BACKGROUND:Satisfactory clinical results have been achieved in the treatment of Sanders Ⅲ calcaneal fractures by percutaneous compression fixation with three-dimensional frame screws.However,whether the stability of minimally invasive plate internal fixation can be achieved in terms of biomechanics,and the advantages and disadvantages after comparison are still unknown. OBJECTIVE:To investigate the fixation effect of different internal fixation devices on Sanders Ⅲ calcaneal fractures by finite element analysis. METHODS:A finite element model of Sanders Ⅲ calcaneal fracture was made based on CT data of a 26-year-old healthy male volunteer.The calcaneal fracture models were fixed by minimally invasive three-dimensional frame screws and minimally invasive Y-plate.The longitudinal loads of 350 and 700 N were applied respectively.The displacement and stress distribution of the two models were analyzed,and the stability of each model was compared. RESULTS AND CONCLUSION:(1)The peak stress of bone block and implant in the minimally invasive three-dimensional frame screw model was significantly lower than that in the minimally invasive minimally invasive plate model.The average stress of bone block and implant in the three-dimensional frame screw model was also significantly lower than that in the minimally invasive plate model.(2)The maximum displacement of the two models was located at the medial side of the articular surface of the posterior talus,and the maximum displacement of the three-dimensional frame screw model was smaller than that of the minimally invasive plate model.(3)The longitudinal displacement between the anterior fragment and the medial fragment of the minimally invasive plate model was smaller,and the transverse and vertical displacement between the medial fragment and the middle fragment of the three-dimensional group screw model was smaller.(4)It is concluded that both of the two internal fixation models can provide satisfactory fixation effect.The three-dimensional frame screw model can provide better transverse and vertical stability with more uniform stress distribution and smaller comprehensive displacement of bone fragments,while the minimally invasive plate has more advantages in maintaining longitudinal stability.

Objective To establish a three-dimensional visualization model of complex anal fistula based on high-resolution mag-netic resonance imaging(HR-MRI),and to explore its feasibility and clinical application value.Methods The clinical and imaging data of 26 patients with complex anal fistula were analyzed retrospectively,and a three-dimensional visualization model based on HR-MRI images was established.The Parks typing,internal orifice,external orifice,branch fistula and abscess were evaluated by radiolo-gists and anorectal surgeons in HR-MRI images and the three-dimensional visualization model,and the SPSS 22.0 software was used to analyze the assessment results against the clinical surgery one by one.Results A total of 26 patients had 17 trans sphincteric fis-tulas,7 inter sphincteric fistulas,and 2 suprasphincteric fistulas,and the accuracy of Parks typing based on HR-MRI images and three-dimensional visualization model was 100％;26 patients had a total of 33 internal orifices,and the evaluation of internal orifices based on HR-MRI images was better than that of three-dimensional visualization model(P=0.180 vs P=0.022);15 patients had a total of 32 external orifices,and the evaluation of external orifices based on three-dimensional visualization model was better than that of HR-MRI images(P=0.791 vs P=0.049);20 patients had perianal abscesses,and the evaluations based on HR-MRI images and three-dimensional visualization model were both highly accurate(P=0.549 vs P=0.625);18 patients with branch fistula,the evaluation of branch fistula based on three-dimensional visualization model was significantly better than that of HR-MRI images(P=1.000 vs P＜0.001).Conclusion Based on three-dimensional visualization model of HR-MRI,the evaluation of complex anal fistula Parks typing,external orifice,branch fistula and abscess is more accurate,which is worthy of further research and promotion.

Objective To investigate the effects of three-dimensional(3D)screws and circular plates on the biomechanical stability of Sanders ABⅢ calcaneal fractures.Methods Calcaneal computed tomography(CT)and magnetic resonance imaging(MRI)data from a 26-year-old volunteer were collected to establish a 3D finite element model of Sanders ⅢAB calcaneal fracture fixed with 3D screws and circular plates.A longitudinal load of 700 N was applied to compare the variations in the stress,displacement of the bone block,and internal fixation in the different models.Results Under 700 N longitudinal loads,the maximum displacement of the bone block and the maximum stress of the bone block and internal fixation were concentrated at the intersection of the posterior talar articular plane internal fixation and fracture line.The overall displacements of the bone blocks in the 3D screw and circular plate models were similar.Compared with the circular plate model,the maximum and average stresses of the bone block and internal fixation in the 3D screw model were lower,and the displacement and stress changes of the 3D screw model were closer to those of the complete calcaneal bone model.Conclusions In the fixation of Sanders ⅢAB calcaneal fractures,both 3D screw and circular plate fixation method can provide good stability.The biomechanical properties of the 3D screws were better than those of the circular plates,which is consistent with the biomechanical characteristics.

