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

Evolução histórica dos utensílios empregados para alimentar lactentes não amamentados Historical evolution of utensils used to feed non breastfed infants

O objetivo desse artigo de revisão é descrever os utensílios empregados ao longo da história para alimentar lactentes não amamentados. O levantamento bibliográfico foi realizado nas bases de dados MEDLINE, LILACS e SciELO, de 1966 a 2007. Para a análise documental, foram processadas buscas na Internet, em enciclopédias, livros de arte, história e museus. Utensílios manufaturados com materiais e formas variadas, dependendo da disponibilidade, poder aquisitivo e cultura, foram empregados desde os primórdios da história para alimentar bebês que, por diferentes motivos, deixaram de ser amamentados. Muitos objetos coexistiram na mesma época e local, outros em tempos e pontos geográficos distantes. A aceitação de uma nova alternativa ocorria sem evidência que comprovasse ou apontasse para os benefícios da mudança. Alguns utensílios voltaram a ser empregados embora a mortalidade infantil fosse elevada à época em que foram utilizados. No início do século XX, as mamadeiras assumiram a forma cilíndrica cônica. A tecnologia trouxe avanços no sentido de melhorar a higienização e possibilitar o controle da contaminação. O vidro deu lugar ao plástico e os bicos de borracha, aos de silicone, mas a mamadeira, como a conhecemos hoje, é a mesma de cem anos atrás.<br>The objective of this article is to describe the utensils used throughout history to feed non breastfed infants. The method used was article review, reference search on the MEDLINE, LILACS and SciELO databases from 1966 to 2007 and documental analysis based on data from the internet, encyclopedias, art and history books, and museums. Utensils manufactured in a variety of materials and shapes, depending on availability, purchasing power and culture have been used since early history to feed babies who for different reasons were not breastfed. Many objects coexisted at the same time and place, others at distant sites and times. New alternatives have been accepted without evidence to prove or point toward the benefits of the change. Some of these alternatives were adopted again, even if infant mortality was high at the time in which they were used at first. In the beginning of the 20th century, bottles became conic-cylindrical. Technology brought about progress as to improve hygiene and enable contamination control. Glass gave way to plastic, and rubber nipples to silicone ones, but the bottle as we know it today is still the same of a 100 years ago

Prevalência de respiradores bucais em crianças de idade escolar Prevalence of mouth breathing in children from an elementary school

Pretende-se identificar a prevalência de respiradores bucais em crianças de uma escola do ensino fundamental. Foram aplicados 496 questionários aos pais ou responsáveis das crianças de 1ª à 4ª série de uma escola fundamental, para identificar respiradores bucais. O questionário incluía questões sobre hábitos, sono, comportamento, alimentação, cuidados pessoais e respiração. Para comparar as variáveis entre respiradores bucais e nasais, foi utilizado o teste de Mann-Whitney e qui-quadrado. Para medir o efeito da exposição das variáveis explicativas sobre o desfecho primário, foi utilizada regressão logística e sua magnitude foi calculada por meio do odds ratio. A significância estatística foi estipulada em 5%. A taxa de devolução dos questionários foi de 84,5%. A prevalência de respiração bucal nessa população foi 56,8%. A mediana de idade foi sete anos (6-9). Não houve diferença estatisticamente significante entre os gêneros, 49,1% masculino e 50,9% feminino. O modelo final de regressão logística identificou as variáveis baba, dorme bem (associação negativa) e ronca como fatores que predizem a ocorrência da respiração bucal. A prevalência de respiradores bucais foi semelhante à encontrada na literatura pesquisada. As variáveis babar, roncar e dormir bem (associação negativa) podem predizer a ocorrência da respiração bucal.<br>The objective of this article is to identify the prevalence of mouth breathing in children from an elementary school. 496 questionnaires were answered by 1st and 4th grade children's parents or sponsors in order to identify mouth-breathing. There were questions about habits, sleeping, behavior, eating, personal care and breathing. Mann-Whitney and the Chi-square tests were used to compare the variables between mouth-breathing and nose-breathing among the groups. To measure the exposure effect of the explanatory variables on mouse breathing, the test of logistic regression was used and its magnitude was calculated through Odds Ratio. The statistical significance was set at 5%, and the rate of returned questionnaires was 84.5%. The prevalence of the mouthbreathing over this population was 56.8%. The average age was 7 years old (6-9). There was no significant statistical difference between genders, considering 49.1% male and 50.9% female. The final model of logistic regression identified the variables dribble, sleeps well (negative association) and snores as factors that predict the occurrence of the mouth-breathing. The prevalence of mouthbreathing was similar to related in the literature. The variables dribble, sleeps well (negative association) and snores may be factors that predict the occurrence of mouth-breathing