22 research outputs found
Analytical performance of a PCR assay for the detection of KRAS mutations (codons 12/13 and 61) in formalin-fixed paraffin-embedded tissue samples of colorectal carcinoma
KRAS mutation testing is mandatory before prescribing anti-epidermal growth factor monoclonal antibodies in the treatment of advanced colorectal cancer. We describe the performance of a TaqMelt polymerase chain reaction (PCR) assay—the cobas® KRAS Mutation Test—designed to detect 19 mutations in codons 12, 13, and 61. The limit of detection was determined using DNA blends from cell lines, plasmids, and formalin-fixed paraffin-embedded tissue specimens. Assay performance was compared to Sanger sequencing using a panel of 188 specimens. Discordant specimens were subjected to next generation pyrosequencing (454). Assay repeatability was assessed using a panel of six specimens. A >95% correct mutation call rate was obtained in all specimen types with ~5% mutant alleles at DNA inputs of 0.8–6.3 ng per PCR reaction; 100% detection rate was observed at the recommended DNA input of 50 ng. The positive percent agreement with Sanger was 97.5% (79/81) for codons 12/13 and 85.7% (6/7) for codon 61. Negative percent agreement was 94.4% (101/107) for codon 12/13 and 99.4% (180/181) for codon 61. Nine of 10 discordant specimens yielded 454 results consistent with the cobas® results. With repeated testing, the assay showed a correct call rate of 100% (192/192) for all operators, instruments, reagent lots, and days tested. The cobas® test detects KRAS mutations in codons 12, 13, and 61 at a limit of detection of <5%. The PCR assay was more sensitive and specific than Sanger sequencing, and performance was highly reproducible. Test performance was not influenced by various endogenous interfering substances or common gut microbes
Dentes inclusos
The aim of this work is to establish a routine for clinicai and radiographical examination of unerupted teeth in order to facilitate the diagnosis and the choice of a suitable surgical technice.O objetivo deste trabalho é estabelecer uma rotina para exame clÃnico e radiográfico de dentes inclusos a fim de facilitar o diagnóstico e a escolha da técnica cirúrgica indicada
Accuracy of tactile assessment in order to detect proximal cavitation of caries lesions in vitro.
OBJECTIVES
Discriminating non-cavitated from cavitated proximal lesions without tooth separation is only limitedly possible using visual-radiographic assessment alone. We evaluated how additional tactile assessment might increase the accuracy of this discrimination in vitro.
METHODS
Surface integrity of 46 primary molars with proximal lesions extending radiographically into outer third of dentin (ICDAS-codes: 2 n = 34, 3 n = 8 and 5 n = 4) were mounted in groups of two in manikin heads and independently assessed by three examiners using visual-radiographic and additional tactile assessment using a cow-horn-ended explorer with or without gingival displacement. After examination, lesion surfaces were evaluated for possible damage using scanning-electronic microscopy. Analysis of variance (ANOVA) was performed for evaluating if tactile assessment and gingival displacement significantly affected accuracy.
RESULTS
Tactile assessment significantly increased sensitivity of detecting cavities (p  0.05). Scanning-electron microscopy revealed no cavitation.
CONCLUSIONS
In vitro, tactile assessment of proximal surfaces was useful and safe.
CLINICAL RELEVANCE
Analysis of the cavitation level by using a cow-horn-ended probe might be leading to useful information in addition to bitewing assessment under clinical circumstances
Dentes inclusos
The aim of this work is to establish a routine for clinicai and radiographical examination of unerupted teeth in order to facilitate the diagnosis and the choice of a suitable surgical technice.O objetivo deste trabalho é estabelecer uma rotina para exame clÃnico e radiográfico de dentes inclusos a fim de facilitar o diagnóstico e a escolha da técnica cirúrgica indicada
Dentição decÃdua: estudo da prevalência dos espaços interproximais em crianças brasileiras Deciduous dentition: prevalence study of interdental spaces in brazilian children
No intuito de conhecer mais sobre as caracterÃsticas da dentição decÃdua, apresentadas pelas crianças brasileiras, realizou-se um estudo de prevalência do qual participaram 400 crianças, com dentição decÃdua completa e idade variando de 2 a 6 anos, na cidade de Petrópolis - RJ. O arco tipo I foi o mais prevalente tanto no arco superior (93,2%) como no inferior (90,5%), sendo que o superior tipo II foi mais comum no sexo feminino (p < 0,01). Os espaços primatas foram os espaços interproximais mais encontrados em ambos os arcos. A associação entre a presença de espaços interproximais e idade foi estatisticamente significante para ambos os arcos (p < 0,05), sugerindo uma tendência para o fechamento dos espaços com o aumento da idade.<br>For the purpose of ascertaining more information about the characteristics of deciduous dentition presented by the Brazilian children, a prevalence study was performed. Four hundred children with complete deciduous dentitions and age ranging from 2 to 6 years, were examined in Petrópolis - RJ - Brazil. The type I arch was the most prevalent in the upper arch (93.2%) and in the lower arch (90.5%). The type II upper arch was more common in the females (p < 0.01). The primate spaces were the most frequent spaces found in both arches. The association between the presence of interdental spaces and age was statistically significant (p < 0.05), suggesting that there is a tendency for the spaces to close with age