The effects of chitosan upon the experimentally induced differentiation of MDPC-23 cells, derived from mouse dental papilla cells, were investigated by RT-PCR, observations of cell morphology and Alizaline red-S staining. Chitosan was found to significantly increase and accelerate the expression of ALP mRNA but decrease the ColI transcript levels, as compared with the control, in a time-dependent manner during the differentiation of MDPC-23 cells. Chitosan also significantly downregulated ON mRNA expression and accelerated mineralization in differentiating MDPC-23 cells. These results suggest that chitosan facilitates odontoblast differentiation and mineralization and may have potential clinical applications as a dentin regeneration material.

The mu opioid receptor (MOR) has been regarded as the main site of interaction with analgesics in major clinical use, particularly morphine. The repressor element-1 silencing transcription factor (REST) functions as a transcriptional repressor of neuronal genes in non-neuronal cells. However, it is expressed in certain mature neurons, suggesting that it may have complex and novel roles. In addition, the interactions between MOR and REST and their functions remain unclear. In this study, we examined the effects of morphine on the expression of REST mRNA and protein in human neuroblastoma NMB cells to investigate the roles of REST induced by MOR activation in neuronal cells. To determine the effects of morphine on REST expression, we performed RT-PCR, real-time quantitative RT-PCR, western blot analysis and radioligand binding assays in NMB cells. By RTPCR and real-time quantitative RT-PCR, the expression of REST was found to be unchanged by either the MOR agonist morphine or the MOR specific antagonist CTOP. By western blot, morphine was shown to significantly inhibit the expression of REST, but this suppression was completely blocked by treatment with CTOP. In the radioligand binding assay, the overexpression of REST led to an increased opioid ligand binding activity of endogenous MOR in the NMB cells. These results together suggest that morphine inhibits the expression of REST in human neuroblastoma cells through a post-transcriptional regulatory mechanism mediated through MOR.

원자전달 라디칼 중합을 이용하여 polystyrene-b-poly (hydroxyethyl methacrylate) (PS-b-PHEMA) 블록 공중합체를 합성한 뒤, 블록 공중합체의 -OH 그룹과 이미다졸 디카르복실릭산 (IDA)의 -COOH 그룹과의 에스테르 반응에 의하여 가교된 전해질막을 제조하였다. 인산(H3PO4)을 도핑하여 이미다졸-인산 착체를 형성한 결과, 인산 함량이 증가함에 따라 공중합체 전해질막의 수소 이온 전도도가 계속 증가하였다. 또한 인장강도와 인장률 모두 인산 함량에 따라 증가하였다. 특히 [HEMA]: [IDA]:[H3PO4] = 3:4:4의 조성을 갖는 PS-b-PHEMA/IDA/H3PO4 블록 공중합체 전해질막은 100°C의 비가습 조건에서 최대 0.01 S/cm의 수소이온 전도도를 나타내었다. 열분석(TGA) 실험을 통하여 전해질막은 350°C의 고온까지 열적으로 안정함을 확인하였다.

고준위방사성폐기물처분을 위한 부지특성평가 기술을 구축하고, 이를 활용하여 심부지질환경을 이해하기 위해 1997년부터 지금까지 한국원자력연구원 주변 지역을 고준위폐기물처분을 위한 연구지역으로 선정하여 다양한 지질 관련 연구를 수행해왔다. 특히, 2002년에는 고준위폐기물의 처분 대상 심도의 시추공 (지하 500m)을 굴착하였으며, 2006년에는 지하처분연구시설 (KURT, KAERI Underground Research Tunnel)을 준공하여 연구지역에 대한 심부지질환경 규명을 위해 노력하고 있다. 현재, 지하처분연구터널의 좌측 연구용 모듈 내에 500 m 길이의 장심도 시추공 및 지하처분연구시설에서 남쪽으로 약 200 m 이격된 위치에서 1,000m의 장심도 시추공에서 다양한 부지특성평가 연구를 수행 중에 있다. 본 연구는 고준위폐기물의 심지층 처분을 위한 요소기술인 심부영역의 부지특성평가기술을 구축하기 위해 수행되었으며, 수리지질학적인 관점에서 부지특성평가의 기본 모델이 되는 3차원 지질모델을 구축한 내용이다. 연구지역에서 수행된 지표 지질조사와 시추공 자료를 이용하여 종합 분석한 결과, 수리지질학적 관점에서 중요한 풍화대, 상부 저경사단열대, 심부 영역에 존재하는 결정론적 단열대를 규명하여 3차원으로 모형화하였으며, 향후 본 연구를 통해 도출된 지질요소의 수리지질특성을 평가하여 고준위방사성폐기물처분 분야에 중요한 기술인 심부 영역의 수리지질환경을 이해하는데 활용될 예정이다.

