955 resultados para gold standard
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Although the search for the ideal bone substitute has been the focus of a large number of studies, autogenous bone is still the gold standard for the filling of defects caused by pathologies and traumas, and mainly, for alveolar ridge reconstruction, allowing the titanium implants installation. Objectives: The aim of this study was to evaluate the dynamics of autogenous bone graft incorporation process to surgically created defects in rat calvaria, using epifluorescence microscopy. Material and methods: Five adult male rats weighing 200-300 g were used. The animals received two 5-mm-diameter bone defects bilaterally in each parietal bone with a trephine bur under general anesthesia. Two groups of defects were formed: a control group (n=5), in which the defects were filled with blood clot, and a graft group (n=5), in which the defects were filled with autogenous bone block, removed from the contralateral defect. The fluorochromes calcein and alizarin were applied at the 7th and 30th postoperative days, respectively. The animals were killed at 35 days. Results: The mineralization process was more intense in the graft group (32.09%) and occurred mainly between 7 and 30 days, the period labeled by calcein (24.66%). Conclusions: The fluorochromes showed to be appropriate to label mineralization areas. The interfacial areas between fluorochrome labels are important sources of information about the bone regeneration dynamics.
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Because of the growing concerns regarding fluoride ingestion by young children and dental fluorosis, it is necessary to develop new dentifrices. Objective: The aim of this study was to evaluate the effect of dentifrices with calcium citrate (Cacit) and sodium trimetaphosphate (TMP) on enamel demineralization. Material and Methods: Enamel blocks (n=70), previously selected through surface hardness analysis, were submitted to daily treatment with dentifrices diluted in artificial saliva and to a pH-cycling model. The fluoride concentration in dentifrices was 0, 250, 450, 550, 1,000 and 1,100 mu g F/g. Crest (TM) was used as a positive control (1,100 mu g F/g). Cacit (0.25%) and TMP (0.25%) were added to dentifrices with 450 and 1,000 mu g F/g. Surface hardness was measured again and integrated loss of subsurface hardness and fluoride concentration in enamel were calculated. Parametric and correlation tests were used to determine difference (p<0.05) and dose-response relationship between treatments. Results: The addition of Cacit and TMP did not provide a higher fluoride concentration in enamel, however it reduced (p<0.05) mineral loss when compared to other dentifrices; the dentifrice with Cacit and TMP and a low fluoride concentration presented similar results when compared to a dentifrice with 1,100 mu g F/g (p>0.05). Conclusions: Dentifrices with 450 and 1,000 mu g F/g, Cacit and TMP were as effective as a gold standard one.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Purpose: The purpose of this study was to assess the influence of cleaning pits and fissures with on aluminum oxide air abrasion system on the detection of occlusal caries in primary teeth using laser fluorescence (LF) and visual examination. Methods. The sample comprised 65 pit and fissure sites on extracted primary teeth suspected to be carious. The sites were submitted to 2 visual examinations (examiner JAR) and 2 LF readings (examiner TMV). Next, the occlusal surfaces were air-abraded and re-examined thereafter using both methods. The teeth were sectioned, and the histological analysis of the sites with a stereoscopic magnifying lens at X32 magnification was used as the gold standard Results. Cohen's kappa statistic for LF and visual examination were, respectively, 0.282/0.884 before and 0.896/0.905 after air abrasion. LF showed a sensitivity of 0.28 increasing to 0.49 and 0 specificity of 0.50 increasing to 0.92. Visual examination showed sensitivity of 0.78 and specificity of 0.73. Both increased after air abrasion. Conclusion: The findings suggest that cleaning pits and fissures with aluminum oxide air abrasion increased the accuracy of LF and visual examination for detection of occlusal caries in primary teeth.