bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Long‐Chain Triglyceride Emulsions on Reticuloendothelial System Function in Humans
Authors: Seidner Douglas L. , Mascioli Edward A. , Istfan Nawfal W. , Porter Kathaleen A. , Selleck Kelley , Blackburn George L. , Bistrian Bruce R. 
Published: May 2008

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 99mTcsulfur 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 > 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 < 0.05). A decrease in the clearance rate of TSC after 3 days of intravenous lipid infusion but not after 1 day suggests that reticuloendothelial system function is impaired in a dose‐response fashion when long‐chain triglyceride emulsions are infused at clinically conventional rates. Long‐term administration of intravenous long‐chain triglyceride emulsion may be deleterious to optimal reticuloendothelial system function. (Journal of Parenteral and Enteral Nutrition 13:614–619, 1989)
Stability of Imipenem and Cilastatin Sodium in Total Parenteral Nutrient Solution
Authors: Zaccardelli David S. , Sanders Krcmarik Claudia , Wolk Robert , Khalidi Nabil 
Published: May 2008

The chemical stability and compatibility of imipenem‐cilastatin sodium (Primaxin) in two different total parenteral nutrient (TPN) solutions was determined. TPN solutions consisted of 4.25% and 5% amino acids with 25% and 35% dextrose, respectively.Imipenem‐cilastatin sodium was constituted with 10 ml of sterile water and admixed with 90 ml of TPN solution for a final concentration of 5 mg/ml of each drug. The final solutions were assayed at times 0 (immediately after admixture), 15 min, 30 min, 1, 4, 8, and 24 hr by a stability‐indicating high‐performance liquid chromatographic assay. Concurrently, test TPN solutions were monitored for pH changes, color changes, and precipitate formation. The potential effect of imipenem‐cilastatin sodium on the stability of amino acids and other TPN additives was not evaluated.Imipenem and cilastatin sodium was stable (≥90% recovered) in each TPN solution at 15 min. A significant (≥10%) and steady decrease of imipenem recovery occurred at subsequent sampling times. Cilastatin appeared more stable than imipenem in both TPN solutions. A physical color change from colorless to dark orange appeared in each TPN solution over the 24‐hr study period.Imipenem‐cilastatin sodium is stable for 15 min in the TPN solutions studied; however, until the stability of the amino acids can be determined, the antibiotic should be administered through a separate line or Y‐site while the TPN infusion is interrupted. (Journal of Parenteral and Enteral Nutrition 14:306–309, 1990)
Effect of Glutamine Infusions on Glutamine Concentration and Protein Synthetic Rate in Rat Muscle
Authors: Wusteman Monica , Elia Marinos 
Published: May 2008

Studies were undertaken in sedated and unsedated rats to raise the depleted intramuscular glutamine concentrations produced by aseptic abscesses, and to assess the effect of this change on muscle protein fractional synthetic rate. Age‐ and weight‐matched control animals were also included in the study.The rats were infused for up to 5 hours via the lateral tail vein with 1 mL/100 g of body weight per hour of either saline or 0.22 M glutamine. The intramuscular concentration of glutamine (mmol/L of intracellular water), which was reduced by 45% after turpentine in the sedated animals, was restored to within 79% of control values, but the muscle fractional protein synthetic rate, which was also reduced by 41% in these animals, was not improved by the glutamine infusions. Glutamine administration also failed to increase muscle protein synthesis in unsedated rats and in those supplemented with a liquid meal.It is concluded that acute elevations in muscle glutamine concentrations do not increase protein synthesis in this tissue and that therefore glutamine is unlikely to be a mediator in the control of muscle protein synthesis under these circumstances. (Journal of Parenteral and Enteral Nutrition 15:521–525, 1991)
Photosensitized Oxidation of Tryptophan: Effect on Liver and Brain Tryptophan
Authors: Bhatia Jatinder , Rassin David K. , Mcadoo David J. 
Published: May 2008

