544 results on '"Xu, Liwen"'
Search Results
502. Analysis of Key Issues on GNSS-R Soil Moisture Retrieval Based on Different Antenna Patterns.
- Author
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Li F, Peng X, Chen X, Liu M, and Xu L
- Abstract
GNSS-R (Global Navigation Satellite System-Reflectometry) has been demonstrated to be a new and powerful tool to sense soil moisture in recent years. Multi-antenna pattern and single-antenna pattern have been proposed regarding how to receive and process reflected signals. Great efforts have been made concerning ground-based and air-borne observations. Meanwhile, a number of satellite-based missions have also been implemented. For the in-depth study of soil moisture remote sensing by the technique of GNSS-R, regardless of the extraction methods of the reflected signals or the types of the observation platform, three key issues have to be determined: The specular reflection point, the spatial resolution and the detection depth in the soil. However, in current literatures, there are no comprehensive explanations of the above three key issues. This paper conducts theoretical analysis and formula derivation, aiming to systematically and quantitatively determine the extent of soil moisture being detected in three dimensions from the above-mentioned aspects. To further explain how the three factors behave in the specific application, the results of two application scenarios are shown: (1) a ground-based GPS measurement in Marshall, Colorado, US from the Plate Boundary Observatory, corresponding to single-antenna pattern. The relative location of the specular reflection points, the average area of the First Fresnel Ellipse Clusters and the sensing depth of the time-series soil moisture are analyzed, and (2) an aviation experiment conducted in Zhengzhou to retrieve soil moisture content, corresponding to the multi-antenna pattern. The spatial distribution of soil moisture estimation with a certain resolution based on the flight tracks and the relevant sensing depth are manifested. For remote sensing using GNSS reflected signals, BeiDou is different from GPS mainly in the carrier frequency. Therefore, the results of this study can provide references for China's future development of the BeiDou-R technique.
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- 2018
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503. Detection of variants in dystroglycanopathy-associated genes through the application of targeted whole-exome sequencing analysis to a large cohort of patients with unexplained limb-girdle muscle weakness.
- Author
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Johnson K, Bertoli M, Phillips L, Töpf A, Van den Bergh P, Vissing J, Witting N, Nafissi S, Jamal-Omidi S, Łusakowska A, Kostera-Pruszczyk A, Potulska-Chromik A, Deconinck N, Wallgren-Pettersson C, Strang-Karlsson S, Colomer J, Claeys KG, De Ridder W, Baets J, von der Hagen M, Fernández-Torrón R, Zulaica Ijurco M, Espinal Valencia JB, Hahn A, Durmus H, Willis T, Xu L, Valkanas E, Mullen TE, Lek M, MacArthur DG, and Straub V
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Dystroglycans metabolism, Female, Genetic Predisposition to Disease, Glycosylation, Heterozygote, Homozygote, Humans, Male, Middle Aged, Muscle Proteins genetics, Muscular Dystrophies, Limb-Girdle metabolism, Mutation, Phenotype, Exome Sequencing methods, Young Adult, Genetic Variation, Muscular Dystrophies, Limb-Girdle genetics
- Abstract
Background: Dystroglycanopathies are a clinically and genetically heterogeneous group of disorders that are typically characterised by limb-girdle muscle weakness. Mutations in 18 different genes have been associated with dystroglycanopathies, the encoded proteins of which typically modulate the binding of α-dystroglycan to extracellular matrix ligands by altering its glycosylation. This results in a disruption of the structural integrity of the myocyte, ultimately leading to muscle degeneration., Methods: Deep phenotypic information was gathered using the PhenoTips online software for 1001 patients with unexplained limb-girdle muscle weakness from 43 different centres across 21 European and Middle Eastern countries. Whole-exome sequencing with at least 250 ng DNA was completed using an Illumina exome capture and a 38 Mb baited target. Genes known to be associated with dystroglycanopathies were analysed for disease-causing variants., Results: Suspected pathogenic variants were detected in DPM3, ISPD, POMT1 and FKTN in one patient each, in POMK in two patients, in GMPPB in three patients, in FKRP in eight patients and in POMT2 in ten patients. This indicated a frequency of 2.7% for the disease group within the cohort of 1001 patients with unexplained limb-girdle muscle weakness. The phenotypes of the 27 patients were highly variable, yet with a fundamental presentation of proximal muscle weakness and elevated serum creatine kinase., Conclusions: Overall, we have identified 27 patients with suspected pathogenic variants in dystroglycanopathy-associated genes. We present evidence for the genetic and phenotypic diversity of the dystroglycanopathies as a disease group, while also highlighting the advantage of incorporating next-generation sequencing into the diagnostic pathway of rare diseases.
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- 2018
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504. A novel compound heterozygous mutation in the POMK gene causing limb-girdle muscular dystrophy-dystroglycanopathy in a sib pair.
- Author
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Strang-Karlsson S, Johnson K, Töpf A, Xu L, Lek M, MacArthur DG, Casar-Borota O, Williams M, Straub V, and Wallgren-Pettersson C
- Subjects
- Adolescent, Child, Dystroglycans metabolism, Female, Humans, Male, Muscle Weakness metabolism, Muscle Weakness pathology, Muscle, Skeletal metabolism, Muscular Dystrophies, Limb-Girdle metabolism, Muscular Dystrophies, Limb-Girdle pathology, Protein Kinases metabolism, Siblings, Muscle Weakness genetics, Muscle, Skeletal pathology, Muscular Dystrophies, Limb-Girdle genetics, Mutation, Missense, Protein Kinases genetics
- Abstract
We describe two Finnish siblings in whom an incidentally detected elevated creatine kinase activity eventually led to a diagnosis of limb-girdle muscular dystrophy-dystroglycanopathy (Type C12; MDDGC12). When diagnosed at age 10 and 13 years, they were mildly affected with a slow or non-progressive disease course. The main symptoms comprised infrequent hip cramps triggered by flexion, neck cramps triggered by yawning, transient growing pains, calf hypertrophy and mild proximal muscle weakness. Their cognitive and motor developments were unremarkable and they were physically active. Whole-exome sequencing revealed compound heterozygous mutations, both of which were novel, in the protein O-mannosyl kinase (POMK) gene in both siblings; a missense mutation, p.Pro322Leu (c.965C > T), and a nonsense mutation, p.Arg46Ter (c.136C > T). The results were confirmed by Sanger sequencing, showing that the parents were heterozygous carriers of one mutation each. This report adds to the literature by providing phenotype and genotype data on this ultra-rare POMK-related dystroglycanopathy., (Copyright © 2018 Elsevier B.V. All rights reserved.)
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- 2018
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505. New Insight into SO 2 Poisoning and Regeneration of CeO 2 -WO 3 /TiO 2 and V 2 O 5 -WO 3 /TiO 2 Catalysts for Low-Temperature NH 3 -SCR.
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Xu L, Wang C, Chang H, Wu Q, Zhang T, and Li J
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- Adsorption, Catalysis, Temperature, Ammonia, Titanium
- Abstract
In this study, the poisoning effects of SO
2 on the V2 O5 -WO3 /TiO2 (1%VWTi) and CeO2 -WO3 /TiO2 (5%CeWTi) selective catalytic reduction (SCR) catalysts were investigated in the presence of steam, and also the regeneration of deactivated catalysts was studied. After pretreating the catalysts in a flow of NH3 + SO2 + H2 O + O2 at 200 °C for 24 h, it was observed that the low-temperature SCR (LT-SCR) activity decreased significantly over the 1%VWTi and 5%CeWTi catalysts. For 1%VWTi, NH4 HSO4 (ABS) was the main product detected after the poisoning process. Both of NH4 HSO4 and cerium sulfate species were formed on the poisoned 5%CeWTi catalyst, indicating that SO2 reacted with Ce3+ /Ce4+ , even in the presence of high concentration of NH3 . The decrease of BET specific surface area, NOx adsorption capacity, the ratio of chemisorbed oxygen, and reducibility were responsible for the irreversible deactivation of the poisoned 5%CeWTi catalyst. Meanwhile, the LT-SCR activity could be recovered over the poisoned 1%VWTi after regeneration at 400 °C, but not for the 5%CeWTi catalyst. For industrial application, it is suggested that the regeneration process can be utilized for 1%VWTi catalysts after a period of time after NH4 HSO4 accumulated on the catalysts.- Published
- 2018
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506. Limb girdle muscular dystrophy due to mutations in POMT2 .
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Østergaard ST, Johnson K, Stojkovic T, Krag T, De Ridder W, De Jonghe P, Baets J, Claeys KG, Fernández-Torrón R, Phillips L, Topf A, Colomer J, Nafissi S, Jamal-Omidi S, Bouchet-Seraphin C, Leturcq F, MacArthur DG, Lek M, Xu L, Nelson I, Straub V, and Vissing J
- Subjects
- Adolescent, Adult, Alleles, Cognitive Dysfunction complications, Cognitive Dysfunction genetics, Cognitive Dysfunction pathology, Cognitive Dysfunction physiopathology, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Muscle Weakness complications, Muscle Weakness physiopathology, Muscle, Skeletal pathology, Muscular Dystrophies, Limb-Girdle complications, Muscular Dystrophies, Limb-Girdle pathology, Muscular Dystrophies, Limb-Girdle physiopathology, Mutation, Neuroimaging, Young Adult, Genetic Predisposition to Disease genetics, Mannosyltransferases genetics, Muscular Dystrophies, Limb-Girdle genetics
- Abstract
Background: Mutations in the gene coding for protein O-mannosyl-transferase 2 ( POMT2 ) are known to cause severe congenital muscular dystrophy, and recently, mutations in POMT2 have also been linked to a milder limb-girdle muscular dystrophy (LGMD) phenotype, named LGMD type 2N (LGMD2N). Only four cases have been reported so far.ClinicalTrials.gov ID: NCT02759302 METHODS: We report 12 new cases of LGMD2N, aged 18-63 years. Muscle involvement was assessed by MRI, muscle strength testing and muscle biopsy analysis. Other clinical features were also recorded., Results: Presenting symptoms were difficulties in walking, pain during exercise, delayed motor milestones and learning disabilities at school. All had some degree of cognitive impairment. Brain MRIs were abnormal in 3 of 10 patients, showing ventricular enlargement in one, periventricular hyperintensities in another and frontal atrophy of the left hemisphere in a third patient. Most affected muscle groups were hip and knee flexors and extensors on strength testing. On MRI, most affected muscles were hamstrings followed by paraspinal and gluteal muscles. The 12 patients in our cohort carried 11 alleles with known mutations, whereas 11 novel mutations accounted for the remaining 13 alleles., Conclusion: We describe the first cohort of patients with LGMD2N and show that unlike other LGMD types, all patients had cognitive impairment. Primary muscle involvement was found in hamstring, paraspinal and gluteal muscles on MRI, which correlated well with reduced muscle strength in hip and knee flexors and extensors. The study expands the mutational spectrum for LGMD2N, with the description of 11 novel POMT2 mutations in the association with LGMD2N., Clinical Trial Registration: NCT02759302., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)
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- 2018
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507. A novel adaptive ensemble classification framework for ADME prediction.
