1,683 research outputs found

    The management of bronchus intermedius complications after lung transplantation: A retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Airway complications following lung transplantation remain a significant cause of morbidity and mortality. The management of bronchial complications in Bronchus Intermedius (BI) is challenging due to the location of right upper bronchus. The aim of this study was to analyze the results of BI Montgomery T-tube stent in a consecutive patients with lung transplantations.</p> <p>Methods</p> <p>Between January 2007 and December 2010, 132 lung transplantations were performed at Foch Hospital, Suresnes, France. All the patients who had BI Montgomery T-tube after lung transplantation were included in this retrospective study. The demographic and interventional data and also complications were recorded.</p> <p>Results</p> <p>Out of 132 lung transplant recipients, 12 patients (9 male and 3 female) were entered into this study. The indications for lung transplantation were: cystic fibrosis 8 (67%), emphysema 3 (25%), and idiopathic pulmonary fibrosis 1 (8%). Most of the patients (83%) had bilateral lung transplantation. The mean interval between lung transplantation and interventional bronchoscopy was 11.5 ± 9.8 (SD) months. There was bronchial stenosis at the level of BI in 7 patients (58.3%). The Montgomery T-tube number 10 was used in 9 patients (75%). There was statistically significant difference in Forced Expiratory Volume in one second (FEV1) before and after stent placement (p = 0.01). The most common complication after stent placement was migration (33%).</p> <p>Conclusion</p> <p>BI complications after lung transplantation are still a significant problem. Stenosis or malacia following lung transplantation could be well managed with modified Montgomery T-tube.</p

    Sequencing of the Hepatitis C Virus: A Systematic Review

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    Since the identification of hepatitis C virus (HCV), viral sequencing has been important in understanding HCV classification, epidemiology, evolution, transmission clustering, treatment response and natural history. The length and diversity of the HCV genome has resulted in analysis of certain regions of the virus, however there has been little standardisation of protocols. This systematic review was undertaken to map the location and frequency of sequencing on the HCV genome in peer reviewed publications, with the aim to produce a database of sequencing primers and amplicons to inform future research. Medline and Scopus databases were searched for English language publications based on keyword/MeSH terms related to sequence analysis (9 terms) or HCV (3 terms), plus "primer" as a general search term. Exclusion criteria included non-HCV research, review articles, duplicate records, and incomplete description of HCV sequencing methods. The PCR primer locations of accepted publications were noted, and purpose of sequencing was determined. A total of 450 studies were accepted from the 2099 identified, with 629 HCV sequencing amplicons identified and mapped on the HCV genome. The most commonly sequenced region was the HVR-1 region, often utilised for studies of natural history, clustering/transmission, evolution and treatment response. Studies related to genotyping/classification or epidemiology of HCV genotype generally targeted the 5'UTR, Core and NS5B regions, while treatment response/resistance was assessed mainly in the NS3-NS5B region with emphasis on the Interferon sensitivity determining region (ISDR) region of NS5A. While the sequencing of HCV is generally constricted to certain regions of the HCV genome there is little consistency in the positioning of sequencing primers, with the exception of a few highly referenced manuscripts. This study demonstrates the heterogeneity of HCV sequencing, providing a comprehensive database of previously published primer sets to be utilised in future sequencing studies

    Genetic Diversity in New Members of the Reticulocyte Binding Protein Family in Thai Plasmodium vivax Isolates

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    Background Plasmodium vivax merozoites specifically invade reticulocytes. Until recently, two reticulocyte-binding proteins (Pvrbp1 and Pvrbp2) expressed at the apical pole of the P. vivax merozoite were considered to be involved in reticulocyte recognition. The genome sequence recently obtained for the Salvador I (Sal-I) strain of P. vivax revealed additional genes in this family, and in particular Pvrbp2a, Pvrbp2b (Pvrbp2 has been renamed as Pvrbp2c) and two pseudogenes Pvrbp2d and Pvrbp3. It had been previously found that Pvrbp2c is substantially more polymorphic than Pvrbp1. The primary goal of this study was to ascertain the level of polymorphism of these new genes. Methodology/Principal Findings The sequence of the Pvrbp2a, Pvrbp2b, Pvrbp2d and Pvrbp3 genes were obtained by amplification/cloning using DNA purified from four isolates collected from patients that acquired the infection in the four cardinal regions of Thailand (west, north, south and east). An additional seven isolates from western Thailand were analyzed for gene copy number variation. There were significant polymorphisms exhibited by these genes (compared to the reference Sal-I strain) with the ratio of mutations leading to a non-synonymous or synonymous amino acid change close to 3∶1 for Pvrbp2a and Pvrbp2b. Although the degree of polymorphism exhibited by these two genes was higher than that of Pvrbp1, it did not reach the exceptional diversity noted for Pvrbp2c. It was interesting to note that variations in the copy number of Pvrbp2a and Pvrbp2b occurred in some isolates. Conclusions/Significance The evolution of different members of the Pvrbp2 family and their relatively high degree of polymorphism suggests that the proteins encoded by these genes are important for parasite survival and are under immune selection. Our data also shows that there are highly conserved regions in rbp2a and rbp2b, which might provide suitable targets for future vaccine development against the blood stage of P. vivax

    Computational Micromodel for Epigenetic Mechanisms

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    Characterization of the epigenetic profile of humans since the initial breakthrough on the human genome project has strongly established the key role of histone modifications and DNA methylation. These dynamic elements interact to determine the normal level of expression or methylation status of the constituent genes in the genome. Recently, considerable evidence has been put forward to demonstrate that environmental stress implicitly alters epigenetic patterns causing imbalance that can lead to cancer initiation. This chain of consequences has motivated attempts to computationally model the influence of histone modification and DNA methylation in gene expression and investigate their intrinsic interdependency. In this paper, we explore the relation between DNA methylation and transcription and characterize in detail the histone modifications for specific DNA methylation levels using a stochastic approach

