• Title/Summary/Keyword: Comet

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Studies on DNA Single Strand Break of Seven Phthalate Analogues in Mouse Lymphoma L5178Y Cells

  • Ryu, Jae-Chun;Kim, Hyung-Tae;Kim, Youn-Jung
    • Environmental Mutagens and Carcinogens
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    • v.22 no.3
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    • pp.164-168
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    • 2002
  • Phthalate analogues are a plasticizer and solvent used in industry and were reported to be a potential carcinogen classified in the category of suspected endocrine disruptors. Most common human exposure to these compounds may occur with contaminated food. They may migrate into food from plastic wrap or may enter food from general environmental contamination. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of phthalates that possibly threaten the public health. To determine whether seven phthalate analogues i.e. diallyl phthalate, diisodecyl phthalate, di-n-nonyl phthalate, butyl benzyl phthalate, di-n-octyl phthalate, di-tridecyl phthalate, and dibutyl phthalate, can induce DNA strand breakage that is one of the various factors related to the mechanism of carcinogenicity, the comet assay which has been widely used for the detection and measurement of DNA strand breaks, was conducted in L5178Y mouse lymphoma cells. From these results, seven phthalates revealed dose-dependent decrease of cell viability, however, no remarkable cytotoxicity was observed even at high concentration of 100 $\mu\textrm{g}$/$m\ell$ phthalates. And also, the results showed that the induction of DNA strand breaks by seven phthalates was not significantly different from the control in this study.

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Effects of Pomegranate Peel (Granati pericarpium) Extracts on the Antioxidant Biomarkers in C57BL/6J Mice Fed a High Fat and Cholesterol Diet (석류 껍질 추출물이 고지방 고콜레스레롤 식이 급여 C57BL/6J 마우스의 항산화 지표 및 DNA 보호에 미치는 영향)

  • Oh Sang-Hee;Yang Yun-Hyoung;Sok Dai-Eun;Kim Mee-Ree
    • Journal of the East Asian Society of Dietary Life
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    • v.16 no.4
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    • pp.414-420
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    • 2006
  • The present study evaluated the effects of pomegranate peel (Granati pericarpium) extract on the lipid profiles and antioxidant biomarkers in mice fed a high fat and cholesterol diet: the measured biomarkers included the TBARS value, GPx, GR, SOD and GST activities. Body fat depositions were significantly decreased in the group that received pomegranate peel. In addition, the activities of GPx, GST and SOD were significantly higher in the liver and plasma of the pomegranate peel group than in the control group. Also, the pomegranate peel diet decreased lipid peroxidation of the liver and kidney. Alkaline single-cell gel electrophoresis (comet assay) showed that the DNA damage in the plasma of the pomegranate peel group was decreased compared to that of control. The present results show that a diet with added pomegranate peel exerts protective effects against oxidative DNA damage and lipid peroxidation possibly via effects on the free radical levels in mice fed a high fat and cholesterol diet.

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Effects of Diet with Added Butterbur (Petasites japonicus Maxim) on the Plasma Lipid Profiles and Antioxidant Index of Mice (머위(Petasites japonicus Maxim) 첨가 식이가 마우스 혈장 지질 수준 및 항산화 지표에 미치는 영향)

  • Oh Sang-Hee;Yang Yun-Hyung;Kwon Oh-Yoon;Kim Mee-Ree
    • Journal of the East Asian Society of Dietary Life
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    • v.16 no.4
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    • pp.399-407
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    • 2006
  • We evaluated the effects of butterbur (Petasites japonicus Maxim) addition to the diet on lipid profiles and antioxidant biomarkers such as total glutathionine, TBARS value, carbonyl value, GPx, GR, SOD and paraoxonase activity in the plasma or liver of mice. The distribution of body fat deposition, total cholesterol (TC) contents, and atherogenic index in the plasma were significantly decreased in the butterbur group. The levels of GSH and the activity of GR and SOD were significantly higher in the liver of the butterbur group than in that of the control group. Lipid oxidation of the liver and kidney and protein oxidation of the liver and heart were decreased in the butterbur group. Additionally, the DNA damage, as determined using the comet assay (single cell gel assay) with alkaline electrophoresis and as quantified by measuring the tail length (TL), was decreased in the butterbur group. The results of the present study showed that a diet with added butterbur exerts degenerative disease-protective effects on oxidative DNA damage and lipid peroxidation.