- Author
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Yang M, Chen J, Xu L, Shi X, Zhou X, Xi Z, An R, and Wang X
- Abstract
It has now become clear that in silico prediction of ADME (absorption, distribution, metabolism, and elimination) characteristics is an important component of the drug discovery process. Therefore, there has been considerable interest in the development of in silico modeling of ADME prediction in recent years. Despite the advances in this field, there remains challenges when facing the unbalanced and high dimensionality problems simultaneously. In this work, we introduce a novel adaptive ensemble classification framework named as AECF to deal with the above issues. AECF includes four components which are (1) data balancing, (2) generating individual models, (3) combining individual models, and (4) optimizing the ensemble. We considered five sampling methods, seven base modeling techniques, and ten ensemble rules to build a choice pool. The proper route of constructing predictive models was determined automatically according to the imbalance ratio (IR). With the adaptive characteristics of AECF, it can be used to work on the different kinds of ADME data, and the balanced data is a special case in AECF. We evaluated the performance of our approach using five extensive ADME datasets concerning Caco-2 cell permeability (CacoP), human intestinal absorption (HIA), oral bioavailability (OB), and P-glycoprotein (P-gp) binders (substrates/inhibitors, PS/PI). The performance of AECF was evaluated on two independent datasets, and the average AUC values were 0.8574-0.8602, 0.8968-0.9182, 0.7821-0.7981, 0.8139-0.8311, and 0.8874-0.8898 for CacoP, HIA, OB, PS and PI, respectively. Our results show that AECF can provide better performance and generality compared with individual models and two representative ensemble methods bagging and boosting. Furthermore, the degree of complementarity among the AECF ensemble members was investigated for the purpose of elucidating the potential advantages of our framework. We found that AECF can effectively select complementary members to construct predictive models by our auto-adaptive optimization approach, and the additional diversity in both sample and feature space mainly contribute to the complementarity of ensemble members., Competing Interests: The authors declare that there is no conflict of interest involved in this paper., (This journal is © The Royal Society of Chemistry.)
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- 2018
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508. Isolation and Characteristics of the Arkansas-Type Infectious Bronchitis Virus in China.
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Han Z, Jiang L, Zhao W, Chen Y, Xu L, Sun J, Zhao Y, and Liu S
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- Animals, China, Coronavirus Infections virology, Infectious bronchitis virus genetics, Virulence, Chickens, Coronavirus Infections veterinary, Genome, Viral, Infectious bronchitis virus pathogenicity, Infectious bronchitis virus physiology, Poultry Diseases virology, Viral Tropism
- Abstract
Two infectious bronchitis virus (IBV) strains, designated as γCoV/ck/China/I0712/11 (I0712/11) and γCoV/ck/China/I0108/17 (I0108/17), were isolated from diseased chicken flocks in different provinces in China and genotyped as Arkansas (Ark)-type viruses with three other Chinese Ark field strains, the Jilin vaccine strain, and the American Ark- and Ark DPI-like viruses. Complete genomic sequence analysis and pairwise comparison of nucleotide sequences encoding the S1 subunit of the spike protein and other structural and accessory proteins revealed that Chinese Ark field isolates were genetically closely related to the Jilin vaccine and American ArkDPI11 strains, although extensive nucleotide changes were found across the genomes of Chinese Ark field isolates. This suggests that Chinese Ark-type isolates are derived from the Jilin vaccine, and have diverged and evolved independently by point mutations since introduction into China. It is also possible that the Chinese Ark viruses have arisen as a result of different introductions of American ArkDPI11-like strains from the United States; this hypothesis requires further investigation. Pathogenicity testing showed that Chinese Ark viruses had comparable virulence to that of the Massachusetts-type M41 strain, although they had lower affinity for the kidneys of chickens than the M41 strain had. Although Ark-type viruses are not widespread in China, surveillance and updating the currently applied vaccination strategy for sound protection against IBV disease are important because this type of virus has caused heavy economic losses in the United States.
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- 2018
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509. Construction of a multicontrol sterility system for a maize male-sterile line and hybrid seed production based on the ZmMs7 gene encoding a PHD-finger transcription factor.
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Zhang D, Wu S, An X, Xie K, Dong Z, Zhou Y, Xu L, Fang W, Liu S, Liu S, Zhu T, Li J, Rao L, Zhao J, and Wan X
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- Hybridization, Genetic genetics, Hybridization, Genetic physiology, Plant Infertility physiology, Plants, Genetically Modified genetics, Seeds genetics, Transcription Factors genetics, Transcription Factors metabolism, Zea mays genetics, Plants, Genetically Modified metabolism, Plants, Genetically Modified physiology, Seeds metabolism, Seeds physiology, Zea mays metabolism, Zea mays physiology
- Abstract
Although hundreds of genetic male sterility (GMS) mutants have been identified in maize, few are commercially used due to a lack of effective methods to produce large quantities of pure male-sterile seeds. Here, we develop a multicontrol sterility (MCS) system based on the maize male sterility 7 (ms7) mutant and its wild-type Zea mays Male sterility 7 (ZmMs7) gene via a transgenic strategy, leading to the utilization of GMS in hybrid seed production. ZmMs7 is isolated by a map-based cloning approach and encodes a PHD-finger transcription factor orthologous to rice PTC1 and Arabidopsis MS1. The MCS transgenic maintainer lines are developed based on the ms7-6007 mutant transformed with MCS constructs containing the (i) ZmMs7 gene to restore fertility, (ii) α-amylase gene ZmAA and/or (iii) DNA adenine methylase gene Dam to devitalize transgenic pollen, (iv) red fluorescence protein gene DsRed2 or mCherry to mark transgenic seeds and (v) herbicide-resistant gene Bar for transgenic seed selection. Self-pollination of the MCS transgenic maintainer line produces transgenic red fluorescent seeds and nontransgenic normal colour seeds at a 1:1 ratio. Among them, all the fluorescent seeds are male fertile, but the seeds with a normal colour are male sterile. Cross-pollination of the transgenic plants to male-sterile plants propagates male-sterile seeds with high purity. Moreover, the transgene transmission rate through pollen of transgenic plants harbouring two pollen-disrupted genes is lower than that containing one pollen-disrupted gene. The MCS system has great potential to enhance the efficiency of maize male-sterile line propagation and commercial hybrid seed production., (© 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.)
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- 2018
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510. DiseaseEnhancer: a resource of human disease-associated enhancer catalog.
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Zhang G, Shi J, Zhu S, Lan Y, Xu L, Yuan H, Liao G, Liu X, Zhang Y, Xiao Y, and Li X
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- Gene Regulatory Networks, Genetic Variation, Genome, Human, Humans, Internet, User-Computer Interface, Databases, Nucleic Acid, Disease genetics, Enhancer Elements, Genetic
- Abstract
Large-scale sequencing studies discovered substantial genetic variants occurring in enhancers which regulate genes via long range chromatin interactions. Importantly, such variants could affect enhancer regulation by changing transcription factor bindings or enhancer hijacking, and in turn, make an essential contribution to disease progression. To facilitate better usage of published data and exploring enhancer deregulation in various human diseases, we created DiseaseEnhancer (http://biocc.hrbmu.edu.cn/DiseaseEnhancer/), a manually curated database for disease-associated enhancers. As of July 2017, DiseaseEnhancer includes 847 disease-associated enhancers in 143 human diseases. Database features include basic enhancer information (i.e. genomic location and target genes); disease types; associated variants on the enhancer and their mediated phenotypes (i.e. gain/loss of enhancer and the alterations of transcription factor bindings). We also include a feature on our website to export any query results into a file and download the full database. DiseaseEnhancer provides a promising avenue for researchers to facilitate the understanding of enhancer deregulation in disease pathogenesis, and identify new biomarkers for disease diagnosis and therapy., (© The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.)
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- 2018
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511. Optimizing prognosis-related key miRNA-target interactions responsible for cancer metastasis.
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Zhao H, Yuan H, Hu J, Xu C, Liao G, Yin W, Xu L, Wang L, Zhang X, Shi A, Li J, and Xiao Y
- Abstract
Increasing evidence suggests that the abnormality of microRNAs (miRNAs) and their downstream targets is frequently implicated in the pathogenesis of human cancers, however, the clinical benefit of causal miRNA-target interactions has been seldom studied. Here, we proposed a computational method to optimize prognosis-related key miRNA-target interactions by combining transcriptome and clinical data from thousands of TCGA tumors across 16 cancer types. We obtained a total of 1,956 prognosis-related key miRNA-target interactions between 112 miRNAs and 1,443 their targets. Interestingly, these key target genes are specifically involved in tumor progression-related functions, such as 'cell adhesion' and 'cell migration'. Furthermore, they are most significantly correlated with 'tissue invasion and metastasis', a hallmark of metastasis, in ten distinct types of cancer through the hallmark analysis. These results implicated that the prognosis-related key miRNA-target interactions were highly associated with cancer metastasis. Finally, we observed that the combination of these key miRNA-target interactions allowed to distinguish patients with good prognosis from those with poor prognosis both in most TCGA cancer types and independent validation sets, highlighting their roles in cancer metastasis. We provided a user-friendly database named miRNATarget (freely available at http://biocc.hrbmu.edu.cn/miRNATar/), which provides an overview of the prognosis-related key miRNA-target interactions across 16 cancer types., Competing Interests: CONFLICTS OF INTEREST The authors declare that they have no conflicts of interest.
- Published
- 2017
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512. Identification of GAA variants through whole exome sequencing targeted to a cohort of 606 patients with unexplained limb-girdle muscle weakness.
