36 research outputs found
Nucleosynthesis of Nickel-56 from Gamma-Ray Burst Accretion Disks
We examine the prospects for producing Nickel-56 from black hole accretion
disks, by examining a range of steady state disk models. We focus on relatively
slowly accreting disks in the range of 0.05 - 1 solar masses per second, as are
thought to be appropriate for the central engines of long-duration gamma-ray
bursts. We find that significant amounts of Nickel-56 are produced over a wide
range of parameter space. We discuss the influence of entropy, outflow
timescale and initial disk position on mass fraction of Nickel-56 which is
produced. We keep careful track of the weak interactions to ensure reliable
calculations of the electron fraction, and discuss the role of the neutrinos.Comment: 10 pages, 9 figure
Ultrasound Effectiveness of Steroid Injection for hand Psoriatic Dactylitis: Results from a Longitudinal Observational Study
Introduction: To assess clinical and ultrasound effectiveness of steroid injection (local treatment, LT) into the digital flexor tendon sheath for the treatment of psoriatic dactylitis compared to systemic treatment (ST) alone. Methods: In this observational, multicentre, prospective study, 88 cases of symptomatic hand dactylitis were evaluated clinically and sonographically by high-frequency ultrasound (US) probe in both greyscale (GS) and power Doppler (PD). The presence of flexor tenosynovitis (FT), soft tissue oedema (STO), peritendon extensor inflammation and synovitis was assessed (including DACtylitis glObal Sonographic—DACTOS—score) before treatment, at 1-month (T1) and 3-months (T3) follow-up. LT was proposed to all patients. Patients refusing LT were treated with oral NSAIDs. Patients continued the same baseline csDMARDs and/or corticosteroid therapy during the whole follow-up period. US response was defined for DACTOS score < 3 and US remission for DACTOS score = 0. Results: At T3 evaluation the ST group showed a significantly higher persistence (grade > 1) of FT and STO (p < 0.001 for all) and MCP synovitis (p = 0.001). US remission was achieved only in the LT group (at T3 31% vs. 0, p < 0.001). The percentage of patients with DACTOS < 3 was significantly greater in the LT group compared with ST group, at both T1 (49% vs. 5%, p < 0.001) and T3 evaluation (76% vs. 7%, p < 0.001). In multiple conditional logistic regression analysis, the only factor associated with US remission was LT (T3 odds ratio = 41.21, p < 0.001). Conclusions: US confirmed the effectiveness of steroid injection for dactylitis by demonstrating that it involves the resolution of extra-articular inflammation, in particular FT and STO
Targeting the hedgehog transcription factors GLI1 and GLI2 restores sensitivity to vemurafenib-resistant human melanoma cells
BRAF inhibitor (BRAFi) therapy for melanoma patients harboring the V600E mutation is initially highly effective, but almost all patients relapse within a few months. Understanding the molecular mechanisms underpinning BRAFi-based therapy is therefore an important issue. Here we identified a previously unsuspected mechanism of BRAFi resistance driven by elevated Hedgehog (Hh) pathway activation that is observed in a cohort of melanoma patients after vemurafenib treatment. Specifically, we demonstrate that melanoma cell lines, with acquired in vitro-induced vemurafenib resistance, show increased levels of glioma-associated oncogene homolog 1 and 2 (GLI1/GLI2) compared with naive cells. We also observed these findings in clinical melanoma specimens. Moreover, the increased expression of the transcription factors GLI1/GLI2 was independent of canonical Hh signaling and was instead correlated with the noncanonical Hh pathway, involving TGF beta/SMAD (transforming growth factor-beta/Sma- and Mad-related family) signaling. Knockdown of GLI1 and GLI2 restored sensitivity to vemurafenib-resistant cells, an effect associated with both growth arrest and senescence. Treatment of vemurafenib-resistant cells with the GLI1/GLI2 inhibitor Gant61 led to decreased invasion of the melanoma cells in a three-dimensional skin reconstruct model and was associated with a decrease in metalloproteinase (MMP2/MMP9) expression and microphthalmia transcription