Showing papers in "Journal of Parenteral and Enteral Nutrition in 1992"
TL;DR: There is a high incidence of GER in patients with orotracheal intubation and NGT and the presence of a NGT is a risk factor for GER, but there is less incidence than in the supine position.
Abstract: The incidence of gastroesophageal reflux (GER) in critically ill patients as well as the effect of a nasogastric tube (NGT) and body position as risk factors for GER were determined. Seventy patients with orotracheal intubation receiving enteral nutrition through a NGT for more than 48 hours were prospectively studied with two randomly assigned body positions: supine or semirecumbent. Detection of GER was achieved by scintigraphy after labeling gastric contents with 500 microCi of technetium-99m sulfur colloid administered through the NGT. In 50 patients scintigraphy was performed after subjects had remained in the randomized position for 2 hours with the NGT pinched. Twenty additional patients were studied after the NGT had been removed. In 50 patients with NGT, GER was present in 74% (37 of 50) and was higher in the supine position (81%, 21 of 26) than in the semirecumbent position (67%, 16 of 24), but this difference was not statistically significant (p = .26). In 20 patients without NGT, the incidence of GER was 35% (7 of 20) and it was also higher in the supine (50%, 6 of 12) than in the semirecumbent position (12%, 1 of 8, p = .16). There was a statistically significant difference between GER in patients with and without NGT (74% vs 35%, p = .0002). These data show that there is a high incidence of GER in patients with orotracheal intubation and NGT. The presence of a NGT is a risk factor for GER. Semirecumbency does not prevent GER, but there is less incidence than in the supine position.
244 citations
TL;DR: Cecal crypt proliferation was raised significantly in all incubation experiments with SCFAs, especially butyrate and propionate, which are luminal trophic factors for the cecal epithelium.
Abstract: Fermentable dietary fiber components are known to stimulate colonic crypt proliferation. As these compounds are rapidly degraded to short-chain fatty acids (SCFAs) by the anaerobic microflora, the hypothesis was tested that this trophic effect of fiber may be mediated by SCFAs. Biopsies were taken from normal cecal mucosa of 45 individuals during routine colonoscopy. They were incubated for 3 hours with sodium salts of SCFAs at physiological concentrations (three SCFAs = acetate 60 mmol/L + propionate 25 mmol/L + butyrate 10 mmol/L; acetate 60 mmol/L; propionate 25 mmol/L; butyrate 10 mmol/L) or equimolar NaCl (control). Cell proliferation was measured autoradiographically by subsequent pulse labeling with [3H]thymidine (1 hour). The labeling index (number of labeled cells divided by the total number of cells) was computed for the crypt as a whole and for five equal crypt compartments (compartment 1 = crypt base, compartment 5 = crypt surface). Cecal crypt proliferation was raised significantly in all incubation experiments with SCFAs. Butyrate (10 mmol/L, increase + 89%) and propionate (25 mmol/L, + 70%) were as effective in stimulating proliferation as the combination of three SCFAs (+103%), although the effect of acetate (+31%) was minor. Increasing the butyrate concentration to 25 mmol/L or 60 mmol/L did not result in a further increase of cell labeling. SCFAs stimulated proliferation in the basal three crypt compartments only. An expansion of the proliferative zone to compartments 4 and 5 was not observed. SCFAs, especially butyrate and propionate, are luminal trophic factors for the cecal epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)
236 citations
199 citations
TL;DR: Data indicate that complications from enterally fed patients are equally common whether the distal port of the feeding tube is in the stomach or beyond the second portion of the duodenum, as well as the mean duration of enteral feeding.
Abstract: Postpylorus delivery of enteral feeding is perceived by many experts to be safer than intragastric delivery. To test this assumption, patients with similar Glasgow Coma Scores were given identical enteral formulas continuously via a 10-French nasoenteric tube, placed into the stomach or beyond the second portion of the duodenum. Observations were made for attainment of desired nutrition, bowel changes, and clinical signs of aspiration. Radiographs of the chest and abdomen were obtained every 3 days. If a tube migrated out of a chosen location, it was replaced. Thirty-three patients were studied. Seventeen patients were fed into the stomach and 16 patients were fed postpylorus. The mean duration of enteral feeding was 11.8 days for the gastric group and 10.9 days for the postpylorus group (p = NS). The time to deliver the desired kilocalories was 3.33 and 2.77 days (p = NS) for gastric and postpylorus-fed patients. Tubes displaced similarly in each group, gastric 0.647, postpylorus 0.750 per duration of fe...
196 citations
TL;DR: This study was designed to determine the RV that indicates intolerance or inadequate gastric emptying and to compare the RV findings in a blinded fashion with those findings obtained on physical examination and radiography.
