Biomedical subjects

T Higashiguchi

Publications and source records attributed to T Higashiguchi.

40 records · Page 3Linked to original sources

PubMedDate not supplied

Addition of glucagon to lipid-free total parenteral nutrition reduces production of prostaglandin E2 by stimulated splenic macrophages.

Sepsis is a major complication of total parenteral nutrition (TPN). Impaired immunity has been suggested as being responsible for TPN-related sepsis, but it is unknown how the immune system is affected by TPN. We recently found that administration of lipid-free TPN resulted in an increase in prostaglandin E2 (PGE2) release by stimulated splenic macrophages. This observation suggested that TPN may impair immunity through the prominent immunosuppressive effects of PGE2. In the present study, we tested the hypothesis that addition of glucagon to TPN solution may protect against the immunosuppressive effect of TPN by modifying PGE2 secretion. Adult, male Sprague-Dawley rats (n = 18) underwent jugular vein cannulation: group 1 (n = 7) received intravenous saline and chow ad libitum; group 2 (n = 6) received TPN (80 mL/24 h); and group 3 (n = 5) received TPN (80 mL/24 h) plus glucagon (100 micrograms/24 h). After 10 days, spleens were removed and splenic macrophages were isolated and cultured for 24 h in plain M199 medium (nonstimulated) or in medium containing Escherichia coli lipopolysaccharide (5 micrograms/mL) (stimulated). PGE2 release was determined by enzyme-linked immunosorbent assay. There were no differences in PGE2 release between the groups of nonstimulated cells, but when stimulated with lipopolysaccharide, the macrophages from the TPN rats (group 2) released more PGE2 (81.68 +/- 25.99 ng/2.5 x 10(6) cells) than the control group (16.04 +/- 3.26 ng/2.5 x 10(6) cells). The release of PGE2 was normalized in the TPN animals treated with glucagon (15.71 +/- 3.33 ng/2.5 x 10(6) cells). This difference was significant, with p < .05 by Tukey's test after analysis of variance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗

PubMedDate not supplied

Effect of glutamine on protein synthesis in isolated intestinal epithelial cells.

The influence of glutamine on protein synthesis in small-bowel enterocytes was tested. Enterocytes were isolated from different levels of the villi of rat jejunum and were incubated in the presence of different glutamine concentrations, up to 3.4 mmol/L. Protein synthesis was determined by measuring incorporation of 3H-phenylalanine into trichloroacetic acid-precipitated proteins. Glutamine, but no other amino acids, stimulated protein synthesis in enterocytes from all levels of the villi. A maximal effect was noted at a glutamine concentration of 0.67 mmol/L, which is the normal plasma concentration. The amino acid stimulated the synthesis of both secreted and nonsecreted proteins. The stimulatory effect of glutamine on protein synthesis was blocked by the glutaminase inhibitor 6-diazo-5-oxo-L-norleucine and was duplicated by equimolar concentrations of acetoacetate or 3-hydroxybutyrate. The results suggest that glutamine stimulates protein synthesis in small-bowel enterocytes and that this effect of glutamine is related to provision of energy. The findings are important because they suggest that increased protein synthesis may be one of the mechanisms by which glutamine exerts its protective effect on gut mucosa during critical illness.

Animals↗

PubMedDate not supplied

Preoperative biliary drainage in obstructive jaundice.

BACKGROUND/AIM: Although the role of preoperative percutaneous transhepatic biliary drainage in obstructive jaundice has been the subject of controversy in many other countries, in Japan, almost all surgeons agree that biliary decompression should be performed prior to the surgical treatment in obstructive jaundice. This study was performed in order to determine the role of preoperative percutaneous transhepatic biliary drainage in obstructive jaundice. PATIENTS AND METHODS: We evaluated 238 patients with preoperative obstructive jaundice, and also studied its pathophysiology in experimental animal models. RESULTS: Both of these studies demonstrated that this procedure should be performed if the value of total bilirubin is more than 5 mg/dl, the ICG Rmax value of the future remnant liver is less than 0.4 mg/kg/min, and the duration of jaundice is more than 3 weeks. Preoperative biliary drainage improves the liver function, so that major operations can be safely performed without major complications. CONCLUSIONS: It therefore seems preferable that patients undergo preoperative biliary decompression to reduce serum total bilirubin to below 5 mg/dl, and to improve hepatic and reticuloendothelial functions and hepatic reserve prior to any major surgical operation.

Adult↗

PubMedDate not supplied

Cell biological evaluation of biliary drainage prior to hepatectomy in obstructive jaundice.

BACKGROUND/AIM: The necessity and efficacy of biliary drainage prior to major surgery in patients with obstructive jaundice have been reported in various clinical and experimental studies in Japan. However, it is not enough that Western countries understand the advantage of preoperative drainage. In this study, therefore, cytoprotective effect of preoperative biliary drainage drainage was evaluated using the cell biological technique. MATERIALS AND METHODS: Ten jaundiced dogs and 10 with drainage (after induction of jaundice) were each divided into two groups: those with and those without 40% hepatectomy. Using these four groups, the advantage of biliary drainage before hepatectomy in obstructive jaundice was studied, using isolated hepatocytes and Kupffer cells. RESULTS: In jaundiced dogs, isolated hepatocyte viability and intracellular cyclic AMP concentration were considerably reduced. The bleb formation rate, culture supernatant lipid peroxide and lactate dehydrogenase contents, and plasma thromboxane B2 and 6-keto-PGF1 alpha levels all markedly increased. These changes were more exaggerated in those after hepatectomy. In the dogs with drainage, all of these values were approximated to those in normal animals. The changes following hepatectomy in dogs with drainage were also less pronounced in comparison with jaundiced animals. CONCLUSIONS: These findings suggest that biliary drainage prior to hepatectomy in obstructive jaundice mitigates liver impairment, both at the cellular level and in terms of prostanoid metabolism. It was concluded that preoperative biliary drainage prior to hepatectomy ensures better results for obstructive jaundice.

Animals↗