Objective To compare the incorporation method of 3H-TdR and 125Ⅰ-UdR on determining the proliferation effect of lymphocytes. Methods The proliferation effects of lymphocyte and Daudi lymphoma cells were estimated by 3H-TdR and 125Ⅰ-UdR incorporation. Results The incorporating fraction of 3H-TdR and 125Ⅰ-UdR into lymphocyte was 20.95% ± 1.06% and 1.00% ±0.04%,respectively, and the incorporating fraction for the lymphoma cells was 29. 94% ± 4. 10% and 6. 02% ±0. 73% ,respectively. The incorporation fractions of 3H-TdR into lymphocyte and lymphoma cells were much higher than those of 125Ⅰ-UdR, but the incorporating fractions of 3H-TdR or 125Ⅰ-UdR into the lymphoma cells were much higher than those of lymphocytes. Conclusions For lymphocytes, 125Ⅰ-UdR cannot substitute 3H-TdR as a tracer agent. But for lymphoma cells, whether 125Ⅰ-UdR could be replace 3H-TdR or not needs further research.

Objective To evaluate the feasibility of 80 kV tube kilovoltage in aortic artery CT angiography with 256-slice CT. Methods A total of 62 patients undergoing aortic artery CTA were enrolled into this study and divided into conventional tube kilovoltage (120 kV, n = 31 ) and low tube kilovoltage (80 kV, n = 31 ). The signal-to-noise ratio (SNR) , contrast-to-noise ratio (CNR), volume CT dose index (CTDIvol) and effective dose (E) were evaluated, respectively. Results The mean image SNR was ( 35.92 ± 5.04) and ( 33.95 ± 8. 30) for conventional tube kilovoltage and low tube kilovoltage,respectively, with no significant difference (t = 1. 131, P =0. 263). The mean image CNR was (30. 32 ±4.78) and (28.71 ± 7.96 ) for conventional tube kilovoltage and low tube kilovoltage, respectively, with no significant difference ( t = 0. 964, P = 0. 339 ). The average effective dose ( E ) was ( 14. 28 ± 0.96 )mSv and (9. 72± 0. 81 )mSv for conventional tube kilovoltage and low tube kilovoltage, respectively, with significant difference ( t = 20. 12, P ＜ 0. 001 ). Conclusions 80 kV tube kilovoltage aortic artery CTA can reduce radiation dose by 31.9% , and contrast dose 50% ,and maintain image quality compared with 120 kV tube kilovoltage.

Objective To explore the protective effect of Tea polyphenols(TP) on radiation injury in submandibular glands. Methods Sixty rats were randomly divided into radiation group(R-group) and tea polyphenols combined radiation group (TPR-group), both groups were irradiated with a single exposure of 15 Gy γ-rays delivered to the head and neck area. The rats were intragastrically administered with normal sodium or TP from 14 days before radiation to the experiment ended. On day 3, day 6 and day 30 after radiation, ten submandibular glands glands were taken from each groups. TUNEL method was used to examine the apoptosis of submandibular glands cells and immunohistochemical technique was used to detect the Bcl-2 and the Bax expression in the glands. The morphologic changes of submandibular glands were observed by transmission electron microscopy. Results Apoptosis index in the cell of submandibular glands were significant decreased on days 3, days 6 and days 30 after irradiation, compared with R-group ( F = 56.383, P ＜ 0.01 ). Expression of Bcl-2 and Bax were not significant difference between the two groups. The lesions of submandibular glands in TPR-group were lighter and the apoptosis in cell nuclear were not typical than that of R-group from electron microscope study. Conclusion TP could protect the sumandibular glands against radiation injuries and the mechanism might be realized with the anti-apoptosis in the glands cell.

