• Reproductive and Developmental Biology
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• 제32권4호
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• pp.223-227
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• 2008

Human embryonic stem (ES) cells retain the capacity for self-renewal, are pluripotent and differentiate into the three embryonic germ layer cells. The regulatory transcription factors Oct4, Nanog and Sox2 play an important role in maintaining the pluripotency of human ES cells. The aim of this research was to identify unknown genes upregulated in human ES cells along with Oct4, Nanog, and Sox2. This study characterizes an unknown gene, named chromosome 1 open reading frame 31 (C1orf31) mapping to chromosome 1q42.2. The product of C1orf31 is the hypothetical protein LOC388753 having a cytochrome c oxidase subunit VIb (COX6b) motif. In order to compare expression levels of C1orf31 in human ES cells, human embryoid body cells, vascular angiogenic progenitor cells (VAPCs), cord-blood endothelial progenitor cells (CB-EPCs) and somatic cell lines, we performed RT-PCR analysis. Interestingly, C1orf31 was highly expressed in human ES cells, cancer cell lines and SV40-immortalized cells. It has a similar expression pattern to the Oct4 gene in human ES cells and cancer cells. Also, the expression level of C1orf31 was shown to be upregulated in the S phase and early G2 phase of synchronized HeLa cells, leading us to purpose that it may be involved in the S/G2 transition process. For these reasons, we assume that C1orf31 may play a role in on differentiation of human ES cells and carcinogenesis.

• 한국발생생물학회지:발생과생식
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• 제14권2호
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• pp.43-50
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• 2010

최근에 체세포 리프로그래밍 기법을 사용하여 체세포에 몇 가지 전사인자(리프로그래밍 인자)를 넣어줌으로써 유도만능줄기세포(induced pluripotent stem cell, iPS)를 만드는데 성공하였다. 유도만능줄기세포는 배아줄기세포와 유사하게 자가재생 할 수 있는 능력이 있으며, 신체의 모든 타입의 세포로 분화할 수 있는 특징을 가지고 있다. 배아줄기세포와는 달리 면역거부반응이 없다는 점과 윤리적인 문제로부터 자유롭다는 장점이 있어 2006년 Yamanaka 팀이 유도만능줄기세포에 관해 처음 보고한 이후로 이 분야 연구의 급속한 발전이 이루어지고 있다. 하지만 안전성의 문제점 때문에 세포치료제로 사용되기 위해서는 리프로그래밍 인자의 도입 방법 및 새로운 리프로그래밍 인자의 발굴 등 몇 가지 해결해야 할 점들이 남아 있다. 본 종설에서는 유도만능줄기세포를 만드는데 사용된 몇 가지 리프로그래밍 인자에 대해 보고된 연구 내용을 리프로그래밍 인자가 존재하는 세포인 배아줄기세포 및 난자와 배아에서 정리하고자 하며, 리프로그래밍 인자의 연구에 관한 방향에 대해 논의하고자 한다.

• 한국수정란이식학회지
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• 제18권3호
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• pp.179-186
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• 2003

Human embryonic stem (hES) cell lines have been derived from human blastocysts and are expected to have far-reaching applications in regenerative medicine. The objective of this study is to improve freezing method with less cryo-injuries and best survival rates in hES cells by comparing various vitrification conditions. For the vitrifications, ES cells are exposed to the 4 different cryoprotectants, ethylene glycol (EG), 1,2-propanediol (PROH), EG with dime-thylsulfoxide (DMSO) and EG with PROH. We compared to types of vehicles, such as open pulled straw (OPS) or electron microscopic cooper grids (EM grids). Thawed hES cells were dipped into sequentially holding media with 0.2 M sucrose for 1 min, 0.1 M sucrose for 5 min and holding media for 5 min twice and plated onto a fresh feeder layer. Survival rates of vitrified hES cells were assessed by counting of undifferentiated colonies. It shows high survival rates of hES cells frozen with EG and DMSO (60.8％), or EG and PROH(65.8％) on EM grids better than those of OPS, compared to those frozen with EG alone (2.4％) or PROH alone (0％) alone. The hES cells vitrified with EM grid showed relatively constant colony forming efficiency and survival rates, compared to those of unverified hES cells. The vitrified hES cells retained the normal morphology, alkaline phosphates activity, and the expression of SSEA-3 and 4. Through RT-PCR analysis showed Oct-4 gene expression was down-regulated and embryonic germ layer markers were up-regulated in the vitrified hES cells during spontaneous differentiation. These results show that vitrification method by using EM grid supplemented with EG and PROH in hES cells may be most efficient at present to minimize cyto-toxicity and cellular damage derived by ice crystal formation and furthermore may be employed for clinical application.

