BACKGROUND: The osteoblastogenetic function of stem cell and local vasoformation is an important influencing factor in bone tissue engineering restoration.OBJECTIVE: To investigate the function of osteoblast induced, cultured and differentiated from mesenchymal stem cells(MSCs) and the expression of vascular endothelial growth factors(VEGF) in rabbits in itro.DESIGN: A single sample study and repetitive observational measurement by using cells as subjects SETTING: Department of histology and embryology in a university MATERIALS: The study was conducted in the Department of Histology and Embryology of Guangdong Medical College between March and December of 2002. The subjects were rabbits' MSCs.METHODS: The MSCs of newborn rabbits ere isolated and cultured. The cultured cells were induced to osteoblastogenesis with an osteo-inductive medium containing dexamethasone, ascorbic acid and β-glycerophosphate to observe the coloration of alkaline phosphates(ALP) and the formation of mineralized nodule in the cultured cells.MAIN OUTCOME MEASURES: ① observation of cell morphology, ②identification of steoblastogenesis from the cultured cells ③ expression of VEGF in osteoblasts derived from the cultured cells RESULTS: fter MSCs osteo-inductive culture, cells had strong ALP staining with the formation of mineralized node, and the VEGF expression enhanced with the grey scale of 132.3 ± 4.6, which was significantly different from that of the VEGF expression in MSCs( 148.5 ± 5.3) ( P ＜ 0.05).CONCLUSION: MSCs can be induced into osteoblasts with enhanced expression of VEGF, which might participate in the formation of endothelial cells.

Objective To investigate the value of Adobe Photashop images software in the verifica-tion of radiation portal. Methods The portal and simulation films or CT reconstruction images were impor-ted into computer using a scanner. The image size, gray scale and contrast scale were adjusted with Adobe Photoshop images software, then image registration and measurement were completed. Results By the com-parison between portal image and simulation image, the set-up errors in right-left, superior-inferior and ante-rior-posterior directions were (1.11 ± 1.37) mm, (1.33 ± 1.25) mm and (0.83±0.79) mm in the head and neck;(1.44±1.03) mm,(1.6±1.52) mm and (1.34±1.17) mm in the thorax;(1.53±0.86) mm, (1.83 ± 1.19) mm and (1.67 ± 0.68)mm in the abdomen; (1.93 ± I. 83) mm, (1.59 ± 1.07)mm and (0.85 ± 0.72)mm in the pelvic cavity. Conclusions Accurate radiation portal verification and posi-tion measurement can be completed by using Adobe Photoshop, which is a simple, safe and reliable method.

Objective: To explore the expression of epidermal growth factor receptor(EGFR) protein during benzo(a)pyrene (BaP) induced carcinogenesis. Methods: This study, we firstly utilized immunofluorescence assay and Western-blot to examine EGFR expression of the BaP which was constructed previously by project team induced malignant transformation human bronchial epithelial cell (BTC) and the control (16HBE cell). Then, we selected 36 healthy SD rats, divided into two groups according to simple random method, 18 rats each group. The constructed rat lung neoplasm model induced by pulmonary injection of BaP (10 mg/ml of BaP solution in 0.2 ml corn oil), contrast group use 0.2 ml corn oil, lung tissue was collected and the EGFR expression of lung tissue was detected by immunofluorescence assay and Western blot. T analysis was used to test the different of EGFR between two groups. Results: Immunofluorescence analysis showed that the EGFR expression in BTC was significantly higher than 16HBE cell. Meanwhile, Western blot also was used to confirmed this result, the relative expression of EGFR protein in the rats of the model group the control group were 1.04±0.13 and 2.32±0.12, respectively, and the difference was statistically significance (t=12.39, P<0.001). In vivo, well-defined tumor was found in the rat with pulmonary injection of BaP, and the lung showed diffuse alveolar septal thickening, alveolar wall destruction and pulmonary alveoli fusion, which suggested that the rat lung neoplasm model was constructive successfully. Furthermore, we found the EGFR expression of lung was increased dramatically in the rat lung neoplasm model by immunofluorescence detection and Western blot. The relative expression of EGFR protein in the rats of the model group the control group were 0.21±0.03 and 1.30±0.07, respectively, and the difference was statistically significance (t=12.84, P<0.001). Conclusion Expression of EGFR protein was increased during BaP carcinogenesis, and EGFR may play an important role in the carcinogenesis of BaP.

