Review of regulatory management on standards and specifications for veterinary medical devices in Korea

Well-established standards and specifications for medical devices not only provide clarity and consistency in licensing processes but also secure device safety and effectiveness. This study reviewed regulatory standards and specifications for veterinary medical devices in Korea based on data obtained through analyses of those medical devices. General standards for electromechanical, electromagnetic, and biological safety and individual standards for 76 electric and 70 general medical device products have been established by the Korean Ministry of Food and Drug Safety. However, the first standards and specifications for veterinary medical devices were established in March 2000 for two products (disposable needle and syringe). Similar to the large number of standards for medical devices, there have been general standards for safety and individual standards for 72 veterinary medical devices (27 electric medical devices, 12 non-electric medical devices, 10 medical supplies, and 23 other types) established since 2014. These new standards considered, among other aspects, the devices' applications, usage characteristics, and industrial environment. To date, the establishment of standards and specifications for veterinary medical devices remains limited. This study suggests that improvements should be made to the regulation of general and individual standards associated with various veterinary medical instruments, supplies, and in vitro diagnostic medical reagents.

Effect of 5-FU and MTX on the Expression of Drug-resistance Related Cancer Stem Cell Markers in Non-small Cell Lung Cancer Cells

Cancer stem cells (CSCs) are often characterized by the elevated expression of drug-resistance related stem-cell surface markers, such as CD133 and ABCG2. Recently, we reported that CSCs have a high level of expression of the IL-6 receptor (IL-6R). The purpose of this study was to investigate the effect of anticancer drugs on the expression of the drug resistance-related cancer stem cell markers, ABCG2, IL-6R, and CD133 in non-small cell lung cancer (NSCLC) cell lines. A549, H460, and H23 NSCLC cell lines were treated with the anticancer drugs 5-fluorouracil (5-FU; 25 microg/ml) and methotrexate (MTX; 50 microg/ml), and the expression of putative CSC markers was analyzed by fluorescent activated cell sorter (FACS) and the gene expression level of abcg2, il-6r and cd133 by reverse transcriptasepolymerase chain reaction (RT-PCR). We found that the fraction of ABCG2-positive(+) cells was significantly increased by treatment with both 5-FU and MTX in NSCLC cells, and the elevation of abcg2, il-6r and cd133 expressions in response to these drugs was also confirmed using RT-PCR. Also, the number of IL-6R(+) cells was increased by MTX in the 3 cell lines mentioned and increased by 5-FU in the H460 cell line. The number of CD133(+) cells was also significantly increased by both 5-FU and MTX treatment in all of the cell lines tested. These results indicate that 5-FU and MTX considerably enhance the expression of drug-resistance related CSC markers in NSCLC cell lines. Thus, we suggest that antimetabolite cancer drugs, such as 5-FU and MTX, can lead to the propagation of CSCs through altering the expression of CSC markers.

Determination of Oxyclozanide in Beef and Milk using High-Performance Liquid Chromatography System with UV Detector / 한국실험동물학회지

This study was developed and validated for the determination of oxyclozanide residue concentrations in beef and commercial milk, using high-performance liquid chromatography system. Oxyclozanide was successfully separated on a reverse phase column (Xbridge-C18, 4.6x250 mm, 5 microm) with a mobile phase composed of acetonitrile and 0.1% phosphoric acid (60:40, v/v%). This analytical procedure involved a deproteinization process using acetonitrile for beef and 2% formic acid in acetonitrile for commercial milk, dehydration by adding sodium sulfate to the liquid analytical sample, and a defatting process using n-hexane; after these steps, the extract was exposed to a stream of nitrogen dryness. The final extracted sample was dissolved in the mobile phase and filtered using a 0.45 microm syringe filter. This method had good selectivity and recovery (70.70+/-7.90-110.79+/-14.95%) from the matrices. The LOQs ranged from 9.7 to 9.8 microg/kg for beef and commercial milk. The recoveries met the standards set by the CODEX guideline.