scholarly journals Quantifying Biophoton Emissions From Human Cells Directly Exposed to Low-Dose Gamma Radiation

Dose-Response ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 155932582092676 ◽  
Author(s):  
Jason Cohen ◽  
Nguyen T. K. Vo ◽  
David R. Chettle ◽  
Fiona E. McNeill ◽  
Colin B. Seymour ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Single Photon ◽  
Photon Emission ◽  
Beta Radiation ◽  
Culture Vessel ◽  
Single Photon Detection ◽  
Cesium 137 ◽  
A Cell ◽  
Radiation Induced ◽  
Gamma Irradiated

Biophoton emission leading to bystander effects (BEs) was shown in beta-irradiated cells; however, technical challenges precluded the analysis of the biophoton role in gamma-induced BEs. The present work was to design an experimental approach to determine if, what type, and how many biophotons could be produced in gamma-irradiated cells. Photon emission was measured in HCT116 p53+/+ cells irradiated with a total dose of 22 mGy from a cesium-137 source at a dose rate of 45 mGy/min. A single-photon detection unit was used and shielded with lead to reduce counts from stray gammas reaching the detector. Higher quantities of photon emissions were observed when the cells in a tissue culture vessel were present and being irradiated compared to a cell-free vessel. Photon emissions were captured at either 340 nm (in the ultraviolet A [UVA] range) or 610 nm. At the same cell density, radiation exposure time, and radiation dose, HCT116 p53+/+ cells emitted 2.5 times more UVA biophotons than 610-nm biophotons. For the first time, gamma radiation was shown to induce biophoton emissions from biological cells. As cellular emissions of UVA biophotons following beta radiation lead to BEs, the involvement of cellular emissions of the same type of UVA biophotons in gamma radiation-induced BEs is highly likely.

scholarly journals Gamma Radiation Imaging System via Variable and Time-Multiplexed Pinhole Arrays

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3013 ◽  
Author(s):  
Ariel Schwarz ◽  
Amir Shemer ◽  
Yossef Danan ◽  
Rachel Bar-Shalom ◽  
Hemy Avraham ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Imaging System ◽  
Single Photon ◽  
Photon Emission ◽  
Three Dimensional ◽  
Medical Diagnostics ◽  
Emission Computed Tomography ◽  
Planar Imaging ◽  
Gamma Imaging ◽  
Image Capturing

Biomedical planar imaging using gamma radiation is a very important screening tool for medical diagnostics. Since lens imaging is not available in gamma imaging, the current methods use lead collimator or pinhole techniques to perform imaging. However, due to ineffective utilization of the gamma radiation emitted from the patient’s body and the radioactive dose limit in patients, poor image signal to noise ratio (SNR) and long image capturing time are evident. Furthermore, the resolution is related to the pinhole diameter, thus there is a tradeoff between SNR and resolution. Our objectives are to reduce the radioactive dose given to the patient and to preserve or improve SNR, resolution and capturing time while incorporating three-dimensional capabilities in existing gamma imaging systems. The proposed imaging system is based on super-resolved time-multiplexing methods using both variable and moving pinhole arrays. Simulations were performed both in MATLAB and GEANT4, and gamma single photon emission computed tomography (SPECT) experiments were conducted to support theory and simulations. The proposed method is able to reduce the radioactive dose and image capturing time and to improve SNR and resolution. The results and method enhance the gamma imaging capabilities that exist in current systems, while providing three-dimensional data on the object.

Investigation of Gamma Radiation on Hydroxyapatite Synthesized from Chicken Eggshell by ESR Spectroscopy

2015 ◽  
Vol 1125 ◽  
pp. 416-420
Author(s):  
Kanokwan Boonsook ◽  
Weeranuch Kaewwiset ◽  
Ekachai Hoonnivathana ◽  
Pichet Limsuwan ◽  
Kittisakchai Naemchanthara
Keyword(s):  
Electron Spin Resonance ◽  
Gamma Radiation ◽  
Electron Spin ◽  
Esr Spectroscopy ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Spin Resonance ◽  
Chicken Eggshell ◽  
Radiation Induced ◽  
Gamma Irradiated

The purpose of this work was investigated the properties and characteristic of gamma radiation on hydroxyapatite which synthesized from biowaste chicken eggshell via the chemical precipitation method. The hydroxyapatite from biowaste chicken eggshell was gamma irradiated in rage 10 Gy to 1 kGy and analyzed by electron spin resonance (ESR). The optimize parameter set ESR read out of Hydroxyapatite were such as microwave power and modulate amplitude corresponded 63.34 mW and 2 mT, respectively. The ESR signal based on the measurement of the concentration of radiation induced radicals CO2- molecular ion also formed in hydroxyapatite. The relative of ESR intensity and dose response was linear. These experiments indicated that the hydroxyapatite from biowaste chicken eggshell could be used good dosimeter in rage 20 to 100 Gy.

