Análise de barreiras e o modelo de ressonância funcional de acidentes de Erik Hollnagel

Partindo de apresentação da proposta de análise de acidentes baseada no modelo sistêmico e não linear de acidentes, dito de ressonância funcional, desenvolvido por Erik Hollnagel, este texto discute críticas às concepções deterministas de acidente e aos modelos lineares de representação desses eventos. Aspectos do modelo de ressonância funcional são usados como eixo definidor de proposta de agenda de discussões a ser desenvolvida pelos interessados no tema da análise de acidentes, destacando-se: a) a defesa do abandono da idéia de causas de acidentes e sua substituição pela de explicação desses eventos; b) apresentação dos conceitos de variabilidade de desempenhos e adaptações locais e a proposta de sua utilização como bases para a identificação de perfis ou aspectos típicos de acidentes. Por fim, discute-se a necessidade de incorporação dos conceitos apresentados no debate sobre novos caminhos para as práticas de análises e de prevenção de acidentes em nosso país.

Occurrence of Cryptosporidium (Apicomplexa, Cryptosporidiidae) in Crotalus durissus terrificus (Serpentes, Viperidae) in Brazil

The objective of the present study was to investigate the prevalence of Cryptosporidium (Apicomplexa, Cryptosporidiidae) in the snake Crotalus durissus terrificus (Serpentes, Viperidae). Fifty animals were evaluated for the presence of oocysts of Cryptosporidium sp. at the time of arrival and 30 and 60 days later. Intestinal washings with saline solution (1% body weight), fecal samples, and organ scrapings were collected during the study. Oocysts were concentrated by an ether-phosphate-buffered saline sedimentation technique and then separated by a density gradient centrifugation technique. Smears were made with the sediment and submitted to modified acid-fast and auramine-rhodamine staining. Cryptosporidium-positive smears were used as controls for the experimental findings. The overall prevalence of Cryptosporidium sp. oocysts was 14%. Among the positive snakes, oocysts were detected only in the intestinal washing in two specimens, only in the feces in four specimens, and in both materials at least once in one specimen. The positive snakes were predominantly from Santa Maria da Serra city State of São Paulo (57.1%). We also observed that all of the examinations that presented positive results were obtained at least 27 days after the capture of the animals.

The occurrence of Crepidobothrium sp. (Cestoda, Proteocephalidae) in Bothrops moojeni (Hoge) (Serpentes, Viperidae)

The occurrence of Crepidobothrium sp.(Cestoda, Proteocephalidae) in the intestine of Bothrops moojeni (Hoge,1965)(Serpentes, Viperidae) is reported. The host snake was rescued from the fauna in Porto Primavera dam, Mato Grosso do Sul State, Brazil. The snake died in captivity on July 13,1999. At necropsy, 28 tapeworms were found in the snake intestine. The analysis of specimens morphology allowed the conclusion that they belong to the Crepidobothrium (Monticelli, 1900) genus. It was not possible to determine the Crepidobothrium species due to the lack of the gravid proglottids. This is the first report of B. moojeni as a host of cestodes.

Evaluation of curcumin and cisplatin-induced DNA damage in PC12 cells by the alkaline comet assay

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polymorphisms of Lewis and Secretor genes are related to breast cancer and metastasis in axillary lymph nodes

ABH and Lewis antigen expression has been associated with cancer development and prognosis, tumor differentiation, and metastasis. Considering that invasive ductal breast carcinoma (IDC) presents multiple molecular alterations, the aim of the present study was to determine whether the polymorphism of ABO, Lewis, and Secretor genes, as well as ABO phenotyping, could be associated with tumor differentiation and lymph nodes metastasis. Seventy-six women with IDC and 78 healthy female blood donors were submitted to ABO phenotyping/genotyping and Lewis and Secretor genotyping. Phenotyping was performed by hemagglutination and genotyping by the polymerase chain reaction with sequence-specific primers. ABO, Lewis, and Secretor genes were classified by individual single nucleotide polymorphism at sites 59, 1067, 202, and 314 of the Lewis gene, 428 of the Secretor gene, and 261 (O1 allele), 526 (O2 and B allele), and 703 (B allele). No association was found between breast cancer and ABO antigen expression (P = 0.9323) or genotype (P = 0.9356). Lewis-negative genotype was associated with IDC (P = 0.0126) but not with anatomoclinical parameters. Nonsecretor genotype was associated with axillary lymph node metastasis (P = 0.0149). In conclusion, Lewis and Secretor genotyping could be useful to predict respectively breast cancer susceptibility and axillary lymph nodes metastasis.

