Protective effect of berberine against ionizing radiation injury in rats and its mechanism of action / 中国辐射卫生

Objective To investigate the protective effect of berberine (BBR) against ionizing radiation injury in rats and its mechanism of action. Methods Sprague-Dawley rats were divided into seven groups: normal control group, 1-Gy radiation group, 1-Gy radiation plus low-dose BBR (50 mg/kg) group, 1-Gy radiation plus high-dose BBR (150 mg/kg) group, 3-Gy radiation group, 3-Gy radiation plus low-dose BBR (50 mg/kg) group, and 3-Gy radiation plus high-dose BBR (150 mg/kg) group. All the groups except the normal control group were exposed to external irradiation with a medical electron linear accelerator, followed by BBR administration by gavage for consecutive ten days. The serum levels of superoxide dismutase (SOD), reduced glutathione (GSH), and malondialdehyde (MDA) were measured by using the micromethod. The pathological changes of the bone marrow and small intestine were observed with HE staining. Results Compared with the normal control group, the radiation groups showed significantly increased MDA levels (P < 0.05), significantly decreased SOD and GSH levels (P < 0.05), and more severe pathological damage of the bone marrow and small intestine. Compared with the radiation groups, the BBR groups showed significantly decreased MDA levels (P < 0.05), significantly increased SOD and GSH levels (P < 0.05), and reduced pathological damage to the bone marrow and small intestine, which were more marked in the high-dose BBR group. Conclusion BBR has a certain protective effect against radiation injury in rats, which may be through increasing the activity of antioxidant substances, enhancing free radical clearance, and thereby alleviating free radicals-caused oxidative damage.

Expresión génica de mediadores moleculares para potencial terapia celular en el síndrome gastrointestinal inducido por radiación / Genetic expression of molecular mediators for potential cell therapy in radiation-induced gastrointestinal syndrome

Antecedentes: Las células madres intestinales generan las distintas estirpes celulares a dicho nivel. Estas se regulan por interacciones entre el epitelio y las células del nicho celular anexo. Estas se pueden ver dañadas en tratamientos con radiación, generando el síndrome gastrointestinal inducido por radiación. Se ha visto que células madre mesenquimales (MSC) y macrófagos de médula ósea (BMM) tienen propiedades de regeneración tisular. Objetivos: Evaluar la expresión génica de IL-4, Wnt6, VEGF y bFGF, a partir de cultivos celulares primarios independientes de MSC derivadas de tejido adiposo y BMM de ratones C57BL/6, por medio de PCR en tiempo real (qRT-PCR). Diseño experimental: A partir de un análisis in silico, se confeccionaron primers para evaluar la expresión génica de las moléculas propuestas, en los cultivos primarios por medio de qRT-PCR y electroforesis. Resultados y proyecciones: IL-4 y Wnt6 no son expresadas en las muestras de BMM y MSC. VEGF y bFGF son expresadas por diferentes células, dando expresión diferenciada. A futuro, se deben evaluar las mismas estirpes celulares en un ambiente inflamatorio y su efecto en la expresión génica, en especial VEGF y bFGF. Limitaciones: El número de moléculas en estudio es limitado y la expresión se evalúo solo a nivel genético.

Background: Intestinal stem cell generates diferents cellular types in their niche. They're regulated by interactions between epithelium and niche's cells, and can be damaged by medical radiation treatments causing radiation-induced gastrointestinal syndrome. It has seen that mesenchymal stem cells (MSC) d and bone marrow-derived macrophages (BMM) have propierties of tissular regeneration. Objectives: Determinated genetic expression of IL-4, Wnt6, VEGF and bFGF, in primary cellular cultures of MSC derivated of adipose tissue and BMM of C57BL/6 mice, through real time PCR (qRT-PCR). Methods: By an in silico analysis, we created primers to evaluate the proposed molecules in the primary cellular cultives, with qRT-PCR and electrophoresis. Results and projections: IL-4 and Wnt6 were not expressed in the MSC and BMM samples. VEGF and bFGF were expressed by different cells, giving differential expression. In the future, the same samples should be analyzed in an inflammatory environment, especially VEGF and bFGF. Limitations: The number of molecules are limited and the expression of them is only in a genetic level.

