• Safety and Health at Work
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• v.2 no.3
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• pp.290-300
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• 2011

Objectives: There is limited data regarding the toxicity of methylcyclohexane, despite its wide use in rubber adhesives, paint diluents, and cleansing agents. This study aimed to verify the toxicity and influence on the reproductive system of methylcyclohexane after its repeated injection in Sprague Dawley (SD) rats. Methods: Methylcyclohexane was injected subcutaneously into male and female SD rats once a day, five times a week, for 13 weeks at different doses (0, 10, 100, and 1,000 mg/kg/day) for each group. The toxicity of testing material was verified by observing the change in body and organ weight, hematological change, pathological findings, and effect on the reproductive system at each different concentration. Results: In the 1,000 mg/kg/day group, there were cases of animal deaths. In animals that survived, hematological changes, including a decrease in the red blood cell count, were observed. A considerable weight gain or loss and pathological abnormalities in the liver, kidney, and other organs were found. However, the 10 and 100 mg/kg/day groups did not cause deaths or other specific abnormalities. In terms of reproductive toxicity, there were changes in hormone levels, including a significant decrease in hormones such as estradiol and progesterone (p < 0.001) in male animals. Menstrual cycle change for female animals did not show concentration dependency. Conclusion: When injected repeatedly for 13 weeks, methylcyclohexane proved to be toxic for the liver, heart, and kidney at a high dose. The absolute toxic dose was 1,000 mg/kg/day, while the no observed adverse effect level was less than 100 mg/kg/day. The substance exerted little influence on the reproductive system.

• Journal of Embryo Transfer
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• v.23 no.1
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• pp.59-64
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• 2008

The objective of this study is to investigate the changes in concentrations of blood urea nitrogen (BUN) and sex steroid hormones, such as estrogen, progesterone, and testosterone in Korean cattle (Hanwoo) with reproductive disorders and to examine the relationship between BUN and body condition score (BCS) in Hanwoo. The concentration of BUN was 16.2 mg/dl, 17.8 mg/dl, 15.1 mg/dl, 17.9 mg/dl, and 28.3mg/dl in pregnancy, repeat breeding, follicular cyst, luteal cyst, and ovarian atrophy, respectively. In Hanwoo with BCS $2.0{\sim}2.9$, $3.0{\sim}3.5$ and $3.6{\sim}4.0$, the concentration of BUN was 15.8 mg/dl, 17.0 mg/dl, and 17.6 mg/dl, respectively. Fluoroimmunoassay showed that serum estrogen and progesterone levels were decreased in reproductive disorders Hanwoo, such as ovarian atrophy, endometritis, and weak estrus. The testosterone level was significantly decreased in Hanwoo with reproductive disorders compared to that in pregnant Hanwoo ($0.02{\sim}0.03\;ng/ml$ vs 0.13 ng/ml, p<0.05). The progesterone and estrogen concentrations in follicular fluid obtained from ovary with follicular cyst were significantly higher (p<0.05) than those in normal follicle fluid. These results show that there is no relationship between BUN and BCS in Hanwoo, and the concentration of sex steroid hormone in serum and follicular fluid are changed in reproductive disorders Hanwoo.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.3
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• pp.95-106
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• 2012

It has been revealed that multiple cohorts of tertiary follicles develop during some animal estrous cycle and the human menstrual cycle. To reach developmental competence, oocytes need the support of somatic cells. During embryogenesis, the primordial germ cells appear, travel to the gonadal rudiments, and form follicles. The female germ cells develop within the somatic cells of the ovary, granulosa cells, and theca cells. How the oocyte and follicle cells support each other has been seriously studied. The latest technologies in genes and proteins and genetic engineering have allowed us to collect a great deal of information about folliculogenesis. For example, a few web pages (http://www.ncbi.nlm. nih.gov; http://mrg.genetics.washington.edu) provide access to databases of genomes, sequences of transcriptomes, and various tools for analyzing and discovering genes important in ovarian development. Formation of the antrum (tertiary follicle) is the final phase of folliculogenesis and the transition from intraovarian to extraovian regulation. This final step coordinates with the hypothalamic-pituitary-ovarian axis. On the other hand, currently, follicle physiology is under intense investigation, as little is known about how to overcome women's ovarian problems or how to develop competent oocytes from in vitro follicle culture or transplantation. In this review, some of the known roles of hormones and some of the genes involved in tertiary follicle growth and the general characteristics of tertiary follicles are summarized. In addition, in vitro culture of tertiary follicles is also discussed as a study model and an assisted reproductive technology model.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.303-313
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• 2019

