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1.
Plasminogen activator and collagenase production by cultured capillary endothelial cells 总被引:33,自引:17,他引:16
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Cultured bovine capillary endothelial (BCE) cells produce low levels of collagenolytic activity and significant amounts of the serine protease plasminogen activator (PA). When grown in the presence of nanomolar quantities of the tumor promoter 12-O-tetradecanoyl phorbol-13-acetate (TPA), BCE cells produced 5-15 times more collagenolytic activity and 2-10 times more PA than untreated cells. The enhanced production of these enzymes was dependent on the dose of TPA used, with maximal response at 10(-7) to 10(-8) M. Phorbol didecanoate (PDD), an analog of TPA which is an active tumor promoter, also increased protease production. 4-O-methyl-TPA and 4α-PDD, two analogs of TPA which are inactive as tumor promoters, had no effect on protease production. Increased PA and collagenase activities were detected within 7.5 and 19 h, respectively, after the addition of TPA. The TPA-stimulated BCE cells synthesized a urokinase-type PA and a typical vertebrate collagenase. BCE cells were compared with bovine aortic endothelial (BAE) cells and bovine embryonic skin (BES) fibroblasts with respect to their production of protease in response to TPA. Under normal growth conditions, low levels of collagenolyic activity were detected in the culture fluids from BCE, BAE, and BES cells. BCE cells produced 5-13 times the basal levels of collagenolytic activity in response to TPA, whereas BAE cells and BES fibroblasts showed a minimal response to TPA. Both BCE and BAE cells exhibited relatively high basal levels of PA, the production of which was stimulated approximately threefold by the addition of TPA. The observation that BCE cells and not BAE cells produced high levels of both PA and collagenase activities in response to TPA demonstrates a significant difference between these two types of endothelial cells and suggests that the enhanced detectable activities are a property unique to bovine capillary and microvessel and endothelial cells. 相似文献
2.
Christian Esposito Massimo Ficco Francesco Palmieri Aniello Castiglione 《Cluster computing》2013,16(4):887-903
Cloud Federation is an emerging computing model where multiple resources from independent Cloud providers are leveraged to create large-scale distributed virtual computing clusters, operating as into a single Cloud organization. This model enables the implementation of environmental diversity for Cloud applications, and overcomes the provisioning and scalability limits of a single Cloud, by introducing minimal additional cost for the Cloud consumer. In such a scenario, it is necessary to leverage on specific networking technologies that enable the effective support of inter-Cloud communication services between Cloud providers. This paper proposes an interconnection solution for Cloud federations based on publish/subscribe services. Moreover, we discuss some fundamental concerns needed to satisfy the inter-Cloud communication requirements in terms of reliability and availability. Finally, we present some experimental results that highlight some key reliability and denial of service vulnerability concerns in this domain. 相似文献
3.
A high-density consensus map of A and B wheat genomes 总被引:1,自引:0,他引:1
Daniela Marone Giovanni Laidò Agata Gadaleta Pasqualina Colasuonno Donatella B. M. Ficco Angelica Giancaspro Stefania Giove Giosué Panio Maria A. Russo Pasquale De Vita Luigi Cattivelli Roberto Papa Antonio Blanco Anna M. Mastrangelo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,125(8):1619-1638
A durum wheat consensus linkage map was developed by combining segregation data from six mapping populations. All of the crosses were derived from durum wheat cultivars, except for one accession of T. ssp. dicoccoides. The consensus map was composed of 1,898 loci arranged into 27 linkage groups covering all 14 chromosomes. The length of the integrated map and the average marker distance were 3,058.6 and 1.6?cM, respectively. The order of the loci was generally in agreement with respect to the individual maps and with previously published maps. When the consensus map was aligned to the deletion bin map, 493 markers were assigned to specific bins. Segregation distortion was found across many durum wheat chromosomes, with a higher frequency for the B genome. This high-density consensus map allowed the scanning of the genome for chromosomal rearrangements occurring during the wheat evolution. Translocations and inversions that were already known in literature were confirmed, and new putative rearrangements are proposed. The consensus map herein described provides a more complete coverage of the durum wheat genome compared with previously developed maps. It also represents a step forward in durum wheat genomics and an essential tool for further research and studies on evolution of the wheat genome. 相似文献
4.