Research progress on the mechanism of cell pyroptosis signaling pathways in radiation injury / 中华放射医学与防护杂志

Pyroptosis is an inflammatory programmed cell death. Unlike apoptosis, pyroptosis is always accompanied by inflammation. It has been found that cell pyroptosis is closely related to the occurrence and development of many diseases. Pyroptosis also plays an important role in radiation injury caused by radiotherapy. Ionizing radiation breaks DNA in cells and induces oxygen free radicals, which are good inducers of pyroptosis. Therefore, this paper reviewed the research progress on the mechanism of cell pyroptosis in radiation injury from the perspective of relative signaling pathways, in order to provide new ideas for weakening or blocking radiation injury.

Research progress of mitochondria as a key target for radioprotection / 中华放射医学与防护杂志

Ionizing radiation can cause damage to biological macromolecules such as DNA and protein, resulting in a series of biological changes such as carcinogenesis, apoptosis and aging. However, after radiation injury, the lack of effective prevention and treatment targets leads to the limited variety of available therapeutic drugs. Recent studies suggest that mitochondria play an important role in radiation injury and are expected to become a new prevention and treatment target. This paper reviewed the effects of ionizing radiation on mitochondria, especially the occurrence of oxidative stress, and the role of mitochondria in radiation-induced biological effects, in order to discuss the feasibility of mitochondria as a potential target for radiation damage prevention and treatment.

Advances on mechanism and treatment of salivary gland in radiation injury / 华西口腔医学杂志

Oral squamous cell carcinoma (OSCC) is the most frequent tumour in head and neck malignant. The current treatment is mainly based on surgery therapy, radiation therapy and chemical therapy. Meanwhile, there are many a defect in the treatment. For example, there are many defects in radiotherapy. Radioactive salivatitis is the most common. In addition, there are a series of changes such as dry mouth, oral mucositis, rampant dental caries, and radioactive osteomyelitis of jaw, which cause swallowing, chewing problems, and taste dysfunction. Currently, the research on radioactive salivatitis is progressing rapidly, but its mechanism is more complication. This paper review aims to summarize the research progress in this field.

Analysis of long-term survival outcomes and late radiation toxicity of 132 nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy / 中华放射肿瘤学杂志

Objective:To retrospectively analyze the long-term survival (10-15 years) and late toxicity of nasopharyngeal carcinoma (NPC) patients after intensity-modulated radiotherapy (IMRT), aiming to provide reference for the optimal treatment of NPC.Methods:132 patients with NPC who were treated with IMRT in Sichuan Cancer Hospital from 2003 to 2009 were recruited. Among them, 3 patients were classified as stage Ⅰ, 22 cases of grade Ⅱ, 61 cases of grade Ⅲ, 43 cases of Ⅳ A and 3 cases of Ⅳ B, respectively. The median dose was 73.37Gy (66 to 85Gy), divided into 33 times. Twenty patients received radiotherapy alone, 112 cases of concurrent radiochemotherapy. The survival rate was calculated by Kaplan-Meier method and log- rank test. Univariate prognostic analysis was performed. Cox model was used to conduct multivariate prognostic analysis. The late radiation toxicity was evaluated by RTOG/EORTC criteria. Results:The median follow-up duration was 128 months (range, 3 to 191 months). The 10-and 15-year local control rates of NPC patients were 86.0% and 79.9%. The disease-free survival rates were 72.5% and 63.2%, and the overall survival (OS) rates were 65.2% and 57.1%. The local recurrence rate was 12.1%, and the distant metastasis rate was 16.7%. A total of 53 patients died, of whom 15 patients died of local recurrence, 20 patients died of distant metastasis and 18 patients died of other diseases (pneumonia, intracranial hemorrhage and accident, etc.). The 10-and 15-year non-tumor-related mortality rates were 11.3% and 13.6%. Univariate analysis showed that age, smoking habit, lactate dehydrogenase (LDH), T stage and clinical stage were the independent prognostic factors of OS in NPC patients. Multivariate analysis demonstrated that LDH, T stage and synchronous chemotherapy were the prognostic factors of OS in NPC patients. The incidence of gradeⅠ-Ⅱ late radiation injury (hearing impairment, dysphagia, dental caries and xerostomia) was 90.4%, and 8.5% for grade Ⅲ-Ⅳ late radiation injury (skin fibrosis, hearing impairment and radiation brain injury).Conclusions:The 10-and 15-year OS of NPC patients treated with IMRT is relatively high. With the prolongation of survival, the non-tumor-related mortality rate is increased. Distant metastasis is the main cause of treatment failure. The main late injuries include grade Ⅰ/Ⅱ hearing impairment, dysphagia, dental caries and xerostomia.

