bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipopolysaccharide and Tumor Necrosis Factor Stimulate Lung Microvascular Arginine Uptake, a Response Attenuated by Dexamethasone
Authors: Pan Ming , Wasa Masafumi , Ryan Una , Souba Wiley
Published: May 2008

Background: Lipopolysaccharide (LPS), tumor necrosis factor‐α, (TNF), and glucocorticoids can modulate endothelial nitric oxide (NO) production. L‐Arginine is the exclusive precursor for NO biosynthesis, suggesting that NO generation and arginine transport are intimately linked. Methods: To further study this relationship, we examined the effects of LPS, TNF, and dexamethasone (DEX) on arginine uptake by rat lung microvascular endothelial cells. The transport of radiolabeled arginine was assayed in confluent cells grown in 24‐well plates. Results: The bulk (>90%) of arginine transport was mediated by the Na+‐independent carriers System y+ and System b0,+. Arginine transport was stimulated independently by LPS and TNF, a response first observed at 10 hours. Together, both agents exerted an additive effect on carrier‐mediated uptake. The LPS‐ and TNFinduced increase in arginine transport activity was blocked by cycloheximide and actinomycin D, indicating the requirement for RNA and protein synthesis. The enhancement in transport activity was primarily due to an increase in Systems y+ maximal transport capacity (V max) with no change in transporter affinity and little change in System b0,+ activity. Treatment of cells with dexamethasone inhibited arginine transport activity in a time‐and dose‐dependent manner, an event that was abrogated by both actinomycin D and cycloheximide. The combination of DEX and LPS and TNF abrogated each other's antagonistic effects. Conclusions: These data indicate that LPS and TNF additively stimulate arginine transport in lung microvascular endothelial cells via a pathway that requires de novo protein synthesis (possibly of the transporter protein itself) and that this response is attenuated by DEX. (Journal of Parenteral and Enteral Nutrition 20:50–55, 1996)
Early Enteral Feeding in the Pediatric Intensive Care Unit
Authors: Chellis Mary Jo , Sanders Suzanne V. , Webster Holly , Dean J. Michael , Jackson Daniel
Published: May 2008

Background: The purpose of this study was to evaluate the feasibility and safety of early enteral feedings of critically ill pediatric patients. Methods: The subject population of 42 critically ill patients ranged in age from 5 days to 18 years (mean 5.8 years), mean weight 17 kg. Transpyloric nasoenteric tubes were placed in all patients by a nonfluoroscopic bedside technique. All subjects were mechanically ventilated; 32 (76%) were on one or more vasoactive medications. Six (15%) patients were fed for more than 13 days while on vasoactive support and pharmacological paralysis. Results: There were no documented complications of early enteral feeding, including aspiration. All patients were able to achieve caloric goals within 48 hours of beginning enteral feedings. All patients developed regular stool patterns despite periodic absence of bowel sounds. Enteral feedings replaced 256 days of total parenteral nutrition. Estimated patient charge savings averaged $425 for each day of enteral feedings. Conclusions: Early enteral feedings are feasible, well tolerated, and cost effective in critically ill pediatric patients. (Journal of Parenteral and Enteral Nutrition 20:71–73, 1996)
Bedside Transpyloric Tube Placement in the Pediatric Intensive Care Unit
Authors: Chellis Mary Jo , Sanders Suzanne V. , Dean J. Michael , Jackson Daniel
Published: May 2008

Background: The purpose of this study was to demonstrate the feasibility of placing transpyloric feeding tubes at the bedside without fluoroscopy in critically ill pediatric patients. Methods: The patient population consisted of 90 patients (ages 1 week to 15 years, median age 9 months) admitted to a 26‐bed pediatric intensive care unit in a university‐affiliated pediatric hospital. Patient weights ranged from 2.4 to 100 kg with a median weight of 7.5 kg. Seventy‐six patients were endotracheally intubated and mechanically ventilated; one patient had a tracheotomy. A total of 24 patients were pharmacologically paralyzed; 38 patients were receiving catecholamine infusions, and 17 patients had intracranial monitoring devices in place. All had concurrent nasogastric suctioning. Nonweighted Silicone Rubber 6F or 8F nasoenteric tubes were inserted at the bedside using metoclopramide, air insufflation, and positioning to achieve transpyloric passage. Blue‐dyed water was instilled in 58 patients to test for reflux and confirm transpyloric position. Results: Successful nonfluoroscopic bedside transpyloric (duodenal or jejunal) tube placement was verified radiographically in 84 (93%) patients; seven of these patients were less than 4 weeks of age. One patient had blue dye in the nasogastric fluids, consistent with duodenogastric reflux or failure of transpyloric passage. The abdominal radiographs confirmed the results of the blue dye test in all 58 patients. There were six (6.7%) unsuccessful attempts at transpyloric bedside tube placement: four were a result of hemodynamic instability, one was a result of oropharyngeal trauma, and one was due to intestinal malrotation. The average time for placement was 15 minutes with a range of 5 to 45 minutes. No complications from tube placement were observed. Conclusions: Bedside placement of transpyloric feeding tubes is a safe and effective method to institute enteral feedings in critically ill pediatric patients. (Journal of Parenteral and Enteral Nutrition 20:88–90, 1996)
Bone Loss and Oral State in Patients on Home Parenteral Nutrition
Authors: Von Wowern Nina , Klausen Bjarne , Hylander Ellinor
Published: May 2008

