摘要:

Background:Dietary fiber is known to influence bowel habit and gastrointestinal mucosal cell morphology and function. Large‐bowel function is particularly influenced by insoluble, poorly fermentable fiber sources, whereas mucosal function is affected by fiber sources that are soluble and highly fermentable. The aim of the present study was to compare bowel function during consumption of a self‐selected diet, a fiber‐free enteral diet, and three polymeric enteral diets, each supplemented with a fiber with different fermentation characteristics. The fiber sources used were oat, soy oligosaccharide, and soy polysaccharide.Methods:Seven healthy subjects consumed four diets in random order for 4 to 7 days. These were a self‐selected diet, a 2‐L polymeric enteral diet, and a 2‐L polymeric enteral diet supplemented with 15 g of total dietary fiber per liter derived from either soy oligosaccharide fiber (75 g/L) or oat fiber (15 g/L). An additional six healthy subjects were randomly assigned to three diets (4 to 7 days): a self‐selected diet, a 2‐L polymeric enteral diet, or the same 2‐L polymeric enteral diet supplemented with 20 g of soy polysaccharide fiber per liter (15 g of total dietary fiber per liter). Bowel function was assessed by measuring whole‐gut transit time, mean daily stool wet weights, and bowel movement frequency per day. Fermentation characteristics of the different fiber sources were determined quantitatively and qualitatively by measuring short‐chain fatty acids produced during in vitro stool culture.Results:Total short‐chain fatty acid and butyric acid production with soy oligosaccharide fiber were significantly higher compared with values observed for soy polysaccharide fiber(p<.003), oat fiber (p<.005), and self‐selected (control) diet (p.05) alter whole‐gut transit time or stool wet weight. However, bowel frequency was significantly improved by consumption of the soy polysaccharide‐fiber‐supplemented diet but not the oat fiber or soy oligosaccharide‐fiber‐supplemented diets.Conclusion:Compared with a fiber‐free polymeric enteral diet, the daily consumption of an enteral diet supplemented with 30 g of total dietary fiber per day derived from a poorly fermentable oat fiber, a highly fermentable soy oligosaccharide fiber, or a moderately fermentable soy polysaccharide fiber has little impact, if any, on bowel function.(Journal of Parenteral and Enteral Nutrition19:63–68, 1995)

ISSN:0148-6071    

DOI:10.1177/014860719501900163

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

摘要:

Background:Glutamine has been shown to be an important dietary component for the maintenance of gut metabolism. The purpose of this study was to assess the potential benefit of glutamine‐enriched diets on experimental gut‐derived sepsis.Methods:BALB/c mice were fed either 2% glutamine‐supplemented or 1% glycine‐supplemented (near‐isonitrogenous control) AIN‐76A diets. Control mice received either nonsupplemented AIN‐76A or regular Purina Rodent Laboratory Mouse Chow 5001 diets. After 10 days of feeding, the mice were transfused with allogeneic blood (from C3H/HeJ mice), and the feeding protocols were continued for an additional 5 days. The mice then underwent gavage with 1010Escherichiacoli labeled with either indium‐111 oxine or [14C]glucose followed immediately by a 20% burn injury. Some mice were observed 10 days postburn for survival rates. Others were killed 4 hours after burn, and the mesenteric lymph nodes, liver, and spleen were harvested to determine radionuclide and bacterial colony counts. The percentages of viable translocatedE coliwere also calculated.Results:Mice fed glutamine‐enriched diets had a lower degree of translocation (as measured by both radionuclide and bacterial counts) to the tissues than did the other groups and had an improvement in the ability to kill translocatedE coli(as measured by the percentage of viable bacteria). Survival was significantly higher in the group fed 2% glutamine (81%) compared with the groups fed 1% glycine (36%), AIN‐76A (35%), and Purina Rodent Laboratory Mouse Chow 5001 (36%) diets(p<.004).Conclusions:Glutamine‐supplemented enteral diets may exert important benefits in preventing gut‐origin sepsis after trauma(Journal of Parenteral and Enteral Nutrition19:69–74, 1995)

ISSN:0148-6071    

DOI:10.1177/014860719501900169

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

摘要:

Background:Two hundred dysfunctional central venous catheters used for total parenteral nutrition and administration of cancer chemotherapy were radiographically examined in order to objectively identify thrombotic occlusions as the cause of catheter dysfunction.Methods:Outcomes of radiographic dye injections were compared with factors such as the inability to aspirate blood or to infuse fluids, catheter type, and duration of catheter placement.Results:Catheter type and duration of placement were not significant factors for predicting the type of dysfunction. Failure to withdraw blood was associated with 96% of the thrombosed catheters; this was also associated with 65% of the catheters with nonthrombotic dysfunctions. Once the cause of catheter occlusion was correctly identified, 90% of the catheters were restored to normal function. Conclusions: Inability to withdraw blood from a catheter does not necessarily mean it is occluded by thrombus. Mechanical complications account for a significant portion of dysfunctional catheters.(Journal of Parenteral and Enteral Nutrition19:75–79, 1995)

ISSN:0148-6071    

DOI:10.1177/014860719501900175

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

摘要:

Background:In previous studies, we demonstrated the overgrowth of gram‐negative bacteria in the gut and an enhanced release of tumor necrosis factor (TNF) by peritoneal macrophages, suggesting that endotoxin, TNF, or both, may act as hepatotoxins to produce hepatic steatosis during total parenteral nutrition (TPN) and bowel rest. The present study attempts to better define the role of each of these two mediators. The first part examines the LD50for various doses of endotoxin in TPN‐treated rats compared with free‐feeding and free‐feeding saline‐infused rats. In the second part we repeatedly administered anti‐TNF monoclonal antibodies to rats subjected to TPN and bowel rest.Methods:In the first set of experiments, 87 male Sabra rats were randomized into three groups: free‐feeding, nfused with normal saline, and infused with TPN. On day 7 of, he experiment, all rats received an IV injection of endotoxin at various doses (1.5, 2.5, 5.0, 7.5, and 10 mg/kg). The LD50in the three groups and at the various doses of lipopolysaccharide ested was determined at 24 hours postinjection. In the second set of experiments, 38 male Sabra rats were randomized into three groups: infused with normal saline and fed rat foodad libitum,infused with TPN, and infused with TPN but also receiving monoclonal antibodies against TNF.Results:Lower endotoxin doses were required to achieve LD50in the two IV‐infused groups (2.5 to 5.0 mg/kg) compared with the free‐feeding group (7.5 mg/kg)(p<.03). These findings suggest a moderate increase in susceptibility to the lethal effect of endotoxin in IV‐treated rats. The total hepatic fat and triglyceride levels, which were markedly increased in TPN rats, were significantly reduced by using anti‐TNF antibodies. Enhanced TNF production by peritoneal macrophages during TPN was completely eliminated by anti‐TNF antibodies, probably the result of suppressed TNF production.Conclusions:The continuous translocation of endotoxin from gram‐negative bacterial overgrowth in the gut during TPN and bowel rest results in enhanced release of TNF by macrophages. TNF causes hepatic dysfunction, portrayed in the present experimental model as hepatic steatosis. TPN‐induced hepatic steatosis was significantly reduced by the administration of monoclonal antibodies against TNF‐α.(Journal of Parenteral and Enteral Nutrition19:80–82, 1995)

ISSN:0148-6071    

DOI:10.1177/014860719501900180

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

摘要:

Background:The objective of this study was to investigate whether luminal perfusion with glutamine or with oxygenated glutamine solutions prevents endotoxin‐induced changes in mucosal permeability.Methods:Three 15‐cm segments of distal ileum were isolated in anesthetized 21‐day‐old piglets (n = 4) and perfused (50 mL/h) with Ringer's lactate solution, Ringer's lactate solution with 2% glutamine (wt/vol), glutamine, or glutamine purged with oxygen at 37°C for 280 minutes. Plasma‐to‐lumen clearances of51Cr‐EDTA and urea were measured to assess mucosal permeability. At time 0 minutes, loading and maintenance IV infusions of markers were begun. Baseline permeabilities were obtained from time 60 to 80 minutes, and IV endotoxin (50 μg/kg) was introduced from time 80 to 140 minutes.Results:Results are expressed as the ratio of the clearances of the two probes (CEDTA/CUREA). Permeability increased from baseline in loops perfused with Ringer's lactate solutionvsloops perfused with glutamine purged with oxygen and with glutamine alone(p.05).Conclusions:These data suggest that endotoxin‐induced permeability changes can be prevented or delayed by the supply of luminal glutamine at the time of insult.(Journal of Parenteral and Enteral Nutrition19:83–87 1995)

ISSN:0148-6071    

DOI:10.1177/014860719501900183

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

摘要:

This study investigated the mechanism of protein depletion and its effect on host toxicity to 5‐fluorouracil. The effects of protein malnutrition on the hepatic metabolism of 5‐fluorouracil were examined using 19F‐nuclear magnetic resonance spectroscopy, pharmacokinetic disposition of 5‐fluorouracil, and hepatic dihydropyrimidine dehydrogenase activity. Harlan Sprague‐Dawley rats were given 5‐fluorouracil (150 mg/kg) by intraperitoneal injection after receiving normal (21.5%) or low (2.5%) protein diets for 19 to 30 days (mean, 25 days). Toxicity was assessed by weight loss, lymphocyte count, and survival. Hepatic fluorine spectra were used to evaluate the time to achieve maximum 5‐fluorouracil concentration, apparent hepatic 5‐fluorouracil half‐life, duration of detectable 5‐fluorouracil concentrations, and time to reach peak fluoro‐β‐alanine concentration (the main 5‐fluorouracil degradation product). Parallel experiments determined the pharmacokinetic disposition of 5‐fluorouracil and the hepatic dihydropyrimidine dehydrogenase activity.In the low‐protein group, the initial detection of the degradation product fluoro‐β‐alanine and the mean duration of 5‐fluorouracil signal in the liver were significantly prolonged: time to reach peak fluoro‐β‐alanine (minutes) 62 ± 39 vs 24 ± 12 (p<.05) and apparent 5‐fluorouracil half‐life (minutes) 96 ± 63 vs 42 ± 22 (p<.001). The 5‐fluorouracil clearance and the hepatic dihydropyrimidine dehydrogenase activity were also significantly lower in the low‐protein group: 1.8 ± 0.8 L/h/kgvs7.3 ± 2.1 Llhlkg (p<.05) and 0.29 ± 0.04 U/mg of protein vs 0.37 ± 0.04 U/mg of protein (p<.05), respectively. Compared with animals fed a normal diet, animals in the low‐protein group sustained greater weight loss (g) 36 ± 17vs16 ± 17(p<.05), lower lymphocyte count (mm3) 1767 ± 993vs5575 ± 2239 (p<.05), and greater mortality 7 days after 5‐fluorouracil (8/9vs1/10) (p<.01).

ISSN:0148-6071    

DOI:10.1177/014860719501900188

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

ISSN:0148-6071    

DOI:10.1177/014860719501900118

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

ISSN:0148-6071    

DOI:10.1177/014860719501900120

出版商:SAGE Publications    

年代:1995

数据来源: WILEY

ISSN:0148-6071    

DOI:10.1177/014860719501900122

出版商:SAGE Publications    

年代:1995

数据来源: WILEY