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@#<b>Objective</b> To investigate the effects of low-dose nuclear radiation exposure on the body by analyzing the antioxidant indices, immune indices, lymphocyte proliferation activity, and blood biochemical indices of persons exposed to long-term low-dose nuclear radiation, and to provide a basis for radiation protection and occupational health monitoring. <b>Methods</b> Eighty nuclear radiation workers were selected as the exposure group, and another 30 non-exposure personnel were selected as the control group. In both groups, blood biochemistry, serum total antioxidant capacity (T-AOC), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), lymphocyte proliferation activity, proliferating cell nuclear antigen (PCNA), apoptosis factors Bcl-2 and Bax, lymphocyte transformation rate, and lymphocyte micronucleus rate were measured. <b>Results</b> Compared with the control group, T-AOC, GSH-Px, SOD, cell proliferation activity, PCNA, Bcl-2, lymphocyte transformation rate, white blood cell count, and platelet count in the exposure group were significantly decreased, while MDA and Bax were significantly increased (<i>P</i> < 0.05). The lymphocyte micronucleus rate showed no significant difference between the two groups (<i>P</i> > 0.05). <b>Conclusion</b> Long-term low-dose exposure to nuclear radiation has certain effects on related indices of workers, but does not cause significant damage. The personnel exposed to nuclear radiation should enhance the awareness of protection and strengthen scientific protection to reduce radiation damage.
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ObjectiveTo explore the effects and possible mechanisms of Jianpi Bushen Formula （健脾补肾方） on radiation-induced immune function damage of mice. MethodsFifty mice were randomly divided into four groups： normal group， model group， thymosin group， high- and low-dose groups of Jianpi Bushen Formula， with 10 mice in each group. Except for the normal group， the mice in the other groups were irradiated with a single whole-body dose of 6.0 Gy X-rays to establish a radiation-injured mouse model. After the successful modeling， the low- and high-dose groups of the Jianpi Bushen Formula were given respectively 13 g/（kg·d）、 26 g/（kg·d） of the formula by gavage， while the thymosin group was given 11.7 mg/（kg·d） of thymosin by gavage， and the normal group and model group were given 0.1 ml/（10g·d） of 0.9% sodium chloride solution by gavage. Each group was administered once a day for 7 consecutive days. After the last gavage， the mice were weighed， and their spleens were separated and weighed to calculate the spleen index. The levels of interferon gamma （IFN-γ） and interleukin 2 （IL-2） in the spleen tissue were detected by enzyme linked immunosorbent assay （ELISA）. The autophagosomes in the spleen were observed by transmission electron microscopy. The mRNA expression levels of phosphatidylinositol 3-kinase （PI3K）， protein kinase B （Akt）， and mammalian target of rapamycin （mTOR） in the spleen were detected by real-time fluorescent quantitative PCR. The protein expression of PI3K， Akt， and mTOR in the spleen， as well as the expression of autophagy-related proteins microtubule-associated light chain protein 3 （LC3）， Beclin1， and p62 were detected by Western blot. ResultsCompared with the normal group， the model group showed significant decreases in body weight， spleen index， and levels of IFN-γ and IL-2 in the spleen （P＜0.01）； the mRNA and protein expression levels of PI3K， Akt， and mTOR in the spleen were also significantly reduced （P＜0.01）； the expression of Beclin1 protein， the ratio of LC3-II/LC3-I significantly increased （P＜0.01）， while the level of p62 protein expression significantly decreased （P＜0.01）. And transmission electron microscopy showed a significant increase in the number of autophagosomes in the spleen and severe cell structure damage in the model group. Compared with the model group， all the above indicators in each medication group were significantly improved （P＜0.05 or P＜0.01）. In the high-dose Jianpi Bushen Formula group， partial intact cristae were visible in the fine mitochondria of the spleen， and there were more autophagosomes. In the low-dose Jianpi Bushen Formula group and thymosin group， the structure of the fine mitochondria in the spleen was relatively intact， and there were fewer autophagosomes. The improvement effect of the low-dose Jianpi Bushen Formula group was better than that of the high-dose group （P＜0.05 or P＜0.01）， and there was no significant difference between the low-dose group and the thymosin group in terms of each indicator （P＞0.05）. ConclusionJianpi Bushen Formula may alleviate the structural damage of the spleen， promote the recovery of immune function， and achieve a best effect at a low dose by enhancing the PI3K/Akt/mTOR signaling pathway in the spleen and inhibiting the over-activation of autophagy induced by radiation.
