Kinya Sando

Alanyl-Glutamine-Supplemented Parenteral Nutrition Increases Luminal Mucus Gel and Decreases Permeability in the Rat Small Intestine

BACKGROUND Effect of supplemental alanyl-glutamine in standard TPN (S-TPN) on luminal mucus gel and small intestinal permeability was investigated. METHODS Thirty Sprague-Dawley rats were divided into group I (n = 10), receiving standard rat diet; group II (n = 10), receiving S-TPN; and group III (n = 10), receiving alanyl-glutamine-supplemented TPN for 1 week. After 1 week, fluorescein isothiocyanate (FITC)-dextran was injected into the small intestine of the rats, and they were killed. A small intestinal sample and portal blood were obtained for morphologic and functional analysis of mucus gel and intestinal permeability. RESULTS In group II, thickness and optical density of mucus gel per millimeter serosal length of intestine were significantly lower than group I (p<.001) and were significantly higher in group III than in group II (p<.001). The number of goblet cells in the villi and in the crypt of the small intestine was significantly lower in group II than in group I (p<.001) and was significantly higher in group III than in group II (p<.001), with the exception of the villi of jejunum. Villous and crypt surface area per millimeter serosal length of intestine was significantly lower in group II than in group I (p<.001) and was significantly higher in group III than in group II (p<.001). Small intestinal permeability to FITC-dextran was significantly higher in group II than in group I (p<.001) and was significantly lower in group III than in group II (p<.001). Glucosamine synthetase level was significantly higher in group III than in group I and ileum of group II (p<.001). CONCLUSIONS Alanyl-glutamine-supplemented TPN prevents a decrease in mucus gel and an increase in small intestinal permeability associated with S-TPN.

Influence of glutamine-supplemented parenteral nutrition on intestinal amino acid metabolism in rats after small bowel resection.

Glutamine (Gln)-supplemented total parenteral nutrition (TPN) has been shown to improve mucosal adaptation after massive small bowel resection (SBR); however, its influences on intestinal amino acid metabolism remain unknown. In this study, intestinal amino acid flux, circulating plasma aminogram, mucosal glutaminase activity and protein, and DNA content were measured 7 days after massive SBR in rats receiving either standard (Std) or Gln-supplemented TPN. Sham-operated rats and rats fed chow after enterectomy served as controls. The uptake of Gln and the release of citrulline (Cit) by the remaining intestine was significantly decreased, with reduced mucosal glutaminase activity after SBR in the Chow and Std-TPN groups. Glutamine supplementation resulted in significantly increased gut Gln uptake compared with Std-TPN (P<0.01). Mucosal glutaminase activity, mucosal protein, and DNA content was also increased by Gln; however, the gut release of Cit remained unchanged (P>0.05). The subsequent decrease in circulating arginine (Arg) in the Gln-TPN group compared with the Std-TPN group (P<0.05) was attributed to an insufficient exogenous supply. These findings show that Gln-supplemented TPN improves mucosal growth and gut Gln uptake after SBR. However, the intestinal production of Cit, which remained low in both TPN groups, may lead to an insufficiency of endogenous Arg synthesis. Thus, both Gln and Arg may be essential amino acids after SBR.

Platelet Glutathione Peroxidase Activity in Long-Term Total Parenteral Nutrition With and Without Selenium Supplementation

Selenium (Se) is not routinely included in total parenteral nutrition (TPN) solution; thus, patients receiving long-term TPN may be at risk of Se deficiency, which may cause fatal cardiomyopathy. Platelet glutathione peroxidase (GSH-Px) activity, as well as Se levels and GSH-Px activity in plasma and erythrocytes during prolonged TPN, was measured in six patients with chronic gastrointestinal disease. During the time course of TPN, Se administration was discontinued for 12 weeks, and then resupplemented for another 12 weeks. Before the study period, all Se indices had been maintained within the normal range. After discontinuation of Se supplementation, a significant decrease in platelet GSH-Px activity was observed after 1 week (from 64 +/- 7 [mean +/- SD] to 39 +/- 5 U/g of protein). After resupplementation, it increased after 1 week (from 44 +/- 9 to 65 +/- 10 U/g of protein). Plasma Se indices significantly changed within 3 weeks after withdrawal and reintroduction of Se (Se: from 136 +/- 28 to 75 +/- 14 and from 61 +/- 22 to 125 +/- 33 micrograms/L; GSH-Px: from 236 +/- 50 to 140 +/- 36 and from 128 +/- 32 to 220 +/- 64 U/L). Erythrocyte Se indices showed no significant changes during the study period. The results demonstrate that platelet GSH-Px activity is the most sensitive index of Se status in TPN patients.

