Gluconeogenesis and nitrogen loss after stomach resection

The relationship between gluconeogenesis from alanine and nitrogen balance after stomach resection was investigated in 13 patients. Partial stomach resection was done in eight patients and total stomach resection was done in five patients. Alanine turnover, carbon flux from alanine to glucose, and glucose turnover were determined by tracer methodology, using the single injection of [U-14C]alanine and [2-3H]glucose. The patients were divided in two groups according to the quantity of administered glucose. Six patients with partial stomach resection received 2.1 to 2.8 g glucose . kg-1 . day-1 and 0.07 to 0.09 g nitrogen . kg-1 . day-1, amounting to 11 to 13 kcal . kg-1 . day-1 (group 1). In group 2 the subjects received 5.4 to 8.2 g glucose . kg-1 . day-1 and 0.12 to 0.26 g nitrogen . kg-1 . day-1; five patients received also 1.2 to 1.8 g fat emulsion . kg-1 . day-1. Total caloric supply was 28 to 60 kcal . kg-1 . day-1. In group 1 the mean potential contribution of gluconeogenesis from alanine to nitrogen loss was between 31 and 67%; in group 2 this contribution was at least 7 to 63%. No correlation was found between nitrogen balance and carbon flux from alanine to glucose. A significant correlation (p less than 0.001) was found between nitrogen balance and, respectively, nitrogen intake and caloric supply. These results suggest that not gluconeogenesis from alanine but nitrogen and caloric demand are major factors influencing nitrogen balance after stomach resection.     

1,6—二磷酸果糖对手术后应激病人应用全肠外营养支持效果的影响

本文在胃癌行全胃或胃大部切除术引起的中等程度应激病人，随机分组对比观察了全肠外营养或ＴＰＮ加用１，６－二磷酸果糖的效果。结果显示，与单纯ＴＰＮ相比，ＴＰＮ加用ＦＤＰ后血清皮质醇和胰高血糖素等应激激素水平有所下降，尿中３－甲基组氨酸排出减少，累积氮平衡增加。     

Protein dynamics during refeeding of protein-depleted rats: effects of increasing amino acid intake by TPN or enteral continuous feeding

The effect of increasing nitrogen intake with constant calorie supply was studied in protein-depleted rats. Animals were randomized into three paired groups to receive either total parenteral nutrition (TPN) or enteral (EF) isocaloric feedings (240 kcal X kg-1 X day-1) differing only in their amount of amino acids. The diets, composed of dextrose, a safflower oil emulsion and crystalline amino acids, were infused continuously for 5 days. Daily nitrogen intakes were for controls (EF, n = 7; TPN, n = 6) 0.25 g/kg; for groups 1 (EF, n = 7; TPN, n = 8) 1.4 g/kg and for groups 2 (EF, n = 7; TPN, n = 7) 2.5 g/kg. The rats in groups 1 and 2 obtained significant protein repletion in terms of body weight, nitrogen retention, liver protein and serum albumin regardless of the route of nutrient delivery. However, rats in groups 2 (higher nitrogen intake) presented a more rapid and greater recovery despite a reduction in nitrogen utilization. Whole-body leucine kinetics studied at the end of controlled feeding periods were similar for EF and TPN rats. However, increasing nitrogen intake (1 and 2) increased whole-body leucine flux and incorporation into protein resulting in a better balance, since leucine release from protein breakdown was comparable to controls. Liver protein fractional synthetic rates were reduced in EF while remaining at a high rate in TPN group 2 and still more elevated in TPN group 1, suggesting a preferential support of liver protein by enteral feeding or the effect of TPN as a non-physiologic route.     

