• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.118.1-118.1
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• 2003

A growing body of scientific research indicates that man-made chemicals (xenobiotics) may interfere with the normal functioning of endocrine, or hormone systems. These endocrine disruptors may cause a variety of problems with development, behavior, and reproduction. Amongst the xenobiotics the World Health Organization classed 2, 3, 7, 8-TCDD as a "known" human carcinogen. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• 제26권3호
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• pp.303-308
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• 2013

Subfertility problems are encountered frequently in the cattle and buffalo bulls commercially maintained for semen production in dairy farms and under field conditions for natural insemination. Reports are scarce on the incidence of subfertility in breeding bulls, especially in India. The objective of the present study was to assess the incidence of the male reproductive anomalies leading to disposal of bovine bulls at GADVASU dairy farm, Ludhiana, Punjab (India). Data on frequency of various subfertility and disposal pattern of bulls maintained at the dairy farm, GADVASU, were collected for 12 yrs (1999 to 2010) and compiled from different record registers. Percentage of bulls that produced freezable semen (out of reserved ones) was less in cattle (25.641%) as compared to that of buffalo (30.4%). Various subfertility traits like poor libido and unacceptable seminal profile were found to be the significant reasons (p<0.01) for culling of the breeding bulls. Inadequate sex drive and poor semen quality were the main contributing factors for bull disposal in cattle whereas poor semen freezability was most frequently observed in buffalo bulls. All the male reproductive traits were significantly different (p<0.05) for the periods of birth, except for semen volume, initial motility (IM), age at last semen collection (ALSC) and age at disposal. The ages at first and last semen collection as well as freezing (i.e. AFSC, ALSC and AFSF, ALSF, respectively) and age at disposal (AD) were higher in buffalo. The spermatological parameters and semen production period (SPP) were higher in cattle. The age at first semen donation and breeding period could be reduced by introducing the bulls to training at an early age. The results revealed an increasing trend in individual motility (IM) while semen volume, AFSC, AFSF, AD, FSPP, SPP, ALSC and ALSF showed a decreasing, however, not a definite trend, over the periods. The semen donation traits like, AFSF, of the cattle and buffalo bulls could be predicted from the AFSC, using prediction equation derived in the present study.

• 한국동물생명공학회지
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• 제37권4호
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• pp.292-297
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• 2022

Direct injection of CRISPR/Cas9 into zygotes enables the production of genetically modified nonhuman primates (NHPs) essential for modeling specific human diseases, such as Usher syndrome, and for developing novel therapeutic strategies. Usher syndrome is a rare genetic disease that causes loss of hearing, retinal degeneration, and problems with balance, and is attributed to a mutation in MYO7A, a gene that encodes an uncommon myosin motor protein expressed in the inner ear and retinal photoreceptors. To produce an Usher syndrome type 1B (USH1B) rhesus macaque model, we disrupted the MYO7A gene in developing zygotes. Identification of appropriately edited MYO7A embryos for knockout embryo transfer requires sequence analysis of material recovered from a trophectoderm (TE) cell biopsy. However, the TE biopsy procedure is labor intensive and could adversely impact embryo development. Recent studies have reported using cell-free DNA (cfDNA) from embryo culture media to detect aneuploid embryos in human in vitro fertilization (IVF) clinics. The cfDNA is released from the embryo during cell division or cell death, suggesting that cfDNA may be a viable resource for sequence analysis. Moreover, cfDNA collection is not invasive to the embryo and does not require special tools or expertise. We hypothesized that selection of appropriate edited embryos could be performed by analyzing cfDNA for MYO7A editing in embryo culture medium, and that this method would be advantageous for the subsequent generation of genetically modified NHPs. The purpose of this experiment is to determine whether cfDNA can be used to identify the target gene mutation of CRISPR/Cas9 injected embryos. In this study, we were able to obtain and utilize cfDNA to confirm the mutagenesis of MYO7A, but the method will require further optimization to obtain better accuracy before it can replace the TE biopsy approach.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.1071-1086
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• 2003

Reproductive biotechnologies continue to be developed for genetic improvement of both river and swamp buffalo. Although artificial insemination using frozen semen emerged some decades back, there are still considerable limitations. The major problem appears to be the lack of efficient methods for estrus detection and timely insemination. Controlled breeding experiments in the buffalo had been limited and similar to those applied in cattle. Studies on multiple ovulation and embryo transfer are essentially a replica of those in cattle, however with inherent problems such as lower number of primordial follicles on the buffalo ovary, poor fertility and seasonality of reproduction, lower population of antral follicles at all stages of the estrous cycle, poor endocrine status and a high incidence of deep atresia in ovarian follicles, the response in terms of transferable embryo recovery has remained low with 0.51 to 3.0 per donor and pregnancy rates between 15 to 30%. In vitro production of buffalo embryos is a valid alternative to recovery of embryos by superovulation. This aspect received considerable attention during the past decade, however the proportion of embryos that develops to the blastocyst stage is still around 25-30% and hence the in vitro culture procedures need substantial improvement. Embryo cryopreservation procedures for direct transfer post thaw need to be developed for bubaline embryos. Nuclear transfer and embryo cloning is a technique that has received attention in various species during recent years and can be of immense value in buffaloes as they have a low rate of embryo recoveries by both in vitro and in vivo procedures. Gender pre-selection, genome analysis, gene mapping and gene transfer are a few of the techniques that have been studied to a limited extent during recent years and are likely to be included in future studies on buffaloes. Very recently, reproductive biotechnologies have been applied to feral buffaloes as well, but the results obtained so far are modest. When fully exploited they can play an important role in the preservation of endangered species.

