An Attempt to Reduce the Background Free Radicals in Fingernails for Monitoring Accidental Hand Exposure of Medical Workers

While it is recognized that some medical workers could receive significantly higher radiation doses to their hands than the routinely monitored personal doses, accurate retrospective dosimetry of their hand exposure is still challenging. To solve this issue, a combination of electron spin resonance (ESR) measurement and fingernails is worth to be investigated. However, the application of fingernail ESR dosimetry requires establishing an effective protocol to eliminate the background signal (BKG) which changes due to mechanical stress and other unclear factors, so that the radiation doses would be precisely evaluated from the radiation-induced signals (RIS) only. Thus, the authors investigated possible applications of antioxidants to remove or reduce the BKG in fingernails. In the present study, the effectiveness of chemical treatment using the dithiothreitol (DTT) reducing reagent was examined in irradiated and unirradiated fingernails. Chemically and non-chemically treated fingernails were subsequently exposed to 20 Gy of 137Cs γ-rays and the time changes of the BKG and RIS were confirmed in two different storage conditions: vacuum chamber and freezer. The results show that the non-chemically treated fingernails displayed significant intra-individual variations in the peak-to-peak intensities of both BKG and RIS. RIS from chemically and non-chemically treated samples showed correlations after freezer storage; signals were more stable than the samples stored in the vacuum chamber. Moreover, while the BKG of non-chemically treated samples demonstrated higher levels than those chemically treated, the intra-individual variations were further reduced by the DTT treatment. Our results imply that the use of an antioxidant for hand washing of medical workers prior to starting their work could be effective in reducing the pre-existing free radicals in their fingernails. This also suggests a practical application of hand exposure monitoring using fingernails as a part of radiological emergency preparedness in occupations where radiation or radionuclides are used. Research for finding safer and easier-to-handle antioxidants is to be focused on in future studies.

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ESR-based Identification of Radiation-Induced Free Radicals in Gamma-Irradiated Basil and Clove Using Different Sample Pre-Treatments

Journal of the Korean Society of Food Science and Nutrition ◽

10.3746/jkfn.2012.41.10.1454 ◽

2012 ◽

Vol 41 (10) ◽

pp. 1454-1459 ◽

Cited By ~ 1

Author(s):

Ji-Young Kwak ◽

Jae-Jun Ahn ◽

Kashif Akram ◽

Joong-Ho Kwon

Keyword(s):

Free Radicals ◽

Radiation Induced ◽

Gamma Irradiated

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Radiation-Induced Noncancer Risks in Interventional Cardiology: Optimisation of Procedures and Staff and Patient Dose Reduction

BioMed Research International ◽

10.1155/2013/976962 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 15

Author(s):

Zhonghua Sun ◽

Aini AbAziz ◽

Ahmad Khairuddin Md Yusof

Keyword(s):

Potential Risk ◽

Medical Staff ◽

Interventional Procedure ◽

Cardiovascular Effects ◽

Interventional Cardiology ◽

Evidence Based ◽

Radiation Doses ◽

High Radiation ◽

Radiation Induced ◽

Patient Dose Reduction

Concerns about ionizing radiation during interventional cardiology have been increased in recent years as a result of rapid growth in interventional procedure volumes and the high radiation doses associated with some procedures. Noncancer radiation risks to cardiologists and medical staff in terms of radiation-induced cataracts and skin injuries for patients appear clear potential consequences of interventional cardiology procedures, while radiation-induced potential risk of developing cardiovascular effects remains less clear. This paper provides an overview of the evidence-based reviews of concerns about noncancer risks of radiation exposure in interventional cardiology. Strategies commonly undertaken to reduce radiation doses to both medical staff and patients during interventional cardiology procedures are discussed; optimisation of interventional cardiology procedures is highlighted.

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Live-cell imaging to detect phosphatidylserine externalization in brain endothelial cells exposed to ionizing radiation: implications for the treatment of brain arteriovenous malformations

Journal of Neurosurgery ◽

10.3171/2015.4.jns142129 ◽

2016 ◽

Vol 124 (6) ◽

pp. 1780-1787 ◽

Cited By ~ 12

Author(s):

Zhenjun Zhao ◽

Michael S. Johnson ◽

Biyi Chen ◽

Michael Grace ◽

Jaysree Ukath ◽

...