Effect of total body 137Cs γ-irradiation on the m 6A modification profile of circRNA in mouse bone marrow cells / 中华放射医学与防护杂志

Objective:To investigate the effect of ionizing radiation on the N 6-methyladenine (m 6A) modification profile of circular RNA (circRNA) in mouse bone marrow cells and provide scientific basis for revealing the relationship between RNA epigenetic modification and hematopoietic radiation injury. Methods:A total of twenty four C57BL/6 J mice were randomly divided into two groups: the healthy control group ( n=12), and ionizing radiation group ( n=12) irradiated in total body with 4 Gy of 137Cs γ-rays. At 5 min after irradiation, mice were killed and bone marrow cells were collected from the femur. Total RNAs were extracted and the changes in circRNA m6A modification profiles were investigated by RNA immunoprecipitation-high-throughput sequencing (MeRIP-Seq) technology and bioinformatics analysis. The representative alterations of m 6A peaks were validated by MeRIP-PCR assay. Results:325 and 455 m 6A sites were identified on circRNAs in the healthy control group and ionizing radiation group (178 common sites, 147 specific sites in the healthy control group and 277 specific sites in ionizing radiation group), respectively. 1 275 and 1 017 deriving genes of m 6A-circRNAs were identified in the healthy control group and ionizing radiation group (767 common genes, 508 specific genes in the healthy control group and 250 specific genes in ionizing radiation group), respectively. Compared with the control healthy group, 414 (178) m 6A peaks was significantly up- (down-) regulated in the ionizing radiation group( P < 10 -10; fold-change cut-off > 5). Moreover, Gene Ontology (GO) assay revealed that the deriving genes of circRNAs with differentially methylated m 6A sites between two groups involves various functions including chromatin regulation, ciliary transition fiber and poly (A)-specific ribonuclease activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) assay revealed that the deriving genes of circRNAs with differentially methylated m 6A sites between two groups included numerous pathways such as platelet activation, Fc γ R-mediated phagocytosis and B cell receptor signaling pathway. Conclusions:Ionizing radiation triggers rapid alterations in the m 6A modification profile of circRNA in mouse bone marrow cells. The deriving genes of differentially methylated circRNAs are associated with a variety of functions and signaling pathways of hematopoietic radiobiology.

Metabonomic study on the effect of fasting on 137Cs γ-ray radiation-induced intestinal injury in mice / 中华放射医学与防护杂志

Objective:To study the effect of fasting on 137Cs γ-ray radiation-induced intestinal injury in mice, and to explore the effect of fasting on fecal metabolites of mice through non-targeted metabolomics. Methods:C57BL/6 mice were divided into healthy control group, 9 Gy γ-ray whole body irradiation (WBI)/ 15 Gy γ-ray whole abdominal irradiation (WAI) group, fasting (24 h, 48 h, 72 h)+ 9 Gy WBI/ 15 Gy WAI group. After irradiation, the survival rate, spleen index and thymus index were calculated. C57BL/6 mice in non-target metabolism experiment were randomly divided into four groups: control group, fasting 24 h group, 15 Gy γ-ray WAI group, fasting 24 h + 15 Gy γ-ray WAI group, 6 mice in each group. After 15 Gy WAI, the feces of mice in each group were collected at 3.5 days for non-targeted metabolomics detection.Results:The median survival time of mice with 48 h and 24 h fasting before 9 Gy γ-ray irradiation was increased by 1 day and 4 days, and the survival rates of mice treated with 48 h and 24 h fasting before 15 Gy WAI were 16.67% and 25%, respectively. 15 Gy γ-ray WAI on mice with fasting for 24 h before irradiation could increase the body weight ( t=2.338, P=0.042) and spleen index ( t=2.289, P=0.045) at 3.5 days after irradiation. Through non-targeted metabonomic analysis, it was found that there were 30 differentially expressed metabolites in fecal samples of fasting and non-fasting mice subjected to WAI, and metabolic pathway enrichment analysis showed that there was an imbalance in the metabolic pathway of steroid biosynthesis. Conclusions:Fasting before irradiation can improve the survival rate of mice with intestinal radiation injury and change their intestinal metabolites, suggesting that pre-irradiation fasting or short-term dietary nutrition changes are involved in the regulation of intestinal radiation damage.

