摘要:

Mechanisms of nutrient alteration of hepatic protein synthesis during sepsis are unclear.In vitro,arginine downregulates endotoxin‐stimulated hepatocyte protein synthesis butin vivoeffects are unknown. This study evaluated the effects of supplemental arginine or glycine on fibrinogen (acute‐phase protein), histone, albumin, and liver protein synthesis after Gram‐negative sepsis in the rat. Adult rats (225 g, n = 36) were randomized to receive isonitrogenous isocaloric total parenteral nutrition supplemented with 264 mg of N per kilogram per day as either arginine or glycine. On day 5, each group was further randomized to control or sepsis. Sepsis was induced by injection of 8 × 107Escherichia coliper 100 g body weight, and then a continuous infusion of [1‐14C]leucine was started. The rats were sacrificed 4 hours later. The fractional protein synthesis rates (percent per day) of histone, fibrinogen, albumin, and liver were determined. Supplemental arginine led to significantly increased histone (p<0.05, analysis of variance) and fibrinogen (p<0.01, analysis of variance) synthesis in the septic rats compared with all other groups. Histone and albumin synthesis were also significantly increased (p<0.05) in the arginine‐supplemented control group compared with the glycine‐supplemented control group. Arginine supplementation during sepsis significantly increased (p<0.05) albumin and liver protein synthesis compared with controls. Histones which are involved in DNA synthesis and are rich in arginine may play a role in the host response to stress and sepsis. Thesein vivoresults appear to contradict hepatocyte‐Kupffer cell coculture studies perhaps because of the hormonal and cytokine responses to nutrient substrate and acute septicemia. (Journal of Parenteral and Enteral Nutrition15:503–508, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005503

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

Circulatory indirect calorimetry (CIC) is a potentially useful method to assess the energy requirements of critically ill patients. Unlike respiratory indirect calorimetry (RIC), which measures oxygen utilization from inhaled and exhaled gases, CIC measures oxygen utilization from arterial and mixed venous blood. Twenty‐two measurements in eight critically ill patients comparing RIC, CIC, and commonly used estimates of energy expenditure were performed. A significant correlation between RIC and CIC was identified (r= 0.831,p<0.001). Poor correlation was noted with either method and the commonly used estimates. CIC may be a useful tool in estimating energy expenditures in the critically ill. (Journal of Parenteral and Enteral Nutrition15:509–512, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005509

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

Risk factors for superior vena cava perforations following central venous catheterization for total parenteral nutrition were identified in a retrospective study of 1058 catheters in 853 patients; 540 of these catheters were size 16‐gauge (51%) and 518 size 14‐gauge (49%). Of the size 14‐gauge catheters, 274 (53%) were right‐sided and 244 (47%) were left‐sided subclavian catheters. Four patients (0.4%) had superior vena cava perforation. All had left‐sided large bore 14‐gauge catheters. All patients experienced acute symptoms and all had pleural effusions. There was no mortality directly related to vascular erosions. Two risk factors were identified for this complication: (1) catheters originating from the left side (p<0.05), or (2) large catheters (size 14‐gauge or larger) (p<0.01). We conclude that large bore or left‐sided central venous catheter placement represents an increased risk of superior vena cava perforation. (Journal of Parenteral and Enteral Nutrition15:513–516, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005513

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

Several studies concerning burn patients have shown that supplementation of enteral nutrition with ornithine α‐ketoglutarate (OKG) favorably modifies protein metabolism. Therefore, the effect of OKG administration on muscular and hepatic protein catabolism was evaluated in burned rats. Four groups of six rats were used. Two groups were scalded by immersion of the dorsum in water at 90°C for 10 seconds and then starved for 24 hours. Controlled enteral nutrition was then administered in three boluses daily (Osmolite, 210 kcal/kg/d, 1.2 g N/kg/d); one group was supplemented with OKG (5 g/ kg/d, ie, 0.68 g N/kg/d), while the other group received an equivalent amount of nitrogen in the form of glycine. One group of healthy control rats received Osmolite supplemented with glycine and the last group was fed adlibitum.The animals were killed after 2 days of nutrition. Protein catabolism was assessedin vitroby measuring the amount of valine (liver catabolism) and phenylalanine (muscle catabolism) released into the incubation medium of isolated tissues. Tissular and serum glutamine were also assayed. Burn injury induced muscle hypercatabolism without affecting hepatic catabolism. The administration of OKG limited both muscle weight loss and muscle protein hypercatabolism and significantly improved the muscle glutamine pool. These results demonstrate the nitrogen‐sparing effect of OKG in muscle in hypercatabolic states. (Journal of Parenteral and Enteral Nutrition15:517–520, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005517

