Determinação de genes potencialmente responsivos à radiação ionizante através de aprendizado de máquina

A predição da resposta do tumor a radioterapia e a questão mais importante durante o tratamento de pacientes com câncer. Como consequência, a predição de genes que sejam responsivos a radiação ionizante e uma possibilidade para a melhoria dos resultados clínicos e a otimização das doses as quais os pacientes são submetidos ao longo do tratamento. Juntamente com esses dados, é possível obter respostas sobre os mecanismos de resistência a radiação dos tumores e até mesmo a identificação de biomarcadores responsáveis pela resistência a radiação ionizante que podem ser potenciais para o desenvolvimento de novas drogas visando a proteção de tecidos saudáveis. A determinação experimental dos genes que sejam responsivos à radiação ionizante é algo caro e que demanda muito tempo e trabalho; porém, se utilizarmos uma forma computacional de direcionar os estudos experimentais diretamente aos genes que têm mais potencial para serem responsivos à radiação ionizante, as pesquisas podem ser mais direcionadas e específicas. Para determinar essa característica, construímos, analisamos e determinamos os dados da topologia da rede integrada de interações moleculares entre genes humanos, contendo interações físicas entre proteínas, interações metabólicas e interações de regulação transcricional. Os dados topológicos foram utilizados como atributos de treinamento para o aprendizado de máquina, no qual os genes conhecidamente responsivos à radiação ionizante foram apresentados a um algoritmo de árvore de decisão que gerou modelos de predição com índices de sensibilidade e precisão de 5% e 72%, respectivamente. Os índices de acerto obtidos para os conjuntos de teste foram satisfatórios, retornando 91% dos genes conhecidos como responsiveis à radiação ionizante utilizados para o treinamento da árvore de decisão. Nós aplicamos o modelo de predição na rede integrada e atribuímos probabilidades ...

Análise da frequência de micronúcleos frente á utilização de colutório bucal com base alcoólica em indivíduos fumantes e não fumantes

Micronuclei (MN) originate from chromosome fragments or whole chromosomes that lag behind at anaphase during cell division can occur due to excessive exposure to harmful agents, defects in mitosis and / or DNA repair process. The study evaluated the frequency of micronuclei in cytological samples after daily use of alcohol -based mouthwash mouth in smokers and non-smokers. We assessed 30 subjects, aged between 17-42 years and established as exclusion criteria: alcohol consumption; periodontal disease; systemic diseases that may interfere with the integrity of the oral mucosa; individuals with medical or pharmacological history that affect the performance of the study, family history of malignancies. For smokers the inclusion criterion was a minimum consumption of 20 cigarettes / day, and the contrast required for non-smokers. The sample was divided into 02 experimental groups: Group 1 Smokers and Group 2 Non-Smokers, both groups performed mouthwash (alcohol 21,6%) with Listerine® Defense of Teeth and Gums for 04 weeks cytological collection were performed on buccal mucosa and portion median border of the tongue, one for initial, week 0 control, and subsequent three weeks with continued use of mouthwash. The collected material was stained by specific staining Feulgen / Fast Green. The analysis of 3000 cells / individual was performed by light microscopy statistics used Kruskal- Wallis and Mann-Whitney tests for frequency MN. The frequency of micronuclei in buccal mucosa was 1.6 ± 1.75 and 1.46 ± 2.06 for the site language to Group 1 Smokers of showing a slight increase compared with Group 2 Non-smoking, which showed a variation of 1.2 ± 1.53 for the buccal mucosa site and 0.86 ± 1.41 for the site language. However, this difference was not statistically significant. The results suggest that alcohol-based mouthwash tested is not an inducer of genotoxic changes, thus not changing the frequency...

Análise microestrutural de tubos API N80 soldados pelo processo HF/ERW para prospecção de petróleo e gás

On the grounds of the great advances achieved over recent years, the process HF/ERW (High-Frequency/Electric Resistance Welding)welded pipe have played an active role in the oil and gas industry for deep water applications, at high and extremely low temperatures, under high pressure and in highly corrosive environments, gradually replacing manufactured pipes by other processes. However, studies have shown that defects in the welded joints are a the leading causes of pipelines failures, which has required the determination of toughness values in this region, in compliance with the strict recommendations of the codes and standards with manufacturers and construction companies, on the oil and gas sector. As part of the validation process required toughness values, this research project focuses on a microstructural analysis in HF / ERW tubes microalloyed, steel grade API 5CT N80, designed to explore oil and gas in deep waters, the subject of strategic relevance to the country because of the recent discoveries in the Santos mega fields: Tupi and Libra (pre-salt). In this scientific work will be presented and discussed the results of mechanical tensile and Charpy, a few CTOD tests curves (showing the trend of toughness values to be obtained), and the microstructures of the base material obtained by optical microscopy, with special emphasis on the formation of non-metallic inclusions in the welded joint

