318 research outputs found

    AIP1 is a novel Agenet/Tudor domain protein from Arabidopsis that interacts with regulators of DNA replication, transcription and chromatin remodeling

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    Background: DNA replication and transcription are dynamic processes regulating plant development that are dependent on the chromatin accessibility. Proteins belonging to the Agenet/Tudor domain family are known as histone modification "readers" and classified as chromatin remodeling proteins. Histone modifications and chromatin remodeling have profound effects on gene expression as well as on DNA replication, but how these processes are integrated has not been completely elucidated. It is clear that members of the Agenet/Tudor family are important regulators of development playing roles not well known in plants. Methods: Bioinformatics and phylogenetic analyses of the Agenet/Tudor Family domain in the plant kingdom were carried out with sequences from available complete genomes databases. 3D structure predictions of Agenet/Tudor domains were calculated by I-TASSER server. Protein interactions were tested in two-hybrid, GST pulldown, semi-in vivo pulldown and Tandem Affinity Purification assays. Gene function was studied in a T-DNA insertion GABI-line. Results: In the present work we analyzed the family of Agenet/Tudor domain proteins in the plant kingdom and we mapped the organization of this family throughout plant evolution. Furthermore, we characterized a member from Arabidopsis thaliana named AIP1 that harbors Agenet/Tudor and DUF724 domains. AIP1 interacts with ABAP1, a plant regulator of DNA replication licensing and gene transcription, with a plant histone modification "reader" (LHP1) and with non modified histones. AIP1 is expressed in reproductive tissues and its down-regulation delays flower development timing. Also, expression of ABAP1 and LHP1 target genes were repressed in flower buds of plants with reduced levels of AIP1. Conclusions: AIP1 is a novel Agenet/Tudor domain protein in plants that could act as a link between DNA replication, transcription and chromatin remodeling during flower development

    Uma Abordagem sobre a Escassez de Professores para o Ensino Médio e o Perfil dos Ingressantes em um Curso de Licenciatura em Química

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    O trabalho aponta a baixa procura por cursos de formação de professores de Química, a partir de dados de oferta de vagas e da relação candidato-vaga nos últimos Vestibulares, e aborda a escassez de professores para o Ensino Médio a partir de dados do INEP. Usando informações do Censo escolar 2011, estimou-se a demanda de professores de Química no município e no Estado do Rio de Janeiro. Com o objetivo de conhecer o perfil e as expectativas dos alunos que buscam o curso de Licenciatura em Química da UERJ foram aplicados questionários aos estudantes ingressantes no curso nos anos de 2011 e 2012. A pesquisa realizada mostrou que 67% dos ingressantes gostariam de lecionar no Ensino Médio, mas somente 23% pretende exercer a profissão de professor ao se formar. Abaixa atratividade pela docência em Química foi discutida com base na análise do discurso dos ingressantes

    Validation of the WHOQOL-Bref instrument in Brazilian sign language (Libras)

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    Purpose: the recognition of the Brazilian Sign Language (Libras) as the official language of the Brazilian deaf, in 2002, reaffirms the linguistic and cultural particularities of the deaf population. Therefore, there is a lack of a validated instrument for assessing the Quality of Life of deaf people using Libras. With authorization from the World Health Organization (WHO), a version of the WHOQOL-Bref in Libras was developed, called WHOQOL-Bref/Libras. However, its psychometric properties have not been examined as yet. Therefore, the purpose of this work is to perform the psychometric validation of the WHOQOL-Bref/Libras. Methods: WHOQOL-Bref/Libras and a sociodemographic questionnaire were applied to 311 deaf people from the five Brazilian regions. To assess temporal stability, the questionnaire was readministered to 52 deaf people, over an interval of 2 weeks. Results: WHOQOL-Bref/Libras demonstrated satisfactory psychometric values for reliability, discriminant and construct validity, temporal stability, and internal consistency. Cronbach's alpha coefficient showed satisfactory values for each of the WHOQOL-Bref domains: Physical health (0.641), Psychological (0.705), Environment (0.710), and Overall-Bref domains (0.873). The WHOQOL-Bref/Libras is the appropriate option to assess the quality of life of deaf people who communicate through Libras. Conclusion: WHOQOL-Bref/Libras had a satisfactory psychometric performance; therefore, it is a valid option that will provide autonomous participation for the deaf in quality of life investigations

    Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

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    The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

    Síndrome de Pendred causada por mutação em homozigoze no gene SLC26A4 em uma família brasileira consangüínea

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    ABSTRACTPendred Syndrome (PS) is an autossomal recessive disorder characterized by sensorineural deafness, goiter and iodide organification defect. The hearing loss is associated with inner ear abnormalities, ranging from an isolated enlarged vestibular aqueduct (EVA) to a typical coclear dysplasia. Mutations in the gene that encodes pendrin (SLC26A4), a chloride/iodide transporter, have been shown to be associated with PS. We describe the clinical and molecular characteristics of a large consanguineous family harboring a mutation in the SLC26A4 gene. The proband was a 26-year-old deaf Brazilian woman who presented a bulky multinodular goiter and hypothyroidism since puberty. Five other siblings were deaf: one brother had a similar phenotype, three siblings also had goiters but normal thyroid function tests, and one brother had only a subtle thyroid enlargement. Other 4 siblings had no thyroid or hearing disorder. Parents were first degree cousins and had normal hearing. The mother was healthy, except for subclinical hypothyroidism; the father was deceased. A perchlorate test in the proband showed a discharge of 21% of the incorporated iodide 2h after the administration of 1g of KClO4. Audiological examinations showed profound hearing loss in all deaf subjects; CT and MRI of the temporal bones showed EVA in all of them. Genomic DNA was isolated from whole blood, from the 6 affected and 4 unaffected siblings, the mother and control. The coding region of the PDS gene (exons 2-21), including exon/intron boundaries, were amplified by PCR and sequenced. A single base-pair (T) deletion at position 1197 of exon 10 was detected in homozygous state in the 6 deaf siblings. The mother and 2 unaffected siblings were heterozygous for this mutation, which has been described by Everett et al. The 1197delT mutation is predicted to result in a frameshift and a truncated protein. The existence of PS phenocopies and intrafamilial phenotypic variability are well documented. The definite diagnosis requires molecular analysis. Our study illustrates the value and challenges of mutational analysis in selected patients with PS. __________________________________________________________________________________ RESUMOA syndrome de Pendred (SP) é uma doença autossômica recessiva caracterizada por surdez neurossensorial, bócio e defeito de organificação do iodo. A perda auditiva está associada a anormalidades do ouvido interno, desde a dilatação isolada do aqueduto vestibular (DAV) até uma típica displasia coclear. Mutações no gene que codifica a pendrina (SLC26A4), um transportador de cloreto/iodeto, têm sido associadas à SP. Descrevemos as características clínicas e moleculares de uma grande família consangüínea portadora de uma mutação no gene SLC26A4. O caso-índice era uma paciente do sexo feminino, brasileira, 26 anos, portadora de surdez congênita, que apresentava um volumoso bócio multinodular e hipotireoidismo desde a puberdade. Outros cinco irmãos eram surdos: um irmão tinha fenotipo semelhante, três também tinham bócio, porém com função tiroideana normal e um irmão tinha apenas um discreto aumento da tiróide. Outros quatro irmãos não apresentavam alteração tiroideana ou auditiva. Os pais eram primos de primeiro grau e tinham audição normal. A mãe era saudável, exceto por hipotireoidismo subclínico; o pai era falecido. O teste do perclorato no caso-índice revelou a liberação de 21% do iodo incorporado duas horas após a administração de 1 g de KClO4. Os exames audiológicos mostraram perda auditiva profunda em todos os indivíduos afetados; TC e RMN dos ossos temporais mostraram DAV em todos eles. O DNA genômico foi isolado do sangue total dos seis irmãos afetados e dos quatro não-afetados, da mãe e do controle. A região codificante do gene PDS (éxons 2-21), incluindo as junções éxon/íntron, foram amplificadas por PCR e seqüenciadas. Foi detectada a deleção de uma base (T) na posição 1197 do éxon 10, em homozigoze, nos seis irmãos afetados. A mãe e dois irmãos não-afetados eram heterozigotos para a mutação, que foi descrita inicialmente por Everett e cols. A mutação 1197delT provavelmente resulta em um erro de fase de leitura (frameshift) e em uma proteína truncada. A existência de fenocópias da SP e a variabilidade fenotípica intrafamiliar são bem conhecidas. O diagnóstico definitivo requer análise molecular. O presente estudo ilustra o valor e os desafios da análise mutacional em pacientes selecionados com SP

