• Journal of the Korean Chemical Society
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• v.28 no.3
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• pp.170-175
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• 1984

The transport rates of $H^+$ ion by DBC and DCC as carrier molecules through organic liquid membranes were determined at 25$^{\circ}$C. The transport rates depend highly on the dielectric constants of membrane solvents and these results were discussed in terms of Born's potential energy barrier methods. The sizes of anions also affect the transport rates and these results were well explained theoreticlly by extended Born's equation.

• YAKHAK HOEJI
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• v.21 no.2
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• pp.55-61
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• 1977

호르몬과 효소와의 관계를 포함하는 사항은 다음과 같이 고려할 수 있다. 즉, 1. 효소생성에 미치는 호르몬의 작용, 2. 효소활성에 미치는 호르몬의 작용, 3. 효소활성에 관여하는 제인자(조효소, activator, inhibitor)에 대한 호르몬의 작용, 4. 효소에 의한 호르몬의 합성, 5. 효소에 의한 호르몬의 분해등이다. 최근 50년간의 이 분야의 발전상은 실로 괄목할 만하며 또 그에 관한 보문도 매거할 수 없을 정도이다. 본고에 주어진 본제에 대하여는 최근에 거론되어 있는 호르몬의 표적세포의 receptor에 대하여, 호르몬의 제2의 messenger로서의 cyclic AMP및 그의 유사체인 DBC-AMP 그리고 호르몬에 의한 효소유도에 대하여 소개하고자 한다.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.239-246
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• 1992

Capacitated and acrosome~reacted spermatozoa were microinjected into the perivitelline space of bovine oocytes matured in vitro. Oocytes obtained from the ovaries of slaughtered heifers and cows were cultured in vitro in the TCM-199 supplemented with 20% FCS for 24 hr at 39$^{\circ}C$ under an atmosphere of 5% CO$_2$ 8% O$_2$. Fresh or frozen spermatozoa were incubated for 2 hr at 39°C under an atmos-phere of 5% CO$_2$, 8% O$_2$ in Ham's F-lO medium containing 0.75% BSA for capacitation, and kept for 30 min in culture medium containing 12 mM of dbcGMP and lOmM of immidazol for acrosome resction. One motile spermatozoon was injected into the perivitelline space of each oocyte. The 2nd polar body and the pronuclei were observed in 9.5% and 5.4% of oocytes, respectively. The rate of cleavage of oocyte over 2-cell stage was 4.1%(10 of 242), These results indicate that the microinjection may be a useful technique to study sperm-oocyte interaction.

• The Korean Journal of Zoology
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• v.18 no.2
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• pp.87-101
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• 1975

Electron microscopic studies on the ultrastructure of the mouse oocyte were made to investigate the inhibition of germinal vesicle breakdown by dibutyryl cAMP. The nuclear membrane of the dibutyryl cAMP-treated oocyte is characterized by a decreased degree of folding, maintains the normal double membrane structure, and shows an increased occurrence of the nuclear pore. It is suggested that these may be related to the suppression of the maturation of oocytes at the germinal vesicle. Mitochondria in the control cell were shown to be spread evenly throughout the cytoplasm and structurally underdeveloped or transitionary having little cristae development. On the contrary, mitochondria in the treated oocyte were found to be localized mainly around the nucleus and to show a greater extent of cristae development. The oocyte treated with dibutyryl cAMP appears to have fewer and structurally simpler lysosomes as compared to the control. The Golgi complex in the control oocyte exhibits the typical granular and lamellar structure, whereas that in the treated cell is poorly developed. Many multivesicular bodies, tonofilaments, and free ribosomes were observed in the control as well as in treated cells. The microvilli become structurally irregular, and a development of the perivitelline space is apparent in the treated oocyte. It is concluded that there is no basic difference in the ultrastructure between the oocytes treated with dibutyryl cAMP for 24 hours in the medium and those collected directly from the follicle. However, the finding that dibutyryl cAMP induces a development of more pores along the nuclear membrane strongly suggests the possibility that this compound inhibits the maturation of oocytes by influencing the permeability of the nuclear membrane.

