Effects of occupational radiation exposure on peripheral blood lymphocyte count and cell cycle in logging workers / 中国辐射卫生

Objective To investigate the effects of prolonged low-dose neutron-γ radiation on peripheral blood lymphocytes of logging workers. Methods The health information of workers in a logging company was collected by on-site blood sample collection and questionnaire survey. Individual doses of γ and neutron radiation were recorded using LiF elements and CR-39, respectively. Lymphocyte count in peripheral blood was measured by blood cytometer. Cell cycle and cyclins were detected by flow cytometry. Results The annual dose of some logging workers exceeded 5 mSv. Lymphocyte counts showed a difference of 15% between the group exposed to the lowest annual dose of 0–1 mSv (mean: 2.45 × 109/L) and the group exposed to the highest annual dose of 5–25 mSv (mean: 2.08 × 109/L). In comparison to pre-shift workers, logging workers exhibited a G1-phase arrest in the lymphocyte cycle, along with increased expression of cyclins p21 and CDK2. Conclusion Prolonged exposure to low-dose neutron-γ radiation leads to reduced lymphocyte counts as well as changes in lymphocyte cycle and cyclin expression.

Monte Carlo simulation-based dose calculation for organs under accidental radiation exposure in flaw detection / 中国辐射卫生

Objective To calculate the doses and their dose conversion coefficients for the personnel whose organs were under accidental exposure to three types of X-ray machines and two γ radiation sources, and to provide a simple method for rapid estimation of accidental doses. Methods The radiation source models of X-ray machines and two γ sources were established with the FLUKA simulation software and a Chinese reference voxel phantom was imported. The organ absorbed dose, dose conversion coefficient between organ absorbed dose and air Kerma, and conversion coefficient between organ absorbed dose and radiation source were calculated for a simulated scenario where the personnel were under antero-posterior exposure to radiation sources 1 meter away. Results For the lungs, heart, muscles, soft tissue, liver, skin, and brain, the conversion coefficient between organ absorbed dose and air Kerma was 0.30-1.19 (Gy/Gy). For X-ray machines, the conversion coefficient between organ absorbed dose and output for the six organs ranged from 6.12 × 10−3 to 2.90 × 10−2 Gy·m2/(mA·min). For γ radiation sources, the conversion coefficient between organ absorbed dose and activity for the six organs ranged from 1.12 × 10−8 to 7.01 × 10−8 Gy·m2/(GBq·s). Conclusion The conversion coefficient between organ absorbed dose and air Kerma and the conversion coefficient between organ absorbed dose and output or activity of a flaw detector can provide important dosimetric parameters for rapid assessment of similar radiation accidents.

Persea americana attenuates inflammatory response associated with hyperlipidemia in ovariectomized and irradiated rats by regulating MMP-3/TIMP-1 levels

Objective: To explore the effect of Persea americana supplementation on inflammation, oxidative stress, and lipid profiles in ovariectomized rats fed with a high-fat diet and exposed to radiation. Methods: The control group was sham operated, while groups 2-5 were ovariectomized and fed a high-fat diet. Groups 4 and 5 were exposed to γ-radiation (1 Gy/week for 5 weeks) after ovariectomy. Groups 3 and 5 were treated with 1 mL/250 g/day of Persea americana for one month. Serum levels of estrogen, alanine aminotransferase, aspartate aminotransferase, cholesterol, triglycerides and lipoproteins were measured. Additionally, hepatic oxidative stress, inflammatory and fibrogenic markers were evaluated. Results: Persea americana treatment reduced the oxidative stress markers as well as the levels of triglyceride, total cholesterol, and low-density lipoprotein cholesterol, which in turn lowered hepatic fat accumulation. Moreover, it suppressed hepatic inflammatory mediators (interleukin-6, tumor necrosis factor-α, and C-reactive protein) and downregulated pro-fibrogenic markers (transforming growth factor-β and tissue inhibitor of metalloproteinase-1). Conclusions: Persea americana provides protection against ovariectomy, and gamma radiation-mediated hepatic inflammation not only through its antioxidant, anti-inflammatory, lipid-lowering effect but also by modulating the fibrogenic markers.

Comparative analysis of air absorbed dose rate with different gamma radiation dose rate instrument / 中国辐射卫生

Objective In order to test and improve the monitoring technical level and ability of radiation environmental monitoring network in Zhejiang Province, ensure the accuracy and reliability of monitoring data and information, and obtain the cosmic ray response values of instruments and equipment in this year. Methods In September 2018，an intercomparison meeting of environmental gamma radiation air absorbed dose rate within the radiation environmental monitoring network of Zhejiang province was held in Ningbo，which was organized by Zhejiang Province Radiation Environmental Monitoring Center.A total of 33 sets of instruments from 15 member units participated in the intercomparison measurements at 5 environmental measuring points, and the comparison results were evaluated by the Z score values. Results It was found that the |Z| of all measurement results were less than or equal to 2, and the evaluation results were satisfactory and acceptable. Conclusion The measured data of scintillation counters have relatively wider dispersion，and the high pressure ionization chambers have bigger response valuetocosmic ray. The measurement results of the two kinds of instruments keep a good linearity except for the measurement points of cosmic ray response.

Scavenging and antioxidant properties of different grape cultivars against ionizing radiation-induced liver damage ex vivo.