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Hyperthermia-induced Apoptosis is Independent upon DNA Strand Breaks in Human Lymphoid Cells

  • Jung, Hwa-Jin;Ka, Won-Hye;Hwang, Jee-Na;Seo, Young-Rok
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.6
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    • pp.345-349
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    • 2004
  • Heat shock ($43^{\circ}C$ for 60 minutes) is sufficient to induce apoptosis in a wide number of cell lines. In this study, we asked whether DNA strand breaks are responsible for this phenomenon. Using the highly sensitive comet assay for DNA damage detection, we were unable to demonstrate DNA breaks immediately after heat shock in Raji human Iymphoid cells. It showed that DNA breaks were not necessary for hyperthermic apoptosis, since its activity is indicative of DNA lesions. Here, we present a suggestion that a protein(s) is the major target for heat shock apoptosis. We firstly found glycerol, which reportedly stabilizes protein structure, showed a protective effect in Raji cells against hyperthermic apoptosis. In addition, quercetin, which modulates transcription of the heat shock protein family members, enhanced apoptotic death induced by hyperthermia. Furthermore, Raji cells are protected by a pre-mild heat treatment prior to the killing dose of heat shock.

Antioxidant Activity of Extracts from Akebia quinata Decne

  • Rim, A-Ram;Kim, Sun-Jung;Jeon, Kyung-Im;Park, Eun-Ju;Park, Hae-Ryong;Lee, Seung-Cheol
    • Preventive Nutrition and Food Science
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    • v.11 no.1
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    • pp.84-87
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    • 2006
  • Antioxidant activity of Akebia quinata Decne was evaluated. Water extract (0.5 g/50 mL) of flowers and leaves of A. quinata were prepared and total phenol contents and radical scavenging activity of the extracts was determined for antioxidant activity. The total phenol contents of extracts from A. quinata flowers (FAQ) and leaves (LAQ) were $30.05{\mu}M\;and\;20.23{\mu}M$, while the radical scavenging activity of FAQ and LAQ were 60.51 % and 52.97%, respectively. In addition, the effect of FAQ and LAQ extract on DNA damage induced by $H_2O_2$ in human lymphocytes was evaluated by comet assay. The FAQ and LAQ showed strong inhibitory effect against DNA damage induced by $200{\mu}M$ of $H_2O_2$. These results suggest that water extracts of A. quinata Decne flowers and leaves showed significant (p<0.05) antioxidant activity and protective effect against oxidative DNA damage.

Protection against Whole Body γ-Irradiation Induced Oxidative Stress and Clastogenic Damage in Mice by Ginger Essential Oil

  • Jeena, Kottarapat;Liju, Vijayasteltar B;Ramanath, Viswanathan;Kuttan, Ramadasan
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1325-1332
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    • 2016
  • Radioprotective effects of ginger essential oil (GEO) on mortality, body weight alteration, hematological parameters, antioxidant status and chromosomal damage were studied in irradiated mice. Regression analysis of survival data in mice exposed to radiation yielded LD50/30 as 7.12 and 10.14 Gy for control (irradiation alone) and experimental (GEO-treated irradiated) mice, respectively, with a dose reduction factor (DRF) of 1.42. In mice exposed to whole-body gamma-irradiation (6 Gy), GEO pre-treatment at 100 and 500 mg/kg b.wt (orally) significantly ameliorated decreased hematological and immunological parameters. Radiation induced reduction in intestinal tissue antioxidant enzyme levels such as superoxide dismutase, catalase, glutathione peroxidase and glutathione was also reversed following administration of GEO. Tissue architecture of small intestine which was damaged following irradiation was improved upon administration of GEO. Anticlastogenic effects of GEO were studied by micronuclei assay, chromosomal aberration and alkaline gel electrophoresis assay. GEO significantly decreased the formation of micronuclei, increased the P/N ratio, inhibited the formation of chromosomal aberrations and protected agaisnt cellular DNA damage in bone marrow cells as revealed by comet assay. These results are supportive of use of GEO as a potential radioprotective compound.

