137 research outputs found

    Transgenic mosquito: from paper to reality

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    Vector-borne diseases are currently the worst challenge of public health in Brazil and worldwide, being the current control measures inefficient. Innovations concerning vector control point to a new perspective to handling with gene engineering, as they may interfere with disease transmission, preventing the pathogen to complete its cycle in the vector, ie, reducing mosquito population. We present some of the mean genetic tools available, SIT and RIDL for example. We discuss how these tools work, some risks and benefitsDoenças transmitidas por vetores são atualmente os maiores desafios da saúde pública no Brasil e no mundo, sendo as atuais medidas de controle ineficientes. Inovações no âmbito do controle vetorial apontam para uma nova perspectiva com a manipulação genética, já que podem interferir na transmissão da doença, seja impedindo que o patógeno complete seu ciclo no vetor, como reduzindo a população de mosquitos vetores. Apresentamos algumas diretrizes das principais ferramentas disponíveis, SIT e RIDL por exemplo. Abordamos ainda a forma como estas ferramentas funcionam, alguns riscos e benefício

    Persistent pods of the tree Acacia caven: a natural refuge for diverse insects including Bruchid beetles and the parasitoids Trichogrammatidae, Pteromalidae and Eulophidae

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    The persistent pods of the tree, Acacia caven, that do not fall from the tree provide opportunities for the appearance of a diverse group of insects the following season. Such pods collected during the spring of 1999 in Chile were indehiscent with highly sclerified pod walls. In contrast, persistent pods collected in Uruguay after a wet winter and spring (2002) were partially dehiscent, inducing the deterioration of the woody pods, and consequently exposing the seeds. These persistent pods are a natural refuge for insect species, namely two bruchid beetles (Pseudopachymeria spinipes, Stator furcatus), one scolytidae (Dendroctonus sp), lepidopterous larvae, ant colonies (Camponotus sp),one species of oophagous parasitoid (Uscana espinae group senex), the gregarious larval-pupae parasitoid Monoksa dorsiplana (Pteromalidae) and two species of Horismenus spp. (Eulophidae). The patriline of M. dorsiplana is frequently formed by 1 son +7 daughters.Comment: 9 page

    Angiotensin II-derived constrained peptides with antiplasmodial activity and suppressed vasoconstriction

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    Angiotensin II (Ang II) is a natural mammalian hormone that has been described to exhibit antiplasmodial activity therefore constituting a promising alternative for the treatment of malaria. Despite its promise, the development of Ang II as an antimalarial is limited by its potent induction of vasoconstriction and its rapid degradation within minutes. Here, we used peptide design to perform targeted chemical modifications to Ang II to generate conformationally restricted (disulfide-crosslinked) peptide derivatives with suppressed vasoconstrictor activity and increased stability. Designed constrained peptides were synthesized chemically and then tested for antiplasmodial activity. Two lead constrained peptides were identified (i.e., peptides 1 and 2), each composed of 10 amino acid residues. These peptides exhibited very promising activity in both our Plasmodium gallinaceum ( > 80%) and Plasmodium falciparum ( > 40%) models, an activity that was equivalent to that of Ang II, and led to complete suppression of vasoconstriction. In addition, peptide 5 exhibited selective activity towards the pre-erythrocytic stage (98% of activity against P. gallinaceum), thus suggesting that it may be possible to design peptides that target specific stages of the malaria life cycle. The Ang II derived stable scaffolds presented here may provide the basis for development of a new generation of peptide-based drugs for the treatment of malaria

    Implementation of the artificial feeders in hematophagous arthropod research cooperates to the vertebrate animal use replacement, reduction and refinement (3Rs) principle

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    Vector-borne diseases are transmitted to humans by hematophagous arthropods and these blood-sucking organisms are target to researches worldwide. The laboratory colonization of these species is an important factor in the development of innovative strategies to control these vectors. However, this maintenance requires blood to make these invertebrates able to complete their life cycle. Although live vertebrate animals are frequently used for this feeding procedure, artificial feeders are available as potential alternatives to replace the use of live animals in some situations, especially in vector colony maintenance. The aim of this commentary is to discuss the use of artificial feeding methods concerning the 3Rs principle application. The scientific community focused on vector-borne diseases studies needs to strongly consider these artificial feeding options as a bioethical alternative to maintain blood-feeding arthropods in laboratory

    Expression and accumulation of the two-domain odorant-binding protein AaegOBP45 in the ovaries of blood-fed Aedes aegypti

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    BACKGROUND: \ud Aedes aegypti mosquitoes are the main vectors of dengue viruses. Despite global efforts to reduce the prevalence of dengue using integrated vector management strategies, innovative alternatives are necessary to help prevent virus transmission. Detailed characterizations of Ae. aegypti genes and their products provide information about the biology of mosquitoes and may serve as foundations for the design of new vector control methods.\ud FINDINGS: \ud We studied the Ae. aegypti gene, AAEL010714, that encodes a two-domain odorant-binding protein, AaegOBP45. The predicted gene structure and sequence were validated, although single nucleotide polymorphisms were observed. Transcriptional and translational products accumulate in the ovaries of blood fed females and are not detected or are at low abundance in other tissues.\ud CONCLUSIONS: \ud We validated the Ae. aegypti AAEL010714 gene sequence and characterized the expression profile of a two-domain OBP expressed in ovaries. We propose that AaegOBP45 function as a component of the mosquito eggshell.São Paulo Research Foundation (FAPESP) 2006/00331-3CNPq 143113/2006-2NIH NIAID (AI29746