• 한국동물학회지
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• 제21권2호
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• pp.43-58
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• 1978

양서류 수정란을 제 1 난할전에 중금속으로 처리하였던바 개구리의 시원생식세포수의 양전변화를 가져 왔다. 중금속의 일정량의 처리는 양서류 초기발생중에 시원생식세포 형성을 저하시켰다. 납 70ppm과 카드뮴 4ppm 이상에서 배양하면 9내지 12mm배에서 시원생식세포의 수적감소를 가져 왔으나 그후의 발생에서는 거의 정상군과같은 증가율을 보였다. 한편 수은 0.8ppm이상의 처리군에서는 생식 세포형성에 보다 심한 저하를 가져 왔으며 그후의 증가율도 대체로 낮았다. 위의 사실들은 자외선 조사 실험에서 얻은 결과와는 달리 양서류란에 있어서 중금속 처리는 조직에 심한 손상을 주는 다량투여에도 시원생식세포의 완전 배제에는 효과가 적다는 것을 암시한다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3443-3446
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• 2015

Background: Testicular tumors constitute a rare type of cancer affecting adolescents and young adults with recent reports confirming an increase in incidence worldwide. The purpose of this study was to estimate the epidemiological characteristics and histological subtypes of testicular tumors in the Lebanese population according to the WHO classification of testicular and paratesticular tumors. Materials and Methods: In this single institutional retrospective study, all patients diagnosed with a testicular tumor in Hotel-Dieu de France Hospital University in Beirut between 1992 and 2014 were enrolled. The age, subtype based on the 2004 WHO classification and body side of tumor were analyzed. Results: A total of two hundred and forty-four (244) patients diagnosed with a testicular tumor in our institution were included in the study. Two hundred and one patients (82.4% of all testicular tumors) had germ cell tumors (TGCT). Among TGCT, 50% were seminomatous tumors, 48% non-seminomatous tumors (NST) and 2% were spermatocytic seminomas. The NST were further divided into mixed germ cell tumors (63.9%), embryonic carcinomas (18.6%), teratomas (15.4%) and yolk sac tumors (2.1%). The mean age for testicular tumors was 32 years. The mean age for germ cell tumors was 31 years and further subtypes such as seminomatous tumors had a mean age of 34 years, 28 years in non-seminomatous tumors and 56 years in spermatocytic seminoma. Patients with right testicular tumor were the predominant group with 55% of patients. Three patients (1.2%) presented with bilateral tumors. Conclusions: The distribution of different subgroups and the mean age for testicular tumors proved comparable to most countries of the world except for some Asian countries. Germ cell tumors are the most common subtype of testicular tumors with seminomatous tumors being slightly more prevalent than non-seminomatous tumors in Lebanese patients.

• Animal cells and systems
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• 제8권3호
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• pp.197-203
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• 2004

CD30 is a member of tumor necrosis factor receptor (TNFR) superfamily and has pleiotropic functions including cell activation, proliferation, differentiation, and death, depending on cell types and stage of differentiation. Although CD30 expression has been described mainly in hematopoietic tissues, several types of nonhematopoietic tumors including embryonic carcinoma and germ-cell tumors express CD30. We examined CD30 distribution in the testis and epididymis from wild type and CD30-deficient mice. In the testis, spermatogonia, spermatocytes and Sertoli cells expressed CD30, but not in spermatids. Spermatogonia and spermatocytes near the basement membrane strongly reacted to anti-CD30. In the epididymis, CD30 expression was exclusively observed in luminal epithelia and some interstitial cells. Taken together, these results show a spatio-temporal regulation of CD30 expression in mouse testis and epididymis and suggest a possible role of CD30 in spermatogonia and spermatocytes.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.1-8
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• 2011

