Time-dependent effects of chitosan on dentin structures

Complete debridement with smear layer removal are essential measures for achieving a successful outcome of root canal treatment. The aim of this study was to evaluate the effects of chitosan at different concentrations on the removal of the smear layer and on dentin structure after 3 and 5 min of application. Twelve recently extracted maxillary canine teeth were instrumented using the crown-down technique and irrigated with 1% sodium hypochlorite. The specimens were distributed according to the time and concentration of the final irrigating solution: G1: 0.1% chitosan for 3 min; G2: 0.2% chitosan for 3 min; G3: 0.37% chitosan for 3 min; G4: 0.1% chitosan for 5 min; G5: 0.2% chitosan for 5 min; G6: 0.37% chitosan for 5 min. All samples were prepared for SEM analysis. G1 exhibited removal of the smear layer, but not the smear plugs. G2 showed visible and open tubules with slight erosion of the peritubular dentin. Cleaning in G3 was similar to that in G2, however, the erosive effect was greater. There was expansion of the diameter of the tubules in G4; and in G5 and G6, there was severe erosion with deterioration of dentin surface. In conclusion, 0.2% chitosan for 3 min appeared to be efficient for removing the smear layer, causing little erosion of dentin.

Clinical evaluation of the failure rate of metallic brackets bonded with orthodontic composites

The purpose of the present study was to evaluate in vivo the failure rate of metallic brackets bonded with two orthodontic composites. Nineteen patients with ages ranging from 10.5 to 38.7 years needing corrective orthodontic treatment were selected for study. The enamel surfaces from second premolars to second premolars were treated with Transbond Plus-Self Etching Primer (3M Unitek). Next, 380 orthodontic brackets were bonded on maxillary and mandibular teeth, as follows: 190 with Transbond XT composite (3M Unitek) (control) and 190 with Transbond Plus Color Change (3M Unitek) (experimental) in contralateral quadrants. The bonded brackets were light cured for 40 s, and initial alignment archwires were inserted. Bond failure rates were recorded over a six-month period. At the end of the evaluation, six bond failures occurred, three for each composite. Kaplan-Meyer method and log-rank test (Mantel-Cox) was used for statistical analysis, and no statistically significant difference was found between the materials (p=0.999). Both Transbond XT and Transbond Plus Color Change composites had low debonding rates over the study period.

Influence of alloy microstructure on the microshear bond strength of basic alloys to a resin luting cement

The aim of this study was to evaluate the influence of microstructure and composition of basic alloys on their microshear bond strength (µSBS) to resin luting cement. The alloys used were: Supreme Cast-V (SC), Tilite Star (TS), Wiron 99 (W9), VeraBond II (VBII), VeraBond (VB), Remanium (RM) and IPS d.SIGN 30 (IPS). Five wax patterns (13mm in diameter and 4mm height) were invested, and cast in a centrifugal casting machine for each basic alloy. The specimens were embedded in resin, polished with a SiC paper and sandblasted. After cleaning the metal surfaces, six tygon tubes (0.5 mm height and 0.75 mm in diameter) were placed on each alloy surface, the resin cement (Panavia F) was inserted, and the excess was removed before light-curing. After storage (24 h/37°C), the specimens were subjected to µSBS testing (0.5 mm/min). The data were subjected to a one-way repeated measures analysis of variance and Turkey's test (α=0.05). After polishing, their microstructures were revealed with specific conditioners. The highest µSBS (mean/standard deviation in MPa) were observed in the alloys with dendritic structure, eutectic formation or precipitation: VB (30.6/1.7), TS (29.8/0.9), SC (30.6/1.7), with the exception of IPS (31.1/0.9) which showed high µSBS but no eutectic formation. The W9 (28.1/1.5), VBII (25.9/2.0) and RM (25.9/0.9) showed the lowest µSBS and no eutectic formation. It seems that alloys with eutectic formation provide the highest µSBS values when bonded to a light-cured resin luting cement.

