Indicações do emprego de ultrassom durante a terapia endodôntica

Objetivou-se, por meio de uma revisão de literatura, analisar a influência do emprego da agitação ultrassônica nas pastas de Hidróxido de Cálcio (HC) e nos cimentos obturadores. Os artigos foram coletados nas bases de dados Scielo e Pubmed, utilizando os descritores Endodontics, Ultrasound, Calcium Hydroxide e/ou Root Canal Filling, entre 2007 e 2017. Encontrou-se 80 artigos, sendo selecionados 6 destes após análise de títulos e resumos. Como critérios de inclusão, selecionou-se estudos clínicos e laboratoriais utilizando dentes humanos e bovinos, sendo excluídos revisões de literatura e casos clínicos. Verificou-se que a agitação ultrassônica permite um aumento na capacidade antimicrobiana e na penetração intratubular das pastas de HC. Ainda, que o uso do aparelho favoreceu, em casos de obturação dos SCR, uma maior penetração de cimento na dentina, diminuiu a presença de espaços vazios, contudo, não promoveu melhorias no selamento apical. Pode-se concluir que o uso do ultrassom demonstra apresentar melhoras significativas durante as etapas do TE, tanto na ação das pastas de HC quanto dos cimentos obturadores.Palavras-chave: Ultrassom. Hidróxido de Cálcio. Cimentos Dentários.

Influência do Ácido Fítico na Durabilidade de Restaurações com Resinas Compostas: uma Revisão de Literatura

O objetivo do presente estudo é revisar a literatura acerca da influência do ácido fítico no aumento da longevidade de restaurações com resinas compostas. Dessa forma, foi realizada uma pesquisa bibliográfica no período entre 2013 e 2017, no idioma inglês nas bases de dados PubMed e Science Direct. Utilizou-se os seguintes descritores: dentin, phytic acid e dentistry. Foram encontrados um total de 14 artigos, sendo 3 desses repetidos, todos os estudos são In vitro. Desses, 4 artigos foram selecionados mediante relevância ao tema. O IP6 se mostrou eficaz como agente condicionante dentinário, apresentando maior resistência de união que o ácido convencionalmente utilizado, ácido fosfórico a 37%. Além disso, o IP6 é capaz de realizar ligações cruzadas em colágeno desnudo melhorando a biomecânica desse subtrato além de inibir atividade colagenolítica, aumentando a durabilidade de restaurações resinosas, entretanto, o mecanismo de ação ainda não foi esclarecido. Apesar da literatura mostrar vantagens do uso do IP6 com essas finalidades, mais estudos precisam ser desenvolvidos com o intuito de aumentar a consistência da fundamentação acerca da utilização desse ácido a longo prazo.Palavras-chave: Dentin. Phytic Acid. Dentistry.

Avaliação da Adesão, Sorção de Água e Solubilidade de Resinas Compostas Autoadesivas Experimentais para Capeamento Pulpar Direto

O objetivo foi analisar resinas compostas experimentais para capeamento pulpar direto em propriedades físico-químicas selecionadas, comparando com hidróxido de cálcio fotopolimerizável e MTA. Duas resinas compostas capeadoras foram preparadas, uma sem adição de partículas bioativas (controle) e a outra com 30% em peso (experimental) de nanopartículas de hidroxiapatita adsorvidas com sinvastatina (10%), com glutationa (10%) e de beta fosfato tricálcio (10%). Foram utilizados 36 terceiros molares hígidos extraídos, onde foi realizado preparo cavitário na região coronária até atingir a câmara pulpar para posterior restauração com um dos materiais. Os espécimes foram cortados em fatias (1mm) e essas foram submetidas ao teste de resistência de união ao push-out. Espécimes em forma de disco (n8) foram preparados e avaliados (ISO4049) quanto a sorção e solubilidade. A análise estatística  foi feita com ANOVA e teste de Tukey (a5%). Os resultados de resistência de união mostraram que o MTA e o hidróxido de cálcio apresentaram pior adesão do que as resinas, e os maiores valores foram obtidos com a resina experimental (p<0,05). Maior sorção de água foi observada com o hidróxido de cálcio e os demais materiais não apresentaram diferenças estatísticas. O hidróxido de cálcio obteve maior solubilidade que a resina controle e a experimental (p<0,05). Em conclusão, a resina experimental com partículas bioativas promove maior adesão à dentina e menor sorção e solubilidade que hidróxido de cálcio e MTA, esses materiais que são tradicionalmente usados para capeamento pulpar.Palavras-chave: Dental Pulp Capping. Simvastatin Calcium Hydroxide.

Estratégias que Promovem Acesso aos Fluoretos para as Populações Indígenas: um Panorama Mundial

O objetivo do estudo é abordar estratégias usadas em diferentes países que promovem o acesso aos fluoretos para as populações indígenas. Foi realizado um levantamento bibliográfico de artigos disponíveis nas bases de dados PubMed e Bireme, entre 2007    e 2017, em língua inglesa, com os descritores: Indigenous Population, Flourides e Dental Caries. Foram encontrados 98 artigos. Através de uma leitura crítica dos títulos e resumos foram selecionados 10 relevantes ao tema: 4 estudos observacionais, 3 ensaios clínicos e 3 ensaios comunitários. Artigos de revisão, protocolos de pesquisa e os que não estavam adequados ao objetivo do trabalho foram excluídos. Os povos indígenas estão entre os grupos mais socioeconomicamente marginalizados nos países em que ainda estão presentes. A saúde oral dessa população remete a um cenário de alta prevalência de doenças bucais, principalmente a cárie. Por ser uma doença multifatorial, a cárie requer um programa de combate que inclua diferentes estratégias. Uma das principais formas de prevenção é o uso de flúor tópico ou sistêmico. Entretanto, o acesso a esse recurso pela população indígena é, muitas vezes, dificultado. Em países como Austrália, Canadá e Estados Unidos as estratégias incluem a ampliação da fluoretação das águas (≤0.5 mg/L) para áreas remotas, múltiplas aplicações de verniz de flúor e selantes, assim como fornecimento de dentifrícios fluoretados (0,243% de fluoreto de sódio). Os estudos apontaram essas estratégias como uma opção sustentável para a redução de cáries nesse grupo e de gastos para os sistemas de saúde.Palavras-chave: População Indígena. Fluoretos. Cárie Dentária.

