Effect of tracer and intravenous fat emulsion on the measurement of reticuloendothelial system function

Since the addition of lipid to intravenous feeding formulas, animal and human studies have shown impairment of the reticuloendothelial system (RES) due to slow rates of clearance and gradual accumulation of long chain triglycerides (LCT) in the liver. Medium chain triglycerides (MCT) accumulate only minimally in the liver and do not impair the RES. However, results from animal studies using technetium sulfur colloid (TSC) to assess RES function have been inconclusive. The present study reevaluates RES function after lipid infusion in guinea pigs as measured by organ distribution of TSC. Guinea pigs were fed 300 kcal/kg/day of total parenteral nutrition (TPN) for 2.5 days, with 50% of nonprotein calories as fat in the form of LCT or MCT, then injected intravenously with 2.5 or 25 microCi of TSC, and uptake by liver, spleen, and lungs was determined. Liver, lungs, and spleen all increased in size after TPN with LCT or MCT. Liver TSC uptake was significantly affected by the dose of TSC (p less than 0.05), with the high dose probably inducing an increased capacity of the liver to clear TSC from the blood. Liver uptake was not influenced by diet, but feeding MCT did significantly stimulate lung uptake of TSC (p less than 0.0001). This suggests that the hepatic TSC uptake system is not saturable, and may not be an appropriate measure of Kupffer cell function since the colloid is not phagocytosed. However, TSC blood clearance remains an excellent prognostic indicator for bacteremia and mortality in humans, and is useful for measuring global RES function.     

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.     

Fat emulsions in parenteral nutrition after liver transplantation: The recovery of the allografts RES function and histological observations

Following liver transplantation, the effect of post-operative parenteral nutrition with MCT LCT (Medium Chain Triglycerides/Long Chain Triglycerides) fat emulsions on the recovery of allografts RES function was investigated in a randomised prospective study of three groups of patients (group I, n = 14: 50g MCT LCT fats twice weekly, group II, n = 15: 0.7 g/kg body weight per day MCT LCT fats, group III, n = 17: 1.5 g/kg body weight per day MCT LCT fats). RES function was assessed using the (99m)Tc-HSA-MM-Clearance ((99m)Technitium-Human serum albumen-Millimicrosphere-Clearance). There were no statistically significant differences in the recovery of RES function between the groups. A negative effect on RES function as a result of the administration of MCT LCT fat emulsions up to 1.5 g/kg b.w. per day can therefore be excluded. The evaluation of liver biopsies before the administration of fats and at the end of TPN (Total Parenteral Nutrition) showed no evidence, in the 20 patients investigated, of any fatty changes in the liver caused by the infusion of fat.     

Energy expenditure in rats maintained with intravenous or intragastric infusion of total parenteral nutrition solutions containing medium- or long-chain triglyceride emulsions.

Energy expenditure was determined in male Fischer 344 rats (235-246 g) fed by intravenous (IV) or intragastric (IG) infusion with total parenteral nutrition solutions providing 65% of nonprotein energy as fat from long-chain triglyceride (LCT) or a 3:1 admixture of medium-chain triglyceride (MCT) and LCT emulsions. Respiratory gas exchange and somatomotor activity were assessed continuously for 24 h during d 5 and 11 of infusion feeding. The MCT infusion resulted in one-third the weight gain noted with LCT infusion (MCT, 10 +/- 2 g/14 d; LCT, 32 +/- 4 g/14 d; P less than 0.0001). Insulin concentration was 60% higher with IV than with IG infusion and approximately 100% higher with IV-MCT than with IG-MCT or LCT infusion (P less than 0.05). Rats receiving IV infusion of MCT displayed similar levels of motor activity but 8-13% greater daily energy expenditure (kJ.kg-0.75.kJ intake-1) than rats receiving IG-MCT or LCT infusion (P less than 0.05). The MCT infusion also resulted in an elevation in respiratory quotient after cessation of nutrient infusion (MCT, 0.87-0.92; LCT, 0.83-0.85; P less than 0.05). Total and resting energy expenditure decreased approximately 13% from 5 to 11 d of infusion feeding. The lower weight gain and greater energy expenditure seen with MCT- compared with LCT-supplemented total parenteral nutrition may be mediated by higher insulin concentrations.     

