2,515 research outputs found
Analysis of polymorphic membrane protein expression in cultured cells Identifies PmpA and PmpH of Chlamydia psittaci as candidate factors in pathogenesis and immunity to infection
The polymorphic membrane protein (Pmp) paralogous families of Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia abortus are putative targets for Chlamydia vaccine development. To determine whether this is also the case for Pmp family members of C. psittaci, we analyzed transcription levels, protein production and localization of several Pmps of C. psittaci. Pmp expression profiles were characterized using quantitative real-time PCR (RT-qPCR), immunofluorescence (IF) and immuno-electron microscopy (IEM) under normal and stress conditions. We found that PmpA was highly produced in all inclusions as early as 12 hpi in all biological replicates. In addition, PmpA and PmpH appeared to be unusually accessible to antibody as determined by both immunofluorescence and immuno-electron microscopy. Our results suggest an important role for these Pmps in the pathogenesis of C. psittaci, and make them promising candidates in vaccine development
Magnetic exchange coupling and Curie temperature of Ni(1+x)MnSb (x=0, 0.25, 0.5, 0.75, 1) from first principles
We study the dependence of magnetic interactions and Curie temperature in
Ni(1+x)MnSb system on the Ni concentration within the framework of the
density-functional theory. The calculation of the exchange parameters is based
on the super-cell and frozen-magnon approaches. The Curie temperatures, Tc, are
calculated within the random-phase approximation. In agreement with experiment
we obtain decrease of the Curie temperature with increasing Ni content.Comment: 3 pages, 2 figure
Mutations in splicing factor genes are a major cause of autosomal dominant retinitis pigmentosa in Belgian families
Purpose : Autosomal dominant retinitis pigmentosa (adRP) is characterized by an extensive genetic heterogeneity, implicating 27 genes, which account for 50 to 70% of cases. Here 86 Belgian probands with possible adRP underwent genetic testing to unravel the molecular basis and to assess the contribution of the genes underlying their condition.
Methods : Mutation detection methods evolved over the past ten years, including mutation specific methods (APEX chip analysis), linkage analysis, gene panel analysis (Sanger sequencing, targeted next-generation sequencing or whole exome sequencing), high-resolution copy number screening (customized microarray-based comparative genomic hybridization). Identified variants were classified following American College of Medical Genetics and Genomics (ACMG) recommendations.
Results : Molecular genetic screening revealed mutations in 48/86 cases (56%). In total, 17 novel pathogenic mutations were identified: four missense mutations in RHO, five frameshift mutations in RP1, six mutations in genes encoding spliceosome components (SNRNP200, PRPF8, and PRPF31), one frameshift mutation in PRPH2, and one frameshift mutation in TOPORS. The proportion of RHO mutations in our cohort (14%) is higher than reported in a French adRP population (10.3%), but lower than reported elsewhere (16.5-30%). The prevalence of RP1 mutations (10.5%) is comparable to other populations (3.5%-10%). The mutation frequency in genes encoding splicing factors is unexpectedly high (altogether 19.8%), with PRPF31 the second most prevalent mutated gene (10.5%). PRPH2 mutations were found in 4.7% of the Belgian cohort. Two families (2.3%) have the recurrent NR2E3 mutation p.(Gly56Arg). The prevalence of the recurrent PROM1 mutation p.(Arg373Cys) was higher than anticipated (3.5%).