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ObjectiveTo investigate the protective effect of Zuoguiwan against 60Co-γ ray-induced premature aging of rats based on the phosphatidylinositol-3-kinases/protein kinase B/mammalian target of rapamycin （PI3K/Akt/mTOR） signaling pathway. MethodSixty sexually mature female SD rats were irradiated with 60Co-γ rays （6.0 Gy， LD40） for 24 h at one time. Then they were randomized into model group， Bujiale group （0.18 g·kg-1·d-1）， Bujiale （0.09 g·kg-1·d-1） + high-dose Zuoguiwan group （23.625 g·kg-1·d-1）， high-dose Zuoguiwan group （23.625 g·kg-1·d-1）， medium-dose Zuoguiwan group （9.45 g·kg-1·d-1）， and low-dose Zuoguiwan group （4.725 g·kg-1·d-1）. The administration （once a day） lasted 21 days. Serum indexes ［follicle-stimulating hormone （FSH）， luteinizing hormone （LH）， and estradiol （E2）］ of rats were detected by enzyme-linked immunosorbent assay （ELISA）， and morphological changes of ovarian tissues were observed based on hematoxylin and eosin （HE） staining. The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） and the protein expression of phosphorylated （p）-PI3K， p-Akt， p-mTOR， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax） in ovarian tissues by Western blot. ResultCompared with normal group， model group demonstrated increase in serum FSH （P<0.01）， decrease in E2 （P<0.05）， and reduction of follicles and luteum in early ovary （P<0.01）. Moreover， the elevation of apoptosis rate of granulosa cells （P<0.01）， down-regulation of p-PI3K， p-Akt， p-mTOR， and Bcl-2 in ovarian tissue， and increase in expression of Bax were also observed in the model group as compared with the normal group （P<0.01）. In comparison with the model group， the administration groups showed rise of the number of early ovarian follicles， decrease in the apoptosis rate of granulosa cells， increase in the expression of p-PI3K， p-Akt， p-mTOR， and Bcl-2， and down-regulation of Bax， particularly the Bujiale + high-dose Zuoguiwan group（P<0.05，P<0.01）. ConclusionZuoguiwan protects radiation-damaged ovary by activating the expression of PI3K/Akt/mTOR protein in ovarian tissue， increasing Bcl-2， and inhibiting the expression of Bax.
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ObjectiveTo investigate the protective effect of Zuoguiwan against 60Co-γ ray-induced premature aging of rats based on the phosphatidylinositol-3-kinases/protein kinase B/mammalian target of rapamycin （PI3K/Akt/mTOR） signaling pathway. MethodSixty sexually mature female SD rats were irradiated with 60Co-γ rays （6.0 Gy， LD40） for 24 h at one time. Then they were randomized into model group， Bujiale group （0.18 g·kg-1·d-1）， Bujiale （0.09 g·kg-1·d-1） + high-dose Zuoguiwan group （23.625 g·kg-1·d-1）， high-dose Zuoguiwan group （23.625 g·kg-1·d-1）， medium-dose Zuoguiwan group （9.45 g·kg-1·d-1）， and low-dose Zuoguiwan group （4.725 g·kg-1·d-1）. The administration （once a day） lasted 21 days. Serum indexes ［follicle-stimulating hormone （FSH）， luteinizing hormone （LH）， and estradiol （E2）］ of rats were detected by enzyme-linked immunosorbent assay （ELISA）， and morphological changes of ovarian tissues were observed based on hematoxylin and eosin （HE） staining. The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） and the protein expression of phosphorylated （p）-PI3K， p-Akt， p-mTOR， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax） in ovarian tissues by Western blot. ResultCompared with normal group， model group demonstrated increase in serum FSH （P<0.01）， decrease in E2 （P<0.05）， and reduction of follicles and luteum in early ovary （P<0.01）. Moreover， the elevation of apoptosis rate of granulosa cells （P<0.01）， down-regulation of p-PI3K， p-Akt， p-mTOR， and Bcl-2 in ovarian tissue， and increase in expression of Bax were also observed in the model group as compared with the normal group （P<0.01）. In comparison with the model group， the administration groups showed rise of the number of early ovarian follicles， decrease in the apoptosis rate of granulosa cells， increase in the expression of p-PI3K， p-Akt， p-mTOR， and Bcl-2， and down-regulation of Bax， particularly the Bujiale + high-dose Zuoguiwan group（P<0.05，P<0.01）. ConclusionZuoguiwan protects radiation-damaged ovary by activating the expression of PI3K/Akt/mTOR protein in ovarian tissue， increasing Bcl-2， and inhibiting the expression of Bax.