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Johnson K, Töpf A, Bertoli M, Phillips L, Claeys KG, Stojanovic VR, Perić S, Hahn A, Maddison P, Akay E, Bastian AE, Łusakowska A, Kostera-Pruszczyk A, Lek M, Xu L, MacArthur DG, and Straub V
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Cohort Studies, Female, Glycogen Storage Disease Type II diagnosis, Glycogen Storage Disease Type II epidemiology, Humans, Male, Middle Aged, Muscle Weakness diagnosis, Muscle Weakness epidemiology, Muscular Dystrophies, Limb-Girdle diagnosis, Muscular Dystrophies, Limb-Girdle epidemiology, Young Adult, Genetic Variation genetics, Glycogen Storage Disease Type II genetics, Muscle Weakness genetics, Muscular Dystrophies, Limb-Girdle genetics, Exome Sequencing methods, alpha-Glucosidases genetics
- Abstract
Background: Late-onset Pompe disease is a rare genetic neuromuscular disorder caused by a primary deficiency of α-glucosidase and the associated accumulation of glycogen in lysosomal vacuoles. The deficiency of α-glucosidase can often be detected using an inexpensive and readily accessible dried blood spot test when Pompe disease is suspected. Like several neuromuscular disorders, Pompe disease typically presents with progressive weakness of limb-girdle muscles and respiratory insufficiency. Due to the phenotypic heterogeneity of these disorders, however, it is often difficult for clinicians to reach a diagnosis for patients with Pompe disease. Six hundred and six patients from a European population were recruited onto our study. Inclusion criteria stipulated that index cases must present with limb-girdle weakness or elevated serum creatine kinase activity. Whole exome sequencing with at least 250 ng DNA was completed using an Illumina exome capture and a 38 Mb baited target. A panel of 169 candidate genes for limb-girdle weakness was analysed for disease-causing variants., Results: A total of 35 variants within GAA were detected. Ten distinct variants in eight unrelated index cases (and four siblings not sequenced in our study) were considered disease-causing, with the patients presenting with heterogeneous phenotypes. The eight unrelated individuals were compound heterozygotes for two variants. Six patients carried the intronic splice site c.-13 T > G transversion and two of the six patients also carried the exonic p.Glu176ArgfsTer45 frameshift. Four of the ten variants were novel in their association with Pompe disease., Conclusions: Here, we highlight the advantage of using whole exome sequencing as a tool for detecting, diagnosing and treating patients with rare, clinically variable genetic disorders.
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- 2017
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513. A Practical Approach to the Diagnosis and Management of Hair Loss in Children and Adolescents.
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Xu L, Liu KX, and Senna MM
- Abstract
Hair loss or alopecia is a common and distressing clinical complaint in the primary care setting and can arise from heterogeneous etiologies. In the pediatric population, hair loss often presents with patterns that are different from that of their adult counterparts. Given the psychosocial complications that may arise from pediatric alopecia, prompt diagnosis and management is particularly important. Common causes of alopecia in children and adolescents include alopecia areata, tinea capitis, androgenetic alopecia, traction alopecia, trichotillomania, hair cycle disturbances, and congenital alopecia conditions. Diagnostic tools for hair loss in children include a detailed history, physical examination with a focused evaluation of the child's hair and scalp, fungal screens, hair pull and tug test, and if possible, light microscopy and/or trichoscopy. Management of alopecia requires a holistic approach including psychosocial support because treatments are only available for some hair loss conditions, and even the available treatments are not always effective. This review outlines the clinical presentations, presents a diagnostic algorithm, and discusses management of these various hair loss disorders.
- Published
- 2017
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514. Large-scale GWAS identifies multiple loci for hand grip strength providing biological insights into muscular fitness.
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Willems SM, Wright DJ, Day FR, Trajanoska K, Joshi PK, Morris JA, Matteini AM, Garton FC, Grarup N, Oskolkov N, Thalamuthu A, Mangino M, Liu J, Demirkan A, Lek M, Xu L, Wang G, Oldmeadow C, Gaulton KJ, Lotta LA, Miyamoto-Mikami E, Rivas MA, White T, Loh PR, Aadahl M, Amin N, Attia JR, Austin K, Benyamin B, Brage S, Cheng YC, Cięszczyk P, Derave W, Eriksson KF, Eynon N, Linneberg A, Lucia A, Massidda M, Mitchell BD, Miyachi M, Murakami H, Padmanabhan S, Pandey A, Papadimitriou I, Rajpal DK, Sale C, Schnurr TM, Sessa F, Shrine N, Tobin MD, Varley I, Wain LV, Wray NR, Lindgren CM, MacArthur DG, Waterworth DM, McCarthy MI, Pedersen O, Khaw KT, Kiel DP, Pitsiladis Y, Fuku N, Franks PW, North KN, van Duijn CM, Mather KA, Hansen T, Hansson O, Spector T, Murabito JM, Richards JB, Rivadeneira F, Langenberg C, Perry JRB, Wareham NJ, and Scott RA
- Subjects
- Actins genetics, Adult, Aged, Cohort Studies, Female, Genetic Loci, Humans, Male, Membrane Proteins genetics, Middle Aged, Neoplasm Proteins genetics, Nuclear Proteins genetics, Polymorphism, Single Nucleotide, Repressor Proteins genetics, Transforming Growth Factor alpha genetics, United Kingdom, White People genetics, Genetics, Population, Genome-Wide Association Study, Hand physiology, Hand Strength
- Abstract
Hand grip strength is a widely used proxy of muscular fitness, a marker of frailty, and predictor of a range of morbidities and all-cause mortality. To investigate the genetic determinants of variation in grip strength, we perform a large-scale genetic discovery analysis in a combined sample of 195,180 individuals and identify 16 loci associated with grip strength (P<5 × 10
-8 ) in combined analyses. A number of these loci contain genes implicated in structure and function of skeletal muscle fibres (ACTG1), neuronal maintenance and signal transduction (PEX14, TGFA, SYT1), or monogenic syndromes with involvement of psychomotor impairment (PEX14, LRPPRC and KANSL1). Mendelian randomization analyses are consistent with a causal effect of higher genetically predicted grip strength on lower fracture risk. In conclusion, our findings provide new biological insight into the mechanistic underpinnings of grip strength and the causal role of muscular strength in age-related morbidities and mortality.- Published
- 2017
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515. A novel recessive TTN founder variant is a common cause of distal myopathy in the Serbian population.
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Perić S, Glumac JN, Töpf A, Savić-Pavićević D, Phillips L, Johnson K, Cassop-Thompson M, Xu L, Bertoli M, Lek M, MacArthur D, Brkušanin M, Milenković S, Rašić VM, Banko B, Maksimović R, Lochmüller H, Stojanović VR, and Straub V
- Subjects
- Adolescent, Adult, Case-Control Studies, Child, Creatine Kinase blood, Distal Myopathies diagnosis, Female, Gene Frequency, Genes, Recessive, Haplotypes, Humans, Male, Middle Aged, Muscular Dystrophies diagnosis, Phenotype, Serbia, Syndrome, Connectin genetics, Distal Myopathies genetics, Founder Effect, Muscular Dystrophies genetics, Mutation, Missense
- Abstract
Variants in the TTN gene have been associated with distal myopathies and other distinctive phenotypes involving skeletal and cardiac muscle. Through whole-exome sequencing we identified a novel stop-gain variant (c.107635C>T, p.(Gln35879Ter)) in the TTN gene, coding a part of the M-line of titin, in 14 patients with autosomal recessive distal myopathy and Serbian ancestry. All patients share a common 1 Mb core haplotype associated with c.107635C>T, suggesting a founder variant. In compound heterozygotes, nine other TTN variants were identified: four stop-gain, three frameshift, one missense and one splice donor variant. Patients homozygous for the common variant did not show significant clinical differences to the compound heterozygous patients. The clinical presentation of all patients was an adult onset distal myopathy with predominant lower limb involvement. In addition, most patients had normal to mildly elevated serum creatine kinase levels, myopathic electromyograms, normal cardiologic and respiratory tests and muscle pathology consistent with a dystrophic process. In this study, we describe a distinct phenotype for patients with distal myopathy associated with novel recessive TTN variants including a Serbian founder variant. Our results expand the phenotypic and genetic spectrum of titinopathies and will facilitate the diagnosis of this condition in patients of Serbian origin.
- Published
- 2017
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516. Methodologic Considerations in the Application of Next-Generation Sequencing of Human TRB Repertoires for Clinical Use.
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Xu L, You X, Zheng P, Zhang BM, Gupta PK, Lavori P, Meyer E, and Zehnder JL
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- Base Sequence, Case-Control Studies, Gene Frequency, Genetic Variation, Graft vs Host Disease genetics, Humans, Neoplasm, Residual, Sequence Analysis, DNA, Transplantation, Homologous, Graft vs Host Disease diagnosis, High-Throughput Nucleotide Sequencing methods, Molecular Diagnostic Techniques methods, Receptors, Antigen, T-Cell, alpha-beta genetics
- Abstract
Next-generation sequencing (NGS) of immune receptors has become a standard tool to assess minimal residual disease (MRD) in patients treated for lymphoid malignancy, and it is being used to study the T-cell repertoire in many clinical settings. To better understanding the potential clinical utility and limitations of this application outside of MRD, we developed a BIOMED-2 primer-based NGS method and characterized its performance in controls and patients with graft-versus-host disease (GVHD) after allogeneic hematopoietic transplant. For controls and patients with GVHD, replicate sequencing of the same T-cell receptor β (TRB) libraries was highly reproducible. Higher variability was observed in sequencing of different TRB libraries made from the same DNA stock. Variability was increased in patients with GVHD compared with controls; patients with GVHD also had lower diversity than controls. In the T-cell repertoire of a healthy person, approximately 99.6% of the CDR3 clones were in low abundance, with frequency <10
-3 . A single library could identify >93% of the clones with frequency ≥10-3 in the repertoire. Sequencing in duplicate increased the average detection rate to >97%. This work demonstrates that NGS reliably and robustly characterizes TRB populations in healthy individuals and patients with GVHD with frequency ≥10-3 and provides a methodologic framework for applying NGS immune repertoire methods to clinical testing applications beyond MRD., (Copyright © 2017 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.)- Published
- 2017
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517. Synthesis and theoretical studies on nitrogen-rich salts of bis[4-nitraminofurazanyl-3-azoxy]azofurazan (ADNAAF).
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Zheng C, Chu Y, Xu L, Lei W, Wang F, and Xia M
- Abstract
Multi-furazan compounds bis[4-nitramino- furazanyl-3-azoxy]azofurazan (ADNAAF) and its derivatives were first synthesized by our research group, and their structures were characterized by IR,
1 H-NMR,13 C-NMR spectrums, and element analysis. ADNAAF was synthesized by nitration reaction of bis[4-aminofurazanyl-3-azoxy]azofurazan (ADAAF), and then reacted with ammonium hydroxide, hydrazine hydrate, and guanidine nitrate to obtain three salts marked as salt 1, 2, and 3, respectively. The thermal stabilities of the three salts were supported by the results of DSC analysis, which shows the decomposition temperatures are all above 190 °C. Their densities, enthalpies of formation, and detonation properties were studied by density functional theory (DFT) method. Salt 1 has the best detonation pressure (P), 37.42 GPa, and detonation velocity (D), 8.88 km/s, while salt 2 has the best nitrogen content and heat of detonation (Q), 1.27 kcal mol-1 . The detonation properties of salt 1 is similar to that of 1,3,5-trinitro-1,3,5-triazineane (RDX). It means that the ammonium cation can provide the better D and P than the cation of hydrazine and guanidine. The three cations offer the enthalpies of formations in the order of hydrazinium > guanidinium > ammonium. Graphical Abstract Nitrogen-rich salts of bis[4-nitraminofurazanyl-3-azoxy]azofurazan(ADNAAF).- Published
- 2017
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518. The complete mitochondrial genome of the masked palm civet (Paguma larvata, Mammalia, Carnivora).
