• 제목/요약/키워드: cleavage.

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Effect of the Presence of Corpus Luteum on Oocyte Recovery and Subsequent in vitro Maturation and Fertilization in Buffaloes

  • Singh, Sajjan;Dhanda, O.P.;Malik, R.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권12호
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    • pp.1675-1677
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    • 2001
  • The effect of the presence or absence of corpus luteum in the ovaries of slaughtered buffaloes was studied for the oocytes recovery and their subsequent maturation and fertilization in vitro. On an average, 0.41 and 0.67 oocytes per ovary were recovered from ovaries with and without corpus luteum, respectively. Immature oocytes were matured in TCM-199 medium. Significant difference was observed in maturation rate between good (74%) and fair (37%) oocytes. However, there was no significant difference in cleavage rate between the two types. The results of this study show that although the presence of corpus luteum in the ovary at the time of recovery significantly affected availability of total oocytes and in-vitro maturation, but fertilization and cleavage remained unaffected under in vitro conditions.

New Links between mRNA Polyadenylation and Diverse Nuclear Pathways

  • Di Giammartino, Dafne Campigli;Manley, James L.
    • Molecules and Cells
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    • 제37권9호
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    • pp.644-649
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    • 2014
  • The 3' ends of most eukaryotic messenger RNAs must undergo a maturation step that includes an endonuc-leolytic cleavage followed by addition of a polyadenylate tail. While this reaction is catalyzed by the action of only two enzymes it is supported by an unexpectedly large number of proteins. This complexity reflects the necessity of coordinating this process with other nuclear events, and growing evidence indicates that even more factors than previously thought are necessary to connect 3' processing to additional cellular pathways. In this review we summarize the current understanding of the molecular machinery involved in this step of mRNA maturation, focusing on new core and auxiliary proteins that connect polyadenylation to splicing, DNA damage, transcription and cancer.

다제내성 황색포도상구균이 가지고 있는 클로람페니콜 내성 플라스미드의 동정 (Characterization of Chloramphenicol Resistant Plasmid of Multidrug-resistant Staphylococcus aureus)

  • 이대운;문경호
    • 약학회지
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    • 제37권6호
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    • pp.621-624
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    • 1993
  • The clirical isolate Staphylococcus aureus SA2 had four kinds of plasmids and was resistant to ampicillin, chloroamphenicol, clindamycin. erythromycin, gentamicin, kanamycin, methicillin, streptomycin, tetracycline and tobramycin. Transformation experiment demonstrated that 4.14kb plasmid(pKH7) encoded resistance to chloramphenicol. The cleavage map of pKH7 was determined by restriction enzyme mapping techniques. The cleavage map is given for BstEll, Hindlll, Hpall, and Xbal. The above restriction endonucleases have a single site, but nucleases BamHl, Bgll, BglII, EcoRl, EcoRV, HaeIII, Hpal, Kpnl, Pstl, PvnII, Sall, Smal, and XhoI have no site on this plasmid.

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인삼 Saponin분획이 제한효소에 의한 pBR322 절단에 미치는 영향 (Effect of Ginseng Saponin Fraction on Cleavage of pBR322 by Several Restriction Endonuclease)

  • 강정훈;조영동
    • Journal of Ginseng Research
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    • 제9권2호
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    • pp.240-247
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    • 1985
  • Attempts were made to see if we could cut more pBR322 in the presence of ginseng saponin fraction in connection with possibly for shortening the enzymatic reaction time and the amount of the enzyme to be used. The following results were obtained restriction endonucleases such as AccI, XhoII, SaII, and HincII were observed to cut pBR322 efficiently at 10-1% ginseng saponin fraction. In case of BamHI, 10-2% ginseng saponin fraction was observed to the most effective concentration. Such cumulative results suggest that ginseng saponin fraction would play important role as far as the cleavage of pBR322 for short period by endonucleases is concerned.

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HL-60 세포에서 Camptothecin의 apoptosis 유도작용 (Induction of Apoptosis by Camptothecin in HL-60 Cells)