Tratamentos Térmicos da Liga de NiTi na Endodontia: Revisão de Literatura

AEndodontia tem sofrido grandes transformações nos princípios físico-químicos e mecânicos que norteiam sua prática. Anecessidade de desenvolver procedimentos com maior eficiência e precisão tem feito com que pesquisadores busquem novas tecnologias a fim de tornar mais efetivo e seguro o preparo químico mecânico (PQM) dos sistemas canais radiculares. Assim, vêm sendo desenvolvidos diversos tratamentos da liga de Níquel-Titâneo (NiTi) utilizada na confecção de instrumentos endodônticos. Seu aperfeiçoamento está pautado com base em seu desempenho na tentativa de produzir ligas com maior resistência à fratura cíclica e torcional, associadas a um melhor padrão de limpeza, menor desvio de canal radicular e menor tempo de execução. O presente trabalho tem por objetivo analisar a evolução da liga de NiTi na endodontia por meio de uma revisão de literatura. Para tanto, realizou-se uma busca bibliográfica na base de dados Pubmed nos últimos cinco anos com os seguintes descritores: Nickel-titanium endodontic Nickel-titanium rotatory Nickel-titanium thermal treatments, resultando em 196 artigos encontrados e 62 artigos considerados válidos seguindo os critérios de inclusão: pesquisas de revisão, estudos laboratoriais, no idioma inglês e com disponibilidade do texto completo. A literatura mostra que os diferentes tratamentos termomecânicos aos quais a liga de NiTi tem passado foram capazes de conferir-lhe maior resistência à fratura, maior flexibilidade e melhor previsibilidade dos preparos com manutenção da morfologia original do canal.Palavras-chave: Níquel-Titânio. Preparo Químico-Mecânico. Endodontia.

A Influência do Uso de Agentes Antioxidantes na Resistência de União em Dentes Clareados: uma Revisão de Literatura

O objetivo do presente estudo é revisar a literatura para avaliar a influência do uso de agentes antioxidantes na resistência de   união em dentes clareados e restaurados imediatamente. Realizou-se uma busca bibliográfica na qual foram selecionados artigos do período de 2012 a 2017, nas bases de dados: PubMed, Bireme e Science Direct, no idioma inglês, utilizando os seguintes descritores: Dental Whitening, Antioxidant e Ascorbate. Sendo encontrados um total de 20 artigos, 10 desses são estudos laboratoriais, 7 são estudos clínicos e 3 revisões de literatura. Através de uma leitura criteriosa de títulos e resumos selecionou-se 10 artigos, de acordo com a relevância do tema, sendo excluídas revisões de literatura, bem como os artigos que fugiam da temática. No clareamento dental ocorrem reações de oxidação, os agentes clareadores liberam oxigênio e radicais com função oxidativa e é essa forte liberação de oxigênio que prejudica a resistência das ligações adesivas estabelecidas na interface dente/material restaurador. Esse oxigênio irá interferir a polimerização do adesivo e da resina, impossibilitando a restauração imediata. Uma variedade de antioxidantes é pesquisada com finalidade de aumentar a resistência de união de dentes clareados, dentre eles o ascorbato de sódio, destacou- se por se mostrar capaz de remover o peróxido de oxigênio residual, de modo a neutralizar os radicais livres remanescentes e possibilitar restituição da capacidade adesiva e de polimerização. A continuidade e o aprofundamento dos estudos sobre a eficácia e aplicabilidade dos antioxidantes são de suma importância para a comunidade científica e cirurgiões-dentistas em geral para que obtenha-se resultados cada vez mais satisfatórios.Palavras-chave: PubMed. Bireme. Science Direct.

Uso das Proantocianidinas como Agente Biomodificador de Dentina: uma Revisão de Literatura

O objetivo do presente estudo é revisar a literatura para avaliar o uso das proantocianidinas como agente biomodificador da dentina. Para isso, foi realizada uma pesquisa bibliográfica na qual foram selecionados artigos publicados no período de 2007 a 2017 nas bases de dados PubMed, Cochrane e SciElo no idioma Inglês, utilizando os descritores: Cross-Linking Reagents, Dentin e Proanthocyanidins. Chegando-se ao total de 35 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 23 são estudos in vitro, 1 caso clínico e 3 revisões de literatura sendo excluídos os artigos que fugiam do objetivo do estudo e as revisões de literatura. Após uma leitura crítica de títulos e resumos, selecionou-se 10 artigos mediante a relevância ao tema. As PACs atuam como agente de ligações cruzadas, podendo aumentar a durabilidade das restaurações resinosas, pois têm o potencial de melhorar a dentina propriedades mecânicas e reduzir a sua degradação enzimática do colágeno tipo I, presente em dentina. Entretanto, estudos que avaliam a ação das PACs são muito recentes, não tendo trabalhos clínicos que comprovem sua efetividade ao longo dos anos. O desenvolvimento de artigos com um maior período de acompanhamento é fundamental para que a comunidade científica obtenha resultados sobre a ação das PACs, na durabilidade de restaurações resinosas. Ainda assim, esse agente biomodificador é bastante promissor na odontologia restauradora.Palavras-chave: Cross-Linking Reagents. Dentin. Proanthocyanidins.

