7,838 research outputs found

    Clinical outcome and prognostic factors in renal medullary carcinoma: a pooled analysis from 18 years of medical literature

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    INTRODUCTION: We describe clinical features and prognostic factors of renal medullary carcinoma (RMC) by performing a pooled analysis of all reported cases since 1995. METHODS: A systematic search was performed to identify all articles describing patients with medullary renal cancer until February 2013. Survivals were estimated using Kaplan-Meier method with 95% confidence intervals and compared across the groups using the log-rank test. The following factors were evaluated using the Cox proportional hazards model: association of extension of disease at diagnosis, response to therapy, and surgical treatment of primary tumour with overall. RESULTS: A total 47 articles were selected; these described 165 patients with RMC plus 1 from our centre. The median age was 21 years and 98% of cases had the sickle cell trait. The mean size of the primary tumours was 6.0 cm, with an involvement of loco-regional lymph nodes in 71% of cases. The overall survival at diagnosis was 4.0 months in metastatic patients and 17.0 months in non-metastatic patients. Patients who received platinum-paclitaxel-gemcitabine had longer control of the disease when compared to topoisomerase inhibitors or targeted therapies. The multivariate analysis confirmed that the advanced stage at diagnosis increased the risk of death of about threefold. CONCLUSION: RMC is a tumour with poorer prognosis; based on these results, platinum-based chemotherapy is the preferred systemic treatment. Even if radical nephrectomy as an up-front strategy did not report a survival benefit, it may be considered to palliate local symptoms and to perform a correct diagnosis

    In systemic sclerosis skin perfusion of hands is reduced and may predict the occurrence of new digital ulcers

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    Systemic sclerosis (SSc) patients are at high risk for the development of ischemic digital ulcers (DUs). The aim of this study was to assess in SSc patients a correlation between skin perfusion evaluated by LDPI and DUs and to evaluate the prognostic value of skin perfusion to predict the new DUs occurrence. Fifty eight (47 female, 11 male) SSc patients were enrolled. Skin perfusion of hands and region of interest (ROIs) was measured by Laser Doppler perfusion Imager (LDPI). The proximal-distal gradient (PDG) was present when the perfusion mean difference between ROI1 and ROI2 was > 30 pU. The skin perfusion of hands is lower in SSc patients than in healthy controls. The skin perfusion decreased with severity of capillaroscopic damage. Both mean perfusion of hand and PDG are significantly (p < 0.01 and p < 0.0001, respectively) lower in SSc patients with new DUs than in SSc patients without DUs. Only 2 of 11 SSc patients (18.2%) with PDG developed new digital ulcers, conversely 36 of 47 (76.6%) SSc patients without PDG developed new digital ulcers (p < 0.001). The ROC curves demonstrated a good accuracy of new DUs prediction for PDG (0.78, p < 0.0001). Using this cut-off value of 30 pU, RR for new DUs development in SSc patients without PDG is 4,2 (p < 0.001). LDPI indices could be used in association to the capillaroscopic and clinical findings or serological tests in the identification of patients at high risk of developing DU

    Topoisomerase II inhibitors induce DNA damage-dependent interferon responses circumventing Ebola virus immune evasion

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    Ebola virus (EBOV) protein VP35 inhibits production of interferon alpha/beta (IFN) by blocking RIG-I-like receptor signaling pathways, thereby promoting virus replication and pathogenesis. A high-throughput screening assay, developed to identify compounds that either inhibit or bypass VP35 IFN-antagonist function, identified five DNA intercalators as reproducible hits from a library of bioactive compounds. Four, including doxorubicin and daunorubicin, are anthracycline antibiotics that inhibit topoisomerase II and are used clinically as chemotherapeutic drugs. These compounds were demonstrated to induce IFN responses in an ATM kinase-dependent manner and to also trigger the DNA-sensing cGAS-STING pathway of IFN induction. These compounds also suppress EBOV replication in vitro and induce IFN in the presence of IFN-antagonist proteins from multiple negative-sense RNA viruses. These findings provide new insights into signaling pathways activated by important chemotherapy drugs and identify a novel therapeutic approach for IFN induction that may be exploited to inhibit RNA virus replication

    Investigating the protective role of the natural hormone Melatonin, in reducing drug-induced cardiotoxicity in the therapy of chronic diseases

