• Molecules and Cells
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• v.19 no.3
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• pp.436-444
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• 2005

We describe the morphology and molecular organization of heterochromatin domains in the interphase nuclei, and mitotic and meiotic chromosomes, of Brassica rapa, using DAPI staining and fluorescence in situ hybridization (FISH) of rDNA and pericentromere tandem repeats. We have developed a simple method to distinguish the centromeric regions of mitotic metaphase chromosomes by prolonged irradiation with UV light at the DAPI excitation wavelength. Application of this bleached DAPI band (BDB) karyotyping method to the 45S and 5S rDNAs and 176 bp centromere satellite repeats distinguished the 10 B. rapa chromosomes. We further characterized the centromeric repeat sequences in BAC end sequences. These fell into two classes, CentBr1 and CentBr2, occupying the centromeres of eight and two chromosomes, respectively. The centromere satellites encompassed about 30% of the total chromosomes, particularly in the core centromere blocks of all the chromosomes. Interestingly, centromere length was inversely correlated with chromosome length. The morphology and molecular organization of heterochromatin domains in interphase nuclei, and in mitotic and meiotic chromosomes, were further characterized by DAPI staining and FISH of rDNA and CentBr. The DAPI fluorescence of interphase nuclei revealed ten to twenty conspicuous chromocenters, each composed of the heterochromatin of up to four chromosomes and/or nucleolar organizing regions.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.172-175
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• 1999

Relative DNA contents in some harmful algae were measured using DAPI staining and image analysis system. This method was useful to identify some morphologically similar species and isolates from harmful algal blooms (HABs). In exponential phase, Prorocentrum micans had higher relative DNA content (RD) of $1.83\pm0.52$ than any other isolates, followed by Cochlodinium polykrikoides $(1.10\pm0.46)$ Alexandrium tamarense $(0.93\pm0.32)$ Gyrodinium impudicum $(0.56\pm0.17)$, Scrippsiella trochoidea $(0.41\pm0.26)$ and P. minimum$(0.05\pm0.01)$. When they were fixed with Lugol's solution, it was difficult to d,iscern C. polykrikoides from G. impudicum under the light microscope, but the DNA contents were quite different in two species. C. polykrikoides contained about twice as much RD as G. impudicum under the same culture conditions and exponential phase. DAPI­stained DNA feature in C. polykrikodes showed concentrated in the peripheral part of the cell, but in G. impudicum showed a compact structure in the central part. Although A. tamarense and S. trochoidea were morphologically similar under the light microscope, nuclear DNA content of A. tamarense was twice as much as that of S. trochoidea.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.121-124
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• 2003

The goals of this study is to elucidate life cycle and to detect genetic differences within a single species of Heterosigma akashiwo. To elucidate life cycle of H. akashiwo, have to study of benthic stage and vegetative cell. So we studied identification of H. akashiwo cyst. The relative contents of DNA in nuclei were determined in Heterosigma akashiwo. Different stages of the life history were obtained from culture and natural sediments, and examined by microfluorometry after staining with the DNA-specific fluorochrome 4'-6-dianudubi-2-phenylindole(DAPI). Large cells mainly in exponensial stage, while small cell, pre-encystment cells(\ulcorner\ulcorner), showed in the end of the late growth stage. Type of DNA content showed the different with growth stage. Usually the small cell has the high level of IOD.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.27-35
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• 2003

No currently available methods to monitor pathogenic protozoa, Cryptosporidium and Giardia in environmental water come close to acceptable sensitivity, specificity and reproducibility, and so it has to be accompanied by thorough quality control and performance evaluation to credibly predict the distribution of them. We collected surface water samples from the Han River and spiked our prepared (oo)cysts, determined Matrix Spike recoveries using USEPA Method 1623 and considered what factors influence MS recovery and validity. As a result, average 46% of spiked oocysts and 60% of spike cysts were recovered, but repetitive sampling and statistical approach seemed to be necessary to determine the environmental pollution level of two protozoa as their variation coefficients was so much as 35oio and 26%. And MS recoveries with two acid dissociations during immunomagnetic separation were improved more 10% than that with one dissociations and the use of spiked suspension enumerated by flow cytometry instead of manual preparation enhanced the validity and reliability in spiking tests. Because fluorescence characteristics of (oo)cysts stained on well slides with FITC-labeled monoclonal antibodies and DAPI was not always same, well Elides from spiked field samples were helpful to evaluate the performance of staining. We found many (oo)cyst-like objects with typical fluorescence, not (co)cysts, from the Han River water samples, and then it was concluded that nuclei staining by DAPI (4',6-diamidino-2-phenylindole) and examination by Differential Interference Contrast Microscope should be critical for valid identification.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.286-293
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• 2016

