The inhibiting effects of low dose radiation on dendritic growth of newborn neurons in rat hippocampus

Objective To investigate the effects of low dose radiation on the level of oxidative damage and antioxidant in population of high background radiation area of Guangdong. Methods A total of 48 male residents who lived in high background radiation area(HBRA) of Guangdong province and 48 male residents who lived in neighboring Enping control area were chosen as the objectives and control respectively. The peripheral venous blood of two groups was collected, and then the levels of 8-OHdG and TrxR were determined by enzyme linked immunosorbent assay (ELISA). Results Compared with the CA group [(315.39±100.59) ng/ml], the level of 8-OHdG [(272.64±96.85) ng/ml] decreased significantly in HBRA (t=2.121, P<0.05). Compared with the CA group [(0.467±0.056) ng/ml], the level of TrxR [(0.496±0.044) ng/ml] increased significantly in HBRA (t=-2.823, P<0.05). The results of multiple linear regression analysis demonstrated that the chronic exposure to low dose of radiation had significant effects on the expression level of 8-OHdG and TrxR(t=-2.327, 2.367, P<0.05) after adjustment for confounding factors such as age, drinking, tea drinking, smoking, medical exposure and stressful events. Conclusions Chronic exposure to low dose radiation may decrease the level of oxidative and enhance the level of antioxidant. Key words: Low dose radiation; Oxidative damage; 8-Hydroxydeoxyguanosine; Thioredoxin reductases

The genesis of carcinogenic diseases is characterized by a multifactor dependence. The effect of low dose radiation in combination with environmental factors has a significant number of features. It was studied the influence of certain features of the environment and the mental state of the person (affect) on the development of the incidence of carcinogenic diseases of the population in Ukraine. Given the various adverse environmental conditions, the effect of radiation in low doses can be enhanced or weakened. Synergism and antagonism of the effect of low dose radiation and environment on the health of the population are discussed.

Objective To observe the effects of low dose radiation on cytokine-induced killer cells on breast cancer cell lines and explore the possible mechanism. Methods Peripheral blood mononuelear cells (PBMC) were separated from healthy human peripheral white blood cells. DCs and CIK cells were prepared from human PBMCs with different cytokines. CIK cells were cocultured with autologous DCs for 7 days at a ratio of 1∶5 to get immunologic effector DC-CIK cells. DC-CIK and CIK cells were irradiated by X-rays at different doses of 40, 80, 120 mGy, then their phenotypes were analyzed by flow cytometry and their cytotoxic effects on breast cancer cell lines were detected by CCK-8 assay. Results Compared with CIK group, DC-CIK group enhanced the cytotoxicity in breast cancer cells at different ratios (t=3.63, 5.62, 8.21, 5.49, P<0.05). Compared with CIK 0 mGy group, low dose irradiated CIK cells induced a higher cytotoxicity to MCF-7 and SK-BR-3 breast cancer cells. But there was no significant difference between DC-CIK 0 mGy group and low dose irradiated DC-CIK cells. Conclusions Low dose radiation has synergistic effect with CIK cells on killing breast cancer. Key words: Low dose radiation; CIK cells; DC-CIK cells; Breast cancer; Killing activity

Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation.

Protective effects of Zuogui Jiangtang Jieyu Formula on hippocampal neurons in rats of diabetes complicated with depression via the TRP/KYN metabolic pathway

Electrophysiology of hippocampal neurons. I. Sequential invasion and synaptic organization.

Objective: To determine the NK activity of lymphocyte subsets and the effects of low dose radiation. Methods: Lymphocyte subsets were separated by monoclonal antibodies. The NK activity of each subset on tumor cells was detected by radioactive release method. Results: The results showed that besides NK cells, CD4, CD8 and B cells alone can kill tumor cells. But the cell-killing activity of NK cells appeared to be strongest There was synergistic effect between CD4 and NK cells. The activity of mixed lymphocytes was more than that of only one subset. The effect of low dose radiation (LDR) on NK activity of panlymphocytes or NK cells was different. Conclusion: This paper demonstrated that NK activity of mononuclear cells was called “NK activity of lymphocytes”, but it is not true. Only when NK cells were separated by monoclonal antibodies, its killer activity can be called “activity of NK cells”.

