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        검색결과 61

        41.
        2015.11 KCI 등재 서비스 종료(열람 제한)
        The surface modified activated carbons (SMACs) were prepared with various P2O5 concentrations using two activated carbons (ACs: waste citrus peel-based activated carbon and coconut-based activated carbon). The characteristics and adsorptivity of bisphenol A (one of phenolic endocrine disrupting chemicals) were compared between ACs and SMACs. The contents of C, H and N of SMACs were similar to those of ACs, but the content of P2O5 for the former increased greatly than for the latter, due to the impregnation of P2O5 into the pores. The specific surface area, total pore volume, average pore diameter and iodine adsorptivity for the former decreased due to the impregnation of P2O5 into the pores, compared to those for the latter. The adsorptivity of bisphenol A for the former were higher than that for the latter, although specific surface area, total pore volume, average pore diameter and iodine adsorptivity for the former were lower than those for the latter.
        43.
        2015.09 서비스 종료(열람 제한)
        Although the toxicological impacts of the xenoestrogen bisphenol-A (BPA) have been studied extensively, but its mechanism of action is poorly understood. Eventually, no standard method exists for evaluating the possible health hazard of BPA. Considering mice spermatozoa as a potential in vitro model, here we demonstrated the effects of BPA exposure (0.0001, 0.01, 1, and 100 μM for 6 h) on spermatozoa and the related mechanisms of action. Our results demonstrated that high concentrations of BPA negatively affect sperm motility, viability, intracellular ATP, and mitochondrial functions by activating the mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and protein kinase-A pathways. The same doses were also employed to identify the differential expressed proteins of exposure and screen their functional affiliation to diseases using sperm proteomics and informatics, respectively. Our results demonstrated that a high concentration of BPA (100 μM) induced differential expression (> 2-fold) of 24 proteins in spermatozoa (16 down- and 9 up-regulated), that are putatively involved in the pathogenesis of several diseases. To the best of our knowledge, this is the first study to demonstrate the mechanisms of BPA action in spermatozoa and to identify the possible biomarkers of exposure. Moreover, we anticipated that current strategy might apply for the hazard assessment of other toxicological agents.
        44.
        2015.09 서비스 종료(열람 제한)
        As an endocrine disruptor, bisphenol-A (BPA) causes several functional and behavioral abnormalities related to reproduction. The current study was design to evaluate the effect of perinatal exposure of female mice to BPA on sperm function of adult F(1) offspring. Pregnant female mice F(0) were gavaged with three different concentration of BPA, such as 50 μg/kg/day (tolerable daily intake value by the European Food Safety Authority), 5 mg/kg/day (no-observed-adverse-effect level; NOAEL), and 50 mg/kg/day (lowest-observed-adverse-effect level; LOAEL) and corn oil (7 mg/kg/day; vehicle control). The functional parameters of F(1) spermatozoa were studied both before and after capacitation, whereas the fertility assessment was evaluated by in vitro and in vivo assay using unexposed females. Our results showed that spermatozoa hyperactivated motility, capacitation, intracellular ATP, Ca2+, and ROS levels after capacitation were significantly affected using NOAEL and LOAEL concentration of BPA. However, the sperm motility was only affected by LOAEL dose after capacitation. All of the tested parameters were potentially unaffected by BPA before capacitation, except intracellular ATP that decreased by all concentrations. Although both NOAEL and LOAEL concentration were effectively reduced the rate of fertilization and embryonic development in vitro, however the average litter size was only affected by LOAEL dose. Our finding suggested that perinatal exposure of 50 μg/kg/day did not produce significant effects; however both NOAEL and LOAEL affects overall sperm function after capacitation, leading to impairments in the fertility of F(1) male offspring.
        45.
        2015.04 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to evaluate the preventive effect of three forms of Korean ginseng roots (fresh, white and red) against bisphenol A (BPA) toxicity in mouse male germ cells (GC-2spd, TM3, TM4). ROS (reactive oxygen species) generation were measured by DCF-DA (2’,7’-dichlorohydrofluorescein diacetate) assay. Also, semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was performed to quantify the mRNA expression levels of apoptosis- related genes, Bax (pro-apoptotic gene) and Bcl2 (anti-apoptotic gene). ROS generation was increased by 50 μM BPA, but definitely decreased by treatment with Korean ginseng extracts (fresh, white and red) in mouse male germ cells. In especial, Korean fresh ginseng extract reduced significantly ROS production to normal control. In addition, Korean fresh and white ginseng extracts suppressed the apoptosis of mouse male germ cells by fine-tuning mRNA levels of apoptotic genes changed by BPA. In general, Korean fresh ginseng extract was more effective than white ginseng extract for reducing BPAinduced oxidative stress and apoptosis in mouse male germ cells. Therefore, Korean fresh and white ginseng may help to alleviate biphenol A toxicity in mouse male germ cells.
        46.