• 대한수의학회지
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• 제43권1호
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• pp.129-137
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• 2003

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failures in sows and respiratory problems in piglets. The nucleocapsid(N) protein, encoded by the open reading frame 7 (ORF7) gene, is known to be the most abundant and antigenic protein in PRRS virus. Therefore, it was suggested that the N protein could be a suitable candidate for the detection of PRRS virus-specific antibodies and diagnosis of PRRS. In the present study, the ORF7 gene encoding the N protein was cloned and expressed as a fusion protein with the glutathione S-transferase (GST) in Escherichia coli. The resulting GST-N recombinant protein was used as an antigen for an indirect sandwich enzyme-linked immunosorbent assay (i-ELISA). Expressed GST-N recombinant protein was migrated at 41 kDa and reacted with ORF7-specific monoclonal antibody by Western blotting. In order to increase the specificity of the ELISA for the detection of PRRS virus-specific antibodes, an i-ELISA was developed using an anti-GST antibody as a capture antibody. The sensitivity and specificity of developed i-ELISA were 92% and 96%, respectively. Based on these results, it was suggested that the i-ELISA is a simple and rapid test for screening a large number of swine sera for the anti-PRRS virus antibodies.

• Asian-Australasian Journal of Animal Sciences
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• 제28권3호
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• pp.451-455
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• 2015

The buffalo is an important livestock resource in several countries of South Asia and the Mediterranean regions. However, reproductive efficiency is compromised due to known problems of biological and management origins, such as lack of animal selection and poor nutrition. Under optimal conditions puberty is attained at 15 to 18 months in river buffalo, 21 to 24 months in swamp buffalo and is influenced by genotype, nutrition, management and climate. However, under field conditions these values deteriorate up to a significant extant. To improve reproductive efficiency, several protocols of oestrus and ovulation synchronization have been adopted from their use in commercial cattle production. These protocols yield encouraging pregnancy rates of (30% to 50%), which are comparable to those achieved in buffaloes bred at natural oestrus. The use of sexed semen in buffalo heifers also showed promising pregnancy rates (50%) when compared with conventional non-sexed semen. Assisted reproductive technologies have been transferred and adapted to buffalo but the efficiency of these technologies are low. However, these latest technologies offer the opportunity to accelerate the genetic gain in the buffalo industry after improving the technology and reducing its cost. Most buffaloes are kept under the small holder farming system in developing countries. Hence, future research should focus on simple, adoptable and impact-oriented approaches which identify the factors determining low fertility and oestrus behaviour in this species. Furthermore, role of kisspeptin needs to be explored in buffalo.

• Reproductive and Developmental Biology
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• 제41권1호
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• pp.17-23
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• 2017

The oocyte undergoes various events during in vitro maturation (IVM) and subsequence development. One of the events is production of reactive oxygen species (ROS) that is a normal process of cell metabolism. But imbalances between ROS production and antioxidant systems induce oxidative stress that negatively affect to mammalian reproductive process. In vitro environments, in vitro matured oocytes have many problems, such as excessive production of ROS and imperfect cytoplasmic maturation. Therefore, in vitro matured oocytes still have lower maturation rates and developmental competence than in vivo matured oocytes. In order to improve the IVM and in vitro culture (IVC) system, antioxidants, vitamins were added to the IVM, IVC medium. Antioxidant supplementation was effective in controlling the production of ROS and it continues to be explored as a potential strategy to overcome mammalian reproductive disorders. Based on these studies, we expect that the use of antioxidants in porcine oocytes could improved maturation and development rates.

• Clinical and Experimental Reproductive Medicine
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• 제13권2호
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• pp.95-100
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• 1986

During the past decade great advance has been made in contraceptive technology. The development and subsequent modification of oral steroid contraceptive together with the improved design of other contraceptives have tremendously altered the contraceptive practise of complete throughout the world. At the present time one of most complex issue is the population explosion. In Korea the population growth rate is remarkably decreased from 3% in 1960s to 1.7% in 1984. Increasing proportion of women practising family planning and improved contraceptive methods have contributed on remarkable reduction of fertility rate. But still about half of married women not involved in family planning practise. One of the reasons why that so many women haven't participated in family planning should be undesirable side effects or inconvenience of currently available contraceptives. So we need more research to develop newer, safer and more effective contraceptive to solve the problems. According to recent report on the family planning program achievement in Korea, sterilization (male and female) is most popular, leading contraceptive method (330 cases/1000 fertile persons) and the I.U.D. (167.5/1000), condom (132.9/1000) and oral pill (61.1/1000) were followed by in the order of favorite choice of contraceptive (KIPH, Family planning evaluation report, 1984; KIPH Family plan Service Statistics, 1981-1984). In present paper the present status and knowledge of contraceptives will be summarized.

