Objective To compare the analytical result of different kinds of film dose analysis software for the same gamma knife,analyze the reasons of difference caused,and explore the measurements and means for quality control and quality assurance during testing gamma knife and analyzing its result.Methods To test the Moon Deity gamma knife with Kodak EDR2 film and γ-Star gamma knife with GAFCHROMIC(R) EBT film,respectively.All the validation films are scanned to proper imagine format for dose analysis software by EPSON PERFECTION V750 PRO scanner.Then imagines of Moon Deity gamma knife are analyzed with Robot Knife Adjuvant 1.09 and Fas-09 1.0,and imagines of γ-Star gamma knife with Fas-09 and MATLAB 7.0.Results There is no significant difference in the maximum deviation of radiation field size ( Full Width at Half Maximum,FWHM) and its nominal value between Robot Knife Adjuvant and Fas-09 for Moon Deity gamma knife (t = -2.133,P ＞0.05).The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicated that the differences are significant (t = - 8.154,P ＜ 0.05 ).There is no significant difference in the maximum deviation of FWHM and its nominal value between Fas-09 and MATLAB for γ-Star gamma knife ( t = - 1.384,P ＞0.05 ).However,following national standards,analysis of φ4 mm width of collimators can obtain different results according to the two kinds software,and the result of Fas-09 is not qualified while MATLAB is qualified.The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicates that the differences are significant ( t = 3.074,P ＜ 0.05 ).The imagines are processed with Fas-09.The analysis of imagine in the pre-and the post-processing indicates that there is no significant difference in the maximum deviation of FWHM and its nominal value ( t = 0.647,P ＞ 0.05 ),and the analytical result of the radiation field' s penumbra region width indicates that there is no significant difference as well ( t = -0.627,P ＞ 0.05 ).Conclusion The study shows that different kinds of film dose analysis software may have some differences in analysis of the same gamma knife validation film,and the results may lead to the different decisions in accordance with national standard.

BACKGROUND: Chitosan-disodium β-glycerol phosphate (C/GP) gel has been shown to be compatible with the entrapment of viable chondrocytes, and bone marrow mesenchymal stem cells (BMSCs) are considered to be the potential cells used in tissue engineering. This experiment is aimed to observe the cytocompatibility of BMSCs with C/GP gel.OBJECTIVE: To study the effect of C/GP gel on the growth, proliferation and chondrogenic differentiation in vitro cultured BMSCs and explore a new carrier for the application of cartilage tissue engineering.DESIGN: Completely randomized controlled experiment.SETTING: Department of Bone and Joint Surgery, Affiliated Hospital of Luzhou Medical College; Center Laboratory of Southwest Hospital Affiliated to the Third Military Medical University of Chinese PLA.MATERIALS: The experiment was performed in Center Laboratory of Southwest Hospital Affiliated to the Third Military Medical University of Chinese PLA between October 2005 and April 2006, Six adult female mini-pigss were employed. C/GP gel is prepared by mixture the HCI solution of chitosan with salt solution of β-glycerol phosphate, allowed gel at 37 ℃ in incubator for about 5 to 10 minutes.METHODS: ① BMSCs culture: 4-6 mL of bone marrow harvested from the posterior superior lilac crest were plated at 20 ×10<'6>/100 mm dish and then grown for 14 days in complete media, consisting of DMEM/F-12 supplemented with 10% fetal ovine serum. Cells were harvested and re-seeded for subculture. ② BMSCs differentiation assays: Osteogenic differentiation was assessed by histologic detection of alkaline phosphatase activity and calcium in cultures under osteogenic conditions. Chondrogenic differentiation was evaluated by histology for toluidine blue and immunohistochemistry for type Ⅱ collagen in cultures under chondrogenic conditions. ③ In vitro assays, expanded BMSCs were suspended in C/GP solution and allowed gel at 37 ℃ in incubator for about 5 to 10 minutes, then cultured under chondrogenic conditions for 3 weeks. Cells attached to and viability in C/GP gel was monitored with the aid of an inverted light microscope. Chondrogenic differentiation of cell in C/GP gel were assessed by histological and immunohistocbemistry. The cell proliferated was monitored by MTT after 2, 5, 8 days seeding.MAIN OUTCOME MEASURES: ① Characterization of mini-pigs' BMSCs; ② BMSCs attached to and viability in C/GP gel; ③ Chondrogenic differentiation of BMSCs in C/GP gel; ④ BMSCs proliferated in C/GP gel.RESULTS: ① Characterization of mini-pigs' BMSCs: Cultured BMSCs showed fibroblastic morphology and were able to differentiate to chondrocytes or osteogenic cells under chondrgenic or osteogenic cultured condition respectively. ②BMSCs attached to and viability in C/GP gel: BMSCs attached to and remained > 90% viable in C/GP gels immediately post-casting, and throughout the 21 days, using MTT staining. ③ Chondrogenic differentiation of BMSCs in C/GP gel: During 21 days culture period in vitro, chondrogenic induced BMSCs produced amounts of de novo cartilage matrix in the chitosan, as assessed by histological and biochemical criteria. ④ BMSCs proliferated in C/GP gel: Chondrogenic induced BMSCs cultured in C/GP gels continued to proliferate. There was a significant difference among the values of optical density in the cells-gel constructs compared to the controls without cells after 2, 5, and 8 days of culture (P<0.05).CONCLUSION: It is confirmed that C/GP gel shows good cytocompatibility with BMSCs and contributes to the growth, proliferation and chondrogenic differentiation for BMSCs in vitro culture. C/GP gel can be a potential cell-carrier for tissue engineering of articular cartilage.