Conclusions : Overall, we identified mutations in 48 of 86 Belgian adRP cases (56%), with the highest prevalence in RHO (14%), RP1 (10.5%) and PRPF31 (10.5%). Finally, we expanded the molecular spectrum of PRPH2, PRPF8, RHO, RP1, SNRNP200, and TOPORS-associated adRP by the identification of 17 novel mutations
Probing Plasmodium falciparum sexual commitment at the single-cell level
Background: Malaria parasites go through major transitions during their complex life cycle, yet the underlying differentiation pathways remain obscure. Here we apply single cell transcriptomics to unravel the program inducing sexual differentiation in Plasmodium falciparum. Parasites have to make this essential life-cycle decision in preparation for human-to-mosquito transmission. Methods: By combining transcriptional profiling with quantitative imaging and genetics, we defined a transcriptional signature in sexually committed cells. Results: We found this transcriptional signature to be distinct from general changes in parasite metabolism that can be observed in response to commitment-inducing conditions. Conclusions: This proof-of-concept study provides a template to capture transcriptional diversity in parasite populations containing complex mixtures of different life-cycle stages and developmental programs, with important implications for our understanding of parasite biology and the ongoing malaria elimination campaign
Evaluation of platform-switching in the peri-implant bone loss – a randomized controlled duble-blind split-mouth clinical trial
The objective of the present randomized controlled clinical study was to evaluate the influence of different implant/abutment horizontal mismatch size on marginal periimplantar bone loss. A total of 12 fully edentulous mandible patients were recruited for this study and received 4 external hexagon implants (Strong SW, SIN® - Implant System, São Paulo, Brazil), with a 4.5 mm of diameter and 13 mm of length, in the region between mentonian forams, to support a fixed total prosthesis. The prosthetic components installed on the implants were mini-abutment, all with 2 mm of height and prosthetic profile of 4.8 mm, with different diameter (4,5 mm - CC, 4, 1 mm - PS41, 3.8 mm - PS38 and 3.3 mm - PS33), thus determining different horizontal mismatches (0.2 mm, 0.35 mm and 0.6 mm) between the implant platform and the abutment (ie platform-switching). At the 1 and 3-year follow-up visits, clinical evaluations were performed (probing pocket depth (PPD), modified gingival index (mGI), and mucosal thickness (MTh). Periapical radiographs were also performed at baseline and 1, 3, 6, 12, 36 months implant placement, using the parallelism technique and a digital sensor (Schick CDR Elite, Schick Technologies, USA). 12 finite element models of a fully edentulous mandible with Ø 4.5 x 13 mm implants, abutments, abutment screws, bar, prosthesis and prosthesis retention screws were constructed, simulating each patient included in the study. Bone equivalent strain (EQV strain) and the abutment screws and prosthesis retaining screws EQV stress a have been evaluated. The PS33 configuration (0.6 mm horizontal adaptation) had a significantly lower bone loss (0.74 ± 0.58 mm) than the CC (1.88 ± 0.41 mm), after 3 years of follow-up and statistically similar to PS38 (0.35 mm horizontal misfit) (1.14 ± 0.94 mm). The DC presented bone loss similar to the PS41 configuration (1.65 ± 0.68 mm). The AEF performed in the present study demonstrated a higher efficiency in the PS in reducing peri-implant bone deformation only for the PS38 configuration. A horizontal mismatch size of less than 0.35 mm, did not result in reduction of the marginal deformations compared to the CC. There were no differences between the groups in any of the clinical parameters evaluated. Thus, within the limitations of the present study it was possible to demonstrate that the efficacy of PS in the preservation of the marginal bone is directly related to the horizontal implant / abutment mismatch size.Tese (Doutorado)O objetivo desse estudo clínico randomizado controlado foi avaliar a influência de diferentes tamanhos de desadaptações horizontais entre a plataforma do implante e o componente protético sobre a perda óssea periimplantar marginal. Um