    Endogenously-expressed NH2-terminus of circumsporozoite protein interferes with sporozoite invasion of mosquito salivary glands

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    Abstract\ud \ud Background\ud The circumsporozoite protein is the most abundant polypeptide expressed by sporozoites, the malaria parasite stage capable of infecting humans. Sporozoite invasion of mosquito salivary glands prior to transmission is likely mediated by a receptor/ligand-like interaction of the parasites with the target tissues, and the amino (NH2)-terminal portion of CSP is involved in this interaction but not the TSR region on the carboxyl (C)-terminus. Peptides based on the NH2-terminal domain could compete with the parasites for the salivary gland receptors and thus inhibit penetration.\ud \ud \ud Methods\ud Peptides based on the NH2-terminus and TSR domains of the CSP from avian or human malaria parasites, Plasmodium gallinaceum and Plasmodium falciparum, respectively, were expressed endogenously in mosquito haemolymph using a transient (Sindbis virus-mediated) or stable (piggyBac-mediated transgenesis) system.\ud \ud \ud Results\ud Transient endogenous expression of partial NH2-terminus peptide from P. falciparum CSP in P. gallinaceum-infected Aedes aegypti resulted in a reduced number of sporozoites in the salivary glands. When a transgenic approach was used to express a partial CSP NH2-terminal domain from P. gallinaceum the number of sporozoites in the salivary glands did not show a difference when compared to controls. However, a significant difference could be observed when mosquitoes with a lower infection were analysed. The same result could not be observed with mosquitoes endogenously expressing peptides based on the TSR domain from either P. gallinaceum or P. falciparum.\ud \ud \ud \ud Conclusion\ud These results support the conclusion that CSP partial NH2-terminal domain can be endogenously expressed to promote a competition for the receptor used by sporozoites to invade salivary glands, and they could be used to block this interaction and reduce parasite transmission. The same effect cannot be obtained with peptides based on the TSR domain.We thank Neuza Saraiva Fernandes and Ediane Saraiva Fernandes for technical\ud assistance and Alexandre Santos de Moura for sample sequencing. This work\ud was supported by FAPESP (Process#04/00889-9 and#00/12138-7). AAJ was\ud supported in part by an award from the National Institute of Allergy and Infec‑\ud tious Diseases (USA) (R37AI029746)

    Atelier Convívio - um espaço comunitário para pessoas idosas

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    Este estudo procura analisar o impacto de um Atelier Convívio para pessoas idosas, com base em informações recolhidas em focus group. A amostra foi constituída pelos dinamizadores, estagiários da licenciatura em Educação Social, e pelos participantes nas atividades. As informações recolhidas foram objeto de análise de conteúdo categorial e realçam benefícios a nível psicológico e social. Este tipo de intervenção permite a construção simultaneamente de prazer, compromisso e significado. Ao apelar ao convívio em grupo, potencia a interação social, comunicação e suporte mútuo, que constituem importantes recursos na fase avançada de vida.info:eu-repo/semantics/publishedVersio

    Mass production of genetically modified Aedes aegypti for field releases in Brazil

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    New techniques and methods are being sought to try to win the battle against mosquitoes. Recent advances in molecular techniques have led to the development of new and innovative methods of mosquito control based around the Sterile Insect Technique (SIT)(1-3). A control method known as RIDL (Release of Insects carrying a Dominant Lethal)(4), is based around SIT, but uses genetic methods to remove the need for radiation-sterilization(5-8). A RIDL strain of Ae. aegypti was successfully tested in the field in Grand Cayman(9,10); further field use is planned or in progress in other countries around the world. Mass rearing of insects has been established in several insect species and to levels of billions a week. However, in mosquitoes, rearing has generally been performed on a much smaller scale, with most large scale rearing being performed in the 1970s and 80s. For a RIDL program it is desirable to release as few females as possible as they bite and transmit disease. In a mass rearing program there are several stages to produce the males to be released: egg production, rearing eggs until pupation, and then sorting males from females before release. These males are then used for a RIDL control program, released as either pupae or adults(11,12). To suppress a mosquito population using RIDL a large number of high quality male adults need to be reared(13,14). The following describes the methods for the mass rearing of OX513A, a RIDL strain of Ae. aegypti (8), for release and covers the techniques required for the production of eggs and mass rearing RIDL males for a control program.Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnologia (CNPq

    Inteligencia artificial: herramienta idónea para la conciliación inteligente, un asunto de celeridad procesal

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    Se tiene como objetivo demostrar la necesidad de asegurar la concurrencia de la inteligencia artificial en el derecho, en los Mecanismos Alternativos de Solución de Conflictos y, en especial, en la conciliación. Además, se demuestra cómo confluyen para generar soluciones a la congestión judicial y maximizando la aplicación del principio de acceso a la justicia, como también la necesidad de transmutar e incorporar una herramienta indispensable que coadyuve al cumplimiento de los fines esenciales del Estado
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