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

Studies were undertaken in sedated and unsedated rats to raise the depleted intramuscular glutamine concentrations produced by aseptic abscesses, and to assess the effect of this change on muscle protein fractional synthetic rate. Age‐ and weight‐matched control animals were also included in the study.The rats were infused for up to 5 hours via the lateral tail vein with 1 mL/100 g of body weight per hour of either saline or 0.22 M glutamine. The intramuscular concentration of glutamine (mmol/L of intracellular water), which was reduced by 45% after turpentine in the sedated animals, was restored to within 79% of control values, but the muscle fractional protein synthetic rate, which was also reduced by 41% in these animals, was not improved by the glutamine infusions. Glutamine administration also failed to increase muscle protein synthesis in unsedated rats and in those supplemented with a liquid meal.It is concluded that acute elevations in muscle glutamine concentrations do not increase protein synthesis in this tissue and that therefore glutamine is unlikely to be a mediator in the control of muscle protein synthesis under these circumstances. (Journal of Parenteral and Enteral Nutrition15:521–525, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005521

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

Dietary fiber plays a role in maintaining colonic structure and function. Recently, fiber‐supplemented liquid diets containing primarily soy polysaccharide have been marketed. However, the effects of these diets on the colon, particularly absorptive function, are not well documented. We compared Jevity (containing 1.4% soy polysaccharide) to fiber‐free Osmolite. In addition, we were interested in comparing the effects of soy polysaccharide to that of pectin, which has previously been shown to facilitate adaptation. A 1% pectin‐supplemented rat liquid diet was compared to the liquid diet alone. After 2 weeks of dietary treatment, rats were anesthetized andin vivocolonic absorption measured. Both Jevity and the pectin‐containing diets led to a significantly greater (p<0.01) basal and butyrate stimulated water absorption as well as 20 mM butyrate absorption compared to their fiber‐free fed controls. After perfusion, rats were killed and parameters of colonic mass measured including mucosal weight, protein, and DNA. The fiber‐containing diets produced a modest, nonsignificantly greater colonic mass compared to their fiber‐free controls. A commercial diet containing soy polysaccharide seems to be equally effective as pectin in maintaining colonic absorptive function. (Journal of Parenteral and Enteral Nutrition15:526–529, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005526

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

Treatment of tumor‐bearing (TB) and control rats with the anabolic beta‐2 agonist drug clenbuterol (CLE) for 14 days reduced food intake for 4 days initially. Feeding was increased in anorectic TB rats, however, during the last 7 days of drug administration. Since minimal muscle savings were observed in chow‐fed TB rats treated with CLE, the anabolic effects of this drug were investigated in a second experiment on TB rats maintained on total parenteral nutrition (TPN). Sixteen days after the subcutaneous transplantation of methylcholanthrene‐induced sarcomas rats was begun on a 2‐week schedule of TPN. One group of these rats was treated daily for 14 days with CLE, while the remaining rats received injections of saline. Additional groups of TB and nonTB rats were maintained on rat chow for this period and treated with saline. Although TB rats maintained on rat chow or TPN and treated with saline exhibited significantly decreased gastrocnemius muscle weight and protein content, treatment of TB‐TPN rats with clenbuterol normalized muscle mass and increased muscle protein content significantly and increased plasma concentrations of branched‐chain amino acids. These results indicate that although nutritional support of TB organisms does not result in protein repletion, the addition of an anabolic drug renders the nutritional support highly efficacious. (Journal of Parenteral and Enteral Nutrition15:530–535, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005530

