2,106 research outputs found

    Direct calibration of PICKY-designed microarrays

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    Abstract Background Few microarrays have been quantitatively calibrated to identify optimal hybridization conditions because it is difficult to precisely determine the hybridization characteristics of a microarray using biologically variable cDNA samples. Results Using synthesized samples with known concentrations of specific oligonucleotides, a series of microarray experiments was conducted to evaluate microarrays designed by PICKY, an oligo microarray design software tool, and to test a direct microarray calibration method based on the PICKY-predicted, thermodynamically closest nontarget information. The complete set of microarray experiment results is archived in the GEO database with series accession number GSE14717. Additional data files and Perl programs described in this paper can be obtained from the website http://www.complex.iastate.edu under the PICKY Download area. Conclusion PICKY-designed microarray probes are highly reliable over a wide range of hybridization temperatures and sample concentrations. The microarray calibration method reported here allows researchers to experimentally optimize their hybridization conditions. Because this method is straightforward, uses existing microarrays and relatively inexpensive synthesized samples, it can be used by any lab that uses microarrays designed by PICKY. In addition, other microarrays can be reanalyzed by PICKY to obtain the thermodynamically closest nontarget information for calibration

    Symptoms and quality of life in late stage Parkinson syndromes: a longitudinal community study of predictive factors

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    BACKGROUND Palliative care is increasingly offered earlier in the cancer trajectory but rarely in Idiopathic Parkinson's Disease(IPD), Progressive Supranuclear Palsy(PSP) or Multiple System Atrophy(MSA). There is little longitudinal data of people with late stage disease to understand levels of need. We aimed to determine how symptoms and quality of life of these patients change over time; and what demographic and clinical factors predicted changes. METHODS We recruited 82 patients into a longitudinal study, consenting patients with a diagnosis of IPD, MSA or PSP, stages 3-5 Hoehn and Yahr(H&Y). At baseline and then on up to 3 occasions over one year, we collected self-reported demographic, clinical, symptom, palliative and quality of life data, using Parkinson's specific and generic validated scales, including the Palliative care Outcome Scale (POS). We tested for predictors using multivariable analysis, adjusting for confounders. FINDINGS Over two thirds of patients had severe disability, over one third being wheelchair-bound/bedridden. Symptoms were highly prevalent in all conditions - mean (SD) of 10.6(4.0) symptoms. More than 50% of the MSA and PSP patients died over the year. Over the year, half of the patients showed either an upward (worsening, 24/60) or fluctuant (8/60) trajectory for POS and symptoms. The strongest predictors of higher levels of symptoms at the end of follow-up were initial scores on POS (AOR 1.30; 95%CI:1.05-1.60) and being male (AOR 5.18; 95% CI 1.17 to 22.92), both were more predictive than initial H&Y scores. INTERPRETATION The findings point to profound and complex mix of non-motor and motor symptoms in patients with late stage IPD, MSA and PSP. Symptoms are not resolved and half of the patients deteriorate. Palliative problems are predictive of future symptoms, suggesting that an early palliative assessment might help screen for those in need of earlier intervention

    Structural insights into RNA processing by the human RISC-loading complex.

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    Targeted gene silencing by RNA interference (RNAi) requires loading of a short guide RNA (small interfering RNA (siRNA) or microRNA (miRNA)) onto an Argonaute protein to form the functional center of an RNA-induced silencing complex (RISC). In humans, Argonaute2 (AGO2) assembles with the guide RNA-generating enzyme Dicer and the RNA-binding protein TRBP to form a RISC-loading complex (RLC), which is necessary for efficient transfer of nascent siRNAs and miRNAs from Dicer to AGO2. Here, using single-particle EM analysis, we show that human Dicer has an L-shaped structure. The RLC Dicer's N-terminal DExH/D domain, located in a short 'base branch', interacts with TRBP, whereas its C-terminal catalytic domains in the main body are proximal to AGO2. A model generated by docking the available atomic structures of Dicer and Argonaute homologs into the RLC reconstruction suggests a mechanism for siRNA transfer from Dicer to AGO2

    Strain engineering and one-dimensional organization of metal-insulator domains in single-crystal VO2 beams