Deformed wing virus (DWV) of honeybees (Apis mellifera) is closely associated with characteristic wing deformities, abdominal bloating, paralysis, and rapid mortality of emerging adult bees. Here, we report for the first time the occurrence of DWV-infected bumble bees (Bombus terrestris). For the present study, the detection of DWV virus from the adult bumble bee, death adult bumble bee, mail bumble bee, pupa and larva to the infection cycle was investigated in the same colony. Using specific RT-PCR protocols for the detection of DWV followed by sequencing of the PCR products we could demonstrate that the bumble bees were indeed infected with DWV. The virus was detected from diseased insects, and its partial DWV gene was cloned and sequenced. The partial DWV gene encoding the polyprotein is 711-nt of 235 amino acid residues. The deduced nucleotide sequence of the polyprotein partial gene of DWV showed 96.9%, 96.2%, 96.8%, and 96.5% homology to other structure polyprotein partial gene of DWV, respectively. Phylogenetic analysis further conformed that the deduced nucleotide sequence of the polyprotein partial gene of DWV divided to the outside tree. We describe the first time that presence of Deformed wing virus(DWV) from bumble bee(Bombus terrestris) in korea using RT-PCR.

We report for the first time the occurrence of DWV-infected bumble bees (Bombus ignitus). For the present study, the detection of DWV virus from the female and male bumble bee was investigated in the same colony. The Deformed wing virus (DWV) of honeybee (Apis mellifera) is closely associated with characteristic wing deformities, abdominal bloating, paralysis, and rapid mortality of emerging adult bees. Using specific RT-PCR protocols for the detection of DWV followed by sequencing of the PCR products we could demonstrate that the bumble bees were indeed infected with DWV. The virus was detected from Bombus ignitus, and its partial DWV gene was cloned and sequenced. The partial DWV gene encoding the polyprotein is 711-nt of 235 amino acid residues. The deduced nucleotide sequence of the polyprotein partial gene of DWV showed 96.9%, 96.2%, 96.8%, and 96.5% homology to other structure polyprotein partial gene of DWV from insects, respectively. Phylogenetic analysis further conformed that the deduced nucleotide sequence of the polyprotein partial gene of DWV divided to the outside tree. We describe the first time that presence of Deformed wing virus(DWV) from bumble bee(Bombus terrestris) in korea using RT-PCR.

Managing the fatty acid composition of grazing ruminant diets could lead to meat and milk products t㏊t have higher conjugated linoleic acid (CLA) concentrations, but forage fatty acid dynamics must be more fully understood for a range of forages before grazing systems can be specified. The fatty acid profiles of 23 different forages, including grasses, legumes and wild forage plants were determined. Linolenic(C18:3, 41.1~58.6% of fatty acid), linoleic(C18:2, 10.1~27.4% of fatty acid), and palmitic(C16:0, 9.8~18.0% of fatty acid) acids were the most abundant fatty acids in all species, together representing ~96% of the fatty acids present. Concentrations of fatty acids declined as plants developed, but the fraction contribution of each fatty acid to total fatty acids remained relatively stable over time.

L-trans-pyrrolidine-2,4-dicarboxylate (PDC) is a potent inhibitor of glutamate transporters. In our current study, we investigated whether the neuronal death induced by PDC involves mechanisms other than excitotoxicity in mixed mouse cortical cultures. Cortical cultures at 13-14 days in vitro were used and cell death was assessed by measuring the lactate dehydrogenase efflux into bathing media. Glutamate and PDC both induced neuronal death in a concentration-dependent manner but the neurotoxic effects of glutamate were found to be more potent than those of PDC. Treatment with 10, 100 and 200 M PDC equally potentiated 50 M glutamate-induced neuronal death. The neuronal death induced by 75 M glutamate was almost abolished by treatment with the NMDA antagonists, MK-801 and AP-5, but was unaffected by NBQX (an AMPA antagonist), trolox (antioxidant), BDNF or ZVAD-FMK (a pan-caspase inhibitor). However, the neuronal death induced by 200 M PDC was partially but significantly attenuated by single treatments with MK-801, AP-5, trolox, BDNF or ZVAD-FMK but not NBQX. Combined treatments with MK-801 plus trolox, MK-801 plus ZVAD-FMK or MK-801 plus BDNF almost abolished neuronal death, whereas combined treatments with trolox plus ZVADFMK, trolox plus BDNF or ZVAD-FMK plus BDNF did not enhance the inhibitory action of any single treatment with these drugs. These results demonstrate that the neuronal death induced by PDC involves not only in the excitotoxicity induced by the accumulation of glutamate but also the oxidative stress induced by free radical generation. This suggests that apoptotic neuronal death plays a role in PDCinduced oxidative neuronal injury.

