Objective To commission a Mobetron intra-operative mobile accelerator and analyze the characteristics of its electron beams. Methods The dosimetrie characteristics of the electron beams genera-ted by Mobetron accelerator were measured and compared with those generated by conventional accelerator (Primus, Siemens). M oberton accelerator can generate electron beams of nominal energies of 4,6,9 and 12 MeV. The measurement items were as followings : percentage depth dose perpendicular to water phantom sur-face and beam profiles parallel to water phantom surface, output factors, applicator leakage, electron beam at-tenuation made by lead blocks,and machine output calibration. The measurement devices included a three-dimensional ( 3 D) water scanning phantom, an electrometer, a 0.6 cm3 Farmer ionization chamber, a parallel-plate ionization chamber and solid water slabs. During measurement, all applicators of different tilt angles and diameters were attached to the machine head,and their ends were adjusted to be tangent to the phantom surface. Results Except for the 12 MeV,skin dose for all energies was no more than 90%. The skin dose was higher for Mobetron accelerator electron beams than for regular electron beams. The Dmax depth in water for a 10 cm flat applicator were 0.7,1.3,2.0 and 2.2 cm for the 4 energies,respectively. The depths of 90% dose were 1.0,1.8,2.7 and 3.6 cm, respectively. The selected flat applicator was just 1 cm larger than the tumor bed. But for the beveled applicators,the field flatness and symmetry became worse,and con-sequently,the applicator size had to be selected based on the isodose distribution. The leakage dose at 1 cm outside the applicator was 1.2% ,5.1%, 10.0% and 9.1%, respectively. The lead thickness for full block was 1.5,3.0,4.5 and 6.0 mm,respectively. Conclusions Through the commissioning of Mobetron accel-erator, the machine characteristics are understood, and the data for clinical implementation and routine quality assurance are acquired.

AIM: To study the effect of genistein on c-myc mRNA expression induced by oxidized low density lipoprotein (ox-LDL) in human vascular endothelial cells (ECV304). METHODS: LDL were isolated from healthy human plasma by gradient ultracentrifugation and oxidized by CuSO4. ECV304 cells were exposed to ox-LDL 200 mg*L-1 in the presence or absence of genistein 100 μmol*L-1 for 1, 2, and 4 h in vitro. Northern blot was employed to measure c-myc mRNA levels of ECV304. RESULTS: In response to ox-LDL 200 mg*L-1, c-myc mRNA expression in ECV304 increased by 3 fold for 1h and 3.3 fold for 2 h and decreased below the control level at 4 h. Expressions of c-myc stimulated by ox-LDL in the presence of genistein 100 μmol*L-1 for 1 h and 2 h were separately 80 percent and 60 percent of that in the absence of genistein 100 μmol*L-1. CONCLUSION: Genistein can effectively inhibit c-myc mRNA expression in ECV304 induced by ox-LDL.

Objective To study mutagenic effects of spaceflight on physiological and biochemical parameters of Rhodobacter sphaeroides and select high-yield mutants in co-enzyme Q10(CoQ10) production for providing the experimental and theoretical basis for industrial production through mutagenic effects of spaceflight.Methods Variations in stress resistance and CoQ10 production of isolated strains were studied,the strain Rhodobacter sphaeroides was taken back by a recoverable satellite after 15 d flight in space.Results Compared to the control,the strain was characterized by highter NaCl tolerance and higher stress resistance,as well as with broader scope in growth temperature and pH value after spaceflight.The mutant colonies appeared white or pink which was different from their original red.The CoQ10 production of mutant 10 strain was increased by 73.13% much higher than that of control.Conclusion Spaceflight mutagenic effects on Rhodobacter sphaeroides shows to be multi-factor compared to the traditional single-factor mutagenesis methods.It can enhance stress resistance and increase CoQ10 production of isolated strains,and can be utilized in industrial microbial mutagenesis and breeding in the future.

