163 research outputs found
Was Kaposi’s sarcoma-associated herpesvirus introduced into China via the ancient Silk Road? An evolutionary perspective
Kaposi’s sarcoma-associated herpesvirus (KSHV) has become widely dispersed worldwide since it was first reported in 1994, but the seroprevalence of KSHV varies geographically. KSHV is relatively ubiquitous in Mediterranean areas and the Xinjiang Uygur Autonomous Region, China. The origin of KSHV has long been puzzling. In the present study, we collected and analysed 154 KSHV ORF-K1 sequences obtained from samples originating from Xinjiang, Italy, Greece, Iran and southern Siberia using Bayesian evolutionary analysis in BEAST to test the hypothesis that KSHV was introduced into Xinjiang via the ancient Silk Road. According to the phylogenetic analysis, 72 sequences were subtype A and 82 subtype C, with C2 (n = 56) being the predominant subtype. The times to the most recent common ancestors (tMRCAs) of KSHV were 29,872 years (95% highest probability density [HPD], 26,851–32,760 years) for all analysed sequences and 2037 years (95% HPD, 1843–2229 years) for Xinjiang sequences in particular. The tMRCA of Xinjiang KSHV was exactly matched with the time period of the ancient Silk Road approximately two thousand years ago. This route began in Chang’an, the capital of the Han dynasty of China, and crossed Central Asia, ending in the Roman Empire. The evolution rate of KSHV was slow, with 3.44 × 10−6 substitutions per site per year (95% HPD, 2.26 × 10−6 to 4.71 × 10−6), although 11 codons were discovered to be under positive selection pressure. The geographic distances from Italy to Iran and Xinjiang are more than 4000 and 7000 kilometres, respectively, but no explicit relationship between genetic distance and geographic distance was detected
DCAF26, an Adaptor Protein of Cul4-Based E3, Is Essential for DNA Methylation in Neurospora crassa
DNA methylation is involved in gene silencing and genome stability in organisms from fungi to mammals. Genetic studies in Neurospora crassa previously showed that the CUL4-DDB1 E3 ubiquitin ligase regulates DNA methylation via histone H3K9 trimethylation. However, the substrate-specific adaptors of this ligase that are involved in the process were not known. Here, we show that, among the 16 DDB1- and Cul4-associated factors (DCAFs) encoded in the N. crassa genome, three interacted strongly with CUL4-DDB1 complexes. DNA methylation analyses of dcaf knockout mutants revealed that dcaf26 was required for all of the DNA methylation that we observed. In addition, histone H3K9 trimethylation was also eliminated in dcaf26KO mutants. Based on the finding that DCAF26 associates with DDB1 and the histone methyltransferase DIM-5, we propose that DCAF26 protein is the major adaptor subunit of the Cul4-DDB1-DCAF26 complex, which recruits DIM-5 to DNA regions to initiate H3K9 trimethylation and DNA methylation in N. crassa
Effects of High-Frequency Transcranial Magnetic Stimulation for Cognitive Deficit in Schizophrenia: A Meta-Analysis
Objective: Repetitive transcranial magnetic stimulation (rTMS) has been applied to dorsolateral prefrontal cortex (DLPFC) to improve cognitive function of patients with schizophrenia (SZs). The aim of this meta-analysis was to evaluate whether a high-frequency rTMS course could enhance cognitive function in SZs.Methods: Studies published in PubMed, Cochrane Library, Embase, ScienceDirect, and Web of science were searched until April 2018. The search terms included: “repetitive transcranial magnetic stimulation” or “Rtms,” “SZ,” or “schizophrenia,” and “neuro-cognition” or “neurocognitive performance” or “cognitive effects” or “cognitive” or “cognition” or “working memory” or “executive function” or “language function” or “processing speed,” After screening the literatures according to inclusion and exclusion criteria, extracting data, and evaluating the methodological quality of the included studies, a meta-analysis was performed using RevMan 5.3 software (The Cochrane Collaboration, USA).Results: A total of 9 studies on cognitive dysfunction of SZs were included and involved 351 patients. A significant efficacy of high-frequency rTMS on working memory in SZs was found compared to sham stimulation [p = 0.009, standardized mean difference (SMD) = 0.34]. Specifically, rTMS treatment positioned on the left DLPFC, with a total pluses <30,000 was more significantly more effective in improving the working memory (SMD = 0.33, p = 0.03). No improvement was found in other cognitive domains such as executive function, attention, processing speed, and language function. For the follow-up observations, high-frequency rTMS had long-lasting sustained effects on working memory (SMD = 0.45, p = 0.01) and language function (SMD = 0.77, p = 0.02) in SZs.Conclusions: High-frequency rTMS over the left DLPFC with a total pulses <30,000 stimulation could significantly improve working memory in SZs for an extended period of time