Fat elimination in acute renal failure: long-chain vs medium-chain triglycerides.

Elimination and hydrolysis of fat emulsions containing long-chain (LCT; Intralipid) or long- and medium-chain triglycerides (MCT; Lipofundin MCT) were compared in seven patients with acute renal failure (ARF) and six healthy control subjects. In control subjects, clearance of MCT was slightly higher than that of LCT (1.93 +/- 0.34 vs 1.55 +/- 0.3 mL.kg body wt-1.min-1, P less than 0.05). The rise in plasma triglycerides was similar and the release of free fatty acids was higher during MCT (P less than 0.02). In ARF, clearance of both LCT and MCT was equally reduced (0.53 +/- 0.12 vs 0.59 +/- 0.14 mL.kg body wt-1.min-1, P less than 0.01 vs control subjects). Again, the rise in triglycerides was comparable. Free fatty acid release was higher during MCT but lower than in control subjects. Plasma concentrations of glucose and lactate were not affected in control subjects but increased during both LCT and MCT in ARF. Thus elimination of both LCT and MCT is profoundly decreased in ARF. The impaired lipolysis in ARF cannot be circumvented by the use of MCT.     

MCT/LCT emulsion ameliorate liver fat deposition in insulin-treated diabetic rats receiving total parenteral nutrition

This study was designed to investigate the effects of high energy infusion and insulin treatment on plasma and liver lipids in diabetic rats receiving total parenteral nutrition (TPN). Diabetes was induced in rats by streptozotocin. The diabetic rats were assigned to two TPN groups to receive either long chain triglyceride (LCT) or medium chain triglyceride (MCT)/LCT (1:1) as a fat source. The TPN solutions were isonitrogenous, isocaloric and identical in nutrient composition except for the fat emulsion. All rats received the TPN solution at an energy level of 35|kcal/100|g of body weight. The LCT and MCT/LCT groups were further divided into two subgroups, depending on whether they were treated with insulin. The results demonstrated that, between the MCT/LCT and LCT groups, no differences were observed in body weight and nitrogen retention, as well as the concentrations of plasma glucose, nonesterified fatty acids, beta-hydroxybutyrate, and total cholesterol. Diabetic TPN rats without insulin treatment had weight loss and negative nitrogen balance during the experiment. Diabetic TPN rats treated with insulin, however, demonstrated less weight loss and positive nitrogen retention. Insulin treated groups had significantly higher liver fat content than did those without insulin treatment. Furthermore, liver fat content was significantly higher in the LCT group than in the MCT/LCT group among insulin treated TPN rats. These results suggest that compared with the LCT emulsion, infusion of the MCT/LCT emulsion ameliorated liver fat deposition in insulin-treated diabetic rats receiving TPN.     

Effects of long-chain triglyceride emulsions on reticuloendothelial system function in humans

Parenteral administration of long-chain triglyceride emulsions has been shown to have deleterious effects on reticuloendothelial system function in animal models. It is unknown whether this interference occurs in humans with clinically relevant doses of intravenous fat. Two studies were done. Eighteen patients were prospectively enrolled for study. Patients received full feeding by continuous total parenteral nutrition (amino acids 1.5 g/kg/day and dextrose 4.5 g/kg/day) with 33.1 kcal/kg/day. Forty-three % of the nonprotein calories were provided as soybean oil emulsion (Travamulsion 20%) and was administered intravenously over 10 hr (0.130 g/kg/hr). Reticuloendothelial system function was determined by measuring the change in the clearance rate of intravenously injected 99mTc-sulfur colloid (TSC) in each patient. In study 1 (n = 10), one day of lipid (10 hr) was infused, with the clearance of 99mTc-sulfur colloid measured before the lipid was infused and then during the last hour of the 10-hr infusion. In study 2 (n = 8), the clearance rates were measured before the lipid emulsion was begun, and then during the last hour of the infusion on the 3rd day. Clearance rates for TSC after 10 hr of lipid infusion in study 1 did not differ (0.27 +/- 1/min to 0.26 +/- 0.1/min, p greater than 0.10). However, after 3 days of lipid infusion (10 hr/day), a statistically significant reduction in TSC was seen (0.46 +/- 0.08/min-0.27 +/- 0.03/min, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Thermogenesis from intravenous medium-chain triglycerides