Malaria at Humaita county, Amazonas state, Brazil: XVII - immune response in patients with Plasmodium falciparum according to gametocytes

Em agosto de 1983, os Autores, estudaram 36 doentes com infecção causada pelo Plasmodium falciparum e 14 indivíduos normais, nascidos na região de Humaitá, que nunca tiveram malária, sem esplenomegalia, com exame parasitológico de sangue e hemaglutinação passiva negativas. Todos eles foram submetidos à observação clínica completa, exame hematológico, exame parasitológico de sangue e tipagem de linfócitos. Os linfócitos foram isolados e congelados em nitrogênio líquido, para posterior tipagem pela formação de rosetas. Os doentes foram classificados em dois grupos de acordo com a presença (13 doentes), ou ausência (23 doentes) de gametócitos antes do tratamento. Houve predomínio de formas graves no grupo de doentes sem gametócitos. Os resultados mostraram diminuição do número de linfócitos T em ambos os grupos de doentes, com ou sem gametócitos antes do tratamento, enquanto que o número de linfócitos B foi normal apenas no grupo de doentes com gametócitos. Essas observações, assim como as que foram relatadas pelos Autores anteriormente, permitem associar a presença de gametócitos circulantes com o número normal de células B em doentes com formas leves de malária causada pelo Plasmodium falciparum.

Frequency of human leukocyte antigen (hla) in patients with malaria and in the general population of Humaitá county, Amazonas state, Brazil

Em agosto de 1983 foram observados 85 habitantes do Município de Humaitá, Estado do Amazonas, Brasil, com a finalidade de estudar a prevalência dos antígenos de HLA -A, -B, -C e DR, dentre os quais 38 eram doentes com malária causada pelo Plasmodium falciparum Todos eles foram examinados para avaliação de esplenomegalia, exame parasitológico de sangue e pesquisa de anticorpos de malária. Foram constituídos três grupos: (I) 25 indivíduos nascidos na região Amazônica que nunca tiveram malária; (II) 38 indivíduos naturais da Amazônia que tinham sido tratados de malária no passado, ou que estavam tendo malária atual, e (III) 22 doentes com malária que contraíram na Amazônia e eram procedentes de outras regiões do Brasil. Foram colhidas amostras de sangue de cada um deles, separados os linfôcitos e os antígenos de HLA foram tipados pelo teste de microlinfocitotoxidade. Houve elevada freqüência de antígenos não identificados, nos grupos estudados, o que sugere ou a existência de homozigoze, oufenôtipo não identificado nessa população. Houve alta freqüência fenotípica de antígeno deAg(W24) (44,7%) no Grupo II, quando comparado ao Grupo 1(32%) ou Grupo III (9%). Os indivíduos do Grupo II mostraram também elevada freqüência do antígeno DR4 (80%) quando comparado ao Grupo 1(36,3%) ou Grupo III(16,6%). Essas observações sugerem a possibilidade de suscetibilidadegenética ã malária entre os nativos da Amazônia e indicam a necessidade da realização de inquéritos mais extensos sobre a freqüência de antígenos de HLA em habitantes de zona endêmica de malária.

Complete denture hygiene and nocturnal wearing habits among patients attending the Prosthodontic Department in a Dental University in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Postsurgical Care for Rehabilitation With Implant-Retained Extraoral Prostheses

The health of a peri-implant tissue is a critical factor for the long-term success of treatment with extraoral implants. However, infection and inflammation may occur and lead to implant loss and prostheses failure. Therefore, some postsurgical care as hygiene with soap and water, soft toothbrush, and Superfloss type dental floss and medication with anti-inflammatory and antibiotic are suggested to avoid complications. In addition, a thin and smooth layer of subcutaneous tissue in the peri-implant area should be preserved during implant insertion to favor the assistance recommended in this phase.

