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Resumo:
Chemoreflex afferent fibers terminate in the nucleus tractus solitarii (NTS), but the specific location of the NTS neurons excited by peripheral chemoreflex activation remains to be characterized. Here, the topographic distribution of chemoreflex sensitive cells at the commissural NTS was evaluated. To reach this goal, Fos-immunoreactive neurons (Fos-ir) were accounted in rostro-caudal levels of the intermediate and caudal commissural NTS, after intermittent chemoreflex activation with intravenous injection of potassium cyanide [KCN (80 mu g/kg) or saline (0.9%, vehicle), one injection every 3 min during 30 min]. In response to intermittent intravenous injections of KCN, a significant increase in the number of Fos-ir neurons was observed specifically in the lateral intermediate commissural NTS [(LI)NTS (82 +/- 9 vs. 174 +/- 16, cell number mean per section)] and lateral caudal commissural NTS [(LI)NTS (71 +/- 9 vs. 199 +/- 18, cell number mean per section)]. To evaluate the influence of baroreceptor-mediated inputs following the increase in blood pressure during intermittent chemoreflex activation, we performed an intermittent activation of the arterial baroreflex by intravenous injection of phenylephrine [1.5 mu g/kg iv (one injection every 3 min during 30 min)]. This procedure induced no change in Fos-ir in (LI)NTS (64 +/- 6 vs. 62 +/- 12, cell number mean per section) or (LC)NTS (56 +/- 15 vs. 77 +/- 12, cell number mean per section). These data support the involvement of the commissural NTS in the processing of peripheral chemoreflex, and provide a detailed characterization of the topographical distribution of activated neurons within this brain region. (C) 2009 Elsevier B.V. All rights reserved.
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Leptospirosis is a widespread re-emerging zoonosis of human and veterinary concern. It has been shown that virulent leptospires protect themselves against the host`s innate immune system, a strategy that allows the bacteria to reach immunologically safe environments. Although extensive studies on host pathogen interactions have been performed, little is known on how leptospires deal with host immune attack. In a previous work, we demonstrated the ability of leptospires to bind human plasminogen (PLC), that after treatment with activators, conferred plasmin (PLA) activity on the bacteria surface. In this study, we show that the PLA activity associated to the outer surface of Leptospira could interfere with the host immune attack by conferring some evasion advantage during infection. We demonstrate that PLA-coated leptospires interfere with complement Ob and IgG depositions on the bacterial surface, probably through the degradation of these components, thus diminishing opsonization process. Similar decrease on the deposition was observed when normal and immune sera from patients diagnosed with leptospirosis were employed as a source of IgG. We believe that decreasing opsonization by PLA generation might be an important aspect of the leptospiral immune escape strategy and survival. To our knowledge, this is the first proteolytic activity of plasmin associated-Leptospira related to anti-opsonic properties reported to date. (C) 2011 Elsevier Ltd. All rights reserved.
