• Molecular & Cellular Toxicology
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• 제4권1호
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• pp.66-71
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• 2008

Long term exposure of Jurkat cells to 2 ATA pressure resulted in the inhibition of cell growth. Under a 2 ATA pressure, the morphological changes in the cells were visualized by electron microscopy. The cells exhibited significant inhibitory responses after three passages. However, short-term exposure study was carried out, 2 ATA pressure may have beneficial effects. The Jurkat cells were exposed to $H_2O_2$ (25 and $50{\mu}M$) in order to induce DNA damage, and then incubated under at either normal pressure or 2 ATA for 1 or 2 hours in order to recover the DNA damage. The extent of DNA damage was determined via Comet assay. More recovery from DNA damage was observed at 2 ATA than at normal pressure. The activity of the DNA repair enzymes, DNA polymerase-$\beta$, was also evaluated at both normal pressure and 2 ATA. The activity of DNA polymerase-$\beta$ was observed to have increased significantly at the 2 ATA than at normal pressure. In conclusion, the effects of hyperbaric pressure from 1 ATA to 2 ATA on biochemical systems can be either beneficial or harmful. Long term exposure to hyperbaric pressure clearly inhibited cell proliferation and caused genotoxic effects, but short-term exposure to hyperbaric pressure proved to be beneficial in terms of bolstering the DNA repair system. The results of the present study have clinical therapeutic application, and might prove to be an useful tool in the study of genotoxicity in the future.

• 약학회지
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• 제29권5호
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• pp.246-252
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• 1985

Ginseng proteins were isolated and partially purified to obtain two fractions, namely GI and GII. Radioprotective effects of these fractions were examined on $\gamma$-ray irradiated ICR mice by observing 30-day survival rates after irradiation. Also investigated were the effects of GI fraction on the recovery of radiation damage. As the results, the GI fraction showed strong protection against radiation indicated by the increment of 30-day survival rates, while the GII fraction did not. The GI fraction enhanced the recovery of body and splenic weights and increased the amount of DNA in liver significantly. It also helped to recover the damage done on erythrocytes by increasing the number to normal in short period, however, it had no effect on the recovery of leukocyte counts.

• BMB Reports
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• 제47권5호
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• pp.249-255
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• 2014

Polo-like kinase-1 (Plk1) belongs to a family of serine-threonine kinases and plays a critical role in mitotic progression. Plk1 involves in the initiation of mitosis, centrosome maturation, bipolar spindle formation, and cytokinesis, well-reported as traditional functions of Plk1. In this review, we discuss the role of Plk1 during DNA damage response beyond the functions in mitotsis. When DNA is damaged in cells under various stress conditions, the checkpoint mechanism is activated to allow cells to have enough time for repair. When damage is repaired, cells progress continuously their division, which is called checkpoint recovery. If damage is too severe to repair, cells undergo apoptotic pathway. If damage is not completely repaired, cells undergo a process called checkpoint adaptation, and resume cell division cycle with damaged DNA. Plk1 targets and regulates many key factors in the process of damage response, and we deal with these subjects in this review.

• 전자공학회논문지
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• 제52권7호
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• pp.51-62
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• 2015

대용량의 DNA 정보 저장, DNA 서열 저작권 보호를 위한 DNA 워터마킹, 및 비밀 통신을 위한 DNA 스테가노그라픽에 대한 관심이 증대되면서, 원본 DNA 서열의 기능 유지와 복원이 가능한 가역성 DNA 워터마킹이 필요하다. 본 논문에서는 비부호영역 DNA 서열을 이용한 DE(Difference expansion) 기반 가역 DNA 워터마킹 기법을 제안한다. 가역 DNA 워터마킹에서는 생물학적 기능 변경이 없고, 문자 형태의 서열 내에 대용량의 데이터를 은닉하여야 하며, 원본 DNA 서열이 복원되어야 한다. 제안한 방법에서는 문자 서열을 십진수 형태의 수치계수로 변환한 다음, 인접 수치 계수 쌍의 DE 기반 다중비트 은닉 방법(DE-MBE, DE based multiple bits embedding)과 이전 은닉 수치계수를 예측으로 한 연속 DE 기반 다중비트 은닉 방법들(C-DE-MBE, consecutive DE based multiple bits embedding)에 의하여 워터마크가 은닉된다. 은닉 과정에서는 워터마크된 서열에 의하여 부호영역을 나타내는 허위 시작코돈 발생을 방지하기 위하여 비교 탐색을 수행한다. 실험 결과로부터 제안한 방법이 기존 방법에 비하여 높은 은닉 용량을 가지며, 허위 시작코돈이 발생되지 않으며, 기준 서열없이 원본 DNA 서열이 복원됨을 확인하였다.