Two cherry tomato plant cultivars (Lycopersicon esculentum Miller, cultivars ‘Koko’ and ‘Pepe’) were supplied with high (395 ppm), medium (266 ppm) and low (199 ppm) concentrations of nitrogen to determine the influence of nitrogen fertilization on development, cultivar preference and honeydew production by greenhouse whiteflies, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). The nitrogen, protein, andchlorophyll content of tomato leaves were higher in the high nitrogen supplied plants than in the medium or low nitrogen supplied plants, but the sugar content showed an inverse relationship. The developmental times of eggsand nymphs decreased as the nitrogen concentrations increased in both cultivars. The preference of T. vaporariorum was compared by counting the number of eggs deposited on leaves in choice and non-choice tests. In the non-choice test, no significant nitrogen treatment effects were observedbut the upper plant stratum was preferred for egg laying. In the choice test, there were significant main effects of cultivar and nitrogen concentration. T. vaporariorum laid eggs more on leaves of plants with higher nitrogen at the upper stratum. In both experiments, T, vaporariorum preferred the ‘Koko’ cultivar to the ‘Pepe’ cultivar. The honeydew production of T. vaporariorum nymphs increased with decreasing nitrogen treatment concentrations. The largest honeydew production was detected in the ‘Pepe’ cultivar grown at low nitrogen concentration. It is concluded that cultivar ‘Pepe’ had an advantage over ‘Koko’ in term of T. vaporariorum management program in tomato greenhouses.

vitellogenin cDNA was cloned from the bumblebee Bombus ignitus. The cDNA encoding B. ignitus vitellogenin (BiVg) is 5473 bases long with an open reading frame of 1773 amino acid residues. BiVg possesses two consensus (RXXR/S) cleavage sites and has the conserved DGXR and GL/ICG motif near its C-terminus. The deduced amino acid sequence of BiVg cDNA showed significant similarity with hymenopteran Vgs (51% identity to Apis mellifera Vg, and 33-36% to other insect Vgs). The BiVg cDNA was expressed as a 200-kDa polypeptide in baculovirus-infected insect Sf9 cells. Northern and Western blot analyses showed the expression of BiVg in fat bodies of pupae and adults. In queens, the expression of BiVg was first detected in late pupal stage fat bodies, and secreted BiVg was also observed in late pupal stage hemolymph.

To determine the characteristics of the Korean porcine reproductive and respiratory syndrome virus (PRRSV), CA, which was isolated from the serum of an infected pig in 2006, we investigated the nucleotide sequence and expression of the structural ORFs (ORFs 2 to 7) using the bApGOZA system. We found that the structural ORFs 2 to 7 of CA consisted of 3188 nucleotides that were the same as those formed from VR-2332. Comparison of the CA with the other strains revealed nucleotide sequence identity ranging from 89.8 to 99.5%. To better understand the genetic relationships between other strains, phylogenetic analyses were performed. The CA strain was closely related to the other North American genotype strains but formed a distinct branch with high bootstrap support. Additionally, expression levels of the PRRSV proteins in Sf21 cells were strong or partially weak. The results of this study have implications for both the taxonomy of PRRSV and vaccine development.

The porcine reproductive and respiratory syndrome virus (PRRSV) has six structural proteins which encoded by ORFs 2 to 7 are designated as GP2, 3, 4, 5, M and N, repectively. In this study, we determined the expression of each protein using novel transfer vector, pBmKSK4 which has the polyhedrin promoter of BmNPV and 6xHis tag. The recombinant transfer vector was co-transfected into Bm5 cells along with bBpGOZA DNA. Recombinant virus was purified by plaque assay and amplified in Bm5 cells. Expression of each protein was identified by SDS-PAGE and Western blot analysis using anti-6xHis monoclonal antibody. The expression levels of the structural proteins in Bm5 cells were stronger than the expression system using pBacPAK9 transfer vector in Sf21 cells. As expected, GP5 was expressed at low levels from its structural properties and its toxicity for cells. In addition, each recombinant protein was purified using Ni-NTA spin columns. The ability to produce each protein in the baculovirus system indicates that these could be major candidates for the development of a vaccine against PRRSV.

