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        검색결과 153

        101.
        2011.10 구독 인증기관·개인회원 무료
        Successful early embryogenesis of somatic cell nuclear transfer (SCNT) embryos is very important to produce cloned animals. However, poor preimplantation development of SCNT embryos has been a major obstacle to the generation of cloned animals due to a lack of understanding of developmental events and underlying mechanism(s). In the current study, we show that production of SCNT embryos with high developmental competence is dependent on the fusion method. Electrofusion causes spontaneous egg activation, accompanied by an increase in intracellular Ca2+ and improper nuclear remodeling, whereas Sendai virus (SV)-mediated fusion greatly reduces these events. In addition, SV-SCNT increased the blastocyst development rate and trophectoderm cell number compared to electrofusion-mediated SCNT (E-SCNT). In particular, expression of ER stress-associated genes and blastomere apoptosis were significantly increased in E-SCNT embryos, which could be alleviated by inhibition of ER stress or by using the SV-mediated fusion method. Taken together, these results strongly suggest that SV is a useful fusion material for improvement of preimplantation development of SCNT embryos through reduction of ER stress-associated apoptosis.
        102.
        2011.10 구독 인증기관·개인회원 무료
        In DNA barcoding, the DNA degradation of old museum specimens has been limited full-length (658bp) sequencing. The challenges associated with the retrieval and authentication of degraded DNA extracts from fossil and old museum specimens were principally limited to analyze the relatively short sequences (<300 bp). Furthermore, almost protocols in other to analyzed the degraded DNA contained the cloning process after PCR causing the time-consuming and the rising costs. To overcome these problematic circumstances, we tried a modified method to analyze full-length of DNA barcoding region in 30~60 year-old butterfly specimens (225 samples in 28 species), using direct sequencing after PCR with species-specific overlapping primer sets per each species. As a result, all of 28 species have been successfully analyzed, although 178 samples (79%) are completely generated barcoding sequences ranged from 640 to 658 bp and 47 samples (21%) are partially sequenced ranged from 100 to 500 bp. Thus, the result showed that the direct PCR sequencing using the overlapping primer sets per species appears to have great potential efficiency for analysis of degraded DNA without incorrect sequences.
        103.
        2011.03 구독 인증기관 무료, 개인회원 유료
        Canine heartworm disease is typically characterized by the presence of heartworms in the pulmonary artery and, to a lesser degree, the right ventricle. Systemic arterial dirofilariasis is an unusual manifestation of heartworm disease of dogs that results from aberrant migration of Dirofilaria immitis into the peripheral arterial circulation. A three-year-old Jindo dog was referred to the Veterinary Medical Center because of hindlimb lameness, paresthesia of hindlimbs, and interdigital ischemic necrosis. Angiography and ultrasonography were performed, resulting in diagnosis of heartworm infestation. In necropsy, entangled heartworms were present throughout the body, including lungs, kidney, small intestinal lumen, and arteries, in addition to the right ventricle and pulmonary artery. Histologically, lung showed adult heart worms in vessels, organized thrombotic vessels, and interstitial pneumonia featuring type II pneumocyte hyperplasia, thickened alveolar wall, and compressed alveolar spaces. Chronic parenchymal lesions, such as focal or diffuse necrosis, fibrosis, and dystrophic calcification were remarkable in liver and kidney. The current case showed a typical canine systemic heartworm disease caused by aberrant migration of Dirofilaria immitis.
        4,000원
        104.
        2011.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        한국원자력연구원 내 지하 처분 연구시설(KURT)에서 채취한 지하수에 존재하는 나노 콜로이드 입자의 크기 및 농도를 현장에서 조사하기 위해 이동식 레이저 유도 파열 검출 장치를 개발하였다. 제작한 장치는 CCD 카메라를 이용하여 레이저 유도 플라즈마가 발생한 위치를 2-차원 영상으로 기록함으로써 광학적으로 입자의 크기를 결정할 수 있다. 크기가 정확히 알려진 폴리스틸렌 표준 입자를 이용하여 입자 크기 측정용 검정 곡선(calibration curve)을 구했고, 이를 이용하여 지하 처분 연구시설에서 채취한 지하수내 콜로이드 입자의 크기를 측정하였다. 지하수 내 존재하는 콜로이드 입자의 평균 크기는 108±26 nm임을 보였고, 농도는 50 ppb 이하인 것으로 추정하였다.
        4,000원
        105.
