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91.
Pre-B cell colony-enhancing factor (PBEF), also known as visfatin, is a highly conserved, 52-kDa protein found in living species from bacteria to humans. Originally a curiosity identified serendipitously in microarray studies but having no obvious functional importance, PBEF has now been shown to exert three distinct activities of central importance to cellular energetics and innate immunity. Within the cell, PBEF functions as a nicotinamide phosphoribosyl transferase, the rate-limiting step in a salvage pathway of nicotinamide adenine dinucleotide (NAD) biosynthesis. By virtue of this role, it can regulate cellular levels of NAD and so impact not only cellular energetics but also NAD-dependent enzymes such as sirtuins. Although it lacks a signal peptide, PBEF is released by a variety of cells, and elevated levels can be found in the systemic circulation of patients with a variety of inflammatory diseases. As an extracellular cytokine, PBEF can induce the cellular expression of inflammatory cytokines such as TNF-alpha, IL-1beta, and IL-6. Finally, PBEF has been shown to be an adipokine expressed by fat cells that exerts a number of insulin mimetic and antagonistic effects. PBEF expression is up-regulated in a variety of acute and chronic inflammatory diseases including sepsis, acute lung injury, rheumatoid arthritis, inflammatory bowel disease, and myocardial infarction and plays a key role in the persistence of inflammation through its capacity to inhibit neutrophil apoptosis. This review summarizes the admittedly incomplete body of emerging knowledge about a remarkable new mediator of innate immunity.  相似文献   
92.
93.
Luk A  Murthy NS  Wang W  Rojas R  Kohn J 《Acta biomaterialia》2012,8(4):1459-1468
Distribution of water in three classes of biomedically relevant and degradable polymers was investigated using small-angle neutron scattering. In semicrystalline polymers, such as poly(lactic acid) and poly(glycolic acid), water was found to diffuse preferentially into the non-crystalline regions. In amorphous polymers, such as poly(d,l-lactic acid) and poly(lactic-co-glycolic acid), the scattering after 7 days of incubation was attributed to water in microvoids that form following the hydrolytic degradation of the polymer. In amorphous copolymers containing hydrophobic segments (desaminotyrosyl-tyrosine ethyl ester) and hydrophilic blocks (poly(ethylene glycol) (PEG)), a sequence of distinct regimes of hydration were observed: homogeneous distribution (~10 Å length scales) at <13 wt.% PEG (~1 water per EG), clusters of hydrated domains (~50 Å radius) separated at 24 wt.% PEG (1–2 water per EG), uniformly distributed hydrated domains at 41 wt.% PEG (~4 water per EG) and phase inversion at >50 wt.% PEG (>6 water per EG). Increasing the PEG content increased the number of these domains with only a small decrease in distance between the domains. These discrete domains appeared to coalesce to form submicron droplets at ~60 °C, above the melting temperature of crystalline PEG. The significance of such observations on the evolution of micrometer-size channels that form during hydrolytic erosion is discussed.  相似文献   
94.
Neuroscience and Behavioral Physiology - Objective. To compare the genotypes at the apolipoprotein E (APOE) gene with outcomes and level of neural markers in children with severe traumatic brain...  相似文献   
95.
Puumala virus (PUUV), carried by bank voles (Myodes glareolus), is the medically most important hantavirus in Central and Western Europe. In this study, a total of 523 bank voles (408 from Germany, 72 from Slovakia, and 43 from Czech Republic) collected between the years 2007–2012 were analyzed for the presence of hantavirus RNA. Partial PUUV genome segment sequences were obtained from 51 voles. Phylogenetic analyses of all three genome segments showed that the newfound strains cluster with other Central and Western European PUUV strains. The new sequences from ?umava (Bohemian Forest), Czech Republic, are most closely related to the strains from the neighboring Bavarian Forest, a known hantavirus disease outbreak region. Interestingly, the Slovak strains clustered with the sequences from Bohemian and Bavarian Forests only in the M but not S segment analyses. This well-supported topological incongruence suggests a segment reassortment event or, as we analyzed only partial sequences, homologous recombination. Our data highlight the necessity of sequencing all three hantavirus genome segments and of a broader bank vole screening not only in recognized endemic foci but also in regions with no reported human hantavirus disease cases.  相似文献   
96.
复合自适应滤波器用于体感诱发电位信噪比的提高   总被引:1,自引:0,他引:1  
本研究以可靠、快速提取体感诱发电位为目标,试图解决相干叠加方法既费时又不能反映体感诱发电位时变特征的缺点。运用以自适应噪声减法器和自适应增强器为基础构造的复合自适应滤波器提取体感诱发电位。仿真实验表明,运用复合自适应滤波器可实现从强噪声背景中快速提取体感诱发电位,能更快地识别体感诱发电位的潜伏期及幅值,并且系统性能稳定。  相似文献   
97.

