• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.4
• /
• pp.230-234
• /
• 2010

This study examined the effect of wall friction on deformation characteristics of the cellular bulkhead, in terms of artificial wall friction based on the results of model tests according to the existing penetration ratio and loading height. 1. The effect of wall friction on deformation characteristics of the cellular bulkhead turned out to be less as the loading height decreases and the penetration ratio increases. The yield load also becomes less as wall friction decreases. 2. The ratio of the rotational displacement to the horizontal displacement of the cellular bulkhead becomes less as the loading height decreases and the penetration ratio increases. Hence it is concluded that the effect of wall friction has close relationship with the rotational displacement.

• The Korean Journal of Cytopathology
• /
• v.6 no.1
• /
• pp.18-26
• /
• 1995

In order to compare cytologic findings ol breast carcinoma in fine needle aspiration cytology (FANC) with histologic findings and prognostic factors including histologic grading, lymph node metastasis and stage, 79 cases of infiltrating ductal carcinoma diagnosed by FANC and confirmed by histology were analysed. We especially attempted to col relate nuclear grade, cellularity and smear pattern with histologic grade, type, status of lymph node metastasis and stage. The results are as fellows. 1. High nuclear grade was correlated with high histologic grade, lymph node metastasis and advanced stage. 2. Individual cell pattern was more frequently identified in high histologic grade and scirrhous or solid-tubular type than in low histolgic grade and papillotubular type. 3. Cellularity increased with higher histologic grade and lymph node metastsis. However cellularity was low in scirrhous type. 4. There is no relationship between nuclear grade and histologic type, between smear pattern and lymph node metastasis or stage, and between cellularity and stage. These results suggest that cytologic findings of breast carcinoma such as nuclear grade, cellularity and smear pattern are indicative of histologic findings in relation to histolgic grade and type. Especially, nuclear grade of FANC may yield valuable prognostic information.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.5
• /
• pp.2689-2698
• /
• 2013

Epithelial-to-mesenchymal transition (EMT) is a collection of events that allows the conversion of adherent epithelial cells, tightly bound to each other within an organized tissue, into independent fibroblastic cells possessing migratory properties and the ability to invade the extracellular matrix. EMT contributes to the complex architecture of the embryo by permitting the progression of embryogenesis from a simple single-cell layer epithelium to a complex three-dimensional organism composed of both epithelial and mesenchymal cells. However, in most tissues EMT is a developmentally restricted process and fully differentiated epithelia typically maintain their epithelial phenotype. Recently, elements of EMT, specially the loss of epithelial markers and the gain of mesenchymal markers, have been observed in pathological states, including epithelial cancers. Increasing evidence has confirmed its presence in human colon during colorectal carcinogenesis. In general, chronic inflammation is considered to be one of the causes of many human cancers including colorectal cancer(CRC). Accordingly, epidemiologic and clinical studies indicate that patients affected by ulcerative colitis and Crohn's disease, the two major forms of inflammatory bowel disease, have an increased risk of developing CRC. A large body of evidence supports roles for the SMAD/STAT3 signaling pathway, the NF-kB pathway, the Ras-mitogenactivated protein kinase/Snail/Slug and microRNAs in the development of colorectal cancers via epithelial-tomesenchymal transition. Thus, EMT appears to be closely involved in the pathogenesis of colorectal cancer, and analysis refered to it can yield novel targets for therapy.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.49 no.4
• /
• pp.445-453
• /
• 2016

Seahorse Hippocampus abdominalis a marine teleost fish, has long been used as one of the essential materials in traditional Chinese medicine. However, the uses of seahorse have been limited due to its high cost, despite its beneficial biological activities. Seahorse has not been widely explored for its biofunctional properties and active components. In the present study, the enzymatic hydrolysates of seahorse were prepared by using two digestive enzymes (trypsin and pepsin) and five food grade enzymes (neutrase, protamex, alcalase, kojizyme, and flavourzyme). The enzymatic hydrolysates indicated higher hydrolysis yields than its water extract. Among them, the distilled water-pepsin hydrolysate (DP) which was obtained by distilled water extraction followed by pepsin hydrolysis, showed the highest yield and protein content as well as the highest alkyl radical scavenging activity. Also, it provided protective effects against oxidative stress induced by AAPH in vero cell and zebrafish. Further fractionation based on the molecular weight was carried out to identify it’s active components, and < 5 kDa (less than 5 kDa) molecular weight fraction was confirmed to have the highest antioxidant activity. In conclusion, this study suggests that DP of seahorse has antioxidant properties, and might be a novel and useful material from the marine origin for healthy functional foods and cosmetics.