In Jeju cirtrus orchards, Panonychus citri, citrus red mite is the most important pest requiring 3 times acaricide sprays. In open field conventional orchards, P. citri usually shows three population peaks; from end of Jun to July, from end of Aug. to Sep., from end of Oct. to Nov. However, natural enemy complex and its function regulating P.citri are poorly understood. From the survey of P.citri natural enemy in citrus orchard in Jeju from 2004 to 2006, predatory beetle, Oligota spp. was most abundant. Three predatory mite, N. californicus, Amblyseius eharai, and N. barkeri, were identified. Among them, the predatory mite, Neoseiulus californicus (McGregor) (Acari: Phytoseiidae), was first found in Korea. Even though it was first found, N. californicus was the dominant species occupying 84% of phytoseiid mites. These predatory mites mostly occurred in Jun and peaked at July, which was accorded with the high humidity season of the year. From the survey, the density relationship with P. citri was unclear. From the study conducted in 2005-2007, N. californicus was more abundant in greenhouse citrus (var. Shirahuhi) than in open field orchards; conventional or organic mandarine citrus. In greenhouse citrus, phytoseiid mites showed suppressing P. citri population. As a next step, the inundative biological control study was conducted using commercial strain of N. californicus, which was originated from Jeju, 2005, in greenhouse citrus. One thousand N. californicus per 1a were released 2 times at 10 day interval on citrus leaves when the initial density of P. citri was about 0.2 per leaf. The release effects were variable depending on the field condition. However, N. californicus did successfully reduce P. citri in greenhouse citrus orchards.

The larvae of Asian rhinoceros beetle, Trypoxylus [Allomyrina] dichotoma (Coleoptera: Scarabaeidae) feed on decaying organic matter and can be found in compost heaps or old dead logs. Mass rearing of this insect with a sawdust-based diet has made it popular commercial pet in many countries of Asia. Recently, lignocellulose, or biomass has been focused as renewable and sustainable resources for energy and many chemical products. It is well-known that gut symbiotic microbes in consortia are inevitable for the lignocellulose digestion in many insects. The cellulase and xylanase activity of the crude extracts from each gut contents and tissues, feces, and blood as a control from Asian rhinoceros beetle were analyzed with the overlaid agar-plate assay and spectrophotometric reduced sugar determination. In the plate assay, the highest activity of cellulase and xylanase was observed from midgut tissue extracts, and next from midgut contents, and minor activity from feces. Whereas no enzyme activity was detected from the samples from blood, crop, and hind gut. Similar results were confirmed from the reducing sugar assay with substrates of Avicell and xylan from birchwood, respectively. Further research on the biochemical and genetic property of symbiotic microbes and their enzymes relating on the lignocellulose degradation is planned.

We have investigated the optical properties of the global haze on Titan from spectra recorded between 7100 and 9200Åwhere CH4 absorption bands of various intensities occur. The Titan spectra were obtained on Feb. 23, 2005 (UT), near the times of the Cassini T3 flyby and Huygens probe, using an optical echelle spectrograph (BOES) on the 1.8-m telescope at Bohyunsan Observatory in Korea. In order to derive the optical properties of the haze as a function of altitude, we developed an inversion radiative-transfer program using an atmospheric model of Titan and laboratory CH4 absorption coefficients available from the literature. The derived extinction coefficients of the haze increase toward the surface, and the coefficients at shorter wavelengths are greater than those at longer wavelengths for the 30 - 120 km altitude range, indicating that the Titanian haze becomes optically thin toward the longer wavelength range. Total optical depths of the haze are estimated to be 1.4 and 1.2 for the 7270 -7360Åand 8940 -9150Å ranges, respectively. Based on the Huygens/DISR data set, Tomasko et al. (2005) reported total optical depths of 2.5 - 3.5 at 8290Å depending on the assumed fractal aggregate particle model. The total optical depths based on our results are smaller than those of Tomasko et al., but they partially overlap with their results if we consider a large uncertainty from possible variations of the CH4 mixing ratio over Titan's disk. We also derived the single scattering albedo of the haze particles as a function of altitude: it is less than 0.5 at altitudes higher than ~150Km the average particle radius is smaller than the wavelengths, whereas near the surface, it becomes comparable or greater.