Objective To investigate the causes of and prevention for cerebral complications in perioperative period in patients with carotid stenosis. Methods The causes and treatment of cerebral complications among 133 cases of carotid stenosis during perioperative period from May 2004 to Jun 2009 were analysed retrospectively. Results Among 133 cases, 94 cases underwent carotid endarterectomy (CEA) and 39 cases had carotid artery stenting(CAS). Cerebral complications developed in 16 cases including 3 cases of more than two attacks. 5 cases suffered from tansient ischemia attacks (TIA)or cerebral ischemia before operation. 5 developed TIA or cerebral hyperperfusion syndrome (CHPS) among those undergoing CEA and 4 developed TIA or CHPS among CAS cases. During postoperative period, 8 cases developed TIA, CHPS,cerebral infarction or cerebral hemorrhage. Conclusions Prevention and treatment of cerebral complications is extremely important durning surgical therapy of carotid stenosis.

Objective To evaluate the effect of magnetic resonance thoracic ductography (MRTD)in the diagnosis of right thoracic duct.Methods MRTD data were analyzed retrospective,and the detection rate of right thoracic duct was summarized and compared with that of lymphoscintigraphy,direct lymphangiography and operation.Results 12 cases of right thoracic duct were detected in 1547 cases of MRTD.The detection rate was 0.78%,in which 1 case was complied with total internal organs inversion,and 1 case with right aortic arch.Lymphoscintigraphy were performed in all 12 cases and right thoracic duct were detected in 4 cases.Direct lymphangiography were performed in 4 cases and right thoracic duct were observed in all of them.7 cases of them received right lum-bar duct adhesiolysis.Conclusion MRTD is a noninvasive method for diagnosis of right thoracic duct,which providing useful guid-ance for surgical operation.Its detection rate and diagnostic accuracy are higher than those of lymphoscintigraphy.

Objective To evaluate the roles of high-resolution computer tomography (HRCT) and bron- choalveolar lavage (BALF) in the diagnosis of connective tissue diseases associated with interstitial lung disease (CTD-ILD). Methods Clinical data of chest HRCT and BALF of patients with CTD-ILD from January 1997 to December 2007 in in-patient department of Peking University First Hospital, were retrospectively analyzed. Results ①Among 46 cases with the picture of chest HRCT, 19 (41.3%)showed usual interstitial pneumonia(UIP) -like pattern and 18 (39.1%) showed lobular and interlobular septa thickening. 8 (8/17) of ANCA vasculitis (AASV) and 5 (5/9) of rheumatoid arthritis (RA) manifested as UIP-like patterns respectively. In polymyositis/dermatomyositis(PM/DM) and Sjogren's syndrome (KS) patients, the organizing pneumonia(OP)-like pattern and lymphocytic interstitial pneumonia(LIP)-like pattern were 2/4 and 2/4 respectively. ②Among 32 cases undergoing BAL, 10/10 patients with AASV-ILD all showed that neutrophils were dominant in BALF, while, the other 22 patients showed that the ratio of neutrophils elevation (14/22, 63.6%) and the ratio of lymphocytes elevation (18/22, 81.8%) were comparable, and there were 12/22(54.5%)patients with both types of cell elevation. Among 13 cases with iymphocytes elevation in BALF who performed analysis of sub-type lymphocytes, 10/13 cases showed decreased CD4/CD8 ratio, 3/13 cases showed increased CD4/CD8 ratio which were all related with SS. ③Among 15 patients undertaken HRCT and BALF detection together, 7/7 UIP-like cases showed the ratio of neutrephils elevation in BALK While in non-UIP-like cases, 5/8 showed the ratio of lymphocytes elevation. Conclusion ①UIP-like patterns and patterns of lobular and interlobular septa thickening are the most common imaging features of HRCT in CTD-ILD, the former are mostly seen in AASV and RA. OP-like patterns and LIP-like patterns are commonly seen in PM/DM and SS respectively. ②Tbe increased neutrophil percentage is dominant in BAL fluid of patients with AASV-ILD, while the others show that the ratio of neutrophil and lymphocyte elevation are comparable, lymphocytes subtype analysis shows decreased CD4/CD8 ratio is dominant in CTD-ILD patients with lymphocytes increased. There is a significant relationship between increased CD4/CD8 ratio and SS-LIP. ③All of the cases with UIP-like patterns show the ratio of neutrophils elevation in BALF. While the ratio of lymphocytes elevation is dominant in non-UIP-like cases.