Toxic products are formed when tryptophan is irradiated with light in the presence of photosensitizers such as riboflavin. In order to further investigate this phenomenon, solutions of tryptophan (48 μmol·mL−1) were irradiated with broad spectrum fluorescent light in the presence or absence of riboflavin (0.01 mg.mL−1). Solutions of riboflavin were similarly irradiated; control solutions were the respective solutions not exposed to light. Two‐week‐old suckling gerbils were then assigned to receiving 7 days of intraperitoneal injections of the light‐exposed or non‐light‐exposed solutions.There were significant differences in the concentrations of tryptophan in serum, liver, and brain; activity of gamma‐glutamyl transferase (GGT) as well as liver protein were also significantly different among the groups. Body and liver weights were also significantly different among the groups.In order to identify the photoproducts responsible for these changes, solutions of tryptophan that had been irradiated with light in the presence of riboflavin were then fractionated based on time of elution during high‐pressure liquid chromatography and the fractions were then injected into the gerbils as before. GGT responses to one of the fractions was similar to that of the parent compound. Chromatographic studies indicated the presence of numerous photoadduct compounds of tryptophan and riboflavin after exposure to light.Both the presence of riboflavin and the exposure of the solutions to light alter brain concentrations of tryptophan in the developing gerbil indicating differing availability to the brain of this serotonin precursor. Clinical implications of the infusion of amino acids in the presence of photosensitizers and light must be considered. (Journal of Parenteral and Enteral Nutrition 15:637–641, 1991)
Comparison of Tolerance and Nutritional Outcome Between a Peptide and a Standard Enteral Formula in Critically Ill, Hypoalbuminemic Patients
Authors: Mowatt‐Larssen Christine A. , Brown Rex O. , Wojtysiak Stacey L. , Kudsk Kenneth A. 
Published: May 2008

Dipeptides have been reported to be more efficiently absorbed from the gastrointestinal tract than free amino acids. The objective of this study was to compare prospectively a peptide enteral formula (PEF) with a standard enteral formula (SEF) for tolerance and nutritional outcome in acutely injured, hypoalbuminemic (<3.0 g/dL) patients who require enteral nutrition support. The prevalence of diarrhea and elevated gastric residuals was assessed daily. Prealbumin, transferrin, colloid oncotic pressure, Prognostic Nutritional Index, and nitrogen balance were measured on days 0, 5, and 10 of enteral nutrition support.Forty‐one patients received 345 days of enteral nutrition support. Prevalences of diarrhea and elevated gastric residuals were similar between groups. Prealbumin increased and the Prognostic Nutritional Index decreased significantly from baseline at day 10 in both groups. Transferrin increased in both groups, but not significantly. Colloid oncotic pressure increased significantly from baseline at days 5 and 10 in the SEF group and day 10 in the PEF group. Nitrogen balance increased significantly from baseline at days 5 and 10 in each group. The only significant difference between groups was for nitrogen balance at day 10, which was higher in the SEF group. We conclude based upon our selected measurements of tolerance and nutritional outcome PEF seams to offer no advantage over SEF in acutely injured, hypoalbuminemic patients. (Journal of Parenteral and Enteral Nutrition 16:20–24, 1992)
Effect of Rate of Enteral Nutrient Supply on Gut Mass
Authors: Zaloga Gary P. , Ward Black Kimberly , Prielipp Richard 
Published: May 2008

Early enteral feeding after injury is important for maintenance of gut integrity. However, enteral nutrients are frequently administered at low rates because of decreased gastrointestinal motility. These low rates are said to “maintain the gut.” This study was performed to evaluate the effect of rate of enteral nutrient delivery on gut mass.Six male Sprague‐Dawley rats had no surgery and served as controls (ad libitum rat chow diet). Twenty‐four male Sprague‐Dawley rats underwent abdominal surgery for placement of gastroduodenal feeding tubes (tip located 2 cm into intestine from pylorus) and were randomized (n = 6 per group) to ad libitum rat chow, 1/2 strength peptide diet (Reabilan HN, RHN) at 1 mL/h (1/2RHN‐1 mL), full‐strength peptide diet at 2 mL/h (RHN‐2 mL), or full‐strength peptide diet at 4 mL/ h (RHN‐4 mL). These diets supplied approximately 30%, 13%, 50%, and 100% of rat recommended daily allowances.The control animals gained weight (38 ± 3 g over 5 days) whereas all postsurgery animals lost weight. Weight loss was greatest in the 1/2 RHN‐1 mL (‐55 ± 3 g over 5 days) and RHN‐2 mL (‐52 ± 6 g over 5 days) groups compared with the RHN‐4 mL animals (‐41 ± 5 g over 5 days). All animals fed liquid enteral diets had reduced gut weights compared with chow‐fed animals. Gut weights did not differ between control and postsurgery ad libitum chow animals. Proximal gut mucosal protein content was significantly (p <.05) higher in the RHN‐4 mL animals (0.88 ± 0.03 mg/cm) compared with control (0.74 ± 0.003 mg/cm) and ad libitum chow animals (0.73 ± 0.05 mg/ cm). There were no differences in mid‐ and distal gut mucosal protein levels between groups. We conclude that the rate of enteral feeding has little effect on gut mass in the early (5 day) postoperative period in rats. (Journal of Parenteral and Enteral Nutrition 16:39–42, 1992)
Total Parenteral Nutrition and Tumor Metastases M. H. TOROSIAN, ROBERT B. DONOWAY Surgery 109:597–601, 1991
Authors: Nussbaum Michael S. 
Published: May 2008

