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31.
Citrullination is a post-translational modification catalysed by peptidylarginine deiminase and is a common feature of inflammation.
The presence of anti-citrullinated protein/peptide antibodies (ACPA), however, is unique to rheumatoid arthritis. Several
lines of evidence suggest that ACPA are important in the pathogenesis of rheumatoid arthritis. A popular hypothesis for this
pathogenesis is a two-hit model. The first hit gives rise to ACPA, and the second hit, an unrelated episode of synovial inflammation
accompanied by citrullination, is perpetuated by the pre-existing antibodies. This model suggests that reducing citrullination
might ameliorate disease. Recent findings indicate that citrullination closely correlates with inflammation, and that glucocorticoids
decrease peptidylarginine deiminase expression independent of their other anti-inflammatory effects. 相似文献
32.
33.
Quantitative conversion of phytate to inorganic phosphorus in soybean seeds expressing a bacterial phytase 总被引:3,自引:0,他引:3
Bilyeu KD Zeng P Coello P Zhang ZJ Krishnan HB Bailey A Beuselinck PR Polacco JC 《Plant physiology》2008,146(2):468-477
Phytic acid (PA) contains the major portion of the phosphorus in the soybean (Glycine max) seed and chelates divalent cations. During germination, both minerals and phosphate are released upon phytase-catalyzed degradation of PA. We generated a soybean line (CAPPA) in which an Escherichia coli periplasmic phytase, the product of the appA gene, was expressed in the cytoplasm of developing cotyledons. CAPPA exhibited high levels of phytase expression, >or=90% reduction in seed PA, and concomitant increases in total free phosphate. These traits were stable, and, although resulted in a trend for reduced emergence and a statistically significant reduction in germination rates, had no effect on the number of seeds per plant or seed weight. Because phytate is not digested by monogastric animals, untreated soymeal does not provide monogastrics with sufficient phosphorus and minerals, and PA in the waste stream leads to phosphorus runoff. The expression of a cytoplasmic phytase in the CAPPA line therefore improves phosphorus availability and surpasses gains achieved by other reported transgenic and mutational strategies by combining in seeds both high phytase expression and significant increases in available phosphorus. Thus, in addition to its value as a high-phosphate meal source, soymeal from CAPPA could be used to convert PA of admixed meals, such as cornmeal, directly to utilizable inorganic phosphorus. 相似文献
34.
J Steinbuch AC van Dijk FHBM Schreuder MTB Truijman J Hendrikse PJ Nederkoorn A van der Lugt E Hermeling APG Hoeks WH Mess 《Cardiovascular ultrasound》2017,15(1):9
Background
Mean or maximal intima-media thickness (IMT) is commonly used as surrogate endpoint in intervention studies. However, the effect of normalization by surrounding or median IMT or by diameter is unknown. In addition, it is unclear whether IMT inhomogeneity is a useful predictor beyond common wall parameters like maximal wall thickness, either absolute or normalized to IMT or lumen size. We investigated the interrelationship of common carotid artery (CCA) thickness parameters and their association with the ipsilateral internal carotid artery (ICA) stenosis degree.Methods
CCA thickness parameters were extracted by edge detection applied to ultrasound B-mode recordings of 240 patients. Degree of ICA stenosis was determined from CT angiography.Results
Normalization of maximal CCA wall thickness to median IMT leads to large variations. Higher CCA thickness parameter values are associated with a higher degree of ipsilateral ICA stenosis (p?<?0.001), though IMT inhomogeneity does not provide extra information. When the ratio of wall thickness and diameter instead of absolute maximal wall thickness is used as risk marker for having moderate ipsilateral ICA stenosis (>50%), 55 arteries (15%) are reclassified to another risk category.Conclusions
It is more reasonable to normalize maximal wall thickness to end-diastolic diameter rather than to IMT, affecting risk classification and suggesting modification of the Mannheim criteria.Trial registration
Clinical trials.gov NCT01208025.35.
Robles-Hernández L J Hernández-Huerta AC González-Franco OA Hernández-Rodríguez A Núñez-Barrios R Pérez-Leal 《Phyton》2015,84(2):253-261
Chili pepper is one of the main crops of economic importance in Mexico, and Fusarium wilting is a disease that limits its production. In addition, the inappropriate use of agrochemicals in farming activities generate environmental and health problems. Therefore, in this study the effectiveness of Streptomyces sp PRIO41 was evaluated as a (1) biocontrol agent of Fusarium spp and (2) plant growth promoter bacteria. Assays of pathogenicity and virulence of Fusarium spp. in jalapeño pepper seeds, and interactions of these pathogens with Streptomyces PRIO41 were evaluated under two nutritional conditions. In the greenhouse, the effectiveness of Streptomyces sp. PRIO41 was determined as a (1) biocontrol of Fusarium, and (2) plant growth promoter of wilt of pepper plants. The results showed that all fungal isolates caused symptoms in pepper seeds and seedlings with different degrees of virulence. Interactions in vitro showed that Streptomyces showed the most effective range of virulence against Fusarium isolates in the poor medium (37.6%-100%), with fungicidal effects in some cases. In the greenhouse, Streptomyces PRIO41 reduced Fusarium wilting up to a 40%, and positively affected all vegetative growth parameters, particularly plant height, leaf area, root length, and leaf and root dry biomasses. This study showed the potential of Streptomyces PRIO41 as a biocontrol agent of Fusarium spp., and as a biofertilizer of pepper plants. 相似文献
36.
