Tolllike receptor 4 (TLR4) polymorphisms in Tunisian patients with Crohn's disease: genotype-phenotype correlation

<p>Abstract</p> <p>Background</p> <p>The immune responses to bacterial products through the pattern recognition receptor (PRR) play a pivotal role in pathogenesis of Crohn's disease. A recent study described an association between CD and some gene coding for bacterial receptor like NOD2/CARD15 gene and TLR4. In this study, we sought to determine whether TLR4 gene was associated with Crohn's disease (CD) among the Tunisian population and its correlation with clinical manifestation of the disease.</p> <p>Methods</p> <p>90 patients with CD and 80 healthy individuals are genotyped for the <it>Asp299Gly </it>and <it>Thr399Ile </it>polymorphisms by restriction fragment length polymorphism analysis.</p> <p>Results</p> <p>The allele and genotype frequency of the TLR4 polymorphisms did not differ between patients and controls. The genotype-phenotype correlation permitted to show that the <it>Thr399Ile </it>polymorphism was associated with early onset disease.</p> <p>Conclusion</p> <p>this study reported the absence of association between CD and TLR4 gene in the Tunisian population, but this gene could play a role in clinical expression of the disease.</p

Setting expectations for educational innovations

This paper considers the problematic enactment of instructional innovations. We examine how different interpretations of “success” might be explained within a frame of reference that confronts the complexities of and uncovers the contingencies relating to educational policy implementation in schools. Based on the detailed description and comparison of three different educational innovations developed and implemented in the same educational context — Singapore — we show how the intricate and delicate interrelationships that exist within and across adopters, innovators and environments influence what might be reasonably expected and achieved from specific innovation initiatives. By doing so, we hope not only to test Cohen and Ball’s framework and conjectures but also lay the groundwork for future comparative work on innovation design and evaluation, moving the research agenda forward by critically examining reasonable expectations for educational innovation