factor upregulation. Gant61 monotherapy did not alter the drug sensitivity of naive cells, but could reverse the resistance of melanoma cells chronically treated with vemurafenib. We further noted that alternating dosing schedules of Gant61 and vemurafenib prevented the onset of BRAFi resistance, suggesting that this could be a potential therapeutic strategy for the prevention of therapeutic escape. Our results suggest that targeting the Hh pathway in BRAFi-resistant melanoma may represent a viable therapeutic strategy to restore vemurafenib sensitivity, reducing or even inhibiting the acquired chemoresistance in melanoma patients.Fapesp-grant number 2012/04194-1, 2013/05172-4, 2014/24400-0 and 2015/10821-7, CNPq-grant number 150447/2013-2 and 471512/2013-3 and PRODOC-grant no 3193-32/2010. Work in the lab of KS Smalley was supported by the National Institutes of Health grants R01 CA161107, R21 CA198550, and Skin SPORE grant P50 CA168536info:eu-repo/semantics/publishedVersio
Future perspectives in melanoma research: meeting report from the "Melanoma Bridge";: Napoli, December 3rd-6th 2014.
The fourth "Melanoma Bridge Meeting" took place in Naples, December 3-6th, 2014. The four topics discussed at this meeting were: Molecular and Immunological Advances, Combination Therapies, News in Immunotherapy, and Tumor Microenvironment and Biomarkers. Until recently systemic therapy for metastatic melanoma patients was ineffective, but recent advances in tumor biology and immunology have led to the development of new targeted and immunotherapeutic agents that prolong progression-free survival (PFS) and overall survival (OS). New therapies, such as mitogen-activated protein kinase (MAPK) pathway inhibitors as well as other signaling pathway inhibitors, are being tested in patients with metastatic melanoma either as monotherapy or in combination, and all have yielded promising results. These include inhibitors of receptor tyrosine kinases (BRAF, MEK, and VEGFR), the phosphatidylinositol 3 kinase (PI3K) pathway [PI3K, AKT, mammalian target of rapamycin (mTOR)], activators of apoptotic pathway, and the cell cycle inhibitors (CDK4/6). Various locoregional interventions including radiotherapy and surgery are still valid approaches in treatment of advanced melanoma that can be integrated with novel therapies. Intrinsic, adaptive and acquired resistance occur with targeted therapy such as BRAF inhibitors, where most responses are short-lived. Given that the reactivation of the MAPK pathway through several distinct mechanisms is responsible for the majority of acquired resistance, it is logical to combine BRAF inhibitors with inhibitors of targets downstream in the MAPK pathway. For example, combination of BRAF/MEK inhibitors (e.g., dabrafenib/trametinib) have been demonstrated to improve survival compared to monotherapy. Application of novel technologies such sequencing have proven useful as a tool for identification of MAPK pathway-alternative resistance mechanism and designing other combinatorial therapies such as those between BRAF and AKT inhibitors. Improved survival rates have also been observed with immune-targeted therapy for patients with metastatic melanoma. Immune-modulating antibodies came to the forefront with anti-CTLA-4, programmed cell death-1 (PD-1) and PD-1 ligand 1 (PD-L1) pathway blocking antibodies that result in durable responses in a subset of melanoma patients. Agents targeting other immune inhibitory (e.g., Tim-3) or immune stimulating (e.g., CD137) receptors and other approaches such as adoptive cell transfer demonstrate clinical benefit in patients with melanoma as well. These agents are being studied in combination with targeted therapies in attempt to produce longer-term responses than those more typically seen with targeted therapy. Other combinations with cytotoxic chemotherapy and inhibitors of angiogenesis are changing the evolving landscape of therapeutic options and are being evaluated to prevent or delay resistance and to further improve survival rates for this patient population. This meeting's specific focus was on advances in combination of targeted therapy and immunotherapy. Both combination targeted therapy approaches and different immunotherapies were discussed. Similarly to the previous meetings, the importance of biomarkers for clinical application as markers for diagnosis, prognosis and prediction of treatment response was an integral part of the meeting. The overall emphasis on biomarkers supports novel concepts toward integrating biomarkers into contemporary clinical management of patients with melanoma across the entire spectrum of disease stage. Translation of the knowledge gained from the biology of tumor microenvironment across different tumors represents a bridge to impact on prognosis and response to therapy in melanoma