Abstract: High gastric residual volumes (RVs) are a frequent cause for cessation of total enteral nutrition (TEN). This study was designed to determine the RV that indicates intolerance or inadequate gastric emptying and to compare the RV findings in a blinded fashion with those findings obtained on physical examination and radiography. Twenty healthy normal volunteers (HNV), 8 stable patients with gastrostomy tubes (GTP), and 10 critically ill patients (CIP) were evaluated prospectively for 8 hours while receiving TEN. No subjects were clearly intolerant (ie, vomiting, aspiration). Of the total RVs recorded, 13.1% were ≥150 mL in the CIP group, whereas only 2.4% of the RVs were ≥150 mL in the HNV group. None of the RVs in the GTP group were ≥150 mL. Objective scores on physical examination failed to correlate with RV (p = .397), as did objective scores on radiography (p = .742). However, objective scores on physical examination were significantly related to scores on radiography (p = .016). Abnormal physical exami...
188 citations
TL;DR: The transmembrane amino acid transport rate can be measured in vivo in muscle with a relatively noninvasive technique, and in the dog hindlimb the equilibration between tissue and plasma free amino acid pool is different for each amino acid depending on the kinetics of the trans Membrane transport systems, suggesting that variations in transport rates could play a role in controlling the rate of protein synthesis.
Abstract: The bidirectional transmembrane transport rates of leucine (Leu), valine (Val), phenylalanine (Phe), lysine (Lys), and alanine (Ala) were measured in vivo in the hindlimb muscle of five dogs and related to the rates of protein synthesis and degradation. The compartmental model was based on the systemic continuous infusion of stable isotopic tracers of the amino acids, and the measurement of the enrichment and concentration in the arterial and femoral vein plasma and the intracellular free water in muscle (obtained by biopsy). The transport rate from plasma to tissue (in micromoles per minute) was: Leu, 18.1 +/- 1.8; Val, 26.9 +/- 3.5; Phe, 10.5 +/- 1.6 Lys; 12.2 +/- 1.8; and Ala, 10.7 +/- 3.4. The transport rate from tissue to plasma (in micromoles per minute) was: Leu, 25.5 +/- 2.5; Val, 32.4 +/- 2.8; Phe, 17.0 +/- 2.8; Lys, 24.9 +/- 3.4; Ala, 34.4 +/- 9.0. When the transmembrane transport rate was normalized per unit of amino acid concentration in the source pool, we found that the transport of Leu, Val, and Phe was significantly faster (p less than .05) than the transport of Lys and Ala. The calculated rates of incorporation into hindlimb muscle protein of Phe and Lys (in micromoles per minute) were 4.2 +/- 1.3 and 19.4 +/- 5.3, respectively, and the rates of intracellular appearance from breakdown were 10.7 +/- 1.9 and 32.1 +/- 6.6, respectively. We concluded, therefore, that (1) the transmembrane amino acid transport rate can be measured in vivo in muscle with a relatively noninvasive technique, (2) in the dog hindlimb the equilibration between tissue and plasma free amino acid pool is different for each amino acid depending on the kinetics of the transmembrane transport systems, and (3) the transport rates of amino acids and their rate of appearance from protein breakdown are roughly comparable, suggesting that variations in transport rates could play a role in controlling the rate of protein synthesis.
164 citations
TL;DR: Patients underwent allogeneic bone marrow transplantation for hematologic malignancies and were randomly assigned to receive either a standard glutamine-free total parenteral nutrition solution or one supplemented with L-glutamine to provide 0.57 g of GLN/ kg per day in a blinded fashion.
Abstract: Glutamine (GLN), long considered to be a nonessential amino acid, may be conditionally essential during periods of metabolic stress.1 It has been suggested that the improved results seen in patients given enteral, as opposed to parenteral, nutrition may in part be due to the provision of GLN. Commercial amino acid solutions do not contain GLN because of its inherent instability. Glutamine-supplemented solutions are currently under investigation and may be of benefit to patients who cannot tolerate enteral feedings. Bone marrow transplantation is one such setting, where the combination of radiation and chemotherapy make enteral support untenable.Forty-five patients underwent allogeneic bone marrow transplantation for hematologic malignancies. They were randomly assigned to receive either a standard glutamine-free total parenteral nutrition solution or one supplemented with L-glutamine to provide 0.57 g of GLN/ kg per day in a blinded fashion. Overall protein intake was 1.5 g/kg per day. Patients were allow...
132 citations
TL;DR: The methods of continuous (C) and intermittent (I) nasogastric tube feedings in 60 patients, 54 men and 6 women, with a mean age of 72 +/- 9 years were compared in terms of number of complications, staff time used, and caloric intake.
