• 한국발생생물학회지:발생과생식
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• 제25권1호
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• pp.1-14
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• 2021

The Syrian (golden) hamsters are seasonal breeders whose reproductive functions are active in summer and inactive in winter. In experimental facility mimicking winter climate, short photoperiod (SP) induces gonadal regression. The blood-testis barrier (BTB) of the sexually involuted animals have been reported to be permeable, allowing developing germ cells to be engulfed or sloughed off the epithelium of the seminiferous tubules. The expressions of genes related to the tight junction composing of BTB were investigated in the reproductive active and inactive testes. Claudin-11, occludin, and junctional adhesion molecule (JAM) were definitely expressed in the active testes but not discernably detected in the inactive testes. And spermatozoa (sperm) were observed in the whole lengths of epididymides in the active testes. They were witnessed in only cauda region of the epididymides but not in caput and corpus regions in animals with the inactive testes. The results imply that the disorganization of BTB is associated with the testicular regression. The developing germ cells are swallowed into the Sertoli cells or travel into the lumen, as supported by the presence of the sperm delayed in the last region of the epididymis. These outcomes suggest that both apoptosis and desquamation are the processes that eliminate the germ cells during the regressing stage in the Syrian hamsters.

• Imaging Science in Dentistry
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• 제52권3호
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• pp.275-281
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• 2022

Purpose: The aim of this study was to assess the performance of a deep learning system for permanent tooth germ detection on pediatric panoramic radiographs. Materials and Methods: In total, 4518 anonymized panoramic radiographs of children between 5 and 13 years of age were collected. YOLOv4, a convolutional neural network (CNN)-based object detection model, was used to automatically detect permanent tooth germs. Panoramic images of children processed in LabelImg were trained and tested in the YOLOv4 algorithm. True-positive, false-positive, and false-negative rates were calculated. A confusion matrix was used to evaluate the performance of the model. Results: The YOLOv4 model, which detected permanent tooth germs on pediatric panoramic radiographs, provided an average precision value of 94.16% and an F1 value of 0.90, indicating a high level of significance. The average YOLOv4 inference time was 90 ms. Conclusion: The detection of permanent tooth germs on pediatric panoramic X-rays using a deep learning-based approach may facilitate the early diagnosis of tooth deficiency or supernumerary teeth and help dental practitioners find more accurate treatment options while saving time and effort

• 한국발생생물학회지:발생과생식
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• 제26권4호
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• pp.145-153
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• 2022

The gut microbiota is involved in the maintenance of physiological homeostasis and is now recognized as a regulator of many diseases. Although germ-free mouse models are the standard for microbiome studies, mice with antibiotic-induced sterile intestines are often chosen as a fast and inexpensive alternative. Pathophysiological changes in the gut microbiome have been demonstrated, but there are no reports so far on how such alterations affect the bacterial composition of the uterus. Here we examined changes in uterine microbiota as a result of gut microbiome disruption in an antibiotics-based sterile-uterus mouse model. Sterility was induced in 6-week-old female mice by administration of a combination of antibiotics, and amplicons of a bacteria marker gene (16S rRNA) were sequenced to decipher bacterial community structures in the uterus. At the phylum-level, Proteobacteria, Firmicutes, and Actinobacteria were found to be dominant, while Ralstonia, Escherichia, and Prauserella were the major genera. Quantitative comparisons of the microbial contents of an antibiotic-fed and a control group revealed that the treatment resulted in the reduction of bacterial population density. Although there was no significant difference in bacterial community structures between the two animal groups, β-diversity analysis showed a converged profile of uterus microbiotain the germ-free model. These findings suggest that the induction of sterility does not result in changes in the levels of specific taxa but in a reduction of individual variations in the mouse uterus microbiota, accompanied by a decrease in overall bacterial population density.

• 한국수정란이식학회지
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• 제24권3호
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• pp.189-197
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• 2009