丙氨酰胺谷氨酰胺对术后化疗消化道肿瘤患者的作用

目的研究添加丙氨酰胺谷氨酰胺(Ala-Gln)的全胃肠外营养(TPN)对术后化疗消化道肿瘤患者的作用。方法30例消化道肿瘤患者,按序随机分为两组传统组和二肽组,每组15例,术后给予等热量(104.6kJ     

Parenteral infusion of long- and medium-chain triglycerides and reticuloendothelial system function in man

Previous study demonstrated that patients who received total parenteral nutrition (TPN) with standard intermittent infusion of long chain triglyceride (LCT) at 0.13 g kg-1hr-1 over 10 hr for each of three days showed a significant decline in 99Tc-sulfur colloid (TSC) clearance rate by the reticuloendothelial system (RES). The present studies evaluated eight patients who received the same total lipid dose of LCT infused continuously as in a three-in-one admixture, and another nine patients receiving the same amount of fat as a medium chain triglyceride (MCT)/LCT (75%/25%) emulsion intermittently over 10 hr at 0.13 g kg-1hr-1 for three consecutive days. Patients were given continuous total parenteral nutrition (TPN) comprised of protein, 1.5 g kg-1day-1, and dextrose, 4.5 g kg-1day-1. RES function was examined by measuring the clearance rates of intravenously injected TSC while receiving TPN containing only protein and dextrose, and again after three days of fat infusion. Mean (+/- SEM) clearance rate constants before and after continuous LCT infusion were 0.38 +/- 0.09 and 0.41 +/- 0.08 min-1, respectively, while those before and after intermittent MCT/LCT infusion were 0.50 +/- 0.18 and 0.73 +/- 0.24 min-1, respectively. In contrast to intermittent LCT infusion, the administration of continuous LCT or an intermittent MCT/LCT mixture does not impair TSC clearance by the RES. These findings suggest that condensing the daily period of LCT infusion at standard dosage may exceed the rate of metabolic utilization, resulting in increased fat removal and diminished TSC uptake by the RES.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary fat level as determinant of protein-sparing actions of structured triglycerides.

This study assessed the effects of total parenteral nutrition (TPN) containing long-chain triglycerides (LCTs), an equimolar physical mixture of LCT and medium-chain triglycerides (MCTs), and a structured triglyceride synthesized from equimolar amounts of MCT and LCT on energy and protein metabolism after thermal injury (25% body surface area full-thickness scald burn). Male Sprague-Dawley rats (245-271 g) received isovolemic diets intravenously that supplied 250 kcal.kg-1.day-1, 2 g amino acid nitrogen.kg-1.day-1, and 50% of nonprotein calories as lipid and 50% as dextrose for 3 days. Whole-body and tissue leucine kinetics were estimated by a 4-h continuous infusion of L-[1-14C]leucine on day 3. Nitrogen balance, plasma albumin, plasma glucose, energy expenditure, and whole-body and liver and rectus muscle protein kinetic parameters were determined. No significant differences were noted in any of the parameters measured. This study suggests that the unique protein-sparing actions usually associated with structured triglyceride administration are not seen when they are provided as 50% of nonprotein calories. In addition, the ratio of MCT to LCT in the starting mixture from which the structured triglycerides are synthesized may be an important determinant of the protein-sparing actions attributed to these lipids.     

消化道肿瘤-T-术后早期肠内营养疗效研究

目的评价消化道肿瘤手术后早期肠内营养的安全性,比较手术后短期应用要素制剂爱伦多的肠内营养与标准肠外营养支持的疗效。 方法62例消化道恶性肿瘤手术患者,随机分为对照组、肠外营养组和肠内营养组。手术后第一天开始等热卡、等氮量的肠外或肠内营养支持一周。检测体重、机体测量指标、血浆各内脏蛋白浓度及氮平衡等营养指标,外周血T细胞亚群、NK细胞和NK细胞活性等免疫指标及血清氨基酸谱。 结果三组病人术后体重下降分别为4．26±1．03ks、2．04±0．65ke和2．12±o．72kg,对照组与肠外营养组、肠内营养组之间差异有显著性(P<0．05),后两组之间无差异。术后各内脏蛋白浓度均低于术前,对照组降低最明显,与肠外或肠内营养组之间差异有显著性(P<0．05),而后两组之间无差异。三组病人平均氮平衡为—8．6±3．12g／d,—4．22±2．02g／d及—3．88±2．35g／d,对照组与肠外或肠内营养组之间差异有显著性(P<0．05),而后两组之间无差异。手术后各组病人外周血T细胞亚群、NK细胞和NK细胞活性均不同程度下降,但三组之间差异无显著性意义。三组病人血清谷氨酰胺水平明显下降,术后1周对照组和肠外营养组血清谷氨酰胺水平仍处于低水平,而肠内营养组却有一定程度恢复。 结论消化道肿瘤手术后早期肠内营养支持是安全、有效的方法,短期肠内营养和肠外营养支持的临床效果基本相同。     

