1,561 research outputs found

    Shock-induced stripping of satellite ISM/CGM in IllustrisTNG clusters at z0z\sim0

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    Using the IllustrisTNG simulation, we study the interaction of large-scale shocks with the circumgalactic medium (CGM) and interstellar medium (ISM) of star-forming (SF) satellite galaxies in galaxy clusters. These shocks are usually produced by mergers and massive accretion. Our visual inspection shows that approximately half of SF satellites have encountered shocks in their host clusters at z0.11z\leq0.11. After a satellite crosses a shock front and enters the postshock region, the ram pressure on it is boosted significantly. Both the CGM and ISM can be severely impacted, either by striping or compression. The stripping of the ISM is particularly important for low-mass galaxies with log(M/M)<10\log (M_{*}/M_{\odot})<10 and can occur even in the outskirts of galaxy clusters. In comparison, satellites that do not interact with shocks lose their ISM only in the inner regions of clusters. About half of the ISM is stripped within about 0.6 Gyr after it crosses the shock front. Our results show that shock-induced stripping plays an important role in quenching satellite galaxies in clusters.Comment: 13 pages,8 figures, submitted to Ap

    Does carbon dioxide pneumoperitoneum enhance wound metastases following laparoscopic abdominal tumor surgery? A meta-analysis of 20 randomized control studies

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    The mechanisms involved in the development of wound metastasis following laparoscopic abdominal tumor surgery remain unclear. The aim of this study was to accurately assess whether the duration of carbon dioxide pneumoperitoneum (CDP) during laparoscopic abdominal tumor surgery enhances wound metastases. We conducted a systematic review of PubMed, Cochrane Library, and Embase through December 2013 to identify animal experiments comparing wound recurrence between laparoscopic and gasless laparoscopic procedures or open procedures. The outcome of interest was the number of animals with a wound tumor. Meta-regression was used to assess whether heterogeneity was explained by study level covariates (animal model, study size, CDP pressure, duration, and evaluated time). Twenty randomized control studies involving 1,229 animals were included. Wound recurrence was not significant in the laparoscopic surgery (LP) vs. gasless laparoscopic surgery (GLP) subgroups [odds ratio (OR), 2.23; 95 % confidence interval (CI), 0.90–5.55; P = 0.08) or the LP vs. laparotomy (LA) subgroups (OR, 0.97; 95 % CI, 0.31–3.00; P = 0.08). Overall postoperative wound recurrence results were not significantly different between the study groups and controls (OR, 1.47; 95 % CI, 0.74–2.92; P = 0.28). A meta-regression analysis showed that the outcome was not correlated with the covariates (animal model: P = 0.82; evaluated time: P = 0.30; pressure of CDP: P = 0.12; duration time: P = 0.80). Current evidence suggests that CDP does not enhance wound metastases following laparoscopic abdominal tumor surgery. Additional large sample, well-designed, randomized, controlled trials are needed to further confirm whether CDP duration in laparoscopic abdominal tumor surgery significantly enhances wound recurrence

    TADKB:Family Classification and a Knowledge Base of Topologically Associating Domains

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    Background: Topologically associating domains (TADs) are considered the structural and functional units of the genome. However, there is a lack of an integrated resource for TADs in the literature where researchers can obtain family classifications and detailed information about TADs. Results: We built an online knowledge base TADKB integrating knowledge for TADs in eleven cell types of human and mouse. For each TAD, TADKB provides the predicted three-dimensional (3D) structures of chromosomes and TADs, and detailed annotations about the protein-coding genes and long non-coding RNAs (lncRNAs) existent in each TAD. Besides the 3D chromosomal structures inferred by population Hi-C, the single-cell haplotype-resolved chromosomal 3D structures of 17 GM12878 cells are also integrated in TADKB. A user can submit query gene/lncRNA ID/sequence to search for the TAD(s) that contain(s) the query gene or lncRNA. We also classified TADs into families. To achieve that, we used the TM-scores between reconstructed 3D structures of TADs as structural similarities and the Pearson’s correlation coefficients between the fold enrichment of chromatin states as functional similarities. All of the TADs in one cell type were clustered based on structural and functional similarities respectively using the spectral clustering algorithm with various predefined numbers of clusters. We have compared the overlapping TADs from structural and functional clusters and found that most of the TADs in the functional clusters with depleted chromatin states are clustered into one or two structural clusters. This novel finding indicates a connection between the 3D structures of TADs and their DNA functions in terms of chromatin states. Conclusion: TADKB is available at href= http://dna.cs.miami.edu/TADKB/ target= _blank \u3ehttp://dna.cs.miami.edu/TADKB