- Author
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Zhang D, Xu L, Bu H, Wang D, Xu C, and Wang R
- Subjects
- Animals, DNA, Mitochondrial genetics, Mitochondrial Proteins genetics, Phylogeny, RNA, Ribosomal genetics, RNA, Transfer genetics, Whole Genome Sequencing, Genome, Mitochondrial, Viverridae genetics
- Abstract
The complete mitochondrial genome of the masked palm civet (Paguma larvata, Mammalia, Carnivora) is a circular molecule of 16 710 bp in length, containing 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes, and a control region. The features of the mitochondrial genome of the masked palm civet are similar to the other mammals. The phylogenetic analysis shows that all species from the family Viverridae cluster together, in which P. larvata exhibits the closest relationship with Genetta servalina.
- Published
- 2016
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519. Theoretical studies on a new furazan compound bis[4-nitramino-furazanyl-3-azoxy]azofurazan (ADNAAF).
- Author
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Zheng C, Chu Y, Xu L, Wang F, Lei W, Xia M, and Gong X
- Abstract
Bis[4-nitraminofurazanyl-3-azoxy]azofurazan (ADNAAF), synthesized in our previous work [1], contains four furazan units connected to the linkage of the azo-group and azoxy-group. For further research, some theoretical characters were studied by the density functional theoretical (DFT) method. The optimized structures and the energy gaps between the HOMO and LUMO were studied at the B3LYP/6-311++G** level. The isodesmic reaction method was used for estimating the enthalpy of formation. The detonation performances were estimated with Kamlet-Jacobs equations based on the predicted density and enthalpy of formation in the solid state. ADAAF was also calculated by the same method for comparison. It was found that the nitramino group of ADNAAF can elongate the length of adjacent C-N bonds than the amino group of ADAAF. The gas-phase and solid-phase enthalpies of formation of ADNAAF are larger than those of ADAAF. The detonation performances of ADNAAF are better than ADAAF and RDX, and similar to HMX. The trigger bond of ADNAAF is the N-N bonds in the nitramino groups, and the nitramino group is more active than the amino group (-NH2).
- Published
- 2016
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520. Dietary licorice root supplementation reduces diet-induced weight gain, lipid deposition, and hepatic steatosis in ovariectomized mice without stimulating reproductive tissues and mammary gland.
- Author
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Madak-Erdogan Z, Gong P, Zhao YC, Xu L, Wrobel KU, Hartman JA, Wang M, Cam A, Iwaniec UT, Turner RT, Twaddle NC, Doerge DR, Khan IA, Katzenellenbogen JA, Katzenellenbogen BS, and Helferich WG
- Subjects
- Absorptiometry, Photon, Animals, Body Fat Distribution, Body Weight drug effects, Diet, High-Fat adverse effects, Female, Flavanones pharmacology, Mice, Inbred C57BL, Ovariectomy, Plant Roots chemistry, Uterus drug effects, Weight Gain drug effects, Dietary Supplements, Glycyrrhiza chemistry, Lipid Metabolism drug effects, Mammary Glands, Animal drug effects, Non-alcoholic Fatty Liver Disease diet therapy
- Abstract
Scope: We studied the impact of dietary supplementation with licorice root components on diet-induced obesity, fat accumulation, and hepatic steatosis in ovariectomized C57BL/6 mice as a menopause model., Materials and Methods: We evaluated the molecular and physiological effects of dietary licorice root administered to ovariectomized C57BL/6 mice as root powder (LRP), extracts (LRE), or isolated isoliquiritigenin (ILQ) on reproductive (uterus and mammary gland) and nonreproductive tissues important in regulating metabolism (liver, perigonadal, perirenal, mesenteric, and subcutaneous fat). Quantitative outcome measures including body weight, fat distribution (magnetic resonance imaging), food consumption, bone density and weight (Dual-energy X-ray absorptiometry), and gene expression were assessed by the degree of restoration to the preovariectomized health state. We characterized histological (H&E and oil red O staining) and molecular properties (expression of certain disease markers) of these tissues, and correlated these with metabolic phenotype as well as blood levels of bioactives., Conclusion: Although LRE and ILQ provided some benefit, LRP was the most effective in reducing body weight gain, overall fat deposition, liver steatosis, and expression of hepatic lipid synthesis genes following ovariectomy. Our data demonstrate that licorice root provided improvement of multiple metabolic parameters under conditions of low estrogen and high-fat diets without stimulating reproductive tissues., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2016
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521. Draft Genome Sequence of Streptococcus sp. X13SY08, Isolated from Murray Cod (Maccullochella peelii peelii).
- Author
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Liu Y, Zeng R, Weng B, Luo T, Luo Q, and Xu L
- Abstract
Streptococcus sp. X13SY08, isolated from freshwater Murray cod fish, likely presents a novel species of Streptococcus. Here, we present an annotated draft genome sequence of this species, which will improve our understanding of its physiology and pathogenesis., (Copyright © 2016 Liu et al.)
- Published
- 2016
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522. Epidemiological characterization of VNNV in hatchery-reared and wild marine fish on Hainan Island, China, and experimental infection of golden pompano (Trachinotus ovatus) juveniles.
- Author
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Ma H, Wen W, Su Y, Feng J, Xu L, Peng C, and Guo Z
- Subjects
- Animals, China epidemiology, Fish Diseases epidemiology, Fish Diseases virology, Fishes classification, Fishes virology, Islands, Molecular Sequence Data, Nodaviridae classification, Nodaviridae genetics, Nodaviridae physiology, Perciformes embryology, Perciformes virology, Phylogeny, RNA Virus Infections epidemiology, RNA Virus Infections virology, Nodaviridae isolation & purification, RNA Virus Infections veterinary
- Abstract
The current epidemiological situation of viral nervous necrosis virus (VNNV) on Hainan Island was investigated. A total of 490 hatchery-reared fish and 652 wild fish were sampled for VNNV detection from March 2013 to May 2014. Positive detection rates of 84.53% (153/181) and 0.97 % (3/309) were obtained in diseased and healthy hatchery-reared samples, respectively, by conventional RT-PCR. However, using more-sensitive nested RT-PCR, the positive detection rates in healthy hatchery-reared fish reached up to 64.08% (198/309), suggesting that asymptomatic VNNV carriers commonly exist among larvae and juveniles breeding on Hainan Island. In wild-fish samples, 2.6% (17/652) and 34.2% (223/652) positive detection rates were observed using RT-PCR and nested RT-PCR, respectively, indicating that wild fish may be a potential reservoir for VNNV. Phylogenetic analysis showed that all 52 VNNV isolates from cultured fish belong to the RGNNV genotype, but 2 out of 48 VNNV isolates from wild fish samples were found to be of the SJNNV genotype. This study is the first to confirm the existence of SJNNV-genotype VNNV in China. Golden pompano, an important fish species for culture, was selected as a fish model to investigate the optimal conditions for RGNNV disease progression in artificial infection experiments. The effects of temperature, salinity, and fish size were evaluated. Results showed that 28 °C and 20 ‰ are the optimal infection temperature and salinity, respectively, and golden pompano juveniles with small body sizes are more susceptible to RGNNV. These findings are highly consistent with those conditions involved in the natural outbreak of RGNNV.
- Published
- 2015
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523. Development of in Silico Models for Predicting P-Glycoprotein Inhibitors Based on a Two-Step Approach for Feature Selection and Its Application to Chinese Herbal Medicine Screening.
- Author
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Yang M, Chen J, Shi X, Xu L, Xi Z, You L, An R, and Wang X
- Subjects
- Computer Simulation, Humans, Models, Biological, ATP Binding Cassette Transporter, Subfamily B antagonists & inhibitors, Drug Evaluation, Preclinical methods, Drugs, Chinese Herbal pharmacology
- Abstract
P-glycoprotein (P-gp) is regarded as an important factor in determining the ADMET (absorption, distribution, metabolism, elimination, and toxicity) characteristics of drugs and drug candidates. Successful prediction of P-gp inhibitors can thus lead to an improved understanding of the underlying mechanisms of both changes in the pharmacokinetics of drugs and drug-drug interactions. Therefore, there has been considerable interest in the development of in silico modeling of P-gp inhibitors in recent years. Considering that a large number of molecular descriptors are used to characterize diverse structural moleculars, efficient feature selection methods are required to extract the most informative predictors. In this work, we constructed an extensive available data set of 2428 molecules that includes 1518 P-gp inhibitors and 910 P-gp noninhibitors from multiple resources. Importantly, a two-step feature selection approach based on a genetic algorithm and a greedy forward-searching algorithm was employed to select the minimum set of the most informative descriptors that contribute to the prediction of P-gp inhibitors. To determine the best machine learning algorithm, 18 classifiers coupled with the feature selection method were compared. The top three best-performing models (flexible discriminant analysis, support vector machine, and random forest) and their ensemble model using respectively only 3, 9, 7, and 14 descriptors achieve an overall accuracy of 83.2%-86.7% for the training set containing 1040 compounds, an overall accuracy of 82.3%-85.5% for the test set containing 1039 compounds, and a prediction accuracy of 77.4%-79.9% for the external validation set containing 349 compounds. The models were further extensively validated by DrugBank database (1890 compounds). The proposed models are competitive with and in some cases better than other published models in terms of prediction accuracy and minimum number of descriptors. Applicability domain then was addressed by developing an ensemble classification model to obtain more reliable predictions. Finally, we employed these models as a virtual screening tool for identifying potential P-gp inhibitors in Traditional Chinese Medicine Systems Pharmacology (TCMSP) database containing a total of 13 051 unique compounds from 498 herbs, resulting in 875 potential P-gp inhibitors and 15 inhibitor-rich herbs. These predictions were partly supported by a literature search and are valuable not only to develop novel P-gp inhibitors from TCM in the early stages of drug development, but also to optimize the use of herbal remedies.
- Published
- 2015
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524. Theoretical studies on vicinal-tetrazine compounds: furoxano-1,2,3,4-tetrazine-1,3,5-trioxide (FTTO-α) and furoxano-1,2,3,4-tetrazine-1,3,7-trioxide (FTTO-β).
