Effect of rotational errors on dose of positive lymph nodes in cervical cancer VMAT plan and its coping strategies / 中华放射肿瘤学杂志

Objective:To evaluate the effect of rotational errors (antero-posterior) on dosimetric parameters of positive lymph nodes in the long target volumetric modulated arc therapy (VMAT) plan for advanced cervical cancer and investigate its coping strategies.Methods:Clinical data of patients with cervical cancer complicated with para-aortic or inguinal lymph node metastasis admitted to Affiliated Hospital of North Sichuan Medical College were randomly selected and retrospectively analyzed. The target areas of the lymph nodes at different distances from the center of the plan were outlined according to the requirements. After designing the VMAT plan on the CT images of each case, the rotational errors (antero-posterior) were introduced by changing the parameters of the treatment couch, and the dose distribution was reconstructed by dose calculation with other parameters unchanged. Then, the external boundary of the original lymph node target was added according to d=2πr(α/360) ( r is the distance from the center of the lymph node to the plan center), re-planned, and the changes of dosimetric parameters in the target area of the original lymph node were analyzed after the corresponding rotational errors were introduced. Results:When the distance between the lymph node target area and the plan center was 6 cm with an error of 3°, the distance was 9 cm and 12 cm with an error of 2.5°, the distance was 15 cm with an error of 2°, and the distance was 18 cm with an error of 1.5°, the mean change of D 95% was more than 5%. When the rotational errors were ≤1°, the mean change of D 95% in lymph node target area was less than 5%, and when the lymph node was 18 cm away from the treatment plan center, the mean change was more than 3%, reaching 3.75%. When the rotational errors were 0.5° and the distance from the plan center was 18 cm (0.5°, 18 cm), the dose change of lymph node target was more than 5%, reaching 5.58%. At (1°, 15 cm), the V 100% change reached 8.96%, and at (1°, 18 cm), the V 100% change was 14.5%. The D 95% and V 100% parameters of the original lymph node target were changed by less than 1% after adding the external boundary of the original lymph node target and introducing corresponding rotational errors. Conclusions:In the long target area radiotherapy of cervical cancer, the variation of dosimetric parameters of lymph node target was increased with the increase of rotational errors and with the increase of distance from the plan center. It is recommended to increase the efferent boundary of lymph nodes in different positions to avoid underdose by d=2πr(α/360).

Application of stereotactic body radiotherapy in small hepatocellular carcinoma / 临床肝胆病杂志

At present, hepatic resection (HR) and radiofrequency ablation of (RFA) are the main radical treatment methods for small hepatocellular carcinoma (sHCC), while stereotactic body radiotherapy (SBRT) is developing rapidly and there is an increasing number of reports on the effective treatment of sHCC with SBRT. This article introduces the technical advantages, therapeutic dose, and fractionation scheme of SBRT in the treatment of sHCC, as well as the limit of normal liver tissue and the protection of surrounding organs at risk. This article also compares the efficacy of SBRT versus HR and RFA in the treatment of sHCC and briefly describes the adverse reactions of SBRT in the treatment of sHCC. Previous studies have shown that for some sHCC cases, SBRT has an equal or even better clinical effect than HR and RFA, with controllable toxicity. Therefore, SBRT is expected to become another radical treatment method for sHCC.

Immune function of red blood cells in chronic gastritis and duodenal ulcer disease / 中国综合临床

Objective To explore changes of the immune function of red blood cells in gastric disease.Methods RBC C3b receptor rosette(RBCC3bRR)and RBC immune complex rosette(RBCICR)were tested in chronic gastritis group(n =103),duodenal ball ulcer group(n =75)and control group(n =30)to evaluate the immune function of RBC.Results RBCC3bRR were(20.83 ± 5.16)％ in the control group,(16.26 ±5.17)％ in the chronic gastritis group and(13.65 ± 5.19)％ in the duodenal ball ulcer group.RBCICR were respectively(7.63 ± 4.09)％,(10.59 + 4.45)％ and(10.04 ± 4.13)％ in these three groups.RBCC3bRR of chronic gastritis and duodenal ball ulcer were lower than control group(P ＜0.0l),while RBCICR were higher than normal control group(P ＜0.05 and P ＜0.01 respectively).There was no significant difference on RBCC3bRR and RBCICR between HP negative chronic gastritis and HP negative duodenal ball ulcer and between HP positive chronic gastritis and HP positive duodenal ball ulcer(P ＞ 0.05).RBCC3bRR of HP positive chronic gastritis and duodenal ball ulcer was significantly lower than that of HP negative(P ＜ 0.05and P ＜ 0.01 respectively),RBCICR significantly higher than that of HP negative(P ＜ 0.01).After HP eradication,RBCC3bRR of patients with chronic gastritis and duodenal ball ulcer was increased significantly (P＜0.05 and P ＜ 0.01 respectively).RBCICR was significantly lower than before treatment(P ＜ 0.01).Conclusion HP infection,chronic gastritis and duodenal ulcer can decrease the immune function of red blood cells.

