Magnetic Centers (Free Radicals) Produced in Cereal Embryos by Ionizing Radiation

1959 ◽  
Vol 11 (1) ◽  
pp. 54 ◽  
Author(s):  
Alan D. Conger ◽  
M. L. Randolph
Keyword(s):  
Free Radicals ◽  
Ionizing Radiation ◽  
Cereal Embryos

scholarly journals Effect of Ionizing Radiation on the Differentiation of ROS 17/2.8 Osteoblasts through Free Radicals

1999 ◽  
Vol 40 (4) ◽  
pp. 323-335 ◽  
Author(s):  
HAN-JUNG CHAE ◽  
SOO-WAN CHAE ◽  
JANG-SOOK KANG ◽  
BYUNG-GWAN BANG ◽  
JO-IL HAN ◽  
...  
Keyword(s):  
Free Radicals ◽  
Ionizing Radiation

Diagnostic Range Ionizing Radiation and Reactive Oxygen Species Production: an Initial Experience

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Sirohi Shikha ◽  
Tandon Prof. Anupama ◽  
Banerjee Prof. B.D. ◽  
Kumar Ranjeet
Keyword(s):  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Ionizing Radiation ◽  
Venous Blood ◽  
Radiation Detection ◽  
Control Sample ◽  
Reactive Oxygen ◽  
P Value ◽  
Oxygen Species ◽  
Mdct Examination

Radiation is a common occurrence in our daily lives that comes from both natural and man-made sources. Ionizing Radiation (IR) causes damage either directly or indirectly through the generation of reactive oxygen species (ROS). Oxidative damage to DNA, lipids, proteins, and many metabolites occurs through a complex series of processes that are enhanced by endogenous signalling which is activated by free radicals. Though literature is abundant on ROS and antioxidants at high doses, no study to the best of our knowledge has assessed the ROS levels after Multi Detector Computed Tomography (MDCT) examination (i.e. in diagnostic range radiation). The aim of the present study was to assess the production of ROS after diagnostic level radiation by MDCT examination and at 24 hour follow up. The study involved fifty patients posted for clinically indicated MDCT which were recruited. The average radiation dose was 2-9 mGy. Three blood samples were drawn, one prior to CT (control sample), within half an hour of CT (post CT) and 24 hrs after CT. 3 ml venous blood was withdrawn in aseptic conditions and immediately serum was isolated for ROS assessment. The blood examination results were compared in immediate and post 24 hour after MDCT and both were compared with control values and correlated with radiation parameters. Our results have shown a significant increase in ROS level in immediate post CT samples compared to prior CT scan samples (control) (p value <0.0001). The ROS levels reduced at 24 hours compared to immediate post CT, however they were still higher than control values. Our findings reflect that there is a rapid increase in free radicals production in the mitochondria after diagnostic level radiation. Detection of higher ROS levels at 24 hours suggests incomplete repair with the presence of some residual oxidative species at 24 hours.

scholarly journals The Critical Role of Tetrahydrobiopterin (BH4) Metabolism in Modulating Radiosensitivity: BH4/NOS Axis as an Angel or a Devil

2021 ◽  
Vol 11 ◽  
Author(s):  
Yang Feng ◽  
Yahui Feng ◽  
Liming Gu ◽  
Pengfei Liu ◽  
Jianping Cao ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Free Radicals ◽  
Ionizing Radiation ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Antiangiogenic Therapy ◽  
Critical Role ◽  
Cellular Radiosensitivity ◽  
Normal Tissues

Ionizing radiation and radioactive materials have been widely used in industry, medicine, science and military. The efficacy of radiotherapy and adverse effects of normal tissues are closed related to cellular radiosensitivity. Molecular mechanisms underlying radiosensitivity are of significance to tumor cell radiosensitization as well as normal tissue radioprotection. 5,6,7,8-Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide synthases (NOS) and aromatic amino acid hydroxylases, and its biosynthesis involves de novo biosynthesis and a pterin salvage pathway. In this review we overview the role of BH4 metabolism in modulating radiosensitivity. BH4 homeostasis determines the role of NOS, affecting the production of nitric oxide (NO) and oxygen free radicals. Under conditions of oxidative stress, such as UV-radiation and ionizing radiation, BH4 availability is diminished due to its oxidation, which subsequently leads to NOS uncoupling and generation of highly oxidative free radicals. On the other hand, BH4/NOS axis facilitates vascular normalization, a process by which antiangiogenic therapy corrects structural and functional flaws of tumor blood vessels, which enhances radiotherapy efficacy. Therefore, BH4/NOS axis may serve as an angel or a devil in regulating cellular radiosensitivity. Finally, we will address future perspectives, not only from the standpoint of perceived advances in treatment, but also from the potential mechanisms. These advances have demonstrated that it is possible to modulate cellular radiosensitivity through BH4 metabolism.

Melatonin: Exceeding Expectations

Physiology ◽  
2014 ◽  
Vol 29 (5) ◽  
pp. 325-333 ◽  
Author(s):  
Russel J. Reiter ◽  
Dun Xian Tan ◽  
Annia Galano
Keyword(s):  
Oxidative Stress ◽  
Circadian Rhythm ◽  
Free Radicals ◽  
Ionizing Radiation ◽  
Reperfusion Injury ◽  
Heart Attack ◽  
Drug Toxicity ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cancer Inhibition

Melatonin is a small, highly conserved indole with numerous receptor-mediated and receptor-independent actions. Receptor-dependent functions include circadian rhythm regulation, sleep, and cancer inhibition. The receptor-independent actions relate to melatonin's ability to function in the detoxification of free radicals, thereby protecting critical molecules from the destructive effects of oxidative stress under conditions of ischemia/reperfusion injury (stroke, heart attack), ionizing radiation, and drug toxicity, among others. Melatonin has numerous applications in physiology and medicine.

scholarly journals NF-κB signaling pathway and free radical impact.

2012 ◽  
Vol 59 (3) ◽  
Author(s):  
Agnieszka Siomek
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Free Radicals ◽  
Free Radical ◽  
Ionizing Radiation ◽  
Physiological Role ◽  
Growth And Survival ◽  
Wide Range ◽  
The Impact ◽  
And Oxidative Stress

The activation of NF-κB transcription factor is critical for a wide range of processes such as immunity, inflammation, cell development, growth and survival. It is activated by a variety of stimuli including cytokines, ionizing radiation and oxidative stress. Redox modulations of NF-κB pathway have been widely demonstrated. Studies carried out during last years have advanced our knowledge about possible connections between NF-κB pathway and the impact of free radicals. This review is an endeavor to gather recent results focused on this issue, although an important question, whether oxidative stress plays a physiological role in NF-κB activation, seems to be still unanswered.

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