• The Korean Journal of Physiology and Pharmacology
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• 제8권4호
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• pp.227-235
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• 2004

The aim of the present study was to examine the effect of leptin on CA release from the isolated perfused model of the rat adrenal gland, and to establish its mechanism of action. Leptin $(1{\sim}100\;ng/ml)$, when perfused into an adrenal vein of the rat adrenal gland for 60 min, enhanced a dose-dependently the secretory responses of CA evoked by ACh $(5.32{\times}10^{-3}\;M)$, DMPP $(10^{-4}\;M)$ and McN-A-343 $(10^{-4}\;M)$, although it alone has weak effect on CA secretion. However, it did not affect the CA secretion evoked by excess $K^+\;(5.6{\times}10^{-2}\;M)$. Leptin alone produced a weak secretory response of the CA. Moreover, leptin (10 ng/ml) in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644, an activator of the dihydropyridine L-type $Ca^{2+}$ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}$ ATPase. However, in the presence of U0126 $(1\;{\mu}M)$, an inhibitor of mitogen-activated protein kinase (MAPK), leptin no longer enhanced the CA secretion evoked by ACh and DMPP. Furthermore, in the presence of anti-leptin (10 ng/ml), an antagonist of Ob receptor, leptin (10 ng/ml) also no longer potentiated the CA secretory responses evoked by DMPP and Bay-K-8644. Collectively, these experimental results suggest that leptin enhances the CA secretion from the rat adrenal medulla evoked by cholinergic stimulation (both nicotininc and muscarinic receptors), but does not that by membrane depolarization. It seems that this enhanced effect of leptin may be mediated by activation of U0126-sensitive MAPK through the leptin receptors, which is probably relevant to the activation of the dihydropyridine L-type $Ca^{2+}$ channels located on the rat adrenomedullary chromaffin cells.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.79-79
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• 2017

Grain Sorghum varieties grown in Korea have low productivity and are constrained by the fact that farmers' choice of improved varieties is limited. Hybrid cultivars have been demonstrated to be more productive and food security than pure line varieties. However, There's no available hybrid cultivars and never planted before in Korea. This study was, therefore, conducted to determine combining ability of Korean landrace varieties and cultivar, the level of heterosis of experimental hybrids depending on environments. Two cytoplasmic male-sterile lines were crossed with six male-fertile lines in accordance with North Carolina II mating scheme to generate 12 experimental hybrids. The hybrids were evaluated in replicated row-column alpha designs at two sites in Texas and South Korea under on-season production conditions. For each trait, general combining ability (GCA) and specific combining ability (SCA) effects were estimated using the line-tester method of analysis. Results indicated significant differences among genotypes for both grain yield potential and secondary traits. Hybrids were predominant for grain yield, and displayed up to 127% heterosis of A03017 ${\times}$ Sodamchal in Korea. Positive GCA for yield was observed for Donganme, Hwanggeumchal and Jungmo4002 in Korea. Among them Jungmo4002 and Donganme had highly positive for yield (227.90 and 84.90 kg ha-1), while it showed negative GCA for yield in College station (-40.90, -189.60 kg ha-1). ATx630 ${\times}$ Sodamchal had the greatest SCA for yield (468.10 kg/ha) in College station but at South Korea its SCA effect was -302.40 kg/ha. A similar trend was observed, followed by A03017 ${\times}$ Donganme (SCA effect = 215 kg ha-1 at College station vs. -44.20 kg ha-1 at South Korea). At South Korea the greatest positive SCA effect for grain was observed in ATx630 ${\times}$ Jungmo4002 as 322.20 kg/ha. Both GCA and SCA effects significantly interacted with site effects demonstrating the need for region adaptation of potential cultivars and test for developing Korea suitable cultivar.

• 생약학회지
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• 제32권2호통권125호
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• pp.121-127
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• 2001

The effect of bear bile on 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD)-induced hepatotoxicity was investigated in 6-week-old C57BL/6 male mice. Bear bile (100 mg/kg or 500 mg/kg) was administered orally daily for 4 weeks, respectively. From the second week, $10\;{\mu}g/kg$ of TCDD was administered to the bear bile-treated animals orally once a week for 3 weeks (a total of $30\;{\mu}g/kg$). There were no specific clinical findings and significant body weight changes in all groups. Although the livers in TCDD-treated mice appeared a severe hypertrophy and many necrotic foci, and changed to yellow-brown color in gross findings, these lesions were remarkably reduced by bear bile administration. The elevated serum activities of alanine transaminase, aspartate transaminase, alkaline phosphatase, and lactate dehydrogenase due to TCDD were significantly decreased by bear bile treatment (P<0.05). The lipid peroxidation induced by TCDD was significantly prevented by bear bile administration (P<0.05). In histological examinations, there were a moderate necrosis of hepatic cells around central veins, severe cytoplasmic vacuolizations, inflammatory cell infiltrations, and remarkable fatty changes in the liver of TCDD-treated animals. However, the lesions were dose-dependently inhibited by the bear bile treatments. These findings indicate that bear bile may have a protective effect against TCDD-induced hepatotoxicity in mice.

