PCTK3/CDK18 regulates cell migration and adhesion by negatively modulating FAK activity

PCTAIRE kinase 3 (PCTK3) is a member of the cyclin dependent kinase family, but its physiological function remains unknown. We previously reported that PCTK3-knockdown HEK293T cells showed actin accumulation at the leading edge, suggesting that PCTK3 is involved in the regulation of actin reorganization. In this study, we investigated the physiological function and downstream signal transduction molecules of PCTK3. PCTK3 knockdown in HEK293T cells increased cell motility and RhoA/Rho-associated kinase activity as compared with control cells. We also found that phosphorylation at residue Tyr-397 in focal adhesion kinase (FAK) was increased in PCTK3-knockdown cells. FAK phosphorylation at Tyr-397 was increased in response to fibronectin stimulation, whereas its phosphorylation was suppressed by PCTK3. In addition, excessive expression of PCTK3 led to the formation of filopodia during the early stages of cell adhesion in HeLa cells. These results indicate that PCTK3 controls actin cytoskeleton dynamics by negatively regulating the FAK/Rho signaling pathway

Inflammatory Polyp in the Common Bile Duct with Pancreaticobiliary Maljunction

A 63-year-old woman was admitted because of epigastric pain and obstructive jaundice. Endoscopic retrograde cholangiopancreatography and intraductal ultrasonography revealed a 25-mm papillary nodule in the middle to inferior portion of the common bile duct (CBD). Pancreaticobiliary maljunction (PBM) was also identified. Contrast-enhanced computed tomography also showed an enhanced nodule in the CBD, and we suspected intraductal papillary neoplasm of the bile duct. We performed pylorus-preserving pancreatoduodenectomy. Postoperative pathological examination revealed an inflammatory polyp in the middle CBD. Inflammatory polyp in the bile duct is rare and there are no previous reports accompanied by PBM. PBM is a major risk factor for biliary tract cancer. Preoperative diagnosis of a benign disorder was difficult in this case

Enhancement of Tritium Release Rate from Ceramic Breeders with Impregnated Catalytic Additives

In most current designs of D-T fusion reactor blankets employing ceramic breeder materials， the use of a helium sweep gas containing O.1％of hydrogen is contemplated to extract tritium efficiently via isotopic exchange reactions． However， at lower temperatures， the release process of tritium from the breeders is rather slow. For this reason， there is still a need to develop techniques that contribute to the enhancement of the recovery of bred tritium． In order to obtain an improved recovery of tritium from a blanket over wide ranges of temperature， the effect of catalytically active metal additives on the heterogeneous isotope exchange reactions at the breeder-sweep gas interface was examined， Platinum and palladium were deposited on solid breeder material pebbles（Li_4SiO_4）by the incipient wet impregnation method． Cold experiments with hydrogen and predeuterated water were performed using packed bed reactors and gas chromatographic analysis systems． Out of pile tritium release experiments were also conducted． using ceramic breeders irradiated in a research reactor． The experimental results reveal that the addition of catalytic additive metals is very effective to increase the tritium release rate from ceramic breeder materials especially at comparatively lower temperatures