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51.
Ponder J Yoo BH Abraham AD Li Q Ashley AK Amerin CL Zhou Q Reid BG Reigan P Hromas R Nickoloff JA LaBarbera DV 《Marine drugs》2011,9(11):2397-2408
Type IIα DNA topoisomerase (TopoIIα) is among the most important clinical drug targets for the treatment of cancer. Recently, the DNA repair protein Metnase was shown to enhance TopoIIα activity and increase resistance to TopoIIα poisons. Using in vitro DNA decatenation assays we show that neoamphimedine potently inhibits TopoIIα-dependent DNA decatenation in the presence of Metnase. Cell proliferation assays demonstrate that neoamphimedine can inhibit Metnase-enhanced cell growth with an IC(50) of 0.5 μM. Additionally, we find that the apparent K(m) of TopoIIα for ATP increases linearly with higher concentrations of neoamphimedine, indicating ATP-competitive inhibition, which is substantiated by molecular modeling. These findings support the continued development of neoamphimedine as an anticancer agent, particularly in solid tumors that over-express Metnase. 相似文献
52.
J Wang Y Yoo C Gao I Takeuchi X Sun H Chang X Xiang PG Schultz 《Science (New York, N.Y.)》1998,279(5357):1712-1714
A quaternary combinatorial masking strategy was used in conjunction with photolithography to generate compositionally diverse thin-film phosphor libraries containing 1024 different compositions on substrates 2.5 centimeters square. A parallel imaging system and scanning spectrophotometer were used to identify and characterize compositions in the library with interesting luminescent behavior. Optimal compositions were identified with the use of gradient libraries, in which the stoichiometry of a material was varied continuously. This process led to the identification of an efficient blue photoluminescent composite material, Gd3Ga5O12/SiO2. Experimental evidence suggests that luminescence in this material may arise from interfacial effects between SiO2 and Gd3Ga5O12. 相似文献
53.
Bok Ryul Yoo Mi Yeon Suk Joon Soo Han Yong-Man Yu Soon-Gyu Hong Il Nam Jung 《Pest management science》1998,52(2):138-144
A series of 1-aryl-1-(1H-1,2,4-triazol-1-yl)alkyl-1-silacyclopentanes has been synthesized by four-step reactions starting from 1-chloroalkyltrichlorosilane and tested for fungicidal activities in vitro for ten fungi and in vivo for four fungi occurring in rice, cucumber, tomato etc. Biological activities of the title compounds are strongly dependent upon the p-substituent on the phenyl group in the following order: F>Cl>Ph>OEt>H. Especially, 1-p-fluorophenyl-1-[1-(1H-1,2,4-triazol-1-yl)alkyl]-1-silacyclopentanes (alkyl=methyl or ethyl) showed significant fungicidal activity with a broad spectrum comparable to flusilazole in in-vivo assay. © 1998 SCI. 相似文献
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56.
Su In Lee Sang Gyun Kang Mi Lan Kang Han Sang Yoo 《Journal of veterinary diagnostic investigation》2008,20(4):492-496
Fimbriae and enterotoxins are major virulence factors associated with enterotoxigenic Escherichia coli (ETEC). In this study, 3 sets of multiplex polymerase chain reaction (mPCR) assays targeting fimbriae, enterotoxins, and other adherence factors were developed for detecting ETEC. A total number of 188 E. coli field isolates were examined, and percentages of E. coli strains carrying each virulence factors were as follows: F4 (7.45%), F5 (29.79%), F6 (6.38%), F18 (15.43%), F41 (3.72%), STa (10.11%), STb (20.74%), LT (9.57%), Stx2e (2.13%), EAST1 (42.02%), F1 (67.55%), AIDA-I (2.66%), and pAA (7.45%). Of the 188 E. coli field isolates examined, 25.53% were found to be pathogenic ETEC, having both fimbriae and enterotoxins. However, the ratio increased to 44.68% when the presence of other adhesins was considered as criteria for virulence. Among the adherence factors, F1 was found to be the most prevalent. AIDA-I and pAA were also found with similar ratio as compared with other virulence factors. In addition, virulence patterns carrying these alternate adhesive genes with enterotoxins were detected with significant ratio. Therefore, it is desirable that alternate adhesins be considered as markers for diagnosis of ETEC. 相似文献
57.