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    Heart failure (HF) is a highly complex disorder and a major end-point of cardiovascular diseases (CVD). The pathogenesis of HF is mostly unresolved but involves interplay between cardiac structural and electrical remodelling, metabolic alterations, cell death and altered gene expression. Mitochondrial dysfunction and HF are common complications of chronic treatment from diverse groups of drugs, in particular anticancer drugs such as doxorubicin (DOX). Treatment of animals and cardiomyocytes with cardiotoxic chemicals such as β-adrenergic receptor agonists (such as isoproterenol) induces cardiac dysfunction and HF. Previous work done by the group have identified the pineal hormone melatonin was protective against stress-induced cardiac arrhythmias and simulated heart failure in cardiomyocytes in vitro. Melatonin synthesis is also dramatically decreased with age and in patients with CVD. The aim of the present project was to better understand the pathogenesis of druginduced cardiac dysfunction and delineate the role of melatonin in cardioprotection in H9c2, a model rat cell line in vitro. Using the Seahorse XF analyser method, it was demonstrated that commonly used medication for chronic diseases such as amiodarone, amitriptyline, and statins all caused altered mitochondrial dysfunction. In addition, cardiotoxic chemicals (isoproterenol, hydrogen peroxide, DOX) altered oxidative phosphorylation and glycolysis in living cardiomyocyte-derived H9c2 cells; these deleterious metabolic changes were ameliorated by melatonin. Flowcytometry and Alamar Blue staining methods demonstrated that DOX robustly induced apoptosis in H9c2 cells (~30%) which was reversed by melatonin. Doxorubicin-induced stress in H9c2 cells dramatically altered gene expression in several key signalling pathways integral in cardiac function and disease. These included mitochondrial metabolism (UCP2, PPARɣ, Drp1, Mfn1, Parp 1, Parp2, Sirt3 and Cav3), apoptosis (Bcl2 and Bcl-xL), cardiac electrophysiology and arrhythmia (Scn5a, SERCA2a), calcium handling (SERCA2a) and cardiac remodelling (Myh7, ms1). Melatonin pre-treatment attenuated or completely blocked this DOX-induced alteration in gene expression in cardiomyocytes. In conclusion, the present result demonstrated for the first time that melatonin is cardioprotective against drug-induced cardiotoxicity and apoptosis via modifying diverse heart failure-related signalling pathways. This provides novel insight on the possible use of melatonin as an adjunct intervention in several therapies including anti-cancer

    Transcriptional Down-Regulation and rRNA Cleavage in Dictyostelium discoideum Mitochondria during Legionella pneumophila Infection

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    Bacterial pathogens employ a variety of survival strategies when they invade eukaryotic cells. The amoeba Dictyostelium discoideum is used as a model host to study the pathogenic mechanisms that Legionella pneumophila, the causative agent of Legionnaire's disease, uses to kill eukaryotic cells. Here we show that the infection of D. discoideum by L. pneumophila results in a decrease in mitochondrial messenger RNAs, beginning more than 8 hours prior to detectable host cell death. These changes can be mimicked by hydrogen peroxide treatment, but not by other cytotoxic agents. The mitochondrial large subunit ribosomal RNA (LSU rRNA) is also cleaved at three specific sites during the course of infection. Two LSU rRNA fragments appear first, followed by smaller fragments produced by additional cleavage events. The initial LSU rRNA cleavage site is predicted to be on the surface of the large subunit of the mitochondrial ribosome, while two secondary sites map to the predicted interface with the small subunit. No LSU rRNA cleavage was observed after exposure of D. discoideum to hydrogen peroxide, or other cytotoxic chemicals that kill cells in a variety of ways. Functional L. pneumophila type II and type IV secretion systems are required for the cleavage, establishing a correlation between the pathogenesis of L. pneumophila and D. discoideum LSU rRNA destruction. LSU rRNA cleavage was not observed in L. pneumophila infections of Acanthamoeba castellanii or human U937 cells, suggesting that L. pneumophila uses distinct mechanisms to interrupt metabolism in different hosts. Thus, L. pneumophila infection of D. discoideum results in dramatic decrease of mitochondrial RNAs, and in the specific cleavage of mitochondrial rRNA. The predicted location of the cleavage sites on the mitochondrial ribosome suggests that rRNA destruction is initiated by a specific sequence of events. These findings suggest that L. pneumophila specifically disrupts mitochondrial protein synthesis in D. discoideum during the course of infection

    Systemic sclerosis - Exploring new pathogenic views

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    An in silico analysis identifies drugs potentially modulating the cytokine storm triggered by SARS-CoV-2 infection

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    The ongoing COVID-19 pandemic is one of the biggest health challenges of recent decades. Among the causes of mortality triggered by SARS-CoV-2 infection, the development of an inflammatory “cytokine storm” (CS) plays a determinant role. Here, we used transcriptomic data from the bronchoalveolar lavage fluid (BALF) of COVID-19 patients undergoing a CS to obtain gene-signatures associated to this pathology. Using these signatures, we interrogated the Connectivity Map (CMap) dataset that contains the effects of over 5000 small molecules on the transcriptome of human cell lines, and looked for molecules which effects on transcription mimic or oppose those of the CS. As expected, molecules that potentiate immune responses such as PKC activators are predicted to worsen the CS. In addition, we identified the negative regulation of female hormones among pathways potentially aggravating the CS, which helps to understand the gender-related differences in COVID-19 mortality. Regarding drugs potentially counteracting the CS, we identified glucocorticoids as a top hit, which validates our approach as this is the primary treatment for this pathology. Interestingly, our analysis also reveals a potential effect of MEK inhibitors in reverting the COVID-19 CS, which is supported by in vitro data that confirms the anti-inflammatory properties of these compounds.Open access funding provided by Karolinska Institute.S

