Long interspersed nuclear element-1 hypomethylation in cancer: biology and clinical applications

Epigenetic changes in long interspersed nuclear element-1s (LINE-1s or L1s) occur early during the process of carcinogenesis. A lower methylation level (hypomethylation) of LINE-1 is common in most cancers, and the methylation level is further decreased in more advanced cancers. Consequently, several previous studies have suggested the use of LINE-1 hypomethylation levels in cancer screening, risk assessment, tumor staging, and prognostic prediction. Epigenomic changes are complex, and global hypomethylation influences LINE-1s in a generalized fashion. However, the methylation levels of some loci are dependent on their locations. The consequences of LINE-1 hypomethylation are genomic instability and alteration of gene expression. There are several mechanisms that promote both of these consequences in cis. Therefore, the methylation levels of different sets of LINE-1s may represent certain phenotypes. Furthermore, the methylation levels of specific sets of LINE-1s may indicate carcinogenesis-dependent hypomethylation. LINE-1 methylation pattern analysis can classify LINE-1s into one of three classes based on the number of methylated CpG dinucleotides. These classes include hypermethylation, partial methylation, and hypomethylation. The number of partial and hypermethylated loci, but not hypomethylated LINE-1s, is different among normal cell types. Consequently, the number of hypomethylated loci is a more promising marker than methylation level in the detection of cancer DNA. Further genome-wide studies to measure the methylation level of each LINE-1 locus may improve PCR-based methylation analysis to allow for a more specific and sensitive detection of cancer DNA or for an analysis of certain cancer phenotypes

The UKCAT-12 study: educational attainment, aptitude test performance, demographic and socio-economic contextual factors as predictors of first year outcome in a cross-sectional collaborative study of 12 UK medical schools

Most UK medical schools use aptitude tests during student selection, but large-scale studies of predictive validity are rare. This study assesses the United Kingdom Clinical Aptitude Test (UKCAT), and its four sub-scales, along with measures of educational attainment, individual and contextual socio-economic background factors, as predictors of performance in the first year of medical school training

Testing Competences Worldwide in Large Numbers: Complying with ISO/IEC 17024:2012 Standard for Competence Testing

The ISO/IEC 17024:2012 describes best-practices regarding competence assessment. The standard emphasizes validity and sound processes to create high-quality competence assessments. The question is how to comply with the ISO/IEC standard when creating large-scale, worldwide assessments. In addition, the competence framework describes competences that require years of experience as part of the competence. We determine to what extent of mastery candidates need to master the competence to start working. We assess this by testing the requisite knowledge with a multiple-choice exam and the required minimum level of mastery of the competence with a Practical Assignment. This assignment is assessed by trainers, which creates the need for supervision and accreditation of the trainers. This paper shows an example of a certification scheme to explain how we comply with the ISO/IEC standard. The creation of the certification scheme and the accreditation of the trainers are described. The compliance with the ISO/IEC standard is explained