• Title/Summary/Keyword: ionizing irradiation

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Browning end Color Characteristics in Mushrooms (Agaricus bisporus) As Influenced by ionizing Energy (버섯의 갈변 및 색도에 대한 전리에너지의 영향)

  • Kwon, Joong-Ho;Byun, Myung-Woo;Cho, Han-Ok
    • Korean Journal of Food Science and Technology
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    • v.22 no.5
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    • pp.509-513
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    • 1990
  • Browning and color characteristics of stored mushrooms (Agaricus bisporus)following ionizing irradiation were investigated in connection with quality deterioration. The phenolic compounds of stored mushrooms showed a gradual decreasing tendency, while extractable browning pigments apparently rose from around 3days of storage under the conditions of $9{\pm}1^{\circ}C,\;80{\pm}7%$ RH and packaging with a corrugated paper box wrapped up in PE. ${\gamma}-irradiation$ at 2 to 3 kGy resulted in a significant reduction of their changes. Immediately after treatment, irradiated mushrooms were more discolored, i.e. a lower Hunter L value and higher Hunter a and b values than control. However, the subsequent storage for 15 days resulted in a preventive influence of ionizing energy on mushroom discoloration. This beneficial effect of ionizing energy was somewhat higher in the pilei than in the stipes of mushrooms and was found to increase lineally with increasing doses up to 3 kGy.

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Structural Characteristics of Low Molecular Weight Laminarin Prepared by Ionizing Irradiation (이온화 방사선 조사에 의해 얻어진 저분자 laminarin의 분자구조 특성)

  • Choi, Jong-Il
    • Korean Chemical Engineering Research
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    • v.51 no.6
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    • pp.780-783
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    • 2013
  • Recently, it has been reported that low molecular weight laminarin had the enhanced biological activities. In this study, molecular structure of low molecular weight laminarin prepared by ionizing irradiation was studied. Low molecular weight laminarin samples of 13.5, 8.5, 7, and 6 kDa were obtained from 15 kDa laminarin by irradiation. From gel permeation chromatography data, low molecular weight laminarin was shown to have low polydispersity. To define the changes of functional groups in laminarin with different molecular weights, Fourier-transform infrared analysis was carried out. There was found no significant changes of functional groups in low molecular weight laminarin, except the increase of carbonyl group. The granular fissures from scanning electron microscopy showed the breakage of glycosidic bond in low molecular weight laminarin. These results could be utilized for the investigation of the enhanced biological activities of low molecular weight polysaccharides including laminarin.

Radioisotope Treatment for Benign Strictures of Non-vascular Luminal Organs (비혈관성 관강 장기의 양성 협착 질환의 방사성동위원소 치료)

  • Shin, Ji-Hoon
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.2
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    • pp.106-112
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    • 2006
  • Tissue hyperplasia is one of the most frequently encountered complications when self-expanding metallic stents are placed in benign non-vascular luminal organ strictures, thus causing restenosis of the lumen. The investigators postulated that ionizing irradiation could be applied to prevent restenosis caused by tissue hyperplasia in non-vascular luminal organs as it reduced coronary or peripheral arterial narrowing successfully. The authors combined $\beta$-irradiation using $^{188}Re-MAG_3$ solution with balloon dilation for animal and clinical studies because this new treatment approach had the advantages such as low penetration depth of $\beta$-ray, self-centering irradiation, and mechanical effect of balloon dilation over using $\gamma$-irradiation with afterloading devices in this article, the concept and mechanism of radioisotope balloon dilation, and animal and clinical studies using radioisotope balloon dilation are reviewed.

Protein Kinase C-$\beta$ Is Induced In Ionizing Irradiation Induced Pigmentation

  • Nelly Rubeiz;Park, Dee-Young;Barbara A. Gilchrest
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.209-212
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    • 2002
  • Cutaneous hyperpigmentation is a well-known consequence of both acute and chronic X-irradiation, although the molecular mechanisms involved are not well understood. Recently, protein kinase C-$\beta$ (PKC-$\beta$) was shown to activate tyrosinase, a key and the rate-limiting enzyme in melanogenesis [1]. In this study, we have investigated its role in mediating ionizing radiation-induced pigmentation by exposing cultured human melanocytes to X-irradiation. Increased tyrosinase activity after the 4 Gys exposure was observed within 48 hrs and total melanin content doubled after 7 days. Interestingly, tyrosinase mRNA level was not affected by X-irradiation. However, there was a 2-3 fold increase in PKC-$\beta$ mRNA after 48 hours of irradiation, coinciding with the increase in tyrosinase activity. This induction was not due to non-specific heat generated during the irradiation because when melanocytes were incubated at 4$0^{\circ}C$, there was no induction of PKC-$\beta$ mRNA. Taken together, these data suggest that X-irradiation induces cutaneous hyperpigmentation, at least in part, by up-regulating the level of PKC-$\beta$.

