30 research outputs found

    quantification of the foreign body reaction by means of a miniaturized imaging window for intravital nonlinear microscopy

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    Brand new biomaterials, intended to be used on humans, must undergo in vivo quantification standardized, expensive and unethical procedures mainly based on histopathological analysis, from dissections, as defined by the ISO 10993 normative set. The aim is to prove the biomaterials biocompatibility. There exist no methods based on intravital microscopy able to satisfy the normative quantification requirements both reducing the number of employed animals and related costs. We developed a miniaturized imaging window, the Microatlas, which allows subcutaneous repeated observations in vivo of the foreign body reactions, for example to the implantation of a biomaterial. Confocal and twophoton microscopy inspections at Microatlas implantation sites demonstrated growth of the recipient tissue inside the microgrids both with micro vascularization formation and collagen generation. In conclusion, the Microatlas guided in vivo a quantifiable localized reaction inside its microscaffold, both in terms of cell repopulation, collagen and capillary formation as a probable foreign body reaction

    Genetic alterations analysis in prognostic stratified groups identified TP53 and ARID1A as poor clinical performance markers in intrahepatic cholangiocarcinoma

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    The incidence and mortality rates of intrahepatic cholangiocarcinoma have been rising worldwide. Few patients present an early-stage disease that is amenable to curative surgery and after resection, high recurrence rates persist. To identify new independent marker related to aggressive behaviour, two prognostic groups of patient were selected and divided according to prognostic performance. All patients alive at 36 months were included in good prognostic performers, while all patients died due to disease within 36 months in poor prognostic performers. Using high-coverage target sequencing we analysed principal genetic alterations in two groups and compared results to clinical data. In the 33 cases included in poor prognosis group, TP53 was most mutated gene (p\u2009=\u20090.011) and exclusively present in these cases. Similarly, ARID1A was exclusive of this group (p\u2009=\u20090.024). TP53 and ARID1A are mutually exclusive in this study. Statistical analysis showed mutations in TP53 and ARID1A genes and amplification of MET gene as independent predictors of poor prognosis (TP53, p\u2009=\u20090.0031, ARID1A, p\u2009=\u20090.0007, MET, p\u2009=\u20090.0003 in Cox analysis). LOH in PTEN was also identified as marker of disease recurrence (p\u2009=\u20090.04) in univariate analysis. This work improves our understanding of aggressiveness related to this tumour type and has identified novel prognostic markers of clinical outcome

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    HDTV satellite broadcasting in the EHF domain: Feasibility Study and Quality Assessment

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    In this work we propose a simulation-based feasibility study for the efficient exploitation of W band (75-110GHz) for high quality HDTV broadcasting applications. In order to obtain a reliable and realistic simulation environment, we have considered the DVB-S2 standard specifications, introducing the typical W-band impairments such as phase noise, rain attenuation, as well as non-linearities. For testing purposes, we have adopted common High-Definition benchmark video sequences, so as to evaluate the H.264 video quality as a function of the available bit-rate on the channel. During the simulation phase we have taken into account adaptive techniques like ACM (Adaptive Coding and Modulation) and scalable video coding (SVC). Eventually, we have evaluated the achieved results in view of implementing future broadcasting services in the EHF domain. Simulation results have demonstrated the suitability of W-band to efficiently support a reliable HDTV service with an increased number of available channels if compared to DVB-S2 standard using Ku and Ka band. The large bandwidth availability should also improve the system flexibility in terms of trade-off between spectral efficiency and video quality

    Multi-Carrier Code Division Multiplexing of Multi-Layered MPEG4 Video Signals for Real-time Mobile Streaming Applications

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    In this report, a novel methodology for the efficient multiplexing and transmission of MPEG4- coded video signals over wireless networks will be presented and discussed. The proposed approach relies on the joint exploitation of variable-bit-rate (VBR) multicarrier code-division multiplexing (MC-CDM), together with MPEG4 coding with Fine-Grain-Scalability (FGS) in order to provide unequal error protection to the transmitted video stream.The innovative scheme proposed employs a shared bandwidth partitioned into orthogonal sub-channels in order to multiplex different layers of MPEG-4-coded signals. The highest number of sub-channels (and hence an increased frequency diversity) is assigned to the lowest-bit-rate base layer and the lowest number of sub-channels is assigned to the highest bit-rate enhancement layer. In such a way, base layer information contents are more protected against channel degradations than information contained in FGS enhancement layers, which can only yield a refinement of the quality of the decoded streams. A 2GHz LEO multicast satellite transmission to mobile users has been regarded as the application testbed for the proposed method. Results achieved in terms of PSNR point out that the VBR MC-CDM technique can provide better results than a conventional MPEG-4 single-layer MC-SS transmission.In the framework of a full-digital implementation of reconfigurable multimedia transceivers, the proposed VBR MC-CDM technique may be regarded as an interesting solution for reliable multimedia transmissions in mobile environments

    Cross-Layer Adaptation of MPEG4 Video Streaming Over Wireless Networks Using Unequal Error Protection and MC-CDMA

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    A novel methodology for the efficient multiplexing and streaming of MPEG4 video over wireless networks is presented and discussed. The proposed cross-layer adaptation jointly exploits variable-bitrate (VBR) multi-carrier code-division multiplexing (MC-CDM) and MPEG4 Fine-Grain-Scalability (FGS) in order to provide unequal error protection to the transmitted video stream. A shared bandwidth is partitioned into orthogonal sub-channels in order to multiplex different layers of MPEG4-coded signals. Lower layers are assigned a higher number of sub-channels (and hence an increased frequency diversity) as compared to FGS enhancement layers, in order to provide a differentiated protection against channel degradations. A 2-GHz LEO multicast satellite transmission system has been considered as a application testbed of the proposed methodology. Results achieved in terms of PSNR show that the VBR MC-CDM technique can provide better results than conventional MPEG4 single-layer MC-SS transmission. In the framework of a full-digital implementation of reconfigurable multimedia transceivers, the proposed VBR MC-CDM technique may be regarded as a convenient solution for reliable multimedia transmissions in mobile environments
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