• 대한의생명과학회지
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• 제10권4호
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• pp.391-395
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• 2004

The demand for the production of gene-defective mice from embryonic stem (ES) cells is increasing to clarify decisive gene function in vivo. Although blastocyst injection is widely used to generate ES cell-mediated knockout mice, coculture method has been alternatively used because of several advantages, such as low cost and simple procedure. Thus, this experiment was designed to demonstrate the feasibility of the coculture method using J1 ES cells, which are known to be efficient for blastocyst injection. Eight-cell embryos were harvested from 2.5 days post-coitum (dpc), denuded with acid tyrode's solution, and transferred onto trypsinized J1 ES cells. Aggregation was carried out following two typical methods, which are simple coculture method and aggregation in groove prepared by aggregation needle. Successfully aggregated-embryos were developed to blastocysts for 24 h and transferred into uterus of pseudo-pregnant foster mother. Chimeric offspring was judged by coat pigmentation. In this study, we could obtain chimeric mice from all the two aggregation methods, but the chimera production efficiencies in coculture using groove were three times higher at least than those in the other group. In conclusion, these observations suggest that coculture method should be available for production of knockout mice from J1 ES cells. Presently, the germ-line transmission rates of the chimeras produced from the two methods are under investigation.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6493-6499
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• 2013

Background: Non-epithelial malignant ovarian tumors and clear cell carcinomas, Brenner tumors, transitional cell tumors, and carcinoid tumors of the ovary are rare ovarian tumors (ROTs). In this study, our aim was to determine the clinicopathological features of ROT patients and prognostic factors associated with survival. Materials and Methods: A total of 167 patients with ROT who underwent initial surgery were retrospectively analyzed. Prognostic factors that may influence the survival of patients were evaluated by univariate and multivariate analyses. Results: Of 167 patients, 75 (44.9%) were diagnosed with germ-cell tumors (GCT) and 68 (40.7%) with sex cord-stromal tumors (SCST); the remaining 24 had other rare ovarian histologies. Significant differences were found between ROT groups with respect to age at diagnosis, tumor localization, initial surgery type, tumor size, tumor grade, and FIGO stage. Three-year progression-free survival (PFS) rates and median PFS intervals for patients with other ROT were worse than those of patients with GCT and SCST (41.8% vs 79.6% vs 77.1% and 30.2 vs 72 vs 150 months, respectively; p=0.01). Moreover, the 3-year overall survival (OS) rates and median OS times for patients with both GCT and SCST were better as compared to patients with other ROT, but these differences were not statistically significant (87.7% vs 88.8% vs 73.9% and 170 vs 122 vs 91 months, respectively; p=0.20). In the univariate analysis, tumor localization (p<0.001), FIGO stage (p<0.001), and tumor grade (p=0.04) were significant prognostic factors for PFS. For OS, the univariate analysis indicated that tumor localization (p=0.01), FIGO stage (p=0.001), and recurrence (p<0.001) were important prognostic indicators. Multivariate analysis showed that FIGO stage for PFS (p=0.001, HR: 0.11) and the presence of recurrence (p=0.02, HR: 0.54) for OS were independent prognostic factors. Conclusions: ROTs should be evaluated separately from epithelial ovarian cancers because of their different biological features and natural history. Due to the rarity of these tumors, determination of relevant prognostic factors as a group may help as a guide for more appropriate adjuvant or recurrent therapies for ROTs.

