Epigenomic analysis of aberrantly methylated genes in colorectal cancer identifies genes commonly affected by epigenetic alterations.

Methylation profiling based on bead-chip arrays is an effective method for screening aberrantly methylated genes in CRC. In addition, we identified novel methylated genes that are candidate diagnostic or prognostic markers for CRC

Genomic Characteristics of Chinese Borrelia burgdorferi Isolates

In China, B. burgdorferi, B.garinii, B. afzelii and B. yangtze sp. nov have been reported; B.garinii and B. afzelii are the main pathogenic genotypes. But until now only one Chinese strain was reported with whole genome sequence. In order to further understand the genomic characteristics and diversity of Chinese Borrelia strains, 5 isolates from China were sequenced and compared with the whole genome sequences of strains in other areas. The results showed a high degree of conservation within the linear chromosome of Chinese strains, whereas plasmid showed a much larger diversity according to the majority genomic information of plasmids. The genome sequences of the five Chinese strains were compared with the corresponding reference strains, respectively, according to the genospecies. Pairwise analysis demonstrates that there are only 70 SNPs between the genomes of CS4 and B31. However, there are many more SNPs between the genomes of QX-S13 and VS116, PD91 and PBi, FP1 and PKo, R9 and Pko, respectively. Gene comparison showed some important different genes. OspA was one of the important different genes. Comparative genomic studies have found that OspA gene sequences of PD91 and R9 had great differences compared with the sequence of B31. OspA gene sequence of R9 had a 96bp deletion; OspA gene of PD91 had two deletions: 9bp and 10 bp. To conclude, we showed the genomic characteristics of four genotype Chinese B. burgdorferi strains. The genomic sequence of B. yangtze sp. nov and differences from B. valaisiana were first reported. Comparative analysis of Chinese strains with the different Borrelia species from other areas will help us to understand evolution and pathogenesis of Chinese Borrelia burgdorferi strains

Dimensionality and predictive validity of the HAM-Nat, a test of natural sciences for medical school admission

<p>Abstract</p> <p>Background</p> <p>Knowledge in natural sciences generally predicts study performance in the first two years of the medical curriculum. In order to reduce delay and dropout in the preclinical years, Hamburg Medical School decided to develop a natural science test (HAM-Nat) for student selection. In the present study, two different approaches to scale construction are presented: a unidimensional scale and a scale composed of three subject specific dimensions. Their psychometric properties and relations to academic success are compared.</p> <p>Methods</p> <p>334 first year medical students of the 2006 cohort responded to 52 multiple choice items from biology, physics, and chemistry. For the construction of scales we generated two random subsamples, one for development and one for validation. In the development sample, unidimensional item sets were extracted from the item pool by means of weighted least squares (WLS) factor analysis, and subsequently fitted to the Rasch model. In the validation sample, the scales were subjected to confirmatory factor analysis and, again, Rasch modelling. The outcome measure was academic success after two years.</p> <p>Results</p> <p>Although the correlational structure within the item set is weak, a unidimensional scale could be fitted to the Rasch model. However, psychometric properties of this scale deteriorated in the validation sample. A model with three highly correlated subject specific factors performed better. All summary scales predicted academic success with an odds ratio of about 2.0. Prediction was independent of high school grades and there was a slight tendency for prediction to be better in females than in males.</p> <p>Conclusions</p> <p>A model separating biology, physics, and chemistry into different Rasch scales seems to be more suitable for item bank development than a unidimensional model, even when these scales are highly correlated and enter into a global score. When such a combination scale is used to select the upper quartile of applicants, the proportion of successful completion of the curriculum after two years is expected to rise substantially.</p

Treatment of small vessel vasculitis affecting the kidneys

Treatment of vasculitis can be divided into two phases: (i) an induction phase to achieve remission, abate destructive inflammation and minimize scarring; and (ii) the maintenance phase to sustain patients in remission with minimal treatment-related side-effects. A combination of corticosteroids and cytotoxic agents is commonly used as induction therapy. The dose and route of administration of corticosteroids have not been studied adequately, but intravenous (i.v.) bolus doses of methylprednisolone are often administered to patients with severe disease. It has the advantage of fewer side-effects compared to prolonged high dose oral corticosteroids, and the immediate immuno-modulatory effects of the steroid boluses may confer additional therapeutic benefits. It is the general impression that cyclophosphamide is more effective than azathioprine in the acute phase of patients with severe disease. The use of cyclophosphamide by i.v. pulse rather than orally is contentious, and some recent studies have demonstrated its failure to induce sustained remission. Azathioprine with low dose corticosteroids is often employed as long-term maintenance immunosuppression, although low dose cyclophosphamide has also been used for such purpose, which should be withdrawn after 1 year of remission because of its potential side-effects. Clinical and serologic parameters are useful monitors during maintenance therapy. Although serial levels of anti-neutrophil cytoplasm antibodies (ANCA) correlate with disease activity, some patients remain well despite positive or increasing levels of ANCA. Consequently, whether immunosuppressive therapy should be escalated based on increasing ANCA levels alone remains controversial.link_to_subscribed_fulltex