Keyword(s):

Cell Cycle ◽

Endothelial Cells ◽

Ionizing Radiation ◽

Live Cell Imaging ◽

Cell Imaging ◽

Live Cell ◽

Vascular Targeting ◽

Radiation Doses ◽

Radiation Induced ◽

Polarity Sensitive

OBJECT Stereotactic radiosurgery (SRS) is an established intervention for brain arteriovenous malformations (AVMs). The processes of AVM vessel occlusion after SRS are poorly understood. To improve SRS efficacy, it is important to understand the cellular response of blood vessels to radiation. The molecular changes on the surface of AVM endothelial cells after irradiation may also be used for vascular targeting. This study investigates radiation-induced externalization of phosphatidylserine (PS) on endothelial cells using live-cell imaging. METHODS An immortalized cell line generated from mouse brain endothelium, bEnd.3 cells, was cultured and irradiated at different radiation doses using a linear accelerator. PS externalization in the cells was subsequently visualized using polarity-sensitive indicator of viability and apoptosis (pSIVA)-IANBD, a polarity-sensitive probe. Live-cell imaging was used to monitor PS externalization in real time. The effects of radiation on the cell cycle of bEnd.3 cells were also examined by flow cytometry. RESULTS Ionizing radiation effects are dose dependent. Reduction in the cell proliferation rate was observed after exposure to 5 Gy radiation, whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with cells treated with sham radiation, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA-positive cells were significantly higher (p = 0.04) 24 hours after treatment in the cultures that received 25- and 15-Gy doses of radiation. This effect was sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation controls at any time points (p > 0.15). Flow cytometric analysis data indicate that irradiation induced growth arrest of bEnd.3 cells, with cells accumulating in the G2 phase of the cell cycle. CONCLUSIONS Ionizing radiation causes remarkable cellular changes in endothelial cells. Significant PS externalization is induced by radiation at doses of 15 Gy or higher, concomitant with a block in the cell cycle. Radiation-induced markers/targets may have high discriminating power to be harnessed in vascular targeting for AVM treatment.

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Eye protection in interventional procedures

British Journal of Radiology ◽

10.1259/bjr.20210436 ◽

2021 ◽

Vol 94 (1126) ◽

pp. 20210436 ◽

Cited By ~ 1

Author(s):

Beth A. Schueler ◽

Kenneth A Fetterly

Keyword(s):

Interventional Procedures ◽

Eye Lens ◽

Radiation Doses ◽

Radiation Induced ◽

Individual Actions ◽

Dose Measurements ◽

Dose Levels ◽

Patient Radiation Dose ◽

Low Radiation Doses

Data suggest that radiation-induced cataracts may form without a threshold and at low-radiation doses. Staff involved in interventional radiology and cardiology fluoroscopy-guided procedures have the potential to be exposed to radiation levels that may lead to eye lens injury and the occurrence of opacifications have been reported. Estimates of lens dose for various fluoroscopy procedures and predicted annual dosages have been provided in numerous publications. Available tools for eye lens radiation protection include accessory shields, drapes and glasses. While some tools are valuable, others provide limited protection to the eye. Reducing patient radiation dose will also reduce occupational exposure. Significant variability in reported dose measurements indicate dose levels are highly dependent on individual actions and exposure reduction is possible. Further follow-up studies of staff lens opacification are recommended along with eye lens dose measurements under current clinical practice conditions.

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Free radicals and food irradiation

Biochemical Society Symposium ◽

10.1042/bss0610247 ◽

1995 ◽

Vol 61 ◽

pp. 247-258 ◽

Cited By ~ 5

Author(s):

"N.J.F. Dodd

Keyword(s):

Free Radicals ◽

Radiation Dosimetry ◽

Food Poisoning ◽

Food Irradiation ◽

Specific Method ◽

Naturally Occurring ◽

Spin Resonance ◽

Radiation Induced ◽

Calcified Tissues ◽

Control Insect

Ionizing radiation can be used to control insect and microbial infestation of foodstuffs, inhibit sprouting, delay ripening and reduce the dangers from food-poisoning bacteria. Irradiation produces free radicals, most of which decay rapidly, although some are more persistent. These latter radicals can be detected and characterized by electron spin resonance (ESR). In bone and other calcified tissues, the radiation-induced radicals are distinguishable from naturally occurring radicals, and their stability makes them ideal for radiation dosimetry. The radicals induced in plant material, such as seeds and dried spices, are generally indistinguishable from the endogenous radicals and decay over a period of days or weeks. However, in many of these materials, a radiation-specific radical can be detected at low concentration, thereby permitting identification of irradiated samples, although precluding accurate dosimetry. ESR, although not universally applicable, currently provides the most specific method for the detection of irradiated food.