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Purpose: The Gow-Gates technique is said to have several advantages over traditional techniques to achieve mandibular nerve anesthesia; however, its routine use is quite limited, mainly due to complications during visual alignment of reference landmarks. The purpose of this study was to verify the validity and accuracy of a new method to reach the injection site. Material and Methods: Fifteen magnetic resonance images were captured. Distances from the ideal injection point in the condylar neck (puncture ideal) to the injection points located in the a and 0 plane intersection (Puncture Gow-Gates and puncture modified) were measured and compared. Results: Positive and significant (P <= .003) Pearson correlations between landmarks and injection points confirmed the validity of the modified technique. Paired t test showed that the segment line puncture ideal-puncture modified, 5.17 mm, was 3 times shorter (P < .001) than the segment line puncture ideal-puncture Gow-Gates, 17.91 mm. As calculated by linear regression, establishing the injection point of the modified technique depended only on the anteroposterior and lateromedial condyle positions. Conclusions: The modified technique proved to be valid and precise and has a determined and an effective injection site. (C) 2009 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 67:2609-2616, 2009
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Limb-girdle muscular dystrophies are a heterogeneous group of disorders characterized by progressive degeneration of skeletal muscle caused by the absence or deficiency of muscle proteins. The murine model of Limb-Girdle Muscular Dystrophy 2B, the SJL mice, carries a deletion in the dysferlin gene. Functionally, this mouse model shows discrete muscle weakness, starting at the age of 4-6 weeks. The possibility to restore the expression of the defective protein and improve muscular performance by cell therapy is a promising approach for the future treatment of progressive muscular dystrophies (PMD). We and others have recently shown that human adipose multipotent mesenchymal stromal cells (hASCs) can differentiate into skeletal muscle when in contact with dystrophic muscle cells in vitro and in vivo. Umbilical cord tissue and adipose tissue are known rich sources of multipotent mesenchymal stromal cells (MSCs), widely used for cell-based therapy studies. The main objective of the present study is to evaluate if MSCs from these two different sources have the same potential to reach and differentiate in muscle cells in vivo or if this capability is influenced by the niche from where they were obtained. In order to address this question we injected human derived umbilical cord tissue MSCs (hUCT MSCs) into the caudal vein of SJL mice with the same protocol previously used for hASCs; we evaluated the ability of these cells to engraft into recipient dystrophic muscle after systemic delivery, to express human muscle proteins in the dystrophic host and their effect in functional performance. These results are of great interest for future therapeutic application.
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Snake venom metalloproteinases (SVMPs) have been extensively studied and their effects associated with the local bleeding observed in human accidents by viper snakes. Representatives of P-I and P-III classes of SVMPs similarly hydrolyze extracellular matrix proteins or coagulation factors while only P-III SVMPs induce significant hemorrhage in experimental models. In this work, the effects of P-I and P-III SVMPs on plasma proteins and cultures of muscle and endothelial cells were compared in order to enlighten the mechanisms involved in venom-induced hemorrhage. To reach this comparison, BnP1 was isolated from B. neuwiedi venom and used as a weakly hemorrhagic P-I SVMPs and jararhagin was used as a model of potently hemorrhagic P-III SVMP. BnP1 was isolated by size exclusion and anion-exchange chromatographies, showing apparent molecular mass of approximately 24kDa and sequence similarity with other members of SVMPs, which allowed its classification as a group P-I SVMP. The comparison of local effects induced by SVMPs showed that BnP1 was devoid of significant myotoxic and hemorrhagic activities and jararhagin presented only hemorrhagic activity. BnP1 and jararhagin were able to hydrolyze fibrinogen and fibrin, although the latter displayed higher activity in both systems. Using HUVEC primary cultures, we observed that BnP1 induced cell detachment and a decrease in the number of viable endothelial cells in levels comparable to those observed by treatment with jararhagin. Moreover, both BnP1 and jararhagin induced apoptosis in HUVECs while only a small increase in LDH supernatant levels was observed after treatment with jararhagin, suggesting that the major mechanism involved in endothelial cell death is apoptosis. Jararhagin and BnP1 induced little effects on C2C12 muscle cell cultures, characterized by a partial detachment 24h after treatment and a mild necrotic effect as evidenced by a small increase in the supernatants LDH levels. Taken together, our data show that P-I and P-III SVMPs presented comparable effects except for the hemorrhagic activity, suggesting that hydrolysis of coagulation factors or damage to endothelial cells are not sufficient for induction of local bleeding. (C) 2007 Elsevier Ltd. All rights reserved.
