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        검색결과 16

        1.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Endocrine-disrupting chemicals found in many commercial products may interfere with the normal functioning of the endocrine system and are unsafe because of their cumulative effect on the human body. However, little is known about the effects of combinations of endocrine-disrupting chemicals in humans. Methoxychlor and bisphenol A are toxic to male reproductive organs. Therefore, we studied the effects of methoxychlor and bisphenol A on male reproductive function. Male mice were divided into four treatment groups: control, 400 mg methoxychlor, 1 mg bisphenol A, and 400 mg methoxychlor + 1 mg bisphenol A/kg/day. Methoxychlor and bisphenol A were dissolved in sesame oil and acetone and administered orally for 4 weeks. After administration, the weight and histological changes in the testicles and epididymis, sperm count and health were observed biochemical tests and whole blood counts were performed. The results showed that the mice in the bisphenol A and methoxychlor + bisphenol A groups gained more weight than those in the control and methoxychlor group. The weights of the testes and epididymis were higher in the experimental groups than in the control. Sperm motility and progression were significantly reduced in the bisphenol A and methoxychlor + bisphenol A groups. Histological observation showed a reduced number of sperm, smaller seminiferous tubules, and destroyed lumen in the methoxychlor + bisphenol A group compared to the other groups. In conclusion, our study showed that methoxychlor and bisphenol A destroy male reproductive tissues and decrease sperm quality.
        4,000원
        2.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lonicera caerulea (Honey berry, HB) has been used in medical treatment in Russia, Japan, China and Korea. It has high level of vitamin C and polyphenolics. Polyphenolics can improve anti-inflammatory effect and prevent cancer, diabetes mellitus type 2. Also, Vitamin C is a representative anti-oxidant. however, it is still unknown what effect it will have on the oxidation stress of the reproductive system. In previous studies, ROS can be produced when it is exposed to heat stress and has negative effect on sperm’s maturation, capacitation, hyperactivation, acrosome reaction and fusion of egg and sperm. Therefore, the purpose of this study is to investigate the antioxidant effects of L. Caerulea on the sperm and mice. At first, it conducted using ICR mouse (n = 20) for 4 weeks. There are four groups of mice (n = 5 per group). Also, L. Caerulea was taken by oral gavage. Group I (control) kept at 23℃-27℃ and administer D.W (0.5 mL/day), Likewise, Group II (HB) kept at room temperature but gave HB (250 mg/kg, 0.5 mL/day), Group III (HB + HS) received heat stress (40℃) using hyperthermia induction chamber and gave HB at same dose. and Group IV (HS) exposed heat stress only. Mainly, we showed degree of gene expression using Western blot in SOD, HSP 70, 17β-HSD and Real-time PCR. It can find correlation between intracellular activity like steroid hormone, apoptosis under ROS and antioxidant activity of L. Caerulea.
        4,000원
        3.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There is increasing demand for the development of a new material with high strength, high stiffness, and good electrical conductivity that can be used for high-voltage direct current cables. In this study, we develop aluminumbased composites containing C60 fullerenes, carbon nanotubes, or graphene using a powder metallurgical route and evaluate their strength, stiffness, coefficient of thermal expansion, and electrical conductivity. By optimizing the process conditions, a material with a tensile strength of 800 MPa, an elastic modulus of 90 GPa, and an electrical conductivity of 40% IACS is obtained, which may replace iron-core cables. Furthermore, by designing the type and volume fraction of the reinforcement, a material with a tensile strength of 380 MPa, elastic modulus of 80 GPa, and electrical conductivity of 54% IACS is obtained, which may compete with AA 6201 aluminum alloys for use in all-aluminum conductor cables.
        4,000원
        4.
