Yoshifumi Matsui

Effectiveness of Hydroxyethyl Starch (HES) on Purification of Pancreatic Islets

BACKGROUND The isolation of large-scale and high-quality islets from the pancreas is essential for a successful islet transplantation. We developed a hydroxyethyl starch (HES)-Collins solution as the purification medium and evaluated its usefulness on islet isolation from the pancreas of beagle dogs. MATERIALS AND METHODS The pancreas of beagle dog was digested using our original 2-step automated technique. Islets were purified by discontinuous purification method on HES-Collins solution (group 1, n = 10) or Euro-Ficoll solution (group 2, n = 16) with a COBE2991 cell processor. Islet yield and purity, changes in islet number during 3-day cultures, static incubation, perifusion study, and insulin content were examined. In addition, the islets were autotransplanted into the liver via the portal vein. RESULTS Although no significant differences were detected, yield and purity were higher in group 1. After 3 days of culture, the islet number decreased less in group 1. Both under static incubation and in the perifusion study, stimulation indices were 4.50 +/- 1.82 and 6.02 +/- 1.05, which were significantly higher than the 2.18 +/- 0.67 and 3.32 +/- 1.46 observed in group 2. Also, insulin content of the islets was significantly higher in group 1 than in group 2. Fasting blood glucose levels were maintained at values below 100 mg/dl for 100 days in group 1 and around 200 mg/dl in group 2. CONCLUSIONS The use of HES-Collins solution was associated with an improvement of islet yield and purity. Also, islet viability and function were preserved longer during culture. Accordingly, islet purification using HES-Collins solution might be recommended for clinical islet transplantation.

Granular cell tumor of the esophagus —report of a case and review of the literature—

We report herein a case of a 46 year old man presenting with a gastric ulcer in whom an endoscopy happened to detect an elevated lesion in the lower esophagus. Endoscopic biopsy proved sufficient for determining the diagnosis of a granular cell tumor (GCT). Electron and microscopic studies suggest that GCT are derived from Schwann cells. Although commonly found in the tongue and skin, GCT are rarely seen in the gastrointestinal tract, especially in the esophagus. However, advances in endoscopic techniques will increase the opportunity of detecting GCT of the esophagus.

Hepatic protein synthesis rate of liver specimens as a predictor of viability in rat cold ischemia liver transplantation model

BACKGROUND/AIMS We have previously reported that the hepatic protein synthesis rate, calculated as the uptake rate of L-[4.5 3H] leucine by the protein fraction during a 10-min incubation of a 16-G needle biopsy specimen of liver tissue, represents a high level of liver function and is therefore useful for evaluating liver function. We investigated the hepatic protein synthesis rate level in a pre-transplant liver to learn if it might predict the outcome in a rat orthotopic liver transplantation model. METHODS Grafts were stored, liver specimens were obtained using a 21-G Chiba type II skinny needle, and the hepatic protein synthesis rate was calculated. Subsequently, liver transplantation was performed, and the hepatic protein synthesis rate level of revascularized liver, tissue blood flow rate, serum alanine aminotransferase, lactate dehydrogenase, hyaluronic acid, ketone body rate, and 2-week survival were examined. RESULTS The hepatic protein synthesis rate of pretransplant liver was correlated with parameters of post-transplant liver function: hepatic protein synthesis rate of the revascularized liver (r=0.92, p<0.0001), tissue blood flow rate (r=0.77, p<0.004), serum alanine aminotransferase (r=-0.69, p<0.003), lactate dehydrogenase (r=-0.54, p<0.03), hyaluronic acid (r=-0.86, p<0.0002), and ketone body rate (r=0.57, p<0.02). Pretransplant hepatic protein synthesis rate in survivors was 263.6+/-54.2 nmol/mg protein/10 min, while that in nonsurvivors was significantly lower at 162.0+/-39.0 (p<0.0001). When evaluation was made using a logistic regression model, the accuracy predicted using the value of hepatic protein synthesis rate was 95% (19/20). CONCLUSIONS These results suggest that measuring the hepatic protein synthesis rate of the grafts with a 21-G Chiba type II skinny needle may be a predictive criterion in the assessment of graft viability.