• 한국지구과학회지
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• 제27권4호
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• pp.390-400
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• 2006

본 연구에서는 사범대학의 현행 지구과학 교사 양성 교육 과정을 크게 교직 이론, 교육 실습, 교과 교육학, 교과 내용학으로 나누어 분석하여 그 개선 방안을 탐색해 보았다. 교직이론의 경우는 교육학 이론 학습에 치중하고 있어 실제성이 떨어지며, 교과 교육학 선수 학습 교과로서 이수 시기에 문제가 있는 것으로 분석되었다. 그러므로 과목간 연계성 유지를 위해 교직 이론을 교과 교육학 이전에 이수하도록 하며, 되도록이면 현장성이 강한 교직 이론 과목을 이수하도록 권장하여야 할 것이다. 교육 실습의 경우는 교육실습 기간이 외국에 비해 짧으며, 신규 교사를 위한 별도의 업무 외 연수과정이 없고 인턴제도나 직무 연수 프로그램이 미흡한 현재의 교사 양성 교육과정 체제에서는 교육 실습이 이런 역할을 대신할 수밖에 없을 것으로 판단된다. 그러므로 학교 시스템의 전반적인 흐름을 이해하기 위해서 교육 실습 기간을 최소$3{\sim}6$개월 이상으로 늘려야 할 필요가 있다. 교과 교육학의 경우는 우선 교과 내용학에 비해 할당된 과목의 비율이 매우 낮았다. 그러므로 교과 교육학 과목의 양적인 증가가 우선되어야 할 것이며, 지구과학 교과 교육 전공 교수의 확보가 필요하다. 교과 내용학의 경우, 다루는 내용이 중등학교 교육 과정과 동떨어진 면이 있으며 대학별로 개설 강좌의 영역별비율에서 상당한 차이가 있는 것으로 나타났다. 이런 문제를 해소하기 위해서는 교과 교육학 강좌와 교과 내용학 강좌를 연계시켜 개설하고, 각 영역별 기본 이수 학점을 적정 비율로 할당하는 방법을 고려해 보아야 할 것이다.는 것을 알 수 있다.충분한 해상도로 인한 경우가 3예(12%), 이전 바륨 검사에 의한 잔존 바륨의 beam harding artifact로 복막파종을 놓친 경우가 2예(8%), 경구 조영제가 미충만된 위장관과 인접 전이성 결절을 오인한 경우가 1예(4%)였다. 판독인자로는 인접 장기와의 지방면 소실을 간과한 경우가 10예(40%), 경미한 복막비 후나 파종을 간과한 경우가 6예(24%), 장간막의 림프절 종대를 간과한 경우가 3예(12%)였다. 결론: 복강 내 지방 조직의 결핍, 불충분한 해상도의 CT, 판독 과정에서 경미한 복막파종이나 인접 장기와의 지방면 소실의 간과 때문에 CT에 의한 수술 전 병기결정의 정확도가 떨어지며 그 중 판독인자에 의한 것이 가장 많은 원인이 되므로 적절한 영상 관리와 함께 세심한 판독이 매우 중요하겠다. 수술적 절제의 적절한 범위를 결정하기 위한 조기 위암의 술 전 위치 결정에 이용될 수 있을 것으로 보인다.^{Waf1/Cip1}(+)/p27^{kip1}(+)$인 경우에 T1-2 (87.5%)가 많았고 $p21^{Waf1/Cip1}(-)/p27^{kip1}(-)$인 경우에는 T3-4(58.1%)가 많았다(P<0.05). 또한 Lauren 분류에서는 $p21^{Waf1/Cip1}(+)/p27^{kip1}$인 경우가 장형 (100%)에서만 나타났으며(P<0.05), $p21^{Waf1/Cip1}(-)/p27^{kip1}(-)$인 경우는 미만형인 경우(87.0%)가 장형(54.9%)의 경우보다 많은

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.966-967
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• 2005

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2006년도 춘계학술대회
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• pp.3-12
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• 2006