• 대한임상검사과학회지
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• 제36권1호
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• pp.55-63
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• 2004

The hepatotherapeutic effect of the extract of Lycii fructus has been studied in rats against $CCl_4$ induced liver toxicity. The rats were orally treated with $CCl_4$ (corn oil/$CCl_4$ 1:1, $1m{\ell}/kg$) and then $CCl_4$ ($0.5m{\ell}/kg$) administered four times for 2 weeks. The extracts of L. fructus have been administered every day for 2 weeks after the last $CCl_4$ injection. The experimental groups consisted of negative control (G1), positive control ($CCl_4$ alone; G2), extract of L. fructus (50 mg/kg; G3, 100 mg/kg; G4, 200 mg/kg; G5), respectively. There was a significant decrement to G2 on the serum level of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in G5. Also, the content of thiobarbituric acid reactive substance, and phosphatidylcholine hydroperxidase, a marker of lipid peroxidation, in the liver were decreased significantly G5 and G4 compared with G2. Although, catalase or superoxide dismutase, antioxidant enzyme, in the liver were decreased significantly too, it would not be a good sign for the liver. In histopathological findings, such a hepatocellular vacuolar degeneration, lobular restructure, cellular infiltration, necrosis, and so on were shown severely in G2. However, G4 and G5 was shown a mild cytoplasmic vacuolation and inflammatory cell. In conclusion, as a protection against cell damage, lipid peroxidation and serum level, it suggested that the extract of Lycii fructus would have been a therapeutic effect of liver injury directly.

• Molecules and Cells
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• 제22권1호
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• pp.70-77
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• 2006

Platelets are anucleate cytoplasmic fragments derived from bone marrow megakaryocytes, and endothelial cells constitute the barrier between bloodstream and adjacent tissues. Although platelets are thought to regulate the biological functions of endothelial cells, the molecular mechanisms involved are poorly understood. With human umbilical vein endothelial cells and freshly isolated platelets, we established an in vitro model of platelet-induced endothelial cell proliferation. Platelets stimulated endothelial cell proliferation in a dose-dependent manner and transwell experiments with semi-permeable membranes suggested that direct cell-to-cell contacts were required. We developed mAbs against platelets and selected a mAb that blocks their proliferative effect. We purified the antigen by immunoprecipitation and identified it by Q-TOF MS analysis as the tetraspanin CD9. Since both platelets and endothelial cells expressed CD9 strongly on their surfaces we carried out a pre-treatment experiment that showed that CD9 molecules on the endothelial cells participate in the mitogenic effect of the platelets. The inhibitory effect of our mAb was comparable to that of a well-known functional anti-CD9 mAb. These results suggest that the tetraspanin CD9 plays an important role in endothelial regeneration.

• 한국식품과학회지
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• 제31권2호
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• pp.522-526
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• 1999

S. mutans에 대한 키토산의 항균효과는 그 분자량에 따라 뚜렷한 차이를 보였으며, 약 30,000의 분자량을 갖는 키토산이 가장 높은 항균활성을 보였다. 키토산 처리에 의해 세포로부터 단백질, 핵산, 2가 양이온 등이 상당량 유출되는 것이 관찰되었으며, 세포내 물질의 유출정도는 키토산의 항균효과와 밀접한 상관성을 보였다. 이러한 세포내 물질의 유출은 양이온성을 띠는 키토산의 아민기와 세포벽내의 음이온 성분과의 강한 결합에 의해 세포벽의 결합력이 약화되면서 생기는 결과로서 추측되었다. 키토산처리에 의해 S. mutans의 세포벽이 원형질로부터 분리되고 세포내 물질이 세포벽 내에서 밖으로 유출되는 현상은 투과전자현미경(TEM)에 의해 확인되었다.