Radiotherapy is the main treatment of nasopharyngeal carcinoma (NPC). With the continuous improvement of radiotherapy technology, the survival time of NPC patients is significantly improved, but the complications after radiotherapy have been paid more and more attention, in which the incidence of radiation-induced temporal lobe injury is higher, which seriously affects the quality of life of patients, and even reduces the survival rate. Therefore, it is particularly important to find a method for the examination of early radiation-induced temporal lobe injury. Three-dimensional arterial spin labeling (3D-ASL) analysis of cerebral blood flow (CBF) changes before and after radiotherapy, magnetic resonance spectroscopy (MRS) analysis to determine the changes of NAA/Cr, Cho/NAA, Cho/Cr ratio in the anterior and posterior temporal lobe before and after radiotherapy, and diffusion tensor imaging (DTI) to determine the changes of temporal lobe average diffusion coefficient (ADC) and anisotropy fraction (FA) before and after radiotherapy can help in the early diagnosis of radiation brain injury, especially through the combined use of the above three tests. It is expected to provide a feasible basis for the early diagnosis of radiation encephalopathy, and early nutritional neurotherapy is of great significance to improve the quality of life and survival rate of patients.

Objective To investigate the safety and acute toxicities of intraoperative electron radiotherapy for patients with abdominal tumors.Methods From May 2008 to August 2009, 52 patients with abdominal tumors were treated with intraoperative electron radiotherapy,including 14 patients with breast cancer,19 with pancreatic cancer,3 with cervical cancer, 4 with ovarian cancer, 6 with sarcoma, and 6 with other tumors.Fifteen patients were with recurrent tumors.The intraoperative radiotherapy was performed using Mobetron mobile electron accelerator, with total dose of 9 - 18 Gy.In all, 29, 4 and 19 patients received complete resection, palliative resection and surgical exploration, respectively.The complications during the operations and within 6 months after operations were graded according to Common Terminology Criteria for Adverse Events v3.0 (CTC 3.0).Results The median duration of surgery was 190 minutes.Intraoperative complications were observed in 5 patients, including 3 with hemorrhage, 1 with hypotension,and 1 with hypoxemia, all of which were treated conservatively.The median hospitalization time and time to take out stitches was 12 and 13 days, respectively.And the in-hospital mortality was 4% (2/52).Twentyfour patients suffered post-operative adverse events, including 3 postoperative infections.With a median follow-up time of 183 days, 20% of patients sufferred from grade 3 to 5 adverse events, with hematological toxicities being the most common complication, followed by bellyache.Grade 1 and 2 toxicities which were definitely associated with intraoperative radiotherapy was 28% and 4%, respectively.None of grade 3 to 5 complications were proved to be caused by intraoperative radiotherapy.Conclusions Intraoperative electron radiotherapy is well tolerable and could be widely used for patients with abdominal tumors, with a little longer time to take out stitches but without more morbidities and toxicities compared surgery alone.

