A transcriptomic analysis of gene expression in the venom gland of the snake Bothrops alternatus (urutu)

<p>Abstract</p> <p>Background</p> <p>The genus <it>Bothrops </it>is widespread throughout Central and South America and is the principal cause of snakebite in these regions. Transcriptomic and proteomic studies have examined the venom composition of several species in this genus, but many others remain to be studied. In this work, we used a transcriptomic approach to examine the venom gland genes of <it>Bothrops alternatus</it>, a clinically important species found in southeastern and southern Brazil, Uruguay, northern Argentina and eastern Paraguay.</p> <p>Results</p> <p>A cDNA library of 5,350 expressed sequence tags (ESTs) was produced and assembled into 838 contigs and 4512 singletons. BLAST searches of relevant databases showed 30% hits and 70% no-hits, with toxin-related transcripts accounting for 23% and 78% of the total transcripts and hits, respectively. Gene ontology analysis identified non-toxin genes related to general metabolism, transcription and translation, processing and sorting, (polypeptide) degradation, structural functions and cell regulation. The major groups of toxin transcripts identified were metalloproteinases (81%), bradykinin-potentiating peptides/C-type natriuretic peptides (8.8%), phospholipases A₂(5.6%), serine proteinases (1.9%) and C-type lectins (1.5%). Metalloproteinases were almost exclusively type PIII proteins, with few type PII and no type PI proteins. Phospholipases A₂were essentially acidic; no basic PLA₂were detected. Minor toxin transcripts were related to L-amino acid oxidase, cysteine-rich secretory proteins, dipeptidylpeptidase IV, hyaluronidase, three-finger toxins and ohanin. Two non-toxic proteins, thioredoxin and double-specificity phosphatase Dusp6, showed high sequence identity to similar proteins from other snakes. In addition to the above features, single-nucleotide polymorphisms, microsatellites, transposable elements and inverted repeats that could contribute to toxin diversity were observed.</p> <p>Conclusions</p> <p><it>Bothrops alternatus </it>venom gland contains the major toxin classes described for other <it>Bothrops </it>venoms based on trancriptomic and proteomic studies. The predominance of type PIII metalloproteinases agrees with the well-known hemorrhagic activity of this venom, whereas the lower content of serine proteases and C-type lectins could contribute to less marked coagulopathy following envenoming by this species. The lack of basic PLA₂agrees with the lower myotoxicity of this venom compared to other <it>Bothrops </it>species with these toxins. Together, these results contribute to our understanding of the physiopathology of envenoming by this species.</p

Avaliação da eficiência da mistura pronta de glyphosate + 2,4-D no controle da Commelina virginica L. em citros Efficacy evaluation of ready mixture of glyphosate + 2,4-D in Commelina virginica L. control in citrus

