2,293 research outputs found
Desensitization of T lymphocyte function by CXCR3 ligands in human hepatocellular carcinoma
Aim: Despite the presence of lymphocyte infiltration, human hepatocellular carcinoma (HCC) is typically a rapidly progressive disease. The mechanism of regulation of lymphocyte migration is poorly understood. In this study, we investigated various factors regulating T cell migration in HCC patients. We examined serum CXC chemokine levels in HCC patients and demonstrated the production of CXC chemokines by HCC cell lines. We determined the effect of both HCC patient serum and tumor cell conditioned supernatant upon lymphocyte expression of chemokine receptor CXCR3 as well as lymphocyte migration. Lastly, we examined the chemotactic responses of lymphocytes derived from HCC patients. Methods: The serum chemokines IP-10 (CXCL10) and Mig (CXCL9) levels were measured by cytometric bead array (CBA) and the tumor tissue IP-10 concentration was measured by ELISA. The surface expression of CXCR3 on lymphocytes was determined by flow cytometry. The migratory function of lymphocytes to the corresponding chemokines was assessed using an in vitro chemotactic assay. Phosphorylation of extracellular signal-regulated kinase (ERK) was determined by Western blot analysis. Results: Increased levels of IP-10 and Mig were detected in HCC patient serum and culture supernatants of HCC cell lines. The IP-10 concentration in the tumor was significantly higher than that in the non-involved adjacent liver tissues. HCC cell lines secreted functional chemokines that induced a CXCR3-specific chemotactic response of lymphocytes. Furthermore, tumor-cell-derived chemokines induced initial rapid phosphorylation of lymphocyte ERK followed by later inhibition of ERK phosphorylation. The culture of normal lymphocytes with HCC cell line supernatants or medium containing serum from HCC patients resulted in a significant reduction in the proportion of lymphocytes exhibiting surface expression of CXCR3. The reduction in T cell expression of CXCR3 resulted in reduced migration toward the ligand IP-10, and both CD4 + and CD8 + T cells from HCC patients exhibited diminished chemotactic responses to IP-10 in vitro compared to T cells from healthy control subjects. Conclusion: This study demonstrates functional desensitization of the chemokine receptor CXCR3 in lymphocytes from HCC patients by CXCR3 ligands secreted by tumor cells. This may cause lymphocyte dysfunction and subsequently impaired immune defense against the tumor. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio
IndiumâHg vacancy interactions in Hg1â x Cd x Te measured by perturbed angular correlation
A method for accurate detection of genomic microdeletions using real-time quantitative PCR
BACKGROUND: Quantitative Polymerase Chain Reaction (qPCR) is a well-established method for quantifying levels of gene expression, but has not been routinely applied to the detection of constitutional copy number alterations of human genomic DNA. Microdeletions or microduplications of the human genome are associated with a variety of genetic disorders. Although, clinical laboratories routinely use fluorescence in situ hybridization (FISH) to identify such cryptic genomic alterations, there remains a significant number of individuals in which constitutional genomic imbalance is suspected, based on clinical parameters, but cannot be readily detected using current cytogenetic techniques. RESULTS: In this study, a novel application for real-time qPCR is presented that can be used to reproducibly detect chromosomal microdeletions and microduplications. This approach was applied to DNA from a series of patient samples and controls to validate genomic copy number alteration at cytoband 22q11. The study group comprised 12 patients with clinical symptoms of chromosome 22q11 deletion syndrome (22q11DS), 1 patient trisomic for 22q11 and 4 normal controls. 6 of the patients (group 1) had known hemizygous deletions, as detected by standard diagnostic FISH, whilst the remaining 6 patients (group 2) were classified as 22q11DS negative using the clinical FISH assay. Screening of the patients and controls with a set of 10 real time qPCR primers, spanning the 22q11.2-deleted region and flanking sequence, confirmed the FISH assay results for all patients with 100% concordance. Moreover, this qPCR enabled a refinement of the region of deletion at 22q11. Analysis of DNA from chromosome 22 trisomic sample demonstrated genomic duplication within 22q11. CONCLUSION: In this paper we present a qPCR approach for the detection of chromosomal microdeletions and microduplications. The strategic use of in silico modelling for qPCR primer design to avoid regions of repetitive DNA, whilst providing a level of genomic resolution greater than standard cytogenetic assays. The implementation of qPCR detection in clinical laboratories will address the need to replace complex, expensive and time consuming FISH screening to detect genomic microdeletions or duplications of clinical importance
Overexpression of Mcl-1 exacerbates lymphocyte accumulation and autoimmune kidney disease in lpr mice
Cell death by apoptosis has a critical role during embryonic development and in maintaining tissue homeostasis. In mammals,
there are two converging apoptosis pathways: the âextrinsicâ pathway, which is triggered by engagement of cell surface âdeath
receptorsâ such as Fas/APO-1; and the âintrinsicâ pathway, which is triggered by diverse cellular stresses, and is regulated by prosurvival
and pro-apoptotic members of the Bcl-2 family of proteins. Pro-survival Mcl-1, which can block activation of the proapoptotic
proteins, Bax and Bak, appears critical for the survival and maintenance of multiple haemopoietic cell types. To
investigate the impact on haemopoiesis of simultaneously inhibiting both apoptosis pathways, we introduced the vavP-Mcl-1
transgene, which causes overexpression of Mcl-1 protein in all haemopoietic lineages, into Faslpr/lpr mice, which lack functional
Fas and are prone to autoimmunity. The combined mutations had a modest impact on myelopoiesis, primarily an increase in the
macrophage/monocyte population in Mcl-1tg/lpr mice compared with lpr or Mcl-1tg mice. The impact on lymphopoiesis was
striking, with a marked elevation in all major lymphoid subsets, including the non-conventional double-negative (DN) T cells
(TCRÎČ+
CD4â
CD8â
B220+
) characteristic of Faslpr/lpr mice. Of note, the onset of autoimmunity was markedly accelerated in Mcl-1tg/lpr
mice compared with lpr mice, and this was preceded by an increase in immunoglobulin (Ig)-producing cells and circulating
autoantibodies. This degree of impact was surprising, given the relatively mild phenotype conferred by the vavP-Mcl-1 transgene
by itself: a two- to threefold elevation of peripheral B and T cells, no significant increase in the non-conventional DN T-cell
population and no autoimmune disease. Comparison of the phenotype with that of other susceptible mice suggests that the
development of autoimmune disease in Mcl-1tg/lpr mice may be influenced not only by Ig-producing cells but also other
haemopoietic cell types
Emotional Sentence Annotation Helps Predict Fiction Genre
Fiction, a prime form of entertainment, has evolved into multiple genres which one can broadly attribute to different forms of stories. In this paper, we examine the hypothesis that works of fiction can be characterised by the emotions they portray. To investigate this hypothesis, we use the work of fictions in the Project Gutenberg and we attribute basic emotional content to each individual sentence using Ekmanâs model. A time-smoothed version of the emotional content for each basic emotion is used to train extremely randomized trees. We show through 10-fold Cross-Validation that the emotional content of each work of fiction can help identify each genre with significantly higher probability than random. We also show that the most important differentiator between genre novels is fear
âLower than a snakeâs bellyâ : discursive constructions of dignity and heroism in low-status garbage work.