Objective To investigate the long-term incidence of in-stent stenosis(ISS)in patients with intracranial aneurysms receiving pipeline embolization device(PED)who showed no ISS at short-to-medium term follow-up examination.Methods The clinical data of patients,who received PED treatment at the Department of Neurointervention,First Affiliated Hospital of Zhengzhou University of China between April 2015 and June 2022,were retrospectively collected.The patients with intracranial aneurysms,who showed no ISS at the initial follow-up with DS A and completed＞12 months long-term follow-up check after treatment at the same hospital,were screened out,and their relevant clinical data and imaging materials were collected.The incidence of ISS occurring in postoperative＞12 months long-term follow-up was calculated.The ISS was defined as a＞25％lumen loss of the parent artery when compared with its lumen size measured immediately after PED implantation.Results A total of 57 patients with 61 aneurysms were enrolled in this study,and a total of 68 PEDs were implanted.Forty-one(67.21％)aneurysms were treated by PED implantation only,and 20(32.79％)aneurysms by PED plus spring coils.The median initial follow-up time was 184.0 days(119.0,212.5).At postoperative＞12 months long-term follow-up visit,DSA was employed for 35(57.38％)aneurysms,CTA was adopted for 22(36.07％)aneurysms,and 3D-SPACE sequence MR scan was performed in 4(6.56％)aneurysms.The median follow-up time was 538.0 days(407.5,678.0),and the incidence of ISS was 0％.No ISS-related neurological symptoms occurred in all patients.Conclusion In treating intracranial aneurysms with PED,the postoperative incidence of ISS is low.No ISS is found during the short-term follow-up period,and long-term follow-up results tend to indicate that no ISS events have occurred.

Since the outbreak of corona virus disease 2019 (COVID-19), viral strains have mutated and evolved. Vaccine research is the most direct and effective way to control COVID-19. According to different production mechanisms, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines included inactivated virus vaccine, live attenuated vaccine, mRNA vaccine, DNA vaccine, viral vector vaccine, virus-like particle vaccine and protein subunit vaccine. Among them, viral protein subunit vaccine has a wide application prospect due to its high safety and effectiveness. Viral nucleocapsid protein has high immunogenicity and low variability which could be a new direction for vaccine production. We summarized the current development of vaccine research by reviewing the current progress, vaccine safety and vaccine immune efficiency. It is hoped that the proposed possible development strategies could provide a reference for epidemic prevention work in future.
Humans ; SARS-CoV-2/genetics* ; COVID-19/prevention & control* ; Protein Subunits ; Vaccines, DNA ; Nucleocapsid Proteins

Objective:To evaluate the necessity, safety and efficacy of endovascular treatment for cerebral infarction caused by middle cerebral artery (MCA) stenosis with hypoperfusion in the blood supply area of the lenticulostriate artery.Methods:The clinical and surgical data of patients with MCA atherosclerotic disease who underwent endovascular treatment in the First Affiliated Hospital of Zhengzhou University from January 2014 to October 2021 were retrospectively analyzed. A total of 6 patients with cerebral infarction caused by MCA stenosis with hypoperfusion in the blood supply area of the lenticulostriate artery were selected. The preoperative and postoperative clinical imaging characteristics, perioperative complications and follow-up of these 6 patients were summarized and evaluated.Results:After the endovascular treatment, the imaging of the lenticulostriate artery in all the 6 patients was clearer than that before the operation, and the number of main trunks of the lenticulostriate artery shown by imaging in 2 patients was more than that before operation. The computer tomography perfusion of 6 patients after the endovascular treatment showed that perfusion in the supply area of the lenticulostriate artery was significantly improved compared with pre-operation. No stroke, transient ischemic attack (TIA) and death occurred during the perioperative period. The time of clinical follow-up was 360 (322, 495) days, and there were no stroke, TIA or death occurring in the corresponding artery. All the 6 patients underwent imaging follow-up, of which 3 patients underwent digital subtraction angiography and 3 underwent CT angiography. The lumen of the target vessels showed patency in all patients.Conclusions:With rigorous imaging evaluation, endovascular treatment may be safe and effective for cerebral infarction caused by MCA stenosis with hypoperfusion in the blood supply area of the lenticulostriate artery.