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Evaluation of apoptosis after ionizing radiation in feeding and starving rats

  • Lee, Jae-Hyun;Cho, Kyung-Ja;Hong, Seok-Il;Park, Min-Kyung
    • Korean Journal of Veterinary Pathology
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    • v.2 no.1
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    • pp.37-46
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    • 1998
  • It has been known that $\gamma$-irradiation usually induces cell death in regenerating stem cell in normal tissues like skin, intestine and hematopoietic organ. The experiment were carried out to evaluate the early response of radiation injury in radiosensitive and intermediate radiosensitive tissues in feeding and starving rats with the doses of 3.5 and 7.0 Gy. The results of the study showed that the histological phenomenon was apoptosis in the doses of the radiation as the early response of tissue injury. Apoptosis were showed organ-specific and cellular specific responses suggesting that the selection of apoptosis be exactly focused on highly renewal organs and cells. It was interesting that the rats starved for 72 hours prior to irradiation induced less apoptosis in liver than fed rats. As for cellular responses it appeared that apoptotic cells were mostly distributed in ductal or periportal cells in liver of feeding rats unlikely in liver of Starving rots which showed no difference in zonal distribution. In salivary gland apoptotic cells in fed rats were highly induced in intercalating and ductal cell population than in acinar cell population although unlikely in starved rats. This study showed the value of apoptosis using the detection system of TUNEL for evaluating cellular damage after radiation injury and the diminished effect of starvation on cell damage after ionizing irradiation.

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SOME EVIDENCE REGARDING REPAIRING, RECOVERY AND OVER-COMPENSATING PROCESSES DURING ONTOGENESIS, AFTERX-RAY-IRRADTATION OF BEAN SEEDS

  • Korosi, F.;Jezierska-Szabo, E.;Laszlo, P.;Felfoldi, J.
    • Korean Journal of Organic Agriculture
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    • v.3 no.1
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    • pp.11-22
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    • 1994
  • Exposing plant organs to high doses of ionizing irradiation, penetrating into the plant tis-sues and cells, along the track structure of particles, lesions, and sublesions are formed on the molecules and organelles. As a result, disorders in the growth and development as well as chlorophyll-deficiency symptoms occur. The time scale of their reparation, recovery and over compensation during ontogenesis, constitutes a question of high theoretical and practical importanced, with special regard to nuclear fallout. With an aim to model the “ut supra”stated phenomena, the seeds of bean, Echo elit licensed variety, were irradiated by 300 Gy dose of X-ray-irradiation (120 kV:4.5 mA). According to the data obtained, the biosynthesis of photosynthetic pigments, will have been completed by the beginning of flowering. In consequence of the overcompensation of the repairing processes, the organs of plants developed from irradiated seeds, showed a partly differing correlative growth, compared to those of control plants. In order to characterize the vivo response of radiation-injured plants, a new method and approach were used. The changes of the electric capacitance of the plants during their ontogenesis, were continously monitored and recorede via a computer-aided and controlled measurement. In view of the data collected in such a way, the repairing plants may respond more quickly and intensively to the changes of environmental factors.

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X-ray radiation at low doses stimulates differentiation and mineralization of mouse calvarial osteoblasts

  • Park, Soon-Sun;Kim, Kyoung-A;Lee, Seung-Youp;Lim, Shin-Saeng;Jeon, Young-Mi;Lee, Jeong-Chae
    • BMB Reports
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    • v.45 no.10
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    • pp.571-576
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    • 2012
  • Radiotherapy is considered to cause detrimental effects on bone tissue eventually increasing bone loss and fracture risk. However, there is a great controversy on the real effects of irradiation itself on osteoblasts, and the mechanisms by which irradiation affects osteoblast differentiation and mineralization are not completely understood. We explored how X-ray radiation influences differentiation and bone-specific gene expression in mouse calvarial osteoblasts. Irradiation at 2 Gy not only increased differentiation and mineralization of the cells, but also upregulated the expression of alkaline phosphatase, type I collagen, osteopontin, and osteocalcin at early stages of differentiation. However, irradiation at higher doses (>2 Gy) did not stimulate osteoblast differentiation, rather it suppressed DNA synthesis by the cells without a toxic effect. Additional experiments suggested that transforming growth factor-beta 1 and runt-transcription factor 2 play important roles in irradiation- stimulated bone differentiation by acting as upstream regulators of bone-specific markers.