• 전자공학회논문지
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• 제53권12호
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• pp.67-75
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• 2016

DNA 컴퓨팅 기술로 DNA 정보를 매개물로 하는 DNA 저장, DNA 스테가노그라픽, 및 DNA 워터마킹에 대한 관심이 많아지고 있다. 생물학적 변이없이 외부 워터마크를 DNA 정보 내에 은닉에서는 원본 DNA 서열의 복원이 가능하고, 은닉과 복원이 반복적으로 이루어지며, 외부 워터마크에 의한 의도적인 변이 분석이 가능한 가역성 정보은닉 기술이 필요하다. 본 논문에서는 DNA 부호계수의 순환형 히스토그램 다중 쉬프팅 (Circular Histogram Shifting, CHS) 기반으로 생물학적 변이없이 허위개시코돈 방지, 원본 서열 길이 유지, 높은 워터마크 용량성, 블라인드 검출이 가능한 가역성 DNA 정보은닉 방법을 제안한다. 제안한 방법은 비부호 영역 DNA 염기서열을 부호계수로 변환한 다음, 높은 용량성을 위하여 순환형 히스토그램 다중 쉬프팅에 의하여 부호계수에 다중비트를 은닉한다. 마지막으로 다중비트 은닉 과정에서 은닉된 인접 염기서열 간의 비교탐색을 통하여 허위개시코돈 생성을 방지한다. 실험 결과로부터 제안한 방법이 기존 방법보다 0.11~0.50 bpn(bit per nucleotide base) 높은 워터마크 용량성을 가지고, 허위개시코돈이 발생되지 않음을 확인하였다.

• 치과방사선
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• 제21권2호
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• pp.183-197
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• 1991

After single fraction of 2, 5, 10 Gy irradiation on submandibular gland of 40 male rats, weighing 150gm, respectively, these animal were sacrificed two hours after 0.1㎎/g bromodeoxyuridine (Sigma) peritoneal injection in 1, 3, 7, 15 hours, 1, 3, 7 days after irradiation. And excised submandibular gland were fixed in Carnoy's and Bouin's solution for 2 hours. Paraffin sections were stained with H&E, and PAS for the observation of the change of salivary gland tissue, and with Feulgen for the study of the DNA distribution, and immunohistochemically stained with anti-bromodeoxyuridine (Sanbyo Co.) for detection of DNA synthetic cells in order to study the distribution of DNA synthetic cells of salivary gland tissue and endothelium after irradiation in 5 different sites of 6 slides on X 200 high power field. The results were as followings. 1. In PAS staining 3 days after 5Gy irradiation, decreased mucine secretion of serous cells were found, and 7 days after l0Gy irradiation, decreased mucine secretion of mucous cells were found. 2. In histopathologic features, degeneration of serous cells were found in 3 days after 2 Gy irradiation and there was little change in mucous cells and excretory duct cells. 3. In Feugen staining, 3 days after 2 Gy, 5 Gy irradiation, more high percentage of DNA synthetic cells were found in intercalated duct cells, striated duct cells and excretory duct cells than in BrdU staining. 4. In immunohistochemical features, DNA synethsis of serous cells and granular convoluted tubular cells abruptly decreased in early period after irradiation and showed no recovery in 7 days after irradiation but there was an increase in DNA synthesis of intercalated duct cells, striated duct cells and excretory duct cells, which have less S-phase cells comparatively, in 7 days after 2 Gy, 5 Gy irradiation. 5. In immunohistochemical features, the DNA synthesis of endothelial cells was continuously decreased after irradiation but showed slight increase in 7 days after 2 Gy and S Gy irradiation.

• Parasites, Hosts and Diseases
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• 제52권3호
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• pp.263-271
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• 2014

PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. $QIAamp^{(R)}$ DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer's protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit's protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume ($50-100{\mu}l$) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ${\approx}2$ oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis.