Eighteen hospitalized patients dependent on total parenteral nutrition (TPN) were randomly enrolled into a prospective study comparing intravenous long-chain triglycerides (LCT) with a physical mixture of 75% medium-chain triglycerides (MCT) and 25% LCT. The TPN was given continuously as amino acids and glucose over 5 days with the respective lipid emulsion given intermittently during each day for 10 hr. Indirect calorimetry was measured on each patient before the lipid emulsion was administered in the morning and again 10 hr later near the end of the lipid infusion, on days 1, 3, and 5. Resting energy expenditure, VO2, VCO2, and calculated fat oxidation were shown to increase during MCT infusion but not during LCT administration, (resting energy expenditure 899 +/- 37 to 1085 +/- 40, compared with 978 +/- 23 to 976 +/- 39, kcal/m2 body surface area [BSA]/day, respectively, p less than 0.0002; VO2: 129.9 +/- 5.2 to 157.2 +/- 5.9, compared with 140.9 +/- 3.6 to 141.2 +/- 5.9 ml O2/min/m2 BSA, respectively, p less than 0.0005; and VCO2: 110.7 +/- 4.4 to 127.5 +/- 4.3, compared with 118.3 +/- 2.8 to 118.0 +/- 5.3, ml CO2/min/m2 BSA, respectively, p less than 0.0076; calculated fat oxidation 10.7 +/- 1.5 to 19.3 +/- 2.4, compared with 20.0 +/- 2.7 to 20.0 +/- 3.6, kcal/m2 BSA/hr, respectively, p less than 0.014). Respiratory quotient tended to fall with lipid infusion but did not change statistically. Body temperatures were unaltered by either fat infusion. It is concluded that TPN consisting of MCT causes an increased thermogenesis, most likely through increased fat oxidation, reflective of MCT's property as an obligate fuel. The increased thermogenesis occurs without an increase in body temperature.     

Changes of hepatic morphology during parenteral nutrition with lipid emulsions containing LCT or MCT/LCT quantified by ultrasound.

Fatty infiltration of the liver with cholestasis is one of the complications of total parenteral nutrition (TPN). The cause has not yet been determined. It seems probable, however, that these alterations could be prevented when a mixture of medium- and long-chain triglycerides (MCT/LCT) is used as a fat component instead of the application of long-chain emulsions (LCT) alone. To determine whether this could also be demonstrated morphologically in man, 14 patients needing TPN (25 kcal/kg BW x day, carbohydrate 45%, fat 35%, protein 20%) were examined by ultrasound in order to compare liver size and gray-scale value before and after 7 days of TPN. Seven of the patients were randomly administered a MCT/LCT emulsion as their fat intake, the other seven were exclusively given LCT. There were no changes in liver size and gray-scale value in the MCT/LCT-group, whereas both parameters showed a significant rise in the patients with LCT (size: 10.4 +/- 1.4 to 11.5 +/- 1.4 cm; gray-scale value: 9.3 +/- 1.0 to 11.6 +/- 0.7). These data suggest that TPN, administered with a mixture of MCT/LCT emulsions as fat components, could reduce the risk of hepatic dysfunction such as cholestasis and fatty infiltration of the liver.     