In this paper, we consider how dignity is discursively constructed in the context of work dominated by physicality and dirt. Based on semi-structured interviews with garbage workers, our analysis considers how the deprivations they experience are cast through discourses intended to construct their individual and collective worth. We consider the manner in which dignity maybe denied to such workers through popular repudiations of individuality and status. We demonstrate how this positioning arises from contact with physical dirt, and associations with socially dirty work based on ascriptions of servility, abuse and ambivalence. We go on to consider how garbage workers respond to this positioning through discourses of âeveryday heroismâ. Heroism is evoked through three inter-related narratives that speaks to a particular type of masculinity. The first takes the form of a classic process of reframing and recalibration through which workers not only renegotiate their public position and status, but also point to the inherent value to be had in working with dirt as part of that which we identify as a process of âaffirmationâ. The second narrative arises from the imposition of favourable social and occupational comparisons that effectively elevate garbage collectorsâ social position. The third discourseâand previously unobserved in respect of garbage workâcentres on paternalistic practices of care. Combined, these discourses disrupt the generally held view that dirty work is antithetical to heroism and wounds dignity
âLower than a Snakeâs Bellyâ : Discursive Constructions of Dignity and Heroism in Low-Status Garbage Work
In this paper, we consider how dignity is discursively constructed in the context of work dominated by physicality and dirt. Based on semi-structured interviews with garbage workers, our analysis considers how the deprivations they experience are cast through discourses intended to construct their individual and collective worth. We consider the manner in which dignity maybe denied to such workers through popular repudiations of individuality and status. We demonstrate how this positioning arises from contact with physical dirt, and associations with socially dirty work based on ascriptions of servility, abuse and ambivalence. We go on to consider how garbage workers respond to this positioning through discourses of âeveryday heroismâ. Heroism is evoked through three interrelated narratives that speaks to a particular type of masculinity. The first takes the form of a classic process of reframing and recalibration through which workers not only renegotiate their public position and status, but also point to the inherent value to be had in working with dirt as part of that which we identify as a process of âaffirmationâ. The second narrative arises from the imposition of favourable social and occupational comparisons that effectively elevate garbage collectorsâ social position. The third discourseâand previously unobserved in respect of garbage workâcentres on paternalistic practices of care. Combined, these discourses disrupt the generally held view that dirty work is antithetical to heroism and wounds dignity
Static condensation optimal port/interface reduction and error estimation for structural health monitoring
Having the application in structural health monitoring in mind, we propose
reduced port spaces that exhibit an exponential convergence for static
condensation procedures on structures with changing geometries for instance
induced by newly detected defects. Those reduced port spaces generalize the
port spaces introduced in [K. Smetana and A.T. Patera, SIAM J. Sci. Comput.,
2016] to geometry changes and are optimal in the sense that they minimize the
approximation error among all port spaces of the same dimension. Moreover, we
show numerically that we can reuse port spaces that are constructed on a
certain geometry also for the static condensation approximation on a
significantly different geometry, making the optimal port spaces well suited
for use in structural health monitoring
Melody, an ENU mutation in Caspase 3, alters the catalytic cysteine residue and causes sensorineural hearing loss in mice
Progeny from the Harwell N-ethyl-N-nitrosourea (ENU) recessive mutagenesis screen were assessed for auditory defects. A pedigree was identified with multiple progeny lacking response to a clickbox test. Auditory brainstem response (ABR) analysis showed that homozygous mutant mice were profoundly deaf and the line was named melody. We subsequently mapped this mutation to a 6-Mb region on chromosome 8 and identified a point mutation in melody that results in a C163S substitution in the catalytic site of Caspase 3, a cysteine protease involved in apoptosis. Melody fails to complement a null Caspase-3 mutant. Scanning electron microscopy (SEM) has revealed disorganised sensory hair cells and hair cell loss. Histological analysis of melody has shown degeneration of spiral ganglion cells in homozygote mice, with a gradient of severity from apical to basal turns. Melody heterozygotes also show evidence of loss of spiral ganglion neurons, suggesting that the C163S mutation may show dominant negative effects by binding and sequestering proteins at the active site. The melody line provides a new model for studying the role of Caspase 3 in deafness and a number of other pathways and systems
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