Research progress in the application of exosomes in radiological medicine and underlying mechanisms / 中华放射医学与防护杂志

Nuclear energy is widely used in various fields such as military, medicine, scientific research, industry and agriculture.Nuclear accident may lead to radiation damage to the bodyofpractitioners. At present, the treatment of severe bone marrow radiation sickness is still not ideal.Exosomes are small vesicles with a size of 30-130 nm secreted by living cells and carry a variety of active substances including protein, RNA, DNA, which isimportant medium of intercellular communication.The contents of exosomes can be used not only as biomarkers of radiation damage, but also for the treatment of radiation damage. This article reviewsthe research progress of the application of exosomes in radiological medicine and underlying mechanisms.

Experimental study on radiation damage of125I seeds implanted in canine gastric wall tissue

Objective: The objective of the study was to investigate the radiation damage to125 I seeds implanted in canine gastric wall tissue. Materials and Methods: Eight beagles were randomly assigned to either the treatment or control group, with four beagles per group. For each beagle in the treatment group, six125 I seeds were implanted in the gastric wall in two rows, spaced at 1.0 cm, with a seed activity of 0.5 mCi and a half-life of 60.2 d. For each beagle in the control group, six 125 I seeds were similarly implanted as a cold source. After implantation, the beagles were scanned by computed tomography (CT) (slice thickness: 2 mm), the region of interest was labeled along the seed boundaries, and postoperative doses were verified. One beagle per group was sacrificed at the 1, 2, 3, and 4 half-lives to be used as gross specimens for observing histological and ultrastructural changes using light microscopy and electron microscopy, respectively. Results: Beagles from the treatment group who had125 I radioactive seeds implanted in their stomach walls had the most radiation damage after two half-lives, damage repair began after three half-lives, and the damage was stabilized and further repaired after four half-lives. In the control group, only mild inflammatory reactions were observed around the seeds. Conclusion: Appropriate and well-planned implantation of125 I radioactive seeds in beagle stomach walls is safe and reliable

Vitamin E reduces radiation injury of hippocampal neurons in mice by inhibiting ferroptosis / 南方医科大学学报

OBJECTIVE@#To explore the protective effect of vitamin E (VE) against radiation injury of hippocampal neurons in mice and explore the possible mechanism.@*METHODS@#Cultured HT-22 and U251 cells with or without exposure to 8 Gy irradiation were treated with VE (200 μmol/L for 24 h), ferroptosis inhibitor (ferrostatin-1, 5 μmol/L for 24 h), apoptosis inhibitor (ZVAD-FMK, 2 μmol/L), or necroptosis inhibitor (100 μmol/L). MTT assay was used to evaluate the cell viability after the treatments, and reduced glutathione (GSH), malondialdehyde (MDA), lipid reactive oxygen species (lipid ROS), and intracellular iron ion levels were detected for assessment of ferroptosis. The mice exposed to 16 Gy irradiation with or without vitamin E (500 U/kg) treatment for 6 weeks were assessed for behavioral changes and cognitive functions using Morris water maze test.@*RESULTS@#Treatment with VE significantly promoted the cell survival following irradiation in HT-22 cells ( < 0.05) but not in U251 cells ( > 0.05). Ferrostatin-1, but not ZVAD or the necroptosis inhibitor, promoted the survival of HT-22 cells following the irradiation. Exposure to irradiation significantly increased ferroptosis-related oxidative stress level in HT-22 cells, manifested by decreased GSH level and increased MDA, lipid ROS and intracellular iron ion levels ( < 0.05); treatment with VE and ferrostatin-1 both obviously reversed radiation-induced ferroptosis-related oxidative stress in the cells ( < 0.05). In Morris water maze test, the mice with radiation exposure showed obviously increased exploration time and distance ( < 0.05), which were significantly decreased after treatment with VE ( < 0.05).@*CONCLUSIONS@#Vitamin E reduces radiation injury by inhibiting ferroptosis in the hippocampal neurons in mice.

