电穿孔介导质粒DNA肿瘤内转移抑制恶性肿瘤生长与转移

利用携带绿色荧光蛋白 (greenfluorescentprotein ,GFP)编码基因的表达质粒 ,测试电穿孔方法介导目的基因活体组织内转移的效率并优化电击参数 .在此基础上采用电穿孔技术直接将编码白介素 12 (IL 12 )、白介素 2 (IL 2 )、粒单细胞克隆刺激因子 (GM CSF)等免疫调节因子或反义血管内皮细胞生长因子 12 1(VEGF12 1)、可溶性血管内皮细胞膜受体 (sFlk 1及ExTek)等血管生成抑制因子表达质粒转移至肿瘤局部 .实验结果表明电穿孔介导GFP表达质粒肌肉内转移的效率较高 ,GFP可在肌细胞内持续高水平表达 3周以上 ,而在肿瘤细胞内只能表达 4～ 6d ,但高电压短脉冲电击组肿瘤内GFP阳性细胞数比低电压长脉冲组高 2 6 8倍 .多次电击介导IL 12表达质粒转移至肿瘤组织内 ,可有效地抑制小鼠膀胱癌BTT gfp、人乳腺癌MCF 7及肝癌SMMC 772 1 gfp的生长 .MCF 7对血管生成抑制因子基因转移治疗较敏感 ,单独应用反义VEGF12 1、sFlk 1或ExTek即显示明确的治疗效果 .SMMC 772 1 gfp单独应用sFlk 1有效 .小鼠膀胱癌对单独应用反义VEGF12 1、sFlk 1或ExTek治疗效果不理想 ,但联合应用sFlk 1和ExTek仍然可以有效地抑制肿瘤生长与转移 ,甚至使肿瘤缩小或消失 .提示电穿孔技术是一项高效、安全。

调强适形放射治疗在临床的应用

目的:介绍调强适形放射治疗(intensitymodulatedradiationtherapyIMRT)在美国Stanford大学医学中心放疗科的临床应用情况。方法:详细描述制作CorvusIMRT治疗计划、质量控制和质量监测的整个过程;利用该IMRT,联合外照射和X刀根治性治疗T4N0M0鼻咽癌1例,及单纯IMRT治疗胸椎体转移癌1例。结果:从靶区各个剖面可见高剂量等剂量曲线按计划设计紧扣靶区,重要器官和敏感组织受到保护,治疗计划统计表显示靶区、重要器官和敏感组织的最高及最低受量和受照射体积,而剂量体积直方图则直观地提示肿瘤组织和周围器官的受量比较。结论:IMRT靶区剂量分布均匀,正常组织及敏感器官受到最大限度的保护,可对某些病种的肿瘤组织施以高剂量放疗。

Comparison of conformal and intensity-modulated techniques for simultaneous integrated boost radiotherapy of upper esophageal carcinoma

AIM:To compare intensity-modulated radiotherapy (IMRT) with conformal radiotherapy (CRT) by investigating the dose profiles of primary tumors,electively treated regions,and the doses to organs at risk. METHODS:CRT and IMRT plans were designed for five patients with upper esophageal carcinoma.For each patient, target volumes for primary lesions (67.2 Gy) and electively treated regions (50.4 Gy) were predefined.An experienced planner manually designed one CRT plan.Four IMRT plans were generated with the same dose-volume constraints,but with different beam arrangements.Indices including dose distributions,dose volume histograms (DVHs) and conformity index were compared. RESULTS:The plans with three intensity-modulated beams were discarded because the doses to spinal cord were lager than the tolerable dose 45Gy,and the dose on areas near the skin was up to 50Gy.When the number of intensity beams increased to five,IMRT plans were better than CRT plans in terms of the dose conformity and homogeneity of targets and the dose to OARs.The dose distributions changed little when the beam number increased from five to seven and nine. CONCLUSION:IMRT is superior to CRT for the treatment of upper esophageal carcinoma with simultaneous integrated boost (SIB).Five equispaced coplanar intensity-modulated beams can produce desirable dose distributions.The primary tumor can get higher equivalent dose by SIB technique. The SIB-IMRT technique shortens the total treatment time, and is an easier,more efficient,and perhaps a less error- prone way in delivering IMRT.

