• Radiation Oncology Journal
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• v.16 no.4
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• pp.377-388
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• 1998

Purpose : To evaluate changes in expression of cell cycle related genes during apoptosis induced in HL60 cells by X-irradiation to understand molecular biologic aspects in mechanism of radiation therapy. Material and Methods : HL-60 cell line (promyelocytic leukemia cell line) was grown in culture media and irradiated with 8 Gr by linear accelerator (6 MV X-ray). At various times after irradiation, ranging from 3 to 48 hours were analyzed apoptotic DNA fragmentation assay for apoptosis and by western blot analysis and semi-quantitative RT-PCR for expression of cell cycle related genes (cyclin A, cyclin B, cyclin C, cyclin Dl, cyclin E, cdc2, CDK2, CDK4, $p16^{INK4a}$, $p21^{WAF1}$, $p27^{KIP1}$, E2F, PCNA and Rb). Results : X-irradiation (8 Gy) induced apoptosis in HL-60 cell line. Cycline A protein increased after reaching its peak 48 h after radiation delivery and cyclin E, E2F, CDK2 and RB protein increased then decreased after radiation. Radiation induced up-regulation of the expression of E2F is due to mostly increase of Phosphorylated retinoblastoma proteins (ppRb). Cyclin Dl, PCNA, CDC2, CDK4 and $p16^{INK4a}$ protein underwent no significant change at any times after irradiation. There was not detected $p21^{WAF1}$ and $p27^{KIP1}$ protein. Cyclin A, B, C mRNA decreased immediately after radiation and then increased at 12 h after radiation. Cyclin Dl mRNA increased immediately and then decreased at 48 h after radiation. After radiation, cyclin E mRNA decreased with the lapse of time. CDK2 mRNA decreased at 3h and increased at eh after radiation. CDK4 mRNA rapidly increased at 6 to 12 h after radiation. There was no change of expression of $p16^{INK4a}$ and not detected in expressin of $p21^{WAF1}$ and $p27^{KIP1}$ mRNA. Conclusion : We suggest that entry into S phase may contribute to apoptosis of HL60 cells induced by irradiation. Increase of ppRb and decrease of pRb protein are related with radiation induced auoptosis of HL60 cells and tosis of HL60 cells induced by irradiation. Increase of ppRb and decrease of PRb protein are related with radiation induced apoptosis of HL60 cells and this may be associated with induction of E2F and cyclinE/CDK2. These results support that $p21^{WAF1}$ and $p27^{KIP1}$ are not related with radiation induced-apoptosis.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.146-152
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• 2001

Purpose : To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. Materials and Methods : 8-week old male mice, C57B1/6J were given whole body $\gamma-radiation$ with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins Bl, Dl, E and cdk2, cdk4, $p34^{cdc2}$ were analysed by Western blotting. Cell cycle was analysed by Flow cytometry. Results : The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is $24.0{\pm}0.25$ (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-Gl, G2-M and S phase in the cell cycle does not specific changes by time. Conclusion : In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle ofter better understanding of radiation response of noraml brain tissue.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.279-285
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• 2015

This study studied samples taken off surfaces at three sites (Unit chairs, light handles, cuspidors) of 19 dental hospitals and 28 clinics located in Gyeonggi-do and Incheon, South Korea. The bacterial contamination levels of surfaces were $44.82{\times}10^3CFU/mL$ in cuspidors, higher than in unit chairs ($5.47{\times}10^3CFU/mL$) and light handles ($16.28{\times}10^3CFU/mL$). The values were statistically higher at dental hospitals than at dental clinics, the greater number of patients being associated with the higher bacterial cell count in the cuspidors. The results of identifying the strains isolated purely from surfaces at dental clinic showed Gram positive 47.3% and Gram negative 52.7%. Among Gram positive, the most numberous bacteria were Micrococcus luteus (10.9%), Bacillus pumilus (3.6%), and Staphylococcus aureus (3.6%). Among Gram negative, the most numberous bacteria were Acinetobacter ursingii (5.5%), Brevundimonas diminuta (4.5%), Chryseobacterium (Flavo.) indologenes (CDC IIb) (4.5%), and Methylobacterium sp. (4.5%). This study measures the level of bacterial contamination and identifies the strains isolated in dental clinics. It recognizes the importance of infection control, and the results of the study may be considered as the basis for establishing specific plans for prevention of infection.

