• Toxicological Research
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• v.19 no.2
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• pp.83-90
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• 2003

Since histopathological examination was known to be the most sensitive evaluation for testicular toxicity, regulatory authorities have been published the guidelines on practical testicular assay approach. Those guidelines specified details of evaluation including fixation, embedding, stain-ing, histological examination and also seminiferous tubular staging methods. However, there have been confusing understanding among toxicologists and even pathologists on staging theory and its application on industrial testicular toxicity. Guidelines did not intend to conduct quantitative assay with staging but recommended the use of knowledge of staging. To count each tubular stage with statistical analysis is known to be time consuming and labor burdening work but the significance of toxicity has little value. It also has been pointed out that the application of staging theory for longer-term toxicity considered to be lacking of rationale. It could be recommended that qualitative assay with aware-ness of germ cell loss is more efficient method rather than quantitative counting of each tubular stage. Therefore it would be required that comprehensive understanding of testicular toxicity evaluation and the use of testicular staging method.

• Korean Journal of Environmental Biology
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• v.32 no.2
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• pp.153-158
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• 2014

In order to determine the testicular cycle of the Korean brown frog, Rana coreana, the gonadosomatic index (GSI) and the changes of germ cells in testis for adult males were investigated throughout the year. The study indicated that the spermatogenesis in the seminiferous tubule of testis began in August and became most active in the month of September, and the GSI was recorded the highest and the cross area of seminiferous tubule was the widest on this period. Furthermore the seminiferous tubules at the post spawning stage appeared in testis during February, and the spermatogenesis was quiescence period of time from March to July and the GSI and the cross area of seminiferous tubule were found to be the lowest. Based on these observations, we suggest that, GSI of male Korean brown frog changes significantly between July to August, indicating the testicular cycle with discontinuous spermatogenic process, and the breeding season was confirmed to be February.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.525-532
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• 2015

In order to determine the testicular cycle of the Asian toad, Bufo gargarizans, adult males of the species were captured around Jeongeup city (Jeollabuk-do, Korea) during March, 2012 to February, 2013 and the gonadosomatic index (GSI) and the changes of germ cells in their testes were investigated throughout the year. The study indicated that the spermatogenesis in the seminiferous tubule of testes began in April and became most active in July. The recorded GSI was the highest and the cross area of seminiferous tubule was the widest in this period. The seminiferous tubules at the post spawning stage appeared in February, the largest amounts occurred in March and primary spermatogonia also appeared in this period. The GSI and the cross area of seminiferous tubules were found to be the lowest in March, indicating a testicular cycle with potentially continuous spermatogenic process. According to the findings above, it is confirmed that testicular spermatogenesis takes place actively between April to July in male Asian toad and that their breeding season is February to March.

• Journal of Yeungnam Medical Science
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• v.38 no.1
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• pp.53-59
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• 2021

Background: There are no guidelines for the optimal incubation time or temperature to improve pregnancy outcomes in testicular sperm extraction-intracytoplasmic sperm injection (TESE-ICSI) cycles. We aimed to evaluate whether a 24-hour in vitro culture of testicular spermatozoa affects pregnancy outcomes in TESE-ICSI cycles. Methods: This was a retrospective study of 83 TESE-ICSI cycles using testicular spermatozoa in 46 couples with male partners suffering from nonobstructive or obstructive azoospermia. Sperm retrieval was performed either on the oocyte retrieval (OR) day (65 cycles in 33 couples; group A) or on the day before OR (18 cycles in 13 couples; group B) followed by in vitro culture for 24 hours. The clinical characteristics and pregnancy outcomes, including the number of retrieved oocytes, fertilization rates, embryo transfer rates, implantation and clinical pregnancy rates, were compared between the two groups. Results: There were no differences in terms of clinical characteristics except for the levels of luteinizing hormone (LH) in males. Group B had higher LH levels than group A (4.56±1.24 IU/L vs. 3.67±1.07 IU/L, p= 0.017). Group B showed higher fertilization rate (72.4%±32.1% vs. 59.2%±21.7%, p=0.045), implantation rate (35.0%±34.1% vs. 14.0%±21.5%, p=0.010), pregnancy rate per cycle (80% vs. 39%, p=0.033), and clinical pregnancy rate per cycle (80% vs. 37.5%, p=0.024) than those of group A. Conclusion: Testicular sperm retrieval performed on the day before OR followed by in vitro culture can potentially improve pregnancy outcomes.

