104 research outputs found
Helicobacter pylori adhesin HopQ engages in a virulence-enhancing interaction with human CEACAMs
Helicobacter pylori adhesin HopQ engages in a virulence-enhancing interaction with human CEACAMs
Helicobacter pylori specifically colonizes the human gastric epithelium and is the major causative agent for ulcer disease and gastric cancer development. Here, we identify members of the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family as receptors of H. pylori and show that HopQ is the surface-exposed adhesin that specifically binds human CEACAM1, CEACAM3, CEACAM5 and CEACAM6. HopQ-CEACAM binding is glycan-independent and targeted to the N-domain. H. pylori binding induces CEACAM1-mediated signalling, and the HopQ-CEACAM1 interaction enables translocation of the virulence factor CagA into host cells and enhances the release of pro-inflammatory mediators such as interleukin-8. Based on the crystal structure of HopQ, we found that a beta-hairpin insertion (HopQ-ID) in HopQ's extracellular 3+4 helix bundle domain is important for CEACAM binding. A peptide derived from this domain competitively inhibits HopQ-mediated activation of the Cag virulence pathway, as genetic or antibody-mediated abrogation of the HopQ function shows. Together, our data suggest the HopQ-CEACAM1 interaction to be a potentially promising novel therapeutic target to combat H. pylori-associated diseases.</p
Supporting survivors of institutional child sexual abuse during the COVID-19 pandemic: A qualitative study of not-for-profit community and legal organisations in Greater Western Sydney
Before, during and since the Australian Royal Commission into Institutional Responses to Child Sexual Abuse (2013–2017), not-for-profit community and legal services have been critical in supporting survivors of institutional child sexual abuse. This qualitative study aimed to explore the perspectives of community and legal service practitioners operating in Greater Western Sydney regarding the ongoing impact of the COVID-19 pandemic on the service system for survivors of institutional child sexual abuse. Semistructured interviews were conducted with 21 practitioners at 15 community and legal services. Through thematic analysis, the study identified five areas of concern regarding service provision and COVID-19, including difficulties in navigating shifts to remote service delivery; changes in service accessibility; complications in accessing the National Redress Scheme; safety challenges for clients; and safety challenges for practitioners. The research identified a need for services to finesse frameworks that ensure remote services can be delivered safely for clients and practitioners alike. Priorities include adequate funding for technology and infrastructure, supporting survivors of abuse perpetrated online and encouraging effective coping strategies for practitioners who undertake trauma support work from home. Future research should consider how shifts to remote service delivery have impacted survivors of different demographic groups and the survivor support workforce
Cellular dissection of psoriasis for transcriptome analyses and the post-GWAS era
Abstract
Background
Genome-scale studies of psoriasis have been used to identify genes of potential relevance to disease mechanisms. For many identified genes, however, the cell type mediating disease activity is uncertain, which has limited our ability to design gene functional studies based on genomic findings.
Methods
We identified differentially expressed genes (DEGs) with altered expression in psoriasis lesions (n = 216 patients), as well as candidate genes near susceptibility loci from psoriasis GWAS studies. These gene sets were characterized based upon their expression across 10 cell types present in psoriasis lesions. Susceptibility-associated variation at intergenic (non-coding) loci was evaluated to identify sites of allele-specific transcription factor binding.
Results
Half of DEGs showed highest expression in skin cells, although the dominant cell type differed between psoriasis-increased DEGs (keratinocytes, 35%) and psoriasis-decreased DEGs (fibroblasts, 33%). In contrast, psoriasis GWAS candidates tended to have highest expression in immune cells (71%), with a significant fraction showing maximal expression in neutrophils (24%, P < 0.001). By identifying candidate cell types for genes near susceptibility loci, we could identify and prioritize SNPs at which susceptibility variants are predicted to influence transcription factor binding. This led to the identification of potentially causal (non-coding) SNPs for which susceptibility variants influence binding of AP-1, NF-κB, IRF1, STAT3 and STAT4.