Two-pore domain 칼륨($K_{2P}$) 통로는 흥분세포 및 비흥분세포의 안정막 전압을 일정하게 유지하는데 관여한다. 그러나 생식세포 및 생식기관에서 발현되는 $K_{2P}$ 통로의 분포영역 및 그 기능에 대해서는 연구자들에 의해 아직 정리되지 못하였다. 본 종설에서는 $K_{2P}$ 통로의 생식세포 및 생식기관에서 발현, 분포 및 생리학적 의의를 논하였다. $K_{2P}$ 통로는 인간 영양막세포, 자궁근층, 태반혈관계, 자궁평활근조직, 태반융모조직 및 임신자궁조직에서 발현되어 임신에 있어서 관련성을 제시되었다. 또한, $K_{2P}$ 통로는 마우스 전핵배, 원숭이 정자 및 한우의 난소, 정소, 난자, 정자 및 수정란에서 발현 변화를 보였다. 특히, $K_{2P}$ 통로는 체외배양 시 변화되는 온도, 산소분압과 같은 배양조건에 의해 조절되는 특징을 보임으로써 수정 및 배 발달에 영향을 줄 수 있는 인자로 제시되었다. 그리고 $K_{2P}$ 통로는 과산화수소에 의해 유도된 마우스 전핵배의 세포 사멸에 있어서 칼륨 이온의 유출에 관여함이 확인되었다. $K_{2P}$ 통로의 생식세포 및 생식기관 내 발현 형태와 생리학적 특징은 생식생리학에 있어서 이온 통로 관련 기능들을 이해하는데 도움이 될 것이다.

• Radiation Oncology Journal
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• 제6권2호
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• pp.169-176
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• 1988

1979년부터 1985년까지 서울대학교병원 치료방사선과에서 외부 방사선조사를 시행한 15명의 뇌하수체상부 배아세포종(전이송과선종) 환자에 대한 후향적 분석을 시행하였다. 생존자의 추적기간은 $30\~91$개월이었다. 10명의 환자는 방사선치료 전 조직학적으로 진단되었으며 나머지 5명은 조직학적 진단이 없이 방사선치료를 시행하였단 조직학적으로 진단된 9명중 배아세포종 환자 6명은 전뇌와 척추에 3명은 전뇌 조사를 시행하였다. 혼합 배아세포종 및 종양 marker양성인 5명의 환자 중 2명은 전뇌, 그리고 1명은 원발병소 부위에만 방사선치료를 시행하였다. 총 방사선량은 원발병소에 $5,000\~5,500 cGy$, 전뇌에 $3,000\~4,400 cGy$ 그리고 척추에 >$1,300\~3,000 cGy$였다. 상기 그룹 14명의 환자에서 원발병소는 완전 관해 되었으며 척추실패는 관찰되지 많았다. 조직학적 진만이 없고 marker의 상승이 없었던 한 환자에서 전뇌 방사선조사를 시행하였으나 원발병소의 완전관해 없이 척추 재발이 발생하였다. 방사선치료는 뇌하수체상부 배아세포종에 유효한 치료방법이며 신경 내분비학적 양상과 함께 조직학적 진단이 불가능한 경우에 있어서 소량의 방사선치료 후 관해정도 관찰은 이후의 치료방향설정에 유용한 수단으로 이용될 수 있다.

• Journal of Animal Science and Technology
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• 제55권5호
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• pp.417-425
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• 2013

동결 닭 PGCs의 생식계열 키메라를 이용한 생체에의 복원을 실용화 하기 위해서는, 닭 PGCs의 동결보존기술의 향상에 의해 동결 및 융해 후의 많은 생존세포를 확보 하는 것과, 생식계열 키메라의 제작효율을 높이는 것이 반드시 필요하다. 닭 PGCs는 배양 5.5일령의 닭 원시생식선으로부터 채취하고, ACS 방법에 의해서 순수 닭 PGCs를 분리했다. 닭 PGCs의 동결보존실험결과 다음의 4종류의 동결방법을 각각 비교 검토했다. 1. 플라스틱 스트로에 의한 완만동결법 (SF), 동결보호물질은 2M 에틸렌 글리콜 (EG), 2. 스트로에 의한 급속동결법 (RF), 8M EG + 7% PVP, 3. 동결용 Cryotube에 의한 SF, 2M EG, 4. 튜브에 의한 SF, 10% DMSO. 동결 및 융해 후의 PGCs의 생존율은 각각 76.4%, 70.6%, 80.5%, 78.1%로 관찰되었다.

