• Tuberculosis and Respiratory Diseases
• /
• v.60 no.5
• /
• pp.554-563
• /
• 2006

Background: PM is known to induce various pulmonary diseases, including asthma, cancer, fibrosis and chronic bronchitis. Despite the epidemiological evidence the pathogenesis of PM-related pulmonary diseases is unclear. Methods: This study examined the effects of PM exposure on the secretion of $TNF-{\alpha}$ and $IL-1{\beta}$ in the cultured alveolar macrophages. The cultured primary alveolar macrophages were treated with the medium, PM ($5{\sim}20{\mu}g/cm^2$), LPS (5ng/ml), and PM with LPS for 24h and 48h respectively. ELISA was used to assay the secreted $TNF-{\alpha}$ and $IL-{\beta}$ in the culture medium. Western blotting was used to identify and determine the level of proteins isolated from the culture cells. The cells cultured in the $Lab-Tek^{(R)}$ chamber slides were stained with immunocytochemical stains. Results: PM induced $TNF-{\alpha}$ and $IL-1{\beta}$ secretion in the culturing alveolar macrophages, collected from the SPF and inflammatory rats. However, the effects were only dose-dependent in the inflammatory macrophages. When the cells were co-treated with PM and LPS, there was a significant synergistic effect compared with the LPS in the both cell types. Conclusion: PM might be play an important role in the induction and/or potentiation of various lung diseases by oversecretion of $TNF-{\alpha}$ and $IL-1{\beta}$.

• Radiation Oncology Journal
• /
• v.19 no.2
• /
• pp.163-170
• /
• 2001

Purpose : The measurement of radiation survival using a clonogenic assay, the established standard, can be difficult and time consuming. In this study, We have used the MTT assay, based on the reduction of a tetrazolium salt to a purple formazan precipitate by living cells, as a substitution for clonogenic assay and have examined the optimal condition for performing this assay in determination of radiation sensitivity. Materials and Methods : Four human cancer cell lines - PCI-1, SNU-1066, NCI-H630 and RKO cells have been used. For each cell line, a clonogenic assay and a MTT assay using Premix WST-1 solution, which is one of the tetrazolium salts and does not require washing or solubilization of the precipitate were carried out after irradiation of 0, 2, 4, 6, 8, 10 Gy. For clonogenic assay, cells in $25\;cm^2$ flasks were irradiated after overnight incubation and the resultant colonies containing more than 50 cells were scored after culturing the cells for $10\~14$ days. For MTT assay, the relationship between absorbance and cell number, optimal seeding cell number, and optimal timing of assay was determined. Then, MTT assay was performed when the irradiated cells had regained exponential growth or when the non-irradiated cells had undergone four or more doubling times. Results : There was minimal variation in the values gained from these two methods with the standard deviation generally less than $5\%$, and there were no statistically significant differences between two methods according to t-test in low radiation dose (below 6 Gy). The regression analyses showed high linear correlation with the $R^2$ value of $0.975\~0.992$ between data from the two different methods. The optimal cell numbers for MTT assay were found to be dependent on plating efficiency of used cell line. Less than 300 cells/well were appropriate for cells with high plating efficiency (more than $30\%$). For cells with low plating efficiency (less than $30\%$), 500 cells/well or more were appropriate for assay. The optimal time for MTT assay was after 6 doubling times for the results compatible with those of clonogenic assay, at least after 4 doubling times was required for valid results. In consideration of practical limits of assay (12 days, in this study) cells with doubling time more than 3 days were inappropriate for application. Conclusion : In conclusion, it is found that MTT assay can successfully replace clonogenic assay of tested cancer cell lines after irradiation only if MTT assay was undertaken with optimal assay conditions that included plating efficiency of each cell line and doubling time at least.

• Journal of Embryo Transfer
• /
• v.19 no.2
• /
• pp.155-163
• /
• 2004

The aims of this study are 1) to test oocytes and embryos collected from in-vitro to achieving the valuable protocol by culturing, vitrifying and thawing of oocytes/embryos, and 2) to transfer them to recipient, and finally have resulted in pregnancies from recipient females after surgical or nonsurgical transfer. In vitro maturation and fertilization were performed according to Funahashi et al (1994). Glucose-free NCSU 23 supplemented with 5 mM sodium pyruvate, 0.5 mM sodium lactate and 4 mg/ml bovine serum albumin for 2 days at $39^{\circ}C$, and 10% fetal bovine serum albumin was added to the culture medium thereafter. Embryos were treated with 7.5 ${\mu}g/ml$ cytochalasin-B for 30 min, centrifuged at 13,000 rpm for 13 min and then exposed sequentially to an ethylene glycol(EG) vitrification solution, aspirated into OPS, and plunged/thawed into/from liquid nitrogen. In vivo embryos were surgically collected from three dornors after AI for control group. Forty-nine embryos were washed 3 times in mPBS + 10% FBS, followed treatments : cultured, centrifuged, vitrified, recovered and transferred to recipients as in vitro prepared embryos. Three recipients were transferred individually with 100, 100 frozen embryos derived from abattoir and 34 fresh embryos by surgically, and another three recipients were transferred individually with 150, 150 frozen embryos and 100 fresh embryos by nonsurgically, respectively. all recipient sows exhibited delayed returns to estrus. To our knowledge, theses results suggest that required an improved techniques, more vigorous embryos preparation and substitute to gilt with cleaner uterous condition.

