Deep-sea amphipods around cobalt-rich ferromanganese crusts: Taxonomic diversity and selection of candidate species for connectivity analysis.

The aim of this study was to select a candidate deep-sea amphipod species suitable for connectivity analyses in areas around cobalt-rich ferromanganese crusts (CRCs). We applied DNA barcoding based on the mitochondrial protein-coding gene, cytochrome c oxidase subunit I (COI), to specimens collected from the Xufu Guyot (the JA06 Seamount) off southeastern Minami-Torishima Island in the North Pacific, where CRCs are distributed. We used baited traps to collect 37 specimens. Comparison of COI sequences with public reference databases (GenBank, BOLD) showed that almost all of the specimens belonged to the superfamily Lysianassoidea, which is known to be ubiquitous in deep-sea areas. In a molecular taxonomic analysis of these sequences, we detected 11 clades. One of these clades (group 9) composed of 18 sequences and was identified by DNA barcoding as a putative species belonging to Abyssorchomene, which has been reported from the New Hebrides Trench in the South Pacific. We considered this species to be a candidate for connectivity analysis and analyzed its genome by restriction site-associated DNA sequencing. The results showed that the genetic variation in this species is adequate for analyzing connectivity patterns in CRC areas in the future.

Biological proliferation of cesium-137 through the detrital food chain in a forest ecosystem in Japan.

Radionuclides, including (137)Cs, were released from the disabled Fukushima Daiichi Nuclear Power Plant and had been deposited broadly over forested areas of north-eastern Honshu Island, Japan. In the forest, (137)Cs was highly concentrated on leaf litters deposited in autumn 2010, before the accident. Monitoring of the distribution of (137)Cs among functional groups clearly showed the role of the detrital food chain as the primary channel of (137)Cs transfer to consumer organisms. Although many studies have reported the bioaccumulation (or dilution) of radioactive materials through trophic interactions, the present results highlight the importance of examining multiple possible pathways (e.g., grazing vs. detrital chains) in the proliferation of (137)Cs through food webs. These results provide important insight into the future distribution and transfer of (137)Cs within forest ecosystems.

Novel acrylonitrile derivatives, YHO-13177 and YHO-13351, reverse BCRP/ABCG2-mediated drug resistance in vitro and in vivo.

Breast cancer resistance protein (BCRP/ABCG2) confers resistance to anticancer drugs such as 7-ethyl-10-hydroxycamptothecin (SN-38, an active metabolite of irinotecan), mitoxantrone, and topotecan. In this study, we examined the reversing effects of YHO-13177, a novel acrylonitrile derivative, and its water-soluble diethylaminoacetate prodrug YHO-13351 on the BCRP-mediated drug resistance. YHO-13177 potentiated the cytotoxicity of SN-38, mitoxantrone, and topotecan in both BCRP-transduced human colon cancer HCT116 (HCT116/BCRP) cells and SN-38-resistant human lung cancer A549 (A549/SN4) cells that express BCRP, but had little effect in the parental cells. In addition, YHO-13177 potentiated the cytotoxicity of SN-38 in human lung cancer NCI-H460 and NCI-H23, myeloma RPMI-8226, and pancreatic cancer AsPC-1 cells that intrinsically expressed BCRP. In contrast, it had no effect on P-glycoprotein-mediated paclitaxel resistance in MDR1-transduced human leukemia K562 cells and multidrug resistance-related protein 1-mediated doxorubicin resistance in MRP1-transfected human epidermoid cancer KB-3-1 cells. YHO-13177 increased the intracellular accumulation of Hoechst 33342, a substrate of BCRP, at 30 minutes and partially suppressed the expression of BCRP protein at more than 24 hours after its treatment in both HCT116/BCRP and A549/SN4 cells. In mice, YHO-13351 was rapidly converted into YHO-13177 after its oral or intravenous administration. Coadministration of irinotecan with YHO-13351 significantly increased the survival time of mice inoculated with BCRP-transduced murine leukemia P388 cells and suppressed the tumor growth in an HCT116/BCRP xenograft model, whereas irinotecan alone had little effect in these tumor models. These findings suggest that YHO-13351, a prodrug of YHO-13177, could be clinically useful for reversing BCRP-mediated drug resistance in cancer chemotherapy.

[Use of compressed images for medical checkups: comparison between radiologists' subjective quality assessment and diagnostic usefulness].

With the increasing demand on picture archiving and communication systems (PACS) to handle larger numbers of images, much research has been conducted on the utilization of lossy compression for efficient communication and storage in PACS systems. The receiver operating characteristics (ROC) method is commonly used to determine the appropriate compression ratio of lossy images. However, conducting an ROC experiment is impractical at actual medical facilities because it is difficult to prepare and interpret images with different compression ratios for each modality, body part, and acquisition method. On the other hand, experienced radiologists have the ability to subjectively assess the level of image quality required for interpretatior and quantitative analysis. Therefore, by simply viewing images, they are able to determine the appropriate criteria for image quality and derive a practical compression ratio for each application. The present study focused on lossy compression as employed in teleradiology systems for medical checkups. Experiments comparing radiologists' subjective assessment of compressed images against the diagnostic results obtained using these images were conducted in order to investigate appropriate compression ratios and efficient methods for determining them.