        2014.09 서비스 종료(열람 제한)
        The present study aims to investigate the effect of BPA on sperm functions, fertilization and to evaluate their association with the activity of fertility related proteins in spermatozoa. We used a comprehensive in vitro test system to evaluate the effect of various concentrations of BPA (0.0001, 0.01, 1, and 100 μM) on mouse spermatozoa following 6 h of incubation. Our results showed that high concentration of BPA inhibited sperm motility and motion kinematics by significantly decreasing ATP levels in spermatozoa. Simultaneously, exposure of spermatozoa to high concentrations of BPA increased the tyrosine phosphorylation of sperm proteins involved in PKA-dependent regulation and induced a robust AR, ultimately results in poor fertilization and compromised embryonic development. Finally, BPA effects on selected group of fertility related proteins in spermatozoa, such as it degraded the β-actin, whereas the levels of peroxiredoxin-5, glutathione peroxidase, glyceraldehyde-3-phosphate dehydrogenase, and succinate dehydrogenase were increased. Based on these results, we propose that high concentration of BPA may alter overall sperm functions, fertilization and embryonic development, in association with degradation and/or phosphorylation of fertility related proteins in spermatozoa.
        47.
        2013.08 서비스 종료(열람 제한)
        Estrogen is a primary steroid hormone to govern cell fates in the endometrium. It induces expression of a spectrum of genes such as early growth response 1 (Egr1) critical for dynamic change of uterine environments for embryo implantation. Egr1 belongs to the Egr family of zinc finger transcription factors consisting of 4 members (Egr1 to Egr4) that are co-expressed in many different tissues, suggesting that they may have some redundant functions. Bisphenol A (BPA) is a well-known endocrine disruptor with potent estrogenic activity on reproductive system. Here we have demonstrated molecular pathway(s) by which estrogen (17β estradiol, E2) and BPA regulates Egr1 in uterus. Eight-week-old female mice were ovariectomized (OVX) and rested for a week. Uteri of OVX mice treated with E2, BPA and/or progesterone (P4) were collected 2 h after hormone treatment unless otherwise indicated. ICI 182,780 [estrogen receptor (ER) antagonist] and RU486 [progesterone receptor (PR) antagonist] were pretreated 30 min before hormone treatment. Collected uteri were mainly utilized for RT-PCR, realtime-RT-PCR and Western blotting. Egr1 mRNA was rapidly induced with the highest level at 2h after E2 treatment and gradually decreased to basal levels at 12 h. Pretreatment of ICI 182,780 effectively inhibited E2-induced phosphorylation of ERK1/2 and AKT as well as Egr1 transcription. U0126 (a pharmacological ERK1/2 inhibitor), but not Watmannin (a AKT inhibitor), significantly blocked E2-induced Egr1 expression as well as ERK1/2 phosphorylation in the uterus. P4 effectively dampened E2-dependent Egr1 transcription, and its antagonistic effects were partially interfered with RU486 pretreatment. Interestingly, Egr2 and Egr3 showed similar hormone-dependent expression profiles to that of Egr1 in the uterus. BPA (100 mg/kg) was able to induce immediate expression of Egr1 as effective as E2 at 2 h after treatment. ICI 182,780 and P4 considerably reduced BPA-induced expression of Egr1. In addition, RU486 counteracted inhibitory action of P4 on BPA-induced expression of Egr1. While overall patterns of BPA- induced expression of Egr2 and Egr3 were similar to that of Egr1, BPA was not as effective as E2 for induction of Egr2 and Egr3. BPA could induce phosphorylation of ERK1/2 as well as expression of Egr family members, too. Collectively, these results strongly suggest that BPA as well as E2 can activate concurrent expression profiles of Egr family members via ER-ERK1/2 pathways in the uterus.
        48.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        Bisphenol A(BPA)는 약한 estrogen 활성도를 보이는 화학물질로서 착상 전 배아나 태아에 영향을 미쳐, 출생 후 그들의 신체발달에 변화를 초래한다고 알려져 있다. 본 연구는 인체에서 임신 중기에 양수 내 BPA 농도를 측정하였으며, 측정된 농도에 따라 임신결과에 영향을 미치는지 여부를 알아보고자 하였다. 임신 15주에서 20주 사이에 유전학적 적응증으로 양수천자 검사를 시행 받았던 120명의 임신부 양수를 연구대상으로 ELISA 방법으로
        50.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 해산어를 이용하여 bisphenol A(BPA)와 nonylphenol(NP)이 난모세포 성숙 과정에 어떤 영향을 미치는지 조사하기 위해 성숙단계에 있는 노래미(Hexagrammos agrammus) 난모세포(난경 약 1.88 ㎜)를 대상으로 in vitro에서 BPA와 NP 처리에 의한 난모세포의 성스테로이드 생성농도를 조사하였다. 난모세포에 BPA와 NP를 농도구별(0.1, 1, 10, 100, 1,000 ng/㎖)로 첨가하고, 50 IU의 human chorionic gonadotropin(HCG)를 농도구별 BPA 또는 NP와 함께 첨가하거나 하지 않고 48시간 동안 배양하였다. 배양 후 배양액 내의 17α,20β-dihydroxy-4-pregnen-3-one(17α20βOHP), estradiol-17β(E2) 그리고 testosterone(T)의 농도를 방사면역측정법(RIA)을 통해 정량하였다. BPA 처리구에서는 100 ng/㎖의 농도구에서 HCG 처리 유무에 상관없이 E2 생성이 촉진되었다. HCG 처리하에서 0.1 ng/㎖의 농도구에서 T 생성은 촉진되었으나, HCG를 처리하지 않은 실험구의 모든 농도구에서 T 생성은 저해되었다. NP 처리구에서는 HCG를 처리하지 않은 실험구의 10 ng/㎖의 농도구에서 17α20βOHP와 T 생성이 촉진되었고, 1 ng/㎖의 농도구에서는 E2 생성이 억제되었다. 이상의 결과를 종합하면, 노래미의 성숙단계의 난모세포에서 BPA는 약한 estrogen-agonistic 효과를, NP는 estrogen- antagonistic 효과를 지니는 것으로 사료된다.