- Author
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Wang T, Zhang T, Xu L, Wu X, Gong X, and Xia M
- Abstract
The derivatives of 1,2,3,4-tetrazine may be promising candidates of high-energy density compounds and are receiving more and more attention. In this study, two 1,2,3,4-tetrazines, furoxano-1,2,3,4-tetrazine-1,3,5-trioxide (FTTO-α) and furoxano-1,2,3,4-tetrazine-1,3,7-trioxide (FTTO-β), were theoretically studied. The geometrical structures in gas phase were studied at the B3LYP/6-311++G(d,p) level of density functional theory (DFT). The gas phase enthalpies of formation were calculated by the homodesmotic reaction method. The enthalpies of sublimation and solid phase enthalpies of formation were predicted with corrections of electrostatic potential method at the B3PW91/6-31G(d,p) level. The detonation properties were estimated with the Kamlet-Jacobs equations based on the predicted densities and enthalpies of formation in solid state. The available free space in the lattice was calculated to evaluate their stability. Calculations of potential energy surface and structure interconversion thermodynamics under different temperatures were carried out to further confirm their stability. FTTOs have better performance than HMX and FTDO but are easy to decompose to 5,6-dinitroso-v-tetrazine 1,3-dioxide. A synthesis route for FTTO-β was proposed to provide a consideration for the further study. We believe FTTOs could be the key compounds to synthesize other v-tetrazines such as TTTO.
- Published
- 2014
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525. Involvement of the PI3K and ERK signaling pathways in largemouth bass virus-induced apoptosis and viral replication.
- Author
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Huang X, Wang W, Huang Y, Xu L, and Qin Q
- Subjects
- Animals, Apoptosis physiology, Caspases metabolism, DNA Virus Infections physiopathology, Flow Cytometry veterinary, In Vitro Techniques, Microscopy, Fluorescence veterinary, Reactive Oxygen Species metabolism, Virus Replication physiology, Bass, DNA Virus Infections veterinary, Fish Diseases physiopathology, Fish Diseases virology, MAP Kinase Signaling System physiology, Phosphatidylinositol 3-Kinases metabolism, Ranavirus
- Abstract
Increased reports demonstrated that largemouth Bass, Micropterus salmoides in natural and artificial environments were always suffered from an emerging iridovirus disease, largemouth Bass virus (LMBV). However, the underlying mechanism of LMBV pathogenesis remained largely unknown. Here, we investigated the cell signaling events involved in virus induced cell death and viral replication in vitro. We found that LMBV infection in epithelioma papulosum cyprini (EPC) cells induced typical apoptosis, evidenced by the appearance of apoptotic bodies, cytochrome c release, mitochondrial membrane permeabilization (MMP) destruction and reactive oxygen species (ROS) generation. Two initiators of apoptosis, caspase-8 and caspase-9, and the executioner of apoptosis, caspase-3, were all significantly activated with the infection time, suggested that not only mitochondrion-mediated, but also death receptor-mediated apoptosis were involved in LMBV infection. Reporter gene assay showed that the promoter activity of transcription factors including p53, NF-κB, AP-1 and cAMP response element-binding protein (CREB) were decreased during LMBV infection. After treatment with different signaling pathway inhibitors, virus production were significantly suppressed by the inhibition of phosphatidylinositol 3-kinase (PI3K) pathway and extracellular-signal-regulated kinases (ERK) signaling pathway. Furthermore, LMBV infection induced apoptosis was enhanced by PI3K inhibitor LY294002, but decreased by addition of ERK inhibitor UO126. Therefore, we speculated that apoptosis was sophisticatedly regulated by a series of cell signaling events for efficient virus propagation. Taken together, our results provided new insights into the molecular mechanism of ranavirus infection., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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526. Rapid detection of mud crab dicistrovirus-1 using loop-mediated isothermal amplification.
- Author
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Guo Z, Zhang D, Ma H, Su Y, Feng J, and Xu L
- Subjects
- Animals, China, DNA Primers genetics, Dicistroviridae genetics, Electrophoresis, Agar Gel, Sensitivity and Specificity, Staining and Labeling methods, Temperature, Time Factors, Viral Structural Proteins genetics, Brachyura virology, Dicistroviridae isolation & purification, Nucleic Acid Amplification Techniques methods
- Abstract
Mud crab dicistrovirus-1 (MCDV-1) was isolated from the mud crab (Scylla paramamosain), resulting in mass mortality and widespread economic loss in China. In this study, a detection method for MCDV-1 using loop-mediated isothermal amplification was developed. Two pairs of primers targeting the VP2 gene were designed. These primers were the outer primers F3 and B3, and the inner primers FIP and BIP. Optimal amplification was carried out using 0.2 μmol/L F3/B3, 1.6 μmol/L FIP/BIP, 6 mmol/L Mg(2+), 0.8 mmol/L dNTPs, and 0.8 mol/L betaine, and completed in 1h at 62°C. The products demonstrated a ladder pattern on agarose gel electrophoresis and could also be detected visually according to turbidity, or by adding SYBR Green I and observing a color change from orange to green. The proposed method could specifically amplify MCDV-1 gene fragments. Sensitivity assay revealed that six copies of the viral genome could be detected by this method, which was 1000-fold more sensitive than that of conventional PCR using constructed plasmid as amplification template. At clinical sample level, sensitivity of LAMP was 100-fold higher than that of conventional PCR., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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527. A new species of Glugea Thélohan, 1891 in the red sea bream Pagrus major (Temminck & Schlegel) (Teleostei: Sparidae) from China.
- Author
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Su Y, Feng J, Sun X, Jiang J, Guo Z, Ye L, and Xu L
- Subjects
- Animals, China, DNA, Ribosomal genetics, Fish Diseases pathology, Glugea cytology, Glugea genetics, Microsporidiosis microbiology, Microsporidiosis pathology, Molecular Sequence Data, Species Specificity, Fish Diseases microbiology, Glugea classification, Microsporidiosis veterinary, Phylogeny, Sea Bream microbiology
- Abstract
A new microsporidian species is described from farmed red sea bream Pagrus major (Temminck & Schlegel) (Teleostei: Sparidae). Large numbers of spherical whitish xenomas were observed throughout the visceral organs of the host. Histological examination showed that the microsporidia caused several xenomas that were embedded in the intestinal muscularis externa or submucosa. Light and transmission electron microscopy examination of the spores also revealed morphological features typical of species of Glugea Thélohan, 1891. This microsporidian parasite has two different types of mature spores: microspores and macrospores. The spores are elongate-ovoid, with a large posterior vacuole. The polaroplast is bi-partite, with anterior and posterior parts comprising densely packed lamellae and loose membranes, respectively, and occupies approximately the anterior half of the spore. The polar filament is anisofilar, with 12-13 coils in a single layer almost touching the posterior spore wall. Comparison of the small subunit rDNA sequences revealed 92.7-98.1% identity with the sequences available from other Glugea spp. from piscine hosts. Phylogenetic analysis demonstrated that the microsporidian species studied clustered within the Glugea clade with strong support. Based on the differences in the morphological characteristics and molecular data, the microsporidian infecting P. major is considered to represent a species new to science, Glugea pagri n. sp.
- Published
- 2014
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528. Identification of lymphocystis disease virus from paradise fish Macropodus opercularis (LCDV-PF).
- Author
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Xu L, Feng J, and Huang Y
- Subjects
- Animals, China, Cluster Analysis, DNA Virus Infections pathology, DNA Virus Infections virology, DNA, Viral chemistry, DNA, Viral genetics, Fish Diseases pathology, Genotype, Histocytochemistry, Microscopy, Electron, Transmission, Molecular Sequence Data, Phylogeny, Sequence Analysis, DNA, Sequence Homology, Skin pathology, Viral Proteins genetics, Virion ultrastructure, DNA Virus Infections veterinary, Fish Diseases virology, Fishes virology, Iridoviridae isolation & purification
- Abstract
Iridoviruses are large DNA viruses that are subdivided into five genera: Ranavirus, Megalocytivirus, Lymphocystivirus, Chloriridovirus and Iridovirus. The iridovirus lymphocystis disease virus (LCDV) is an important fish pathogen that can infect marine and freshwater fish worldwide. In this study, we have identified the pathogen in paradise fish (Macropodus opercularis) with lymphocystis. On the skin and fins of diseased paradise fish, a large number of nodules were observed. H&E staining showed that the nodules were composed of encapsulated hypertrophied cells. Using electron microscopy, numerous virus particles with a diameter of >210 nm and with hexagonal profiles were observed in the cytoplasm. Phylogenetic analysis based on the major capsid protein (MCP), DNA polymerase and myristylated membrane protein (MMP) genes revealed that LCDV from paradise fish (LCDV-PF) was closely related to lymphocystis disease virus from China (LCDV-C), followed by lymphocystis disease virus 1 (LCDV-1). Taken together, our data provide the first molecular evidence that, in addition to megalocytivirus, LCDV is an important iridoviral pathogen in paradise fish besides megalocytivirus.
- Published
- 2014
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529. Trypanosoma epinepheli n. sp. (Kinetoplastida) from a farmed marine fish in China, the brown-marbled grouper (Epinephelus fuscoguttatus).
- Author
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Su Y, Feng J, Jiang J, Guo Z, Liu G, and Xu L
- Subjects
- Animals, Aquaculture, Base Sequence, China, DNA, Protozoan genetics, DNA, Ribosomal genetics, Oceans and Seas, Phylogeny, Trypanosoma genetics, Trypanosoma isolation & purification, Trypanosoma ultrastructure, Perciformes parasitology, Trypanosoma classification, Trypanosomiasis veterinary
- Abstract
An outbreak of trypanosomosis occurred in farmed Epinephelus fuscoguttatus in Xincun Bay, province of Hainan, South China Sea. The infected fish showed loss of appetite, lethargy, emaciation, severe anemia, and splenomegaly. Light and scanning electron microscopic examination of bloodstream trypomastigotes revealed morphological features typical for small-sized marine fish trypanosomes. The trypanosome possesses a short body length (mean 22.3 μm, range 17.6-25.9 μm) and narrow body width (mean1.7 μm, range 1.3-2.0 μm), a central nucleus, a narrow but distinct undulating membrane, and a relatively long free flagellum (mean 10.1 μm, range 7.4-13.3 μm). The kinetoplast is situated at approximately one quarter of body length from posterior extremity. The division process of this trypanosome was observed in the peripheral blood of the host, and occurred by transverse constriction at a point between the kinetoplasts. Comparison of the small subunit rDNA (SSU rDNA) sequences revealed that the trypanosome from E. fuscoguttatus showed 93.4-97.1% identity with the available sequences from Trypanosoma spp. from other piscine hosts. Phylogenetic analysis supported the existence of an aquatic clade, and the present trypanosome grouped with other marine fish trypanosomes, in a subclade together with Trypanosoma senegalense. Based on the differences in morphological characteristics, host species, and molecular data, the trypanosome infecting E. fuscoguttatus is considered to be a new species, for which we propose the name Trypanosoma epinepheli n. sp.