Therapeutic effects and prognostic factors in three-dimensional conformal radiotherapy combined with transcatheter arterial chemoembolization for hepatocellular carcinoma

AIM: To evaluate the therapeutic efficacy of threedimensional conformal radiotherapy (3D-CRT) combined with transcatheter arterial chernoembolization (TACE) on the patients with hepatocellular carcinoma (HCC).METHODS: Between 1998 and 2001, 94 patients with HCC received 3D-CRT combined with TACE. A total 63 patients had a Okuda stage Ⅰ lesion and 31 patients had stage Ⅱ. The median tumor size was 10.7 cm (range 3.0-18 cm), and liver drrhosis was present in all the patients. There were 43 cases of class A and 51 dass B. TACE was performed using lipiodol,5-fluorouracil, cisplatin, doxorubicin hydrochloride and mitomycin, followed by gelatin sponge cubes. Fifty-nine patients received TACE only one time, while the others 2 to 3 times. 3D-CRT was started 3-4 wk after TACE. All patients were irradiated with a stereotactic body frame and received 4-8 Gy single high-dose radiation for 8-12 times at the isocenter during a period of 17-26 d (median 22 d).RESULTS: The median follow-up was 37 mo (range 10-48 mo) after diagnosis. The response rate was 90.5%. The overallsurvival rate at 1-, 2-, and 3- year was 93.6%, 53.8% and 26.0% respectively, with the median survival of 25 too. On univariate analysis, age (P=-0.026), Child-Pugh classification for cirrhosis of liver (P=0.010), Okuda stage (P=-0.026),tumor size (P=0.000), tumor type (P=0.029), albuminemia (P=0.035), and radiation dose (P=0.000) proved to be significant factors for survival. On multivariate analysis,age (P=-0.024), radiation dose(P=-0.001), and tumor size (P=0.000) were the significant factors.CONCLUSION: 3D-CRT combined with TACE is an effective and feasible approach for HCC. Age, radiation dose and tumor size were found to be significant prognostic factors for survival of patients with HCC treated by 3D-CRT combined with TACE. Further study for HCC is needed to improve the treatment efficacy.

Patients with brain metastases from gastrointestinal tract cancer treated with whole brain radiation therapy:Prognostic factors and survival

AIM: To identify the prognostic factors with regard to survival for patients with brain metastasis from primary tumors of the gastrointestinal tract. METHODS: Nine hundred and sixteen patients with brain metastases, treated with whole brain radiation therapy (WBRT) between January 1985 and December 2000 at the Department of Radiation Oncology, University Hospital Freiburg, were analyzed retrospectively. RESULTS: Fifty-seven patients presented with a primary tumor of the gastrointestinal tract (esophagus: n=0, stomach: n=10, colorectal: n=47). Twenty-six patients had a solitary brain metastasis, 31 patients presented with multiple brain metastases. Surgical resection was performed in 25 patients. WBRT was applied with daily fractions of 2 Gray (Gy) or 3Gy to a total dose of 50Gy or 30Gy, respectively. The interval between diagnoses of the primary tumors and brain metastases was 22.6mo vs 8.0mo for patients with primary tumors of the colon/rectum vs other primary tumors, respectively (P<0.01, log-rank). Median overall survival for all patients with brain metastases (n=916) was 3.4mo and 3.2mo for patients with gastrointestinal neoplasms. Patients with gastrointestinal primary tumors presented significantly more often with a solitary brain metastasis than patients with other primary tumors (P<0.05, log-rank). In patients with gastrointestinal neoplasms (n=57), the median overall survival was 5.8 mo for patients with solitary brain metastasis vs 2.7mo for patients with multiple brain metastases (P<0.01, log-rank). The median overall survival for patients with a Karnofsky performance status (KPS) ≥70 was 5.5mo vs 2.1mo for patients with KPS <70 (P<0.01, log-rank). At multivariate analysis (Cox Model) the performance status and the number of brain metastases were identified as independent prognostic factors for overall survival. CONCLUSION: Brain metastases occur late in the course of gastrointestinal tumors. Pretherapeutic variables like KPS and the number of brain metastases have a profound influence on treatment outcome.

