438 resultados para ANCA associated vasculites
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The epidermal growth factor receptor (EGFR) is commonly expressed in non-small-cell lung cancer (NSCLC) and promotes a host of mechanisms involved in tumorigenesis. However, EGFR expression does not reliably predict prognosis or response to EGFR-targeted therapies. The data from two previous studies of a series of 181 consecutive surgically resected stage I-IIIA NSCLC patients who had survived in excess of 60 days were explored. Of these patients, tissue was available for evaluation of EGFR in 179 patients, carbonic anhydrase (CA) IX in 177 patients and matrix metalloproteinase-9 (MMP-9) in 169 patients. We have previously reported an association between EGFR expression and MMP-9 expression. We have also reported that MMP-9 (P=0.001) and perinuclear (p)CA IX (P=0.03) but not EGFR expression were associated with a poor prognosis. Perinuclear CA IX expression was also associated with EGFR expression (P<0.001). Multivariate analysis demonstrated that coexpression of MMP-9 with EGFR conferred a worse prognosis than the expression of MMP-9 alone (P<0.001) and coexpression of EGFR and pCA IX conferred a worse prognosis than pCA IX alone (P=0.05). A model was then developed where the study population was divided into three groups: group 1 had expression of EGFR without coexpression of MMP-9 or pCA IX (number=21); group 2 had no expression of EGFR (number=75); and group 3 had coexpression of EGFR with pCA IX or MMP-9 or both (number=70). Group 3 had a worse prognosis than either groups 1 or 2 (P=0.0003 and 0.027, respectively) and group 1 had a better prognosis than group 2 (P=0.036). These data identify two cohorts of EGFR-positive patients with diametrically opposite prognoses. The group expressing either EGFR and or both MMP-9 and pCA IX may identify a group of patients with activated EGFR, which is of clinical relevance with the advent of EGFR-targeted therapies. © 2004 Cancer Research UK.
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Purpose To evaluate carbonic anhydrase (CA) IX as a surrogate marker of hypoxia and investigate the prognostic significance of different patterns of expression in non-small-cell lung cancer (NSCLC). Methods Standard immunohistochemical techniques were used to study CA IX expression in 175 resected NSCLC tumors. CA IX expression was determined by Western blotting in A549 cell lines grown under normoxic and hypoxic conditions. Measurements from microvessels to CA IX positivity were obtained. Results CA IX immunostaining was detected in 81.8% of patients. Membranous (m) (P = .005), cytoplasmic (c) (P = .018), and stromal (P < .001) CA IX expression correlated with the extent of tumor necrosis (TN). The mean distance from vascular endothelium to the start of tumor cell positivity was 90 μm, which equates to an oxygen pressure of 5.77 mmHg. The distance to blood vessels from individual tumor cells or tumor cell clusters was greater if they expressed mCA IX than if they did not (P < .001). Hypoxic exposure of A549 cells for 16 hours enhanced CAIX expression in the nuclear and cytosolic extracts. Perinuclear (p) CA IX (P = .035) was associated with a poor prognosis. In multivariate analysis, pCA IX (P = .004), stage (P = .001), platelet count (P = .011), sex (P = .027), and TN (P = .035) were independent poor prognostic factors. Conclusion These results add weight to the contention that mCA IX is a marker of tumor cell hypoxia. The absence of CA IX staining close to microvessels suggests that these vessels are functionally active. pCA IX expression is representative of an aggressive phenotype. © 2003 by American Society of Clinical Oncology.
