• YAKHAK HOEJI
• /
• v.43 no.4
• /
• pp.502-508
• /
• 1999

Chitin is an important structural component of fungal cell wall and is synthesized by chitin synthase I, II, and III. The chitin synthase II is an essential enzyme for the formation of primary septum in Saccharomyces cerevisiae. Therefore, specific inhibitors of this enzyme might block the formation of fungal cell wall and could be used as effective antifungal agents. To search chitin synthase IIinhibitors from natural products, 67 plants were extracted with methanol and examined for the inhibitory activities against chitin synthase II of S. cerevisiae by our cell free assay system. As a result, the extracts from 16 plants showed more than 70% inhibition at the concentration of $280{\;}\mu\textrm{g}/ml$. Of note, Laurus nobilis (81.4%), Lonicera maackii (81.5%), Berchemia berchemiaefolia (82.9%), Koelreuteria paniculata (87.9%), Chamaecyparis pisifera (86%) and Taxus cuspidata (83.9%) inhibited strogly the chitin synthase IIactivity.

• Journal of the Korean Chemical Society
• /
• v.63 no.2
• /
• pp.85-93
• /
• 2019

A panel of chalcone-sulphonamide hybrids has been designed by tethering appropriate sulphonamide scaffold with substituted chalcones as a multi-target drug for anticancer screening. Chalcones were prepared by Claisen-Schmidt condensation reaction of a substituted aldehyde with para aminoacetophenone. All the synthesized compounds were evaluated against selected five cancer cell lines, MCF-7 (Breast cancer), DU-145 (Human prostate Carcinoma), HCT-15 (Colon cancer), NCIH-522 (stage 2, adenocarcinoma; non-small cell lung cancer) and HT-3 (Human cervical cancer). Most of the synthesized chalcone-sulphonamide hybrids showed amended cytotoxic activity against various cancer cell lines which may be attributed to the linkage of sulphonamide with chalcone skeleton. The synthesized compounds were characterized by FT-IR, $^1H$ NMR, $^{13}C$ NMR and HR-LCMS and spectral study assert the structures of synthesized sulphonamide-chalcone hybrids.

• KSBB Journal
• /
• v.31 no.1
• /
• pp.33-39
• /
• 2016

Developing the method for the selection of animal cell line producing therapeutic monoclonal antibody (mAb) is invaluable as its market is rapidly growing. Although the quality of produced mAb is as important as quantity, however there is no method developed for the selective screening of cell lines on the basis of both quantity and quality. From recent reports, the ratio of light and heavy chain mRNAs of mAb in the cell is a key parameter for the indication of product quality. Therefore, it is obvious that developing the novel method that can detect both light and heavy chain mRNAs in single live cell will provide unprecedented opportunities in bio-industry. Here, we have constructed oligonucleotide probes, molecular beacons for the detection of light or heavy chain mRNAs, respectively, in the live cells producing mAbs. Both beacons showed increased fluorescent intensity after transient transfection of plasmid expressing mAbs analyzed by fluorometer. Flow cytometric analysis clearly demonstrated that both molecular beacons can simultaneously detect the expression of light and heavy chain mRNAs of mAb in the same cell. The technique described in the thesis provides the new direction and concept for developing the method for the smart selection of cell lines producing recombinant proteins including therapeutic mAbs.