Background: The purpose was to analyze changes in the mandible and the forearm bone mineral content and oral state in patients on home parenteral nutrition due to short bowel syndrome in relation to the bone mineral values and oral findings in a normal population. Methods: The bone mineral content was measured by dual‐photon absorptiometry and the dental and periodontal state were studied in 15 adults patients (12 women, and 3 men, aged 26 to 65 years). All patients were on free oral intake as a supplement to the parenteral nutrition. Results: Forty‐seven percent of the patients (2 males, 2 young and 3 elderly females) showed mandibular osteoporosis (Z‐scores < ‐2.00), and all young females showed Z‐scores < 0. Moreover, 34% of the patients showed osteoporosis in the forearm bones (Z‐scores < ‐2.00) and also radiographic signs of osteoporotic fractures of the columna. The dental and the periodontal state in the patients did not differ clearly from that of the normal Danish population of the same age. Conclusions: Such patients seem to have a high risk of developing systemic osteoporosis, including the jaws, but apparently do not show a higher risk for deterioration of the dental or periodontal state than age‐matching normals from the same population. (journal of Parenteral and Enteral Nutrition 20:105–109, 1996)
Gluconeogenesis in the Livers of Diet‐Restricted Rats‐A 13C Nuclear Magnetic Resonance Study
Authors: Liu Katherine J.M. , Jarad Jehad , Donahue Philip E.
Published: May 2008

Background: Gluconeogenic activity is reduced during starvation. However, it is less clear whether the utilization of gluconeogenic substrates is diminished with mild but prolonged diet restriction and, if so, whether there are intrinsic changes in the gluconeogenic pathway. We examined gluconeogenesis in the livers of diet‐restricted rats with 13C nuclear magnetic resonance (NMR) spectroscopy. Methods: Fischer 344 rats were given 88% (DR group) of what was consumed by the weight‐matched ad libitum‐ fed normal rats (CL group). At the end of 5 weeks, the removed livers were perfused with [3‐13C]alanine while 13C NMR spectroscopy was performed. Results: The fmal body and liver weights were the same for the two groups. In DR rats, both intrahepatic [3‐13C]alanine and metabolites generated via pyruvate and oxaloacetate, including aspartate and carbamoyl aspartate, appeared in significantly reduced amounts. There was also marked diminution in the production of glucose. Conclusions: In the livers of DR rats, alanine uptake through System A transport, the fluxes through pyruvate carboxylase, the biosynthesis of pyrimidine nucleotides, and the production of glucose from alanine were all significantly decreased with mild intake restriction. Attenuated protein synthesis in the liver of diet‐restricted animals may be the cause for this decreased utilization of alanine for gluconeogenesis. (Journal of Parenteral and Enteral Nutrition 20:178–181, 1996)
Metabolic Complications of Total Parenteral Nutrition: Effects of a Nutrition Support Service
Authors: Chrisanderson Donna , Heimburger Douglas C. , Morgan Sarah L. , Geels Wilma J. , Henry Kathy L. , Conner Wendy , Hensrud Donald D. , Thompson Glen , Weinsier Roland L.
Published: May 2008

Background: The effectiveness of Nutrition Support Services in optimizing parenteral nutrition has not been evaluated since the 1980s. Methods: We prospectively monitored medical and surgical patients on total parenteral nutrition (TPN) in a university hospital who did not receive Nutrition Support Service recommendations to compare the incidence of metabolic complications in 1979 (group 1, n = 100) with that in 1992 (group 2, n = 106). The Service provided automatic recommendations on a subsequent group of medical service patients (group 3, n = 128) and compared them with the patients in group 2 who were on the medical service (group 2B, n = 29). Results: Statistically significant changes between 1979 and 1992 included a decline in the incidence of hyperglycemia from 47% to 22% and in hypokalemia from 12% to 3% of surgical patients and an increase in hypomagnesemia from 0% to 23% of surgical patients and from 2% to 14% of medical patients. The incidence of hypophosphatemia remained >20% in both medical and surgical patients. Within 1992, the addition of automatic recommendations had little impact on metabolic abnormalities and was associated with slightly but insignificantly lower TPN costs (not counting Service personnel costs). Conclusions: Factors such as the general integration of parenteral nutrition into tertiary medical care, standard protocols and order forms, automatic Nutrition Support Service consultations in an affiliated hospital, and nutrition curricula may be responsible for the improvements seen since 1979. However, the addition of automatic Service consultation in 1992 had only a marginal effect on metabolic complications and costs of parenteral nutrition. (Journal of Parenteral and Enteral Nutrition 20:206–210, 1996)
Effects of Succinic Acid Dimethyl Ester Infusion on Metabolic, Hormonal, and Enzymatic Variables in Starved Rats
Authors: Ladriere Laurence , Zhang Tie‐Mei , Malaisse Willy J.
Published: May 2008

Background: Succinic acid dimethyl ester (SAD) is efficiently metabolized in several cell types as pancreatic islet cells, hepatocytes, and colonocytes. The purpose of this study was to assess the overall nutritional value of SAD in the whole organism. Methods: SAD was infused at a rate of 80 μmol/g body weight per day in rats starved for either 2 or 4 days. For comparison, similar experiments were conducted in starved rats receiving an equimolar infusion ofD‐glucose. Results: The ester failed to prevent the starvation‐induced fall in body weight, paraovarian fat mass, and liver or muscle protein content. The infusion of SAD minimized, however, the decrease in plasma glucose and insulin concentrations, liver glycogen content, hepatic glucokinase activity, and islet secretory responsiveness to glucose, otherwise caused by starvation. Likewise, the infusion of SAD delayed the rise in free fatty acid and β‐hydroxybutyrate plasma concentration occurring during starvation. Nevertheless, SAD was less efficient than glucose, infused in an equimolar amount, in preventing the starvation‐induced fall in liver glycogen content, decrease in the pancreatic B‐cell secretory responsiveness to glucose, and stimulation of lipolysis and ketogenesis. Conclusions: SAD displays a significant nutritional value when infused in starved rats. It could thus be used as a tool to prevent the imbalance between ATP generation and use in selected metabolic situations. (Journal of Parenteral and Enteral Nutrition 20:251–256, 1996)
Cerebrospinal and Plasma Amino Acid Concentrations After Administration of IV Glycyl‐Glutamine and Glycyl‐Tyrosine Containing Amino Acid Solutions in Humans
Authors: Himmelseher Sabine , Pfenninger Ernst , Herrmann Petra
Published: May 2008