Background

Lumbar disc disease (LDD) is one of the leading causes of disability in the working‐age population. A functional single‐nucleotide polymorphism (SNP), +1184T→C, in exon 8 of the cartilage intermediate layer protein gene (CILP) was recently identified as a risk factor for LDD in the Japanese population (odds ratio (OR) 1.61, 95% CI 1.31 to 1.98), with implications for impaired transforming growth factorβ1 signalling.

Aim

To validate this finding in two different ethnic cohorts with LDD.

Methods

This SNP and flanking SNPs were analysed in 243 Finnish patients with symptoms of LDD and 259 controls, and in 348 Chinese subjects with MRI‐defined LDD and 343 controls.

Results and conclusion

The results showed no evidence of association in the Finnish (OR = 1.35, 95% CI 0.97 to 1.87; p = 0.14) or the Chinese (OR = 1.05, 95% CI 0.77 to 1.43; p = 0.71) samples, suggesting that cartilage intermediate layer protein gene is not a major risk factor for symptoms of LDD in Caucasians or in the general population that included individuals with or without symptoms.Lumbar disc disease (LDD) is one of the leading causes of disability in the working‐age population. Radiological changes indicative of LDD are common, but only a proportion develops complications such as disc herniation and sciatica. Although the aetiology of LDD is not well understood, there is strong evidence for the involvement of both genetic and environmental factors.1,2A recent study reported an association between LDD and a functional single‐nucleotide polymorphism (SNP) (rs2073711), +1184T→C, in exon 8 of the cartilage intermediate layer protein gene (CILP) in a Japanese group (odds ratio (OR) 1.61, 95% CI 1.31 to –1.98).3 The allelic change resulted in amino acid substitution Ile395Thr. CILP is expressed widely in intervertebral discs and its expression increases as disc degeneration progresses.3 CILP interacts directly with transforming growth factor (TGF)β1, inhibiting the TGFβ1‐mediated induction of extracellular matrix proteins such as aggrecan and collagen II.3 Functional studies showed that the C allele (coding for Thr395) increased binding and inhibition of TGFβ1, suggesting that regulation of TGFβ1 signalling by CILP plays a crucial role in the aetiology and pathogenesis of LDD.3Argument for a causal role would be strengthened if the same association could be replicated in a distinct population, and in clinical cases of LDD defined by MRI changes indicative of LDD in general. Therefore, we investigated the association between CILP polymorphisms and LDD in a Finnish sample with symptoms of LDD, and in a Chinese sample with only MRI‐defined LDD. These samples were informative in previous studies demonstrating association of LDD with the vitamin D receptor gene4 and the Gln326Trp (Trp2) allele of COL9A25 in Chinese and the Arg103Trp (Trp3) allele of COL9A3 in Finns.6 Thus, the Chinese sample is comparable with the Finnish dataset, and a correlation can then be drawn with the Japanese dataset.  相似文献   
98.
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of gastrointestinal tract and are characterized by presence of mutations in tyrosine kinases cKIT (KIT) and PDGFRα (PDGFRA). Mutations identified are highly heterogeneous, but some mutations are associated with specific clinical features of the tumor. Samples from 278 GIST patients collected during the period 2004–2011 were screened for mutations in exons 9, 11, 13, and 17 of KIT and 12, 14 and 18 of PDGFRA. Results of mutation screening were summarized and tested for possible association with clinical parameters of tumors. Mutations were identified in 83.81% of patients. Most frequent mutations were found in KIT exon 11 reaching frequency of 62.95%. Other exons contributed to the mutation pool with frequencies 8.27%, 7.55%, 2.52%, 1.44%, 1.08%, and 0.00%, in decreasing order KIT exon 9, PDGRFA exons 18 and 12, KIT exon 13, PDGFRA exon 14, and KIT exon 17. General linear model analysis showed no effect of any individual analyzed mutation on the phenotypic variables, but we confirmed association between mutations KIT exon 9 p. 503‐504_dup2, and PDGFRA exon 18 p. D842V and intestinal and gastric localization of tumors.  相似文献   
99.
Cholinesterases (ChEs) have been identified in vertebrates and invertebrates. Inhibition of ChE activity in invertebrates, such as bivalve molluscs, has been used to evaluate the exposure of organophosphates, carbamate pesticides, and heavy metals in the marine system. The golden apple snail (Pomacea canaliculata) is considered as one of the worst invasive alien species harmful to rice and other crops. The ChE(s) in this animal, which has been found recently, but poorly characterized thus far, could serve as biomarker(s) for environmental surveillance as well as a potential target for the pest control. In this study, the tissue distribution, substrate preference, sensitivity to ChE inhibitors, and molecular species of ChEs in P. canaliculata were investigated. It was found that the activities of both AChE and BChE were present in all test tissues. The intestine had the most abundant ChE activities. Both enzymes had fair activities in the head, kidney, and gills. The BChE activity was more sensitive to tetra-isopropylpyrophosphoramide (iso-OMPA) than the AChE. Only one BChE molecular species, 5.8S, was found in the intestine and head, whereas two AChE species, 5.8S and 11.6S, were found there. We propose that intestine ChEs of this snail may be potential biomarkers for manipulating pollutions.  相似文献   
100.
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