Yoo DH Lee BH Chang PS Lee HG Yoo SH 《Journal of agricultural and food chemistry》2007,55(5):1656-1662
Cereal beta-glucan is a linear biopolymer linked by beta-(1,3)/(1,4)-glycosidic bonds. More specifically, the beta-(1,4)-linked glucose chain is interrupted with beta-(1,3)-linkages in cereal beta-glucan structure. Elucidation of the exact length and distribution of linear beta-(1,4)-linked portion facilitates the understanding of the fine structure of cereal beta-glucan. A HPAEC assisted by lichenase treatment has been used for the structural and quantitative analysis of cereal beta-glucan. The absence of authentic standard oligosaccharides, putatively 3-O-beta-cellobiosyl-D-glucose (DP3) and 3-O-beta-cellotriosyl-D-glucose (DP4), was a potential problem to the characterization of beta-glucan structure. In this study, two major lichenase-hydrolyzed products were generated from the barley beta-glucan, and putative 3-O-beta-cellobiosyl-D-glucose and 3-O-beta-cellotriosyl-D-glucose were separated and highly purified by recycling preparative HPLC technology. Structural analysis of highly purified putative 3-O-beta-cellobiosyl-D-glucose and 3-O-beta-cellotriosyl-D-glucose was performed by TLC and LC-MS analysis. Two putative DP3 and DP4 displayed the nonreducing end/(1,4)/(1,3) linkage ratios of 1:0.96:0.90 and 1:2.18:1.16, respectively; the molecular masses (m/z) of their sodium adducts were 527.0 and 689.0, respectively. Using these structurally confirmed oligosaccharides, the exact amounts of beta-glucan lichenase hydrolysates from domestic barley cultivars were quantified. The amount of two major DP3 and DP4 accounted for only 71.4-73.3% of water-extractable beta-glucan fraction, and the (1,4)/(1,3) linkage ratios of the extracted beta-glucans were almost identical in the range of 2.24-2.25 among the barley cultivars tested. 相似文献
58.
Yoo KY Hwang IK Lee JC Cho JH Kim SM Jung JY Kang TC Won MH 《Anatomia, histologia, embryologia》2006,35(2):93-96
Information on the localization and the roles of glutamate in the nervous system is becoming valuable because the axon terminals of the olfactory sensory neurons and the synapses of the mitral and tufted output cells appear to be glutamatergic. In this study, we have analysed the distribution of glutamate immunoreactivity in the main olfactory bulb (MOB) of the Mongolian gerbil using an antiserum directed against glutamate. Glutamate immunoreactivity in the MOB was present in the olfactory nerve layer (Onl), glomerular layer (GL), external plexiform layer (EPL) and mitral cell layer (ML), but not in the granule cell layer (GCL). Glutamate immunoreactivity detected in the Onl was thought to be terminal ramifications of glomeruli. Some neurons in the periglomerular region showed glutamate immunoreactivity. In the EPL, glutamate immunoreactivity was found in some neuronal somata (tufted cells) and processes. In addition, mitral cells in the ML were labelled by the glutamate antibody. The pattern of glutamate immunoreactivity in the mitral cells was similar to that in the tufted cells. In brief, glutamate in the gerbil MOB is the neurotransmitter used by primary afferents and output neurons. 相似文献
59.
Age-related changes in calretinin-immunoreactive periglomerular cells in the rat main olfactory bulb
Hwang IK Yoo KY Nam YS Choi JH Seo K Lee IS Jung JY Kang TC Oh YS Won MH 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(5):465-469
The changes of calretinin (CR)-immunoreactive periglomerular cells in the glomerular layer of the main olfactory bulb (MOB) were investigated in rats differing ages from postnatal month 1 (PM 1) to PM 24. The number of cresyl violet-positive periglomerular cells was similar between PM 1 and PM 12, but they decreased slightly in the PM 24 group. The size of CR-immunoreactive periglomerular cells in the glomerular layer increased with age, while their numbers did not change significantly in the PM 6-PM 24 groups. In the PM 24 group, numbers of CR-positive periglomerular cell bodies and their processes decreased, while the size of CR-positive cell bodies in the glomeruli was larger than that of the previous groups. These results suggest that CR-immunoreactive periglomerular cells in the rat MOB are well-developed in the PM 6 group, and that periglomerular cells in the PM 24 group show poor CR-immunoreactivity compared to those in the PM 6 group. 相似文献
60.
Yang SJ Park KY Kim SH No KM Besser TE Yoo HS Kim SH Lee BK Park YH 《Veterinary microbiology》2002,86(4):295-301
Fourteen and 22 each of Salmonella Enteritidis and Salmonella Typhimurium (S. Typhimurium) were isolated from animals from 1983 to 1999 in Korea and tested for their antibiotic resistance patterns, phage types and resistance gene patterns. S. Typhimurium isolates were highly resistant to streptomycin, sulfisoxazole and tetracycline, 95, 95 and 86%, respectively. The incidence of multiple antibiotic resistance (resistant to more than two drugs tested) of S. Typhimurium isolates was extremely high (100%) comparing to S. Enteritidis isolates (21%). Two of the five ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfisoxazole and tetracycline) resistant type S. Typhimurium isolates were phage type definitive type 104 (DT104).For the detection of resistance related genes in S. Enteritidis and S. Typhimurium isolates, particularly ACSSuT type S. Typhimurium, antibiotic resistance genes, cmlA/tetR, bla(PSE-1) and bla(TEM), and genus Salmonella specific gene, sipB/C, were amplified using four pairs of primers in a hot-start multiplex polymerase chain reaction (PCR). Two Korean isolates of S. Typhimurium DT104 showed bla(TEM) amplicons instead of bla(PSE-1) for the ampicillin resistance and they were susceptible to florfenicol. The multiplex PCR used in this study was useful in characterization of multiple drug resistant Salmonella isolates, especially ACSSuT type S. Typhimurium, and identification of beta-lactamase gene distribution among Salmonella isolates. 相似文献