• 한국패류학회지
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• 제26권1호
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• pp.51-62
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• 2010

The ultrastructures of germ cells and the accessory cells during spermatogenesis and mature sperm ultrastructure in male Gomphina veneriformis, which was collected on the coastal waters of Yangyang, East Sea of Korea, were investigated by transmission electron microscope observations. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves in that it contains a short midpiece with four mitochondria surrounding the centrioles. Accessory cells are observed to be connected to adjacent germ cells, they contain a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in the supplying of the nutrients for germ cell development, while any phenomena associated with phagocytosis of undischarged, residual sperms by lysosomes in the cytoplasm of the accessory cells after spawning was not observed in this study. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylindrical and modified long cone shape, respectively. In particular, the axial filaments in the lumen of the acrosome, and subacrosomal granular materials are observed in the subacrosomal space between the anterior nuclear fossa and the beginning part of axial filaments in the acrosome. The spermatozoon is approximately $50-55{\mu}m$ in length including a long sperm nucleus (about $7.80{\mu}m$ in length), an acrosome (about $1.13{\mu}m$ in length) and tail flagellum ($40-45{\mu}m$). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure. Some charateristics of sperm morphology of this species in the family Veneridae are (1) acrosomal morphology, (2) the number of mitochondria in the midpiece of the sperm,. The axial filament appears in the acrosome as one of characteristics seen in several species of the family Veneridae in the subclass heterodonta, unlikely the subclass pteriomorphia containing axial rod instead of the axial filament. As some characteristics of the acrosome structures, the peripheral parts of two basal rings show electron opaque part (region), while the apex part of the acrosome shows electron lucent part (region). These charateristics belong to the family Veneridae in the subclass heterodonta, unlikely a characteristic of the subclass pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosome structures. The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species in the family Veneridae.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.587-594
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• 2000

At present embryonic stem (ES) cells with confirmed pluripotential properties are only available in the mouse. Recently, we were able to isolate, culture and genetically transform primordial germ cell (PGC)-derived cells from pig embryos and demonstrate their ability to contribute to chimera development in the pig. In order to determine whether the system we developed could be used to isolate embryonic germ (EG) cells from other mammalian species, we placed isolated PGCs from cattle, goats, rabbits and rats in culture. Briefly, PGCs were isolated from fetuses of cow (day 30-50), goat (day 25), rabbit (day 15-18) and rat (day 11-12), and plated on STO feeder cells in Dulbecco's modified Eagle's medium (DMEM): Ham's F10 medium (1:1) supplemented with 0.01 mM nonessential amino acids, 2 mM L-glutamine, 0.1 mM $\beta$ - mercaptoethnol, soluble recombinant human stem cell factor (SCF; 40ng/ml), human basic fibroblast growth factor (bFGF; 20ng/ml) and human leukemia inhibitory factor (LIF; 20ng/ml). For maintenance of the cells, colonies were passed to fresh feeders every 7-10 days. In all species tested, we were able to obtain and maintain colonies with ES-like morphology. Their developmental potential was tested by alkaline phosphatase (AP) staining and in vitro differentiation assay. For genetic transformation, cells were electroporated with a construct containing the green fluorescent protein (GFP) under the control of the cytomegalovirus (CMV) promoter. GFP-expressing colonies were detected in cattle, rabbits and rats. These results suggest that PGC-derived cells from cattle, goats, rabbits and rats can be isolated, cultured, and genetically transformed, and provide the basis for analyzing their developmental potential and their possible use for the precise genetic modification of these species.

• 한국식품영양학회지
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• 제15권2호
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• pp.151-157
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• 2002

대두 배아로부터 saponin을 분리.정제하여 유리기 억제효과 및 동물의 암세포에 대한 세포 독성을 조사하였다. 유리기 억제활성에 대한결과를 보면 대두 배아 saponin을 0.5 및 1.0%씩 첨가한 급여 식에서 4주 동안 사육한 후 간장을 절취하여 간장 획분의 활성산소 및 항산화 관련 효소에 대하여 평가하였다. 간장의 mitochondria 및 microtome 획분의 hydroxy radical(.OH)의 생성에 미치는 영향에서 급여식에 사포닌을 첨가한 급여군에서 .OH기의 생성억제 효과를 나타내었다. 간장의 microsome 획 분에서도 0.5 및 1.0% 투여군에서 $H_2O$$_2$생성억제 효과가 인정되었다. 또한 간장의 cytosol획분에서 $O_2$.$^{-}$의 생성은 대조군에 비하여 현저한 억제 효과를 나타내었다. 대두 배아 사포닌의 세포독성을 P338 (mouse Iyoupoid neoplasm)과 L1210 (mouse leukemia) 세포주를 사용하여 실시한 결과 200 $\mu$g/mL 농도에서 높은 성장억제효과를 나타내었다. 그리고 처리 농도에 따른 대두배아 추출물이 P338과 L1210에 대한 성장 효과 실험에서도 200 $\mu$g/mL에서 은 성장억제 효과가 나타났으며 농도가 높을 수록 완전히 억제되는 것을 볼 수 있었다.

• 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.