• Development and Reproduction
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• v.11 no.3
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• pp.219-226
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• 2007

This study was conducted to identify optimistic primordial germ cells'(PGCs) migration activity using heat activated busulfan treatment for the increasing germline chimerism. Donar PGCs viability tests of important conditions for useful germ line chimerism indicated approximately $70{\sim}80%$ viability was time dependent. Transplantation experiments of PGCs into recipient embryos after busulfun treatment, showed the treatment group having 23.5% viability. By comparison, the control group showed 4.8% viability. The 96 hour treatment group and the 118 hour treatment group of the cultured PGCs showed high migration activity. Generally, the transplantation method would consider morphological and physiological characteristics before transplantation. In the present study, the effect of busulfan on migration activity showed viability highest at 53.4% after 48-hour incubation time. However, a previous study showed the best condition for transplantation time to be prior to the 48-hour incubation period, when the chicken embryo does not yet have a developed blood vessel system. In conclusion, an important condition for the production of a transgenic chicken is that most donor PGCs migrate into the recipient embryo without any inhibitory factors. The present results suggest, perhaps by using this modified method of transplantation, it can produce a more efficient chimeric germ line, transgenic chicken.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.53-61
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• 2007

In case of missing tooth caused by dental caries or periodontal disease, it can be restored by various methods, and there has been much interest in implant and tooth transplantation. The success of tooth transplantation is going to be attained through the knowledge of growth, development and calcification of tooth. Tooth transplantation has been experimented in vivo and in vitro. Many animals such as rats, mice, cats and dogs are used for tooth transplantation experiment in vivo. In most experiments, tooth was transplanted into the extraoral site, but rare into the intraoral site In this study, to observe the capacity of formation and mineralization of tooth germ, first molar of a matured white rat was extracted and the cap stage tooth germ of a 13.5 Embryonic day embryo rat was transplanted into the extracted socket. The rats were killed 6 months later and the radiographical and histological results are as followings. 1. Tooth germ transplanted for 2 and 6 months are developing calcified tooth material such as dentin, cementum, pulp tissue, and epithelium around enamel space in the maxilla was seen. 2. The epithelium around enamel space was located beneath the oral epithelium and contained connective tissue and periodontal ligament. 3. Tooth formation was progressed as transplantation period but the size of newly formed tooth was small and the shape of tooth was incomplete.

• The Korean Journal of Malacology
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• v.31 no.1
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• pp.9-19
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• 2015

Germ cell development and cyclic changes in the epithelial cells of the seminal vesicle of the male rapa whelk, Rapana venosa, were investigated by cytological and histological observations. The process of germ cell development can be classified into five stages: (1) spermatogonial, (2) primary spermatocyte, (3) secodary spermatocyte, (4) spermatid, and (5) spermatozoon. In particular, four atypical cells (Type IA, IB, IIA and IIB cells) occur among normal germ cells in the acini during spermatogenesis. Presumably, the atypical cells, which have lysosome-like vacuoles or lysosome-like bodies in the cells, are involved in breakdown and absorption themselves in the acini. However, atypical cells were not found in the epithelial cells of the inner layer of the seminal vesicle. A considerable amount of spermatozoa are transported from the testis towards the the seminal vesicles until late July. The main coupulation period is between June and July. The process of the cyclical changes of the seminal vesicles can be classified into three phases: (1) resting, (2) accumulating, and (3) spent. Yellow granular bodies are involved in resorption or digestion of residual spermatozoa.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.1008-1018
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• 1996

Primary mediastinal nonseminomatous germ cell tumor is extremely rare. Apart from rarity and large size, mediastinal germ cell tumors show striking similarity to testicular tumors in age, incidence, and tumor type. The symptoms associated with these tumors are related mainly to size, invasion of neighboring structures, and distant metastases. Tissue diagnosis is obtained by biopsy of the primary lesion or by biopsy of metastatic sites. Tumors often present with advanced bulky disease, which are unresectable. So these tumors require an aggressive multidisciplinary approach to management. Optimal management includes aggressive surgical debulking and early use of cisplatin-bleomycin-based combination chemotherapy. Serial biomarker measurements permit early recognition of recwrence and improved timing of surgical intervention. The prognosis for mediastinal germ cell tumors is poor, not only because they are far advanced at the time of diagnosis but also because some of the tumors-such as embryonal carcinomas, choriocarcinomas, and endodermal sinus tumors-are very aggressive. In these cases, we present three young male patients with large mass on anterior mediastinum. Tissue diagnosis was obtained by primary lesion biopsy. All patients received surgical debulking and combination chemotherapy and experienced a brief response and eventually had relapses. We report these cases with a review of literatures.