The authors studied the effect of total parenteral nutrition on primary tumor growth and spontaneous prostate adenocarcinoma (PA III) implants. Thirty‐four immature female Lobund/Wistar rats were inoculated subcutaneously with fragments of PA III tumor cells. This is a prostate adenocarcinoma that spontaneously metastasizes to the lungs and lymph nodes. After tumor inoculation all animals received a standard protein diet for 18 days, followed by a protein‐delayed diet from day 18 to day 25. On day 25 all animals underwent superior vena cava cannulation. Subsequently animals were randomized to receive one of five regimens: (1) 3% amino acid/9% dextrose/3.6% lipids parenterally, (2) 3% amino acids/18% dextrose parenterally, (3) 18% dextrose parenterally, (4) protein depleted food ad libitum enterally, (5) standard protein diet ad libitum enterally. All parenteral nutrient regimens were isocaloric (175 calories/ kg per day) and those containing amino acids were iso‐nitrogenous (1.16 g of nitrogen/kg per day). Tumor volume and doubling time were determined daily from day 25 to 35. Animals were killed 35 days later, the implanted tumors were completely excised, and carcass weights were determined. The lungs and trachea were excised for quantitative analyses of pulmonary metastases.Animals given parenteral amino acids/dextrose/lipid, parenteral amino acids/dextrose, or central standard protein diet weighed significantly more at the time of death than did animals in the other two groups. Primary tumor volumes and tumor weights were greater in animals receiving either parenteral amino acids/dextrose/ lipid or enteral standard protein diet. Animals given either parenteral dextrose alone or protein‐depleted food enterally had the smallest primary tumors, as determined by volume and weight measurements. It was also noted that tumor doubling time correlated inversely with tumor volume and weight; thus, the longest tumor doubling time occurred in the animals with the smallest primary tumor volume and weight. The number of pulmonary metastases was greatest in animals receiving either the mixed substrate parenteral diet (amino acids/dextrose/ lipid) or the enteral standard protein diet. A significant increase in metastases occurred in animals given parenteral mixed substrate diet compared with animals receiving parenteral amino acids/dextrose or dextrose alone. Compared with the protein‐depleted group, animals given a standard protein diet enterally showed a significantly greater number of large tumor metastases.
Colonic Fermentation of Ispaghula, Wheat Bran, Glucose, and Albumin to Short‐Chain Fatty Acids and Ammonia Evaluated in Vitro in 50 Subjects
Authors: Mortensen Per Brøbech , Clausen Mette Rye , Bonnén Helen , Hove Hanne , Holtug Klavs 
Published: May 2008