Resistência de União em Restaurações Resinosas com o Uso do Laser Er: YAG para Remoção de Cárie: uma Revisão de Literatura

O objetivo do presente estudo é avaliar a resistência de união com o uso do laser Er:YAG para remoção de cárie. Revisou-se a literatura no período de 2012 a 2017, nas bases de dados PubMed, Bireme e Science Direct, no idioma Inglês, utilizando os seguintes descritores: lasers, dentin e dental bonding. Foram encontrados 95 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 24 são estudos in vitro, 68 estudos clínicos e 3 revisões de literatura, sendo excluídos artigos que fugiam do objetivo do estudo. Selecionou-se 14 artigos mediante a relevância ao tema. O laser emite radiação de 2,94 μm e atua através de microexplosões causada pelo calor resultante da absorção dessa radiação, fenômeno esse chamado de ablação dos tecidos dentais. Preparos cavitários dentários confeccionados com laser de Er: YAG pode resultar em uma maior conservação de tecidos sadios, maior abertura dos túbulos dentinários sem presença de lama dentinária, além de menor sensibilidade dolorosa durante sua confecção. A literatura ainda é muito controversa a respeito desse tema, mas a maioria dos autores relatam que há um comprometimento da resistência de união em uma dentina irradiada com o laser Er:YAG quando utilizado sistemas adesivos de condicionamento total. No entanto, são necessários mais estudos a fim de avaliar o a resistência de união à longo prazo após tratamento com Laser ER:YAG.Palavras-chave: Lasers. Dentin and Dental Bonding.

Uso das Resinas Infiltrantes no Tratamento de Cárie Dental: uma Revisão de Literatura

Este estudo tem como objetivo avaliar o uso das resinas infiltrantes (RI) no tratamento de cárie dental. Foi realizada uma busca bibliográfica onde foram selecionados artigos publicados no período entre 2012 e 2017 nas bases de dados PubMed, ScienceDirect e Bireme, no idioma inglês. Utilizaram-se os seguintes descritores: Icon Infiltrants, Synthetic Resins e Dental Caries. No total foram encontrados 61 artigos, 10 ensaios clínicos, 12 estudos laboratoriais e 2 revisões sistemáticas. Após uma leitura crítica de títulos e resumos foram selecionados 18 artigos mediante a relevância do tema. Foram excluídos revisões de literatura e artigos que fugiam ao tema. As resinas infiltrantes apresentam uma baixa viscosidade e foram desenvolvidas a fim de preencher as lesões de cárie paralisando a progressão desta, configurando-se um tratamento minimamente invasivo. As RI apresentam uma alta taxa de penetrabilidade, vedando e impedindo a difusão de ácidos cariogênicos que levam a progressão de lesões cariosas. Além disso, as RI possuem índices de microdureza significativos o que conferem uma boa firmeza do material nas lesões das unidades dentárias. Conclui-se que as RI são efetivas na interação de superfícies desmineralizadas reduzindo potencialmente lesões cariosas não cavitárias.Palavras-chave: Icon Infiltrants. Synthetic Resins. Dental Caries.

Avaliação de Propriedades Mecânicas de Resinas Nanohíbridas Comerciais para Dentina

O objetivo do estudo foi avaliar a microdureza Knoop, o módulo de elasticidade e a resistência flexural de compósitos nanohíbridos para dentina. Foram utilizadas três resinas nanohíbridas comerciais: IPS Empress Direct (Ivoclar Vivadent) Aura (SDI) e Opallis (FGM). Para o teste de microdureza foram confeccionados seis corpos-de-prova para cada grupo, com uma matriz de silicona, medindo 5 mm de diâmetro e 2 mm de profundidade, fotopolimerizados por 40s. Foi utilizado microdurômetro com ponta Knoop com carga de 50 gf por 15 segundos em que cada corpo de prova recebeu 5 indentações, sendo calculada a média de cada espécime. As indentações foram realizadas na superfície que estava em contato com fita de poliéster. Os testes de resistência flexural e módulo de elasticidade foram realizados em uma máquina de ensaio universal com velocidade de carga de 1 mm/min com espécimes com formato de barra com dimensões 7mmx2mmx1mm. Os dados foram submetidos à ANOVA um fator e teste post hoc de Tukey com nível de confiança de 95%. Os resultados mostraram que houve diferença estatística significativa entre os grupos testados quanto   à microdureza (p0,723), módulo de elasticidade (p0,42) e resistência flexural (p0,386). A resina Opallis apresentou microdureza superior quando comparada às outras duas, assim como quando analisada a resistência flexural. Em relação ao módulo de elasticidade, a resina Opallis e Aura não apresentaram diferença estatística entre si, mas se mostraram com valor superior quando comparada a IPS Empress Direct.Palavras-chave: Composite. Resins. Nanohybrid. Classification.

Cones Auto-Ajustáveis (CPoint) na Endodontia, Quais Suas Perspectivas: uma Revisão de Literatura

Muitas são as técnicas propostas à obturação dos Sistemas de Canais Radiculares (SCR), todavia, nenhuma delas alcançam o completo selamento. Em 2013, foi introduzido o cone auto-ajustável CPoint, que promete adaptar-se às paredes de canais produzindo obturações tridimensionais. Portanto, objetivou-se realizar uma revisão de literatura a fim de discutir este material e elucidar sua eficácia na obturação dos SCR. Foi utilizada a base de dados PubMed, usando os descritores Endodontics, Obturation e\ou CPoint, nos últimos 10 anos. Encontrou-se 5 estudos, os quais foram incluídos na revisão. Dentre as avaliações, analisou-se sua biocompatibilidade, expansão lateral e a influência de penetração de cimento nos túbulos dentinários, independente dos pontos avaliados, os resultados apresentam-se promissores. Verificou-se que o cone deve ser associado, idealmente, a um cimento biocerâmico, possuindo duas porções principais: um núcleo central que confere características de inserção e um revestimento polimérico hidrofílico que expande radialmente até encontrar às paredes dos canais. Tanto a expansão do CPoint quanto a presa do cimento dão-se pela absorção da umidade presente no SCR. Em outros testes, proporcionou uma maior resistência à fratura das raízes obturadas, contudo, demonstrou defeitos significativos nas obturações quando associado ao cimento biocerâmico. Conclui-se que o CPoint representa uma opção às técnicas de obturação dos SCR, porém, é necessária a realização de mais estudos no intuito de confirmar seu desempenho e indicá-lo para uso clínico.Palavras-chave: Endodontia. Materiais Dentários. Obturação do Canal Radicular.