Different roles of total flavonoids of astragalus on human normal mesenchymal stem cells and hepatoma cells in radiation protection / 中华放射医学与防护杂志

Objective To investigate the different radioprotective effects of total flavonoids of Astragalus (TFA) on human normal mesenchymal stem cells(hMSCs) and hepatoma cells injured by 60 Coγ-ray radiation.Methods hMSCs and HepG-2 cells were cultured and randomly divided into TFA-treated and untreated groups.The cells of different groups were irradiated with 60 Co γ-rays at the dose of 6 Gy.MTT method was utilized to detect the survival rates of the hMSCs and HepG-2 cells pretreated or untreated with TFA before irradiation.Cell clone formation test was used to measure the cellular radiosensitivity.The apoptosis rates of different groups were determined by flow cytometer assay.The expression rates of the apoptosis-promoting proteins Fas and Bax and the apoptosis-inhibiting protein Bcl-2 were analyzed by Western blotting.Results MTT showed that the survival rates of hMSCs pretreated by TFA were 1.15-1.95 times higher than that of the pure irradiation group.On the contrary,the survival rates of the TFA pretreated HepG-2 cells were only 0.53-0.23 times that of the pure irradiation group.There was a good dose-effect relationship between the cell survival rate and the TFA concentration.Cell clone formation rate indicated that combined treatment of TFA and radiation inhibited the cell proliferation more effectively than single TFA or pure radiation.Flow cytometry showed that 6,24 and,48 h post-irradiation to 6 Gy,the apoptosis rates of the hMSCs were 23.3% ,11.2% ,and 2.9% ,respectively in the TFA pretreated group and were 29.3% ,24.9% ,and 13.6% in the pure radiation group.However,the apoptosis rates of the HepG-2 cells at 6,24,and 48 h post-irradiation to 6 Gy were 11.6% ,17.3% ,and 20.1% ,respectively in the TFA pretreated group and were 6.9% ,9.3% ,and 15.8% ,respectively in the direct radiation group.Western blotting showed that the expression levels of Fas and Bax proteins in the HepG-2 cells were significantly higher in the TFA pretreated group than in the pure radiation group.On the contrary,the expression level of the apoptosis inhibiting protein Bcl-2 was significantly lower in the TFA pretreated group than in the pure radiation group.Conclusions TFA has obvious effects of radiological protection on human hMSCs and has no effects of radiological protection but effects of apoptosis enhancement on hepatoma cells.The promotion of apoptosis of TFA on hepatoma cells is primarily through increasing the expression of apoptotic proteins such as Fas and Bax and reducing the expression of anti-apoptotic protein Bcl-2.

Retrospective analysis on the maintenance of BJ-6B accelerator / 中华放射肿瘤学杂志

Objective To study the maintenance of BJ-6B accelerator. Methods Analyzed retrospectively the maintenance record of BJ-6B accelerator, including phenomena, causes and handle from 2002 to 2009. Results In 231 records, there were motion-controlling 64, hand-controlling-pendant 20.modulator 41, anti-peak overload 36, charging overload 5. Flatness 7, mechanical 21, digital-display 20,others lie in magnetron power, water-cooling system, light-indicator system, dose-monitor system and wedge system. Motion-controlling system is the highest among those, followed by high-voltage modulator and mechanical system. Conclusions The down time for BJ-6B accelerator is low because of its perfect technology. To keep its stability in clinic, the hospital authorities should emphasize training of engineer for improving their maintenance ability. The engineer must be familiar with the circuit diagram, check the electric wire and machine unit on time and prepare unit for maintenance. The temperature and humidity in machine house must be controlled on demand. The engineer must pay attention to machine parameters when beam is on for avoiding the spark's damage to magnetron and accelerating-tube

Personality and mental health of supercargoes / 中华健康管理学杂志

Objective To investigate mental health and personality characteristics of supercargoes. Methods Catell 16 Personality Factor Test (16PF) and Symptom Checklist 90 (SCL-90) were used in 470 supercargoes for quantitative analysis. Pearson correlation analysis, multiple regressions and t test were used for data analysis. Results The participants showed a significantly lower score, although specific items were higher than normal models. There was no difference in different age groups. 16PF were positively correlated with total score of SCL-90, except for gregariousness, intelligence, ambition, fantasy,worldly-wisdom,creativity and independency. All factors in SCL-90 were significantly related with the subfactor (i. e. adaptation and anxiety) of 16PF. Conclusion The mental health of supercargoes may not be optimistic,and the personality problems may have some effects on their mental health.

