331 research outputs found

    ZD6474 – a novel inhibitor of VEGFR and EGFR tyrosine kinase activity

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    Angiogenesis is crucial for maintaining the supply of oxygen and nutrients required to support solid tumour growth. Inhibitors of tumour blood vessel formation are therefore being sought, in particular, inhibitors of vascular endothelial growth factor-A (VEGF)-signalling, which has a pivotal role in stimulating neovascular growth and survival. ZD6474 is an orally bioavailable inhibitor of VEGF receptor-2 tyrosine kinase activity that in preclinical studies has been shown to inhibit both VEGF-induced signalling in endothelial cells and tumour-induced angiogenesis. Consistent with inhibition of angiogenesis, once-daily oral dosing of ZD6474 produced significant broad-spectrum antitumour activity in a panel of histologically diverse human tumour xenografts. In addition to its antiangiogenic properties, ZD6474 also has activity against the epidermal growth factor receptor (EGFR) tyrosine kinase, which could impart a direct inhibitory effect on tumour cell growth and survival. This may be particularly relevant in tumours with a dependency upon EGFR signalling, for example in certain tumours harbouring activating mutations in EGFR. RET kinase has also been identified as a third target for ZD6474. This review summarises preclinical studies with this unique agent and considers its future direction in cancer treatment

    Comparing COI and ITS as DNA Barcode Markers for Mushrooms and Allies (Agaricomycotina)

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    DNA barcoding is an approach to rapidly identify species using short, standard genetic markers. The mitochondrial cytochrome oxidase I gene (COI) has been proposed as the universal barcode locus, but its utility for barcoding in mushrooms (ca. 20,000 species) has not been established. We succeeded in generating 167 partial COI sequences (∼450 bp) representing ∼100 morphospecies from ∼650 collections of Agaricomycotina using several sets of new primers. Large introns (∼1500 bp) at variable locations were detected in ∼5% of the sequences we obtained. We suspect that widespread presence of large introns is responsible for our low PCR success (∼30%) with this locus. We also sequenced the nuclear internal transcribed spacer rDNA regions (ITS) to compare with COI. Among the small proportion of taxa for which COI could be sequenced, COI and ITS perform similarly as a barcode. However, in a densely sampled set of closely related taxa, COI was less divergent than ITS and failed to distinguish all terminal clades. Given our results and the wealth of ITS data already available in public databases, we recommend that COI be abandoned in favor of ITS as the primary DNA barcode locus in mushrooms

    Selenium and Lung Cancer: A Systematic Review and Meta Analysis

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    Selenium is a natural health product widely used in the treatment and prevention of lung cancers, but large chemoprevention trials have yielded conflicting results. We conducted a systematic review of selenium for lung cancers, and assessed potential interactions with conventional therapies.Two independent reviewers searched six databases from inception to March 2009 for evidence pertaining to the safety and efficacy of selenium for lung cancers. Pubmed and EMBASE were searched to October 2009 for evidence on interactions with chemo- or radiation-therapy. In the efficacy analysis there were nine reports of five RCTs and two biomarker-based studies, 29 reports of 26 observational studies, and 41 preclinical studies. Fifteen human studies, one case report, and 36 preclinical studies were included in the interactions analysis. Based on available evidence, there appears to be a different chemopreventive effect dependent on baseline selenium status, such that selenium supplementation may reduce risk of lung cancers in populations with lower baseline selenium status (serum<106 ng/mL), but increase risk of lung cancers in those with higher selenium (≥ 121.6 ng/mL). Pooling data from two trials yielded no impact to odds of lung cancer, OR 0.93 (95% confidence interval 0.61-1.43); other cancers that were the primary endpoints of these trials, OR 1.51 (95%CI 0.70-3.24); and all-cause-death, OR 0.93 (95%CI 0.79-1.10). In the treatment of lung cancers, selenium may reduce cisplatin-induced nephrotoxicity and side effects associated with radiation therapy.Selenium may be effective for lung cancer prevention among individuals with lower selenium status, but at present should not be used as a general strategy for lung cancer prevention. Although promising, more evidence on the ability of selenium to reduce cisplatin and radiation therapy toxicity is required to ensure that therapeutic efficacy is maintained before any broad clinical recommendations can be made in this context

