• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6469-6475
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• 2015

Background: Diffusion-weighted magnetic resonance imaging (DWI) makes it possible to detect malignant tumors based on the diffusion of water molecules. It is uncertain whether DWI is more useful than positron emission tomography-computed tomography (PET-CT) for distinguishing benign from malignant mediastinal tumors and mass lesions. Materials and Methods: Sixteen malignant mediastinal tumors (thymomas 7, thymic cancers 3, malignant lymphomas 3, malignant germ cell tumors 2, and thymic carcinoid 1) and 12 benign mediastinal tumors or mass lesions were assessed in this study. DWI and PET-CT were performed before biopsy or surgery. Results: The apparent diffusion coefficient (ADC) value ($1.51{\pm}0.46{\times}10^{-3}mm^2/sec$) of malignant mediastinal tumors was significantly lower than that ($2.96{\pm}0.86{\times}10^{-3}mm^2/sec$) of benign mediastinal tumors and mass lesions (P<0.0001). Maximum standardized uptake value (SUVmax) ($11.30{\pm}11.22$) of malignant mediastinal tumors was significantly higher than that ($2.53{\pm}3.92$) of benign mediastinal tumors and mass lesions (P=0.0159). Using the optimal cutoff value (OCV) $2.21{\times}10^{-3}mm^2/sec$ for ADC and 2.93 for SUVmax, the sensitivity (100%) by DWI was not significantly higher than that (93.8%) by PET-CT for malignant mediastinal tumors. The specificity (83.3%) by DWI was not significantly higher than that (66.7%) for benign mediastinal tumors and mass lesions. The accuracy (92.9%) by DWI was not significantly higher than that (82.1%) by PET-CT for mediastinal tumors and mass lesions. Conclusions: There was no significant difference between diagnostic capability of DWI and that of PET-CT for distinguishing mediastinal tumors and mass lesions. DWI is useful in distinguishing benign from malignant mediastinal tumors and mass lesions.

• Development and Reproduction
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• v.2 no.1
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• pp.101-109
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• 1998

Spermatogenesis and reproductive cycle of the razor clam, solen grandis, were investigated monthly by histological and cytological observations. Samples were collected from natural intertidal population at Oshik-do, Kunsan, Korea, for one year, beginning from January to December, 1993. solen grandis is dioecious. Morphological structures of the spermatozoon of this species ar esimilar to those of other bivalve spermatozoa having a primitive type; i.e., a small head, a cap-shaped acrosome and a short mid-piece with four mitochondria surrounding axial filament. The head of spermatozoon is approximately 2 \mu m in length and sperm tail is about 20 \mu m long. The axoneme of tail flagellum consists of nine pairs of peripheral microtubules at the periphery and a pair of central microtubules at the center. Four spherical mitochondria form the paranucleus. Spawning occures once a year between early June and July, and the main spawning was observed in July when seawater temperature reaches above 20 \circ C. The reproductive cycle of male razor clam can be divieded into fivesuccessive stages; early active (December to january), late active (January to march), mature (March to early August), partially spawned (June to July), and spent/inactive stage (August to December).

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1566-1577
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• 2010

Nandrolone, 19-nortestosterone, is a synthetic androgenic-anabolic steroid promoting muscle growth. Nandrolone is also present in pig meat and sera at non-negligible levels. A number of scientific reports have suggested a positive relationship between incidence of infertility and increased meat consumption in humans. The present study was designed to determine out the effect of feeding nandrolone on the testis of the male reproductive tract. Mixtures of food and nandrolone at different concentrations (0.005 ppm and 0.5 ppm) were supplied to pubertal male rats for 6 weeks. Body weight was recorded every week during the entire experimental period. At the end of the treatment, the testis, epididymis, and epididymal fat were collected and weighted. Sperm numbers in the caudal epididymis were counted. Differential gene or protein expression of steroidogenic enzymes in the testes among experimental groups was determined by semi-quantitative real-time PCR or western blotting analysis, respectively. Histological changes of the testis induced by nandrolone treatment were examined by hematoxylin and eosin staining. Immunohistochemical analysis was employed to detect changes in the localization of steroidogenic enzymes in the testes among experimental animals. There were no significant changes on body, testis, epididymis, and epididymal fat weights among experimental groups. A significant increase of caudal sperm number was found in the 0.5 ppm nandrolone-treated group. Histological examination of the testes noted a high frequency of germ cell sloughing in seminiferous tubules of 0.5 ppm nandrolone-treated rats. Even though transcript levels of $3{\beta}$-hydroxysteroid dehydrogenase (HSD) I, $17{\beta}$-HSD4, and $17{\alpha}$-hydroxylase were influenced by nandrolone treatments, protein levels of all molecules examined in the present study were not significantly affected. Immunohistochemical analysis showed no visible changes in the localization of steroidogenic enzymes in the testes among experimental groups. The current study showed that oral intake of nandrolone in male rats for 6 weeks did not cause significant damage to the testis. It is considered that a feeding effect of nandrolone on male fertility would not be remarkable.