D Marone G Panio DB Ficco MA Russo P De Vita R Papa D Rubiales L Cattivelli AM Mastrangelo 《Molecular genetics and genomics : MGG》2012,287(9):741-753
Diversity array technology (DArT) markers are largely used for mapping, genetic diversity, and association mapping studies. For years, they have been used as anonymous genomic markers, as their sequences were not known. As the sequences of 2,000 wheat DArT clones are now available, this study was designed to analyze these sequences with bioinformatic approaches, and to study the genetic features of a subset of 291 markers positioned on the A and B genomes in three durum wheat genetic maps. A set of 1,757 non-redundant sequences was identified, and used as queries for similarity searches. Analysis of the genetic positions of markers corresponding to nearly identical sequences indicates that redundancy of sequences is one of the factors that explains the clustering of these markers in specific genomic regions. Of a total of 1,124 DArT clones (64?%) that represent putatively expressed sequences, putative functions are proposed for more than 700 of them. Of note, many clones correspond to genes that are related to disease resistance, as characterized by leucine-rich repeat domains, and 40 of these clones are positioned in the three genetic maps presented in this study. Finally, DArT markers have been used to find syntenic regions in the Brachypodium and rice genomes. In conclusion, the analyses herein presented contribute to explain the main features of DArT markers observed in genetic maps, as clustering in short chromosome regions. Moreover, the attribution of putative gene functions for more than 700 sequences makes these markers an optimal tool for collinearity studies or for the identification of candidate genes. 相似文献
5.
A common polygenic basis for quinine and PROP avoidance in mice 总被引:3,自引:2,他引:1
Inbred strains of mice (Mus musculus) differ greatly in ability to taste
various bitter compounds. For some compounds, the differences result from
allelic variation at a single locus. However, segregation patterns
incompatible with monogenic inheritance have been found for quinine
avoidance. The Soa bitter sensitivity locus exerts some influence on this
phenotype, but an unknown number of other loci also contribute. Relative
avoidance patterns for quinine sulfate in panels of naive inbred strains
resembled avoidance patterns for 6-n-propyl-2- thiouracil (PROP),
suggesting a common genetic basis. In particular, C57BL/6J mice strongly
avoided both 0.1 mM quinine sulfate and 1 mM PROP in two-bottle preference
tests, whereas C3H/HeJ mice were indifferent to both. Therefore, 12 BXH/Ty
recombinant inbred strains, derived from these strains, were tested with
both solutions to begin identification of the unknown bitter loci. Naive
mice were tested for four consecutive days with each compound (order
counterbalanced). Some BXH/Ty strain means resembled those of the parent
strains, but others were intermediate. This indicated recombination among
loci affecting avoidance, and therefore polygenic inheritance. The strain
means were highly correlated across compounds (r = 0.98), suggesting that
the same polygenes controlled both phenotypes. The BXH/Ty means for both
compounds were then compared with the strain genotypes at 212 chromosome
position markers distributed throughout the genome. Eight markers on five
chromosomes (3, 6, 7, 8 and 9) yielded significant correlations. Six of the
markers were correlated with both phenotypes, again suggesting common
polygenic inheritance. The marker with the highest correlation was Prp,
tightly linked to Soa on chromosome 6. The correlated marker regions likely
contain quantitative trait loci affecting bitter avoidance. The phenotypic
similarity of PROP to quinine, rather than to phenylthiourea, apparently
stemming from a common polygenic basis, indicates a difference between mice
and humans in gustatory organization related to bitters.
相似文献
6.
Carla DB Fernandez Fernanda F Bellentani Glaura SA Fernandes Juliana E Perobelli Ana Paula A Favareto André F Nascimento Antonio C Cicogna Wilma DG Kempinas 《Reproductive biology and endocrinology : RB&E》2011,9(1):32
Background
Obesity is rapidly becoming a worldwide epidemic that affects children and adults. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. Thus, the aim of the present study was to investigate the effect of high-fat diet-induced obesity on male reproductive parameters. 相似文献7.
Whitehouse DB; Tomkins J; Lovegrove JU; Hopkinson DA; McMillan WO 《Molecular biology and evolution》1998,15(4):456-462
The expanding molecular database provides unparalleled opportunities for
characterizing genes and for studying groups of related genes. We use
sequences drawn from the database to construct an evolutionary framework
for examining the important glycolytic enzyme phosphoglucomutase (PGM).
Phosphoglucomutase plays a pivotal role in the synthesis and utilization of
glycogen and is present in all organisms. In humans, there are three
well-described isozymes, PGMI, PGM2, and PGM3. PGM1 was cloned 5 years ago;
however, repeated attempts using both immunological approaches and
molecular probes designed from PGM1 have failed to isolate either PGM2 or
PGM3. Using a phylogenetic strategy, we first identified 47 highly
divergent prokaryotic and eukaryotic PGM-like sequences from the database.