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The p53 protein is a key regulator of cell responses to DNA damage, and it has been shown that It sensitizes glioma cells to the alkylating agent temozolomide by up-regulating the extrinsic apoptotic pathway, whereas it increases the resistance to chloroethylating agents, such as ACNU and BCNU, probably by enhancing the efficiency of DNA repair. However, because these agents induce a wide variety of distinct DNA lesions, the direct Importance of DNA repair is hard to access. Here, it is shown that the Induction of photoproducts by UV light (UV-C) significantly Induces apoptosis In a p53-mutated glioma background. This Is caused by a reduced level of photoproduct repair, resulting In the persistence of DNA lesions in p53-mutated glioma cells. UV-C-Induced apoptosis in p53 mutant glioma cells Is preceded by strong transcription and replication inhibition due to blockage by unrepaired photolesions. Moreover, the results Indicate that UV-C-induced apoptosis of p53 mutant glioma cells Is executed through the intrinsic apoptotic pathway, with Bcl-2 degradation and sustained Bax and Bak up-regulation. Collectively, the data Indicate that unrepaired DNA lesions Induce apoptosis In p53 mutant gliomas despite the resistance of these gliomas to temozolomide, suggesting that efficiency of treatment of p53 mutant gliomas might be higher with agents that Induce the formation of DNA lesions whose global genomic repair is dependent on p53. (Mol Cancer Res 2009;7(2):237-46)
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Thyroid hormone receptors (TR) are hormone-dependent transcription regulators that play a major role in human health, development, and metabolic functions. The thyroid hormone resistance syndrome, diabetes, obesity, and some types of cancer are just a few examples of important diseases that are related to TR malfunctioning, particularly impaired hormone binding. Ligand binding to and dissociation from the receptor ultimately control gene transcription and, thus, detailed knowledge of binding and release mechanisms are fundamental for the comprehension of the receptor`s biological function and development of pharmaceuticals. In this work, we present the first computational study of ligand entry into the ligand binding domain (LBD) of a nuclear receptor. We report molecular dynamics simulations of ligand binding to TRs using a generalization of the steered molecular dynamics technique designed to perform single-molecule pulling simulations along arbitrarily nonlinear driving pathways. We show that only gentle protein movements and conformational adaptations are required for ligand entry into the LBDs and that the magnitude of the forces applied to assist ligand binding are of the order of the forces involved in ligand dissociation. Our simulations suggest an alternative view for the mechanisms ligand binding and dissociation of ligands from nuclear receptors in which ligands can simply diffuse through the protein surface to reach proper positioning within the binding pocket. The proposed picture indicates that the large-amplitude protein motions suggested by the apo- and holo-RXR alpha crystallographic structures are not required, reconciling conformational changes of LBDs required for ligand entry with other nuclear receptors apo-structures that resemble the ligand-bound LBDs.
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TEMA: crianças deficientes auditivas não adquirem linguagem no mesmo período e velocidade de uma criança normo-ouvinte, pois o aprendizado da linguagem oral é um evento essencialmente auditivo. O desenvolvimento da criança consiste na aquisição progressiva de habilidades motoras e psicocognitivas, e a entrada no mundo simbólico é fator preponderante para que a criança possa atingir os níveis de maior complexidade no domínio da linguagem. OBJETIVO: relacionar o jogo simbólico e aspectos do desenvolvimento infantil em crianças deficientes auditivas com seus pares ouvintes. MÉTODO: 32 crianças, de ambos os sexos, de 2 a 6 anos de idade, pareadas por idade, foram submetidas à Avaliação da Maturidade Simbólica e ao Teste de Triagem do Desenvolvimento de Denver II, sendo 16 deficientes auditivas neurossensorial de grau moderado a profundo (grupo pesquisa - GP) e 16 normo-ouvintes (grupo controle - GC). RESULTADOS: observou-se simbolismo na brincadeira de 81,25% do GP, enquanto que no GC isto ocorreu em 87,5%. No Teste de Denver II 100% do GP foi classificado como risco, e o GC apresentou 94% de crianças normais e 6% de risco (p < 0,001). CONCLUSÃO: observou-se desempenho semelhante nos dois grupos quanto ao jogo simbólico. Entretanto, numa análise qualitativa, o GP apresentou brincadeiras menos complexas que o GC. Observou-se que o GP apresentou desempenho no jogo simbólico compatível ao seu desempenho nos aspectos pessoal-social, motor fino-adaptativo e motor grosseiro do Teste de Denver II.