Antidepressant Effects of Repetitive Transcranial Magnetic Stimulation Over Prefrontal Cortex of Parkinson's Disease Patients With Depression: A Meta-Analysis
Objective: The purpose of this meta-analysis was to investigate the antidepressant effects of repetitive transcranial magnetic stimulation (rTMS) over the prefrontal cortex (PFC) of patients with Parkinson's disease (PD) and to determine the optimal rTMS parameters, such as the intensity, frequency and the delivered pattern of rTMS stimulation.Methods: EMBASE, PubMed, Web of Science, MEDLINE, and Cochrane data bases were researched for papers published before March 12, 2018. Studies investigating the anti-depression effects of rTMS over PFC in patients with PD were considered. The main outcomes of pre- and post-rTMS treatment as well as score changes were all extracted. The mean effect size was estimated by calculating the standardized mean difference (SMD) with 95% confidence interval (CI) by using fixed or random effect models as appropriate.Results: Nine studies containing 137 PD patients with depression were included. The pooled results showed significant pre-post anti-depressive effects of rTMS over PFC in PD patients with depression (SMD = −0.80, P < 0.00001). The subgroup analyses of stimulation intensity, frequencies, and models also revealed significant effects (Intensities: 90% RMT: SMD = −1.16, P = 0.0006; >100% RMT: SMD = −0.82, P < 0.0001. Frequencies: < 1.0 Hz: SMD = −0.83, P = 0.03; 5.0 Hz: SMD = −1.10, P < 0.0001; ≥10.0 Hz: SMD = −0.55, P = 0.02. Models: Continuous: SMD = −0.79, P < 0.0001; Discontinuous: SMD = −0.84, P = 0.02). But the results of the studies with place-controlled designs were not significant (Overall: SMD = −0.27, P = 0.54. Intensities: 90% RMT: SMD = 0.27, P = 0.68; 100% RMT: SMD = −0.32, P = 0.33. Frequencies: 5.0 Hz: SMD = −0.87, P = 0.10; ≥10.0 Hz: SMD = 0.27, P = 0.66. Models: Continuous: SMD = −0.28, P = 0.68; Discontinuous: SMD = −0.32, P = 0.33). The greater effect sizes of rTMS with 90% RMT, 5.0 Hz in discontinuous days can be observed rather than the other parameters in both kinds of analyses across study design.Conclusions: rTMS may have a significant positive pre-post anti-depressive effect over PFC on patients with depression, especially by using 5.0 Hz frequency with 90% RMT intensity in discontinuous days, which may produce better effects than other parameters. The real effect, though, was not different from that of the placebo. Future studies with larger sample sizes and high-quality studies are needed to further corroborate our results and to identify the optimal rTMS protocols
High-Throughput RNA Sequencing of Pseudomonas-Infected Arabidopsis Reveals Hidden Transcriptome Complexity and Novel Splice Variants
We report the results of a genome-wide analysis of transcription in Arabidopsis thaliana after treatment with Pseudomonas syringae pathovar tomato. Our time course RNA-Seq experiment uses over 500 million read pairs to provide a detailed characterization of the response to infection in both susceptible and resistant hosts. The set of observed differentially expressed genes is consistent with previous studies, confirming and extending existing findings about genes likely to play an important role in the defense response to Pseudomonas syringae. The high coverage of the Arabidopsis transcriptome resulted in the discovery of a surprisingly large number of alternative splicing (AS) events – more than 44% of multi-exon genes showed evidence for novel AS in at least one of the probed conditions. This demonstrates that the Arabidopsis transcriptome annotation is still highly incomplete, and that AS events are more abundant than expected. To further refine our predictions, we identified genes with statistically significant changes in the ratios of alternative isoforms between treatments. This set includes several genes previously known to be alternatively spliced or expressed during the defense response, and it may serve as a pool of candidate genes for regulated alternative splicing with possible biological relevance for the defense response against invasive pathogens