        2010.05 구독 인증기관·개인회원 무료
        Our previous study demonstrated that Coprisin, a peptide from Copris tripartitus infected with bacterial pathogens, has an antibacterial activity. We assessed in this study whether Coprisin caused cellular toxicity in various mammalian cell lines. Coprisin selectively caused a marked drop of cell viability in Jurkat T cells, U937 cells and AML-2 cells belonging to the human leukemia cells but not in Caki cells and Hela cells. Fragmentation of DNA, a maker of apoptosis, was also confirmed in theleukemia cell lines but not in other cells. The Coprisin-induced apoptosis in leukemia cells was mediated by AIF (apoptosis inducing factor), a caspase -independent pathway.
        106.
        2009.12 구독 인증기관 무료, 개인회원 유료
        Human mesenchymal stem cell (hMSCs) isolated from human adult bone marrow have self-renewal capacity and can differentiate into multiple cell types in vitro and in vivo. A number of studies have now demonstrated that MSCs can differentiate into various neuronal populations. Due to their autologous characteristics, replacement therapy using MSCs is considered to be safe and does not involve immunological complications. The basic helix-loop-helix (bHLH) transcription factor Olig2 is necessary for the specification of both oligodendrocytes and motor neurons during vertebrate embryogenesis. To develop an efficient method for inducing neuronal differentiation from MSCs, we attempted to optimize the culture conditions and combination with Olig2 gene overexpression. We observed neuron-like morphological changes in the hMSCs under these induction conditions and examined neuronal marker expression in these cells by RTPCR and immunocytochemistry. Our data demonstrate that the combination of Olig2 overexpression and neuron-specific conditioned medium facilitates the neuronal differentiation of hMSCs in vitro. These results will advance the development of an efficient stem cell-mediated cell therapy for human neurodegenerative diseases.
        4,000원
        107.
        2009.10 구독 인증기관·개인회원 무료
        COPRISIN is an antibiotic substance extracted from Copris tripartitus. This study is intended to identify various cell biological stimuli that COPRISIN, widely known as an antibacterial substance, has on human cells and to identify its molecule mechanism. A variety of human cell lines were divided into epithelial cells including kidney cells or womb cells, and immunocyte including T cells or macrophages and, after their being cultivated and maintained, cell biological changes of the respective cells according to COPRISIN treatment were compared. As a result, it was confirmed that, different from other experiment cells, COPRISIN specifically caused cell kill in T cells and macrophages. That is, fragmentation of DNA, typical characteristics observed in the process of apoptosis, was confirmed in the nucleus of cells dying owing to COPRISIN treatment. An Apoptosis process is one dependent upon activity of caspase family protein, it was proved that COPRISIN medium cell kill process was one through a caspase-independent route such as AIF. Though it was found out that transcription of TNF-α and extracellular TNF-α secretion increased in blood cells stimulated by COPRISIN, it was also confirmed that TNF-α was a major medium factor in a COPRISIN induced cell kill process from the fact that a cell kill process by COPRISIN was not inhibited at all with TNF-α inhibiting antibody treatment. Above results revealed that COPRISIN, different from other tissue origin cells including kidney cells, can specifically induce apoptosis in immunocyte, which is caused by a caspase-independent cell signal transmission route.
        116.
        2003.12 구독 인증기관 무료, 개인회원 유료
        The effects of additions/deletions in glycosylated residues of recombinant human EPO (rhEPO) produced in CHO-K1 on their secretion were examined. hEPO cDNA was amplified from human liver mRNA and cloned into the pCR2.1 TOPO. Using overlapping-extension site-directed mutagenesis method, glycosylation sites at 24th, 38th, 83rd, and 126th were respectively or accumulatively removed by substituting its asparagine (or serine) with glutamine. To add novel glycosylation sites, 69 and 105th leucine was mutated to asparagine. Mutant and wild type rhEPO constructs were cloned into the pcDNA3 expression vector with CMV promoter and transfected into CHO cell line, CHO-K1, to produce mutant rhEPO mutant rhEPO proteins. Enzyme-linked immunosorbant assay (ELISA) and Western analysis with monoclonal anti-EPO antibody were performed using supernatants of the cultures showing transient and stable expressions respectively. Addition of novel glycosylation reduced rhEPO secretion dramatically while deletion mutants had little effect except some double deletion mutants (△24/83 and △38/83) and triple mutant (△24/38/83). This fact suggests that not single but combination of changes in glycosyl groups affect secretion of rhEPO in cell culture, possibly via changes in their conformations.
        4,000원
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