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The aim of this work was to characterize an exopolysaccharide by Rhodotorula glutinis KCTC 7989 and to investigate the effect of the culture conditions on the production of this polymer. The extracellular polysaccharide (EPS) produced from this strain was a novel acidic heteropolysaccharide composed of neutral sugars (85%) and uronic acid (15%). The neutral sugar composition was identified by gas chromatography as mannose, fucose, glucose, and galactose in a 6.7:0.2:0.1:0.1 ratio. The molecular weight of purified EPS was estimated to be 1.0-3.8 x 10(5) Dalton, and the distribution of the molecular weight was very homogeneous (polydispersity index = 1.32). The EPS solution showed a characteristic of pseudoplastic non-Newtonian fluid at a concentration >2.0% in distilled water. The maximum EPS production was obtained when the strain was grown on glucose (30 g/L). Ammonium sulfate was the best suitable nitrogen source for EPS production. The highest yield of EPS was obtained at a carbon to nitrogen ratio of 15. The EPS synthesis was activated at the acidic range of pH 3.0-5.0 and increased when the pH of the culture broth decreased naturally to <2.0 during the fermentation. When the yeast was grown on glucose (30 g/L) and ammonium sulfate (2 g/L) at 22 degrees C at an initial pH of 4.0, EPS production was maximized (4.0 g/L), and the glucose-based production yield coefficient and carbon-based production yield coefficient were 0.30 g of EPS/g of glucose and 0.34 g (carbon of EPS)/g (carbon of glucose), respectively.

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The anticancer activity of ginseng originated mainly from lipid-soluble components. The hexane extract of ginseng marc (HEGM) showed a potent inhibitory activity on human hepatoma (HepG2, GI 50 = 41.7 lg/ml) and breast (MCF-7, GI 50 = 54.4 lg/ml) cancer cell proliferation in vitro in a concentration-dependent manner as did the hexane extract of ginseng (HEG), with GI 50 values of 21.1 lg/ml in HepG2 and 41.2 lg/ml in MCF-7. The water extract of ginseng (WEG) possessed a low anticancer activity against both cancer cell lines, but the hexanesoluble fraction of WEG (HSF/WEG) showed a potent anticancer activity against HepG2 (GI 50 = 38.7 lg/ml) and MCF-7 cells (GI 50 = 51.1 lg/ml). The hexane extraction in ginseng was a very promising protocol for the maximum recovery of the anticancer active components in high concentrations. Also the adoption of hexane extraction after water extraction of ginseng was successful in the effective utilization of the residual lipid-soluble anticancer active components in ginseng marc.

Iatrogenic gastric perforation is one of the most serious complications during therapeutic endoscopy, despite significant advances in endoscopic techniques and devices. This case study evaluated the clinical efficacy and safety of the rescue endoscopic band ligation (EBL) technique in iatrogenic gastric wall perforation following the failure of primary endoclip closure. Five patients were enrolled in this study. These patients underwent emergency endoscopy following the onset of acute gastric wall perforation during endoscopic procedures. The outcome measurements were primary technical success and immediate or delayed procedure-related complications. Successful endoscopic closure using band ligation was reported in all patients, with no complication occurring. We conclude that EBL may be a feasible and safe alternate technique for the management of acute gastric perforation, especially in cases where closure is difficult with endoclips.

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Immobilization of a protease, Flavourzyme, by covalent binding on various carriers was investigated. Lewatit R258-K, activated with glutaraldehyde, was selected among the tested carriers, because of the highest immobilized enzyme activity. The optimization of activation and immobilization conditions was performed to obtain high recovery yield. The activity recovery decreased with increasing carrier loading over an optimal value, indicating the inactivation of enzymes by their reaction with uncoupled aldehyde groups of carriers. The buffer concentrations for carrier activation and enzyme immobilization were optimally selected as 500 and 50 mM, respectively. With increasing enzyme loading, the immobilized enzyme activity increased, but activity recovery decreased. Immobilization with a highly concentrated enzyme solution was advantageous for both the immobilized enzyme activity and activity recovery. Consequently, the optimum enzyme and carrier loadings for the immobilization of Flavourzyme were determined as 1.8 mg enzyme/mL and 0.6 g resin/mL, respectively.