A study on the conversion of prescribed dose for radiotherapy of logistic nanodosimetry model and microdosimetric kinetic model based on gamma analysis / 中华放射肿瘤学杂志

Objective:To validate the feasibility of the gamma analysis method in the study of prescription dose conversion between logistic nanodosimetry model (LNDM) and microdosimetric kinetic model (MKM) basing on the Chinese self-developed model LNDM by applying clinical experiences of National Institute of Radiological Science (NIRS).Methods:Physical dose distributions derived from the MKM- and LNDM-based carbon ion treatment plans were compared via the method of gamma analysis under the open-source treatment planning platform matRad. In this way, the prescribed dose conversion factor between the MKM- and LNDM-based treatment plans was obtained. Using water phantoms, the influence of geometric shape, size, depth of target volume (TV), prescribed dose and field setting on the conversion factor was investigated comprehensively. Moreover, preliminary verification of the acquired conversion factor was conducted on the C-shape model and a case of liver cancer patient.Results:The conversion factor depended on the field setting rather than the TV shape. Under the condition of single field, the conversion factor was positively correlated with the size and depth of TV, and the prescribed dose. Moreover, the conversion factor was successfully verified using the C-shape model and the patient with liver cancer, where the gamma passing rates (2%/2 mm) of the physical dose distribution generated by the MKM and LNDM treatment plans were 92.79% and 91.19%, respectively.Conclusions:The conversion factors (f=D LNDM/D MKM) obtained in this study might provide guidance for the prescribed dose setting during the carbon ion treatment planning based on the LNDM. Besides, the gamma analysis method could be used for the study of the prescribed dose conversion between different models.

Survivin as a factor of radioresistance to high-LET carbon ions in human hepatoma SMMC.7721 cells / 中华放射医学与防护杂志

Objective To investigate the influences of survivin down-regulation on cell G2/M phase arrest,apeptosis and sensitivity to carbon ion irradiation. Methods Small interfering RNA (siRNA) targeting survivin mRNA was designed, in vitro chemo-synthesized and transfected into SMMC-7721 cells. Survivin mRNA expression in SMMC-7721 cells was measured by real-time PCR, and the apeptotic rates by Annexin-FTTC at 24 and 48 h after transfection. Cell G2/M phase arrest after transfection was assessed with flow eytometry as well. Cellular sensitivity to high-LET carbon ions was determined by means of colony-forming assay. Results The expressions of survivin at mRNA level were down-regulated to be 59% and 39% in relation to the non-treated cells at 24 and 48 h after siRNA transfeetion, respectively. G2/M phase arrest in SMMC-7721 cells at 24 h after transfection was observed while much more obvious at 48 h. The apeptotic rate of SMMC-7721 cells was 21.41 % at48 h after survivin siRNA transfection, which was significantly higher than that of the cells transfected with negative siRNA. Moreover, a decreased clonogenic survival in siRNA treated group was shown. Conclusion Down-regulation of survivin gene expression in SMMC-7721 cells by siRNA could effectively induce cell apeptosis and G2/M phase arrest, and enhance the cellular radiosensitivity to high-LET heavy ions.

Survey on age of menarche in 56 924 women recruited from Pudong district of Shanghai / 中华妇产科杂志

Objective To survey age of menarehe in Pudong district in Shanghai. Methods Data in this study were derived from 56 924 women at age of 20 -81 years in screening for cervical cancer between January 2007 and July 2008 in Pudong district. The age of menarche were recorded in a questionnaire. To investigate the trends in age at menarehe in different socioeconomic status, the subjects were divided into 12 groups in 5-year birth cohorts. The mean menarche age in each group was analyzed by analysis of variance(ANOVA). The percentage of menarche age at 10- 12 years and more than 18 years was analyzed by χ2 method. Results (1 ) The minimum age of menarcbe recorded is 10 years old, and the maximum is 28 years old, with average age of menarche at 15.7 years. In all groups, the smallest average age of menarcbe is 14. 6 years in 26 - 30 years old age group, while the biggest average age of menarche age is 16. 5 years in ＞ 75 years old group; The difference showed statistical significance (P ＜ 0. 01 ). (2) The percentages for participants with early menarehe age (10 - 12 years old) or late menarehe age (＞ 18-year-old menarche) were 1.82% (1034/56 924 ) and 5.20 % (2959/56 924 ) respectively. However, the maximum percentage for early menarche was recorded in 31 -35 years old group (4. 45% ,197/4431 ), only 0. 84% (10/1191 ) of participants in ＞75 years old group was classified as early menarebe. Meanwhile, the lowest percentage for late menarehe was 0. 38% (17/4431 ) in 31 - 35 years old group, and the highest percentage was 14. 70% (91/619) in ＞ 75 years old group. The changes in the percentages for early menarche or late menarche are significantly associated with age differences (P ＜ 0. 01 ). Conclusion The study suggested that the average of onset age of menarche in Pudong district has declined over the past decades in an age-based way, accompanied with the increase of the percentage for early menarche and the decrease of percentage for late menarehe.

Decreasing bleeding effect of transamin on the induced abortion / 中华妇产科杂志

0 05) between the two groups in the patient′s age, pregnancy age, parities, the cavity volume of uterine, hemoglobin and blood platelet count The bleeding volume was (51 6?17 2) ml for the treated group and (63 3?17 1) ml for the control group ( P 2 months It could decrease the volume of bleeding during the operation and benefit for patients recovering