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The aim of this phase I/II dose escalating study was to establish the maximum tolerated dose (MTD) of gemcitabine and paclitaxel given in combination in non-small cell lung cancer (NSCLC). 12 patients with stage IIIB and IV NSCLC received paclitaxel administered intravenously over 1 h followed by gemcitabine given over 30 min on days 1, 8 and 15 every 28 days. Pneumonitis was the principal side-effect observed with 4 patients affected. Of these, 1 experienced grade 3 toxicity after one cycle of treatment and the others had grade 2 toxicity. All 4 cases responded to prednisolone. No other significant toxicities were observed. Of the 8 evaluable patients, 3 had a partial response and 2 had minor responses. The study was discontinued due to this dose-limiting toxicity. The combination of paclitaxel and gemcitabine shows promising antitumour activity in NSCLC, however, this treatment schedule may predispose to pneumonitis. (C) 2000 Elsevier Science Ltd.
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Purpose Cancer cells have been shown to be more susceptible to Ran knockdown than normal cells. We now investigate whether Ran is a potential therapeutic target of cancers with frequently found mutations that lead to higher Ras/MEK/ERK [mitogen-activated protein/extracellular signal-regulated kinase (ERK; MEK)] and phosphoinositide 3-kinase (PI3K)/Akt/mTORC1 activities. Experimental Design Apoptosis was measured by flow cytometry [propidium iodide (PI) and Annexin V staining] and MTT assay in cancer cells grown under different conditions after knockdown of Ran. The correlations between Ran expression and patient survival were examined in breast and lung cancers. Results Cancer cells with their PI3K/Akt/mTORC1 and Ras/MEK/ERK pathways inhibited are less susceptible to Ran silencing-induced apoptosis. K-Ras-mutated, c-Met-amplified, and Pten-deleted cancer cells are also more susceptible to Ran silencing-induced apoptosis than their wild-type counterparts and this effect is reduced by inhibitors of the PI3K/Akt/mTORC1 and MEK/ERK pathways. Overexpression of Ran in clinical specimens is significantly associated with poor patient outcome in both breast and lung cancers. This association is dramatically enhanced in cancers with increased c-Met or osteopontin expression, or with oncogenic mutations of K-Ras or PIK3CA, all of which are mutations that potentially correlate with activation of the PI3K/Akt/mTORC1 and/or Ras/MEK/ERK pathways. Silencing Ran also results in dysregulation of nucleocytoplasmic transport of transcription factors and downregulation of Mcl-1 expression, at the transcriptional level, which are reversed by inhibitors of the PI3K/Akt/mTORC1 and MEK/ERK pathways. Conclusion Ran is a potential therapeutic target for treatment of cancers with mutations/changes of expression in protooncogenes that lead to activation of the PI3K/Akt/mTORC1 and Ras/MEK/ERK pathways. ©2011 AACR.
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tRNA-derived RNA fragments (tRFs) are 19mer small RNAs that associate with Argonaute (AGO) proteins in humans. However, in plants, it is unknown if tRFs bind with AGO proteins. Here, using public deep sequencing libraries of immunoprecipitated Argonaute proteins (AGO-IP) and bioinformatics approaches, we identified the Arabidopsis thaliana AGO-IP tRFs. Moreover, using three degradome deep sequencing libraries, we identified four putative tRF targets. The expression pattern of tRFs, based on deep sequencing data, was also analyzed under abiotic and biotic stresses. The results obtained here represent a useful starting point for future studies on tRFs in plants. © 2013 Loss-Morais et al.; licensee BioMed Central Ltd.
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Carrot mottle umbravirus (CMoV) has always been found co-infecting plants with carrot red leaf luteovirus (CRLV) and in carrot (Daucus carota) these co-infections are associated with carrot motley dwarf disease (CMD). CMD occurs wherever carrots are grown. Hence, CMoV was believed to have a corresponding global distribution. However, little or no hybridisation was detected between cDNA generated from the sequenced Australian isolate of CMoV (CMoV-A) and RNA from the much studied Scottish isolate of CMoV (CMoV-S). A weak hybridisation signal was obtained using cDNA to a conserved part of the RNA-dependent RNA polymerase gene of CMoV-A, but when cDNAs to other parts of the CMoV-A genome were used as probes there was no detectable hybridisation with CMoV-S RNA. This lack of hybridisation suggests that the two virus isolates have relatively divergent genomes and that they should be regarded as distinct virus species. Both viruses are transmitted by Cavariella aegopodii, but only with the help of CRLV, and they yield almost identical double-stranded RNA profiles. For these reasons, we propose that the CMoV isolate from Australia be renamed carrot mottle mimic umbravirus (CMoMV). cDNA to CMoMV RNA hybridised with RNA from an isolate from New Zealand, whereas cDNA to CMoV-S RNA hybridised with RNA from isolates from England and Morocco but not to RNA from the isolate from New Zealand. Although preliminary, these data suggest that CMoV and CMoMV may have different global distributions.
