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排序方式: 共有709条查询结果,搜索用时 31 毫秒
71.
Masoud Zamani Esteki Eftychia Dimitriadou Ligia Mateiu Cindy Melotte Niels Van der Aa Parveen Kumar Rakhi Das Koen Theunis Jiqiu Cheng Eric Legius Yves Moreau Sophie Debrock Thomas D’Hooghe Pieter Verdyck Martine De Rycke Karen Sermon Joris R. Vermeesch Thierry Voet 《American journal of human genetics》2015,96(6):894-912
Methods for haplotyping and DNA copy-number typing of single cells are paramount for studying genomic heterogeneity and enabling genetic diagnosis. Before analyzing the DNA of a single cell by microarray or next-generation sequencing, a whole-genome amplification (WGA) process is required, but it substantially distorts the frequency and composition of the cell’s alleles. As a consequence, haplotyping methods suffer from error-prone discrete SNP genotypes (AA, AB, BB) and DNA copy-number profiling remains difficult because true DNA copy-number aberrations have to be discriminated from WGA artifacts. Here, we developed a single-cell genome analysis method that reconstructs genome-wide haplotype architectures as well as the copy-number and segregational origin of those haplotypes by employing phased parental genotypes and deciphering WGA-distorted SNP B-allele fractions via a process we coin haplarithmisis. We demonstrate that the method can be applied as a generic method for preimplantation genetic diagnosis on single cells biopsied from human embryos, enabling diagnosis of disease alleles genome wide as well as numerical and structural chromosomal anomalies. Moreover, meiotic segregation errors can be distinguished from mitotic ones. 相似文献
72.
Zahra Zamani Masoud Bahar Marie Agnès Jacques Mohammad Reza Lak Alireza Akhavan 《World journal of microbiology & biotechnology》2011,27(10):2371-2378
Xanthomonad-like bacteria that are associated with common bacterial blight of bean in Iran were identified on the basis of
their colonial morphology, biochemical and serological properties, presence of a specific DNA fragment using PCR primers and
pathogenicity on bean. Xanthomonas axonopodis pv. phaseoli (Xap) strains were further characterized using rep-PCR and restriction fragment length polymorphism (RFLP). RFLP profiles
generated by the restriction endonucleases RsaI, TaqI, HaeIII and Sau96I and rep-PCR analysis revealed that Iranian strains were relatively genetically homogenous. The similarity coefficients
among the strains ranged from 0.87 to 1. The genetic diversity coefficients among strains from three infected provinces, Isfahan,
Markazi and Lorestan, were 0.019, 0.072 and 0.033, respectively. The low overall level of polymorphism within Xap isolates
collected from the three Iranian infected regions could suggest that few initial inoculum introductions might have distributed
among these different bean-growing areas in Iran. 相似文献
73.
Zabet-Moghaddam M Shaikh AL Jones LB Niwayama S 《Bioorganic & medicinal chemistry letters》2011,21(15):4629-4632
Benzoyloxysuccinimide and its d5-labeled version, which react with amino groups in the N-termini and lysine side chains in proteins, were synthesized and applied to quantitative analysis of peptides and a commercially available protein in combination with a MALDI mass spectrometer. 相似文献
74.
Mehdipour P Kheirollahi M Mehrazin M Kamalian N Atri M 《Cell biology international》2011,35(9):915-925
It was previously reported that tumour samples had shorter telomeres than the surrounding normal tissue. Hereby, the initial sign of correlation between malignant tissue and telomere behaviour could be noticed. Bridging knowledge between germ and somatic cells could facilitate understanding cellular evolution. The aim of our investigation was to provide evidence for the evolutionary hypothesis of TL (telomere length) in primary BC (breast cancer) and BTs (brain tumours), which might be applied as a prognostic and/or predictive marker. DNA extraction from the frozen tissues was performed using high pure PCR template preparation kit. Standard protocol of Telo TTAGGG Telomere Length Assay kit, a non‐radioactive chemiluminescent assay, was used. The protein expression in extracted cells was analysed by immunofluorescence. We also detected telomerase activity. The G/T (genomic/tumour ratio) for TL in two groups of patients affected with primary BC and primary BT revealed significant differences in both BC patients (P=0.025) and in BTs (P=0.001). The pattern of telomere signals by Q‐FISH (quantitative fluorescent in situ hybridization) show that in all samples, except one, SI (signal intensity) has been significantly decreased in tissue related to blood, either in BC patients or in patients with BTs (0.041≥P≥0.001). However, the data achieved by Q‐FISH support the results of Southern blot. These data reflect a significant diversity either in BC or in BT patients, providing evidence for the evolutionary hypothesis of TL in cancer development and progression. 相似文献
75.