The production of short‐chain fatty acids and ammonia was measured in 16.6% fecal homogenates from 50 subjects incubated at 37°C for 6 and 24 hours. All 50 homogenates produced ammonia and short‐chain fatty acids of any chain length (C2‐C5). Incubation for 24 hours with dietary fiber (ispaghula husk or wheat bran), albumin, or glucose (10 mg/ mL) increased the short‐chain fatty acid production (43.6 ± 2.8, 45.4 ± 2.0, 60.3 ± 3.2, and 65.8 ± 3.1 mmol/L, respectively) compared with controls (21.4 ± 1.3 mmol/L). The degradation of different substrates was associated with the production of different amounts of ammonia and short‐chain fatty acids. Ispaghula, wheat bran, albumin, and glucose were fermented to acetate (>2 mmol/L; 24‐hour incubations) in 86%, 96%, 98%, and 98% of the homogenates, to propionate in 80%, 76%, 100%, and 68%, and to butyrate in 32%, 94%, 88%, and 54% of the homogenates, respectively. Isobutyrate, valerate, and isovalerate were produced from albumin in all (100%) of the homogenates, but only in 2 to 4% of the homogenates incubated with ispaghula or glucose. Ammonia was always (100%) produced after the addition of albumin and always (98%) consumed (assimilated) when glucose was fermented. Surgery (sigmoid or right‐ or left‐sided colonic resection) did not change the pattern of ammonia and short‐chain fatty acid production from these substrates.This study suggests that the different colonic flora from a large number of subjects share general biochemical characteristics, which metabolize different substrates to specific patterns of ammonia and short‐chain fatty acids. (Journal of Parenteral and Enteral Nutrition 16:433–439, 1992)
Smoke, CO, and CO2 Measurements and Evaluation using Different Fire Testing Techniques for Flame Retardant Unsaturated Polyester Resin Formulations
Authors: Nazaré S. , Kandola B.K. , Horrocks A.R. 
Published: May 2008

Smoke is considered to be the main fire hazard but its production depends on major variables, principally the chemical character and the burning rate of the polymer plus the availability of oxygen and hence ventilation. The main aim of this work is to study the effect of smoke suppressants on flammability and smoke production of flame retarded unsaturated polyester resin-nanocomposites using four different testing regimes representing different fire scenarios. Samples containing zinc borate, zinc stannates, ammonium polyphosphate with and without nanoclay are analyzed for smoke generation using cone calorimetry (well-ventilated fire), a tube furnace (fully developed fire), and a smoke density chamber (under-ventilated fire). Carbon monoxide (CO) and carbon dioxide (CO2) measurements using thermogravimetry-evolved gas analysis (TG-EGA), cone calorimetry, and tube furnace have also been analyzed and compared. Results have confirmed that the production of smoke, CO, and CO2 depend upon smoke suppressants and fire conditions used during testing samples. From this study it is evident that tin additives have very little influence on flammability of unsaturated polyester resin but they reduce smoke formation. The slight flame retardant action of the Res/APP/ZB sample is due to enhanced cross-linking of APP in the presence of zinc borate, whereas zinc stannates do not promote cross-linking of APP and hence show no improvement in flame retardancy. Finally, the presence of nanoclay in flame retarded resin shows significant reduction in smoke formations in both well-ventilated and under-ventilated fire condition. However, in the presence of smoke suppressants used in this study, the nanoclay is not instrumental in further suppressing smoke formation.
Protective effects of ethyl pyruvate treatment on paraquat-intoxicated rats
Authors: Lee JH , Kwon WY , Jo YH , Suh GJ , Youn YK 
Published: May 2008

Although, numerous studies have attempted to reduce the oxygen radical injury induced by the antioxidants in paraquat intoxication, these antioxidant therapies have showed few survival benefits. Ethyl pyruvate (EP) may function as an effective scavenger of oxygen radicals, an anti-inflammatory agent and an energy source in many ischemia reperfusion models. The aim of this study was to evaluate the antioxidant and anti-inflammatory effects of EP on the lung and the liver tissues in paraquat-intoxicated rats. Rats were randomly given either a low (2 mg/kg i.p.) or high (40 mg/kg i.p.) EP dose, 30 min before or 1 h after paraquat (50 mg/kg i.p.) administration, and subsequently killed at 6 and 24 h. Glutathione (GSH) and malondialdehyde (MDA) levels of the lungs and the livers, and plasma nitric oxide (NO) concentrations were measured. Pretreatment of EP significantly decreased the MDA level in the lung and the liver tissues. EP also significantly decreased plasma NO concentrations at 6 h. EP pretreatment, however, failed to show significant change in GSH concentration. In post-treatment of EP, MDA levels in the lung tissue and plasma NO levels were significantly decreased. In conclusion, EP decreased the lipid peroxidation and seemed to exert an anti-inflammatory action in the paraquat intoxication rat model.
Pivotal Advance: IgE accelerates in vitro development of mast cells and modifies their phenotype
Authors: Kashiwakura Jun-ichi , Xiao Wenbin , Kitaura Jiro , Kawakami Yuko , Maeda-Yamamoto Mari , Pfeiffer Janet R , Wilson Bridget S , Blank Ulrich , Kawakami Toshiaki 
Published: May 2008

