BACKGROUND: Osteoporosis is a serious threat to the health and quality of life in the elderly. It is important to establish an ideal experimental animal model to study the etiology and treatment of osteoporosis.OBJECTIVE: To establish a rat model of osteoporosis induced by different dosages of retinoic acid, thus selecting the optimal dosage.METHODS: Eighty female Sprague-Dawley rats were randomly divided into control, low-, middle- and high-dosage groups based on body mass (n=20 per group), The rats in the latter three groups were induced with 80, 100, and 120 mg/(kg?d) retinoic acid via gastric lavage for 14 days.RESULTS AND CONCLUSION: Compared with the control group, the bone mineral density, number of osteoblasts and osteoclasts, and bone microarchitecture in the low-dosage group showed no significant changes, while there were significant decrease in the serum level of calcium and bone mineral density of femur, significant increase in the number of osteoclasts at the femur and significant changes in the femoral microarchitecture in the middle- and high-dosage groups, especially in the middle-dose group. To conclude, 120 mg/(kg?d) retinoic acid via gastric lavage for 14 days can induce a stable osteoporosis model in rats.

With the ongoing epidemic of the Coronavirus disease in China and the widespread development of radiotherapy, radiation-induced lung injury has gradually become a clinical problem that has attracted much attention. The pathogenesis of radiation-induced lung injury is complex, involving an imbalance in the polarization state of alveolar macrophages and an upregulation of alveolar epithelial cell apoptosis. Previous studies have shown that vitamin C is an important antioxidant substance, and preventive use of vitamin C can effectively treat acute lung injury. However, whether prophylactic use of vitamin C can effectively prevent or treat lung injury caused by radioactive substances, and its specific molecular mechanism remains to be studied. The purpose of this study is to investigate whether the prophylactic use of vitamin C to treat the alveolar macrophage cell line RAW 264. 7 and human lung epithelial cells BEAS-2B can effectively control the abnormal polarization of macrophages and the abnormal apoptosis of lung epithelial cells. This study found that after 4 weeks and 8 weeks of radioactive X-ray irradiation, the expression of macrophage M1 polarization state markers such as iNOS was significantly up-regulated (P< 0. 05), and preventive use of vitamin C to treat macrophages and lung epithelial cells can alleviate the polarization state disorder of macrophages and the apoptosis of alveolar epithelial cells caused by external radiation exposure, which is manifested in the down-regulation of the expression of Cleaved Caspase3. In addition, the preventive application of vitamin C treatment can inhibit the MAPK signaling pathway activated by external radiation exposure. Further experimental results showed that the inhibition of the MAPK pathway is the key to inhibiting the M1 polarization of macrophages and the apoptosis of lung epithelial cells. In summary, our findings suggest that vitamin C may play a protective role in acute radiation-induced lung injury by inhibiting macrophage M1 polarization/ promoting macrophage M2 polarization and alleviating alveolar epithelial cell apoptosis. This study will help to better understand the process and mechanism of the preventive effect of vitamin C, a common vitamin, on radiation-induced lung injury.

BACKGROUND: Ankle fracture combined with deltoid ligament rupture and distal tibiofibular syndesmosis injury occurs occasionally. Its treatment with distal tibiofibular syndesmosis screw fixation or deltoid ligament repair remains controversial. The former appears with poor reduction, broken nails, secondary surgery and other problems.OBJECTIVE: To observe the clinical effectiveness of suture anchor repair for ankle fracture combined with deltoid ligament injury.METHODS: Twelve patients with ankle fracture combined with deltoid ligament injury were selected from the First Affiliated Hospital of Guangzhou University of Chinese Medicine between January 2013 and December 2015. All patients were treated with open reduction, internal fixation, and anchor repair, but without distal tibiofibular syndesmosis screw fixation. The curative efficacy and joint stability were observed.RESULTS AND CONCLUSION: (1) All patients were followed-up for more than 12 months. (2) The modified Baird-Jackson scoring system showed excellent in nine cases, good in two cases, average in one case, poor in none case, and the excellent and good rate was 92%. (3) At 1 year after internal fixation, the X-ray examination showed the malleolus gap and talus slope angle of the affect side were (3.47±0.12) mm and (0.45±0.18)°, and the malleolus gap and talus slope angle of the healthy side were (3.44±0.05) mm and (0.43±0.14)°, and there was no significant difference between two sides (P > 0.05). (4) These results indicate that the suture anchor can repair the anatomy and biomechanics of deltoid ligament with stable ankle joint, and secondary surgery is unnecessary.

10.3969/j.issn.1000-3606.2013.06.010

Objective:To study the effects of ~(125)I-(α_v)ASODN on the in vitro invasive ability of heptocellular carcino-ma cell line(HepG2) through PEI-RGD-mediated receptor process. Methods: Intergrin α_v-specific antisense oligonucle-otide was labeled with ~(125)I, and PEI-RGD/~(125)I-(α_v)ASODN complex was prepared by combining ~(125)I-(α_v)ASODN with polyethyleneimine derivative PEI-RGD. PEI-RGD/~(125)I-(α_v)ASODN complex was transferred into HepG2 cells through the receptor-mediated process. The effect of PEI-RGD/~(125)I-(α_v)ASODN complex on the invasive ability of HepG2 cells was examined by Boyden chamber invasive assay. Results: (1) The labeling yield and radiochemical purity of ~(125)I-(α_v) ASODN were(73.78±4.09)% and(96.68±1.38)%, respectively, and the labeled compound had a good stability in vitro after 48 h at 37℃; (2) The ability of HepG2 cells to uptake PEI-RGD/~(125)I-(α_v)ASODN reached its peek ([12.77±0.85] % ) when PEI-RGD/~(125)I-(α_v)ASODN was at 4 μl/2 μg ([12.77±0.85] %), and then gredually decreased thereafter. So the dosage of PEI-RGD/~(125)I-(α_v)ASODN for the following experiment was chosen as 2 μl/1 μg; (3) The invasive capacity of HepG2 cells was significantly reduced in PEI-RGD/~(125)I-(α_v)ASODN group compared with those in other experiment and control groups (P <0.01 ). Conclusion: ~(125)I-(α_v)ASODN mediated by PEI-RGD can effectively inhibit the invasive capacity of HepG2 cells.

