• Title/Summary/Keyword: Radiation biology

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High Performance of Temperature Gradient Chamber Newly Built for Studying Global Warming Effect on a Plant Population

  • Lee, Jae-Seok;Tetsuyuki Usami;Takehisa Oikawa;Lee, Ho-Joon
    • The Korean Journal of Ecology
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    • v.23 no.4
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    • pp.293-298
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    • 2000
  • To study the effect of global warming on the growth of plants and plant populations throughout their life cycle under a field-like condition, we constructed a Temperature Gradient Chamber (TGC) in Tsukuba, Japan. The chamber had slender shape : 30 m long. 3 m wide, and 2.5 m high. That satisfactory performance was confirmed by a test throughout all seasons in 1998: the projected global warming condition in the near future was simulated. That is, independent of a great daily or seasonal change in ambient meteorological conditions, air temperatures at the air outlet were warmed 5$^{\circ}C$ higher than those at the ambient (the annual mean was 14.3$^{\circ}C$) with precision of ${\pm}$0.2$^{\circ}C$ (the annual means were 19.2$^{\circ}C$) with a rising rate of approximately 1$^{\circ}C$ every 5 m. This chamber will enable us to study the effects of global warming on growth of plants and plant populations because their abilities to control air temperature are excellent. TGC is expected that it would be utilized for studying the effect of global warming on plant growth under natural weather conditions.

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The hepatocyte growth factor/c-Met signaling pathway as a therapeutic target to inhibit angiogenesis

  • You, Weon-Kyoo;McDonald, Donald M.
    • BMB Reports
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    • v.41 no.12
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    • pp.833-839
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    • 2008
  • Angiogenesis in tumors is driven by multiple growth factors that activate receptor tyrosine kinases. An important driving force of angiogenesis in solid tumors is signaling through vascular endothelial growth factor (VEGF) and its receptors (VEGFRs). Angiogenesis inhibitors that target this signaling pathway are now in widespread use for the treatment of cancer. However, when used alone, inhibitors of VEGF/VEGFR signaling do not destroy all blood vessels in tumors and do not slow the growth of most human cancers. VEGF/VEGFR signaling inhibitors are, therefore, used in combination with chemotherapeutic agents or radiation therapy. Additional targets for inhibiting angiogenesis would be useful for more efficacious treatment of cancer. One promising target is the signaling pathway of hepatocyte growth factor (HGF) and its receptor (HGFR, also known as c-Met), which plays important roles in angiogenesis and tumor growth. Inhibitors of this signaling pathway have been shown to inhibit angiogenesis in multiple in vitro and in vivo models. The HGF/c-Met signaling pathway is now recognized as a promising target in cancer by inhibiting angiogenesis, tumor growth, invasion, and metastasis.

BREEDING EXPERIMENT ON MUTATION INDUCTION BY IRRADIATION (2) Effects of X-ray and Thermal Neutron Irradiation on Dry Seeds of Chinese Cabbage and Radish.

  • Kim, Dawng Woo;Kim, Yang Choon;Cho, Mi Kyung
    • Journal of Plant Biology
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    • v.5 no.1
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    • pp.1-6
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    • 1962
  • 1) Germination rate was rather irregular than decreasing as increasing dose of radiation and there were no differences between Kyong-Sam and Chuong-Bang of Chinese cabbage. 2) In R1 generation, abnormal leaves from seedling of irradiated seeds were observed. These were more apparent in X-ray irradiation than in thermal neutron. 3) Seedling height was inhibited with increasing dose of X-ray and thermal neutrons. Growth inhibition was more remarkable in X-ray than in thermal neutron. Kyong-Sam demonstrated more sensitivity than Chyong-Bang in both X-ray and thermal neutron. 4) Seedling height produced from seeds subjected to thermal neutrons showed small variation around its mean value, while in X-irradiation there was a greater deviaton from the mean value. 5) Fertility was decreased as increasing with dose, while the frequency of abortive pollen was increased. There were variability of the fertility and frequency of abortive pollen among plants or branches of a plant. 6) The mutants were obtained more in thermal neutron irradiation than in X-ray. The types of mutations obtained in Chinese radish of R2 generation were abnormal leaf, densely glowing leaf, degeneration in growing point and dwarf. The maximum frequency of phenotypic mutations was abnormal leaf mutation.

