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        검색결과 57

        41.
        2012.06 구독 인증기관·개인회원 무료
        The objective of the current study was to describe in vitro embryo production in Hanwoo, analyzing oocytes yield and embryo production. The effects of oocytes production and the number of OPU procedures per animal on embryo production were also evaluated. OPU was done every 3~4 days during experimental period and collected oocytes were fertilized in vitro in both OPU and needle puncture groups. First, we compared the recovery rate of oocytes based on OPU session (Experiment 1). The average of collected oocytes was calculated from every 10 session. The average number of total oocytes recovered per animalonsessionwas 5.16 (mean). Second, we compared the recovery rate base on collection period of OPU (Experiment 2). The following results show the difference of the number of recovered oocytes in every month during the procedure between the months of session. Every animal shows the constant number of recovered oocytes for the first 5 months. However, the recovery rate of oocytes was decreased from month 6 to 8. Third, we compared the developmental rate to blastocyst in two groups (Experiment 3). Oocytes by needle puncture were fertilized with frozen-thawing semen; the cleavage rate 24~48 h after in vitro fertilization (IVF) was 75.8% and blastocyst development rate was 18.8% in needle puncture group. Even though there is lower cleavage rate after IVF in OPU group (61.1%), blastocyst development rate was higher compared with needle puncture group (28.4%). In conclusion, Blastocyst developmental rate could be increased by OPU than classical method of needle puncture. Improvement of bio- technique in collecting oocytes could be applied to understand the reproductive physiology in cattle, expecially Hanwoo. Therefore, further investigation should be done to clarify the efficiency and advantage of OPU involved in reproduction in animals and human being.
        42.
        2011.10 구독 인증기관·개인회원 무료
        The objective of this study was to evaluate in vitro production of bovine embryos in Hanwoo. Oocytes were collected by ovum pick up (OPU) from ovaries of genetically high-value Hanwoo or by needle puncture from ovaries of slaughtered cattle. OPU was done every 3 4 days duing experimental period and collected oocytes were fertilized in vitro in both OPU and needle puncture groups. First, We compared the in vitro maturation rate in two groups (Experiment 1). 545 oocytes were recoverd from 4 females by 32 trials of OPU and then 433 oocytes were shown MⅡ stage after in vitro maturation (79.4%). In case of needle puncture group, 1905 oocytes were collected and then 1420 oocytes were matured to MⅡ stage during in vitro culture(74.5%). Second, we compared the developmental rate to blastocyst in two groups (Experiment 2). 1420 oocyte by needle puncture were fertilized with frozen-thawing semen; the cleavage rate 24 48 h after in vitro fertilization (IVF) was 88.6% and blastocyst development rate was 20.5% in needle puncture group. Even though there is lower cleavage rate after IVF in OPU group (84.8%), blastocyst development rate was higher compared with needle puncture group (26.4%). In conclusion, Blastocyst developmental rate could be increased by OPU than classical method of needle puncture. Improvement of bio-technique in collecting oocytes could be applied to understand the reproductive physiology in cattle, expecially Hanwoo. Therefore, further investigation should be done to clarify the efficiency and advantage of OPU involved in reproduction in animals and human being. This research was suppoted by Imsil-gun agricultural technology service center.