    Distribution, characterization, and induction of CD8+ regulatory T cells and IL-17-producing CD8+ T cells in nasopharyngeal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>CD8<sup>+ </sup>effector cells often have an antitumor function in patients with cancer. However, CD8<sup>+</sup>Foxp3<sup>+ </sup>regulatory T cells (Tcregs) and interleukin (IL)-17-producing CD8<sup>+ </sup>T cells (Tc17 cells) also derive from the CD8<sup>+ </sup>T cell lineage. Their role in the antitumor response remains largely unknown. In the present study, we aimed to investigate the distribution, characterization, and generation of CD8<sup>+ </sup>Tcregs and Tc17 cells in NPC patients.</p> <p>Methods</p> <p>Peripheral blood and tumor biopsy tissues from 21 newly diagnosed patients with nasopharyngeal carcinoma (NPC) were collected, along with peripheral blood from 21 healthy donors. The biological characteristics of Tcregs and Tc17 cells from blood and tumor tissues were examined by intracellular staining, tetramer staining and fluorescence-activated cell sorting (FACS) analysis. The suppressive function of Tcregs was investigated using a proliferation assay that involved co-culture of sorted CD8<sup>+</sup>CD25<sup>+ </sup>T cells with naïve CD4<sup>+ </sup>T cells <it>in vitro</it>.</p> <p>Results</p> <p>We observed an increased prevalence of Tcregs and Tc17 cells among tumor-infiltrating lymphocytes (TILs) and different distribution among peripheral blood mononuclear cells (PBMCs) in NPC patients. Cytokine profiles showed that the Tcregs expressed a high level of IL-10 and low level of transforming growth factor β, whereas Tc17 cells expressed a high level of tumor necrosis factor α. Interestingly, both subsets expressed a high level of interferon γ in TILs, and the Tcregs suppressed naïve CD4<sup>+ </sup>T cell proliferation by a cell contact-dependent mechanism <it>in vitro</it>. Moreover, we demonstrated the existence of Epstein-Barr virus latent membrane protein (LMP) 1 and LMP2 antigen-specific Tcregs in NPC.</p> <p>Conclusions</p> <p>Our data provide new insights into the composition and function of CD8<sup>+ </sup>T-cell subsets in NPC, which may have an important influence on NPC immunotherapy.</p

    Binding site profiles and N-terminal minor groove interactions of the master quorum-sensing regulator LuxR enable flexible control of gene activation and repression

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    LuxR is a TetR family master quorum sensing (QS) regulator activating or repressing expression of hundreds of genes that control collective behaviors in Vibrios with underlying mechanism unknown. To illuminate how this regulator controls expression of various target genes, we applied ChIP-seq and DNase I-seq technologies. Vibrio alginolyticus LuxR controls expression of ∼280 genes that contain either symmetric palindrome (repDNA) or asymmetric (actDNA) binding motifs with different binding profiles. The median number of LuxR binding sites for activated genes are nearly double for that of repressed genes. Crystal structures of LuxR in complex with the respective repDNA and actDNA motifs revealed a new mode of LuxR DNA binding that involves contacts of its N-terminal extension to the minor groove. The N-terminal contacts mediated by Arginine-9 and Arginine-11 differ when LuxR binds to repDNA vs actDNA, leading to higher binding affinity at repressed targets. Moreover, modification of LuxR binding sites, binding profiles, and N-terminal extension have important consequences on QS-regulated phenotypes. These results facilitate fundamental understanding of the high flexibility of mechanisms of LuxR control of gene activation and repression in Vibrio QS, which may facilitate to design QS inhibiting chemicals that interfere with LuxR regulation to effectively control pathogens