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Pulp repair is a complex process whose mechanisms are not yet fully understood. The first immune cells to reach the damaged pulp are neutrophils that play an important role in releasing cytokines and in phagocytosis. The objective of this study was to analyze the effect of different pulp-capping materials on the secretion of interleukin-1 beta (IL-1β) and interleukin-8 (IL-8) by migrating human neutrophils. Neutrophils were obtained from the blood of three healthy donors. The experimental groups were calcium hydroxide [Ca(OH)2], an adhesive system (Single Bond), and mineral trioxide aggregate (MTA). Untreated cells were used as control. Transwell chambers were used in performing the assays to mimic an in vivo situation of neutrophil chemotaxis. The pulp-capping materials were placed in the lower chamber and the human neutrophils, in the upper chamber. The cells were counted and the culture medium was assayed using ELISA kits for detecting and quantifying IL-1β and IL8. The data were compared by ANOVA followed by Tukey's test (p < 0.05). The secretion of IL-8 was significantly higher in all groups in comparison to the control group (p < 0.05). The adhesive system group showed higher IL-8 than the MTA group (p < 0.05). The secretion of IL-1β was significantly greater only in the MTA group (p < 0.001). It was concluded that only MTA is able to improve the secretion of IL-1β, and all materials tested increased IL-8 secretion. These results combined with all the other biological advantages of MTA indicate that it could be considered the material of choice for dental pulp capping.
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The new species herein described, collected in the Jacuí and Uruguay River basins, Rio Grande do Sul, Brazil, can be distinguished from the already known species of the genus, but Oligosarcus jenynsii, O. perdido, O. acutirostris, O. solitarius and O. hepsetus, by the number of perforated lateral line scales. It shares with the first two species the absence of a premaxillary foramen, present in the last three species and differs from O. jenynsii by having a smaller orbital diameter and the tip of the pectoral fin failing to reach the pelvic-fin origin, and from O. perdido by the presence of more horizontal scale rows around the caudal peduncle.
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The study objective was to evaluate the feasibility of interviews by cell phone as a complement to interviews by landline to estimate risk and protection factors for chronic non-communicable diseases. Adult cell phone users were evaluated by random digit dialing. Questions asked were: age, sex, education, race, marital status, ownership of landline and cell phones, health condition, weight and height, medical diagnosis of hypertension and diabetes, physical activity, diet, binge drinking and smoking. The estimates were calculated using post-stratification weights. The cell phone interview system showed a reduced capacity to reach elderly and low educated populations. The estimates of the risk and protection factors for chronic non-communicable diseases in cell phone interviews were equal to the estimates obtained by landline phone. Eligibility, success and refusal rates using the cell phone system were lower than those of the landline system, but loss and cost were much higher, suggesting it is unsatisfactory as a complementary method in such a context.
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A regionalização tem sido apontada como um dos principais desafios para viabilizar a equidade e a integralidade do SUS. Este artigo tem como objetivo avaliar o processo de implementação de um projeto de organização de regiões de saúde no município de São Paulo. Para tanto, foi realizado um estudo de caso em uma região selecionada desse município, a partir do referencial da análise de implantação, utilizando-se como fonte de dados documentos da gestão e entrevistas semiestruturadas com informantes-chave da gestão municipal 2005-2008. A análise temática evidenciou que o projeto de regionalização idealizado no início da gestão não foi efetivamente implementado. Dentre os fatores que interferiram nesse insucesso, destacam-se: a) a Secretaria Municipal de Saúde (SMS), além de seu caráter centralizador, manteve estruturas político-administrativas independentes para a gestão da atenção básica e da assistência hospitalar; b) a SMS não assumiu a gestão, de fato, de ambulatórios e hospitais estaduais; c) o poder institucional e a resistência dos hospitais em se integrar ao sistema de saúde. Discute-se, ainda, a necessidade de avançar na descentralização intramunicipal do SUS e buscar novas estratégias para a construção de pactos que consigam superar as resistências e articular instituições historicamente consolidadas, visando uma regionalização cooperativa e solidária.