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Objective:To confirm the mechanism of Sedum alfredii extract (SafE) alleviating radiation injury in human small intestinal epithelial cells (HIEC-6). Methods:HIEC-6 cells were divided into 4 groups, including control group (Con), irradiation group (IR), SafE alone group (SafE) and SafE plus irradiation group (SafE+ IR). All of the SafE groups were treated with 0.02 g/ml (W/V) SafE for 24 h. Cell viability (CCK-8 method ) and intracellular ROS levels were investigated at 24 h after 2, 4, and 6 Gy irradiation. Samples were taken at 24 h after 4 Gy irradiation for transcriptome analysis, and the intracellular E3 ubiquitin ligase PRKN expression level was measured. The thickness of endoplasmic reticulum was detected at 24 h after 4 Gy irradiation using fluorescent dye.Results:SafE could maintain cell viability after irradiation ( t=2.94-10.40, P<0.05), and significantly reduced the level of ROS in the irradiated cells ( t=-13.29--4.53, P<0.05). PRKN was preliminarily verified to be the target gene of SafE that maintained PRKN transcript level and endoplasmic reticulum thickness after irradiation (IR group vs. Con group: t=-5.55, 3.27, P<0.05, SafE group vs. SafE+ IR group: P>0.05). Conclusion:SafE is effective in maintaining ER thickness and reducing cellular radiation damage and its target gene PRKN could be regulated by ionizing radiation.
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X-ray examination is an important part of modern precision medicine,and plays an irreplaceable role in the diagnosis and evaluation of disease outcomes as well as the surgical planning.With the widespread use of digital radiology and CT examinations,repeated and excessive X-ray examinations occur that cause the subject to receive excessive or additional radiation doses which cause radiation damage.How to optimize the radiation dose to meet the diagnosis of the disease and reduce the radiation damage of the subject is an important topic for researchers and equipment developers.As a result,X-ray radiation damage has attracted the attention of governments,society,subjects and X-ray inspection workers.This article explores ways to reduce radiation dose and reviews its progress.
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Objective@#To explore the long-term effects of radiation injury and to provide scientific basis for the evaluation of the effects of ionizing radiation injury by carrying out medical follow-up of patients involved in the " 5.7" radiative source accident in Nanjing in 2014.@*Methods@#Through interviewing and investigating, we inquired about the new disease history of the exposed patients from rehabilitation treatment to medical follow-up peroid. Physical and laboratory examinations were carried out. According to relevant standards, physiological and biochemical indexes such as hematopoietic system, immune system, endocrine system, ophthalmology, circulatory system, digestive system, urinary system and bone mineral density were systematically evaluated, with the long-term effects being evaluated.@*Results@#The patient′s vital signs were good without new diseases. The indexes of hematopoietic system, immune system and endocrine system tended to be normal, the circulatory system, digestive system and urinary system showed degenerative changes, the ophthalmic examination showed visual acuity continue to decline, and bone mineral density examination indicated low bone mass.@*Conclusions@#Physiological and biochemical indicators of the patients gradually returned to normal without obvious symptoms of radiation damage. Further medical follow-up observation still needs to continue.
