• Radiation Oncology Journal
• /
• v.14 no.4
• /
• pp.255-264
• /
• 1996

Purpose : Paclitaxel is a chemotherapeutic agent with potent microtubule stabilizing activity that arrests cell cycle in $G_2$-M Because $G_2$-M is the most radiosensitive Phase of the cell cycle, paclitaxel has potential as a cell cycle- specific radiosensitizer. This study was designed to investigate the ability of paclitaxel to increase the radiotoxicity in normal small bowel mucosa of the rat. materials and Methods : A sigle intraperitoneal infusion of paclitaxel (10mg/kg), and a single irradiation(8 Gy, x-ray) to the whole abdomen and combination of radiation(8 Gr, x-ray) 24 hours after paclitaxel infusion in the rats were done. The changes of jejunal mucosa, and kinetics of mitotic arrest and apoptosis in the jejunal crypt were defined at 6 hours - 5 days after each treatment histologically. Results : Paclitaxel blocked jejunal crypt cell in mitosis and induced minmal apoptosis. Mitotic arrest by paclitaxel was peaked at 6 hours after infusion and returned to normal by 24 hours. Radiation induced apoptosis and peaked at 6 hours and returned to normal by 24 hours. Combination of paclitaxel and radiation blocked crypt cell in mitosis at 3 days and induced apoptosis slightly at 6 hours and 24 hours and returned to normal by 3 days. The incidence of apoptosis in combined group at 6 hours was slightly higher than normal control but significantly lower than radiation alone group. The major changes of jejunal mucosa were nuclear vesicle and atypia which were appeared at 6 hours - 3 days and returned to normal by 5 days The degree of the mucosal changes are not different in 3 groups except for absence of inflmmatory reaction in radiation group. Conclusion : Mitotic arrest by paclitaxel was peaked at 6 hours and returned to normal by 24 hours and paclitaxel induced minimal apoptosis. Radiation induced apoptosis, peaked at 6 hours and returned to normal by 24 hours. Radiation-induced apoptosis was less in combined group which suggested that paclitaxel have a radioprotective effect when radiation was given 24 hours after paclitaxel infusion.

• Development and Reproduction
• /
• v.2 no.1
• /
• pp.69-74
• /
• 1998

The early gonadal development and sexual differentiation of Rhynchocypris oxycephalus are described from the stage of hatching to 150 days after hatching. During this peroid, the average length of the body grew from 0.64 cm to 5.96 cm. the primordial germ cells (PGCs), which could be recognized at the time of hatching, began to protrude into peritoneal cavity at a standard total length of 1.91 cm. At a standard total length of 2.29cm, initial ovarian differentiation wasidentified by the transformation of PGCs to meiotic oocytes. Finally, at the standard total length of 5.96 cm, the female gonads gradually developed towards migratory nucleus oocytes, characterisiing the maturation. Oocytes proliferated rapidly after sex differentiation while the testis entered a period of quiescence, as they continued to multiply but did not undergo growth until the standard total length of 4.00 cm. At a standard total length of 4.00 cm, spermatocytes arrested in thephase of interkinesis, Sertoli-like cells and sperm duct formation, with signs of meiotic activity, were observed. Therefore it may be concluded that R. oxycephalus belongs to the differentiated type of gonochoristic teleosts.

• Korean Journal of Microbiology
• /
• v.45 no.4
• /
• pp.300-305
• /
• 2009

We constructed the deletion mutants of fission yeast Schizosaccharomyces pombe spNab2 gene that is homologous to poly(A)-binding protein NAB2 in budding yeast Saccharomyces cerevisiae, which plays crucial roles in mRNA 3' end formation and mRNA export from nucleus into the cytoplasm. A null mutant in an $h^+$/ $h^+$ diploid strain was constructed by replacing the spNab2-coding region with an $ura4^+$ gene using one-step gene disruption method. Tetrad analysis showed that the spNab2 is not essential for vegetative growth and mRNA export. However, over-expression of spNab2 cause the severe growth defects and intensive accumulation of poly(A) RNA in the nucleus. Also, the spNab2-GFP fusions were localized mainly in the nucleus. These results suggest that spNab2 is also involved in mRNA export out of the nucleus.