Expert consensus document:Cholangiocarcinoma: current knowledge and future perspectives consensus statement from the European Network for the Study of Cholangiocarcinoma (ENS-CCA)
Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. CCA is the second most common primary liver tumour and the incidence is increasing worldwide. CCA has high mortality owing to its aggressiveness, late diagnosis and refractory nature. In May 2015, the "European Network for the Study of Cholangiocarcinoma" (ENS-CCA: www.enscca.org or www.cholangiocarcinoma.eu) was created to promote and boost international research collaboration on the study of CCA at basic, translational and clinical level. In this Consensus Statement, we aim to provide valuable information on classifications, pathological features, risk factors, cells of origin, genetic and epigenetic modifications and current therapies available for this cancer. Moreover, future directions on basic and clinical investigations and plans for the ENS-CCA are highlighted
Future perspectives in melanoma research: meeting report from the “Melanoma Bridge”: Napoli, December 3rd–6th 2014
The new dyskerin isoform 3 over-expression promotes DNA damage repair inducing p21 (CDKN1A)
Second-line chemotherapy withthe association of liposomal daunorubicin, carboplatin and etoposide in children with recurrent malignant brain tumors.
We have treated six children with recurrent high-grade glioma after surgery, radiotherapy and chemotherapy, and one child with progressive teratoid/rhabdoid tumor with the combination of liposomal daunorubicin and carboplatin plus etoposide. Five out of seven children showed a major response and the 29 month progression-free survival was 38%
Monoclonal antibody-based immunotherapy of ovarian cancer: Targeting ovarian cancer cells with the B7-H3-specific mAb 376.96
Objective The high rate of relapse in patients with advanced ovarian cancer likely reflects the chemoresistance of cancer initiating cells (CICs). We evaluated the anti-tumor activity of monoclonal antibody (mAb) 376.96, which recognizes a B7-H3 epitope expressed on ovarian carcinoma cells (OCCs), in combination with the tyrosine kinase inhibitor Sunitinib and chemotherapy on chemosensitive and chemoresistant cells and CICs. Methods Eight ovarian cancer cell lines including platinum- and taxane-resistant cell lines were analyzed by flow cytometry to establish expression of the mAb 376.96-defined-B7-H3-epitope on differentiated ovarian cancer cells and CICs. Samples from 10 ovarian cancer patients were analyzed via immunohistochemistry for mAb 376.96-defined-B7-H3- epitope expression. In vitro studies assessed mAb 376.96 alone and in combination with Sunitinib on the growth of chemosensitive and chemoresistant cell lines and on the content of CICs. Results The mAb-376.96-defined-B7-H3 epitope is expressed on both differentiated cells and CICs in chemosensitive and chemoresistant ovarian cancer cell lines and 10 patient derived ovarian cancer tumors. In vitro treatment of chemoresistant cell lines with mAb 376.96 resulted in decreased cell viability. mAb 376.96 enhanced the cytotoxicity of Sunitinib and reduced the content of CICs. Conclusion The mAb-376.96-defined-B7-H3-epitope was found to be expressed on both differentiated ovarian cancer cells and CICs in chemosensitive and chemoresistant ovarian cancer cell lines. mAb 376.96 inhibited the in vitro growth of chemosensitive and chemoresistant OCCs and reduced the content of CICs when used with Sunitinib. Further studies examining B7-H3 as a potential target of mAb-based immunotherapy for this type of malignancy are warranted. © 2013 Elsevier Inc