• Title/Summary/Keyword: Sasaki

Search Result 265, Processing Time 0.027 seconds

Identification of Molecular Markers for Photoblastism in Weedy Rice

  • Lee, Hyun-Sook;Ahn, Sang-Nag;Sasaki, Kazuhiro;Chung, Nam-Jin;Choi, Kwan-Sam;Sato, Tadashi
    • Korean Journal of Breeding Science
    • /
    • v.42 no.2
    • /
    • pp.144-150
    • /
    • 2010
  • The objective of this study was to map gene/QTL for photoblastism in a weedy rice (photoblastic rice: PBR) using DNA markers. Light-induced effect on germination of seeds was compared among three accessions (Oryza sativa L.), PBR, Milyang 23 and Ilpum. Results showed that PBR seeds started to show photoblastism during seed development, different from Ilpum and Milyang 23. Frequency distribution of germination in the F4 lines from crosses between Ilpum and PBR and, Milyang 23 and PBR revealed bimodal distributions suggesting that photoblastism was controlled by a few genes. Bulked segregant analysis using $F_4$ populations derived from the above two crosses was conducted to identify gene/QTL for photoblastism. Two QTL were identified on chromosomes 1 and 12 explaining 11.2 and 12.8% of the phenotypic variance, respectively. Two QTL were further mapped between two SSR markers, RM8260 and RM246 on chromosome 1, and between RM270 and 1103 on chromosome 12. It is noteworthy that two QTL for photoblastism were colocalized with the QTL for seed dormancy reported in the previous QTL studies. The clustering of two genes for photoblastism and dormancy possibly indicates that these regions constitute rice phytochrome gene clusters related to germination. Because PBR has a low degree of dormancy, a pleiotropic effect of a single gene controlling dormancy and photoblastism can be ruled out. The linked markers will provide the foundation for positional cloning of the gene.

Tc-99m hydroxymethylene diphosphonate scintigraphy, computed tomography, and magnetic resonance imaging of osteonecrosis in the mandible: Osteoradionecrosis versus medication-related osteonecrosis of the jaw

  • Ogura, Ichiro;Sasaki, Yoshihiko;Sue, Mikiko;Oda, Takaaki;Kameta, Ayako;Hayama, Kazuhide
    • Imaging Science in Dentistry
    • /
    • v.49 no.1
    • /
    • pp.53-58
    • /
    • 2019
  • Purpose: To present characteristic findings of Tc-99m hydroxymethylene diphosphonate (HMDP) scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging for osteonecrosis in the mandible, especially osteoradionecrosis(ORN) and medication-related osteonecrosis of the jaw(MRONJ). Materials and Methods: Thirteen patients with MRONJ and 7 patients with ORN in the mandible underwent Tc-99m HMDP scintigraphy, CT, and MR imaging (T1-weighted images[T1WI], T2-weighted images[T2WI], short inversion time inversion recovery images[STIR]), diffusion-weighted images[DWI], and apparent diffusion coefficient [ADC] mapping). The associations of scintigraphy, CT, and MR imaging findings with MRONJ and ORN were analyzed using the chi-square test with the Pearson exact test. Results: Thirteen patients with MRONJ and 7 patients with ORN in the mandible showed low signal intensity on T1WI and ADC mapping, high signal intensity on STIR and DWI, and increased uptake on scintigraphy. Periosteal bone proliferation on CT was observed in 69.2% of patients with MRONJ(9 of 13) versus 14.3% of patients with ORN(1 of 7)(P=0.019). Conclusion: This study presented characteristic imaging findings of MRONJ and ORN on scintigraphy, CT, and MR imaging. Our results suggest that CT can be effective for detecting MRONJ and ORN.

Calculation of an Indicator for Early Death Using Atomic Bomb Survivors' Data

  • Sasaki, Michiya;Fujimichi, Yuki;Yoshida, Kazuo;Iwasaki, Toshiyasu
    • Journal of Radiation Protection and Research
    • /
    • v.47 no.1
    • /
    • pp.22-29
    • /
    • 2022
  • Background: A comprehensive, traceable, and easy-to-understand radiation risk indicator is desired for radiological protection. The early-onset hypothesis could be used for this purpose. Materials and Methods: An indicator for early death (IED) was developed and calculated using the epidemiological dataset from the 14th Report of the Life Span Study (LSS) of Hiroshima and Nagasaki. By clarifying the calculation process, IED for all-cause mortality was estimated. In addition, the characteristics of IED for solid cancer mortality and cardiovascular mortality as well as those of men and women, and their dependence on age at exposure were investigated for detailed analysis. Results and Discussion: The IED for all-cause mortality was estimated to be approximately 4 years for an acute radiation exposure of 1 Gy regardless of the fitting dose range. The cumulative death rate for all solid cancers also indicated the early-death tendency (approximately 7-10 years at 1 Gy). Although, there is a slight difference in the characteristics of the risk obtained from the LSS study and this study, it is considered that the IED in a unit of years can also be used to show the overall picture of risk due to radiation exposure. Conclusion: We developed and calculated the indicator for early death, IED, for the cumulative mortality rate of all causes of death, all solid cancers, and circulatory diseases. The quantitative values of IED were estimated to be 4 years for all causes of death, 7-10 years for all solid cancers. IED has an advantage for intuitively understanding the meaning of radiation risk since it can be obtained by a simple and traceable method.