Effects of a small natural barrier on the spatial distribution of the fish assemblage in the Verde River, Upper Paraná River Basin,Brazil

Geographical barriers influence species distribution and play an important role in the segregation of fish assemblages. The present study aims to test the influence of a small natural barrier on the spatial distribution of fish species in the Verde River, Upper Paraná River Basin, Brazil, considering two biotopes: upstream and downstream of the Branca Waterfall. We observed the highest species richness downstream of the Branca Waterfall, which also had the highest number of exclusive species. Richness, evenness, and abundance varied significantly among biotopes. The composition and structure of the fish assemblage differed between biotopes, which were characterized by different indicator species, mainly downstream of the Branca Waterfall. Physical and chemical variables and geographical distance between sites were not responsible for the differences observed. Hence, the present study shows that small barriers can also be crucial in structuring fish fauna and play a key role in the segregation of fish assemblages.

Population structure and genetic diversity in Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae): is there a correlation between genetic and geographic proximity?

Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae) is a minuscule insect species, which forms galls, is subsocial, and parthenogenetic. It is associated with Ficus benjamina L. (Moraceae) and has a pantropical occurrence. The paucity of genetic studies on the order Thysanoptera led us to use inter-simple sequence repeat molecular marker to assess intra- and inter-gall, as well as intra- and inter-site, genetic variability and population structure of G. uzeli. Analyses indicated low genetic variability, probably related to haplodiploidy, genetic drift, the galling habit, and the low dispersal ability of G. uzeli. Populations were highly structured, with higher variation within populations than among them. Geographic distance does not appear to affect structure and genetic diversity, the latter being influenced by G. uzeli's bioecological traits, by numerous introductions during a short period, and by a possible recent, common ancestry.

Middle Miocene closure of the Central American Seaway

Uranium-lead geochronology in detrital zircons and provenance analyses in eight boreholes and two surface stratigraphic sections in the northern Andes provide insight into the time of closure of the Central American Seaway. The timing of this closure has been correlated with Plio-Pleistocene global oceanographic, atmospheric, and biotic events. We found that a uniquely Panamanian Eocene detrital zircon fingerprint is pronounced in middle Miocene fluvial and shallow marine strata cropping out in the northern Andes but is absent in underlying lower Miocene and Oligocene strata. We contend that this fingerprint demonstrates a fluvial connection, and therefore the absence of an intervening seaway, between the Panama arc and South America in middle Miocene times; the Central American Seaway had vanished by that time.

CoffeebEST: an integrated resource for Coffea spp expressed sequence tags

Coffee is one of the most important commodities in the world, and its production relies mainly on two species, Coffea arabica and Coffea canephora. Although there are diverse transcriptome datasets available for coffee trees, few research groups have exploited the potential knowledge contained in these data, especially with respect to fruit and seed development. Here, we present a comparative analysis of the transcriptomes of Coffea arabica and Coffea canephora with a focus on fruit development using publicly available expressed sequence tags (ESTs). Most of the fruit and seed EST data has been obtained from C. canephora. Therefore, we performed a fruit EST analysis of the 5 developmental stages of this species (18, 22, 30, 42, and 46 weeks after flowering) comprising 29,009 sequences. We compared C. canephora fruit ESTs to reference unigenes of C. canephora (7710 contigs and 8955 singletons) and C. arabica (15,656 contigs and 16,351 singletons). Additional analyses included functional annotation based on Gene Onthology, as well as an annotation using PlantCyc, a curated plant protein database. The Coffee Bean EST (CoffeebEST) is a public database available at http://bioinfo-02.cp.utfpr.edu.br/. This database represents an additional resource for the coffee scientific community, offering a user-friendly collection of information for non-specialists in coffee molecular biology to support experimental research on comparative and functional genomics.

The biomaterial-mediated healing of critical size bone defects in the ovariectomized rat

This study demonstrated an impaired biomaterial-mediated bone regeneration in a critical sized calvarial defect established within an ovariectomized rat model. Histological and microtomographic evidences were supported by an impaired osteoblastic gene expression and altered expression of estrogen receptors and adipogenic markers.

INTRODUCTION

This work aims to address the bone regeneration process in the ovariectomized rat model, by assessing a calvarial critical size defect implanted with a biocompatible bovine bone mineral graft.

METHODS

Animals were randomly divided into two groups: Ovx (bilateral ovariectomy) and Sham (control surgery). Following 8 weeks, all animals were submitted to a surgical bicortical craniotomy (5-mm circular critical size defect), which was filled with a biocompatible mineral graft. Animals were euthanized at 1, 3, and 6 months following graft implantation (n = 10), and results on the orthotopic bone regeneration process were blindly evaluated by radiographic, microtomographic, histological, histomorphometric, and gene expression techniques.

RESULTS

In the attained model, in both Sham and Ovx groups, the bone regenerative process was found to occur in a slow-paced manner. Likewise, a qualitative evaluation of the microtomographic and histological analysis, as well as quantitative data from histomorphometric indexes, revealed reduced bone regeneration in Ovx animals, at the assayed time points. Significant differences were attained at the 3 and 6 months. Gene expression analysis revealed a reduced expression of osteoblastic-related genes and an altered expression of estrogen receptors and adipogenic markers, within the regenerating bone of Ovx animals.

CONCLUSIONS

Due to the similarities between the osteoporotic animal model and the human condition of postmenopausal osteoporosis, it might be relevant to consider the potential clinical implication of the osteoporotic condition in the biomaterial-mediated bone tissue healing/regeneration process.

Inhibition of human in vitro osteoclastogenesis by Equisetum arvense

OBJECTIVES

Equisetum arvense has long been used in traditional medicines to treat different disorders, including bone pathologies. In this study a hydromethanolic extract of E. arvense was assessed for its effects on human osteoclastogenesis.

MATERIALS AND METHODS

Osteoclast precursors were maintained in non-stimulated and stimulated (presence of M-CSF and RANKL) conditions, or in co-cultures with osteoblasts. Cell cultures were treated with 0.00016-0.5 mg/ml of a hydromethanolic E. arvense extract.

RESULTS

The extract did not affect spontaneous osteoclastogenesis. In osteoclast precursors committed to osteoclastogenesis (stimulated or co-cultured with osteoblasts), E. arvense caused dose-dependent inhibitory effect that became statistically significant at concentrations ≥0.004 mg/ml. This was observed using different osteoclast differentiation and activation markers. Cell response was associated with changes in relative contribution of MEK and NFkB signalling pathways, as well as PGE2 production. As there were differences in the response of osteoclast precursors maintained in the presence of inductive factors, or co-cultured with osteoblastic cells, it seems that E. arvense extract had the ability to modulate osteoclastogenesis, either by acting directly on osteoclast precursor cells, and/or via osteoblasts.