• The Korean Journal of Cytopathology
• /
• v.14 no.2
• /
• pp.60-65
• /
• 2003

Objective: The sensitivity of the AutoPap Primary Screening System with Location-Guided Screening (AutoPap LGS) for Identifying atypical cells in cervicovaginal smears was evaluated. Methods: Two hundred forty one slides with atypical cervical cytology randomly sampled were rescreened both manually and by the AutoPap LGS. The AutoPap LGS localized the atypical cells as 15 fields of view(FOVs), which were reexamined by manual review. The sensitivity was also evaluated in accordance with the cellularity of the smears. Results: The AutoPap LGS successfully processed 232 out of 241 slides. The sensitivity of the AutoPap LGS identifying the atypical cells in successfully processed slides was 97.4%(226/232). The false negative rate was 2.6%(6/232). There was no false negative case on high grade squamous intraepithelial lesion (HSIL) or squamous cell carcinoma(SCC) smears in the AutoPap LGS. The FOVs localized the diagnostic-atypical cells in 97.8%(221/226). The number of diagnostic-atypical FOVs was increased in higher-degree of atypical cytology. The AutoPap LGS localized the atypical cells in 100% of adequately cellular smears and in 92.5% even in low cellular smears. Conclusion: The AutoPap LGS showed relatively good sensitivity to detect atypical cells. It can be a valuable system to localize atypical cells, especially in HSIL or cancer slides, even in smears with low cellularity.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1645-1649
• /
• 2011

[ ${\beta}$ ]Ketoacyl acyl carrier protein synthase I (KAS I) is involved in the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and a therapeutic target of designing novel antibiotics. In this study, we performed receptor-oriented pharmacophore-based in silico screening of E. coli KAS I (ecKAS I) with the aim of identifying novel inhibitors. We determined one pharmacophore map and selected 8 compounds as candidates ecKAS I inhibitors. We discovered one antimicrobial compound, YKAe1008, N-(3-pyridinyl) hexanamide, displaying minimal inhibitory concentration (MIC) values in the range of 128-256 ${\mu}g/mL$ against MRSA and VREF. YKAe1008 was subsequently assessed for binding to ecKAS I using saturation-transfer difference NMR spectroscopy. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

• The Plant Pathology Journal
• /
• v.24 no.1
• /
• pp.24-30
• /
• 2008

Colletotrichum gloeosporioides forms an appressorium, a specialized infection structure, to infect its hosts. Among 400 and 600 culture filtrates from fungi and class Actinomycetes, six methanol extracts (A5005, A5314, A5387, A5560, A5597, and A5598) from the class Actinomycetes significantly inhibited appressorium formation in C. gloeosporioides infecting pepper fruits in a dose-dependent manner, while conidial germination was slightly enhanced. Two (A5005 and A5560) of them also exhibited distinctive inhibitory effect on the disease progress of pepper anthracnose. Water fractions of both culture filtrates also specifically inhibited appressorium formation in C. gloeosporioides and pepper anthracnose disease. Inhibition of appressorium formation by culture filtrate of A5005 was partially restored by the exogenous calcium. This results suggests that chemicals within A5005 extents its biological activity through disturbance of intracellular $Ca^{2+}$ regulation during prepenetration morphogenesis by C. gloeosporioides. Together, cell-based and target-oriented screening system used in this study should be applicable for other plant pathogenic fungi prerequisite appressorium formation to infect their hosts.

• YAKHAK HOEJI
• /
• v.39 no.6
• /
• pp.622-630
• /
• 1995

Inoculation of Friend anemia virus, which was a Kind of retro virus such as HIV, results splenomegaly, anemia, the increase of WBC counts and reverse transcriptase activity in serum. These results were due to the inhibition of the differentiation of erythroid progenitor cell by the FVA at the spleen. Using these as index of antiviral effects, we pursued the establishment of in vivo screening method for the new anti-ADS drugs. Among zidovudine, didanosine and zalcitabine, which were already approved as anti-AIDS drugs, treatment of zidovudine for 18 days in BALB/c mice inoculated with Friend anemia virus resulted the most potent inhibitory effects on the splenomegaly, the increase of WBC counts and reverse transcriptase activity, but did not recovered the anemia due to the tomcity of zidovudhie itself on the bone marrow. The antiviral effects of zidovudine was reduced in case of zidovudine treatment 7 days after Friend anemia virus inoculation. These results suggested that the sooner treatment of zidovudine would be better improved when the virus was inoculated. Human recombinant interferon itself .alpha. did not showed the antiviral activity against Friend anemia virus and did not also affected the antiviral activity of zidovudine. These results suggested that Friend anemia virus would be used as a tool in vivo screening method for the Lobster of reverse transcriptase.