On-Off Study of Manganese Administration to Adult Patients Undergoing Home Parenteral Nutrition: New Indices of In Vivo Manganese Level:

BACKGROUND Recently, there have been reports that magnetic resonance imaging (MRI) reveals high-intensity T1-weighted images (HI) in the basal ganglia (especially in the globus pallidus) of patients receiving total parenteral nutrition (TPN). This finding is presumably due to excess administration of manganese. We investigated the reversibility and reproducibility of these changes by means of an on-off manganese administration study. We also investigated the temporal relationships between the intensity of T1-weighted images (MRI intensity) and the whole-blood and plasma manganese concentrations to evaluate the potential for the MRI intensity to serve as an index of the in vivo manganese level. METHODS Eleven adult patients undergoing home parenteral nutrition received TPN solutions containing manganese (0 or 20 micromol/d) according to an on-off design. The whole-blood and plasma manganese concentrations were determined at the same time the brain MRI was performed. RESULTS Both the whole-blood manganese concentration and the MRI intensity in the globus pallidus changed in response to the administration and withdrawal of manganese. It took at least 5 months for HI to disappear when manganese was withdrawn, and this change was reversible and reproducible. The whole-blood manganese concentration showed strong correlations with both the MRI intensity and the T1 value (r = 0.7693, -0.7011). The MRI intensity and the T1 value showed a strong correlation (r = -0.9051). CONCLUSIONS The whole-blood manganese concentration, the MRI intensity in the globus pallidus and the T1 value, an objective index of the MRI intensity, may be useful indices of the manganese level in the body.

Long-Term Outcome of Short Bowel Syndrome in Adult and Pediatric Patients

We reviewed 12 pediatric and 18 adult patients with short bowel syndrome (SBS) from Osaka University Hospital and compared clinical characteristics between them. The length of the residual small intestine ranged from 0 to 75 cm (mean 47 cm) in pediatric patients and from 0 to 150 cm (mean 47 cm) in adult patients. In all cases, total parenteral nutrition (TPN) was started immediately after surgery and was gradually replaced by enteral nutrition. Eight pediatric patients (67%) and 4 adult patients (22%) were weaned from TPN. Residual intestinal length in these patients ranged from 27 to 75 cm (mean 57 cm) in pediatric patients and 57 to 150 cm (mean 96 cm) in adult patients. Pediatric patients with residual small intestinal lengths of 0, 16, 25, and 45 cm were not weaned from TPN. None of the adult patients with residual small intestinal length less than 40 cm could achieve complete intestinal adaptation. Five adult patients died due to liver failure (2 cases), heart failure (2 cases), or pneumonia (1 case), whereas all pediatric patients survived. The average life span of indwelling central venous catheters was 511 days and 780 days, and the rate of catheter-related sepsis per 1000 catheter days was 0.73 and 0.48 in pediatric and adult patients, respectively. Plasma levels of arginine and citrulline in patients receiving TPN were significantly decreased compared with those in patients receiving TPN without SBS both in pediatric and adult patients (p < .01). These results indicate that pediatric and adult patients with SBS can survive with TPN and enteral nutrition. The minimum remaining intestinal length necessary for complete bowel adaptation is shorter for pediatric patients than adults, suggesting better bowel adaptation in pediatric patients.

Nitric oxide synthase inhibitor attenuates inflammatory lesions in the skin of zinc-deficient rats

Skin lesions are common manifestations of zinc deficiency in humans and animals, but the pathogenic mechanisms have not been fully clarified. In the present study, a nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), was given to zinc-deficient (ZD) rats to see whether it prevents or delays the occurrence of skin lesions. Weanling male rats were given free access to a ZD diet (2 mg zinc/kg) for 4 wk to induce zinc deficiency. Control rats, including pair-fed (PF) and ad libitum (AL) groups, were given a diet supplemented with zinc (50.8 mg zinc/kg. L-NAME (0.3 g/L in drinking water) was given to some ZD rats for 3 wk, starting at the second week of their ZD dieting. Dermatitis of the extremities, balanitis, stomatitis, and alopecia appeared in ZD but not in AL and PF rats. Administration of L-NAME significantly reduced the frequency of cutaneous and mucocutaneous inflammatory lesions but did not prevent alopecia in the ZD rats. Reverse transcription polymerase chain reaction showed that inducible nitric oxide synthase mRNA was expressed in the paw skin of ZD but not of AL and PF rats. Evaluation of skin microvascular permeability by the Evans blue leakage technique indicated that L-NAME administration significantly attenuated extravasation of Evans blue in the paw skin of ZD rats. Furthermore, stains positive for terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling were condensed and diffusely distributed over the epidermis, dermis, and subcutaneous tissue of paws in ZD rats. ZD rats had intense cell infiltration and parakeratosis in the paw skin. L-NAME administration effectively prevented these morphologic changes. These results demonstrate that nitric oxide synthase inhibitor ameliorates inflammatory lesions of the skin in ZD rats.