CONCLUSIONS

Equisetum appeared to have a negative effect on human osteoclastogenesis, which is in line with its putative beneficial role in pathophysiological conditions associated with increased osteoclastic activity, and might suggest potential utility for treatment with bone regeneration strategies.

Population structure and genetic diversity analysis in Gynaikothrips uzeli (Zimerman, 1909) (Thysanoptera: Phlaeothripidae) by RAPD markers

Thrips are small insects (0.5-3.0 mm) with distinct habits and life histories characterized by haplodiploid sex determination. In general, low levels of genetic diversity have been reported in haplodiploid insects, although most reports focus on the order Hymenoptera. Therefore, we used RAPD markers to evaluate the structure and both inter- and intra-population genetic variability of Gynaikothrips uzeli (Thysanoptera: Phlaeothripidae). Six populations, three from Paraná state, southern Brazil, and three from Bahia, northeastern Brazil, were studied. Similarly to other haplodiploid insects, the genetic diversity of G. uzeli was reduced. This result is putatively related to the haplodiploid sex determination system, which yields little genetic variation, and to ecological traits of the studied species, such as the low dispersal abilities and life mode in leaf galls. All individuals were homogeneously clustered in their respective collection sites, forming two main groups in which populations from similar environments were more closely related. The analyzed populations were highly structured, and the genetic variation was higher among than within populations.

Human FEZ1 protein forms a disulfide bond mediated dimer: implications for cargo transport

The human proteins FEZ1 (fasciculation and elongation protein zeta 1) and FEZ2 are orthologs of the protein UNC-76 from C. elegans, involved in the growth and fasciculation of the worms axon. Pull down assays showed that the protein FEZ1 interacts with other proteins (e.g., the protein SCOCO, short coiled-coil protein), mitochondria, and vesicles. These components may therefore represent cargoes to be transported along the microtubule, and the transport may be mediated through FEZ1 reported binding to kinesins (KIF3A). We previously showed that FEZ1 dimerizes in its N-terminal region and interacts with other proteins, including the candidate cargoe proteins, through its C-terminus. Here, we studied the fragment FEZ1(92-194) as well as full-length 6xHis-FEZ1 (1-392) in vitro and endogenous FEZ1 isolated from HEK 293 cells and were able to demonstrate the formation of an intermolecular disulfide bond through FEZ1 Cys-133, which appears to be essential for dimerization. This disulfide bond may be important for the FEZ1 role as a dimeric and bivalent transport adaptor molecule, since it establishes a strong link between the monomers, which could be a prerequisite for the simultaneous binding of two cargoes.

Chromosomal diversity and phylogenetic inferences concerning thrips (Insecta, Thysanoptera) in a semi-arid region of Brazil

The order Thysanoptera is composed of cosmopolitan phytophagous and predaceous insects with diverse life histories, behaviors and habits. This order is currently thought to form a trichotomy with Hemiptera and Psocodea; Hemiptera and Thysanoptera are considered to be sister groups. The interrelationships within Thysanoptera remain unclear and cytotaxonomic studies are scarce in thrips. We report, for the first time, chromosomal data on seven species of thrips collected from a semi-arid region in the States of Bahia and Pernambuco (Northeast Brazil). A distinctive chromosomal pattern was observed in Thysanoptera when compared to other members within the infraclass Paraneoptera. Considerable karyotypic differences were also found within genera and species of Thysanoptera. Based on these data, we suggest that Paraneoptera forms a polyphyletic group and that Terebrantia and Tubulifera should be regarded as sister groups. The high chromosomal variability observed in Thysanoptera indicates that chromosomal rearrangements have played a key role in their speciation pathways.

Conserved fragments of transposable elements in intergenic regions: evidence for widespread recruitment of MIR- and L2-derived sequences within the mouse and human genomes

We analysed the distribution of transposable elements (TEs) in 100 aligned pairs of orthologous intergenic regions from the mouse and human genomes. Within these regions, conserved segments of high similarity between the two species alternate with segments of low similarity. Identifiable TEs comprise 40-60% of segments of low similarity. Within such segments, a particular copy of a TE found in one species has no orthologue in the other. Overall, TEs comprise only approximately 20 % of conserved segments. However, TEs from two families, MIR and L2, are rather common within conserved segments. Statistical analysis of the distributions of TEs suggests that a majority of the MIR and L2 elements present in murine intergenic regions have human orthologues. These elements must have been present in the common ancestor of human and mouse and have remained under substantial negative selection that prevented their divergence beyond recognition. If so, recruitment of MIR- and L2-derived sequences to perform a function that increases host fitness is rather common, with at least two such events per host gene. The central part of the MIR consensus sequence is over-represented in conserved segments given its background frequency in the genome, suggesting that it is under the strongest selective constraint.

Analyses of P-like transposable element sequences from the genome of Anopheles gambiae

We have identified 50 P element-homologous sequences in the genome of Anopheles gambiae by performing homology searches against the public genome database of A. gambiae using the canonical P element from Drosophila melanogaster as a query sequence. While most of these sequences belong to P subfamilies previously described from anopheline mosquitoes, at least four new subfamilies were identified. One of these A. gambiae P elements, which we termed AgPLS, was analysed in detail. AgPLS consists of three exons and does not have inverted terminal repeats. This element retains several of the structural features of other P-encoded peptides, such as motifs involved in DNA-protein and protein-protein interaction, and a motif involved in GTP utilization. Strong sequence and structural similarity to functional P elements, a number of nonsynonymous substitutions that is smaller than that of synonymous substitutions and the presence of putative nuclear localization signals suggest that the A. gambiae elements may retain the capacity for transposition or its repression. These sequences seem to be most closely related to P elements described from Musca domestica and Lucilia cuprina, the only P element hosts known outside the family Drosophilidae.