  • 김해종;천영진;김미영
    • 약학회지
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    • 제43권3호
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    • pp.385-390
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    • 1999
  • Camptothecin (CPT) has been known to induce apoptosis in various cancer cell lines. To examine the intracellular apoptotic death signal initiated by CPT, we investigated the possible connection between caspase-3 activation and GSH depletion during CPT-induced apoptosis in HL-60 cells. Treatment of cells with $1{\;}{\mu}M$ CPT induced PARP cleavage accompanied by DNA fragmentation. z-VAD-fmk, a caspase-3 inhibitor, blocked the CPT-induced DNA fragmentation. Pretreatment of cells with N-acetylcysteine, a precursor of GSH biosynthesis, failed to inhibit CPT-induced PARP celavage and DNA gragmenatation. No significant changes in GSH depletion is not essential for caspase activation during CPT-induced apoptosis. We also investigated whether CPT-induced apoptosis is associated with changes of the levels of Bax and Bcl-2, two proteins involved in the control of apoptosis. Bcl-2 levels exhibited a late decrease compared with the kinetics of DNA fragmentation, whereas Bax levels increased more rapidly after CPT treatment. These results suggest that Bax plays more important role than Bcl-2 in inducing DNA fragmentation and may function upsteam of proteolytic activation of caspase-3 pathway in CPT-induced apoptosis.

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황색포도상구균의 항생제 다제내성을 갖는 플라스미드의 동정 (Characterization of Multidrug Resistant Plasmid of Staphylococcus aureus)

  • 김기현;이대운;김종명;문경호
    • 약학회지
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    • 제36권5호
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    • pp.486-490
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    • 1992
  • The clinical isolate Staphylococcus aureus SA2 was resistant to ampicillin, Chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, methicillin, streptomycin, and tobramycin and harboured more than two kinds of plasmids. Transformation experiment demonstrated that 40.98-kb plasmid(pKH2) encoded resistance to ampicillin, clindamycin, erythromycin, kanamycin, and streptomycin. The cleavage map of a pKH2 was determined by restriction enzyme mapping techniques. Cleavage map is given for BamHI, BglI, BstEII, SalI and XhoI.

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Triphenylphosphine Phenylimide의 전기화학적인 환원 (Electrochemical Reduction of Triphenylphosphine Phenylimide)

  • 박종민
    • 대한화학회지
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    • 제18권5호
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    • pp.341-353
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    • 1974
  • Triphenylphosphine phenylimide의 비수용액에서의 전기화학적인 환원반응을 polarography, cyclic voltammetry, controlled-potential coulometry 및 electron spin resonance 법을 써서 고찰하였다. 이 유기인화합물은 one-electon transfer에 따라서 anion radical이 형성되나 순간일 뿐이고 protonation과 재차 one-electon reduction 결과 인과 질소사이의 이중결합이 끊어진다. 그 결과 아닐린이 주요 반응생성물로서 발견되었다. 또 한편 동반하는 화학반응결과 생긴 주산물의 하나인 triphenylposphine oxide의 환원결과 인과 페닐 사이의 단일결합이 끊어지는 것도 관찰할 수 있었다.

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저온환경에서 압력 구조용 강의 피로균열특성 (Fatigue Crack Properties of Pressure Structural Steel at Low Temperature)

  • 최용범;박원조;이광영;허선철;김정호
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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    • pp.146-151
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    • 2001
  • Low temperature fatigue crack propagation ratio and characteristics of the pressure structural steel which is used for the low temperature pressure vessels. Fatigue crack properties was studied at room temperature of $25^{\circ}C$ and low temperature ranges $-60^{\circ}C,\; -80^{\circ}C \;and\; -100^{\circ}C$ with stress ratio of R=0.05, 0.1, 0.3 in the logarithmic relationship between the fatigue crack propagation rate (da/dN) and stress intensity factor $\DeltaK$, in low temperature case the relationship was extend to the range of low crack propagation rate. The fractured specimens were examined by SEM tested. That results showed specimen failed at low temperature exhibit the quasi-cleavage fracture formation, however, considerable ductility proceed final fracture.

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Photoinduced Electron Transfer Reactions of Aryl Benzyl Sulfides Promoted by 2,4,6-Triphenylpyrilium Tetrafluoroborate (TP+BF4-)

  • Memarian, Hamid Reza;Ira, Mohammadpoor Baltork;Bahrami, Kiumars
    • Bulletin of the Korean Chemical Society
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    • 제27권1호
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    • pp.106-110
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    • 2006
  • Photocatalytic electron transfer reactions of aryl benzyl sulfides using 2,4,6 triphenylpyrilium tetrafluoroborate ($TP^+BF_4^-$) resulted in the oxidation of these sulfides to the corresponding sulfoxides and also in most cases in the C-S bond cleavage of them along with formation of aromatic aldehydes. In these reactions, the formation of sulfide radical cation has been proposed, which undergoes either oxidation to the corresponding sulfoxide or C-S bond cleavage to the formation of aromatic aldehydes. The further oxidation of sulfoxides to sulfones has not been observed. The influence of substrate structures on the reaction pathways as well as the role of $O_2$ in this respect is discussed.