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    Spatial phase inhomogeneity at the nano- to microscale is widely observed in strongly-correlated electron materials. The underlying mechanism and possibility of artificially controlling the phase inhomogeneity are still open questions of critical importance for both the phase transition physics and device applications. Lattice strain has been shown to cause the coexistence of metallic and insulating phases in the Mott insulator VO2. By continuously tuning strain over a wide range in single-crystal VO2 micro- and nanobeams, here we demonstrate the nucleation and manipulation of one-dimensionally ordered metal-insulator domain arrays along the beams. Mott transition is achieved in these beams at room temperature by active control of strain. The ability to engineer phase inhomogeneity with strain lends insight into correlated electron materials in general, and opens opportunities for designing and controlling the phase inhomogeneity of correlated electron materials for micro- and nanoscale device applications.Comment: 14 pages, 4 figures, with supplementary informatio

    Avelumab alone or in combination with chemotherapy versus chemotherapy alone in platinum-resistant or platinum-refractory ovarian cancer (JAVELIN Ovarian 200): an open-label, three-arm, randomised, phase 3 study

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    BACKGROUND: Most patients with ovarian cancer will relapse after receiving frontline platinum-based chemotherapy and eventually develop platinum-resistant or platinum-refractory disease. We report results of avelumab alone or avelumab plus pegylated liposomal doxorubicin (PLD) compared with PLD alone in patients with platinum-resistant or platinum-refractory ovarian cancer. METHODS: JAVELIN Ovarian 200 was an open-label, parallel-group, three-arm, randomised, phase 3 trial, done at 149 hospitals and cancer treatment centres in 24 countries. Eligible patients were aged 18 years or older with epithelial ovarian, fallopian tube, or peritoneal cancer (maximum of three previous lines for platinum-sensitive disease, none for platinum-resistant disease) and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were randomly assigned (1:1:1) via interactive response technology to avelumab (10 mg/kg intravenously every 2 weeks), avelumab plus PLD (40 mg/m2 intravenously every 4 weeks), or PLD and stratified by disease platinum status, number of previous anticancer regimens, and bulky disease. Primary endpoints were progression-free survival by blinded independent central review and overall survival in all randomly assigned patients, with the objective to show whether avelumab alone or avelumab plus PLD is superior to PLD. Safety was assessed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02580058. The trial is no longer enrolling patients and this is the final analysis of both primary endpoints. FINDINGS: Between Jan 5, 2016, and May 16, 2017, 566 patients were enrolled and randomly assigned (combination n=188; PLD n=190, avelumab n=188). At data cutoff (Sept 19, 2018), median duration of follow-up for overall survival was 18·4 months (IQR 15·6-21·9) for the combination group, 17·4 months (15·2-21·3) for the PLD group, and 18·2 months (15·8-21·2) for the avelumab group. Median progression-free survival by blinded independent central review was 3·7 months (95% CI 3·3-5·1) in the combination group, 3·5 months (2·1-4·0) in the PLD group, and 1·9 months (1·8-1·9) in the avelumab group (combination vs PLD: stratified HR 0·78 [repeated 93·1% CI 0·59-1·24], one-sided p=0·030; avelumab vs PLD: 1·68 [1·32-2·60], one-sided p>0·99). Median overall survival was 15·7 months (95% CI 12·7-18·7) in the combination group, 13·1 months (11·8-15·5) in the PLD group, and 11·8 months (8·9-14·1) in the avelumab group (combination vs PLD: stratified HR 0·89 [repeated 88·85% CI 0·74-1·24], one-sided p=0·21; avelumab vs PLD: 1·14 [0·95-1·58], one-sided p=0·83]). The most common grade 3 or worse treatment-related adverse events were palmar-plantar erythrodysesthesia syndrome (18 [10%] in the combination group vs nine [5%] in the PLD group vs none in the avelumab group), rash (11 [6%] vs three [2%] vs none), fatigue (ten [5%] vs three [2%] vs none), stomatitis (ten [5%] vs five [3%] vs none), anaemia (six [3%] vs nine [5%] vs three [2%]), neutropenia (nine [5%] vs nine [5%] vs none), and neutrophil count decreased (eight [5%] vs seven [4%] vs none). Serious treatment-related adverse events occurred in 32 (18%) patients in the combination group, 19 (11%) in the PLD group, and 14 (7%) in the avelumab group. Treatment-related adverse events resulted in death in one patient each in the PLD group (sepsis) and avelumab group (intestinal obstruction). INTERPRETATION: Neither avelumab plus PLD nor avelumab alone significantly improved progression-free survival or overall survival versus PLD. These results provide insights for patient selection in future studies of immune checkpoint inhibitors in platinum-resistant or platinum-refractory ovarian cancer. FUNDING: Pfizer and Merck KGaA, Darmstadt, Germany

