63 research outputs found

    Neoadjuvant radiochemotherapy in the treatment of fixed and semi-fixed rectal tumors. Analysis of results and prognostic factors

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    PURPOSE: To report the retrospective analysis of patients with locally advanced rectal cancer treated with neodjuvant radiochemotherapy. METHODS AND MATERIALS: From January 1994 to December 2003, 101 patients with fixed (25%) or semi-fixed (75%) rectal adenocarcinoma were treated by preoperative radiotherapy with a dose of 45Gy at the whole pelvis and 50.4Gy at primary tumor, concomitant to four weekly chemotherapies with 5-Fluorouracil (425 mg/m(2)) and Leucovorin (20 mg/m(2)). In 71 patients (70.3%) the primary tumor was located up to 6 cm from the anal verge and in 30 (29.7%) from 6.5 cm to 10 cm. Age, gender, tumor fixation, tumor distance from the anal verge, clinical response, surgical technique, and postoperative TNM stage were the prognostic factors analyzed for overall survival (OS), disease-free survival (DFS), and local control (LC) at five years. RESULTS: Median follow-up time was 38 months (range, 2–141). Complete response was observed in eight patients (7.9%), partial in 54 (53.4%) and absence in 39 (38.7%). OS, DFS and LC were 52.6%, 53.8%, and 75.9%, respectively. Distant metastasis occurred in 40 (39.6%) patients, local recurrence in 20 (19.8%) and both in 16 (15.8%). Patients with fixed tumors had lower OS (17% Vs 65.6%; p < 0.001), DFS (31.2% Vs 60.9%; p = 0.005), and LC (58% Vs 82%; p = 0.004). Patients with tumors more than 6 cm above the anal verge had better LC (93% Vs 69%; p = 0.04). The postoperative TNM stage was a significant factor for DFS (I:64.1%, II:69.6%, III:35.2%, IV:11.1%; p < 0.001) and for LC (I:75.7%, II: 92.9%, III:54.1%, IV:100%; p = 0.005). Patients with positive lymph nodes had worse OS (37.9% Vs 70.4%, p = 0.006), DFS (32% Vs 72.7%, p < 0.001) and LC (56.2% Vs 93.4%; p < 0.001). CONCLUSION: This study suggests that the neoadjuvant treatment employed was effective for local control. Fixation of the lesion and lymph nodes metastasis were the main adverse prognostic factors. Distant failures were frequent, supporting the need of new drugs for adjuvant chemotherapy

    Polymorphisms in the MBL2 gene are associated with the plasma levels of MBL and the cytokines IL-6 and TNF-α in severe COVID-19

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    IntroductionMannose-binding lectin (MBL) promotes opsonization, favoring phagocytosis and activation of the complement system in response to different microorganisms, and may influence the synthesis of inflammatory cytokines. This study investigated the association of MBL2 gene polymorphisms with the plasma levels of MBL and inflammatory cytokines in COVID-19.MethodsBlood samples from 385 individuals (208 with acute COVID-19 and 117 post-COVID-19) were subjected to real-time PCR genotyping. Plasma measurements of MBL and cytokines were performed by enzyme-linked immunosorbent assay and flow cytometry, respectively.ResultsThe frequencies of the polymorphic MBL2 genotype (OO) and allele (O) were higher in patients with severe COVID-19 (p&lt; 0.05). The polymorphic genotypes (AO and OO) were associated with lower MBL levels (p&lt; 0.05). IL-6 and TNF-α were higher in patients with low MBL and severe COVID-19 (p&lt; 0.05). No association of polymorphisms, MBL levels, or cytokine levels with long COVID was observed.DiscussionThe results suggest that, besides MBL2 polymorphisms promoting a reduction in MBL levels and therefore in its function, they may also contribute to the development of a more intense inflammatory process responsible for the severity of COVID-19

    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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    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 understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    Riqueza e similaridade florística de oito remanescentes florestais no norte de Minas Gerais, Brasil

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    Os objetivos deste estudo foram caracterizar e comparar a composição florística de oito fragmentos de Mata Seca Calcária e Caatinga Arbórea localizados no norte do Estado de Minas Gerais. O levantamento das espécies arbóreas foi realizado através de visitas periódicas aos fragmentos para coleta de material botânico. Nos oito fragmentos foram encontradas 114 espécies arbóreas pertencentes a 40 famílias botânicas. Dentre as 89 espécies encontradas nos fragmentos de Mata Seca, 37 (42%) foram peculiares a essa formação. No entanto, das 75 espécies amostradas nos remanescentes de Caatinga Arbórea, 25 (33%) ocorreram apenas nesses fragmentos. A análise de agrupamento sugere que a composição florística dos fragmentos é afetada pela fitofisionomia e pelas condições bioecológicas locais a que estes fragmentos estão submetidos. Além disso, a relação observada entre a área dos fragmentos e o número de espécies arbóreas, evidenciou que área é um bom indicador da riqueza de espécies arbóreas nos fragmentos florestais. Portanto, os resultados deste estudo indicaram que fatores históricos (fitofisionomia) e ecológicos (área dos fragmentos e ocorrência de perturbações antrópicas) constituem importantes elementos caracterizadores da composição e riqueza de espécies em fragmentos florestais do norte de Minas Gerais.The objective of this study was to characterize and compare the floristic composition of eight fragments of Calcareous Dry Forest and Arboreal Caatinga in the north of Minas Gerais State, Brazil. The survey of the tree species was performed by periodic visits to the fragments. We found 114 tree species belonging to 40 botanical families in the eight fragments. Of a total of 89 species found in the Calcareous Dry Forest fragments, 37 (42%) were typical of this formation. On the other hand, from the 75 species sampled in the Arboreal Caatinga remnants, 25 species (33%) occurred only in these fragments. The cluster analysis suggested that the floristic composition of the fragments was affected by the phytophysiognomy and by local bioecological conditions. The observed relationship between remnant area and tree species richness suggests that area was a good indicator of species richness in the forest fragments. The results of this study indicate that both historical (phytophysiognomy) and ecological (e.g., remnant area and occurrence of human disturbance) factors constitute important elements that determine the composition and richness of tree species of forest fragments in the north of Minas Gerais State
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