Activity concentration of Fukushima-derived radiocesium in the western subarctic area of the North Pacific Ocean in summer 2017

Vertical profiles of radiocesium (134Cs and 137Cs) were measured in the western subarctic area of the North Pacific in 2017. The highest concentration of 134Cs, which was derived from the accident of the Fukushima Dai-ichi Nuclear Power Plant in 2011, was 0.14 Bq m−3 (or 1.19 Bq m−3 after the decay correction to the accident date). Although the vertical inventory of 134Cs decreased between 2014 and 2017, the inventory in 2017 was larger than that expected. That was probably arose from the return of some portion of the high-concentration water mass along with the anticlockwise subarctic gyre current

冷凍保存骨芽細胞シートの骨形成能評価

Cryopreservation of tissue engineered bone (TEB), whilst maintaining its osteogenic ability, is imperative for large-scale clinical application. We previously reported a novel cell transplantation method, in which bone-marrow-derived mesenchymal stem cells (BMSCs) were cultured to confluence and differentiated down the osteogenic lineage to form osteogenic matrix cell sheets (OMCS). OMCS have high alkaline phosphatase (ALP) activity and osteocalcin (OC) contents and can be easily used for producing TEB. The aim of the present study was to investigate whether TEB produced by cryopreserved OMCS maintains sufficient osteogenic potential in vivo. OMCS were prepared and divided into three groups according to storage period of cryopreservation (fresh (no cryopreservation), 4 week and 12 week cryopreservation groups). OMCS were cryopreserved by storage in freezing medium (Cell Banker 1®) at -80 °C. Cryopreserved OMCSs were rapidly thawed at room temperature and wrapped around Hydroxyapatite (HA) scaffolds prior to implantation into subcutaneous sites in rats, to determine their in vivo bone-forming capability. The constructs were harvested 4 weeks after transplantation and examined histologically and biochemically. Histological analysis of the constructs showed extensive bone formation in the HA pores with high ALP activity and OC content detected in the cryopreservation groups. The present study clearly indicates that cryopreserved/thawed OMCS are still capable of producing mineralized matrix on scaffolds, resulting in bone formation. This cryopreservation technique could be applied for hard tissue reconstruction to ease the cell preparation method prior to time of use.博士（医学）・甲第607号・平成25年11月27

トウカ ニオケル ラジオハ ショウシャク リョウホウ オ モチイタ カンシュヨウ チリョウ : preliminary report

Radiofrequency ablation (RFA) has recently been used to treat liver tumors. RFA is a safe and effective treatment of liver tumors and requires fewer treatment sessions. Between June 2000 and April 2003, hepatocellular carcinoma (77 patients with 106 lesions) and metastatic liver tumors (21 patients with 30 lesions) and cholangiocellular carcinoma (1 patient with 1 lesion) were treated with RFA. The liver tumors were treated percutaneously or during surgery under ultrasound guidance using a LeVeen needle (55 lesions) and cool tip RF needle (82 lesions). To evaluate the response, contrast-enhanced CT scans or MRI were obtained. Most patients experienced moderate pain during RFA procedure, especially when the tumor was superficially located. Complete necrosis was achieved in all HCCs with RFA.This result was obtained with an average of 1.12 sessions per HCC. With a median follow-up of 15 months, HCCs have recurred in 6 of 90 treated lesions (6.7%), and metastatic liver tumors have recurred in 2 of 17 treated lesions (11.8%). We are initiating a combining RFA of hepatic malignancies with regional or systemic chemotherapy will reduce hepatic and extrahepatic recurrence rates and enhance long-term survival rates. We believe that RFA will be effective treatment to achieve in patients with unresectable meastatic liver tumors