• Archives of Pharmacal Research
• /
• v.18 no.3
• /
• pp.169-172
• /
• 1995

The changes in blood pressure may relate to the alterations of the responsiveness to vasoconstrictors and vasodilators, and these alterations can arise the modifications in the properties of angiotensin II (AII) receptor. In order to examine the changes of AII receptor in the hypertensive mechanism of renin-dependent hypertensive rats (RHRs; two-kidney, one-ligated type), we compared the equilibrium binding characteristics of $[^3H]$All in adrenal cortex and medulla from RHRs and normotensive rats. The dissociation constants of AII binding in both tissues of RHRs were very similar to those in the respective tissue of normotensive rats. However, the maximum binding was increased from 805 to 1050 fmole/mg protein in the adrenal cortex of RHRs, and decreased from 172 to 126 fmole/mg protein in the adrenal medulla of RHRs. These results imply that the up- and down-regulation of the All receptor population on the cell surface of adrenal glands from RHRs are consorted with the elevation of blood pressure and the activation of renin-angiotensin system.

• Tuberculosis and Respiratory Diseases
• /
• v.84 no.2
• /
• pp.89-95
• /
• 2021

Lung cancer is one of the leading causes of cancer-related deaths in Korea. Although the smoking rate has decreased over time, the prevalence of lung cancer still remains high. In this study, we reviewed recent trends on the incidence, epidemiology, screening, diagnosis, and treatment of lung cancer in Korea by analyzing data from the national lung cancer registry and recently-published studies. Although approximately 40% of patients with non-small cell lung cancer (NSCLC) were diagnosed as stage IV, the 5-year relative survival rate improved from 11.3% (1993-1995) to 30.2% (2013-2017), possibly due to advances in methods of diagnosis and therapy. In addition, the 2019 implementation of the national lung cancer screening program with low-dose computed tomography may have also contributed to these improvements in survival rates. Recently, molecular diagnosis has become more widely used in the identification of genetic mutations in tissue specimens. Target therapy and immune checkpoint inhibitors have also been successfully used, particularly in cases of advanced NSCLC. In the future, further research on the optimal management of lung cancer remains necessary.

• Journal of Periodontal and Implant Science
• /
• v.36 no.3
• /
• pp.613-625
• /
• 2006

Periodontal ligament(PDL) cells and human gingival fibroblasts(HGFs) play important roles in development, regeneration, normal function, and pathologic alteration. PDL cells and HGFs have the similarity related with general characteristics of fibroblast such as spindle shaped morphology, the presence of vimentin intermediate filament and the synthesis of interstitial collagens and fibronectin. There were many studies about the differences between PDL cells and HGFs, but they were not about whole gene level. In this study, we tried to explain the differences of gene expression profiles between PDL cells and HGFs, and the differences among three individuals by screening gene expression patterns of PDL cells and HGFs, using cDNA microarray. Although there were some variants among three experiments, a set of genes were consistentely and differentially expressed in one cell type. Among 3,063 genes, 49 genes were more highly expressed in PDL cells and 12 genes were more highly expressed in HGFs. The genes related with cell structure and motility were expressed more highly in PDL cells. These are cofilin 1, proteoglycan 1 secretory granule, collagen type I(${\alpha}$ 1), adducin gamma subunit, collagen type III(${\alpha}$ 1), fibronectin, lumican(keratan sulfate proteoglycan), and ${\alpha}$ -smooth muscle actin. Tissue inhibitor of metalloproteinase known as the enzyme controlling extracellular matrix with matrix metalloproteinase is more highly expressed in PDL cells, osteoprotegerin known as osteoclastogenesis inhibitory factor is more highly expressed in HGFs. We performed northern blot to verify cDNA microarray results on selected genes such as tissue inhibitor of metalloproteinase, fibronectin, osteoprogeterin. The result of northern blot analysis showed that each cell expressed the genes in similar pattern with cDNA microarray result. This result indicates that cDNA microarray is a reliable method in screening of gene expression profiles.