Abstract: The methods of continuous (C) and intermittent (I) nasogastric tube feedings in 60 patients, 54 men and 6 women, with a mean age of 72 +/- 9 years were compared in terms of number of complications, staff time used, and caloric intake. Patients were randomly assigned between these two methods and followed for 7 days. Diarrhea, aspiration pneumonia, clogged tubes, and self-extubation were observed in both groups. Diarrhea was significantly more frequent (96% of 30 patients) in the I group than the C group (66% of 30 patients) (p < .008). Furthermore, diarrhea was more prolonged (4 days or more) in 64% of 30 patients in the I group than the C group (4 days or more) in 58% of 30 patients (p < .02). However, clogged tubes occurred 3 times more often in the C group (p < .01). Self-extubation and aspiration pneumonia tend to be more frequent in the I group but the difference was not significant. The average time used by staff nurses in the maintenance of NGT feedings was not significantly longer in the I group (48.45 +/- 11 min/patient per day) than the C group (46.46 +/- 11 min/patient per day). In the C group the mean calories recommended were 2248 +/- 36 kcal/day but the actual caloric intake was only 1465 +/- 281 kcal/day, a deficiency of 783 +/- 291 kcal/day. The recommended calorie count for the I group was 2021 +/- 5 kcal/day but the amount delivered was only 1226 +/- 254 kcal/day, which resulted in a deficit of 795 +/- 259 kcal/day.(ABSTRACT TRUNCATED AT 250 WORDS)
122 citations
TL;DR: In this review, the authors provide a conceptual view of the mechanism of carrier-mediated amino acid transport as well as an overview of the various models that can be used in the laboratory to study this process.
Abstract: The bloodstream provides a readily available pool of amino acids, which can be taken up by all cells of the body to support the myriad of biochemical reactions that are essential for life. The transport of amino acids into the cytoplasm occurs via functionally and biochemically distinct amino acid transport systems that have been defined on the basis of their amino acid selectivities and physico-chemical properties. Each system presumably relates to a discrete putative membrane-bound transporter protein that resides within the cell membrane and functions to translocate the amino acid from the extracellular environment into the cytoplasm. Many of these transporters require sodium for maximal activity. The sodium-dependent model presented is consistent with "preferred random" kinetics, with sodium binding preferentially before the amino acid. The transporter acts as an enzyme that catalyzes the movement of its bound amino acid (and sodium) into the cell. In this review, the authors provide a conceptual view of the mechanism of carrier-mediated amino acid transport as well as an overview of the various models that can be used in the laboratory to study this process. In addition, the known agencies that accomplish transport and their regulation by nutrition, hormones, and other mediators of critical illness are discussed.
118 citations
TL;DR: This study compares the effect of drug treatment for Crohn's disease with that of enteral nutrition alone as a therapeutic modality for this disease and shows significantly more patients in the drug treatment group achieved remission.
Abstract: This study compares the effect of drug treatment for Crohn's disease with that of enteral nutrition alone as a therapeutic modality for this disease. Patients were randomly divided into two groups: One group (n = 52) was treated with 6-methylprednisolone (48 mg/day, subsequently tapered) and sulfasalazine (3 g/day). The second group (n = 55) was treated with enteral nutrition consisting of an oligopeptide diet. The two groups were matched for severity of illness and demographic characteristics. Remission was defined as a decrease in Crohn's Disease Activity Index by 40% (or at least 100 points). Significantly more (p < .01, χ 2) patients in the drug treatment group (41 of 52) achieved remission, compared with the dietary treatment group (29 of 55). The median time to remission for the drug treatment group was 8.2 days compared with 30.7 days for the dietary treatment group (p < .01; Mantel Cox). Further data analysis was carried out to determine whether certain subgroups within the dietary group might hav...
111 citations
TL;DR: More frequent aspiration among ward than intensive care unit patients suggests that aspiration is not an inevitable consequence of severe illness, but can be prevented with adequate nursing care and pulmonary precautions.
Abstract: We investigated the prevalence, incidence, and risk factors for pulmonary aspiration in all tube-fed adult patients over 6 months Twelve aspiration events occurred among 276 patients (prevalence, 44%; 95% confidence interval, 22% to 76%) The incidence of aspiration was 24 per 1000 tube-feeding days (95% confidence interval, 12 to 39 per 1000) Despite 17% overall mortality, there was no excess mortality and little morbidity associated with aspiration The major risk factors for aspiration were patient age (p less than 015) and location in the hospital (p less than 008): the probability of aspiration in the intensive care units (n = 113) was 09% compared with 49% on medical or surgical wards (n = 142), 167% among patients transferred from the intensive care unit to the ward (n = 18), and 33% among patients transferred from the ward to the intensive care unit (n = 3) Pulmonary aspiration is an uncommon and generally benign event among enterally supported patients More frequent aspiration among ward than intensive care unit patients suggests that aspiration is not an inevitable consequence of severe illness, but can be prevented with adequate nursing care and pulmonary precautions The fear of aspiration is not a sufficient cause to withhold enteral nutrition support in acutely ill patients
TL;DR: There has been no consistent finding that one cytokine is universally involved in cancer cachexia in histologically distinct tumor models, raising the intriguing possibility that these cytokines, although contributors to tissue wasting and anorexia, may also serve the tumor as either direct or indirect cell growth factors.