    Genome-Wide and Differential Proteomic Analysis of Hepatitis B Virus and Aflatoxin B1 Related Hepatocellular Carcinoma in Guangxi, China

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    Both hepatitis B virus (HBV) and aflatoxin B1 (AFB1) exposure can cause liver damage as well as increase the probability of hepatocellular carcinoma (HCC). To investigate the underlying genetic changes that may influence development of HCC associated with HBV infection and AFB1 exposure, HCC patients were subdivided into 4 groups depending upon HBV and AFB1 exposure status: (HBV(+)/AFB1(+), HBV(+)/AFB1(-), HBV(-)/AFB1(+), HBV(-)/AFB1(-)). Genetic abnormalities and protein expression profiles were analyzed by array-based comparative genomic hybridization and isobaric tagging for quantitation. A total of 573 chromosomal aberrations (CNAs) including 184 increased and 389 decreased were detected in our study population. Twenty-five recurrently altered regions (RARs; chromosomal alterations observed in ≥10 patients) in chromosomes were identified. Loss of 4q13.3-q35.2, 13q12.1-q21.2 and gain of 7q11.2-q35 were observed with a higher frequency in the HBV(+)/AFB1(+), HBV(+)/AFB1(-) and HBV(-)/AFB1(+) groups compared to the HBV(-)/AFB(-) group. Loss of 8p12-p23.2 was associated with high TNM stage tumors (P = 0.038) and was an unfavorable prognostic factor for tumor-free survival (P=0.045). A total of 133 differentially expressed proteins were identified in iTRAQ proteomics analysis, 69 (51.8%) of which mapped within identified RARs. The most common biological processes affected by HBV and AFB1 status in HCC tumorigenesis were detoxification and drug metabolism pathways, antigen processing and anti-apoptosis pathways. Expression of AKR1B10 was increased significantly in the HBV(+)/AFB1(+) and HBV(-)/AFB1(+) groups. A significant correlation between the expression of AKR1B10 mRNA and protein levels as well as AKR1B10 copy number was observed, which suggest that AKR1B10 may play a role in AFB1-related hepatocarcinogenesis. In summary, a number of genetic and gene expression alterations were found to be associated with HBV and AFB1- related HCC. The possible synergistic effects of HBV and AFB1 in hepatocarcinogenesis warrant further investigations

    The effects of nail rigidity on fracture healing in rats with osteoporosis

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    Background and purpose Stress shielding from rigid internal fixation may lead to refracture after removal of the osteosynthesis material. We investigated the effect of a low-rigidity (Ti-24Nb-4Zr-7.9Sn) intramedullary nail regarding stress shielding and bone healing of osteoporotic fractures in the rat

    Menin Deficiency Leads to Depressive-like Behaviors in Mice by Modulating Astrocyte-Mediated Neuroinflammation

