• Clinical and Experimental Reproductive Medicine
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• v.41 no.2
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• pp.47-61
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• 2014

Stored maternal factors in oocytes regulate oocyte differentiation into embryos during early embryonic development. Before zygotic gene activation (ZGA), these early embryos are mainly dependent on maternal factors for survival, such as macromolecules and subcellular organelles in oocytes. The genes encoding these essential maternal products are referred to as maternal effect genes (MEGs). MEGs accumulate maternal factors during oogenesis and enable ZGA, progression of early embryo development, and the initial establishment of embryonic cell lineages. Disruption of MEGs results in defective embryogenesis. Despite their important functions, only a few mammalian MEGs have been identified. In this review we summarize the roles of known MEGs in mouse fertility, with a particular emphasis on oocytes and early embryonic development. An increased knowledge of the working mechanism of MEGs could ultimately provide a means to regulate oocyte maturation and subsequent early embryonic development.

• Journal of Veterinary Clinics
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• v.38 no.2
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• pp.49-55
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• 2021

We aimed to identify the biological factors during the voluntary waiting period (VWP) that are associated with subsequent reproductive performance in dairy cows. Two hundred and one pregnant dairy cows had their body condition score (BCS) evaluated and blood samples taken 4 weeks before calving, at calving, and 1, 2, 4, 6, and 8 weeks after calving, to measure serum metabolite and progesterone concentrations. In addition, any peri- and postpartum disorders within 4 weeks of calving, and the mean milk yields 4 and 8 weeks postpartum, were recorded. The cows were allocated to two groups according to whether they had become pregnant or not by 120 days after calving: a pregnant group (n = 50) and a non-pregnant group (n = 151). Analyses of serum metabolite concentrations showed that the aspartate aminotransferase and γ-glutamyltransferase activities 2 weeks (p < 0.05) and the non-esterified fatty acid concentration 6 weeks (p < 0.01) postpartum were higher in the non-pregnant than in the pregnant group. However, the albumin concentrations between 2 and 8 weeks and the total cholesterol and magnesium concentrations between 4 and 8 weeks postpartum were lower in the non-pregnant group (p < 0.05). The BCS (p < 0.05) and percentages of cows that had resumed cyclicity (p < 0.001) by 6 and 8 weeks postpartum were higher in the pregnant than in the non-pregnant group, whereas the incidence of peri- and postpartum disorders was higher in the non-pregnant group (p < 0.05). In conclusion, high serum enzyme activities, which imply liver damage, imbalances in energy metabolites and magnesium, and a higher incidence of peri- and postpartum disorders, are associated with poorer reproductive performance, whereas high BCS and early resumption of cyclicity during the VWP are associated with superior reproductive performance in dairy cows.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5077-5083
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• 2013

Background: Breast cancer is the most frequent cancer in women globally and represents the second leading cause of cancer death among women (after lung cancer). India is going through epidemiologic transition. It is reported that the incidence of breast cancer is rising rapidly as a result of changes in reproductive risk factors, dietary habits and increasing life expectancy, acting in concert with genetic factors. Materials and Methods: In order to understand the existing epidemiological correlates of breast cancer in South India, a systematic review of evidence available on epidemiologic correlates of breast cancer addressing incidence, prevalence, and associated factors like age, reproductive factors, cultural and religious factors was performed with specific focus on screening procedures in southern India. Results: An increase in breast cancer incidence due to various modifiable risk factors was noted, especially in women over 40 years of age, with late stage of presentation, lack of awareness about screening, costs, fear and stigma associated with the disease serving as major barriers for early presentation. Conclusions: Educational strategies should be aimed at modifying the life style, early planning of pregnancy, promoting breast feeding and physical activity. It is very important to obtain reliable data for planning policies, decision-making and setting up the priorities.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2991-2995
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• 2012

Background: India shows some of the highest rates of cervical cancer worldwide, and more than 70% of the population is living in rural villages. Prospective cohort studies to determine the risk factors for cervical cancer are very rare from low and medium resource countries. The aim of this study was to quantify the effect of risk factors related to cervical cancer in a rural setting in South India. Material and methods: Sociodemographic and reproductive potential risk factors for cervical cancer were studied using the data from a cohort of 30,958 women who constituted the unscreened control group in a randomised screening trial in Dindigul district, Tamilnadu, India. The analysis was accomplished with the Cox proportional hazard regression model. Results: Women of increasing age (HR=2.4; 95% CI: 1.6, 3.8 in 50-59 vs 30-39), having many pregnancies (HR=7.1; 1.0, 52 in 4+ vs 0) and no education (HR=0.6; 0.2, 0.7 in high vs none) were found to be at significantly increased risk of cervical cancer. Conclusion: This cohort study gives very strong evidence to say that education is the fundamental factor among the sociodemographic and reproductive determinants of cervical cancer in low resource settings. Public awareness through education and improvements in living standards can play an important role in reducing the high incidence of cervical cancer in India. These findings further stress the importance of formulating public health policies aimed at increasing awareness and implementation of cervical cancer screening programmes.

• 대한생식의학회:학술대회논문집
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• 2004.06a
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• pp.39-42
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• 2004

• Proceedings of the KSCN Conference
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• 2002.11a
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• pp.894-906
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• 2002

• 대한생식의학회:학술대회논문집
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• 2002.05a
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• pp.38-39
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• 2002

• 대한생식의학회:학술대회논문집
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• 1997.06a
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• pp.43-44
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• 1997

• 대한생식의학회:학술대회논문집
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• 2001.03a
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• pp.33-40
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• 2001

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.369-378
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• 2016

Improving the reproductive traits of Hanwoo might decrease their production cost. Therefore, this study was conducted to investigate the effects of environmental factors [registration grade (basic, pedigree or advanced), birth year, birth season, parity, delivery year, and delivery season] on various reproductive traits (age at 1st service, age at 1st conception, age for 1st calving, days at 1st service postpartum, non-pregnant condition period, calving interval, gestation length, and number of services for conception) in Hanwoo (primiparous 12,219 heads, multiparous 10,471 heads). All data was acquired from Gyeongnam province areas which were surveyed from 2007 to 2015. All environmental factors significantly influenced (p < 0.01) reproductive traits of primiparous cows but, but not all environmental factors influenced multiparous cows. Primiparous cows registered as advanced grade showed significantly lower age at 1st service (by 15.36 days), age at 1st conception (by 8.66 days), and age for 1st calving (by 8.77 days) (p < 0.01) than those registered as basic grades. Age at 1st service, age at 1st conception and age for 1st calving were not significantly related to birth year in primiparous cows. As delivery years advanced from 2005 to 2012, all durations associated to reproductive traits tended to be shorter. Days at 1st service postpartum, non-pregnant condition period, and calving interval tended to be shortened as parity increased. Days at 1st service postpartum, days open, calving interval, and gestation in multiparous cows calved in winter were shorter than those in summer. The registration grade was not a effected with reproductive traits in Hanwoo.