Abstract: There is, at present, considerable interest in the possible role for the proinflammatory cytokines, tumor necrosis factor-alpha, interleukin-1, interleukin-6, and interferon-gamma in the pathogenesis of cancer cachexia. Indirect evidence for such a role is based on the observation that chronic administration of many of these cytokines, either alone or in combination, can reproduce the myriad of host responses seen in experimental and human cancer cachexia. Elevated plasma levels of tumor necrosis factor-alpha, interleukin-2, and interferon-gamma have rarely been detected in patients or experimental animals with cancer, although interleukin-6 levels appear to correlate with tumor progression in animal models. The strongest evidence for a causal role for cytokines has come from rodent studies in which tumor-bearing animals have been passively immunized with antibodies directed against individual cytokines. Several groups have shown modest but significant improvements in food intake and lean tissue retention with antibodies directed against tumor necrosis factor-alpha, interleukin-1, interleukin-6, and interferon-gamma. However, there has been no consistent finding that one cytokine is universally involved in cancer cachexia in histologically distinct tumor models. One ominous finding in several tumor models has been that the endogenous production of cytokines appears to support tumor growth. Such findings raise the intriguing possibility that these cytokines, although contributors to tissue wasting and anorexia, may also serve the tumor as either direct or indirect cell growth factors.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The results indicate that home parenteral nutrition has allowed many patients to survive gut failure and return to work but problems with chronic fluid, electrolyte and micronutrient deficiencies, catheter sepsis, and insurance coverage often restrict optimal rehabilitation.
Abstract: We report a 3-year analysis (1986 to 1989) of the management of 63 home parenteral nutrition patients, 40 with short-bowel syndrome and 23 with chronic intestinal obstruction with or without intestinal resection. Intravenous fluid requirements varied from 0.9 to 6 L/day, and the content of glucose varied between 46 and 531 g/day, protein varied from .0 to 85 g/day, fat from .0 to 100 g/day, sodium from 37 to 695 mEq/day, potassium from 30 to 220 mEq/day, chloride from 60 to 760 mEq/day, and acetate from 0 to 200 mEq/day. Body weight was normalized and well maintained in the majority of patients, but using the strict definition of deficiency as the presence of one abnormal value during 3 years, more than half had abnormal plasma chloride, glucose, alkaline phosphatase, serum glutamic oxaloacetic transaminase, total protein, albumin, selenium, and iron concentrations, and more than a third had low calcium, magnesium, vitamin D, and vitamin C levels. Normochromic anemia was seen in 73% and high blood creatinine associated with low urine volumes in 42%. Most (78%) returned to relatively normal lifestyles, but employability was occasionally impaired by loss of third-party insurance coverage resulting from a therapy that may cost $100,000 per year. Overall mortality was low (5% per year), but 73% needed readmission to hospital, mainly for suspected catheter sepsis. The results indicate that home parenteral nutrition has allowed many patients to survive gut failure and return to work but problems with chronic fluid, electrolyte and micronutrient deficiencies, catheter sepsis, and insurance coverage often restrict optimal rehabilitation.
TL;DR: It is likely that no single substance is the sole cause of cachexia in most cancer patients, which makes it likely that specific strategies to reverse the cachectic effects of these substances may be developed to ultimately improve cancer treatment.
Abstract: Cancer cachexia describes a syndrome that consists of weight loss, and abnormalities in carbohydrate, protein, and lipid metabolism, which result in a state of persistent net negative energy balance. Patients suffering from cancer cachexia have a significantly shortened survival after cancer treatment. Recent experimental studies have focused on the belief that the mechanisms of cancer cachexia involve the host's production of inflammatory cytokines, which through broad physiologic actions ultimately lead to a chronic state of wasting, malnourishment, and death. Cytokines that have been thought to play a role in the pathophysiology of cachexia include tumor necrosis factor, interleukin-1, interleukin-6, interferon-gamma and differentiation factor. It has become clear that these cytokines have overlapping physiologic activities, which makes it likely that no single substance is the sole cause of cachexia in most cancer patients. Only further investigation may make it possible to more clearly define the role of cytokines in the pathophysiology of cancer cachexia. Specific strategies to reverse the cachectic effects of these substances may then be developed to ultimately improve cancer treatment.
TL;DR: This study evaluated the safety of triple vs single-lumen catheters in intravenous nutrition in patients at increased risk of catheter-related infection because of one or more of the following conditions: > 60 years of age, breakdown of skin integrity, severe underlying illness, diagnosis of acute pancreatitis, recent head or neck surgery, or presence of a preexisting infection.