Abedi-Ardekani B Kamangar F Sotoudeh M Villar S Islami F Aghcheli K Nasrollahzadeh D Taghavi N Dawsey SM Abnet CC Hewitt SM Fahimi S Saidi F Brennan P Boffetta P Malekzadeh R Hainaut P 《PloS one》2011,6(12):e29488
Background
Golestan Province in northeastern Iran has one of the highest incidences of esophageal squamous cell carcinoma (ESCC) in the world with rates over 50 per 100,000 person-years in both sexes. We have analyzed TP53 mutation patterns in tumors from this high-risk geographic area in search of clues to the mutagenic processes involved in causing ESCC.Methodology/Principal Findings
Biopsies of 119 confirmed ESCC tumor tissue from subjects enrolled in a case-control study conducted in Golestan Province were analyzed by direct sequencing of TP53 exons 2 through 11. Immunohistochemical staining for p53 was carried out using two monoclonal antibodies, DO7 and 1801. A total of 120 TP53 mutations were detected in 107/119 cases (89.9%), including 11 patients with double or triple mutations. The mutation pattern was heterogeneous with infrequent mutations at common TP53 “hotspots” but frequent transversions potentially attributable to environmental carcinogens forming bulky DNA adducts, including 40% at bases known as site of mutagenesis by polycyclic aromatic hydrocarbons (PAHs). Mutations showed different patterns according to the reported temperature of tea consumption, but no variation was observed in relation to ethnicity, tobacco or opium use, and alcoholic beverage consumption or urban versus rural residence.Conclusion/Significance
ESCC tumors in people from Golestan Province show the highest rate of TP53 mutations ever reported in any cancer anywhere. The heterogeneous mutation pattern is highly suggestive of a causative role for multiple environmental carcinogens, including PAHs. The temperature and composition of tea may also influence mutagenesis. 相似文献76.
Nasr-Esfahani M Moghadam M Tangestaninejad S Mirkhani V 《Bioorganic & medicinal chemistry letters》2005,15(13):3276-3278
Efficient oxidation of Hantzsch 1,4-dihydropyridines to their corresponding pyridine derivatives with (Bu(4)N)IO(4) catalyzed by tetraphenylporphyrinatomanganese(III) chloride [Mn(TPP)Cl] is reported. This catalytic system shows high efficiency in the oxidation of 1,4-dihydropyridines at room temperature in the presence of imidazole. 相似文献
77.
Stem cells: from epigenetics to microRNAs 总被引:11,自引:0,他引:11
78.
Intracerebroventricular administration of gut peptide PYY3-36 stimulates food intake. In contrast, peripheral administration inhibits food intake, suggesting that the peptide has the opposite effect by virtue of accessing a unique subset of brain sites. A previous study suggested that peripheral PYY3-36 activates anorexigenic POMC neurons in the arcuate nucleus, and this was proposed to be the mechanism underlying the peptide's anorexigenic activity. Here, we demonstrate in an electrophysiological slice preparation that, in contrast to the original model, PYY3-36 potently and reversibly inhibits POMC neurons via postsynaptic Y2 receptors. These data show a complex role for Y2 receptors in regulation of the NPY/POMC circuitry, as they are present as inhibitory receptors on both the orexigenic NPY neurons as well as the anorexigenic POMC neurons. Secondly, these data argue against a direct role of POMC neurons in mediating the anorexigenic response to administration of peripheral PYY3-36. 相似文献
79.
80.
The Asmari Formation, a thick carbonate succession of the Oligo-Miocene in Zagros Mountains (southwest Iran), has been studied
to determine its microfacies, paleoenvironments and sedimentary sequences. Detailed petrographic analysis of the deposits
led to the recognition of 10 microfacies types. In addition, five major depositional environments were identified in the Asmari
Formation. These include tidal flat, shelf lagoon, shoal, slope and basin environmental settings and are interpreted as a
carbonate platform developed in an open shelf situation but without effective barriers separating the platform from the open
ocean. The Asmari carbonate succession consists of four, thick shallowing-upward sequences (third-order cycles). No major
hiatuses were recognized between these cycles. Therefore, the contacts are interpreted as SB2 sequence boundary types. The
Pabdeh Formation, the deeper marine facies equivalent of the Asmari Limestone is interpreted to be deposited in an outer slope-basin
environment. The microfacies of the Pabdeh Formation shows similarities to the Asmari Formation. 相似文献