• Development and Reproduction
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• v.20 no.4
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• pp.289-296
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• 2016

This report describes the sex differentiation of the Korean rose bitterling, Rhodeus uyekii, from hatching to 170 days post-hatch (DPH) in relation to total length (TL), body weight (BW), and integral water temperature (IWT). The growth curve of TL from just hatching to 83 DPH was $5.144e^{0.045t}$ ($R^2=0.961$; t, time), and that of BW was $2.398e^{0.086t}$ ($R^2=0.725$). Primordial germ cells (PGCs) were observed at 17 DPH (7.9 mm TL, 3.74 mg BW, $374^{\circ}C$ IWT), and thereafter began to protrude into the peritoneal cavity. At 21 DPH ($9.2{\pm}0.14mm$ TL, $4.8{\pm}0.07mg$ BW, $462^{\circ}C$ IWT), some PGCs contained condensed chromatin and oocyte were observed in meiotic prophase. In contrast to the ovaries, which grew gradually after sexual differentiation, testes began multiplying at 25 DPH (10.1 mm TL, 5.42 mg BW, $550^{\circ}C$ IWT), when testicular differentiation was first identified, and multiplied continuously thereafter. At 33 DPH (11.2 mm TL, 10.5 mg BW, $726^{\circ}C$ IWT), the developing testes contained spermatogonia that exhibited mitotic activity. No spermatocyte or sperm cell was observed until 83 DPH (18.9 TL, 48.2 mg BW, $1,826^{\circ}C$ IWT). At 170 DPH (32.5 mm TL, 270.1 mg BW, $3,740^{\circ}C$ IWT), which was the end point of this study, the mature ovaries showed germinal vesicle breakdown, while the mature testes contained observable spermatocytes and sperm cells. These results allow us to identify the sex differentiation type of the Korean rose bitterling as differentiated gonochoristic.

• Korean Journal of Environmental Biology
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• v.30 no.2
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• pp.128-135
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• 2012

The individual toxicity of lead (Pb) and zinc (Zn) has been investigated by using the sea urchin (Hemicentrotus pulcherrimus) germ cell and pluteus-larvae. The gametotoxic and embryotoxic effects of Pb and Zn on H. pulcherrimus were each investigated at 31, 63, 125, 250, 500 ppb and 16, 31, 63, 125, 250 ppb, respectively. Spawning was induced by 0.5 M KCl solution and the fertilization and normal embryogenesis rates test were performed for 10 min and 64 h after fertilization, respectively. In exposure to Pb, the fertilization rate was not significantly changed compared with control but normal embryogenesis rate was significantly decreased with concentration dependent manner. Fertilization and normal embryogenesis rates showed a significant decreased with concentration dependent manner in exposed to Zn. The normal embryogenesis rates were significantly inhibited in exposed to Pb ($EC_{50}$=45.13 ppb, 95% Cl=40.12~50.05 ppb) and Zn ($EC_{50}$=19.82 ppb, 95% Cl=18.26~21.31 ppb). In exposure to Pb and Zn, the NOEC of normal embryogenesis rate was <31.25 and <15.63 ppb, respectively. The LOEC showed each 31.25 and 15.63 ppb in exposed to Pb and Zn. These results suggest that the early embryo development of H. pulcherrimus is highly sensitive to heavy metals such as Pb and Zn, H. pulcherrimus can be used as a test organism for risk assessment in marine ecosystems.

• Journal of Embryo Transfer
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• v.18 no.2
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• pp.143-149
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• 2003

This study was carried out to cryopreserve and to investigate characteristics of semen in Hanwoo. Semen was obtained from bulls selected by Daekwanryeong Branch station. Semen was collected each morning of the experiment, placed in water jacketed tubes at 37$^{\circ}C$, and trans-ported to the research laboratory within 10 minutes. Semen was extended with Egg yolk-glycerol extender to contain 50${\times}$10$^{6}$ sperm/ml. Semen was cooled over a 6h period in water jacketed tubes from about 25 to 5$^{\circ}C$, Egg yolk-glycerol extender was added in one step at 5$^{\circ}C$. Semen was aspirated into 0.5ml straws, which were sealed with powder. Egg yolk-glycerol extender, which is used in Hanwoo sperm frozen and stored, semen from 13 Hanwoo bulls collected, the postthawed percentages of motile sperm were 65.7%. In semen characteristics of Hanwoo bulls, number of bulls volume are 5.7 ml and total cell count are 975${\times}$10$^{6}$ m1 ejaculate.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.632-638
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• 1996

