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排序方式: 共有995条查询结果,搜索用时 15 毫秒
81.
Smith WM Zhou XP Kurose K Gao X Latif F Kroll T Sugano K Cannistra SA Clinton SK Maher ER Prior TW Eng C 《Human genetics》2001,109(2):146-151
Peroxisome proliferator activated receptor gamma (PPARgamma) is a nuclear hormone receptor that has been shown to regulate differentiation and cell growth. Studies of the differentiative effects of PPARgamma agonists on several cancer cell lines led to the hypothesis that dysfunction of PPARgamma contributes to tumorigenesis. These functional observations were strengthened by genetic evidence: somatic loss-of-function mutations in PPARG, encoding PPARgamma, in sporadic colorectal carcinomas and somatic translocation of PAX8 and PPARG in follicular thyroid carcinoma. Recently overrepresentation of the H449H variant was found in a cohort of American patients with glioblastoma multiforme. The glioblastoma multiforme data suggest that PPARG contributes common, low-penetrance alleles for cancer susceptibility. To test this hypothesis in a broader range of cancers we examined a series of carcinomas of the cervix, endometrium, ovary, prostate, and kidney for germline sequence variation in PPARG. In addition to the two common sequence variants, P12A and H449H, there were five other sequence variants. P12A alleles were underrepresented in renal cell carcinoma patients compared to country-of-origin race-matched controls (3.75% vs. 12.1%, P<0.04). In contrast, the H449H variant was overrepresented in individuals with endometrial carcinoma compared to controls (14.4% vs. 6.25%, P<0.02). These observations lend genetic evidence consistent with our hypothesis that PPARG serves as a common, low-penetrance susceptibility gene for cancers of several types, especially those epidemiologically associated with obesity and fat intake. 相似文献
82.
Ryan KA Moran AP Hynes SO Smith T Hyde D O'Morain CA Maher M 《FEMS immunology and medical microbiology》2000,28(2):113-120
Much work has focused on trying to identify markers in Helicobacter pylori that might allow the eventual disease outcome of an infection to be predicted. In this study we examined the cagA and vacA genotype, and Lewis status in a panel of 43 Irish H. pylori clinical isolates, and investigated a possible correlation with disease pathology. In addition, differences in the poly-(C) tract of the alpha(1,3)-fucosyltransferase gene were examined to identify a possible correlation with gene expression. Only three of 43 isolates were cagA-negative, whereas the remaining 40 isolates, independent of pathology, were cagA-positive. In all the strains we examined, the vacA signal-sequence was type s1a. For the vacA mid-region 12/43 isolates were type m1 and 31/43 isolates were type m2. These data, and examination of isolates from different pathology groups, suggests that there is no correlation between virulence and vacA genotype in the Irish population of H. pylori isolates. Western blotting of whole cell lysates from 32 H. pylori isolates showed 3/32 displayed only the Le(x) epitope, 12/32 only the Le(y), 13/32 both epitopes and 4/32 neither epitope. No apparent association between Lewis phenotype and disease pathology was evident. A range of lengths of poly-(C) tract were observed in the alpha(1, 3)-fucosyltransferase gene, however the length of the tract in an isolate did not correlate with the Lewis structures present. We conclude that future studies on H. pylori pathogenesis should not alone focus on the importance of molecular markers, but also on the host response, including genetic background and immune responsiveness. 相似文献
83.
84.
Construction, expression, and characterization of a novel fully activated recombinant single-chain hepatitis C virus protease. 总被引:6,自引:0,他引:6
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S. S. Taremi B. Beyer M. Maher N. Yao W. Prosise P. C. Weber B. A. Malcolm 《Protein science : a publication of the Protein Society》1998,7(10):2143-2149
Efficient proteolytic processing of essential junctions of the hepatitis C virus (HCV) polyprotein requires a heterodimeric complex of the NS3 bifunctional protease/helicase and the NS4A accessory protein. A single-chain recombinant form of the protease has been constructed in which NS4A residues 21-32 (GSVVIVGRIILS) were fused in frame to the amino terminus of the NS3 protease domain (residues 3-181) through a tetrapeptide linker. The single-chain recombinant protease has been overexpressed as a soluble protein in E. coli and purified to homogeneity by a combination of metal chelate and size-exclusion chromatography. The single-chain recombinant protease domain shows full proteolytic activity cleaving the NS5A-5B synthetic peptide substrate, DTEDVVCCSMSYTWTGK with a Km and k(cat) of 20.0 +/- 2.0 microM and 9.6 +/- 2.0 min(-1), respectively; parameters identical to those of the authentic NS3(1-631)/NS4A(1-54) protein complex generated in eukaryotic cells (Sali DL et al., 1998, Biochemistry 37:3392-3401). 相似文献
85.
Relationship between lifestyle behaviors and obesity in children ages 9–11: Results from a 12‐country study
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Peter T. Katzmarzyk Tiago V. Barreira Stephanie T. Broyles Catherine M. Champagne Jean‐Philippe Chaput Mikael Fogelholm Gang Hu William D. Johnson Rebecca Kuriyan Anura Kurpad Estelle V. Lambert Carol Maher Jose Maia Victor Matsudo Timothy Olds Vincent Onywera Olga L. Sarmiento Martyn Standage Mark S. Tremblay Catrine Tudor‐Locke Pei Zhao Timothy S. Church for the ISCOLE Research Group 《Obesity (Silver Spring, Md.)》2015,23(8):1696-1702
86.
