• Journal of Yeungnam Medical Science
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• 제11권2호
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• pp.375-380
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• 1994

저자들은 말초 혈액에서 현저한 호산구 증가를 보이면서 간, 임파선, 골수 및 폐에 호산구 침윤을 보여 hydroxyurea로 치료한 특발성 과호산구 증후군 1례를 경험하였기에 문헌고찰과 함께 보고하는바이다.

• 한국임상수의학회지
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• 제36권3호
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• pp.180-183
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• 2019

A 7-year-old, male Maltese dog with a body weight of 2.8 kg was presented with a history of hind limbs ataxia that progressed to tetraparesis over a one-month period. Based on physical and neurological examinations, tetraparesis with concomitant UMN signs, kyphosis and severe neck pain were identified. On MRI scan, we tentatively diagnosed this patient as a primary intramedullary spinal cord tumor. Therapy with lomustine plus hydroxyurea and prednisolone was initiated and the clinical signs rapidly improved. The patient was regularly checked by MRI scan and the range of the mass was gradually reduced to complete remission for 11 months. About 19 months after treatment, the patient showed anemia and hematochezia which suspected as adverse effects of chemotherapy. The condition was getting worse over 2 months and the patient suddenly expired 657 days after initial presentation. On histopathological examination, the spinal cord sample was identified as a neuronal atrophy without evidence of tumor cell.

• 미생물학회지
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• 제46권2호
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• pp.122-126
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• 2010

RAD53은 효모의 검문지점 경로가 DNA 손상을 감지하여 여러 가지 후속적인 세포 내 반응을 일으키는 데 핵심적인 역할을 하는 인산화 효소일 뿐만 아니라, dNTP 생성에 중요한 RNR 유전자 등의 전사 활성화 과정에도 관여하는 효모의 생존에 필수적인 유전자이다. 본 연구에서는 rad53${\Delta}$ 돌연변이의 hydroxyurea에 대한 민감성을 억제하는 억제자로서 CYC8을 동정하였다. CYC8 유전자가 많은 사본으로 존재할 때 rad53${\Delta}$ 균주의 hydroxyurea에 대한 내성이 증가하였으나, CYC8과 복합체로 작용하는 TUP1은 다사본 억제자로 작용하지 못하였다. 반면, 삭제 돌연변이의 경우, cyc8${\Delta}$과 tup1${\Delta}$ 모두 억제자로 작용하였다. CYC8은 효모에서 프리온 단백질로 작용하기 때문에 과량 발현되면 정상적인 CYC8 단백질의 잘못된 접힘을 유발하게 되고, 결과적으로 우성의 $cyc8^-$ 표현형이 나타나게 된다. 따라서 CYC8이 다사본 억제자로 작용하는 이유는 이러한 프리온의 특성 때문으로 추측된다. CYC8이 다사본이거나 cyc8${\Delta}$ 돌연변이일 경우 모두 RNR 유전자의 전사가 증가되는 것을 관찰하였다. 따라서 CYC8에 의한 rad53${\Delta}$ 돌연변이의 억제는 RNR 증가에 따른 세포 내 dNTP 증가 때문으로 생각된다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1994년도 한국생물과학협회 학술발표대회
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• pp.234.2-234
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• 1994

No Abstract, See Full Text

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 춘계학술대회 논문집
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• pp.36-37
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• 2003

The potential application of toxicogenomics to predictive toxicology has been discussed widely, but the utility of the approach remains largely unproven. Using cDNA microarrays, we have compared the gene expression profiles produced in mouse lymphoma cells by three genotoxic compounds, hydroxyurea (a carcino- gen), p-anisidine (a noncarcinogen) and paclitaxel (carcinogenicity unknown). (omitted)

• BMB Reports
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• 제44권5호
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• pp.352-357
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• 2011

The effect of human MutY homolog (hMYH) on the activation of checkpoint proteins in response to hydroxyurea (HU) and ultraviolet (UV) treatment was investigated in hMYH-disrupted HEK293 cells. hMYH-disrupted cells decreased the phosphorylation of Chk1 upon HU or UV treatment and increased the phosphorylation of Cdk2 and the amount of Cdc25A, but not Cdc25C. In siMYH-transfected cells, the increased rate of phosphorylated Chk1 upon HU or UV treatment was lower than that in siGFP-transfected cells, meaning that hMYH was involved in the activation mechanism of Chk1 upon DNA damage. The phosphorylation of ataxia telangiectasia and Rad3-related protein (ATR) upon HU or UV treatment was decreased in hMYH-disrupted HEK293 and HaCaT cells. Co-immunoprecipitation experiments showed that hMYH was immunoprecipitated by anti-ATR. These results suggest that hMYH may interact with ATR and function as a mediator of Chk1 phosphorylation in response to DNA damage.