    Repercussion of megakaryocyte-specific Gata1 Loss on megakaryopoiesis and the hematopoietic precursor compartment

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    During hematopoiesis, transcriptional programs are essential for the commitment and differentiation of progenitors into the different blood lineages. GATA1 is a transcription factor expressed in several hematopoietic lineages and essential for proper erythropoiesis and megakaryopoiesis. Megakaryocyte-specific genes, such as GP1BA, are known to be directly regulated by GATA1. Mutations in GATA1 can lead to dyserythropoietic anemia and pseudo gray-platelet syndrome. Selective loss of Gata1 expression in adult mice results in macrothrombocytopenia with platelet dysfunction, characterized by an excess of immature megakaryocytes. To specifically analyze the impact of Gata1 loss in mature committed megakaryocytes, we generated Gata1-Lox|Pf4-Cre mice (Gata1cKOMK). Consistent with previous findings, Gata1cKOMK mice are macrothrombocytopenic with platelet dysfunction. Supporting this notion we demonstrate that Gata1 regulates directly the transcription of Syk, a tyrosine kinase that functions downstream of Clec2 and GPVI receptors in megakaryocytes and platelets. Furthermore, we show that Gata1cKOMK mice display an additional aberrant megakaryocyte differentiation stage. Interestingly, these mice present a misbalance of the multipotent progenitor compartment and the erythroid lineage, which translates into compensatory stress erythropoiesis and splenomegaly. Despite the severe thrombocytopenia, Gata1cKOMK mice display a mild reduction of TPO plasma levels, and Gata1cK-OMK megakaryocytes show a mild increase in Pf4 mRNA levels; such a misbalance might be behind the general hematopoietic defects observed, affecting locally normal TPO and Pf4 levels at hematopoietic stem cell niches. © 2016 Meinders et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    CD8+ T-Cells Expressing Interferon Gamma or Perforin Play Antagonistic Roles in Heart Injury in Experimental Trypanosoma Cruzi-Elicited Cardiomyopathy

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    In Chagas disease, CD8+ T-cells are critical for the control of Trypanosoma cruzi during acute infection. Conversely, CD8+ T-cell accumulation in the myocardium during chronic infection may cause tissue injury leading to chronic chagasic cardiomyopathy (CCC). Here we explored the role of CD8+ T-cells in T. cruzi-elicited heart injury in C57BL/6 mice infected with the Colombian strain. Cardiomyocyte lesion evaluated by creatine kinase-MB isoenzyme activity levels in the serum and electrical abnormalities revealed by electrocardiogram were not associated with the intensity of heart parasitism and myocarditis in the chronic infection. Further, there was no association between heart injury and systemic anti-T. cruzi CD8+ T-cell capacity to produce interferon-gamma (IFNγ) and to perform specific cytotoxicity. Heart injury, however, paralleled accumulation of anti-T. cruzi cells in the cardiac tissue. In T. cruzi infection, most of the CD8+ T-cells segregated into IFNγ+ perforin (Pfn)neg or IFNγnegPfn+ cell populations. Colonization of the cardiac tissue by anti-T. cruzi CD8+Pfn+ cells paralleled the worsening of CCC. The adoptive cell transfer to T. cruzi-infected cd8−/− recipients showed that the CD8+ cells from infected ifnγ−/−pfn+/+ donors migrate towards the cardiac tissue to a greater extent and caused a more severe cardiomyocyte lesion than CD8+ cells from ifnγ+/+pfn−/− donors. Moreover, the reconstitution of naïve cd8−/− mice with CD8+ cells from naïve ifnγ+/+pfn−/− donors ameliorated T. cruzi-elicited heart injury paralleled IFNγ+ cells accumulation, whereas reconstitution with CD8+ cells from naïve ifnγ−/−pfn+/+ donors led to an aggravation of the cardiomyocyte lesion, which was associated with the accumulation of Pfn+ cells in the cardiac tissue. Our data support a possible antagonist effect of CD8+Pfn+ and CD8+IFNγ+ cells during CCC. CD8+IFNγ+ cells may exert a beneficial role, whereas CD8+Pfn+ may play a detrimental role in T. cruzi-elicited heart injury