KAI1 gene expression in colonic carcinoma and its clinical significances

AIM: To investigate KAI1 gene expression in the progression of human colonic carcinoma and its clinical significances.METHODS: KAI1 expression was detected by in situ hybridization and immunohistochemistry in the 4 established cell lines of colorectal carcinoma with different metastatic potentials, and in 80 specimens of colonic carcinoma, 21 colonic carcinoma specimens with lymphatic metastasis and 20 controls of normal colonic mucosa.RESULTS: The expressions of KAI1 in HT29 and SW480 cell lines were higher than those in LoVo and SW620. Theexpression of KAI1 gene was significantly higher in colorectal carcinoma compared with normal colonic mucosa andlymphatic metastasis (X^2=46.838, P<0.01). The expression of KAI1 gene had no relationship with histological grade.The KAI1 expressions in Dukes A and B carcinoma were higher at both mRNA and protein levels compared to Dukes C carcinoma (72=16.061, P<0.05). The expression of KAI1 in colonic carcinoma specimens with lymphatic metastasis was almost lost. The results of in situ hybridization were in concordance with immunohistochemistry.CONCLUSION: KAI1 is highly related to the metastasis of colonic carcinoma and may be a useful indicator of metastasis in colonic carcinoma.

Docetaxel inhibits SMMC-7721 human hepatocellular carcinoma cells growth and induces apoptosis

AIM: To investigate the in vitro anti-hepatocellular carcinoma (HCC) activity of docetaxel against SMMC-7721 HCC cells and its possible mechanism.METHODS: The HCC cells were given different concentrations of docetaxel and their growth was measured by colony forming assay. Cell cycle and apoptosis were analyzed by flow cytometry and fluorescence microscopy (acridine orange/ethidium bromide double staining, AO/EB), as well as electronic microscopy. The SMMC-7721 HCC cell reactive oxygen species (ROS) and glutathione (GSH) were measured after given docetaxel.RESULTS: Docetaxel inhibited the hepatocellular carcinoma cells growth in a concentration dependent manner with IC505×10-10 M. Marked cell apoptosis and G2/M phase arrest were observed after treatment with docetaxel ≥10-8M.Docetaxel promoted SMMC-7721 HCC cells ROS generation and GSH deletion.CONCLUSION: Docetaxel suppressed the growth of SMMC7721 HCC cells in vitro by causing apoptosis and G2/M phase arrest of the human hepatoma cells, and ROS and GSH may play a key role in the inhibition of growth and induction of apoptosis.

Effect of intraoperative radiotherapy combined with external beam radiotherapy following internal drainage for advanced pancreatic carcinoma

AIM: To determine the survival of advanced pancreatic cancer patients treated with intraoperative radiotherapy (IORT) combined with external beam radiation therapy (EBRT) following internal drainage (cholecystojejunostomy or choledochojejunostomy). METHODS: Eighty-one patients with advanced pancreatic cancer who received IORT combined with EBRT following internal drainage (ID) between 1996 and 2001 were retrospectively analyzed. Among the 81 patients, 18 underwent ID+IORT, 25 ID+IORT+EBRT (meanwhile, given 5-Fu 300 mg/m^2 iv drip, 2f/w), 16 EBRT, 22 had undergone simple internal drainage. The IORT dose was 15-25Gy in a single fraction. The usual EBRT dose was 30-40Gy with a daily fraction of 1.8-2.0 Gy. RESULTS: The complete remission rate, partial remission rate of patients with backache and abdominal pain treated with ID+IORT were 55.5%, 33.3% respectively. Alleviation of pain was observed 2 or 3 wk after IORT. The median survival time (MST) of ID+IORT group was 10.7 mo. The pain remission rate of patients treated with ID+IORT+EBRT was 92%, and their MST was 12.2 mo. The MST of patients treated with EBRT and simple internal drainage was 5.1 mo and 7.0 mo, respectively. The survival curve of ID+IORT group and ID+IORT+EBRT group was significantly better than that of EBRT group (P<0.05). The difference between the ID+IORT+EBRT group and ID group was significant (P<0.05). CONCLUSION: IORT combined with EBRT following internal drainage can alleviate pain, improve quality of life and prolong survival time of patients with advanced pancreatic cancer.