        2018.11 구독 인증기관·개인회원 무료
        Mitochondria is energy generating organelle. It synthesizes ATP, which is the essential energy source of many cellular processes. During producing energy, some redox centres leak electrons to oxygen and it is contributory to the reactive oxygen species. Besides, mitochondria have significant functions in metabolism, calcium homeostasis, and fatty acid oxidation. Also mitochondria has importance to the breakdown of the ovarian follicles and could be factor determining oocyte of quality adversely. Increasing evidence shows that the number of mitochondria affect oocyte of developmental competence and maturation detrimentally during aging. Oocyte is the mitochondria-rich cell and enable the organelle to have competence for fertilization and early embryonic development. Occurrence of blastomere depends on distribution change of mitochondria which present in the egg. Lonicera caerulea treatment inhibited ovarian mitochondrial oxidative damage by suppressing mitochondrial reactive oxygen species (mROS) generation, decreasing apoptosis, controlling disintegration of mitochondrial membrane potential and conserving respiratory chain complex activities. The purpose of this study is to identify if mouse accepting treatment with L. caerulea could counter age-induced sterility and ovarian mitochondrial OS in a model organism of ovarian ageing.
        5.
        2018.11 구독 인증기관·개인회원 무료
        Sex hormones including progesterons, androgens, and estrogens are influential in differentiation of ovarian tissues and competence of fertility. These steroid hormones derived from cholesterol are required for cumulus-oocyte complexes(COCs) during oocyte maturation. COCs is a total functional and active entity playing a central role in oocyte. Lipid metabolism in the mammalian COCs is controlled by environmental factors. The intracellular cholesterol contents go through remarkable changes. It plays an important part of oocyte developmental competence. However, heat stress affects steroid hormone by decreasing progesterone, estrogen concentrations, and resumption of meiosis in COCs maturation. Reduction of the hormone and meiotic resumption might lead to the decline of ovarian function, follicle maturation, and subsequent embryogenesis. In the same vein, heat stress also influence on germinal vesicle breakdown, lipolytic variations, and loss of the nuclear envelope in the course of maturation of oocytes. In summary, we examined the effects of thermal stress on oocyte maturation through steroid hormone contents of change identifying the molecular mechanisms of lipids metabolism. It may have the solution to further the therapy methods for disorders regarding sterility.
        6.
        2018.11 구독 인증기관·개인회원 무료
        Mammalian oocytes are sensitive to psychological stress at each period of follicular development. Especially, thermal stress interfere with reproductive condition by inducing formation of reactive oxygen species (ROS) and oxidative stress (OS). ROS lead to oocyte apoptosis, weakening oocyte quality and lowering the fertilization rate. As a result, the pregnancy rate is lowered, leading to infertility. Thermal stress also seems to influence zygotes through physiological changes in the maternal environment surrounding them. Loss of developmental competence suggests hyperthermia-induced oxidative stress in embryos. Interest in organic Lonicera caerulea berries has increased in recent years. They are abundant in various health-improving materials. Berries that found from natural products can be as free as possible from the bioactive toxicity of the active ingredient without side effects, and it can be a big advantage because it can work. Mammalian oocytes are arrested at the first meiotic prophase stage and get their meiotic competence to produce offspring during the development of follicle. A series of nuclear and cytoplasmic maturations are involved in this process and these vary in temperature sensitivity. Our study demonstrated that L. caerulea can relieve the negative effects of maternal hyperthermia by reducing ROS level at the developmental stage.
        7.
        2018.11 구독 인증기관·개인회원 무료
        Lonicera Caerulea(Honey berry) has been used in medical treatment in Russia, Japan, China and Korea. It has high level of vitamin C and polyphenolics. Polyphenolics can improve anti-inflammatory effect and prevent cancer, diabetes mellitus type 2. Also, Vitamin C is a representative anti- oxidant. however, It is still unknown what effect it will have on the oxidation stress of the reproductive system. In previous studies, ROS can be produced when it is exposed to heat stress and has negative effect on sperm's maturation, capacitation, hyperactivation, acrosome reaction and fusion of egg and sperm. Therefore, The purpose of this study is to investigate the antioxidant effects of L.caerulea on the sperm and egg cells of mice. At first, it conducted using ICR mouse(n=20) during 4 weeks. There are four groups of mouse(n=5 per group). Also, L.caerulea was taken by oral gavage. Group Ⅰ(control) kept at 23℃~27℃ and administer D.W(0.5ml/day), Likewise, Group Ⅱ(HB) kept at room temperature but gave HB(0.5ml/day), Group Ⅲ (HB+HS) received heat stress (40℃) using hyperthermia induction chamber and gave HB at same dose. and Group Ⅳ(HS) exposed heat stress only. Mainly, we showed degree of gene expression using Western blot in SOD, HSP 70, 17β-HSD and Real time PCR. It can find correlation between intracellular activity like steroid hormone, apoptosis under ROS and antioxidant activity of L.caerulea.