• Journal of Aquaculture
• /
• v.1 no.1
• /
• pp.85-102
• /
• 1988

An experimental study on seedling production and wintering to develop pearl oyster, Pinctada fucata culture in Korea was carried out. from December 1986 to November 1988 in waters of Kori and of Seogwipo as wintering and of Eogu as culturing grounds. All pearl oysters as the sample were imported from Japan. The highest water temperature at Eogu was $23.6^{\circ}C$ in August and the lowest at Kori and Seogwipo were $13.2^{\circ}C$ and $14.0^{\circ}C$c in February, respectively, Phytoplankton was relatively plentiful but mortality of pearl oysters was $20.5\%$, which was twice at Seogwipo, due to high amount of suspended muds. It shows that Seogwipo is better wintering ground even though the amount of phytoplankton is lower than Kori. Average rates of pearl production after 6-months and 15-months period were $58.2\%$ and $48.3\%$ respecitively. Thickness of pearl layer and coating rate were also satisfactory. More than half of the pearls produced was so-called the pink-pearl, the best colour. About $10\%$ of them was the best quality. There were three peaks of D-shape larvae from July to September and it took about one month for D-shape larvae to become seed-shells. Settling was satisfactory and most of them settled at 1$\~$3 m layer and the best was 2 m-layer. Success of settling was supposed due to high water temperature and low precipitation than the normal year.

• KSBB Journal
• /
• v.14 no.5
• /
• pp.593-599
• /
• 1999

In this study, optimal conditions to infect CD34 positive cells containing hematopoietic stem cells obtained from cord blood and bone marrow were found using two different retroviral vectors expressing human growth hormone (hGH) and $\beta$-galactosidase. CD34 positive cells were successfully infected with recombinant retroviruses only when the CD34 positive cells were co-cultured with packaging cells secreting recombinant retroviruses. To find the highest infection efficiency for the gene transfer, CD34 positive cells from cord blood were co-cultured with packaging cells secreting recombinant retroviruses encoding E. coli lacZ gene. The highest infection efficiency was obtained when CD34 positive cells were cultured for 3 days, and then co-culturing was done for another 2 days. When CD34 positive cells from bone marrow were co-cultured with packaging cells secreting recombinant retroviruses encoding hGH gene, the maximum amount of hGH was also secreted at the same conditions found above, i.e. 3 days of culture and 2 days of co-culture. These results show that there are optimal conditions for the gene transfer into hematopoietic stem cells regardless of sources of target cells or retroviral vectors used to infect.

• Journal of Korean Society of Forest Science
• /
• v.81 no.3
• /
• pp.273-279
• /
• 1992

Protoplasts isolated from leaf mesophyll tissues of Populus koreana ${\times}$ P. nigra var. italica were fused with those of P. euramericana cv. Guardi. Well expended healthy leaves of 5 to 7 week-old-plantlet grown in vitro were used as source materials. Leaves from P. koreana ${\times}$ P. nigra var. italica and P. euramericana cv. Guardi were digested in enzyme solution I (2.0% Cellulase, 1.2% Hemicellulase, 0.4% Macrozyme, 2.0% Driselase, 0.05% Pectolyase ; w/v) and enzyme solution II (1.0% Cellulase, 1.2% Hemicellulase, 0.4% Macrozyme, 2.0% Driselase, 0.05% Pectolyase ; w/v), respectively, The highest frequency of fusion among the protoplasts originated from the two source materials was approximately 21% using 40% PEG or 15% dextran. In addition, fusion frequency was enhanced by incorporating 30mM of $Ca^{2+}$ in eluting solution at pH 10.5. Dividing cells and/or mint-calli were obtained by culturing the fusion products in a liquid 8p-KM medium supplemented with 0.6M sucrose, $0.45{\mu}M$ 2, 4-D, and $0.5{\mu}M$ BA. Shoots were regenerated from the fusion product-derived calli after culture on MS medium containing $5.0{\mu}M$ zeatin. To verify the putative hybrid or cybrid, SDS-PAGE was carried out. From the 24 regenerants, just two plants showed intermediate protein band patterns compared with those of the original source plants.