Effect of sodium hypochlorite and edta irrigation, individually and in alternation, on dentin microhardness at the furcation area of mandibular molars

The aim of this study was to evaluate the effect of irrigation regimens on dentin microhardness at the furcation area of mandibular molars, using sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA), individually and in alternation. The occlusal surface and the roots of 20 non-carious extracted human permanent mandibular molars were cut transversally and discarded. The tooth blocks were embedded in acrylic resin and randomly assigned to 4 groups (n=5) according to the irrigating regimens: 1% NaOCl solution, 17% EDTA solution, 1% NaOCl and 17% EDTA and distilled water (control). Knoop microhardness of dentin at the furcation area was evaluated. Data were analyzed using one-way ANOVA and Tukey's multiple comparison tests (α=0.05). The results of this study indicated that all irrigation solutions, except for distilled water (control), decreased dentin microhardness. EDTA did not show a significant difference with NaOCl/EDTA (p>0.05), but showed a significant difference with NaOCl (p<0.01). EDTA and NaOCl/EDTA showed a maximum decrease in microhardness. The 17% EDTA solution, either alone or in combination with 1% NaOCl reduced significantly dentin microhardness at the furcation area of mandibular molars.

Perfil das mulheres submetidas à cesareana e assistência obstétrica na maternidade pública em Ribeirão Preto

O artigo apresenta o perfil social e obstétrico das mulheres submetidas ao parto cesárea em uma maternidade pública do interior do Estado de São Paulo. Trata-se de estudo quantitativo, retrospectivo, do tipo descritivo, com pesquisa documental. Os dados coletados referem-se ao período entre os meses de junho e dezembro de 2005, e janeiro a junho de 2006. Foram consultados 670 prontuários. A taxa de parto cesárea na instituição-campo foi calculada em 23% para o período supracitado. Foram características da população estudada a baixa escolaridade formal, a união consensual e o trabalho não remunerado. As principais indicações para as cesarianas foram a iteratividade e o sofrimento fetal agudo. Como desdobramento dos achados está a ênfase pela valorização da enfermagem obstétrica no cenário de atendimento ao parto normal de baixo risco, considerando seu caráter não-intervencionista inerente à sua formação.

Conhecimento e percepção sobre tuberculose das famílias de pacientes em tratamento diretamente observado em um serviço de saúde de Ribeirão Preto-SP, Brasil

Pesquisa epidemiológica descritiva que objetivou descrever o perfil demográfico das famílias de pacientes em Tratamento Diretamente Observado em um serviço de saúde de Ribeirão Preto-SP, analisar o contexto em que estavam inseridas, no que refere ao grau de parentesco e aspectos clínico-epidemiológicos do familiar portador da tuberculose, e avaliar o conhecimento e a percepção dessas famílias em relação à tuberculose. Os dados foram coletados em julho de 2010, utilizando-se um questionário semiestruturado com 16 familiares, sendo analisados por meio da estatística descritiva. O perfil demográfico dos familiares corrobora com a associação da tuberculose às condições de pobreza e má distribuição de renda. Verificou-se um número substancial de comunicantes no domicílio, sendo a tuberculose pulmonar a forma clínica predominante. O conhecimento das famílias foi satisfatório, entretanto, alguns sujeitos associam a transmissão da doença, ao uso compartilhado de utensílios domésticos. Os resultados apontam fragilidades relacionadas à gestão do cuidado às famílias.

Trabalho, saúde e migração nos canaviais da região de Ribeirão Preto (SP), Brasil: o que percebem e sentem os jovens trabalhadores?

