摘要:

The salvage function of the colon for absorption of unabsorbed sodium and water from the jejunum and ileum depends upon the metabolic integrity of colonic epithelial cells maintained by luminal short‐chain fatty acids. With the depletion of luminal short‐chain fatty acids under conditions of starvation, metabolic compensation from vascular substrates is incomplete. Loss of luminal short‐chain fatty acids diminishes cell membrane integrity and causes secretion by colonic epithelial cells, leading to starvation diarrhea. Because sodium absorption is dependent upon CO2production fromn‐butyrate, no compensatory absorption occurs during starvation. Under conditions in which luminal short‐chain fatty acids are depleted, dietary fiber is useful as a low osmolality food constituent and for renewal of short‐chain fatty acid levels by bacterial fermentation. The “antisecretory” effect of dietary fiber depends on the degree of the preexisting depletion of short‐chain fatty acids and the methodology used to assess absorptive function. Dietary fiber has not been found harmful in refeeding starvation victims for whom it is an essential food constituent. (Journal of Parenteral and Enteral Nutrition18:4–8, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800104

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Dicarboxylic acids have been proposed as an alternate lipid energetic substrate for total parenteral nutrition. No data are yet available on the possible effect of dicarboxylic acids on glucose metabolism in humans. Thus, we examined the effect of a continuous intravenous infusion of the sodium salt of the10‐carbon atom alyphatic dicarboxylic acid, sebacate (Sb), on insulin‐dependent glucose metabolism in four control subjects, four patients with insulin‐dependent diabetes mellitus, and four obese subjects. All subjects received a constant 5‐hour infusion of saline or sebacate (6.6 g/h), in a randomized order on two different days. After 3 hours of infusion, a 120‐minute euglycemic, hyperinsulinemic clamp procedure was performed (insulin infusion rate = 40 mU/m2per minute). Glucose uptake, plasma sebacate, insulin, glucagon, C‐peptide, and ketone bodies were measured. No significant differences in insulinemia were found among groups either during the saline infusion or the sebacate infusion. On the contrary, glucose uptake (molar) was significantly reduced during the sebacate vs the saline day in all three groups: 6.7 ± 0.04vs3.7 ± 1.3 in control subjects (p<.001), 4.6 ± 0.4vs2.5 ± 1.2 in patients with insulin‐dependent diabetes mellitus (p<.001), and 4.8 ± 0.5vs2.7 ± 0.2 mg/kg per minute in obese subjects (p<.001). In conclusion, Sb administration was associated with a glucose‐sparing effect as shown by the reduced glucose uptake in all patients studied. Sebacate did not stimulate insulin secretion, inasmuch as no modification of C‐peptide plasma levels was observed after 3 hours of Sb infusion. In addition, no change in Sb steady‐state levels was observed during hyperinsulinemia, suggesting that insulin does not influence Sb plasma clearance. (Journal of Parenteral and Enteral Nutrition18:9–13, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800109

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Short‐chain fatty acids (SCFAs) are products of dietary fiber fermentation. As such, fiber digestibility is thought to be related to SCFA production. The effects of two concentrations of cereal fiber as wheat bran (WB) and vegetable fiber (VF) on fiber digestibility were examined in 34 free‐living volunteers. Five diets consisting of a fiber‐free liquid nutrition supplement and quick breads containing either (1) 0 g of fiber, (2) 10 g of WB, (3) 30 g of WB, (4) 10 g of VF, or (5) 30 g of VF were consumed in random order. Apparent digestibility of neutral detergent fiber (NDF) was determined. Colonic fluid, collected byin vivodialysis in 9 subjects, was analyzed for SCFAs by gas chromatography. Digestibility of NDF was greater with WB than with VF ingestion in those 9 subjects, but digestibility was not different with ingestion of both fibers when all 34 subjects were considered. No effect of intake level was seen with either WB or VF. Fiber ingestion increased acetate, propionate, and butyrate concentrations above those on the 0 g of fiber diet (43%, 31%, and 90%, respectively;p<.0001). Propionate and butyrate concentrations were greater on WB than VF (p<.01); acetate concentrations were similar with both fibers. No correlation between NDF digestibility and SCFA concentrations was observed. Despite differences in origin, chemistry, particle size, and subject transit time, the WB and VF were similar in NDF fermentability. Molar ratios of specific SCFAs were influenced by type of fiber ingested. (Journal of Parenteral and Enteral Nutrition18:14–19, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800114