Impact of simultaneous assay, the PCNA, cyclinDl, and DNA content with specimens before and after preoperative radiotherapy on prognosis of esophageal cancer-possible incorporation into clinical TNM staging system

AIM: The aim of the present study is to use immunohisto chemical methods to investigate the clinical implications of tumor markers in esophageal squamous cell carcinoma and evaluate their impact on prognosis. METHODS: From November 1990 to December 1996, 47 patients were treated with preoperative radiation followed by radical esophagectomy. All patients were confirmed pathologically as suffering from squamous cell carcinoma. Immunohistochemical stain was done for PCNA, cyclinDl protein expression and DNA content analyzed by image cytometry. Kaplan-Meier method for single prognostic factor and log-rank test was used to test the significant difference. Cox stepwise regression model and prognosis index model were used for survival analysis with multiple prognostic factors. RESULTS: Radio-pathological change, T stage and N stage, as the traditional prognostic factors had statistical difference in 3-, 5- and 10-year survival rates. While, tumor cell proliferating marked PCNA, cyclinDl and DNA content served as independent prognostic factors of esophageal carcinoma. There was definitely an identity between the single and multiple factor analyses. PI was more accurate to evaluate the prognosis of esophageal carcinoma. CONCLUSION: It is possible that tumor cell proliferating marked PCNA, cyclinD1 and DNA content would become the endpoints for evaluating the prognosis of esophageal carcinoma.

Tiaml gene expression and its significance in colorectal carcinoma

AIM: To explore the expression of Tiam1 gene in colorectal carcinoma and its correlation with tumor metastasis. METHODS: Expressions of Tiaml gene in 8 colorectal carcinoma cell lines were detected by reverse transcriptase-polymerase chain reaction. In vitro invasiveness was determined by means of Matrigel invasion assay. The correlation of Tiaml expression with the invasive ability was also analyzed. RESULTS: Tiaml gene was highly expressed in LoVo and SW620, which were established from metastatic colorectal carcinomas in comparison with LS174T, SW480, HCT116, LST, HRT-18 and Hee8693, which were established from primary colorectal carcinomas. In vitro cell invasivion demonstrated that LoVo and SW620 had a higher invasive ability than LS174T, SW480, HCT116, LST, HRT-18 and Hee8693. The expression of Tiaml gene was highly related to the metastatic potential of colorectal carcinoma cells. CONCLUSION: Tiaml gene may play an important role in invasion and metastasis of colorectal carcinoma and is a metastasis-related gene.

Effects of KAI1/CD82 on biological behavior of human colorectal carcinoma cell line

AIM: To investigate the effects of KAI1/CD82 on biological behavior of colorectal carcinoma cells. METHODS: KAI1 cDNA was transfected into highly malignant colorectal carcinoma cell line, LoVo, which had low level of endogenous KAI1 expression, and established stable transfectant clones with high KAI1/CD82 expression.The cell-cell adhesion, cell aggregation, cell-matrix adhesion and cell invasion assay were performed to determine whether KAI1 transfectant could have an effect on proliferation,adhesion and tumor metastasis in comparison with the control transfectant cells. RESULTS: KAI1 expression did not alter in vitro cell proliferation. But the KAI1 transfectant cells exhibited significantly increased homotypic cell-cell adhesion and cell aggregation in comparison with the control transfectant cells (P＜0.05). Furthermore, KAI1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in KAI1-transfected LoVo cells. The data indicated that KAI1 expression significantly suppressed the metastatic potential of KAI1-transfected LoVo cells. CONCLUSION: Our results suggest that KAI1 might function as a negative regulator of colorectal carcinoma metastasis.

Post-radiation survival time in hepatocellular carcinoma based on predictors for CT-determined, transarterial embolization and various other parameters

AIM: In this retrospective study of unresectable hepatocellular carcinoma (HCC), we have investigated the efficacy of CT-derived parameters, laboratory measurements, clinical assessment and associated transarterial embolization (TAE) as predictors of post-radiotherapy survival time. METHODS: Sixty-six patients diagnosed with unresectable HCC that had undergone radiotherapy at two medical university hospitals in Taipei were enrolled in the study. Using multivariant analysis, pre-treatment parameters including tumor number and CT confirmation of PVT and ascites were compared. Multivariant analysis was also used for comparison of the mean pretreatment values for laboratory measurements, including alpha-fetoprotein, direct/total bilirubin and GOT/GPT levels, and clinical history of chronic hepatitis across the three survival-time categories. The x2 was used to test the significance of the relationship between survival time and TAE procedure. The P values for the above tests were deemed statistically significant where P<0.05. RESULTS: Portal vein thrombosis (P= 0.032) and ascites (P><0.05) were negative predictors of post-radiation survival time. Low-grade liver cirrhosis (A or B), lower tumor volume and low levels of AFT, GOT/GPT, and total bilirubin were predictors of longer post-radiation survival time (P<0.05). CONCLUSION: The CT and clinical and laboratory assessment provide a reference for, and enable estimation of, probable survival times in HCC patients after radiotherapy. Tumor volume, severity of liver cirrhosis, status with respect to portal vein thrombosis and ascites and AFT, GOT/GPT and total bilirubin values were significant predictors of survival in this study.