Leek Yellow Stripe Virus Can Adjust for Host Adaptation by Trimming the N-Terminal Domain to Allow the P1 Protein to Function as an RNA Silencing Suppressor

  • Sasaki, Jun;Kawakubo, Shusuke;Kim, Hangil;Kim, Ok-Kyung;Yamashita, Kazuo;Shimura, Hanako;Masuta, Chikara
    • The Plant Pathology Journal
    • /
    • v.38 no.4
    • /
    • pp.383-394
    • /
    • 2022
  • In Japan, the P1 protein (S-type) encoded by leek yellow stripe virus (LYSV) isolates detected in Honshu and southward is shorter than the P1 (N-type) of LYSV isolates from garlic grown in Hokkaido due to a large deletion in the N-terminal half. In garlic fields in Hokkaido, two types of LYSV isolate with N- and S-type P1s are sometimes found in mixed infections. In this study, we confirmed that N- and S-type P1 sequences were present in the same plant and that they belong to different evolutionary phylogenetic groups. To investigate how LYSV with S-type P1 (LYSV-S) could have invaded LYSV with N-type P1 (LYSV-N)-infected garlic, we examined wild Allium spp. plants in Hokkaido and found that LYSV was almost undetectable. On the other hand, in Honshu, LYSV-S was detected at a high frequency in Allium spp. other than garlic, suggesting that the LYSV-S can infect a wider host range of Allium spp. compared to LYSV-N. Because P1 proteins of potyviruses have been reported to promote RNA silencing suppressor (RSS) activity of HC-Pro proteins, we analyzed whether the same was true for P1 of LYSV. In onion, contrary to expectation, the P1 protein itself had RSS activity. Moreover, the RSS activity of S-type P1 was considerably stronger than that of N-type P1, suggesting that LYSV P1 may be able to enhance its RSS activity when the deletion is in the N-terminal half and that acquiring S-type P1 may have enabled LYSV to expand its host range.

Ursolic acid improves the indoxyl sulfate-induced impairment of mitochondrial biogenesis in C2C12 cells

  • Sasaki, Yutaro;Kojima-Yuasa, Akiko;Tadano, Hinako;Mizuno, Ayaka;Kon, Atsushi;Norikura, Toshio
    • Nutrition Research and Practice
    • /
    • v.16 no.2
    • /
    • pp.147-160
    • /
    • 2022
  • BACKGROUND/OBJECTIVES: Patients with chronic kidney disease (CKD) have a high concentration of uremic toxins in their blood and often experience muscle atrophy. Indoxyl sulfate (IS) is a uremic toxin produced by tryptophan metabolism. Although an elevated IS level may induce muscle dysfunction, the effect of IS on physiological concentration has not been elucidated. Additionally, the effects of ursolic acid (UA) on muscle hypertrophy have been reported in healthy models; however, it is unclear whether UA ameliorates muscle dysfunction associated with chronic diseases, such as CKD. Thus, this study aimed to investigate whether UA can improve the IS-induced impairment of mitochondrial biogenesis. MATERIALS/METHODS: C2C12 cells were incubated with or without IS (0.1 mM) and UA (1 or 2 μM) to elucidate the physiological effect of UA on CKD-related mitochondrial dysfunction and its related mechanisms using real-time reverse transcription-polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay. RESULTS: IS suppressed the expression of differentiation marker genes without decreasing cell viability. IS decreased the mitochondrial DNA copy number and ATP levels by downregulating the genes pertaining to mitochondrial biogenesis (Ppargc1a, Nrf1, Tfam, Sirt1, and Mef2c), fusion (Mfn1 and Mfn2), oxidative phosphorylation (Cycs and Atp5b), and fatty acid oxidation (Pdk4, Acadm, Cpt1b, and Cd36). Furthermore, IS increased the intracellular mRNA and secretory protein levels of interleukin (IL)-6. Finally, UA ameliorated the IS-induced impairment in C2C12 cells. CONCLUSIONS: Our results indicated that UA improves the IS-induced impairment of mitochondrial biogenesis by affecting differentiation, ATP levels, and IL-6 secretion in C2C12 cells. Therefore, UA could be a novel therapeutic agent for CKD-induced muscle dysfunction.