Background: Glycyl‐glutamine and glycyl‐tyrosine may supply adequate glutamine and tyrosine in amino acid solutions for parenteral nutrition. However, plasma peptides may be transported into the cerebrospinal fluid, exerting effects on the neuronal tissue. Cerebrospinal fluid (CSF) and plasma amino acid concentrations after administration of a glycyl‐glutamine/glycyltyrosine supplemented amino acid solution were therefore evaluated in a randomized controlled comparison with a conventional amino acid infusion. Methods: Dipeptide/amino acid solutions (0.60 mL/h/kg; 82.2 mg total dipeptides/amino acids/h/kg) or conventional amino acid solutions (0.73 mL/h/kg; 83.2 mg total amino acids/h/kg) were infused in 15 patients per group scheduled to undergo spinal anesthesia for urologic surgery over a 12‐hour period preoperatively. Plasma amino acids were measured before the infusion was started. CSF and venous concentrations were analyzed simultaneously before the infusion was stopped. CSF samples were drawn through the spinal needle for anesthesia. Results: The dipeptide‐containing solution did not increase either dipeptide to detectable levels in the CSF (detection limit < 5.0 nmol/mL). Venous glycyl‐glutamine increased from below detection limits up to 308 ± 111 nmol/mL (p <.05), whereas glycyl‐tyrosine could not be found. In the dipeptide group, venous glutamine and tyrosine were higher (p <.05) but only tyrosine appeared in small amounts (p <.05) in the cerebrospinal fluid. Conclusions: This study provides no evidence to support a CSF entry of IV glycyl‐tyrosine and glycyl‐glutamine under conditions of a normal blood‐brain barrier in the adult (detection limit 5 nmol/mL). The data suggest that amino acid solutions containing these dipeptides may be used in parenteral solutions for nutrition support. (Journal of Parenteral and Enteral Nutrition 20 :281–286, 1996)
Glutamine Content of Protein and Peptide‐Based Enteral Products
Authors: Kuhn Katharina S. , Stehle P. , Fürst P.
Published: May 2008

Background: Glutamine is a conditionally essential amino acid for patients with severe catabolic illness, intestinal dysfunction, or immunodeficiency syndromes. Glutamine is a natural component in many enteral preparations, yet lacking methodology hampers its quantitative determination in dietary products. Objective: The present study was assigned to assess glutamine contents in selected enteral products by using a newly developed method enabling the assessment of protein/peptide bound glutamine. Methods: Fourteen commercially available enteral diets (10 protein based and 4 peptide based) were investigated. After removal of interfering fat and carbohydrates, the nitrogen content of the purified preparations was determined by chemiluminescence and protein/peptide bound glutamine was assessed using a three‐step procedure; by using a novel prehydrolysis derivatization technique with bis(1,1‐trifluoroacetoxy)iodobenzene, glutamine is converted to acid stable diaminobutyric acid. The derivatives are hydrolyzed with a new microwave technology, and subsequently the amino acid composition is determined by reversed phase‐high‐performance liquid chromatography after dansyl‐chloride derivatization. Results: The content in the protein‐based preparations varied between 5.2 and 8.1 g/16 g nitrogen. In the peptide‐based products, considerably lower glutamine contents were measured (1.3 to 5.6 g/16 g nitrogen). Conclusion: In the present study, we report for the first time glutamine contents in ready to use enteral products. The daily amount might be satisfactory for healthy individuals but probably not sufficient for the adequate support of the stressed patient. Reliable assessment of glutamine in enteral formulae is a prerequisite to perform clinical studies investigating glutamine requirements in the catabolic state. (Journal of Parenteral and Enteral Nutrition 20:292–295, 1996)
Short‐Chain Fatty Acids Increase Proglucagon and Ornithine Decarboxylase Messenger RNAs After Intestinal Resection in Rats
Authors: Tappenden Kelly A. , Thomson Alan B.R. , Wild Gary E. , McBurney Michael I.
Published: May 2008

Background: Intestinal adaptation is a complex physiological process that is not completely understood. Systemic administration of short‐chain fatty acids (SCFAs) has been shown to facilitate adaptation to small bowel resection; however the mechanisms underlying this phenomena are unknown. Methods: Forty‐six male Sprague‐Dawley rats underwent an 80% jejunoileal resection and jugular catheterization. After surgery, rats were randomly assigned to receive standard total parenteral nutrition (TPN) or an isoenergetic, isonitrogenous TPN supplemented with SCFAs. On day 3 or 7 after surgery, ileal samples were removed for determination of mucosal wet weight, DNA, RNA, and protein concentrations. Total cellular RNA was extracted for use in Northern blot analysis to quantify proglucagon and ornithine decarboxylase messenger RNAs (mRNAs). Results: Total, mucosal, and submucosal weights were increased (p <.05) in the SCFA group both 3 and 7 days after surgery. Ileal DNA and RNA concentrations were increased (p <.05) in the SCFA group at both time points; however ileal protein concentration did not differ between groups until 7 days after resection. Levels of proglucagon and ornithine decarboxylase messenger RNAs were higher (p <.05) in the SCFA group at both time points. Conclusion: The upregulation of proglucagon and ornithine decarboxylase gene expression may be the mechanism by which SCFAs facilitate intestinal adaptation. (Journal of Parenteral and Enteral Nutrition 20:357–362, 1996)
Esophageal Bezoar Resulting From Enteral Feedings
Authors: Cremer Steven A. , Gelfand David W.
Published: May 2008