• Journal of Digital Convergence
• /
• v.10 no.4
• /
• pp.323-331
• /
• 2012

Cell division in biological education is an important and unintelligible unit. Most of students have no interest in learning the content, and don't concentrate on it because cell division unit contains relatively difficult content. In this vein, during considering the effective learning methods, the researcher found role-play as the method for student's positive access to important and unintelligent learning content. Effect of role-play on their learning achievement of science was analysed through the Chapter of cell division on 3rd grade of middle school students. For this study three levels of middle school students were selected from the school located in Seoul. And divided this students into experiment group and control group by 2 classes respectively. Before putting into practice this instruction, there took into account the before and after of students' learning achievement and their learning attitude by using same questionnaire. On the other hand, the researcher put into practice co-variate analysis by using SPSS statistical package as the measurement method.

• Korean Journal of Microbiology
• /
• v.30 no.5
• /
• pp.333-338
• /
• 1992

Saccharomyces cerevisiae contains 10-nm tilament ring which lies just under the inner surface of the plasma membrane within the mother-bud neck. Although H)-nm filaments may he involved in cellular morphogenesis. their role and organization are not clear. Here we report the production of antihodies specific for the CDel2 protein hy use of gene fusion techniques. and studies on the organization and function of IO-nm filaments using these antibodies. The CDCl2 protein arc translated through the whtlle cell cycle and present in the cytosol. 'They are polymerized just before bud emergence and unpolymerized alier cytokinesis. and do not have organizational relationship with actin. Thc possible role of 10-nm filaments is the determination of bud emergence site and completion of cytokinesis.

• Korean Journal of Weed Science
• /
• v.8 no.3
• /
• pp.219-236
• /
• 1988

Bensulfuron concentrations of $10^{-7}$, $10^{-6}$, $10^{-5}$ and $10^{-4}M$ were applied to agar medium on susceptible (cv. KH 17854 and cv. IR 1846) and tolerant (cv. Chinsurah Boro II and IR 14252) rice cultivars were grown for microscopic inspection. Susceptible cultivars showed the decrease in shoot and root growth at the concentration of $10^{-5}M$ while ones showed no difference. Such a tendency was also observed from microscopic inspection in the elongation zone of shoot meristematic tissue. Seedlings grown in soil for 10 days were transfered to distilled water containing only bensulfuron solutions. There were significant differences between cultivars in terms of supression of shoot meristematic activity and swelling of cell volume. Observations of those cells made it clear that especially susceptible cultivars showed the irregular cell layering, vacuolation, cell swelling and partial damage in membrane of shoot tissue. The major response of root tips of susceptible cultivars showed the disorganization of cortex, rupture and contraction of membrane, inhibition of cell division, swelling and emergence of lateral root while tolerant ones showed no such responses.

• Clinical and Experimental Reproductive Medicine
• /
• v.32 no.3
• /
• pp.231-242
• /
• 2005

연구목적: 본 연구는 아직 그 기능이 파악되지 않은 탈유비퀴틴효소 중 하나인 HIDE에 대한 기본적인 생화학적 특징과 고환에서의 발현 양상을 파악하고 있다. 연구재료 및 방법: 인간의 HIDE 유전자를 클로닝하여 효소활성이 있는지 세포 외 실험을 통해 확인하였고, 아미노산 서열을 분석하여 진화상 보존된 부분을 찾아 그 기능을 파악한 다음 HSP90과의 상호작용을 공동면역침전반응으로 확인하였다. HIDE의 조직별 발현양상을 파악하기 위해서 인간과 쥐의 RNA 블롯과 쥐의 단백질 블롯을 이용하여 각각 노던 블롯팅과 웨스턴 블롯팅을 수행하여 고환에서 많이 발현된다는 것을 알았고 이 사실을 바탕으로 쥐의 고환을 절개하여 면역조직화학반응으로써 고환 내의 HIDE 단백질의 발현양상을 파악하였다. 결　과: HIDE는 세포 외에서 유비퀴틴 잔기를 제거하는 탈유비퀴틴 활성이 있으나 세포 내에서 전체적인 유비퀴틴 복합체를 줄여주는 효과는 없었다. HIDE는 HSP90이라는 분자 샤페론과 상호작용한다. HIDE의 전사체는 고환에서 가장 많이 발현되며 다른 조직에서도 소량 발현된다. HIDE의 단백질은 웨스턴 블롯상에서 고환에서만 확인되었다. 고환 내에서의 HIDE의 발현양상은 왕성한 감수분열을 하는 정모세포에서 높았으며 지지세포나 정조세포에는 발현되지 않았다. 결　론: HIDE는 분자 샤페론 HSP90과 상호작용하며 고환 내의 감수분열 중인 세포에서 많이 발현되는 것으로 보아 감수분열이나 정자형성에 관여하는 것으로 보인다.