Seroprevalence of Toxoplasma gondii in captive neotropical felids from Brazil

Seroprevalence of Toxoplasma gondii was determined in 865 captive neotropical felids from 20 states from Brazil, sampled from September 1995 to April 1997. Sera were tested by the modified agglutination test (MAT) using formalin-fixed whole tachyzoites and mercaptoethanol. Antibodies (MAT> or =1:20) to T. gondii were found in 472 of 865 (54.6%) cats: in 45 of 99 (45.9%) jaguarundis (Herpailurus yagouaroundi), in 97 of 168 (57.7%) ocelots (Leopardus pardalis), in 68 of 131 (51.9%) oncillas (L. tigrinus), in 35 of 63 (55.5%) margays (L. wiedii), in 1 of 8 (12.5%) Pampas-cat (Oncifelis colocolo), in 9 of 12 (75.0%) Geoffroys-cat (O. geoffroyi), in 134 of 212 (63.2%) jaguars (Panthera onca), and in 83 of 172 (48.2%) pumas (Puma concolor). Antibody titers were: 1:20 in 27 felids, 1:25 in 142 felids, 1:40 in 6 felids, 1:50 in 292 felids, and > or =1:500 in 5 felids. The high seroprevalence of T. gondii antibodies found in the present study suggested a widespread exposure of neotropical cats to T. gondii in zoos in Brazil. The results warrant an investigation on the mode of exposure and oocyst shedding by neotropical cats.

Drosophila mediopunctata P elements: a new example of horizontal transfer

Sequences homologous to the P element of Drosophila melanogaster were previously identified in Drosophila mediopunctata, a member of the tripunctata group, subgenus Drosophila. We report here that the P element is present in about three to five copies in the D. mediopunctata genome. While one of the insertion sites appears to be fixed, others may be polymorphic, indicating relatively recent P element activity. Phylogenetic analysis revealed that the D. mediopunctata element belongs to the canonical subfamily of P elements and that divergence of the D. mediopunctata element from other members of this subfamily ranges from 2% to 5% at the nucleotide level. This is the first report of a canonical P element outside the subgenus Sophophora. Based primarily on the striking incongruence between P element and host species phylogenies, the presence of a canonical P element in D. mediopunctata is most likely explained by horizontal transfer between species.

Toxoplasma gondii antibodies in exotic wild felids from Brazilian zoos

Serum samples from 37 captive exotic felids in 12 zoos from six Brazilian states were assayed for antibodies to Toxoplasma gondii by the modified agglutination test using formalin-fixed whole tachyzoites. Titers greater than or equal to 1:20 were considered positive. Antibodies to T. gondii were found in 24 of 37 (64.9%) felids, including one European lynx (Lynx lynx), two jungle cats (Felis chaus), two servals (Leptailurus serval), two tigers (Panthera tigris), three leopards (Panthera pardus), and 14 of 27 lions (Panthera leo). This is the first serologic analysis for T. gondii infection in exotic wild felids from Brazilian zoos.

[Nursing practice and public health policy in Campinas, São Paulo, Brazil]

Redemocratization in the 1970s brought about changes in the public health system in Brazil. The Unified National Health System (SUS) was implemented in 1988, based on local and regional administrative systems. This was an important step that resulted in greater local control and the introduction of new technologies. This study focuses on the local health system in Campinas, a relatively affluent and technologically advanced region some 100km from the city of São Paulo in Southeast Brazil. Qualitative and quantitative methods were used to evaluate the work of 233 nurses in the local health system. The first nurse was hired in 1977, and now there are 53 nurses working in specific areas: 10 in the central health administration, 36 in district administrations, and the rest in local services. Nursing services are organized in six main areas: administration, coordination of human resources, education, information technology, health surveillance, and health administration. Nursing intervention may be found in various areas, but it generally focuses on medical consultations, and there is little emphasis on collective activities and health promotion. Local health objectives can only be achieved by creating new practices that promote collective health.

Hemodynamic results of femoral vein valve repair

Our aim was to assess the hemodynamic and clinical responses associated with valve repair surgery in 37 patients with severe chronic venous insufficiency. Patients classified as C(4-6)E(P)A(SDP)P(R) (primary venous dysfunction with skin changes with reflux of superficial, deep and perforating veins) were submitted to a novel procedure combining the closed technique described by Kistner with the Dacron sleeve technique described by Hallberg (mean follow-up = 24 months). A significant improvement in Valsalva test results (P < 0.0001), ambulatory pressure (P = 0.0099), venous refilling time (P < 0.0001), and reflux index (P < 0.0001) was observed. Postoperative reactive hyperemia and gradient tests confirmed absence of venous obstruction signs. On their last visit, 85.3% of the patients had no ulceration, and edema was absent or minimal in over 90%. About 70% of the patients referred partial or complete relief of pain in the affected limb. The combined surgical technique was effective to control venous reflux 24 months after the procedure. A longer follow-up would be necessary to assess long-term results.

Whole-genome effects of ethyl methanesulfonate-induced mutation on nine quantitative traits in outbred Drosophila melanogaster

We induced mutations in Drosophila melanogaster males by treating them with 21.2 mm ethyl methanesulfonate (EMS). Nine quantitative traits (developmental time, viability, fecundity, longevity, metabolic rate, motility, body weight, and abdominal and sternopleural bristle numbers) were measured in outbred heterozygous F3 (viability) or F2 (all other traits) offspring from the treated males. The mean values of the first four traits, which are all directly related to the life history, were substantially affected by EMS mutagenesis: the developmental time increased while viability, fecundity, and longevity declined. In contrast, the mean values of the other five traits were not significantly affected. Rates of recessive X-linked lethals and of recessive mutations at several loci affecting eye color imply that our EMS treatment was equivalent to approximately 100 generations of spontaneous mutation. If so, our data imply that one generation of spontaneous mutation increases the developmental time by 0.09% at 20 degrees and by 0.04% at 25 degrees, and reduces viability under harsh conditions, fecundity, and longevity by 1.35, 0.21, and 0.08%, respectively. Comparison of flies with none, one, and two grandfathers (or greatgrandfathers, in the case of viability) treated with EMS did not reveal any significant epistasis among the induced mutations.