Manipulation of tissue fatty acid profile by intravenous lipids in dogs

This study was undertaken to determine the effects on the fatty acid (FA) composition of various dog tissues of 4 different lipid emulsions (a 100% long-chain triacylglycerol (LCT) derived from soya bean oil emulsion, a mixed 50% medium-chain triacylglycerol (MCT)/50% LCT emulsion as well as both these emulsions supplemented with 10% fish oil (FO) triacylglycerols), when daily infused over 15 days as a substantial component of total parenteral nutrition. Lipids represented 55% of the non-protein energy. Blood samples as well as biopsies from liver, muscle and adipose tissue were taken 15 days before, and again immediately after TPN. In addition, the spleen was also removed immediately after TPN. Tissue FA composition was analysed by gas liquid chromatography of each lipid component after separation by thin layer chromatography. No differences in either safety or tolerance were detected between the different TPN preparations. In particular, infusion over 2 weeks of fat emulsions containing 10% fish oil was tolerated as well as conventional LCT and MCT/LCT emulsions. Relative linoleate content of tissue triacylglycerol (TG) was markedly increased in animals that received the LCT emulsions (e.g. from 22.6 +/- 2.5% to 32.2 +/- 0.6% in the liver), this effect being markedly reduced with MCT/LCT preparations. n-3FA were slightly incorporated into liver TG (from 0.0 +/- 0.0% to 2.3 +/- 0.7% and 1.2 +/- 0.4% for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) respectively, with LCT + FO), but remained undetectable in extrahepatic tissue TG. Of interest, medium chain FA were found in tissue TG after infusion of the mixed MCT/LCT emulsions. As expected, changes of tissue phospholipid (PL) composition involved only long-chain FA. Infusion of soya bean oil emulsion was associated with an increased content of linoleate in liver PL (from 13.6 +/- 0.4% to 17.7 +/- 0.4%), but not in other tissues. MCT/LCT did not markedly affect PL/FA pattern in any tissue. Supplementation with fish oil was associated with an efficient incorporation of n-3FA into tissue PL, particularly in the liver (from 0.4 +/- 0.1% to 2.5 +/- 0.3% for EPA and from 3.9 +/- 0.8% to 9.1 +/- 0.4% for DHA, with the LCT + FO emulsion).     

Effects of medium-chain triglyceride in parenteral nutrition on rats undergoing gastrectomy

This study was designed to investigate the effects of pre-infusion with total parenteral nutrition (TPN) using medium-chain triglyceride (MCT) versus long-chain triglyceride (LCT) emulsion as fat sources on hepatic lipids, inflammatory mediators and antioxidant capacity in rats undergoing gastrectomy. Rats with internal jugular catheter, were divided into two groups and received TPN. TPN supplied 300 kcal/kg/d with 39% of the energy provided as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fat emulsion, which was composed of MCT/LCT (1 : 1) or LCT. After receiving TPN for 5 days, the rats underwent partial gastrectomy and were sacrificed 24 h after surgery. The results of the study demonstrated that the MCL/LCT group had lower hepatic lipids than did the LCT group. No differences in interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha in peritoneal lavage fluid were observed between the two groups. Erythrocyte glutathione peroxidase activity was significantly higher in the LCT group than the MCT/LCT group, although erythrocyte superoxide dismutase activity did not differ significantly between the two groups. These results suggest that infusion with MCT/LCT before an abdominal operation did not have an effect on modulating the production of inflammatory mediators in the location of the injurious stimulus. However, pre-infusion with MCT/LCT have beneficial effect in improving liver lipid metabolism and reducing oxidative stress in rats with gastrectomy.     

脂肪乳剂对完全胃肠外营养大鼠血清游离脂肪酸谱的影响

为研究脂肪乳剂对机体脂肪代谢的影响，用气相色谱法观测了完全胃肠外营养（ＴＰＮ）大鼠血清游离脂肪酸（ＦＦＡ）谱的变化。将４０只雄性Ｗｉｓｔａｒ大鼠随机分成５组，每组８只：（１）ＳＨ（Ｓｈａｍｏｐｅｒａｔｉｏｎ）组，仅进行颈外静脉结扎，正常饲养；（２）ＮＳ（Ｎｏｔｍａｌｓａｌｉｎｅ）组：正常饲养，输入生理盐水；（３）ＧＳ（Ｇｌｕｃｏｓｅ）组：全部能量由葡萄糖提供，即不含脂肪乳剂ＴＰＮ组；（４）ＬＣＴ（Ｌｏｎｇｃｈａｉｎｔｒｉｇｌｙｃｅｒｉｄｅ）组：含１０％Ｉｎｔｒａｌｉｐｉｄ脂肪轧的ＴＰＮ组；（５）ＭＣＴ（Ｍｅｄｉｕｍｃｈａｉｎｔｒｉｇｌｙｃｅｒｉｄｅ）组：含１０％Ｌｉｐｏｆｕｎｄｉｎ脂肪乳ＴＰＮ组。ＴＰＮ各组大鼠等能量等氮量等液量匀速连续输入“生合一”营养液（即将所有营养物混合在一个溶器内）。于第７天取血标本进行血清ＦＦＡ测定。结果表明：不含脂肪乳的ＴＰＮ大鼠血清各种ＦＦＡ下降，并出现必需脂肪酸缺乏（ＥＦＡＤ）症状，如精神不振活动少，毛发无光泽、脱落等；脂肪乳剂的使用，使大鼠血清各种ＦＦＡ升高，对机体的代谢和功能有着不同的生理、药理作用。     

