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Objective To analyze the effects of position shift and dose adjustment on the pass rate of IMRT dose verification to facilitate to obtain rapidly high-pass-rate IMRT dose verification report.Methods At first,the dose unit of measuring dose map image and planning Dose Profile was unified.Secondly,the planning Dose Profile was moved at lateral and cephal-ocaudal directions respectively in contrast mode so as to determine the position error with the maximum pass rate.Thirdly,the highest pass rate point of dose verification was found in the range of dose adjustment.Fourthly,the plan report with the highest pass rate of dose verification was found out by adjusting position error and dose coefficient.Results The highest pass rate was obtained in case the displacement was-3 mm at lateral direction or +3 mm at cephal-ocaudal direction;high pass rate was got when dose adjustment coefficient was 1.02;high pass rate was achieved in case the displacement was-3 mm at lateral direction,+2 mm at cephal-ocaudal direction and the dose adjustment coefficient was 1.02,which was significantly different from those with other combined values (P＜0.05).Conclusion The dose verification technique is convenient and quick when used to obtain a high-pass-rate dose verification report.
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Objective: The reliability of multiple exposure technique in QA imaging was evaluated by combining IP plate of X-ray radiography and homemade QA verification plate. Methods: The QA verification films with different properties derived from placing the QA verification plate and the IP plate on corresponding location were compared with established traditional QA methods. Results: The data from verification films of light and radiation field overlapping derived from combining QA verification plate and IP plate were analyzed by eFilm software in 10cm×10cm radiation field. The results were similar with that of 3D water tank scanning, and were basically same with the analytical results collected from the PTW 2D-ARRAY729 matrix. Conclusion:Using described method in this paper, the result was accurate, the operation was easy, and the cost was low. This method was of good practicability.
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Objective To investigate the effects of expressions of NF ?B and survivin on the anti tumor activity of TRAIL in gastric carcinoma cells. Methods Gastric carcinoma cells were cultured in RPMI 1640. The apoptotic rates of gastric carcinoma cells SGC 7901, MKN28, AGS, and MKN45 after treatment with TRAIL were analyzed by flow cytometry. The expressions of NF ?B and survivin in the 4 gastric carcinoma cells were determined by Western blotting. Results At 24 h after gastric carcinoma cells exposed to TRAIL at the dose of 300 ng/mL, the apoptosis percent ages were 36 05% for MKN28, 20 27% for MKN45, 16 50% for AGS, and 11 80% for SGC 7901. Western blotting showed that expressions of NF ?B and survivin were lower in MKN28 than those in MKN45, AGS and SGC 7901. Conclusion The anti tumor sensitivity of TRAIL to gastric carcinoma cells is related to the expressions of NF ?B and survivin.
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Objective To investigate the effects of nu cleus transcription factor (NF)-?B, survivin, Bcl-2 and Caspase-3 on apoptos is of gastric cancer cells induced by tumor necrosis factor related apoptosis in ducing ligand(TRAIL). Methods Gastric cancer cells were cultured in RPMI-1640 and the proportions of apoptosis were analyzed by flow cytometry. The expressions of N F-?B, survivin, Bcl-2 and Caspase-3 in gastric cancer cells were evaluated b y Western blot. Results After gastric cancer cells were exposed to 50 ng/ml TRAIL f or 24 hours, the proportions of apoptosis were 24.05% in line MKN28, 7.83% in MK N45, 8.05% in AGS and 3.17% in SGC-7901 respectively; after 300 ng/ml TRAIL for 24 ho urs, the proportions of apoptosis were 36.05% in MKN28, 20.27% in MKN45, 16.50% in AGS and 11.80% in SGC-7901 respectively. The expressions of NF-?B and surv ivin under Western blot were lower in MKN28 than that in MKN45, AGS and SGC-79 0 1. In contrast, the expression of Caspase-3 was higher in MKN28 than that in MK N45, AGS a nd SGC-7901. The expression of Bcl-2 had no difference among the 4 lines of ga stric cancer cells. Conclusions The anti-tumor sensitivity of TRAIL to gastric cancer c ell may be associated with both increased expressions of NF-?B and survivin an d decreased expression of Caspase-3.
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Objective To study the effects of ?-tocopheryl succinate (?-TOS) on apoptosis of gastric cancer cells induced by TRAIL. Methods The cell cycles and the percentage of apoptosis were analyzed with flow cytometer and the expressions of NF-?B, survivin, bcl-2 and caspase-3 in gastric cancer cells were assessed with Western blot. Results After being exposed to TRAIL 300ng/ml for 24 hours, the apoptosis rate was 36.05% for MKN28 and 11.80% for SGC-7901. When exposed to ?-TOS at 60?mol/L for 24 hours, the apoptosis rate was 9.0% for MKN28 and 8.5% for SGC-7901. With a combination of ?-TOS 60?mol/L and TRAIL 300ng/ml for 24 hours, the apoptosis rate was elevated to 48.1% for SGC-7901 and 63.7% in MKN28, respectively. The results of Western blot showed that TRAIL inhibited the expressions of NF-?B and survivin, while had no inhibition on the expressions of bcl-2 of SGC-7901 and MKN28 cell lines. The expression levels of bcl-2 and survivin had no change when the cells were exposed to ?-TOS alone. When the cells were treated with ?-TOS and TRAIL simultaneously, the expressions of NF-?B, bcl-2, and survivin were greatly decreased. Conclusions ?-TOS can enhance the activity of TRAIL in inducing apoptosis, and the down-regulation of the expression of NF-?B, bcl-2 and survivin may be involved in the mechanisms.
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0.05). The incidence of acute esophagitis was increased but it was acceptable in the LACF group (P
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Objective To study the effect of methylation state of C5 of the cytosine in the CpG di nucleotide of caspase 8 promoter on tumor necrosis factor related apoptosis inducing ligand (TRAIL) antitumor activity in gastric carcinomas. Methods The methylation states of the caspase 8 promoter region of 5 kinds of gastric carcinoma strains were measured by methylation specific PCR method. The antitumor activity of TRAIL protein was measured by MTT method. Results No methylation of caspase 8 promoter was found in gastric carcinoma cells. Treatment with demethylation agent 5 Aza 2′ deoxycytidine (5 Aza CdR) increased sensitivity of gastric cancer cells to TRAIL, but did not change methylation status of caspase 8 promoter in gastric carcinoma cells. Conclusion Caspase 8 promoter methylation status is not associated with TRAIL antitumor activity.
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Objective To study the effects of demethylation agent 5-Aza-2′-deoxycytidine (5-Aza-CdR) on the antitumor activity of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) against gastric carcinoma. Methods Expression of caspase-8 mRNA was examined by RT-PCR. Antitumor activity of TRAIL protein was measured by MTT method. Results The inhibition rates of treatment with 200 ng/ml TRAIL for 72 h on gastric cell lines SGc 7901, Kato 3, and AGS were 9.83%, 11.94%, and 4.04%. After treatment with 5-Aza-CdR, the inhibition rates of 200 ng/ml TRAIL on gastric cell lines increased to 38.98%, 52.42%, and 30.72%. Before exposure to 5-Aza-CdR, expression of caspase-8 mRNA was low and an increased expression of the caspase-8 was found in the three gastric cancer cells after treatment with 5-Aza-CdR. Conclusion Treatment with 5-Aza-CdR can increase TRAIL antitumor activity on human gastric cancer and its mechanisms might be involved in the up-regulation of caspase-8 gene.