The present paper reviews recent experimental data obtained from studies on stimulation of immune functions and induction of cytogenetic adaptive response by low level radiation. An attempt is made to integrate recent observations in the author's laboratory. Emphasis is given to the effects of single and chronic whole-body irradiation (WBI) with X- or γ-rays. A schematic diagram of the interactions of the immune cells after low dose radiation is proposed to elucidate the possible cellular mechanism of the stimulatory effect of low dose radiation on immunity. Experimental data on the dose-effect relationship of induction of cytogenetic adaptive response in somatic and germ cells by single and chronic whole-body irradiation are presented. In the analysis of the molecular mechanism of the stimulatory effect of low dose radiation the activation of signal transduction pathways and induction of genes related to cell survival and proliferation are emphasized. The implications of the existing data are discussed and future investigations for the elucidation of possible common molecular basis of stimulation of biological defense and adaptation by WBI with low doses are suggested.

British Nuclear Energy Society. Third International Conference on Health Effects of Low Dose Radiation: Challenges for the 21st Century, Stratford-upon-Avon, UK, 11 - 14 May 1997

Objective To investigate the effect of low dose radiation on the expression of p16 gene in chronic myelogenous leukemia.Methods Leukemic stem cells(LSCs)which expressed CD34+,CD38- and CD123+ were isolated from bone marrow cells obtained from twenty patients newly-diagnosedas chronic myeloid leukemia with EasySepTM magnet beads.Hematopoietie stem cells(HSCs) which expressed CD34+ and CD38- were isolated from human cord blood cells obtained from twenty full-term deliveries with EasySepTM magnet beads as control.HSCs vs LSCs samples were further divided into three dose groups,including 0,12.5 and 50 cGy,respectively.RT-PCR and real-time quantitative reverse transcription-polymerase chain reaction methods were used to detect mRNA expression of p16 gene in HSCs and LSCs after irradiation.Cells were harvested at different time for detection of cell cycle and apoptosis by flow cytometer.Results p16 mRNA level in CML-LSCs was increased slightly at 12.5 cGy,and significantly increased at 50 cGy(Z=-3.39,P<0.01),but ho significant change was found in HSCs.The percentage of CML-LSCs cell in G0/G1 stagewas increased 48 h after 12.5 cGy irradiation,and 72 h post-irradiation with 50 cGy.The apoptosis rate of CML-LSCs was gradually raised after LDR,especially at 72 h post-irradiation of 50 cGy[(17.75±11.76)%vs(6.13±4.71)%,Z=-2.37,P<0.01 ].Conclusions p16 gene transcription could be up-regulated by low dose radiation,which might provide a theoretical evidence for CML therapy and LDR in leukemic clinical application. Key words: Low dose radiation; p16 gene; Leukemia; Stem cell

New insights concerning insulin synthesis and its secretion in rat hippocampus and cerebral cortex: Amyloid-β1–42-induced reduction of proinsulin level via glycogen synthase kinase-3β

2001 International Symposium on Radiation and Health (2001 ISRH): Low Dose Radiation Effects on Human Health

Effects of low dose ionizing radiation on the brain- a functional, cellular, and molecular perspective

Objective: To study the effects of low dose radiation (LDR) on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods: Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguen as an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGy whole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumor sizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flow cytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cells were observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantly slower after LDR (P<0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2 protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h after LDR (P<0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumor cells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. The organized immune function and anti-tumor ability are markedly increased after LDR. Our study provides practical evidence of clinical application to cancer treatment.

Ablehnung der Behandlung von Patienten mit MRE in geriatrischen Kliniken und Rehabilitationseinrichtungen: Einzelfälle oder gängige Praxis?