• 지역사회간호학회지
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• 제11권1호
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• pp.127-145
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• 2000

The objectives of this study are to identify health behaviors and health problems. and the relations between health behaviors and health problems of female workers in the retail business. The number of subjects were 200 female workers of 6 department stores in Seoul and Kyonggi area, whose jobs last more than 6 months as retail employees. The data was collected during 2 months from July 1 to August 30, 1998. The Cornell Medical Index Health Questionnaire(CMI) was used to measure their health problems, while health behaViorn were investigated in terms of 'smoking', 'alcohol', exercise', 'diet', and 'sleeping'. The data were analyzed with frequency. percentage, t-test, ANOVA test, and $X^2-test$ by SPSS PC+ program. The results of this study are as follows: 1. Out of health problems. Digestive symptoms occupied the highest percent number. nervous ones the second and cardiovascular ones the third among physical health problems of retail female workers. The most frequent mental health problem was 'adequacy' and the next, 'tension' and 'anger', 2, Health problems according to general characteristics of subjects were shown that the younger or the unmarried complained more than the older or the married, especially in the items of 'eye and ear', 'respiratory system', 'cardiovascular system', 'digestive tract', 'nervous system', 'adequacy', and 'depression'. The longer working duration they have had, the more they complained of 'respiratory system' and 'adequacy'. The lower academic careers complained of 'nervous' than the higher ones with statistical significance. 3. The analysis of daily health clinic notes showed that respiratory complaints were the highest percent, successively followed by digestive tract, nervous one, external injury, musculoskeletal system, urinary-reproductive system and others. 4. The level of their health practice was generally low in smoking, diet habit and alcohol intake, exercise, sleeping, very low especially in smoking, diet, alcohol intake, and exercise among them all. 5. Present smokers and ones with past experience complained of physical and mental health problems of 'respiratory system', 'digestive tract', 'skin', 'nervous', 'urinary-reproductive system', 'fatigability', adequacy', 'depression', 'anxiety', 'anger' and 'tension', than non smokers, with statistical difference. Workers without having breakfast and with irregular diet had more complaints on 'digestive tract', 'adequacy' and 'tension', than those who had regular dietary habit. The less the subjects slept, the more they complained of eye and ear, cardiovascular system. The subjects who drank alcohol complained more digestive problem. However, whether they exercise or not did not affect physical and mental health problems in a significant manner. 6. The subjects' age and marital status were statistically significant relating to health behaviors, as the younger or unmarried recorded a low level of health practice in smoking, drinking, dietary habit. Based on the results, the suggestions are made as follows: 1. Health education program on smoking, alcohol intake, diet habit is needed to improve health problems and health behavior of female retail workers. 2. The unmarried workers of late teen and twenties, who are transitional period from teenagers to adulthood are important targets for health promotion program especially for maternal health. 3. Better working environment with sufficient time and facilities for workers to relax is required to promote female sales workers' health. 4. Further research is required to identify the relation between workers' visual fatigue and intense lights for the display of goods.

• Animal Bioscience
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• 제36권1호
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• pp.43-52
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• 2023

Objective: This study aimed to examine the influence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on pregnancy in cytokeratin-18 (K18)-hACE2 transgenic mice. Methods: To determine the expression of hACE2 mRNA in the female reproductive tract of K18-hACE2 mice, real-time polymerase chain reaction (RT-PCR) was performed using the ovary, oviduct, uterus, umbilical cord, and placenta. SARS-CoV-2 was inoculated intranasally (30 μL/mouse, 1×10⁴ TCID₅₀/mL) to plug-checked K18-hACE2 homozygous female mice at the pre-and post-implantation stages at 2.5 days post-coitum (dpc) and 15.5 dpc, respectively. The number of implantation sites was checked at 7.5 dpc, and the number of normally born pups was investigated at 20.5 dpc. Pregnancy outcomes, including implantation and childbirth, were confirmed by comparison with the non-infected group. Tissues of infected mice were collected at 7.5 dpc and 19.5 dpc to confirm the SARS-CoV-2 infection. The infection was identified by performing RT-PCR on the infected tissues and comparing them to the non-infected tissues. Results: hACE2 mRNA expression was confirmed in the female reproductive tract of the K18-hACE2 mice. Compared to the non-infected group, no significant difference in the number of implantation sites or normally born pups was found in the infected group. SARS-CoV-2 infection was detected in the lungs but not in the female reproductive system of infected K18-hACE2 mice. Conclusion: In K18-hACE2 mice, intranasal infection with SARS-CoV-2 did not induce implantation failure, preterm labor, or miscarriage. Although the viral infection was not detected in the uterus, placenta, or fetus, the infection of the lungs could induce problems in the reproductive system. However, lung infections were not related to pregnancy outcomes.