Yet reimbursement remains controversial and limited. The technique for performing and interpreting CTC is established with minor variations. Active research is ongoingon reduced cathartic or “prepless” CTC, electronic subtraction of tagged stool, detection of flat lesions, computer-aided detection, cost-effectiveness, reporting of extracolonic findings, and ultra-low radiation dose exams. With improvement in CT scanners and computer technology, further advances in visualization tools, such as automated reporting, supine–prone
comparison, and polyp volume, may also improve the technique. Ongoing trials will also help ABT-199 mouse with the study of the natural history of diminutive polyps when patients opt for evaluation by follow-up examinations rather than polypectomy. “
“MicroRNAs
(miRNAs) are recently discovered small RNA molecules that regulate developmental processes, such as proliferation, differentiation, and apoptosis; however, the identity of miRNAs and their functions during liver development are largely unknown. Here we investigated the miRNA and gene expression profiles for embryonic day (E)8.5 endoderm, E14.5 Dlk1+ liver cells (hepatoblasts), and adult liver Nutlin-3a cell line by employing Illumina sequencing. We found that miRNAs were abundantly expressed at all three stages. Using K-means clustering analysis, 13 miRNA clusters with distinct temporal expression patterns were identified. mir302b, an endoderm-enriched miRNA, was identified as an miRNA whose predicted targets are expressed highly in E14.5 hepatoblasts but low in the endoderm. We validated the expression of mir302b in the endoderm by whole-mount in situ hybridization. Interestingly, mir20a, the most highly expressed miRNA in the endoderm library, was also predicted to regulate some of the same targets as mir302b. We found that through targeting Aspartate Tgfbr2, mir302b and mir20a are able to regulate transforming growth factor beta (TGFβ) signal transduction. Moreover, mir302b can repress liver markers in
an embryonic stem cell differentiation model. Collectively, we uncovered dynamic patterns of individual miRNAs during liver development, as well as miRNA networks that could be essential for the specification and differentiation of liver progenitors. (HEPATOLOGY 2013) Generation of hepatocyte-like cells from differentiated pluripotent stem cells or reprogrammed cells provides a potential cell source for liver transplantation and drug testing. However, hepatocyte-like cells generated through in vitro culture cannot fully recapitulate the characteristics of their in vivo counterparts.1 Improving methods for hepatocyte derivation in vitro may benefit from enhancing our understanding of molecular networks regulating liver development in vivo. During mouse embryonic development, liver progenitor cells are specified from definitive endoderm at the 7-8 somite stage (embryonic day [E]8.5).1 At E9.