Pathological changes and functional reconstruction of radiation-induced salivary glands repaired by stem cells and biomaterials / 中国组织工程研究

BACKGROUND: Radiation therapy is currently one of the main treatments for head and neck cancer. Radiation therapy can kill cancer cells, but it can also damage normal cells or tissues. OBJECTIVE: To summarize the research progress of the changed structure of radioactive salivary glands and repair in recent years. METHODS: PubMed database, Wanfang database and China Full-Text Journal Database were searched. The search terms were “salivary glands; radiation injury; histological change; cell therapy” in English and Chinese. The time range was from 1991 to 2020. By reading the title, abstract and full text, repetitive studies were excluded. Finally, 57 articles were summarized. RESULTS AND CONCLUSION: In the treatment of head and neck cancer patients, xerostomia caused by radioactive damage to salivary gland tissue is its typical chronic side effect. At present, it is believed that radiation will mainly affect the structure of salivary gland tissues and lead to the decline of its function, including changes in the structure of salivary glands and ducts, as well as changes in saliva secretion and excretion after blood vessel and nerve injury. However, the mechanism of radiation damage has not been pointed out. Studies have shown that stem cells derived from fat, bone marrow and human amniotic membrane epithelium can treat radiation-induced salivary gland damage, improve salivary secretion, and the transplanted cells can form secretory alveoli and duct structures in the body.

Sciatic nerve injury after contact with a radioactive metal piece containing iridium-192 isotope

@#Gamma ray sources containing the iridium-192 isotope are widely used for industrial radiologic imaging. Irradiation causes biological damages and tissue injuries by the interaction of molecules in the body. The injury is correlated with the amount of energy absorbed. Peripheral nerves are more resistant to radiation injuries than other tissues because of their protected positions, low metabolic rates and low reproductive capabilities. We present here a 17-year-old male who had sciatic nerve denervation after handling a radioactive metal piece containing iridium-192 isotope that dropped accidentally from an industrial radiography machine. Although there are previous case reports of radiation injury after handling gamma ray projector inadvertently, this is the first case with sciatic nerve injury.

Radioactive Enteritis and Gut Microecology / 中国医学科学院学报

Radioactive enteritis(RE)is one of the most serious and common complications of intestinal tract caused by radiotherapy for malignant tumors in abdominal cavity,pelvic cavity,or retroperitoneum.Involved intestinal diseases are widespread,complex,and persistent,which make treatment difficult and ineffective.Short bowel syndrome can develop in some serious cases.Gut flora is the largest and most complex micro-ecosystem in human body and has a wide range of functions.Studies have shown that intestinal flora plays an important role in radiation-induced RE.This article summarizes recent research advances in the relationship between RE and gut flora.

Analysis of Radiotherapy optimization scheme after modified radical mastectomy / 中国综合临床

Objective To study the application value of radiotherapy optimization after modified radical mastectomy.Methods From January 2012 to January 2015,one hundred and twelve patients treated with modified radical mastectomy in Taizhou Cancer Hospital were enrolled and divided randomly into group A,B and C.40 patients in group A received modulated radiation therapy(MRT) with 2.0Gy/f,25 times,DT50Gy for 33-35d;35 cases in group B received concurrent chemoradiotherapy with MRT and 37 cases in group C received concurrent chemoradiotherapy with large segmentation scheme of 2.66Gy/f,16 times,DT42.56Gy for 22-24d.The recurrence rate,survival rate and the incidence of acute and chronic radiation injury of the 3 groups were compared.The parameters of V5,V10,V20 and V30 of ipsilateral lung was recorded by dose volume histogram(DVH).Results The total recurrence rate in group C was significantly lower than that of the other two groups (16.2％(6/37) vs.28.6％(10/35) vs.42.5％(17/40),x2 =6.409,P=0.041),while the total survival rate was significantly higher than that of the other two groups (89.2％ (33/37) vs.77.1％ (27/35) vs.65.0％ (26/40),x2 =6.313,P =0.043),and there was no significant difference in the local recurrence and distant metastasis rate in the 3 groups (P＞0.05).The incidence of total radiation injury in group C was lower than that of the other two groups (21.6％ (8/37) vs.42.9％ (15/35) vs.50％ (20/40),x2 =6.973,P =0.031),and there was no significant difference in the incidence of acute and chronic injury and the grade of injury in the 3 groups (P＞0.05).The values of VS,V10,V20 and V30 increased gradually in the 3 groups.The V5 and V10 in group C were significantly higher than those of the other two groups ((32.9 ± 7.4) ％ vs.(17.5 ± 5.9) ％ vs.(16.8 ± 6.4) ％,F =18.625,P=0.000,(42.4±7.3)％ vs.(39.3±5.8)％ vs.(35.5±6.0)％,F=15.624,P=0.000),and there was no significant difference in V20 and V30 among the three groups (P＞ 0.05).Conclusion The combination of concurrent chemoradiotherapy and breast cancer after modified radical mastectomy is of great value in improving prognosis and reducing radiation damage.