    Phonons and related properties of extended systems from density-functional perturbation theory

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    This article reviews the current status of lattice-dynamical calculations in crystals, using density-functional perturbation theory, with emphasis on the plane-wave pseudo-potential method. Several specialized topics are treated, including the implementation for metals, the calculation of the response to macroscopic electric fields and their relevance to long wave-length vibrations in polar materials, the response to strain deformations, and higher-order responses. The success of this methodology is demonstrated with a number of applications existing in the literature.Comment: 52 pages, 14 figures, submitted to Review of Modern Physic

    Sequence variations in DNA repair gene XPC is associated with lung cancer risk in a Chinese population: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>The nucleotide excision repair (NER) protein, xeroderma pigmentosum C (XPC), participates in recognizing DNA lesions and initiating DNA repair in response to DNA damage. Because mutations in <it>XPC </it>cause a high risk of cancer in XP patients, we hypothesized that inherited sequence variations in <it>XPC </it>may alter DNA repair and thus susceptibility to cancer.</p> <p>Methods</p> <p>In this hospital-based case-control study, we investigated five <it>XPC </it>tagging, common single nucleotide polymorphisms (tagging SNPs) in 1,010 patients with newly diagnosed lung cancer and 1,011 matched cancer free controls in a Chinese population.</p> <p>Results</p> <p>In individual tagging SNP analysis, we found that rs3731055<it>AG+AA </it>variant genotypes were associated with a significantly decreased risk of lung adenocarcinoma [adjusted odds ratio (OR), 0.71; 95% confidence interval (CI), 0.56–0.90] but an increased risk of small cell carcinomas [adjusted OR, 1.79; 95% CI, 1.05–3.07]. Furthermore, we found that haplotype <it>ACCCA </it>was associated with a decreased risk of lung adenocarcinoma [OR, 0.78; 95% CI, 0.62–0.97] but an increased risk of small cell carcinomas [OR, 1.68; 95% CI, 1.04–2.71], which reflected the presence of rs3731055<it>A </it>allele in this haplotype. Further stratified analysis revealed that the protective effect of rs3731055<it>AG+AA </it>on risk of lung adenocarcinoma was more evident among young subjects (age ≤ 60) and never smokers.</p> <p>Conclusion</p> <p>These results suggest that inherited sequence variations in <it>XPC </it>may modulate risk of lung cancer, especially lung adenocarcinoma, in Chinese populations. However, these findings need to be verified in larger confirmatory studies with more comprehensively selected tagging SNPs.</p

    Discriminating neutrino mass models using Type II seesaw formula

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    In this paper we propose a kind of natural selection which can discriminate the three possible neutrino mass models, namely the degenerate, inverted hierarchical and normal hierarchical models, using the framework of Type II seesaw formula. We arrive at a conclusion that the inverted hierarchical model appears to be most favourable whereas the normal hierarchical model follows next to it. The degenerate model is found to be most unfavourable. We use the hypothesis that those neutrino mass models in which Type I seesaw term dominates over the Type II left-handed Higgs triplet term are favoured to survive in nature.Comment: No change in the results, a few references added, some changes in Type[IIB] calculation

    Over-Expression of PDGFR-β Promotes PDGF-Induced Proliferation, Migration, and Angiogenesis of EPCs through PI3K/Akt Signaling Pathway

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    The proliferation, migration, and angiogenesis of endothelial progenitor cells (EPCs) play critical roles in postnatal neovascularization and re-endothelialization following vascular injury. Here we evaluated whether the over-expression of platelet-derived growth factor receptor-β (PDGFR-β) can enhance the PDGF-BB-stimulated biological functions of EPCs through the PDGFR-β/phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. We first confirmed the expression of endogenous PDGFR-β and its plasma membrane localization in spleen-derived EPCs. We then demonstrated that the PDGFR-β over-expression in EPCs enhanced the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. Using AG1295 (a PDGFR kinase inhibitor), LY294002 (a PI3K inhibitor), and sc-221226 (an Akt inhibitor), we further showed that the PI3K/Akt signaling pathway participates in the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. In addition, the PI3K/Akt signaling pathway is required for PDGFR-β over-expression to enhance these PDGF-BB-induced phenotypes
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