109 research outputs found

    Seismic Q estimates in Umbria-Marche (central Italy): hints for the retrieval of a new attenuation law for seismic risk

    Get PDF
    In the Umbria Marche (Central Italy) region an important earthquake sequence occurred in 1997, characterized by nine earthquakes with magnitudes in the range between 5 and 6, that caused important damages and causalities. In the present paper we separately estimate intrinsic- and scattering- Q −1 parameters, using the classical MLTWA approach in the assumption of a half space model. The results clearly show that the attenuation parameters Qi −1 and Qs −1 are frequency dependent. This estimate is compared with other attenuation studies carried out in the same area, and with all the other MLTWA estimates obtained till now in other tectonic environments in the Earth. The bias introduced by the half space assumption is investigated through numerical solutions of the Energy Transport equation in the more realistic assumption of a heterogeneous crust overlying a transparent mantle, with a Moho located at a depth ranging between 35 and 45 km below the surface. The bias introduced by the half space assumption is significant only at high frequency. We finally show how the attenuation estimates, calculated with different techniques, lead to different PGA decay with distance relationships, using the well known and well proven Boore’s method. This last result indicates that care must be used in selecting the correct estimate of the attenuation parameters for seismic risk purposes. We also discuss the reason why MLTWA may be chosen among all the other available techniques, due to its intrinsic stability, to obtain the right attenuation parameters

    The role of microRNA in head and neck cancer: Current knowledge and perspectives

    Get PDF
    Head and neck cancer is one of the most commonly diagnosed malignancies worldwide. Patients with advanced disease stages frequently develop recurrences or distant metastasis, which results a five-year survival rates of less than 60% despite considerable advances in multimodality therapy. A better understanding of molecular basis of tumorigenesis is required to improve clinical outcomes and to develop new anti-cancer drugs. microRNAs (miRNAs) are a class of small, non-coding, RNA molecules that modulate gene expression post-Transcriptionally. They are important regulator in normal biological process; however miRNAs deregulation has been observed in many different tumors and is involved in tumorigenesis. miRNAs may act as tumor suppressors or as oncogenes. Several studies on head and neck cancer demonstrated how aberrant expression of miRNAs is involved in proliferation, metastasis, chemoresistence, and radioresistance. In addition, miRNAs are excellent biomarker targets because they circulate stable in human body fluids and can be obtained with non-invasive methods. Moreover, miRNAs up and down regulation has been correlated with specific cancer phenotype (poor prognosis, aggressiveness and resistance to treatment), playing a role as prognostic biomarkers. This review summarizes current finding on miRNAs in head and neck cancer and their potential role as target for next drug therapy. © 2014 by the authors

    Eradication of isolated para-aortic nodal recurrence in a patient with an advanced high grade sorous ovarian carcinoma: our experience and review of literature

    Get PDF
    Abstract: We report a case report regarding the eradication of isolated lymph-nodal para-aortic recurrence in the aortic region down the left renal vein (LRV) in a patient treated two years earlier in another hospital for a FIGO stage IC2 high-grade serous ovarian carcinoma with a video showing the para-aortic space after eradication of the metastatic tissue. A 66 year-old woman was admitted 24 months after the initial surgical procedure for an increased Ca 125 level and CT scan that revealed a 3 cm para-aortic infrarenal lymph-nodal recurrence that was confirmed by PET/CT scan. A secondary cytoreductive surgery (SCS) with a para-aortic lymph-nodal dissection of the tissue down the LRV and radical omentectomy were performed: during the cytoreduction, the right hemicolon was mobilized. The anterior surface of the inferior vena cava (IVC), aorta and LRV were exposed. The metastatic lymph nodes were detected in the para-ortic space down the proximal part of the LRV and eradicated; an en bloc infrarenal lymph-node dissection from the aortocaval region was performed. The operative time during the surgical procedure was 212 min with a blood loss of 120 mL. No intra- and postoperative complications, including ureteral or vascular injury or renal dysfunction, occurred. At histological examination, three dissected lymph nodes were positive for metastasis, and the patient was discharged five days after laparotomy without side effects and underwent chemotherapy 3 weeks later; after a follow-up of 42 months, no recurrence was detected. In conclusion, secondary debulking surgery can be considered a safe and effective therapeutic option for the management of recurrences, although long-term follow-ups are necessary to evaluate the overall oncologic outcomes of this procedure