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

ISSN:0148-6071    

DOI:10.1177/0148607194018001011

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Intravenous fluid requirements for patients with permanent end‐jejunostomy syndrome often exceeds 3 L/d, making rehabilitation difficult. The effect of the somatostatin analogue, octreotide (100 μg TID, subcutaneously) in reducing requirements was measured in 10 patients established on home parenteral nutrition. After 10 days of treatment, 72‐hour balance measurements demonstrated significant reductions in stomal fluid and electrolyte losses from (mean ± SE) 8.1 ± 1.8 to 4.8 ± 0.7 L/d (p<.03), sodium from 510 ± 71 to 340 ± 41 mEq/d (p<.03), chloride from 533 ± 70 to 315 ± 32 mEq/d (p<.002), and potassium from 101 ± 41 to 79 ± 34 mEq/d (p<.02), permitting an average reduction in intravenous fluid requirements of 1.3 L/d (p<.0003), 118 mEq Na+/d (p<.03), 41 mEq K+/d (p<.02), and 178 mEq Cl−/d (p<.01). This meant that daytime intravenous infusions could be stopped in all patients. Fecal nitrogen losses were decreased (P<.05), but overall there was no significant change in fat and caloric absorption. In addition, hormonal stimulated gastric acid and pancreatic lipase secretions were significantly reduced (p<.05). The effect was most marked in those patients with massive stomal losses and uncontrollable thirst. Continuation of treatment for more than 1 year in 8 of the patients suggested preservation of potency and good tolerance, with the possible exception of accelerated gallstone formation and subacute intestinal obstruction. In conclusion, octreotide has the potential to improve the quality of life of those end‐jejunostomy syndrome patients with massive stomal losses, resistant to conventional medical treatment. (Journal of Parenteral and Enteral Nutrition18:26–36, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800102

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Intravenous lipid emulsions are an important component of parenteral nutrition. Despite their benefits, lipid emulsions have been associated with higher rates of bacteremia in neonates. Therefore we investigated the effect of lipid emulsions on the inflammatory response by examining their effect onin vitromacrophage tumor necrosis factor (TNF) production of two distinct macrophage populations. Through the use of endotoxin‐free phosphate buffered saline, peritoneal (PER) and alveolar (ALV) macrophages were isolated from male Sprague‐Dawley rats (weighing 125 to 150 g) with endotoxin‐free phosphate buffered saline. Cell counts were adjusted to 2 × 106 cells/mL in RPMI with 2% fetal calf serum. Three hundred microliters of the cells were incubated in a 24‐well culture dish with media or media with intralipid (100 μg/dL) for 16 hours. After washing each well three times, the cells were stimulated for 2 or 16 hours withEscherichiacoli lipopolysaccharide (150 μL of 1 μg/mL). The supernatants were assayed for TNF using the WEHI 164:13 bioassay and TNF levels were expressed as picograms per milliliter. Student's unpairedttest was used for data analysis. Lipid‐exposed PER and ALV macrophagesin vitroTNF levels were significantly lower after 2 hours (12,591 pg/mL ± 3837 vs 20,591 pg/mL ± 6344 for PER, 3894 pg/mL ± 1258 vs 13,177 pg/mL ± 3266 for ALV) and 16 hours (6427 pg/mL ± 3050vs12,353 pg/mL ± 4877 for PER; 131,6000 pg/mL ± 7317 vs 354,680 pg/mL ± 31,605 for ALV) of endotoxin stimulation. TNF production seems to be impaired in macrophages exposed to a.1% lipid emulsion for 16 hours. By impairing TNF production, lipid emulsions may mitigate an important proximal mediator of the immune response. (Journal of Parenteral and Enteral Nutrition18:35–39, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800135

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

The effect of glutamine on hepatic steatosis and serum amino acid pattern was studied in rats receiving total parenteral nutrition (TPN) with different levels of caloric intake. Rats were divided into four groups; a control group (n = 10) was fed a chow diet and infused with saline only. Three experimental groups (n = 8 to 10) received TPN solutions at energy levels of 25 kcal, 30 kcal, and 35 kcal/100 g body weight, respectively. The experimental groups were maintained with TPN for a period of 6 days. Each experimental group was divided into two subgroups, one of which was supplemented with glutamine, replacing 40% of the total amino acid nitrogen. All of the basal TPN solutions were isonitrogenous and identical in nutrient composition, except for the difference in energy level, which was adjusted with glucose. The results demonstrated that liver fat increased in accordance with the increase of glucose supply, and this increase was mainly due to triglyceride accumulation. Very‐low‐density lipoprotein‐triglyceride and serum free fatty acid were significantly higher in the 30‐kcal groups. There were no differences in hepatic lipid content, very‐low‐density lipoprotein‐triglyceride secretion, or hepatic uptake of fatty acids between subgroups with and without glutamine supplementation. It was concluded that glutamine enrichment of a TPN solution did not have any effect on hepatic steatosis in normal rats. (Journal of Parenteral and Enteral Nutrition18:40–44, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800140