Um dos herbicidas mais utilizados para o controle de plantas daninhas em pós-emergência nos pomares cítricos paulistas é o glyphosate. No entanto, este herbicida aplicado isoladamente e nas doses recomendadas, tem proporcionado seleção da planta daninha trapoeraba (Commelina virginica L.), devido à grande tolerância da mesma, somada à eficiente eliminação das demais espécies da comunidade infestante. Em vista disso, e pela falta de opções , faz-se necessária a pesquisa de outros herbicidas ou misturas de herbicidas que sejam eficientes no controle da trapoeraba, de baixa toxicidade para os aplicadores, sistêmicos, e que sejam seletivos às plantas cítricas. O presente trabalho foi desenvolvido com o objetivo de estudar a eficiência da mistura pronta dos herbicidas glyphosate + 2,4-D amina no controle da trapoeraba em citros [Citrus sinensis (L.) Osbeck], em comparação com estes mesmos herbicidas aplicados isoladamente, bem como os possíveis efeitos fitotóxicos da mesma à cultura. O experimento foi instalado na região de Catanduva-SP, em um pomar de laranja Pera clone Rio, enxertada sobre limão Cravo, com dez anos de idade, plantado em um espaçamento de 8,0 x 6,5 m. A aplicação dos herbicidas foi realizada em 20 de fevereiro de 1991, de forma dirigida, em pós-emergência tardia da trapoeraba, quando a mesma já florescia e tinha altura variável entre 15 e 60 cm. A análise e interpretação dos resultados obtidos mostraram que a mistura pronta de glyphosate + 2,4-D apresenta um controle superior da trapoeraba em relação aos produtos aplicados isoladamente, não havendo diferenças significativas no controle para doses superiores a 0,60 + 0,80 kg i.a./ha. Os dados obtidos reforçam a teoria de sinergismo entre os dois produtos. Em nenhum dos tratamentos foi verificado sintomas visuais de intoxicação nas laranjeiras.<br>In citrus orchard of São Paulo state, Brazil, one of the most employed post-emergency herbicide for weed control is glyphosate. However, when this herbicide is applied alone and at the recommended rates, it has been observed a selection of the weed Commelina virginica L. due to its great tolerance and the elimination of other weeds. Because of that, other chemicals must be studied to solve the problem. In this particular case, the herbicide should be sistemic and have a low toxicity to the operator and to the citrus trees. This work was conducted to study the efficacy of a ready mixture of glyphosate + 2,4-D compared to the products sprayed alone in orange orchards [Citrus sinensis (L.) Osbeck]. The phytotoxicity effects were studied too. The experiment was carried out in Catanduva, São Paulo, Brazil, in a ten years old orange orchard, with 8,0 x 6,0m spacing. On february, 20 th, 1991, the herbicides were sprayed directly on 15-60cm height Commelina during its flowering. The results showed that the ready mixture was better in Commelina control than other treatments. No significant differences were observed for the rates greater than 0,60 + 0,80 kg a.i./ha. The results reinforced the sinergism theory within both products. None of the treatments caused visual phytotoxicity to orange trees

Frequentist, Bayesian Analysis and Complementary Statistical Tools for Geriatric and Rehabilitation Fields: Are Traditional Null-Hypothesis Significance Testing Methods Sufficient?

Dahan da Cunha Nascimento,1,&ast; Nicholas Rolnick,2,&ast; Isabella da Silva Almeida,3,&ast; Gerson Cipriano Junior,4,&ast; João Luiz Durigan3,&ast; 1Physical Education Department, Universidade Católica de Brasília, Brasília, DF, Brazil; 2The Human Performance Mechanic Department, Lehman College, Bronx, NY, USA; 3Laboratory of Muscle and Tendon Plasticity, Faculdade de Ceilândia, Universidade de Brasília, Brasília, DF, Brazil; 4Graduate Program in Rehabilitation Science, Faculdade de Ceilândia, Universidade de Brasília, Brasília, DF, Brazil&ast;These authors contributed equally to this workCorrespondence: João Luiz Durigan, Laboratory of Muscle and Tendon Plasticity, Faculdade de Ceilândia, Universidade de Brasília, Centro Metropolitano, conjunto A, lote 01, Brasília, DF, 72220-275, Brazil, Tel/Fax +55 (61) 3376-0252, Email [email protected]: Null hypothesis significant testing (NHST) is the dominant statistical approach in the geriatric and rehabilitation fields. However, NHST is routinely misunderstood or misused. In this case, the findings from clinical trials would be taken as evidence of no effect, when in fact, a clinically relevant question may have a “non-significant” p-value. Conversely, findings are considered clinically relevant when significant differences are observed between groups. To assume that p-value is not an exclusive indicator of an association or the existence of an effect, researchers should be encouraged to report other statistical analysis approaches as Bayesian analysis and complementary statistical tools alongside the p-value (eg, effect size, confidence intervals, minimal clinically important difference, and magnitude-based inference) to improve interpretation of the findings of clinical trials by presenting a more efficient and comprehensive analysis. However, the focus on Bayesian analysis and secondary statistical analyses does not mean that NHST is less important. Only that, to observe a real intervention effect, researchers should use a combination of secondary statistical analyses in conjunction with NHST or Bayesian statistical analysis to reveal what p-values cannot show in the geriatric and rehabilitation studies (eg, the clinical importance of 1kg increase in handgrip strength in the intervention group of long-lived older adults compared to a control group). This paper provides potential insights for improving the interpretation of scientific data in rehabilitation and geriatric fields by utilizing Bayesian and secondary statistical analyses to better scrutinize the results of clinical trials where a p-value alone may not be appropriate to determine the efficacy of an intervention.Keywords: statistics, statistical significance, effect size, p-valu