AbstractAntigen-dependent activation of IgE-bound mast cells is critical for immediate hypersensitivity and other allergic disorders. Recent studies have revealed the effects of monomeric IgEs on mast cell survival and activation. Furthermore, IgE molecules exhibit a wide range of heterogeneity in the ability to induce mast cell activation in the absence of antigen. Highly cytokinergic (HC) IgEs can induce a variety of activation events including cell survival, degranulation, cytokine production, and migration, whereas poorly cytokinergic (PC) IgEs can do so inefficiently. Here, we show that culture of bone marrow cells in the presence of monomeric IgEs results in an increased number of mast cells compared with cultures grown without IgE. Furthermore, time in culture required to generate ≥80% pure mast cells is decreased. IgE molecules can directly influence mast cell progenitors to differentiate into mast cells. mRNA expression of several mast cell proteases and mast cell-related transcription factors is higher in mast cells cultured with an HC IgE than those cultured with a PC IgE or without IgE. Expression of early growth response factor-1, a transcription factor that is involved in the production of TNF-α in mast cells, is enhanced in cultures containing high and low concentrations of HC IgE and a high concentration of PC IgE. Consistent with this, expression of TNF-α is higher in mast cells cultured with HC IgE than PC IgE. Therefore, our results suggest that monomeric IgEs, especially HC IgEs, not only promote mast cell development but also modulate the mast cell phenotype.
The Unfolded Protein Response: A Pathway That Links Insulin Demand with β-Cell Failure and Diabetes
Authors: Scheuner Donalyn , Kaufman Randal J. 
Published: May 2008

AbstractThe endoplasmic reticulum (ER) is the entry site into the secretory pathway for newly synthesized proteins destined for the cell surface or released into the extracellular milieu. The study of protein folding and trafficking within the ER is an extremely active area of research that has provided novel insights into many disease processes. Cells have evolved mechanisms to modulate the capacity and quality of the ER protein-folding machinery to prevent the accumulation of unfolded or misfolded proteins. These signaling pathways are collectively termed the unfolded protein response (UPR). The UPR sensors signal a transcriptional response to expand the ER folding capacity, increase degredation of malfolded proteins, and limit the rate of mRNA translation to reduce the client protein load. Recent genetic and biochemical evidence in both humans and mice supports a requirement for the UPR to preserve ER homeostasis and prevent the β-cell failure that may be fundamental in the etiology of diabetes. Chronic or overwhelming ER stress stimuli associated with metabolic syndrome can disrupt protein folding in the ER, reduce insulin secretion, invoke oxidative stress, and activate cell death pathways. Therapeutic interventions to prevent polypeptide-misfolding, oxidative damage, and/or UPR-induced cell death have the potential to improve β-cell function and/or survival in the treatment of diabetes.
Comparison of gastroretentive microspheres and sustained-release preparations using theophylline pharmacokinetics
Authors: Miyazaki Yasunori , Yakou Shigeru , Takayama Kozo 
Published: May 2008

Abstract
The objective of this study was to use the pharmacokinetics of theophylline to compare various gastroretentive microspheres. Three types of theophylline microspheres prepared from a hydrophobic dextran derivative were characterized in terms of drug release in-vitro and floating and mucoadhesive properties. Theophylline pharmacokinetic studies were conducted in Beagle dogs, comparing bulk powder, commercial sustained-release granules (Theodur™), sustained-release microspheres, floatable microspheres and mucoadhesive microspheres. Theodur and sustained-release microspheres resulted in a lower maximum concentration (Cmax) (P &lt; 0.01) and larger values for mean residence time (MRT) (P &lt; 0.05) than bulk powder, whereas area under the concentraion-time curve (AUC) were lower. The floatable microspheres showed a larger value for MRT than bulk powder (P &lt; 0.01), and a larger AUC than Theodur (P &lt; 0.05). The pharmacokinetic parameters of the mucoadhesive microspheres indicated an increase in AUC without decreasing the rate of bioavailability. Overall, the gastroretentive microspheres improved the extent of bioavailability of theophylline, which is absorbable from the entire gastrointestinal tract. The mucoadhesive microsphere showed a prolonged serum drug level, indicating a superior sustained-release delivery system for theophylline.