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Brain metastases are the most common intracranial malignancies, and radiotherapy is an effective treatment of controlling the localized lesions. However, conventional radiotherapy techniques have their own shortcomings that limit the effectiveness of radiotherapy. Metastatic brain tumors are highly likely to recur or progress after treatment. Clinical studies have shown that arginine can penetrate the blood-brain barrier and subsequently improve the radiosensitization of metastatic brain tumors. In this article, the mechanisms underlying the effect of arginine on the radiosensitization of metastatic brain tumors by inhibition of tumor glycolytic metabolism, reduction of DNA damage repair and alteration of tumor hemodynamic parameters were reviewed, aiming to provide new ideas for clinical research and treatment of brain metastases.
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Objective:To analyze the dosimetric differences between 3D printed oral stents and corked oral stents in the target area and perioral organ at risk (OAR) in radiotherapy for head and neck cancer, and the effectiveness in reducing acute adverse reactions associated with radiotherapy.Methods:A total of 58 patients with head and neck cancer admitted to Department of Oncology of Affiliated Hospital of North Sichuan Medical College were selected and divided into experimental group (Group A, n=28, wearing 3D printed oral stents during radiotherapy) and control group (Group B, n=30, wearing corked oral stents during radiotherapy) in this retrospective cohort study. The incidence of radiotherapy - induced oral mucositis (RTOM), xerostomia and oropharyngeal mucosal pain was compared between two groups. Meanwhile, informed consent was obtained from 21 patients in Group A. Using the self control method, each patient wore a 3D printed oral stent (Group C) and a corked oral stent (Group D) to make two radiotherapy plans. The differences in the conformity index (CI), homogeneity index (HI) and exposure dose of OAR (D max, D mean) in the target area were analyzed between two groups. SPSS 25.0 statistical software was used for statistical analysis. Measurement data were expressed as Mean±SD. Comparison between two groups was conducted by paired t-test or repeated measurement analysis. Count data were expressed as ratio. Comparison between two groups was performed by Chi - square test or Fisher's exact test. P<0.05 was considered as statistically significant difference. Results:The severity of RTOM ( P<0.05), oropharyngeal mucosal pain ( P=0.004) and xerostomia score ( P<0.001) in Group A were significantly lower than those in Group B. There was no significant difference in the HI and CI of the target area between Group C and Group D (both P>0.05). The D max ( P=0.014, 0.009) and D mean ( P<0.001, P=0.033) of the upper lip and the affected buccal mucosa in Group C were significantly lower than those in Group D. Conclusion:3D printed oral stents obtain favorable HI and CI in radiotherapy for head and neck cancer, significantly reduce the irradiated dose to perioral OAR, and effectively lower the incidence and mitigate the severity of acute RTOM, xerostomia and oropharyngeal mucosal pain associated with radiotherapy.
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Hypoxia inducible factor (HIF-1α) is a hypoxia response regulator,which is highly expressed in malignant tumors.Researches have shown that HIF-1α plays an important role in epithelial mesenchymal transformation.It can regulate epithelial mesenchymal transition through a series of signal pathways and mechanisms at many levels,to participate in the invasion and metastasis of tumors.To explore the mechanism of HIF-lα controlling epithelial mesenchymal transformation has important significance for the development of new,effective tumor treatment methods.
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Objective To explore the factors related to the prognosis and survival duration of primary liver cancer patients after hepatectomy.Methods The data of primary liver cancer patientswho were treated by surgical resection were analyzed retrospectively.Kaplain-Meier method was used to evaluate survival rates.Log-rank test and Cox regression analysis were used to screen out related clinical phathology factors.Results The median survival time was eighteen months.Univarivate analysis showed that liver function Child-Pugh classification,cirrhosis,tumor size,HBV infection,AFP,portal vein tumor thrombus significantly correlated with survival rates (P ＜ 0.05).Multivariate analysis showed that liver function Child-Pugh classification,tumor size,AFP and portal vein tumor thrombus were the independent prognostic factors of primary liver cancer (P ＜ 0.05).Conclusion Many factors are related to the prognosis of primary liver cancer after operation.Liver function Child-Pugh classification,tumor size,AFP and portal vein tumor thrombus affect prognostic independently.
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Objective To retrospectively analyze the efficacy of radiotherapy on nasal NK/T-cell lymphoma, and to explore the prognostic factors. Methods Between January 2000 and December 2008, 62 patients with nasal NK/T-cell lymphoma were treated with radiotherapy in our hospital. Their clinic data and efficiency were reviewed retrospectively. Kaplan-Meier methods were applied in unifactorial analysis and the COX regression model was applied in multivariate analysis. Results The median overall survival time was 69.7 months (95 % CI, 63.0-78.0 months), and 3, 5-year survival rate was 66.1% and 46.8 %. Metastasis was 61.8 % for the first reason which resulted in failure. The median survival time was 72.6 months in the increased group of numbers of T lymphocyte CD3 and 39.6 months in the decreased group, the difference was significant(x2 =4.9309, P =0.0264). Multivariate analysis confirmed that modified IPI 0-1 (x2 = 7.5266, P =0.0061), the numbers increased for CD3 (x2 =9.0912, P =0.0266), and complete remission(x2 = 9.0912, P =0.0106) were significant favorable prognostic factors for survival. Conclusion The radiotherapy was effective for patients with nasal NK/T-cell lymphoma, but was failure on account of distant metastasis, so systematic therapy still has an important role. modified IP1 0-1, the number increased for CD3 and complete remission were significant favorable prognostic factors for survival.
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Objective To analyze the genetic polymorphism of GSTM1 to lung cancer patients in north Sichuan of China and compare with race from other district.Methods PCR-based technique was used to detect the genotypes of GSTM1 in lung cancer patients.Results In local lung cancer patients,the frequency of homozygous deletions(null genotype) for GSTM1 was 58.4 % (73/125).Among the patients,the frequencys of null genotype for GSTM1 were 62.5 % (20/32) in female,56.9 % (53/93) in male,56.1% (32/57)in patients with squamous cell carcinoma and 54.8 % (17/31) in patients with adenocarcinoma,respectively.The frequency of deletions of GSTM1 in lung cancer patients from north Sichuan of China is slightly exceeding those of Europe and Americas (P ＜0.05) and similar to the domestic result (P ＞0.05).Conclusion The genetic polymorphism of GSTM1 to lung cancer patients in north Sichuan of China dosen' t show distinguished feature for this district and race.
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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.
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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
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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.
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Vasculogenic mimicry (VM) can promote tumor growth, invasion, and metastasis. The formation of VM is regulated by various proteins including epithelial cell kinase, phosphoinositide-3 kinase, and hypoxia-inducible factor 1. Local microenvironment also plays an important role in regulating VM formation.
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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.