127 research outputs found

    Silver(I) 1,10-Phenanthroline Complexes Are Active against Fonsecaea Pedrosoi Viability and Negatively Modulate Its Potential Virulence Attributes

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    The genus Fonsecaea is one of the etiological agents of chromoblastomycosis (CBM), a chronic subcutaneous disease that is difficult to treat. This work aimed to evaluate the effects of copper(II), manganese(II) and silver(I) complexes coordinated with 1,10-phenanthroline (phen)/1,10- phenanthroline-5,6-dione (phendione) on Fonsecaea spp. Our results revealed that most of these complexes were able to inhibit F. pedrosoi, F. monophora and F. nubica conidial viability with minimum inhibitory concentration (MIC) values ranging from 0.6 to 100 M. The most effective complexes against F. pedrosoi planktonic conidial cells, the main etiologic agent of CBM, were [Ag(phen)2]ClO4 and [Ag2(3,6,9-tdda)(phen)4].EtOH, (tdda: 3,6,9-trioxaundecanedioate), displaying MIC values equal to 1.2 and 0.6 M, respectively. These complexes were effective in reducing the viability of F. pedrosoi biofilm formation and maturation. Silver(I) tdda-phen, combined with itraconazole, reduced the viability and extracellular matrix during F. pedrosoi biofilm development. Moreover, both silver(I) complexes inhibited either metallo- or aspartic-type peptidase activities of F. pedrosoi as well as its conidia into mycelia transformation and melanin production. In addition, the complexes induced the production of intracellular reactive oxygen species in F. pedrosoi. Taken together, our data corroborate the antifungal action of metal-phen complexes, showing they represent a therapeutic option for fungal infections, including CBM

    Vector Transmission of Leishmania Abrogates Vaccine-Induced Protective Immunity

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    Numerous experimental vaccines have been developed to protect against the cutaneous and visceral forms of leishmaniasis caused by infection with the obligate intracellular protozoan Leishmania, but a human vaccine still does not exist. Remarkably, the efficacy of anti-Leishmania vaccines has never been fully evaluated under experimental conditions following natural vector transmission by infected sand fly bite. The only immunization strategy known to protect humans against natural exposure is “leishmanization,” in which viable L. major parasites are intentionally inoculated into a selected site in the skin. We employed mice with healed L. major infections to mimic leishmanization, and found tissue-seeking, cytokine-producing CD4+ T cells specific for Leishmania at the site of challenge by infected sand fly bite within 24 hours, and these mice were highly resistant to sand fly transmitted infection. In contrast, mice vaccinated with a killed vaccine comprised of autoclaved L. major antigen (ALM)+CpG oligodeoxynucleotides that protected against needle inoculation of parasites, showed delayed expression of protective immunity and failed to protect against infected sand fly challenge. Two-photon intra-vital microscopy and flow cytometric analysis revealed that sand fly, but not needle challenge, resulted in the maintenance of a localized neutrophilic response at the inoculation site, and removal of neutrophils following vector transmission led to increased parasite-specific immune responses and promoted the efficacy of the killed vaccine. These observations identify the critical immunological factors influencing vaccine efficacy following natural transmission of Leishmania

    Uptake of Aggregating Transthyretin by Fat Body in a Drosophila Model for TTR-Associated Amyloidosis

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    Background: A functional link has been established between the severe neurodegenerative disorder Familial amyloidotic polyneuropathy and the enhanced propensity of the plasma protein transthyretin (TTR) to form aggregates in patients with single point mutations in the TTR gene. Previous work has led to the establishment of an experimental model based on transgenic expression of normal or mutant forms of human TTR in Drosophila flies. Remarkably, the severity of the phenotype was greater in flies that expressed a single copy than with two copies of the mutated gene. Methodology/Principal Findings: In this study, we analyze the distribution of normal and mutant TTR in transgenic flies, and the ultrastructure of TTR-positive tissues to clarify if aggregates and/or amyloid filaments are formed. We report the formation of intracellular aggregates of 20 nm spherules and amyloid filaments in thoracic adipose tissue and in brain glia, two tissues that do not express the transgene. The formation of aggregates of nanospherules increased with age and was more considerable in flies with two copies of mutated TTR. Treatment of human neuronal cells with protein extracts prepared from TTR flies of different age showed that the extracts from older flies were less toxic than those from younger flies. Conclusions/Significance: These findings suggest that the uptake of TTR from the circulation and its subsequent segregation into cytoplasmic quasi-crystalline arrays of nanospherules is part of a mechanism that neutralizes the toxic effect of TTR.Original Publication:Malgorzata Pokrzywa, Ingrid Dacklin, Monika Vestling, Dan Hultmark, Erik Lundgren and Rafael Cantera, Uptake of Aggregating Transthyretin by Fat Body in a Drosophila Model for TTR-Associated Amyloidosis, 2010, PLOS ONE, (5), 12.http://dx.doi.org/10.1371/journal.pone.0014343Licensee: Public Library of Science (PLoS)http://www.plos.org