Maturing maize kernels are a rich source of cytokinins and cytokinin oxidase/dehydrogenase activity, but the relationship between kernel development, cytokinin levels, the induction of cytokinin oxidase/dehydrogenase and the control of cell division is not known. Using polyclonal antibodies raised against recombinant maize cytokinin oxidase/dehydrogenase, we investigated the appearance of cytokinin oxidase/dehydrogenase (ZmCKX1) in both hybrid and inbred maize kernels as a function of time after pollination. Cytokinin oxidase/dehydrogenase was detected by five days after pollination (5 DAP) in a hybrid line, but significantly later in inbred lines. The bulk of the cytokinin oxidase/dehydrogenase detected was associated with the embryo and placental/chalazal region of the kernels rather than with the endosperm. We identified additional maize sequences in the database that appear to encode cytokinin oxidase/dehydrogenase gene family members and correspond closely with a subset of the ten cytokinin oxidase/dehydrogenase genes identified in the rice genome. Gene expression of Zmckx1 was examined by RT-PCR in immature kernels and compared with that of three putative maize cytokinin oxidase/dehydrogenase homologs. We conclude that the manipulation of kernel cytokinin levels to increase endosperm cell division will require a more detailed understanding of specific expression patterns and localization of multiple cytokinin oxidase/dehydrogenases within kernels. 相似文献
37.
A covariotide model explains apparent phylogenetic structure of oxygenic photosynthetic lineages 总被引:17,自引:13,他引:4
Lockhart PJ; Steel MA; Barbrook AC; Huson DH; Charleston MA; Howe CJ 《Molecular biology and evolution》1998,15(9):1183-1188
The aims of the work were (1) to develop statistical tests to identify
whether substitution takes place under a covariotide model in sequences
used for phylogenetic inference and (2) to determine the influence of
covariotide substitution on phylogenetic trees inferred for photosynthetic
and other organisms. (Covariotide and covarion models are ones in which
sites that are variable in some parts of the underlying tree are invariable
in others and vice versa.) Two tests were developed. The first was a
contingency test, and the second was an inequality test comparing the
expected number of variable sites in two groups with the observed number.
Application of these tests to 16S rDNA and tufA sequences from a range of
nonphotosynthetic prokaryotes and oxygenic photosynthetic prokaryotes and
eukaryotes suggests the occurrence of a covariotide mechanism. The degree
of support for partitioning of taxa in reconstructed trees involving these
organisms was determined in the presence or absence of sites showing
particular substitution patterns. This analysis showed that the support for
splits between (1) photosynthetic eukaryotes and prokaryotes and (2)
photosynthetic and nonphotosynthetic organisms could be accounted for by
patterns arising from covariotide substitution. We show that the additional
problem of compositional bias in sequence data needs to be considered in
the context of patterns of covariotide/covarion substitution. We argue that
while covariotide or covarion substitution may give rise to
phylogenetically informative patterns in sequence data, this may not always
be so.
相似文献
38.
Data from population- and clinic-based epidemiologic studies of rheumatoid arthritis patients suggest that individuals with
rheumatoid arthritis are at risk for developing clinically evident congestive heart failure. Many established risk factors
for congestive heart failure are over-represented in rheumatoid arthritis and likely account for some of the increased risk
observed. In particular, data from animal models of cytokine-induced congestive heart failure have implicated the same inflammatory
cytokines produced in abundance by rheumatoid synovium as the driving force behind maladaptive processes in the myocardium
leading to congestive heart failure. At present, however, the direct effects of inflammatory cytokines (and rheumatoid arthritis
therapies) on the myocardia of rheumatoid arthritis patients are incompletely understood. 相似文献
39.
Cytokinins form a diverse class of compounds that are essential for plant growth. Cytokinin dehydrogenase has a major role in the control of the levels of these plant hormones by catalysing their irreversible oxidation. The crystal structure of Zea mays cytokinin dehydrogenase displays the same two-domain topology of the flavoenzymes of the vanillyl-alcohol oxidase family but its active site cannot be related to that of any other family member. The X-ray analysis reveals a bipartite architecture of the catalytic centre, which consists of a funnel-shaped region on the protein surface and an internal cavity lined by the flavin ring. A pore with diameter of about 4A connects the two active-site regions. Snapshots of two critical steps along the reaction cycle were obtained through the structural analysis of the complexes with a slowly reacting substrate and the reaction product, which correspond to the states immediately before (Michaelis complex) and after (product complex) oxidation has taken place. The substrate displays a "plug-into-socket" binding mode that seals the catalytic site and precisely positions the carbon atom undergoing oxidation in close contact with the reactive locus of the flavin. A polarising H-bond between the substrate amine group and an Asp-Glu pair may facilitate oxidation. Substrate to product conversion results in small atomic movements, which lead to a planar conformation of the reaction product allowing double-bond conjugation. These features in the mechanism of amine recognition and oxidation differ from those observed in other flavin-dependent amine oxidases. 相似文献
40.
Determinants of Readiness for Adopting Healthy Lifestyle Behaviors Among Indigenous Adolescents with Type 2 Diabetes in Manitoba,Canada: A Cross‐Sectional Study 下载免费PDF全文