642 research outputs found

    Applications of bioluminescence in biotechnology and beyond.

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    Bioluminescence is the fascinating natural phenomenon by which living creatures produce light. Bioluminescence occurs when the oxidation of a small-molecule luciferin is catalysed by an enzyme luciferase to form an excited-state species that emits light. There are over 30 known bioluminescent systems but the luciferin-luciferase pairs of only 11 systems have been characterised to-date, whilst other novel systems are currently under investigation. The different luciferin-luciferase pairs have different light emission wavelengths and hence are suitable for various applications. The last decade or so has seen great advances in protein engineering, synthetic chemistry, and physics which have allowed luciferins and luciferases to reach previously uncharted applications. The bioluminescence reaction is now routinely used for gene assays, the detection of protein-protein interactions, high-throughput screening (HTS) in drug discovery, hygiene control, analysis of pollution in ecosystems and in vivo imaging in small mammals. Moving away from sensing and imaging, the more recent highlights of the applications of bioluminescence in biomedicine include the bioluminescence-induced photo-uncaging of small-molecules, bioluminescence based photodynamic therapy (PDT) and the use of bioluminescence to control neurons. There has also been an increase in blue-sky research such as the engineering of various light emitting plants. This has led to lots of exciting multidisciplinary science across various disciplines. This review focuses on the past, present, and future applications of bioluminescence. We aim to make this review accessible to all chemists to understand how these applications were developed and what they rely upon, in simple understandable terms for a graduate chemist

    Synthesis and bioluminescence of electronically modified and rotationally restricted colour-shifting infraluciferin analogues

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    Synthetic nIR emitting luciferins can enable clearer bioluminescent imaging in blood and tissue. A limiting factor for all synthetic luciferins is their reduced light output with respect to D-luciferin. In this work we explore a design feature of whether rigidification of an exceptionally red synthetic luciferin, infraluciferin, can increase light output through a reduction in the degrees of freedom of the molecule. A rigid analogue pyridobenzimidazole infraluciferin was prepared and its bioluminescence properties compared with its non-rigid counterpart benzimidazole infraluciferin, luciferin, infraluciferin and benzimidazole luciferin. The results support the concept that synthetic rigidification of π-extended luciferins can increase bioluminescence activity while maintaining nIR bioluminescence

    Towards brighter bioluminescence: Synthesis and properties of rigid infra-luciferins

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    Trends in the availability and usage of electrophysical agents in physiotherapy practices from 1990 to 2010: A review

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    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Maney PublishingBackground: The use of electrophysical agents has a historically important role in physiotherapy practice. There are anecdotal reports that the availability and usage of electrotherapy modalities are declining, which may have implications for physiotherapy practice. The aim of this literature review was to provide scientific evidence on electrotherapy usage in the last 20 years by identifying trends in availability, use, and non-use of nine electrotherapeutic modalities in physiotherapy practices during 1990s and 2000s. Methods: Review of empirical studies published in the English language from 1990 to 2010 and identified through searching online bibliographic databases, which included: Medline/OvidSP, PubMed Central, CINAHL/EBSCOhost, ScienceDirect, Scopus, ISI Web of Science, and Google Scholar. Findings: In the last 20 years, ultrasound availability and usage show increasing trends in several countries. The availability and use of pulsed shortwave diathermy and laser have shown steady trends. Transcutaneous electrical nerve stimulation, interferential, and biofeedback availability and usage have shown increasing trends in the UK and decreasing trends in Australia and the Republic of Ireland. Trends of continuous shortwave diathermy availability and use are declining irrespective of the country of the study. The availability and usage of microwave diathermy and H-wave show steeply declining trends, while there is a sharp rise in their non-availability over the last several years. Conclusions: The availability and use of electrophysical agents have greatly changed in the last 20 years. Declining trends in the availability and usage along with increasing trend of non-availability of electrotherapy modalities may have implications for electrotherapy education, training, and practice in the coming years.This study was funded by Health & Safety Executive, UK (grant no. 4371/R47.022)

    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

    Exploiting the multiplexing capabilities of tandem mass tags for high-throughput estimation of cellular protein abundances by mass spectrometry

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    The generation of dynamic models of biological processes critically depends on the determination of precise cellular concentrations of biomolecules. Measurements of system-wide absolute protein levels are particularly valuable information in systems biology. Recently, mass spectrometry based proteomics approaches have been developed to estimate protein concentrations on a proteome-wide scale. However, for very complex proteomes, fractionation steps are required, increasing samples number and instrument analysis time. As a result, the number of full proteomes that can be routinely analyzed is limited. Here we combined absolute quantification strategies with the multiplexing capabilities of isobaric tandem mass tags to determine cellular protein abundances in a high throughput and proteome-wide scale even for highly complex biological systems, such as a whole human cell line. We generated two independent data sets to demonstrate the power of the approach regarding sample throughput, dynamic range, quantitative precision and accuracy as well as proteome coverage in comparison to existing mass spectrometry based strategies