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Background. To establish whether sensorimotor function and balance are associated with on-road driving performance in older adults. Methods. The performance of 270 community-living adults aged 70–88 years recruited via the electoral roll was measured on a battery of peripheral sensation, strength, flexibility, reaction time, and balance tests and on a standardized measure of on-road driving performance. Results. Forty-seven participants (17.4%) were classified as unsafe based on their driving assessment. Unsafe driving was associated with reduced peripheral sensation, lower limb weakness, reduced neck range of motion, slow reaction time, and poor balance in univariate analyses. Multivariate logistic regression analysis identified poor vibration sensitivity, reduced quadriceps strength, and increased sway on a foam surface with eyes closed as significant and independent risk factors for unsafe driving. These variables classified participants into safe and unsafe drivers with a sensitivity of 74% and specificity of 70%. Conclusions. A number of sensorimotor and balance measures were associated with driver safety and the multivariate model comprising measures of sensation, strength, and balance was highly predictive of unsafe driving in this sample. These findings highlight important determinants of driver safety and may assist in developing efficacious driver safety strategies for older drivers.
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Introduction The clinically known importance of patient sex as a major risk factor for compromised bone healing is poorly reflected in animal models. Consequently, the underlying cellular mechanisms remain elusive. Because mesenchymal stem cells (MSCs) are postulated to regulate tissue regeneration and give rise to essential differentiated cell types, they may contribute to sex-specific differences in bone healing outcomes. Methods We investigated sex-specific variations in bone healing and associated differences in MSC populations. A 1.5 mm osteotomy gap in the femora of 8 male and 8 female 12-month-old Sprague-Dawley rats was stabilized by an external fixator. Healing was analyzed in terms of biomechanical testing, bridging and callus size over time (radiography at 2, 4, and 6 weeks after surgery), and callus volume and geometry by μCT at final follow-up. MSCs were obtained from bone marrow samples of an age-matched group of 12 animals (6 per gender) and analyzed for numbers of colony-forming units (CFUs) and their capacity to differentiate and proliferate. The proportion of senescent cells was determined by β-galactosidase staining. Results Sex-specific differences were indicated by a compromised mechanical competence of the callus in females compared with males (maximum torque at failure, p = 0.028). Throughout the follow-up, the cross-sectional area of callus relative to bone was reduced in females (p ≤ 0.01), and the bridging of callus was delayed (p 2weeks = 0.041). μCT revealed a reduced callus size (p = 0.003), mineralization (p = 0.003) and polar moment of inertia (p = 0.003) in female animals. The female bone marrow contained significantly fewer MSCs, represented by low CFU numbers in both femora and tibiae (p femur = 0.017, p tibia = 0.010). Functional characteristics of male and female MSCs were similar. Conclusion Biomechanically compromised and radiographically delayed bone formation were distinctive in female rats. These differences were concomitant with a reduced number of MSCs, which may be causative for the suboptimal bone healing.
