• Clinical and Experimental Reproductive Medicine
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• v.32 no.1
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• pp.47-54
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• 2005

Objective: Evaluation of embryos using early cleavage to 2-cell stage has been proposed, but a critical time-point for selecting embryos is unclear. The aim of the present study is to provide a guideline including critical time-point in the selection of early cleaving embryo for the reduction of multiple pregnancies as well as the increase of pregnancy rate in human IVF. Methods: This prospective study was performed in 116 cycles from 85 patients who underwent conventional IVF or ICSI at the infertility clinic of Good Moonhwa Hospital from January 2002 to December 2003. Early cleavage (EC) of embryos to 2-cell stage was assessed at 25 h and 27 h postinsemination/microinjection. Embryos that had early cleaved at each time point were designated as EC-1 and EC-2, respectively, while others were designated as non-early cleavage (NEC). Results: At least one early cleavage embryo was observed in 54 (46.6%) for the EC-1 and 84 (72.4%) for the EC-2 of the 116 cycles assessed. Clinical pregnancy rates (PR) were significantly higher in the EC-1 group (66.7%) compared to the EC-2 group (53.6%) or the NEC group (31.2%) (p<0.05). Significant improvement of the pregnancy rate was found when at least two or more embryos were early cleaved at 25 h postinsemination or when the proportion of early cleavage embryo at 25 h postinsemination was higher than 20% (p<0.05). Conclusion: The critical time-point for the selection of early cleavage embryos with high implantation potential is more effective in 25 h postinsemination/microinjection compared to 27 h. The proportion as well as number of early cleavage embryos is also an important factor for the prediction of pregnancy outcome and the chance of multiple pregnancies. These results demonstrated that the evaluation of early cleavage embryos to 2-cell stage is an easy, simple, and objective method for the selection of good quality embryos suitable for embryo transfer.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3403-3408
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• 2012

The molecular mechanisms involved in the progression of clear cell renal cell carcinomas (ccRCCs) are still unclear. The aim of this study was to analyse the relationships between expression of RALYL and clinical characteristics. In 41 paired samples of ccRCCs and adjacent normal tissues, we used real-time qPCR to evaluate the expression of RALYL mRNA. RALYL protein levels were determined in 146 samples of ccRCC and 37 adjacent normal tissues by immunohistochemistry. Statistical analysis was used to explore the relationships between expression of RALYL and the clinical characteristics (gender, age, tumor size, T stage, N stage, M stage, survival times and survival outcome) in ccRCC. In addition, these patients were follow-up period 64 months (range: 4~116months) to investigate the influence on prognosis. We found significantly differences between ccRCC tissues and normal tissues (p<0.001, paired-sample t test) in mRNA levels of RALYL. Immunohistochemistry analyses in 146 ccRCC samples and 37 adjacent normal tissues showed significantly lower RALYL protein levels in ccRCC samples (${\chi}^2$-test, p<0.001), inversely correlating with tumour size (p=0.024), T stage (0.005), N stage (p<0.001) as well as M stage (p=0.019), but not age (p=0.357) and gender (p=0.348). Kaplan-Meier survival analysis demonstrated that people with lower level of RALYL expression had a poorer survival rate than those with a higher level of RALYL expression, significantly different by the log-rank test (p=0.011). Cox regression analysis indicated that RALYL expression (p=0.039), N stage (p=0.008) and distant metastasis (p<0.001) were independent prognosis factors for the overall survival of ccRCC patients. We demonstrated that the expression of RALYL was significantly low in ccRCC and correlated with a poor prognosis in a large number of clinical samples. Our findings showed that RALYL may be a potential therapeutic target as well as a poor prognostic factor.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.1
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• pp.55-61
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• 2009

Objective: To compare the clinical outcomes of ICSI with sperm retrieved from testicular tissue in patients with obstructive azoospermia (OA) or hypospermatogenesis (HS). Methods: From January 2003 through December 2006, 155 patients with OA (241 cycles) and 28 patients with HS (34 cycles) were included in this study. We compared clinical outcomes of ICSI with testicular sperm such as fertilization rate, implantation rate, clinical pregnancy rate and delivery rate. Data were statistically analyzed using t-test and ${\chi}^2$-test. Results: Testicular spermatozoa could not be retrieved in 1 out of the 21 cycles where fresh testicular sperm extraction in HS patients. Fertilization rate (FR) was significantly higher in OA than HS (75.6 % vs. 62.6%, p<0.001). Cleavage rate (CR) per fertilized zygote was also significantly higher in OA than that in HS (66.8% vs. 54.8% p<0.001). However, there were no significant differences in good embryo rate (GER), clinical pregnancy rate (CPR), implantation rate (IR) and delivery rate (DR). Conclusion: Our results show that testicular sperm of HS does not affect CPR, IR, and DR although it has shown reduced FR and CR.

• 대한생식의학회:학술대회논문집
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• 2005.11a
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• pp.123.1-123.1
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• 2005

• 대한생식의학회:학술대회논문집
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• 1997.11a
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• pp.65-66
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• 1997

• 대한생식의학회:학술대회논문집
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• 2007.11a
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• pp.140.1-140.1
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• 2007

• Journal of Radiation Protection and Research
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• v.20 no.3
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• pp.187-200
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• 1995

This paper reviews studies on potential health effects of electric and magnetic fields at extremely low frequencies(ELF). Recent studies focus on the epidemiological investigation of cancer, reproductive outcome and neurobehavioral effects due to residential and occupational exposure to ELF. Laboratory experiments are also carried out to find the possible mechanism of biological effects of ELF. Firm conclusion regarding whether ELF cause cancer are not yet conclusive but suggestive and other health effects of exposure to ELF have also been suggested but the evidence is even weaker than that related to cancer.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.79-85
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• 2012

Minipigs are regarded as one of the most important laboratory animal in that anatomical and physiological properties are similar to human and their reproduction efficiency is relatively higher compared to other large animal species. Particularly, several diseases that cannot be mimicked in rodent models are successfully occurred or induced in pig models therefore it has been interested in a valuable model for human diseases. Pigs are also 'standard' species in xenotransplantation research. To maximize experimental outcome using minipigs, establishment and management of proper animal facility, right animal husbandry and control of pathogens are very important. In this review, we summarized several international guidelines related with minipigs published by several companies or governments and discuss optimal conditions for providing informative ideas to the researchers who want to use minipigs in their future studies.

• 대한생식의학회:학술대회논문집
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• 2002.11a
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• pp.71-71
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• 2002

• 대한생식의학회:학술대회논문집
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• 1999.11a
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• pp.101-101
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• 1999