1,848 research outputs found

    Developing speed-related safety performance indicators from floating car data

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    In the road traffic safety domain there is a need for using proactive (non-crash-based) indicators, known as safety performance indicators (SPIs). Traffic speed based on big data (floating car data [FCD]) could help develop network-wide SPIs, but related knowledge and experience are insufficient so far. The authors attempted to fill this gap by using nationwide Italian FCD to develop speed-related SPIs and validating their relationship to crashes to see their potential explanatory value. The authors calculated the coefficient of variance (CV), congestion index (CI), and the number of incidents as candidate SPIs. For validation, the authors used linear correlation, crash frequency model, and ranking consistency. Incidents turned out to be the best SPI, especially for motorways

    Mutations in Conserved Residues of the C. elegans microRNA Argonaute ALG-1 Identify Separable Functions in ALG-1 miRISC Loading and Target Repression

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    microRNAs function in diverse developmental and physiological processes by regulating target gene expression at the post-transcriptional level. ALG-1 is one of two Caenorhabditis elegans Argonautes (ALG-1 and ALG-2) that together are essential for microRNA biogenesis and function. Here, we report the identification of novel antimorphic (anti) alleles of ALG-1 as suppressors of lin-28(lf) precocious developmental phenotypes. The alg-1(anti) mutations broadly impair the function of many microRNAs and cause dosage-dependent phenotypes that are more severe than the complete loss of ALG-1. ALG-1(anti) mutant proteins are competent for promoting Dicer cleavage of microRNA precursors and for associating with and stabilizing microRNAs. However, our results suggest that ALG-1(anti) proteins may sequester microRNAs in immature and functionally deficient microRNA Induced Silencing Complexes (miRISCs), and hence compete with ALG-2 for access to functional microRNAs. Immunoprecipitation experiments show that ALG-1(anti) proteins display an increased association with Dicer and a decreased association with AIN-1/GW182. These findings suggest that alg-1(anti) mutations impair the ability of ALG-1 miRISC to execute a transition from Dicer-associated microRNA processing to AIN-1/GW182 associated effector function, and indicate an active role for ALG/Argonaute in mediating this transition

    Giant pulmonary bulla mimicking pneumothorax in children. Diagnostic and morphopathological considerations

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    Rezumat Introducere. Bula pulmonară gigantă la copii se întâlnește rar. În acest context, autorii prezintă un caz clinic, care demonstrează dificultățile diagnostice, modalitatea de tratament chirurgical și aspectele morfopatologice ale acestei entități nozologice. Prezentare de caz. Pacient de sex masculin, în vârstă de 12 ani, care prezenta astenie, slăbiciune la efort fizic și dispnee timp de 8 luni, a fost internat pentru pneumotorax spontan pe dreapta, diagnosticul fiind stabilit la radiografie toracică și confirmat la tomografie computerizată. Concomitent, pacientul suferea de timomegalie cu hipotiroidie primară congenitală, în legătură cu ce urmează tratament cu L-tiroxină, și formațiune chistică a glandei tiroide supusă tratamentului chirurgical. Pacientul a fost supus intervenției chirurgicale toracice video asistate (VATS), intraoperator fiind identificată o bulă gigantă localizată în lobul superior al plămânului drept, care a fost excizată prin micro toracotomie latero-posterioară dreaptă. Evoluția postoperatorie a fost fără particularități, radiologic fiind constatată expansiunea treptată a lobului superior al plămânului drept, în care scintigrafia pulmonară a pus în evidență modificări nesemnificative de perfuzie pulmonară. Concluzii. 1. Diagnosticul diferențial dintre bula pulmonară gigantică și pneumotorax este destul de dificil, fiind esențial în aprecierea tacticii de tratament. 2. Bulectomia cu suturarea și aerostaza adecvată a liniei de rezecție la nivelul țesutului pulmonar sănătos reprezintă un procedeu tehnic sigur și fezabil în rezolvarea acestei patologii. 3. Investigațiile histologice efectuate în acest caz au permis de a stabili unele particularități morfopatologice ale componentelor structurale, acestea fiind caracteristice pentru o formațiune chistică de origine bronșică, care conținea elemente de țesuturi musculare reziduale, fascicule nervoase, arterii obliterate sclerogenizate, precum și componenta limfocitară pseudo-foliculară, modificările constatate punând în discuție originea dizontogenetică a bulei pulmonare gigante la copii.Summary Introduction. Giant lung blistering in children is rare. In this context, the authors present a clinical case, which demonstrates the diagnostic difficulties, the way of surgical treatment and the morphopathological aspects of this nosological entity. Case report. A 12-year-old male patient with asthenia, weakness on exertion and dyspnea for 8 months was hospitalized for spontaneous right pneumothorax, the diagnosis being established by chest radiography and confirmed by computed tomography. At the same time, the patient was suffering from thymomegaly with congenital primary hypothyroidism, because of which gets treatment with L-thyroxin, and cystic formation of the thyroid gland undergoing surgical treatment. The patient underwent video-assisted thoracic surgery (VATS), and a giant bladder located in the upper lobe of the right lung was identified intraoperative, which was excised by right latero-posterior micro thoracotomy. The postoperative evolution was without particularities, radiologically being found the gradual re-expansion of the upper lobe of the right lung, in which the pulmonary scintigraphy revealed insignificant changes of pulmonary perfusion. Conclusions. 1. The differential diagnosis between giant lung blister and pneumothorax is quite difficult, being essential in assessing treatment tactics. 2. Bulectomy with suturing and adequate aerostasis of the resection line at the level of healthy lung tissue is a safe and feasible technical procedure in resolving this pathology. 3. The carried out histological investigations, in this case, established some morphopathological features of the structural components, which are characteristic of a cystic formation of bronchial origin, which contained elements of residual muscle tissue, nerve bundles, sclerogenized-obliterated arteries and lymphocyte component. Pseudo-follicular, the changes found questioning the dysontogenetic origin of the giant lung bubble in children