Effect of epigallocatechin-3-gallate on radiation-induced esophagitis of rabbit / 中华放射医学与防护杂志

Objective To analyze the effect of epigallocatechin-3-gallate (EGCG) in radiation induced esophagitis of model rabbit.Methods Thirty male New Zealand rabbits were randomly divided into EGCG group,saline group,blank group.The rabbits in EGCG and saline groups were irradiated with 6 MV X-rays.The blank group did not receive radiation.After irradiation,rabbits were given with 440 μmol/L EGCG or saline three times a day in continuous 5 days.The scores of pathological changes of esophagus were observed by optical microscope.The serum levels of interleukine-1 beta (IL-1β),interleukine-6 (IL-6),transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme linked immunosorbent assay.The expression levels of 67KD laminin receptor (67LR)was detected by immunohistochemistry.Results After treatment,the scores of pathological changes of esophagus in blank group,saline group,EGCG group were 0,3.9± 1.10 and 2.80±0.92,respectively.At different time points after drug treatment,the levels of serum inflammatory factors among three groups were significantly different (F=23.66-236.32,P＜0.05).The expressions of 67LR in esophageal tissue of 3 groups were also significantly different (F=585.38,P＜0.05).Conclusions EGCG reduced radiationinduced esophagitis in rabbits by decreasing the levels of serum inflammatory factors,which may be related to the expression of 67LR protein.

Effect of epigallocatechin-3-gallate on radiation-induced esophagitis of rabbit / 中华放射医学与防护杂志

Objective@#To analyze the effect of epigallocatechin-3-gallate (EGCG) in radiation induced esophagitis of model rabbit.@*Methods@#Thirty male New Zealand rabbits were randomly divided into EGCG group, saline group, blank group. The rabbits in EGCG and saline groups were irradiated with 6 MV X-rays. The blank group did not receive radiation. After irradiation, rabbits were given with 440 μmol/L EGCG or saline three times a day in continuous 5 days. The scores of pathological changes of esophagus were observed by optical microscope.The serum levels of interleukine-1 beta (IL-1β), interleukine-6 (IL-6), transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme linked immunosorbent assay. The expression levels of 67KD laminin receptor (67LR) was detected by immunohistochemistry.@*Results@#After treatment, the scores of pathological changes of esophagus in blank group, saline group, EGCG group were 0, 3.9±1.10 and 2.80±0.92, respectively. At different time points after drug treatment, the levels of serum inflammatory factors among three groups were significantly different (F=23.66-236.32, P<0.05). The expressions of 67LR in esophageal tissue of 3 groups were also significantly different (F=585.38, P<0.05).@*Conclusions@#EGCG reduced radiation-induced esophagitis in rabbits by decreasing the levels of serum inflammatory factors, which may be related to the expression of 67LR protein.

Establishment of Sprague-Dawley Rat Submandibular Gland Cell Model of Radiation Injury and Repairing Effect of Compatibility of Fructus Mume and Radix Glycyrrhizae / 广州中医药大学学报