Effects of medium-chain and long-chain triacylglycerols in pediatric surgical patients

Medium-chain triacylglycerols (MCTs) have been shown to provide better nutritional support than long-chain triacylglycerols (LCTs). This study compares the efficacy of MCT combined with LCT with LCT alone in pediatric patients with surgical stress. Two groups of patients (n = 19 in each) received equivalent amounts of glucose (12 g. kg. d) and amino acids (2 g. kg. d), but one group received 10% Lipofundin MCT/LCT and the other received 10% LCT (1.5 g. kg. d) in a randomized study. Total parenteral nutrition (TPN) was given for 14 d. Blood and urine samples were collected before and after TPN administration for determination of various biochemical parameters. Indirect calorimetry was also performed to determine respiratory quotients and fuel utilization. After 14 d of TPN in the MCT/LCT group, there was a significantly higher blood lymphocyte percentage, a decreasing tendency of serum asparate aminotransferase and of total and direct bilirubin (P < 0.05). These changes were not observed in the LCT group. A significantly better nitrogen balance and a higher ketogenesis from day 3 were observed in the MCT/LCT group. The MCT/LCT group showed a more marked increased utilization of fat than the LCT group, whereas carbohydrate oxidation was less in the MCT/LCT group than in the LCT group (P < 0.05). In children after surgery, MCT/LCT is more protein sparing and induces a better immune response when compared with LCT-containing lipid emulsion. A TPN regimen containing MCT/LCT is likely to result in rapid oxidation of fats for energy without compromising the respiratory system.     

丙氨酰胺谷氨酰胺对烫伤大鼠的作用

目的研究添加丙氨酰谷氨酰胺(Ala-Gln)全胃肠外营养对烫伤大鼠的蛋白质代谢、肠粘膜形态学、创面肉芽组织的影响。方法将22只30%TBSAⅢ度烫伤SD大鼠行颈外静脉插管后,随机分为传统TPN组(传统组)和添加二肽TPN组(二伏组),每组各11例,两组接受等热量(780kg     

Nutritional support after liver transplantation: a randomized prospective study

Nutritional support in patients with advanced cirrhosis is difficult due to protein, fluid and salt restrictions. Successful liver transplantation should improve nutrient tolerance. We randomly assigned 28 hypoalbuminemic cirrhotic patients to receive, immediately after liver transplantation, one of three regimens: group 1, no nutritional support (n = 10); group 2, total parenteral nutrition (TPN) (35 kcal/kg/day) with standard amino acids (1.5 g/kg/day) (n = 8); or group 3, isocaloric isonitrogenous TPN with added branched-chain amino acids (n = 10). Therapy was continued for 7 days posttransplant. Jaundice resolution was unaffected by nutritional support. Nitrogen balance favored both TPN groups. Branched-chain amino acid (BCAA) aromatic amino acid ratios were highest in group 3. Coma scores and serum ammonia levels were similar in all groups. Both TPN groups achieved respirator independence earlier; this difference was not statistically significant. Group 1 patients stayed longest in ICU; the difference was statistically significant. TPN with either standard or BCAA- enriched amino acids is tolerated well immediately after successful liver transplant. Positive nitrogen balance is achieved; large protein loads do not worsen encephalopathy. Nutritional support may improve respiratory muscle function, allowing earlier weaning from ventilatory support. A shortened length of ICU stay justifies the expense of TPN.     

谷氨酰胺对肿瘤病人术后营养状况及免疫功能的影响

目的 探讨谷氨酰胺对肿瘤病人术后营养状况及免疫功能的影响。方法 20例胃肠道肿瘤病人术后随机分为常规TPN组（对照组）10例和TPN＋Gln组（研究组）10例，治疗8天，观察血清前白蛋白、血清转铁蛋白、氮平衡变化。并检查其前后外周血IgG、IgM、IgA、C3、C4的变化。结果 （1）两组病人负氮平衡改善，研究组与对照组比较差异明显（P＜0．01）。两组病人血清蛋白均上升，研究组回升更明显，与对照组比较具有显差异（P＜0．01）。（2）研究组外周血IgG、IgM、IgA明显升高，与对照组比较差异显（P＜0．05）。研究组C3、C4明显升高与对照组比较差异显（P＜0．05）。结论 谷氨酰胺改善了肿瘤术后病人的营养状况，提高了免疫功能。     

