• The Korean Journal of Ecology
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• 제20권3호
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• pp.169-173
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• 1997

The measurement of cell death constant in Anabaena flos-aquae was tested by the Live/Dead BacLight Viability kit(Molecular Probes Co., Seatle, WA). When the Live/Dead BacLight Viability kit was applied to Anabaena flos-aquae, the cells with intact cell membranes(live cells) stained fluorescent green, while the cell with damaged membranes(dead cells) stained fluorescent red and the background remained virtually nonfluorescent. The rations of live : dead cells in the cell suspension were controlled artifically and Live/Dead BacLight Viability kit was applied to them. The ratios of green:red fluorescent cells in the cell suspension were the same as those of live : dead cells controlled artifically. It was also approved by the fluorescence emission. The cell death constant was measured in the P-limited Anabaena flos-aquae chemostal culture in the N-fixing and $KNO_3-supplied$ conditions. The culture in N-fixing chemostat had a dead cell proportion of 1.2% at the growth rate of 0.7/day and increased to 2.6% at the growth rate of 0.3/day. The cell death constant of N-fixing culture was 0.008/day.There was a same trend in the $KNO_3-supplied$ chemostat culture. The proportion of dead cell was 1.6% of dead cell proportion at the growth rate of 0.7/day and increased to 4.3% at the growth rate of 0.3/day.

• Journal of Photoscience
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• 제9권2호
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• pp.454-456
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• 2002

It is important to determine the action spectrum of UV-B radiation contained in the sunlight to estimate the risk of skin cancer. We have investigated action spectra for induction of apoptosis and reproductive cell death in L5178Y cells using the Okazaki Large Spectrograph at NIBB. L5178Y cells were exposed to light at different wavelengths in UV-B or UV-A region. Frequencies of apoptosis induction and reproductive cell death were determined by counting cells with chromatin condensation, and by the colony formation assay, respectively. The measured sensitivity spectra for the two end-points were in very good agreement. Sensitivity decreased steeply with increase of wavelength in UV-B region and remains nearly constant in UV-A region. The action spectra were also slightly steeper than that for the minimum erythematic dose (MED), but very similar to the light absorption spectrum of DNA in UV-B region. On the other hand, the spectra for both endpoints were similar to MED spectrum but not DNA spectrum in the UV-A region. Also different time-course and morphological difference of apoptosis were found between UV-B (long time, fragmentation) and UV-A (short time, shrinkage) region. These results suggest that DNA damage induced by UV-B light triggers apoptosis and reproductive cell death, but other damaged targets (membrane, protein and so on) trigger these effects in UV-A region.

• The Plant Pathology Journal
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• 제40권4호
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• pp.358-376
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• 2024

Inoculation of Chinese cabbage leaves with high titer (10⁷ cfu/ml) of the non-adapted bacteria Xanthomonas campestris pv. vesicatoria (Xcv) strain Bv5-4a.1 triggered rapid leaf tissue collapses and hypersensitive cell death (HCD) at 24 h. Electrolyte leakage and lipid peroxidation markedly increased in the Xcv-inoculated leaves. Defence-related gene expressions (BrPR1, BrPR4, BrChi1, BrGST1 and BrAPX1) were preferentially activated in the Xcv-inoculated leaves. The Xcv-triggered HCD was attenuated by continuous light but accelerated by a dark environment, and the prolonged high relative humidity also alleviated the HCD. Constant dark and increased relative humidity provided favorable conditions for the Xcv bacterial growth in the leaves. Pretreated fluridone (biosynthetic inhibitor of endogenous abscisic acid [ABA]) increased the HCD in the Xcv-inoculated leaves, but exogenous ABA attenuated the HCD. The pretreated ABA also reduced the Xcv bacterial growth in the leaves. These results highlight that the onset of HCD in Chinese cabbage leaves initiated by non-adapted pathogen Xcv Bv5-4a.1 and in planta bacterial growth was differently modulated by internal and external conditional changes.

• KSBB Journal
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• 제11권3호
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• pp.276-287
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• 1996

하이브리도마 세포의 성장과 사망, 모노클론 항체의 생산, 포도당과 글루타민의 소비, 그리고 유산과 암모늄 이옹의 생산에 미치는 클루타민의 영 향을 조사하기 위해 초기 글루타민 농도를 변화시키면서 하이브리도마 세포의 회분식 현탁배양을 실시하였다. 실험 결과에 기초하여 세포의 성장속도, 영양물(포도당과 글루타민) 소비속도, 그리고 모노클론 항체 및 대사 부산물(유산과 암모늄이온)의 생산 속도를 예측할 수 있는 수학적 모델이 제시되었다. 포도당과 글루타민에 대해서는 중첩 적인 Monod 형식이며 암모늄 이옹과 유산에 대해 서는 Non-copmetitive inhibition 관계로 표시되는 세포의 비성장 속도에 관한 방정식이 개발되었다. 유산에 대한 억제 상수는 유산농도에 반바례하였다. 세포의 비사망 속도는 포도당, 글루타민, 암모 늄 이온과 유산 농도의 함수로 유도되었다.

