ObjectiveTo test a three-dimensional dose verification system,which reconstructing dose to anatomy based on modeling and online measurements ( RDBMOM ),and to evaluate the accuracy and feasibility of its application in clinical intensity-modulated radiotherapy (IMRT) quality assurance.Methods Phantom plans of regular and irregular fields were selected for the testing.All test plans were implemented and the dose distributions were measured using the thimble ion-chamber and two-dimensional ion-chamber array,the accuracy of RDBMOM were then evaluated by comparing the corresponding results.Two practical treated nasopharyngeal carcinoma IMRT plans were verified with RDBMOM and the clinic significancy were valued.ResultsCompared with measurements of the thimble ion-chamber,deviations of RDBMOM were within 1％ in all tested cases except small field of 3 cm ×3 cm.The largest deviation of reconstructed dose in IMRT cases was 2.12％.The dose profile reconstructed by RDBMOM coincided with the measurement using two-dimensional ion-chamber array.The γ rates (3％/3 mm) were 94.56％ - 100％.The RDBMOM verification of IMRT cases shown that the γ rate ＞ 99％ in total and ＞ 98％ in planning target volume,deviation in D95 ＜0.4％,but the largest deviations in mean dose of the parotids and lens were 2.97％ and 59.58％ respectively.ConclusionsAccuracy of the tested system satisfies the demand of IMRT dose verification.RDBMOM is able to provide information of volumetric dosimctry and anatomical location of dose error,which is benefit for evaluating the clinical value of verification results.

Wnt signaling is implicated in the control of cell growth and differentiation during neural stem cell(CNS) development.Wnt3a, one of wnt gene family members, has effect on regeneration neurospheres and differentiation into neurons.Wnt3a inhibits regeneration of neurospheres, and promotes its differentiation. In vitro neurosphere was cultured in a serum-free defined medium DMEM/F12 supplemented with bFGF and EGF. Dissociated cells were plated onto poly-d-lysine-coated coverslips and propagated in medium containing recombined Wnt3a-adenovirus. Plenty of Nurr1 were detected by RT-PCR after 3 days. Wnt3a combined AA would improve NSC differentiation into dopaminergic (DA) neuron. The quantity of DA neuron is obviously more than the AA alone group's. Moreover, the expression of TH mRNA is 1.86 fold in Wnt3a combined AA group. Induced cells were immunostained for TH and DAT. The proportion of TH-positive was (37.42 ? 2.54) % (P

Objective To observe the value of combined synthetic MRI and multiplexed sensitivity encoding diffusion weighted imaging(MUSE-DWI)for differentiating benign and malignant endometrial lesions.Methods Data of 112 patients with benign or malignant endometrial lesion confirmed by pathology were retrospectively analyzed.According to pathologic diagnosis,the patients were divided into malignant group(n=72)and benign group(n=40).Synthetic MRI and MUSE-DWI quantitative parameters,including T1,T2,proton density(PD)and apparent diffusion coefficient(ADC)of all lesions were acquired.The clinical data as well as ADC,T1,T2 and PD values of lesions were compared between groups,and those being significantly different between groups were included in univariate and multivariate logistic regression.Then the univariate and combined models were established for differentiating benign and malignant endometrial lesions.The receiver operating characteristic curves were drawn,and areas under the curves(AUC)were calculated to evaluated the diagnostic efficacy of the models,which were compared with DeLong test.Results Patients'age in malignant group were higher than that in benign group(P＜0.05).The length of the maximum diameter was larger,ADC,T2 and PD values were lower in malignant lesions than those in benign ones(all P＜0.05),while no significant difference of T1 value was found between groups(P=0.074).The AUC of ADC univariate model was 0.966,and there was no significant difference in AUC(0.970)between the combined ADC+T2+PD model(adjusted P＞0.05),but both higher than AUC of T2 univariate model(0.618),PD univariate model(0.664)and the combined T2+PD model(0.668)(all adjusted P＜0.05).Conclusion ADC univariate model and combined model with other parameters of combined synthetic MRI and MUSE-DWI could be used to effectively differentiate benign and malignant endometrial lesions.