Effect of glutamine-supplemented total parenteral nutrition on the small bowel of septic rats

In order to study the effect of total parenteral nutrition (TPN) with or without glutamine supplementation in septic rats, septic Wistar albino rats were randomly assigned to receive 0.23 g of nitrogen and 113 kJ (100 g BW)(-1) per day in the form of amino acids with (group 2) or without (group 1) glutamine supplementation or 10% (w/v) glucose only (group 3). After 4 days of TPN treatments, rats receiving glutamine-supplemented TPN had a cumulative nitrogen balance of -24.4 +/- 3.3 mg N, which was significantly (P < 0.001) better compared to other TPN-treated groups. Septic rats of group 2 survived sepsis significantly (P < 0.001) better than those in groups 1 and 3. Glutamine-supplemented TPN treatment resulted in significant increases in jejunal weight (P < 0.001), DNA and protein contents (P < 0.001), villous height (P < 0.001) and crypt depth (P < 0.001) when compared with septic rats of group 1. Septic rats of group 2 extracted and metabolised glutamine by the small bowel at higher rates (P < 0.001) than that observed in septic rats of group 1. Increases in jejunal glutaminase (38.2%, P < 0.001) and decreases in glutamine synthetase (41.7%, P < 0.001) activities were observed in response to glutamine-supplemented TPN treatment. It is concluded that the administration of glutamine-supplemented TPN is beneficial to the small bowel of septic rats.     

The effect of glutamine-supplemented total parenteral nutrition on nitrogen economy depends on severity of diseases in surgical patients

BACKGROUND: Gln is an important substrate for enterocyte and rapid proliferation cells. Studies have shown that parenteral supplementation of Gln maintains the intracellular Gln pool, improves nitrogen balance and shortens hospital stay. However, some studies showed Gln-supplemented TPN had no effect on restoring the Gln pool in critically ill patients. OBJECTIVE: To evaluate the effect of glutamine (Gln) dipeptide supplementation of total parenteral nutrition (TPN) on postoperative nitrogen balance and immune response of patients undergoing surgery. METHODS: This study is a prospective, randomized double-blind clinical trial. APACHE II score and TISS were used to evaluate the patients after admission. Forty-eight patients with major abdominal surgery were allocated to two groups to receive isonitrogenous (0.228 g nitrogen/kg/day) and isoenergetic (30 kcal/kg/day) TPN for 6 days. Two groups (Conv and Ala-Gln) were further divided to high (APACHE>or=6) and low (APACHE <6) groups. Control group (Conv) received 1.5 g amino acids/kg/day, whereas the Ala-Gln group received 0.972 g amino acids/kg/day and 0.417 g of L-alanyl-L-glutamine (Ala-Gln)/kg/day. Blood samples were collected on day 1 and day 6 after surgery for plasma amino acid and CD4, CD8 cell and T lymphocyte analysis. Cumulative nitrogen balance were also measured on day 2, 3, 4, 5 postoperatively. RESULTS: Although there was a tendency to have better cumulative nitrogen balance on the postoperative days in the Ala-Gln group, no significant difference was observed between two groups. However, a better significant cumulative nitrogen balance was observed on the 2nd, 3rd and 5th postoperative day in the Ala-Gln group than in the Conv group in patients with APACHE II <6, whereas no significant difference was noted in patients with APACHE II >or= 6. No difference in urine 3-methylhistidine excretion were observed between the 2 groups. Patients in the Ala-Gln group had significant higher T lymphocyte and CD4 cells than did those in the Conv group.CONCLUSION: TPN supplemented with Gln dipeptide had beneficial effect on enhancing the immune response. However, the effect of Ala-Gln administration on improving nitrogen economy was only observed in patients with low APACHE II scores. These results may indicate that Gln required for reversing the catabolic condition may depend on the characteristics and severity of the diseases.     

