• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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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)

• 생명과학회지
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• 제11권4호
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• pp.362-370
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• 2001

Regulation of cell proliferation is a complex process involving the regulated expression and /or modification of discrete gene products. which control transition between different stages of the cycle. The purpose of this short review is to provide an overview of somatic cell cycle events and their controls. Cycline have appeared as major positive regulators in this network, because their association to the cyclin-dependent kinases(Cdks) allows the subsequent activation on the Cdk/cyclin complexes and their catalatic activity. In mammalian cells, early to mid G1 progression and late G1 progression leading to S phase entry are directed by D-type cyclins-Cdk4, 6 and cyclin E-Cdk 2 both of which can phosphorylate the retinoblastoma protein (pRB). pRB is a transcriptional repressor which, in its unphosphorylated state, binds to members of the E2F transcription factor family and blocks E2F-dependent transcription of genes controlling the G1 to S phase transition an subsequent DNA synthesis. Cyclin A is produced in late G1 and expressed during S and G2 phae, and expression of B-type cyclins is typically maximal during the G2 to M phase transition and it controls the passage through M phase. They primarily associate with the activate Cdk2, and Cdc2, respectively. On the other hand, the Cdk inhibitors negatively control the activity of C아/cyclin complex by coordinating internal and/or external signals and impending proliferation at several key checkpoints. These current and further findings will provide novel approaches to understanding and treating major diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8313-8319
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• 2016

We have recently shown that thymoquinone (TQ) has a potent cytotoxic effect and induces apoptosis via caspase-3 activation with down-regulation of XIAP in mouse neuroblastoma (Neuro-2a) cells. Interestingly, our results showed that TQ was significantly more cytotoxic towards Neuro-2a cells when compared with primary normal neuronal cells. In this study, the effects of TQ on cell-cycle regulation and the mechanisms that contribute to this effect were investigated using Neuro-2a cells. Cell-cycle analysis performed by flow cytometry revealed cell-cycle arrest at G2/M phase and a significant increase in the accumulation of TQ-treated cells at sub-G1 phase, indicating induction of apoptosis by the compound. Moreover, TQ increased the expression of p53, p21 mRNA and protein levels, whereas it decreased the protein expression of PCNA, cyclin B1 and Cdc2 in a dose-dependent manner. Our finding suggests that TQ could suppress cell growth and cell survival via arresting the cell-cycle in the G2/M phase and inducing apoptosis of neuroblastoma cells.

• BMB Reports
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• 제34권2호
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• pp.123-129
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• 2001

Cellular response to ionizing radiation is affected by cell types, radiation doses, and post-irradiation time. Based on the trypan blue dye exclusion assay in normal oral mucosal cells (OM cells), a 48 h post-irradiation was sufffcient and an adequate time point for the evaluation of radiation sensitivity Its $LD_{50}$ was approximately 1.83 Gy To investigate possible biomarkers useful for the biological radiodosimetry of normal epithelial cells (p53, c-fos, cyclin D1, cdc-2, pRb) EGF receptor phosphorylation and Erk activation were evaluated at different radiation doses and different post-irradiation times. From 0.5 Gy, p53 was accumulated in the nucleus of basal cells of the OM raft culture at 4 h post-irradiation and sustained up to 24 h post-irradiation, which suggests that radiation-induced apoptosis or damage repair was not yet completed. The number of p53 positive cells and biosynthesis of p53 were correlated with radiation doses. Both cyclin D1 and c-fos were only transiently induced within 1 h post-irradiation. Cyclin D1 was induced at all radiation doses. However, cfos induction was highest at 0.1 Gy, approximately 7.3 fold more induction than the control, whose induction was reduced in a reverse correlation with radiation dose. The phosphorylation pattern of cdc-2 and pRb were unaffected by radiation. In contrast to A431 tails overexpressing the EGF receptor approximately 8.5 fold higher than normal epithelial, the OM cells reduced the basal level of the EGF receptor phosphorylation in a radiation dose dependent fashion. In conclusion, among radiation-induced biomolecules, the p53 nuclear accumulation may be considered for the future development of a useful marker far biological radiodosimetry in normal epithelial tissue since it was sustained for a longer period and showed a dose response relationship. Specific c-fos induction at a low dose may also be an important finding in this study It needs to be studied further for the elucidation of its possible connection with the low dose radio-adaptive response.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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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.

• Annals of Clinical Microbiology
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• 제18권2호
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• pp.37-43
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• 2015

배경: 결핵은 전세계적으로 단일 원인균으로는 가장 높은 치사율을 가진 질병이다. 결핵의 치료에 있어서 마이코박테리아를 빠르고 정확하게 확인하는 것이 필수적이다. 본 연구에서는 임상 객담 검체의 도말 슬라이드에서 결핵균과 비결핵 항산균의 감별을 위해 Peptide Nucleic Acid (PNA) Probe를 이용한 FISH assay를 평가하고자 한다. 방법: 결핵균과 비결핵 항산균의 16s rRNA를 타겟으로 한 PNA probe를 합성하였다. 각 probe의 특이도는 표준 균주인 Mycobacterium tuberculosis ATCC 13950, M. kansasii ATCC 12479, 임상 검체에서 분리된 마이코박테리아 3종(M. abscessus, M. avium, and M. intracellulare) 그리고 호흡기계에서 흔히 분리되는 10종류의 박테리아를 이용하였다. Centers for Disease Control and Prevention (CDC)의 Acid fast bacili (AFB) 염색 기준상 trace 이상인 128개의 임상 객담 검체를 이용하여 Probe의 성능을 평가하였다. PNA FISH와 항산균 염색결과는 CDC 기준에 따라 단계를 분류하고 서로 비교하였다. 결과: 결핵균과 비결핵 항산균 특이 PNA probe는 결핵균과 M. kansasii 표준 균주 그리고 임상검체에서 분리된 3종의 마이코박테리아에 대해 특이적인 반응을 보였고 다른 박테리아와 교차반응을 보이지 않았다. 또한 89개의 결핵균 배양 양성 객담 검체와 29개의 비결핵 항산균 배양 양성 객담 검체에 각각 특이적인 반응을 보였고 CDC 기준에 따라 분류한 PNA FISH와 AFB염색 결과는 2+ 이상의 검체에서 서로 잘 일치하였다. 결론: PNA FISH 방법은 임상 객담 검체에서 결핵을 진단하고, 항산균과 비결핵 항산균을 구분하는데 있어서 민감하고 정확한 결과를 보였다.