Antitumor effects and radiosensitization of cytosine deaminase and thymidine kinase fusion suicide gene on colorectal carcinoma cells

AIM: To investigate the killing effect and radiosensitization of double suicide gene mediated by adenovirus on colorectal carcinoma cells. METHODS: Colorectal carcinoma cell line SW480 was transfected with adenovirus expression vector containing cytosine deaminase (CD) and thymidine kinase (TK) fusion gene. The expression of CD-TK fusion gene was detected by reverse transcriptase-polymerase chain reaction. The toxic effect of ganciclovir (GCV) and 5-fluorocytosine (5-FC) on infected cells was determined by MTT assay. The radiosensitization of double suicide gene was evaluated by clonogenic assay. RESULTS: After prodrugs were used, the survival rate of colorectal carcinoma cells was markedly decreased. When GCV and 5-FC were used in combination, the cytotoxicity and bystander effect were markedly superior to a single prodrug (X2 = 30.371, P<0.01). Both GCV and 5-FC could sensitize colorectal carcinoma cells to the toxic effect of radiation, and greater radiosensitization was achieved when both prodrug were used in combination. CONCLUSION: CD-TK double suicide gene can kill and radiosensitize colorectal carcinoma cells.

Intensity modulated radiation therapy and chemotherapy for Ioca advanced pancreatic cancer:Results of feasibility study

AIM: To explore whether intensity modulated radiation therapy (IMRT) in combination with chemotherapy could increase radiation dose to gross tumor volume without severe acute radiation related toxicity by decreasing the dose to the surrounding normal tissue in patients with locally advanced pancreatic cancer.METHODS: Twenty-one patients with locally advanced pancreatic cancer were evaluated in this clinical trial,Patients would receive the dose of IMRT from 21Gy to 30Gy in 7 to 10 fractions within two weeks after conventional radiotherapy of 30Gy in 15 fractions over 3 weeks. The total escalation tumor dose would be 51, 54,57, 60Gy, respectively. 5-fluororacil (5-FU) or gemcitabine was given concurrently with radiotherapy during the treatment course.RESULTS: Sixteen patients who had completed the radiotherapy plan with doses of 51Gy (3 cases), 54Gy (3 cases), 57Gy (3 cases) and 60Gy (7 cases) were included for evaluation. The median levels of CA19-9 prior to and after radiotherapy were 716 U/ml and 255 U/ml respectively (P<0.001) in 13 patients who demonstrated high levels of CA19-9 before radiotherapy. Fourteen patients who suffered from pain could reduce at least 1/3-1/2 amount of analgesic intake and 5 among these patients got complete relief of pain. Ten patients improved in Kamofsky performance status (KPS). The median follow-up period was 8 months and one-year survival rate was 35 %. No patient suffered more than grade Ⅲ acute toxicities induced by radiotherapy.CONCLUSION: Sixty Gy in 25 fractions over 5 weeks with late course IMRT technique combined with concurrent 5-FU chemotherapy can provide a definitely palliative benefit with tolerable acute radiation related toxicity for patients with advanced pancreatic cancer.

Expression of a novel immunoglobulin gene SNC73 in human cancer and non-cancerous tissues

AIM: To investigate the expression of immunoglobulin gene SNC73 in malignant tumors and non-cancerous normal tissues.METHODS: Expression level of SNC73 in tumors and non-cancerous tissues from the same patient was determined by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay (RT-PCR-ELISA) in 90 cases of malignant tumors, including colorectal cancer, gastric cancer, breast cancer, lung cancer and liver cancer, Analysis on the correlation of SNC73 expression with sex, age, site,grade of differentiation, depth of invasion, and metastases in colorectal cancer patients was made.RESULTS: Expression level of SNC73 in non-cancerous colorectal mucosa and colorectal cancerous tissues was 1.234±0.842 and 0.737±0.731, respectively (P<0.01), with the mean ratio of 7.134±14.092 (range, 0.36-59.54).Expression of SNC73 showed no significant difference among gastric cancer, breast cancer, lung cancer and liver cancer when compared with non-cancerous tissues (P>0.05). No correlation was found between SNC73 expression level and various clinicopathological factors, including sex, age, site,grade of differentiation, depth of invasion and metastases of CRC patients.CONCLUSION: Down-regulation of SNC73 expression may be a relatively specific phenomenon in colorectal cancer.SNC73 is a potential genetic marker for the carcinongenesis of colorectal cancer. The relationship of SNC73 expression and carcinogenesis of colorectal cancer merits further study.