Malene Bech Vester-Christensen Maher Abou Hachem Henrik Naested Birte Svensson 《Protein expression and purification》2010,69(1):112-119
Heterologous production of large multidomain proteins from higher plants is often cumbersome. Barley limit dextrinase (LD), a 98 kDa multidomain starch and α-limit dextrin debranching enzyme, plays a major role in starch mobilization during seed germination and is possibly involved in starch biosynthesis by trimming of intermediate branched α-glucan structures. Highly active barley LD is obtained by secretory expression during high cell-density fermentation of Pichia pastoris. The LD encoding gene fragment without signal peptide was subcloned in-frame with the Saccharomyces cerevisiae α-factor secretion signal of the P. pastoris vector pPIC9K under control of the alcohol oxidase 1 promoter. Optimization of a fed-batch fermentation procedure enabled efficient production of LD in a 5-L bioreactor, which combined with affinity chromatography on β-cyclodextrin–Sepharose followed by Hiload Superdex 200 gel filtration yielded 34 mg homogenous LD (84% recovery). The identity of the recombinant LD was verified by N-terminal sequencing and by mass spectrometric peptide mapping. A molecular mass of 98 kDa was estimated by SDS–PAGE in excellent agreement with the theoretical value of 97419 Da. Kinetic constants of LD catalyzed pullulan hydrolysis were found to Km,app = 0.16 ± 0.02 mg/mL and kcat,app = 79 ± 10 s?1 by fitting the uncompetitive substrate inhibition Michaelis–Menten equation, which reflects significant substrate inhibition and/or transglycosylation. The resulting catalytic coefficient, kcat,app/Km,app = 488 ± 23 mL/(mg s) is 3.5-fold higher than for barley malt LD. Surface plasmon resonance analysis showed α-, β-, and γ-cyclodextrin binding to LD with Kd of 27.2, 0.70, and 34.7 μM, respectively. 相似文献
87.
Discovery and synthesis of 6,7,8,9-tetrahydro-5H-pyrimido-[4,5-d]azepines as novel TRPV1 antagonists
Hawryluk NA Merit JE Lebsack AD Branstetter BJ Hack MD Swanson N Ao H Maher MP Bhattacharya A Wang Q Freedman JM Scott BP Wickenden AD Chaplan SR Breitenbucher JG 《Bioorganic & medicinal chemistry letters》2010,20(23):7137-7141
Utilization of a tetrahydro-pyrimdoazepine core as a bioisosteric replacement for a piperazine-urea resulted in the discovery a novel series of potent antagonists of TRPV1. The tetrahydro-pyrimdoazepines have been identified as having good in vitro and in vivo potency and acceptable physical properties. 相似文献
88.
Imed Sbissi Mohamed Neffati Abdellatif Boudabous Claude Murat Maher Gtari 《Antonie van Leeuwenhoek》2010,98(4):429-436
The molecular phylogeny and comparative morphological studies reported here provide evidence for the recognition of the genus
Picoa, an hypogeous desert truffle, in the family Pyronemataceae (Ascomycota, Pezizales). Picoa juniperi and Picoa lefebvrei were reassigned to the genus Picoa based on large subunit (LSU) sequence (28S) rDNA and internal transcribed spacer (ITS) rDNA (including the partial 18S, ITS1,
ITS2, 5.8S gene, and partial 28S of the nuclear rDNA) data. Morphological studies of spores, asci, perida, and gleba revealed
high similarities between P. lefebvrei and P. juniperi, thereby confirming the membership of both species in the genus Picoa. These two species were primarily distinguishable based on ascospore ornamentation. 相似文献
89.
There is a lack of studies on the occurrence and diversity of Frankia in African soils, including those in northern African regions. The present study on Tunisian soils is an attempt to address this issue using Alnus glutinosa , Elaeagnus angustifolia and Casuarina glauca in a plant capturing bioassay on 30 soil samples, followed by amplified 16S ribosomal DNA restriction pattern analysis (ARDRA). A total of seven ARDRA haplotypes of Frankia have been detected in root actinorhizas that have been affiliated to theoretical ARDRA haplotypes upon in silico digestion of selected 16S ribosomal RNA (rRNA) gene sequences retrieved from GeneBank and confirmed by their partial 16S rRNA gene sequencing. Elaeagnus -compatible Frankia isolates were widespread and form four ARDRA haplotypes affiliated to Frankia , colonizing Elaeagnaceae and Rhamnaceae in two different phylogenetic subgroups. Alnus -compatible strains occurring in northern subhumid area were closely related to Alnus – Morella -compatible strains and clustered in two ARDRA haplotypes. Casuarina -compatible strains lack variability in several northern arboreta. The relatively wide diversity of Tunisian Frankia strains opens the perspective that African soil could be an interesting reservoir for the isolation of new actinorhizal strains that could be used as potential biofertilizers to counteract the progressive soil desertification which indeed is a crucial environmental problem in Northern Africa. 相似文献
90.