    The role of GLI-SOX2 signaling axis for gemcitabine resistance in pancreatic cancer

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    Pancreatic cancer, mostly pancreatic ductal adenocarcinomas (PDAC), is one of the most lethal cancers, with a dismal median survival around 8 months. PDAC is notoriously resistant to chemotherapy. Thus far, numerous attempts using novel targeted therapies and immunotherapies yielded limited clinical benefits for pancreatic cancer patients. It is hoped that delineating the molecular mechanisms underlying drug resistance in pancreatic cancer may provide novel therapeutic options. Using acquired gemcitabine resistant pancreatic cell lines, we revealed an important role of the GLI-SOX2 signaling axis for regulation of gemcitabine sensitivity in vitro and in animal models. Down-regulation of GLI transcriptional factors (GLI1 or GLI2), but not SMO signaling inhibition, reduces tumor sphere formation, a characteristics of tumor initiating cell (TIC). Down-regulation of GLI transcription factors also decreased expression of TIC marker CD24. Similarly, high SOX2 expression is associated with gemcitabine resistance whereas down-regulation of SOX2 sensitizes pancreatic cancer cells to gemcitabine treatment. We further revealed that elevated SOX2 expression is associated with an increase in GLI1 or GLI2 expression. Our ChIP assay revealed that GLI proteins are associated with a putative Gli binding site within the SOX2 promoter, suggesting a more direct regulation of SOX2 by GLI transcription factors. The relevance of our findings to human disease was revealed in human cancer specimens. We found that high SOX2 protein expression is associated with frequent tumor relapse and poor survival in stage II PDAC patients (all of them underwent gemcitabine treatment), indicating that reduced SOX2 expression or down-regulation of GLI transcription factors may be effective in sensitizing pancreatic cancer cells to gemcitabine treatment

    Randomized controlled trial of an internet-based self-guided hand exercise program to improve hand function in people with systemic sclerosis: the Scleroderma Patient-centered Intervention Network Hand Exercise Program (SPIN-HAND) trial

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    BACKGROUND: Systemic sclerosis (scleroderma; SSc) is a rare autoimmune connective tissue disease. Functional impairment of hands is common. The Scleroderma Patient-centered Intervention Network (SPIN)-HAND trial compared effects of offering access to an online self-guided hand exercise program to usual care on hand function (primary) and functional health outcomes (secondary) in people with SSc with at least mild hand function limitations. METHODS: The pragmatic, two-arm, parallel-group cohort multiple randomized controlled trial was embedded in the SPIN Cohort. Cohort participants with Cochin Hand Function Scale (CHFS) scores ≥ 3 and who indicated interest in using the SPIN-HAND Program were randomized (3:2 ratio) to an offer of program access or to usual care (targeted N = 586). The SPIN-HAND program consists of 4 modules that address (1) thumb flexibility and strength; (2) finger bending; (3) finger extension; and (4) wrist flexibility and strength. The primary outcome analysis compared CHFS scores 3 months post-randomization between participants offered versus not offered the program. Secondary outcomes were CHFS scores 6 months post-randomization and functional health outcomes (Patient-Reported Outcomes Measurement Information System profile version 2.0 domain scores) 3 and 6 months post-randomization. RESULTS: In total, 466 participants were randomized to intervention offer (N = 280) or usual care (N = 186). Of 280 participants offered the intervention, 170 (61%) consented to access the program. Of these, 117 (69%) viewed at least one hand exercise instruction video and 77 (45%) logged into the program website at least 3 times. In intent-to-treat analyses, CHFS scores were 1.2 points lower (95% CI − 2.8 to 0.3) for intervention compared to usual care 3 months post-randomization and 0.1 points lower (95% CI − 1.8 to 1.6 points) 6 months post-randomization. There were no statistically significant differences in other outcomes. CONCLUSION: The offer to use the SPIN-HAND Program did not improve hand function. Low offer uptake, program access, and minimal usage among those who accessed the program limited our ability to determine if using the program would improve function. To improve engagement, the program could be tested in a group format or as a resource to support care provided by a physical or occupational therapist. TRIAL REGISTRATION: NCT03419208. Registered on February 1, 2018