Twenty crossbred (Yorkshire ${\times}$ Landrace) gestating sows were used to determine the effects of Moringa Oleifera leaf (MOL) supplementation in lactating sow diets with or without banana peel powder (BPP) on reproductive performance, fecal moisture content, rectal temperature and hormone profile. The treatments were as follows: 1) CON (control diet), 2) M1 (control diet + 0.5% MOL), 3) M2 (control diet + 1.0% MOL), 4) M3 (control diet + 0.75% MOL and 0.75% BPP), and 5) M4 (control diet + 1.5% MOL and 1.5% BPP). The diets was fed from da 107 of gestation to weaning. MOL and BPP supplementation decreased (p < 0.05) the fecal moisture content compared with that of the CON at day 0 and 7 after farrowing, and 1.0% supplementation of MOL also decreased (p < 0.05) the fecal moisture content at day 14 after farrowing. On farrowing day, MOL supplementation decreased (p < 0.05) the blood cortisol and norepinephrine concentrations compared with the CON. In conclusion, the results of this study show that MOL supplementation decreased the fecal moisture content and plasma concentrations of cortisol and norepinephrine, and MOL and BPP supplementation also decreased the fecal moisture content in lactating sows.

• Clinical and Experimental Reproductive Medicine
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• v.12 no.1
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• pp.83-98
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• 1985

In order to study the mechanism of follicular atresia, the follicles of the porcine ovary were isolated according to the presence or absence of the corpus luteum and their size, and then classified to the normal? or atretic?follicle on the morphological observation such as the transparency, the vascularization of follicle, the nuclear phase of oocyte, and the homogeneity of the granulosa cell layer. The viability of granulosa cells was examined. The concentrations of progesterone ($P_4$), testosterone (T), and estradiol-17 beta ($E_2$) in each follicular fluid were estimated by the radioimmunoassay. The viability of granulosa cells in the atretic follicle was much lower than that of the normal one. The concentration of each steroid hormone increased as the follicular size was increased, was not different in quantity between the normal- and the atretic follicle of which diameter was below 3mm, and were much higher in the atretic follicle than those in the normal one of which diameter was above 7mm. The ratio of the concentration of E2 to T in the large atretic follicle valued higher than that in the normal one, but smaller in the small and medium atretic follicle than that in the normal one. The present study suggests that the mechanism of atresia of the large follicle may be different from that of the small and the medium follicle and that the amount of steroid hormones regarded as the one of the criteria for the atretic follicles.

• Reproductive and Developmental Biology
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• v.37 no.1
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• pp.29-33
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• 2013

The objective of this work was to analyze the concentrations of progesterone (P4) and estrogen (E2) hormones changed during estrus synchronization in dairy heifers. Estrus synchronization was carried out with CIDR$^{(R)}$ (Controlled Intravaginal Drug Release) devices. Corpus luteum (CL) was classified into three grades based on its size and palpable characteristics. The concentrations of P4 and E2 were measured by enzyme-amplified chemiluminescence. Serum P4 concentration was markedly low at the estrus stage (36 hrs after removal of CIDR) compared to other stages, while E2 concentration was kept high during estrus stage. The serum P4 concentration was highest in the CL classified into grade I. These results indicate that P4 concentration could be used as a criteria for determining recipients for artificial insemination or embryo transfer in dairy cattle.

• Development and Reproduction
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• v.5 no.1
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• pp.73-79
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• 2001

Recently many studies have reported that total and bioavailable androgens reduced in male and female athletes and that physical exercise reduces the body weight and increases the reproductive abnormalities such as oligomenorrhea, anovulation, inadequate luteal phase, and delayed puberty in women by the inhibition of the hypothalamic-pituitary-gonadal (HPG) axis . In addition, high mileage endurance 겨nning, psychological stress, and military endurance training in men also reduce the secretion of reproductive hormones. To investigate the efffcts of physical endurance exercise on the secretion of reproductive hormones in men, androgenic hormones from adrenal glands and testis were measured in serum by the conventional radioimmunoassays after long-term (more than3 months), short-term (1 week), and acute (1${sim}$2 hours) physical exercises. Androgenic hormones from adrenal glands and testis such as total testosterone (TT), free testosterone (fT), dehydroepiandrosterone (DHEA), and androstenedione (A) decreased after thesestrenuous endurance trainings, whereas ACTH, cortisol, and dehydroepiandrosterone sulfetes (DHEAS) increased. Conadotropins (LH and FSH) were not idluenced by the physical exercises. Based upon the present results, we assume that the decrease in adrenal and testicular androgens by physical endurance exercises might be associated with the reproductive abnormalities in athletes by unknown factor(s) in addition to the HPG axis disturbance.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3635-3640
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• 2014