• Journal of the korean veterinary medical association
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• v.38 no.9
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• pp.781-800
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• 2002

Recently, biological weapons (BWs) prepared with pathogenic microorganisms, toxins and biological vectors have been used maliciously for biological warfare, bioterrorism and/or agroterrorism by hostile countries and terrorists. In this review, historical background of disease and malicious use of BWs pathogenicity of microorganisms, advanced methodology involved in laboratory diagnosis, and prevention and control of anthrax (Bacillus anthracis), plague (Yersinia pseudotuberculosis subs. pestis), glanders (Burkholderia mallei), and smallpox (Variola virus) which have been abused for biological warfare or bioterrorism were discussed. In addition, the pathogenicity of microorganisms and the methodology needed to diagnose and control 6 diseases identified by WHO/CDC, ie., smallpox, inhalation anthrax, pneumonic plague, botulism, tularemia, and hemorrhagic fevers that would wreak havoc if terrorists successfully disseminated the germs by air were described.

• The Journal of the Korean dental association
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• v.32 no.6 s.301
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• pp.409-416
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• 1994

이 자료는 이전에 공표 되었던 치과계에서의 감염방지 실무에 관한 CDC 권장사항을 개정한 것으로, 새로운 데이터, 재료, 기술, 및 장비 등이 반영되었다. 이러한 권장사항을 이행하면 치과 환경 내에서, 환자에서 치과의료종사자로, 치과의료종사자에서 환자로, 그리고 환자에서 환자로 질병이 전염될 수 있는 위험성을 감소시켜 줄 것이다. 이 문서에는 감염방지의 원칙에 근거하여 다음과 같은 특정 권장사항들이 서술되어 있다. 즉, 치과의료종사자들의 예방접종; 보호용 치장과 방책 기법; 수세와 손의 보호; 날카로운 기구와 바늘의 사용과 관리; 기구들의 멸균이나 소독; 치과진료대 및 주위 표면들의 세척 및 소독; 소독과 치과기공소; 치과진료대의 공기관과 수관에 연결된 핸드피스; 역류방지용 밸브; 기타 구내용 치과 장비 등의 사용과 관리; 한번 쓰고 버리는 기구; 생검 표본의 취급; 치과교육 현장에서 발치 치아를 사용하는 것; 폐기물의 폐기; 권장사항들의 이행.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.81-81
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• 2002

The recent development of cDNA microarray or cDNA chip technology has made it possible to analyze the expression of thousands of genes at once. In present study, we made radioresistant clones (#1 and #4) from NIH3T3 cells which are not tumorigenic and we identified 4 genes using microarray system, cdk6, cdc25B, mdm-2 and nidogene, which were altered in radiaiton resistanct NIH3T3 cells.(omitted)

• Animal cells and systems
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• v.9 no.4
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• pp.191-198
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• 2005

The effects of 6-aminonicotinamide (6-AN) on viability of IMR32 neuroblastoma cells in the presence of ATP or $NAD^+$ have been investigated. 6-AN caused marked reduction in cell viability and similar observations were also made with cells treated with 6-AN+ATP. However, cells treated with $6-AN+NAD^+$ showed cell viability similar to untreated cells. Morphologically, 6-AN and 6-AN+ATP treated cells showed loss of neurites, polyhedric shapes, shrinkage of cell bodies and formation of lysed cells, while $6-AN+NAD^+$ cells did not show any such changes. The flow cytometry analysis demonstrated that 6-AN increased cell population in $G_0/G_1$ phase and decreased cell population in Sand $G_2/M$ phase following a 72 h exposure. Western blot analysis showed that 6-AN stimulated a substantial increase in the level of the cdk inhibitor $p27^{kip1}$, but lowered the levels of cdk2, cyclin E and p-Rb. However, cdc25A and p53R2 were not significantly affected. Immunofluorscence staining of $p27^{kip1}$, cdk2, cyclin E and p-Rb revealed close correlation between the signal observed in the Western blot analysis. 6AN+ATP treated cells showed similar results obtained with 6-AN treated cells in expression of cdk2, cyclin E, p-Rb proteins and $p27^{kip1}$, $6-AN+NAD^+$ cells showed greater expression of cdk2, cyclin E and p-Rb than those in 6-AN and 6-AN+ATP treated cells. The results suggest that 6-AN induced the $G_0/G_1$ phase arrest in IMR32 neuroblastoma cell lines through the increase of $p27^{kip1}$ and the decrease of cdk2, cyclin E and p-Rb.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.2
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• pp.91-97
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• 2020