The growing importance of materials that prevent microbial adhesion: antimicrobial effect of medical devices containing silver

Research has clarified the properties required for polymers that resist bacterial colonisation for use in medical devices. The increase in antibiotic-resistant microorganisms has prompted interest in the use of silver as an antimicrobial agent. Silver-based polymers can protect the inner and outer surfaces of devices against the attachment of microorganisms. Thus, this review focuses on the mechanisms of various silver forms as antimicrobial agents against different microorganisms and biofilms as well as the dissociation of silver ions and the resulting reduction in antimicrobial efficacy for medical devices. This work suggests that the characteristics of released silver ions depend on the nature of the silver antimicrobial used and the polymer matrix. In addition, the elementary silver, silver zeolite and silver nanoparticles, used in polymers or as coatings could be used as antimicrobial biomaterials for a variety of promising applications. (C) 2009 Elsevier B. V. and the International Society of Chemotherapy. All rights reserved.

Silver Distribution and Release from an Antimicrobial Denture Base Resin Containing Silver Colloidal Nanoparticles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of Rat Alveolar Bone Response to Angelus MTA or Experimental Light-cured Mineral Trioxide Aggregate Using Fluorochromes

Introduction: The aim of this study was to evaluate the rat alveolar bone response after the implantation of experimental light-cured mineral trioxide aggregate (MTA) or Angelus MTA (Angelus, Londrina, Parana, Brazil) by histological and fluorescence analysis. Methods: Thirty Wistar Albino rats were divided into three groups. In the control group, empty polyethylene tubes were inserted into the rat alveolar sockets immediately after extraction. In the other groups, the tubes were filled with light-cured MTA or Angelus MTA. Five animals from each group were injected with calcein on day 7, alizarin on day 14, and oxytetracycline on day 21. on day 30, these animals were killed, and the right hemimaxillas were removed and histologically processed. Half of the maxillas were processed and stained with hematoxylin and eosin. The remaining maxillas were processed for fluorescence analysis and stained with Stevenel blue and alizarin red. New bone was histomorphometrically evaluated using a Merz grid. Results: The light-cured MTA presented a similar response when compared with Angelus MTA; it was characterized by a mild inflammatory response and complete bone healing. In the light-cured MTA group, the fluorescence areas were more evident at 21 days, showing an increase in bone formation. However, dystrophic mineralization was observed only with Angelus MTA. Conclusions: It was concluded that both materials present a similar inflammatory response and bone healing, but dystrophic mineralization was observed only with Angelus MTA. (J Endod 2011;37:250-254)

Exploring CBCT-Based DICOM Files. A Systematic Review on the Properties of Images Used to Evaluate Maxillofacial Bone Grafts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization and in vitro evaluation of bacterial cellulose membranes functionalized with osteogenic growth peptide for bone tissue engineering

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental infections with Paracoccidioides brasiliensis obtained from armadillos: comparison to clinical isolates

Paracoccidioides brasiliensis causes paracoccidioidomycosis (PCM) that is one of the most prevalent systemic human mycoses in Latin America. Armadillos show a high incidence of PCM infection and could, therefore, be a natural reservoir for this fungus. In this study were compared the virulence profiles of isolates obtained from nine-banded armadillos (Dasypus novemcinctus) (PbT1 and PbT4) and isolates from PCM patients (Pb265 and Bt83). Pathogenicity was evaluated by fungal load and analysis of colony morphology. Immunity against the fungus was tested by delayed type hypersensitivity test (DTH) and antibody quantification by ELISA. The higher virulence of PbT1 and PbT4 was suggested by higher fungal load in spleen and lungs. Armadillo isolates and Bt83 presented a cotton-like surface contrasting with the cerebriform appearance of Pb265. All isolates induced cellular and humoral immune responses in infected BALB/c mice. DTH reactions were similarly induced by the four isolates, however, a great variability was observed in specific antibody levels, being the highest ones induced by Bt83 and PbT4. The present work confirms that armadillos harbor P. brasiliensis, whose multiplication and induced immunity in experimentally infected mice are heterogeneous, resembling the behavior of isolates from human PCM. This study reinforces the possibility that armadillos play an important role in the biological cycle of this pathogen.