Abstract: This study evaluated the safety of triple vs single-lumen catheters in intravenous nutrition. Patients who were judged likely to benefit from a triple-lumen catheter were randomized to receive either a single-lumen catheter, with additional peripheral or central venous access as needed, or a triple-lumen catheter. All patients were at increased risk of catheter-related infection because of one or more of the following conditions: > 60 years of age, breakdown of skin integrity, severe underlying illness, diagnosis of acute pancreatitis, recent head or neck surgery, or presence of a preexisting infection. Patients were excluded who had neutropenia, were immunosuppressed, had body burns > 40%, or had contaminated wounds in the subclavicular area. Of 204 patients entered between June 1989 and November 1991, 177 completed the required > or = 7 days of therapy. Seventy-eight of these patients were randomized to a single-lumen catheter and 99 to a triple-lumen catheter. Catheters were inserted and maintained by the Nutrition Support Team. Dressings were monitored daily and changed weekly using a bio-occlusive dressing. When parameters were met for a possible septic episode, simultaneous peripheral and central catheter blood cultures were obtained using the Isolator method. Catheter-related sepsis was considered present if the colony count from a central catheter lumen was > or = 5 times that of the peripheral blood. The incidence of catheter-related sepsis for single-lumen catheters was 2.6% (2 of 78) compared with 13.1% for triple-lumen catheters (13 of 99) (p < .01). No correlation was found with the number of insertion attempts, catheter days, or patient's age.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The presence of HAF-PCM increased four-fold the odds of dying, and thedds of developing nosocomial infection and sepsis almost 2.5 times above that seen in its absence, and MF-PCm had no clinical effect of its own on any of the outcome parameters, but instead exerted only an interactive synergistic effect on length of hospitalization and cost of total parenteral nutrition.
Abstract: Clinical nutrition assessment has identified two types of protein-calorie malnutrition (PCM), a stress-induced hypoalbuminemic form (HAF-PCM) and a marasmic form (MF-PCM) generated by adaptation to starvation. This study evaluated the differences between these two patterns of PCM with regard to precipitating factors and the clinical sequelae of mortality, cost of total parenteral nutrition, length of hospitalization, and rate of sepsis and nosocomial infection. Of 220 patients receiving total parenteral nutrition over a 12-month period (0.7% of 30, 127 admissions), 180 were included in this study. HAF-PCM was diagnosed in 45% and MF-PCM in 25% of study patients. HAF-PCM was more common in older age groups. Women had PCM less often than did men (57% vs 83%), but whereas men developed both forms of PCM equally, women were more likely to develop HAF-PCM. Prolonged mechanical ventilation increased the likelihood of both patterns, whereas the presence of malignancy, concomitant organ failure, trauma, burns, or surgery did not increase the likelihood of developing either pattern of PCM. HAF-PCM increased the length of hospitalization by 29% and the cost of total parenteral nutrition by 42%. The presence of HAF-PCM increased four-fold the odds of dying, and the odds of developing nosocomial infection and sepsis almost 2.5 times above that seen in its absence. MF-PCM had no clinical effect of its own on any of the outcome parameters, but instead exerted only an interactive synergistic effect with HAF-PCM on length of hospitalization and cost of total parenteral nutrition.
TL;DR: This study was performed to determine whether the addition of alanyl-glutamine (Ala-Gln) can prevent intestinal mucosal atrophy induced by standard solution of total parenteral nutrition (S-TPN).
Abstract: This study was performed to determine whether the addition of alanyl-glutamine (Ala-Gln) can prevent intestinal mucosal atrophy induced by standard solution of total parenteral nutrition (S-TPN). Forty-one male Sprague-Dawley rats weighing 250 g were randomly divided into four groups: group I was killed after overnight fasting; group II received S-TPN. The other groups received S-TPN supplemented with amino acids other than glutamine (group III) or supplemented with Ala-Gln 2 g/100 mL (group IV); both solutions were isocaloric and isonitrogenous. After 1 week of TPN the rats were killed, and the duodenum, proximal jejunum, mid-small bowel, and distal ileum were obtained for morphologic and functional analysis. Weight gain did not differ significantly among these four groups, and there was no difference in nitrogen balance between groups III and IV. Serum glutamine in group IV (102.8 +/- 13.3 mumol/dL) was significantly increased (p less than .05) compared with groups I, II, and III (66.2 +/- 3.9, 55.7 +/- 7.8, and 61.3 +/- 10.8 mumol/dL, respectively). Mucosal wet weight, protein, RNA, sucrase, and maltase of group IV were significantly increased (p less than .05) compared with groups II and III. Villus height was significantly increased (p less than .05) in the jejunum of group IV rats compared with groups II and III, but not in any other segments of the intestine. No significant changes were observed in crypt depth among all groups. Diamine oxidase in groups II, III, and IV was significantly decreased (p less than .05) compared with group I in all segments except for the ileum.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: It is indicated that an intermittent defined formula diet can improve growth failure and significantly decrease disease activity in children with Crohn's disease.
