Molecular and structural biology on the giant hemoglobin from pogonophoran Oligobrachia mashikoi(有鬚動物マシコヒゲムシの巨大ヘモグロビンに関する分子および構造生物学的研究)

取得学位：博士(理学)，学位授与番号：博甲第692号，学位授与年月日：平成16年9月30日,学位授与年：200

A screening method for detecting formaldehyde emitted from textile products

Formaldehyde is widely used to improve textile quality, but it is categorized as a potential carcinogen in humans. The concentration of formaldehyde emitted from textile products therefore has implications for public health. The standard method uses acetylacetone for determining formaldehyde extracted from textile products, but requires a water solution and the use of an analyzer. In this study, we present a method for screening textile-emitted formaldehyde via a porous glass sensor that we previously developed. Our method is suitable for on-site screening, whereas the commonly used method is not. The glass sensor was used to measure formaldehyde concentrations emitted from several kinds of textile products. The results showed good agreement (coefficient 0.92) with those of the acetylacetone method. Moreover, we estimate the effects of temperature, and suggest a formula to calculate concentration including temperature correction

Direct evidence that extracellular giant hemoglobin is produced in chloragogen tissues in a beard worm, Oligobrachia mashikoi (Frenulata, Siboglinidae, Annelida)

金沢大学環日本海域環境研究センター生物多様性研究部門In Oligobrachia mashikoi, a mouthless and gutless polychaete known as a beard worm, sites of production of extra-cellular giant hemoglobin were examined with whole-mount in-situ hybridization and semi-quantitative RT-PCR. An RNA probe was prepared from mRNA of the A2-globin subunit. Clear signals were obtained from a peritoneal membrane covering the trophosome in the posterior body in all seven individuals examined in this study. In addition, weak signals were observed in the peritoneal membrane covering tissues in the middle part of the body in some individuals. Furthermore, in one individual, signals were obtained in complicated bodies invaginated into the dorsal vessel from a peritoneal membrane that also released signals. The results of RT-PCR regarding the expression levels of four kinds of globin-subunit genes suggest that the main site of hemoglobin production is the peritoneal membrane in the posterior body. © 2008 Zoological Society of Japan.全文公開20091

Constraint on the giant planet production by core accretion

The issue of giant planet formation by core instability (CI) far from the central star is rather controversial because the growth of massive solid core necessary for triggering the CI can take longer than the lifetime of the protoplanetary disk. In this work we assess the range of separations at which the CI may operate by (1) allowing for arbitrary (physically meaningful) rate of planetesimal accretion by the core and (2) properly taking into account the dependence of the critical mass for the CI on the planetesimal accretion luminosity. This self-consistent approach distinguishes our work from similar studies in which only a specific planetesimal accretion regime was explored and/or the critical core mass was fixed at some arbitrary level. We demonstrate that the largest separation at which the CI can occur within 3 Myr corresponds to the surface density of solids in the disk higher than 0.1 g cm^{-2} and is 40-50 AU in the minimum mass Solar nebula. This limiting separation is achieved when the planetesimal accretion proceeds at the fastest possible rate, even though the high associated accretion luminosity increases the critical core mass delaying the onset of the CI. Our constraints are independent of the mass of the central star and vary only weakly with the core density and its atmospheric opacity. We also discuss various factors which can strengthen or weaken our limits on the operation of the CI.Comment: 8 pages, 1 figure, submitted to Ap

Successful management of hyperammonemia with hemodialysis on day 2 during 5-fluorouracil treatment in a patient with gastric cancer: a case report with 5-fluorouracil metabolite analyses