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Influence of Temperature and Oxygen Concentration on the Radiation Induced Oxidation of Phenylalanine

Zeitschrift für Naturforschung A ◽

10.1515/zna-1995-0912 ◽

1995 ◽

Vol 50 (9) ◽

pp. 864-870 ◽

Cited By ~ 7

Author(s):

P. Krajnik ◽

R. M. Quint ◽

S. Solar ◽

N. Getoff ◽

G. Sontag

Keyword(s):

Oxygen Concentration ◽

Room Temperature ◽

Degradation Process ◽

Storage Conditions ◽

Food Storage ◽

Reaction Conditions ◽

Influence Of Temperature ◽

Influence Of Temperature On ◽

Radiation Induced ◽

Induced Changes

AbstractThe formation of tyrosine isomers by γ-radiolysis of neutral aqueous phenylalanine solutions was found to be strongly dependent on oxygen concentration and temperature. Changing the dose rate did not influence the degradation process. In the presence of 0.25 x 10-3 mol dm-3 oxygen at room temperature the yields of o-tyrosine as well as of m- and p-tyrosine drop from G(o-Tyr) = 0.5 and G(m-Tyr) = G(p-Tyr) = 0.4 at a dose of 0.3 kGy to 0.18 and 0.16 at 2.5 kGy, respectively. In solutions containing 1.25 x 10-3 mol dm-3 oxygen the initial yields remain unchanged but decrease at 2.5 kGy only to G(o-Tyr) = 0.3 and G(m-Tyr) = G(p-Tyr) = 0.20. Under the latter reaction conditions also 3,4-dihydroxyphenylalanine was found.Samples irradiated in frozen state did not show remarkable radiolysis of phenylalanine and tyrosine formation. In the range between 5 and 20°C no essential influence of temperature on the phenylalanine radiolysis and tyrosine yields was observable. The obtained results are important for methods using the tyrosine yields as markers for the detection of irradiated food. Storage conditions and irradiation temperature play an essential role on radiation induced changes of food.

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Modeling of Respiratory System Dysfunction among Nuclear Workers: A Preliminary Study

Dose-Response ◽

10.2203/dose-response.06-117.belyaeva ◽

2008 ◽

Vol 6 (4) ◽

pp. dose-response.0 ◽

Cited By ~ 3

Author(s):

Z.D. Belyaeva ◽

S.V. Osovets ◽

B.R. Scott ◽

G.V. Zhuntova ◽

E.S. Grigoryeva

Keyword(s):

Cigarette Smoking ◽

Respiratory System ◽

Respiratory Function ◽

Radiation Doses ◽

Alpha Radiation ◽

Nuclear Workers ◽

Chronic Radiation ◽

Mayak Production Association ◽

Radiation Induced ◽

Total Body

Numerous studies have reported on cancers among Mayak Production Association (PA) nuclear workers. Other studies have reported on serious deterministic effects of large radiation doses for the same population. This study relates to deterministic effects (respiratory system dysfunction) in Mayak workers after relatively small chronic radiation doses (alpha plus gamma). Because cigarette smoke is a confounding factor, we also account for smoking effects. Here we present a new empirical mathematical model that was introduced for simultaneous assessment of radiation and cigarette-smoking-related damage to the respiratory system. The model incorporates absolute thresholds for smoking- and radiation-induced respiratory system dysfunction. As the alpha radiation dose to the lung increased from 0 to 4.36 Gy, respiratory function indices studied decreased, although remaining in the normal range. The data were consistent with the view that alpha radiation doses to the lung above a relatively small threshold (0.15 to 0.39 Gy) cause some respiratory system dysfunction. Respiratory function indices were not found to be influenced by total-body gamma radiation doses in the range 0–3.8 Gy when delivered at low rates over years. However, significant decreases in airway conductance were found to be associated with cigarette smoking. Whether the indicated cigarette smoking and alpha radiation associated dysfunction is debilitating is unclear.

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