Objective To investigate the mouse liver blood vessel images using phase contrast X-ray imaging with synchrotron radiation. Methods 6 female C57BL/6 mice were randomly divided into two groups, 3 mice in each group. In one group, livers excised after hgated arteries, veins and common bile duct. In another group, iodine infused via the portal vein and drained from inferior vena cave until all the blood in the portal veins and hepatic veins was displaced. After infusion, arteries, veins and common bile duct were ligated and livers were excised. Results Blood vessel images were clearly produced by diffraction enhanced imaging. This method can discriminate vessels down to about 40 μm in diameter without contrast agent. Using a contrasting agent more details could be produced. In one liver lobe, the entire branch of the portal vein could be clearly produced by one by one phase contrast image from the main axial blood vessels of liver lobe to the nine generation of branching. Conclusions Phase contrast imaging has the advantage of good contrast and high spatial resolution. [Key wnrds] Synchrotron radiation; Phase contrast imaging; Diffraction enhanced imaging; Blood vessel; X-rays

Objective To investigate solar radiation and its effects on human tooth enamel electron spin resonance (ESR) dosimetry. Methods 11 tooth enamel samples were prepared by mechanical method. The intensity of solar iUuminanee was measured with a light meter, the measured illuminance was converted to insolation using a coefficient. Summation of solar radiation was evaluated. Enamel samples were exposed to 60 Co γ rays followed by sunlight on sunny days, and ESR spectra were scanned after different exposure. Results The solar radiation to the samples was (580 ± 16) MJ/m2. Solar exposure also caused dosimetrie signal. The perpendicular component of dosimetrie signal increased linearly with the amount of solar radiation, another signal close to background tended to saturation. Conclusions The average effect of the solar radiation on the signal was be used to recognize the effect of solar radiation on the enamel, and estimate external dose accurately.

Objective To evaluate efficiency of brain metastases tumor using X-knife under farctionational stereotactie radiotherapy (FSRT) combine with whole brain radiotherapy (WBRT). Methods Retrospective comparing 51 patients treated by FSRT plus WBRT (FSRT + WBRT group) with 35 patients treated by WBRT alone (WBRT group) on the effecting rate and survival rate. Results The completeness response rate was 49 % and 26 % (P < 0.05) in FSRT + WBRT and WBRT groups, respectively. The effecting rate was 80 % and 71 % (P 0.05) in FSRT + WBRT and WBRT groups, respectively. The middle survival time was (11.0 ± 1.5) months and (6.5 ± 0.5) months (P < 0.05) in FSRT + WBRT and WBRT groups, respeetivley. The 0.5-, 1.0- and 1.5-years survival rate was 63 % and 41 % (P 0.05), 51 % and 23 % (P 0.05) and 24 % and 9 % (P < 0.05) in FSRT + WBRT and WBRT groups, respectively. Conclusions The method with FSRT plus WBRT in the treatment of brain metastases tumor is safe and relieved focal symptom of patients quickly with lesser injury on normal tissue and the survival time be prolonged, it has better therapeutic effects than WBRT alone for treating brain metastases tumor.

Objective To construct the RNAi vector targeting survivin gene, in order to observe its effect on lung adenoearcinoma A549 cell radiosensitivity, and explore the possible mechanism. Methods One pair of RNA interference sequence targeting survivin gene was designed according to the eDNA sequence, the recombinant RNAi plasmid pGenesil2-survivin was constructed. After certified by enzyme digestion and sequencing, the pGenesil2-survivin plasmid was transfected into A549 cells. Survivin mRNA and protein was measured by RT-PCR and Western blot, respectively. The apoptosis was analyzed with flow cytometry. The radiosensitivity was measured by clone formation assay. Results The pGenesil2-survivin vector was successfully established. After the pGenesil2-survivin was transfeeted into A549 cells for 48 h, surviving protein and mRNA in pGenesil2 group were not obviously changed compared with that in normal group. They were increased after 5 Gy X-ray irradiation, but obviously inhibited in pGenesil2-survivin group. The cell apoptosis in pGenesil2-survivin and 5 Gy X-ray groups was obviously increased (t1 = 10.63, P < 0.001 ; t2 = 3.75 , P < 0.05), the effect was more manifest in combined group(t = 4.83, P < 0.05). D0 and Dq in normal and pC, enesil2 group were not obviously different, but those in pGenesil2-survivin group were lower. Conclusions RNAi targeting survivin gene could inhibit survivin mRNA and protein expression, enhance the A549 cell apoptosis rate and cell radiosensitivity.