scholarly journals Non-Invasive Targeted Hepatic Irradiation and SPECT/CT Functional Imaging to Study Radiation-Induced Liver Damage in Small Animal Models

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1796
Author(s):  
Rafi Kabarriti ◽  
N. Patrik Brodin ◽  
Hillary Yaffe ◽  
Mark Barahman ◽  
Wade R. Koba ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Guidance ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal ◽  
Emission Computed Tomography ◽  
Cancer Treatments ◽  
Non Invasive ◽  
Radiation Induced ◽  
Computed Tomography Image

Radiation therapy (RT) has traditionally not been widely used in the management of hepatic malignancies for fear of toxicity in the form of radiation-induced liver disease (RILD). Pre-clinical hepatic irradiation models can provide clinicians with better understanding of the radiation tolerance of the liver, which in turn may lead to the development of more effective cancer treatments. Previous models of hepatic irradiation are limited by either invasive laparotomy procedures, or the need to irradiate the whole or large parts of the liver using external skin markers. In the setting of modern-day radiation oncology, a truly translational animal model would require the ability to deliver RT to specific parts of the liver, through non-invasive image guidance methods. To this end, we developed a targeted hepatic irradiation model on the Small Animal Radiation Research Platform (SARRP) using contrast-enhanced cone-beam computed tomography image guidance. Using this model, we showed evidence of the early development of region-specific RILD through functional single photon emission computed tomography (SPECT) imaging.

scholarly journals Thymoquinone Rescues T Lymphocytes from Gamma Irradiation-Induced Apoptosis and Exhaustion by Modulating Pro-Inflammatory Cytokine Levels and PD-1, Bax, and Bcl-2 Signaling

2016 ◽  
Vol 38 (2) ◽  
pp. 786-800 ◽  
Author(s):  
Mona Samy Guida ◽  
Ali Abd El-Aal ◽  
Yehya Kafafy ◽  
Safwat Farid Salama ◽  
Badr Mohamed Badr ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cell ◽  
Gamma Radiation ◽  
Inflammatory Cytokine ◽  
Caspase 3 ◽  
Flow Cytometry Analysis ◽  
Tnf Α ◽  
Cytokine Levels ◽  
Radiation Induced ◽  
Gamma Irradiated

Background/Aims: Recent studies have shown that thymoquinone (TQ) exerts protective effects against ionizing radiation-induced cataracts in lens after total cranium irradiation of rats. Nevertheless, there is no published work investigated the effects of TQ on T cell development and biology in animal models exposed to gamma radiation. Therefore, in the present study we focused on determining the effects of TQ on radiation damage in the thymus, radiation-induced T cell imbalance, and on immune dysfunction induced by gamma-rays. Methods: Three groups of rats were used: a control group, a gamma-irradiated group, and a gamma-irradiated group that was orally supplemented with TQ. Serum lipid profiles, malondialdehyde (MDA) levels, and pro-inflammatory cytokine levels were measured to assess gamma irradiation-induced oxidative stress and inflammatory capacity. T cell apoptosis was evaluated by annexin V/propidium iodide staining followed by flow cytometry analysis. The expression of pro-apoptotic proteins such as Bax and caspase-3, the anti-apoptotic protein Bcl-2, and an exhaustion marker of T cells (PD-1) in CD4+ and CD8+ T cell populations was evaluated using flow cytometry analysis. The T cell architecture of the thymus gland was evaluated by histological analysis. Results: Exposure to gamma radiation increased triglyceride, cholesterol, LDL-C, MDA, TNF-α and IL-6 levels and decreased HDL-C levels. The altered lipid profile and MDA and pro-inflammatory cytokine (TNF-α and IL-6) levels induced by exposure to gamma radiation were significantly restored in TQ-treated gamma-irradiated rats. Rats exposed to gamma radiation exhibited increased exhaustion of T lymphocytes via down-regulation of Bcl-2 expression and upregulation of PD-1, Bax, and caspase-3 expression, which sensitized these cells to apoptosis. Interestingly, treatment of gamma-irradiated rats with TQ decreased T cell exhaustion and apoptosis by modulating the expression of Bcl-2, PD-1, Bax, and caspase-3. Conclusions: Our results provide evidence for the beneficial effects of TQ as an effective radioprotective candidate that enhances cellular immunity.

scholarly journals Ubiquitination of p53 and p21 is differentially affected by ionizing and UV radiation.