Esophageal bezoars are rare but are known to occur in patients with structural or functional abnormalities of the esophagus. Additionally, sucralfate and casein containing enteral feeding formulas have been implicated in the formation of esophageal bezoars, particularly in the setting of decreased esophageal pH. We present a case in which a patient with functional impairment of the esophagus related to myasthenia gravis developed an esophageal bezoar. Gastroesophageal reflux, altered esophageal pH, and direct instillation of feeding formula through a rent in the feeding tube were additional factors likely leading to bezoar formation in this patient. Endoscopic examination revealed puttylike material consistent with coagulated enteral feeding formula. An esophagram demonstrated a large bezoar filling the middle and distal thirds of the esophagus. The conditions predisposing to bezoar formation and the proposed mechanisms are discussed. We also summarize the reported cases of esophageal bezoars related to enteral feeding formula, sucralfate, or both. (Journal of Parenteral and Enteral Nutrition 20:371–373, 1996)
Plasma Amino Acid Concentrations in Term‐Born Infants Fed a Whey Predominant or a Whey Hydrolysate Formula
Authors: Hauser B. , Blecker U. , Keymolen K. , Suys B. , Gerlo E. , Vandenplas Y.
Published: May 2008

Background: Hydrolysates are used in the treatment and prevention of cow's milk protein allergy. Hydrolysis might alter the plasma level of amino acids. Methods: Forty‐five infants were included in a double‐blind prospective study and were randomized in two groups: one receiving a whey predominant formula (n = 20) and the second group receiving a whey hydrolysate formula (n = 25). Weight and length gain was evaluated up to the age of 13 weeks, when blood was sampled for determination of fasting plasma amino acids. Results: Four infants of the hydrolysate group dropped out because refusal to ingest the formula. Weight and length gain at 13 weeks of age were extremely comparable. Significant differences in plasma concentrations were observed for a number of nonessential and essential amino acids (p =.035 to.0001). Threonine and lysine were both higher in the hydrolysate group, and aspartic acid, cystine, methionine, tyrosine, phenylalanine, histidine, and arginine were lower in the hydrolysate group. Conclusions: These differences in plasma amino acid levels have to be regarded with care because all concentrations were within normal ranges, with the exception of threonine. Weight and length gain of the hydrolysate and the whey predominant formula were identical. (Journal of Parenteral and Enteral Nutrition 21: 027–030, 1997)
Effects of Nucleosides and a Nucleotide Mixture on Gut Mucosal Barrier Function on Parenteral Nutrition in Rats
Authors: Kishibuchi Masanori , Tsujinaka Toshimasa , Yano Masahiko , Morimoto Takashi , Jima Shohei , Ogawa Atsuhiro , Shiozaki Hitoshi , Monden Morito
Published: May 2008

Background: We have previously reported that the addition of nucleosides and a nucleotide mixture (OG‐VI) to total parenteral nutrition (TPN) prevents TPN‐induced intestinal mucosal atrophy and results in increased intestinal cathepsin activities under TPN. The aims of the present study are to examine the effects of OG‐VI on mucosal barrier functions and to clarify whether the intestinal cathepsins can be used as a new marker of mucosal barrier function. Method: Male Wistar rats were divided into three groups: FED (food ad libitum), TPN (a standard TPN solution), and OG (OG‐VI in addition to the TPN solution). Mucosal barrier functions were analyzed by the lactulose/mannitol (L/M) test, mucosal ZO‐1 messenger RNA level, and electron micrographs in the gut. Intestinal cathepsin B, H, and L activities were also measured. Results: The L/M ratio for TPN was much higher than that for FED. Only lactulose excretion was significantly reduced by OG‐VI. The intercellular spaces of the mucosal cells for TPN were significantly wider than those for FED, but were reduced in size by the addition of OG‐VI. All cathepsin activities of the ileum were higher for TPN than for FED, whereas OG showed no increase. Conclusion: OG‐VI contributes to the improvement of gut mucosal barrier function. Intestinal cathepsin activities can be used as a new marker of mucosal barrier function. (Journal of Parenteral and Enteral Nutrition 21:104–111, 1997)
Insulin‐Like Growth Factor 1 Inhibits Degradation and Improves Retention of Protein in Hindlimb Muscle of Lambs
Authors: Svanberg Elisabeth
Published: May 2008