    R534C mutation in hERG causes a trafficking defect in iPSC-derived cardiomyocytes from patients with type 2 long QT syndrome

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    Patient-specific cardiomyocytes obtained from induced pluripotent stem cells (CM-iPSC) offer unprecedented mechanistic insights in the study of inherited cardiac diseases. The objective of this work was to study a type 2 long QT syndrome (LQTS2)-associated mutation (c.1600C > T in KCNH2, p.R534C in hERG) in CM-iPSC. Peripheral blood mononuclear cells were isolated from two patients with the R534C mutation and iPSCs were generated. In addition, the same mutation was inserted in a control iPSC line by genome editing using CRISPR/Cas9. Cells expressed pluripotency markers and showed spontaneous differentiation into the three embryonic germ layers. Electrophysiology demonstrated that action potential duration (APD) of LQTS2 CM-iPSC was significantly longer than that of the control line, as well as the triangulation of the action potentials (AP), implying a longer duration of phase 3. Treatment with the IKr inhibitor E4031 only caused APD prolongation in the control line. Patch clamp showed a reduction of IKr on LQTS2 CM-iPSC compared to control, but channel activation was not significantly affected. Immunofluorescence for hERG demonstrated perinuclear staining in LQTS2 CM-iPSC. In conclusion, CM-iPSC recapitulated the LQTS2 phenotype and our findings suggest that the R534C mutation in KCNH2 leads to a channel trafficking defect to the plasma membrane.Fil: Mesquita, Fernanda C. P.. Universidade Federal do Rio de Janeiro; BrasilFil: Arantes, Paulo C.. Universidade Federal do Rio de Janeiro; BrasilFil: Kasai Brunswick, Tais H.. Universidade Federal do Rio de Janeiro; BrasilFil: Araujo, Dayana S.. Universidade Federal do Rio de Janeiro; BrasilFil: Gubert, Fernanda. Universidade Federal do Rio de Janeiro; BrasilFil: Monnerat, Gustavo. Universidade Federal do Rio de Janeiro; BrasilFil: Silva dos Santos, Danúbia. Universidade Federal do Rio de Janeiro; BrasilFil: Neiman, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Leitão, Isabela C.. Universidade Federal do Rio de Janeiro; BrasilFil: Barbosa, Raiana A. Q.. Universidade Federal do Rio de Janeiro; BrasilFil: Coutinho, Jorge L.. National Institute Of Cardiology; BrasilFil: Vaz, Isadora M.. Pontificia Universidad Catolica de Parana; BrasilFil: dos Santos, Marcus N.. Universidade Federal do Rio de Janeiro; BrasilFil: Borgonovo, Tamara. Pontificia Universidad Catolica de Parana; BrasilFil: Cruz, Fernando E. S.. National Institute of Cardiology; BrasilFil: Miriuka, Santiago Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Medei, Emiliano H.. Universidade Federal do Rio de Janeiro; BrasilFil: Campos de Carvalho, Antonio C.. Universidade Federal do Rio de Janeiro; Brasil. National Institute of Cardiology; Brasil. National Institute for Science and Technology in Regenerative Medicine; BrasilFil: Carvalho, Adriana B.. Universidade Federal do Rio de Janeiro; Brasil. National Institute for Science and Technology in Regenerative Medicine; Brasi
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