OBJECTIVE: To investigate the expression of galectin-1 with the stimulation of peritoneal dialysis solution (PDS) and its role in the epithelial-to-mesenchymal transition (EMT) in human peritoneal mesothelial cells (HPMCs). METHODS: HPMCs were stimulated with PDS containing different concentrations of high glucose (1.5%, 2.5%, and 4.25%). After 24 h, mRNA and protein expressions of galectin-1,vimentin, and zo-1 were analyzed with real-time PCR and Western blot, respectively. Liposome transfected siRNA technique was used to knock down the expression of galectin-1 and the effect of galectin-1 siRNA on the EMT of HPMCs was also observed under 4.25% PDS condition. RESULTS: mRNA expression of galectin-1 in HPMCs increased in PDS groups, especially in group with 4.25% PDS (P<0.05). Protein expression of galectin-1 in HPMCs significantly increased in PDS groups with a dose dependent manner (P<0.05).Expression of vimentin in HPMCs significantly increased in PDS groups, especially in groups of 2.5% PDS and 4.25% PDS (P<0.05), but zo-1 expression markedly decreased (P<0.05). The expression of galectin-1 correlated positively with vimentin (P<0.05) but negatively with zo-1 (P<0.05). Expression of vimentin in groups of 4.25% PDS was markedly inhibited (P<0.05) by galectin-1 siRNA, whereas zo-1 expression was significantly increased (P<0.05). CONCLUSION Galectin-1 can mediate high glucose PDS-induced EMT in HPMCs and may be a new target for the prevention and treatment of peritoneal fibrosis.
Cells, Cultured ; Dialysis Solutions ; pharmacology ; Epithelial Cells ; cytology ; Epithelial-Mesenchymal Transition ; drug effects ; Galectin 1 ; genetics ; metabolism ; Glucose ; pharmacology ; Humans ; Peritoneal Dialysis ; adverse effects ; Peritoneal Fibrosis ; etiology ; Peritoneum ; cytology ; RNA, Messenger ; genetics ; metabolism

In order to analyze the image noise effect on the results of Gamma knife dosimetry parameter test, we tested the dosimetry parameters of the Gamma knives according to GBZ 168-2005. Radiological protection standards of X (gamma)-ray stereotactic radiosurgery for head treatment. Dose analysis software was applied to examine the testing film before and after image denoising, and SPSS 11.0 software was used for statistical analysis. The results showed that there was a significant difference in the results of the maximum deviation between radiation field size and its nominal value (t = 7.600, P < 0.01) and the radiation field's penumbra region width of collimators also had significantly different sizes (t = 5.334, P < 0.01) before and after image denoising. This study indicated that the image noise could influence the results of testing Gamma knife dosimetry parameters, so as to cause deviations.
Algorithms ; Artifacts ; Gamma Rays ; Head ; surgery ; Humans ; Radiometry ; instrumentation ; Radiosurgery ; instrumentation ; Radiotherapy Planning, Computer-Assisted ; methods ; Stereotaxic Techniques

Objective To measure the positioning accuracy of multi-leaf collimators (MLC) leaves by using radiochromic films,with aim to providing data in support of IAEA's methodology validation.Methods The present study focused on 8 accelerators (Varian,Elekta and Siemens machines) at 6 hospitals in Henan province with highly skilled physicists.The 25 cm × 25 cm radiochromic films were put on 30 cm × 30 cm homogeneous solid phantoms and covered with a 2.0-cm-thick homogeneous solid phantom slabs.The CT-scanned images were transmitted to TPS for plan formulation.With 6 MV X-ray,MLC created 5 strip 3 cm × 0.6 cm picket fence field,each with 3.0 cm strip separation.The SSD was 100 cm at the maximum dose point,with a 250 MU to each strip.The irradiated radiochromic films were returned to IAEA for analysis within one week and compared with the values given by IAEA.Results The difference of film-measured and TPS-planned positions of MLC leaves for each strip picket fence should be within ± 0.5 mm as required by IAEA.For 7 of 8 accelerators selected,the differences of accurately measured MLC leaf positions were all within ±0.5 mm,which were in line with the IAEA requirements,with only other one being beyond-0.5 mm,not consistent with the IAEA requirements.The differences of film-measured actual widths between each pair and all pairs of leaves were within ±0.75 mm as required by IAEA for 7 accelerators,whereas the other one was outside ± 0.75 mm,not consistent with the IAEA requirements.The standard deviation of film-measured actual width of MCL leaf between each pair and all pairs for 7 accelerators were ≤ 0.3 mm as required by IAEA,whereas the other one was 0.5 mm,not consistent with IAEA requirements.Conclusions The MLC positioning accuracy of a few of medical accelerators in Henan is not qualified.It is of great significance to carry out regular quality examination as well as third-party verification to ensure precise delivery of radiotherapy.