In this study in sheep with differing nutritional status, the authors present a model to investigate local as well as systemic effects of recombinant IGF‐1 on hind limb muscle metabolism. Recombinant human IGF‐1 (12.3;jbg‐kg‐h) was infused for 4 hours directly into the left femoral artery. The rates of protein synthesis, degradation, and gain of protein in the treated (infused) and contralateral limbs of well‐fed, feeding‐restricted, and starved sheep were calculated by the kinetics of L‐12,6‐_Hlphenylalanine infused into the jugular vein (8.5 kBq‐min for 8 hours). Reducing feed intake decreased net protein gain of hind limb muscles, reduced hind limb glucose uptake, and lowered arterial concentration of IGF‐1, insulin, glucose, phenylalanine, tyrosine, and isoleucine. The effect of nutrition on IGF binding proteins (IGFBP) was generally small; IGFBP‐2 was more abundant in fasted animals. Infusion of IGF‐1 into the left femoral artery increased plasma IGF‐1 levels 2‐ to 4‐fold in the left femoral vein, and by 1.5‐ to 3‐fold in the artery and right femoral vein. In the IGF‐1 infused left limb, IGF‐1 reduced protein degradation, increased protein gain, and increased glucose uptake, without alterations in blood flow or oxygen uptake, regardless of feed intake. Systemically, IGF‐1 reduced plasma concentrations of insulin, phenylalanine, tyrosine, isoleucine, and leucine in all nutrition groups. Plasma IGFBP‐3 levels were increased by 4 hours of IGF‐1 treatment in fasted but not in fed lambs. In fed but not fasted lambs, IGF‐I increased blood glucose concentration. Effects of IGF‐1 on protein metabolism in the right hind limb were affected by nutrition to a greater extent in fasted than in fed lambs.
Clinical Characteristics of Preoperative Hypoalbuminemia Predict Outcome of Cardiovascular Surgery
Authors: Rady Mohamed Y. , Ryan Thomas , Starr Norman J.
Published: May 2008

Objective: To define the clinical characteristics and outcome of preoperative hypoalbuminemia in adult cardiovascular surgery. Study: Inception cohort. Setting: Adult cardiovascular intensive care unit (CVICU). Patients: Admissions to CVICU between January 1 and December 31, 1993. Intervention: Preoperative hypoalbuminemia (serum albumin ≤3.5 g/dL) was classified by the presence of malnutrition cachexia (body mass index of ≤20 kg/m2), liver insufficiency (serum bilirubin ≥2.0 mg/dL), history of congestive heart failure, or hypoalbuminemia alone. Demographics, chronic diseases, systemic hemodynamics, and laboratory data were obtained at preoperative and later on admission and during the stay in the CVICU. Outcome measures: Postoperative organ dysfunction, nosocomial infections, length of mechanical ventilation, hospitalization and death. Results: A total of 2,743 patients (91%) of 3,025 patients who were admitted to the CVICU were enrolled in the study. Preoperative hypoalbuminemia was found in 325 patients (12%): hypoalbuminemia and cachexia in 21 patients (6%), hypoalbuminemia and liver insufficiency in 26 patients (8%), hypoalbuminemia and history of congestive heart failure in 102 patients (31%), and hypoalbuminemia alone in 176 patients (54%). Clinical features of preoperative hypoalbuminemia were age ≥75 years, female gender, left ventricular ejection fraction ≤35%, hematocrit ≤34%, serum creatinine ≥1.9 mg/dL, systemic oxygen delivery ≤350 mL/min · m2, acute stressful conditions (eg, infective endocarditis, acute myocardial infarction, or emergency surgery) and chronic obstructive pulmonary airway disease. Redo operations, combined valve and coronary artery bypass graft, mitral valve replacement, and thoracic aortic surgery were the commonest types of surgery performed in these patients. All types of hypoalbuminemia except for malnutrition cachexia increased the likelihood of postoperative organ dysfunction (cardiac, pulmonary, renal, hepatic, and neurologic), gastrointestinal bleeding, nosocomial infections, length of mechanical ventilation, stay in the CVICU, and hospital death. Cachectic hypoalbuminemia increased the requirement for postoperative parenteral nutrition and prolonged the length of stay in hospital. Conclusion: Preoperative hypoalbuminemia was attributed to malnutrition cachexia, liver insufficiency or congestive heart failure in <50% of cardiac patients undergoing cardiovascular surgery. All types of hypoalbuminemia except for malnutrition cachexia increased the likelihood of postoperative organ dysfunction, nosocomial infections, prolonged mechanical ventilation, and death. The morbidity and mortality attributed to hypoalbuminemia could be explained by the underlying clinical characteristics rather than malnutrition cachexia in cardiac patients. (journal of Parenteral and Enteral Nutrition 21:81–90, 1997)
Epidermal Growth Factor Up‐Regulates Sodium‐Glucose Cotransport in Enterocyte Models in the Presence of Cholera Toxin
Authors: Mehta Devendra I. , Horváth Karoly , Chanasongcram Somchoke , Hill Ivor D. , Panigrahi Pinaki
Published: May 2008

Background: Sodium‐glucose cotransport by enterocytes is key to the successful implementation of oral rehydration in diarrhea. Confluent, differentiated Caco‐2 cells have enterocyte‐like characteristics. We have previously shown that short‐term incubation of isolated rat jejunal enterocytes with epidermal growth factor (EGF) results in the up‐regulation of sodium‐glucose cotransport. The aim of this study was to examine the effect of EGF on Caco‐2 cells in the presence of cholera toxin. Methods: Caco‐2 cells grown on tissue culture dishes were used for glucose and sodium uptake studies and cells were grown on polycarbonate membranes for transport examinations. Effects of EGF on the kinetic parameters of sodium‐glucose cotransporter, thymidine transport, and on the activity of Na+/K+‐ATPase were examined. The efficacy of basolateral vs apical EGF on sodium and glucose transport was compared after incubation of the monolayers with 10 nmol/L of cholera toxin. Results: EGF increased both glucose and sodium uptake and transport, and we observed a simultaneous increase in the activity of Na+/K+ ‐adenosine triphosphatase (ATPase). Kinetic studies performed on brush‐border membrane vesicles prepared from EGF‐incubated confluent monolayers and on intact cells showed an increase in the maximum velocity but not the Michaelis constant, suggesting increased availability of transporters rather than conformational change. This effect was seen within minutes in both of the two putative transporters, high‐affinity, low‐capacity and low‐affinity, high‐capacity. There was no acute effect on thymidine uptake. Studies in the presence of cholera toxin demonstrated a significant up‐regulation in sodium‐glucose cotransport when EGF was applied from the basolateral side; the increase was smaller but significant with apical application. Conclusions: Differentiated Caco‐2 cells have two kinetically distinct sodium‐glucose cotransporters. Short‐term incubation of Caco‐2 cells with EGF resulted in an up‐regulation of sodium‐glucose cotransport and subsequent increase in Na+/K+‐ATPase activity. The effect of basolaterally applied EGF was more significant with or without incubation with cholera toxin. The early effect of EGF on glucose and sodium cotransport may have important therapeutic implications in diarrhea and dehydration states. The in vitro model described here uses a homogeneous cell population and provides a versatile system for uptake and transport studies.(Journal of Parenteral and Enteral Nutrition 21:185–191, 1997)
Arginine‐Enhanced Enteral Nutrition Augments the Growth of a Nitric Oxide‐Producing Tumor
Authors: Edwards P.D. , Topping D. , Kontaridis M.I. , Moldawer L.L. , Copeland E.M. , Lind D.S.
Published: May 2008