A migração de jovens do nordeste brasileiro em busca de emprego na região Sudeste é historicamente recorrente. Este estudo objetivou compreender como jovens trabalhadores foram atraídos para o corte de cana-de-açúcar na região de Ribeirão Preto (SP) e conhecer como percebiam suas condições de trabalho e suas repercussões em sua saúde. Na pesquisa, de abordagem qualitativa, foram entrevistados 14 trabalhadores migrantes do Maranhão, de ambos os sexos, com idades entre 18 e 24 anos, entre julho de 2008 e maio de 2009. Os relatos obtidos indicaram que a migração dos jovens trabalhadores em busca de trabalho não foi uma opção, mas a única alternativa frente à realidade na região de origem. Revelaram sentimento de frustração quando perceberam que o trabalho real era bem diferente do imaginado. Os jovens apresentaram desesperança quanto às suas perspectivas de futuro e demonstraram preocupação com as possíveis consequências para sua saúde. Apesar de explicitar desapontamento com a realidade, manifestaram intenção de retorno para as lavouras da cana em outras safras, mostrando conformismo com sua realidade social. O estudo possibilitou aprofundar conhecimentos acerca da exploração da força de trabalho empregada na cultura da cana-de-açúcar na maior região produtora do país, mostrando que os trabalhadores percebem como precárias e desgastantes as condições a que são submetidos.

Atraso na busca por serviço de saúde para o diagnóstico da tuberculose em Ribeirão Preto (SP)

Foi analisado o atraso na busca por serviço de saúde para o diagnóstico da Tuberculose (TB) em Ribeirão Preto, 2009, em um estudo epidemiológico, transversal, realizado com 94 doentes. Utilizou-se questionário baseado no Primary Care Assessment Tool, adaptado para avaliar a atenção à TB. Estabeleceu-se a mediana (15 dias ou mais) para caracterizar atraso na busca pelo primeiro atendimento. Através da Razão de Prevalência, identificaram-se as variáveis relacionadas ao maior atraso. O primeiro serviço de saúde procurado foi o de pronto atendimento (57,4%). Verificou-se um maior tempo na procura pelos serviços de saúde entre os doentes: do sexo masculino; com idade entre 50 a 59 anos; com renda familiar inferior a cinco salários mínimos; forma pulmonar; casos novos; não coinfecção TB/HIV; não consumiam bebida alcoólica, conhecimento satisfatório sobre TB (apresentou significância estatística na associação com o atraso) e que não procuravam o serviço de saúde próximo do domicílio antes de ter TB. Verificou-se a necessidade de capacitação para os profissionais de saúde quanto aos sinais e sintomas da doença, reduzindo as barreiras de acesso ao diagnóstico oportuno da TB e divulgação ampla para a comunidade em geral.

Epidemiological and clinical characteristics of injuries among adolescents attended at an emergency service in the city of Ribeirão Preto, São Paulo

CONTEXT AND OBJECTIVE: Injuries are an important cause of morbidity during adolescence, but can be avoided through learning about some of their characteristics. This study aimed to identify the most frequent injuries among adolescents attended at an emergency service. DESIGN AND SETTING: Retrospective descriptive study on adolescents attended at the emergency service of the Teaching Health Center, Faculdade de Medicina de Ribeirão Preto (FMRP), between January 1, 2009, and September 30, 2009. METHODS: Age, sex, type of injury, site, day and time of occurrence, part of body involved, care received, whether the adolescent was accompanied at the time of injury and whether any type of counseling regarding injury prevention had been given were analyzed. RESULTS: Among 180 adolescents attended, 106 (58.8%) were boys and 74 (41.1%) were girls. Their ages were: 10 to 12 (66/36.6%), 12 to 14 (60/33.3%) and 14 to 16 years (54/30%). The injuries had occurred in public places (47.7%) and at home (21.1%). The main types were bruises (45.1%) and falls (39.2%), involving upper limbs (46.1%), lower limbs (31%) and head/neck (13.1%). The injuries occurred in the afternoon (44.4%) and morning (30%), on Mondays (17.7%) and Thursdays (16.6%). Radiological examinations were performed on 53.8%. At the time of injury, 76.1% of the adolescents were accompanied. Some type of counseling about injury prevention had been received by 39.4%. CONCLUSIONS: Although the injuries were of low severity, preventive attitudes need to be incorporated in order to reduce the risks and provide greater safety for adolescents.