Comparison of substrate utilization by indirect calorimetry during cyclic and continuous total parenteral nutrition

Five male adult home patients were studied in a randomized order under continuous (24 h/d) and nocturnal cyclic (15 h/d) isocaloric, isonitrogenous total parenteral nutrition (TPN). They received 2626 +/- 265 total kcal/d as 60% dextrose and 40% lipids; the 3-h lipid infusion was followed by the dextrose amino acid infusion on both regimens. Substrate oxidation was measured by indirect calorimetry during four periods on the fourth day of each regimen. During cyclic TPN net lipogenesis occurred with a nonproteic respiratory quotient (npRQ) greater than 1 during dextrose amino acid infusion followed by net lipolysis with an npRQ less than 1 during the nonnourishing phase. In contrast, during continuous TPN net lipogenesis persisted with an npRQ greater than 1 over the 21 h of dextrose amino acid infusion. During the 3-h lipid infusion, fat oxidation was observed during both regimens but was more pronounced during cyclic TPN (p less than 0.05). As a consequence, 24-h lipid oxidation was higher and 24-h dextrose utilization lower during cyclic vs continuous TPN (p less than 0.05). These results suggest that cyclic TPN when alternating between substrate storage and oxidation, mimics the physiological pattern of oral feeding.     

Larger diet-induced thermogenesis and less body fat accumulation in rats fed medium-chain triacylglycerols than in those fed long-chain triacylglycerols

It has been previously shown that a diet containing medium-chain triacylglycerols (MCT) leads to less body fat accumulation as compared to a diet containing long-chain triacylglycerols (LCT). We investigated the involvement of diet-induced thermogenesis in the accumulation of body fat in rats fed a diet containing MCT. Twelve male Wistar rats were administered 1 g of MCT or LCT by gavage, and their oxygen consumption was measured for 6 h (experiment 1). Forty male Wistar rats were fed a diet containing 10% MCT or LCT for 6 wk, and their body composition was determined (experiment 2). In experiment 1, oxygen consumption increased to a greater extent after MCT administration than after LCT administration. Diet-induced thermogenesis was significantly (0.67 +/- 0.14 kcal) larger after the administration of 1 g of MCT. In experiment 2, there were no differences in food intake or carcass protein content between the LCT group and MCT group. However, carcass fat and intra-abdominal fat content were significantly lower in rats fed MCT than in those fed LCT. We calculated that ingestion of 1 g of MCT decreased body fat by 0.94 +/- 0.27 kcal relative to the ingestion of LCT. These results suggest that the larger diet-induced thermogenesis observed in rats fed MCT, compared to that of those fed LCT, is one of the main factors involved in the suppression of body fat accumulation in rats fed MCT.     