Background: Arginine‐enhanced diets have been shown to be beneficial in tumor‐bearing hosts, but no data exist regarding their effects in hosts bearing nitric oxide (NO)‐producing tumors. Objective: To examine the effect of arginine supplementation on the growth of a NO‐producing murine breast cancer cell line. Methods: EMT‐6 cells were grown in various concentrations of arginine in the presence or absence of the inducible nitric oxide synthase (iNOS) inhibitor, aminoguanidine (1 mmol/L). Forty‐eight hours later, nitrite accumulation and viable cell number were assessed. BALB/c mice were then pair‐fed basal purified diets (n = 10), 4% casein diets (isonitrogenous control, n = 5), or 4% arginine‐enhanced diets (n = 10). One week later, 105 EMT‐6 cells were implanted subcutaneously into the dorsal flank. After tumor implantation, five mice fed basal purified diets and five mice fed arginine‐enhanced diets also received aminoguanidine (100 mg/kg subcutaneously twice daily). Two weeks after tumor cell implantation, tumor size (mean diameter), animal weight, serum and tumor nitrite and nitrate levels were measured. Results: There was minimal nitrite accumulation in arginine‐free media, while increasing the arginine concentration increased nitrite levels. Viable cell number did not increase in arginine‐free media, but increased nearly twofold in 100 and 1000 μmol/L arginine. In 5000 and 10,000 μmol/L arginine, the difference in viable cell number was not statistically different than that seen in arginine‐free media, whereas the addition of aminoguanidine blocked nitrite accumulation and increased viable cell number at these arginine concentrations. Arginine‐enhanced diets stimulated tumor growth in vivo more than twofold over tumor growth in mice fed isonitrogenous control or basal purified enteral diets. Mice fed arginine‐enhanced diets also had increased serum nitrite and nitrate levels over mice fed basal purified enteral diets, whereas tumors from mice fed arginine‐enhanced diets had nitrite and nitrate levels similar to mice fed basal purified enteral diets. Aminoguanidine blocked the increase in serum nitrite and nitrate, but failed to block the increased tumor growth in mice receiving the arginine‐supplemented diets. Conclusions: Arginine concentration influences the growth of EMT‐6 tumor cells in vitro and dietary arginine supplementation augments tumor growth in vivo. The mechanism of the growth modulation in vitro is NO‐dependent whereas the enhanced tumor growth in vivo is NO‐independent. (Journal of Parenteral and Enteral Nutrition 21:215–219, 1997)
Determination of the Route of Medium‐Chain and Long‐Chain Fatty Acid Absorption by Direct Measurement in the Rat
Authors: Sigalet David L. , Winkelaar Gerrit B. , Smith Leslie J.
Published: May 2008

Background: Medium‐chain triglycerides are used for the treatment of malabsorptive states. We measured directly the absorption of medium‐ and long‐chain fatty acids via the mesenteric lymphatics and portal vein in normal animals. These results may be useful in guiding therapy for short‐bowel syndrome. Methods: Under anesthesia, male Lewis rats (n = 6) underwent placement of jugular and portal venous lines, mesenteric lymphatic duct cannula, and a duodenal tube. After recovery, a 0.3% lauric acid (C12:0) and 0.37% palmitic acid (C16:0) solution solublized with 3.25 mmol/L lecithin and 23.75 mmol/L taurocholic acid in phosphate‐buffered saline was infused at a rate of 3 mL/h via the duodenal tube. After stabilization of lymphatic flow (6 hours), a pulse of radiolabeled lauric and palmitic acid was given via the duodenal tube; absorption was measured by collection of lymphatic fluid and sampling of the portal and jugular venous blood for 4 hours. Results: The amount of acid recovered in the lymphatics was 51% ± 6% (mean ± SD) for lauric and 59% ± 6% for palmitic. For both fatty acids, < 1% in total was recovered from the portal vein during the 4‐hour postbolus period; thereafter, levels in the blood were constant and very low. At necropsy, the majority of the remaining label was found in the intestine. Conclusions: These results show no evidence for the preferential absorption of medium‐chain fatty acids directly via the portal vein in this model. We suggest that further studies be done to measure directly portal vein absorption of the medium‐chain fatty acids. (Journal of Parenteral and Enteral Nutrition 21:275–278, 1997)
In Vitro Fermentation of High‐Amylose Cornstarch by a Mixed Population of Colonic Bacteria
Authors: Christl Stefan U. , Katzenmaier Uta , Hylla Silke , Kasper Heinrich , Scheppach Wolfgang
Published: May 2008

