A new method for accurate assessment of DNA quality after bisulfite treatment

The covalent addition of methylgroups to cytosine has become the most intensively researched epigenetic DNA marker. The vast majority of technologies used for DNA methylation analysis rely on a chemical reaction, the so-called ‘bisulfite treatment’, which introduces methylation-dependent sequence changes through selective chemical conversion of non-methylated cytosine to uracil. After treatment, all non-methylated cytosine bases are converted to uracil but all methylated cytosine bases remain cytosine. These methylation dependent C-to-T changes can subsequently be studied using conventional DNA analysis technologies. The bisulfite conversion protocol is susceptible to processing errors, and small deviation from the protocol can result in failure of the treatment. Several attempts have been made to simplify the procedure and increase its robustness. Although significant achievements in this area have been made, bisulfite treatment remains the main source of process variability in the analysis of DNA methylation. This variability in particular impairs assays, which strive for the quantitative assessment of DNA methylation. Here we present basic mathematical considerations, which should be taken into account when analyzing DNA methylation. We also introduce a PCR-based assay, which allows ab initio assessment of the DNA quality after bisulfite treatment and can help to prevent inaccurate quantitative measurement resulting from poor bisulfite treatment

Laparoscopic ileocolic resection versus infliximab treatment of distal ileitis in Crohn's disease: a randomized multicenter trial (LIR!C-trial)

Contains fulltext : 69534.pdf (publisher's version ) (Open Access)BACKGROUND: With the availability of infliximab, nowadays recurrent Crohn's disease, defined as disease refractory to immunomodulatory agents that has been treated with steroids, is generally treated with infliximab. Infliximab is an effective but expensive treatment and once started it is unclear when therapy can be discontinued. Surgical resection has been the golden standard in recurrent Crohn's disease. Laparoscopic ileocolic resection proved to be safe and is characterized by a quick symptom reduction.The objective of this study is to compare infliximab treatment with laparoscopic ileocolic resection in patients with recurrent Crohn's disease of the distal ileum with respect to quality of life and costs. METHODS/DESIGN: The study is designed as a multicenter randomized clinical trial including patients with Crohn's disease located in the terminal ileum that require infliximab treatment following recent consensus statements on inflammatory bowel disease treatment: moderate to severe disease activity in patients that fail to respond to steroid therapy or immunomodulatory therapy. Patients will be randomized to receive either infliximab or undergo a laparoscopic ileocolic resection. Primary outcomes are quality of life and costs. Secondary outcomes are hospital stay, early and late morbidity, sick leave and surgical recurrence. In order to detect an effect size of 0.5 on the Inflammatory Bowel Disease Questionnaire at a 5% two sided significance level with a power of 80%, a sample size of 65 patients per treatment group can be calculated. An economic evaluation will be performed by assessing the marginal direct medical, non-medical and time costs and the costs per Quality Adjusted Life Year (QALY) will be calculated. For both treatment strategies a cost-utility ratio will be calculated. Patients will be included from December 2007. DISCUSSION: The LIR!C-trial is a randomized multicenter trial that will provide evidence whether infliximab treatment or surgery is the best treatment for recurrent distal ileitis in Crohn's disease. TRIAL REGISTRATION: Nederlands Trial Register NTR1150

With a falling budget, and chaotic administration, Austria’s development policy is in serious need of reform

Austria’s development policy is chaotic. Organized by eight ministries, and in the face of declining budgets, a mere 130 bureaucrats from the Austrian Development Agency (ADA) have the job of fostering change in more than a dozen countries all over the world. Dirk van den Boom assesses what needs to change to get the Austrian development community back on track

Regionale Kooperation in Westafrika: Politik und Probleme der ECOWAS

Muenster, Univ., Diss., 1995Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel A 210597 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Overlay of three mass spectra showing the ΔF508-specific mass signal changes generated in the T-specific cleavage reaction of the reverse strands

<p><b>Copyright information:</b></p><p>Taken from "Multiplexed discovery of sequence polymorphisms using base-specific cleavage and MALDI-TOF MS"</p><p>Nucleic Acids Research 2005;33(4):e38-e38.</p><p>Published online 24 Feb 2005</p><p>PMCID:PMC549577.</p><p>© The Author 2005. Published by Oxford University Press. All rights reserved</p> The mass signal pattern is derived from a triplexed reaction encompassing exon 10, 21 and 24 of the CFTR gene. Three different individuals were analyzed, the upper mass spectrum representing a homozygous wild-type for ΔF508, a carrier of the ΔF508 mutation (middle) and an individual homoyzgous mutant ΔF508 (lower mass spectrum). Mass signals specific for the mutation are indicated with a line

Lattice Boltzmann simulation of 2D and 3D non-Brownian suspensions in Couette flow

In this study, the Lattice Boltzmann (LB) method is applied for computer simulation of suspension flow in Couette systems. Typical aspects of Couette flow such as wall effects and non-zero Reynolds numbers can be studied well with the LB method because of its time-dependent character. Couette flow of single, two and multi-particle systems was studied, where two-dimensional (2D) systems were compared with three-dimensional (3D) systems.\ud \ud Computations on multi-particle 3D suspensions, for instance to assess the viscosity or shear-induced diffusivity, were found to be very intensive. This was only partly a consequence of the 3D system size. The critical particle grid size, necessary for accurate results, was found to be relatively large, increasing the system to impractical sizes.\ud \ud It is however demonstrated that it is possible to carry out computer simulations on 2D suspensions and use relatively simple, linear scaling relations to translate these results to 3D suspensions, in this way avoiding intensive computations. By doing so, the LB method is shown to be well-suited for study of suspension flow in Couette systems, particularly for aspects as particle layering near solid walls, hydrodynamic particle interactions and viscous stresses at non-zero Reynolds numbers, which cannot be easily solved with alternative methods. It also opens the way to employ the LB method for other unexplored aspects, such as particle polydispersity and high Reynolds number flow, with large relevance to practical processing of suspensions

Liquid-crystalline ordering in polymeric networks as studied by polarized Raman scattering

Uniaxially oriented polymer networks are produced by photoinitiated bulk polymerization of liquid-crystalline diacrylates. The order parameters S 2 and S 4 of the mesogenic moieties in these networks are simultaneously determined by means of the polarized Raman scattering technique. It yields an estimate of the orientation distribution function for different polymerization temperatures and for different lengths of the alkyl chain, present as a spacer in the liquid-crystalline diacrylate