• 한국동물학회지
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• 제28권3호
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• pp.151-165
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• 1985

솔나방의 變態에 따른 中腸上皮의 形態的 變化를 終齡幼蟲類에서 踊化直後까지 5단계로 나누어 光學 및 電子顯微鏡을 사용하여 관찰하였다. 終齡類蟲의 中腸上皮는 圓桂狀細胞, 再生細胞 및 內分泌細胞로 구성되어 있다. 終齡幼蟲의 圓桂狀細胞에서는 核으로부터 유출되는 분비물질이 核膜에 규칙적으로 배열되어 관찰되며, 정단부에서는 lysosome이 점차 증가해 간다. 또한, 遊離綠에서는 微細絨毛사이로 팽출한 細胞質突起가 나타나는데 細胞小器官은 관찰되지 않는다. 再生細胞는 分化가 활발해짐에 따라 杯胞가 있는 杯狀細胞型으로 관찰되며, 細胞質에서는 液胞가 점차 증가한다. 踊化直前에는 Ca의 주성분으로 사료되는 물질이 동심원상으로 나타나며 杯胞는 腸內腔으로 분리된다.幼蟲類의 圓桂狀細胞에서 관찰되는 lysosome의 증가, 核物質의 細胞質로 유출, 遊離綠의 細胞質突起는 幼蟲期 中腸上皮의 退化過程을 반영하고 있다고 사료되며, 再生細胞는 杯狀細胞型으로 分化되지만 杯胞가 腸內腔으로 분리되고저 踊化期의 새로운 中腸上皮를 구성한다고 믿어진다.

• 대한의생명과학회지
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• 제2권1호
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• pp.57-69
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• 1996

한국산 대륙밭쥐 (Clethrionomys rufocanus regulus) 정자변태 과정을 알아보기 위하여 정소내 세정 관상피의 세포분화에 따른 형태적 특징들을 기초로 하여 전자현미경으로 관찰한 결과는 다음과 같다. 1. 대륙밭쥐의 정자변태 과정은 골지(Golgi), 두모(cap), 첨체(acrosome), 성숙(maturation) 및 이탈기(spermiation phase)로 구분하였고, 다시 각각 전후단계로 세분하여 전과정을 10단계로 나누었다. 2. 염색질 변화는 골지 후기에서 서서히 응축하여 성숙기에서 균질화되고, 이탈기에서 완전한 핵을 형성하였다. 3. 정자두부는 낫꼴모양을 가지며, 정자꼬리는 골지 전기에서 형성되기 시작하여 이탈기에서 완성되었다. 4. 이탈 전 후기의 정자세포의 형태적 특징으로서는, 이탈전기의 정자 세포는 3가지 유형으로 구분 되어졌다. (1).미토콘드리아의 불규칙 배열과 더불어 경부와 중편부에 세포질 소적을 함유한 정자세포(A-type). (2). 미토콘드리아가 축사를 중심으로 완전히 배열되고, 중편부에 세포질 소적을 함유한 정자세포(B-type). (3) 축사를 중심으로 미토콘드리아의 배열 후 경부에만 세포질 소적을 함유한 정자세포(C-type). 그리고 이탈후기의 경우, 정자세포들이 정자두부만 Sertoli cell의 세포질에 싸여져 있거나 또는 Sertoli cell의 세포질로부터 이탈되기 직전의 정자로 구분되었다.

