• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.282-283
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• 2000

The egg development of various fishes is studied by various methods including electron microscopy(Matsuyama et al, 1991) and hormone treatment(Schoonbee et al. 1980). In addition to attempt to induce final maturation and spawning, the present experiments were conducted to investigate the influence of hCG upon reproductive cycles in catfish(Silurus asotus) with developing gonads and to stimulate the reproductive system during the rapid phase of gonadal development. (omitted)

• 한국수산과학회지
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• 제42권1호
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• pp.48-55
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• 2009

The gonad maturation and spawning of blue crab, Portunus trituberculatus (Miers, 1876) using samples caught by trammer net in the western coast of Korea from January to December. The gonadosomatic index (GSI) showed the highest value of 15.0 in June and lowest value of 1.29 in August. Hepatosomatic index (HSI) showed the lowest in the spawning season from June to July. Thereafter, from August the value started to increase to 5.77 in December, showing an adverse trend against GSI. In the histological studies of the female reproductive organ, the gonad filled with primary oocytes from January to February and secondary oocytes in May. The female gonads mature from June, and mature and immature groups could be distinguished from December to February or March. In August, female developed another cycle of gonad development, showing new primary oocytes in the gonads again. Some of female crabs had receptaculum filled with already active sperm cells in it from March to May. In the time of August to September, almost all the females had the sperm sacs in the receptaculum. From the result, the coupling period estimated from August to September. Total RNA and DNA values of the crabs were highest in May (2.51, $0.57{\mu}g/mg$). The DNA value remained unchanged except for the value in May ($0.09-0.13{\mu}g/mg$). while RNA value was lowest in January ($1.08{\mu}g/mg$). The RAN/DNA ratio was the lowest (6.23%) in May and highest (18.05%) in July. The value of correlations coefficient between body weight and fecundity of the crabs was higher that of between carapace width and fecundity.

• 한국양식학회지
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• 제1권1호
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• pp.53-66
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• 1988

틸라피아는 암수간에 성장차가 커 수컷 종묘만을 생산하여 양식함은 산업적으로 매우 중요시된다. 본 연구는 나일틸라피아의 암컷을 수컷으로 성전환시키기 위한 연구로써 본 종의 초기생식소 분화 및 여러 농도의 호르몬 처리에 의한 성전환율을 구한 후 호르몬이 성장에 미치는 효과를 조사하여 다음과 같은 결과를 얻었다. 나일틸라피아의 초기 생식소는 원생식세포의 점진적인 분열에 의해 부화후 9일째 형성되었으며, 난소와 정소로의 성 분화는 부화후 약 20일부터 조직학적으로 식별되었다. 17$\alpha$-mrthyltestosterone (MT)을 15, 30 및 60ppm의 농도로 10$\~$40일 동안 처리한 후 성전환율을 조사한 결과 모든 실험군에서 $95\%$ 이상의 수컷이 생산되었다. 특히 15ppm-40일, 30ppm-30일과 30ppm-40일 처리군에서는 $100\%$ 수컷이 유도되었다. 호르몬 처리에 의한 성장의 증가는 대조군에 비해 비교적 뚜렷하게 나타났으며, condition factor 역시 크게 나타나 MT는 틸라피아의 성장을 증가시킴은 물론 비만하게 함을 알 수 있었다.

• Advances in Traditional Medicine
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• 제9권1호
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• pp.49-57
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• 2009

