The Role of Proteinase in Acanthamoeba keratitis and the Effect of Amniotic Membrane as a Proteinase Inhibitor

This study was performed to investigate the biochemical properties of Acanthamoeba proteinase, its role in the pathogenesis of Acanthamoeba keratitis and the therapeutic effect of the homogenate of amniotic membrane as a proteinase inhibitors. Acanthamoeba castellanii isolated from the keratitis patient was cultured in PYG medium, in which the excretory and secretory products were analysed. The secretory proteinases of A. castellanii wre identified using in vitro azocasein assay, activity-PAGE, and various protein substrate degradation assays, and one of them was purified and characterized. The pruified secretory proteinase was a kind of serine proteinase. Its molecular weight was 105 kDa and optimal pH was 8.5. It was able to degrade the various protein substrates such as fibronectin, IgA, IgG, fibrinogen. The various proteinase ingibitors and the amniotic membrane homogenates were tested in vitro against the purified seirne proteinase. The amniotic membrane homegenates markedly showed the inhibitory effect against the enzyme activity and this inhibitory effect was also revealed in animal study. In vivo study, this purified proteinase was infected into 14 pigmented rabbit corneas, pretreated with steroids. The corneal lesions induced by both of the purified proteinase and A. castellanii, showed similar clinical findings each other, in which the stromal infiltration and opacity with epithelial defect was revealed. These corneal lesions were significantly inhibited without any side effects of the amniotic membrane homogenates. Conclusively, Acanthamoeba proteinase was closely associated with the pathogenesis of Acanthamoeba keratitis. This study provides a successful animal model of Acanthamoeba keratitis using pigmented rabbit. And the fact that Acanthamoeba-induced corneal lesions were inhibited by the amniotic membrane homogenate, suggested that the amniotic membrane homogenate have the ability of the serine protinase inhibition further investigative studies are also necessary.

Reasonable Time for Removal of the Nasogastric Tube after a Radical Gastrectomy

The necessity for routine prophylactic nasogastric tube decompression after a gastrectomy is still in controversy. Several reports have indicated that nasogastric tube decompression is unnecessary and that the tube may even be harmful with serious discomforts. A D2 gastrectomy (which means a D2 lymph node dissection during gastric cancer surgery) for a gastric carcinoma is an extensively destructive procedure which takes a longer operation time than a conventional gastrectomy, destroys both sympathetic and parasympathetic nerve fibers in the upper retroperitoneum, and may interfere with the gastrointestinal motility after the operation. Therefore, we have carried out a retrospective study with 206 gastrectomized gastric-cancer patients to evaluate the necessity of nasogastric tube decompression and whether the tube influences the gas-passing time, the morbidity, and mortality after operation.

Hepatic Resection for Intrahepatic Stones

The intrahepatic stones and associated cholangitis result in progressive biliary stricture, hepatic atrophy, hepatic abscess and ultimately in irreversible liver cirrhosis and biliary malignancy of the liver. Although removal of intrahepatic stones using stone fragmentation and cholangioscope has been a general treatment modality, hepatic resection with removal of the affected ducts should be required for a permanent cure. We experienced hepatic resection of 100cases with intrahepatic duct calculi from November 1978 to May 1996 in the Department of Surgery, Hanyang University Hospital. The results were as follows: 1) The peak incidence of age was noted in the 4th decade (35 cases, 35.0%),5th decade (26 cases, 26.0%). 2) The male to female ratio was 46(46.0%):54(54.0%) in 100 cases. 3) Previous biliary operation(cholecystectomy with T-tube choledochostomy) was done in 30(30.0%) cases. 4) The most common clinical symptom and sign were RUQ pain(75 cases, 75.0%) and RUQ tenderness(75 cases, 75.0%). 5) In the lab findings, Alk P(55 cases, 55.0%) and ALT(52 cases, 52.0%) were especially increased. 6) 80 cases(80.0%) of intrahepatic stones were found in the left intrahepatic duct and 60 cases(60.0%) of Intrahepatic duct stones were associated cholelithiasis and/or choledocholithiasis. 7) 79 out of 100 cases had left lateral segmentectomy,15 out of 100 cases had left lobectomy, 3 cases had right lobectomy, 1 case pleurisegmentectomy, 1 case bisegmentectomy and 1 case atypical resection of the liver. 8) The incidence of residual stones was 10.0% and the incidence of recurrent cholangitis was 9.0%(9 cases). 9) The postoperative complications were wound complications(16 cases, 16.0%), chest complications(13 cases, 13.0%), bile leakage(4 cases, 4.0%), subhepatic abscess(3 cases, 3.0%). 10) The intrahepatic stones were combined with 3 cholangiocarcinoma,2 hepatocellular carcinoma and 1 GB cancer.