Although overall amino acid identity often fell below 20%, the relative
order, position, and sequence of three structural motifs, the active site
and the magnesium-- and sugar-binding sites, were conserved in all 47
sequences. The phylogenetic history of these sequences was complex and
marked by duplications and translocations; two instances of transkingdom
horizontal gene transfer were identified. Nonetheless, the sequences fell
within six well-defined evolutionary lineages, three of which contained
only prokaryotes. Of the two prokaryotic/eukaryotic lineages, one contained
bacterial, yeast, slimemold, invertebrate, and vertebrate homologs to human
PGM1 and the second contained likely homologs to human PGM2. Indeed, an
amino acid sequence, derived from a partial human cDNA, that fell within
the second cross-kingdom lineage bears several characteristics expected for
PGM2. A third lineage may contain homologs to human PGM3. On a general
level, our phylogenetic-based approach shows promise for the further
utilization of the extensive molecular database.
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8.
Incorporation of axonally transported glycoproteins into axolemma during nerve regeneration 总被引:14,自引:4,他引:10
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The insertion of axonally transported fucosyl glycoproteins into the axolemma of regenerating nerve sprouts was examined in rat sciatic motor axons at intervals after nerve crush. [(3)H]Fucose was injected into the lumbar ventral horns and the nerves were removed at intervals between 1 and 14 d after labeling. To follow the fate of the “pulse- labeled” glycoproteins, we examined the nerves by correlative radiometric and EM radioautographic approaches. The results showed, first, that rapidly transported [(3)H]fucosyl glycoproteins were inserted into the axolemma of regenerating sprouts as well as parent axons. At 1 d after delivery, in addition to the substantial mobile fraction of radioactivity still undergoing bidirectional transport within the axon, a fraction of label was already associated with the axolemma. Insertion of labeled glycoproteins into the sprout axolemma appeared to occur all along the length of the regenerating sprouts, not just in sprout terminals. Once inserted, labeled glycoproteins did not undergo extensive redistribution, nor did they appear in sprout regions that formed (as a result of continued outgrowth) after their insertion. The amount of radioactivity in the regenerating nerves decreased with time, in part as a result of removal of transported label by retrograde transport. By 7-14 d after labeling, radioautography showed that almost all the remaining radioactivity was associated with axolemma. The regenerating sprouts retained increased amounts of labeled glycoproteins; 7 or 14 d after labeling, the regenerating sprouts had over twice as much of radioactivity as comparable lengths of control nerves or parent axons. One role of fast axonal transport in nerve regeneration is the contribution to the regenerating sprout of glycoproteins inserted into the axolemma; these membrane elements are added both during longitudinal outgrowth and during lateral growth and maturation of the sprout. 相似文献
9.
10.
Goldstein DB; Zhivotovsky LA; Nayar K; Linares AR; Cavalli-Sforza LL; Feldman MW 《Molecular biology and evolution》1996,13(9):1213-1218
It has recently been suggested that observed levels of variation at
microsatellite loci can be used to infer patterns of selection in genomes
and to assess demographic history. In order to evaluate the feasibility of
these suggestions it is necessary to know something about how levels of
variation at microsatellite loci are expected to fluctuate due simply to
stochasticity in the processes of mutation and inheritance (genetic
sampling). Here we use recently derived properties of the stepwise mutation
model to place confidence intervals around the variance in repeat score
that is expected at mutation-drift equilibrium and outline a statistical
test for whether an observed value differs significantly from expectation.
We also develop confidence intervals for the time course of the buildup of
variation following a complete elimination of variation, such as might be
caused by a selective sweep or an extreme population bottleneck. We apply
these methods to the variation observed at human Y-specific
microsatellites. Although a number of authors have suggested the
possibility of a very recent sweep, our analyses suggest that a sweep or
extreme bottleneck is unlikely to have occurred anytime during the last
approximately 74,000 years. To generate this result we use a recently
estimated mutation rate for microsatellite loci of 5.6 x 10(-4) along with
the variation observed at autosomal microsatellite loci to estimate the
human effective population size. This estimate is 18,000, implying an
effective number of 4,500 Y chromosomes. One important general conclusion
to emerge from this study is that in order to reject mutation-drift
equilibrium at a set of linked microsatellite loci it is necessary to have
an unreasonably large number of loci unless the observed variance is far
below that expected at mutation-drift equilibrium.
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