577 research outputs found

    Tumores Odontogénicos Queratoquísticos Múltiplos em Síndrome de Gorlin-Goltz

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    Introdução: A síndrome de Gorlin‐Goltz ou síndrome dos basaliomas nevoides múltiplos é uma patologia autossómica dominante, provocada por uma mutação no gene de supressão tumoral PTCH, localizado no cromossoma 9 (q22,3‐q31). As principais manifestações clínicas são o aparecimento de múltiplos carcinomas de células basais, associado a alterações osteoesqueléticas e a tumores odontogénicos queratoquísticos. Estes últimos estão presentes em 80% dos casos e podem ser diagnosticados nas primeiras décadas de vida, constituindo geralmente a primeira manifestação da síndrome. São habitualmente indolores, podem ser múltiplos, afetando qualquer região dos maxilares e estando quase sempre relacionados com alterações da erupção dentária. É frequente a presença de outras anomalias craniofaciais, nomeadamente fenda lábio‐palatina, bosseladura frontal e temporoparietal, macrocefalia e hipertelorismo. Descrição do caso clínico: Rapaz de 13 anos, proveniente dos Açores, referenciado a consulta hospitalar por múltiplas lesões hipertransparentes dos maxilares; antecedentes de parto pré‐termo, macrocefalia, pectus carinatus, hipercifose dorsal e atrofia dos músculos da cintura escapular. Objetivamente, apresentava bosseladura frontal e temporoparietal, face assimétrica, implantação baixa dos pavilhões auriculares e tumefação mandibular bilateral. No exame objetivo, reconhecia‐se marcado abaulamento vestibular do 3.° e 4.° quadrantes. A ortopantomografia revelou 5 lesões hipertransparentes, 4 na mandíbula e uma na maxila. Pela suspeita de síndrome de Gorlin‐Goltz foram também pedidas radiografias do crânio, tórax e extralongo da coluna, reforçando a suspeita diagnóstica inicial, pela presença de calcificação da foice cerebral, costelas aplanadas e bífidas e múltiplas alterações vertebrais. Tendo em conta a idade, a dimensão das lesões e a probabilidade de recidiva, optou‐se por uma abordagem conservadora inicial, pela descompressão pré‐cirúrgica das lesões com tubos acrílicos, para posterior enucleação. Discussão e conclusões: A suspeita desta síndrome deve desencadear uma avaliação sistémica que permita o diagnóstico precoce e um seguimento apropriado, de modo a reduzir a morbilidade e a mortalidade associadas às lesões potencialmente malignas. Desconhece‐se a prevalência real desta síndrome em Portugal, não deixando de ser curioso que alguns dos doentes diagnosticados nesta unidade sejam oriundos do arquipélago dos Açores, sugerindo um possível cluster genético.info:eu-repo/semantics/publishedVersio

    Light propagation and Anderson localization in disordered superlattices containing dispersive metamaterials: Effects of correlated disorder

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We have investigated the effects of disorder correlations on light propagation and Anderson localization in one-dimensional dispersive metamaterials. We consider and compare the cases where disorder is uncorrelated to situations where it is totally correlated and anticorrelated. The photonic gaps of the corresponding periodic structure are not completely destroyed by the presence of disorder, which leads to minima in the localization length. In the vicinities of a gap, the behavior of the localization length depends crucially on the physical origin of the gap (Bragg or non-Bragg gaps). Within a Bragg gap, the localization length increases as the degree of disorder increases, an anomalous behavior that only occurs for the uncorrelated and completely correlated cases. In these cases, minima of the localization length at the positions of Bragg gaps are shifted by increasing disorder, which does not occur for the anticorrelated case, where the positions of the minima remain unaltered. Minima in the localization length corresponding to non-Bragg gaps are not shifted by increasing disorder, albeit the widths of these minima are changed. We have found that the asymptotic behavior for the localization length xi proportional to lambda(6) for disordered metamaterials is not affected by correlations. Finally, we have investigated the role of absorption on the delocalized Brewster modes and argue that it could be mitigated in light of the state-of-the-art of metamaterials research.849Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brazilian Agency FUJBConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Remarks on (1q)(1-q) expansion and factorization approximation in the Tsallis nonextensive statistical mechanics

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    The validity of (1-q) expansion and factorization approximations are analysed in the framework of Tsallis statistics. We employ exact expressions for classical independent systems (harmonic oscillators) by considering the unnormalized and normalized constrainsts. We show that these approxiamtions can not be accurate in the analysis of systems with many degrees of freedom.Comment: Latex, 6 pages, 2 figure

    Plasmodium knowlesi Genome Sequences from Clinical Isolates Reveal Extensive Genomic Dimorphism.