• Journal of Radiation Protection and Research
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• 제30권4호
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• pp.209-219
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• 2005

소핵분석은 방사선의 생물학적 선량계로서 활용되고 있으나 이의 생성 기전은 아직까지 확실치 않다. 본 연구에서는 사람 림프구에 방사선을 조사한 후 DNA 손상회복 저해물질, Cytosine Arabinoside(Ara C)와 3-Aminobenzamide(3-AB) 그리고 Hydroxyurea(HU)를 특정 세포주기에 처리하고 소핵분석과 FISH기법을 이용하여 방사선에 의한 소핵 및 이수성의 정도를 구명하고자 하였다. 방사선 선량에 따라 소핵과 이수성의 빈도는 양반응 관계를 보이며 증가하였고 DNA 손상회복 저해물질 처리 후 소핵의 빈도는 모든 DNA 손상 회복 저해물질에 의해 증가하였으며 Ara C, 3AB, HU 순으로 나타났다. 이수성의 빈도는 HU와 Ara C에 의해서 크게 증가하였으나, 3AB는 아무런 영향을 주지 않았다. 또한 1번 염색체가 4번 염색체보다 방사선에 의한 소핵형성 및 이수성에 더 많이 관여되었다. 본 연구 결과, 방사선에 의한 소핵 및 이수성의 형성 과정은 여러 다른 기전이 관여하고 있음을 알 수 있었다.

• Journal of Microbiology
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• 제34권1호
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• pp.30-36
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• 1996

We have exmained the re-establishment of HIMRE mediated silencing function on the transcriptional activity of yeast heast shock gene HSP82. To test whether the onset of SIR repression can occur in growing cells in the rpesence of a potent inhibitor of DNA replication, HMRa/HSP82 strains with SIR4- and SIR4S$^{+}$ genetic backgrounds were arrested in S phase by incubation of a culture in 200 mM hydroxyurea for 120 min. It was clear that following a 20 minute heat shock, silencing of the HMRa/HSP82 allele in cells pretreated with hydroxyurea does occur in a SIR4-dependen fashion, even though the kinetics of repression appears to be substantially delayed. We also have tested whether re- establishement of silencing at the HMR/hsp82 locus can occur in G1-arrested cells. Cell cycle arrest at G1 phase was achieved by treatment of early log a cell cultures with .alpha.-factor mating pheromone, which induces G1 arrest. The result suggests that passage through S phase (and therefore DNA replication) is nor required for re-establishing silencer-mediated repression at the HMNRa/HSP82 locus. Finally, to test whether de nono protein synthesis is required for re-establishment of silencer-mediated repression, cells were pretreated with cycloheximide (500 /.mu.g/ml) 120 min. It was apparent that inhibiting protein synthesis delays, but does not prevent, re-establishment of silencer-mediated repression. Altogether, these results indicate that re-establishment of silencer-mediated repression is not dependent on the DNA replication and has no requirement for protein synthesis.s.

• Molecules and Cells
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• 제22권2호
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• pp.203-209
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• 2006

TBP (TATA-binding protein)-related factor 2 (TRF2) regulates transcription during a nuber of cellular processes. We previously demonstrated that it is localized in the cytoplasm and is translocated to the nucleus by DNA-damaging agents. However, the cytoplasmic localization of TRF2 is controversial. In this study, we reconfirmed its cytoplasmic localization in various ways and examined its nuclear migration. Stresses such as heat shock, redox agents, heavy metals, and osmotic shock did not affect localization whereas genotoxins such as methyl methanesulfonate (MMS), cisplatin, etoposide, and hydroxyurea caused it to migrate to the nucleus. Adriamycin, mitomycin C and ${\gamma}$-rays had no obvious effect. We determined optimal conditions for the nuclear migration. The proportions of cells with nuclei enriched for TRF2 were 25-60% and 5-10% for stressed cells and control cells, respectively. Nuclear translocation was observed after 1 h, 4 h and 12 h for cisplatin, etoposide and MMS and hydroxyurea, respectively. The association of TRF2 with the chromatin and promoter region of the proliferating cell nuclear antigen (PCNA) gene, a putative target of TRF2, was increased by MMS treatment. Thus TRF2 may be involved in genotoxin-induced transcriptional regulation.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.365-371
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• 2017

Hydrogen has potential for preventive and therapeutic applications as an antioxidant. However, micro- and macroparticles of hydrogen in water disappear easily over time. In order to eliminate reactive oxygen species (ROS) related with the aging process, we used functional water containing nanoparticle hydrogen. Nanoparticle hydrogen does not disappear easily and collapse under water after long periods of time. We used murine embryonic fibroblasts that were isolated from 12.5-day embryos of C57BL/6 mice. We investigated the ability of nanoparticle hydrogen in water to suppress hydroxyurea-induced ROS production, cytotoxicity, and the accumulation of ${\beta}-galactosidase$ (an indicator of aging), and promote cell proliferation. The accumulation of ${\beta}-galactosidase$ in the cytoplasm and the appearance of abnormal nuclei were inhibited by daily treatment of cells with hydrogen water. When the aging process was accelerated by hydroxyurea-induced oxidative stress, the effect of hydrogen water was even more remarkable. Thus, this study showed the antioxidant and anti-senescence effects of hydrogen water. Nanoparticle hydrogen water is potentially a potent anti-aging agent.