Docetaxel shows radiosensitization in human hepatocellular carcinoma cells

AIM: To determine the radiosensitizing potential of docetaxel in human hepatocellular carcinoma SMMC-7721 cells and its mechanisms.METHODS: SMMC-7721 cells were incubated with docetaxel at 0.125, 0.25, and 0.5 nmoL/L for 24 h and at 0.125 and 0.25 nmol/L for 48 h before irradiation. Radiation doses were given from 0 to 10 Gy. Cell survival was measured by a standard clonogenic assay after a 9-d incubation. The reactive oxygen species (ROS) and glutathione (GSH) are detected after being given the same dose of docetaxel for the same time. RESULTS: The sensitization enhancement ratios (SER) for SMMC-7721 cells determined at the 50% survival level were 1.15, 1.21 and 1.49 at 0.125, 0.25, and 0.5 nmol/L for pre-incubation of 24 h, respectively; the SER were 1.42, 1.67 at 0.125 and 0.25 nmol/L, for pre-incubation of 48 h, respectively. The ROS of SMMC-7721 cells increased and GSH decreased after pretreatment with the same doses of docetaxel for 24 or 48 h.CONCLUSION: A radiosensitizing effect of docetaxel could be demonstrated unambiguously in this cell line used. In addition, our data showed that the mechanism of radiopotentiation by docetaxel probably does not involve a G2/M block in SMMC-7721 cells, and ROS generation and GSH deletion may play a key role in the radiosensitizing effect of docetaxel.

Endoscopic banding ligation can effectively resect hyperplastic polyps of stomach

AIM: Bleeding and perforation are the major and serious complications associated with endoscopic polypectomy. To develop a safe and effective method to resect hyperplastic polyps of the stomach, we employed rubber bands to strangulate hyperplastic polyps and to determine the possibility of inducing avascular necrosis in these lesions.METHODS: Forty-seven patients with 72 hyperplastic polyps were treated with endoscopic banding ligation (EBL). On 14 days after endoscopic ligation, follow-up endoscopies were performed to assess the outcomes of the strangulated polyps.RESULTS: After being strangulated by the rubber bands,all of the polyps immediately became congested (100 %),and then developed cyanotic changes (100 %) approximately 4 minutes later. On follow-up endoscopy 2 weeks later, all the polyps except one had dropped off. The only one residual polyp shrank with a rubber band in its base, and it also dropped off spontaneously during subsequent follow-up.No complications occurred during or following the ligation procedures.CONCLUSION: Gastric polyps develop avascular necrosis following ligation by rubber bands. Employing suction equipment, EBL can easily capture sessile polyps. It is an easy, safe and effective method to eradicate hyperplastic polyps of the stomach.

Utility of SPECT Lung Perfusion Scans in Assessing the Early Changes in Pulmonary Function after Radiotherapy for Patients with Lung Cancer

OBJECTIVE Radiation-induced lung injury commonly follows radiotherapy(RT) for tumors within and near the thorax. Lung function is usually measured by pulmonary function tests (PFTs). But RT-induced regional changes of pulmonary function cannot be accurately evaluated by PFTs. Lung perfusion scintigraphy compared with other radiographic methods can assess well regional pulmonary physiological function, and a 3-dimensional conformal radiotherapy planning system can quantitatively calculate irradiation dosage. The purpose of this study is to assess, by lung perfusion scintigraphy, early changes in the pulmonary function of patients with lung cancer when receiving thoracic 3-dimensional conformal radiotherapy (3D-CRT).METHODS Nineteen patients receiving thoracic 3D-CRT for lung cancer were studied. A single photon emission computed tomography (SPECT) lung perfusion scan, X-ray or CT scan before RT and after 40～50Gy radiation were performed. Pre-RT SPECT lung perfusion images were classified by comparing lung perfusion defects with radiological abnormalities before RT. Grade 0: There was no lung perfusion defect in the area of radiological abnormality. Grade 1: The size of the radiological abnormality was similar to the area of the lung perfusion defect. Grade 2: The area of the lung perfusion defect was bigger than the size of the radiological abnormality and extended to one lobe of the lung. Grade 3: The area of lung perfusion defect exceeded one lobe of the lung. The radiation field with more than 20Gy was drawn as a region of interest (ROI). The proportion of radioactive dose within this ROI relative to total lung dose in one slice was calculated. RESULTS All patients had lung perfusion defects, nine patients with grade 1, five patients with grade 2 and five patients with grade 3 damage, respectively. All tumors in the 19 patients were reduced in CT or X-ray images to various degrees after 40～50Gy radiation. The mean proportion of ROI in 19 patients was 53.7±29.8% before radiation as compared to 57.6±22.6% during RT. The difference between these two groups was not significant (P=0.280). The decreased relative lung perfusion post-RT was found in six patients, whereas the increased relative lung perfusion post-RT was observed in 13 patients. CONCLUSION SPECT lung perfusion scaning is a simple, convenient and useful method for assessing regional lung function pre-RT and for monitoring the changes in regional lung function after irradiation.