    How to minimise the effect of tumour cell content in detection of aberrant genetic markers in neuroblastoma

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    Background:Clinical heterogeneity reflects the complexity of genetic events associated with neuroblastoma (NB). To identify the status of all described genetic loci with possible prognostic interest, high-throughput approaches have been used, but only with tumour cell content >60%. In some tumours, necrotic, haemorrhagic and/or calcification areas influence the low amount of neuroblasts. We evaluated the effect of tumour cell content in the detection of relevant aberrant genetic markers (AGM) diagnosed by fluorescence in situ hybridisation (FISH) on tissue microarrays (TMA) in NB.Methods:Two hundred and thirty-three MYCN non-amplified primary NB included in 12 TMAs were analysed.Results:Presence of AGM reduced event-free survival (EFS) (P=0.004) as well as overall survival (OS) (P=0.004) of patients in the whole cohort. There were no differences in prognostic impact of presence of AGM according to tumour cell content.Conclusion:We propose the use of FISH to diagnose AGM of all NB samples having the above-mentioned areas to determine patient risk

    Direct visualization of the native structure of viroid RNAs at single-molecule resolution by atomic force microscopy

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    [EN] Viroids are small infectious, non-protein-coding circular RNAs that replicate independently and, in some cases, incite diseases in plants. They are classified into two families: Pospiviroidae, composed of species that have a central conserved region (CCR) and replicate in the cell nucleus, and Avsunviroidae, containing species that lack a CCR and whose multimeric replicative intermediates of either polarity generated in plastids self-cleave through hammerhead ribozymes. The compact, rod-like or branched, secondary structures of viroid RNAs have been predicted by RNA folding algorithms and further examined using different in vitro and in vivo experimental techniques. However, direct data about their native tertiary structure remain scarce. Here we have applied atomic force microscopy (AFM) to image at single-molecule resolution different variant RNAs of three representative viroids: potato spindle tuber viroid (PSTVd, family Pospiviroidae), peach latent mosaic viroid and eggplant latent viroid (PLMVd and ELVd, family Avsunviroidae). Our results provide a direct visualization of their native, three-dimensional conformations at 0 and 4 mM Mg2+ and highlight the role that some elements of tertiary structure play in their stabilization. The AFM images show that addition of 4 mM Mg2+ to the folding buffer results in a size contraction in PSTVd and ELVd, as well as in PLMVd when the kissing-loop interaction that stabilizes its 3D structure is preserved.This work was supported by the Spanish Ministerio de Economia y Competitividad (MINECO) grants BIO2016-79618-R (funded by EU under the FEDER programme) to C.B. and BFU2104-56812-P to R.F., as well as by the Comunidad de Madrid grant S2018/NMT-4349 to L.V. CIBERehd is funded by the Instituto de Salud Carlos III (ISCIII).Moreno, M.; Vázquez, L.; López Carrasco, A.; Martín-Gago, JA.; Flores Pedauye, R.; Briones, C. (2019). Direct visualization of the native structure of viroid RNAs at single-molecule resolution by atomic force microscopy. RNA Biology. 