Objective To construct an eukaryotic expression vector of human telomerase reverso transcriptase (hTERT) gene specific shRNA, and investigate the effect of pshRNA-hTERT combined with γ-irradiation on telomerase activity and DNA damage. Methods The recombinant expression plasmid pshRNA-hTERT was constructed and transfected into Hep-2 cells. The telomerase activity was examined by the PCR-hased telomeric repeat amplification protocol (TRAP). DNA single-stranded break (SSB) and the DNA double-stranded break (DSB) were detected by Comet assay. The xenograft model of human laryngeal carcinoma with the same genetic background and different radiosensitivity (Hep-2 and Hep-2R) was established in nude mice. The mixture of pshRNA-hTERT and liposome was injected to the transplanted tumor to observe the inhibition of the tumor growth. The cell apoptosis was detected by TUNEL. The hTERT protein expression was determined by streptavidin-peroxidase conjugated method (AP). Results Recombinant expression plasmid pshRNA-hTERT was successfully constructed and transfected into Hep-2 cells. The hTERT expression inhibition rate reached 60.78 %. pshRNA-hTERT not only inhibited telomerase activity of Hep-2 inehiding the increase of telomerase activity induced by γ-irradiation, but also inhibited the repair of the SSB and DSB induced by irradiation in the human laryngeal carcinoma xenograft in nude mice with the same genetic background and different radiosensitivity. The pshRNA-hTERT combined with γ-irradiation could inhibit the growth of transplanted tumor (Hep-2: EPO = 1.79; Hep-2R: EPO = 2.01) with reduced telomerase activity and hTERT protein expression. Conclusions The eukaryotic expression vector pshRNA-hTERT could enhance the radiosensitivity of Hep-2 cells in vitro and the human laryngeal carcinoma xenograft in nude mice which had the same genetic background with different radiosensitivity.