• 대한의생명과학회지
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• 제15권1호
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• pp.93-96
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• 2009

House dust mites (HDMs) play an important role in the occurrence of allergic diseases such as asthma and atopic dermatitis. Dermatophagoides pteronyssinus (Der p) is one of the most prevalent HDMs. It mediates the activation of T cells and monocytes, and induces the elevation of immunoglobulin E levels in allergic diseases. However, the effects of Der p on human monocytes have not been fully understood. In the present study, we investigated whether or not Der p has a great effect on the chemotactic activity of the human monocytic cell line, THP-1 cells, as induced by CC chemokines. We also show that the Der p extract (DpE) increased the chemotactic activity of THP-1 cells in response to MCP-1, RANTES, MIP-1${\alpha}$, and TARC, but had no effect on the expressions of CC chemokine receptors (CCRs) binding to CC chemokines in THP-1 cells. Protease inhibitors, such as aprotinin and E64, blocked the increased chemotaxis, while cytoplasmic $Ca^{2+}$ influx mediated by these chemokines was inhibited by DpE. These results indicate that DpE increases the chemotactic activity of THP-1 cells in response to CC chemokines by regulating the cells' protease-dependent mechanism. This finding may be useful in identifying the pathogenesis of allergic diseases induced by Der p.

• 한국수정란이식학회지
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• 제9권1호
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• pp.1-6
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• 1994

This experiment was investigated the effect of presence of granulosa cells from follicles of different size on bovine oocyte maturation, cleavage and development to late stage. The nuclear and cytoplasmic maturation of oocytes in the IVM-IVF system are critical for subsequent embryo development. Granulosa cells when the co-cultured with oocytes may interact with cumulus-oocytes complexes and influence the development competence of the oocytes. Granulosa cells from medium (2~6 mm) and large(>1O mm) size follicles were recovered by aspiration, washed 3 times by centrifugation at 500 x g for 5 min. and used for co-culture at a concentration of 2~3 x 106 cells/mi. The oocytes were matured in vitro (IVM) for 24 hrs. in TCM-199 supplemented with 35 $\mu$g/ml FSH, 10 $\mu$g/ml LH, 1 $\mu$g/ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (I VC) with bovine oviductal epithelial cells for 7 to 9 days. The assessment of maturation revealed that Grade J oocytes showed significantly(P

• 동의생리병리학회지
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• 제20권6호
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• pp.1561-1566
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• 2006

Sebum is secreted due to the effect of androgen, which start to be secreted at puberty. Androgens have profound effects on the physiology of the sebaceous gland, Using the human sebocyte cell line SZ95, we investigated the inhibitory effect of Chelidonii Harba (CH) on the subum production. Our results showed that numerous cytoplasmic lipid droplets were examined by Oil red staining and lipid droplets were increased markedly by testosterone. Cell viability was dose-dependently decreased by CH as compared with untreated cells, while total lipid content and cholesterol slightly were increased by CH. Testosterone significantly stimulated the synthesis of total lipid and the synthesis of specific sebaceous lipids such as cholesterol and triglyceride. Combined treatment with CH and testosterone resulted in a lower lipid synthesis than with testosterone alone. Especially cholesteol content was reduced by combined treatment with CH and testosterone. These results indicate that CH inhibits the testosterone-induced lipid synthesis in SZ95 cells and acts antagonistically to androgen at the cellular level.

• Journal of Photoscience
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• 제9권2호
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• pp.509-511
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• 2002

In this study, we investigated apoptotic cell death induced by photodynamic therapy using 5-aminolaevulinic acid (ALA-PDT) in human promyelocytic leukemia cells (HL-60). ALA-PDT induced apoptosis in HL-60 cells as confirmed by DNA agarose gel electrophoresis and nuclear staining with Hoechst 33342. The apoptotic cell death was inhibited by addition of broad-spectrum caspase inhibitor Z-Asp-CH$_2$-DCB, indicating that the apoptotic cell death was induced in a caspase-dependent manner. Actually, western blotting analysis revealed that caspase-3 was processed as early as 1.5 h after ALA-PDT. Cytoplasmic cytochrome c released from mitochondria was detected by western blotting. However, inhibitor of caspase-9, a cysteine protease located in the downstream of cytochrome c release, was not able to reduce the apoptotic cell death. Therefore, the mitochondrial apoptotic pathway was not involved in the ALA-PDT-induced apoptosis. On the other hand, it was found that ALA-PDT-induced apoptosis was clearly inhibited by pretreatment of caspase-8 inhibitor. These data suggest that caspase-8-mediated apoptotic pathway is important in ALA-PDT-induced cell death.