16(3):295-308. https://doi.org/10.1080/15476286.2019.1572436S295308163Diener, T. O. (2003). Discovering viroids — a personal perspective. Nature Reviews Microbiology, 1(1), 75-80. doi:10.1038/nrmicro736Flores, R., Hernández, C., Alba, A. E. M. de, Daròs, J.-A., & Serio, F. D. (2005). Viroids and Viroid-Host Interactions. Annual Review of Phytopathology, 43(1), 117-139. doi:10.1146/annurev.phyto.43.040204.140243Ding, B. (2009). The Biology of Viroid-Host Interactions. Annual Review of Phytopathology, 47(1), 105-131. doi:10.1146/annurev-phyto-080508-081927Zhang, Z., Qi, S., Tang, N., Zhang, X., Chen, S., Zhu, P., … Wu, Q. (2014). Discovery of Replicating Circular RNAs by RNA-Seq and Computational Algorithms. PLoS Pathogens, 10(12), e1004553. doi:10.1371/journal.ppat.1004553Serra, P., Messmer, A., Sanderson, D., James, D., & Flores, R. (2018). Apple hammerhead viroid-like RNA is a bona fide viroid: Autonomous replication and structural features support its inclusion as a new member in the genus Pelamoviroid. Virus Research, 249, 8-15. doi:10.1016/j.virusres.2018.03.001Hadidi, A., Barba, M., Hong, N., & Hallan, V. (2017). Apple Scar Skin Viroid. Viroids and Satellites, 217-228. doi:10.1016/b978-0-12-801498-1.00021-8Flores, R., Minoia, S., Carbonell, A., Gisel, A., Delgado, S., López-Carrasco, A., … Di Serio, F. (2015). Viroids, the simplest RNA replicons: How they manipulate their hosts for being propagated and how their hosts react for containing the infection. Virus Research, 209, 136-145. doi:10.1016/j.virusres.2015.02.027Hammann, C., & Steger, G. (2012). Viroid-specific small RNA in plant disease. 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J., Domdey, H., Lossow, C., Jank, P., Raba, M., Alberty, H., & Sänger, H. L. (1978). Nucleotide sequence and secondary structure of potato spindle tuber viroid. Nature, 273(5659), 203-208. doi:10.1038/273203a0Gast, F.-U., Kempe, D., Spieker, R. L., & Sänger, H. L. (1996). Secondary Structure Probing of Potato Spindle Tuber Viroid (PSTVd) and Sequence Comparison with Other Small Pathogenic RNA Replicons Provides Evidence for Central Non-canonical Base-pairs, Large A-rich Loops, and a Terminal Branch. Journal of Molecular Biology, 262(5), 652-670. doi:10.1006/jmbi.1996.0543Giguère, T., Raj Adkar-Purushothama, C., & Perreault, J.-P. (2014). Comprehensive Secondary Structure Elucidation of Four Genera of the Family Pospiviroidae. PLoS ONE, 9(6), e98655. doi:10.1371/journal.pone.0098655López-Carrasco, A., & Flores, R. (2016). Dissecting the secondary structure of the circular RNA of a nuclear viroid in vivo: A «naked» rod-like conformation similar but not identical to that observed in vitro. RNA Biology, 14(8), 1046-1054. doi:10.1080/15476286.2016.1223005Wang, Y., Zirbel, C. L., Leontis, N. B., & Ding, B. (2018). RNA 3-dimensional structural motifs as a critical constraint of viroid RNA evolution. PLOS Pathogens, 14(2), e1006801. doi:10.1371/journal.ppat.1006801Zhong, X., Leontis, N., Qian, S., Itaya, A., Qi, Y., Boris-Lawrie, K., & Ding, B. (2006). Tertiary Structural and Functional Analyses of a Viroid RNA Motif by Isostericity Matrix and Mutagenesis Reveal Its Essential Role in Replication. Journal of Virology, 80(17), 8566-8581. doi:10.1128/jvi.00837-06Zhong, X., Tao, X., Stombaugh, J., Leontis, N., & Ding, B. (2007). Tertiary structure and function of an RNA motif required for plant vascular entry to initiate systemic trafficking. 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    Biodistribution and function of extracellular miRNA-155 in mice

