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排序方式: 共有239条查询结果,搜索用时 15 毫秒
81.
Ting-Hein Lee William McKleroy Amin Khalifeh-Soltani Stephen Sakuma Stanislav Lazarev Kirsi Riento Stephen L. Nishimura Ben J. Nichols Kamran Atabai 《Molecular biology of the cell》2014,25(5):583-593
Tissue fibrosis occurs when matrix production outpaces matrix degradation. Degradation of collagen, the main component of fibrotic tissue, is mediated through an extracellular proteolytic pathway and intracellular pathway of cellular uptake and lysosomal digestion. Recent studies demonstrate that disruption of the intracellular pathways can exacerbate fibrosis. These pathways are poorly characterized. Here we identify novel mediators of the intracellular pathway of collagen turnover through a genome-wide RNA interference screen in Drosophila S2 cells. Screening of 7505 Drosophila genes conserved among metazoans identified 22 genes that were required for efficient internalization of type I collagen. These included proteins involved in vesicle transport, the actin cytoskeleton, and signal transduction. We show further that the flotillin genes have a conserved and central role in collagen uptake in Drosophila and human cells. Short hairpin RNA–mediated silencing of flotillins in human monocyte and fibroblasts impaired collagen uptake by promoting lysosomal degradation of the endocytic collagen receptors uPARAP/Endo180 and mannose receptor. These data provide an initial characterization of intracellular pathways of collagen turnover and identify the flotillin genes as critical regulators of this process. A better understanding of these pathways may lead to novel therapies that reduce fibrosis by increasing collagen turnover. 相似文献
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Brachiopods of the family Linoproductidae from the Kasimovian Stage of the Moscow Region 总被引:1,自引:1,他引:0
S. S. Lazarev 《Paleontological Journal》2008,42(4):378-388
Brachiopods from the Kasimovian Stage of the Moscow Region that for more than 70 years were referred to the genus Linoproductus (family Linoproductidae) are revised and redescribed. New characters connected with the ornamentation and inner structure of the dorsal valve are used for the first time in the analysis of the taxonomic structure of the group. Six species from three genera are described; four of them are new: one species of Linispinus Lazarev, 2006, three species of Linipalus Lazarev, 2007, and two species of Sublinoproductus gen. nov. The new genus is considered to be transitional between the genera Linispinus and Linoproductus. 相似文献
84.
Control of nematode parasites with reduced reliance on the use of anthelmintics was studied in 16 ewes with suckling twin
lambs on contaminated pasture in Denmark. Ewes and lambs were treated with albendazole at turn-out 3 May. Ewes were removed
from the groups on 26 July, and lambs were slaughtered on 11 October. The animals were allocated to 4 groups of 8 lambs and
their 4 ewes. Group TS was treated with albendazole at weeks 3, 6 and 8 after turnout and set-stocked; group TM was similarly
treated but moved to clean pasture in conjunction with the last drenching; group US was untreated and set-stocked, and group
UM was left untreated but moved to clean pasture week 8 after turn-out. Supplementary feed was offered in June and August
due to scarcity of pasture. Strategic treatments of ewes and lambs weeks 3, 6 and 8 after turn-out, with or without a move
to clean pasture, were highly effective in controlling nematode infections for most of the season. This was reflected in better
weight gains and carcass characteristics in the treated compared to untreated lambs, resulting in an average increase in the
value of the product by 36%. The effect of moving without treatment (UM) on faecal egg counts was limited but peak pasture
infectivity was reduced to less than 10% compared to the set-stocked group and weight gains of lambs were significantly better
despite poor feed availability in late season. The study showed that under set-stocked conditions repeated anthelmintic treatments
of both ewes and lambs in early season may ensure sufficient nematode control whereas moving animals to clean pasture without
dosing was less efficient. The latter may, however, still be a viable option in organic and other production systems where
routine use of anthelmintics is banned, particularly if weaning and moving are combined or a second move is performed. 相似文献
85.