• IMMUNE NETWORK
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• 제3권4호
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• pp.268-275
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• 2003

Background: Hemopoietic cells require the constant presence of growth factors for survival in vitro and in vivo. Caspases have been known as central executors of apoptotic cell death. We have, therefore, investigated the pathways that regulate caspase activity and apoptosis using the $CD34^+$ cell line, TF-1 which requires GM-CSF for survival. Methods: Apoptosis was measured by annexin V staining and mitochondrial membrane potential was measured by DiOC6 labelling. Intracellular pH was measured using pH sensitive fluorochrome, BCECF or SNARF-1, followed by flow cytometry analysis. Caspase activation was analyzed by PARP cleavage using anti-PARP antibody. Results: Removal of GM-CSF induceed PARP cleavage, a hallmark of caspase activity, concomitant with pHi acidification and a drop in mitochondrial potential. Treatment with ZVAD, a competitive inhibitor of caspases, partially rescued cell death without affecting pHi acidification and the reduction of mitochondrial potential, suggesting that both these events act upstream of caspases. Overexpression of Bcl-2 prevented cell death induced by GM-CSF deprivation as well as pHi acidification and the reduction in mitochondrial membrane potential. In parental cells maintained with GM-CSF, EIPA, a competitive inhibitor of $Na^+/H^+$ antiporter induced apoptosis, accompanied by a drastic reduction in mitochondrial potential. In contrast, EIPA induced apoptosis in Bcl-2 transfectants without causing mitochondrial membrane depolarization. Conclusion: Taken together, our results suggest that the regulation of $H^+$fluxes, either through a mitochondriondependent or independent pathway, is central to caspase activation and apoptosis.

• 한국미생물·생명공학회지
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• 제29권4호
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• pp.240-247
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• 2001

본 연구에서는 동물세포 배양장치를 개발키 위한 기초연구로서 초미세 통기법이 산소 전달 속도와 세포의 생존율에 미치는 영향에 대해 알아보았다. 통기 장치로 통기 구멍 크기가 다른 microsparger 를 사용하였을 때, 모형 반응기 내에서 측정한 산소 전달계수(k$_{L}$a)는 microsprager의 통기 구멍 크기가 작아질수록 현저히 증가하였다. 이는 공기 방울들과 매질 사이의 접촉 면적이 증가했기 때문인 것으로 판단된다. 두 가지 다른 형태의 임펠러 (square-pitch marine impeller 와 $45^{\circ}$) pitched flat blade impller) 를 사용하여 교반하였을 때, $k_{L}$ a 값은 marine impeller 를 사용하였을 때 다소 높았다. $100\mu\textrm{m}$ 이하의 통기 구멍을 가진 microsparger 를 사용하여 직접 통기가 세포에 미치는 손상에 대해 알아본 결과, 세포들의 손상 정도는 통기 속도가 증가할수록, 공기방울 크기가 작아질수록 더 커졌다. 2.5 L 용량의 소형 세포 반응기에 $0.5\mu\textrm{m}$ 의 통기 구멍 크기를 가진 micro-sparger를 장치하여 세포를 배양한 결과 , 지속적인 통기시에는 세포의 생존율이 80% 이하로 떨어지고, 정상적인 성장을 하지 못하였다. 그러나 용존 산소 농도가 20% 이하로 떨어졌을 때에만 통기하였을 때 세포는 정상적으로 자랐으며 세포 생존율도 대수기 전반에 걸쳐 90% 이상을 유지하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권6호
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• pp.509-515
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• 2004

광역동치료(PDT)는 갖가지 고형 종양의 치료를 위한 임상적시도로 시작되어 화학요법 및 방사선 요법에 내성이 있는 종양의 대체 치료법의 하나로 제시되고 있다. PDT는 전신적 또는 국소적으로 투여하여 유해한 조직에 선택적으로 농축되도록 한 광증감제와 이를 활성화하는 적절한 파장과 에너지를 가진 레이저광의 조합에 기초한다. 이 연구에서는, 인체 골육종 세포(HOS)에 미치는 레이저 EIT 21의 광독성 효과에 대해 알아보았으며, 그런 광독성 효과가 세포고사를 유발하는가를 규명하고자 하였다. 본 연구는 레이저 EIT 21이 HOS 세포에 대해 광독성을 효과를 가진다는 것을 증명했다. 세포 죽음이 세포괴사에 의해 유발되는지 아니면 세포고사에 의해 유발되는지를 알아보기 위해 세포 고사를 평가 하는 여러 실험 기법을 이용하였다. TUNEL 분석은 극소수만이 응축된 핵의 양성반응을 보여주었다. Hemacolor와 AO/EB 염색 또한 대부분의 세포가 괴사로 죽는 것을 보여주었다. 레이저 EIT로 조사된 HOS 세포에서 응축되거나 분절된 핵을 발견하는 것은 어려웠다. DNA 전기영동에서, 세포고사에서 보여지는 DNA 분절의 전형적인 특징인 사다리형 절편 형태(ladder fragmentation pattern)가 나타나지 않았다. Western blotting에 의한 분석에서 p53의 발현은 일정하게 나타났고 레이저로 조사된 세포는 caspase-3과 PARP의 분열을 나타내지 않는 것으로 보아 레이저 유도 세포 죽음(laser-induced cell death)은 p53과는 관련이 없는 것 같다.