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The future on-road safety of drivers affected by Whiplash Associated Disorder (WAD), the most common soft-tissue injury suffered in a traffic crash, has not been extensively explored. We obtained an anonymised file of 4280 insurance claimants with WAD and, as controls, 1116 claimants with comparably severe soft-tissue injuries who are considered to be at no increased risk than the general population. Their demographic information, road user type and traffic crash records both prior and subsequent to the traffic incident in which the injury occurred, the index crash, were obtained. Rates of subsequent crash involvement in these two groups were then compared, adjusting for age, sex, road user type and prior crash experience. The risk of a subsequent crash in the WAD group relative to controls was 1.14 (95% confidence interval, 0.87–1.48). To allow for differentially altered driving exposure after index crash we distributed a brief survey asking about changes in driving habits after a traffic crash involving injury via physiotherapy clinics and online through the electronic newsletter of a local motoring organisation. The survey yielded responses from 113 drivers who had experienced WAD in a traffic crash and 53 with other soft tissue injuries. There were no differences on average between the groups in their prior driving levels or their percentage change therein at one, three or six months after injury. There was thus no evidence that drivers with WAD are at any higher safety risk than drivers with other types of relatively minor post-crash soft tissue injury.
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This exploratory enquiry employs qualitative methods to advance knowledge and understanding of physical environmental attributes related to active living among residents of Australian retirement villages. Six focus groups (n = 51 residents) were held and participants described how their current, and subsequently ideal, retirement village and neighborhood supported active lifestyles. Thematic analysis revealed three key environmental factors associated with active living: a positive social environment within the village; services and facilities provided in the village and wider neighborhood; and the presence of suitable pedestrian infrastructure. The unique discovery that environmental factors of both the retirement village and the surrounding neighborhood were associated with residents’ active living raises many questions for study. Findings informed the development of a survey instrument, and further understanding in this area has the potential to contribute to the design and siting practices of senior housing complexes within neighborhoods.
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Bcl-x(l) and Bax play important roles in the regulation of apoptosis. This study investigated the involvement of the mitochondrial death pathway and the role of Bcl-x(l) and Bax in the escape from apoptosis after prolonged serum deprivation in Madin-Darby canine kidney (MDCK) cells. Low level apoptosis and basal activity of the mitochondrial death pathway were detectable in normal cell growth. In serum deprivation, mitosis was partially suppressed, and the mitochondrial activity was stimulated. The level of apoptosis continuously rose over 48 h. This rise was concomitant with the increasing presence of cytochrome c in cytosol. However, both apoptosis and cytosolic cytochrome c fell dramatically at 72 h. Elevation of whole cell Bcl-x(l) and redistribution of Bcl-x(l) protein from cytosol to the membrane at 48 h and 72 h was observed. Redistribution of Bax protein from the membrane to cytosol occurred at 24 h, and remained steady to 72 h. Bax/Bcl-x(l) coimmunoprecipitation by anti-Bax antibody showed reduced Bax/Bcl-x(l) interaction at the membrane at 72 h, but not at 24 or 48 h. These results suggest that apoptosis upon serum withdrawal results from the leakage of cytochrome c to cytosol. Amelioration of the leakage of cytochrome c and apoptosis requires not only the increase of Bcl-x(l)/Bax ratio, but also the release of Bcl-x(l) from Bax at the membrane.