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Methotrexate toxicity is increased in protein‐calorie malnutrition. The influence of protein‐calorie malnutrition on the pharmacokinetics and binding of methotrexate (MTX) and the formation of its major hepatic metabolite, 7‐hydroxy‐methotrexate was examined in 30 adult, female Lewis rats. Animals were randomized to receive either a standard diet (22.0% protein; 4.20 kcal/g) or a protein‐depleted diet (PD) (0.03% protein; 4.27 kcal/g)adlibitum for 35 days. Animals were then separated into two groups for either methotrexate pharmacokinetics (n = 20) or serum protein binding (n = 10) studies. The mean weight loss in the PD group was 26% of their initial body weight, as compared with a 29% weight gain in the control group. In the protein binding study, a significant decrease in serum albumin (19%), uncorrected creatinine clearance (38%), and free fraction of MTX (15%) was found in the PD group. All animals in the pharmacokinetic study received a single intraperitoneal injection of MTX (10 mg/kg), and serum MTX and 7‐hydroxy‐methotrexate concentrations were determined using a specific, reversed phase, high‐performance liquid chromatography assay. The mean AUC0–3in the PD group was 43.6 ± 3.9 μg/mL per hour compared with 15.8 ± 1.1 μg/mL per hour in the control group (p<.001). The time to peak and the peak serum concentrations were significantly greater in the PD animals, which indicated delayed absorption and clearance. These results suggest that the increase in MTX toxicity observed in protein‐calorie malnutrition is associated with a decrease in MTX clearance, and is not related to changes in protein binding or formation of 7‐hydroxy‐methotrexate. (Journal of Parenteral and Enteral Nutrition18:45–49, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800145

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

The 24‐hour urinary creatinine excretion value can be used as an index of protein nutrition; the creatinine height index and lean body mass can be estimated from this value. On the basis of longitudinally measured 24‐hour urinary creatinine excretions during the initial 7 years of type 1 diabetes in an incidence cohort of 147 adult patients, we studied creatinine height index and lean body mass and possible relationships to sequential measurements of glycated hemoglobin (HbA1c). The patients were divided into four groups according to their glycemic control during these 7 years: I, HbA1c8.9% (n = 35). One year after the onset of diabetes, height indices were as follows (% of normal values, median and quartiles): I, 104% (90 to 116); II, 101% (78 to 105); III, 121% (92 to 128); IV, 87% (78 to 109) ([IV]<[I to III];p<.05). During the following 6 years no significant differences in height index were observed among the four groups of patients at any point in time. Slightly higher calculated lean body mass values were found in the most well‐controlled patients, but otherwise no differences were found in lean body mass. It is concluded that, apart from the first year, indices of protein nutrition remain normal during the initial 7 years of type 1 diabetes, even in patients with poor glycemic control. (Journal of Parenteral and Enteral Nutrition18:50–54, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800150

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Clostridium difficilecolitis is a disabling complication in critically ill patients who commonly receive broad‐spectrum antibiotics and liquid diets. To date, there is no experimental model specifically designed to investigate the effects of liquid diets on this type of colitis. The addition of fiber to liquid diets normalizes gut structure and improves absorptive function in selected conditions of intestinal dysfunction. The purposes of this study were the following: (1) to develop a reproducible model to examine the interaction of acuteC difficile‐induced colitis and liquid diets, (2) to determine whether the addition of soy fiber to a liquid diet improves disease, and (3) to investigate possible mechanisms of fiber‐mediated disease improvement. Syrian hamsters were pair‐fed with either a polymeric liquid diet or the same diet with 1.4% soy fiber for 10 days. Animals were given either clindamycin andC difficile(to produce ileocecitis), or equivalent volumes of saline. Mean survival time and systematic stool examinations forC difficiletoxin positivity, liquidity, and percent water were performed to determine the effect of soy fiber on disease. Survival time was prolonged by 34% (p<.05), andC difficiletoxin positivity and stool liquidity were significantly reduced (p<.05) with fiber. Additional animals were studied to determine possible mechanisms for improved survival in fiber‐supplemented animals. Cecal histology, colonic water absorption, cecal microflora, and gastric to anus transit time were measured in these animals. Colonic water absorption and gastric to anus transit time were significantly increased (p<.05) and decreased (p<.05) with fiber, respectively. A hamster model ofC difficileileocecitis has been designed to investigate the effects of liquid diets. Fiber supplementation prolongs survival in this model due in part to a delay in onset of C difficile infection and improved colonic water absorption. (Journal of Parenteral and Enteral Nutrition18:55–61, 1994)

ISSN:0148-6071    

DOI:10.1177/014860719401800155

出版商:SAGE Publications    

年代:1994

数据来源: WILEY