        43.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Several lines of evidence suggest that osteocytes play a critical role in bone remodeling. Both healthy and apoptotic osteocytes can send signals to other bone surface cells such as osteoblasts, osteoclasts, osteoclast precursors, and bone lining cells through canalicular networks. Osteocytes responding to mechanical strain may also send signals to other cells. To determine the role for osteocytes an mechanical strain in bone remodeling, we examined the effects of fluid flow shear stress on osteoclast precursor cell and osteoblast proliferation and recruitment induced by osteocytes. In addition, the effects of fluid flow shear stress on osteocyte M-CSF, RANKL, and OPG mRNA expression were also examined. MLO-Y4 cells were used as an in vitro model for osteocytes, RAW 264.7 cells and MOCP-5 cells as osteoclast precursors, and 2T3 cells as osteoblasts. MLO-Y4 cells conditioned medium (Y4-CM) was collected after 24h culture. For fluid flow experiments, MLO-Y4 cells were exposed to 2h of pulsatile fluid flow (PFF) at 2, 4, 8, 16±0.6dynes/cm² using the Flexcell StreamerTM system. For proliferation assays, MOCP-5, RAW 264.7, and 2T3 cells were cultured with control media or 10-100% Y4 CM. Cells were cultured for 3d, and then cells were counted. RAW 264.7 and 2T3 cell migration was assayed using transwells with control media or 10-100% Y4-CM. M-CSF, RANKL and OPG in MLO-Y4 mRNA expression was determined by semiquantitative RT-PCR. Y4-CM increased osteoclast precursor proliferation and migration, but decreased 2T3 cell proliferation and migration. CM from MLO-Y4 cells exposed to PFF caused decreased RAW 267.4 cell proliferation and migration and 2T3 migration compared to control Y4-CM. However, Y4-CM from cells exposed to PFF had no effect on 2T3 osteoblastic cell proliferation. PFF decreased RNAKL mRNA and increased OPG mRNA in MLO-Y4 cells compared to control(without PFF). PFF had no effect on M-CSF mRNA expression in MLO-Y4 cells. These results suggest that osteocytes can regulate bone remodeling by communication with osteoclast precursors and osteoblasts and that osteocytes can communicate mechanical signals to other cells.
        4,000원
        44.
        2007.12 구독 인증기관 무료, 개인회원 유료
        Embryonic stem (ES) cells are known to have an infinite proliferation and pluripotency that are associated with complex processes. The objective of this study was to examine expression of genes differentially regulated during differentiation of human ES cells by suppression subtractive hybridization (SSH). Human ES cells were induced to differentiate into neural precursor cells via embryoid body. Neural precursor cells were isolated physically based on morphological criteria. Immunocytochemical analysis showed expression of pax6 in neural precursor cells, confirming that the isolated cells were neural precursor cells. Undifferentiated human ES cells and neural precursor cells were subject to the SSH. TPX2 (Targeting Protein for Xklp2 (Xenopus centrosomal kinesin-like protein 2)) was identified, cloned and analyzed during differentiation of human ES cells into neural lineages. Expression of TPX2 was gradually down-regulated in embryoid bodies and neural precursor cells relative to undifferentiated ES cells. Targeting Protein for Xklp2 has been shown to be involved in cell division by interaction with microtubule development in cancer cells. Taken together, result of this study suggests that TPX2 may be involved in proliferation and differentiation of human ES cells.
        4,000원
        47.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        Mushrooms have been widely cultivated and consumed as foods and herbal medicines owing to their various biological properties. However, few studies have evaluated the anti-inflammatory effects of mushrooms. Here, we investigated the effects of mushroom extracts (MEs) on lipopolysaccharide (LPS)-induced inflammation in macrophages (RAW264.7 cells). First, we extracted MEs with either water or ethanol. Using LPS-treated RAW264.7 cells, we measured cell proliferation and NO production. Gene expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 (IL-6), and IL-1β was assessed by RT-PCR, and protein abundance of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) and phosphorylation of p65 were determined by immunoblotting. MEs prepared using both water and ethanol inhibited LPS-induced inflammation in RAW264.7 cells. Nitric oxide (NO) levels induced by LPS were reduced by treatment with MEs. Isaria japonica Yasuda water extracts and Umbilicaria esculenta (Miyoshi) Minks ethanol extracts significantly decreased the mRNA expression of inflammation-related cytokine genes including TNF-α, IL-6, and IL-1β. Similarly, the protein abundance of iNOS and COX-2 was also decreased. The phosphorylation of p65, a subunit of nuclear factor-κB was at least partly suppressed by MEs. This study suggests that mushrooms could be included in the diet to prevent and treat macrophage-related chronic immune diseases.