OBJECTIVETo investigate the effect of poly-ADP-ribosylation in hexavalent chromium Cr(VI) induced cell damage.

METHODSThe study object, poly (ADP-ribose) glycohydrolase (PARG) deficient human bronchial epithelial cells (16HBE cells), was constructed previously by our research group. Normal 16HBE cells and PARG-deficient cells were treated with different doses of Cr (VI) for 24 h to compare the differences to Cr (VI) toxicity, meanwhile set up the solvent control group. On this basis, 5.0 µmol/L of Cr (VI) was selected as the exposure dose, after the exposure treatment, total proteins of both cells were extracted for two dimension fluorescence difference gel electrophoresis (2D-DIGE) separation, statistically significant differential protein spots were screened and identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS/MS), and further validated by Western blot.

RESULTSAfter Cr (VI) treatment, the survival rate of PARG-deficient cells was higher than normal 16HBE cells. When the doses reached up to 5.0 µmol/L, the survival rate of 16HBE cells and PARG-deficient cells were respectively (59.67 ± 6.43)% and (82.00 ± 6.25)%, the difference between which was significant (t = -4.32, P < 0.05). 18 protein spots were selected and successfully identified after 2D-DIGE comparison of differential proteins between normal 16HBE cells and PARG-deficient cells before and after exposure. The function of those proteins was involved in the maintenance of cell shape, energy metabolism, DNA damage repair and regulation of gene expression. The differential expression of cofilin-1 was successfully validated by Western blot. The expression level of cofilin-1 in the 16HBE cells increased after Cr (VI) exposure with the relative expression quantity of 1.41 ± 0.04 in treated group and 1.00 ± 0.01 in control group, the difference of which was statistically significant (t = -18.00, P < 0.05), while the expression level in PARG-deficient cells had no statistically significant difference (t = -8.61, P > 0.05).

CONCLUSIONMost of the identified differential proteins are closely related to tumorigenesis, suggesting that poly-ADP-ribosylation reaction may resist the cytotoxicity of Cr(VI) by inhibiting Cr (VI) induced tumorigenesis, which provides important reference data to clarify the mechanisms of poly-ADP-ribosylation in Cr (VI) induced cell damage.

Bronchi ; Cell Transformation, Neoplastic ; genetics ; Chromium ; Cofilin 1 ; DNA Repair ; Epithelial Cells ; Glycoside Hydrolases ; deficiency ; physiology ; Humans ; Tandem Mass Spectrometry

Objective:To obtain the inter-fractional set-up errors of intensity-modulated radiotherapy (IMRT) of cervical cancer by cone-beam CT (CBCT), and to analyze the variations of the set-up errors on the cumulative dose deviation of the target volume.Methods:A total of 48 patients with cervical cancer who underwent IMRT were enrolled in this study, and the set-up errors of 696 CBCTs were obtained. The set-up errors were input into the treatment planning system, and the cumulative set-up error dose was obtained by superposing the set-up errors dose. The deviation percentage was calculated by the deviation formula and the standard planning dose.Results:The set-up errors caused the offset of isocenter distance by 0.58(0.36, 0.80) cm. Different statistical differences were noted between the cumulative set-up error dose and the standard planning dose by WilCoxon test. All the dose deviations in the target volume were reduced, and the differential dose volume histogram (DVH) appeared negatively skewed, and the peak value was declined. The DVH diagram shifted to the left with an inverse S-curve and the slope was increased. The HI deviation of the target volume from small to large were: CTV 1, CTV 2, GTV/CTV, CTV 3, CTV n, CTV all, and GTV nd; The HI deviation of the target volume were increased. Conclusions:The effect of set-up errors in IMRT of cervical cancer upon the cumulative doses of the target volume significantly differs. The cumulative dose of the target volume is reduced, and the uniformity of the target volume dose becomes worse. The uncertainty of the inter-fractional position leads to an increase or decrease in the the fractional doses of the target volume. The biological effect on tumor cells and the tumor recurrence remains to be investigated. In IMRT of cervical cancer, the CBCT position calibration is required before each treatment to ensure the dose accuracy of each structure in the target volume.