Sulfur is commonly used in Asia as an herbal medicine to treat inflammation and cancer , a nd potent chemo preventi ve effects have been demons tra ted in various in vivo and in vitromodels for s ul fur-containing compounds found in natura l1y occurring product s. Here, we 1'eport the growth inhibitory and apoptosis-related effects of a n ewly developedhigh-puri ty edible sulfur(ES) on immo1'tali zed human o1'al ke1'atinocytes(IHOKs) and on oral cancer cells representing two stages of oral cancer (HN4‘ HN12) based on an 3-(4,5-Dimethylthiazol-2-yl) -2.5- diphe n yltetrazolium bromide(MTI) assay, Western blotting, cell cycle analysis, and nuclear staining. The puri ty of the ES used in thi s study was ve1'ified by high performance liquid chromatog1'aphy (HPLC) , ami no acid analysis and energy dispersive spectroscopy(EDS). ES inhibited the prolife1'ation of imrnortalized and ma lig nant o1'al kerati nocytes in a dose- and time-dependent manne1' FITC-Annex.in V staining, DNA fragmentation t esting. and Hoechst 33258 s taining revealed that ES inhibits cell growth via apoptosis. ES bl ocked cell-cycle prog1'ession at t he sub-Gl phase‘ wi th decreased expression of cyclins Dl, D2‘ and E, and their activating partn ers cdk2‘ cdk4‘ and cdkfì, and a concomitant induction of p53 and p21/WAF1. Furthe1'more, ES treatment in creased the cytosolic level of cytochrome c and resulted in caspase- 3 activation‘ and thi s effect was co1'1'elated with Bax up-regulation and Bcl-2 down-1'egulation Taken together‘ these data suggest that ES is a potential chemopreventive and chemotherapeut ic agent fo r oral ca ncer

To induce the enhanced mutants of dinitroaniline herbicide pendimethalin degrading bacterium, Bacillus sp. MS202 was irradiated with gamma radiation at the dose of LD99 (3.35 kGy). Three enhanced mutants (MS202m7, MS202m14, MS202m18) were isolated fr

Interlellkin • 8(IL-8) is an important cytokine involved in tllmor growth and angiogenesis in a variety of malig nancies. bllt the regll lation of IL-8 in 01 외 cancer cells are llnderstood . We invesLigated whether mi togen-activated protein kinases pathway is involved in iron chelator-mediated lL-8 produdion in inunortalized and malignant oral keratinocytes. In this study we examined the role of p38 and extracellular signal- reglllated kinase• 1/2 in the expression of [L-8 by DFO. Incllbation of IHOK and HN12 cel ls with DF'O increased the expression of 11-8 mRNA. as well as the release of IL-8 protein. The signal transdllction study revealed that both p38 and ERK1/2 were significantly activated in response to DFO. Accord ingly. the selective inhibitors for both kinases‘ eit her a lone or combination. abolished DFO- induced lL-8 secretion. indicating an importance of MAP kinase pathway. Interestingly. however‘ inhibition of the p38 and ERK pathway more attenuated IL-8 secretion in IHOK than in HN12 cells. DFO induced NF-kB activation , suggesting a NF-kB- dependent mechanism in DFO- induced IL-8 production. In addition, p38 and ERK inhi bition resulted in the accelerated degradation of lL-8 mRNA, suggesting that in IHOK and HN12 cells, p38 and ERK cunLr iullLe Lo DFO imluced IL-8 secretion by IHOK and HN12 cells via a posttranscriptional mechanism that involves stabilization 01' the IL-8 transcript. Finally. we investigatecl llsing specific inhibitors : 8NP and G8NO for NO c1onor. PDTC for potent inhibitor of NF-kB. Cycloheximide for inhibition of de novo protein synthesis. We observecl 8NP ancl PD1'C clepenclent IL-8 gene incluction in IHOK cell s. but not in HN12 cells used specific inhibitors‘ Collectively. these results demonstrate that‘ targeting MAP kinase ancl NF-kB pathway may be a potentiaI approacb to controlling the angiogenes is ancl growth 이 human oral cancers