• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.267-273
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• 2004

Maturation of oocytes is maintained by complex procedures along with follicular genesis and is a critical step for embryonic development. Purine known as an oocyte maturation regulator is present in follicular fluid. In this study, the roles of guanosine as a strong inhibitor of GVBD and a modulator of cyclic GMP concentration in ooyctes were revealed. Denuded immature oocytes were treated with guanosine, and the maturation rates and cGMP concentration of oocytes were measured. GVBD was blocked in a concentration dependent manner by guanosine, but this effect was reversible. However, GVBD was lagged yet not significant by adenosine. Both guanosine and adenosine modified cGMP concentration in oocytes. The characteristic of the guanosine-treated oocyte was significantly higher cGMP compared with the adenosine-treated oocyes at initial time of the maturation. Based these results, guanosine may be a strong and reversible GVBD inhibitor. Although the precise mechanism of guanosine presently is unclear, the results suggest that guanosine may lead the accumulation of cGMP in oocyte cytoplasm, which in turn suppresses GVBD.

• Journal of Embryo Transfer
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• v.33 no.4
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• pp.271-280
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• 2018

Here, we evaluated the mode of programmed cell death during porcine oocyte maturation by comparing the two major pathways associated with programmed cell death, apoptosis (type I), and autophagy (type II). We investigated the expression and localization of major genes involved in autophagy and apoptosis at mRNA and protein levels. Furthermore, the effect of hormonal stimulation on autophagy and apoptosis was analyzed. We found that the activity of autophagy-associated genes was increased in the cumulus-oocyte complexes (COCs) following follicle-stimulating hormone (FSH) treatment, while the addition of luteinizing hormone (LH) reversed this effect. The expression of proteins associated with autophagy was the highest in FSH-treated COCs. On the other hand, caspase-3 protein level was maximum in COCs cultured with LH. The treatment with rapamycin resulted in the effect similar to that observed with FSH treatment and increased autophagy activity. Thus, hormonal stimulation of pig oocytes resulted in distinct patterns of maturation. The high-quality oocytes majorly relied on the type II pathway (autophagy), while the type I pathway (apoptosis) was more prominent among poor-quality oocytes. Further investigation of this distinction may allow the development of techniques to produce high-quality oocytes in porcine in vitro fertilization.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.293-300
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• 1997

Supplementation of maturation medium with additional granulosa cells has beneficial effect on in vitro maturation of bovine follicular oocytes and their subsequent cleavage and development in vitro. However, maturation system using granulosa cells have some disadvantages that collection of granulosa cells is cumbersome and metabolic activity of the cells is variable according to ovarian cycle or follicular size. We hypothesized that bovine immsture oocytes matured without granulosa cell coculture can fertilize and develop normally if the medium volume per oocyte is reduced during in vitro maturation. Immature oocytes were matured for 24 hours in a TCM199 containing 10% fetal calf serum, anterior pitultary hormone (0.02 AU /ml Antrinⓡ) and estradiol with or without granulosa cells in vitro. In Group 1, 35 to 40 oocytes were matured in a well of 4-well plastic dish containing 500 $\mu$l of maturation medium and granulosa cells, and 9 to 10 oocytes were matured in a 50-$\mu$l drop of maturation medium without granulosa cells in Group 2. After maturation, oocytes were coincubated with sperm for 30 hours in a modified Tyrode's medium (IVF). Inseminated oocytes were cultured in a microdrop (30 $\mu$l) of a synthetic oviduct fluld medium (SOFM) containing BSA, Minimum Essential Medium essential and non-essential amino acids for 9 days. As a preliminary experiment, we investigated the beneficial effect of granulosa cells during maturation on subsequent cleavage and development using the same type of culturedishes (4-well dish). Granulosa cells could not increase embryo cleavage after fertilization but significantly improved (p<0.05) embryo development to expanding blastocyst (Table1 and 2). In Group 1, 68 and 80% of inseminated oocytes have cleaved at 30 hours and 2 days after IVF, respectively, which is similar (p>0.05) to the result of Group 2 (69% at 30 hours and 78% at 2 days after IVF). The oocytes in Group 2 showed 21 and 11% of developmental rates to expanding and hatching blastocysts, respectively, which was not significantly different (p>0.05) from those (20 and 10%, respectively) of oocytes in Group 1. In conclusion, it has been clarified that a microdrop culture system without granulosa cells for in vitro maturation can support bovine embryonic development to blastocyst in vitro as readily as a granulosa cell coculture system.

• The Korean Journal of Zoology
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• v.28 no.2
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• pp.99-107
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• 1985

In order to investigate the synergistic effect of dbcAMP and progesterone which are known as the agents to inhibit maturation of mammalian oocytes in vitro, the present studies were done and the results were obtained as follow: 1) if 10 $\\mug$/ml of dbcAMP or 2 $\\mug$/ml of progesterone was given into the medium, each of the agents at the concentration above did not give any inhibitory effect on the maturation of the mouse oocytes in vitro; 2) however, when the two agents at the concentration shown above were given together into the medium, the mouse oocytes were arrested at GV stage; and 3) the oocytes, precultured in the medium containing two agnts at the same concentration as above for four hours, resumed their maturation division upon transfer to the plain medium for the extended culture. Thus, it was found that dbcAMP and progesterone were capable to suppress the maturation of mouse oocytes at the suboptimal concentration when they were given together, and such inhibitory effect was reversible.

