1,777 research outputs found

    How human papillomavirus replication and immune evasion strategies take advantage of the host DNA damage repair machinery

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    The DNA damage response (DDR) is a complex signalling network activated when DNA is altered by intrinsic or extrinsic agents. DDR plays important roles in genome stability and cell cycle regulation, as well as in tumour transformation. Viruses have evolved successful life cycle strategies in order to ensure a chronic persistence in the host, virtually avoiding systemic sequelae and death. This process promotes the periodic shedding of large amounts of infectious particles to maintain a virus reservoir in individual hosts, while allowing virus spreading within the community. To achieve such a successful lifestyle, the human papilloma virus (HPV) needs to escape the host defence systems. The key to understanding how this is achieved is in the virus replication process that provides by itself an evasion mechanism by inhibiting and delaying the host immune response against the viral infection. Numerous studies have demonstrated that HPV exploits both the ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia and rad3-related (ATR) DDR pathways to replicate its genome and maintain a persistent infection by downregulating the innate and cell-mediated immunity. This review outlines how HPV interacts with the ATM-and ATR-dependent DDR machinery during the viral life cycle to create an environment favourable to viral replication, and how the interaction with the signal transducers and activators of transcription (STAT) protein family and the deregulation of the Janus kinase (JAK)-STAT pathways may impact the expression of interferon-inducible genes and the innate immune responses

    Ovarian surgery for bilateral endometriomas influences age at menopause.

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    BACKGROUND: Questions remain as to whether surgical excision of ovarian endometriomas might cause damage to ovarian function. To test the hypothesis that ovarian surgery for endometrioma compromises ovarian function and accelerates ovarian failure. METHODS: In a tertiary university Clinic, longitudinal prospective cohort study. Patients who underwent laparoscopy for endometriosis between March 1993 and November 2007 were assessed for inclusion in the study. A prospective follow-up at 3, 6 and 12 months then yearly was conducted. Evolution of menstrual pattern, symptoms and reproductive outcomes were investigated. RESULTS: From over the 14-year period, 302 patients were included in the study. The mean age (±SD) of patients was 32.6 ± 5.6 years; the median duration of follow-up was 8.5 years (range 2-17 years). Menopause was documented in 43 women (14.3%) at a mean age of 45.3 ± 4.3 years (range 32-52 years). Women previously submitted to bilateral cystectomy were younger at menopause than those with monolateral endometrioma (42.1 ± 5.1 years versus 47.1 ± 3.5 years, P = 0.003). Premature ovarian failure (POF) was observed in 7 of 43 (16.3%) menopausal patients; the majority (4, 57.1%) after bilateral cystectomy. The relationship between the preoperative ovarian endometriomas total diameter and menopausal age was significant in case of surgery for bilateral endometriomas (R(2) = 0.754, P = 0.002). CONCLUSIONS: Patients who had been operated on for bilateral endometriomas have an increased risk of POF. Ovarian parenchyma loss at the time of surgery seems related to cyst diameter. In the case of unilateral ovarian endometrioma, the contralateral intact ovary might adequately compensate

    Identification of platelet hyper-reactivity measured with a portable device immediately after percutaneous coronary intervention predicts in stent thrombosis

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    Introduction: Platelet hyper-reactivity, despite a standard anti-thrombotic therapy, is a recognized risk factor for recurrent myocardial ischemia and in-stent thrombosis following PCI. We have investigated whether this detrimental condition, measured by collagen-epinephrine closure times (CEPI-CT) with the Platelet Function Analyzer (PFA-100) device could predict IST defined as the composite of cardiovascular death or myocardial infarction. Materials and methods: CEPI-CT was measured in 256 consecutive patients with stable angina (n=103) or ACS (n=153) 30?8 h after PCI (T0) and 1 month later (T1). All patients were followed up for a mean period of 9 months. Platelet hyperactivity was defined as a CEPI-CTb190 s. Results: Baseline CEPI-CTb190 s was associated with a higher rate of death or MI (LogRank χ2 =4.23, p=0.039) as compared with CEPI-CTN190 s (4.6% vs. 0.7%). Multivariable analysis after adjustment for other risk factors confirmed that baseline CEPI-CTb190 s was an independent correlate for death or MI (Hazard ratio 6.981, p=0.008). At T1 there was a significant prolongati

    Ripplocations provide a new mechanism for the deformation of phyllosilicates in the lithosphere

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    Deformation in Earth’s lithosphere is localised in narrow, high-strain zones. Phyllosilicates, strongly anisotropic layered minerals, are abundant in these rocks, where they accommodate much of the strain and play a significant role in inhibiting or triggering earthquakes. Until now it was understood that phyllosilicates could deform only by dislocation glide along layers and could not accommodate large strains without cracking and dilation. Here we show that a new class of atomic-scale defects, known as ripplocations, explain the development of layer-normal strain without brittle damage. We use high-resolution transmission electron microscopy (TEM) to resolve nano-scale bending characteristic of ripplocations in the phyllosilicate mineral biotite. We demonstrate that conjugate delamination arrays are the result of elastic strain energy release due to the accumulation of layer-normal strain in ripplocations. This work provides the missing mechanism necessary to understand phyllosilicate deformation, with important rheological implications for phyllosilicate bearing seismogenic faults and subduction zones

    Ellagic acid containing Nanostructured Lipid Carriers for topical application: a preliminary study

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    Ellagic acid (EA) is a potent antioxidant substance of natural origin characterized by poor biopharmaceutical properties and low solubility in water that limit their use. The aim of the present study was to develop lipid based nanoparticle formulations able to encapsulate EA for dermal delivery purpose. The EA-loaded nanoparticles were prepared using two different lipid compositions, namely tristearin/tricaprylin (NLC-EA1) and tristearin/labrasol (NLC-EA2). The influence of formulations on size, entrapment efficiency and stability of EA-loaded nanoparticles was investigated. Cryo-TEM and SAXS analysess showed that no morphological differences are evident among all the types of loaded and unloaded NLC. The macroscopic aspect of both NLC-EA1 and NLC-EA2 did not change by time. No difference in size is appreciable between empty and drug-containing NLC, thus the nanoparticle diameter is not affected by the presence EA and in general no variations of the diameters occur during time. The percentage of entrapment efficiency of both EA-loaded nanoparticles was almost quantitative. In addition NLC-EA1 maintain EA stability for almost 2 months, while NLC-EA2 up to 40 days. FRAP assay showed an antioxidant activity around 60% for both the loaded NLC, as compared to the solution. Although both types of NLC are characterized by some toxicity, NLC-EA1 are less cytotoxic than NLC-EA2. Taken together these results demonstrated that the inclusion of EA within NLC could improve the water solubility, allowing for a reduction of the dosage. Moreover, the maintaining of high antioxidant effect and low toxicity were evidenced for both types of NLC-EA
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