• Nutrition Research and Practice
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• v.5 no.4
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• pp.301-307
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• 2011

The hypolipidemic and hypoglycemic effects of two dietary dosages (0.1% and 0.5%) of water and 80% ethanol extracts from hot-air dried Orostachys japonicus A. Berger were evaluated in the serum and organ tissues of streptozotocin-induced diabetic rats. The STZ-induced diabetic groups supplemented with the O. japonicus extracts showed significantly higher body weight compared to a diabetic control group at the end of experiment. The extracts exhibited substantial hypoglycemic effects by significant reductions of fasting blood glucose levels at all time points tested compared to the initial stage before treatment of the extracts. Declines of serum and hepatic triglyceride levels were greater than declines of total cholesterol in the groups treated with the 0.5% O. japonicus extract (DBW2 and DBE2) when compared to the DBC group. Hepatic glycogen content was higher in the groups treated with O. japonicus extract, while lipid peroxide content was decreased in these treated groups compared to the DBC group. Hepatic antioxidant activity was significantly increased in the groups supplemented with the O. japonicus ethanol extract The hypolipidemic and hypoglycemic effects of the O. japonicus ethanol extract were significantly greater than the effects of the water extract. Based on this study, it seems that O. japonicus ethanol extract, due to its higher phenolic and flavonoid components than the water extract, may control blood glucose and alleviate hyperlipidemia in diabetes.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.33-33
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• 2003

This study was conduct to compare the efficacy to produce male and female somatic cloned piglets. Maturation of porcine COCs was accomplished by incubation in NCSU-23 medium supplemented with 0.6 mM cysteine, 10% porcine follicular fluid, 1mM dibutyryl cyclic adenosine monophosphate (dbc-AMP, Sigma, USA), and 0.1 IU/ml human menopausal gonadotrophin (hMG, Teikokuzoki, Japan) for 20h and then cultured without dbcAMP and hMG for another 18 to 24 h. Female and male fetal cells were isolated from each fetus, cultured in ES-DMEM medium containing 10% FCS. Enucleated oocytes were fused with fetal fibroblasts (passage 4 to 15). Reconstructed embryos were cultured in NCSU-23 with 4 mg/ml BSA under mineral oil at 39$^{\circ}C$ in 5% $CO_2$ in air. A total of 12,328 nuclear-transferred embryos (1- to 4-cell stage) were surgically transferred into 69 surrogate gilts. Three recipients aborted during the period of conception. Three gilts delivered eleven female piglets, and five recipients gave rise to birth 22 male piglets. The average birth weigh of the cloned piglets was 1.52 kg (1.38~1.83 kg) in female piglets and 0.84 kg (0.45~1.25 kg) in male piglets. Alive cloned pigs was seven in female piglets (63.6%) and four in male piglets (18.2%). The other two recipients is ongoing. This study suggests that female-derived fetal cell as a nuclear donor has more capability on production of cloned piglets than male.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.448-468
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• 1996

To maintain its functional integrity, bone is continuously remodelled by a process involving resorption by osteoeclasts and formation by osteoblasts, In order to respond to changes in the physical environment or to trauma with the relevant action, this process is strictly regulated by locally synthesized or systemic fators, Prostaglandin $E_2(PGE_2$) is perhaps one of the best studied factors, having been known to affect bone cell function for several decades.$PGE_2$ has both anabolic and catabolic activities. Excess of $PGE_2$ has been implicated in a number of pathological states associated with bone loss in a number of chronic inflammatory conditions such as periodontal disease and rheumatoid arthritis. $PGE_2$ and other arachidonic acid metabolites have been shown to be potent stimulators of osteoclastic bone resorption in organ culture. The anabolic effects of $PGE_2$ were first noticed when an increase in periosteal woven bone formation was seen after the infusion of $PGE_2$ into infants in order to prevent closure of the ductus arteriosus. The cellular basis for the catabolic actions of $PGE_2$ has been well characterized. $PGE_2$increases osteoclast recruitment in bone marrow cell cultures. Also $PGE_2$ has a direct action on osteoclast serving to inhibit activity and can also indirectly activate osteoclast via other cells in the vicinity, presumably osteoblast. The cellular mechanisms for the anabolic actions of $PGE_2$ are not nearly so well understood. The purpose of this paper was to study the effects of $PGE_2$ and dibutyl(DB)cAMP on osteoblastic clone MC3T3El cells and on the generation of osteoclasts from their precursor cells. The effect of $PGE_2$ and DBcAMP on the induction of alkaline phoaphatase(AlP) was investigated in osteoblastic clone MC3T3El cells cultured in medium containing 0.4% fetal bovine serum. $PGE_2$ and DBcAMP stimulated ALP activity and MTT assay in the cells in a dose-dependent manner at concentrations of lO-SOOng/ml. Cycloheximide, protein synthesis inhibitor, inhibited the stimulative effect of $PGE_2$ and DBcAMP on ALP activity in the cells. $PGE_2$also increased the intracellular cAMP content in a dose-dependent fashion with a maximal effect at 500ng/ml. The effect of $PGE_2$ on the generation of osteoclasts was investigated in a coculture system of mouse bone marrow cells with primary osteoblastic cells cultured in media containing 10% fetal bovine serum.After cultures, staining for tartrate-resistant acid phosphatase(TRAP)-marker enzyme of osteoclast was performed. The TRAP(+) multinucleated cells(MNCs), which have 3 or more nuclei, were counted. More TRAP(+) MNCs were formed in coculture system than in control group. $PGE_2(10^{-5}10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in culture. $PGE_2(10^{-6}M)$ stimulated the formation of osteoclast cells from mouse bone marrow cells in coculture of osteoblastic clone MC3T3E1 cells This results suggest that $PGE_2$ stimulates the differentiation of osteoblasts and generation of osteoclast, and are involved in bone formation, as well as in bone resorption.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.183-189
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• 1991