    Standard requirements for GCP-compliant data management in multinational clinical trials

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    <p>Abstract</p> <p>Background</p> <p>A recent survey has shown that data management in clinical trials performed by academic trial units still faces many difficulties (e.g. heterogeneity of software products, deficits in quality management, limited human and financial resources and the complexity of running a local computer centre). Unfortunately, no specific, practical and open standard for both GCP-compliant data management and the underlying IT-infrastructure is available to improve the situation. For that reason the "Working Group on Data Centres" of the European Clinical Research Infrastructures Network (ECRIN) has developed a standard specifying the requirements for high quality GCP-compliant data management in multinational clinical trials.</p> <p>Methods</p> <p>International, European and national regulations and guidelines relevant to GCP, data security and IT infrastructures, as well as ECRIN documents produced previously, were evaluated to provide a starting point for the development of standard requirements. The requirements were produced by expert consensus of the ECRIN Working group on Data Centres, using a structured and standardised process. The requirements were divided into two main parts: an IT part covering standards for the underlying IT infrastructure and computer systems in general, and a Data Management (DM) part covering requirements for data management applications in clinical trials.</p> <p>Results</p> <p>The standard developed includes 115 IT requirements, split into 15 separate sections, 107 DM requirements (in 12 sections) and 13 other requirements (2 sections). Sections IT01 to IT05 deal with the basic IT infrastructure while IT06 and IT07 cover validation and local software development. IT08 to IT015 concern the aspects of IT systems that directly support clinical trial management. Sections DM01 to DM03 cover the implementation of a specific clinical data management application, i.e. for a specific trial, whilst DM04 to DM12 address the data management of trials across the unit. Section IN01 is dedicated to international aspects and ST01 to the competence of a trials unit's staff.</p> <p>Conclusions</p> <p>The standard is intended to provide an open and widely used set of requirements for GCP-compliant data management, particularly in academic trial units. It is the intention that ECRIN will use these requirements as the basis for the certification of ECRIN data centres.</p

    Dynamic and Polarized Muscle Cell Behaviors Accompany Tail Morphogenesis in the Ascidian Ciona intestinalis

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    BACKGROUND: Axial elongation is a key morphogenetic process that serves to shape developing organisms. Tail extension in the ascidian larva represents a striking example of this process, wherein paraxially positioned muscle cells undergo elongation and differentiation independent of the segmentation process that characterizes the formation of paraxial mesoderm in vertebrates. Investigating the cell behaviors underlying the morphogenesis of muscle in ascidians may therefore reveal the evolutionarily conserved mechanisms operating during this process. METHODOLOGY/PRINCIPLE FINDINGS: A live cell imaging approach utilizing subcellularly-localized fluorescent proteins was employed to investigate muscle cell behaviors during tail extension in the ascidian Ciona intestinalis. Changes in the position and morphology of individual muscle cells were analyzed in vivo in wild type embryos undergoing tail extension and in embryos in which muscle development was perturbed. Muscle cells were observed to undergo elongation in the absence of positional reorganization. Furthermore, high-speed high-resolution live imaging revealed that the onset and progression of tail extension were characterized by the presence of dynamic and polarized actin-based protrusive activity at the plasma membrane of individual muscle cells. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that in the Ciona muscle, tissue elongation resulted from gradual and coordinated changes in cell geometry and not from changes in cell topology. Proper formation of muscle cells was found to be necessary not only for muscle tissue elongation, but also more generally for completion of tail extension. Based upon the characterized dynamic changes in cell morphology and plasma membrane protrusive activity, a three-phase model is proposed to describe the cell behavior operating during muscle morphogenesis in the ascidian embryo

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Resistance to DDT and Pyrethroids and Increased kdr Mutation Frequency in An. gambiae after the Implementation of Permethrin-Treated Nets in Senegal

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    Introduction: The aim of this study was to evaluate the susceptibility to insecticides of An. gambiae mosquitoes sampled in Dielmo (Senegal), in 2010, 2 years after the implementation of Long Lasting Insecticide-treated Nets (LLINs) and to report the evolution of kdr mutation frequency from 2006 to 2010. Methods: WHO bioassay susceptibility tests to 6 insecticides were performed on adults F0, issuing from immature stages of An. gambiae s.l., sampled in August 2010. Species and molecular forms as well as the presence of L1014F and L1014S kd

    The same frequency of planets inside and outside open clusters of stars

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    Most stars and their planets form in open clusters. Over 95 per cent of such clusters have stellar densities too low (less than a hundred stars per cubic parsec) to withstand internal and external dynamical stresses and fall apart within a few hundred million years. Older open clusters have survived by virtue of being richer and denser in stars (1,000 to 10,000 per cubic parsec) when they formed. Such clusters represent a stellar environment very different from the birthplace of the Sun and other planet-hosting field stars. So far more than 800 planets have been found around Sun-like stars in the field. The field planets are usually the size of Neptune or smaller. In contrast, only four planets have been found orbiting stars in open clusters, all with masses similar to or greater than that of Jupiter. Here we report observations of the transits of two Sun-like stars by planets smaller than Neptune in the billion-year-old open cluster NGC6811. This demonstrates that small planets can form and survive in a dense cluster environment, and implies that the frequency and properties of planets in open clusters are consistent with those of planets around field stars in the Galaxy.Comment: 18 pages, 6 figures, 1 table (main text + supplementary information
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