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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JUSTIFICATIVA E OBJETIVOS: Identificar as queixas dolorosas dos pacientes é essencial para determinar diagnósticos e intervenções terapêuticas adequadas em dor orofacial (DOF). Assim, o objetivo deste estudo foi verificar a frequência das queixas de dor relatadas comparando-as àquelas marcadas pelos pacientes em mapas de dor. MÉTODO: Os dados foram coletados dos prontuários de 532 pacientes da Clínica de Dor Orofacial da Faculdade de Odontologia de Araraquara. Os indivíduos responderam a um questionário informando suas queixas de dor e completaram um mapa corporal indicando as áreas dolorosas. A frequência dos relatos foi comparada à frequência dos locais identificados nos mapas. Foram consideradas nove regiões anatômicas: cabeça, face, pescoço, ombros, braços, tórax, abdômen, costas e pernas. Também foram calculados sensibilidade, especificidade e valores kappa comparando os relatos de dor aos mapas, os últimos considerados padrão-ouro. RESULTADOS: A média etária da amostra foi de 33,5 ± 13,8 anos, 33,9 ± 13,9 anos para as mulheres e 31,7 ± 13,1 anos para os homens. Foi observada maior prevalência de dor entre as mulheres. em ambos os gêneros, as regiões com mais queixas de dor estavam localizadas na parte superior do corpo e uma diferença significativa entre os relatos de dor e os desenhos de dor foi observada para as regiões abaixo do pescoço. Os mapas de dor corporal demonstraram superioridade sobre os relatos de dor na identificação das queixas dolorosas durante a anamnese. CONCLUSÃO: O relato da queixa principal não foi um método eficiente para conhecer todas as queixas dolorosas, pois os mapas corporais evidenciaram a presença de dores adicionais em pacientes com DOF.
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The fragile X syndrome (FXS), the most common cause of hereditary mental retardation, is caused by expansions of CGG repeats in the FMR1 gene. The gold-standard method to diagnose FXS is the Southern blot (SB). Because SB is laborious and costly, some adaptations in the polymerase chain reaction (PCR) method have been utilized for FXS screening. A previous PCR-based screening method for FXS identification utilizing small amounts of DNA was reported as simple and efficient. The aim of this study was to reproduce the mentioned PCR-based screening method for identification of expanded alleles of the FMR1 gene in Brazilian individuals and to investigate the efficiency of this method in comparison with SB. Utilizing the enzyme Expand Long Template PCR System, 78 individuals were investigated by that PCR-based screening method for FXS identification. Conclusive results were obtained for 75 samples. Considering all the allelic forms of FXS (normal [NL], premutation [PM], and full-mutation [FM]), the comparison of the PCR-based screening method with SB demonstrated 100% of accuracy, sensitivity, and specificity. However, when the PM and the FM were analyzed separately from each other, but together with the NL allele, the accuracy, sensitivity, and specificity decreased (to 42.9%-97.4%). We concluded that the PCR-based screening method was reproducible and capable of identifying all different FXS alleles, but because the differentiation between the PM and the FM alleles was not accurate, SB is still the gold-standard method for the molecular diagnosis of FXS.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Oxacillin is the main drug of choice for the treatment of S. aureus infections. However, S. aureus resistance to oxacillin has become a major problem in the recent decades. The study aimed assess the rates of oxacillin resistance in S. aureus samples obtained at the Botucatu Medical School Hospital, UNESP, and to compare phenotypic techniques for the detection of MRSA against the gold standard method (mecA gene detection) in these samples. A total of 102 samples, previously isolated between 2002 and 2006, and kept at the Culture Collection of the Department of Microbiology and Immunology, in the Botucatu Biosciences Institute, UNESP, were included. Oxacillin resistance was assessed by oxacillin and cefoxitin disk diffusion and agar dilution tests, screening tests using Mueller-Hinton agar with 6 mu g/mL of oxacillin and 4% NaCl, E-test, and mecA gene detection. of the samples analyzed, 46 (45.1%) were mecA-positive. Oxacillin disk sensitivity and specificity were 86.9% and 91.1%, respectively. Cefoxitin disk sensitivity and specificity were respectively 91.3% and 91.1%. The screening test with the cefoxitin disk showed almost the same level of sensitivity (91.3%) and specificity (91.1%). With E-test strips, sensitivity was higher (97.8%) and specificity was comparable to that found with the other methods (91.1%). Ninety-three percent of the samples produced beta-lactamase and five of them were mecA-negative. There was a gradual increase in the number of oxacillin-resistant S. aureus samples between 2002 and 2004. However, from 2004 to 2006, the number of resistant samples dropped from 55% of MRSA in 2004, to 45% in 2005 and 34.6% in 2006. The data obtained reveal that, among phenotypic methods, the E-test yielded the best results, with higher sensitivity levels when compared to the other methods. The decreased resistance rate observed over the most recent years may be explained by the rational use of antimicrobial agents associated with good practices in the control of hospital infection, or may be related to the diminished use of oxacillin as a treatment option.