The present study was performed to elucidate the factors which modulate uterine prostaglandin synthesis during the implantation period in rats, by employing delayed implantation model. Administration of estradiol sharply increased uterine cAMP concentration 4 hrs later during the delayed implantation process. Concentrations of uterine PGE and $PGF_2{\alpha}$ were increased at 12 hrs after the estradiol treatment although an increase in $PGF_2{\alpha}$ was not statistically significant. The concomitant treatment of indomethacin with estradiol significantly suppressed estradiol-induced PGE and $PGF_2{\alpha}$ at 12 hrs, while uterine cAMP concentration was not suppressed. The treatment of dbcAMP without estradiol gradually increased uterine PGE and $PGF_2{\alpha}$ showing the maximum 8 hrs later, suggesting that cAMP minics estradiol effect on uterine prostaglandin synthesis during the implantation process. Furthermore, the pretreatment of theophylline, phosphodiesterase inhibitor, induced significantly greater concentrations of uterine PGE and $PGF_2{\alpha}$, compared with estradiol-only treated group. These results suggest that estradiol stimulates uterine prostaglandin synthesis and this process may be mediated by an elevation of cAMP during the delayed implantation process in rats.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.161-167
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• 2015

The performance of high power LEDs highly depends on the junction temperature. Operating at high junction temperature causes elevation of the overall thermal resistance which causes degradation of light intensity and lifetime. Thus, appropriate thermal management is critical for LED packaging. The main goal of this research is to improve thermal resistance by optimizing and comparing nano-pore silicon-based thermal substrate to insulated metal substrate and direct bonded copper thermal substrate. The thermal resistance of the packages are evaluated using computation fluid dynamic approach for 1 W single chip LED module.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.50-50
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• 1993

최근의 암치료용 제제는 암세포의 분화를 재개시켜서 정상적인 세포로 분화 유도하는 약재개발에 촛점을 맞추고 있으므로 본 연구에서는 F9 EC세포주에 의한 분화인자 스크리닝 시스템을 확립하고 나아가 새로운 분화 유도인자를 스크리닝 하는데 그 목표를 두고 연구를 수행하였다. 즉 F9 EC세포의 세포 배양조건을 먼저 확립하였으며 retinoic acid에 의한 F9 EC세포의 분화유도 시스템을 다음과 같이 확립하였다. 1 단계: F9 EC세포에 스크리닝할 물질의 단독처리 2 단계: 스크리닝할 물질에 dibutyryl cyclic AMP(dbc-AMP)와 theophylline을 첨가하여 처리 3 단계: 분화 marker유전자의 발현조사 그리고 이 시스템을 이용하여 천연 식물 및 해양동식물에서 추출한 성분을 대상으로 하여 새로운 분화인자의 검색을 시도한 결과, saponin, steroid 및 glycolipid계열의 물질이 분화인자로서 효과가 있음이 나타났다.