含中链甘油三脂的脂肪乳剂有利于胃切除术后大鼠的脂类代谢和抗氧化能力

研究胃切除大鼠于术前接受以中链甘油三酯或长链甘油三酯为脂肪来源的肠外营养对肝内脂类，炎性介质和抗氧化能力的影响。大鼠经颈内静脉插管，分成两组接受肠外营养治疗。肠外营养的能量为30kcal/kg/d， 脂肪占能量的39％。除了脂肪乳剂外所有肠外营养制剂都是等氮的并含有相同的营养成分，脂肪乳剂的成分中链／长链（1：1）或长链脂肪乳剂。大鼠于接受肠外营养5天后经部分胃切除术，于术后24小时处死。研究结果显示，中逻／长链组肝内脂肪少于长链组。提示中链／长链脂肪乳剂能改善肝脏脂类代谢。两组大鼠的腹腔灌洗液（PLF）和血液中白介素－1β（Ⅱ-1β），白介素－6（Ⅱ－6）和肿瘤坏死因子α（TNF－α）无显差别，说明术前输入中链／长链脂肪乳剂对调节大鼠循环血液中的炎性介质和手术刺激没有影响。长链脂肪乳剂组的红细胞谷胱甘肽超氧化物酶（GSHPx)的活力明显高于输入中链／长链脂肪乳剂组，但红细胞超氧化物歧化酶（SOD）的活力在两组之间无显性差别。这些结果说明，腹部手术前输入中链／长链脂肪乳剂能改善脂类代谢和减少氧化物的刺激。结论：推荐对准备行胃手术的肠外营养支持的病人使用中链／长链脂肪乳剂。     

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.     

Comparison of effects of long-chain and medium-chain triglyceride emulsions during hepatic regeneration in rats.

We examined the effect of long-chain triglyceride (LCT) and medium-chain triglyceride (MCT) emulsions on hepatic regeneration. After approximately 70% hepatectomy, Sprague-Dawley rats were maintained for 96 hours on total parenteral nutrition (TPN) (250 kcal/kg per day; nonprotein calories-nitrogen 160:1) with LCT or MCT as 30% of nonprotein calories. There were no significant differences in the body weight, cumulative nitrogen balance, urinary 3-methylhistidine excretion, or changes in the energy stores between the two groups; but the fatty acid composition of the phospholipid fraction of the regenerating liver differed significantly between the LCT and the MCT groups. The extent of hepatic regeneration by weight was 88.7 +/- 10.5% in the MCT group and 99.1 +/- 10.6% in the LCT group by 96 hours after hepatectomy. Furthermore, the incorporation of 3H-orotic acid into DNA and RNA of regenerating liver cells in the LCT group was higher than in the MCT group 24 hours after hepatectomy. These observations indicate that essential fatty acids--components of the cell membrane and precursors as functional mediators--are very important to hepatic regeneration.     

Replacement of long-chain triglyceride with medium-chain triglyceride/long-chain triglyceride lipid emulsion in patients receiving long-term parenteral nutrition: effects on essential fatty acid status and plasma vitamin K1 levels

BACKGROUND: In long-term parenteral nutrition (LTPN) patients, the use of a 50:50 mixture of medium- and long-chain triglyceride emulsion (MCT/LCT) has been suggested to prevent or correct fatty liver infiltration. However, the use of MCT/LCT lipid emulsion results in a 50% reduction of essential fatty acids and vitamin K1 supply and could induce essential fatty acid and vitamin K1 deficiencies. This study evaluated the effect of a long-term infusion of MCT/LCT lipid emulsion on plasma fatty acid (FA) and vitamin K1 levels on LTPN patients. METHODS: In a prospective nonrandomized crossover study, we measured plasma phospholipid FA composition by gas chromatography and vitamin K1 levels by high-performance liquid chromatography in 11 LTPN patients before and after a 4-month replacement of the usual 20% LCT lipid emulsion (20% Lipoven; Fresenius-Kabi France, Sèvres, France) by a 20% MCT/LCT lipid emulsion (Medialipide B; Braun Medical, Boulogne, France). RESULTS: Patient received LTPN for 46 +/- 40 months; IV lipid emulsion was 827 +/- 336 mL/week. MCT/LCT lipid substitution did not change most of the essential plasma fatty acid concentrations and did not induce essential fatty acid deficiency. With both lipid emulsions, the triene/tetraene (20:3n-9/20:4n-6) ratio remained within the normal ranges. However, with MCT/LCT lipid emulsion, 22:4n-6 (LCT: 0.50 +/- 0.12; MCT/LCT: 0.63 +/- 0.11%) and 22:5n-6 (LCT: 0.32 +/- 0.11; MCT/LCT: 0.48 +/- 0.15%) increased significantly (p = .022 and 0.011, respectively). Plasma vitamin K1 levels decreased drastically with MCT/LCT lipid emulsion. CONCLUSIONS: An amount of 2.85 +/- 1.55 g x kg(-1) week(-1) of MCT/LCT lipid emulsion neither induced essential fatty acid deficiency nor improved the fatty acid disturbances usually observed in LTPN patients but did induce a drop in plasma vitamin K1 levels.     