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The efficacy of fluorescence spectroscopy to detect squamous cell carcinoma is evaluated in an animal model following laser excitation at 442 and 532 nm. Lesions are chemically induced with a topical DMBA application at the left lateral tongue of Golden Syrian hamsters. The animals are investigated every 2 weeks after the 4th week of induction until a total of 26 weeks. The right lateral tongue of each animal is considered as a control site (normal contralateral tissue) and the induced lesions are analyzed as a set of points covering the entire clinically detectable area. Based on fluorescence spectral differences, four indices are determined to discriminate normal and carcinoma tissues, based on intraspectral analysis. The spectral data are also analyzed using a multivariate data analysis and the results are compared with histology as the diagnostic gold standard. The best result achieved is for blue excitation using the KNN (K-nearest neighbor, a interspectral analysis) algorithm with a sensitivity of 95.7% and a specificity of 91.6%. These high indices indicate that fluorescence spectroscopy may constitute a fast noninvasive auxiliary tool for diagnostic of cancer within the oral cavity. (C) 2008 Society of Photo-Optical Instrumentation Engineers.
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Introduction: The aim of this study was to evaluate craniofacial asymmetry by using 2-dimensional (2D) poster-oanterior cephalometric images, 3-dimensional cone-beam computed tomography (CBCT), and physical measurements (gold standard). Methods: Ten dry human skulls were assessed, and radiopaque markers were placed on 17 skeletal landmarks. Twenty linear measurements were taken on each side to compare the right and left sides and to compare these measurements with the physical measurements made with a digital caliper. To acquire the 2D posteroanterior radiographs, an Extraoral Phosphor Storage Plate (Air Techniques, Chicago, Ill) was used as the image receptor with a Eureka x-ray-Duocon Machlett unit (Machlett Laboratores, Chicago, Ill). Three-dimensional imaging data were acquired from a CB MercuRay (Hitachi Medical, Tokyo, Japan). Results: on average, the right side was larger than the left for most of the 20 distances evaluated in the digital 2D and the CBCT images, and there was poor agreement between the digital 2D images and the physical measurements (kappa = 0.0609) and almost perfect agreement (kappa = 0.92) between the CBCT and physical measurements when individual measurements were considered. Conclusions: Human skulls, with no apparent asymmetry, had some differences between the right and left sides, with dominance for the right side but with no clinical significance. CBCT can better evaluate craniofacial morphology when compared with digital 2D images. (Am J Orthod Dentofacial Orthop 2011; 139: e523-e531)
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Indirect drug susceptibility tests of Mycobacterium tuberculosis was done to investigate the accuracy and feasibility of a broth microdilution method (BMM) for determining minimal inhibitory concentrations of conventional drugs against M. tuberculosis. Test drugs included isoniazid (H), rifampicin (R), ethambutol (E), streptomycin (S) and pyrazinamide (Z). Fifty isolates of M. tuberculosis from patients who had never received drug therapy, and H37Rv strain for control, were evaluated in the system. When comparing this method with the gold standard proportional method in Lowenstein-Jensen medium, sensitivity of 100% for all drugs and specifities of 91, 100, 96, 98 and 85% were observed respectively for H, R, E, S and Z. The BMM was read faster (14-20 days) than the proportional method (20-28 days). The microdilution method evaluated allows the testing of multiple drugs in multiple concentrations. It is easy to perform and does not require special equipment or expensive supplies. In contrast to radiometric method it does not use radioactive material.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)