        8.
        2018.11 구독 인증기관·개인회원 무료
        Previous studies have shown that Lonicera caerulea has a chemical protective effect. Phenolic and vitamin C contained in Lonicera caerulea prevent cancer, diabetes and cardiovascular disease, lower blood pressure and delay the aging process. However, the antioxidant mechanism of male reproductive system to heat stress is still unknown. Male reproductive system is very sensitive to heat. When scrotum temperature increase, oxidative stress can occur. Oxidative stress affects sperm motility and spermatogenesis, resulting in infertility. Therefore, we investigated the antioxidant effect of L. Caerulea in male genitalia by inducing oxidative stress by artificially exposing the testicles to heat at 42 ° C. The experiment was performed by dividing the ICR mouse into four groups. Each group is n = 5. Control group (C) and heat stress group (HS) were oral gavage administered D.W. Honey berry group (HB) and Honeyberry / heat stress group (HB + HS) were oral gavage administered honey berry (250mg / kg / day). HS groups (n=5, per n=5) received heat stress by exposing their lower bodies in the water bath at 42℃ for 30 minutes. We confirmed that there was a significant difference in the motility, morphology and the number of sperms using CASA(computer-assisted semen analysis). Lipid peroxidation assay results showed heat causes oxidative stress in serum. This study is conducting to investigate the antioxidant effect of L. Caerulea. Histologically analyzed the testicular form of each group, the activity level of heat shock protein and the level of reactive oxygen species were measured by Western blot and the level of catalase and HSP-90 was examined by RT-PCR analysis. Thus, studies of testicular morphology, sperm kinetics, hormone levels, heat shock protein expression and antioxidant enzymes under heat stress have shown that L. Caerulea ingestion has Anti-oxidant and thermal protective activity on the testis by heat damage.
        9.
        2017.05 구독 인증기관·개인회원 무료
        Embryo transfer is one of the important process of assisted reproductive technology (ART) and that is associated with uterus endometrial receptivity. Recently, mouse endometrial stimulation by artificial injury had shown the favorable effect on conception. In this experiment, we used uterus stimulation method that injury the endometrium to increase implantation rate for spontaneous Diabetes Mellitus (sDM) rat. Rats are divided into several groups involved a control group. We performed the surgical method to Experimental group bilaterally or unilaterally After that, we investigated morphological change and calculated implanted embryos respective sides of the uterus. The number of implanted embryo in the experimental group was significantly higher and there were lots of morphological changes including glands and endometrial cells that support implantation. Our results showed that rat uterus endometrial injury in ART help enhancing implantation rate.
        10.
        2017.05 구독 인증기관·개인회원 무료
        The purpose of this study is to evaluate the effects of astaxanthin added to freezing buffer on semen parameters, total sperm oxidation stress after post-thawing of boar sperm and lipid peroxidation (LPO) which is caused by reactive oxygen species (ROS) in sperm membrane. Varying concentrations of astaxanthin (0, 10, 50, 100 and 500 μM) were used in the freezing buffer during cryopreservation to protect the DNA of thawed miniature pig sperm. Semen parameter was measured using computer assisted sperm analysis (CASA) for sperm motility and determine ROS rate, oxidative stress of boar sperm using fluorescence-activated cell sorting (FACS). Sperm motility was higher (p<0.05) in the astaxanthin group than in the control group. Sperm motility and the number of progressive motile sperm was higher (p<0.05) in the astaxanthin 500 μM group (66±1.7%) than in the control group (49.8±4%). In ROS evaluation, the astaxanthin group lowered intracellular O2 and H2O2 in viable sperm. The Yo-Pro-I/HE and PI/H2DCFDA staining as revealed using flow cytometry was lower in astaxanthin groups than in the other groups. As the result, we found that astaxanthin could protect the sperm plasma membrane from free radical and LPO during boar sperm post-thawing.