A retrospective analysis of primary mediastinal tumors and cysts was performed on 42 patients who underwent surgical resection at our institution from january, 1985 to December, 1995. The patients consisted of 27 males and 15 females. The mean age was 40 years with a range of 10 month to 76 years. The patients were composed of thymlc tumor 12 cases (28.6 %), germ cell tumor 8 cases (19.0 %), primary cyst 7 cases (16.7 %), neurogenic tumor 6 cases (14.3 %) and other miscellanious tumor 9 cases. Overall, 3) (78.6 %) of the tumors were histologically benign, and 9 (21.4 %) were malig- nant. The noted clinical manifestations were respiratory symptoms such as chest pain, dyspnea and coughing. All of the patients with malignancy and 55 oyo of the patients with benign tumor were symptomatic on presentation. All of the patients were operated for tis ue diagnosis and curative resection. All the benign tumors ex- cept two cases of sarcoidosis were performed adequate curative resection. A few patients with malignant unresectable tumors were treated with chemotherapy or radiotherapy There were 7 (18 %) postoperative complications without mortality. In conclusion, Mediastinal tumors have long fascinated the thoracic surgeon because of their variety and unpredictability of diagnosis prior to exploration. We consider that active surgery and various combined modality can be accomplished with satisfactory result.

• Journal of Aquaculture
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• v.20 no.1
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• pp.47-50
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• 2007

The primordial germ cells of the oblong rockfish, Sebastes oblongus were buried under fibrous mesenchymal tissues between gut and mesonephric duct of pre-larva with 4.0 mm total length (TL) at 1 day after the parturition. In the juvenile of 22.0 mm TL at 71 days after the parturition, the gonad composed of a large number of gonial cell and formed of cavity along the lateral side of the gonad, differentiated to the ovary. At this time, the gonad formed seminiferous tubules by somatic cells, was differentiated to the testis. The smallest oblong rockfish that possessed primary oocytes was about 42.1 mm TL at 141 days. Spermatogonia remained quiescent until most fish were over 42.1 mm TL at 141 days. The oblong rockfish the differentiated directly into male or female without an intermediate female phase at the early indifferentiated stage. Therefore, the oblong rockfish belongs to the differentiated type of gonochoristic teleosts.

• Journal of Aquaculture
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• v.10 no.2
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• pp.179-187
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• 1997

Early development growth and sexual phenomena of the hybrid between male spotted flounder (Verasper variegatus) and female olive flounder (Paralichthys olivaceus) were investigated. The hybrid produced was newly called the "Bumnupchi" in Korean name, "Mottled flounder" in English name. Fertilization rate, hatching rate and early survival rate of the mottled flounder were 56.9~72.3%, 86.7~92.5% and 89.1~96.0%, respectively. At 50th day and 240th day after hatching, they were 2.1$\pm0.2cm\;and\;22.9\pm2.1cm\;in\;total\;length, \;0.10\pm0.002g\;and\;179.0\pm38.5g$ in body weight, respectively. Eye position of the mottled flounder was mixed with both dextral (77.7%) and sinistral type (22.3%). Gonads were differentiated into ovarian type and testis type at 80th day after hatching, and its ratio was 1:1 (P>0.05). Most Gonads seemed to be sterile without having germ cell, whereas only 3.6% of investigated indiciduals turned out to have oocytes in the gonad. When the induction of sex reversal were attempted by daily oral administration of $17\beta$-methyltestosterone (0.5mg/kg fish) andestradiol-17$17\beta$(0.5mg/kg fish)from 40th to 100th day after hatching, both testis and ovary type were induced 81.9% and 87.7% of each hormone-treated fish, respectively.fish, respectively.

• Applied Microscopy
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• v.32 no.2
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• pp.163-170
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• 2002

Experimatal maxillary sinusitis was induced in New Zealand white rabbits by blocking the maxillary sinus ostium. The distribution of lectin receptors was explored in the mucosa with induced maxillary sinusitis using colloidal gold label complex with lectin WGA purified from wheat germ (Triticum vulgaris). The lectin WGA gold complex, shown to recognize GlcNac (N-acetylglucosamine) and NeuNAc (N-acetylneuraminic acid) regions, was applied to detect binding sites in Lowicryl HM 20 sections and viewed under the electron microscope. An increased height of the cylindric cells, ciliary loss and hyperplasia of the secretory cells were observed. Examination of normal sinus mucosa labeled with gold-labeled lectins showed the distribution of sialoglycoconjugates to be mainly in the ciliary layer and the granules in the secretory cells. Inflamed mucosa had increased labeling intensity of gold-labeled WGA in the cilia and the secretory granules. These results indicate that lectin WGA receptors are located in the cilia and secretory granules. Specific changes in the lectin binding pattern were apparent in the inflamed mucosa in the experimentally induced acute sinusitis, in comparison with normal mucosa, conceivably as a part of host defense reactions.