Ionizing Radiation-Induced Release of a Cell Surface Nuclease from Micrococcus radiodurans

1975 ◽  
Vol 61 (2) ◽  
pp. 204 ◽  
Author(s):  
N. E. Gentner ◽  
R. E. J. Mitchel
Keyword(s):  
Ionizing Radiation ◽  
Cell Surface ◽  
A Cell ◽  
Radiation Induced

scholarly journals Involvement of reactive oxygen species in ionizing radiation–induced upregulation of cell surface Toll-like receptor 2 and 4 expression in human monocytic cells

2017 ◽  
Vol 58 (5) ◽  
pp. 626-635 ◽  
Author(s):  
Hironori Yoshino ◽  
Ikuo Kashiwakura
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Synthesis ◽  
Ionizing Radiation ◽  
Cell Surface ◽  
Reactive Oxygen ◽  
Mitogen Activated Protein Kinase ◽  
Protein Synthesis Inhibitor ◽  
Oxygen Species ◽  
X Ray ◽  
Radiation Induced

Abstract Toll-like receptors (TLRs) are pattern recognition receptors that recognize pathogen-associated molecular patterns and are indispensable for antibacterial and antiviral immunity. Our previous report showed that ionizing radiation increases the cell surface expressions of TLR2 and TLR4 and enhances their responses to agonists in human monocytic THP1 cells. The present study investigated how ionizing radiation increases the cell surface expressions of TLR2 and TLR4 in THP1 cells. The THP1 cells treated or not treated with pharmaceutical agents such as cycloheximide and N-acetyl-L-cysteine (NAC) were exposed to X-ray irradiation, following which the expressions of TLRs and mitogen-activated protein kinase were analyzed. X-ray irradiation increased the mRNA expressions of TLR2 and TLR4, and treatment with a protein synthesis inhibitor cycloheximide abolished the radiation-induced upregulation of their cell surface expressions. These results indicate that radiation increased those receptors through de novo protein synthesis. Furthermore, treatment with an antioxidant NAC suppressed not only the radiation-induced upregulation of cell surface expressions of TLR2 and TLR4, but also the radiation-induced activation of the c-Jun N-terminal kinase (JNK) pathway. Since it has been shown that the inhibitor for JNK can suppress the radiation-induced upregulation of TLR expression, the present results suggest that ionizing radiation increased the cell surface expressions of TLR2 and TLR4 through reactive oxygen species–mediated JNK activation.

Radiation-induced surface decomposition

1983 ◽  
Vol 41 ◽  
pp. 368-369
Author(s):  
M. L. Knotek
Keyword(s):  
Ionizing Radiation ◽  
Atomic Structure ◽  
Chemical Bonding ◽  
Neutral Species ◽  
Radiation Induced ◽  
Physical And Chemical ◽  
Surface Decomposition ◽  
The Relationship ◽  
Electron And Photon ◽  
Surface Bond

Modern surface analysis is based largely upon the use of ionizing radiation to probe the electronic and atomic structure of the surfaces physical and chemical makeup. In many of these studies the ionizing radiation used as the primary probe is found to induce changes in the structure and makeup of the surface, especially when electrons are employed. A number of techniques employ the phenomenon of radiation induced desorption as a means of probing the nature of the surface bond. These include Electron- and Photon-Stimulated Desorption (ESD and PSD) which measure desorbed ionic and neutral species as they leave the surface after the surface has been excited by some incident ionizing particle. There has recently been a great deal of activity in determining the relationship between the nature of chemical bonding and its susceptibility to radiation damage.

Amifostine-Loaded Dissolving Armored Microneedles for Long-Term Prevention of Ionizing Radiation-Induced Injury

2020 ◽  
Author(s):  
Xiang Yu ◽  
Minshu Li ◽  
Lin Zhu ◽  
Jingfei li ◽  
Guoli Zhang ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Radiation Induced

Evaluation of the Radioprotective Effects of Melatonin Against Ionizing Radiation-Induced Muscle Tissue Injury

2019 ◽  
Vol 12 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Dheyauldeen Shabeeb ◽  
Mansoor Keshavarz ◽  
Alireza Shirazi ◽  
Gholamreza Hassanzadeh ◽  
Mohammed Reza Hadian ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Gastrocnemius Muscle ◽  
Tissue Injury ◽  
Histopathological Examination ◽  
Compound Action Potential ◽  
Optimal Dose ◽  
Treatment Method ◽  
Major Product ◽  
Muscle Tissues ◽  
Radiation Induced

Background: Radiotherapy (RT) is a treatment method for cancer using ionizing radiation (IR). The interaction between IR with tissues produces free radicals that cause biological damages.As the largest organ in the human body, the skeletal muscles may be affected by detrimental effects of ionizing radiation. To eliminate these side effects, we used melatonin, a major product secreted by the pineal gland in mammals, as a radioprotective agent. Materials and Methods: For this study, a total of sixty male Wistar rats were used. They were allotted to 4 groups: control (C), melatonin (M), radiation (R) and melatonin + radiation (MR). Rats’ right hind legs were irradiated with 30 Gy single dose of gamma radiation, while 100 mg/kg of melatonin was given to them 30 minutes before irradiation and 5 mg/ kg once daily afternoon for 30 days. Five rats in each group were sacrificed 4, 12 and 20 weeks after irradiation for histological and biochemical examinations. Results: Our results showed radiation-induced biochemical, histological and electrophysiological changes in normal rats’ gastrocnemius muscle tissues. Biochemical analysis showed that malondialdehyde (MDA) levels significantly elevated in R group (P<0.001) and reduced significantly in M and MR groups after 4, 12, and 20 weeks (P<0.001), However, the activity of catalase (CAT) and superoxide dismutase(SOD)decreased in the R group and increased in M and MR groups for the same periods of time compared with the C group (P<0.001), while melatonin administration inverted these effects( P<0.001).Histopathological examination showed significant differences between R group for different parameters compared with other groups (P<0.001). However, the administration of melatonin prevented these effects(P<0.001). Electromyography (EMG) examination showed that the compound action potential (CMAP) value in the R group was significantly reduced compared to the effects in the C and M groups after 12 and 20 weeks (P<0.001). The administration of melatonin also reversed these effects (P<0.001). Conclusion: Melatonin can improve biochemical, electrophysiological and morphological features of irradiated gastrocnemius muscle tissues.Our recommendation is that melatonin should be administered in optimal dose. For effective protection of muscle tissues, and increased therapeutic ratio of radiation therapy, this should be done within a long period of time.

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