Phase analysis of simulated nuclear fuel debris synthesized using UO2, Zr, and stainless steel and leaching behavior of the fission products and matrix elements

  • Ryutaro Tonna;Takayuki Sasaki;Yuji Kodama;Taishi Kobayashi;Daisuke Akiyama;Akira Kirishima;Nobuaki Sato;Yuta Kumagai;Ryoji Kusaka;Masayuki Watanabe
    • Nuclear Engineering and Technology
    • /
    • v.55 no.4
    • /
    • pp.1300-1309
    • /
    • 2023
  • Simulated debris was synthesized using UO2, Zr, and stainless steel and a heat treatment method under inert or oxidizing conditions. The primary U solid phase of the debris synthesized at 1473 K under inert conditions was UO2, whereas a (U, Zr)O2 solid solution formed at 1873 K. Under oxidizing conditions, a mixture of U3O8 and (Fe, Cr)UO4 phases formed at 1473 K, whereas a (U, Zr)O2+x solid solution formed at 1873 K. The leaching behavior of the fission products from the simulated debris was evaluated using two methods: the irradiation method, for which fission products were produced via neutron irradiation, and the doping method, for which trace amounts of non-radioactive elements were doped into the debris. The dissolution behavior of U depended on the properties of the debris and aqueous solution for immersion. Cs, Sr, and Ba leached out regardless of the primary solid phases. The leaching of high-valence Eu and Ru ions was suppressed, possibly owing to their solid-solution reaction with or incorporation into the uranium compounds of the simulated debris.

SUMRAY: R and Python Codes for Calculating Cancer Risk Due to Radiation Exposure of a Population

  • Michiya Sasaki;Kyoji Furukawa;Daiki Satoh;Kazumasa Shimada;Shin'ichi Kudo;Shunji Takagi;Shogo Takahara;Michiaki Kai
    • Journal of Radiation Protection and Research
    • /
    • v.48 no.2
    • /
    • pp.90-99
    • /
    • 2023
  • Background: Quantitative risk assessments should be accompanied by uncertainty analyses of the risk models employed in the calculations. In this study, we aim to develop a computational code named SUMRAY for use in cancer risk projections from radiation exposure taking into account uncertainties. We also aim to make SUMRAY publicly available as a resource for further improvement of risk projection. Materials and Methods: SUMRAY has two versions of code written in R and Python. The risk models used in SUMRAY for all-solid-cancer mortality and incidence were those published in the Life Span Study of a cohort of the atomic bomb survivors in Hiroshima and Nagasaki. The confidence intervals associated with the evaluated risks were derived by propagating the statistical uncertainties in the risk model parameter estimates by the Monte Carlo method. Results and Discussion: SUMRAY was used to calculate the lifetime or time-integrated attributable risks of cancer under an exposure scenario (baseline rates, dose[s], age[s] at exposure, age at the end of follow-up, sex) specified by the user. The results were compared with those calculated using another well-known web-based tool, Radiation Risk Assessment Tool (RadRAT; National Institutes of Health), and showed a reasonable agreement within the estimated confidential interval. Compared with RadRAT, SUMRAY can be used for a wide range of applications, as it allows the risk projection with arbitrarily specified risk models and/or population reference data. Conclusion: The reliabilities of SUMRAY with the present risk-model parameters and their variance-covariance matrices were verified by comparing them with those of the other codes. The SUMRAY code is distributed to the public as an open-source code under the Massachusetts Institute of Technology license.

Covered self-expandable metallic stents versus plastic stents for endoscopic ultrasound-guided hepaticogastrostomy in patients with malignant biliary obstruction