Aim: To determine whether induced abortion (IA) increases breast cancer (BC) risk. Materials and Methods: A population-based case-control study was performed from Dec, 2000 to November, 2004 in Shanghai, China, where IA could be verified through the family planning network and client medical records. Structured questionnaires were completed by 1,517 cases with primary invasive epithelial breast cancer and 1,573 controls frequency-matched to cases for age group. The information was supplemented and verified by the family planning records. Statistical analysis was conducted with SAS 9.0. Results: After adjusting for potential confounders, induced abortions were not found to be associated with breast cancer with OR=0.94 (95%CI= 0.79-1.11). Compared to parous women without induced abortion, parous women with 3 or more times induced abortion (OR=0.66, 95%CI=0.46 to 0.95) and women with 3 or more times induced abortion after the first live birth (OR=0.66, 95%CI =0.45 to 0.97) showed a lower risk of breast cancer, after adjustment for age, level of education, annual income per capita, age at menarche, menopause, parity times, spontaneous abortion, age at first live birth, breast-feeding, oral contraceptives, hormones drug, breast disease, BMI, drinking alcohol, drinking tea, taking vitamin/calcium tablet, physical activity, vocation, history of breast cancer, eating the bean. Conclusions: The results suggest that a history of induced abortions may not increase the risk of breast cancer.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1142-1147
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• 2011

Lysine intake during gestation has a major impact on subsequent reproductive performance. The objective of this experiment was to determine the effect of lysine intake from mid-gestation until farrowing on the reproductive performance of multiparous sows. On day 30 of gestation, 200 Landrace${\times}$Large White sows were randomly assigned to one of four groups based on body weight and parity (n = 50). The gestation diets contained 0.46, 0.56, 0.65 or 0.74% lysine. Increasing dietary lysine concentration improved sow body condition at farrowing and increased litter weights (p<0.05). Dietary lysine level also had a significant effect on the dry matter (p<0.05) and protein content (p<0.05) of colostrum. Increased lysine intake increased serum insulin concentration (p<0.05) and there was a trend towards increased serum prolactin content (linear, p = 0.07). However, increased lysine tended to decrease blood urea N (quadratic, p = 0.05). These results suggest that higher lysine levels (0.65-0.75%) than those recommended by the National Research Council improved reproductive performance for multiparous gestating sows and this increase may be partially mediated through blood metabolites or metabolic hormone levels.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.3
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• pp.221-228
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• 2021

Objective: This study investigated the effect of crocin in methylglyoxal (MGO)-induced diabetic male mice. Methods: Seventy 1-month-old male NMRI mice weighing 20-25 g were divided into seven groups (n=10): sham, MGO (600 mg/kg/day), MGO+crocin (15, 30, and 60 mg/kg/day), MGO+metformin (150 mg/kg/day), and crocin (60 mg/kg/day). MGO was administered orally for 30 days. Starting on day 14, after confirming hyperglycemia, metformin and crocin were administered orally. On day 31, plasma and tissue samples were prepared for experimental assessments. Results: Blood glucose and insulin levels in the MGO group were higher than those in the sham group (p<0.001), and decreased in response to metformin (p<0.001) and crocin treatment (not at all doses). Testis width and volume decreased in the MGO mice and improved in the crocin-treated mice (p<0.05), but not in the metformin group. Superoxide dismutase levels decreased in diabetic mice (p<0.05) and malondialdehyde levels increased (p<0.001). Crocin and metformin improved malondialdehyde and superoxide dismutase. Testosterone (p<0.001) and sperm count (p<0.05) decreased in the diabetic mice, and treatment with metformin and crocin recovered these variables. Luteinizing hormone levels increased in diabetic mice (p<0.001) and crocin treatment (but not metformin) attenuated this increase. Seminiferous diameter and height decreased in the diabetic mice and increased in the treatment groups. Vacuoles and ruptures were seen in diabetic testicular tissue, and crocin improved testicular morphology (p<0.01). Conclusion: MGO increased oxidative stress, reduced sex hormones, and induced histological problems in male reproductive organs. Crocin and metformin improved the reproductive damage caused by MGO-induced diabetes.