Objective To observe the effects of low dose irradiation (LDI) on autoiogous CIK cell proliferation, phenotype and killing activity in tumor patients, and to provide the evidence for clinical application of adoptive immunotherapy with CIK cells. Methods Peripheral blood mononuclear cells (PBMC) were separated from 10 patients with malignant tumor, and CIK cells were cultured with different cytokines. (1) After 10 d culture, C1K cells were irradiated with different doses as 30, 50, 80, 100 and 200 Gy of X-rays was also detected. The CIK cell proliferation and killing activity were measured with 3H-TdR incorporation assay and 3H-TdR release assay, respectively and the percentage variation of CD3 +CD56 + were measured with flow cytometry after 24 h. ( 1 ) Autologous CIK cells were irradiated with 80 mGy X-rays. At different culture time ( 12, 24, 48, 72 h) after irradiation, the killing activity was measured with 3H-TdR release assay. (3) The effect of 3d low dose irradiation of 80 mGy X-rays on thekilling activity of CIK cells was also detected. Results After the CIK cells were irradiated with different doses as 50, 80, 100, 200 mGy of X-rays, the CPM values were 20 048.6 ± 2332. 2 ( t = 2.2, P ＜0.05), 21 832.2 ±2975.9 (t=3.5, P＜0.01), 21 000.3 ±2451.1 (t=3.3, P＜0.01), 19908.1 ±2051.0 ( t = 2.2, P ＜ 0.05 ), respectively and the proliferation of CIK cells were significantly higher than that of control group. The CD3 + CD56 + cell percentage of 50, 80, 100 mGy groups were ( 30.3 ±3.8)% (t=2.3, P＜0.05), (32.3±3.4)% (t=4.2, P＜0.01), (29.742.9)% (t = 2.4, P＜0.05 ), respectively. The killing activity of CIK cells of 80, 100 mGy groups were 55.2 ± 5.0 ( t = 3.3, P ＜ 0.01 ), 52.8 ± 4.1 ( t = 2.3, P ＜ 0.05 ), respectively. The killing activity of CIK cells up-regulated significantly at 24 h, dropped to normal levels at 48 h and 72 h. After 80 mGy X-ray irradiation for 3 consecutive days, the killing activity of CIK cells at different time points were 55.2 ± 5.3 (t = 2.6, P ＜0.05),61.9 ± 4.4 (t = 4.7, P ＜0.01), 67.2 ±5.7 (t = 5.7, P ＜0.01) for 24, 48, 72 h,respectively. Conclusions LDI might have the hormesis effect on CIK cells.

Objective To investigate the radiosensitizing effect of knock-down the expression of miR-21 on human SHG-44 glioma cells and explore the possible mechanism. Methods Antisense oligonuleotidas of miR-21, mediated by LipofectamineTM 2000, were transfected to SHG-44 cells. Three groups were: blank control group ( mock group), negative control and antisense transfected group ( AS-miR-21 gorup). Cells of each group were irradiated with 6 MeV X-rays at the doses of 0,1,2,4,6 and 8 Gy.Dose-suvivial curve was established by colony-forming assay. The influence of AS-miR-21 on cell cycle and cell apoptosis was analyzed by flow cytometry assay after 6 Gy irradiation. Results The value of D0 and Dq of AS-miR-21 group declined obviously compared with the mock group and negative control group. Flow cytometric analysis showed that cell cycle distribution changed( G0/G1 phase arrest, S phase decreased)after transfected with AS-miR-21 (t = 8.18, -4.52,P ＜ 0.05 ). The sensitization enhancement ratios of D0 and Dq were 1.32 and 2.10 respectively. Apoptosis assay showed the early apoptosis rate was signiflcantely increased in AS-miR-21 、irradition alone and combined group than mock control group( t = 20.14,11.11,50.07, P ＜ 0.05). Conclusions AS-miR-21 can enhance the radiosensitivity of human glioma cells SHG-44 by promoting cell apoptosis and faciliating cell cycle redistribution.

Objective To observe the changes of cell cycle on cancer cells after dihydroartemisinin and X-ray irradiation. Methods Human HeLa cells of cervical cancer with p53 mutation was used and human SiHa cells of cervical cancer with wild p53 was used as control. Flow cytometry was used to detect the effect of dihydroartemisinin (20 and 100 μmol/L) and irradiation (6 Gy)on cell cycle. Western blot was used to measure the levels of cell cycle protein. Results G2 arrest was observed in irradiated HeLa cells, which the proportion of cells in G2 phase was increased from 14.45% to 73. 58% after 6 Gy X-ray irradiation, but it was abrogated by dihydroartemisinin from 73. 58% to 48.31%in HeLa cells, and it had no change on the SiHa cells. The elevated Weel protein and the lowered Cyclin B1 protein were observed with the G2 arrest severity. The expression of radiation-induced Weel protein was suppressed and the Cyclin B1 protein was increased after dihydroartemisinin treatment, which was in accordance with the abrogation of radiation-induced G2 delay. Conclusions The main effect of irradiation on cell cycle of p53 mutated HeLa cells is G2 arrest. Dihydroartemisinin could abrogate it, which is associated with the changes of Weel protein and Cyclin B1 protein. In Siha cells, the main effect of irradiation on cell cycle is G1 arrest, and dihydroartemisinin has no effect on it.