1 The present work was performed to investigate the effects of ginsenoside Rh2 on proliferation, cell cycle-regulation and differentiation of human leukemia HL-60 cells as well as the underlying mechanisms for these effects. 2 Ginsenoside Rh2 potently inhibited the proliferation of HL-60 cells in both a dose- and time-dependent manner with an $IC_{50}$, $20{\mu}M$. 3 DNA flow-cytometry indicated that ginsenoside Rh2 markedly induced a $G_1$ phase arrest of HL-60 cells. 4 Among the $G_1$ phase cell cycle-related proteins, the levels of cyclin-dependent kinase(CDK)4, 6 and cyclin D1, cyclin D2, cyclin D3 were reduced by ginsenoside Rh2, whereas the steadystate levels of CDK2 and cyclin E were unaffected. 5 The protein levels of a CDK inhibitor p16, $p21^{CIP1/WAF1}$ and $p27^{KIP1}$ were markedly increased by ginsenoside Rh2. 6 Ginsenoside Rh2 markedly enhanced the binding of $p21^{CIP1/WAF1}$ and $p27^{KIP1}$ with CDK2 and CDK6, resulting in the reduced activity of both kinases and the hypophosphorylation of Rb protein. 7 We furthermore suggest that ginsenoside Rh2 is a potent inducer of the differentiation of HL-60 cells, based on observations such as a reduction of the nitroblue tetrazolium level, an increase in the esterase activities and phagocytic activity, morphology changes, and the expression of CD11b, CD14, CD64 and CD66b surface antigens. 8 In conclusion, the onset of ginsenoside Rh2-induced the $G_0/G_1$ arrest of HL-60 cells prior to the differentiation is linked to a sharp up-regulation of the $p21^{CIP1/WAF1}$ level and a decrease in the CDK2, CDK4 and CDK6 activities. This is the first report demonstrating that ginsenoside Rh2 potently inhibits the proliferation of human promyelocytic HL-60 cells via the $G_1$ phase cell cycle arrest and differentiation induction.

• Biomolecules & Therapeutics
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• 제19권2호
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• pp.187-194
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• 2011

Atherosclerosis and post-angiography restenosis are associated with intimal thickening and concomitant vascular smooth muscle cell (VSMC) proliferation. Obovatol, a major biphenolic component isolated from the Magnolia obovata leaf, is known to have anti-inflammatory and anti-tumor activities. The goal of the present study was to enhance the inhibitory effects of obovatol to improve its potential as a preventive or therapeutic agent in atherosclerosis and restenosis. Platelet-derived growth factor (PDGF)-BB-induced proliferation of rat aortic smooth muscle cells (RASMCs) was examined in the presence or absence of a newly synthesized obovatol derivative, OD78. The observed anti-proliferative effect of OD78 was further investigated by cell counting and [$^3H$]-thymidine incorporation assays. Treatment with 1-4 ${\mu}M$ OD78 dose-dependently inhibited the proliferation and DNA synthesis of 25 ng/ml PDGF-BB-stimulated RASMCs. Accordingly, OD78 blocked PDGF-BB-induced progression from the $G_0/G_1$ to S phase of the cell cycle in synchronized cells. OD78 decreased the expression levels of CDK4, cyclin E, and cyclin D1 proteins, as well as the phosphorylation of retinoblastoma protein and proliferating cell nuclear antigen; however, it did not change the CDK2 expression level. In addition, OD78 inhibited downregulation of the cyclin-dependent kinase inhibitor (CKI) $p27^{kip1}$. However, OD78 did not affect the CKI $p21^{cip1}$ or phosphorylation of early PDGF signaling pathway. These results suggest that OD78 may inhibit PDGF-BB-induced RASMC proliferation by perturbing cell cycle progression, potentially through $p27^{kip1}$ pathway activation. Consequently, OD78 may be developed as a potential anti-proliferative agent for the treatment of atherosclerosis and angioplasty restenosis.

• Applied Biological Chemistry
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• 제49권3호
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• pp.233-237
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• 2006

Sprague-Dawley 랫트(실험용 쥐)에서 간을 적출하여 Collagen coating된 세포 배양 접시에 간세포 배양을 하여 친환경 재배 배 추출물과 일반 관행 재배 배 추출물의 간세포 기능성을 분석하였다. 3일간 적응 시킨 후 관행 재배 배 추출물과 친환경 재배 배 추출물을 농도 별(동결 건조된 $5\;{\mu}g/ml$, $20\;{\mu}g/ml$, $40\;{\mu}g/ml$) 처리하여 간세포의 에너지원인 ATP assay를 실시한 결과 관행 재배 배 추출물의 경우는 대조군과 유의한 차이는 인정이 되지 않았으나 친환경 재배 배 추출물의 경우 농도 의존적으로 정상군에 비해 180%까지 증가하는 것으로 나타났다. 한편 세포 성장의 경우도 DNA의 특유 염기 구성성분중의 하나인 thymine의 전구체인 $[^3H]$-thymidine을 간세포에 처리하여 DNA 합성을 알아본 결과 친환경 재배 배 추출물 을 농도별로 처리하였을 때 관행재배 배 추출물에 비해 간세포의 세포 성장율이 증가하는 것으로 나타났다($40\;{\mu}g/ml$ 투여 시 관행 재배 배추출물 112% vs. 친환경 재배 배 추출물은 234%; p<0.05). 아울러 세포성장 단백질인 CDK-2, CDK-4의 경우도 친환경 배 추출물 처리 시 현저하게 증가하는 것으로 나타났으며 세포성장 억제 단백질인 p21WAF1/Cip1 및 p27 Kip1의 경우는 억제시키는 것으로 나타났다.