Background: Malabsorbed starch is probably the most important substrate for bacterial fermentation in the human large intestine. Fermentability of starch may depend on the composition of the colonic flora and its adaptation to the substrate supply. Methods: Ten healthy volunteers were fed a controlled diet containing either 7.0 to 8.3 or 50.7 to 59.7 g/d of resistant starch (Hylon VII) for 4 weeks. At the end of each diet period, fecal starch concentrations were measured. Fecal samples were incubated in 48‐hour batch cultures containing 10 g/L Hylon VII or digestible Lintner's starch. Bacterial breakdown of starch and short‐chain fatty acid concentrations were measured at 0, 3, 6, 12, 24, and 48 hours. Results: Fecal starch concentrations were higher during the Hylon VII period (35.7 ± 16 vs 8.9 ± 3.3 mg/g). Starch was fermented rapidly and completely in vitro in all but two subjects. Fermentability of resistant starch was comparable to that of digestible starch. No differences were found between the dietary periods. Fermentation of resistant starch produced higher rates of n‐butyrate. Two subjects had substantially higher fecal starch concentrations. In vitro starch breakdown in these subjects was slow and incomplete. Conclusions: Fermentation of resistant starch by the colonic microflora was rapid and complete in 8 of 10 subjects. No adaptation of the fermentation capacity was observed after 4 weeks of dietary resistant starch supplementation. Fermentation of resistant starch increased the proportion of n‐butyrate in vitro. In two subjects, fecal starch concentrations were substantially higher than in the other subjects and in vitro starch fermentation was slow and incomplete. (journal of Parenteral and Enteral Nutrition 21:290–295, 1997)
Glutamine and Intestinal Immune Cells in Humans
Authors: Van Der Hulst R.R.W.J. , Von Meyenfeldt M.F. , Tiebosch A. , Blturman W.A. , Soeters P.B.
Published: May 2008

Background: Total parenteral nutrition (TPN) is associated with depletion of intestinal immune cells and increased gut permeability (GP). Adding glutamine (GLN) to TPN preserves GP by an unknown mechanism. Intestinal immune cells situated between the enterocytes (intraepithelial lymphocytes, [IEL]) influence GP in vitro. To obtain insight into the underlying mechanism of GLN on GP, we investigated the effects of GLN‐supplemented TPN on IEL, immunoglobulin A (IgA) plasma cells and goblet cells, and enterocyte proliferation in intestinal biopsies. Methods: Twenty patients randomly received GLN‐enriched TPN (GT) or isonitrogenous standard TPN (ST). Proliferation and number of immune cells were measured in intestinal biopsies obtained before and after 10 days of TPN. Results: No change in proliferative activity or in number of IgA plasma cells was observed. Goblet cells increased in the ST group, whereas the change seen in the GT group did not reach significance. In the GT group, IEL decreased, whereas in the ST group, no change in the number of IEL was observed. Conclusions: TPN was not associated with changes in proliferative activity or with depletion of gut immune cells. The data indicate that GLN‐supplemented TPN has a different effect on intestinal immune cells compared with standard TPN. (Journal of Parenteral and Enteral Nutrition 21:310–315, 1997)
Opiate and Sedative Dependence Predicts a Poor Outcome for Patients Receiving Home Parenteral Nutrition
Authors: Richards David M. , Scott Nigel A. , Shaffer Jon L. , Irving Miles
Published: May 2008

Background: Home parenteral nutrition (HPN) is used to treat intestinal failure. A minority of HPN patients are dependent on opiates and benzodiazepines to control pain and anxiety. The aim of this study was to determine what effects such drug dependence had on patient outcomes. Methods: Ten dependent patients were prospectively compared with 10 well‐matched, nondependent HPN patients for the same 12‐month period. Episodes of line sepsis and other complications were documented and the cost of treatment estimated. Health status was measured using the SF36 and EuroQol instruments. Results: The dependent group had significantly more episodes of central line sepsis (p =.0007) as well as other complications (p =.0002). This led to significantly longer periods of inpatient care (p =0004) and therefore higher costs of treatment. Health status was lower in the dependent group; they reported more pain (p =.04) and less energy (p =.04). Conclusions: The complication rate and increased cost of treatment for opiate‐ and sedative‐dependent patients receiving HPN significantly detract from the overall outcome of this therapy. (Journal of Parenteral and Enteral Nutrition 21:336–338, 1997)
Prophylactic Locking of Enteral Feeding Tubes With Pancreatic Enzymes
Authors: Sriram Krishnan , Jayanthi V. , Lakshmi R. Geetha , George Veronica Subashini
Published: May 2008

Background: Obstruction of feeding tubes is a common mechanical complication associated with enteral feeding. Standard methods of flushing are not always effective. Methods: This study was conducted with patients receiving enteral feeding via nasogastric, nasoenteral, gastrostomy, or jejunostomy tubes to determine if prophylactic use of pancreatic enzymes would maintain patency of feeding tubes. Interrupted feeding regimens were used. Control patients (n = 24) received only water for flushing. After water flushing of the tube, study patients (n = 33) received a 5‐mL suspension of pancreatic enzyme containing the following enzyme activity (in Federation Internationale Pharmaceutique [FIP] units): lipase, 2000; amylase, 1500; and protease, 100. The suspension also contained 90 mg of NaHCO3 to maintain a pH of 7.5. The mean duration of observation in the control and study groups was 25 and 48 days, respectively. Results: Compared with eight episodes (23.5%) of tube occlusions in the control group (n = 34), there was only one episode (2.6%) in the study group (n = 38). This difference was significant by the test of proportions (z = 2.68, p =.01). Conclusions: In addition to routine water flushing, the routine prophylactic use of pancreatic enzyme‐sodium bicarbonate suspension (pH 7.5) prevents occlusion of feeding tubes. (Journal of Parenteral and Enteral Nutrition 21:353–356, 1997)
Electrolyte Abnormalities in Patients With Chronic Renal Failure Receiving Parenteral Nutrition
Authors: Duerksen Donald R. , Papineau Noreen
Published: May 2008