Uso do beta fosfato tricálcio em levantamento da membrana de seio maxilar: estudo histológico, histomorfométrico e imunoistoquímico em coelhos

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

Expansão térmica de nanotubos de carbono de duas camadas

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Reparo ósseo dedefeitos de tamanho crítico tratados com aspirado de medula óssea associado ou não a terapia com laser em baixa intensidade: estudo imunoistoquímico em calvárias de ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Limitations of enamel microabrasion technique applied in a pediatric patient: case report

Enamel microabrasion is a non-invasive method that removes intrinsic and superficial defects from teeth aimed to improve dental esthetic with minimal loss of dental tissue. This case presentation describes the attempt for teeth color correction utilizing that conservative technique in a young girl whose upper central incisor presented an opaque white stain. Scanning electron microscopy (SEM) was conducted in order to illustrate the glasslike luster and a smooth texture of microabraded enamel surface. The correct diagnosis of defect is a difficult task, when consider this conservative approach.

Effect of platele-rich plasma on healing of class III furcation defects treated with autogenous bone grafting and guided tissue regeneration: a histomorphometric sutdy in dogs

Objective: The purpose of this study was to evaluate the effects of the platelet-rich plasma (PRP) when used in combination with autogenous bone graft and bioabsorbable membrane (Resolut® ) in the treatment of Class  III furcation defects in dogs. Material and method: Class III furcation defects (5 mm in height and in depth) were surgically created in the mandibular third premolars of five mongrel dogs. After nine weeks, the lesions were treated with scaling and root planning and each defect received one of the following treatments: autogenous bone graft + membrane (group C) or PRP + autogenous bone graft + membrane (group T). After a healing period of 90 days, the animals were sacrificed. Routine histological processing and staining with hematoxilyn and eosin and Masson trichrome were performed and a histomorphometric analysis determined the effect of the treatments on periodontal tissue regereneration. Data were analyzed by Hotelling’s T-squared (p < 0.05). Result: No statistically significant difference between C and T groups was observed by the histomorphometric analysis of the furcation area. Both treatment groups demonstrated similar regenerative results with the furcation defects partially filled and periodontal regeneration limited to the experimental notches of the lesions. (p > 0.05). Conclusion: According to the present results, PRP does not enhance the periodontal regeneration in class III furcation defects treated with autogenous bone graft and bioabsorbable membrane.

Caracterização radiográfica ex vivo de biomateriais utilizados para regeneração óssea em mandíbulas de porcos

Introduction: The radiographic characteristics of a biomaterial, such as its density, may influence the evaluation of the results obtained following its clinical use. Objective: The aim of this study was to evaluate the radiographic density of biomaterials used as bone substitutes, inserted into dental sockets and bone defects in created in the jaws of pigs. The influence of a soft tissue simulator on the results was also evaluated. Material and method: Two and three-millimeter-deep bone defects were created in the pigs mandible and the right first molar extraction socket were used. Commercial samples of five biomaterials were tested: Hydroxyapatite, Lyophilized Bovine Bone, 45S5 bioglass (generic), PerioGlass and β-Tri-Calcium Phosphate, and compared to a positive (mandibular bone) and negative (empty alveolar bone defects) controls. Radiographic images were acquired with and without a 10 mm thick soft-tissue simulator. Result: The results for the extraction sockets showed no differences between the biomaterials and the negative control. For the bone defects, the depth of the defect density influenced the density, both in the negative control (p < 0.01) and biomaterials (p < 0.05) groups. The soft- tissue simulator did not alter the results. Conclusion: The type of the evaluated defect can interfere in the radiographic features presented by each biomaterial, while the simulation of soft tissues was not statistically significant.

Reabilitação total da maxila com enxerto intraoral: relato de caso

The early tooth loss and periodontal disease often leave inadequate bone volume for installation of osseointegrated implants. The autogenous bone graft is considered the gold standard for reconstruction of residual bone defects. Some surgical techniques can be performed, including extra or intraoral donor sites depending on the degree of bone loss, depending on surgical-prosthetic planning and general condition of the patient. The intraoral bone grafts offer a safe option to rebuilt bone volume in smaller rehabilitations, with low morbidity and minimal postoperative discomfort. Among the possible donor sites, the mandibular ramus and body, which offer predominantly cortical bone, and the chin area, which offers corticomedullary bone tissue, can be harvested. The graft will be suitable both in quantity and quality, preserving the capacity of osteogenesis, osteoinduction and osteoconduction, which differentiate autogenous grafts from other biomaterials. The aim of this study was to report a clinical case in which the mandibular ramus graft was used for total reconstruction of an edentulous maxilla, showing that even large areas can be reconstructed with grafts from intraoral origin. All the steps that allowed the complete reconstruction of the maxilla done by an intraoral donor area are listed in the text, culminating in an extremely satisfactory clinical result.