- Published
- 2014
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530. Notch/Rbpjκ signaling regulates progenitor maintenance and differentiation of hypothalamic arcuate neurons.
- Author
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Aujla PK, Naratadam GT, Xu L, and Raetzman LT
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors metabolism, Body Weights and Measures, Cell Count, Female, Gene Expression Regulation, Developmental genetics, Histological Techniques, Homeodomain Proteins metabolism, Immunoglobulin J Recombination Signal Sequence-Binding Protein deficiency, Immunoglobulin J Recombination Signal Sequence-Binding Protein metabolism, Immunohistochemistry, In Situ Hybridization, Ki-67 Antigen, Male, Mice, Mice, Transgenic, Pro-Opiomelanocortin, Receptors, Notch metabolism, Transcription Factor HES-1, Arcuate Nucleus of Hypothalamus cytology, Body Size physiology, Cell Differentiation physiology, Gene Expression Regulation, Developmental physiology, Interneurons cytology, Signal Transduction physiology, Stem Cells physiology
- Abstract
The hypothalamic arcuate nucleus (Arc), containing pro-opoiomelanocortin (POMC), neuropeptide Y (NPY) and growth hormone releasing hormone (GHRH) neurons, regulates feeding, energy balance and body size. Dysregulation of this homeostatic mediator underlies diseases ranging from growth failure to obesity. Despite considerable investigation regarding the function of Arc neurons, mechanisms governing their development remain unclear. Notch signaling factors such as Hes1 and Mash1 are present in hypothalamic progenitors that give rise to Arc neurons. However, how Notch signaling controls these progenitor populations is unknown. To elucidate the role of Notch signaling in Arc development, we analyzed conditional loss-of-function mice lacking a necessary Notch co-factor, Rbpjκ, in Nkx2.1-cre-expressing cells (Rbpjκ cKO), as well as mice with expression of the constitutively active Notch1 intracellular domain (NICD) in Nkx2.1-cre-expressing cells (NICD Tg). We found that loss of Rbpjκ results in absence of Hes1 but not of Hes5 within the primordial Arc at E13.5. Additionally, Mash1 expression is increased, coincident with increased proliferation and accumulation of Arc neurons at E13.5. At E18.5, Rbpjκ cKO mice have few progenitors and show increased numbers of differentiated Pomc, NPY and Ghrh neurons. By contrast, NICD Tg mice have increased hypothalamic progenitors, show an absence of differentiated Arc neurons and aberrant glial differentiation at E18.5. Subsequently, both Rbpjκ cKO and NICD Tg mice have changes in growth and body size during postnatal development. Taken together, our results demonstrate that Notch/Rbpjκ signaling regulates the generation and differentiation of Arc neurons, which contribute to homeostatic regulation of body size.
- Published
- 2013
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531. Identification and expression analysis of a CC chemokine from cobia (Rachycentron canadum).
- Author
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Feng J, Su Y, Guo Z, Xu L, Sun X, and Wang Y
- Subjects
- Animals, Bacterial Vaccines pharmacology, Base Sequence, Cloning, Molecular, Cluster Analysis, DNA Primers genetics, DNA, Complementary genetics, Gene Expression Profiling, Molecular Sequence Data, Phylogeny, Polynucleotides pharmacology, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Species Specificity, Chemokines, CC genetics, Chemokines, CC metabolism, Gene Expression Regulation drug effects, Perciformes genetics
- Abstract
Chemokines are small, secreted cytokine peptides known principally for their ability to induce migration and activation of leukocyte populations and regulate the immune response mechanisms. The cobia (Rachycentron canadum), a marine finfish species, has a great potential for net cage aquaculture in the South China Sea. We isolated and characterized a CC chemokine cDNA from cobia-designated RcCC2. Its cDNA is 783 bp in length and encodes a putative protein of 110 amino acids. Homology and phylogenetic analysis revealed that the RcCC2 gene, which contains four conserved cysteine residues, shares a high degree of similarity with other known CC chemokine sequences and is closest to the CCL19/21 clade. The mRNA of RcCC2 is expressed constitutively in all tested tissues, including gill, liver, muscle, spleen, kidney, head kidney, skin, brain, stomach, intestine and heart, but not blood, with the highest level of expression in gill and liver. The reverse transcription quantitative polymerase chain reaction was used to examine the expression of the RcCC2 gene in immune-related tissues, including head kidney, spleen and liver, following intraperitoneal injection of the viral mimic polyriboinosinic polyribocytidylic acid, formalin-killed Vibrio carchariae (bacterial vaccine) and phosphate-buffered saline as a control. RcCC2 gene expression was up-regulated differentially in head kidney, spleen and liver during 12 h after challenge. These results indicate that the RcCC2 gene is inducible and is involved in immune responses, suggesting RcCC2 has an important role in the early stage of viral and bacterial infections.
- Published
- 2013
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532. Study on diversity of endophytic bacterial communities in seeds of hybrid maize and their parental lines.
- Author
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Liu Y, Zuo S, Xu L, Zou Y, and Song W
- Subjects
- Bacteria genetics, Chimera microbiology, China, Molecular Sequence Data, RNA, Ribosomal, 16S genetics, Zea mays genetics, Bacteria classification, Biodiversity, Seeds microbiology, Zea mays microbiology
- Abstract
The seeds of plants are carriers of a variety of beneficial bacteria and pathogens. Using the non-culture methods of building 16S rDNA libraries, we investigated the endophytic bacterial communities of seeds of four hybrid maize offspring and their respective parents. The results of this study show that the hybrid offspring Yuyu 23, Zhengdan958, Jingdan 28 and Jingyu 11 had 3, 33, 38 and 2 OTUs of bacteria, respectively. The parents Ye 478, Chang 7-2, Zheng 58, Jing 24 and Jing 89 had 12, 36, 6, 12 and 2 OTUs, respectively. In the hybrid Yuyu 23, the dominant bacterium Pantoea (73.38 %) was detected in its female parent Ye 478, and the second dominant bacterium of Sphingomonas (26.62 %) was detected in both its female (Ye 478) and male (Chang 7-2) parent. In the hybrid Zhengdan 958, the first dominant bacterium Stenotrophomonas (41.67 %) was detected in both the female (Zheng 58) and male (Chang 7-2) parent. The second dominant bacterium Acinetobacter (9.26 %) was also the second dominant bacterium of its male parent. In the hybrid Jingdan 28, the second dominant bacterium Pseudomonas (12.78 %) was also the second dominant bacterium of its female parent, and its third dominant bacterium Sphingomonas (9.90 %) was the second dominant bacterium of its male parent and detected in its female parent. In the hybrid Jingyu 11, the first dominant bacterium Leclercia (73.85 %) was the third dominant bacterium of its male parent, and the second dominant bacterium Enterobacter (26.15 %) was detected in its male parent. As far as we know, this was the first research reported in China on the diversity of the endophytic bacterial communities of the seeds of various maize hybrids with different genotypes.
- Published
- 2012
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533. A fully substituted 3-silolene functions as promising building block for hyperbranched poly(silylenevinylene).
- Author
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Zhao Z, Guo Y, Jiang T, Chang Z, Lam JW, Xu L, Qiu H, and Tang BZ
- Subjects
- Catalysis, Crystallography, X-Ray, Molecular Weight, Organosilicon Compounds chemistry, Polymers chemistry, X-Ray Diffraction, Organosilicon Compounds chemical synthesis, Polymers chemical synthesis, Silanes chemistry
- Abstract
A 3-silolene derivative, 2,2,5,5-tetrakis(dimethylsilyl)-1,1-dimethyl-3,4-diphenyl-3-silolene (TDMSHS), is first synthesized and characterized by X-ray diffraction crystallography and spectroscopic methods. Hydrosilylation polymerization of TDMSHS with 1,1-dimethyl-2,5-bis(4-ethynylphenyl)-3,4-diphenylsilole in the presence of Karstedt's catalyst generates a stereoregular silole-containing hyperbranched poly(silylenevinylene) (hb-SPSV) with a high molecular weight (M(w) = 146,000, M(w)/M(n) = 1.5) in high yield (≈95%). hb-SPSV exhibits excellent thermal stability and strong fluorescence, and the emission of its aggregates in aqueous mixture can be quenched efficiently by picric acid with large quenching constants K(SV) up to 414400 M(-1)., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2012
- Full Text
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534. High throughput automated chromatin immunoprecipitation as a platform for drug screening and antibody validation.
- Author
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Wu AR, Kawahara TL, Rapicavoli NA, van Riggelen J, Shroff EH, Xu L, Felsher DW, Chang HY, and Quake SR
- Subjects
- Automation, Cell Proliferation drug effects, Drug Evaluation, Preclinical, HeLa Cells, High-Throughput Screening Assays, Histones metabolism, Humans, Microfluidic Analytical Techniques, Tumor Necrosis Factor-alpha metabolism, Tumor Necrosis Factor-alpha pharmacology, Antibodies immunology, Chromatin Immunoprecipitation
- Abstract
Chromatin immunoprecipitation (ChIP) is an assay for interrogating protein-DNA interactions that is increasingly being used for drug target discovery and screening applications. Currently the complexity of the protocol and the amount of hands-on time required for this assay limits its use to low throughput applications; furthermore, variability in antibody quality poses an additional obstacle in scaling up ChIP for large scale screening purposes. To address these challenges, we report HTChIP, an automated microfluidic-based platform for performing high-throughput ChIP screening measurements of 16 different targets simultaneously, with potential for further scale-up. From chromatin to analyzable PCR results only takes one day using HTChIP, as compared to several days up to one week for conventional protocols. HTChIP can also be used to test multiple antibodies and select the best performer for downstream ChIP applications, saving time and reagent costs of unsuccessful ChIP assays as a result of poor antibody quality. We performed a series of characterization assays to demonstrate that HTChIP can rapidly and accurately evaluate the epigenetic states of a cell, and that it is sensitive enough to detect the changes in the epigenetic state induced by a cytokine stimulant over a fine temporal resolution. With these results, we believe that HTChIP can introduce large improvements in routine ChIP, antibody screening, and drug screening efficiency, and further facilitate the use of ChIP as a valuable tool for research and discovery.
- Published
- 2012
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535. Identification of a cobia (Rachycentron canadum) CC chemokine gene and its involvement in the inflammatory response.