Ozaki, Y., Imamaki, H., Ikeda, A. et al. Correction to: Successful management of hyperammonemia with hemodialysis on day 2 during 5‑fluorouracil treatment in a patient with gastric cancer: a case report with 5‑fluorouracil metabolite analyses. Cancer Chemotherapy and Pharmacology (2020) 86:693-699.Purpose: Hyperammonemia is an important adverse event associated with 5-fluorouracil (5FU) from 5FU metabolite accumulation. We present a case of an advanced gastric cancer patient with chronic renal failure, who was treated with 5FU/leucovorin (LV) infusion chemotherapy (2-h infusion of LV and 5FU bolus followed by 46-h 5FU continuous infusion on day 1; repeated every 2 weeks) and developed hyperammonemia, with the aim of exploring an appropriate hemodialysis (HD) schedule to resolve its symptoms. Methods: The blood concentrations of 5FU and its metabolites, α-fluoro-β-alanine (FBAL), and monofluoroacetate (FA) of a patient who had hyperammonemia from seven courses of palliative 5FU/LV therapy for gastric cancer were measured by liquid chromatography–mass spectrometry. Results: On the third day of the first cycle, the patient presented with symptomatic hyperammonemia relieved by emergency HD. Thereafter, the 5FU dose was reduced; however, in cycles 2–4, the patient developed symptomatic hyperammonemia and underwent HD on day 3 for hyperammonemia management. In cycles 5–7, the timing of scheduled HD administration was changed from day 3 to day 2, preventing symptomatic hyperammonemia. The maximum ammonia and 5FU metabolite levels were significantly lower in cycles 5–7 than in cycles 2–4 (NH3 75 ± 38 vs 303 ± 119 μg/dL, FBAL 13.7 ± 2.5 vs 19.7 ± 2.0 μg/mL, FA 204.0 ± 91.6 vs 395.9 ± 12.6 ng/mL, mean ± standard deviation, all p < 0.05). After seven cycles, partial response was confirmed. Conclusion: HD on day 2 instead of 3 may prevent hyperammonemia in 5FU/LV therapy

A novel efficient feeder-free culture system for the derivation of human induced pluripotent stem cells

Nakagawa, M.et al. A novel efficient feeder-free culture system forthe derivation of human induced pluripotent stem cells.Sci. Rep.4, 3594; DOI:10.1038/srep03594 (2014)

A Large X-ray Flare from a Single Weak-lined T Tauri Star TWA-7 Detected with MAXI GSC

We present a large X-ray flare from a nearby weak-lined T Tauri star TWA-7 detected with the Gas Slit Camera (GSC) on the Monitor of All-sky X-ray Image (MAXI). The GSC captured X-ray flaring from TWA-7 with a flux of $3\times10^{-9}$ ergs cm$^{-2}$ s$^{-1}$ in 2--20 keV band during the scan transit starting at UT 2010-09-07 18:24:30.The estimated X-ray luminosity at the scan in the energy band is 3$\times10^{32}$ ergs s$^{-1}$,indicating that the event is among the largest X-ray flares fromT Tauri stars.Since MAXI GSC monitors a target only during a scan transit of about a minute per 92 min orbital cycle, the luminosity at the flare peak might have been higher than that detected. At the scan transit, we observed a high X-ray-to-bolometric luminosity ratio, log $L_{\rm X}/L_{\rm bol}$ = $-0.1^{+0.2}_{-0.3}$; i.e., the X-ray luminosity is comparable to the bolometric luminosity. Since TWA-7 has neither an accreting disk nor a binary companion, the observed event implies that none of those are essential to generate such big flares in T Tauri stars.Comment: 4 pages, 2 figures, 1 table accepted for publication in PAS

Post-progression survival and progression-free survival in patients with advanced hepatocellular carcinoma treated by sorafenib

Aim: Although sorafenib is a standard drug for advanced hepatocellular carcinoma (HCC), little is known about a patient\u27s clinical course after treatment. We investigated the effect of post-progression survival (PPS) and progression-free survival (PFS) on overall survival (OS) in patients whose advanced HCC was treated by sorafenib. Methods: We searched in the PubMed database for reports with survival data of patients with HCC treated with sorafenib monotherapy, and selected reports with 20 or more patients each that provided data for both OS and PFS or time to progression (TTP). Median PPS (mPPS) was defined as the period obtained by subtracting median PFS or TTP (mPFS/TTP) from median OS (mOS). We identified 56 reports with 5803 patients. We investigated the correlation of mOS and either mPPS or mPFS/TTP using weighted linear regression. Results: Median PPS correlated with mOS (r=0.834) very strongly, whereas mPFS/TTP did not correlate with mOS as highly as PPS did (r=0.546). When we stratified survival data by Child-Pugh classification, a significantly greater average percentage of mPPS to mOS was seen in Child-Pugh class A (54.4±17.6%) than in Child-Pugh class B (32.0±11.6%) (P=0.015). Conclusion: PPS highly correlated with OS, and its importance should be more emphasized for advanced HCC patients treated after sorafenib therapy, whereas we need to take more care in interpreting the results of PFS to evaluate treatment efficacy in clinical trials of advanced HCC. © 2015 The Japan Society of Hepatology.Embargo Period 12 month