Determinants of in-hospital mortality in women with acute myocardial infarction who underwent primary coronary angioplasty

INTRODUCTION

According to recent data, women have a greater risk of dying from an acute coronary event. The determinants of this ominous prognosis are not completely understood. Preliminary analysis of our data suggested that this poorer prognosis is also observed in the subgroup of patients with acute myocardial infarction submitted to direct coronary angioplasty (PTCA). This finding prompted us to investigate gender differences and their determinants in this particular context.

OBJECTIVE

To identify risk factors associated with the greater in-hospital mortality of women with acute infarction who underwent PTCA.

METHODS

One hundred and forty-five consecutive patients with acute myocardial infarction who underwent direct PTCA in the same hospital were studied retrospectively. Data were collected from the database of the catheterisation laboratory and from clinical files. The following parameters were analysed: in-hospital mortality, age, prevalence of diabetes mellitus, history of coronary heart disease, time elapsed from beginning of symptoms to coronary intervention, peak values of CK and MB-CK, number of coronary arteries with significant disease at angiography, culprit lesion localisation, and prevalence of shock on admission. For statistical analysis, cross-tabulation (Pearson x2) and comparison of means (Student's t test) were employed when appropriate; an error of 5% was admitted for the rejection of the null hypothesis.

RESULTS

Women (n = 39) represented 26.9% of sample. In hospital mortality was 28.2% (n = 11) for women and 11.3% (n = 12) for men (p = 0.014). The prevalence of coronary heart disease before the current acute event, the time elapsed from beginning of symptoms to coronary intervention, and maximum values of CK and MB-CK were similar in both genders. Differences between women and men were found as regards the following variables (women vs men): age (61.7 +/- 10 vs 56.1 +/- 12.6 years), prevalence of left main disease (15.3 vs 1.9%) and prevalence of shock (41 vs 17%) and diabetes (38.7 vs 13.6%). Considering women and men who died, only disease severity as evaluated by the number of vessels involved distinguished both genders (p = 0.05).

CONCLUSIONS

In our experience, women admitted with acute myocardial infarction and treated by direct PTCA are, on average, older than men and have a greater prevalence of shock at admission, of left main disease and of diabetes, and more severe coronary artery disease. In the present series and as regard in-hospital mortality, disease severity as evaluated by the number of vessels involved is the only variable that discriminates women from men.

Horizontal transfer and selection in the evolution of P elements

The roles of selection and horizontal transfer in the evolution of the canonical subfamily of P: elements were studied in the saltans and willistoni species groups of the genus Drosophila (subgenus Sophophora). We estimate that the common ancestor of the canonical P: subfamily dates back 2-3 Myr at the most, despite the much older age (more than 40 Myr) of the P: family as a whole. The evolution of the canonical P: subfamily is characterized by weak selection at nonsynonymous sites. These sites have evolved at three quarters the rate of synonymous sites, in which no selective constraints were detected. Their recent horizontal transfer best explains the high degree of similarity among canonical P: elements from the saltans and willistoni species groups. These results are consistent with a model of P:-element evolution in which selective constraints are imposed at the time of horizontal transfer. Furthermore, it is estimated that the spread and diversification of the canonical subfamily involved a minimum of 11 horizontal transfer events among the 18 species surveyed within the past 3 Myr. The presence of multiple P: subfamilies in the saltans and willistoni species groups is likely to be the result of multiple invasions that have previously swept through these taxa in a succession of horizontal transfer events. These results suggest that horizontal transfer among eukaryotes might be more common than anticipated.

Intestinal paracoccidioidomycosis simulating colon cancer

We report a case of intestinal involvement of Paracoccidioidomycosis, in a patient considered to have colonic cancer. The diagnosis of this mycosis should be considered when an abdominal mass associated with intra-lesional calcifications on X-ray is observed. CT scans increase the findings.

Managed care organization authorization denials: lack of patient knowledge and timely alternative ambulatory care

STUDY OBJECTIVE

To assess patient knowledge of managed care organization (MCO) regulations, availability of alternative ambulatory care, and patient outcome after MCO insurance authorization denial for an emergency department visit.

METHODS

A medical screening examination and a follow-up structured interview were conducted with patients denied authorization for ED visits. The study was conducted at a large urban hospital with 36,000 annual ED visits and 40% MCO patients.

RESULTS

During a 7-month period, 151 patients did not receive MCO authorization for ED care. The interview response rate was 75% (104/138) with 13 patients excluded. Eighty-three percent (86/104) of respondents came to the ED because they believed their problem was an emergency. Four percent (4/104) of the respondents had been instructed to go to the ED but were later denied authorization, whereas 85.6% (89/104) did not know that the MCO could deny payment. Only 37% (38/104) of the respondents reported having received instruction on the MCO preauthorization process, whereas of the 19% who contacted their MCO as instructed, all resulted in scheduling difficulties. Although 57% (59/104) received follow-up within 24 hours, 11% (11/104) of the respondents had a subsequent return visit to the ED with a subsequent admission rate of 4% (4/104).

CONCLUSION

Few patients are aware of the need for MCO preauthorization for ED care, and almost half do not receive alternative care within 24 hours. A significant number of patients (11%) returned to the ED with an admission rate of 4%.

Effects of pentoxifylline and nabumetone on the serum levels of IL-1beta and TNFalpha in rats with adjuvant arthritis

OBJECTIVE AND DESIGN

This study examined whether serum levels of cytokines, IL-1beta and TNFalpha were elevated in rats with adjuvant arthritis in relation to disease progression, and if so, to verify the treatment effects of nabumetone (20 mg/kg, p. o.), a COX-2 inhibitor and pentoxifylline (20 mg/kg, p.o.), a type-4 phosphodiesterase (PDE4) inhibitor, alone or in combination.

MATERIALS AND METHODS

Female Wistar rats were used. Freund's complete adjuvant (FCA) was used to induce arthritis. The increment in contralateral hind paw volume (the secondary lesion) was determined by plethysmometry and the serum cytokines were measured by ELISA.

