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The review considers the structure, evolution, and possible mechanisms of formation and spreading of intrachromosomal and interchromosomal segmental duplications (SD), which account for more than 5% of the human genome. Most SD consist of multiple modules, which occur in several copies in different genome regions. SD are preferentially located in pericentric and subtelomeric regions, which are least studied on the human chromosomes. Homologous recombination between SD results in various chromosome rearrangements, contributing to the genome instability and the origin of several human hereditary disorders. 相似文献
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E. S. Kropotova R. A. Tychko O. L. Zinov’eva A. F. Zyryanova S. L. Khankin V. L. Cherkes V. A. Aliev S. F. Beresten N. Yu. Oparina T. D. Mashkova 《Molecular Biology》2010,44(2):216-222
Colorectal cancer is one of the most common cancers in the world. Changes in AKR1B1 and AKR1B10 expression levels, whose diagnostic value was previously shown for several other cancer types, were studied in colorectal
tumors. These genes encode aldose reductases, members of the aldo-keto reductase superfamily, which comprises enzymes capable
to reduce a range of aromatic and aliphatic aldehydes and ketones. They are also involved in retinoid metabolism and carcinogenesis.
AKR1B1 and AKR1B10 mRNA levels were compared in paired specimens of normal and colorectal tumor tissues using RT-PCR and quantitative real-time
PCR. For the first time, the downregulation of these genes was demonstrated in colorectal carcinoma. AKR1B10 expression was decreased in most tumor specimens (88%, 65/74) even at the early stages, and in more than 60% of cases mRNA
levels were decreased more than 10-fold. AKR1B1 mRNA levels were decreased in 10% of specimens. Therefore, these two structurally similar genes show quite different mRNA
expression patterns in colorectal cancer, suggestive of their different functional roles in the intestine. Significant downregulation
of AKR1B10 expression can be considered a potential diagnostic marker of colorectal cancer. 相似文献
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G. S. Krasnov S. L. Khankin Yu. A. Bukurova O. G. Zatsepina N. Yu. Oparina D. G. Garbuz A. N. Ershov T. D. Mashkova V. L. Karpov S. F. Beresten 《Molecular Biology》2009,43(4):562-566
Colorectal cancer is one of the most common malignancies in developed countries. Scarce clinical signs at the early stages
of the disease and the lack of fast and sensitive diagnostic techniques based on the detection of tumor specific protein markers
contribute greatly to the high mortality rate. The search for such markers is significantly complicated by the high levels
of major structural and cytoskeletal proteins in normal and tumor tissues. Extraction with 0.2 M NaCl in the presence of the
nonionic detergent NP-40 was performed to enrich the soluble protein fraction. This modification resulted in a considerably
increased sensitivity of detection of minor proteins that may enter the circulation during carcinogenesis. The soluble protein
profiles of the paired colon adenocarcinoma and normal tissue specimens were compared using 2D gel electrophoresis, which
enabled the detection of 10 proteins whose levels in tumors were elevated at least 10-fold as compared to normal tissue. The
proteins were identified by MALDI-TOF mass spectrometry, and two new protein markers of colon cancer, TAF9 and CISH, were
discovered. Low levels of CISH synthesis in most normal human tissues and tumors other than colorectal cancer make it a prospective
candidate diagnostic marker for this type of cancer. 相似文献
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Intrachromosomal and interchromosomal segmental duplications account for more than 5% of the human genome. To analyze the processes resulting in the complex mosaic structure of duplicons, a draft human genome sequence was searched for duplicated segments of a genomic fragment of the pericentric region of the chromosome 21 short arm. The duplicons found consist of modules having paralogs in various genome regions. Module ends are flanked with various tandem or interspersed repeats, which are more unstable as compared with unique sequences. In most cases, the boundaries of duplicated segments exactly coincide with or are in close proximity to hot spots of various rearrangements within repeats or boundaries between repeats and unique sequences or between two different repeats. Homologous recombination between repetitive elements was assumed to be the major mechanism contributing to the mosaic structure of duplicons. 相似文献
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Biology Bulletin - Abstract—The dynamics of the numbers of larks inhabiting several areas differing in the physical and geographical (landscape) conditions and the level of anthropogenic... 相似文献
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Biology Bulletin - Abstract—We studied the population structure and the number of larks in the steppe and semidesert zones of the Caspian Lowland (within the territories of the Alexandrov-Gai... 相似文献
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