        11.
        2017.05 구독 인증기관·개인회원 무료
        Superovulation is a technique to acquire rats to produce many eggs than normal rats. Superovulated eggs were used to make cloned animals through somatic cell nuclear transfer technology (SCNT). Healthy and valuable oocyte retrieval is essential for successful somatic cell nuclear transfer. Superovulation is also essential to maximize to the yield of IVF-derived rat eggs. Osmotic pumps (Alzet®) are miniature in order to provide research with a convenient, and reliable alternative to chronic injections. Acquiring superovulated oocytes through osmotic pump in minimizing irritation to the uterus and ovaries are competitive. We investigated the effects of pregnant mare serum gonadotropin (PMSG) and human Chorionic Gonadotropin (hCG) using osmotic pump in sDM rat. Adult female rats at 11 wks of age were used for superovulation. The response to PMSG and hCG were examined by osmotic pump of 150 IU/kg PMSG + 75 IU/kg hCG or 150 IU/kg PMSG + 150 IU/kg hCG or 300 IU/kg PMSG + 150 IU/kg hCG or 300 IU/kg PMSG + 300 IU/kg hCG. HCG was administered 48 hrs later after administration of PMSG. Oocytes were collected from the oviducts 16–18 hrs after hCG administration. Superovulation was significantly higher in rats administrated 150 IU/kg PMSG + 75 IU/kg hCG. This study demonstrated that healthy oocytes were produced in DM rat by PMSG and hCG that flowed through the osmotic pump ameliorate on uterus and ovaries.
        12.
        2017.05 구독 인증기관·개인회원 무료
        Several species show low sensitivity to IVM, and the development of optimized medium possible oocyte quality and stable growth. Furthermore, adding additive to the medium can effectively reducing development cost and leads to easy handling of oocytes. Isoliquritigenin and formononetin are extracts found in licorice. Previous studies reported that isoliquritigenin and formononetin affected the activity of sperm, but the oocytes are unknown. This study adds isoliquritigenin or formononetin to αMEM to mature oocytes under simple IVC conditions. Recovered oocytes are cultured in αMEM, isoliquritigenincontaining medium and formononetin-containing medium. In study we proved that in addition to the medium, above the quality of oocytes cultured when specific additives were added, more stable growth is possible. collection and IVM of oocyte. SD rats at 6 to 8 wks of age are injected is intraperitoneal with 30 IU/mL of PMSG and 48 hrs later, HCG 50 IU/mL is intraperitoneal injected. Oocytes are collected ovary after 17 hrs. Collected oocytes are cultured for 16 hrs with 200 μL αMEM and 200 μL αMEM containing isoliquritigenin or formononetin at 0, 0.01, 0.02, 0.04, 0.1 mg/mL. Also, isoliquritigenin and formononetin were mixed with 200 μL αMEM at a ratio of 0.25: 0.75, 0.50: 0.50, and 0.75: 0.25 mg/mL respectively. Oocytes supplemented with isoliquritigenin and Formononetin had high quality than oocytes cultured with αMEM and showed an increase in the IVF fertility rate. Our experimental results indicate that using isoliquritigenin, formononetin when cell culture, rather than used only in medium, more effective oocyte quality and stable growth.
