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Sohn YS Goodey A Anslyn EV McDevitt JT Shear JB Neikirk DP 《Biosensors & bioelectronics》2005,21(2):303-312
The development of a micromachined fluidic structure for the introduction of liquid samples into a chip-based sensor array composed of individually addressable polymeric microbeads is presented. The micromachined structure consists of micromachined storage cavities combined with a covering glass layer that confines the microbeads and fluidic channels. In our sensor array transduction occurs via optical (colorimetric and fluorescence) changes to receptors and indicator molecules that are covalently attached to termination sites on the polymeric microbeads. Spectral data are acquired for each of the individual microbeads using a charged-coupled device (CCD) allowing for the near-real-time analysis of liquid sample. Hence the micromachined fluidic structure must allow for both optical access to the microbeads and fluid flow through the micromachined cavities that serve as the microreactors/analysis chambers. One of the key parts of the structure is a passive fluid introduction system driven only by capillary force. This simple means of fluid introduction realizes a compact device. The capillary flow on the inlet channel has been studied, and the responses of the microbeads (alizarin complexone) to a liquid sample have been characterized. The test results show that this system is useful in a micro-total-analysis-system (mu-TAS) and biomedical applications. 相似文献
23.
Lee KH Lee CT Kim YW Han SK Shim YS Yoo CG 《The Journal of biological chemistry》2005,280(13):13179-13186
Heat shock (HS) activates mitogen-activated protein (MAP) kinases. Although prior exposure to nonlethal HS makes cells refractory to the lethal effect of a subsequent HS, it is unclear whether this also occurs in MAP kinase activation. This study was undertaken to evaluate the effect of a heat pretreatment on MAP kinase activation by a subsequent HS and to elucidate its possible mechanism. Preheating did not make BEAS-2B cells refractory to extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK) activation by a second HS but accelerated their inactivation after HS. The rapid inactivation of ERK and JNK was dependent on de novo protein synthesis and associated with the up-regulation of heat shock protein 70 (HSP70). Moreover, the inhibition of phosphatase activity reversed this rapid inactivation. MAP kinase phosphatase-1 (MKP-1) expression was increased by HS, and the presence of its phosphorylated form (p-MKP-1) correlated with the observed rapid ERK and JNK inactivation. Blocking induction of p-MKP-1 with antisense MKP-1 oligonucleotides suppressed the rapid inactivation of ERK and JNK in preheated cells. HSP70 overexpression caused the early phosphorylation of MKP-1. Moreover, MKP-1 phosphorylation and the rapid inactivation of ERK were inhibited by blocking HSP70 induction in preheated cells. In addition, MKP-1 was insolubilized by HS, and HSP70 associated physically with MKP-1, suggesting that a chaperone effect of HSP70 might have caused the early phosphorylation of MKP-1. These results indicate that preheating accelerated MAP kinase inactivation after a second HS and that this is related to a HSP70-mediated increase in p-MKP-1. 相似文献
24.
Greenhouse Gas (GHG) emissions from the offshore fisheries industry in the Republic of Korea (Korea) were examined in response to growing concerns about global warming and the contribution of emissions from different industrial sectors. Fuel usage and GHG emissions (CO2, CH4, N2O) were analysed using the ‘Tier 1’ method provided by the Intergovernmental Panel on Climate Change (IPCC) from the offshore fishery, which is the primary domestic seafood production sector in Korea. In 2013, fuel usage in the offshore fishery accounted for 59.7% (557,463 KL) of total fuel consumption of fishing vessels in Korea. Fuel consumption and thus GHG emissions were not stable through time in this industry, increasing by 2.4% p.a. for three consecutive years, from 2011 to 2013, despite a decrease in the number of vessels operating. GHG emissions generated in offshore fisheries also changed through time and increased from 1,442,975 tCO2e/year in 2011 to 1,477,279 tCO2e/year in 2013. Changes in both fuel use and GHG emissions per kg offshore fish production appeared to be associated with decreasing catch rates by the fleet, which in turn were a reflection of decrease in fish biomass. Another important feature of GHG emissions in this industry was the high variation in GHG emission per kg fish product among different fishing methods. The long line fishery had approximately three times the emissions of the average production while the jigging fishery was more than two times higher than the average. Lowest emissions were from the trawl sector, which is regarded as having greatest environmental impact using traditional biodiversity metrics although had lowest environmental impact in terms of fuel and GHG emission metrics used in this study. The observed deterioration in fuel efficiency of the offshore fishery each year is of concern but also demonstrates that fuel efficiency can change, which shows there is opportunity to improve efficiency with changes to fishery management and harvesting operations. 相似文献
25.
