Byungmoo Yoo

Novel antioxidant ameliorates the fibrosis and inflammation of cerulein-induced chronic pancreatitis in a mouse model.

Background/Aim: Oxygen free radicals (OFRs) mediate an important step in the initiation of experimental acute pancreatitis and several clinical findings suggested the possible contribution of OFRs to the pathogenesis of pancreatic fibrosis. So far, there are no studies which reporting potential role of OFRs in development of chronic pancreatitis with the prevention with antioxidants. This study was aimed to establish the mice model of chronic fibrosing pancreatitis and to prove the involvement of OFRs in chronic pancreatitis with fibrosis. Methods: Repeated intraperitoneal cerulein injection was performed to induce chronic pancreatitis in mice. Histological changes in the pancreas were examined, and markers for oxidative stress were measured in the pancreatic tissue and serum of the mice. DA-9601, a phytochemical possessing anti-inflammatory and antioxidative action, was given together with cerulein to the mice. Results: Repeated intraperitoneal injection of cerulein provoked significant severity of chronic fibrosing pancreatitis after 5 weeks. After treatment of DA-9601, the extents of pancreatic fibrosis were statistically significantly decreased in accordance with lessened pancreatic inflammations. The NF-ĸB binding activities were increased in chronic pancreatitis, which were significantly attenuated after DA-9601 treatment. The levels of myeloperoxidase and iNOS activities were also significantly decreased in DA-9601-treated group compared to the pancreatitis only group. Cytoprotective proteins such as heat shock protein-70 (HSP) and metallothionein were significantly increased in the DA-9601-treated group. DA-9601 decreased the expressions of α-SMA and type I collagen in cultured pancreatic stellate cells. Conclusions: Oxidative stress was principally involved in the pathogenesis of chronic pancreatitis with fibrosis.

Effect of long-term administration of rebamipide on Helicobacter pylori infection in mice.

Background : It has been suggested that chronic, persistent, uncontrolled inflammations in the stomach could provide the basic step for the beginning of carcinogenesis. One of the potential clinical applications of rebamipide is the inhibition of the immunoinflammatory response in gastric mucosa imposed by Helicobacter pylori.

Effect of gastric distension on sphincter of Oddi motility in humans

Background~Aim: Although there are many reports in the literature of clinical syndromes resulting from sphincter of Oddi (SO) dysfunction, little is known about the effects of normal physiologic stimuli on SO function. The present study was designed to evaluate the effect of gastric distension on the SO motility through percutaneous transhepatic manometry. Methods: The motility of SO and small bowel(SB) were measured simultaneously by percutaneous transhepatic manometry using 8-lumen perfusion catheter (Zinetic Medical, 3 orifices for SO manometry: 2mm apart and 5 orifices for SB manometry: 10mm apart) in 6 patients(M:F=3:3, mean age: 67.5 years) with intrahepatic stones after complete stone removal by cholangioscopic lithotripsy. They had no previous hepatobiliary or gastrointestinal operation, papillary stenosis, and periampullary diverticulum. After positioning the catheter via PTBD tract, basal recording was performed. Gastric balloon was performed by ballooned nasogastric tube. The balloon was inflated on the regular contraction phase of SO until the patients felt epigastric discomfort. Result: The mean inflation volume of gastric balloon was 450ml (range: 300-700ml). At baseline manometric study, the basal pressure and amplitude and frequency of phasic contraction wave were 20.8 ± 2.3mmHg, 93.4 + 39.1mmHg, and 3.5 ± 1.3/min, respectively. After inflating the gastric balloon, the frequency of phasic contraction decreased to 0.8 + 1.2/min(p 0.05) and 36.6 ± 50.8mmHg(p>0.05), respectively. Conclusion: Gastric distension does not affect SO basal pressure and amplitude of phasic contraction wave, but decreases the contraction frequency of SO in humans.