• 대한본초학회지
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• 제29권5호
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• pp.91-95
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• 2014

Objectives : This study was carried out to evaluate whether the water extract from cause the cellular damage in HepG2 cell line. It was reported that Dictamnus dasycarpus Turcz(DDT) intake induce poisoning symptoms in human population. These symptoms was closely related to liver toxicity, however, mechanisms for liver toxicity caused by DDT have not been elucidated exactly. Here, hepatotoxicity caused by DDT was evaluated using HepG2 cell line. Methods : Water extract of DDT was treated into HepG2 cell with various doses such as 0, 0.1, 0.5, 1.0 and $5.0mg/m{\ell}$. In order to cell viability, both MTT and LDH assay were carried out. Also, apoptosis array kit was used to identify whether cell death caused by DDT is due to apoptosis or not. In addition, reactive oxygen species (ROS) was measured after treatment of water extract. Results : We found out significant changes in the apoptosis related factors of hepatocyte. The cell viability of HepG2 treated with DDT water extract was decreased in dose-dependent. Also most of the apoptosis related factors were significantly increased. We found out that Caspase 3, Cytochrome C and ROS had increased in dose-dependent. In addition, other apoptosis related factors Bcl 2 and Bax, which were also constant changes. However, there was no significance. Conclusions : These results suggest that water soluble extract of DDT is expected to have oral toxicity, including hepatocellular damage Therefore, it is suggested that DDT could cause various side effects and toxicity of clinical conditions.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2004년도 Annual Meeting of KSAP : New Drug Development from Natural Products
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• pp.3-10
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• 2004

Oxidative stress is a constant threat to all living organisms and an immense repertoire of cellular defense systems is being employed by most pro- and eukaryotic systems to eliminate or to attenuate oxidative stress. Ischemia and reperfusion is characterized by both a significant oxidative stress and characteristic changes in the antioxidant defense. Heme oxigenase-l (HO-l) is up-regulated by various stimuli including oxidative stress so that it is thought to participate in general cellular defense mechanisms against ischemic injury in mammalian cells. Higenamine, an active ingredient of Aconite tuber, has been shown to have antioxidant activity along with inhibitory action of inducible nitric oxide synthase (iNOS) expression in various cells. In the present study, we investigated whether higenamine and related analogs protect cells from oxidative cellular injuries by modulating antioxidant enzymes, such as HO-l, MnSOD etc. R-form of YS-51 was the most potent inducer of HO-l in bovine endothelial cells, which inhibited apoptotic cell death by H$_2$O$_2$. HO-1 induction by YS 51 was mediated by PI3 kinase activation in which PKA- as well as PKG pathway is considered as important regulators. YS-51 also induced Mn-SOD mRNA expression by activating c-jun N-terminal kinase in endothelial cells and Hela cells. In ROS 17/2.1 cells, higenamine and enetiomers of related compounds inhibited iNOS expression by cytokine mixtures. Taken together, higenamine and related compounds can be developed as possible protective agents from oxidative cell injury or death.

• International Journal of Oral Biology
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• 제47권2호
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• pp.17-24
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• 2022

Preserving intact genetic material and delivering it to the next generation are the most significant tasks of living organisms. The integrity of DNA sequences is under constant threat from endogenous and exogenous factors. The accumulation of damaged or incompletely-repaired DNA can cause serious problems in cells, including cell death or cancer development. Various DNA damage detection systems and repair mechanisms have evolved at the cellular level. Although the mechanisms of these responses have been extensively studied, the global RNA expression profiles associated with genomic instability are not well-known. To detect global gene expression changes under different DNA damage and hypoxic conditions, we performed RNA-seq after treating human cervical cancer cells with ionizing radiation (IR), hydroxyurea, mitomycin C (MMC), or 1% O₂ (hypoxia). Results showed that the expression of 184-1037 genes was altered by each stimulus. We found that the expression of 51 genes changed under IR, MMC, and hypoxia. These findings revealed damage-specific genes that varied differently according to each stimulus and common genes that are universally altered in genetic instability.