Mitsuko Ichimura

Study on free radicals and pancreatic fibrosis-pancreatic fibrosis induced by repeated injections of superoxide dismutase inhibitor

The exact mechanisms of the development of pancreatic fibrosis are still unknown. To clarify the relationship between pancreatic fibrosis and free radicals, the effect of the administration of a superoxide dismutase (SOD) inhibitor, diethyldithiocarbamate (DDC), on pancreatic fibrosis in rats was studied. A single intraperitoneal injection of 500 mg/kg of DDC significantly reduced SOD activity and significantly increased lipid peroxidation products in the pancreas, showing no histologic changes of inflammation or necrosis. Repeated administration of 500 mg/kg DDC, twice a week, caused inter-and intralobular fibrosis with atrophy of acinar cells in the pancreas for at least 2 weeks without fibrosis of the liver and kidney. Administration of allopurinol showed preventive effects against DDC-induced pancreatic fibrosis. In conclusion, repeated administration of DDC, which caused pancreatic fibrosis, is a new experimental model of pancreatic fibrosis from the viewpoint of oxidative stress.

Matrix metalloproteinase-2 in pancreatic juice for diagnosis of pancreatic cancer

Introduction Matrix metalloproteinase-2 (MMP-2) has an activity to degrade type IV collagen and is associated with invasion angiogenesis of malignant tumor. Aim A diagnostic value of MMP-2 in pancreatic juice was studied in the diagnosis of pancreatic cancer. Methodology Using gelatin zymography, active MMP-2 and proMMP-2 were determined in pancreatic juice obtained endoscopically from 12 patients with pancreatic cancer, 11 with chronic pancreatitis, and 7 control subjects. Results ProMMP-2 was detected in 12 of 12 patients (100%) with pancreatic cancer, 6 of 11 (54.5%) with chronic pancreatitis, and 3 of 7 (42.9%) controls. Active MMP-2 was detected in 11 patients (91.6%) with pancreatic cancer, 2 (18.2%) with chronic pancreatitis, and none of the control subjects. An activation ratio of MMP-2 (active MMP-2/total MMP-2) in pancreatic juice is significantly higher in pancreatic cancer (23.4 ± 4.4%, mean ± SE) than in chronic pancreatitis (2.1 ± 1.7%) and controls (0%) (p < 0.01). Active MMP-2 was also detected in pancreatic juice from three cases of small pancreatic cancer (tumor <2 cm in diameter). Conclusion Our observation suggests that detection of active MMP-2 in pancreatic juice using gelatin zymography may be useful for the diagnosis of pancreatic cancer.

Camostat, an oral trypsin inhibitor, reduces pancreatic fibrosis induced by repeated administration of a superoxide dismutase inhibitor in rats

Background and Aim:  An oral trypsin inhibitor, camostat (CM), has a beneficial effect on chronic pancreatitis, but its mechanism is not yet fully understood. Recently, pancreatic stellate cells (PSC) have been reported to play an essential role in pancreatic fibrosis. An experimental model of pancreatic fibrosis induced by a superoxide dismutase (SOD) inhibitor (diethyldithiocarbamate [DDC]) was developed in rats. Thus, the effect of an oral trypsin inhibitor on pancreatic fibrosis and PSC was investigated.

Prevention of hyperlipidemic acute pancreatitis during pregnancy with medium-chain triglyceride nutritional support

SummaryConclusionA combination of diet therapy, nutritional support with medium-chain triglycerides (MCT), and well-planned preterm Cesarean delivery on demand is an effective measure to prevent gestational hyperlipidemic pancreatitis and leads to successful childbirth.BackgroundPrevention and therapy of gestational hyperlipidemic pancreatitis are important, although difficult, because the condition carries a high maternal and fetal morbidity and mortality.ResultsWe describe a 32-yr-old female with lipoprotein lipase-deficient familial hypertriglyceridemia who had recurrent episodes of acute pancreatitis. The third episode occurred with worsened hyperlipidemia 7 yr earlier at 32 wk of her first pregnancy and resulted in fetal death. The fourth and fifth episodes were also accompanied by marked hyperlipidemia probably caused by drug discontinuance and dietary noncompliance. She became pregnant. Serum triglyceride levels were controlled below 2000 mg/dL by strict monitoring with low-fat, low-calorie diet and MCT nutritional support. A premature but healthy infant was born by Cesarean delivery at 36 wk of gestation when the mother presented with mild abdominal pain and was found to have uterine contractions. The ensuing clinical course has been uneventful.

Purification and characterization of alkaline phosphatase from Bacillus stearothermophilus.

Soluble alkaline phosphatase from the thermophilic bacterium Bacillus stearothermophilus was purified by a combination of chromatographic methods, and its properties were examined. The purified enzyme had specific activity of 4.43 μmol p‐nitrophenol/min per mg of protein and seemed to be a single band on SDS/PAGE with a molecular mass of 32 kDa. Its apparent Km for p‐nitrophenyl phosphate was 1.114 mM. The enzyme exhibited an optimal pH of approx. 9.0 and exhibited its highest activity at 60–70 °C. It also showed a bivalent cation requirement for activity, with maximal enhancement in the presence of Mg2+. In addition, significant thermal stability was observed in comparison with counterparts from mesophiles. Its partial N‐terminal sequence was T1FSIVAFDPATGELGIAVQ19 as estimated by automated Edman degradation method. A search on the SwissProt database did not reveal any similar protein sequences from other sources.

Pancreatic enzyme supplement improves dysmotility in chronic pancreatitis patients

Background and Aims:  Impaired gallbladder contraction and rapid gastric emptying in patients with chronic pancreatitis may be the result of depleted pancreatic exocrine function. The authors tested whether oral pancreatic enzymes can improve the dysmotility or not.

Xanthine oxidase-derived free radicals directly activate rat pancreatic stellate cells.

Background and Aim:  Free radicals are reported to be associated with fibrosis in the pancreas. It is generally accepted that pancreatic stellate cells (PSC) play an important role in pancreatic fibrosis. However, the exact role of free radicals in activation of PSC has not been fully elucidated. In the present study, using a superoxide dismutase (SOD) inhibitor, diethyldithiocarbamate (DDC) with cultured PSC, we investigated how free radicals act on the activation of PSC.

Oral administration of taurine improves experimental pancreatic fibrosis

Background and Aim:  The mechanism of pancreatic fibrosis is unclear. Taurine is used in the clinical treatment of a wide variety of diseases, but its effect on improving pancreatic fibrosis is unknown. We examined whether a diet with added taurine improves pancreatic fibrosis induced by dibutyltin dichloride (DBTC) in an experimental chronic pancreatitis rat model. In addition, we examined the influence of taurine on pancreatic stellate cells.