Iododeoxyuridine uptake in proliferating smooth musc le cells:an in vitro model to assess drug effects on intimal hyperplasia

Purpose To assess the maximum uptake of Iododeo xyur idine (IUdR) by proliferating smooth muscle cells in vitro to determine the opti mal concentration to be administrated in an in vivo experiment. The long-term g oal is to utilize radioactive IUdR to inhibit smooth muscle cell proliferation a nd restenosis of arteries after balloon angioplasty in vivo. Methods Porcine smooth muscle cells (SMCs) were cultured in 5% FBS medium and stim ulated to proliferate by the addition of medium containing 10% FBS and insulin. IUdR was added at 5 μM, 10 μM, 20 μM, 30 μM, 40 μM, respectively, in prolif erating SMCs with control for 1, 3, 5, 7 day incubation. Fluorescence Activated Cell Scanning (FACS) was performed after the SMCs were harvested and double-sta ined with FITC-conjugated anti-IUdR antibody (B44) and propidium iodide (PI). The ratio of IUdR-labeled cells to total cell population for each IUdR concentr ation and duration was determined by FACS. All data were repeated three times at each time point. The doubling times, growth curve and cell density of the proli ferating SMCs were investigated using Beckman Coulter Particle Counter and digit al microscopy. Results The percentage of proliferating SMCs uptaking IUdR incr eased from 1 to 5 days incubation with all concentrations of IUdR; In day 5, the uptake rate reached the peak value, then decreased by 7 days. IUdR uptake on d ay 5 was higher with concentrations of 10 μM and 20 μM. The doubling times of the SMCs were prolonged with IUdR concentration increasing, while the proliferat ing cell number and density compared with control decreased obviously by day 5 ( P<0.05).Conclusion The peak time to uptake IUdR was 5 days and optimal concentration of IUdR was between10 μM to 20 μM for proliferating SMCs to upta ke in vitro. IUdR itself could inhibit the SMCs’ proliferation and the inhibito ry effect was related to the concentration.[

EFFECT OF ADENOVIRUS—MEDIATED p53 GENE TRANSFER ON APOPTOSIS AND RADIOSENSITIVITY OF HUMAN

To evaluate the effect of adenovirus-mediated p53 gene(Adp53) on apoptosis and radiosensitivity of human gastric carcinoma cell lines.Methods:Recombinant adenovirus expressing wild-type p53 lines with different p53 genetic status.p53 protein expression was detected by immunohistochemistry assay and western blot assay.Cell survival was assessed using a clonogenic assay.TUNEL assay was used in determination of apoptosis.Four human gastric carcinoma cells infected with Adp53 were irradiated with 4Gy and cell cycle distribution and Sub-G1 peak were assayed by flow cytometry.Results:G2/M arrest,apoptosis and inhibition of tumor cell proliferation were induced by infection at Adp53 at 100 MOI which caused high transfer rate of wild-type p53 and strong expression of p53 protein in four human gastric carcinoma cells.The radio-enhancement ratio of Adp53 at 4Gy were3.0 for W cell,3.6 for M cell,2.2 for neo cell and 2.5 for 823 cell in vitro.Conclusion :This study demonstrated that Adp53 transfer increased cellular apoptosis and radiosensitivity of human gastric carcinoma cell lines in vitro independently on cellular intrinsic p53 status thus supporting the combination of p53 gene therapy with radiotherapy in clinical trials.