Clinical and metabolic effects of two lipid emulsions on the parenteral nutrition of septic patients

OBJECTIVE: We compared the metabolic and clinical effects of two lipid emulsions, long-chain triacylglycerols (LCT) and a mixture of medium- and long-chain triacylglycerols (MCT/LCT), in septic patients. METHODS: Both groups received total parenteral nutrition (TPN) with a solution enriched with branched-chain amino acids (BCAA). Seventy-two septic patients received TPN with MCT/LCT (group 1) or LCT (group 2). Before starting TPN (basal) and 10 d after (final), various parameters were evaluated. RESULTS: Twenty-six subjects in each group completed the study. Both groups showed an increase in cholestasis enzymes, with no significant changes in lipid parameters. The rise of retinol-binding protein and the recovery of nitrogen balance were significantly greater in group 1. A multivariate analysis of nutritional markers and catabolic parameters showed a better evolution in group 1 (P = 0.002). The MCT/LCT group exhibited a significant increase of insulin levels. Overall mortality and length of stay in the intensive care unit were not affected by the lipid emulsion. CONCLUSIONS: In septic patients who received TPN with a solution enriched with BCAAs, the use of an emulsion containing MCT provided them with a greater recovery of their nutrition status than the traditional LCT formula, without influencing the outcome.     

Comparison of the effects of continuous and cyclic nocturnal parenteral nutrition on energy expenditure and protein metabolism

Although cyclic nocturnal total parenteral nutrition is a widely used technique, its metabolic consequences have not been fully investigated. During two successive 7-day periods, 12 patients received randomly either standard continuous (infusion 24 hr/day) or cyclic (infusion between 5 pm and 9 am) total parenteral nutrition (TPN). Calorie and nitrogen intakes were identical during both periods. Energy expenditure was investigated by indirect calorimetry and showed practically no difference between continuous standard (1383 +/- 41 kcal/day-1) and cyclic total parenteral nutrition (1428 +/- 46 kcal/day-1). However, in the cyclic regimen, when compared with continuous infusion, energy expenditure was higher between 5 pm and 9 am and lower between 9 am and 5 pm. At the end of the noninfusion period, the 24-hr profile of the nonprotein respiratory quotient showed a slight decrease in patients receiving the cyclic infusion, in contrast with the stability of the quotient in the standard regimen. However, the nitrogen balance and variations in nutritional status did not differ significantly. In conclusion cyclic TPN is efficient for achieving a positive energy and nitrogen balance and in addition it induces a metabolic profile closer to physiological conditions.     

Enteral versus parenteral nutrition: a pragmatic study

Controversy persists as to the optimal means of providing adjuvant nutritional support. The aim of this study was to compare enteral nutrition (EN) and parenteral nutrition (TPN) in terms of adequacy of nutritional intake, septic and nonseptic morbidity, and mortality. This was a prospective pragmatic study, whereby the route of delivery of nutritional support was determined by the attending clinician's assessment of gastrointestinal function. Patients considered to have inadequate gastrointestinal function were given TPN (group 1), while those deemed to have a functioning gastrointestinal tract received EN (group 2). Patients in whom there was reasonable doubt as to the adequacy of intestinal function were randomized to receive either TPN (group 3) or EN (group 4). The trial setting was a large district general hospital with a dedicated nutrition team. A total of 562 patients were included in the study (331 males; median age 67 y). Gastrointestinal function on entry into the study was considered inadequate in 267 patients who were given TPN (group 1) and adequate in 231 whom received EN (group 2). There was clinical uncertainty about the adequacy of gut function in 64 patients (11.4%) who were randomized to receive either TPN (group 3, 32 patients) or EN (group 4, 32 patients). The incidence of inadequate nutritional intake was significantly higher in group 4 compared with group 3 (78.1% versus 25%, P < 0.001). Complications related to the delivery system and other feed-related morbidity were significantly more frequent in both EN groups compared with the respective TPN groups. EN was associated with a higher overall mortality in both nonrandomized and randomized patients. There were no significant differences observed in the incidences of septic morbidity between patients receiving TPN and those given EN. EN is associated with a higher incidence of inadequate nutritional intake, complications related to the delivery system, and other feed-related morbidity than TPN. There is no evidence from this study to support a difference between the two modalities in terms of septic morbidity. Patients in whom there is reasonable doubt as to the adequacy of gastrointestinal function should be fed by the parenteral route.     