    Pain levels and associated factors in the Scleroderma Patient-centered Intervention Network (SPIN) cohort: a multicentre cross-sectional study

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    Background: Pain is an important and detrimental feature of systemic sclerosis but is often overlooked or deprioritised in research and clinical care. Raynaud's phenomenon, arthritis, and cutaneous ulcers are among the commonly reported disease manifestations of systemic sclerosis that could be associated with pain. We aimed to assess levels of pain intensity and interference and to evaluate disease factors associated with pain intensity and interference. Methods: In this multicentre cross-sectional study, participants from the Scleroderma Patient-centered Intervention Network cohort who completed pain intensity and interference measures (Patient Reported Outcomes Information System-29 profile, version 2·0) as part of baseline assessments were included. Patients were recruited from 46 centres in Australia, Canada, France, Mexico, Spain, the UK, and the USA between April 15, 2014, and Jan 7, 2020. Eligible patients included those aged 18 years or older who met the criteria for systemic sclerosis devised by the American College of Rheumatology and the European League Against Rheumatism. Associations of pain intensity and pain interference with systemic sclerosis-related variables and overlap syndromes, controlling for sociodemographic variables, were assessed with multiple linear regression. Continuous independent variables were standardised. Findings: Among 2157 participants with systemic sclerosis (268 [12%] males and 1889 [88%] females), 1870 (87%) reported mild, moderate, or severe pain (defined as ≥1 on a 0 to 10 scale), and 815 (38%) reported moderate or severe pain (defined as ≥5). Moreover, 757 (35%) participants reported moderate or severe pain interference. Greater pain intensity was independently associated with female sex (0·58 points [95% CI 0·26–0·90]), non-White race or ethnicity (0·50 points [0·21–0·79]), fewer years in formal education (0·30 points per SD [0·19–0·41]), country (reference: USA; Canada: 0·29 points [0·01–0·57] and UK: 0·58 points [0·21–0·95]), greater body-mass index (0·35 points per SD [0·24–0·45]); joint contractures (0·67 points [0·39–0·94]), digital ulcers (0·33 points [0·10–0·55]), gastrointestinal involvement (0·66 points [0·33–0·98]), skin involvement (measured using modified Rodnan skin score; 0·22 points per SD [0·10–0·35]), rheumatoid arthritis (0·96 points [0·50–1·43]), and Sjögren's syndrome (0·42 points [0·01–0·83]). Pain interference results were similar. Interpretation: Pain is common among people with systemic sclerosis. Controlling for sociodemographic variables, greater pain was associated with multiple systemic sclerosis-related manifestations, including joint contractures, digital ulcers, gastrointestinal involvement, skin involvement, and the presence of overlap syndromes. Health-care providers should work with patients to address pain, including identifying and addressing systemic sclerosis manifestations associated with their pain, and supporting behavioural approaches to minimise impact on function and quality of life. Funding: Canadian Institutes of Health Research, Arthritis Society, The Lady Davis Institute for Medical Research of the Jewish General Hospital, Jewish General Hospital Foundation, McGill University, Scleroderma Society of Ontario, Scleroderma Canada, Sclérodermie Québec, Scleroderma Manitoba, Scleroderma Atlantic, Scleroderma Association of BC, Scleroderma SASK, Scleroderma Australia, Scleroderma New South Wales, Scleroderma Victoria, and Scleroderma Queensland

    Patterns of patient-reported symptoms and association with sociodemographic and systemic sclerosis disease characteristics: a scleroderma Patient-centered Intervention Network (SPIN) Cohort cross-sectional study