• Korean Journal of Animal Reproduction
• /
• v.23 no.3
• /
• pp.271-278
• /
• 1999

This study was conducted to investigate the cytogenetic properties, in vitro development, and their relationship in the bovine reconstituted embryos following cell cycle-controlled nuclear transfer. Sixteen-cell stage embryos were treated by nocodazole, and after release from nocodazole treatment, their blastomeres were separated and allowed to subsequent cleavage. Blastomeres within 1.5 h post cleavage(hpc) and at 3hpc were transferred to enucleated oocytes at MII-phase or S-phase. Donor nuclei transferred into M II-phase recipients underwent various nuclear remodeling, such as extrusion of a polar body(PB)-like structure, premature chromosome condensation(PCC) and chromatin modifications. These nuclear remodeling patterns varied by the time post cleavage of donor blastomeres. Developmental rate to the blastocyst stage differed with time post cleavage of donor blastomeres and existence of a PB-like structure. Whereas do-nor nuclei transferred into S-phase oocytes did not undergo PCC and other major modifications, and their developmental potentials less depended on the nuclei types. This result confirms that the nuclear remodeling type differs with donor and recipient cell cycle stage, which affect the development of reconstituted bovine embryos.

• Journal of Life Science
• /
• v.13 no.5
• /
• pp.732-739
• /
• 2003

The purpose of this study was to determine if the addition of spermatozoa into the culture medium could influence the nuclear maturation of denuded porcine germinal vesicle (GV) oocytes in vitro. Cumulus-oocyte complexes were collected from follicles of 3 to 5 mm in diameter, The cumulus and corona cells were removed from oocytes. Porcine denuded oocytes were cultured in tissue culture medium containing spermatozoa. After 48 h culture, oocytes were examined for the evidence of GV breakdown, metaphase I, anaphase-telophase I, and metaphase II (M II). The proportion of oocytes reaching M II stage was significantly (P<0.01) increased in the oocytes cultured in media containing spermatozoa compared to those in media without spermatozoa $(31.9\pm1.8%\; vs\; 14.9\pm1.0%)$.No differences in the rates of M II were observed among the different period of spermatozoa exposure nor among the spermatozoa from different species. The proportion of oocytes reaching M II stage was significantly different between high and low concentrations of spermatozoa. The present study suggests that mammalian spermatozoa contain a substance(s) that improves nuclear maturation in vitro of GV oocytes. Enhancing effect of spermatozoa for oocytes maturation in vitro is a highly dose-dependent.

• Korean Journal of Weed Science
• /
• v.9 no.3
• /
• pp.245-249
• /
• 1989

The effects of varying concentrations and durations of butachlor [N-(bytoxymety 1,)-2-chlor -2, 6-diethy lacetanilide treatment on oat(Avena sativa L.) root cell division and protein synthesis were studied. The highest concentration ($1{\times}10^{-3}M$) of butachlor caused the significant inhibition of cell division after 18hrs treatment. After 18hrs treatment, 59% and 82% inhibition of cell division occurred at $1{\times}10^{-4}M$ and $1{\times}10^{-3}M$, respectively, while 9% inhibition of cell division did at $1{\times}10^{-6}M$ concentration at the same exposure period. To investigate protein synthesis, the oats were treated for 18 and 24hrs with concentrations ranging from $1{\times}10^{-6}M$ to $1{\times}10^{-3}M$ butachlor. After 18hrs, butachlor treatment of oat with $1{\times}10^{-4}M$ inhibitited 23% protein synthesis, and butachlor treatment with $1{\times}10^{-4}M$ caused 34% inhibition after 24hrs. With SDS-PAGE of proteins extracted from oat root tips, butachlor usually inhibited the 16, 18, 30, 43 and 43.5 kD polypeptide, and proteins of root tips are made up of subunits below 100 kD polypeptide.