125 research outputs found

    Modeling of Mid-IR Amplifier Based on an Erbium-Doped Chalcogenide Microsphere

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    An optical amplifier based on a tapered fiber and an Er3+-doped chalcogenide microsphere is designed and optimized. A dedicated 3D numerical model, which exploits the coupled mode theory and the rate equations, is used. The main transitions among the erbium energy levels, the amplified spontaneous emission, and the most important secondary transitions pertaining to the ion-ion interactions have been considered. Both the pump and signal beams are efficiently injected and obtained by a suitable design of the taper angle and the fiber-microsphere gap. Moreover, a good overlapping between the optical signals and the rare-earth-doped region is also obtained. In order to evaluate the amplifier performance in reduced computational time, the doped area is partitioned in sectors. The obtained simulation results highlight that a high-efficiency midinfrared amplification can be obtained by using a quite small microsphere

    Antimicrobial prophylaxis and modifications of the gut microbiota in children with cancer

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    In children with cancer, chemotherapy can produce cytotoxic effects, resulting in immuno-suppression and an augmented risk of febrile neutropenia and bloodstream infections. This has led to widespread use of antibiotic prophylaxis which, combined with intensive chemotherapy treatment, could have a long-term effect on the gastrointestinal microbiome. In this review, we aimed to analyze the current literature about the widespread use of antibiotic prophylaxis in children experiencing infectious complications induced by chemotherapy and its effects on the gut microbiome. Our review of the literature shows that antimicrobial prophylaxis in children with cancer is still a trending topic and, at the moment, there are not enough data to define universal guidelines. Children with cancer experience long and painful medical treatments and side effects, which are associated with great economic and social burdens, important psychological consequences, and dysbiosis induced by antibiotics and also by chemotherapy. Considering the importance of a healthy gut microbiota, studies are needed to understand the impact of dysbiosis in response to therapy in these children and to define how to modulate the microbiome to favor a positive therapeutic outcome

    Effectiveness and safety of vedolizumab in a matched cohort of elderly and nonelderly patients with inflammatory bowel disease: the IG-IBD LIVE study

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    Vedolizumab registration trials were the first to include elderly patients with moderate-to-severe ulcerative colitis (UC) or Crohn's disease (CD), but few real-life data have been reported in this population. Aims: We investigated the effectiveness and safety of vedolizumab in matched cohorts of elderly and nonelderly UC and CD patients. Methods: The Long-term Italian Vedolizumab Effectiveness (LIVE) study is a retrospective-prospective study including UC and CD patients who started vedolizumab from April 2016 to June 2017. Elderly patients (≄65 years) were matched clinically 1:2 to nonelderly patients (18-64 years); the 2 groups were followed until drug discontinuation or June 2019. Results: The study included 198 elderly (108 UC, 90 CD) and 396 matched nonelderly patients (205 UC, 191 CD). Nonelderly UC patients had a significantly higher persistence on vedolizumab compared to elderly patients (67.6% vs. 51.4%, p = 0.02). No significant difference in effectiveness was observed between elderly and nonelderly CD patients (59.4% vs. 52.4%, p = 0.32). Age ≄65 years was associated with lower persistence in UC; for CD, previous exposure to anti-TNF-α agents, Charlson comorbidity index >2 and moderate-to-severe clinical activity at baseline were associated with lower persistence. There were recorded 130 adverse events, with comparable rates between the two groups. A Charlson comorbidity index >2 was associated with an increased risk of adverse events. Conclusion: Vedolizumab can be considered a safe option in elderly IBD patients. Its effectiveness in elderly UC patients may be reduced, while no age-dependent effect on effectiveness was observed in CD

    Endo-therapies for biliary duct-to-duct anastomotic stricture after liver transplantation: outcomes of a nationwide survey

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    BACKGROUND: The most appropriate endo-therapeutic approach to biliary anastomotic strictures is yet to be defined. AIM: To retrospectively report on the endo-therapy of duct-to-duct anastomotic strictures during 2013 in Italy. METHODS: Data were collected from 16 Endoscopy Units at the Italian Liver Transplantation Centers (BASALT study group). RESULTS: Complete endo-therapy and follow-up data are available for 181 patients: 101 treated with plastic multistenting, 26 with fully covered self-expandable metal stenting (SEMS) and 54 with single stenting. Radiological success was achieved for 145 patients (80%), i.e. 88% of plastic multistenting, 88% of SEMS and 61% of single stenting (p<0.001 vs plastic multistenting; p<0.05 vs SEMS)]. After first-line endo-therapy failure, the patients underwent a second-line endo-therapy with plastic multistenting for 25%, fully covered SEMS for 53% and single stenting for 22% of cases, and radiological success was achieved for 84%, i.e. 100%, 85%, and 63% with plastic multistenting, SEMS and single stenting (p<0.05 vs plastic multistenting or SEMS), respectively. Procedure-related complications occurred in 7.8% of ERCP. Overall clinical success was achieved in 87% of patients after a median follow-up of 25 months. CONCLUSION: Plastic multistenting is confirmed as the preferred first-line treatment, while fully covered SEMS as rescue option for biliary anastomotic strictures. Single stenting has sub-optimal results and should be abandoned. This article is protected by copyright. All rights reserved