Nutritional and hormonal effects of biosynthetic human growth hormone in surgical patients on total parenteral nutrition.

The anabolic effects of biosynthetic human growth hormone (BHGH) were tested on 30 patients, aged 37-68 yr, divided into four groups: group 1 received surgery plus total parenteral nutrition (TPN) plus BHGH, group 2 received just surgery and TPN, Group 3 received TPN and BHGH, and group 4 received just TPN. TPN was given as an all-in-one formula (glucose 4.7 g.kg.-1day-1, amino acids 1.2 g.kg-1.day-1, lipids 0.7 g.kg-1.day-1, electrolytes and trace elements. BHGH (0.25 IU.kg-1.day-1) or placebo were administered subcutaneously at 0800 for 10 days. Nitrogen and phosphorous balance, as well as the common plasma nutritional markers (transferrin, albumin, prealbumin), triglycerides, apolipoprotein B, insulin, and cortisol were evaluated daily. Urinary creatinine loss was evaluated on days 3, 7, and 10. Cumulative nitrogen balance was better in group 1 (-16.1 +/- 3.2 g N2) than in group 2 (-33.7 +/- 4.6 g N2) (P less than 0.01), whereas the difference was nonsignificant in groups 3 and 4. Phosphorous balance and creatinine excretion paralleled nitrogen balance. Plasma markers were not significantly improved in group 1 compared with group 2; however, they were significantly better in group 3 than in group 4. Lipids were better metabolized in the BHGH-treated groups. Insulin was increased in both groups 1 and 3, whereas cortisol did not rise after surgical stress, probably because of BHGH administration. A positive effect of BHGH on nutritional status and hormonal background is suggested by these data.     

Work ability, physical activity, and cardiorespiratory fitness: 2-year results from Project Active

An adequate level of physical activity may maintain or promote work ability in aging workers. Project Active is a randomized trial comparing a Lifestyle physical activity program with a Structured exercise program in sedentary but healthy adults aged 35 to 60 years. Subjects in both groups received 6 months of intensive intervention followed by 18 months of active follow-up. The total number of subjects was 235, from which 80 subjects participated in the work ability assessment. Primary outcome measures were energy expenditure (kcal.kg-1.day-1), cardiorespiratory fitness (peak oxygen uptake in ml.min-1.kg-1), and the Work Ability Index. At 6 months, daily energy expenditure had increased significantly over baseline (mean +/- SD, from 33.0 +/- 0.9 to 34.4 +/- 1.8 kcal.kg-1.day-1) and was maintained over baseline at 24 months (34.0 +/- 2.5 kcal.kg-1.day-1). The significant increase in energy expenditure was observed particularly in moderate levels of activity. The average percentage of body fat was significantly higher at baseline compared with 6 months and 24 months. Peak oxygen uptake increased from baseline significantly during the first 6 months (from 29.6 +/- 5.7 to 30.6 +/- 6.3 ml.min-1.kg-1) and decreased to the baseline level (29.1 +/- 5.5 ml.min-1.kg-1) at 24 months. At baseline, the average Work Ability Index was 44.2 +/- 4.0, and it remained unchanged at 6 months (44.4 +/- 3.9) and at 24 months (44.2 +/- 3.1). In conclusion, a 2-year physical activity intervention increased daily energy expenditure, reduced body fat, and maintained peak oxygen uptake in healthy, middle-aged, sedentary subjects. The average Work Ability Index score at baseline was excellent and did not change during the 2-year physical activity interventions.