepsis reduced TG, cholesterol, and phospholipid synthesis by 58%, 79%, and 71%, respectively. The rise in TG synthesis in the septic rats prefed the corn oil diet was associated with an 89% increase in the activity of phosphatidate phosphohydrolase. There was no significant difference in the activities of glycerol‐3‐phosphate acyltransferase and phosphatidate phosphohydrolase between control and septic rats. The glycerol‐3‐phosphate acyltransferase activity was lower in the livers of septic rats prefed fish oil than in the septic rats prefed corn oil. The hypertriglyceridemia of sepsis was not ameliorated by prefeeding the fish oil diet. The fish oil had a significant effect on the activity of lipoprotein lipase in peripheral tissues from both control and septic rats. The activities of lipoprotein lipase were depressed in the retroperitoneal fat pads and heart from the septic rats fed fish oil in comparison with their controls. The data from this study indicate that a fish oil diet will prevent the sepsis‐induced fatty liver.(Journal of Parenteral and Enteral Nutrition16:353–358, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016004353

出版商:SAGE Publications    

年代:1992

数据来源: WILEY