• The Korean Journal of Malacology
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• v.26 no.3
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• pp.235-244
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• 2010

Ultrastructural characteristics of the testis and spermatogenesis of Crassostrea gigas were investigated by Transmission and Scanning Electron microscope observations. The testis is a diffuse organ consisting of branching acini containing differentiating germ cells in a variety of stages. The acinus is surrounded by an intermitent layer of myoepithelial cells andis divided into subcompartments that are partially separated by pleomorphic accessory cells which remain in close contact with germ cells until late stages of development. these accessory cells 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 could be find in the cytoplasm of the accessory cells. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves. Mature spermatozoa consist of broad, cap-shaped acrosomal vesicle, subacrosomal material (containing axial rod embedded in a granular matrix), a oval nucleus showing deeply invaginated anteriorly, two triplet substructure centrioles surrounded by four spherical mitochondria, and satelite fibres appear to the distal centriole and plasma membrane. Spermatozoa of C. gigas resemble to those of other investigated ostreids. In particular, the anterior region of the acrosomal vesicle is transversely banded. It is assumed that differences in this acrosomal substructure are associated with the inability of fertilization between the genus Crassostrea and other genus species in Ostreidae. Therefore, we can use sperm morphology in the resolution of taxonomic relationships within the Ostreidea. The spermatozoon is approximately $42-47{\mu}m$ in length including an oval sperm nucleus (about $0.91{\mu}m$ in length), an acrosome (about $0.42{\mu}m$ 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. These morphological charateristics of acrosomal vesicle belong to the family Ostreidae in the subclass Pteriomorphia.

• Food Engineering Progress
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• v.14 no.4
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• pp.292-298
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• 2010

Wheat germ contains the glycosylated forms of 2-methoxy-p-benzoquinone (2-MBQ) and 2,6-dimethoxy-p-benzoquinone (2,6-DMBQ), both of which have antimicrobial and immunostimulatory effects. Conversion of glycosylated 2-MBQ and 2,6-DMBQ to their more functional unglycosylated forms requires enzymatic action of $\beta$-glucosidase. We investigated the applications of lactic acid bacteria and yeast that produce $\beta$-glucosidase as starters for production of unglycosylated 2-MBQ and 2,6-DMBQ from wheat germ. Lactobacillus zeae and Pichia pijperi were selected through $\beta$-glucosidase enzyme assays for 37 yeast strains and five strains of lactic acid bacteria. Lb. zeae was more efficient than P. pijperi at producing 2-MBQ and 2,6-DMBQ from wheat germ. After 48 hr of fermentation with a mixed culture of Lb. zeae and P. pijperi, the concentration of 2-MBQ was 0.46${\pm}$0.07 mg/g, indicating an approximately 1.6-fold higher concentration than that obtained by pure culture of Lb. zeae. However, the concentration of 2,6-DMBQ was not significantly enhanced by fermentation with a mixed culture of Lb. zeae and P. pijperi.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.151-158
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• 2007

The possibility of inadvertent introduction of therapeutic gene expressing viral vectors has raised safety concerns about germ-line infection. Particularly, for indications such as prostate cancer and ovarian cancer, the proximity of the point of viral administration to organs of the reproductive system raises concerns regarding inadvertent germ-line transmission of genes carried by the virus vector. To evaluate the safety of in vivo adenovirus mediated gene transfer, we explored the biodistribution, persistance and potential germ-line transmission of p53-expressing adenovirus (Ad-CMV-p53). Both male and female Balb/c mice were injected with $1{\times}10^9$ PFU of Ad-CMV-p53. The PCR analysis showed that there were detectable vector sequences in liver, kidney, spleen, seminal vesicle, epididymis, prostate, ovary, and uterus. The RT-PCR analysis for detecting inserted gene, p53 showed that Ad-CMV-p53 viral RNA were present in spleen, prostate and ovary. Direct injected male and female mice of adenovirus vector into testis and ovary were mated and their of offspring were evaluated for germ-line transmission of the adenoviral vector. The PCR and RT-PCR analysis showed no evidence of germline transmission, although vector sequences were detected in DNA extracted from gonadal tissues. Real-time PCR result confirmed a significant decrease of adenovirus in gonad tissues 1 week after injection. We have also analysed the cell specific localization of viral DNA in gonad tissues by using in-situ PCR. Positive signals were detected in interstitial tissue but not in seminiferous tubule in sperm. In the case of ovary, adenovirus signal were localized to the stromal tissue, but no follicular signals were observed. Together, these data provide strong evidence that the risk of the Inadvertent germ-line transmission of vector sequences following intraperitoneal or direct injection into genito-urinary system of adenovirus is extremely low.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.10a
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• pp.11-13
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• 2001

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2001.05a
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• pp.9-11
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• 2001

• The Journal of the Korean dental association
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• v.4 no.1
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• pp.19-24
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• 1963