Objective To investigate the expression of IL-17-producing regulatory T cells ( Treg) in patients with systemic lupus erythematosus ( SLE) and to analyze their clinical significance. Methods This study recruited 32 patients with SLE ( including 14 with active SLE and 18 with inactive SLE) and 13 healthy subjects matched for age and sex. Flow cytometry was performed to detect the expression of Foxp3 and IL-17 in CD4 T lymphocytes and the phenotypic characteristics of IL-17-producing Treg. Correlations between these cells and clinical indicators of SLE were analyzed. Peripheral CD4+CD25+ T cells were isola-ted from five healthy subjects and then stimulated with IL-6 and IL-1βalone or in combination. An in vitro T cell polarization assay was performed to investigate the role of cytokines in the polarization and regulation of IL-17-producing Treg. Results Compared with the healthy subjects and patients with inactive SLE, the pa-tients with active SLE had a higher percentage of IL-17-producing Treg in peripheral blood. Moreover, the expression of Foxp3 and CD45RA by IL-17-producing Treg in the active SLE group was down-regulated, while that of IL-2, granzyme B (GramB), programmed cell death protein 1 (PD-1) and glucocorticoid-in-duced tumor necrosis factor receptor ( GITR) was up-regulated. Inflammatory cytokines such as IL-6 and IL-1 could induce Treg to produce IL-17. Conclusions This study suggested that increased inflammatory cytokines might correlate with higher percentages of IL-17-producing Treg in patients with active SLE. These cells were a subset of pathogenic Treg failing to prevent autoimmune.

Objective:To investigate the changes of thyroid hormones and the flow velocity of superior thyroid artery in patients with Graves' disease and Hashimoto's thyrotoxicosis before and after treatment with methimazole.Methods:A case-control study was conducted to select 45 cases of Graves' disease and 45 cases of Hashimoto's thyroiditis from October 2021 to December 2022 in the Department of Endocrinology, North China University of Science and Technology Affiliated Hospital. The changes of thyroid hormone and blood flow velocity of superior thyroid artery in patients with Graves' disease and Hashimoto's thyroiditis before and after treatment with methimazole were analyzed. Measurement data satisfying normal distribution were expressed by xˉ±s, and the mean between two groups was compared by t test. Measurement data not satisfying normal distribution were expressed by M( Q1, Q3), and the median between two groups was compared by Wilcoxon rank sum test. χ 2 test was used to compare the constituent ratio of enumeration data among groups. Results:There was no significant difference in thyroid stimulating hormone (TSH) between the two groups before treatment, and there was no significant difference in TSH between the two groups after 1 month and 3 months of treatment (all P>0.05). The levels of free triiodothyronine (FT3) were (24.09±9.29) pmol/L and (17.41±9.36) pmol/L in Graves' disease group and Hashimoto's thyroiditis group respectively before treatment. FT4 were (60.23±20.82) and (43.47±21.71) pmol/L, respectively, and the peak stolie vloiy (PSV) were (69.53±5.70) and (52.65±4.64) cm/s, respectively in Graves' disease group and Hashimoto's thyroiditis group respectively before treatment. There were significant differences between the two groups ( t values wrere 3.39 and 3.74, Z=13.83, all P<0.001). The difference of FT3 between one month after treatment and before treatment was (-6.36±5.32) and (-12.64±9.08) pmol/L ( t=4.02, P<0.001) and the difference in FT3 between 3 months of treatment and before treatment was (-10.14±9.50) and (-17.80±11.17) pmol/L, respectively ( t=3.51, P<0.001) between the Graves disease group and the Hashimoto's thyroiditis group. The difference in FT4 between the Graves disease group and the Hashimoto's thyroiditis group after 1 month of treatment and before treatment was (-28.47±10.09) and (-20.57±14.48) pmol/L ( t=7.01, P<0.001), and the difference of FT4 was (-47.06±20.57) and (-30.17±20.54) pmol/L ( t=3.91, P<0.001) between the Graves disease group and the Hashimoto toxin group. The difference between one month after treatment and before treatment was (-13.10(-34.10,-2.60)) and (-10.50(-27.5,-0.20)) cm/s ( Z=2.63, P=0.009), respectively. The difference between 3 months and before treatment was (-31.40(-53.20,-12.70)) and (-19.90(-46.00,-4.70)cm/s ( Z=4.40, P<0.001)) between the Graves disease group and the Hashimoto's thyroiditis group, and the difference was statistically significant. Conclusion:Thyroid hormone levels were decreased after treatment with methimazole in patients with diffuse toxic goiter and Hashimoto toxemia, but the difference was not statistically significant. The PSV level of superior thyroid artery in patients with diffuse toxic goiter was significantly lower than that in patients with Hashimoto's thyrotoxicosis.