• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.2
• /
• pp.177-180
• /
• 2010

Purpose: As PET test came to be covered by the pay system of medical insurance (July 1, 2006) and the needs for it becoming increased for laboratory purpose, it became necessary to purchase expensive medical equipments to solve those problems. However, as most of equipments that are operated by cyclotron are very expensive as to amount from tens of millions up to hundreds of millions of won, it is difficult to purchase those equipments from the point of medical organizations. It may be possible to self manufacture those equipments with least costs if their parts functions that meets the operators demands. The Nuclear Medicine department of National Cancer Center (NCC) is trying to manufacture and use equipments that can be made with least costs, including introducing 2 medical equipments that can improves the operator's works. Materials and Methods: Example 1: Self production of radioisotope($^{18}F$) divider was fabricated. The NCC's Nuclear Medicine department acquired one acrylic panel, seven 3-way valve, tubing etc. that can be found in the market to make the main body of divider in cooperation with biomedical engineering, and placed them inside hot cell, and installed switching box outside of hot cell to make it possible to control them from outside. This main body of divider were placed in radioisotope transfer line that are manufactured in the cyclotron. Example 2: Self production of $^{18}F$-FDG automated divider was fabricated. The NCC's Nuclear Medicine department used cavro pump syringe that consists the main body of divider in cooperation with biomedical engineering, biomedical engineering developed programs that divides a certain amount. $^{18}F$-FDG automated divider is placed inside hot cell, and cable chords were used in the equipment, and then it was connected to PC outside hot cell to make it possible to control the $^{18}F$-FDG automated divider. Results: From the NCC's Nuclear Medicine department tests that were carried out from March, 2007 until now, we found out that radioisotope can be sent to radiopharmaceuticals composite module we want, and from the tests that are carried out at NCC's Nuclear Medicine department using $^{18}F$-FDG automated divider since August, 2009 it was possible to distribute radiopharmaceuticals into vial intended. Conclusion: Through the two examples above, we found out that costs can be reduced by self manufacturing expensive equipments from NCC's cyclotron room with least costs. Also, it decreased radiation exposure dose on workers, and set up problem solving processes in cooperation with lots of parties related.

• Journal of Life Science
• /
• v.20 no.1
• /
• pp.103-112
• /
• 2010

Pemetrexed has demonstrated clinical activity in non-small cell lung cancer (NSCLC) as well as other solid tumors. It transports into the cells via reduced folate carrier (RFC) and is polyglutamated by folypolyglutamate synthetase (FPGS). Pemetrexed directly inhibits several folate-dependent enzymes such as thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). We investigated the effects of genetic variations and the expression of RFC, FPGS, TS and DHFR enzymes on drug sensitivity to pemetrexed in NSCLC cells. Polymorphisms in RFC, FPGS, and DHFR were genotyped in four NSCLC cells - A549, PC14, HCC-1588, and H226. Real-time RT-PCR and Western blot was performed to evaluate mRNA transcripts and protein of these genes. The cytotoxicity of pemetrexed was measured by SRB assay. In PC14 and H226 cells, increased mRNA expressions of RFC and FPGS were associated with higher cytotoxicity to pemetrexed. 2R/2R genotype of TS and its increased mRNA expression were associated with drug resistance to pemetrexed in A549 cells, whereas 3R/3R genotype in TS with decreased mRNA expression was associated with higher sensitivity in H226 cells. After pemetrexed treatment, an inverse change of DHFR mRNA and protein expression was found. The strongest linkage disequilibrium (LD) was discovered between-1726C>T and -1188A>C SNP of DHFR gene. Our findings suggest the cytotoxic effect of pemetrexed may be associated with genetic polymorphisms and the expression level of genes involved in pemetrexed metabolisms in NSCLC cells.

• Radiation Oncology Journal
• /
• v.19 no.4
• /
• pp.381-388
• /
• 2001

Purpose : This study was conducted to assess the effects of x-irradiation on the expression of the novel glutathione S-transferase K1 gene. Materials and methods : Human glutathione S-transferase K1 (hGSTK1) DNA was purified and ligated to a pcDNA3.1/Myc-His(+) vector for the overexpression of hGSTK1 gene. MCF-7 cells were transfected with or without the recombinant hGSTK1 gene, and irradiated with 6 MV x-ray. After incubation of 14 days, cell survival was measured and compared. The expression of hGSTK1 and the effect of x-irradiation on hGSTK1 expression were also estimated in MCF-7 cells transfected with or without the hGSTK1 gene by RT-PCR. Results : Following 2 to 12 Gy of x-irradiation, the cell survivals were higher in the MCF-7 cells transfected with the hGSTK1 gene than in those without transfection. Despite the higher cell survival in the hGSTK1-transfected cells, RT-PCR for hGSTK1 mRNA revealed no significant differences according to radiation dose, fractionation, and time after irradiation. Conclusion : The MCF-7 cells transfected with the hGSTK1 gene showed higher cell survival than those without transfection of the gene. The hGSTK1 gene might be associated with the radiosensitivity of MCF-7 cell line and further analysis should be needed.