    Immunotherapeutic approaches for hepatocellular carcinoma

    Get PDF
    Hepatocellular carcinoma (HCC) is a cancer with a high mortality rate due to the fact that the diagnosis usually occurs at anadvanced stage. Even in case of curative surgical treatment, recurrence is common. Sorafenib and regorafenib are the only therapeutic agents that have been demonstrated to be effective in advanced HCC, thus novel curative approaches are urgently needed. Recent studies focus on the role of immune system in HCC. In fact, the unique immune response in the liver favors tolerance, which can represent a real challenge for conventional immunotherapy in these patients. Spontaneous immune responses against tumor antigens have been detected, and new immune therapies are under investigation: dendritic cell vaccination, immune-modulator strategy, and immune checkpoint inhibition. In recent years different clinical trials examining the use of immunotherapy to treat HCC have been conducted with initial promising results. This review article will summarize the literature data concerning the potential immunotherapeutic approaches in HCC patient

    The Role of Eif6 in Skeletal Muscle Homeostasis Revealed by Endurance Training Co-expression Networks

    Get PDF
    Regular endurance training improves muscle oxidative capacity and reduces the risk of age-related disorders. Understanding the molecular networks underlying this phenomenon is crucial. Here, by exploiting the power of computational modeling, we show that endurance training induces profound changes in gene regulatory networks linking signaling and selective control of translation to energy metabolism and tissue remodeling. We discovered that knockdown of the mTOR-independent factor Eif6, which we predicted to be a key regulator of this process, affects mitochondrial respiration efficiency, ROS production, and exercise performance. Our work demonstrates the validity of a data-driven approach to understanding muscle homeostasis

    Penile cancer: prognostic and predictive factors in clinical decision-making

    Get PDF
    : Penile cancer (PC) is a typical tumor of non-industrialized countries. The incidence is 20-30 times higher in Africa and South America, considering the elevated prevalence of sexually transmitted diseases. Histologically, PC includes squamous cell carcinoma (SCPC), the most frequent, and nonsquamous carcinoma (NSCPC). Early diagnosis is the goal, whereas later diagnosis relates to poor functional outcomes and worse prognosis. The 5-year survival rate is 85% for patients with histologically regional negative lymph nodes, compared to 29%-40% for those with histologically regional positive lymph nodes. To date no new drugs are approved, and there are few new data about molecular mechanisms underlying tumorigenesis. The SCPC remains a rare tumor and the current therapeutic algorithm is based principally on retrospective analysis and less on prospective trials. In this review article, biomarkers of prognosis and efficacy of current treatments are summarized with a focus on those that have the potential to affect treatment decision-making in SCPC

    Activation of acid sphingomyelinase and its inhibition by the nitric oxide/cyclic guanosine 3′,5′-monophosphate pathway: Key events in Escherichia coli-elicited apoptosis of dendritic cells

    Get PDF
    Depletion of dendritic cells (DCs) via apoptosis contributes to sepsis-induced immune suppression. The mechanisms leading to DC apoptosis during sepsis are not known. In this study we report that immature DCs undergo apoptosis when treated with high numbers of Escherichia coli. This effect was mimicked by high concentrations of LPS. Apoptosis was accompanied by generation of ceramide through activation of acid sphingomyelinase (A-SMase), was prevented by inhibitors of this enzyme, and was restored by exogenous ceramide. Compared with immature DCs, mature DCs expressed significantly reduced levels of A-SMase, did not generate ceramide in response to E. coli or LPS, and were insensitive to E. coli- and LPS-triggered apoptosis. However, sensitivity to apoptosis was restored by addition of exogenous A-SMase or ceramide. Furthermore, inhibition of A-SMase activation and ceramide generation was found to be the mechanism through which the immune-modulating messenger NO protects immature DCs from the apoptogenic efects of E. coli and LPS. NO acted through formation of cGMP and stimulation of the cGMP-dependent protein kinase. The relevance of A-SMase and its inhibition by NO/cGMP were confirmed in a mouse model of LPS-induced sepsis. DC apoptosis was significantly higher in inducible NO synthase-deficient mice than in wild-type animals and was significantly reduced by treatment ex vivo with NO, cGMP, or the A-SMase inhibitor imipramine. Thus, A-SMase plays a central role in E. coli/LPS-induced DC apoptosis and its inhibition by NO, and it might be a target of new therapeutic approaches to sepsis
    • …
    corecore