Yu Jeong Jeong Su Gyeong Woo Chul Han An Hyung Jae Jeong Young-Soo Hong Young-Min Kim Young Bae Ryu Mun-Chual Rho Woo Song Lee Cha Young Kim 《Molecules and cells》2015,38(4):318-326
We previously reported that the SbROMT3syn recombinant protein catalyzes the production of the methylated resveratrol derivatives pinostilbene and pterostilbene by methylating substrate resveratrol in recombinant E. coli. To further study the production of stilbene compounds in E. coli by the expression of enzymes involved in stilbene biosynthesis, we isolated three stilbene synthase (STS) genes from rhubarb, peanut, and grape as well as two resveratrol O-methyltransferase (ROMT) genes from grape and sorghum. The ability of RpSTS to produce resveratrol in recombinant E. coli was compared with other AhSTS and VrSTS genes. Out of three STS, only AhSTS was able to produce resveratrol from p-coumaric acid. Thus, to improve the solubility of RpSTS, VrROMT, and SbROMT3 in E. coli, we synthesized the RpSTS, VrROMT and SbROMT3 genes following codon-optimization and expressed one or both genes together with the cinnamate/4-coumarate:coenzyme A ligase (CCL) gene from Streptomyces coelicolor. Our HPLC and LC-MS analyses showed that recombinant E. coli expressing both ScCCL and RpSTSsyn led to the production of resveratrol when p-coumaric acid was used as the precursor. In addition, incorporation of SbROMT3syn in recombinant E. coli cells produced resveratrol and its mono-methylated derivative, pinostilbene, as the major products from p-coumaric acid. However, very small amounts of pterostilbene were only detectable in the recombinant E. coli cells expressing the ScCCL, RpSTSsyn and SbROMT3syn genes. These results suggest that RpSTSsyn exhibits an enhanced enzyme activity to produce resveratrol and SbROMT3syn catalyzes the methylation of resveratrol to produce pinostilbene in E. coli cells. 相似文献
26.
Mi-Hyun Ahn Byung-Lae Park Shin-Hwa Lee Sung-Woo Park Jong-Sook Park Do-Jin Kim An-Soo Jang Jai-Soung Park Hwa-Kyun Shin Soo-Taek Uh Yang-Ki Kim Young Whan Kim Sung Koo Han Ki-Suck Jung Kye Young Lee Sung Hwan Jeong Jeong Woong Park Byoung Whui Choi In Won Park Man Pyo Chung Hyoung Doo Shin Jin Woo Song Dong Soon Kim Choon-Sik Park Young-Soo Shim 《Respiratory research》2011,12(1):73
Background
Interleukin-8 (IL-8) is a potent chemo-attractant cytokine responsible for neutrophil infiltration in lungs with idiopathic pulmonary fibrosis (IPF). The IL-8 protein and mRNA expression are increased in the lung with IPF. We evaluated the effect of single nucleotide polymorphisms (SNPs) of the IL-8 gene on the risk of IPF.Methods
One promoter (rs4073T>A) and two intronic SNPs (rs2227307T>G and rs2227306C>T) of the IL-8 genes were genotyped in 237 subjects with IPF and 456 normal controls. Logistic regression analysis was applied to evaluate the association of these SNPs with IPF. IL-8 in BAL fluids was measured using a quantitative sandwich enzyme immunoassay, and promoter activity was assessed using the luciferase reporter assay.Results
The minor allele frequencies of rs4073T>A and rs2227307T>G were significantly lower in the 162 subjects with surgical biopsy-proven IPF and 75 subjects with clinical IPF compared with normal controls in the recessive model (OR = 0.46 and 0.48, p = 0.006 and 0.007, respectively). The IL-8 protein concentration in BAL fluids significantly increased in 24 subjects with IPF compared with 14 controls (p = 0.009). Nine IPF subjects homozygous for the rs4073 T>A common allele exhibited higher levels of the IL-8 protein compared with six subjects homozygous for the minor allele (p = 0.024). The luciferase activity of the rs4073T>A common allele was significantly higher than that of the rs4073T>A minor allele (p = 0.002).Conclusion
The common allele of a promoter SNP, rs4073T>A, may increase susceptibility to the development of IPF via up-regulation of IL-8. 相似文献27.
Human embryonic stem cell-derived neural precursors as a continuous, stable, and on-demand source for human dopamine neurons 总被引:1,自引:0,他引:1
Ko JY Park CH Koh HC Cho YH Kyhm JH Kim YS Lee I Lee YS Lee SH 《Journal of neurochemistry》2007,103(4):1417-1429
Human embryonic stem (hES) cells can be guided to differentiate into ventral midbrain-type neural precursor (NP) cells that proliferate in vitro by specific mitogens. We investigated the potential of these NP cells derived from hES cells (hES-NP) for the large-scale generation of human dopamine (DA) neurons for functional analyses and therapeutic applications. To address this, hES-NP cells were expanded in vitro for 1.5 months with six passages, and their proliferation and differentiation properties determined over the NP passages. Interestingly, the total hES-NP cell number was increased by > 2 × 104 -folds over the in vitro period without alteration of phenotypic gene expression. They also sustained their differentiation capacity toward neuronal cells, exhibiting in vitro pre-synaptic DA neuronal functionality. Furthermore, the hES-NP cells can be cryopreserved without losing their proliferative and developmental potential. Upon transplantation into a Parkinson's disease rat model, the multi-passaged hES-NP cells survived, integrated into the host striatum, and differentiated toward the neuronal cells expressing DA phenotypes. A significant reduction in the amphetamine-induced rotation score of Parkinson's disease rats was observed by the cell transplantation. Taken together, these findings indicate that hES-NP cell expansion is exploitable for a large-scale generation of experimental and transplantable DA neurons of human-origin. 相似文献
28.
