MicroRNA (miRNA, miR) is essential in regulating cell differentiation either by inhibiting mRNA translation or by inducing its degradation. However, the role of miRNA in odontoblastic cell differentiation is still unclear. In this study, we examined the molecular mechanism of miR-27-mediated regulation of odontoblast differentiation in MDPC-23 mouse odontoblastic cells derived from mouse dental papilla cells. The results of the present study demonstrated that the miR-27 expression increases significantly during MDPC-23 odontoblastic cell differentiation. Furthermore, miR-27 up-regulation promotes the differentiation of MDPC-23 cells and accelerates mineralization without cell proliferation. The over-expression of miR-27 significantly increased the expression levels of Wnt1 mRNA and protein. In addition, the results of target gene prediction revealed that Wnt1 mRNA has an miR-27 binding site in its 3’UTR, and is increased by miR-27. These results suggested that miR-27 promotes MDPC-23 odontoblastic cell differentiation by targeting Wnt1 signaling. Therefore, miR-27 is a critical odontoblastic differentiation molecular target for the development of miRNA based therapeutic agents in dental medicine.

The current standard solutions for somatic cells used for calibration of electronic somatic cell counts as reference material in raw milk are preserved with bronopol, boric acid, sodium azide, or potassium dichromate, and have a shelf-life of only up to 6 days at 4 ± 2℃. In the present study, a set of somatic cell standard solutions (SCSS) with a stability of 5 months for calibration of electronic instruments was developed. Somatic cells collected from cow’s milk and stored in a bulk tank at a dairy plant were treated with 10% formaldehyde in order to improve stability, and then separated by centrifugation. The resulting somatic cell suspension was preserved with glycerin, thimerosal, and dimethyl sulfoxide, and diluted in 3% processed skim milk solution ranging from 200,000～250,000 (low level), 350,000～ 450,000 (medium level), and 550,000～650,000 (high level) cells/㎖. Each SCSS was verified by direct microscope somatic cell counting (DMSCC), C-reader, and commercial standard samples. The average somatic cell count determined by DMSCC was 248, 214, 226 × 103 cells/㎖, 436, 382, 420 × 103 cells/㎖, and 612, 595, 609 × 103 cells/㎖. The coefficient of variation representing the repeatability of DMSCC decreased as the number of cells increased, and was <10.0% in almost all SCSS samples (range 4.6～7.1%). No statistically significant difference in somatic cell concentration was observed after storage at refrigeration temperature (2～6℃) over a period of 22 weeks (5 months). The stabilized SCSS may be useful as a reference material for determination of somatic cell count and quality control in testing of bovine raw milk.

We compared between an automated most-probable-number technique TEMPO®TVC and traditional plating methods PetrifilmTM for estimating populations of total aerobic bacteria in various livestock products. 257 samples randomly selected in local retail stores and 87 samples inoculated with E. coli ATCC 25922, Staphylococcus aureus ATCC 12868 were tested in this study. The degree of agreement was estimated according to the CCFRA (Campden and Chorleywood Food Research Association Group) Guideline 29 and the agreement indicates the difference of two kinds methods is lower than 1 log base 10(log10). The samples of hams, jerky products, ground meat products, milks, ice creams, infant formulas, and egg heat formed products were showed above 95% in the agreement of methods. In contrast, proportion of agreement on meat extract products, cheeses and sausages were 93.1%, 92.1%, 89.1%, respectively. One press ham and five sausages containing spice and seasoning, two pork cutlets containing spice and bread crumbs, two meat extract product and two natural cheeses and one processing cheese with a high fat content, and one ice cream containing chocolate of all samples showed the discrepancy. Our result suggest that TEMPO®TVC system is efficient to analyses total aerobic bacteria to compare manual method in time-consuming and laborious process except livestock products having limit of detection.

To determine the prevalence of Campylobacter jejuni and Campylobacter coli in meats, a total of 4,161 samples (1,953 domestic and 2,208 imported) were collected from 304 slaughterhouses nationwide and registered cold storages for imported meats in Korea during 2005～2009. The isolation rates of C. jejuni and C. coli in domestic beef, pork, chicken and duck meats were 0.1% (1/630), 0% (0/630), and 0.1% (1/644), 0% (0/644) and 20.5% (125/609), 10.2% (62/609) and 25.7% (18/70), 20.0% (14/70), respectively. In the case of imported meats, C. jejuni were isolated from 0.1% (1/943) and 15.2% (83/546) of pork and chicken meats, respectively, and C. coli were detected only from 4.8% (26/546) of chicken meats. Neither C. jejuni nor C. coli were detected from imported beef, and C. coli were also not detected from imported pork. In conclusion, chicken meats had much higher rate of contamination with Campylobacter compared to beef and pork. Therefore, HACCP system that is now mandatory for slaughterhouses should be actively practiced for safe and sanitary processing, handling, and marketing of chicken meats. In addition, all critical control points should be determined by processing procedures at processing plants as well as farms and slaughterhouses, and monitoring should be carried out at regular intervals.

Drift data from 17 Argo profiling floats in the East Sea are used to understand the mean flow and its variability in the upper portion of the East Sea Proper Water (UESPW) (around 800 m). The flow penetrates into the Ulleung basin (UB) through two paths: an extension of the southward flowing of the North Korean Cold Water along the east coast of Korea and between Ulleung Island and Dok island. Flows at 800 m are observed in the range of from 0.2 to 4.29 cms-1 and the variability in the north of the UB is larger than that in the south of the UB. In the UB, cyclonic flows from 0.3 to 1.6 cms-1 are observed with the bottom topography. We found that the mean kinetic energy (MKE) and the mean eddy kinetic energy (EKE) are 1.3 and 2.1 cm2s-2 respectively