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Objective To study the radiation-induced mitochondrial damage and energy metabolic alteration in pancreatic exocrine cells,and to explore underlying mechanism.Methods Rat pancreatic exocrine cells (AR42 J) were divided into control group and experimental group irradiated with 6 Gy of X-rays.Mitochondrial membrane potential was detected at 24,48,72 and 96 h,the lactic acid and ATP production were detected at 24 h and 48 h,and reactive oxygen species (ROS) were detected at 24 h after irradiation.The expressions of energy metabolism related factors of HIF-1α,LDHA and PDH were detected by Western blot.The animal experiments were conducted to confirm the changes.According to random number table,eight rats were randomly divided into two groups with 4 rats in each.The irradiated group was exposed to 12 Gy of X-rays,while the control group sham-irradiated.Results Compared with the nonirradiated control group,the mitochondrial membrane potential (△Ψm) of the experimental group was progressively decreased at 24-96 h after irradiation (t =5.438-17.687,P＜0.05).The ATP content in the experimental group decreased at 24 h and 48 h (q=17.300,8.328,P＜0.05),the lactic acid increased (q =21.790,16.250,P＜0.05),and the ROS level increased (t =7.935,P＜0.05).The expressions of HIF-1α and LDHA were significantly increased,but PDH was reduced after radiation.Silencing HIF-1α by siRNA eliminated radiation-induced energy metabolic alteration.These changes were confirmed with animal experiments by locally irradiating rats.Conclusions The expression of HIF-1α is upregulated by irradiation,which leads to the change of energy metabolism as the enhancement of glycolysis pathway and the inhibition of aerobic oxidation of mitochondria in pancreatic exocrine cells.
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DNA repair pathways, cell cycle checkpoints, and redox protection systems are essential factors for securing genomic stability. The aim of the present study was to analyze the effect of Ilex paraguariensis (Ip) infusion and one of its polyphenolic components rutin on cellular and molecular damage induced by ionizing radiation. Ip is a beverage drank by most inhabitants of Argentina, Paraguay, Southern Brazil, and Uruguay. The yeast Saccharomyces cerevisiae (SC7Klys 2-3) was used as the eukaryotic model. Exponentially growing cells were exposed to gamma rays (γ) in the presence or absence of Ip or rutin. The concentrations used simulated those found in the habitual infusion. Surviving fractions, mutation frequency, and DNA double-strand breaks (DSB) were determined after treatments. A significant increase in surviving fractions after gamma irradiation was observed following combined exposure to γ+R, or γ+Ip. Upon these concomitant treatments, mutation and DSB frequency decreased significantly. In the mutant strain deficient in MEC1, a significant increase in γ sensitivity and a low effect of rutin on γ-induced chromosomal fragmentation was observed. Results were interpreted in the framework of a model of interaction between radiation-induced free radicals, DNA repair pathways, and checkpoint controls, where the DNA damage that induced activation of MEC1 nodal point of the network could be modulated by Ip components including rutin. Furthermore, ionizing radiation-induced redox cascades can be interrupted by rutin potential and other protectors contained in Ip.