• 한국작물학회지
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• 제38권5호
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• pp.413-417
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• 1993

우리나라 japonica 벼의 일대잡종을 다양하게 육성할 목적으로 세포질 유전자적 웅성불임인 BTCMS에 대한 임성회복력이 있는 계통 AR-3을 교잡하여 그 F1을 모본으로 하고 조ㆍ중ㆍ만생의 한국 japonica형 벼 4품종씩을 교본 반복친으로 5회 backcross하여 우리나라 벼 품종 배경의 우엉불임 계통과 임성회복계통을 육성하고 이들의 주요 작물학적 특성을 각각의 반복친과 비교한 결과를 요약하면 다음과 같다. 1. 우리나라 japonica형 품종의 배경을 갖는 세포질 유전자적 웅성불임계통을 조ㆍ중ㆍ만생군으로 각각 4개씩 도합 12계통 육성하였으며, 동일한 품종의 배경을 갖는 임성회복계통친도 조ㆍ중ㆍ만생군으로 각각 4개씩 12계통 육성하였다. 2. 육성된 웅성불임계통은 조중군에서 소백벼 A, 오대벼,A, 관악벼A, 대성벼A, 중생군에서 화진벼A, 팔달A, 수원 224A, 이리 386A, 만생군에서 낙동벼A, 팔굉A, 화청벼A 및 밀양 97A 등으로 명명하였다. 3. 육성된 임성회복계통은 조생군에서 소백벼R, 오대벼R, 팔달R, 수원 224R, 이리 386R, 만생군에서 낙동벼R, 팔굉R, 화청벼R 및 밀양 97R 등으로 명명하였다. 4. 육성된 웅성불임계통들은 반복친(불임유지친)에 비하여 간장이 단축되는 경향이었으나 출수기, 수장 및 수량구성요소 등은 대체로 비슷하였다. 5. 육성된 임성회복계통들은 반복친과 비교하면 대체로 간장, 수장, 수량구성요소 및 수량의 차이가 없었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권19호
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• pp.8019-8026
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• 2014

The promyelocytic leukemia (PML) gene is a gene known to be a tumor suppressor, although recent data suggest that it has a dual function in tumorigenesis. It was initially discovered in acute promyelocytic leukemia (APL) in which a t(15; 17) chromosomal translocation fused it to the retinoic acid receptor alpha ($RAR{\alpha}$). It has been shown to be involved in various types of cancer. It has at least 6 nuclear isoforms and a cytoplasmic type with different characteristics. Its multiple functions in growth inhibition, apoptosis induction, replicative senescence, inhibition of oncogenic transformation, and suppression of migration and angiogenesis have made it a therapeutic target for cancer therapy. However, its dual role in the process of tumorigenesis has made this field challenging. In this review, we discuss PML structure, functions and expression in tumors.

• IMMUNE NETWORK
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• 제5권3호
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• pp.144-149
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• 2005

Background: Fc receptor-mediated phagocytosis is a complex process involving the activation of kinases and phosphatases. FcgammaRIIB has been known to transduces inhibitory signals through an immunoreceptor tyrosine-based inhibitory motif (ITIM) in cytoplasmic domains. In this study, we examined the involvement of inositol-phosphatase in the Fc receptor-mediated phagocytosis. Methods: J774 cells were infected using vaccinia viral vector containing SH2 domain-containing inositol-phosphatase (SHIP) cDNA and stimulated with the sensitized sheep red blood cells. Results: Stimulation of J774 cells induced the tyrosine phosphorylation of SHIP which was maximal at 5 minutes. Phosphatidylinositol-3 (PI-3) kinase inhibitor (wortmannin) inhibits J774 cell phagocytosis of sensitized sheep red blood cells in a dose-dependent manner. Heterologious expression of SHIP in J774 cells inhibits phagocytosis of sensitized sheep red blood cells in a dose-dependency manner, but catalytically dead mutants of SHIP has no effect on phagocytosis. Conclusion: These results strongly suggest that the active signals mediated by PI-3 kinase are opposed by inhibitory signals through SHIP in the regulation of Fc receptor-mediated phagocytosis.