Abstract: Growth failure is the most common extraintestinal manifestation of Crohn's disease in childhood, occurring in up to 50% to 88% of affected patients. Previous studies have shown malnutrition to be the most likely cause of the decrease in height and weight velocities in these children. The purpose of this study was to determine the effect of an intermittent defined formula diet on growth and disease activity in children with Crohn's disease and growth failure. Six Tanner stage I-II patients, mean age 13.6 years with height less than the 5th percentile or height velocity less than the 3rd percentile were enrolled in a 1-year prospective study. An isotonic, hydrolyzed whey, medium-chain triglyceride formula was given by nocturnal nasogastric infusion at a caloric equivalent of 50th percentile for age, as the exclusive nutrient source 1 out of 4 months during a 1-year period. A 2-week exclusion diet and a 2-week low-residue diet followed the defined formula diet before resuming the regular diet for 2 months. Patients served as their individual control based on observations of at least 1 year before the study. Height and weight velocity significantly increased. Prednisone intake significantly decreased, and significant improvement was seen in disease activity, albumin, and somatomedin C. The results indicate that an intermittent defined formula diet can improve growth failure and significantly decrease disease activity in children with Crohn's disease.
TL;DR: Current evidence indicates that the cause of Pn-related bone disease is multifactorial, and the prevention of PN-relatedBone disease awaits better delineation of the exact sequence of pathogenic events.
Abstract: Parenteral nutrition (PN)-related bone disease remains a problem in patients of all ages. Understanding of the pathogenesis of PN-related bone disease is complicated by the effect of underlying illnesses, therapeutic interventions, and pre-existing nutrition deficiencies before the initiation of PN therapy. Interrelation of various nutrients, for example, calcium, phosphorus, and vitamin D, in their effects on bone mineralization, demands simultaneous assessment of the role of multiple nutrients and increases the difficulty in defining the role of a single nutrient in the development of bone disease. However, recent reports indicate that there exist a number of factors important in the development of PN-related bone disease and some factors such as increased mineral requirement are unique to growing infants whereas other factors such as aluminum toxicity may be common to both adult and pediatric populations. Nonnutritional factors, including chronic use of potent loop diuretics and altered acid-base status, can affect urine mineral loss, cell metabolism, and bone mineralization, particularly in small, preterm infants. Current evidence indicates that the cause of PN-related bone disease is multifactorial, and the prevention of PN-related bone disease awaits better delineation of the exact sequence of pathogenic events.
TL;DR: It is concluded that protein restriction can increase mortality in this model and on the other hand, short-term calorie restriction can improve survival.
Abstract: We studied the separate effects of protein and calorie restriction in mice challenged with Salmonella typhimurium, an intracellular pathogen eliminated by cell-mediated immunity. Female A/J mice (n = 73) were placed on one of eight solid diets for 3 weeks. Animals were weighed at the beginning and the end of the feeding period. Diets were adjusted by two factors. The total amount of protein in the diet was 1%, 5%, 20%, or 40% by weight. The diets were fed to half the mice in quantities of 3 g and to the other half at 1.5 g per mouse per day. At the end of 3 weeks, mice were injected intraperitoneally with bacteria and mortality was observed for 2 weeks. Mortality was related to protein intake and was significantly higher in the 1% and 5% groups (chi 2: p = .0021). However, mortality was lower in the calorie-restricted groups (chi 2: p = .0242). Although caloric intake did not affect cell-mediated immunity, the response to 2,4-dinitrofluorobenzene was greater in the low protein groups. Lymphoproliferative responses in the mixed lymphocyte response were not affected by either caloric or protein intake. Lymphoproliferative responses to both lipopolysaccharide and phytohemagglutinin were affected by dietary protein but not by caloric intake; proliferative responses were higher in the low-protein groups. We conclude that protein restriction can increase mortality in this model. On the other hand, short-term calorie restriction can improve survival.
TL;DR: Glutamine supplementation enhances the tumoricidal effectiveness of methotrexate while reducing its morbidity and mortality in this sarcoma rat model.