Techniques to evaluate gene expression profiling, such as sufficiently sensitive cDNA microarrays or real-time quantitative PCR, are efficient methods for monitoring human pluripotent stem cell (hESC/iPSC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turn-around time, and the involvement of highly specialized technical expertise. Hence, there is an urgency of rapid, cost-effective, robust, yet sensitive method development for routine screening of hESCs/hiPSCs. A critical requirement in hESC/hiPSC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all three germ layers, including ectoderm, mesoderm, and endoderm. To quantify the modulation of gene expression in hESCs/hiPSC during their propagation, expansion, and differentiation via embryoid body (EB) formation, we developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR platform technology. Among the 9 gene primers tested, 5 were pluripotent markers comprising set 1, and 3 lineage-specific markers were combined as set 2, respectively. We found that these 2 sets were not only effective in determining the relative differentiation in hESCs/hiPSCs, but were easily reproducible. In this study, we used the hES/hiPS cell lines to standardize the technique. This multiplex RT-PCR assay is flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC/hiPSC lines during routine maintenance and directed differentiation.

• Clinical and Experimental Reproductive Medicine
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• 제39권1호
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• pp.1-9
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• 2012

The safety of human exposure to an ever-increasing number and diversity of electromagnetic field (EMF) sources both at work and at home has become a public health issue. To date, many in vivo and in vitro studies have revealed that EMF exposure can alter cellular homeostasis, endocrine function, reproductive function, and fetal development in animal systems. Reproductive parameters reported to be altered by EMF exposure include male germ cell death, the estrous cycle, reproductive endocrine hormones, reproductive organ weights, sperm motility, early embryonic development, and pregnancy success. At the cellular level, an increase in free radicals and $[Ca^{2+}]i$ may mediate the effect of EMFs and lead to cell growth inhibition, protein misfolding, and DNA breaks. The effect of EMF exposure on reproductive function differs according to frequency and wave, strength (energy), and duration of exposure. In the present review, the effects of EMFs on reproductive function are summarized according to the types of EMF, wave type, strength, and duration of exposure at cellular and organism levels.

• Reproductive and Developmental Biology
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• 제35권4호
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• pp.491-498
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• 2011

During mammalian fertilization, germ cell-specific hyaluronidases, such as sperm adhesion molecule 1 (SPAM1) and hyaluronoglucosaminidase 5 (Hyal5), are important for the dispersal of the cumulus mass. In this study, we demonstrated that bull Hyal5 is a single copy gene on chromosome 4 that is expressed specifically in the testis. In addition, we expressed recombinant bull SPAM1 and Hyal5 in human embryonic kidney 293T cells and showed that these enzymes possessed hyaluronidase activity. We also demonstrated that a polyclonal antibody against bull sperm hyaluronidase inhibits sperm-egg interactions in an in vitro fertilization (IVF) assay. Our results suggested that bull Hyal5 may have a critical role in bull fertilization.

• 한국가금학회지
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• 제26권2호
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• pp.119-129
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• 1999

In recent years, numerous researches have been carried out in author's laboratory to develop several kinds of methods for producing transgened chicken, leaving a lot of new findings. Some of them are very useful to search for new approaches necessary to improve the efficiency of hatchability and the survival rate of developing trasgened embryos. The results obtained hitherto might be summarized as follows: (1) foreign gene(Lac Z/ Miw Z) introduced into blastodermal cells of developing embryos was successfully transferred to embryos, leading to the production of primordial germ cells(PGCs) carrying foreign DNA. However, hatched hickens failed to show the incorporation of introduced gene into the gonads. (2) When foreign gene was introduced into germinal crescent region (GCR), the gene was also efficiently incorporated into germ cells, resulting in the production of transgened chickens(offspring) which produced fruther offspring having foreign gene in the gonads. In this case, 2nd and 3rd generations of chickens were obtained through the reproduction of transgened birds. (3) In another way, the gene was injected into blood vessels of developing embryos at stage 13∼15, creating PGCs having foreign gene, and produced some transgened chickens. In this work, the PGCs were transfered between embryos, resulting in the production of transgenic chickens. (4) in these experiments, PGCs were effectively employed for producing transgenic birds, developing some kinds of chimeric chickens from homo- or hetero-sexual transfer of the PGCs from embryos. This means that the gonads from donor PGCs developed in some degree to the stage of hatching. However, these gonads showed slightly abnormal tissues similar to ovotestis like organs through histological examination. (5) Avian Leukosis Virus(ALV) induced B cell line(DT40) successfully carried foreign genes into chicken embryos, suggesting the possibility of the cells as a vector in this field of study in the future. (6) Inter-embryonic transfer of the PGCs also gave us some.