  • Taro Shibuki;Kei Okumura;Masanari Sekine;Ikuhiro Kobori;Aki Miyagaki;Yoshihiro Sasaki;Yuichi Takano;Yusuke Hashimoto
    • Clinical Endoscopy
    • /
    • v.56 no.6
    • /
    • pp.802-811
    • /
    • 2023
  • Background/Aims: Covered self-expandable metallic stents (cSEMS) have become popular for endoscopic ultrasound-guided hepaticogastrostomy with transmural stenting (EUS-HGS). We compared the time to recurrent biliary obstruction (TRBO), complications, and reintervention rates between EUS-HGS using plastic stent (PS) and cSEMS in patients with unresectable malignancies at multicenter institutions in Japan. Methods: Patients with unresectable malignant biliary obstruction who underwent EUS-HGS between April 2015 and July 2020 at any of the six participating facilities were enrolled. Primary endpoint: TRBO; secondary endpoints: rate of complications other than recurrent biliary obstruction and technical success rate of reintervention were evaluated. Results: PS and cSEMS were used for EUS-HGS in 109 and 43 patients, respectively. The TRBO was significantly longer in the cSEMS group than in the PS group (646 vs. 202 days). Multivariate analysis identified two independent factors associated with a favorable TRBO: combined EUS-guided antegrade stenting with EUS-HGS and the use of cSEMS. No significant difference was observed in the rate of complications other than recurrent biliary obstruction between the two groups. The technical success rate of reintervention was 85.7% for PS and 100% for cSEMS (p=0.309). Conclusions: cSEMS might be a better option for EUS-HGS in patients with unresectable malignancies, given the longer TRBO.

Evaluation of the mechanical properties of current biliary selfexpandable metallic stents: axial and radial force, and axial force zero border

  • Wataru Yamagata;Toshio Fujisawa;Takashi Sasaki;Rei Ishibashi;Tomotaka Saito;Shuntaro Yoshida;Shizuka No;Kouta Inoue;Yousuke Nakai;Naoki Sasahira;Hiroyuki Isayama
    • Clinical Endoscopy
    • /
    • v.56 no.5
    • /
    • pp.633-649
    • /
    • 2023
  • Background/Aims: Mechanical properties (MPs) and axial and radial force (AF and RF) may influence the efficacy and complications of self-expandable metallic stent (SEMS) placement. We measured the MPs of various SEMSs and examined their influence on the SEMS clinical ability. Methods: We evaluated the MPs of 29 types of 10-mm SEMSs. RF was measured using a conventional measurement device. AF was measured using the conventional and new methods, and the correlation between the methods was evaluated. Results: A high correlation in AFs was observed, as measured by the new and conventional manual methods. AF and RF scatterplots divided the SEMSs into three subgroups according to structure: hook-and-cross-type (low AF and RF), cross-type (high AF and low RF), and laser-cut-type (intermediate AF and high RF). The hook-and-cross-type had the largest axial force zero border (>20°), followed by the laser-cut and cross types. Conclusions: MPs were related to stent structure. Hook-and-cross-type SEMSs had a low AF and high axial force zero border and were considered safest because they caused minimal stress on the biliary wall. However, the increase in RF must be overcome.

In vivo Antifungal Activity of Pyrrolnitrin Isolated from Burkholderia capacia EB215 with Antagonistic Activity Towards Colletotrichum Species (탄저병균에 대하여 길항작용을 보이는 Burkholderia cepacia EB215로부터 분리한 Pyrrolnitrin의 항균활성)

  • Park, Ji-Hyun;Choi, Gyung-Ja;Lee, Seon-Woo;Jang, Kyoung-Soo;Choi, Yong-Ho;Chung, Young-Ryun;Cho, Kwang-Yun;Kim, Jin-Cheol
    • The Korean Journal of Mycology
    • /
    • v.32 no.1
    • /
    • pp.31-38
    • /
    • 2004
  • An endophytic bacterial strain EB215 that was isolated from cucumber (Cucumis sativus) roots displayed a potent in vivo antifungal activity against Colletotrichum species. The strain was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, and 16S rDNA gene sequence. Optimal medium and incubation period for the production of antifungal substances by B. cepacia EB215 were nutrient broth (NB) and 3 days, respectively. An antifungal substance was isolated from the NB cultures of B. cepacia EB215 strain by centrifugation, n-hexane partitioning, silica gel column chromatography, preparative TLC, and in vitro bioassay. Its chemical structure was determined to be pyrrolnitrin by mass and NMR spectral analyses. Pyrrolnitrin showed potent disease control efficacy of more than 90% against pepper anthracnose (Colletotrichum coccodes), cucumber anthracnose (Colletotrichum orbiculare), rice blast (Magnaporthe grisea) and rice sheath blight (Corticium sasaki) even at a low concentration of $11.1\;{\mu}g/ml$. In addition, it effectively controlled the development of tomato gray mold (Botrytis cinerea) and wheat leaf rust (Puccinia recondita) at concentrations over $33.3\;{\mu}g/ml$. However, it had no antifungal activity against Phytophthora infestans on tomato plants. Further studies on the development of microbial fungicide using B. cepacia EB215 are in progress.