Objective To explore the possibility and safety of ~(32)P-colloidal chromic phosphate interstitial injection.Methods Ten Beagle dogs were randomly divided into 5 groups (n ＝ 2) according to different doses (185 and 370 MBq) ,different sites (gluteus maximus and liver) and cold colloid as a control group.At different time-points after surgery,the weights of dogs were measured,and the blood and blood biochemical inspections were examined.ECT imaging was performed and histomorphology was observed dynamically.The radioactive counts of body surface for 90 days,blood for 12 weeks and urine and feces for 30 days were measured continuously.Measured data were expressed by mean ±standard error ((x) ±s) and SPSS 13.0 software was used for statistical analysis.Results ECT imaging demonstrated that the whole liver imaging was obtained although the radioactive distribution was uneven in liver groups,and the radioactivity concentrated continuously in the area of injection,but no liver imaging in muscle groups.Dogs in group 4 lost weight progressively and reduced by 2.7 kg till 45 d after operation.While the mean weight increments in the other groups were 3.0,1.6,0.8 and 3.1 kg in order.In group 4,PLT and RBC reduced obviously.Dogs died at 23 or 45 d.AST and ALT were elevated sharply before death.In the other groups,blood and blood biochemistry inspection showed there were no significant statistical differences.The highest radioactive counts after operation were obtained from the injection spot,while the urinary bladder and the spleen were followed.The peak of blood cpm in liver groups presented at 5 min.Peak values were 0.5 × 10~7/min and 1.0 × 10~7/min,respectively.The blood cpm in the muscle groups was always maintained at 3 × l0~5/min.Histology study showed the hyperemia dropsy changes in muscle groups and 185 MBq liver group in 4 weeks,while after 8 weeks the organizational structure restored normally.There were partial liver cells necrosis in 4 weeks,and the massive liver cells balloon type changes in 6 weeks,as well as obvious hyperemia dropsy and the hepatic lobe structure unclear in 370 MBq liver group.For the radioactive counts of urine and excrement,the peak appeared at 13 and 12 d respectively,and the peak values were (42.0 ±3.3) × 10~4 and (29.6 ±4.5) ×10~4 /min in muscle groups,respectively ;while the peak appeared at 5 and 9 d,respectively and the peak values were (49.0 ± 10.2) × 10~4 and (28.5 ± 7.1) × 10~4 /min in liver groups,respectively.Cumulative excretion ratios in urine and excrement were 36.58% and 10.62% in muscle groups,respectively and 23.48% and 8.76% in liver groups till 30 d,respectively.The liver absorbed doses were 30.6 and 55.6 Gy in liver groups,while those were 2.3 and 6.5 Gy in muscle groups.The maximus absorbed doses of gluteus were 53.4 and 98.1 Gy in muscle groups.Conclusions When ~(32)P- colloidal chromic phosphate of 794.39 MBq/m~2 was injected into the liver of Beagle,the liver absorbed dose was 56 Gy,which could be lethal dose for its strong liver toxicity and systemic side effects.Injection of 463.98-772.93 MBq/m~2 in muscle of Beagle could be safe.~(32) P-colloidal chromic phosphate interstitial injection is secure to treat the solid tumors with poor and middle blood supply which could be reached by puncture.

Objective To evaluate the clinical effects of CT-guided 125I radioactive seed implantation in treatment of stage Ⅲ non-small cell lung cancer ( NSCLC ) and the influential factors of prognosis.Methods 247 patients of stage Ⅲa/Ⅲb NSCLC underwent CT-guided 125I radioactive seed implantation.The clinical effects and the factors affecting prognosis were analyzed by univariate and multivariate analyses.Results The 1-,3-,and 5- year overall survival rates were 82.8％,23.8％,and 11.5 ％,respectively.The median survival time was 24.8 months,and the local control rate was 92.2 ％,63.8％,and 25.7％,respectively.The 5- year overall survival rate was 14.7％,and the median survival time was 29.7 months of the stage Ⅲ,patients.And the 5- year overall survival rate was 11.2％,and the median survival time was 24.0 months at the stage Ⅲb.Univariate analysis showed that age,course of disease,hemoglobin before treatment,clinical stage,maximum diameter of tumor,prescribed dose (PD),post-operational mean dose,post-operational dose covering 100％ volume (D100),remedial model were the main prognostic factors; however,multivariate analysis revealed that hemoglobin ≥ 120 g/L before treatment,post-operational dose covering 100％ volume (D100) and maximum diameter of tumor were the independent risk factors for predicting the survival.Aerothorax was observed in 37 patients with an incidence rate of 14.9％,and hemothorax was observed in 22 patients with an incidence rate of 9％.Conclusions 125I radioactive seed implantation therapy is effective in the treatment of stage Ⅲ NSCLC.Hemoglobin level before treatment,post-operational dose covering 100％ volume (D100 ),and maximum diameter of tumor are the main prognostic factors for the NSCLC patients treated with radiotherapy for NSCLC.