Objective To establish a submandibular gland(SMG) cell model of radiation injury, and to observe the effect of compatibility of Fructus Mume(Wumei) and Radix Glycyrrhizae(Gancao) on the proliferation of the modeled cells. Methods SMG cells were primarily cultured in vitro for the experiment. After immunofluorescence identification and growth curve analysis, SMG cells were given one-time exposure to X electron-ray at dose of 0.1, 0.2, 1, 2, 4 Gy respectively, and then were cultured with Wumei-Gancao solution at the concentration of 500, 50, 5, 0.5 μg/mL separately. Methyl thiazolyl tetrazolium (MTT) was used to determine the survival rate of SMG cells exposed to different doses of X electron-ray and proliferation vitality of SMG cells treated with different concentrations of Wumei-Gancao solution for 24 h. Results The survival rate of SMG cells was decreased gradually with the increase of X electron-ray dose. When the concentrations of Wumei-Gancao solution were in the range of 50 ～ 0.5 μg/mL, the cell proliferation rate showed an increasing trend with the increase of drug concentration, the effect being dose-dependent. When the solution concentration arrived to 500 μg/mL, the cell proliferation rate was declined. Conclusion The SMG cell model of radiation injury has been established successfully under the conditions of 0.1 Gy of one-time exposure, 9 Mev of energy at dose rate 3 Gy/min, hop count at 12 MU and source-skin distance being 100 cm. The concentration of the solution with the compatibitity ratio of Wumei to Gancao being 3:1 has certain effects on repairing the modeled cells.

Mesenchymal stem cells transplantation promote the structural repairation of mice intestinal injury induced by radiation / 重庆医学

Objective To study the effect of human umbilical cord mesenchymal stem cells (hMSCs) on the survival rate of mice with radiation-induced intestinal injury and its effect on the repair of intestinal damage.Methods Adult C57BL/6J mice were selected and divided into control group and abdomen irradiation + PBS(IR + PBS) group and abdominal irradiation+hMSCs transplantation treatment (IR+hMSCs)group.Intestinal injury model was induced by abdominal irradiation at 13 Gy of T ray and the 30-day survival rate was recorded.On the 3.5th and 5.0th day after irradiation,HE staining was used to observe changes in the villus structure and thc number of intestinal crypts in each segment of the small intestine (duodenum,jejunum,and ileum).Results The survival rate of IR+hMSCs group was significantly higher than that of IR+PBS group (P＜0.05).On the 3.5th day after 13 Gy of abdomen irradiation,the duodenum,cavities and ileum villus in IR+PBS group were all fractured,the length was shortened,and the numbers were sparse when compared with the control group,while the hMSCs reduced the intestinal damage.On the 5.0th day after irradiation,the structural integrity of the small intestine in IR+PBS group was repaired slightly,but it still more serious than that of IR+hMSCs group (P＜0.01).The amount of intestine crypts were significantly higher in IR+hMSCs group than that of IR+PBS group,but were significantly lower than that of control group (P＜0.01) at 3.5th day and 5.0th day after radiation.Conclusion Transplantation of hMSCs can improve the survival rate and promote the repairation of intestinal injury induced by radiation in mice.MSCs are hopeful to be used on the treatment of radiation-induced intestinal injury.

Protective effects and possible mechanism of 12-O-tetradecanoylophorbol-13-decano-ate against acute intestinal radiation injury of mice / 军事医学

Objective To investigate the effect of 12-O-tetradecanoylophorbol-13-decanoate(TPD)on protection against acute intestinal radiation injury of mice and the possible mechanism.Methods Twenty female BALB/c mice aged 6-8 weeks were divided by random number table method into the control group and TPD groups(25,50,and 100 μg/kg). A radiation-damaged model of mice was irradiated by 10 Gy 60Co γ-rays,while the TPD groups were pretreated for 3 d with caudal vein injection before irradiation.The survival time of 20 days and the number of crypts at 3.5 days after irradiation were detected.Rat intestinal epithelial cells(IEC-6)were treated with 1 nmol/L TPD for 12 h before irradiation with 10 Gy 60Co γ-rays,and CCK-8 was used to detect the capability of cell proliferation at 0,1,2,3 and 4 d after irradiation. Results The mice in the control group survived for an average of 4.2 days,compared to 10 days in the optimal TPD group (100 μg/kg).The average number of crypts in the control group and the best TPD group was 11.0 ±1.3 and 35.1 ±1.9 respectively.The proliferation activity of IEC-6 was measured for four consecutive days.The average D value of the TPD groups was significantly higher than that of control.Conclusion TPD has a protective effect against acute intestinal radiation injury, and its protective mechanism may be achieved by promoting intestinal crypt cell proliferation and increasing the number of crypts in the intestine.