The antifertility activity of methanol extract of Cuscuta reflexa Roxb. stem (MECR) and Corchorus olitorius Linn. seed (MECO) were studied on male Swiss albino mice. The extracts were found to decrease sperm count, percentage of motile sperm and testosterone level in treated mice when compared with vehicle control after 17 days of treatment. The weight of gonads, epididymis were decreased whereas no significant changes of the body weight of mice were observed after methanol extract treatments. The fertility test showed 100% negative result in MECR and MECO treated mice at medium and high dose level of treatment. MECR and MECO in low (25 mg/kg and 15 mg/kg, respectively), medium (50 mg/kg and 20 mg/kg, respectively) and high (75 mg/kg and 25 mg/kg, respectively) dose level caused a simultaneous fall in testicular ${\Delta}5$-$3{\beta}$-hydroxy steroid dehydrogenase and glucose-6-phosphate dehydrogenase activities which are involved in testicular steroidogenesis. Total cholesterol and ascorbic acid content in testis were increased significantly in gonads. The activities of lactate dehydrogenase, malic dehydrogenase and ascorbic acid oxidase were reduced whereas that of carbonic anhydrase was increased significantly in the testis of MECR and MECO treated mice. All these observations indicate that the methanol extract of C. reflexa stem and C. olitorius seed produced antifertility activity in sexually matured male mice, which may be due to inhibition of gonadal steroidogenesis. This activity may be attributed due to the presence of flavonoids and steroids, respectively.

• 한국어류학회지
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• 제20권3호
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• pp.149-155
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• 2008

The effects of noise stress response on hematological parameters (hemoglobin, hematocrit and MCHC) and plasma parameters (cortisol, glucose and albumin) in Korean rockfish (Sebastes schlegeli), a very important commercial marine fish in Korea, were investigated. These parameters were analyzed on fish exposed to an explosion of noise. There were no significant differences or trends in hematological parameters (hematocrit; control $29.7{\pm}4.8%$, experiment 32.0 35.5%; hemoglobin; control $6.5{\pm}0.7g/dL$, experiment 6.2 7.8 g/dL; MCHC; control $19.6{\pm}0.6g/dL$, experiment 19.9~22.2 g/dL). However, plasma cortisol and glucose exhibited significant differences from start to finish and displayed the following patterns (cortisol; control $180.7{\pm}35.4ng/mL$, experiment 247.0 444.5 ng/mL; glucose; control $32.5{\pm}6.3mg/dL$, experiment 50.5 109.0 mg/dL). In addition, the glucocorticoid receptor (GR) mRNA expression and basal levels of various tissues (eye, gills, liver, intestine, skin and gonads) were investigated for the first time in this marine fish. When the Korean rockfish was exposed to explosive noise stress, the GR mRNA was expressed more in the gonads than in other tissues tested and was elevated significantly from two and four times in the liver and gills, respectively, after noise exposure.

• 한국양식학회지
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• 제19권2호
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• pp.133-139
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• 2006

The gossypol existed in cottonseed meal is a well known antispermatogenic agent which can impair reproductive performances of male fish as well as mammals. Two feeding experiments were conducted to examine a toxic effect of dietary supplementation of cottonseed meal on reproduction in juvenile olive flounder (the first experiment) for 19 weeks and growing olive flounder (the second experiment) for 26 weeks. After each feeding study, females and males were sampled for histological examination in gonads and liver to verify any negative effects by the dietary supplementation of cottonseed and soybean meal on reproduction. After two feeding trial, the gonad somatic index (GSI) of male and female (from the first feeding trial) were not significantly different among all the dietary treatments. The GSI values of female (from the second feeding trial) were not significantly different among all the dietary treatments. However, males fed cottonseed and soybean meal containing diets exhibited significantly lower GSI than that fed the control diet after the second feeding trial. Histological examination of gonads and liver of fish fed cottonseed and soybean meal did not show any negative effects compared to those of fish ffd the control diet. Hepatosomatic index of fish in the first and second feeding trials were not significantly different among all the dietary treatments. The findings in this study suggest that dietary supplementation of cottonseed and soybean meal up to 40% fish meal replacement might not deteriorate the gametogenesis of juvenile and growing olive flounder. However, the supplementation in diets over 30% fish meal replacement might reduce GSI of male in growing olive flounder.