Objective To investigate the role of epidermal growth factor receptor and cyclooxygenase-2 pathways in the erlotinib and celecoxib enhanced radiation sensitivity in A549 human lung cancer cell line. Methods IC20 of erlotinib and celecoxibon in A549 human lung cancer cells was measured by MTT assay,Clonogenic assays were used to evaluate the antitumor effects of the drugs and Xirradiation.Flow cytometry was used to assess the apoptosis and cell cycle alteration,and Western blot was used for the detection of Akt and phospho-Akt.Results Both erlotinib and celecoxib could inhibit the proliferation of A549 cells in vitro in a dose-dependent manner and their values of IC20 were (5.15 ± 0.14)and (40.32 ± 1.26) μmol/L,respectively. For radiation survival,the values of Dq,Do,SF2 of the combination of two drugs were lower than those of either drug ( t =6.62,P ＜ 0.05).The SER of celecoxib,erlotinib and their combination were 1.299,1.503 and 2.217,respectively.Flow cytometry assay showed that both celecoxib and erlotinib could enhance radiation-induced G0/G1 arrest,reduce the cell numbmer in S phase,and enhance radiation-induced apoptosis,especially for the combination of drugs.Western blot assay showed that the expressions of Akt protein were similar in all groups.However,pAkt expression was suppresssed by erlotinib and celecoxib,but promoted by radiation.pAkt had the lowest expression in the radiated cells with the treatment of two drugs ( t =4.89,P ＜ 0.05 ).Conclusions The edotinib and/or celecoxib could enhance radiosensitivity probably by increasing cell apoptosis and reducing the number of Sphase cells with low radiosensitivity.

Objective To investigate the role of NF-kB in radiation-induced apoptosis ot human non-Hodgkin lymphoma (NHL) cells and the mechanism involved.Methods Three human non-Hodgkin lymphoma cell lines,Namalwa,Ramos,and Raji cells were divided into control,IR and IR + QNZ ( 10nmol/L) groups,respectively.Annexin-V kit was used to determine cell apoptosis. Protein expression levels of Survivin,Bax,Bcl-2 and cleaved Caspase-3 were evaluated by Western blot.Survivin mRNA was quantified by real-time PCR.Results Inhibition of NF-kB by QNZ pretreatment significantly enhanced X-ray induced apoptosis in human NHL cells in a dose-dependent manner (t =2.93 - 12.52,P ＜ 0.05).At the same time,QNZ significantly reversed the expression levels of Survivin protein and mRNA that were upregulated by radiation(t =3.29 - 16.72,P ＜ 0.05).QNZ also increased the levels of Caspase-3 and proapoptotic protein Bax,but reduced anti-apoptotic protein Bcl-2 expression level and hence the ratio of Bcl-2/Bax.Conclusions Inhibition of NF-kB could enhance radiation-induced cell apoptosis in human NHL cells through down-regulating Survivin expression and decreasing Bcl-2/Bax ratio.

Objective To retrospectively analyze the influence of intensity-modulated radiotherapy (IMRT) on tumor regression in primary nasopharyngeal carcinoma (NPC).Methods 272 patients with NPC received radical radiotherapy alone,196 by IMRT with a total treatment time of 6 weeks,and 76 by bilateral field conventional radiotherapy (CRT) with the total treatment timc of 7 weeks.Results By the end of radiotherapy,the primary tumor and neck lymph node residual rates of the IMRT group were 36.7％ and 44.2％,respectively,both significantly higher than those of the GRT group (21.1％ and 26.6％,x2 =6.15,3.99,P ＜ 0.05).Three months after the radiotherapy,residual lesions were observed at the nasopharynx or neck lymph nodes in 12 of the IMRT group,with a residual rate of 6.1％,not significantly different from that of the CRT group (9.2％,7/76).The 12 residual lesions of the IMRT group all vanished completely 4 -9 months after the radiotherapy.Conclusions There is an obvious difference in regressive mode between IMRT and CRT technique in NPC treatment.At the end of IMRT,the tumor residual rate is slightly increased.However,the delivered dose of gross tumor volume (GTV) is sufficient,and the boost dose should not be delivered indiscreetly.