919 research outputs found

    Stretchable, fully polymeric electrode arrays for peripheral nerve stimulation

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    There is a critical need to transition research level flexible polymer bioelectronics toward the clinic by demonstrating both reliability in fabrication and stable device performance. Conductive elastomers (CEs) are composites of conductive polymers in elastomeric matrices that provide both flexibility and enhanced electrochemical properties compared to conventional metallic electrodes. This work focuses on the development of nerve cuff devices and the assessment of the device functionality at each development stage, from CE material to fully polymeric electrode arrays. Two device types are fabricated by laser machining of a thick and thin CE sheet variant on an insulative polydimethylsiloxane substrate and lamination into tubing to produce pre‐curled cuffs. Device performance and stability following sterilization and mechanical loading are compared to a state‐of‐the‐art stretchable metallic nerve cuff. The CE cuffs are found to be electrically and mechanically stable with improved charge transfer properties compared to the commercial cuff. All devices are applied to an ex vivo whole sciatic nerve and shown to be functional, with the CE cuffs demonstrating superior charge transfer and electrochemical safety in the biological environment

    Identification of genes expressed by immune cells of the colon that are regulated by colorectal cancer-associated variants.

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    A locus on human chromosome 11q23 tagged by marker rs3802842 was associated with colorectal cancer (CRC) in a genome-wide association study; this finding has been replicated in case-control studies worldwide. In order to identify biologic factors at this locus that are related to the etiopathology of CRC, we used microarray-based target selection methods, coupled to next-generation sequencing, to study 103 kb at the 11q23 locus. We genotyped 369 putative variants from 1,030 patients with CRC (cases) and 1,061 individuals without CRC (controls) from the Ontario Familial Colorectal Cancer Registry. Two previously uncharacterized genes, COLCA1 and COLCA2, were found to be co-regulated genes that are transcribed from opposite strands. Expression levels of COLCA1 and COLCA2 transcripts correlate with rs3802842 genotypes. In colon tissues, COLCA1 co-localizes with crystalloid granules of eosinophils and granular organelles of mast cells, neutrophils, macrophages, dendritic cells and differentiated myeloid-derived cell lines. COLCA2 is present in the cytoplasm of normal epithelial, immune and other cell lineages, as well as tumor cells. Tissue microarray analysis demonstrates the association of rs3802842 with lymphocyte density in the lamina propria (p = 0.014) and levels of COLCA1 in the lamina propria (p = 0.00016) and COLCA2 (tumor cells, p = 0.0041 and lamina propria, p = 6 × 10(-5)). In conclusion, genetic, expression and immunohistochemical data implicate COLCA1 and COLCA2 in the pathogenesis of colon cancer. Histologic analyses indicate the involvement of immune pathways

    Synergistic Antibacterial Effects of Metallic Nanoparticle Combinations

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    © The Author(s) 2019.Metallic nanoparticles have unique antimicrobial properties that make them suitable for use within medical and pharmaceutical devices to prevent the spread of infection in healthcare. The use of nanoparticles in healthcare is on the increase with silver being used in many devices. However, not all metallic nanoparticles can target and kill all disease-causing bacteria. To overcome this, a combination of several different metallic nanoparticles were used in this study to compare effects of multiple metallic nanoparticles when in combination than when used singly, as single elemental nanoparticles (SENPs), against two common hospital acquired pathogens (Staphylococcus aureus and Pseudomonas. aeruginosa). Flow cytometry LIVE/DEAD assay was used to determine rates of cell death within a bacterial population when exposed to the nanoparticles. Results were analysed using linear models to compare effectiveness of three different metallic nanoparticles, tungsten carbide (WC), silver (Ag) and copper (Cu), in combination and separately. Results show that when the nanoparticles are placed in combination (NPCs), antimicrobial effects significantly increase than when compared with SENPs (P < 0.01). This study demonstrates that certain metallic nanoparticles can be used in combination to improve the antimicrobial efficiency in destroying morphologically distinct pathogens within the healthcare and pharmaceutical industry.Peer reviewe

    Lentiviral Engineered Fibroblasts Expressing Codon Optimized COL7A1 Restore Anchoring Fibrils in RDEB

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    Cells therapies, engineered to secrete replacement proteins, are being developed to ameliorate otherwise debilitating diseases. Recessive dystrophic epidermolysis bullosa (RDEB) is caused by defects of type VII collagen (C7), a protein essential for anchoring fibril formation at the dermal-epidermal junction (DEJ). Whilst allogeneic fibroblasts injected directly into the dermis can mediate transient disease modulation, autologous gene-modified fibroblasts should evade immunological rejection and support sustained delivery of C7 at the DEJ. We demonstrate the feasibility of such an approach using a therapeutic grade, self-inactivating-lentiviral vector, encoding codon optimized COL7A1, to transduce RDEB fibroblasts under conditions suitable for clinical application. Expression and secretion of C7 was confirmed, with transduced cells exhibiting supra-normal levels of protein expression and ex vivo migration of fibroblasts was restored in functional assays. Gene modified RDEB fibroblasts also deposited C7 at the DEJ of human RDEB skin xenografts placed on NOD-scid IL2Rgamma(null) recipients, with reconstruction of human epidermal structure and regeneration of anchoring fibrils at the DEJ. Fibroblast mediated restoration of protein and structural defects in this RDEB model strongly supports proposed therapeutic applications in man