• Journal of Aquaculture
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• v.14 no.2
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• pp.73-79
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• 2001

Testicular development of the male African lungfish, Protopterus annectens (Owen) was investigated histologically. The testis was found to be an elongated structure that possessed two distinct portions: an anterior spermatogenic part that was made up of a system of testicular tubules and a posterior vesicular part that invaded the kidney tissue. Spermatogenesis can be divided into five stages; primary spermatogonia, secondary spermatogonia, spermatocyte, spermatids and spermatozoa. Based on the gonadosomatic index (GSI) and histological changes observed, the reproductive cycle can be divided onto four distinct stages: resting and quiescent (December to February), growing (March to June) ripe and spent (July to August) and postspawning (September to November). The GSI was the maximum on July when reproductive cells were mature, ripe and ready for spawning; and the minimum in August after fish spawned.

• 대한생식의학회:학술대회논문집
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• 1999.11a
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• pp.73-74
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• 1999

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.171-177
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• 1998

The combination of testicular sperm extraction (TESE) with ICSI can achieve normal fertilization and pregnancy rate and is effective method in obstructive and non-obstructive azoospermic patients. But, when pregnancy was not occurred, repeated testicular biopsies are not evitable. Therefore, in this study, we observed the survival rate of testicular spemratozoa and spermatozoa extracted from the seminiferous tubules after cryopreserved-thawed used for next IVF cycle with ICSI. In a total of 23 cases, obstructive azoospermia was 17 cases and non-obstructive azoospermia was 6 cases. In obstructive azoospermia, after thawing, motile spermatozua was observed in 13 cases (76.5%). The fertilization rate with 2PN was 67.6% and 5 pregnancies (29.4%) were achieved. In non-obstructive azoospermia, motile spermatozoa was observed in 2 case (33.3%) after thawing. The fertilization rates with 2PN was 53.7% and 3 pregnancies (50.0%) were achieved. A comparison of the results of motile spermatozoa after thawed testicular spermatozoa and spermatozoa extracted from the thawed seminiferous tubule section were 3 cases (60.0%) and 12 cases (66.6%), respectively. The fertilization and pregnancy rates of thawed testicular spermatozoa and spermatozoa extracted from the thawed seminiferous tubule section were 69.4% and 20.0%, 62.5% and 38.8%, respectively. Conclusively, thawed testicular spermatozoa and spermatozoa extracted from the thawed seminiferous tubule section can achieve normal fertilization and pregnancy and cryopreservation of testicular spermatozoa and seminiferous tubule may avoid repetition of testicular biopsies in azoospermic patients in whom the only source of spermatozoa is the testis.

• 대한생식의학회:학술대회논문집
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• 2004.06a
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• pp.92.1-92.1
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• 2004

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.229-229
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• 2005

• Development and Reproduction
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• v.25 no.3
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• pp.145-155
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• 2021

Reproductive cycle of the blue-striped angelfish, Chaetodontoplus septentrionalis were histologically investigated. Fish were monthly collected in the coastal waters of Munseom, Seogwipo, Jeju-Island from February to December 2018. The gonadosomatic index (GSI) increased from May and maintained high values in August. The reproductive cycle of female fish can be classified by the characteristics observed during gonadal development as followed: growing stage (November to June), early mature stage (May to June), mature and spawning stage (June to September), and degenerative and recovery stage (September to December). In the male, testicular development period was similar to that of ovarian development period, but mature and spawning period was one month longer from June to October. Fecundity of mature female ranged from 4,601 to 22,840 and was correlated positively with total length and body weight. The histological analysis of gonadal development indicated that the C. septentrionalis was summer-spawning type and is considered a multiple spawner during spawning season.