• Parasites, Hosts and Diseases
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• 제53권4호
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• pp.403-411
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• 2015

Plasmodium falciparum can invade all stages of red blood cells, while Plasmodium vivax can invade only reticulocytes. Although many P. vivax proteins have been discovered, their functions are largely unknown. Among them, P. vivax reticulocyte binding proteins (PvRBP1 and PvRBP2) recognize and bind to reticulocytes. Both proteins possess a C-terminal hydrophobic transmembrane domain, which drives adhesion to reticulocytes. PvRBP1 and PvRBP2 are large (>326 kDa), which hinders identification of the functional domains. In this study, the complete genome information of the P. vivax RBP family was thoroughly analyzed using a prediction server with bioinformatics data to predict B-cell epitope domains. Eleven pvrbp family genes that included 2 pseudogenes and 9 full or partial length genes were selected and used to express recombinant proteins in a wheat germ cell-free system. The expressed proteins were used to evaluate the humoral immune response with vivax malaria patients and healthy individual serum samples by protein microarray. The recombinant fragments of 9 PvRBP proteins were successfully expressed; the soluble proteins ranged in molecular weight from 16 to 34 kDa. Evaluation of the humoral immune response to each recombinant PvRBP protein indicated a high antigenicity, with 38-88% sensitivity and 100% specificity. Of them, N-terminal parts of PvRBP2c (PVX_090325-1) and PvRBP2 like partial A (PVX_090330-1) elicited high antigenicity. In addition, the PvRBP2-like homologue B (PVX_116930) fragment was newly identified as high antigenicity and may be exploited as a potential antigenic candidate among the PvRBP family. The functional activity of the PvRBP family on merozoite invasion remains unknown.

• Clinical and Experimental Reproductive Medicine
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• 제29권4호
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• pp.303-310
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• 2002

Objective s: To estimate the frequency of Y chromosome microdeletions in the Korean population of infertile men and to evaluate the relationship between microdeletion on the Y chromosome and clinical phenotypes of infertile men with idiopathic azoospermia and oligozoospermia. Materials and Methods: Genomic DNA was extracted from blood samples collected from 330 infertile men attending the Infertility Clinic at Samsung Cheil Hospital, Korea. Six sequence tagged sites (STSs) spanning the azoospermia factor (AZF) regions of the Y chromosome were amplified by polymerase chain reactions (PCRs). Results: Microdeletions on Y chromosome were detected in 35 (10.6%) of the 330 infertile men. Most of the microdeletions (91.4%) involved AZFb or AZFc. The high incidence of microdeletions were found in AZFc region (57.1%), but the low in AZFa (8.6%) and AZFb (5.7%). Larger microdeletions involving two or three AZF regions were detected in 28.6% of cases. All patients (6 patients) with deletion of AZFa region showed no germ cell phenotypes, Sertoli cell only syndrome or Leydig cell hyperplasia in histopathologic examinations. Conclusion: Microdeletions on the Y chromosome, especially, at AZFc/DAZ regions may be the major cause of azoospermia and severe oligozoospermia. We suggest that idiopathic infertile men have genetic counselling and microdeletion analysis on the Y chromosome before IVF-ET and ART program.

• Clinical and Experimental Reproductive Medicine
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• 제32권3호
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• pp.207-216
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• 2005

Objective: To understand the crucial requirement for the normal early folliculogenesis, we evaluated molecular as well as physiological differences during in vitro ovarian culture. Among the important regulators for follicle development, anti-Müllerian hormone (AMH) and FSH Receptor (FSHR) have been known to be expressed in the cuboidal granulosa cells. Meanwhile, it is known that c-kit is germ cell-specific and GDF-9 is also oocyte-specific regulator. To evaluate the functional requirement for the competence of normal follicular development, we investigated the differential mRNA expression of several factors secreted from granulosa cells and oocytes between in vivo and in vitro developed ovaries. Materials and Methods: Ovaries from ICR neonates (the day of birth) were cultured for 4 days (for primordial to primary transition) or 8 days (for secondary follicle formation) in ${\alpha}$-MEM glutamax supplemented with 3 mg/ml BSA without serum or growth factors. The mRNA levels of the several factors were investigated by quantitative real-time PCR analysis. Freshly isolated 0-, 4-, and 8-day-old ovaries were used as control. Results: The mRNA of AMH and FSHR as granulosa cell factors was highly increased according to the ovarian development in both of 4- and 8-day-old control. However, the mRNA expression was not induced in both of 4- and 8-day in vitro cultured ovaries. The mRNA expression of GDF-9 known to regulate follicle growth as an oocyte factor was different between in vivo and in vitro developed ovaries. In addition, the transcript of GDF-9 was expressed in the primordial follicles of mouse ovaries. The mRNA expression of c-kit was not significantly different during the early folliculogenesis in vitro. Conclusion: This is the first report regarding endogenous AMH and FSHR expression during the early folliculogenesis in vitro. In conclusion, it will be very valuable to evaluate cuboidal granulosa cell factors as functional marker(s) for normal early folliculogenesis in vitro.

• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.658-671
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• 2018

Objective: Nandrolone decanoate (ND) is an anabolic-androgenic steroid frequently used for clinical treatment. However, the inappropriate use of ND results in the reduction of serum testosterone level and sperm production. The suppressive effect of ND on testosterone production has not been investigated in detail. The present study was designed to examine the effect of ND on the expression of steroidogenic enzymes in the rat testis. Methods: Male Sprague Dawley rats at 50 days of age were subcutaneously administrated with either 2 or 10 mg of ND/kg body weight/week for 2 or 12 weeks. The changes of transcript and protein levels of steroidogenic enzymes in the testis were determined by real-time polymerase chain reaction and western blotting analyses, respectively. Moreover, immunohistochemical analysis was employed to determine the changes of immunostaining intensity of these enzymes. The steroidogenic enzymes investigated were steroidogenic acute regulatory protein, cytochrome P450 side chain cleavage enzyme, $17{\alpha}-hydroxylase$, $3{\beta}-hydroxysteroid$ dehydrogenase, and cytochrome P450 aromatase. Results: The treatment of ND resulted in depletion of Leydig cells and sloughing of germ cells in the testis. The ND treatment caused significant expressional decreases of steroidogenic enzymes at transcript and protein levels, and the destructive effects of ND on the testis were more apparent with a higher dose and a longer period of the treatment. Evident reduction of immunostaining intensity present in Leydig cells was clearly detected by the ND treatment. Conclusion: The exposure to ND in young male results not only in histological changes of the testis but also in aberrant gene expression of testicular steroidogenic enzymes, consequently leading into the reduction of testosterone production in the testis and thus likely disruption of spermatogenesis.

• 한국어류학회지
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• 제21권3호
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• pp.141-148
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• 2009

Oryzias dancena를 해양생태계 위해성 평가를 위한 해양 생물모델로 연구하기 위한 기초적인 연구로 초기 성분화와 생식소 발달 과정을 조직학적으로 조사하였다. 원시생식세포가 처음 관찰된 시기는 수정 후 5일째이고, 수정 후 9일째에 장과 앞신장관 사이의 생식소 형성 부근으로 이동한 것이 관찰되었다. 부화 후 12일째의 생식소는 암 수로 분화가 이루어졌다. 부화 후 28일째 난소에서는 주변인기의 난모세포가 관찰되었으며, 28일째의 정소에서는 정소 소관의 수와 정원세포의 증가를 확인할 수 있었다. 산란은 부화 후 9주째에 이루어졌으며, 이 시기의 난소에서는 난황과립이 난 전체에 형성되는 성숙난과 배란 직후 성숙난이 빠져나간 흔적이 관찰되었다. 수컷 생식소에서 역시 많은 수의 정세포가 관찰되었으며 사정 직후 정자가 빠져나간 부분이 관찰되었다. 이상의 결과 본 종은 초기 성분화 과정에 자성 단계를 거치지 않고 정소와 난소로 분화하는 분화형 자웅이체에 속한다.