- Author
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Su Y, Guo Z, Xu L, Jiang J, Wang J, and Feng J
- Subjects
- Adjuvants, Immunologic pharmacology, Amino Acid Sequence, Animals, Bacterial Vaccines pharmacology, Base Sequence, Gene Expression Profiling, Molecular Sequence Data, Poly I-C pharmacology, Sequence Alignment, Sequence Homology, Amino Acid, Chemokines, CC genetics, Chemokines, CC immunology, Gene Expression Regulation drug effects, Perciformes genetics, Perciformes immunology
- Abstract
The chemokines regulate immune cell migration under inflammatory and physiological conditions. We investigated a CC chemokine gene (RcCC1) from cobia (Rachycentron canadum). The full-length RcCC1 cDNA is comprised 673 nucleotides and encodes a four-cysteine arrangement 99-amino-acid protein typical of known CC chemokines. The genomic DNA of RcCC1 consists of three exons and two introns. Phylogenetic analysis showed that RcCC1 was closest to the MIP group of CC chemokines. Quantitative real-time RT-PCR (qRT-PCR) analysis revealed RcCC1 was constitutively expressed in all tissues examined, with relative strong expression in gill, blood, kidney, spleen, and head kidney. The RcCC1 transcripts in the head kidney, spleen, and liver were quickly up-regulated after stimulation with formalin-inactivated Vibrio carchariae (bacterial vaccine) or polyriboinosinic polyribocytidylic acid (poly I:C). These results indicate RcCC1 not only plays a role in homeostasis, but also may be involved in inflammatory responses to bacterial and viral infection., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
536. Treatment of higher risk myelodysplastic syndrome patients unresponsive to hypomethylating agents with ON 01910.Na.
- Author
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Seetharam M, Fan AC, Tran M, Xu L, Renschler JP, Felsher DW, Sridhar K, Wilhelm F, and Greenberg PL
- Subjects
- Aged, Aged, 80 and over, Antineoplastic Agents adverse effects, Antineoplastic Agents therapeutic use, DNA (Cytosine-5-)-Methyltransferase 1, DNA (Cytosine-5-)-Methyltransferases antagonists & inhibitors, DNA Methylation drug effects, Female, Glycine adverse effects, Glycine therapeutic use, Humans, Male, Myelodysplastic Syndromes mortality, Myelodysplastic Syndromes pathology, Risk, Sulfones adverse effects, Survival Analysis, Treatment Outcome, Drug Resistance, Neoplasm drug effects, Enzyme Inhibitors therapeutic use, Glycine analogs & derivatives, Myelodysplastic Syndromes drug therapy, Sulfones therapeutic use
- Abstract
In a Phase I/II clinical trial, 13 higher risk red blood cell-dependent myelodysplastic syndrome (MDS) patients unresponsive to hypomethylating therapy were treated with the multikinase inhibitor ON 01910.Na. Responses occurred in all morphologic, prognostic risk and cytogenetic subgroups, including four patients with marrow complete responses among eight with stable disease, associated with good drug tolerance. In a subset of patients, a novel nanoscale immunoassay showed substantially decreased AKT2 phosphorylation in CD34+ marrow cells from patients responding to therapy but not those who progressed on therapy. These data demonstrate encouraging efficacy and drug tolerance with ON 01910.Na treatment of higher risk MDS patients., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
537. Reactive oxygen species regulate nucleostemin oligomerization and protein degradation.
- Author
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Huang M, Whang P, Chodaparambil JV, Pollyea DA, Kusler B, Xu L, Felsher DW, and Mitchell BS
- Subjects
- Acetylcysteine pharmacology, Animals, Blast Crisis genetics, Blast Crisis metabolism, Carrier Proteins genetics, Cell Proliferation drug effects, Cell Transformation, Neoplastic genetics, Cell Transformation, Neoplastic metabolism, Cysteine Proteinase Inhibitors pharmacology, Free Radical Scavengers pharmacology, GTP-Binding Proteins genetics, Gene Expression Regulation, Leukemic drug effects, Gene Expression Regulation, Leukemic genetics, HL-60 Cells, Humans, Leukemia, Myelogenous, Chronic, BCR-ABL Positive genetics, Leukemia, Myelogenous, Chronic, BCR-ABL Positive metabolism, Leupeptins pharmacology, Lymphoma genetics, Lymphoma metabolism, Mice, Mice, Transgenic, Mutagenesis, Site-Directed, Neoplasms, Experimental genetics, Neoplasms, Experimental metabolism, Nuclear Proteins genetics, Proteasome Endopeptidase Complex genetics, Proteasome Endopeptidase Complex metabolism, Proteasome Inhibitors, Proto-Oncogene Proteins c-myc genetics, Proto-Oncogene Proteins c-myc metabolism, RNA-Binding Proteins, Carrier Proteins metabolism, GTP-Binding Proteins metabolism, Hydrogen Peroxide pharmacology, Nuclear Proteins metabolism, Oxidants pharmacology, Protein Multimerization
- Abstract
Nucleostemin (NS) is a nucleolar-nucleoplasmic shuttle protein that regulates cell proliferation, binds p53 and Mdm2, and is highly expressed in tumor cells. We have identified NS as a target of oxidative regulation in transformed hematopoietic cells. NS oligomerization occurs in HL-60 leukemic cells and Raji B lymphoblasts that express high levels of c-Myc and have high intrinsic levels of reactive oxygen species (ROS); reducing agents dissociate NS into monomers and dimers. Exposure of U2OS osteosarcoma cells with low levels of intrinsic ROS to hydrogen peroxide (H(2)O(2)) induces thiol-reversible disulfide bond-mediated oligomerization of NS. Increased exposure to H(2)O(2) impairs NS degradation, immobilizes the protein within the nucleolus, and results in detergent-insoluble NS. The regulation of NS by ROS was validated in a murine lymphoma tumor model in which c-Myc is overexpressed and in CD34+ cells from patients with chronic myelogenous leukemia in blast crisis. In both instances, increased ROS levels were associated with markedly increased expression of NS protein and thiol-reversible oligomerization. Site-directed mutagenesis of critical cysteine-containing regions of nucleostemin altered both its intracellular localization and its stability. MG132, a potent proteasome inhibitor and activator of ROS, markedly decreased degradation and increased nucleolar retention of NS mutants, whereas N-acetyl-L-cysteine largely prevented the effects of MG132. These results indicate that NS is a highly redox-sensitive protein. Increased intracellular ROS levels, such as those that result from oncogenic transformation in hematopoietic malignancies, regulate the ability of NS to oligomerize, prevent its degradation, and may alter its ability to regulate cell proliferation.
- Published
- 2011
- Full Text
- View/download PDF
538. CD4(+) T cells contribute to the remodeling of the microenvironment required for sustained tumor regression upon oncogene inactivation.
- Author
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Rakhra K, Bachireddy P, Zabuawala T, Zeiser R, Xu L, Kopelman A, Fan AC, Yang Q, Braunstein L, Crosby E, Ryeom S, and Felsher DW
- Subjects
- Animals, Apoptosis physiology, Cell Proliferation drug effects, Cellular Senescence drug effects, Chemokines genetics, Chemokines metabolism, Cyclosporine pharmacology, Fusion Proteins, bcr-abl genetics, Gene Expression Regulation, Neoplastic, Gene Silencing, Immunosuppressive Agents pharmacology, Leukemia, Experimental genetics, Leukemia, Experimental immunology, Mice, Mice, Transgenic, Neoplasms genetics, Neoplasms immunology, Neoplasms pathology, Neovascularization, Pathologic genetics, Neovascularization, Pathologic immunology, Proto-Oncogene Proteins c-myc genetics, Remission Induction, Thrombospondin 1 genetics, Thrombospondin 1 metabolism, Tumor Microenvironment drug effects, Tumor Microenvironment genetics, CD4-Positive T-Lymphocytes immunology, Oncogenes genetics, Tumor Microenvironment immunology
- Abstract
Oncogene addiction is thought to occur cell autonomously. Immune effectors are implicated in the initiation and restraint of tumorigenesis, but their role in oncogene inactivation-mediated tumor regression is unclear. Here, we show that an intact immune system, specifically CD4(+) T cells, is required for the induction of cellular senescence, shutdown of angiogenesis, and chemokine expression resulting in sustained tumor regression upon inactivation of the MYC or BCR-ABL oncogenes in mouse models of T cell acute lymphoblastic lymphoma and pro-B cell leukemia, respectively. Moreover, immune effectors knocked out for thrombospondins failed to induce sustained tumor regression. Hence, CD4(+) T cells are required for the remodeling of the tumor microenvironment through the expression of chemokines, such as thrombospondins, in order to elicit oncogene addiction., (Copyright © 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
539. Nanofluidic proteomic assay for serial analysis of oncoprotein activation in clinical specimens.
- Author
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Fan AC, Deb-Basu D, Orban MW, Gotlib JR, Natkunam Y, O'Neill R, Padua RA, Xu L, Taketa D, Shirer AE, Beer S, Yee AX, Voehringer DW, and Felsher DW
- Subjects
- Burkitt Lymphoma genetics, Burkitt Lymphoma therapy, Enzyme Activation, Extracellular Signal-Regulated MAP Kinases genetics, Genes, myc, Humans, Immunoassay methods, Lymphoma, B-Cell genetics, Lymphoma, B-Cell therapy, Lymphoma, Follicular genetics, Lymphoma, Follicular therapy, Neoplasms therapy, Oncogenes, Phosphoproteins genetics, Protein Isoforms analysis, Protein Isoforms genetics, Gene Expression Regulation, Neoplastic, Neoplasms genetics, Oncogene Proteins genetics, Proteomics methods
- Abstract
Current methods of protein detection are insensitive to detecting subtle changes in oncoprotein activation that underlie key cancer signaling processes. The requirement for large numbers of cells precludes serial tumor sampling for assessing a response to therapeutics. Therefore, we have developed a nanofluidic proteomic immunoassay (NIA) to quantify total and low-abundance protein isoforms in nanoliter volumes. Our method can quantify amounts of MYC oncoprotein and B cell lymphoma protein-2 (BCL2) in Burkitt's and follicular lymphoma; identify changes in activation of extracellular signal-related kinases-1 (ERK1) and ERK2, mitogen-activated kinase-1 (MEK), signal transducer and activator of transcription protein-3 (STAT3) and STAT5, c-Jun N-terminal kinase (JNK) and caspase-3 in imatinib-treated chronic myelogeneous leukemia (CML) cells; measure an unanticipated change in the phosphorylation of an ERK2 isomer in individuals with CML who responded to imatinib; and detect a decrease in STAT3 and STAT5 phosphorylation in individuals with lymphoma who were treated with atorvastatin. Therefore, we have described a new and highly sensitive method for determining oncoprotein expression and phosphorylation in clinical specimens for the development of new therapeutics for cancer.