• Tribology and Lubricants
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• 제25권1호
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• pp.20-24
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• 2009

TiC-derived carbon coatings have been synthesized at $600^{\circ}C$ temperature treatment with $H_2/Cl_2$ mixture gases. From Raman spectroscopy measurements, the modified layer was covered with carbon and the thick-ness of the layer was increased with increasing reaction time. And $I_D/I_G$ ratio was decreased with increasing reaction time. The superior tribological property was obtained from TiC reacted with $Cl_2$ gas for 2 hrs. And the tribological property measurements indicate that TiC-derived carbon layer has $0.9{\times}10_{-6}mm^3/Nm$ in wear coefficient and 0.13 in friction coefficient.

• 기본간호학회지
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• 제19권2호
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• pp.223-232
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• 2012

Purpose: The purpose of this study was to compare the effects of preventing CAUTIs through the practice of using 0.05% chlorhexidine gluconate (CHG) versus normal saline for perineal care in ICU patients. Methods: A randomized controlled trial was used, and participants were randomly allocated to either the CHG group (n=79) or normal saline group (n=81). CAUTI was diagnosed following the criteria of the Centers of Disease Control and Prevention (CDC). Incidence of CAUTI and characte oftics of infection were evaluated. Results: In the CHG group, 8 epofodes of CAUTI were obsevend in 79 patients and 875 foley catheter e ys. Tnce ate of CAUTI was 9.14 per 1,000 foley catheter e ys. Tncre were 2 epofodes of CAUTI in the 81 patients and 837 foley catheter e ys of the normal saline group. Tnce ate of CAUTI was 2.39 per 1,000 foley catheter e ys. Tnc difference between both groups was not significant (p=.1e ConConclusevaluUsing normal saline to provide perineal care to ICU patients with a foley catheter inserted will not increase the risk for CAUTI.

• Reproductive and Developmental Biology
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• 제31권2호
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• pp.71-76
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• 2007

Previous studies have shown that BMI-1026 is a potent inhibitor of the cyclin-dependent kinases (cdk). In cell culture, the compound also arrests G2/M strongly and G1/S and S weakly. Two key kinases, cdk1 (p34cdc2 kinase) and mitogen-activated protein (MAP) kinase (erk1 and 2), perform crucial roles during oocyte maturation and, later, metaphase II (MII) arrest. In mammalian oocytes, both kinases are activated gradually around the time of germinal vesicle breakdown (GVBD) and maintain high activity in eggs arrested at metaphase II. In this study, we examined the effects of BMI-1026 on GVBD and MII arrest in mouse oocytes. BMI-1026 inhibited GVBD of immature oocytes and activated MII-arrested oocytes in a concentration-dependent manner, with more than 90% of oocytes exhibiting GVBD inhibition and MII activation at 100 nM This is approximately 500$\sim$1,000 times more potent than the activity reported for the cdk inhibitors roscovitine (${\sim}50{\mu}M$) and butyrolactone (${\sim}100{\mu}M$). Based on the results of previous in vitro kinase assays, we expected BMI-1026 to inhibit only cdk1 activation in oocytes and eggs, not MAP kinase. However, in our cell-based system, it inhibited the activity of both kinases. We also found that the effect of BMI-1026 is reversible. Our results suggest that BMI-1026 inhibits GVBD and activates MII-arrested oocytes efficiently and reversibly and that it also inhibits both cdk1/histone HI kinase and MAP kinase in mouse oocytes.

• 대한한의학회지
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• 제29권2호
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• pp.133-150
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• 2008

Objective: This study was performed to examine Danggui (DG, Angelica gigas Nakai)'s potential activity for promoting axonal regeneration in the injured peripheral nerve. Methods: Using the sciatic nerve in the rats, DG extract 5 ${\mu}l$(10 mg/ml in 0.5% saline) was dripped into the injury site of the nerve. Results: DG treatment facilitated axonal elongation responses in the distal portion to the injury site. GAP-43 protein levels were upregulated by DG treatment in the injured nerve and also in the DRG, suggesting the induction of GAP-43 expression at gene expression level after nerve injury. Phospho-Erk1/2 protein levels were upregulated in the injured nerve area and also in the DRG, suggesting retrograde transport of phospho-Erk1/2 protein from the injury area to the cell body. Cdc2 protein levels were slightly upregulated by DG treatment. DG treatment increased the number of non-neuronal cells in the distal portion to the injury site. Conclusions: The present data suggest that DG is effective for enhanced axonal regrowth after sciatic nerve injury.