• Korean Journal of Medicinal Crop Science
• /
• v.21 no.2
• /
• pp.105-111
• /
• 2013

This study was performed to investigate the enhancement of immunomodulatory activities of Lithospermum erythrorhizon by extreme process. The extracts are WE100 (water extract for 24 hours at $100^{\circ}C$), WE80 (water extract for 24 hours at $80^{\circ}C$), EE (70% ethyl alcohol extract for 24 hours at $80^{\circ}C$) and EPE (extreme process for 30 minutes at $25^{\circ}C$, 500 MPa after 70% ethyl alcohol extracts for 3 hours at 40, 50, $60^{\circ}C$). Extraction yield was increased up to 5~10% by extreme process, compare to the normal extraction such as water solvent extraction, 70% ethyl alcohol solvent extraction. The cytotoxicity of the extracts was showed in the range of 12.68~15.89% at $1.0mg/m{\ell}$ for human lung cell (HEL299). The EPE40 was showed the lowest cytotoxicity 12.68%. The EPE60 extracted by extreme process increased the growth of human B and T cells up to $12.12{\times}10^4\;cells/m{\ell}$ and $14.88{\times}10^4\;cells/m{\ell}$, respectively and the EPE60 greatly increased the cytokine secretion of both IL-6 and TNF-${\alpha}$. The extracts by extreme process also exhibited higher levels of nitric oxide production from macrophages than the lipopolysaccaharides. It can be concluded that Lithospermum erythrorhizon has immune activities and The extreme process could increase higher immune activities possibly by immunomodulatory compounds.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.1
• /
• pp.117-120
• /
• 1999

High yields of protoplasts were obtained following enzymatic digestion of the vagetative thalli of marine green alga Monostroma nitidum. The enzyme mixtures containing $4\%$ Cellulase R-10+$3\%$ Macerozyme R-10+$3\%$ Abalone acetone power produced $4.41\times10^6$ protoplasts per 300 mg of fresh tissue. The highest yield of protoplasts was obtained by 270 minutes treatment of the thalli in enzyme solution. Freshly isolated protoplasts were spherical in shape and ranged between $13\~33\mu$m in diameter. The high efficiency of differentiation were obtained by incubating freshly isolated protoplasts in 0.4 M mannitol f/2 medium for 7 days and then transferring to 0.2 M mannitol f/2 medium. Protoplasts began to form new cell walls three days after initial culture and began to germinate after 10 days, and then form a leafy thallus after further culture in f/2 medium. The addition of antibiotics in media inhibited the differentiation of protoplasts in culture.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.1
• /
• pp.65-71
• /
• 2009

Microbial oxidoreductive systems have been widely used in asymmetric syntheses of optically active alcohols. However, when reused in multi-batch reaction, the catalytic efficiency and sustainability of non-growing cells usually decreased because of continuous consumption of required cofactors during the reaction process. A novel method for NADPH regeneration in cells was proposed by using pentose metabolism in microorganisms. Addition of D-xylose, L-arabinose, or D-ribose to the reaction significantly improved the conversion efficiency of deracemization of racemic 1-phenyl-1,2-ethanediol to (S)-isomer by Candida parapsilosis cells already used once, which afforded the product with high optical purity over 97%e.e. in high yield over 85% under an increased substrate concentration of 15 g/l. Compared with reactions without xylose, xylose added to multi-batch reactions had no influence on the activity of the enzyme catalyzing the key step in deracemization, but performed a promoting effect on the recovery of the metabolic activity of the non-growing cells with its consumption in each batch. The detection of activities of xylose reductase and xylitol dehydrogenase from cell-free extract of C. parapsilosis made xylose metabolism feasible in cells, and the depression of the pentose phosphate pathway inhibitor to this reaction further indicated that xylose facilitated the NADPH-required deracemization through the pentose phosphate pathway in C. parapsilosis. moreover, by investigating the cofactor pool, the xylose addition in reaction batches giving more NADPH, compared with those without xylose, suggested that the higher catalytic efficiency and sustainability of C. parapsilosis non-growing cells had resulted from xylose metabolism recycling NADPH for the deracemization.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.3
• /
• pp.542-549
• /
• 2010