• Reproductive and Developmental Biology
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• v.28 no.2
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• pp.95-99
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• 2004

This study was carried out to assess whether the addition of myo-inositol to maturation medium could improve porcine oocyte maturation in vitro. Oocytes were cultured for the first 22 h in Witten's medium containing 10IU/$m\ell$ PMSG, 10 IU/$m\ell$ HCG supplemented with or without myo-inositol. Subsequently, they were cultured for additional 22 h in Witten's medium without hormone supplemented with or without myo-inositol. When the porcine oocytes were cultured in maturation medium containing myo-inositol, the proportion of metaphase II oocytes 44h after culture was higher in the myo-inositol group(P<0.05). To study effects of cumulus cell on the maturation induced by myo-inositol, we examined the maturation status of cumulus-enclosed or cumulus-denuded porcine follicular oocytes. The rates of maturation were significantly higher in the cumulus-enclosed oocytes(P<0.05). However, the maturation rates of cumulus-denuded oocytes cultured in medium containing myo-inositol were higher than those of control group(P<0.05). Our results suggest that myo-inositol may affect meiotic progression of porcine follicular oocytes and supplementation of myo-inositol in maturation medium may be useful for the in vitro maturation of porcine follicular oocytes.

• Journal of Animal Science and Technology
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• v.57 no.8
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• pp.27.1-27.6
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• 2015

This study was designed to investigate the effects of ${\alpha}$-tocopherol and granulosa cells monolayer on nuclear maturation and cleavage rates of ovine cumulus-oocyte complexes (COCs). The COCs (n = 2814) were matured in maturation medium supplemented with various concentration of ${\alpha}$-tocopherol (0, 5, 10, $15{\mu}g/ml$), oocytes were incubated at $39^{\circ}C$ with 5 % $CO_2$ for 24 h in three culture systems: (a) maturation medium (MM; n = 884), (b) co-cultured with granulosa cells (CG; n = 982) and (c) co-cultured with granulosa cells and cells were further cultured in MM for 12 h (CG + 12hMM; n = 948). Our results showed that ${\alpha}$-tocopherol had no effect on GVBD and MII as compared to control group, but when ${\alpha}$-tocopherol added to maturation medium the rate of cleavage decreased. This indicates interaction of above mentioned factors in any of the treatments showed no significant differences on the rate of maturation and cleavage stages (MII, GVBD and cleavage) (p > 0.05). The oocytes co-cultured with granulosa cells for 24 h had beneficial effects on cleavage rate. The maximum MII and cleavage rates were achieved when oocytes had extra 12 h culture in the maturation medium without granulosa cells. Results also showed our modified co-culture system (CG + 12hMM), improved rates of MII and the cleavage in comparison with other studied maturation systems.

• The Korea Journal of Herbology
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• v.22 no.3
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• pp.127-132
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• 2007

Objectives : FLOS CHRYSANTHEMI (FC) has been reported to possess a variety of pharmacological activities. However, the effect of FC on the dendritic cells has not been determined. Methods : To examine the effect of FC on the immune response, we used several methods such as flow cytometric analyses, enzyme-linked immunosorbent assay. Results : 1. FC inhibited lipopolysacchride (LPS)-induced maturation of bone marrow-derived dendritic cells (BMDC) such as down-regulation of MHC class II and CD40. 2. FC also inhibited uptake of FITC-Dextran in BMDC stimulated with LPS. 3. Furthermore, FC inhibited several kinds of cytokine production such as TNF-a, IL-6 and IL-12 in BMDC. Conclusions : These results suggest that FC plays pivotal role m the development of inflammatory diseases.

• Food Science and Preservation
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• v.11 no.4
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• pp.461-467
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• 2004

Antioxidant effect of traditional doenjang(TD) was reduced by increasing of maturation period. Methanol fractionate of TD matured for 1 year showed strong antioxidant effect against linoleic acid, following the order of hexane and water layer. Antioxidant effect in lipophilic and hydrophilic extracts of TD were gradually increased according to increasing maturation period, whereas their values or two extracts were lower than those or fractionates from TD. Hydrogen-scavenging effect in hydrophobic extract, methanol and butanol fractionates of TD were much higher than those of the other samples. Chloroform and ethylacetate fractionates were markedly lower in the range of $10.57{\sim}22.84\%\;and\;7.82{\sim}22.58\%$, respectively. Anticarcinogenic effect of extracts and fractionates from TD were higher in water fractionates for A549 cell (human lung carcinoma) and methanol fractionates fur MCF-7 cell (human breast adenocarcinoma). Especially, inhibitory effect for growth of cancer cell was increased by the increasing maturation period of TD.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.242-242
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• 2004

This study was conducted to investigate the effects of various supplements added into maturation medium of immature porcine oocytes on quantity of cytoplasmic lipid droplets(LD), subsequent fertilization and development to the blastocyst stage in vitro. The basic maturation medium was TCM 199 + 1 ㎍/㎖ FSH, 0.57 mM cystein, 10 ng/㎖ EGF and was supplemented various supplements(10% FBS, 10% pFF, 0.4% BSA, 1.0% BSA, 0.4% PVP, 1.0% PVP). (omitted)

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.72-72
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• 2002

Oocytes maturation, characterized by germinal vesicle (GV) breakdown, formation of the first meiotic spindle, expulsion of the first polar body and arrest in metaphase of second meiotic division (MII), occurs in preovulatory follicles in response to the surge of gonadotropin and leads to an ovulated oocyte in vivo. However, meiotic resumption in vitro occurs spontaneously following removal of cumulus-oocytes complexes (COCs) from the follicle. (omitted)