Abstract: Dose intensification of chemotherapy is thought to increase survival. With recent advances in hemopoietic cell modulators such as granulocyte colony stimulating factor, the limiting toxicity of intensifying chemotherapeutic regimens has become the severity of the associated enterocolitis. In animal models, glutamine protects the host from methotrexate-induced enterocolitis. This study evaluates the effects of a glutamine-supplemented diet on the tumoricidal effectiveness of methotrexate. Sarcoma-bearing Fisher 344 rats (n = 30) were pair-fed an isocaloric elemental diet containing 1% glutamine or an isonitrogenous amount of glycine beginning on day 25 of the study. Rats from each group received two intraperitoneal injections of methotrexate (5 mg/kg) or saline on days 26 and 33 of the study. On day 40, rats were killed, tumor volume and weight were recorded, and tumor glutaminase activity and tumor morphometrics were measured. Blood was taken for arterial glutamine content, complete blood count, and blood culture. The gut was processed for glutaminase activity and synthesis phase of the deoxyribonucleic acid. In rats receiving methotrexate, the tumor volume loss was nearly doubled when glutamine was added to the diet. Significant differences in tumor glutaminase activity and morphometrics were not detected. The toxicity to the host was ameliorated. Significantly increased synthesis phase of deoxyribonucleic acid of the whole jejunum, decreased bacteremia, "sepsis," and mortality were demonstrated. Glutamine supplementation enhances the tumoricidal effectiveness of methotrexate while reducing its morbidity and mortality in this sarcoma rat model.
TL;DR: Both protein malnutrition and endotoxin impaired systemic and gut-associated immune responsiveness to mitogens, however, in the protein-malnourished mice, the degree of immune suppression did not correlate with endotoxin-induced mortality.
Abstract: Because protein-malnourished or endotoxemic patients are at an increased risk of developing nosocomial infections, this study was performed to investigate the effects of protein malnutrition and endotoxemia, alone and in combination, on systemic and intestinal immunity. Protein malnutrition was created by feeding the animals a solid diet containing 0.03% protein. Subgroups of these protein-malnourished mice were killed after being challenged with saline or endotoxin on days 0, 7, 14, or 21. At death, the animals were weighed, tissues were harvested for histologic analysis (ileum, mesenteric lymph node [MLN], liver, and spleen), mitogen responsiveness (MLN, Peyer's patches, and spleen), and xanthine oxidase measurements (ileum and cecum). Separate groups were evaluated for survival. Both the saline and endotoxin-challenged mice had lost about 30% of their body weight after 21 days on the low-protein diet. The protein-malnourished mice were more susceptible to endotoxin-induced mortality (70% at 21 days) th...
TL;DR: Nineteen central venous catheters with radiographically proven thrombotic occlusion failed to have function restored with a mean of 1.6 5000-unit boluses of urokinase per catheter, but catheter function was restored in 15 patients after a 6-hour infusion of low-dose u rokinase.
Abstract: Nineteen central venous catheters with radiographically proven thrombotic occlusion failed to have function restored with a mean of 1.6 5000-unit boluses of urokinase per catheter. Catheters then underwent a 6-hour infusion of urokinase at 40,000 units per hour followed by repeat contrast injection and evaluation of function. Reduction in thrombus size occurred in all but one patient. Catheter function was restored in 15 patients. In two patients, thrombus dissolved but catheters remained occluded because of tip malposition. In the remaining two patients, catheter function was restored with an additional 6-hour infusion. No adverse reactions to the infusion were seen. After infusion catheters continued to function normally for a mean of 36.2 days. Five catheters rethrombosed, two of which responded to urokinase bolus instillation. Thrombosed catheters failing standard intracatheter bolus urokinase are generally salvaged with a 6-hour infusion of low-dose urokinase.
TL;DR: It is believed polymyxin B protects the liver during TPN by both its antimicrobial effect which prevents overgrowth of gut Gram-negative bacteria and the subsequent translocation of endotoxin, and by its specific antilipopolysaccharide activity which, in the present study, completely abolished hepatic steatosis and TNF productionDuring TPN.
Abstract: Overgrowth of Gram-negative bacteria as a result of total parenteral nutrition (TPN) and bowel rest could be responsible for the release of a variety of hepatotoxic substances such as endotoxin or tumor necrosis factor (TNF) and the ensuing TPN-associated liver function derangements. Polymyxin B is an effective antimicrobial agent as well as a blocking agent for endotoxin (lipopolysaccharide) activity and TNF production. In the present study we compared the oral and intravenous effects of polymyxin in rats receiving TPN in an attempt to define these two possible mechanisms of action of polymyxin on TPN-associated hepatic steatosis. Both oral, as well as intravenous polymyxin B, significantly reduced total hepatic fat and triglyceride accumulation in TPN rats, more so in the intravenous group exhibiting close to control levels. Both polymyxin-treated groups exhibited significantly lower Gram-negative bacterial counts in the cecum, with the oral group exhibiting a lower count than the IV group. The spontaneous production of TNF by peritoneal macrophages was markedly increased in rats receiving TPN and very close to being undetected in both groups receiving TPN and polymyxin. We believe polymyxin B protects the liver during TPN by both its antimicrobial effect which prevents overgrowth of gut Gram-negative bacteria and the subsequent translocation of endotoxin, and by its specific antilipopolysaccharide activity which, in the present study, completely abolished hepatic steatosis and TNF production during TPN.
