BACKGROUND: Long-term radioactive ray accumulation leads to surrounding tissues fibrosis accompanied by limitation of mouth-opening, which seriously affects life quality of tumor patients. OBJECTIVE: To observe pathological change of soft tissues in rats with radiation masseter injury and the level of transforming growth factor β1 (TGF-β1) mRNA expression in vivo.METHODS: A total of 30 Wistar rats were randomly divided into control group (n=10) and radiated group (n=20). Radiated group were radiated with linear accelerator at a dose of 40 Gy. The pathological changes of vessels were observed under light microscope and electron microscope and expression of TGF-β1 was detected by RT-PCR. RESULTS AND CONCLUSION: The microvessel density of radiated group was obviously decreased than that of the control group (P < 0.01), but the mRNA expression of was higher than that in the control group (P < 0.01). It suggests that radiated injury can induce fibrosis to repair the radiated injury.

10.3969/j.issn.2095-4344.2013.24.021

Objective:To investigate the application and effect of the virtual reality (VR) combined with the augmented reality (AR) integrated teaching system in stomatology general medical education of clinical medicine students.Methods:A total of 160 undergraduates from the five-year clinical medicine Batch 2015 of Naval Medical University were randomly divided into VR+AR group and traditional group, with 80 students in each group. A comparative analysis was made on the previous and teaching achievements of the two groups of students, and a questionnaire survey was conducted after the completion of the class. Epidata 3.0 was used to input questionnaire data, and SPSS 23.0 software was used to carry out t test, chi-square test and Fisher precision test. Results:There was no statistical difference in written test scores between the VR+AR group and the traditional group [(52.65±3.76) vs. (51.90±3.46), P=0.516], but the VR+AR group was significantly higher than the traditional group in case analysis scores [(35.85±2.56) vs. (31.40±2.96), P < 0.001] and overall performance [(88.50±4.95) vs. (83.30±4.86), P= 0.002]. The questionnaire survey results showed that the scores of "teaching mode" [(92.30±6.90) vs. (85.20±7.30), P<0.001], "teaching method" [(91.70±5.90) vs. (86.00±6.70), P=0.012] and "teaching improvement" [(90.70± 8.70) vs. (82.30±8.40), P<0.001] in VR + AR group were significantly higher than those in the traditional teaching group. Conclusion:The VR combined with AR integrated teaching system can significantly improve teaching performance and teaching quality, and is convenient for teaching demonstrations and simulation operations in small oral spaces, and is especially suitable for oral general medical education for clinical medicine.

This study aims to investigate whether displacement force on stents can accurately represents the displacement of the stent after endovascular aneurysm repair (EVAR) by comparing the measured stent displacement with the displacement forces calculated by computational fluid dynamics (CFD). And the effect of cross-limb and parallel-limb EVAR on stent displacements is further studied. Based on our objective, in this study, ten cross-limb EVAR patients and ten parallel-limb EVAR patients in West China Hospital of Sichuan University were enrolled. Patient-specific models were first reconstructed based on the computed tomography angiography images, then the stent displacements were measured, and the displacement forces acting on the stents were calculated by CFD. Finally, the cosα value of the angle between the displacement force and the displacement vector was used to analyze the matching degree between the displacement and the displacement force. The results showed that the displacement forces on cross-limb stents and parallel-limb stents were (2.67 ± 2.14) N and (1.36 ± 0.48) N, respectively. Displacements of stent gravity center, stent displacements relative to vessel, and vessel displacements of cross-limb and parallel-limb stents were (4.43 ± 2.81) mm and (6.39 ± 2.62) mm, (0.88 ± 0.67) mm and (1.11 ± 0.71) mm, (3.55 ± 2.88) mm and (5.28 ± 2.52) mm, respectively. The mean cosα for cross-limb and parallel-limb stents were 0.02 ± 0.66 and - 0.10 ± 0.73, respectively. This study indicates that the displacement force on the stent can't accurately represent the displacement of the stent after EVAR. In addition, the cross-limb EVAR is probably safer and more stable than the parallel-limb EVAR.
Aortic Aneurysm, Abdominal/surgery* ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; Endovascular Procedures/methods* ; Humans ; Prosthesis Design ; Retrospective Studies ; Stents ; Treatment Outcome

Objective: To analyze the clinical characteristics of oral and maxillofacial space infection between the diabetic and non-diabetic patients and to explore the common pathogenic bacteria and antibiotic sensitivity of diabetic patients, to guide the clinical medication. Methods : A retrospective study was conducted on 61 patients who received treatment in Qingdao municipal hospital affiliated to Qingdao university, between December 2014 and December 2016 with Oral and maxillofacial space infection. The 61 patients were divided into diabetic group and non-diabetic group. The research contented the patients'age, sex, source of infection, pathogenic bacteria, antibacterial drugs sensitivity, fasting blood glucose levels, white blood cell total and neutrophils percentage, and days of hospitalization. T test and chi-square test in SASS.19.0 software was used. Results : In the 2 groups of patients, the most common etiological factor was odontogenic infection; the most easiest affected space was submandibular space. The most common pathogenic bacteria were streptococcus. Vancomycin was the most sensitive drug, then levofloxacin and cefotaxime. In addition, the diabetes patients'age, fasting blood glucose levels and hospitalization days were significantly higher than non-diabetic patients'. Conclusion For the diabetic patients with maxillofacial space infection, levofloxacin and cefotaxime was first used for the conservative treatments when the results of the bacterial culture and drug susceptibility test are not obtained. Meanwhile, according to the oral and maxillofacial anatomy, combination of anti-anaerobic agents such as Tinidazole is also suggested. But the final situation of medication is based on the result of the drug susceptibility test.

Objective To study the effects of aneurysmal neck angle on stent displacement after endovascular repair of abdominal aortic aneurysm (AAA). Methods The CT images of 28 patients were selected to establish preoperative AAA model, postoperative AAA model and covered stent model respectively, and the models were divided into non-severe angulation group ( n = 14) and severe angulation group ( n = 14) according to the preoperative angle of tumor neck. The geometric shape of each model was measured, and the changes of AAA geometric parameters and postoperative stent displacements before and after surgery were analyzed. The displacement force of the model during the first follow-up was calculated by hemodynamic simulation. Results Significant differences were found in tumor length, maximum diameter, displacement force, tumor neck length and tumor volume between two groups of patients (P<0. 05), while there was no significant difference between COG (the center of gravity) displacement and proximal displacement (P> 0. 05). For the incidence of internal leakage, there were 2 cases in non-severe angulation group and 4 cases in severe angulation group (P>0. 05).Conclusions Severe neck angulation can lead to a significant increase in support displacement force and decrease in proximal anchorage zone, and thus increase the possibility of support displacement. It is suggested that doctors should strengthen postoperative follow-up for patients with severe neck angulation and be vigilant of the occurrence of long-term internal leakage in clinic.