• Journal of Life Science
• /
• v.20 no.12
• /
• pp.1896-1901
• /
• 2010

This study was conducted using quantitative real-time PCR using Lactobacilli as probiotics. Quantitative real-time PCR (RT PCR) was conducted via a method involving SYBR Green 1 and a probe. Plasmid DNA was cloned using the 16S-23S rRNA intergenic species region. Gene clones were diluted from $10^2$ to $10^{10}$. Standard curves were constructed via Ct values obtained from the results of Real-time PCR via the aforementioned SYBR Green 1 and probe method. Plasmid DNA was also cloned using the 16S-23S rRNA intergenic species region and the gene clones were diluted from $10^2$ to $10^{10}$ copy numbers via the probe method. Using RT PCR, a standard curve of plasmid DNA copy numbers was also determined. The slope value for the Y-axis intercept and $R^2$ value were measured as -3.346, 33.18, and 0.993, respectively, via the first method. For the second method, the slope value for the Y-axis intercept and $R^2$ were -3.321, 31.10 and 0.995, respectively. The PCR inhibitor could not express the detection curve at a copy number over $10^{10}$ via either method, owing to high DNA density. The DNA extract from probiotics was diluted without pre-culturing, and 16 products were amplified via both methods. The Ct value was 11.06~18.12 in the first method and 16.74~22.11 in the second method. Measured probiotics and log copy values were largely similar among the methods used. It was concluded that both methods are effective for analysis, but further research will be required to verify the optimal method.

• Research in Plant Disease
• /
• v.17 no.3
• /
• pp.288-294
• /
• 2011

Rice bakanae disease, caused by the fungus Fusarium fujikuroi, is one of the most important rice diseases and distributed widely in Asia. Resistance screening system in rice field had been established. However, the evaluation results of the system vary according to the environmental conditions when the test is conducted. To develop precise and rapid evaluation method of disease resistance of rice to bakanae disease, in vitro screening system was attempted in this study. The six cultivars namely, 'Nampyeongbyeo', 'Junambyeo', 'Chucheongbyeo', 'Samcheonbyeo', 'Odaebyeo' and 'Hwasinbyeo' were tested. They were planted onto MS agar medium (10 ml) in test tube ($450\;mm{\times}{\phi}30\;mm$) and incubated at $25^{\circ}C$ and $28^{\circ}C$ in growth chamber under 12 hr light condition. Symptoms of over growth appeared a few days after seeding and then seedling were withered 2-3 weeks after over growth. The disease symptoms such as leaf dryness on top of rice were appeared in the 'Nampyeongbyeo' from 28 days at the concentration of $10^5$ spores/ml culturing at $28^{\circ}C$ and then withered completely 35 days after seeding. Whereas the other varieties withered entirely 19-23 days after seeding. Using the in vitro seedling screening method, 72 rice varieties were investigated to select resistant cultivar. Finally, two resistant cultivars ('Nampyeongbyeo' and 'Inwolbyeo') and seven moderately resistant cultivars ('Hwadongbyeo', 'Seokjeongbyeo', 'Samgwangbyeo', 'Sampyeongbyeo', 'Nonghobyeo', 'Heukjinjubyeo' and, 'Joanbyeo') were selected. If in vitro seedling screening method was used for evaluation of bakanae disease resistance, it would be completed within 35 days after sowing of rice seed.

• Journal of Sericultural and Entomological Science
• /
• v.9
• /
• pp.49-66
• /
• 1969

Eri-silkworm is known as a tropical insect where as poly-voltine type in that area. It eats caster oil plant leaves which are cultivated as an every year cultivatable seed oil use in this country, even though it grows for many years in tropical countries. That is why, farmers have freedom for its cultivation in any year if they want. Therefore, eri-silkworm rearing service is flexible for its diet procurment as wish of farmer. The eri-cocoon price or economical fluctuation may be reactable for the rearing work not like as mulberry cocoon. Fortunately, it also eats cynthia tree leaves. Standing from such a easy condition, the authors have studied about this problem since 1963 to develope a culturing method of eri-silkworm rearing in this country and the authors brought out the matters to be produced as an industry scale. Here, the authors summarized their works of the results covering with thirty three work tables. The obtained results are as follows.

• Korean Journal of Medicinal Crop Science
• /
• v.1 no.1
• /
• pp.28-37
• /
• 1993

The low seed propagation is one of the problem needed a lot of seed tuber for the propagation in yam. Therefore this experiment was carried out to understand the possiblility of seed tuber propagation by tissue culture of yam. In-vitro stem node of yam was cultured by concentration treatments of 1/2, 1/4 and 1/8 with MS medium additted with each concentration levels of IAA, NAA, IBA, kinetin and BA. Acorrding to the Iower concentration than MS medium, length of shoots was promoted, leaf emergence shoots and rooting shoots were increased at 1/8 MS medium during the culturing period of stem node in yam. Fixed IBA and kinetin under the concentration of MS mdeium was inhibited severely by the heigh concentration additted with lAA $1mg\;/\;{\ell}\;and\;NAA\;4mg\;/\;{\ell}$. But fixed IBA $5mg\;/\;{\el}l\;and\;kinetin\;2mg\;/\;{\ell}$ with concentration of 1/8MS medium was remarkably promoted leaf emergence shoots and rooting shoots by $1mg\;/\;{\ell}$ of additted lAA and NAA. Percentage of induced shoots was increased by combination treatments of lAA. $1.5mg\;/\;{\ell}\;and\;kinetin\;2mg\;/\;{\ell}$, also leaf emergence shoots and rooting shoots were promoted by combination treatments of lAA $1.5mg\;/\;{\ell}\;and\;kinetin\;2mg\;/\;{\ell}$.