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Rutin/pharmacology , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/radiation effects , Plant Extracts/pharmacology , Antimutagenic Agents/pharmacology , Ilex paraguariensis/chemistry , Radiation Protection/methods , Mass Spectrometry , DNA, Fungal/radiation effects , Cell Survival/drug effects , Cell Survival/radiation effects , Cells, Cultured , Reproducibility of Results , Chromatography, Liquid , Mutagenesis , DNA Repair , Dose-Response Relationship, Radiation , DNA Breaks, Double-Stranded , Mutation Rate , Gamma RaysABSTRACT
Objective@#To investigate occupational health status about radiation workers from township hospitals in Gansu, China, and to explore the dose-effect relationship of exposure dose of radiation workers.@*Methods@#A total of 390 X-ray workers from township hospitals in Gansu Province and 450 X-ray workers from the county/district-level hospitals in the county/district where the township hospitals were located were divided into research group and control group. Their workload, radiation protection condition, and occupational health monitoring data were used for impact assessment and risk estimation.@*Results@#The annual workload of radiation workers from township hospitals was 845.33±361.622 people, and that of radiation workers from county/district-level hospitals was 1967.74±762.055 people; there was a significant difference in annual workload between the two groups of subjects (P<0.05) . Indices such as detection rate of lens opacity, detection rate of abnormal platelet count, red blood cell count, and hemoglobin count, micronucleated lymphocyte rate, and chromosome aberration rate were significantly different between the two groups (P<0.05) .@*Conclusion@#Radiation workers from township hospitals suffer from certain radiation damage.
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Objective@#To understand the healthy status of radiation workers on the staff in Nanjing, and to analysis the relationship between abnormal crystalline lens and its influencing factors.@*Methods@#We described physical indicators including blood pressure (BP) 、blood sugar (BG) 、thyroid B ultrasound、crystalline lens、chromosome and so on among 3 349 radiation workers on the staff in the year 2016 from Jan 1 to Dec 31, and the abnormal results of crystalline lens were analyzed statistically.@*Results@#The rate of abnormal BP、BG、WBC、Thyroid B ultrasound、crystalline lens was 19.0%、2.2%、5.8%、30.0%、3.6% respectively; The rate of chromosome aberration was 0.1%, and the chromosomal micronuclei are all within normal range. With the rate of abnormal crystalline lens increasing in age and working years, statistical significance both existed in the trend; Compared to the lowest group, the risk of abnormal crystalline lens increased 3.86 times in ≥60 year old group and 3.16 times in ≥30 years working group; The risk of abnormal crystalline lens in nosocomial radation group was higher than non-medical group; There's no found in smoking and drinking alcohol increasing the risk. Morphologically, dot abnormal focused on 30~39 years old and 0~9 working years group, while lamellar abnormal concentrated upon ≥60 year old、≥30 working years group; Age and working-year were both the risk factors of lamellar abnormal; The risk of lamellar abnormal in nosocomial radiation group was significantly higher than non-medical group.@*Conclusion@#Existing nisk foctions in the radiation work has a serious impact on several healthy physiology indicators, the more prominent was crystalline lens. Attention should be paid to eye protection and comprehensive health management.
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Objective To evaluate the effect of iodine contrast agent on the biological responses of CT examination. Methods A total of sixty patients with suspected urinary tract disease who underwent computed tomography urography ( CTU ) examination were randomly divided into control group and experimental group. The control group was treated with routine CTU, where only CT scan was performed on the first day. CTU was added after 3 days. The test group was treated with fractional injection CTU and injected with enhanced scanning agent on the first day. Before and after CT examination, the patients′peripheral blood was collected and the number of γ-H2AX foci in lymphocytes ( mononuclear cells) was measured by immunofluorescence, and the differences of DNA damage in these two groups were observed. Results Before and after CT examination, the number ofγ-H2AX foci was 0. 06 ± 0. 02 and 1. 06 ± 0. 27 in the lymphocytes of control group,0. 06 ± 0. 03 and 1. 42 ± 0. 50 in the test group, respectively. Hence, the number ofγ-H2AX foci in the test group was increased by 38. 14%. Moreover, the change ofγ-H2AX foci in these two groups was not influenced by gender, but correlated with ages( between≤50 years old and>50 years old) in control group (t= -4. 76, P<0. 05) and in test group(t= -8. 16, P <0. 05). Conclusions The iodine contrast agent can increase DNA damage of CT examination, and therefore the use of iodine contrast agent in CT should be reduced as much as possible in clinical work.