The mRNA Expression of Radio-Sensitive Genes Exposed to Various Dosage of Ionizing Radiation in U-937 Cell (U-937 세포에서 이온화 방사선의 조사선량에 따른 감수성 유전자들의 발현 변화)

  • 김종수;임희영;오연경;김인규;강경선;윤병수
    • Toxicological Research
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    • v.20 no.1
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    • pp.21-29
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    • 2004
  • We used cDNA microarray to assess gene expression profiles in hematopoetic cell line, U-937, exposed to low doses of ionizing irradiation. The 1,000 DNA elements on this array were PCR-amplified cDNAs selected from named human cancer related genes. According to the strength of irradiation, the levels of some gene expression were increased or decreased as dose-dependent manner. The gene expressions of Tubulin alpha, protein kinase, interferon-alpha, -beta, -omega receptor and ras homolog gene family H were significantly increased. Especially, Tubulin gene was shown 2.5 fold up-regulated manner under stress of 500 rad irradiation than 200 rad. On the other hand, fibroblast growth factor 12 and four and a half LIM domains, etc. were significantly down-regu-lated. Also, tumor protein 53(TP53) related genes that p53 inducible protein, tumor protein 53-binding protein looks of little significance as radiation sensitive manner. The radio-sensitivity of tubulin gene etc. that we proposed could be useful to rapid and correct survey for the bio-damage by exposure to low dose irradiation.

Evaluation of Sensory Quality of Spices Treated with Ethylene Oxide and Ionizing Radiation (Ethylene Oxide 처리(處理)와 방사선조사(放射線照射) 살균(殺菌) 향신료(香辛料)의 관능적(官能的) 품질평가(品質評價))

  • Byun, Myung-Woo;Kwon, Joong-Ho;Lee, Jae-Won;Cho, Han-Ok
    • Korean Journal of Food Science and Technology
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    • v.18 no.6
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    • pp.427-430
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    • 1986
  • Ionizing irradiation and E.O were used for sterilization of 5 different types of spices and mixed spices, and then each treated sample was evaluated using rank-order test to compare the sensory quality of the E.O fumigated sample to that of the irradiated sample. Preference of tested samples was in the descending order of control, the irradiated and the fumigated samples. According to the results of analysis of variance. 5 spices were significantly different at the 1% (P<0.01) or 5% (P<0.05), while mixed spices showed no significance. The results of Duncan's multiple range test showed that there was no significance difference between control and the irradiated sample, while the E.O fumigated sample was significantly different from control and irradiated samples. In conclusion, no adverse effects was found in quality of spices by ionizing radiation for sterilization, but the E.O fumigated sample showed deterioration of quality. The results were corresponded with the changes in major physicochemical components of each sample.

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Effect on the Inhibition of DNA-PK in Breast Cancer Cell lines(MDA-465 and MDA-468) with DNA-PKcs Binding Domain Synthetic Peptide of Ku80 (Ku80의 DNA-PKcs 결합부위 합성 Peptide 투여에 의한 유방암세포의 DNA-dependent protein kinase 억제 효과)

  • 김충희;김태숙;문양수;정장용;강정부;김종수;강명곤;박희성
    • Journal of Veterinary Clinics
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    • v.21 no.3
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    • pp.253-258
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    • 2004
  • DNA double-strand break (DSB) is a serious treat for the cells including mutations, chromosome rearrangements, and even cell death if not repaired or misrepaired. Ku heterodimer regulatory DNA binding subunits (Ku70/Ku80) bound to double strand DNA breaks are able to interact with 470-kDa DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and the interaction is essential for DNA-dependent protein kinase (DNA-PK) activity. The Ku80 mutants were designed to bind Ku70 but not DNA end binding activity and the peptides were treated in breast cancer cells for co-therapy strategy to see whether the targeted inhibition of DNA-dependent protein kinase (DNA-PK) activity sensitized breast cancer cells to ionizing irradiation or chemotherapy drug to develop a treatment of breast tumors by targeting proteins involved in damage-signaling pathway and/or DNA repair. We designed domains of Ku80 mutants, 26 residues of amino acids (HN-26) as a control peptide or 38 (HNI-38) residues of amino acids which contain domains of the membrane-translocation hydrophobic signal sequence and the nuclear localization sequence, but HNI-38 has additional twelve residues of peptide inhibitor region. We observed that the synthesized peptide (HNI-38) prevented DNA-PKcs from binding to Ku70/Ku80, resulting in inactivation of DNA-PK complex activity in breast cancer cells (MDA-465 and MDA-468). Consequently, the peptide treated cells exhibited poor to no DNA repair, and became highly sensitive to irradiation or chemotherapy drugs. The growth of breast cancer cells was also inhibited. These results demonstrate the possibility of synthetic peptide to apply breast cancer therapy to induce apoptosis of cancer cells.