• Journal of Life Science
• /
• v.19 no.1
• /
• pp.9-14
• /
• 2009

The prostate cancer is the critical health problem, increasing of its related death in worldwide. Unfortunately present surgery and chemotherapeutic choices seem to be impossible in curing or controlling prostate cancer, because metastasis occasionally advances even after these potentially curative therapies. Therefore, there is immediate need to alternative chemoprevention and chemotherapeutic agents. Over one hundred species of dried medicinal herbs were tested for proliferation inhibitory effects on prostate cancer cell line, PC-3. One of them, Anthriscus sylvestris was selected because of potent anti-proliferation effect. The dried root of A. sylvestris was extracted with 100% methanol for 2-3 days and its extract was fractionated by using ethyl acetate. And ethyl acetate layer was subjected to column chromatographies on silica gel, reverse phase-18 (RP-18) and Sephadex LH-20, in turn. Finally, the pure compound was obtained by crystallization in methanol at $4^{\circ}C$ for overnight and identified as deoxypodophyllotoxin by NMR spedorscopic and physico-chemical analyses. In addition, it was confirmed that deoxypodophyllotoxin clearly inhibits the proliferation of PC-3 cells in a dose and time-dependent manner.

• Progress in Medical Physics
• /
• v.14 no.4
• /
• pp.211-217
• /
• 2003

The Principal component analysis (PCA) is a well-known data analysis method that is useful in linear feature extraction and data compression. The PCA is a linear transformation that applies an orthogonal rotation to the original data, so as to maximize the retained variance. PCA is a classical technique for obtaining an optimal overall mapping of linearly dependent patterns of correlation between variables (e.g. neurons). PCA provides, in the mean-squared error sense, an optimal linear mapping of the signals which are spread across a group of variables. These signals are concentrated into the first few components, while the noise, i.e. variance which is uncorrelated across variables, is sequestered in the remaining components. PCA has been used extensively to resolve temporal patterns in neurophysiological recordings. Because the retinal signal is stochastic process, PCA can be used to identify the retinal spikes. With excised rabbit eye, retina was isolated. A piece of retina was attached with the ganglion cell side to the surface of the microelectrode array (MEA). The MEA consisted of glass plate with 60 substrate integrated and insulated golden connection lanes terminating in an 8${\times}$8 array (spacing 200 $\mu$m, electrode diameter 30 $\mu$m) in the center of the plate. The MEA 60 system was used for the recording of retinal ganglion cell activity. The action potentials of each channel were sorted by off­line analysis tool. Spikes were detected with a threshold criterion and sorted according to their principal component composition. The first (PC1) and second principal component values (PC2) were calculated using all the waveforms of the each channel and all n time points in the waveform, where several clusters could be separated clearly in two dimension. We verified that PCA-based waveform detection was effective as an initial approach for spike sorting method.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.12
• /
• pp.1672-1678
• /
• 2009

This study was carried out to investigate the total polyphenol, total flavonoid content, antioxidant activity, angiotensin I-converting enzyme (ACE) inhibitory activity, $\alpha$-glucosidase inhibitory activity, and antiproliferation activity of the citron seed. The citron seed were separated to hull and embryo, and extracted with n-hexane and 70% ethanol. Antioxidant activity of ethanol extract was higher than that of n-hexane extract. IC50 value for DPPH radical scavenging activity of ethanol extract of hull (CSE1) and embryo (CSE2) were 3.18 and 8.43 mg/mL, and those of total antioxidant activity were 19.96 and 11.28 mg AA eq/g, respectively. ACE inhibitory activity and $\alpha$-glucosidase inhibitory activity on CSE1 showed the highest values of 31.61 and 45.17%, respectively. Antiproliferation effects on the MCF7, HepG2, H460, HCT-116, and PC3 cell line showed the highest values of 14.09, 19.12, 12.29, 9.78, and 9.12% in extract concentration of 5 mg/mL, respectively. These results suggested that citron seed can be used for development of functional food material which have biological activities.