- Published
- 2009
- Full Text
- View/download PDF
540. Mechanical ventilation uncouples synthesis and assembly of elastin and increases apoptosis in lungs of newborn mice. Prelude to defective alveolar septation during lung development?
- Author
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Bland RD, Ertsey R, Mokres LM, Xu L, Jacobson BE, Jiang S, Alvira CM, Rabinovitch M, Shinwell ES, and Dixit A
- Subjects
- Animals, Animals, Newborn, Apoptosis, Kinetics, Mice, Mice, Inbred BALB C, Models, Animal, Pancreatic Elastase metabolism, Polymerase Chain Reaction, RNA genetics, RNA isolation & purification, Elastin metabolism, Lung growth & development, Lung physiology, Pulmonary Alveoli physiology, Respiration, Artificial
- Abstract
Prolonged mechanical ventilation (MV) with O2-rich gas inhibits lung growth and causes excess, disordered accumulation of lung elastin in preterm infants, often resulting in chronic lung disease (CLD). Using newborn mice, in which alveolarization occurs postnatally, we designed studies to determine how MV with either 40% O2 or air might lead to dysregulated elastin production and impaired lung septation. MV of newborn mice for 8 h with either 40% O2 or air increased lung mRNA for tropoelastin and lysyl oxidase, relative to unventilated controls, without increasing lung expression of genes that regulate elastic fiber assembly (lysyl oxidase-like-1, fibrillin-1, fibrillin-2, fibulin-5, emilin-1). Serine elastase activity in lung increased fourfold after MV with 40% O2, but not with air. We then extended MV with 40% O2 to 24 h and found that lung content of tropoelastin protein doubled, whereas lung content of elastin assembly proteins did not change (lysyl oxidases, fibrillins) or decreased (fibulin-5, emilin-1). Quantitative image analysis of lung sections showed that elastic fiber density increased by 50% after MV for 24 h, with elastin distributed throughout the walls of air spaces, rather than at septal tips, as in control lungs. Dysregulation of elastin was associated with a threefold increase in lung cell apoptosis (TUNEL and caspase-3 assays), which might account for the increased air space size previously reported in this model. Our findings of increased elastin synthesis, coupled with increased elastase activity and reduced lung abundance of proteins that regulate elastic fiber assembly, could explain altered lung elastin deposition, increased apoptosis, and defective septation, as observed in CLD.
- Published
- 2008
- Full Text
- View/download PDF
541. Mechanical ventilation with 40% oxygen reduces pulmonary expression of genes that regulate lung development and impairs alveolar septation in newborn mice.
- Author
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Bland RD, Mokres LM, Ertsey R, Jacobson BE, Jiang S, Rabinovitch M, Xu L, Shinwell ES, Zhang F, and Beasley MA
- Subjects
- Animals, Animals, Newborn, Cytokines metabolism, Gene Expression Regulation, Mice, Mice, Inbred BALB C, Oxygen Inhalation Therapy, Pulmonary Alveoli metabolism, Vascular Endothelial Growth Factor A metabolism, Vascular Endothelial Growth Factor Receptor-2 metabolism, Biomarkers metabolism, Lung growth & development, Lung metabolism, Oxygen metabolism, Pulmonary Alveoli pathology, Respiration, Artificial
- Abstract
Mechanical ventilation with 40% oxygen reduces pulmonary expression of genes that regulate lung development and impairs alveolar septation in newborn mice. Am J Physiol Lung Cell Mol Physiol 293: , 2007. First published August 17, 2007; - Mechanical ventilation (MV) with O(2)-rich gas offers life-saving treatment for extremely premature infants with respiratory failure but often leads to neonatal chronic lung disease (CLD), characterized by defective formation of alveoli and blood vessels in the developing lung. We discovered that MV of 2- to 4-day-old mice with 40% O(2) for 8 h, compared with unventilated control pups, reduced lung expression of genes that regulate lung septation and angiogenesis (VEGF-A and its receptor, VEGF-R2; PDGF-A; and tenascin-C). MV with air for 8 h yielded similar results for PDGF-A and tenascin-C but did not alter lung mRNA expression of VEGF or VEGF-R2. MV of 4- to 6-day-old mice with 40% O(2) for 24 h reduced lung protein abundance of VEGF-A, VEGF-R2, PDGF-A, and tenascin-C and resulted in lung structural abnormalities consistent with evolving CLD. After MV with 40% O(2) for 24 h, lung volume was similar to unventilated controls, whereas distal air space size, assessed morphometrically, was greater in lungs of ventilated pups, indicative of impaired septation. Immunostaining for vimentin, which is expressed in myofibroblasts, was reduced in distal lung after 24 h of MV with 40% O(2). These molecular, cellular, and structural changes occurred without detectable lung inflammation as evaluated by histology and assays for proinflammatory cytokines, myeloperoxidase activity, and water content in lung. Thus lengthy MV of newborn mice with O(2)-rich gas reduces lung expression of genes and proteins that are critical for normal lung growth and development. These changes yielded lung structural defects similar to those observed in evolving CLD.
- Published
- 2007
- Full Text
- View/download PDF
542. Dysregulation of pulmonary elastin synthesis and assembly in preterm lambs with chronic lung disease.
- Author
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Bland RD, Xu L, Ertsey R, Rabinovitch M, Albertine KH, Wynn KA, Kumar VH, Ryan RM, Swartz DD, Csiszar K, and Fong KS
- Subjects
- Animals, Animals, Newborn, Bronchopulmonary Dysplasia physiopathology, Bronchopulmonary Dysplasia therapy, Female, Gene Expression Regulation, Developmental, Gestational Age, Humans, Infant, Newborn, Oxygen pharmacology, Pancreatic Elastase metabolism, Peroxidase metabolism, Platelet-Derived Growth Factor metabolism, Pregnancy, Receptor, Platelet-Derived Growth Factor alpha metabolism, Respiration, Artificial, Serine metabolism, Sheep, Vascular Endothelial Growth Factor A genetics, Vascular Endothelial Growth Factor A metabolism, Vascular Endothelial Growth Factor Receptor-2 genetics, Vascular Endothelial Growth Factor Receptor-2 metabolism, Bronchopulmonary Dysplasia metabolism, Lung embryology, Lung metabolism, Tropoelastin genetics, Tropoelastin metabolism
- Abstract
Failed alveolar formation and excess, disordered elastin are key features of neonatal chronic lung disease (CLD). We previously found fewer alveoli and more elastin in lungs of preterm compared with term lambs that had mechanical ventilation (MV) with O(2)-rich gas for 3 wk (MV-3 wk). We hypothesized that, in preterm more than in term lambs, MV-3 wk would reduce lung expression of growth factors that regulate alveolarization (VEGF, PDGF-A) and increase lung expression of growth factors [transforming growth factor (TGF)-alpha, TGF-beta(1)] and matrix molecules (tropoelastin, fibrillin-1, fibulin-5, lysyl oxidases) that regulate elastin synthesis and assembly. We measured lung expression of these genes in preterm and term lambs after MV for 1 day, 3 days, or 3 wk, and in fetal controls. Lung mRNA for VEGF, PDGF-A, and their receptors (VEGF-R2, PDGF-Ralpha) decreased in preterm and term lambs after MV-3 wk, with reduced lung content of the relevant proteins in preterm lambs with CLD. TGF-alpha and TGF-beta(1) expression increased only in lungs of preterm lambs. Tropoelastin mRNA increased more with MV of preterm than term lambs, and expression levels remained high in lambs with CLD. In contrast, fibrillin-1 and lysyl oxidase-like-1 mRNA increased transiently, and lung abundance of other elastin-assembly genes/proteins was unchanged (fibulin-5) or reduced (lysyl oxidase) in preterm lambs with CLD. Thus MV-3 wk reduces lung expression of growth factors that regulate alveolarization and differentially alters expression of growth factors and matrix proteins that regulate elastin assembly. These changes, coupled with increased lung elastase activity measured in preterm lambs after MV for 1-3 days, likely contribute to CLD.
- Published
- 2007
- Full Text
- View/download PDF
543. A novel and effective Ni complex catalyst system for the coupling reactions of carbon dioxide and epoxides.
- Author
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Li F, Xia C, Xu L, Sun W, and Chen G
- Abstract
The coupling of carbon dioxide and mono-substituted terminal epoxides or cyclohexene oxide to form cyclic carbonates under a Ni complex catalyst system without using additional organic solvents was achieved in excellent selectivity and TOF.
- Published
- 2003
- Full Text
- View/download PDF
544. The inhibition of degradation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase by sterol regulatory element binding protein cleavage-activating protein requires four phenylalanine residues in span 6 of HMG-CoA reductase transmembrane domain.
- Author
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Xu L and Simoni RD
- Subjects
- Amino Acid Sequence, Animals, CHO Cells, Cell Membrane metabolism, Cricetinae, DNA, Complementary metabolism, Dose-Response Relationship, Drug, Farnesol metabolism, Golgi Apparatus metabolism, Humans, Molecular Sequence Data, Mutagenesis, Site-Directed, Plasmids metabolism, Protein Binding, Protein Structure, Tertiary, Sequence Homology, Amino Acid, Sterol Regulatory Element Binding Protein 1, Sterols metabolism, Time Factors, Transfection, beta-Galactosidase metabolism, CCAAT-Enhancer-Binding Proteins metabolism, DNA-Binding Proteins metabolism, Enzyme Inhibitors pharmacology, Hydroxymethylglutaryl CoA Reductases chemistry, Hydroxymethylglutaryl-CoA Reductase Inhibitors pharmacology, Phenylalanine chemistry, Transcription Factors
- Abstract
3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is the rate-limiting enzyme in the cholesterol biosynthetic pathway. This endoplasmic reticulum membrane protein contains a cytosolic catalytic domain and a transmembrane domain with eight membrane spans that are necessary for sterol-accelerated degradation. Competition experiments showed that wild-type transmembrane domains of HMGR and sterol regulatory element binding protein cleavage-activating protein (SCAP) blocked sterol-accelerated degradation of intact HMGR and HMGal, a model protein containing the membrane domain of HMGR linked to Escherichia coli beta-galactosidase. However, mutant transmembrane domains of HMGR and SCAP whose sterol-sensing functions were abolished did not inhibit sterol-accelerated degradation of HMGR and HMGal. In addition, our mutagenesis studies on HMGal indicated that four Phe residues conserved in span 6 of HMGR and the sterol-sensing domains of other sterol-related proteins are required for the regulated degradation of HMGR. These results suggest that HMGR and SCAP compete for binding to a sterol-regulated regulator protein, and this binding may need the four Phe residues.
- Published
- 2003
- Full Text
- View/download PDF
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