Insulin-Like Growth Factor-1 Modulation of Intestinal Epithelial Cell Restitution

After superficial intestinal injury, the mucosal integrity is reestablished by rapid migration of epithelial cells from the adjacent area in a process called restitution. Our previous study suggested that growth hormone improves intestinal healing in an experimental small bowel ulceration, mediated by insulin-like growth factor-1 (IGF-1). The aim of the present study was to assess the role of IGF-1 in mucosal epithelial restitution using an in vitro epithelial wound model. Wounds were established in confluent monolayers of the intestinal cell line, IEC-6. Migration was quantitated in the presence or absence of IGF-1 as the number of cells migrating across the wound edge. Proliferation was assessed by thymidine incorporation. IGF-1-enhanced epithelial cell migration by 2- to 2.5-fold after 12- and 24-hour treatment, respectively, the first step involved in gastrointestinal wound healing. Cell proliferation was significantly stimulated by IGF-1 as well. In addition, expression of transforming growth factor-beta (TGF-beta) mRNA was significantly enhanced in the wounded monolayers treated with IGF-1. IGF-1 receptor mRNA was found to be detectable throughout the gastrointestinal mucosa and in the intestinal epithelial cells. In conclusion, these findings suggest that IGF-1 plays an important role in reconstitution of intestinal epithelial integrity after mucosal injury.

Adhesive mucous gel layer and mucus release as intestinal barrier in rats

BACKGROUND Although it has been reported that total parenteral nutrition induces an increased intestinal permeability and a decreased mucous gel layer covering the intestinal epithelium, the role of mucous gel on intestinal permeability has not been well understood. We examined the in vivo effects of N-acetyl cysteine (NAC) as mucolytic agent and colchicine as suppressant of the mucus production on the intestinal transmission of fluorescein isothiocyanate dextran 70,000 (FITC-dextran). METHODS Rats were divided into four groups. In each group, FITC-dextran (750 mg/kg) with or without NAC (3000 mg/kg) was injected into the small intestinal lumen 3 hours after intraperitoneal injection of saline or colchicine (Col, 10 mg/kg). Thirty minutes after injection of FITC-dextran, blood samples were taken from portal vein to analyze plasma fluorescein concentration by fluorescence spectrometry. Samples of small intestine were sectioned in a cryostat for fluorescence microscopy, and the identical sections were stained by periodic acid-Schiff reaction. RESULTS Plasma FITC-dextran level in NAC group was higher than that in control group (p < .01), that in Col + NAC group was higher than that in Col group (p < .01) and that in Col + NAC group was higher than that in NAC group (p < .05). The spaces between villi were filled with mucous gel in the control and Col groups, whereas those were not entirely filled with mucous gel in NAC and Col + NAC groups. FITC-dextran and mucous gel showed complementary distribution in all rats. The villous interstitial edema was recognized in NAC group and the villi were disrupted in Col + NAC group. CONCLUSIONS These results suggest that intestinal permeability is possibly affected not only by the mucous gel covering the intestinal epithelium but also by mucus release from goblet cells of the small intestine.

Effects of isolated small bowel transplantation on liver dysfunction caused by intestinal failure and long-term total parenteral nutrition

Abstract: It has not been fully determined whether isolated small bowel transplantation (ISBTx) can reverse liver dysfunction caused by intestinal failure requiring long‐term total parenteral nutrition (TPN). A boy with congenital microvillus inclusion disease presented with vomiting and severe diarrhea since the first day of life and had been managed by TPN since then. He suffered from catheter‐related sepsis several times. At 14 yr of age he developed progressive hepatosplenomegaly with thrombocytopenia and coagulopathy. He underwent ISBTx with an ileal graft from his blood‐identical grandmother at the age of 16 yr. Oral feeding was started on the 14th day after ISBTx and gradually increased. TPN was completely withdrawn after 5 months. Liver was palpated 5 cm below the costal margin before ISBTx, while it became non‐palpable 5 months after ISBTx. Serum liver enzyme levels and prothrombin time normalized in the 5 months following ISBTx. Liver biopsy showed marked steatosis, slight cholestasis, and mild bridging fibrosis before ISBTx. Although histological examination of liver biopsy revealed complete disappearance of steatosis 7 and 11 months after ISBTx, liver fibrosis remained unchanged. This clinical experience has shown that although steatosis and cholestasis are reversible after successful ISBTx and withdrawal of TPN, liver fibrosis may remain unchanged.

Lock method using sodium hydroxide solution to clear occluded central venous access devices.

Occlusion of central venous access devices (CVADs) is not an uncommon problem duringlong-term parenteral nutrition. A number of techniques have been developed to deal with obstructed CVADs. This study investigated the effectiveness of the sodium hydroxide (NaOH) lock method for gradual CVAD occlusion. When a progressively declining flow was noticed, 0.1 N NaOH solution was injected into the CVAD and locked. Nineteen CVAD occlusions in 11 home parenteral nutrition patients were treated Sixteen of 19 trials cleared the occlusions, whereas 3 of 19 failed. One of the failures was due to a mechanical occlusion and the other two were able to be restored by using ethanol. There were no significant complications. The benefits of this method are: (1) a shorter treatment time and a lower dose than NaOH infusion therapy, (2) it does not require hospital admission and (3) it does not result in bursting of the catheter.