Combined Genotoxic Effects of Aflatoxin B1, Ochratoxin A and Zearalenone in Rat Bone Marrow and Blood Leukocytes

  • Tigran, Harutyunyan;Anna, Karapetyan;Galina, Hovhannisyan;Rouben, Aroutiounian
    • Korean Journal of Environmental Biology
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    • v.31 no.3
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    • pp.189-191
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    • 2013
  • Mycotoxins such as aflatoxin B1 (AFB1), ochratoxin A (OTA) and zearalenone (ZEA) are widespread contaminants of food and feedstuffs. It is very likely, that humans and animals are always exposed to mixtures of mycotoxins rather than to individual compounds. Therefore, risk assessments should consider mixture toxicity data. In the present study the combination of AFB1, OTA and ZEA was tested for genotoxicity in rat bone marrow and blood leukocytes after 15, 30 and 60 days treatment. The level of DNA damage was determined by the comet assay. The tail intensity and Olive tail moment in leukocytes and bone marrow cells were significantly higher than in controls. At the same time, the level of DNA damage in bone marrow cells was higher than in leukocytes. The data suggests that prolonged exposure to mycotoxins combination through food consumption can induce DNA damage contributing to the harmful effects in vivo.

Small-scale structures in the dust cloud associated with 17P/Holmes outburst

  • Ham, Ji-Beom;Ishiguro, Masateru;Kuroda, Daisuke;Fukushima, Hideo;Watanabe, Jun-Ichi
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.92-92
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    • 2010
  • A short-period comet, 17P/Holmes, is one of the most outstanding comets because of the outburs in 2007. It orbits the sun at the distance between 2.1AU and 5.2 AU with the orbital period of 6.9 year. On 2007 October 23, its brightness was suddenly increased by about a million times from 17 mag to 2.5 mag. We made observations of 17P/Holmes soon after the outburst on October 25, 27 and 28, using a 105cm telescope at the Ishigakijima Astronomical observatory, Japan. We took the images with V, R and I-band filters simultaneously. Total exposure times are 15 (October 25), 69 (October 27), and 37 (October 28) minute in each filter. The composite images provide good signal to noise ratio and help us to recognize faint structures embedded in the dust cloud. We examined a sequence of images using a digital filter that enhances the small-scale structures. As the result of the data analysis, we confirm (1) the radial expanded structure coming out from the nucleus of comet, and (2) dozens of blobs that moved radially away from the nucleus. In this presentation, we introduce the observations and the data reductions, and consider the origins of these fine structure.

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Photometric Observation of the Asteroid-Comet Transition Object 4015 Wilson-Harrington

  • Kim, Myung-Jin;Choi, Young-Jun;Byun, Yong-Ik
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.87.2-87.2
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    • 2010
  • Near-Earth asteroid-comet transition object 4015 Wilson-Harrington is a possible target of the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) Marco Polo sample return mission. 4015 W-H was discovered showing cometary activity by Albert G. Wilson and Robert G. Harrington at Palomar Observatory in 1949. After recovered in 1979, 4015 W-H has been observed at every apparition, it always was seen as a point source. We made time series observations for 4015 W-H using the 1.8m telescope with 2K CCD at Bohyunsan Observatory, on the nights of 2009 November 17-19. The geocentric distance of 4015 H-W was about 0.38 AU at that time. No trace of cometary activity is seen from our images. From the light curve analysis, we find a double-peaked rotational period of 2.2 hours with amplitude of 0.4 magnitude. Our result is much shorter than previous measurements of 3.6 hours (Harris & Young 1983) and 6.1 hours (Osip et al 1995). We will discuss possible origin of the period variations.

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