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Background Nontuberculous mycobacteria (NTM) are normal inhabitants of a variety of environmental reservoirs including natural and municipal water. The aim of this study was to document the variety of species of NTM in potable water in Brisbane, QLD, with a specific interest in the main pathogens responsible for disease in this region and to explore factors associated with the isolation of NTM. One-litre water samples were collected from 189 routine collection sites in summer and 195 sites in winter. Samples were split, with half decontaminated with CPC 0.005%, then concentrated by filtration and cultured on 7H11 plates in MGIT tubes (winter only). Results Mycobacteria were grown from 40.21% sites in Summer (76/189) and 82.05% sites in winter (160/195). The winter samples yielded the greatest number and variety of mycobacteria as there was a high degree of subculture overgrowth and contamination in summer. Of those samples that did yield mycobacteria in summer, the variety of species differed from those isolated in winter. The inclusion of liquid media increased the yield for some species of NTM. Species that have been documented to cause disease in humans residing in Brisbane that were also found in water include M. gordonae, M. kansasii, M. abscessus, M. chelonae, M. fortuitum complex, M. intracellulare, M. avium complex, M. flavescens, M. interjectum, M. lentiflavum, M. mucogenicum, M. simiae, M. szulgai, M. terrae. M. kansasii was frequently isolated, but M. avium and M. intracellulare (the main pathogens responsible for disease is QLD) were isolated infrequently. Distance of sampling site from treatment plant in summer was associated with isolation of NTM. Pathogenic NTM (defined as those known to cause disease in QLD) were more likely to be identified from sites with narrower diameter pipes, predominantly distribution sample points, and from sites with asbestos cement or modified PVC pipes. Conclusions NTM responsible for human disease can be found in large urban water distribution systems in Australia. Based on our findings, additional point chlorination, maintenance of more constant pressure gradients in the system, and the utilisation of particular pipe materials should be considered.
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Objective To describe the changing prevalence of healthcare- and community-associated MRSA. Methods Susceptibility phenotypes of MRSA were observed from 2000 to 2012 using routine susceptibility data. Phenotypic definitions of major clones were validated by genotyping isolates from a nested period prevalence survey in 2011. Results The predominant healthcare-associated (AUS-2/3 like) MRSA phenotype decreased from 42 to 14 isolates per million occasions of service in outpatients (P < 0.0001) and from 650 to 75 isolates per million accrued patient days in inpatients (P 0.0005), while the respective rates of the healthcare-related EMRSA-15 like phenotype increased from 1 to 19 in outpatients (P < 0.0001) and from 11 to 83 in inpatients (P < 0.0001) and those of the community-associated MRSA phenotype increased from 17 to 296 in outpatients (P < 0.0001) and from 71 to 486 in inpatients (P < 0.0001). When compared with single nucleotide polymorphism genotyping the AUS-2/3 like phenotype had a sensitivity and positive predictive value (PPV) for CC239 of 1 and 0.791 respectively, while the EMRSA-15 like phenotype had a sensitivity and PPV for CC22 of 0.903 and 0.774. PVL-positive CA-MRSA, predominantly ST93 and CC30, accounted for 60.8% of MRSA, while PVL-negative CA-MRSA, mainly CC5 and CC1, accounted for 21.4%. Conclusions The initially dominant healthcare-associated MRSA clone has been progressively replaced, mainly by four community-associated lineages.
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AIMS: To investigate the evolutionary origins of Australian healthcare-associated (HCA) methicillin-resistant Staphylococcus aureus (MRSA) strains from a panel of historical isolates typed using current genotyping techniques. METHODS: Nineteen MRSA isolates from 1965 to 1981 were examined and antibiotic susceptibility profiles determined. Genetic characterisation included real-time (RT) polymerase chain reaction (PCR) assays to identify single nucleotide polymorhpism (SNP) clonal complexes (SNP CC) and sequence type (SNP ST), multi locus sequence typing (MLST) and staphylococcal chromosomal cassette mec typing. RESULTS: All SNP CC30 isolates belonged to a novel sequence type, ST2249. All SNP CC239 isolates were confirmed as ST239-MRSA-III, except for a new single locus variant of ST239, ST2275. A further new type, ST2276, was identified. CONCLUSIONS: The earliest MRSA examined from 1965 was confirmed as ST250-MRSA-I, consistent with archaic European types. Identification of ST1-MRSA-IV in 1981 is the earliest appearance of this clinically important lineage which manifested in Australia and the United States in the 1990s. A previously unknown multi-resistant clone, ST2249-MRSA-III, was identified from 1973. Gentamicin resistance first appeared in this novel strain from 1976 and not ST239 as previously suspected. Thus, ST2249 was present in the earliest phase of the HCA MRSA epidemic in eastern Australia and was perhaps related to the emergence of the globally epidemic strain ST239.