Objective:To explore the imaging features of intraductal pancreatic neuro-endocrine tumor (PNET).Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 17 patients with intraductal PNET who were admitted to the First Affiliated Hospital of Naval Medical University (Changhai Hospital of Shanghai) from January 2013 to October 2020 were collected. There were 7 males and 10 females, aged (47±13)years. Preoperative contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) of the pancreas was performed on patients. Observation indicators: (1) imaging features of intraductal PNET, including ① imaging features of CT and ② imaging features of MRI; (2) treatment and histopathological examination of intraductal PNET. Measurement data with normal distribution were described as Mean± SD and count data were described as absolute numbers. Results:(1) Imaging features of intraductal PNET. ① Imaging features of CT: 17 patients underwent preoperative contrast-enhanced CT of pancreas. There were 9 cases with tumor located in the head of the pancreas, 5 cases with tumor located in the neck of the pancreas and 3 cases with tumor located in the body and tail of the pancreas. The tumor diameter of the 17 patients was (8.7±2.5)mm, with a range of 5.2?15.5 mm. The tumor shape was round-like in the 17 patients. All the 17 patients showed isodensity on plain CT and markedly enhancement in arterial, venous and portal phases on enhanced CT. The degree of enhancement of tumor was higher than surrounding normal pancreatic parenchyma. All tumors of 17 patients were located at the truncation of main pancreatic duct (MPD) dilation, showing abrupt change in caliber of MPD without the "beak sign". The diameter of dilated MPD was (11.4±5.3)mm, with a range of 4.5?22.5 mm. Other imaging manifestations of the 17 patients included 11 cases with pancreatic parenchymal atrophy, 1 case with retention cyst, 1 case with choledochal dilation, 1 case with calcification, and all cases without cystic degeneration or hemorrhage. ② Imaging features of MRI: preoperative contrast-enhanced MRI was performed in 14 patients. Five cases showed slightly low signal but 9 cases showed unclear on T1-weighted imaging. Five cases showed low signal, 2 cases showed slightly high signal but 7 cases showed unclear on T2-weighted imaging. Of the 14 patients, 9 cases showed diffusion limited on diffusion weighted imaging and 5 cases showed unlimited diffusion. Nine cases showed marked enhancement in tumor higher than in normal pancreatic parenchyma, but 5 cases were unclear on contrast-enhanced MRI. (2) Treatment and histopathological exmination of intraductal PNET: all the 17 patients underwent surgical treatment, including 9 cases with pancreaticoduodenectomy, 4 cases with distal pancreatectomy and splenectomy, 4 cases with pancreatic segmentectomy. Postoperative histopatho-logical examination results showed 10 cases of G1 and 7 cases of G2, including 1 case of G2 with lymph node metastasis, 1 case of G2 with lymph node and liver metastasis. The pathological gross showed that the tumor body was mainly located in the pancreatic duct and blocked the pancreatic duct, with upstream pancreatic dilation. There were pancreatic acinar atrophy and fibrous tissue hyperplasia. The tumor was grayish-yellow or brownish red, solid, medium in texture and well-defined with the surrounding tissues. Microscopically, the tumor of 17 patients was mainly located in the pancreaic duct and invaded into surrounding pancreatic parenchyma. The cells of tumor were polygonal with a central nucleus, but the mitosis was rare. The cytoplasm was eosinophilic or hyaline. The tumor stroma was mainly collagen fiber with abundant capillary network.Conclusions:The imaging features of intraductal PNET are small size, marked enhancement on contrast-enhanced CT and MRI. The tumor obstructs the MPD with distal MPD dilation and pancreatic parenchyma atrophy.

ObjectiveTo explore the effect of Youguiwan on the rats with adriamycin-induced nephrotic syndrome （NS） and its mechanism. MethodSD rats were randomly divided into a normal group， a model group， three Youguiwan low， medium， and high-dose groups， and a prednisone group. Rats in the model group were intravenously injected with adriamycin in the tail vein to induce the NS model. Rats in the Youguiwan low， medium， and high-dose groups were given 2.8， 5.6， 11.2 g·kg^-1·d^-1 of crude drugs， respectively， and rats in the prednisone group were given 6.3 mg·kg^-1·d^-1 of prednisone acetate. Each administration group was given continuous medicine for 6 weeks， and the normal group and model group were given an equal volume of normal saline. Bicinchoninic acid （BCA） assay was used to detect 24 h urine protein （24 h UP）. Automatic biochemical analyzer was used to detect serum urea nitrogen （BUN）， creatinine （SCr）， albumin （ALB）， total cholesterol （TC）， and triglyceride （TG） levels. Hematoxylin-eosin （HE） staining was used to observe renal tissue morphology， and kit was used to detect serum advanced oxidized protein products （AOPPs） and reactive oxygen species （ROS）. Western blot was used to detect the receptor of advanced glycation endproducts （RAGE） of renal tissue， nuclear factor-κB （NF-κB） phosphorylation levels， Wnt， and β-catenin protein expression. ResultAs compared with the normal group， 24 h UP， serum BUN， SCr， TC， TG， AOPPs， and ROS levels in the model group increased significantly （P<0.01）， whereas ALB decreased （P<0.01）. There were typical pathological injuries in the renal tissue， and the expressions of RAGE， phosphorylation（p）-NF-κB， Wnt1， and β-catenin protein were significantly increased （P<0.01）. As compared with the model group， the 24 h UP， serum BUN， SCr， TC， TG， AOPPs， and ROS levels of rats in the Youguiwan low， medium， and high-dose groups significantly reduced （P<0.01）， and ALB significantly increased （P<0.01）. The renal tissue damage was reduced， and the expressions of RAGE， p-NF-κB， Wnt1， and β-catenin protein were significantly decreased （P<0.01） in a dose-dependent manner. ConclusionYouguiwan improves the kidney injury of rats with adriamycin-induced NS. The mechanism may be related to the reduction of AOPPs level， inhibition of RAGE/ROS/NF-κB axis， and activation of Wnt/β-catenin signal.