Burkholderia sp. C3 was isolated from a polycyclic aromatic hydrocarbon (PAH)-contaminated site in Hilo, Hawaii, USA, and studied for
its degradation of phenanthrene as a sole carbon source. The initial 3,4-C dioxygenation was faster than 1,2-C dioxygenation
in the first 3-day culture. However, 1-hydroxy-2-naphthoic acid derived from 3,4-C dioxygenation degraded much slower than
2-hydroxy-1-naphthoic acid derived from 1,2-C dioxygenation. Slow degradation of 1-hydroxy-2-naphthoic acid relative to 2-hydroxy-1-naphthoic
acid may trigger 1,2-C dioxygenation faster after 3 days of culture. High concentrations of 5,6-␣and 7,8-benzocoumarins indicated
that meta-cleavage was the major degradation mechanism of phenanthrene-1,2- and -3,4-diols. Separate cultures with 2-hydroxy-1-naphthoic
acid and 1-hydroxy-2-naphthoic acid showed that the degradation rate of the former to naphthalene-1,2-diol was much faster
than that of the latter. The two upper metabolic pathways of phenanthrene are converged into naphthalene-1,2-diol that is
further metabolized to 2-carboxycinnamic acid and 2-hydroxybenzalpyruvic acid by ortho- and meta-cleavages, respectively. Transformation of naphthalene-1,2-diol to 2-carboxycinnamic acid by this strain represents the first
observation of ortho-cleavage of two rings-PAH-diols by a Gram-negative species. 相似文献
29.
Kwon DJ Bae YS Ju SM Goh AR Youn GS Choi SY Park J 《Biochemical and biophysical research communications》2012,417(4):1254-1259
Casuarinin is a naturally occurring tannin that is isolated from the leaves of Hippophae rhamnoides. It has been shown to have anti-oxidant, anti-cancer, anti-viral, and anti-inflammatory activities. The aim of this study was to investigate the possible mechanism by which casuarinin inhibits TNF-α/IFN-γ-induced Th2 chemokines expression in the human keratinocytes cell line HaCaT. We found that casuarinin suppressed TNF-α/IFN-γ-induced expression of TARC and MDC mRNA and protein in HaCaT cells. Casuarinin significantly inhibited TNF-α/IFN-γ-induced activation of NF-κB, STAT1, and p38 MAPK. Furthermore, we observed that p38 MAPK contributes to inhibition of TNF-α/IFN-γ-induced TARC and MDC production by blocking NF-κB and STAT1 activation in HaCaT cells. Taken together, these results suggest that casuarinin may exert anti-inflammatory responses by suppressing TNF-α/IFN-γ-induced expression of TARC and MDC via blockage of p38 MAPK activation and subsequent activation of NF-κB and STAT1. We propose that it could therefore be used as a therapeutic agent against inflammatory skin diseases. 相似文献
30.
Enzymatic Glycosylation of Nonbenzoquinone Geldanamycin Analogs via Bacillus UDP-Glycosyltransferase
Cheng-Zhu Wu Jae-Hyuk Jang Mihee Woo Jong Seog Ahn Joong Su Kim Young-Soo Hong 《Applied and environmental microbiology》2012,78(21):7680-7686
Geldanamycin (GM) is a naturally occurring anticancer agent isolated from several strains of Streptomyces hygroscopicus. However, its potential clinical utility is compromised by its severe toxicity and poor water solubility. For this reason, considerable efforts are under way to make new derivatives that have both good clinical efficacy and high water solubility. On the other hand, glycosylation is often a step that improves the water solubility and/or biological activity in many natural products of biosynthesis. Here, we report the facile production of glucose-conjugated nonbenzoquinone GM analogs using the Bacillus UDP-glycosyltransferase BL-C. Five aglycon substrates containing nonbenzoquinone aromatic rings were chosen to validate the in vitro glycosylation reaction. Putative glucoside compounds were determined through the presence of a product peak(s) and were also verified using LC/MS analyses. Further, the chemical structures of new glucoside compounds 6 and 7 were elucidated using spectroscopy data. These glucoside compounds showed a dramatic improvement in water solubility compared with that of the original aglycon, nonbenzoquinone GM. 相似文献