Metabolic and thermogenic response to continuous and cyclic total parenteral nutrition in traumatised and infected patients

16 traumatised or infected patients on mechanical ventilation were randomised to continuous TPN or to cyclic TPN after a 24-h period of glucose infusion (1.25 kJ x kg BW(-1) x h(-1)). Energy supply was equivalent to 1.3 x baseline energy expenditure. Glucose, fat and amino acids were administered at a constant rate over 24 h in the continuous TPN group and over 12 h, followed by glucose (1.25 kJ x kg BW(-1) x h(-1)), in the cyclic TPN group. Nutrient-induced thermogenesis was lower during continuous than during cyclic TPN (5 +/- 4 vs. 12 +/- 7%, mean +/- SD, p < 0.05), as was the increase in CO(2) elimination (13 +/- 11 vs. 30 +/- 7%, respectively, p < 0.01). Energy balance was more positive during continuous TPN. In both groups, energy expenditure reached a plateau during the first 12 h of TPN infusion. The lower nutrient-induced thermogenesis and more positive energy balance, indicates a more efficient utilisation of nutrients during continuous than during cyclic TPN. The lower CO(2) production during continuous TPN, may be advantageous when respiratory function is compromised. The plateau in energy expenditure in response to TPN infusion may be useful as a guideline for nutritional therapy.     

Comparison of glucose vs. Glucose fat solutions in cancer patients: A controlled crossover study

The purpose of this investigation was to evaluate in a randomised crossover study the effects on nutritional status of two isonitrogenous-isocaloric regimens of total parenteral nutrition (TPN) in 12 severely cachectic cancer patients. The regimens consisted of (1) G: 50 kcal of glucose.kg(-1).day(-1) + 2g amino-acids.kg(-1).day(-1) (2) GL: 30 kcal glucose and 20 kcal lipids.kg(-1) + 2g amino-acids.kg(-1).day(-1). Regimens G and GL were delivered sequentially for a period of 10 days each. Six patients (Group A) were randomised to receive regimen G first and regimen GL subsequently. In Group B patients the regimens alternated in the opposite way. The following nutritional variables were measured before TPN, after regimen G and after regimen GL: weight, arm circumference, arm muscle circumference, triceps skin fold, serum proteins, serum albumin, cholinesterase, transferrin, pre-albumin, retinol-binding protein, peripheral lymphocytes, cumulative nitrogen balance and mean urinary excretion of creatinine and 3-methylhistidine. The data showed that body weight and retinol-binding protein significantly increased with both G and GL regimens. No difference was found in the remaining variables, not even when comparing regimen G to GL. Increase in retinol-binding protein and in nitrogen balance were significantly better in the first period of treatment than in the second. These results show that the two regimens had a similar impact on the nutritional status of the cachectic cancer patients and choice between a glucose or a glucose-fat TPN should depend mainly on tolerance of the patients, duration and cost of therapy.     

谷氨酰胺二肽对全肠外营养短肠综合征大鼠血清蛋白及肝功能的影响

目的观察谷氨酰胺二肽对Wistar大鼠短肠模型血清蛋白和肝功能的影响,及其减轻脂肪乳剂引起肝损害的作用机理。     

Leucine kinetics at graded leucine intakes in young men

A study was carried out with 12 young men to examine the relationships between the intake of leucine and indices of leucine kinetics, using L-[1-13C]leucine as a tracer. Six subjects received L-amino acid diets during 7-day periods supplying leucine in the range of 79 to 20 mg.kg-1.day-1 (Group I) and another six subjects (Group II) received leucine intakes ranging from 20 to 4 mg.kg-1.day-1. Estimations were made of leucine kinetics, at the end of each diet period, when subjects were receiving small isonitrogenous, isocaloric meals during the isotope infusion period. Leucine flux declined with reduced leucine intake and leucine oxidation tended not to change at intakes below 20 mg.kg-1.day-1 (slope not statistically different than zero). Plasma valine increased markedly with further restriction in leucine intake below this level. The daily mass balance of leucine, estimated from the difference between intake and oxidation, became negative at an intake of about 20 mg.kg-1.day-1. These findings are discussed in relation to the published mean and upper range of requirement for leucine in healthy adults, currently taken to be 11 mg.kg-1.day-1 and 14 mg.kg-1.day-1, respectively.