TL;DR: PEF seems to offer no advantage over SEF in acutely injured, hypoalbuminemic patients, and the only significant difference between groups was for nitrogen balance at day 10, which was higher in the SEF group.
Abstract: 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 (less than 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 seems to offer no advantage over SEF in acutely injured, hypoalbuminemic patients.
TL;DR: Glucerna produced a significantly lower blood glucose response than did Enrich, Ensure HN, or Compleat Modified, although this response was greater than the response to EN-8715 in 1988, and freezing and thawing was not found to significantly alter the glucose response.
Abstract: These studies were performed to evaluate the postprandial blood glucose responses to a variety of differently formulated enteral feeding products in patients with type I diabetes. Eleven subjects with type I diabetes were evaluated in three studies, all using a Biostator (artificial endocrine pancreas) that delivered a small, basal amount of insulin and measured blood glucose levels. Subjects consumed 20 mL of the assigned formula every 15 minutes for the 240 minutes of the study. Study 1 evaluated the response to each of five products: Glucerna, Enrich, Ensure HN, Pulmocare, and Compleat Modified. When the postprandial blood glucose response to Glucerna was greater than when its research formulation (EN-8715) had been tested in 1988, studies 2 and 3 were undertaken to assess why this discrepancy occurred. Study 2 compared stored EN-8715 to Glucerna and study 3 compared frozen and thawed vs nonfrozen EN-8715, because of a concern that the original product had been frozen during shipping. In study 1 the glucose response (assessed as area under the glucose curve) correlated with the grams of carbohydrate present in the enteral feeding formula (r = .58, p = .002). The presence or absence of fiber, in the form of soy polysaccharide, did not affect the glucose response. Glucerna produced a significantly lower blood glucose response than did Enrich, Ensure HN, or Compleat Modified, although this response was greater than the response to EN-8715 in 1988. However, in study 2 no differences were found between stored EN-8715 and Glucerna and in study 3, freezing and thawing was not found to significantly alter the glucose response.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: Although SCFA has a modest effect on colonic structure, they do not influence absorptive function in TPN rats.
Abstract: Short-chain fatty acids (SCFA), fermentation products of fiber, are believed to play a role in intestinal adaptation. Although the administration of fiber or the infusion of SCFA has been shown to cause colonic growth, studies have been done primarily in enterally fed animals. In addition, the effects of SCFA on absorptive function have not been determined. Adult male rats were maintained on total parenteral nutrition (TPN) and, in addition, received either 150 mmol/L of saline or 150 mmol/L of SCFA mixture (60:25:15, acetate:propionate:butyrate) into the proximal colon. One week later, the in vivo absorption of water, electrolytes, and 20 mmol/ L of butyrate was measured. After the rats were killed, parameters of colonic mass were determined. SCFA infusion into the colon had no significant effect on absorptive function. However, significantly greater mucosal height (p < .01) and mucosal DNA (p < .05), were observed. Although SCFA has a modest effect on colonic structure, they do not influence absorptive ...
TL;DR: It is concluded that dietary arginine can increase extrathymic T-cell maturation and function, but cannot induce in vivo allogeneic graft recognition in athymic nude mice.
Abstract: Supplemental L-arginine has been shown to enhance thymic and T-cell responses in rodents. We examined the ability of supplemental dietary L-arginine to induce T-cell function in athymic nude mice that lack a normally developed T-cell system. Groups of male nude (nu/nu) mice (Balb/c background) 7 to 8 weeks old were given for 2 weeks 1.2% arginine hydrochloride solution for drinking, whereas controls received acidified tap water. All mice ingested a standard laboratory chow. In the first experiment, the arginine-supplemented animals had significantly greater number of T cells in the spleen (assessed by the number of Thy 1.2-positive lymphocytes) and these cells had enhanced mitogenic responses to mitogenic stimulation (phytohemagglutinin and concanavalin A). In vivo delayed-type hypersensitivity responses to 2,4-dinitro-1-difluorobenzene were also significantly increased after the 2 weeks of arginine supplementation. In a second experiment, mice maintained under the same conditions were skin grafted with r...
TL;DR: Tumor-associated increases in plasma free tryptophan that occurred before the manifestation of anorexia are confirmed and support a possible role of brain serotonin in cancerAnorexia.
Abstract: Tumor growth is accompanied by an anorexia mediated by humoral factors that appear to influence appetitive mechanisms in the brain. Because tumor resection is followed by resumption of normal food intake, the circulating anorexigenic substance(s) are produced either by the neoplastic tissue or by the host in response to the tumor
TL;DR: It is suggested 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.
Abstract: The production of short-chain fatty acids and ammonia was measured in 16.6% fecal homogenates from 50 subjects incubated at 37 degrees 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.