BACKGROUND: Splint fixation was a common treatment for limb fracture, but there were some limitations, such as lack of individual difference, easy to lose and being unable to self-adjusting.OBJECTIVE: To explore the design method of digital splint and related finite element analysis.METHODS: Forearms were scanned with CT; periphery parameters were extracted, followed by reverse modeling and modifying. The digital splint models were constructed. Material attribute and mechanical loading were conducted. Thelimb length, maximum stress and displacement of the bone, soft tissue and splint were calculated by finite elementanalysis. RESULTS AND CONCLUSION: The digital splint has favorable tight attaching and balanced stress to skin, and whichkeeps well stability for the micro-motion fracture ends. Our study indicated that better tight attaching splint could bedesigned by digital modeling technology. Favorable fracture fixation and mechanical property could be also achieved.

Objective:To investigate the effects of SuperPATH approach versus conventional posterolateral approach in total hip replacement on inflammatory response, hip function, and quality of life in patients with hip diseases. Methods:The clinical data of 140 patients with hip diseases who underwent total hip replacement in Shanxian Central Hospital from March 2017 to May 2019 were retrospectively analyzed. These patients were divided into SuperPATH approach ( n = 70) and posterolateral approach ( n = 70) groups. Operation-related indexes, inflammatory response indexes, hip function, quality of life, and pain were compared between the two groups. Results:Intraoperative blood loss was significantly less in the SuperPATH approach group than in the posterolateral approach group [(105.40 ± 15.11) mL vs. (196.89 ± 24.26) mL, t = 26.74, P < 0.001]. Incision length, postoperative time to getting out of bed, length of hospital stay in the SuperPATH approach group were (6.85 ± 1.42) cm, (2.92 ± 0.28) days, and (6.67 ± 1.36) days, respectively, which were significantly shorter than those in the posterolateral approach group [(13.07 ± 1.89) cm, (8.36 ± 1.45) days, (10.91 ± 1.34) days, t = 19.36, 30.82, 18.58, P < 0.001]. Operative time was significantly longer in the SuperPATH approach group than in the posterolateral approach group [(69.38 ± 8.62) minutes vs. (60.45 ± 7.79) minutes, t = 6.43, P < 0.001). The scores of social role functioning, general health perceptions, vitality, mental health, bodily pain, emotional role functioning, physical functioning, and physical functioning measured 6 months after surgery were significantly higher in the SuperPATH approach group than in the posterolateral approach group ( t = 9.12, 11.80, 11.64, 11.69, 6.45, 11.79, 6.04, 10.74, all P < 0.001). There were no significant differences in C-reactive protein and erythrocyte sedimentation rate measured 3 and 14 days after surgery between the two groups (both P > 0.05). Harris score used for evaluation of hip function 1 month after surgery was significantly higher in the SuperPATH approach group than in the posterolateral approach group [(76.42 ± 4.17) points vs. (69.37 ± 5.11) points, t = 8.94, P < 0.001]. The Visual Analog Scale score 3 days after surgery was significantly lower in the SuperPATH approach group than in the posterolateral approach group [(3.18 ± 0.21) points vs. (4.26 ± 0.29) points, t = 25.23, P < 0.001]. Conclusion:Compared with the conventional posterolateral approach, the SuperPATH approach for total hip arthroplasty takes longer operative time, but it can better reduce early postoperative pain, promote hip function recovery, and improve quality of life.

Objective To study biomechanical effects of cannulated screws at different fixation angles on posterior malleolus fracture based on finite element method, so as to determine the best fixation method of cannulatedscrew. Methods The finite element model of ankle joint, including tibia, fibula, astragalus, corresponding cartilage and ligaments was reconstructed using CT images, and 1 / 2 posterior malleolus fracture model was established on the basis of verifying its validity. The biomechanical effects of cannulated screw fixation on posterior malleolus fracture fixation model were analyzed. Results Compared with 0°,5°,10°,20° fixation model, the 15° fixation model had the smallest displacement. The screw stress of 15° fixation model was lower than that of 5°, 10°, 20° fixation model, and higher than that of 0° fixation model. But when the screw fixation angle was 0°, the peak contact pressure of ankle joint was much larger than that of normal ankle joint, which was easy to cause traumatic osteoarthritis. Conclusions Cannulated screw is safe and effective for treating posterior malleolus fracture which is less than 1 / 2 fragment size. The displacement and stress of the model are different at different fixation angles of screws. When the fixation angle of screw is 15°, the biomechanical stability is the best, which can be used to guide clinical operation.

Resection is one of the most important treatments for esophageal squamous cell carcinoma, and routine postoperative follow-up is an effective method for early detection and treatment of recurrent metastases, which can improve patients' quality of life and prognosis. This consensus aims to provide a reference for colleagues responsible for postoperative follow-up of esophageal squamous cell carcinoma patients in China, and further improve the standardization of the diagnosis and treatment of esophageal squamous cell carcinoma.