• 한국수산과학회지
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• 제41권2호
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• pp.119-124
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• 2008

Reproductive ecology of the snow crab Chionoecetes opilio was investigated in terms of the reproductive organs, abdominal flap, fecundity, and maturity. Specimens were collected with gill nets and trawls from June 2002 to May 2003 in the eastern waters of Korea. The female and male C. opilio are distinguished only by the shape of the abdominal flap, which is triangular in males and circular in females. The gonads of female and male crabs are generally X-shaped. The male gonad is white, while the female gonad appears milk-white after spawning and then turns from light orange to dark orange with maturation. The female gonads matured from June, and mature and immature groups could be distinguished from December to February or March. Brooding eggs changed from bright orange to dark brown with formation of the compound eye immediately before hatching. Accordingly, the main spawning season is February and March. The minimum maturity carapace width of female crabs was 61.1 mm, and the mean fecundity is about 108,300 eggs.

• 한국임상수의학회지
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• 제29권5호
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• pp.422-426
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• 2012

3세령 코커 스파니엘 개가 질의 종괴를 평가하기 위해서 내원하였다. 이 종괴는 방사선 상에서 음경골이 있는 음핵이 확인 되었다. 생식선과 확장된 음핵의 제거를 보호자에게 추천하였다. 수술적으로 제거하는 동안 정관과 자궁 둘 다 관찰 되었으며, 난소가 있어야 할 곳에서 정소형태의 생식선이 관찰 되었다. 조직병리학적인 평가에서 정상적인 자궁과 고환과 부고환조직, 정관이 확인 되었다. 핵형분석에서는 정상적인 암컷의 염색체 (78, XX)를 보였고, PCR에서 Sry 가 나타나지 않았다. 이 결과들을 바탕으로 본 환축은 Sry-negative XX 성전환으로 진단되었다.

• Fisheries and Aquatic Sciences
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• 제21권11호
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• pp.34.1-34.13
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• 2018

Sexual maturity ($L_{50}$), the length at which 50% of fish in a size class are mature, is a key aspect of domestication of new fish species because it guides the procedure for identification of appropriate broodstock size for artificial spawning. In this study, the $L_{50}$ was determined for 1083 Barbus altianalis samples obtained from Lake Edward and the Upper Victoria Nile. Gonads of freshly killed samples were examined macroscopically and verified with standard histological procedures for the maturation stages that were used to determine $L_{50}$. Oocytes and spermatogenic cell sizes were compared for fish obtained from both water bodies. Results indicated that there were no variations in macro gonad features observed for fish from Lake Edward and Upper Victoria Nile. Similarly, there were no significant differences in oocyte sizes (P > 0.05) between the two populations but significant differences in spermatogenic cell sizes were noted (P < 0.05) except for spermatozoa (P > 0.05). This however did not suggest peculiar differences between the two populations for staging the gonads. Consequently, no staging variations were suggested for both populations in determination of $L_{50}$. Sexual maturity was found in the same class size of fork length (FL) 20-24.9 cm and 35-39.9 cm for males and females from both water bodies, respectively. At this FL, however, males were too small, and for good selection of vigor broodstocks for spawning and conservation purposes, they are better picked from class size of 30-34.9 cm FL and above. These findings were crucial for integration of appropriate breeding size in spawning protocol by farmers and fisheries scientists conserving wild B. altianalis populations.

• 한국방사선학회논문지
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• 제14권7호
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• pp.931-936
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• 2020

본 연구는 자동노출선량장치을 사용했을 때 생식선 차폐체의 유무와 크기 변화에 따른 소아 환자의 방사선 피폭선량과 화질의 변화를 관찰하기 위하여 수행되었다. X-ray 장비를 이용하여 소아 팬텀의 복부와 생식선에서 차폐체가 없을 때와 3가지 크기의 차폐체를 사용했을 때의 방사선 피폭선량을 측정하였으며, 얻어진 영상을 통하여 SNR과 CNR을 측정하였다. 연구 결과 방사선 차폐체의 크기에 비례하여 생식선의 방사선 피폭선량은 감소하였으나 복부의 방사선 피폭선량은 오히려 증가되는 것으로 나타났으며 화질의 변화는 나타나지 않았다. AEC System 사용으로 인하여 방사선 차폐체로 인하여 증가된 방사선으로 인하여과 피폭되지 않도록 소아 환자의 연령과 몸무게, 신체 크기에 최적화된 크기의 차폐체를 사용하는 것이 효과적이라는 것을 확인할 수 있었다.