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A Study on Dosimetric Characterization of Direct Yellow 12 Dye at High Radiation γ-Dose

  • Batool, Javaria;Shahid, Shaukat Ali;Ramiza, Ramiza;Akhtar, Nasim;Naz, Afshan;Yaseen, Maria;Ullah, Inam;Nadeem, Muhammad;Shakir, Imran
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2265-2268
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    • 2012
  • Aqueous solution of oxygenated Direct yellow 12 dye has been evaluated spectrophotometrically as a possible gamma rays dosimeter. The neutral (pH-7), alkaline (pH-12.5) and acidic (pH-5.5) aqueous solution of the dye were prepared and exposed to various gamma doses. Absorption spectra of unirradiated and irradiated solutions were recorded at 400 nm peak. The increase in absorbance with the increase in irradiation dose was observed from 1 to 6 kGy. The stability response of the dye solution for different environmental conditions such as temperature (low & high), light and darkness were investigated during post irradiation storage for ten days. The dye solution showed high stability in darkness for the studied period. The optical density of the dye solution was found to be decreased at high temperature storage.

The trinity of ribosome-associated quality control and stress signaling for proteostasis and neuronal physiology

  • Park, Jumin;Park, Jongmin;Lee, Jongbin;Lim, Chunghun
    • BMB Reports
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    • v.54 no.9
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    • pp.439-450
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    • 2021
  • Translating ribosomes accompany co-translational regulation of nascent polypeptide chains, including subcellular targeting, protein folding, and covalent modifications. Ribosome-associated quality control (RQC) is a co-translational surveillance mechanism triggered by ribosomal collisions, an indication of atypical translation. The ribosome-associated E3 ligase ZNF598 ubiquitinates small subunit proteins at the stalled ribosomes. A series of RQC factors are then recruited to dissociate and triage aberrant translation intermediates. Regulatory ribosomal stalling may occur on endogenous transcripts for quality gene expression, whereas ribosomal collisions are more globally induced by ribotoxic stressors such as translation inhibitors, ribotoxins, and UV radiation. The latter are sensed by ribosome-associated kinases GCN2 and ZAKα, activating integrated stress response (ISR) and ribotoxic stress response (RSR), respectively. Hierarchical crosstalks among RQC, ISR, and RSR pathways are readily detectable since the collided ribosome is their common substrate for activation. Given the strong implications of RQC factors in neuronal physiology and neurological disorders, the interplay between RQC and ribosome-associated stress signaling may sustain proteostasis, adaptively determine cell fate, and contribute to neural pathogenesis. The elucidation of underlying molecular principles in relevant human diseases should thus provide unexplored therapeutic opportunities.

Crystallization and X-ray crystallographic analysis of the PH-like domain of lipid transfer protein anchored at membrane contact sites from Saccharomyces cerevisiae

  • Tong, Junsen;Im, Young Jun
    • Biodesign
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    • v.5 no.4
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    • pp.136-140
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    • 2017
  • Lam6 is a member of sterol-specific ${\underline{l}ipid$ transfer proteins ${\underline{a}}nchored$ at ${\underline{m}ebrane$ contact sites (LAMs). Lam6 localizes to the ER-mitochondria contact sites by its PH-like domain and the C-terminal transmembrane helix. Here, we purified and crystallized the Lam6 PH-like domain from Saccharomyces cerevisiae. To aid crystallization of the Lam6 PH-like domain, T4 lysozyme was fused to the N-terminus of the Lam6 PH-like domain with a short dipeptide linker, GlySer. The fusion protein was crystallized under the condition of 0.1 M HEPES-HCl pH 7.0, 10% (w/v) PEG 8000, and 0.1 M $Na_3$ Citrate at 293K. X-ray diffraction data of the crystals were collected to $2.4{\AA}$ resolution using synchrotron radiation. The crystals belong to the orthorhombic space group $P2_12_12_1$ with unit cell parameters $a=59.5{\AA}$, $b=60.1{\AA}$, and $c=105.6{\AA}$. The asymmetric unit contains one T4L-Lam6 molecule with a solvent content of 58.7%. The initial attempt to solve the structure by molecular replacement using the T4 lysozyme structure was successful.

Draft genome sequence of Streptococcus sp. strain NM isolated from head and neck cancer patients (두경부암 환자로부터 분리된 Streptococcus sp. strain NM의 유전체분석)

  • Kim, Young Suk;Do, Kyoung-Tag;Park, Soo-Je
    • Korean Journal of Microbiology
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    • v.55 no.1
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    • pp.61-63
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    • 2019
  • Streptococcus sp. strain NM belonging to Firmicutes was isolated from head and neck cancer patients. Here, we report the draft genome sequence of strain NM with a size of approximately 1.90 Mbp and a mean G+C content of 39.3%. The draft genome included 1,845 coding sequences, and 12 ribosomal RNA and 58 transfer RNA genes. In the draft genome, genes involved in the antimicrobial resistance, hemolysis and defense system have been identified.