• 한국어병학회지
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• 제36권2호
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• pp.191-211
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• 2023

Rock bream iridovirus (RBIV) causes high mortality and economic losses in rock bream (Oplegnathus fasciatus) aquaculture industry in Korea. Although, the immune responses of rock bream under RBIV infection have been studied, there is not much information at the different stages of infection (initial, middle and recovery). Gene expression profiling of rock bream under different RBIV infection stages was investigated using a microarray approaches. In total, 5699 and 6557 genes were significantly up- or down-regulated over 2-fold, respectively, upon RBIV infection. These genes were grouped into categories such as innate immune responses, adaptive immune responses, complements, lectin, antibacterial molecule, stress responses, DNA/RNA binding, energy metabolism, transport and cell cycle. Interestingly, hemoglobins (α and β) appears to be important during pathogenesis; it is highly up-regulated at the initial stage and is gradually decreased when the pathogen most likely multiplying and fish begin to die at the middle or later stage. Expression levels were re-elevated at the recovery stage of infection. Among up-regulated genes, interferon-related genes were found to be responsive in most stages of RBIV infection. Moreover, X-linked inhibitor of apoptosis (XIAP)-associated factor 1 (XAF1) expression was high, whereas expression of apoptosis-relate genes were low. In addition, stress responses were highly induced in the virus infection. The cDNA microarray data were validated using quantative real-time PCR. Our results provide novel inslights into the broad immune responses triggered by RBIV at different infection stages.

• 분석과학
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• 제31권2호
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• pp.65-70
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• 2018

이 연구에서는 대규모 병렬형 염기서열 분석 (massively parallel sequencing)에 적용할 샷건 라이브러리 (shotgun library)를 성공적으로 제작하기 위해 두 가지 유형의 고대 DNA (ancient DNA, aDNA) 분리 방법을 비교하였다. 헝가리 선사 시대 늑골 뼈 시료로 실리카 현탁액을 이용한 추출법과 Amicon Ultracel-15 10K 초원심 분리 장치(Millipore)를 이용한 추출법을 비교하였다. 약 150 mg의 뼛가루에서 각각의 방법으로 3 회 반복 추출한 후 이중 가닥 DNA (double stranded DNA, ds DNA)의 양을 측정하였다. 초원심분리 농축 방법은 실리카 현탁액을 사용하는 것보다 더 빠르고, 더 쉬운 공정이며 약 11 배 높은 DNA 회수율을 나타냈다. 또한 초원심 분리 장치로 획득한 DNA 주형은 실리카 현탁액으로 획득한 것보다 샷건 라이브러리가 훨씬 성공적으로 만들어졌다. 두 종류의 aDNA 추출 방법을 비교한 본 연구는 Amicon 장치를 사용하는 분리법이 시간의 절약, 단순한 프로세스 및 높은 효율 등의 장점을 지니고 있음을 보여주었다.

• 대한본초학회지
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• 제21권2호
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• pp.9-13
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• 2006

Objectives : To determine the DNA sequence of the 18S rRNA gene of the Rehmannia glutinosa and analyze it phylogenetically Methods : Dried root of the Rehmannia glutinosa was ground with a mortar and pestle. Glass beads(0.5 mm in diameter), TE buffer and SDS solution were added to that. The mixture was vortexed vigorously and extracted with the mixture of phenol, chloroform and isoamyl alcohol and with the mixture of the chloroform and isoamyl alcohol. The nucleic acids were precipitated with ethanol and resuspended in TE buffer. Contaminating RNA was digested with RNAse A and the DNA was purified further with the Geneclean Turbo Kit. This DNA was used as a template for amplification of the 18S rRNA gene by PCR. The PCR product was cloned in the pBluescript SK II plasmid by blunt-end ligation and the DNA sequence of the insert was determined. This DNA sequence was analyzed phylogenetically by the BLAST program. Results and Conclusion : Vortexing the ground powder of the dried plant root with glass beads during cell lysis improved recovery of DNA. The DNA sequence of the Rehmannia glutinosa 18S rRNA gene was determined and deposited at the GenBank as the accession number DQ469606. Phylogenetic analysis of that sequence showed the relationship between the members of the family of Scrophulariaceae and also the close relationship of the Buddleja davidii to the members of the Scrophulariaceae family.