• Biomolecules & Therapeutics
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• 제19권4호
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• pp.411-418
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• 2011

Ginsenoside Rp1 (G-Rp1) is a novel ginseng saponin derivative with anti-tumor activity. However, the biochemical and molecular mechanisms of G-Rp1 on anti-tumor activity are not fully understood. In the present study, we report that G-Rp1 inhibits lung cancer cell proliferation, migration and adhesion in p53 wild-type A549 and p53-defi cient H1299 cells. Anti-proliferative activity of G-Rp1 in lung cancer cells is mediated by enhanced nuclear localization of cyclin-dependent kinase inhibitors including $p27^{Kip1}$ and $p21^{WAF1/Cip1}$, and subsequent inhibition of pRb phosphorylation. We also show that these anti-tumor activities of G-Rp1 in both A549 and H1299 cells appear to be mediated by suppression of mitogenic signaling pathways such as ERK, Akt and $p70^{S6K}$. Taken together, these findings suggest further development and evaluation of G-Rp1 for the treatment of lung cancers with mutated p53 as well as wild-type p53.

• 생명과학회지
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• 제20권2호
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• pp.281-291
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• 2010

본 연구는 유근피(root bark of Ulmus davidiana)에서 분리한 화합물인 hederagenin 3-O-b-D-glucopyranosyl($1{\rightarrow}3$)-a-L-rhamnopyranosyl($1{\rightarrow}2$)-a-L-arabinopyranoside (HDL)을 이용하여 $CoCl_2$에 의해 생성된 ROS에 대한 항산화 기전을 밝히기 위하여, ROS 생성과 관련된 산화 효소 및 항산화 효소에 대한 저해효과를 조사하였다. 또한 HDL이 $CoCl_2$에 의해 생성된 ROS의 조절을 통해 산화적 스트레스와 관련된 단백질 발현 및 세포주기에 미치는 영향을 조사하였다. 그 결과 HDL은 $CoCl_2$에 의해 유발된 xanthine oxidase와 $H_2O_2$ 생성 증가를 억제하였고, 산화와 관련된 SOD, CAT의 활성을 증가시켜 $H_2O_2$의 가수분해를 촉진하였다. 그리고 HDL은 $CoCl_2$에 의해 유발된 ferritin의 손상과 ferritin iron의 방출을 억제하 였으며, 지질과산화의 증가를 억제하였다. 뿐만 아니라 HDL은 $CoCl_2$에 의해 증가된 G1 phase의 세포를 감소시켰으며, 세포주기와 관련된 p53 및 $p21^{CIP1/WAF1}$의 발현을 감소시켰다. 이러한 연구결과들은 HDL이 천연물로부터 유래한 독성이 없는 항산화제로서의 가능성을 제시한다.

• 동의생리병리학회지
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• 제20권1호
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• pp.163-170
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• 2006