1997 ◽  
Vol 17 (1) ◽  
pp. 355-363 ◽  
Author(s):  
C G Maki ◽  
P M Howley
Keyword(s):  
Gamma Radiation ◽  
Uv Radiation ◽  
Radiation Effects ◽  
P53 Protein ◽  
Proteolytic Pathway ◽  
Radiation Induced ◽  
The Stability ◽  
Gamma Irradiated ◽  
In Cells

Levels of the tumor suppressor protein p53 are normally quite low due in part to its short half-life. p53 levels increase in cells exposed to DNA-damaging agents, such as radiation, and this increase is thought to be responsible for the radiation-induced G1 cell cycle arrest or delay. The mechanisms by which radiation causes an increase in p53 are currently unknown. The purpose of this study was to compare the effects of gamma and UV radiation on the stability and ubiquitination of p53 in vivo. Ubiquitin-p53 conjugates could be detected in nonirradiated and gamma-irradiated cells but not in cells which were UV treated, despite the fact that both treatments resulted in the stabilization of the p53 protein. These results demonstrate that UV and gamma radiation have different effects on ubiquitinated p53 and suggest that the UV-induced stabilization of p53 results from a loss of p53 ubiquitination. Ubiquitinated forms of p21, an inhibitor of cyclin-dependent kinases, were detected in vivo, demonstrating that p21 is also a target for degradation by the ubiquitin-dependent proteolytic pathway. However, UV and gamma radiation had no effect on the stability or in vivo ubiquitination of p21, indicating that the radiation effects on p53 are specific.

MORTALITY OF GAMMA IRRADIATED LARVAL TRIBOLIUM CONFUSUM SUBJECTED TO VARIOUS GASES OR PHYSICAL STRESSES1

1985 ◽  
Vol 20 (4) ◽  
pp. 465-469
Author(s):  
E. W. Tilton ◽  
H. H. Vardell ◽  
R. D. Jones
Keyword(s):  
Carbon Dioxide ◽  
Gamma Radiation ◽  
Tribolium Confusum ◽  
Cold Air ◽  
First Instar ◽  
Radiation Induced ◽  
Gamma Irradiated ◽  
Radiation Time ◽  
Partial Vacuum

Treatment by gamma radiation, cold air, partial vacuum, phosphine, nitrogen, and carbon dioxide have all been proposed to control insects in stored food. There is some evidence that radiation-induced mortality of some insects can be inhibited by these gases, partial vacuum, or cold treatments. Collateral exposure of first-instar larvae of Tribolium confusum Jacquelin du Val to CO2 and 75 Gy gamma radiation produced a significant reduction in radiation-induced mortality when compared with radiation alone. Mortality produced by gamma radiation simultaneous with treatment by nitrogen, partial vacuum of 3.33 kPa (25 Torr) or cold air (2°) for 30 min., which included radiation time, did not differ significantly from that of gamma radiation alone. The treatments with phosphine and phosphine with gamma radiation did not differ significantly.

New Flexible High Gamma Dose Dosimeter Based on Luminescent and Biodegradable Polymer Blend

2013 ◽  
Vol 1576 ◽  
Author(s):  
T. Schimitberger ◽  
M.R. Franco ◽  
F.A. Lopes ◽  
P.S. Curti ◽  
R.F. Bianchi ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Photon Emission ◽  
Emission Spectra ◽  
Gamma Dose ◽  
Copolymer Films ◽  
High Gamma ◽  
Biodegradable Poly ◽  
Radiation Induced ◽  
High Doses ◽  
Induced Changes

ABSTRACTIn this work we investigate the radio-degradation of MEH-PPV polymer film as a tool for measuring high doses of gamma radiation. In order to produce film samples with thickness in the micron range, we have mixed the photoluminescent poly(2-methoxy-5(2'-ethylhexyloxy)-p-phenylenevinylene) copolymer (MEH-PPV) with a biodegradable poly(butylene adipate-co-terephthalate) copolymers (PBAT). The system was irradiated with a Co-60 source with doses ranging from 1 to 1,000 kGy. Ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy have been used to investigate the radiation induced changes in the absorption and photon-emission spectra of the irradiated samples. Results indicate that the PL emission intensity varies exponentially with the applied gamma radiation dose for doses ranging from 30 to 500 kGy. The unambiguous relationship between PL & Dose together with the good flexibility of the copolymer films indicate that MEH-PPV/PBAT blends have great potential for applications in high gamma dose dosimetry.

Sign in / Sign up

Export Citation Format

Share Document