    ASPECTOS EPIDEMIOLÓGICOS E PREVALÊNCIA DE ENTEROPARASITOSES EM CRIANÇAS DO BAIRRO JAMBEIRO, SÃO LUÍS, MA

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    A carĂȘncia de condiçÔes bĂĄsicas de higiene e saneamento, aliadas Ă  falta de limpeza dos reservatĂłrios de ĂĄgua e a nĂŁo utilização de ĂĄgua fltrada ou fervida, intensifcam a ocorrĂȘncia de problemas de saĂșde pĂșblica. Com o intuito de contribuir para a conscientização da população acerca dos problemas de saĂșde decorrentes da contaminação da ĂĄgua, realizou-se no Bairro do Jambeiro, localizado nas mediaçÔes da Universidade Federal do MaranhĂŁo, um projeto interdisciplinar que visou, pela divulgação dos dados da pesquisa cientĂ­fca, avaliar a ĂĄgua utilizada pelos moradores atravĂ©s de anĂĄlise fĂ­sico-quĂ­mica, microbiolĂłgica e parasitolĂłgica, de modo que os resultados permitissem a conscientização, atravĂ©s de atividades educacionais dos moradores. Os resultados endossam a precariedade de condiçÔes sanitĂĄrias encontradas nessa comunidade. Os poços, as torneiras e o cĂłrrego apresentam nĂ­veis de contaminação acima do recomendĂĄvel pela Resolução CONAMA e ANVISA, sendo, portanto, imprĂłprias para o consumo. Os exames parasitolĂłgicos revelaram alta prevalĂȘncia (91%) de enteroparasitoses nas crianças. A partir desses resultados os integrantes do projeto e seus parceiros realizaram palestras destinadas Ă  comunidade sobre os meios de tratamento da ĂĄgua, biologia dos parasitas e medidas proflĂĄticas das principais verminoses. Concomitante, ocorreu a entrega e esclarecimentos dos laudos da anĂĄlise fĂ­sico-quĂ­mica, microbiolĂłgica e parasitolĂłgica, onde houve a distribuição de remĂ©dios Ă s crianças que estavam infectadas.Descritores:  Enteroparasitos; Epidemiologia; PrevalĂȘncia.Abstract: The lack of basic conditions hygiene and sanitation, allied to grubbiness of water reservoirs and no use of fltered or boiled water, enhance the occurrence of health public problems. With the aim of contribute to awareness of the population about the health problems resulting from the water contamination, was held in the District of the Jambeiro, located near the Federal University of MaranhĂŁo, an interdisciplinary project the aimed, by disclosure of scientifc research, to evaluate the water used by population through physico-chemical, microbiological and parasitological analyses, so that the results allow awareness through educational activities of population. The results comproved the precarious sanitary conditions found in this community. The level contamination of the wells, taps and stream is higher than recommended by Resolution CONAMA and ANVISA, therefore, unft for consumption. The parasitological revealed a high prevalence (91%) of intestinal parasites in children. Based on these results the members of the project and its partners held talks for the community about the water treatment, biology of parasites and worms and of the main prophylactic measures. Concomitantly, there was the delivery and clarifcation of reports of physico-chemical, microbiological and parasitological, where there was the distribution of drugs to children who were infected.Descriptors: Enteroparasites; Epidemiology; Prevalence

    Loss-of-Function Mutations in PTPN11 Cause Metachondromatosis, but Not Ollier Disease or Maffucci Syndrome