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    Plasmodium knowlesi is a newly described zoonosis that causes malaria in the human population that can be severe and fatal. The study of P. knowlesi parasites from human clinical isolates is relatively new and, in order to obtain maximum information from patient sample collections, we explored the possibility of generating P. knowlesi genome sequences from archived clinical isolates. Our patient sample collection consisted of frozen whole blood samples that contained excessive human DNA contamination and, in that form, were not suitable for parasite genome sequencing. We developed a method to reduce the amount of human DNA in the thawed blood samples in preparation for high throughput parasite genome sequencing using Illumina HiSeq and MiSeq sequencing platforms. Seven of fifteen samples processed had sufficiently pure P. knowlesi DNA for whole genome sequencing. The reads were mapped to the P. knowlesi H strain reference genome and an average mapping of 90% was obtained. Genes with low coverage were removed leaving 4623 genes for subsequent analyses. Previously we identified a DNA sequence dimorphism on a small fragment of the P. knowlesi normocyte binding protein xa gene on chromosome 14. We used the genome data to assemble full-length Pknbpxa sequences and discovered that the dimorphism extended along the gene. An in-house algorithm was developed to detect SNP sites co-associating with the dimorphism. More than half of the P. knowlesi genome was dimorphic, involving genes on all chromosomes and suggesting that two distinct types of P. knowlesi infect the human population in Sarawak, Malaysian Borneo. We use P. knowlesi clinical samples to demonstrate that Plasmodium DNA from archived patient samples can produce high quality genome data. We show that analyses, of even small numbers of difficult clinical malaria isolates, can generate comprehensive genomic information that will improve our understanding of malaria parasite diversity and pathobiology

    β-Amyloid 25-35 Peptide Reduces the Expression of Glutamine Transporter SAT1 in Cultured Cortical Neurons

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    β-Amyloid (Aβ) peptides may cause malfunction and death of neurons in Alzheimer’s disease. We investigated the effect of Aβ on key transporters of amino acid neurotransmission in cells cultured from rat cerebral cortex. The cultures were treated with Aβ(25-35) at 3 and 10 μM for 12 and 24 h followed by quantitative analysis of immunofluorescence intensity. In mixed neuronal–glial cell cultures (from P1 rats), Aβ reduced the concentration of system A glutamine transporter 1 (SAT1), by up to 50% expressed relative to the neuronal marker microtubule-associated protein 2 (MAP2) in the same cell. No significant effects were detected on vesicular glutamate transporters VGLUT1 or VGLUT2 in neurons, or on glial system N glutamine transporter 1 (SN1). In neuronal cell cultures (from E18 rats), Aβ(25-35) did not reduce SAT1 immunoreactivity, suggesting that the observed effect depends on the presence of astroglia. The results indicate that Aβ may impair neuronal function and transmitter synthesis, and perhaps reduce excitotoxicity, through a reduction in neuronal glutamine uptake

    Mutation detection analysis of a region of 16S-like ribosomal RNA gene of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii

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    <p>Abstract</p> <p>Background</p> <p>The level of intra-species genetic variation in <it>Entamoeba histolytica, Entamoeba dispar </it>and <it>Entamoeba moshkovskii </it>populations in a localized geographic area, like Puducherry, India, remains unknown.</p> <p>Methods</p> <p>In the present study the existence of genetic variation in the nested multiplex polymerase chain reaction (NM-PCR) amplified region of the 16S-like ribosomal RNA genes of <it>E. histolytica, E. dispar </it>and <it>E. moshkovskii </it>was investigated by riboprinting and single strand conformation polymorphism (SSCP) analysis.</p> <p>Results</p> <p>We found that 70 stool specimens were positive for <it>E. histolytica</it>, 171 stool specimens were positive for <it>E. dispar</it>, and 37 stool specimens were positive for <it>E. moshkovskii </it>by NM-PCR. Ninety liver abscess pus specimens, 21 urine specimens, and 8 saliva specimens were positive for <it>E. histolytica </it>by NM-PCR. Riboprinting analysis detected a mutation in the PCR product of only one <it>E. histolytica </it>isolate from a stool specimen. However, SSCP analysis detected mutations in the PCR products of five <it>E. histolytica </it>isolates and three <it>E. moshkovskii </it>isolates from stool specimens, and one <it>E. histolytica </it>isolate from a saliva specimen. The mutations detected by riboprinting and SSCP analysis were confirmed by sequencing. All the nucleotide sequences showing mutations in this study have already been deposited into the NCBI GenBank database under accession numbers [GenBank: <ext-link ext-link-type="gen" ext-link-id="EF682200">EF682200</ext-link> to GenBank: <ext-link ext-link-type="gen" ext-link-id="EF682208">EF682208</ext-link>].</p> <p>Conclusion</p> <p>The present study has revealed the subsistence of mutations in the ribosomal RNA genes of <it>E. histolytica </it>and <it>E. moshkovskii</it>, which points towards the existence of intra-species genetic variation in <it>E. histolytica </it>and <it>E. moshkovskii </it>isolates infecting humans.</p
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