BK Channel Deficiency in Osteoblasts Reduces Bone Formation via the Wnt/β-Catenin Pathway

  • Jiang, Lan;Yang, Qianhong;Gao, Jianjun;Yang, Jiahong;He, Jiaqi;Xin, Hong;Zhang, Xuemei
    • Molecules and Cells
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    • v.44 no.8
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    • pp.557-568
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    • 2021
  • Global knockout of the BK channel has been proven to affect bone formation; however, whether it directly affects osteoblast differentiation and the mechanism are elusive. In the current study, we further investigated the role of BK channels in bone development and explored whether BK channels impacted the differentiation and proliferation of osteoblasts via the canonical Wnt signaling pathway. Our findings demonstrated that knockout of Kcnma1 disrupted the osteogenesis of osteoblasts and inhibited the stabilization of β-catenin. Western blot analysis showed that the protein levels of Axin1 and USP7 increased when Kcnma1 was deficient. Together, this study confirmed that BK ablation decreased bone mass via the Wnt/β-catenin signaling pathway. Our findings also showed that USP7 might have the ability to stabilize the activity of Axin1, which would increase the degradation of β-catenin in osteoblasts.

Effect of Salicylic Acid Formulations on Induced Plant Defense against Cassava Anthracnose Disease

  • Sangpueak, Rungthip;Phansak, Piyaporn;Thumanu, Kanjana;Siriwong, Supatcharee;Wongkaew, Sopone;Buensanteai, Natthiya
    • The Plant Pathology Journal
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    • v.37 no.4
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    • pp.356-364
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    • 2021
  • This study was to investigate defense mechanisms on cassava induced by salicylic acid formulation (SA) against anthracnose disease. Our results indicated that the SA could reduce anthracnose severity in cassava plants up to 33.3% under the greenhouse condition. The 𝛽-1,3-glucanase and chitinase enzyme activities were significantly increased at 24 hours after inoculation (HAI) and decrease at 48 HAI after Colletotrichum gloeosporioides challenge inoculation, respectively, for cassava treated with SA formulation. Synchrotron radiation-based Fourier-transform infrared microspectroscopy spectra revealed changes of the C=H stretching vibration (3,000-2,800 cm-1), pectin (1,740-1,700 cm-1), amide I protein (1,700-1,600 cm-1), amide II protein (1,600-1,500 cm-1), lignin (1,515 cm-1) as well as mainly C-O-C of polysaccharides (1,300-1,100 cm-1) in the leaf epidermal and mesophyll tissues treated with SA formulations, compared to those treated with fungicide carbendazim and distilled water after the challenged inoculation with C. gloeosporioides. The results indicate that biochemical changes in cassava leaf treated with SA played an important role in the enhancement of structural and chemical defense mechanisms leading to reduced anthracnose severity.

Z-DNA-Containing Long Terminal Repeats of Human Endogenous Retrovirus Families Provide Alternative Promoters for Human Functional Genes

  • Lee, Du Hyeong;Bae, Woo Hyeon;Ha, Hongseok;Park, Eun Gyung;Lee, Yun Ju;Kim, Woo Ryung;Kim, Heui-Soo
    • Molecules and Cells
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    • v.45 no.8
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    • pp.522-530
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    • 2022
  • Transposable elements (TEs) account for approximately 45% of the human genome. TEs have proliferated randomly and integrated into functional genes during hominoid radiation. They appear as right-handed B-DNA double helices and slightly elongated left-handed Z-DNAs. Human endogenous retrovirus (HERV) families are widely distributed in human chromosomes at a ratio of 8%. They contain a 5'-long terminal repeat (LTR)-gag-pol-env-3'-LTR structure. LTRs contain the U3 enhancer and promoter region, transcribed R region, and U5 region. LTRs can influence host gene expression by acting as regulatory elements. In this review, we describe the alternative promoters derived from LTR elements that overlap Z-DNA by comparing Z-hunt and DeepZ data for human functional genes. We also present evidence showing the regulatory activity of LTR elements containing Z-DNA in GSDML. Taken together, the regulatory activity of LTR elements with Z-DNA allows us to understand gene function in relation to various human diseases.