    Atypical right diaphragmatic hernia (hernia of Morgagni), spigelian hernia and epigastric hernia in a patient with Williams syndrome: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Williams syndrome is rare genetic disorder resulting in neurodevelopmental problems. Hernias of the foramen of Morgagni are rare diaphragmatic hernias and they mostly present on the right side, in the anterior mediastinum. They are usually asymptomatic and are difficult to diagnose, especially in patients with learning disabilities.</p> <p>Case presentation</p> <p>This 49-year-old woman with Williams syndrome, cognitive impairment and aortic stenosis presented to physicians with right-sided chest pain. She had previously undergone repair of her right spigelian and epigastric hernia. Her abdominal examination was unremarkable. Chest X-ray suggested right-sided diaphragmatic hernia and pleural effusion for which she received treatment. The computed tomography scan showed a diaphragmatic hernia with some collapse/consolidation of the adjacent lung. Furthermore, the patient had aortic stenosis and was high risk for anaesthesia (ASA grade 3). She underwent successful laparoscopic repair of her congenital diaphragmatic hernia leading to a quick and uneventful postoperative recovery.</p> <p>Conclusion</p> <p>These multiple hernias suggest that patients with Williams syndrome may have some connective tissue disorder which makes them prone to develop hernias especially associated with those parts of the body which may have intracavity pressure variations like the abdomen. Diaphragmatic hernia may be the cause of chest pain in these patients. A computed tomography scan helps in early diagnosis, and laparoscopic repair helps in prevention of further complications, and leads to quick recovery especially in patients with learning disabilities. In the presence of significant comorbidities, a less invasive operative procedure with quick recovery becomes advisable.</p

    Temporal trends in hepatitis B and C infection in family blood donors from interior Sindh, Pakistan

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    <p>Abstract</p> <p>Background</p> <p>Hepatitis B (HBV) and C (HCV) infections are a serious global and national public health problem. Earlier studies have reported increasing rates of hepatitis infection in Pakistan, particularly in rural areas. Pakistan has no active surveillance program to monitor trends of these infections. The objective of this study was to verify this trend in blood donors from the rural Sindh area of the country.</p> <p>Methods</p> <p>The study analysed the data of blood donors of interior Sindh who donated blood at JPMC blood bank from January 1, 2004 to September 15, 2007. HBsAg status was determined by using HBsAg Serodia kit and antibodies to HCV using the Detect HCV ™ V.3 Kit. Samples repeatedly reactive for HBsAg or anti-HCV were considered positive for HBV or HCV infection respectively.</p> <p>Results</p> <p>The overall seroprevalence of HBV infection among donors was 6.2 % (95% CI 5.5%–6.9%) and did not change significantly over the study period. Overall seroprevalence of HBV infection in literate blood donors was 5.7 %(95% CI 4.7%–6.8%). Prevalence decreased significantly in this group over the study period (p = 0.05). No other significant trends in seroprevalence of HBV infection were seen in the stratified analyses.</p> <p>The overall seroprevalence of HCV among donors was 7.5% (95% CI 6.8%–8.3%) and increased significantly over the study period from 7.2% (95% CI 5.8%–8.7%) in 2004 to 8.9% (95% CI 7.4%–10.6%) in 2007 (p = 0.02). Significant increase in seroprevalence was particularly seen in literate (p = 0.03), non–first time (p = 0.01) and Sindhi speaking (p = 0.01) donors.</p> <p>Conclusion</p> <p>Our study finds a steady increase in the prevalence of HCV infection in blood donors from interior Sindh between 2004 and 2007. On the contrary, decreasing prevalence of HBV was found, particularly in literate blood donors. There may be a need to have rural community-based epidemiological studies to identify the determinants of the spread of HCV infection and also those that are limiting the spread of HBV infection particularly in the literate blood donor population.</p

    Bidirectional lipid droplet velocities are controlled by differential binding strengths of HCV Core DII protein

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    Host cell lipid droplets (LD) are essential in the hepatitis C virus (HCV) life cycle and are targeted by the viral capsid core protein. Core-coated LDs accumulate in the perinuclear region and facilitate viral particle assembly, but it is unclear how mobility of these LDs is directed by core. Herein we used two-photon fluorescence, differential interference contrast imaging, and coherent anti-Stokes Raman scattering microscopies, to reveal novel core-mediated changes to LD dynamics. Expression of core protein’s lipid binding domain II (DII-core) induced slower LD speeds, but did not affect directionality of movement on microtubules. Modulating the LD binding strength of DII-core further impacted LD mobility, revealing the temporal effects of LD-bound DII-core. These results for DII-core coated LDs support a model for core-mediated LD localization that involves core slowing down the rate of movement of LDs until localization at the perinuclear region is accomplished where LD movement ceases. The guided localization of LDs by HCV core protein not only is essential to the viral life cycle but also poses an interesting target for the development of antiviral strategies against HCV
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