Objective To assess the value of magnetic resonance imaging compilation(MAGiC)sequence in predicting lympho-vascular space invasion(LVSI)in early cervical cancer.Methods The data of 48 patients with cervical cancer confirmed by pathology were collected retrospectively,and classified into LVSI-positive group(n=29)and LVSI-negative group(n=19)according to postop-erative pathological results.MAGiC sequence images of patients were obtained before injecting contrast agents,then the region of interest(ROI)was delineated along the largest dimension edge of the lesion,and T1,T2 and proton density(PD)values were automatically generated by the software.Predictors were screened by univariate analysis and receiver operating characteristic(ROC)curves were drawn to assess their diagnostic efficacy for predicting LVSI in cervical cancer.Results Significant differences were found in T1 and PD values between LVSI-positive and LVSI-negative groups(P=0.003,P=0.017).There were no significant differences in T2 values between the two groups(P=0.414).The area under the curve(AUC)for T1 and PD values to predict LVSI status were 0.73 and 0.721,respectively.Conclusion LVSI-positive group of cervical cancer has lower T1 and PD values than LVSI-negative group based on MAGiC sequence.The MAGiC sequence has a certain application value for predicting LVSI status in early cervical cancer.

OBJECTIVETo build a protocol of separation and induction of megakaryocytes derived from cord blood mononuclear cells.

METHODSRed blood cells were precipitated by hydroxyethyl starch (HES). Mononuclear cells were obtained by density gradient centrifugation with Ficoll. The inducing efficiencies of megakaryocytes by using of different cytokine cocktails and culture media were analyzed.

RESULTSThe best choice for erythrocyte sedimentation and high efficiency of nucleated cells retrieving were obtained by using of 1.5% HES. The isolated cord blood mononuclear cells were cultured with domestic serum-free medium supplemented with 116t (IL-11, IL-6, TPO), st36(SCF, TPO, IL-3, IL-6), pt36 (PDGF,TPO,IL-3,IL-6) or pst36 for 7 days. St36 group (50 ng/ml SCF, 50 ng/ml TPO, 20 ng/ml IL-3 and 50 ng/ml IL-6) yielded the most CD41/CD61 positive [(6.79±1.97)×10⁴]. The cell viability [(82.85 ± 0.64)%] of st36 group by using of imported serum-free medium was better than [(60.90±6.93)%] that in domestic medium on day 7 after induction, and CD41/CD61 positive cells count [(18.60±1.97)×10⁴] were more than domestic serum-free medium group. Therefore, we chose imported serum-free medium containing st36 to induce cord blood mononuclear cells. After a prolonged culture, the total cell numbers increased accompanied with an elevated percentage of CD41/CD61 positive cells, which reached (54.27 ± 6.31)% on day 14. Wright-Giemsa staining showed that different phase cells, such as megakaryoblast, promegakaryocyte and granular megakaryocyte, occurred after 10 days'culture. Clone forming unit-megakarocytes (CFU-MK) assay showed that the colonies count increased with the prolonged incubation. CFU-MK colonies were [1 236.0±32.9] on day 14, which was higher than that in medium without induction (P<0.01). Platelets from megakaryocytes showed agglutination function after 10 days'culture.

CONCLUSION1.5% HES was the best solution to precipitate erythrocytes. The combination of an imported serum-free medium with IL-3, IL-6, SCF and TPO showed better induction efficiency than domestic medium or other cytokine cocktails. Meanwhile, induced megakaryocytes produced functional platelets.

Cell Culture Techniques ; Cell Differentiation ; Cell Division ; Cell Separation ; methods ; Cells, Cultured ; Culture Media, Serum-Free ; Fetal Blood ; cytology ; Humans ; Megakaryocyte Progenitor Cells ; cytology