Nardostachyos Rhizoma (N. Rhizoma) belonging to the family Valerianaceae has been anti-arrhythmic effect, and sedation to the central nerve and a smooth muscle. We reported that the water extract of N. Rhizoma induced apoptotic cell death and differentiation in human promyelocytic leukemia (HL-60) cells. Cytotoxicity of N. Rhizoma was detected only in HL-60 cells (IC50 is about 200 ${\mu}g/ml$). The cytotoxic activity of N. Rhizoma in HL-60 cells was increased in a dose-dependent manner. We used several measures of apoptosis to determine whether these processes were involved in N. Rhizoma-induced apoptotic cell death. The high-dose (200 ${\mu}g/ml$) treatment of N. Rhizoma to HL-60 cells showed cell shrinkage, cell membrane blobbing, apoptotic bodies, and the fragmentation of DNA, suggesting that these cells underwent apoptosis. Treatment of HL-60 cells with N. Rhizoma time-dependently induced activation of caspase-3, caspase-8, and caspase-9 and proteolytic cleavage of poly(ADP-ribose) polymerase. Also, we investigated the effect of N. Rhizoma on cellular differentiation and proliferation in HL-60 cells. Differentiation and proliferation of HL-60 cells was determined through expression of CD11b and CD14 surface antigens using flow cytometry and nitroblue tetrazolium (NBT) assay, and through analysis of cell cycle using propidium iodide assay, respectively. N. Rhizoma induced the differentiation of HL-60 at the low-dose (100 ${\mu}g/ml$) treatment, as shown by increased expression of differentiation surface antigen CD11b, but not CDl4 and increased reducing activity of NBT. When HL-60 cells were treated with N. Rhizoma at concentration of $50{\mu}g/ml\;and\;100{\mu}g/ml$, NBT-reducing activities induced approximately 1.5-fold and 20.0-fold as compared with the control. In contrast, HL-60 cells treated with the N. Rhizoma-ATRA combination showed markedly elevated levels of 26.3-fold at $50{\mu}g/ml$ N. Rhizoma-0.1 ${\mu}M$ ATRA combination and 27.5-fold at 50 ${\mu}g/ml$ N. Rhizoma-0.2 ${\mu}M$ ATRA combination than when treated with N. Rhizoma alone or ATRA alone. It may be that N. Rhizoma plays important roles in synergy with ATRA during differentiation of HL-60 cells. DNA flow-cytometry indicated that N. Rhizoma markedly induced a G1 phase arrest of HL-60 cells. N. Rhizoma-treated HL-60 cells increased the cell population in G1 phase from 32.71% to 42.26%, whereas cell population in G2/M and S phases decreased from 23.61% to 10.33% and from 37.78% to 33.98%, respectively. We examined the change in the $p21^{WAF1/Cip1}\;and\;p27^{Kip1}$ proteins, which are the CKIs related with the G1 phase arrest. The expression of the CDK inhibitor $p27^{Kip1},\;but\;not\;p21^{WAF1/Cip1}$ were markedly increased by N. Rhizoma. Taken together, these results demonstrated that N. Rhizoma induces apoptotic cell death through activation of caspase-3, and potently inhibits the proliferation of HL-60 cells via the G1 phase cell cycle arrest in association with $p27^{Kip1}$ and granulocytic differentiation induction .

• International Journal of Oral Biology
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• 제41권3호
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• pp.113-118
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• 2016

An FDA approved drug for the treatment of type II diabetes, Troglitazone (TRO), a peroxisome proliferator-activated receptor gamma agonist, is withdrawn due to severe idiosyncratic hepatotoxicity. In the search for new applications of TRO, we investigated the cellular effects of TRO on YD15 tongue carcinoma cells. TRO suppressed the growth of YD15 cells in the MTT assay. The inhibition of cell growth was accompanied by the induction of cell cycle arrest at $G_0/G_1$ and apoptosis, which are confirmed by flow cytometry and western blotting. TRO also suppressed the expression of cell cycle proteins such as cyclin D1, cdk2, cdk4, cyclin B1, cdk1(or cdc2), cyclin E1 and cyclin A. The inhibition of cell cycle proteins was coincident with the up-regulation of $p21^{CIP1/WAF1}$ and $p27^{KIP1}$. In addition, TRO induces the activation of caspase-3 and caspase-7, as well as the cleavage of PARP. Further, TRO suppressed the expressions of Bcl-2 without affecting the expressions of Bad and Bax. Overall, our data supports that TRO induces cell cycle arrest and apoptosis on YD15 cells.

• 동의생리병리학회지
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• 제21권5호
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• pp.1170-1175
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• 2007

We have examined the effect of water extract of Phellinus linteus, a raw material of Korean traditional herbal medicine, on the induction of HL-60 cell differentiation. The proliferation of HL-60 cell was inhibited dose-dependently by treatment with various doses of P. linteus extract. It also caused a significant change in NBT reduction (7.5 times). The expression of CD11b and CD14 was increased in the cells treated with the extract, especially in those arrested at G0/G1 stage, which suggested that some components in P. Linteus extract induced HL-60 cell differentiation to granulocytic and monocyte lineages. Moreover, the expression levels of $p21^{WAF1/CIP}$ and $p27^{KIP}$ were up-regulated during HL-60 cell differentiation induced by P. Linteus extract. These results together suggest that P. Linteus extract contains potential HL-60 cell differentiation agents.