• 한국발생생물학회지:발생과생식
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• 제12권2호
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• pp.159-168
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• 2008

Nanog is a newly identified member of the homeobox family of DNA binding transcription factors that functions to maintain the undifferentiated state of stem cells. However, molecular mechanisms underlying the function of Nanog remain largely unknown. To elucidate the regulatory roles of Nanog involved in maintenance of P19 embryonal carcinoma (EC) stem cells, we transfected three small interfering RNA (siRNA) duplexes targeted against different regions of the Nanog gene into P19 cells. The Nanog siRNA-100 duplexes effectively decreased the expression of Nanog up to 30.7% compared to other two Nanog siRNAs, the Nanog siRNA-400 (67.9 %) and -793 (53.0%). When examined by RT-PCR and real-time PCR, the expression of markers for pluripotency such as Fgf4, Oct3/4, Rex1, Sox1 and Yes was downregulated at 48 h after transfection with Nanog siRNA-100. Furthermore, expression of the ectodermal markers, Fgf5 and Isl1 was reduced by Nanog knockdown. By contrast, the expression of other markers for pluripotency such as Cripto, Sox2 and Zfp57 was not affected by Nanog knockdown at this time. On the other hand, the expression of Lif/Stat3 pathway molecules and of the endoderm markers including Dab2, Gata4, Gata6 and the germ cell nuclear factor was not changed by Nanog knockdown. The results of this study demonstrated that the knockdown of Nanog expression by RNA interference in P19 cells was sufficient to modulate the expression of pluripotent markers involved in the self-renewal of EC stem cells. These results provide the valuable information on potential downstream targets of Nanog and add to our understanding of the function of Nanog in P19 EC stem cells.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.60-60
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• 2003

Embryonic stem (ES) cells have property of self-renewal and can differentiate into the cells of all three primary germ layers. Recently, many growth factors, alteration of culture condition and gene modifications have been used to differentiate mouse and human ES cells into specific cell types. This study was performed to evaluate the differentiation protocol for human ES cells to the endodermal lineage cells. Human ES cells (Miz-hESl ) were cultured on STO feeder layer mitotically inactivated with mitemycin C, and embryoid bodies (EBs) were formed by suspension culture. Differentiation protocol of EBs consisted of three steps: stage I, culture of EBs for 6 days with ITSFn medium; stage II, culture of stage I cells for 8 days with N2 medium ; stage III, culture of stage II cells for 22 days with N2 medium. mRNA levels of the endodermal lineage differentiation genes were analyzed by semi- quantitative RT-PCR. The Oct-4 expression, a marker of the pluripotent state, was detected in undifferentiated human ES cells but progressively decreased after EBs formation. Differentiating human ES cells expressed marker genes of endodermal differentiation and pancreatic islet cells. GATA4, a-fetoprotein, Glut-2, and Ngn3 were expressed in all stages. However, albumin and insulin were expressed in only stage III cells. The human ES cells can be differentiated into endodermal lineage cells by multiple step culture system using various supplements. We are developing the more effective protocols for guided differentiation of human ES cells.

• International Journal of Oral Biology
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• 제36권1호
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• pp.31-35
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• 2011

Teeth develop via a reciprocal induction between the ectomesenchyme originating from the neural crest and the ectodermal epithelium. During complete formation of the tooth morphology and structure, many cells proliferate, differentiate, and can be replaced with other structures. Apoptosis is a type of genetically-controlled cell death and a biological process arising at the cellular level during development. To determine if apoptosis is an effective mechanism for eliminating cells during tooth development, this process was examined in the rat mandible including the developing molar teeth using the transferase-mediated dUTP-biotin nick labeling (TUNEL) method. The tooth germ of the mandibular first molar in the postnatal rat showed a variety of morphological appearances from the bell stage to the crown stage. Strong TUNEL-positive reactivity was observed in the ameloblasts and cells of the stellate reticulum. Odontoblasts near the prospective cusp area also showed a TUNEL positive reaction and several cells in the dental papilla, which are the forming pulp, were also stained intensively in this assay. Our results thus show that apoptosis may take place not only in epithelial-derived dental organs but also in the mesenchyme-derived dental papilla. Hence, apoptosis may be an essential biological process in tooth development.