Rehabilitation with forage grasses of an area degraded by urban solid waste deposits

Dry matter yield and chemical composition of forage grasses harvested from an area degraded by urban solid waste deposits were evaluated. A split-plot scheme in a randomized block design with four replicates was used, with five grasses in the plots and three harvests in the subplots. The mineral content and extraction and heavy metal concentration were evaluated in the second cut, using a randomized block design with five grasses and four replicates. The grasses were Brachiaria decumbens cv. Basilisk, Brachiaria ruziziensis, Brachiaria brizantha cv. Marandu and cv. Xaraés, and Panicum maximum cv. Tanzânia, cut at 42 days of regrowth. The dry matter yield per cut reached 1,480 kg ha-1; the minimum crude protein content was 9.5% and the average neutral detergent fiber content was 62.3%. The dry matter yield of grasses was satisfactory, and may be an alternative for rehabilitating areas degraded by solid waste deposits. The concentration of heavy metals in the plants was below toxicity levels; the chemical composition was appropriate, except for phosphorus. The rehabilitated areas may therefore be used for grazing.

Factors associated with failure of clinical screening among blood donors who have altered serological results in the Centro Regional de Hemoterapia de Ribeirão Preto

OBJECTIVE: This study aimed to investigate the frequency of positive results for hepatitis B and C, HIV and syphilis in blood donations at the Centro Regional de Hemoterapia de Ribeirão Preto, to describe donors with positive results according to some demographic and socioeconomic variables, to identify risk factors associated to these donors and the reasons that they were not detected during clinical screening. METHODS: A descriptive study was performed between July 1st 2005 and July 31st 2006 by interviewing 106 donors after medical consultations where they were informed of positive results for hepatitis B, hepatitis C, HIV or syphilis. RESULTS: There was a predominance of first-time donors, males, under 50-year olds, married individuals, from Ribeirão Preto, with elementary education, low economic status and of people who donated at the request of friends or relatives. Hepatitis C was the most frequently detected infection (56.6%), followed by hepatitis B (20.7%), HIV (12.3%) and syphilis(10.4%). About 40% of donors had omitted risk factors for different reasons: because they trusted the results of serological tests, did not feel comfortable about talking of risk factors or did not consider them relevant. Other justifications were the duration of the interview, the interviewer was unskilled, embarrassment and doubts about confidentiality. CONCLUSION: The results indicate the need for changes in the approach to clinical screening and a review of methods to attract and guide potential donors.

Frequency and precision of feedback and the adaptive process of learning a dual motor task

This work investigated the effects of frequency and precision of feedback on the learning of a dual-motor task. One hundred and twenty adults were randomly assigned to six groups of different knowledge of results (KR), frequency (100%, 66% or 33%) and precision (specific or general) levels. In the stabilization phase, participants performed the dual task (combination of linear positioning and manual force control) with the provision of KR. Ten non-KR adaptation trials were performed for the same task, but with the introduction of an electromagnetic opposite traction force. The analysis showed a significant main effect for frequency of KR. The participants who received KR in 66% of the stabilization trials showed superior adaptation performance than those who received 100% or 33%. This finding reinforces that there is an optimal level of information, neither too high nor too low, for motor learning to be effective.