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Objective To investigate radiation-related human plasma metabolic features by using metabonomics method and to analyze relative metabolic pathway .Methods The plasma samples of 40 patients pre-and post-total body irradiation (TBI) from January 2012 to May 2014 were collected, and the effect of TBI on human plasma metabolites was studied by gas chromatography mass spectrometry ( GC-MS) , and the differential plasma metabolic features related to irradiation damage were screened . Results The levels of glucose, myristic acid, oxalic acid, 3-hydroxy butyric acid, urea, aspartic acid, valine, leucine, lysine and threonine in plasma were significantly (P<0.05) increased after TBI, while the levels of cholesterol, pyruvic acid, propionic acid, lactic acid, alanine, glycine, inositol, sorbitan, ethylene glycol and hypoxanthine were decreased drastically (P<0.05).Conclusions TBI could cause significant changes in the levels of human plasma metabolites including amino acid metabolism , glucose metabolism, lipid metabolism and so on.
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Objective To investigate the radiobiological effects of radiation with different dose rates on human nasopharyngeal carcinoma cell line CNE-2 treated with or without a poly ADP-ribose polymerase (PARP) inhibitor,olaparib.Methods The concentration of olaparib used to treat cells equaled to the inhibition concentration IC10 of olaparib to CNE-2 cells.The CNE-2 cells were divided into acute radiotherapy (RT) group,fractionated radiotherapy (FRT) group,olaparib + RT group,and olaparib + FRT group.All groups were exposed to radiation of 0,1,2,3,5,7,and 10 Gy at a dose rate of 3 Gy/min.The delivery time for each dose point was 4 min in RT and 30 min in FRT.The colony forming assay was used to evaluate the survival of CNE-2 cells at each dose point.The multi-target,single-hit model was used to fit the cell survival curves and the parameters,D0,Dq,and SF2,were calculated.At dose points of 0.1,and 2 Gy,western blot was used to determine the expression of PARP-1 in the RT group and the FRT group and γH2AX in each group.Immunofluorescence was used to evaluate the γH2AX focus formation.A single factor analysis of variance was used to compare the 4 groups,and two two compared with SNK-q test.Results The IC10 value of olaparib to CNE-2 cells was 4.0 μmoL/L.At dose points of 1 and 2 Gy,the PARP-1 expression was significantly higher in the FRT group than in the RT group (P=0.029,0.022),while the γH2AX focus number was significantly smaller in the FRT group than in the other three groups (all P＜0.05);compared with the RT group,the D0,Dq,and SF2 values in the FRT group were increased by 11.67％,15.78％,and 23.61％,respectively;compared with the FRT group,the D0,Dq,and SF2 values in the Olaparib+ FRT group decreased by 11.19％,6.44％,and 13.26％,respectively;there were no significant differences in above indices between the RT group,the Olaparib+RT group,and the Olaparib+FRT group.Conclusions For the same radiation dose,fractionation reduces the relative dose rate and weakens the radiobiological effects.lowdose olaparib can compromise the single strand break repair induced by the decline of the relative dose rate in a fractionated irradiation mode,which promotes the formation of double-strand break and improves the radiobiological effects.
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The number of people needed to accept radiotherapy is increasing with the higher incidence of tumor,and the continuous development of radiation therapy technology has extended the longterm survival of patients.Avoiding the occurrence of radiation damage is particularly important.Since NF-κB plays an important role in gene transcription and regulation of radiation damage,this article introduced the structure,activation and function of NF-κB,reviewed the findings of NF-κB alterations in radiation injuries of brain and lung,and sketched the studies of NF-κB inhibitor.
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Radiation ulcers are wounds caused by acute or chronic effects of ionizing radiation. The injury may involve the skin, underlying soft tissue, and even deeper into bones. Radiation is used alone or in combination with surgery and chemotherapy. Although it is useful to affect tumor death, it also exerts a deleterious effect on surrounding normal tissues. These effects are either acute or can manifest months or years after the treatment. The chronic wounds are a result of impaired wound healing. This impairment leads to fibrosis, nonhealing ulcers, lymphedema and radionecrosis amongst others.
