Dental pulp (DP) can be extracted from child’s primary teeth (deciduous), whose loss occurs spontaneously by about 5 to 12 years. Thus, DP presents an easy accessible source of stem cells without ethical concerns. Substantial quantities of stem cells of an excellent quality and at early (2–5) passages are necessary for clinical use, which currently is a problem for use of adult stem cells. Herein, DPs were cultured generating stem cells at least during six months through multiple mechanical transfers into a new culture dish every 3–4 days. We compared stem cells isolated from the same DP before (early population, EP) and six months after several mechanical transfers (late population, LP). No changes, in both EP and LP, were observed in morphology, expression of stem cells markers (nestin, vimentin, fibronectin, SH2, SH3 and Oct3/4), chondrogenic and myogenic differentiation potential, even after cryopreservation. Six hours after DP extraction and in vitro plating, rare 5-bromo-2′-deoxyuridine (BrdU) positive cells were observed in pulp central part. After 72 hours, BrdU positive cells increased in number and were found in DP periphery, thus originating a multicellular population of stem cells of high purity. Multiple stem cell niches were identified in different zones of DP, because abundant expression of nestin, vimentin and Oct3/4 proteins was observed, while STRO-1 protein localization was restricted to perivascular niche. Our finding is of importance for the future of stem cell therapies, providing scaling-up of stem cells at early passages with minimum risk of losing their “stemness”.

Chagas disease, or American trypanosomiasis, is a parasitic disease caused by the protozoan Trypanosoma cruzi and is transmitted by insects from the Triatominae subfamily. To identify components involved in the protozoan-vector relationship, we constructed and analyzed cDNA libraries from RNA isolated from the midguts of uninfected and T. cruzi-infected Triatoma infestans, which are major vectors of Chagas disease. We generated approximately 440 high-quality Expressed Sequence Tags (ESTs) from each T. infestans midgut cDNA library. The sequences were grouped in 380 clusters, representing an average length of 664.78 base pairs (bp). Many clusters were not classified functionally, representing unknown transcripts. Several transcripts involved in different processes (e.g., detoxification) showed differential expression in response to T. cruzi infection. Lysozyme, cathepsin D, a nitrophorin-like protein and a putative 14 kDa protein were significantly upregulated upon infection, whereas thioredoxin reductase was downregulated. In addition, we identified several transcripts related to metabolic processes or immunity with unchanged expressions, including infestin, lipocalins and defensins. We also detected ESTs encoding juvenile hormone binding protein (JHBP), which seems to be involved in insect development and could be a target in control strategies for the vector. This work demonstrates differential gene expression upon T. cruzi infection in the midgut of T. infestans. These data expand the current knowledge regarding vector-parasite interactions for Chagas disease.

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BackgroundSnakes belonging to the Bothrops genus are vastly distributed in Central and South America and are responsible for most cases of reported snake bites in Latin America. The clinical manifestations of the envenomation caused by this genus are due to three major activities—proteolytic, hemorrhagic and coagulant—mediated by metalloproteinases, serine proteinases, phospholipases A2 and other toxic compounds present in snake venom. Interestingly, it was observed that snakes are resistant to the toxic effects of its own and other snake’s venoms. This natural immunity may occur due the absence of toxin target or the presence of molecules in the snake plasma able to neutralize such toxins.MethodsIn order to identify anti-venom molecules, we construct a cDNA library from the liver of B. jararaca snakes. Moreover, we analyzed the expression profile of four molecules—the already known anti-hemorrhagic factor Bj46a, one gamma-phospholipase A2 inhibitor, one inter-alpha inhibitor and one C1 plasma protease inhibitor—in the liver of juvenile and adult snakes by qPCR.ResultsThe results revealed a 30-fold increase of gamma-phospholipase A2 inhibitor and a minor increase of the inter-alpha inhibitor (5-fold) and of the C1 inhibitor (3-fold) in adults. However, the Bj46a factor seems to be equally transcribed in adults and juveniles.DiscussionThe results suggest the up-regulation of different inhibitors observed in the adult snakes might be a physiological adaptation to the recurrent contact with their own and even other snake’s venoms throughout its lifespan. This is the first comparative analysis of ontogenetic variation of expression profiles of plasmatic proteins with potential anti-venom activities of the venomous snake B. jararaca. Furthermore, the present data contributes to the understanding of the natural resistance described in these snakes.

amo, meu porto seguro. Aos meus pais Antônia Maria da Silva Gomes e José Geraldo Gomes, que sempre acreditaram em mim, e sempre fizeram o melhor pela minha educação.Às minhas irmãs Cristiane Maria Gomes e Thais Maria Gomes, minhas companheiras de sempre.Sem vocês nada disso seria possível. E claro ao meu cachorro Theo por sua alegria toda vez que chego em casa." "In memoriam de Faustemira das GraçasCruz Alves Pereira que rezou por mim e me deu força para continuar em meu caminho." AGRADECIMENTOSGostaria de agradecer a todos que direta ou indiretamente tenham contribuído para o término do mestrado e especialmente para a conclusão deste trabalho, que é apenas o início de um longo caminho a ser percorrido, a começar pela minha orientadora Dra. Anita Mitico Tanaka-Azevedo pelos seus ensinamentos, por ter confiado a mim este trabalho e por ter me aceito no seu grupo de trabalho com quem tive a oportunidade de aprender muito, e foi muito importante para o meu crescimento profissional.À Professora Dra. Aparecida Sadae Tanaka, minha co-orientadora, que me acompanhou durante toda a realização deste trabalho, por seu exemplo de profissionalismo, seriedade à pesquisa, e por sempre me fazer enxergar mais longe.Ao amigo Dr. Diego de Souza Buarque que me acompanhou durante todas as fases deste trabalho, obrigada por sua ajuda e companhia em todos os momentos, "inclusive quando escapamos do raio". Obrigada pela paciência.Aos amigos Tatiane Sanches Soares e Felipe Araújo de Oliveira, meus parceiros de todos os momentos, "meu triângulo", obrigada por poder sempre contar com vocês e por vocês sempre me aguentarem durante meus momentos, sou privilegiada por poder contar com vocês! A todos os companheiros do laboratório do Infar e do Instituto Butantan que me ajudaram de diferentes maneiras durante a realização deste trabalho, Gabriela Catalano, Lucyla Tiemi "que sempre tem uma bala para mim", Patrícia Andrade, Thyago Cardoso "por me fazer sempre rir", Stephen Lu, Karla Oliveira, Ricardo Torquato e Karen de Morais Zani. À Dra Kathleen Fernandes Grego do Laboratório de Herpetologia do InstitutoButantan, pela ajuda na coleta do fígado das serpentes B. jararaca. À Professora Glória por sua colaboração e orientação na parte de bioinformática.Aos funcionários do Infar, em especial à técnica Jucilene Barbosa da Silva, pelo sequenciamento e por sua amizade.Às minhas amigas, Andréa Carvalho e Fernanda Soma por sempre me entenderem e me apoiarem durante todas as fases deste trabalho, que sempre estiveram presentes, mesmo à distância quando eu precisava, e sempre me fizeram companhia, à nossas tardes na Starbucks, aos filmes e, claro, aos shows que sempre fizeram parte dessas nossas histórias. Valeu meninas! À minha eterna amiga Tais Costa de Oliveira, que mesmo eu estando longe, e não muito presente, ainda é minha amiga, que mesmo me achando "louca" ainda assim consegue me entender. Porque amizade é assim! Aos meus amigos do Laboratório de Genética do Instituto Butantan, Dra. Sueli "Sesso", Fernando e Prof. Dr. Carlos Marandová, que não est...