Resumo:
OBJETIVO: Conhecer a atribuição de significado dada por bioeticistas brasileiros quanto à equidade no sistema de saúde. MÉTODOS: Pesquisa qualitativa, exploratória. Entre julho de 2007 e julho de 2008, foram entrevistados 20 bioeticistas, dirigentes e ex-dirigentes da Sociedade Brasileira de Bioética e de suas regionais (2005-2008). O tratamento dos dados foi realizado por análise de discurso. RESULTADOS: Os discursos levaram ao estabelecimento das seguintes ideias centrais: tratar desigualmente os desiguais conforme suas necessidades; equidade e desigualdades compensadas; equidade e maximização dos benefícios; equidade e mérito social; equidade e direitos. CONCLUSÃO: Os resultados da pesquisa evidenciam a existência entre os bioeticistas pesquisados de uma diversidade de interpretações sobre equidade no sistema de saúde, reforçando a noção de que é difícil, no mundo contemporâneo, decidir sobre o que seria um sistema justo e equânime.
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A great challenge for the primary healthcare system, implemented by the strategy called the Family Health Program, is to incorporate actions for facing situations of violence and mental health problems. This study analyzed the care delivered to 411 children between five and eleven years of age in a primary care unit in the city of São Paulo. The clinical findings were compared to a standard inventory of symptoms (CBCL). In addition, semi-structured interviews were held with pediatricians. The study shows low capacity of the pediatricians to recognize mental health problems in children. This is mainly due to deficiencies in their training and lack of possibilities for concrete intervention to face a complaint or diagnostic hypothesis. The reorganization process of primary care will need to provide specific technical support in mental health, incorporating more appropriate technologies for intervention such as a humanized approach and qualified listening. The inclusion of psychosocial aspects in the everyday practice of primary care will make it possible to broaden the concept of health and open way for an integrated approach to situations of violence related to children assisted by the primary care network of the Brazilian Health System.
Resumo:
O acesso regular à água potável e segura tem causado preocupação, principalmente em países em desenvolvimento e, mais enfaticamente em áreas periurbanas, que abrigam a população socialmente excluída. O objetivo deste trabalho é abordar questões de acesso à água em regiões periurbanas e para tanto foi realizado levantamento bibliográfico nas bases de dados Pubmed, Medline e SciELO assim como relatórios da OMS, OPAS, IBGE e Ministério das Cidades. A falta ou a precariedade do acesso à água representa situação de risco que propicia aumento da incidência de doenças infecciosas agudas e da prevalência de doenças crônicas. O estabelecimento do grau de acesso à água de qualidade considera fatores como distância e tempo percorrido até a fonte de água, volume coletado, demanda atendida e nível de prioridade de ações de intervenção. Na qualidade da água, consideram-se como fatores de impacto o manuseio - maneira como ocorre a coleta, o transporte, o armazenamento e o uso -, a presença de patógenos nas fontes e as práticas rotineiras da população. A determinação da presença de patógenos nas fontes evidencia o risco à saúde e a identificação do agente etiológico indica a origem da contaminação. O caminho para reverter esse cenário é a implementação integrada de políticas públicas de gestão, que envolvam ações conjuntas e ajustadas nos setores de desenvolvimento urbano, habitação, saneamento e saúde e que visem à promoção e à proteção da saúde da população local e ao enfrentamento da complexidade de fatores que evidenciam sua vulnerabilidade.