Ionizing Radiation Induces Disc Annulus Fibrosus Senescence and Matrix Catabolism via MMP-Mediated Pathways.

Previous research has identified an association between external radiation and disc degeneration, but the mechanism was poorly understood. This study explores the effects of ionizing radiation (IR) on inducing cellular senescence of annulus fibrosus (AF) in cell culture and in an in vivo mouse model. Exposure of AF cell culture to 10-15 Gy IR for 5 min followed by 5 days of culture incubation resulted in almost complete senescence induction as evidenced by SA-ßgal positive staining of cells and elevated mRNA expression of the p16 and p21 senescent markers. IR-induced senescent AF cells exhibited increased matrix catabolism, including elevated matrix metalloproteinase (MMP)-1 and -3 protein expression and aggrecanolysis. Analogous results were seen with whole body IR-exposed mice, demonstrating that genotoxic stress also drives disc cellular senescence and matrix catabolism in vivo. These results have important clinical implications in the potential adverse effects of ionizing radiation on spinal health.

Use of High-Field Electron Injection into Dielectrics to Enhance Functional Capabilities of Radiation MOS Sensors.

The paper suggests a design of radiation sensors based on metal-oxide-semiconductor (MOS) structures and p-channel radiation sensitive field effect transistors (RADFET) which are capable to function under conditions of high-field tunnel injection of electrons into the dielectric. We demonstrate that under these conditions, the dose sensitivity of the sensor can be significantly raised, and, besides, the intensity of radiation can be monitored in situ on the basis of determining the ionization current arising in the dielectric film. The paper proposes the model allowing to make a quantitative analysis of charge effects taking place in the radiation MOS sensors under concurrent influence of ionization radiation and high-field tunnel injection of electrons. Use of the model allows to properly interpret results of the radiation control. In order to test the designed sensors experimentally, we have utilized γ-rays, α-particle radiation, and proton beams. We have acquired experimental results verifying the enhancement of function capabilities of the radiation MOS sensors when these have been under high-field injection of electrons into the dielectric.

Increasing use of computed tomography scans in the North Denmark Region raises patient safety concern.

PURPOSE: Use of computed tomography (CT) scans raises safety concern as lifetime cumulative ionising radiation exposure is associated with risk of developing malignancies. This study aimed to investigate use of abdominal CT scans in the Danish health care sector. METHODS: Data on abdominal CT scans performed annually in the North Denmark Region between 2005 and 2018 were extracted from the regional registry with emphasis on patients with a medical history of a repeated abdominal CT scan within 28 days. An audit of the medical files was subsequently conducted in 100 randomly selected patient cases to evaluate clinical information being provided, in addition to justification for a repeated abdominal CT scan, and finally if other radiology modalities could have been applied. RESULTS: Number of annually performed abdominal CT scans in this demographically stable regional population increased by a factor 4.3 from 15 in 2005 to 65 in 2018 per 1,000 inhabitants. The audit revealed that 31% of the secondabdominal CT scans within a 28 days period were categorized as either doubtful whether justified or not justified. Moreover, 20% of theCT scans were considered replaceable by ultrasonography. CONCLUSIONS: Annual performance of abdominal CT scans increased fourfold during the 14 years period. This tendency is probably attributable to changes in the Danish health care sector by which CT scan examination are used more frequently aiming at more accelerated patient investigation flow in conjunction with shorter length of hospitalization stay. Alertness is strongly warranted towards the associated risk of cancer due to life-time cumulative ionising radiation exposure by this strategy.

Influence of E-beam irradiation on microbiological and physicochemical properties and fatty acid profile of frozen duck meat.

This study investigated the effect of different doses (0, 3, and 7 kGy) of e-beam on the microbiological and physicochemical qualities and the profile of fatty acids of the frozen duck meat (FDM). Electron beam at the dose of 3 kGy showed more than 2 log and 1 log cycles of reduction in the total bacterial (TAB) and coliform counts (TCC), respectively. The results indicated an increase in the TBARS values (1.50 ± 0.02 mg MDA/kg), peroxide value (0.83 ± 0.04 meq peroxide/kg), and total volatile base nitrogen (1.31 ± 0.16 mg/100 ml), but no effect on the sensory parameters. Irradiation lowered the lightness (L*) (31.87 ± 0.98) and redness (a*) (11.04 ± 0.20) values but elevated the metmyoglobin content in FDM. In addition, irradiation had no effect on the benzopyrene content; however, a reduction was observed in the vitamin A (0.239 ± 0.015 µg/g) and vitamin E (1.847 ± 0.075 µg/g) contents of the FDM samples. There were no trans-fatty acids present in the treated (irradiated) as well as the untreated (nonirradiated) meat samples (FDM), whereas the fatty acid content decreased in irradiated samples, in contrast with the nonirradiated control. Electronic nose clearly discriminated between the nonirradiated and irradiated FDM based on principal component analysis. It is concluded that the e-beam successfully improved the microbial quality of FDM with slight changes in physicochemical properties, but without altering its sensory properties.