This study is an experiment for gastric protective effects of ursolic acid. In order to identify the effects of ursolic acid on gastrointestinal disorder, acute and chronic gastritis were also observed using HCl ethanol and indomethacin-induced gastric lesion models, respectively. As for gastric acid, it was also identified through proton pump ($H^+/K^+-ATPase$) inhibiting activity. In regards to protective factor for gastric damage, prostaglandin $E_2$ ($PGE_2$) was quantitatively analyzed. Antibacterial activity experiment was done on Helicobacter pylori (H.pylori), which is known to be the causing factor of chronic gastritis, gastric ulcer and gastric cancer. By making use of AGS cell, it was confirmed that ursolic acid was involved in apoptosis of gastric cancer cell through 4',6-diamidino-2-phenylindol (DAPI) staining and flow cytometry analysis. As a result, ursolic acid reduced gastric lesions caused by HCl ethanol and indomethacin. Ursolic acid inhibited acid secretion by inhibiting proton pump ($H^+/K^+-ATPase$), which is the gastric acid secreting enzyme involved at the final phase of gastric acid secretion. And ursolic acid was identified with gastric mucosa protection effects by increasing the concentration of $PGE_2$, a protective factor of gastric mucosa preservation. The antibacterial activity on H. pylori, which is aggressive factor in gastrointestinal disorder, ursolic acid showed inhibitory effects on H. pylori colonization. In the DAPI nuclear staining, unlike the control group, shape of the nucleus has deformed, and has been observed either shrinked cell or chromatin condensation phenomenon. In the Flow cytometry assay, confirmed the growth rate of apoptosis in a concentration-dependent manner.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.149-150
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• 2003

• Research in Plant Disease
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• v.7 no.2
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• pp.116-119
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• 2001

Witches' broom symptoms were firstly found on tubers of Solanum tuberosum cv, Deijima, showing dense growth of spindly sprouts in Cheju province, Korea. Plantlets from the diseased plants also produced the typical witches' broom symptoms, having densely-growing small leaves when they became adult plants. At the later stages the diseased leaves were blightened. Presence of phytoplasma in plant tissues was confirmed by DAPI-staining fluorescence microscopy and electron microscopy, exhibiting its localization in sieve tubes of stem, petiole, and midrib. This is the first report of potato witches' broom in Korea.

• Toxicological Research
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• v.7 no.2
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• pp.157-163
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• 1991

The effect of patulin, a mycotoxin, on the growth of Escherichia coli cell was investigated. E. coli cell elongation usually shown in SOS-response for DNA repair was induced by 20 mg of patulin per ml. After staining the E. coli chromosome with fluorescence dye(DAPI, 4', 6-diamino-2-phenyl-indole), chromosomal DNA partitioning was not affected by patulin. The observation indicateds that patulin acts as a DNA damaging agent which is effective for E. coli cell elongation introduced by the inhibition of septum formation.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.318.1-318.1
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• 2002

We found that 23-hydroxyursolic acid, triterpenoid was isolated from Cussonia bancoensis have a significant cytotoxic activity against HL -60 human promyelocytic leukemia cells. The IC of 23-hydroxyursolic acid was 32.83 $\mu$M. These anti-proliferative activity was due to induction of apoptosis. The effect of apoptosis was identified by DNA laddering, DAPI assay. PI staining, and Annerxin V-FITC binding assay. (omitted)

• Journal of Pharmacopuncture
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• v.13 no.1
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• pp.15-35
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• 2010

연구목적 : 이 연구는 봉약침의 봉독이 NF-${\kappa}B$ 활성억제와 안드로겐 수용체 조절 단백질 및 세포자멸사 조절 단백질의 발현을 통하여 세포자멸사를 유도하고, 전립선 암세포를 이식한 쥐에서의 세포자멸사 유도 효과를 확인함으로써, 봉약침의 봉독이 생체 내에서도 세포자멸사를 유도하여 전립선암에 효과를 나타냄을 확인하고자 하였다. 실험방법 : 세포자멸사의 관찰에는 DAPI, TUNEL staining assay를 시행하였으며, 세포자멸사 조절 단백질의 변동 관찰에는 western blot analysis를 시행하였고, 세포자멸사와 연관된 NF-${\kappa}B$의 활성 변화를 관찰하기 위해 EMSA를 시행하였다. 결과 : 1. DAPI, TUNEL staining assay 결과 봉독 및 melittin을 처리한 LNCaP 세포 모두에서 세포자멸사 유도율이 유의한 증가를 나타내었다. 2. LNCaP 세포에 봉독이나 melittin을 처리한 결과, 안드로겐 수용체 조절 단백질 중 p-Akt, COX-2, calpain은 봉독과 melittin 모두에서 유의한 감소를 나타내었고, Akt는 melittin에서 유의한 감소를 나타냈으며, 봉독에서 증가하는 경향을 보였고, MMP-9은 증가하였다. 3. 생체 내에서의 봉독의 항암효과를 확인하기 위해 전립선암세포가 이식된 쥐에 봉독을 처리한 후 암세포의 부피와 무게, 쥐의 체중을 측정한 결과, 봉독을 처리한 군에서 암 세포 부피비율 및 무게는 감소하였고, 쥐의 체중은 증가하였다. 4. 전립선암세포가 이식된 쥐에 봉독을 처리한 결과, NF-${\kappa}B$ 활성에서 유의한 감소를 나타내었다. 5. 전립선암세포가 이식된 쥐에 봉독을 처리한 결과, 세포자멸사 조절 단백질 중 Bax/Bcl-2, p53, caspase-3, caspase-9, calpain은 유의한 증가를, COX-2는 유의한 감소를 나타냈으며, MMP-9는 증가를 나타내었다. 결론 : 이상의 결과는 봉독이 시험관 내에서 뿐만 아니라 생체 내에서도 NF-${\kappa}B$의 활성을 억제하고 안드로겐 수용체 조절 단백질 및 세포자멸사 조절 단백질의 조절을 통하여 인간 전립선암 세포주인 LNCaP의 세포자멸사를 유도함으로써 전립선암 세포 증식억제 효과 및 호르몬 비의존적인 전립선암으로의 전이를 지연시키는 경향이 있을 것으로 사료되고, 봉독이 전립선암의 예방과 치료에 효과적으로 활용될 수 있을 것으로 기대된다.