Standardization of vitamin analysis continues around the world, and much effort has been made to improve the accuracy of the results. This study analyzed the sigma metrics of the vitamin D test using the external quality assessment (EQA) program. Sigma metrics is used for quantitative tests performed in the laboratory, and the test results can be objectively visualized in terms of quality. This analysis was performed based on the accuracy of the College of American Pathologists (CAP) using the results of the 2019 accuracy-based vitamin D (ABVD) survey, and about 300 laboratories participated in the survey. Reference values were obtained by the Center for Disease Control and Prevention (CDC) reference laboratory. At six different concentrations, the sigma metrics were analyzed to be 1.00, 1.85, 2.42, 1.01, 1.54 and 0.78, respectively. An average of 1.43 sigma metrics was determined. In particular, only positive biases for ABVD-16 and 17 were shown in the liquid chromatography tandem-mass spectrometry (LC-MS/MS), which is the standard method for vitamin D determination when compared to the reference values. The causes of the difference can be explained by cross reactivity to various vitamin D metabolites. Laboratories need to improve their overall performance.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.27-34
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• 2000

The chloroform and methanol (2;1, v/v) extract from an edible plant, Actinidia arguta Planchon, appeared to possess antitumor activity against human leukemias Jurkat T and U937 cells through inducing apoptosis. The substance in the solvent extract was purified by silica gel column chromatography, preparative TLC, and Sephadex LH-20 column chromatography. Characteristics of the substance analyzed by UV scanning analysis, $^1H$ and $^{13}C$ NMR spectra suggested that the substance belongs to the chlorophyll derivatives-like group. The $IC_{50}$ value of the chlorophyll derivative (Cp-D) determined by MTT assay was $15\mu\textrm{g}/ml$ for Jurkat, $10\mu\textrm{g}/ml$ for U937, and $11.4\mu\textrm{g}/ml$ for HL-60m and was more toxic to these leukemias than to solid tumors or normal fibroblast. In order to elucidate cellular mechanisms underlying the cytotoxicity, the effect of the Cp-D on Jurkat T cells was investigated. When cells were treated with the Cp-D at a concentration of $15\mu\textrm{g}/ml$, [3H]thymidine incorporation declined rapidly and wa undetectable in 1h. However, no significant changes were made in the cell cycle distribution of the cells by 24h. The sub-Gl peak representing apoptotic cells began to be detectable in 36h, at which time apoptotic DNA fragmentation was also detected on agarose gel electrophoresis, demonstrating that the cytotoxic effect of the Cp-D is attributable to the induced apoptosis. Under the same conditions, although the protein level of cyclin-dependent kinases such as cdc4, csk6, cdk2, and cdc2 was not significantly changed until 24h, the kinase activity of all c안 rapidly declined and reached a minimum level within 1-6h and then recovered to the initial level by 12h and sustained until 24h. These results suggest that inactivation of cdks at an inappropriate time during the cell cycle progression in jurkat T cells following a treatment with the Cp-D leads to induction of apoptotic cell death.

• Journal of Life Science
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• v.19 no.8
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• pp.1047-1054
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• 2009

Oral squamous carcinoma (OSC) cells present resistance to chemotherapeutic agents-mediated apoptosis in the late stages of malignancy. Advances in the understanding of bacterial toxins have produced new strategies for the treatment of cancers. It was demonstrated here that Pseudomonas aeruginosa exotoxin A (PEA) significantly decreased the viability of chemoresistant YD-9 cells in the apoptosis mechanism. Apoptotic manifestations were evident through changes in nuclear morphology and generation of DNA fragmentation. PEA treatment induced caspase-3, -6 and -9 cleavage, and activation. These events preceded proteolysis of the caspase substrates poly (ADP-ribose) polymerase (PARP), DNA fragmentation factor 45 (DFF45), and lamin A in YD-9 cells. The reduction of mitochondrial membrane potential, release of cytochrome c and SmacjDlABLO from mitochondria to cytosol, andtranslocation of AlF into nucleus were shown. While p53, p21 and $14-3-3{\gamma}$ were upregulated, cyclin Band cdc2 were downregulated by PEA treatment. Taken together, PEA induces apoptosis in chemoresistant YD-9 cells via activation of caspases, mitochondrial events and regulation of cell cycle genes.