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

Vancomycin usage at British Columbia's Children's Hospital has increased substantially in the Special Care Nursery as a consequence of a study demonstrating a reduced morbidity and mortality in neonates with necrotizing enterocolitis when treated with vancomycin and cefotaxime. The inability to place more than one peripheral intravenous access necessitates interruption of parenteral nutrition to infuse vancomycin, resulting in a reduction of the planned daily intake of these neonates. This is clinically significant with the administration of vancomycin because of the long administration period required for this drug (60 minutes). This study was designed to assess the physical and chemical stability of vancomycin with a standard neonatal parenteral nutrition solution, Vamin A, when coadministered through the same intravenous line. To simulate the actual clinical setting, the dose of vancomycin and the infusion rate of Vamin A were chosen to represent those commonly used in a 1‐kg neonate. Physical compatibility was assessed using effluent obtained after coinfusion of vancomycin with parenteral nutrition solution. Duplicate samples were visually checked for color changes and precipitate. High‐pressure liquid chromatography (HPLC) and pH testing were used to assess chemical compatibility of vancomycin. The results of physical compatibility revealed no color change or precipitate. No changes in pH were observed. HPLC determination confirmed that there were no significant time‐dependent changes in vancomycin stability. The samples were studied over 24 hours to determine the rate of degradation of vancomycin, if any, under various temperature conditions. The concentrations were not significantly different from each other at the different temperatures studied. Thus, there was no apparent change in the concentration of vancomycin in the presence of Vamin A. The results support the findings observed in other studies, which indicate that vancomycin is compatible when coinfused with Vamin A parenteral nutrition solution. It is concluded that vancomycin can be safely coinfused via four‐way stopcock with Vamin A in those neonates in whom no other intravenous access can be obtained. The benefits of coinfusion include (1) maintenance of planned daily intake for the neonate, (2) a decrease in nonnutrient fluid intake, and (3) a decrease in nursing time for line manipulation. (Journal of Parenteral and Enteral Nutrition15:536–539, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005536

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

The effect of methionine‐deprived nutrition on cell growth and cell kinetics was investigated in cell cultures and in tumor‐bearing rats using the total parenteral nutrition (TPN) technique. A simultaneous flow cytometric measurement of the cellular DNA content and the amount of 5‐bromodeoxyuridine incorporated into cellular DNA was performed for analysis of cell kinetics. The methionine‐free medium demonstrated a cytocidal effect on the growth of SLC cells after 6 hours of culturing. It decreased viability from 80% in the control medium to 23%, and it decreased the S phase and increased the G0/G1phase of the cell cycles. The methionine‐deprived medium showed a concentration‐dependent inhibition in cellular growth. Methionine‐deprived TPN was seen to inhibit AH109A and SLC tumor growth compared with conventional TPN and decreased the S phase and increased the Go/ G1phase of cell cycles. These results confirm that methionine deprivation blocks cells from processing into the G1phase and recycling, and that it is effective in inhibiting tumor growth in cultures and in vivo. (Journal of Parenteral and Enteral Nutrition15:540–545, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005540

出版商:SAGE Publications    

年代:1991

数据来源: WILEY

摘要:

To clarify the mechanisms of hyperlipidemia during intravenous Intralipid 10%, lipoprotein profiles including lipoprotein X were studied in 13 patients receiving 2.0 g of fat per kilogram per day by Intralipid 10% over a period of 8 weeks. All patients were fed exclusively by total parenteral nutrition providing 1.1 g of amino acid and 30 kcal/kg per day. Intravenous administration of Intralipid 10% caused a marked increase of low‐density lipoprotein (LDL), phospholipid, and cholesterol, especially free cholesterol, whereas triglyceride, very‐low‐density lipoprotein, and high‐density lipoprotein remained within the normal range. Lipid composition of LDL approximated that of lipoprotein X progressively with the intravenous Intralipid 10%. Quantification of lipoprotein X revealed that its increase was proportionate with that of LDL and total lipid. From these findings, hyperlipidemia during intravenous Intralipid 10% is induced almost exclusively by the increased lipoprotein X. (Journal of Parenteral and Enteral Nutrition15:546–550, 1991)

ISSN:0148-6071    

DOI:10.1177/0148607191015005546

出版商:SAGE Publications    

年代:1991

数据来源: WILEY