Olhares distintos sobre a noção de estabilidade e mudança no desempenho da coordenação motora grossa

Estudos sobre coordenação motora grossa (CMG) de crianças focam na descrição dos valores normativos em razão da idade e sexo. Poucos analisam a dinâmica da mudança do desempenho de cada criança em relação ao seu grupo ao longo do tempo. O objetivo do presente estudo foi estimar a estabilidade das diferenças interindividuais na mudança intraindividual da CMG ao longo de 18 meses. Participaram do estudo 120 escolares de sete anos de idade da cidade de Muzambinho - MG. Foram realizadas quatro coletas com intervalos de seis meses. A CMG foi avaliada pelas provas do KTK. Os valores médios apresentaram incrementos em todas as provas, diferindo entre gênero apenas para o equilíbrio à retaguarda. Os resultados da correlação entre o desempenho inicial e a mudança ao longo do tempo indicaram uma forte heterogeneidade. Os resultados da estabilidade se mostraram fracos, os quais foram discutidos em relação a diferentes trajetórias do desenvolvimento da CMG.

Effects of Aedes aegypti salivary components on dendritic cell and lymphocyte biology

Abstract Background Saliva is a key element of interaction between hematophagous mosquitoes and their vertebrate hosts. In addition to allowing a successful blood meal by neutralizing or delaying hemostatic responses, the salivary cocktail is also able to modulate the effector mechanisms of host immune responses facilitating, in turn, the transmission of several types of microorganisms. Understanding how the mosquito uses its salivary components to circumvent host immunity might help to clarify the mechanisms of transmission of such pathogens and disease establishment. Methods Flow cytometry was used to evaluate if increasing concentrations of A. aegypti salivary gland extract (SGE) affects bone marrow-derived DC differentiation and maturation. Lymphocyte proliferation in the presence of SGE was estimated by a colorimetric assay. Western blot and Annexin V staining assays were used to assess apoptosis in these cells. Naïve and memory cells from mosquito-bite exposed mice or OVA-immunized mice and their respective controls were analyzed by flow cytometry. Results Concentration-response curves were employed to evaluate A. aegypti SGE effects on DC and lymphocyte biology. DCs differentiation from bone marrow precursors, their maturation and function were not directly affected by A. aegypti SGE (concentrations ranging from 2.5 to 40 μg/mL). On the other hand, lymphocytes were very sensitive to the salivary components and died in the presence of A. aegypti SGE, even at concentrations as low as 0.1 μg/mL. In addition, A. aegypti SGE was shown to induce apoptosis in all lymphocyte populations evaluated (CD4+ and CD8+ T cells, and B cells) through a mechanism involving caspase-3 and caspase-8, but not Bim. By using different approaches to generate memory cells, we were able to verify that these cells are resistant to SGE effects. Conclusion Our results show that lymphocytes, and not DCs, are the primary target of A. aegypti salivary components. In the presence of A. aegypti SGE, naïve lymphocyte populations die by apoptosis in a caspase-3- and caspase-8-dependent pathway, while memory cells are selectively more resistant to its effects. The present work contributes to elucidate the activities of A. aegypti salivary molecules on the antigen presenting cell-lymphocyte axis and in the biology of these cells.

Proteome of Rhipicephalus sanguineus tick saliva induced by the secretagogues pilocarpine and dopamine

One dimensional gel electrophoresis was used to separate proteins from the saliva of Rhipicephalus sanguineus female ticks fed on rabbits. Gel slices were subjected to tryptic digestion and analyzed by reversed-phase HPLC followed by MS/MS analysis. The data were compared to a database of salivary proteins of the same tick and to the predicted proteins of the host. Saliva was obtained by either pilocarpine or dopamine stimulation of partially fed ticks. Electrophoretic separations of both yielded products that were identified by mass spectrometry, although the pilocarpine-derived sample was of much better quality. The majority of identified proteins were of rabbit origin, indicating the recycling of the host proteins in the tick saliva, including hemoglobin, albumin, haptoglobin, transferring, and a plasma serpin. The few proteins found that were previously associated with parasitism and blood feeding include 2 glycine-rich, cement-like proteins, 2 lipocalins, and a thyropin protease inhibitor. Among other of the 19 tick proteins identified, albeit with undefined roles, were SPARC and cyclophilin A. This catalog provides a resource that can be mined for secreted molecules that play a role in tick–host interactions.