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    厦门大学医学院、神经科学研究所张杰教授团队发现了抑郁症新的致病基因MEN1,并阐明了MEN1调控星形胶质细胞炎症导致抑郁发生发展的新机制,为抑郁症的诊治提供了新靶点和方向。抑郁症是严重威胁人类健康的重大神经系统疾病,危及全球30%的人口。但对其发病机制并不清楚。张杰教授团队发现,在慢性不可预测以及LPS处理的模拟抑郁小鼠模型中,多发性内分泌肿瘤蛋白(menin)在大脑中的表达显著降低,并且在星形胶质细胞中降低最明显。为了研究menin是否参与了小鼠抑郁表型的产生,研究团队制作了多种神经系统menin条件性敲除小鼠。通过对这些小鼠行为学的检测,锁定了只有在星形胶质细胞中敲除menin后,小鼠才会表现出抑郁样表型。证实了menin可能是通过调控星形胶质细胞的功能促进了抑郁的发生。 MEN1基因的突变会导致多发性内分泌肿瘤,而内分泌的紊乱和抑郁等精神疾病有着密切的联系。下丘脑-垂体-肾上腺轴(HPA轴)的功能紊乱直接参与了抑郁的产生。基于此研究团队推测MEN1的基因突变是否也会导致抑郁的发生。通过和中国医学科学院基础所的许琪教授合作,研究团队对1000多例重度抑郁患者和800多例对照人群进行了MEN1基因的外显子测序。通过测序发现MEN1的一个SNP s375804228和抑郁的发生有着显著关联。该SNP导致menin第503位的氨基酸由G突变成D。通过功能研究进一步证实该突变可以阻断menin和p65的结合,从而过度激活NF-κB-IL-1β通路,导致神经炎症的发生。 张杰,厦门大学特聘教授、博士生导师。国家优秀青年科学基金;教育部新世纪优秀人才;福建省杰出青年科学基金;厦门市五四青年奖章等获得者。2011年8月加入厦门大学医学院神经科学研究所担任教授至今。张杰博士主要从事重大神经系统疾病(老年痴呆、帕金森、抑郁症、自闭症、术后认知障碍、胶质瘤)等的发病机制和药物开发研究。至今以第一作者或者通讯作者在国际知名期刊发表研究论文21篇。其中回国独立开展研究工作以后,作为通讯作者在 Neuron,Cell Reports, PNAS, The Journal of Neuroscience, Clinical Cancer Research,Cell Death and Disease, JBC, Chemistry,Chem. Biol. Drug Des.等杂志上发表多篇研究论文。【Abstract】Astrocyte dysfunction and inflammation are associated with the pathogenesis of major depressive disorder (MDD). However, the mechanisms underlying these effects remain largely unknown. Here, we found that multiple endocrine neoplasia type 1 (Men1; protein: menin) expression is attenuated in the brain of mice exposed to CUMS (chronic unpredictable mild stress) or lipopolysaccharide. Astrocyte-specific reduction of Men1 (GcKO) led to depressive-like behaviors in mice. We observed enhanced NF-κB activation and IL-1β production with menin deficiency in astrocytes, where depressive-like behaviors in GcKO mice were restored by NF-κB inhibitor or IL-1β receptor antagonist. Importantly, we identified a SNP, rs375804228, in human MEN1, where G503D substitution is associated with a higher risk of MDD onset. G503D substitution abolished menin-p65 interactions, thereby enhancing NF-κB activation and IL-1β production. Our results reveal a distinct astroglial role for menin in regulating neuroinflammation in depression, indicating that menin may be an attractive therapeutic target in MDD.We thank Prof. Guanghui Jin (Xiamen University) and Prof. Xianxin Hua (University of Pennsylvania) for providing the Men1-floxp mice. This work was supported by the National Natural Science Foundation of China (grants 81522016, 81271421, and 31571055 to J.Z.; 81625008 and 31430048 to Q.X.; 81630026 to Z.Y.; 81771163 and U1405222 to H.X.; U1505227 to G.B.; 81472725 to W.M.), the Natural Science Foundation of Fujian Province of China (grant 2013J01147 and 2014J06019 to J.Z.), the Fundamental Research Funds for the Central Universities (grants 20720150062 and 20720180049 to J.Z.), the National Key Research and Development Program of China (2016YFC1305903), and CAMS Innovation Fund for Medical Sciences (grant 2016I2M1004 to Q.X.).研究工作得到国家自然科学基金项目(81522016、81271421、31571055)以及厦门大学校长基金等资助
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