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    Metachondromatosis (MC) is a rare, autosomal dominant, incompletely penetrant combined exostosis and enchondromatosis tumor syndrome. MC is clinically distinct from other multiple exostosis or multiple enchondromatosis syndromes and is unlinked to EXT1 and EXT2, the genes responsible for autosomal dominant multiple osteochondromas (MO). To identify a gene for MC, we performed linkage analysis with high-density SNP arrays in a single family, used a targeted array to capture exons and promoter sequences from the linked interval in 16 participants from 11 MC families, and sequenced the captured DNA using high-throughput parallel sequencing technologies. DNA capture and parallel sequencing identified heterozygous putative loss-of-function mutations in PTPN11 in 4 of the 11 families. Sanger sequence analysis of PTPN11 coding regions in a total of 17 MC families identified mutations in 10 of them (5 frameshift, 2 nonsense, and 3 splice-site mutations). Copy number analysis of sequencing reads from a second targeted capture that included the entire PTPN11 gene identified an additional family with a 15 kb deletion spanning exon 7 of PTPN11. Microdissected MC lesions from two patients with PTPN11 mutations demonstrated loss-of-heterozygosity for the wild-type allele. We next sequenced PTPN11 in DNA samples from 54 patients with the multiple enchondromatosis disorders Ollier disease or Maffucci syndrome, but found no coding sequence PTPN11 mutations. We conclude that heterozygous loss-of-function mutations in PTPN11 are a frequent cause of MC, that lesions in patients with MC appear to arise following a “second hit,” that MC may be locus heterogeneous since 1 familial and 5 sporadically occurring cases lacked obvious disease-causing PTPN11 mutations, and that PTPN11 mutations are not a common cause of Ollier disease or Maffucci syndrome

    Search for diboson resonances with boson-tagged jets in pp collisions at √s=13 TeV with the ATLAS detector

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    Narrow resonances decaying into WW, WZ or ZZ boson pairs are searched for in 36.7 fb−1 of proton–proton collision data at a centre-of-mass energy of √s=13 TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The diboson system is reconstructed using pairs of large-radius jets with high transverse momentum and tagged as compatible with the hadronic decay of high-momentum W or Z bosons, using jet mass and substructure properties. The search is sensitive to diboson resonances with masses in the range 1.2–5.0 TeV. No significant excess is observed in any signal region. Exclusion limits are set at the 95% confidence level on the production cross section times branching ratio to dibosons for a range of theories beyond the Standard Model. Model-dependent lower limits on the mass of new gauge bosons are set, with the highest limit set at 3.5 TeV in the context of mass-degenerate resonances that couple predominantly to bosons

    Search for high-mass resonances decaying to Ï„Îœ in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for high-mass resonances decaying to τ Îœ using proton-proton collisions at √ s = 13     TeV produced by the Large Hadron Collider is presented. Only τ -lepton decays with hadrons in the final state are considered. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1     fb − 1 . No statistically significant excess above the standard model expectation is observed; model-independent upper limits are set on the visible τ Îœ production cross section. Heavy W â€Č bosons with masses less than 3.7 TeV in the sequential standard model and masses less than 2.2–3.8 TeV depending on the coupling in the nonuniversal G ( 221 ) model are excluded at the 95% credibility level

    Development and validation of a targeted gene sequencing panel for application to disparate cancers

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    Next generation sequencing has revolutionised genomic studies of cancer, having facilitated the development of precision oncology treatments based on a tumour’s molecular profile. We aimed to develop a targeted gene sequencing panel for application to disparate cancer types with particular focus on tumours of the head and neck, plus test for utility in liquid biopsy. The final panel designed through Roche/Nimblegen combined 451 cancer-associated genes (2.01 Mb target region). 136 patient DNA samples were collected for performance and application testing. Panel sensitivity and precision were measured using well-characterised DNA controls (n = 47), and specificity by Sanger sequencing of the Aryl Hydrocarbon Receptor Interacting Protein (AIP) gene in 89 patients. Assessment of liquid biopsy application employed a pool of synthetic circulating tumour DNA (ctDNA). Library preparation and sequencing were conducted on Illumina-based platforms prior to analysis with our accredited (ISO15189) bioinformatics pipeline. We achieved a mean coverage of 395x, with sensitivity and specificity of >99% and precision of >97%. Liquid biopsy revealed detection to 1.25% variant allele frequency. Application to head and neck tumours/cancers resulted in detection of mutations aligned to published databases. In conclusion, we have developed an analytically-validated panel for application to cancers of disparate types with utility in liquid biopsy
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