Identification of potential radiation-responsive biomarkers based on human orthologous genes with possible roles in DNA repair pathways by comparison between Arabidopsis thaliana and homo sapiens.

Rapid and reliable ionization radiation (IR) exposure estimation has become increasingly important in environment due to the urgent requirement of medical evaluation and treatment in the event of nuclear accident emergency. Human DNA repair genes can be identified as important candidate biomarkers to assess IR exposure, while how to find the enough sensitive and specific biomarkers in the DNA repair networks is still challenged and not fully determined. The conserved features of DNA repair pathways may facilitate interdisciplinary studies that cross the traditional boundaries between animal and plant biology, with the aim of identifying undiscovered human DNA repair genes for potential radiation-responsive biomarkers. In this work, an in silico method of homologous comparison was performed to identify the human orthologues of A. thaliana DNA repair genes, and thereby to explore the sensitive and specific human radiation-responsive genes to evaluate the IR exposure levels. The results showed that a total of 16 putative candidate genes were involved in the human DNA repair pathways of homologous recombination (HR) and non-homologous end joining (NHEJ), and most of them were confirmed by previous experiments. Additionally, we analyzed the gene expression patterns of these 16 candidate genes in several human transcript microarray datasets with different IR treatments. The results indicated that most of the gene expression levels for these candidate genes were significantly changed under different radiation treatments. Based on these results, we integrated these putative human DNA repair genes into the DNA repair pathways to propose new insights of the HR and NHEJ pathways, which can also provide the potential targets for the development of radiation biomarkers. Notably, two putative DNA repair genes, named ERCC1 and ESCO2, were identified and were considered to be the sensitive and specific biomarkers in response to γ-ray exposures.

Biofabrication of silver nanoparticles and their combined effect with low intensity ultrasound for treatment of lung cancer.

Ablation treatments are the minimally invasive surgical procedures that are used to treat early stage cancers. High intensity ultrasonic treatments that are used to treat solid cancers are not much successful in differentiating between healthy and cancerous cells. In this study, a method of combining ultrasound treatment with Garcinia mangostana bark extract mediated silver nanoparticles (AgNPs) was extended by making use of human lung epithelial cells, that could preferentially destruct the cancerous cells. Flow cytometry analysis is used to study the effect of ultrasound and AgNPs on cancerous (A549) cell lines and healthy (BEAS-2B) lung cells by means of counting viable cells (Q4). These experimental data showed a minor decline in the percentage of living cells from (66.8 ±â€¯3.2) to (56 ±â€¯6.2) % after the addition of bark extract synthesized AgNPs to the US-treated normal BEAS- 2B cell lines. However, the percentage of live A549 cancer cells presented a significant reduction from (61.4 ±â€¯4.2) % for US-treated cells to (28.7 ±â€¯6.4) % for the combination treatment of US with AgNPs. This study conducted against various cell lines denoted that nanoparticle-assisted ultrasound therapy (NAUT) could serve as an effective novel means for targeted destruction of cancer cells.

Recent advance in mechanism of cognitive impairment induced by brain ionization radiation / 中华神经医学杂志

Nerve toxicity, such as cognitive dysfunction, often appears in patients with brain tumors after radiotherapy. Cognitive dysfunction after radiotherapy can even appear in patients with extra-cranial tumors such as head and neck cancers. These declines in cognition can seriously affect the patient's quality of life. Therefore, it is very important to find a clear mechanism of brain ionization radiation induced cognitive impairment. At present, the exact mechanism of brain ionization radiation induced cognitive impairment is unclear, and it may be mainly associated with the decline of hippocampal neurogenesis, changes of microenvironment, inflammation, oxidative stress, vascular injury and blood-brain barrier damage, dendritic morphology and N-methyl- D aspartate changes. This review summarizes the recent advance in main mechanism of brain ionization radiation induced cognitive impairment.

Preliminarily Study of the Effect of ?-ray of ~(60)Co on the Growth of Spirulina / 航天医学与医学工程

Objective A foundation for one of the biological components,Spirulina,to be applied in Controlled Ecological Life Support System(CELSS)would be laid with exploring effects of ionization radiation on the growth of Spirulina.Methods By using the ?-rays of ~(60)Co,Spirulina were irradiated.The dose of the ionization radiation covered 0,0.5,1.0,1.5,2.0,2.5,3.0 kGy.After irradiated,these Spirulina were cultured under the same conditions.The growth state,shape change,photodensity change,photosynthetic efficiency(O2 produced),and trophic physiological indexes of Spirulina or its solution,were observed,measured and analyzed.Its anti-irradiation ability was investigated.Results After irradiared with ~(60)Co ray,the growth rate,photosynthetic O2 produced efficiency,length of fila and other trophic physiological indexes were all affected in certain degree,but as compared to the higher plants,Spirulina have stronger radiation proof and self-rehabilitation capacity.Even if under high radiation condition(3.0 kGy),there was no complete death of cells,and the dose resulted in 50% death of the Spirulina was 2.0 kGy.Conclusion Spirulina has stronger ionization radiation proof and self-rehabilitation capacity,it can be considered as one of the key biological components in CELSS for future long-term space missions.