Conclusions
These findings underscore the role of innate immunity in psoriasis and highlight neutrophils as a cell type linked with pathogenetic mechanisms. Assignment of candidate cell types to genes emerging from GWAS studies provides a first step towards functional analysis, and we have proposed an approach for generating hypotheses to explain GWAS hits at intergenic loci.http://deepblue.lib.umich.edu/bitstream/2027.42/109537/1/12920_2013_Article_485.pd
Reduction in psychotic symptoms as a predictor of patient satisfaction with antipsychotic medication in schizophrenia: Data from a randomized double-blind trial
Poly(I:C) induces intense expression of c-IAP2 and cooperates with an IAP inhibitor in induction of apoptosis in cancer cells
<p>Abstract</p> <p>Background</p> <p>There is increasing evidence that the toll-like receptor 3 (TLR3) is an interesting target for anti-cancer therapy. Unfortunately, most laboratory investigations about the impact of TLR3 stimulation on human malignant cells have been performed with very high concentrations - 5 to 100 μg/ml - of the prototype TLR3 ligand, poly(I:C). In a previous study focused on a specific type of human carcinoma - nasopharyngeal carcinoma - we have shown that concentrations of poly(I:C) as low as 100 ng/ml are sufficient to induce apoptosis of malignant cells when combined to a pharmacological antagonist of the IAP family based on Smac mimicry.</p> <p>Methods</p> <p>This observation prompted us to investigate the contribution of the IAP family in cell response to poly(I:C) in a variety of human malignant cell types.</p> <p>Results</p> <p>We report a rapid, intense and selective increase in c-IAP2 protein expression observed under stimulation by poly(I:C)(500 ng/ml) in all types of human malignant cells. In most cell types, this change in protein expression is underlain by an increase in c-IAP2 transcripts and dependent on the TLR3/TRIF pathway. When poly(I:C) is combined to the IAP inhibitor RMT 5265, a cooperative effect in apoptosis induction and/or inhibition of clonogenic growth is obtained in a large fraction of carcinoma and melanoma cell lines.</p> <p>Conclusions</p> <p>Currently, IAP inhibitors like RMT 5265 and poly(I:C) are the subject of separate therapeutic trials. In light of our observations, combined use of both types of compounds should be considered for treatment of human malignancies including carcinomas and melanomas.</p
Correlation between virulence markers of Helicobacter pylori in the oral cavity and gastric biopsies
Orientational Effects and Random Mixing in 1‑Alkanol + Nitrile Mixtures
1-Alkanol + alkanenitrile or + benzonitrile systems have been investigated by means of the molar excess
functionsenthalpies (Hm E ), isobaric heat capacities (Cp,m
E ), volumes (Vm E ), and entropiesand using the Flory model and the
concentration−concentration structure factor (SCC(0)) formalism. From the analysis of the experimental data available in the
literature, it is concluded that interactions are mainly of dipolar type. In addition, large Hm E values contrast with rather low Vm E
values, indicating the existence of strong structural effects. Hm E measurements have been used to evaluate the enthalpy of the
hydroxyl−nitrile interactions (ΔHOH−CN). They are stronger in methanol systems and become weaker when the alcohol size
increases. In solutions with a given short chain 1-alkanol (up to 1-butanol), the replacement of ethanenitrile by butanenitrile
weakens the mentioned interactions. Application of the Flory model shows that orientational effects exist in methanol or 1-
nonanol, or 1-decanol + ethanenitrile mixtures. In the former solution, this is due to the existence of interactions between unlike
molecules. For mixtures including 1-nonanol or 1-decanol, the systems at 298.15 K are close to their UCST (upper critical
solution temperature), and interactions between like molecules are dominant. Orientational effects also are encountered in
methanol or ethanol + butanenitrile mixtures because self-association of the alcohol plays a more important role. Aromaticity
effect seems to enhance orientational effects. For the remainder of the systems under consideration, the random mixing
hypothesis is attained to a rather large extent. Results from the application of the SCC(0) formalism show that homocoordination
is the dominant trend in the investigated solutions, and are consistent with those obtained from the Flory model
Rethinking place-making: aligning placeness factors with perceived urban design qualities (PUDQs) to improve the built environment in historical district
Understanding the concept of place is critically important for urban design and place-making practice, and this research attempted to investigate the pathways by which perceived urban design qualities (PUDQs) influence placeness factors in the Chinese context. Twelve hypotheses were developed and combined in a structural equation model for validation. The Tanhualin historical district in Wuhan, China was selected for the analysis. As a result, place attachment was verified as a critical bridge factor that mediated the influence of PUDQs on place satisfaction. Among the five selected PUDQs, walkability and space quality were revealed as the most influential factors associated with place attachment and place satisfaction. Accessibility was actually indirectly beneficial to place-making via the mediation of walkability. Corresponding implications and strategies were discussed to maintain the sense of place for historic districts
Cyclic behavior of perforated masonry walls strengthened with glass fiber reinforced polymers
AbstractMany of the existing unreinforced masonry buildings are seismically vulnerable and require retrofitting. In this experimental study, the cyclic behavior of six, one-half scale, perforated unreinforced brick walls, before and after retrofitting, using Glass Fiber Reinforced Polymers (GFRPs), is investigated. The walls were built using one-half scale solid clay bricks and cement mortar to simulate the traditional walls built in Iran during the last 40 years of the 20th century. These walls had a window opening at their center. One brick wall was unreinforced and considered a reference specimen. Three walls were directly upgraded after construction using GFRPs. The fifth wall was first strengthened and tested. Then, the seismically damaged specimen was retrofitted, using GFRPs, and tested again. Each specimen was retrofitted on the surface of two sides. All specimens were tested under constant gravity load and incrementally increasing in-plane loading cycles. During the test, each wall was allowed to displace in its own plane. The key parameter was the strengthening configuration including the cross layout, grid layout, and combined layout. Strengthening by means of GFRPs significantly improved the strength, deformation capacity, and energy absorption of the brick wall. The increase in performance parameters was dependent upon GFRP layout
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