83 research outputs found

    Survival trends of patients with oral and oropharyngeal cancer treated at a cancer center in Sa˜o Paulo, Brazil

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    OBJECTIVE: We aimed to estimate the overall survival (OS) and conditional survival (CS) in patients diagnosed with oral and oropharyngeal squamous cell carcinoma (SCC) and to determine their survival trends. METHODS: The study included all consecutive patients treated at the A.C. Camargo Cancer Center for oral or oropharyngeal SCC between 2001 and 2012. Data were obtained from the Hospital Cancer Registry. OS and CS were analyzed using the Kaplan-Meier method to evaluate the probability of survival with Cox predictor models. RESULTS: Data of 505 oral and 380 oropharyngeal SCC patients obtained in 2001–2006 and 2007–2012 were analyzed. Most of the oral SCC (59%) and oropharyngeal SCC (90%) patients had stages III–IV SCC. The 5-year OS for patients with oral SCC was 51.7%, with no significant difference between the first and second periods. The CS rates in 2007–2012 were 65% after the first year and 86% up to the fifth year. For oropharyngeal SCC, the 5-year OS rate was 45.0% in the first period. The survival rate increased to 49.1% from 2007 to 2012, with a reduction in the risk of death (HR=0.69;0.52–09.2). The CS estimates from 2007 to 2012 were 59% after the first year and 75% up to the fifth year. CONCLUSION: Survival across the two time periods remained stable for oral SCC but showed a significant increase for oropharyngeal SCC, possibly because of improvements in the patients’ response to radiotherapy, such as intensity-modulated radiation therapy, and the use of more accurate diagnostic imaging approaches

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Síndrome de Chiari e Hidrossiringomielia com comprometimento neurológico: um relato de caso

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    A Malformação de Chiari (MC) pertence a um amplo grupo de raras deformidades estruturais da junção craniocerebelomedular. O tipo I da doença caracteriza-se pela herniação tonsilar ou amigdaliana cerebelar devido à anomalia da base do crânio e da parte superior da coluna cervical, além de a porção medial do lobo inferior do cerebelo pelo canal cervical também se protuberar através do forame magno, impedindo que o líquor flua normalmente através do canal. A real prevalência da doença é desconhecida, pois muitos pacientes com herniação cerebelar são assintomáticos e o problema agrava-se na fase adulta, com queixas de cefaleia intensa e, por vezes, parestesia. O objetivo deste estudo é relatar um caso de síndrome de Chiari (SC) em uma paciente de 53 anos, ao abordar sua apresentação clínica, diagnóstico e tratamento. Paciente do sexo feminino, 53 anos, foi admitida em um hospital da rede pública de referência se queixando de cefaleia occipital intensa e cervicalgia com irradiação da dor para os membros superiores, acompanhada de parestesia nos quatro segmentos. Relatou já sentir dor há 2 anos, mas apresentou piora do quadro clínico há 8 meses. Foi, também, observada incontinência urinária devido à dissinergia detrusora-esfincteriana por provável bexiga neurogênica. Foi, então, realizado exame de imagem de ressonância magnética (RNM) do crânio e da coluna cervical, com obtenção de sequências ponderadas em T1, T2 e STIR, nos planos sagital e transverso com contraste, o qual evidenciou leve alargamento medular, além de sinais de hidrossiringomielia difusa, com hipossinal na sequência T2 intramedular na altura de D1-D2 (coluna dorsal). Foi notada discreta herniação das tonsilas cerebelares junta ao forame magno, típica da SC, sendo, por fim, confirmado o diagnóstico. A paciente, no entanto, não apresentava hidrocefalia, mesmo com a interrupção do fluxo do líquido cefalorraquidiano (LCR) para o canal vertebral. Ela encaixou- se nos parâmetros de indicação cirúrgica, sendo realizada craniotomia occipital, com acesso ao plexo coroide do quarto ventrículo do tronco encefálico com o intuito de elevar as tonsilas cerebelares baixas, herniadas no canal espinhal cervical e bloqueando o fluxo do LCR. Após a descompressão craniocervical, o curso do líquor foi restaurado e a paciente foi, por fim, encaminhada à sala de recuperação pós-operatória. A SC é uma rara doença que apresenta quadro clínico e alterações radiológicas complexas e extensas e, por vezes, o diagnóstico é retardado devido à inespecificidade dos sintomas confundidos com cervicalgias e cefaleias comuns. A hipótese diagnóstica deve ser embasada nas queixas do paciente, na anamnese minuciosa, exame clínico e nos exames de imagens, sendo a prevalência desta patologia de difícil definição e com faixas etárias distintas

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types
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