Impact of voltage fluctuation on dose delivery of BJ-6B accelerator / 中华放射肿瘤学杂志

Objective To study the impact of main source voltage fluctuation on dose rate and dose delivery accuracy of BJ-6B accelerator. Methods The accelerator was calibrated by a voltage regulator at an output voltage of 332 V. The main source voltage fluctuation was simulated by changing the output of voltage regulator within the range of 321 - 338 V. The change of dose rate was recorded. Using a water phantom, each absorption dose was measured five times and averaged along the central beam axis at the depth of 1.5 cm, 5 cm and 10 cm, respectively, with the conditions of monitor unit: 100 MU ,field: 10 cm× 10 cm and SSD = 100 cm. The impact of voltage fluctuation on dose rate and dose delivery of BJ-6B accelerator was analyzed. Results Voltage fluctuation had an significant effect on dose rate. In a certain range, dose rate and absorption dose at different depths increased as the output voltage increased. Conclusions It is essential to equip the BJ-6B accelerator with a high accurate voltage stabilizer, and the voltage stabilizer must be adjusted to its highest accuracy.

Impact of CT scanning condition on the precision and accuracy of target position / 中华放射肿瘤学杂志

Objective To study the effect of CT scanning condition on the target position coordinate with WIMRT radiotherapy planning system using the" Z" form localizing frame. Methods The whole Head Phantom containing three metal targets was scanned under the following conditions: localizing frame transver-sally tilting, CT gantry tilting and localizing frame axially tilting. Then the three target coordinates were com-puted respectively and compared with those under the standard condition. Results The height and width of coordinate under the localizing frame transversally tilting condition deviated from those under the standard scanning condition,which was in an angle dependent manner. On the other hand ,a tendency was shown that the greater the absolute height value of the targets coordinate, the greater the width value deviation. And so was the relation between the absolute width value of the coordinate and height value deviation. If CT gantry angle was not zero degree or localizing frame axis is not in the same line with the CT bed moving direction, the calculated longititude value of the targets coordinate was mainly affected. Conclusions CT scanning must be performed strictly under the standard localizing scanning condition by a proficient physicist.

Establishment of Epstein-Barr virus-transformed B cell lines from healthy volunteers of type B / 医学研究生学报

Objective: To develop Epstein-Barr virus(EBV)-transformed human peripheral blood B cell lines from healthy volunteers of type B.Methods: B lymphocytes from healthy volunteers of type B capable of producing anti-A antibodies were transformed by EBV,while Cyclosporine A(CsA),as an immunosuppressive agent that could selectively inhibit T-lymphocytes and protect B-lymphocytes from regression,was used in the experiment.Then,the supernanant of the cell culture medium was tested with red blood cells of type A,B and O by agglutinin assay.Results: Twelve of the15 EBV-transformed B lymphocyte cell lines were established,with a success rate of 80%,while 9 human B lymphocyte lines secreted anti-A antibodies.Conclusion: Human B lymphocyte lines secreting antibodies to A antigens were successfully developed,which helps further studies of human blood specific monoclonal antibodies.

Cloning and expression of human anti-Rh(D) single-chain Fv fragment / 医学研究生学报

Objective: To construct a phage display library of human single-chain Fv antibodies against blood group Rh(D) substance. Methods: Combining phage display library techniques, isolated total RNA from B lymphoblastoid cell lines secreting anti-Rh(D) antibodies was used for the synthesis of the first strand of cDNA, V_ H and V_ L genes were amplified by 2nd PCR and linked together by splicing overlap extension (SOE) with the use of a (Gly_ 4Ser)_ 3 linker. The resulted scFv genes were then cloned into pCANTAB5E vectors and displayed on the phage. Phage clones were selected using intact red cells as a source of antigen. After 4 rounds of "binding-elution-enrichment", each clone was assayed for specificity by Dot ELISA. Results: A phage antibody library, with the sink size being 1.2?107, was obtained. The percentage of full-length scFv gene inserted into phage DNA was 0.80. Rescued by helper phage, a phage scFv library with titer of 3?108 pfu/ml was established. Specific phages with scFv were acquired after 4 rounds of panning, one clone exhibiting specific binding to Rh+ cell was identified by Dot ELISA. Conclusion: A strategy for construction phage antibody library by means of phage display technique was practicable, which would be useful in screening engineered antibodies against human Rh (D) blood group substances.