O uso do beta-tricálcio fosfato como substituto ósseo em odontologia

The correction of bone defects is the restoration of lost structures which can be replaced by alloplastic implants or bone grafts. Due to the known disadvantages of removal of autogenous grafts, most researches in dentistry aim to develop alloplastic or non-alloplastic materials able to replace bone without these limitations. Beta-Tricalcium Phosphate (β-TCP) is a synthetic granular bone substitute, biocompatible, osteoconductive, which can be used in the alveolar reconstruction. In this work, we perform a literature review on the β-TCP characteristics and discuss its application in dentistry.

A utilização do enxerto ósseo autógeno para tratamento de lesão de furca grau II

Destruction of bone and periodontal ligament as a result of periodontal disease can lead to anatomical defects in the furcation area. Treatment of these lesions is a major challenge to the clinician. Periodontal instruments have limited access to this area and plaque and calculus removal from root surfaces are extremely difficult. For proper treatment planning a number of factors must be taken into consideration to achieve immediate and long term success. Surgical therapy associated with bone grafts may be a viable option in the treatment of class II furcation defects, aiming to restore lost tissues. The aim of this paper is to report a clinical case where a simplified surgical approach with the use of autogenous graft was used to treat a class II furcation defect Twelve months after the surgery, an increase in clinical attachment level and pocket depth reduction resulted in a complete closure of the furcation lesion.

Effect of platelet-rich plasma on healing of class III furcation defects treated with autogenous bone grafting and guided tissue regeneration: a histomorphometric study in dogs

The purpose of this study was to evaluate the effects of the platelet-rich plasma (PRP) when used in combination with autogenous bone graft and bioabsorbable membrane (Resolut® ) in the treatment of Class  III furcation defects in dogs. Material and method: Class III furcation defects (5 mm in height and in depth) were surgically created in the mandibular third premolars of five mongrel dogs. After nine weeks, the lesions were treated with scaling and root planning and each defect received one of the following treatments: autogenous bone graft + membrane (group C) or PRP + autogenous bone graft + membrane (group T). After a healing period of 90 days, the animals were sacrificed. Routine histological processing and staining with hematoxilyn and eosin and Masson trichrome were performed and a histomorphometric analysis determined the effect of the treatments on periodontal tissue regereneration. Data were analyzed by Hotelling’s T-squared (p < 0.05). Result: No statistically significant difference between C and T groups was observed by the histomorphometric analysis of the furcation area. Both treatment groups demonstrated similar regenerative results with the furcation defects partially filled and periodontal regeneration limited to the experimental notches of the lesions. (p > 0.05). Conclusion: According to the present results, PRP does not enhance the periodontal regeneration in class III furcation defects treated with autogenous bone graft and bioabsorbable membrane.

Cirurgia estética para remoção de hiperplasia gengiva: granuloma piogênico

The pyogenic granuloma, a lesion considered hyperplastic regenerative inflammatory reaction is a finding commonly found in the oral cavity, affecting large numbers of individuals, being more prevalent in females. But its pathogenesis is not well defined and may be associated with numerous factors that stimulate tissue proliferation. Correct diagnosis and treatment plan are essential for success in approach, restoring function and aesthetics to the periodontal tissues. In agreement with the literature, the most common treatment and greater predictability is surgical removal, which involves resection of the lesion, together with its base inserted into the underlying tissue, periosteum and bone tissue. However, the excision can promote aesthetic defects, particularly in anterior regions where it is most affected. This article reports on the importance of a correct surgical approach for removal of pyogenic granuloma in the region of the interdental papilla between teeth 42 and 43, resulting in a good anatomical result and aesthetic.

Análise histomorfométrica do reparo ósseo em tíbias de ratos castrados submetidos ao efeito do alendronato sódico

This study used histomorphometric analysis to investigate the effect of sodium alendronate, used for the treatment of osteoporosis, on the repair of surgically-induced bone defects in the tibia of castrated rats. Methods: The castrated animals were given subcutaneous injections of sodium alendronate (0.7mg/Kg) diluted in saline once a week; the control animals were given the same dose of saline. At 16, 30 and 44 days after the first injection of sodium alendronate, the animals were sacrificed and the right tibias were removed and processed for histomorphometric analysis. The volumetric bone mineral density was estimated by a reticular grid (25 points) attached to a light microscope. The number of points on the bone tissue was counted in the histological sections, totaling 100 points/animal. Results: The results revealed that sodium alendronate stimulated bone formation in castrated rats in all occasions, mainly at 16 and 30 days. Conclusion: Sodium alendronate affects mineral homeostasis, promoting bone repair.