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    Circulating miRNAs can be found in extracellular vesicles (EV) and could be involved in intercellular communication. Here, we report the biodistribution of EV associated miR-155 using miR-155 KO mouse model. Administration of exosomes loaded with synthetic miR-155 mimic into miR-155 KO mice resulted in a rapid accumulation and clearance of miR-155 in the plasma with subsequent distribution in the liver, adipose tissue, lung, muscle and kidney (highest to lowest, respectively). miR-155 expression was detected in isolated hepatocytes and liver mononuclear cells of recipient KO mice suggesting its cellular uptake. In vitro, exosome-mediated restoration of miR-155 in Kupffer cells from miR-155 deficient mice augmented their LPS-induced MCP1 mRNA increase. The systemic delivery of wild type plasma to miR-155 KO mice also resulted in a rapid accumulation of miR-155 in the circulation and distribution to the liver and adipose tissue. In summary, our results demonstrate tissue biodistribution and biologic function of EV-associated miR-155

    The C. Elegans Heterochronic Gene lin-46 Affects Developmental Timing at Two Larval Stages and Encodes a Relative of the Scaffolding Protein Gephyrin

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    The succession of developmental events in the C. elegans larva is governed by the heterochronic genes. When mutated, these genes cause either precocious or retarded developmental phenotypes, in which stage-specific patterns of cell division and differentiation are either skipped or reiterated, respectively. We identified a new heterochronic gene, lin-46, from mutations that suppress the precocious phenotypes caused by mutations in the heterochronic genes lin-14 and lin-28. lin-46 mutants on their own display retarded phenotypes in which cell division patterns are reiterated and differentiation is prevented in certain cell lineages. Our analysis indicates that lin-46 acts at a step immediately downstream of lin-28, affecting both the regulation of the heterochronic gene pathway and execution of stage-specific developmental events at two stages: the third larval stage and adult. We also show that lin-46 is required prior to the third stage for normal adult cell fates, suggesting that it acts once to control fates at both stages, and that it affects adult fates through the let-7 branch of the heterochronic pathway. Interestingly, lin-46 encodes a protein homologous to MoeA of bacteria and the C-terminal domain of mammalian gephyrin, a multifunctional scaffolding protein. Our findings suggest that the LIN-46 protein acts as a scaffold for a multiprotein assembly that controls developmental timing, and expand the known roles of gephyrin-related proteins to development

    International consensus for neuroblastoma molecular diagnostics: report from the International Neuroblastoma Risk Group (INRG) Biology Committee

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    Neuroblastoma serves as a paradigm for utilising tumour genomic data for determining patient prognosis and treatment allocation. However, before the establishment of the International Neuroblastoma Risk Group (INRG) Task Force in 2004, international consensus on markers, methodology, and data interpretation did not exist, compromising the reliability of decisive genetic markers and inhibiting translational research efforts. The objectives of the INRG Biology Committee were to identify highly prognostic genetic aberrations to be included in the new INRG risk classification schema and to develop precise definitions, decisive biomarkers, and technique standardisation. The review of the INRG database (n=8800 patients) by the INRG Task Force finally enabled the identification of the most significant neuroblastoma biomarkers. In addition, the Biology Committee compared the standard operating procedures of different cooperative groups to arrive at international consensus for methodology, nomenclature, and future directions. Consensus was reached to include MYCN status, 11q23 allelic status, and ploidy in the INRG classification system on the basis of an evidence-based review of the INRG database. Standardised operating procedures for analysing these genetic factors were adopted, and criteria for proper nomenclature were developed. Neuroblastoma treatment planning is highly dependant on tumour cell genomic features, and it is likely that a comprehensive panel of DNA-based biomarkers will be used in future risk assignment algorithms applying genome-wide techniques. Consensus on methodology and interpretation is essential for uniform INRG classification and will greatly facilitate international and cooperative clinical and translational research studies
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