A. V. Sekridova A. M. Varizhuk O. N. Tatarinova V. V. Severov N. A. Barinov I. P. Smirnov V. N. Lazarev D. V. Klinov G. E. Pozmogova 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2017,11(1):62-71
We report results of the first systematic study of conformational polymorphism of G-rich DNA fragments of Alu-repeats. Alu retrotransposons are primate-specific short interspersed elements. Using the Alu sequence of the prooncogen bcl2 intron and the consensus AluSx sequence as representative examples, we have determined characteristic Alu sites that are capable of adopting G-quadruplex (GQ) conformations (i.e., potential quadruplex sites—PQSAlu), and demonstrated by bioinformatics methods that these sites are Alu-specific in the human genome. Genomic frequencies of PQSAlu were assessed (~1/10000 bp). These sites were found to be characteristic of young (active) Alu families (Alu-Y). A recombinant DNA sequence bearing the Alu element of the human bcl2 gene (304 bp) and its PQS-mutant (Alu-PQS) were constructed. The formation of noncanonical structures in Alubcl2 dsDNA and their absence in the case of Alu-PQS have been shown using DMS-footprinting and atomic force microscopy (AFM). Expression vectors bearing wild-type and mutant Alu insertions in the promoter regions of the reporter gene have been prepared, and their regulatory effects have been compared during transfection of НЕК293 and HeLa cells. We suggest that the dynamic study of the spatial organization of Alu repeats may provide insight into the mechanisms of genomic rearrangements responsible for the development of many oncological and neurodegenerative diseases. 相似文献
86.
Jan Willem Erisman Nelleke Domburg Wim de Vries Hans Kros Bronno de Haan Kaj Sanders 《中国科学:生命科学英文版》2005,48(Z2)
The Netherlands is "well known" for its nitrogen problems; it has one of the highest reactive nitrogen (Nr) emission densities in the world. It is a small country at the delta of several large European rivers. Ever since the industrial revolution, there has been a growing excess of nutrients and related emissions into the atmosphere (ammonia, nitrogen oxides and nitrous oxide) and into groundwater and surface water (nitrate), leading to a large range of cascading environmental impacts. Vehicular traffic, sewage and animal husbandry are the main sources of oxidized and reduced forms of Nr. This paper provides an overview of the origin and fate of nitrogen in the Netherlands, the various reported impacts of nitrogen, the Dutch and European policies to reduce nitrogen emissions and related impacts. In addition, ways are presented to go forward to potentially solve the problems in a European perspective. Solutions include the improvement of nitrogen efficiencies in different systems, technological options and education. 相似文献
87.
TJS Alves GS Cruz V Wanderley-Teixeira AAC Teixeira JV Oliveira AA Correia 《Biotechnic & histochemistry》2014,89(4):245-255
The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), not only damages crops, but controlling its population also requires synthetic insecticides, which leads to selection of resistant populations and environmental contamination. Essential oils are an alternative for controlling this insect. There are few studies of the effects of these oils on the insect's reproductive system. We evaluated the effects of the long pepper, Piper hispidinervum, essential oil on the gonads of the armyworm and tested its possible influence on the fertility of this insect. Dosages of 30 and 50 mg/ml were tested in 3rd instar caterpillars using the leaf immersion method. Testes and ovarioles were collected, fixed with 10% formalin and embedded in Historesin. The sections were stained with toluidine blue and Mallory trichrome to detect connective tissue, periodic acid-Schiff to detect neutral carbohydrates, and bromophenol blue to detect proteins. We found that the long pepper essential oil affected negatively the spermatogenesis and altered the histochemistry of the ovarioles of S. frugiperda. The effects of long pepper oil suggest that it is a promising tool for controlling the armyworm pest. 相似文献
88.
89.
90.
Borkhsenius SN Vishniakov IE Budantseva EV Vonskiĭ MS Jakobs E Lazarev VN 《Tsitologiia》2008,50(7):613-618
A considerable increase in several heat shock proteins (HSPs) amount in Acholeplasma laidlawii cells has been revealed after temperature rising of liquid culture; and the quantity of small HSP, named p17, was increased in a hundred of times. The p17 protein was isolated and identified as HSP of alpha-crystallin type (alpha-HSP). It became possible as a result of sequencing of 15 amino acids from N-terminal of the p17 polypeptide chain, followed by revealing of a corresponding open reading frame (ORF) in a completely sequenced genome of A. laidlawii PG 8A. Computer-based search for homologous ORFs in all 17 genomes of Mycoplasmataceae family (the mycoplasmas themselves) that had been completely sequenced to date, gives negative result. But among the representatives of Mollicutes (mycoplasma) class, the genes coding alpha-HSPs were found in two Phytoplasma species (Phytoplasmataceae family) and the acholeplasma examined (Acholeplasmataceae family). It supposed that presence or absence of alpha-HSPs in microorganisms might be connected with the fact that representatives of Acholeplasmataceae and Phytoplasmataceae families inhabit principally in plant tissues in contrast to majority of Mycoplasmataceae family, that inhabit animal and human tissues, i. e. use ecological niches with relatively constant temperature. 相似文献