• 대한핵의학회지
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• 제38권2호
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• pp.190-197
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• 2004

Apoptosis plays a role in the pathophysiology of many kinds of diseases and in the response of treatment. Compared to the necrosis, the apoptosis is a genetically controlled and energy-dependent process which removes the unwanted cells from the body; programmed cell death or cell suicide. During the apoptosis, phosphatidylserine is expressed in the cytoplasmic outer membrane in the early phase. Annexin V, an endogenous human protein (MW=35 kD), has an affinity of about $10^{-9}\;M$ for the phosphatidylserine exposed on the outer membrane of apoptotic cells. Annexin V can be radiolabeled with $^{99m}Tc$ by HYNIC or EC chelators, which can be used as an radiotracer for the in vivo imaging of apoptosis. In this article, we reviewed the apoptosis, radiolabeling of annexin V, and the experimental and clinical data using annexin V imaging.

• 아시안잔디학회지
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• 제11권1호
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• pp.9-22
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• 1997

This study was performed to elucidate the mechanisms involved in efflux process of phosphate from intact and excised roots of Oryza sativa (Tongil). The rapid loss of phosphate during the first 40-minutes of treatment is mainly from the cytoplasmic fraction, and the gradual loss taking place afterwards is possibly reflecting the losses at the tonoplast. During the first 60 minutes, loss of phosphate from the excised roots treated with KCN was more rapid than the control but slower thereafter. The effect of $CaCl_2$ and KCl appeared to decrease the rate of phosphate efflux in excised roots of rice. The mechanism of phosphate efflux by rice roots seems to be passive and oscillatory in the short period. Key words: Oryza sativa(Tongil), Phosphate efflux.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.37-42
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• 2002

In ascidians, a primitive chordate, maternal cytoplasmic factors and inductive interactions are involved in the specification of cell fate in early embryos. The larval structure of ascidians is relatively simple, and the major mesodermal tissues of the tadpole larva are notochord, muscle and mesemchyme. Formation of muscle cells is a cell-autonomous process, and localized maternal macho-1 mRNA specify muscle fate in the posterior marginal zone of the early embryo. In contrast, inductive influence from endoderm precursors plays important roles in the specification of notochord and mesenchyme fates. FGF-Ras-MAPK signaling is involved in the induction of both tissues. The difference in responsiveness of the posterior mesenchyme and anterior notochord precursors is caused by the presence or absence of the posterior-vegetal egg cytoplasm, respectively. In these cases, directed signal may polarizes the responding cells and cause asymmetric cell divisions that operate in both the anterior and posterior regions.

• Molecules and Cells
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• 제38권5호
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• pp.381-389
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• 2015

Autophagy is a lysosome-dependent intracellular degradation process that allows recycling of cytoplasmic constituents into bioenergetic and biosynthetic materials for maintenance of homeostasis. Since the function of autophagy is particularly important in various stress conditions, perturbation of autophagy can lead to cellular dysfunction and diseases. Accumulation of abnormal protein aggregates, a common cause of neurodegenerative diseases, can be reduced through autophagic degradation. Recent studies have revealed defects in autophagy in most cases of neurodegenerative disorders. Moreover, deregulated excessive autophagy can also cause neurodegeneration. Thus, healthy activation of autophagy is essential for therapeutic approaches in neurodegenerative diseases and many autophagy-regulating compounds are under development for therapeutic purposes. This review describes the overall role of autophagy in neurodegeneration, focusing on various therapeutic strategies for modulating specific stages of autophagy and on the current status of drug development.

• Applied Microscopy
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• 제27권3호
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• pp.309-320
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• 1997

The spermatogenesis of korean leech, Whitmania edentula was observed, using both light and electron microscopes. The spermatogonium and maturing spermatozoon are connected with long cytoplasmic process to the cytophore, which supplys nutrition to the germ cells and supports synchronous maturity. The truck of korean leech is divided into three regions; a long ladder-shaped acrosome and head, long middle piece and long tail. Long head region twists to the dextral helix, and nuclei are surrounded with microtubules (manchette).The nebenkern formed with long mitochondrion exists in the middle pieces, and a long tail of Whitmania edentula ($9\times2+1$ axoneme) differs from the $9\times2+2$ axoneme of Rhynchobdellae. The late cytophore is mostly formed with crystalloid matter and a number of lysosomes, and matured spermatozooms are engulfed into the late cytophore.