Subject(s)
Drug Therapy , Fibrosis , Lymphedema , Radiation, Ionizing , Radiotherapy , Skin , Ulcer , Wound Healing , Wounds and InjuriesABSTRACT
Megakaryocytic hematopoietic disorders is one of the leading causes of death in patients with acute radiation sickness bleeding. Thrombopoietin (TPO),the main stimulation factor of megakaryocytopoiesis, can promote megakaryocytic hematopoietic recovery after radiation injury and increase peripheral platelet count. Early application of TPO after irradiation can play a key role in prevention and treatment of bleeding complications of acute radiation sickness. Studies have shown that TPO may have a stronger role in promoting hematopoiesis. In this paper, a brief overview of new progress on the TPO and acute radiation sickness is summarized.
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Objective To investigate the role of epigallocatechin gallate ( EGCG) in reversing the CpG island methylation of Rad23b and Ddit3 gene promoter and its mRNA expression induced by 0?5 Gy X-rays. Methods Thirty BALB/c male mice were randomly divided into 6 groups: control group, irradiation group, low/high dose of EGCG group, low/high dose of EGCG with irradiation group. For the irradiation group, mice were fractionally exposed with 6 MV X-rays for 10 d (0?05 Gy/d × 10 d). 2 hours after the final irradiation, all mice were killed and such tissues as blood, kidney, liver, spleen, brain, and lung were collected. Methylation and expression levels of Rad23b and Ddit3 were measured by bisulfate sequencing primers ( BSP) and Real-time PCR, respectively. Results Compare to the control group, Rad23b was hypermethylated in PBMC, liver, spleen, brain and lung (t= -20?19, -14?80, -12?05,-28?42, -12?58, P<0?05) in the irradiation group. Meanwhile, its mRNA expression level was down-regulated in PBMC, liver, brain and lung (t=25?25, 17?43, 11?53, 22?85, P<0?05). Similarly, a significant hypermethylation change of Ddit3 was observed in PBMC, liver and lung after irradiation ( t=-52?89, -20?31, -3?85, P<0?05) so that the mRNA expression of Ddit3 decreased in PBMC and liver ( t = 11?89, 16?52, P < 0?05 ). Compared to the irradiation group, EGCG with different concentrations of 10, 20 mg/kg significantly reduced the methylation level of Rad23b and Ddit3 ( t =-13?39-7?99, P<0?05), and induced re-expression of mRNA (t= -34?02 - -2?89, P<0?05). This change was more notable in the irradiation group with the high dose of EGCG. Conclusions As a natural drug, EGCG may play an important role in affecting DNA methylation and hence protects DNA from radiation damage.
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Megakaryocytic hematopoietic disorders is one of the leading causes of death in patients with acute radiation sickness bleeding. Thrombopoietin (TP0)the main stimulation factor of megakaryocytopoiesis ’ can promote megakaryocytic hematopoietic recovery after radiation injury and increase peripheral platelet count. Early application of TP0 after irradiation can play a key role in prevention and treatment of bleeding complications of acute radiation sickness. Studies have shown that TP0 may have a stronger role in promoting hematopoiesis. In this paper,a brief overview of new progress on the TP0 and acute radiation sickness is summarized.
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In the field of medicine or dentistry, cancer is one of the most common causes for death of the individual worldwide, in which oral cancer accounts for about 10% of it. One of the most important treatment modalities for cancer includes radiotherapy. During radiotherapy, exposure of the normal tissue to these ionizing radiations, results in mutagenesis and cell death. Several modalities and clinical approaches have been made to reduce these early and late complications of the radiotherapies and one among them is, by the means of pharmacological agents. Many experimental and clinical studies have given rise to new concepts of chemical and molecular pharmacological agents that could be effective in protection and treatment of radiation damage to surrounding normal tissues. Clinical Significance: To reduce the significant complications in irradiated patients, the clinical implication of these radioprotective agents have emerged as potential drugs and with anti-tumour effect in the radiotherapy of various cancers including oral carcinomas.