Ionizing radiation (IR) has become an integral part of the modern medicine— both for diagnosis as well as therapy. However, normal tissues or even distant cells also suffer IR-induced free radical insult. It may be more damaging in longer term than direct radiation exposure. Antioxidants provide protection against IR-induced damage. Grapes are the richest source of antioxidants. Here, we assessed the scavenging properties of four grape (Vitis vinifera) cultivars, namely Flame seedless (Black), Kishmish chorni (Black with reddish brown), Red globe (Red) and Thompson seedless mutant (Green), and also evaluated their protective action against -radiation-induced oxidative stress in liver tissue ex vivo. The scavenging abilities of grape seeds [2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50=0.008±0.001 mg/mL), hydrogen peroxide (IC50=0.49 to 0.8 mg/mL), hydroxyl radicals (IC50=0.08±0.008 mg/mL), and nitric oxide (IC50=0.8±0.08 mg/mL)] were higher than that of skin or pulp. Gamma () radiation exposure to sliced liver tissues ex vivo from goat, @ 6 Gy significantly (P <0.001) decreased reduced glutathione (GSH) content by 21.2% and also activities of catalase, glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione s-transferase (GST) by 49.5, 66.0, 70.3, 73.6%, respectively. However, it increased thiobarbituric acid reactive substances (TBARS) by 2.04-fold and nitric oxide level by 48.6% compared to untreated group. Further increase in doses (10 or 16 Gy) of -radiation correspondingly decreased GSH content and enzyme activities, and increased TBARS and nitric oxide levels. Grape extract treatment prior to ionizing radiation exposure ameliorated theses effects at varying extent. The seed extracts exhibited strong antioxidant potential compared to skin or pulp extracts of different grape cultivars against oxidative damage by ionizing radiation (6 Gy, 10 Gy and 16 Gy) in sliced liver tissues ex vivo. Grape extracts at higher concentration (10 mg extract/g liver tissue) showed stronger antioxidant potential against lower dose (6 Gy) of ionizing radiation. Our results suggest that grape extracts could serve as a potential source of natural antioxidant against lower doses of IR-induced oxidative stress in liver extracts ex vivo.

Ameliorative effect of septilin, an ayurvedic preparation against γ-irradiation-induced oxidative stress and tissue injury in rats.

Ionizing radiation is known to induce multiple organ dysfunctions directly related to an increase of cellular oxidative stress, due to overproduction of reactive oxygen species (ROS). This study was aimed to investigate the effect of septilin (an ayurvedic poly-herbal formulation containing the principal herbs, namely Commiphora wightii, Trinospora cordifolia, Rubia cardifolia, Emblica officinalis, Saussurea lappa and Glycyrrhiza glabra) against whole body γ-irradiation-induced oxidative damage in hepatic and brain tissues in rats. Administration of septilin for 5 days (100 mg/kg) prior to radiation resulted in a significant increase in both superoxide dismutase (SOD) activity and total glutathione (GSH) level in hepatic and brain tissues, while serum high-density lipoprotein-cholesterol (HDL) was reduced by γ-irradiation. Also, septilin resulted in a significant decrease in NO(x), nitric oxide and malondialdehyde (MDA) levels in hepatic and brain tissues and a significant decrease in serum triglycerides, low-density lipoprotein-cholesterol (LDL) and total cholesterol levels and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels and alkaline phosphatase (ALP), γ-glutamyl transferase (GGT) activities, as well as serum tumor necrosis factor-alpha (TNF-α), compared to irradiated group. In conclusion, data obtained from this study indicated that septilin exhibited potential antioxidant activity and showed radioprotective effect against γ-radiation by preventing oxidative stress and scavenging free radicals.

Influence of atmospheric rainfall to γ radiation Kerma rate in surface air / 中华放射医学与防护杂志

Objective To investigate the influence rule of the atmospheric Rainfall to the γ radiation Kerma rate in surface air in order to revise the resuh of its measurement during rainfall.Methods The influence factors of rainfall to the measurement of the γ radiation Kerma rate in air were analyzed and then the differential equation of the correlation factors was established theoretically,and by resolving the equation,the mathematical model Was obtained.The model was discussed through several practical examples.Results The mathematical model was coincided with the tendency of curve about the measured data on the influence rule of rainfall to the γ radiation Kerma rate in surface air.Conclusion By using the theoretical formula in this article which is established to explain the relationship between the rainfall and the γ radiation Kerma rate in surface air,the influence of rainfall to the γ radiation Kerma rate in surface air could be correctly revised.

CLONING AND EXPRESSION OF A GENE MEDIATINGγ-RADIATION-INDUCED APOPTOSIS IN HL-60 CELLS / 药物分析学报

Objective To identify the member of the caspase family proteases involved in γ-radiation-induced apoptosis in HL-60 cells and to study the expression of the caspase gene in normal, apoptotic cells and in immortal tu mor cells. Methods By using degenerate oligonucleotide primers encoding the highly conserved peptides that were pre sent in all known caspases, we performed RT-PCR on poly(A)RNA from γ-radiation-induced apoptotic HL-60 cells. Caspase-3 mRNA in apoptotic HL-60 cells and in human tumor cell lines was analyzed by Northern blot. Results The amplified DNA fragment was identified with caspase-3 cDNA by cloning and sequencing. The Northern blot analysis of caspase-3 mRNA of different human tumor cell lines showed that the caspase-3 gene transcript was more highly ex pressed in leukemia cell lines and the SH-SY5Y cell line than in HeLa and MCF-7 cells. It was more highly expressed in the radiation-induced apoptotic HL-60 cells than in control HL-60 cells. Conclusion These results indicated that caspase-3 was involved in γ-radiation-induced apoptosis in HL-60 cells. The high level of expression of caspase-3 may aid efforts to understand the insensitivity of some tumor cells to radiation, their inherent ability to survive, and apop tosis.