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    Background: Systemic sclerosis is a heterogenous disease in which little is known about patterns of patient-reported symptom clusters. We aimed to identify classes of individuals with similar anxiety, depression, fatigue, sleep disturbance, and pain symptoms and to evaluate associated sociodemographic and disease-related characteristics. Methods: This multi-centre cross-sectional study used baseline data from Scleroderma Patient-centered Intervention Network Cohort participants enrolled from 2014 to 2020. Eligible participants completed the PROMIS-29 v2.0 measure. Latent profile analysis was used to identify homogeneous classes of participants based on patterns of anxiety, depression, fatigue, sleep disturbance, and pain scores. Sociodemographic and disease-related characteristics were compared across classes. Findings: Among 2212 participants, we identified five classes, including four classes with “Low” (565 participants, 26%), “Normal” (651 participants, 29%), “High” (569 participants, 26%), or “Very High” (193 participants, 9%) symptom levels across all symptoms. Participants in a fifth class, “High Fatigue/Sleep/Pain and Low Anxiety/Depression” (234 participants, 11%) had similar levels of fatigue, sleep disturbance, and pain as in the “High” class but low anxiety and depression symptoms. There were significant and substantive trends in sociodemographic characteristics (age, education, race or ethnicity, marital or partner status) and increasing disease severity (diffuse disease, tendon friction rubs, joint contractures, gastrointestinal symptoms) across severity-based classes. Disease severity and sociodemographic characteristics of “High Fatigue/Sleep/Pain and Low Anxiety/Depression” class participants were similar to the “High” severity class. Interpretation: Most people with systemic sclerosis can be classified by levels of patient-reported symptoms, which are consistent across symptoms and highly associated with sociodemographic and disease-related variables, except for one group which reports low mental health symptoms despite high levels of other symptoms and substantial disease burden. Studies are needed to better understand resilience in systemic sclerosis and to identify and facilitate implementation of cognitive and behavioural strategies to improve coping and overall quality of life. Funding: National Institute of Nursing Research (F31NR019007), Canadian Institutes of Health Research, Arthritis Society Canada, the Lady Davis Institute for Medical Research, the Jewish General Hospital Foundation, McGill University, Scleroderma Society of Ontario, Scleroderma Canada, Sclérodermie Québec, Scleroderma Manitoba, Scleroderma Atlantic, Scleroderma Association of BC, Scleroderma SASK, Scleroderma Australia, Scleroderma New South Wales, Scleroderma Victoria, and Scleroderma Queensland

    Evaluation of Measurement Properties and Differential Item Functioning in the English and French Versions of the University of California, Los Angeles, Loneliness Scale-6: A Scleroderma Patient-Centered Intervention Network (SPIN) Study

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    Objective: Loneliness has been associated with poorer health-related quality of life but has not been studied in patients with systemic sclerosis (SSc). The current study was undertaken to examine and compare the psychometric properties of the English and French versions of the University of California, Los Angeles, Loneliness Scale-6 (ULS-6) in patients with SSc during the COVID-19 pandemic. Methods: This study used baseline cross-sectional data from 775 adults enrolled in the Scleroderma Patient-Centered Intervention Network (SPIN) COVID-19 Cohort. Reliability and validity of ULS-6 scores overall and between languages were evaluated using confirmatory factor analysis (CFA), differential item functioning (DIF) through the multiple-indicator multiple-cause (MIMIC) model, omega/alpha calculation, and correlations of hypothesized convergent relationships. Results: CFA for the total sample supported the single-factor structure (comparative fit index [CFI] 0.96, standardized root mean residual [SRMR] 0.03), and all standardized factor loadings for items were large (0.60–0.86). The overall MIMIC model with language as a covariate fit well (CFI 0.94, SRMR 0.04, root mean square error of approximation 0.11). Statistically significant DIF was found for 3 items across language (βitem2 = 0.14, P < 0.001; βitem4 = –0.07, P = 0.01; βitem6 = 0.13, P < 0.001), but these small differences were without practical measurement implications. Analyses demonstrated high internal consistency with no language-based convergent validity differences. Conclusion: Analyses demonstrated evidence of acceptable reliability and validity of ULS-6 scores in English- and French-speaking adults with SSc. DIF analysis supported use of the ULS-6 to examine comparative experiences of loneliness without adjusting for language
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