    Anti-fibroblast antibodies detected by cell-based ELISA in systemic sclerosis enhance the collagenolytic activity and matrix metalloproteinase-1 production in dermal fibroblasts

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    Objectives. Antibodies binding to the surface of fibroblasts (anti-fibroblast antibodies: AFA) have been described in systemic sclerosis (SSc). We aimed to assess the effect of AFA on extracellular matrix (ECM) turnover and whether AFA were associated with anti-topoisomerase-I antibody. Methods. IgG were purified from AFA-positive and AFA-negative sera selected within 20 SSc and 20 healthy individuals, and tested on normal dermal fibroblasts, at protein and mRNA level, for their capacity to induce collagen deposition or degradation. Results. Fibroblasts stimulated with AFA-positive but not with AFA-negative and control IgG showed an increased capacity to digest collagen matrix and produce metalloproteinase-1 (MMP-1) while their production of total collagen, type I collagen and tissue inhibitor of metalloproteinase-1 (TIMP-1) was unaffected. The steady-state mRNA levels of MMP-1, COL1A1 and TIMP-1 paralleled the protein levels. AFA-positive IgG did not induce Smad 2/3 phosphorylation, indicating that this transforming growth factor-β signalling pathway was not involved. IL-1 and tumour necrosis factor (TNF) neutralization did not reverse the enhanced production of MMP-1, suggesting a direct effect of AFA on fibroblasts. Finally, anti-topoisomerase-I antibodies were present in 11 of 12 AFA-negative IgG, and an anti-topoisomerase-I monoclonal antibody failed to enhance MMP-1 production, thus indicating a lack of correlation between AFA and anti-topoisomerase-I antibody. Conclusions. These results indicate that SSc antibodies binding to fibroblasts enhance matrix degradation and MMP production events that may favour inflammation but do not directly impact on fibrosis developmen

    Antibodies against specific extractable nuclear antigens (ENAs) as diagnostic and prognostic tools and inducers of a profibrotic phenotype in cultured human skin fibroblasts: are they functional?

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    Background: The importance of systemic sclerosis (SSc) autoantibodies for diagnosis has become recognized by their incorporation into the 2013 ACR/EULAR classification criteria. Clear prognostic and phenotypic associations with cutaneous subtype and internal organ involvement have been also described. However, little is known about the potential of autoantibodies to exert a direct pathogenic role in SSc. The aim of the study is to assess the pathogenic capacity of anti-DNA-topoisomerase I (anti-Topo-I) and anti-centromeric protein B (anti-Cenp-B) autoantibodies to induce pro-fibrotic markers in dermal fibroblasts. Methods: Dermal fibroblasts were isolated from unaffected and affected skin samples of (n = 10) limited cutaneous SSc (LcSSc) patients, from affected skin samples of diffuse cutaneous (DcSSc) patients (n = 10) and from healthy subjects (n = 20). Fibroblasts were stimulated with anti-Topo-I, anti-Cenp-B IgGs, and control IgGs in ratios 1:100 and 1:200 for 24 h. Cells were also incubated with 10% SSc anti-Topo-I+ and anti-Cenp-B+ whole serum and with 10% control serum for 24 h. Viability was assessed by MTT test, while apoptosis was assessed by flow cytometry. Activation of pro-fibrotic genes ACTA2, COL1A1, and TAGLN was evaluated by quantitative real-time PCR (qPCR), while the respective protein levels alpha-smooth-muscle actin (\u3b1-SMA), type-I-collagen (Col-I), and transgelin (SM22) were assessed by immunocytochemistry (ICC). Results: MTT showed that anti-Cenp-B/anti-Topo-I IgGs and anti-Cenp-B+/anti-Topo-I+ sera reduced viability (in a dilution-dependent manner for IgGs) for all the fibroblast populations. Apoptosis is induced in unaffected LcSSc and control fibroblasts, while affected LcSSc/DcSSc fibroblasts showed apoptosis resistance. Basal mRNA (ACTA2, COL1A1, and TAGLN) and protein (\u3b1-SMA, Col-1, and SM22) levels were higher in affected LcSSc/DcSSc fibroblasts compared to LcSSc unaffected and to control ones. Stimulation with anti-Cenp-B/anti-Topo-I IgGs and with anti-Cenp-B+/anti-Topo-I+ sera showed a better induction in unaffected LcSSc and control fibroblasts. However, a statistically significant increase of all pro-fibrotic markers is reported also in affected LcSSc/DcSSc fibroblasts upon stimulation with both IgGs and sera. Conclusions: This study suggests a pathogenic role of SSc-specific autoantibodies to directly induce pro-fibrotic activation in human dermal fibroblasts. Therefore, besides the diagnostic and prognostic use of those autoantibodies, these data might further justify the importance of immunosuppressive drugs in the early stages of the autoimmune disease, including SSc
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