total de 12 pacientes desdentados totais inferiores foram recrutados para este estudo e receberam 4 implantes do tipo hexágono externo (Strong SW, SIN® - Sistema de Implantes, São Paulo, Brasil), com plataforma de 4,5 mm de diâmetro e comprimento de 13 mm, na região interforames mentonianos, para suportar uma prótese fixa do tipo protocolo. Os componentes protéticos instalados nos implantes foram do tipo mini-abutment, todos com 2 mm de altura e perfil protético de 4.8 mm, diferindo apenas no diâmetro da base de adaptação do componente na plataforma do implante (4,5 mm - CC, 4,1 mm – PS41, 3,8 mm – PS38 e 3,3 mm – PS33), determinando assim, respectivamente, as diferentes “desadaptações horizontais” (0,2 mm, 0,35 mm e 0,6 mm) entre o implante e o pilar (isto é, o “platform-switching”). Nas visitas de acompanhamento de 1 e 3 anos, foram realizadas avaliações clínicas (profundidade de bolsa à soldagem (PPD), índice gengival modificado (mGI) e espessura da mucosa (MTh). Também foram feitas radiografias periapicais no início do estudo (instalação do componente protético) e aos 1, 3, 6, 12 e 36 meses após, usando a técnica de paralelismo e um sensor digital (Schick CDR Elite, Schick Technologies, EUA). 12 modelos em elementos finitos de uma mandíbula totalmente edêntula com implantes Ø 4,5 x 13 mm, pilares, parafusos de pilares, barra, prótese e parafusos de retenção da prótese foram construídos, simulando cada paciente incluído no estudo. Foram avaliados o pico de deformação equivalente (deformação EQV) no osso e o pico de tensão von Mises (tensão EQV) nos parafusos dos pilares e nos parafusos de retenção da prótese. No presente trabalho, a configuração PS33 (0,6 mm de desadaptação horizontal) apresentou uma perda óssea significativamente menor (0.74 ± 0.58 mm) que a CC (1.88 ± 0.41 mm), após 3 anos de acompanhamento e estatisticamente similar à PS38 (0,35 mm de desadaptação horizontal) (1.14 ± 0.94 mm). A CC apresentou perdas ósseas semelhantes à configuração PS41 (1.65 ± 0.68 mm). A AEF realizada no presente estudo demonstrou uma maior eficiência do PS em reduzir as deformações ósseas periimplantares somente a partir da configuração PS38. Uma desadaptação horizontal menor que 0,35 mm não resultou em diminuição das deformações marginais comparada com a CC. Não houve diferenças entre os grupos em relação a nenhum dos parâmetros clínicos avaliados. Sendo assim, dentro das limitações do presente estudo foi possível demonstrar que a eficácia do PS na preservação do osso marginal está diretamente relacionada ao tamanho da desadaptação horizontal implante/abutment
Natureza e pátios escolares : percepção, conhecimento ambiental e efeitos no comportamento pró-ambiental de crianças em duas escolas públicas do município de Viamão-RS
O objetivo deste estudo é investigar a percepção, conhecimento ambiental e efeitos que o contato com elementos naturais, produzem no comportamento pró-ambiental de crianças. Participaram do estudo 132 crianças e pré-adolescentes de ambos os sexos, com idades entre 9 e 12 anos. Matriculados no 4º e 5º ano do Ensino Fundamental. Também se buscou conhecer como as crianças da amostra percebem, definem e interagem com a natureza. Para tanto, este estudo foi realizado em duas Etapas. Na primeira, quantitativa, se utilizou questionário sociodemográfico, Escala de natureza percebida nos pátios e entorno escolar, Escala de frequência de contato com a natureza, Escala de conduta pró-ambiental e Escala de satisfação dos participantes com a atividade proposta pelo estudo. Na segunda Etapa, qualitativa, foi investigado como as crianças dessa amostra definem e percebem a natureza e pátio escolar. Nessa atividade foi utilizado desenho livre, mostra de imagens fotografadas por elas e entrevista semiestruturada. Os resultados assinalaram que o distanciamento do contato com a natureza, ocasionado pela urbanização, contribui para a construção de um sentido idealizado da natureza pelas crianças e que o contato com a natureza é um potencializador de comportamentos pró-ambientais
Panel Discussion: American Tax Credits and Foreign Taxes and Royalties
This panel discussion primarily focuses on U.S. tax policy with regards to international oil companies
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