RESULTS

In control rats, the serum IL-1beta and TNFalpha levels were greatly elevated on the very first day i.e. 5 h after FCA, and thereupon a progressive decrease in IL-1beta but not TNFalpha was observed until day 30. The secondary arthritic lesion began to increase on day 14 (125+/-26 microl), and attained its peak (330+/-79 microl) on day 21 post-adjuvant injection. The peak arthritic lesion was significantly (p<0.001) less in rats that received nabumetone and pentoxifylline, alone or in combination (20+/-8, 41+/-15 and 65+/-10 microL, respectively). When serum cytokine levels were analysed on day 20 postadjuvant injection, rats treated with pentoxifylline or in association with nabumetone, but not nabumetone alone showed significantly lowered levels of serum TNFalpha. Unlike TNFalpha, serum IL-1beta did not vary significantly.

CONCLUSIONS

The drugs nabumetone and pentoxifylline although appearing to produce differential effects on serum cytokine levels, seem to be equally efficacious in attentuating the progression of FCA-induced arthritis. Serum cytokine levels may not accurately reflect the treatment efficacy.

Antioestrogenic effect of trans-dehydrocrotonin, a nor-clerodane diterpene from Croton cajucara Benth. in rats

This study examined trans-dehydrocrotonin (t-DCTN), a nor-clerodane diterpene isolated from the Brazilian medicinal plant Croton cajucara Benth., for a possible antioestrogenic activity using immature rats as a model system for bioassay of oestrogen, and for an antiimplantation effect in regularly cycling rats of proven fertility. In the antioestrogen test, t-DCTN (25 and 50 mg/kg) effectively prevented oestrogen-induced increases of uterine wet weights. In addition, the vaginal openings provoked by oestrogen were completely prevented by t-DCTN. However, blastocyst-implantation was only insignificantly affected in t-DCTN pretreated animals. These results suggest that t-DCTN may be an antioestrogen and warrants further studies with regard to its mechanism of action.

Intrinsic myenteric denervation: a new model to increase the intestinal absorptive surface in short-bowel syndrome

INTRODUCTION

Short-bowel syndrome (SBS) is caused by resection of massive portions of the small intestine and is characterized by symptoms related to malabsorption, of which severe weight loss is the most apparent. Surgical treatments for SBS are not yet satisfactory. In rats, the myenteric denervation by benzalkonium chloride (BAC) leads to development of megaileum with visceral dilatation and mucosal hyperplasia and increases the intestinal transit time. Such operation in the remaining intestinal segment after massive small bowel resection could increase the duration of contact between luminal nutrients and ileal mucosal epithelium, and furthermore, it could increase the superficial area of the mucosa. Thus, our aim in this study was to evaluate the epithelial morphology and body weight changes of animals after intrinsic ileal denervation associated with extensive small intestine resection.

MATERIAL AND METHODS

Wistar rats were submitted to resection of 80% of small intestinal length (Group R). Another group (B) of animals also received topical serosal application of BAC 0.3%. Control animals were submitted to simulated surgery (Group C). Animals were weighed weekly and sacrificed after 90 days. Intestinal walls were collected for histological procedure and morphometry.

RESULTS

At the end of the experimental period all groups showed weight increase, which was reduced in the R group (P < 0.01). Interestingly, the denervated Group B showed a marked increase in weight, similar to the control animals. Morphometric analysis of the mucosal layer area showed a major increase in mucosal surface area, mainly in Group B.

CONCLUSIONS

Our results showed that the ileal intrinsic denervation associated with massive intestinal resection induced an increase in the superficial absorptive area and was able to improve the postsurgical conditions for the animals, with accentuated weight increase. This procedure may be a useful model for further studies related to the role of the enteric nervous system on intestinal adaptations after extensive resections and may provide a new approach for the surgical treatment of short-bowel syndrome.

The rate and risk of heat-related illness in hospital emergency departments during the 1995 Chicago heat disaster

OBJECTIVES

To conduct an Emergency Department (ED)-based treated prevalence study of heat morbidity and to estimate the rate and risk of heat morbid events for all Chicago MSA EDs (N = 95; 2.7 million visits per year).

METHODS

ED patient log data were compiled from 13 randomly selected hospitals located throughout the Chicago MSA during the 2 weeks of the 1995 heat disaster and from the same 2-week period in 1994 (controls). Measurements included: age, sex, date, and time of ED service, up to three ICD-9 diagnoses, and disposition.

RESULTS

Heat morbidity for Chicago MSA hospital EDs was calculated at 4,224 (95% CI = 2964-5488) cases. ED heat morbidity increased significantly 5 days prior to the first heat-related death. In 1995, there was an increase in the estimated relative risk for the city = 3.85 and suburbs = 1.89 over the control year of 1994.

CONCLUSIONS

Real time ED-based computer automated databanks should be constructed to improve public health response to infectious or noninfectious outbreaks. Rapid area-wide M&M tabulations can be used for advancing the effectiveness of community-based prevention programs, and anticipating hospital ED resource allocation.

Metastatic thyroid carcinoma arising from congenital goiter due to mutation in the thyroperoxidase gene

A very large cervical tumor that extended to the upper mediastinum was seen in a newborn after an uneventful pregnancy. The computed axial tomography scan confirmed the presence of a solid mass with precise limits and scattered foci of calcifications situated in the anterolateral region of the neck. The infant underwent thyroidectomy on the seventh day after birth. Pathological examination revealed a follicular carcinoma of the thyroid and probable dyshormonogenetic hyperplastic goiter. At 5 months of age, whole body scans indicated the presence of lung and bone metastases, which were treated with therapeutic doses of radioiodine. Genomic DNA was obtained from the newborn, her parents, her paternal aunt, and her paternal grandparents. Denaturing gradient gel electrophoresis analysis of PCR fragments corresponding to exon 14 of the thyroid peroxidase (TPO) gene indicated the presence of a mutant TPO allele present in the propositus, her father, and her paternal grandmother. Sequencing of the TPO gene demonstrated a mutation resulting from an insertion of a single extra cytosine in a stretch of seven cytosines at positions 2505-2511. The insertion caused a frame shift and a stop signal in exon 16. This sequence would translate into a structurally modified and probably inactive TPO protein. We conclude that the aggressive thyroid metastatic carcinoma arose from a dyshormonogenetic goiter caused by a defective TPO protein.