        48.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        근접방사선치료는 일반적으로 외부방사선치료와 병행하여 수행되고 치료단계가 매우 복잡하며 이로 인 해 방사선 사고가 발생될 수 있다. 본 연구에서는 이를 해결하기 위해 근접방사선치료에 사고유형과 영향 분석(Failure mode and effects analysis, FMEA) 방법을 적용하여 프로세스 맵을 구성하고 이를 기반으로 각 치료단계에 대한 위해도를 산출하였다. 프로세스 맵은 “외래 및 진료”와 “근접방사선 모의치료”, “CT 모의 치료”, “근접방사선치료계획”, “방사선치료”로 총 5단계로 구성하였으며, 각 치료단계를 세분화하여 세부단 계를 작성하였다. 위해도를 산출하기 위해 의사와 의학물리사, 선량설계사, 방사선사, 간호사가 참여하여 세부단계마다 발생빈도와 심각도, 불검출도를 평가하였다. 전반적으로 프로세스 맵은 각 치료단계마다 환 자 신원 확인 절차가 우선적으로 수행되며, 이는 다른 환자로 오인하여 서로 다른 치료계획이 수립되어 방 사선사고가 발생될 우려가 있다. 프로세스 맵을 기반으로 작성한 세부단계에 대해 위해도를 평가한 결과, 전반적으로 “외래 및 진료”와 “근접방사선치료계획” 과정이 높은 위해도로 평가되었다. 직종마다 평가한 위해도는 서로 다른 경향을 보였으며, 간호사는 방사선치료를 제외한 모든 과정이 55점 이상의 위해도를 보였으며, “근접방사선 모의치료” 과정이 88.8점으로 가장 높았다. 방사선치료를 수행하는 의료기관마다 치 료단계가 다소 차이가 있으므로 해당 기관에 대한 프로세스 맵을 작성하고 위해도를 산출하여 중점관리 항목을 집중적으로 리스크 관리가 수행되어야 할 것으로 생각된다.
        49.
        2015.07 서비스 종료(열람 제한)
        Molecular characterization of crops improved through biotechnology has traditionally been conducted using Southern blot analysis which has been used to determine T-DNA copy number, the presence or absence of backbone (sequence outside of the T-DNA) and to demonstrate generational stability of the T-DNA insert. The advancement of high-throughput DNA sequencing (HTS) technology allows efficient characterization of the transgene incorportated into the genome of the plant by rapidly sequencing the entire plant genome. By combining NGS (Next Generation Sequencing) technologies with bioinformatic methods that identify the T-DNA insert derived from the plasmid vector and genome-T-DNA junction sequences, it has been shown that conclusions equivalent to those of a Southern blot are readily obtained. NGS is done at sufficient coverage depth (>75x) across the entire genome. By mapping the sequence reads to the plasmid vector, and identifying the number of unique junctions, we can confirm insert number, copy number, absence of backbone, across multiple generations. With the widespread availability of NGS and steadily decreasing costs it is likely that academia and industry will fully transition to NGS-based molecular characterizations in the near future.
        52.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        Safflower (Carthamus tinctorius L.) is a herb primarily distributed throughout in the world. We have used the inter-simple sequence repeats (ISSR) technique to investigate the phylogenetic relationships and genetic diversity of C. tinctorius. Of all germplasms, 88.7% were polymorphic among all germplasms. Mean genetic diversity within germplasms was very low (0.048). The Turkey germplasm had the highest expected diversity (0.082) and Australia germplasm was the lowest (0.020). These values indicate that most of the genetic diversity of safflower is found among germplasms and there is a high among-germplasm differentiation. We found eight phenetic bands for determining the specific marker of germplasm with SCAR markers. The regions of the Mediterranean Sea and India may be the most probable candidates for the origin of safflower. The tree showed four major clades: (1) European germplasms, (2) Azerbaijan, Egypt, and Ethiopia, (3) Australia, and (4) America.
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