CRL4Wdr70 regulates H2B monoubiquitination and facilitates Exo1-dependent resection
Double strand breaks repaired by homologous recombination (HR) are first resected to form single stranded DNA which binds replication protein A (RPA). RPA attracts mediators which load the Rad51 filament to promote strand invasion, the defining feature of HR. How the resection machinery navigates nucleosome-packaged DNA is poorly understood. Using Schizosaccharomyces pombe we report that a conserved DDB1-CUL4-associated factor (DCAF), Wdr70, is recruited to DSBs as part of the Cullin4-DDB1 ubiquitin ligase (CRL4Wdr70) and stimulates distal H2B lysine 119 monoubiquitination(uH2B). Wdr70 deletion, or uH2B loss, results in increased loading of the checkpoint adaptor and resection inhibitor Crb253BP1, decreased Exo1 association and delayed resection. Wdr70 is dispensable for resection upon Crb253BP1 loss, or when the Set9 methyltransferase that creates docking sites for Crb2 is deleted. Finally we establish that this histone regulatory cascade similarly controls DSB resection in human cells
Prognostic value of neutrophil-to-lymphocyte ratio in breast cancer
AbstractInflammation is an essential component of pathogenesis and progression of cancer. A high neutrophil-to-lymphocyte ratio (NLR) is considered as a prognostic indicator for breast cancer. This meta-analysis was conducted to establish the overall accuracy of the NLR test in the diagnosis of breast cancer. A comprehensive search of the literature was conducted by using PubMed, Web of Science and China National Knowledge Infrastructure (CNKI). Published studies dating up to July 2014 and 4,293 patients were enrolled in the present study. In order to evaluate the association between NLR and overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS) or cancer specific survival (CSS), the hazard ratios (HRs) and their 95% confidence intervals (CIs) were extracted. OS was the primary outcome. The results suggested that increased NLR was a strong predictor for OS with HR of 2.28 (95% CI=1.08–4.80, Pheterogeneity<0.001). Stratified analyses indicated that a high NLR appeared to be a negative prognostic marker in Caucasian populations (HR=4.53, 95% CI=3.11–6.60, Pheterogeneity=0.096), multivariate analysis method (HR=2.10, 95% CI=1.52–2.89, Pheterogeneity=0.591), and mixed metastasis (HR=4.53, 95% CI=3.11–6.60, Pheterogeneity=0.096). Elevated NLR was associated with a high risk for DFS (HR=1.38, 95% CI=1.09–1.74, Pheterogeneity=0.050) and in subgroups of multivariate analysis (HR=1.64, 95% CI=1.25–2.14, Pheterogeneity=0.545) and mixed metastasis (HR=1.99, 95% CI=1.28–3.09, Pheterogeneity=0.992). In summary, NLR could be considered as a predictive factor for patients with breast cancer
Prognostic value of pre-operative inflammatory response biomarkers in gastric cancer patients and the construction of a predictive model
A universal optical modulator for synthetic topologically tuneable structured matter
Topologically structured matter, such as metasurfaces and metamaterials, have
given rise to impressive photonic functionality, fuelling diverse applications
from microscopy and holography to encryption and communication. Presently these
solutions are limited by their largely static nature and preset functionality,
hindering applications that demand dynamic photonic systems with reconfigurable
topologies. Here we demonstrate a universal optical modulator that implements
topologically tuneable structured matter as virtual pixels derived from
cascading low functionality tuneable devices, altering the paradigm of phase
and amplitude control to encompass arbitrary spatially varying retarders in a
synthetic structured matter device. Our approach opens unprecedented
functionality that is user-defined with high flexibility, allowing our
synthetic structured matter to act as an information carrier, beam generator,
analyser, and corrector, opening an exciting path to tuneable topologies of
light and matter
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