Background and Methods:Chronic renal failure frequently is complicated by elevations in serum potassium, phosphate, and magnesium. Consequently, parenteral nutrition (PN) solutions used to treat malnourished patients with chronic renal failure usually are prepared with little supplementation of these cations. Four malnourished patients with chronic renal failure and electrolyte abnormalities are reported.Results:Four patients developed significant hypophosphatemia 3 to 5 days after starting PN. Although carbohydrate infused via PN initially was not excessive (1.4 to 2.0 mg/kg/min), two patients received additional dextrose through continuous ambulatory peritoneal dialysis (CAPD). Two of the four patients received insulin during PN. Other electrolyte abnormalities included hypomagnesemia (1 patient) and hypokalemia (3 patients).Conclusions:Malnourished patients with chronic renal failure receiving PN are at risk of developing electrolyte abnormalities, particularly hypophosphatemia. The electrolytes of these patients should be monitored closely when nutrition support is begun, and supplementation should be started as levels begin to fall within a normal range. (Journal of Parenteral and Enteral Nutrition22:102–104, 1998)
Review: Glutamine and Nucleotide Metabolism Within Enterocytes
Authors: McCauley Rosalie , Kong Sung‐Eun , Hall John
Published: May 2008

Glutamine has an important role as a source of energy for enterocytes. However, it may also have a key role as a source of nitrogen for the synthesis of nucleotides. The relative contribution of de novo synthesis and salvage pathways seems to be affected by the position of enterocytes within the crypt‐villus axis as well as the dietary intake of nucleic acids and glutamine. Nucleotides are especially important to enterocytes during intestinal development, maturation, and repair. Hence an understanding of nucleotide metabolism within enterocytes has important implications regarding both the composition and route of administration of nutrient solutions. Many important questions remain unanswered, in particular: Does glutamine stimulate intestinal de novo pyrimidine synthesis via the action of carbamoyl phosphate synthetase I? Can de novo purine synthesis maintain intestinal purine pools in the absence of dietary nucleic acids? And, what are the specific effects of parenterally administered nucleotides on the metabolism and well‐being of enterocytes? A greater understanding of these issues will lead to a more rational approach toward the nutritional modulation of gut dysfunction. (Journal of Parenteral and Enteral Nutrition 22:105–111, 1998)
N‐Acetylcysteine Protects From Glutathione Depletion in Rats Exposed to Hyperoxia
Authors: Shattuck Karen E. , Rassin David K. , Grinnell Chali D.
Published: May 2008

Background: N‐acetylcysteine (NAC) may protect against oxidative injury by providing cysteine for glutathione (GSH) biosynthesis or by direct reactions with electrophiles. We have recently shown that hyperoxic exposure of rats prior to liver perfusion is associated with significant decreases in hepatic GSH and significant changes in biliary amino acid concentrations. We hypothesized that NAC administration during hyperoxic exposure would prevent depletion of hepatic GSH by providing cysteine for GSH biosynthesis. Methods: NAC was administered during two conditions known to induce GSH depletion : hyperoxic exposure and biochemical inhibition of GSH synthesis using buthionine sulfoximine (BSO). After 48 hours, GSH concentrations in bile, liver and perfusate and biliary amino acid concentrations were determined using isolated perfused liver preparations. Results: Administration of NAC to rats maintained in normoxic or hyperoxic conditions, prior to liver perfusion, resulted in dose‐dependent increases in GSH concentrations in bile, liver and perfusate, increases in bile flow rates and changes in biliary amino acid concentrations. When BSO was given concurrently with NAC in normal or hyperoxic conditions, these effects were not observed, and oxidant stress was evident. Conclusions: NAC prevents oxidant stress during hyperoxic exposure, most likely by supplying cysteine as a precursor for GSH synthesis. (Journal of Parenteral and Enteral Nutrition 22:228–233, 1998)
Central Venous Catheters Versus Peripheral Veins for Sampling Blood Levels of Commonly Used Drugs
Authors: Shulman Robert J. , Ching Ou  , Reed Theresa , Gardner Pat
Published: May 2008

Background: Our objective was to compare the accuracy of drug levels in blood samples obtained from central venous catheters with those from peripheral blood samples taken to monitor various drug levels. Methods: Pediatric patients with central venous catheters receiving aminoglycosides, vancomycin, or cyclosporine had central and peripheral blood samples obtained within 5 minutes of each other and analyzed simultaneously. We ascertained how well blood levels from central venous catheters compared with those from peripheral blood (the criterion standard). Results: There were no clinically significant differences between central and peripheral values for amikacin, gentamicin, tobramycin, and vancomycin (both peaks and troughs). Preliminary data indicated that oral cyclosporine can be monitored via central venous catheter. In contrast, there was poor agreement between peripheral and central values when cyclosporine was administered by IV. Conclusions: Amikacin, gentamicin, tobramycin, vancomycin, and probably oral cyclosporine can be monitored accurately via central venous catheter. In contrast, IV cyclosporine should be monitored via peripheral blood. (Journal of Parenteral and Enteral Nutrition 22:234–237, 1998)