        51.
        2006.05 KCI 등재 서비스 종료(열람 제한)
        We investigated the relationship between the TiO2 photocatalytic decomposition of bisphenol A in water and biological toxicity to zebrafish (Danio rerio) during 1~28 weeks post development stage. The bisphenol A in water was completely degraded by the TiO2 photocatalysis in 50 hours. After the photocatalysis, no toxic effects on the morphogenesis of the zebrafish were observed during the development, growth, and maturate stages. Catalase activity of control group was not different from 1~5 week post fertilized group. However, toxic effect on the catalase activity of adult stage(28 weeks) decreased 50% than control group.
        52.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        본 연구는 Leydig 세포주와 Sertoli 세포주상에 bisphenol A(BPA)와 diethylstilbestrol(DES)의 영향을 알아보고자 수행하였다. 세포 종류에 따른 BPA의 영향을 알아보기 위해, BPA의 농도별로 두 세포주에 처리하여 세포생존율을 비교하였다. Sertoli 세포주가 Leydig 세포주에 비해서 저농도의 BPA에서 생존율이 유의하게 감소되는 것을 확인할 수 있어, Sertoli 세포가 Leydig 세포주에 비해 BPA에
        55.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        The effects of bisphenol A on the catalase activities in the development stage of zebrafish were investigated. In this study, the catalase activities for zebrafish fries exposed to bisphenol A of 1×10-10 g/ℓ during 1 week, 2 week, and 4 week post-hatching were examined. Also, the changes of organs weight and the catalase activities for adult zebrafishes exposed to bisphenol A during 3 weeks were investigated. Catalase activities for zebrafish fries exposed to bisphenol A of 1×10-10 g/ℓ during 1 week post-hatching were significantly lower, compared to the control. Somewhat, for zebrafish fries exposed to bisphenol A during 4 week post-hatching, catalase activities were significantly increased. For adult zebrafishes, the effects of bisphenol A were higher for female than male. Specially, catalase activities were significantly increased in the ovary of zebrafishes exposed to bisphenol A during 3 weeks. The ovary weight were increased for zebrafishes exposed to bisphenol A during 3 weeks. Catalase activities were increased in the intestine of female exposed to bisphenol A during 3 weeks. Catalase activities were increased in testis exposed to bisphenol A during 3 weeks but there was no significance. In conclusion, the damages of an endocrine disrupter were higher in the earlier development stage compared with adult. The damages were higher for female exposed to an endocrine disrupter compared with male.
        60.
        2001.03 서비스 종료(열람 제한)
        This study examined the extent of mammary excretion and placental transfer of bisphenol A in rats. Bisphenol A was given by simultaneous i.v. bolus injection plus infusion to steady-state at low, medium and high doses. The steady-state serum levels of bisphenol A were linearly increased with increasing the dosing rate. The systemic clearance (mean range, 119.2-154.1 ml/min/kg) remained unaltered over the dosing rate studied. The levels of bisphenol A in milk exceeded those in serum, with the steady-state milk to serum concentration ratio being 2.4-2.7. The steady-state milk levels of bisphenol A were also increased linearly with increasing the infusion rate. In a separate study, the kinetic disposition of bisphenol A in the rat maternal-fetal unit was studied in pregnant rats. After i.v. injection, bisphenol A concentration in the maternal serum declined biexponentially. Bisphenol A was rapidly distributed into placenta, fetus and amniotic fluid, with maximum concentrations in these tissues achieved within 1 hr of injection. The decline of bisphenol A in placenta, fetus and amniotic fluid paralleled that of maternal serum. A simultaneous computer simulation showed that the observed concentrations were well represented by a 5-compartmental model consisting of the maternal central, placenta, fetus, amniotic fluid, and maternal tissue compartments.
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