    Modulation of extracellular matrix by nutritional hepatotrophic factors in thioacetamide-induced liver cirrhosis in the rat

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    Nutritional substances associated to some hormones enhance liver regeneration when injected intraperitoneally, being denominated hepatotrophic factors (HF). Here we verified if a solution of HF (glucose, vitamins, salts, amino acids, glucagon, insulin, and triiodothyronine) can revert liver cirrhosis and how some extracellular matrices are affected. Cirrhosis was induced for 14 weeks in 45 female Wistar rats (200 mg) by intraperitoneal injections of thioacetamide (200 mg/kg). Twenty-five rats received intraperitoneal HF twice a day for 10 days (40 mL·kg-1·day-1) and 20 rats received physiological saline. Fifteen rats were used as control. The HF applied to cirrhotic rats significantly: a) reduced the relative mRNA expression of the genes: Col-α1 (-53%), TIMP-1 (-31.7%), TGF-β1 (-57.7%), and MMP-2 (-41.6%), whereas Plau mRNA remained unchanged; b) reduced GGT (-43.1%), ALT (-17.6%), and AST (-12.2%) serum levels; c) increased liver weight (11.3%), and reduced liver collagen (-37.1%), regenerative nodules size (-22.1%), and fibrous septum thickness. Progranulin protein (immunohistochemistry) and mRNA (in situ hybridization) were found in fibrous septa and areas of bile duct proliferation in cirrhotic livers. Concluding, HF improved the histology and serum biochemistry of liver cirrhosis, with an important reduction of interstitial collagen and increased extracelullar matrix degradation by reducing profibrotic gene expression

    Surveillance of Summer Mortality and Preparedness to Reduce the Health Impact of Heat Waves in Italy

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    Since 2004, the Italian Department for Civil Protection and the Ministry of Health have implemented a national program for the prevention of heat-health effects during summer, which to-date includes 34 major cities and 93% of the residents aged 65 years and over. The Italian program represents an important example of an integrated approach to prevent the impact of heat on health, comprising Heat Health Watch Warning Systems, a mortality surveillance system and prevention activities targeted to susceptible subgroups. City-specific warning systems are based on the relationship between temperature and mortality and serve as basis for the modulation of prevention measures. Local prevention activities, based on the guidelines defined by the Ministry of Health, are constructed around the infrastructures and services available. A key component of the prevention program is the identification of susceptible individuals and the active surveillance by General Practitioners, medical personnel and social workers. The mortality surveillance system enables the timely estimation of the impact of heat, and heat waves, on mortality during summer as well as to the evaluation of warning systems and prevention programs. Considering future predictions of climate change, the implementation of effective prevention programs, targeted to high risk subjects, become a priority in the public health agenda

    In Vitro Effects of Pirfenidone on Cardiac Fibroblasts: Proliferation, Myofibroblast Differentiation, Migration and Cytokine Secretion

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    Cardiac fibroblasts (CFs) are the primary cell type responsible for cardiac fibrosis during pathological myocardial remodeling. Several studies have illustrated that pirfenidone (5-methyl-1-phenyl-2-[1H]-pyridone) attenuates cardiac fibrosis in different animal models. However, the effects of pirfenidone on cardiac fibroblast behavior have not been examined. In this study, we investigated whether pirfenidone directly modulates cardiac fibroblast behavior that is important in myocardial remodeling such as proliferation, myofibroblast differentiation, migration and cytokine secretion. Fibroblasts were isolated from neonatal rat hearts and bioassays were performed to determine the effects of pirfenidone on fibroblast function. We demonstrated that treatment of CFs with pirfenidone resulted in decreased proliferation, and attenuated fibroblast α-smooth muscle actin expression and collagen contractility. Boyden chamber assay illustrated that pirfenidone inhibited fibroblast migration ability, probably by decreasing the ratio of matrix metalloproteinase-9 to tissue inhibitor of metalloproteinase-1. Furthermore, pirfenidone attenuated the synthesis and secretion of transforming growth factor-ÎČ1 but elevated that of interleukin-10. These direct and pleiotropic effects of pirfenidone on cardiac fibroblasts point to its potential use in the treatment of adverse myocardial remodeling
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