Objective:To investigate the effectiveness and safety of middle-column preserved pedicle subtraction closing-opening wedge osteotomy for the treatment of stiff kyphosis.Methods:From January 2016 to April 2018, 12 patients with stiff kyphosis in our department were treated with middle-column preserved pedicle subtraction closing-opening wedge osteotomy. The patients' operative time, intraoperative blood loss, postoperative drainage, surgical complications, low back pain and leg pain visual analogue scale (VAS), Oswestry dysfunction index (ODI) score, and SF-36 were recorded.These parameters were compared at preoperative, postoperative, and at the final follow-up. Coronal parameters included lumbar scoliosis Cobb angle, C 7 vertebral body center to humeral vertical line distance (C 7PL-CSVL), whilesagittal parameters includedlumbar Lordosis (LL), sacral slope (SS), pelvic tilt (PT), and sagittalvertical axis (SVA). Results:All of 12 patients successfully completed the operation.The mean operation time was 238.20±65.95 min, the mean intraoperative blood loss was 440.50±133.60 ml.The patients’ODI score was 65.92%±6.96% at the preoperative, and 21.00%±3.19% at the final follow-up. The difference was statistically significant ( t=20.32, P<0.0001).The VAS score of back pain was 6.00±0.95 at preoperative, 2.33±0.89 at 3 months postoperatively, and 1.42±0.51 at the final follow-up. The VAS score of leg pain was 6.91±1.24 at preoperative, 2.50±1.00 at 3 months postoperatively, and1.50±0.52 at the final follow-up. There was significant difference in SF-36 at preoperative and at final follow-up ( P<0.05). The differences in LL, SS, PT and SVA at the preoperative and at final follow-up were statistically significant ( F=17.47, P<0.001; F=5.015, P=0.0125; F=14.66, P<0.001; F=81.11, P<0.001) . There was significant difference in lumbar scoliosis Cobb angle and C 7PL-CSVL at the preoperative and at final follow-up ( F=87.19, P<0.001; F=100.9, P<0.001) . Conclusion:The advantages of this surgical procedure includesimple operation, reducedsurgery time, and shorten intraoperative bleeding, which can effectively relief clinical symptoms, improve the quality of life, correctkyphosis, and maintain the patient's spinal-pelvic balance.

Objective:To investigate the imaging features of undifferentiated pancreatic carcinoma (UCOGCP) with osteoclast-like giant cells.Methods:CT and MRI data of 4 pathologically diagnosed UCOGCP patients admitted in the First Affiliated Hospital of Naval Medical University from December 2014 to January 2019 were retrospectively analyzed. The tumor location, major length, shape, border, density or signal, capsule, calcification, hemorrhage, cystic degeneration, degree of enhancement, as well as the presence or absence of pancreatic duct dilatation, pancreatic parenchymal atrophy, peripheral vascular invasion, lymph node and organ metastasis were recorded.Results:Of 4 UCOGCP patients, 1 case had the mass located in head of pancreas, 2 cases in body of pancreas , and 1 in tail of pancreas. The length of tumor ranged from 3.3 cm to 13.0 cm, and the average was 8.8 cm.3 cases were round-like, and 1 was irregular; 2 tumors were well defined with capsules, 2 with unclear border. 4 cases showed solid-cystic masses, 3 of which had cystic separation. 4 cases showed heterogeneous low density on unenhanced CT, and 1 case had spotted calcification. The solid component of the mass was mild enhanced on enhanced CT, and partial solid component of the mass showed obvious enhancement in 2 cases. 2 cases showed mixed low signal on T 1WI, 1 of which had small patchy high signal indicating hemorrhage. 2 cases showed mixed high signal on T 2WI, and high signal on DWI. 2 cases had major pancreatic duct dilation. 1 case had pancreatic parenchyma atrophy. 1 case had descending duodenum invasion. 3 cases had peripheral vascular invasion, including portal vein, splenic artery, and splenic vein. 1 case had tumor thrombosis in the portal vein and splenic vein. 1 case was associated with pancreatogenous portal hypertension. Conclusions:The imaging features of UCOGCP showed a large solid-cystic mass with hemorrhage and calcification. The solid component of the mass was mild enhanced and the partially solid component was obviously enhanced. The combination of its imaging characteristics and clinical data can improve the accuracy of diagnosis.