• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.250-256
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• 1998

D-Tagatose production from D-galactose was investigated using 35 type strains of American Culture Type Collection (ATCC) and Korean Collection for Type Cultures (KCTC) which have potential to produce D-tagatose. Enterobacter agglomerans ATCC 27987 was selected as a D-tagatose producing strain due to its short fermentation time and high production of D-tagatose. Optimization of the culture conditions for D-tagatose production by E. agglomerans ATCC 27987 was performed. Among various carbon sources, D-galactose was the most effective carbon source for D-tagatose production. As the D-galactose concentration was increased, cell growth and D-tagatose production increased. Effect of nitrogen sources on D-tagatose production was studied. Of inorganic nitrogen sources, ammonium sulfate was effective one for D-tagatose production and yeast extract was the most suitable organic nitrogen nutrient. The concentrations of inorganic compounds such as KH$_2$PO$_4$, K$_2$HPO$_4$, and MgSO$_4$$.$7H$_2$O were also optimized for D-tagatose production. The optimal medium was determined to contain D-galactose of 20 g/l, yeast extract of 5.0 g/l, (NH$_4$)$_2$SO$_4$ of 2.0 g/l, KH$_2$PO$_4$ of 5.0 g/l, K$_2$HPO of 5.0 g/l, and MgSO$_4$$.$7H$_2$O of 5 mg/l. The optimal environmental conditions in a 250-$m\ell$ flask were found to be pH of 6.0, temperature of 30$^{\circ}C$, and agitation speed of 150 rpm. D-tagatose of 0.41 g/l could be obtained in 24 h from 20 g/l D-galactose at the optimal culture condition without induction and cell concentration.

• Journal of Plant Biotechnology
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• v.33 no.3
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• pp.171-184
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• 2006

According to ISAAA report, the global area of genetically modified (GM) crops increased more than 50 fold during the ten-year period from 1996 to 2005 with a sustained double-digit growth rate of 10%. This biotechnology adoption is one of the highest rates of technology adoption in agriculture history and this phenomenon indicates that the industrial value of the GM crops is highly perspective. In addition, the year 2010, 60% of cereal seeds in the global market would be GM or biotechnology related seeds so that the GM crop regards as the second green revolution that could provide a huge impact to food and agriculture. Nevertheless, there has not been any GM variety ever successfully commercialized in Korea and even none of the GM crops has ever been approved for safety testing by risk assessment. This seems that Korean agriculture industry might be indeed lost in the war of future seed market. However, lots of evidence show that Korean scientists have established advanced technologies and protocols to develop GM crops for last 20 years. Actually there have been many cases of successful transformation of crops that were previously known very difficult in transforming. Therefore, Korean agbiotechnology arena firmly holds an infrastructure for developing GM crops with a superior technology. Then what were the problems? Why has even a single GM crop not been commercialized in Korea? The tardiness shown by business in adopting the GM crop is caused by many factors: academical weakness, poor research funding, short knowledge of risk assessment, public concern, no successful experience, lack of professional leaders on GM variety development, lack of systems toward industrialization and inappropriate target transgenes from the beginning. In order to catch up in the race for the new green industry, each one of us in private sectors alongside academia and national research institutes needs to focus altogether on what can be done best in terms of choosing crops, investing fund and establishing a road map for commercialization of GM crops.

• Journal of dental hygiene science
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• v.6 no.1
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• pp.1-9
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• 2006

Cathepsin K (cat K) is the major cysteine protease expressed in osteoclasts and was thought to play a key role in matrix degradation during bone resorption. It was shown that the intracellular maturation of cat K was prevented by the cAMP antagonist, Rp-cAMP, and the protein kinase A (PKA) inhibitors of KT5720 and H89. In contrast, forskolin, a adenylate cyclase agonist, rather induced Cat K processing and maturation in osteoclasts. Furthermore, to determine whether cat K processing and maturation signaling involves protein kinase C (PKC), mouse total bone cells were treated with calphostin C, a specific inhibitor of PKC, however, no effect was observed, indicating that calphostin C did not affect to osteoclast-mediated cat K processing and maturation. Thus, it is indicated that the cAMP-PKA signaling pathway regulates cat K maturation in osteoclasts. Since secreted proenzymes have the potential to reenter the cell via M6P receptor, to prevent this possibility, it was tested cAMP antagonist Rp-cAMP and the PKA inhibitors KT5720 and H89 in the absence or presence of M6P. Inhibition of cat K processing by Rp-cAMP, KT5720, or H89 was observed in a dose-dependent manner. Furthermore, the addition of M6P resulted in enhanced potency of Rp-cAMP, KT5720 and H89. These dose-dependently inhibited in vitro bone resorption with a potency similar to that observed for inhibition of cat K processing.

• Journal of Gastric Cancer
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• v.5 no.2
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• pp.89-94
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• 2005

Purpose: Early gastric cancer (EGC) has an excellent prognosis compared to advanced gastric cancer. The 5-year survival rate for EGC now exceeds $90\%$, and EGC is recognized as a curable malignancy. The important prognostic factor in EGC is the status of lymph-node metastasis. Despite conserving surgery being suggested for EGC at present, it is of vital importance to select a surgical method appropriate to each individual case. This retrospective study was undertaken to clarify clinicopathologic features and factors related to lymph-node metastasis in submucosal gastric cancer in order to determine an appropriate therapy. Materials and Methods: This study analyzed the clinicopathologic features for 279 patients with a submucosal gastric carcinoma (Group I) and compared with those of patients with mucosal (Group II) or muscularis proprial gastric carcinoma (Group III). All patients were operated on from 1981 to 1999 at Chonnam University Hospital. There were no statistically significant differences among the groups with respect to age, gender, tumor location, hepatic metastasis, or peritoneal dissemination. Results: Positive lymph node metastasis was found in 47 ($16.8\%$) of the 279 patients with a submucosal gastric carcinoma. The incidence of lymph-node metastasis was significantly higher in patients with a submucosal gastric carcinoma than in patients with a mucosal gastric carcinoma ($16.8\%\;vs.\;3.9\%\;$; P<0.01). Therefore, depth of invasion was a significant factor affecting in lymph-node metastasis. The 5-year survival rates were $88.6\%$ for patients in Group I, $95.2\%$ for patients in Group II, and $72.7\%$ for patients in Group III (P<0.01 for Group I vs. Group II; Group I vs. Group III). In patients with a submucosal gastric carcinoma, the survival rate with positive lymph nodes was significantly poorer than that of patients without lymph-node metastasis ($87.3\%\;vs.\;94.2\%$; P<0.01). Conclusion: Gastrectomy with D2 lymph node dissection is an appropriate operative procedure for patients with a submucosal gastric carcinoma.