Objective To explore the effect of β-element on the oadiosensitivity of transplanted tumor, and its relationship with the expression of survivin. Methods The transplanted mice model was established through the cell suspension inoculation. The mice with transplanted tumor size of 0. 8-1.0 cm3 were randomly divided into 8 groups as blank control, 25, 45 and 100 mg/kg group, irradiation group,25 mg/kg + irradiation group, 45 mg/kg + irradiation group, 100 mg/kg + irradiation group. The tumor size was measured every other day until tumor size was double, and the growth curve was obtained. The average tumor growth inhibition rate of β-element and tumor size were attained at 2,4,6 and 8 d after β-element injection. The expression of survivin was detected with immunohistochemistry. Results The nude mice model was successfully established and the growth curves were obtained according to the tumor size.Between 2 and 8 d after β-elemene injection, the variation tendency of the average tumor growth inhibition rate was consistent with the size in β-elemene treatment groups. The antitumor effect of β-elemene was in a dose-dependent manner. The values of radiosensitivity enhancement factor were 0. 84,1.24,2.04 for 25,45 and 100 mg/kg group, respectively ,and the optimal dose was 45 mg/kg. β-element had little effect on the expression of survivin, and the expression of survivin significantly enhanced in irradiation group and decreased in β-element + irradiation groups. Conclusions β-elemene could enhance the tumor radiosensitivity through inhibitiong the expression of survivin.

Objective To explore the inhibitory effects of Corilagin on the production of proinflammatory cytokines in microglia induced by radiation. Methods The cytotoxicity of Corilagin was measured by MTT assay. Microglia BV-2 cells were irradiated 0 or 32 Gy after pretreated with Corilagin for 12 hours. Realtime-PCR was used to detect the mRNA levels of inflammatory cytokines, such as IL-1β,TNF-α on several time-points. The content of nitric oxide (NO) was determined with nitrate reductase method. The translocation of NF-κB was measured by Western blot and immunocytochemical stain.Confocal microscopy was used to observe the expression of Iba-1 and Nemo. Results No cytotoxicity was detected on BV-2 cells with 1-10 μg/ml Corilagin. Iba-1 expression in microglia cells was activated by irradiation, the expression levels of inflammatory cytokines, such as IL-1β, TNF-α and NO were also elevated. Whereas, the production of IL-1 β, TNF-α in activated microglia cells was significantly inhibited with 5 μg/mL corilagin ( tIL-1β = 6. 341, tTNF-α = 3.41 1, tNO = 3. 134, P ＜ 0. 05 ). Corilagin significantly inhibited the expression of Nemo and the translocation of NF-κB p65. Conclusion Corilagin could inhibit the activation of irradiated microglia cells and down-regulate the expression of inflammatory cytokines, via inhibition of the NF-κB signaling pathway.

Objective To study the expression level of miR-21 in UVB irradiated HaCaT cells and A431 cells. Methods Real-time qPCR was used to examine the expression level of miR-21 in HaCaT cells and A431 cells after 50 J/m2UVB radiation. The possible target genes were predicted by PicTar and performed function categories with Gostat analysis. Results Compared with the HaCaT cells, miR-21 the expression level in A431 cells increased over 4 times. At 2h and 4h after UVB irradiation, the expression level of miR-21 in HaCaT cells were up regulated, and it lowered 2 times at 8 h compared with the control.There was no further change in the expression level of miR-21 after 12 h. While miR-21 expression levels in A431 cells were not changed signifcantly. The results of target prediction and Gostat analysis suggested that PIK3R1, BCL2 and E2F3 were involved in the cell differentiation and cell process. Conclusion miR-21 possibly involved in the pathogenesis of epidermal squamous cell carcinoma and the mechanism of UVB-induced injury.

Objective To evaluate the role of mesenchymal stem cells (MSCs) derived from mouse bone and embryo dorsal aorta(DA) area in the treatment of irradiation induced lung injury of mouse model. Methods The mice were divided into four groups as normal control group, irradiation group,bone MSCs treatment group and DA MSCs treatment group. Immunohistochemical Analysis of lung tissue was observed after 9 months of treatment. Results Fibrosis and alveolar infiltration were scored in each group. The score for fibrosis and alveolar is 0. 17 in normal control group, 2 in irradiation group, 1 in bone MSCs treat group and 1.38 in DA MSCs treat group. Conclusion The extent of irradiation Induced Lung Injury could be reduced thorough the treatment of MSCs derived from mouse bone and embryos dorsal aorta ( DA ) area.