    Dead on arrival in a low-income country: results from a multicenter study in Pakistan

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    BACKGROUND: This study assessed the characteristics of dead on arrival (DOA) patients in Pakistan. METHODS: Data about the DOA patients were extracted from Pakistan National Emergency Department Surveillance study (Pak-NEDS). This study recruited all ED patients presenting to seven tertiary care hospitals during a four-month period between November 2010 and March 2011. This study included patients who were declared dead-on-arrival by the ED physician. RESULTS: A total of 1,557 DOA patients (7 per 1,000 visits) were included in the Pak-NEDS. Men accounted for two-thirds (64%) of DOA patients. Those aged 20-49 years accounted for about 46% of DOA patients. Nine percent (n = 72) of patients were brought by ambulance, and most patients presented at a public hospital (80%). About 11% of DOA patients had an injury. Factors significantly associated (p \u3c 0.05) with ambulance use were men (adjusted odds ratio [aOR] = 2.72), brought to a private hospital (OR = 2.74), and being injured (aOR = 1.89). Cardiopulmonary resuscitation (CPR) was performed on 6% (n = 42) of patients who received treatment. Those brought to a private hospital were more likely to receive CPR (aOR = 2.81). CONCLUSION: This study noted a higher burden of DOA patients in Pakistan compared to other resourceful settings (about 1 to 2 per 1,000 visits). A large proportion of patients belonging to productive age groups, and the low prevalence of ambulance and CPR use, indicate a need for improving the prehospital care and basic life support training in pakistan

    Bullying of medical students in Pakistan: a cross-sectional questionnaire survey.

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    Background: Several studies from other countries have shown that bullying, harassment, abuse or belittlement are a regular phenomenon faced not only by medical students, but also junior doctors, doctors undertaking research and other healthcare professionals. While research has been carried out on bullying experienced by psychiatrists and psychiatry trainees in Pakistan no such research has been conducted on medical students in this country. Methodology/Principal Findings: We conducted a cross-sectional questionnaire survey on final year medical students in six medical colleges of Pakistan. The response rate was 63%. Fifty-two percent of respondents reported that they had faced bullying or harassment during their medical education, about 28% of them experiencing it once a month or even more frequently. The overwhelming form of bullying had been verbal abuse (57%), while consultants were the most frequent (46%) perpetrators. Students who were slightly older, males, those who reported that their medical college did not have a policy on bullying or harassment, and those who felt that adequate support was not in place at their medical college for bullied individuals, were significantly more likely to have experienced bullying. Conclusion: Bullying or harassment is faced by quite a large proportion of medical students in Pakistan. The most frequent perpetrators of this bullying are consultants. Adoption of a policy against bullying and harassment by medical colleges, and providing avenues of support for students who have been bullied may help reduce this phenomenon, as the presence of these two was associated with decreased likelihood of students reporting having being bullied

    Possession and Usage of Insecticidal Bed Nets among the People of Uganda: Is BRAC Uganda Health Programme Pursuing a Pro-Poor Path?

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    The use of insecticidal bed nets is found to be an effective public health tool for control of malaria, especially for under-five children and pregnant women. BRAC, an indigenous Bangladeshi non-governmental development organization, started working in the East African state of Uganda in June 2006. As part of its efforts to improve the health and well-being of its participants, BRAC Uganda has been distributing long lasting insecticide-treated bed nets (LLIN) at a subsidized price through health volunteers since February 2008. This study was conducted in March-April 2009 to examine how equitable the programme had been in consistence with BRAC Uganda's pro-poor policy

    A multi-gene signature predicts outcome in patients with pancreatic ductal adenocarcinoma.

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    © 2014 Haider et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Improved usage of the repertoires of pancreatic ductal adenocarcinoma (PDAC) profiles is crucially needed to guide the development of predictive and prognostic tools that could inform the selection of treatment options

    Underweight and overweight men have greater exercise-induced dyspnoea than normal weight men.

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    INTRODUCTION: Persons with high or low body mass index (BMI), involved in clinical or mechanistic trials involving exercise testing, might estimate dyspnoea differently from persons with a normal BMI. AIMS: Our objective was to investigate the relationship between BMI and dyspnoea during exercise in normal subjects with varying BMI. MATERIAL AND METHODS: A total of 37 subjects undertook progressive exercise testing. Subjects were divided into three groups: underweight (UW), normal weight (NW), and overweight (OW). Dyspnoea was estimated using the visual analogue scale (VAS). Spirometry, maximum voluntary ventilation (MVV), and respiratory muscle strength (RMS) were measured. RESULTS AND DISCUSSION: The intercept of the VAS/ventilation relationship was significantly higher in NW subjects compared to UW (P = 0.029) and OW subjects (P = 0.040). Relative to the OW group, FVC (P = 0.020), FEV(1) (P = 0.024), MVV (P = 0.019), and RMS (P = 0.003) were significantly decreased in the UW group. The greater levels of dyspnoea in UW subjects could possibly be due to decreased RMS. Healthy persons should aim to achieve an optimum BMI range to have the lowest exercise-induced dyspnoea
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