        13.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The cryopreservation of sperm has become the subject of research for successful artificial insemination technologies. Antifreeze proteins (AFPs), one of the factors necessary for effective cryopreservation, are derived from certain Antarctic organisms. These proteins decrease the freezing point of water within these organisms to below the temperature of the surrounding seawater to protect the organism from cold shock. Accordingly, a recent study found that AFPs can increase the motility and viability of spermatozoa during cryopreservation.To evaluate this relationship, we performed cryopreservation of boar sperm with AFPs produced in the Arctic yeast Leucosporidium sp. AFP expression system at four concentrations (0, 0.01, 0.1, and 1 μg/ml) and evaluated motility using computer assisted sperm analysis. DNA damage to boar spermatozoa was measured by the comet assay, and sperm membrane integrity and acrosome integrity were evaluated by flow cytometry. The results showed that motility was positively affected by the addition of AFP at each concentration except 1 μg/ml (p<0.001).Although cryopreservation with AFP decreased the viability of the boar sperm using, the tail DNA analyses showed that there was no significant difference between the control and the addition of 0.1 or 0.01 μg/ml AFP. In addition, the percentage of live sperm with intact acrosomes showed the least significant difference between the control and 0.1 μg/ml AFP (p<0.05), but increased with 1 μg/ml AFP (p<0.001). Our results indicate that the addition of AFP during boar sperm cryopreservation can improve viability and acrosome integrity after thawing.
        4,200원
        15.
        2016.10 구독 인증기관·개인회원 무료
        Our objective was to evaluate the function of treahlose and erythritol in reducing ROS concentrations, which is associated with a general improvement in the quality of frozen-thawing miniature pig sperm. Semen was mixed in modified Modena B extender, added to cooling media and freezing media, followed by the supplement of 100 mM trehalose and/or 100 mM erythritol with spermatozoa (1000x 109cells/straw). The trehalose plus erythritol (TE) added group had less intracellular H2O2 than did control and trehalose (36.6±1.6 vs. 49.0±5.8 and 48.8±7.9; P<0.05). The percentage of viable acrosome-intact sperm (FITC-PNA-/PI-) was higher in erythritol and TE than controls (57.0±5.5% and 62.5±4.3% vs. 45.4±5.4%; P<0.05 and P<0.001). The percentage of sperm with high fragmented DNA was observed in control group when compared with erythritol and TE also trehalose (65.5±1.3% vs 59.3±0.7% and 59.0±0.3% vs 62.2± 0.8%; P<0.001). The percentage of sperm LPO was higher in control and trehalose than erythritol (4.4±0.5% and 5.0±0.5% vs. 3.5±0.2; P<0.01 and P<0.001), and was lowest in the TE (control and trehalose vs. TE: P<0.001, erythritol vs. TE: P<0.05). Also, we performed that surgical insemination based on above data to evaluate the function of new cryoprotectant such as trehalose plus erythritol in vivo. Finally, 1 pregnant gilt showed natural estrus was allowed to go to term and 8 live piglets were born. In conclusion, miniature pig sperm was successfully cryopreserved with trehalose plus erythritol provided the increasing the sperm quality and reducing the ROS.
        16.
        2016.10 구독 인증기관·개인회원 무료
        Cryopreservation of miniature pig sperm is essential because of high demand of organ transplant in mass production. However, miniature pig sperm are vulnerable to oxidative stress more than other mammals. Erythritol is a naturally occurring sugar alcohol with powerful antioxidant property. Thus, the aim of our study is to verify if erythritol could reduce lipid peroxide and enhance viability of frozen thawed miniature pig sperm. Ejaculated semen samples were frozen with cryoprotectant subjected to erythritol treatment (0, 10, 100, 500 mM). After frozen thawed, spematozoa viability were examined using the computer assisted sperm analysis (CASA) system. The product of lipid peroxidation, malondialdehyde (MDA) were quantified using spectrophotometer with DPPH and ABTS assays as ROS scavenger markers. Our result showed that erythritol enhanced sperm viability (p<0.05), reduced lipid peroxides significantly (p<0.05), proving the concentration of 100 mM erythritol to be an effective for lowing oxidative damage. Data from our study suggest that erythritol exhibits significant lipid peroxidation scavenging characteristics which may prevent oxidative damage, enhance viability of frozen thawed sperm and thus could be a effective additive as cryoprotectant.