In the present study, overexpression, purification, and characterization of Aeropyrum pernix K1 chaperonin B in E. coli were investigated. The chaperonin $\beta$-subunit gene (ApCpnB, 1,665 bp ORF) from the hyperthermophilic archaeon A. pernix K1 was amplified by PCR and subcloned into vector pET21a. The constructed pET21a-ApCpnB (6.9 kb) was transformed into E. coli BL21 Codonplus (DE3). The transformant cell successfully expressed ApCpnB, and the expression of ApCpnB (61.2 kDa) was identified through analysis of the fractions by SDS-PAGE (14% gel). The recombinant ApCpnB was purified to higher than 94% by using heat-shock treatment at $90^{\circ}C$ for 20 min and fast protein liquid chromatography on a HiTrap Q column step. The purified ApCpnB showed ATPase activity and its activity was dependent on temperature. In the presence of ATP, ApCpnB effectively protected citrate synthase (CS) and alcohol dehydrogenase (ADH) from thermal aggregation and inactivation at $43^{\circ}$ and $50^{\circ}$, respectively. Specifically, the activity of malate dehydrogenase (MDH) at $85^{\circ}$ was greatly stabilized by the addition of ApCpnB and ATP. Coexpression of pro-carboxypeptidase B (pro-CPB) and ApCpnB in E. coli BL21 Codonplus (DE3) had a marked effect on the yield of pro-CPB as a soluble and active form, speculating that ApCpnB facilitates the correct folding of pro-CPB. These results suggest that ApCpnB has both foldase and holdase activities and can be used as a powerful molecular machinery for the production of recombinant proteins as soluble and active forms in E. coli.

• Microbiology and Biotechnology Letters
• /
• v.41 no.1
• /
• pp.70-78
• /
• 2013

Rhizoctonia solani and Fusarium oxysporum cause yield losses in numerous economically important crops. To develop a bio-control agent, cell free extracellular compounds (ECs) of 5 bacterial strains Burkholdria sp. L1, Pseudomonas sp. L4, Pseudomonas chlororaphis VN391, Bacillus subtilis VN21 and Enterobacter sp. VN99 from Vietnamese fields, which reduced levels of R. solani root rot in lettuces and F. oxysporum root rot in tomatoes, were investigated. In a growth chamber, ECs of all antagonists markedly enhanced the biomass of lettuces (10 to 14.1%) and tomatoes (11.38 to 13.88%). In greenhouses, the disease's severity on both crops treated with ECs of the antagonists was reduced significantly and biomass losses in the plants decreased markedly. The reduction level of R. solani root rot in lettuces was 75, 66.7, 50, and 16.7% by ECs of strains L1, L4, VN21 and VN391, respectively. The biomass of lettuces increased markedly by 29.13%, 21.67%, and 23.4% by ECs of strains L1, L4 and VN21, respectively. Similarly, the reduction levels of F. oxysporum root rot in tomatoes was 76.3, 75, 41.7 and 25% by ECs of strain L1, L4, VN21 and VN391, respectively, and the biomass was significantly enhanced by 14.42, 12.7 and 13%, respectively. The ECs of strain L1 exhibited the most effective bio-control agents to suppress R. solani and F. oxysporum.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.3
• /
• pp.235-242
• /
• 1999

We investigated the growth-inhibitory mechanism of Helicobacter pylori by omeprazole (OMP) and its activated sulfenamide (OAS). Using dithiothreitol (DTT) and 5,5'-dithio-bis[2-nitrobenzoic acid] (DTNB; Ellman's reagent), we first determined the relationship between the binding capacity of these compounds to H. pylori membrane and its significance to membrane P-type ATPase activity. After incubation of the intact H. pylori cells with either OMP or OAS, the residual quantity of free SH-groups on the cell membrane was measured, and, the resulting values were plotted as a function of time. From this experiment, we found that there was a considerable difference in the membrane-binding rates between OMP and OAS. At neutral pH, the disulfide bond formation on H. pylori membrane was completed within 2 min of incubation of the intact cells with OAS. By OMP, however, it was gradually formed, exceeding 10 min of incubation for completion, whereby, the extent of P-type ATPase inhibition appeared to be proportional to the disulfide forming rate. From this data, it was suggested that the disulfide formation might directly affect enzyme activity. Since OMP per se cannot yield a disulfide bond with cysteine, it is predicted that the enzyme inactivation must be caused by the OAS form. Accordingly, we postulated that, under the neutral pH, OMP could be converted to OAS in the course of transport. By extrapolating the inhibitory slopes, we could evaluate K₁ values, relating to their minimal inhibitory concentrations (MICs) for H. pylori growth. In these MIC ranges, H. pylori uptake or vesicular export of nutrients such as peptides were totally prohibited, but their effect in Escherichia coli were negligible. From these observations, we strongly suggest that the P-type ATPase activity is essential for the survival of H. pylori cells in particular.