Objective To compare the biomechanical properties of single-segment and two-segment fusion for Denis type B spinal fracture.Methods Two female patients with Denis type B L1 vertebral fracture were enrolled in this study.The 45-year-old patient (Frankel B) underwent posterior reduction and fixation with pedicle screw system plus anterior two-segment fusion and the 41-year-old patient (Frankel C) underwent posterior reduction and fixation with pedicle screw system plus anterior one-segment fusion.The intervertebral fusion was achieved in both patients 1 year after operation.CT data of the two patients at 1 year after surgery was collected,including data of 41-year-old patient before and after removal of pedicle screws and data of 45-year-old patient without removal of pedicle screws.These three sets of data were imported into the Mimics software to establish T11-L2 three dimensional models.After construction of the models,they were imported into ANSYS software.An axial load (260 N) and 10 Nm torque were loaded to simulate the flexion,extension,lateral bending and rotation of the spine,respectively.Meantime,under above 6 kinds of motion form,the average displacement of the spine and the average Von Mises stress of T11-12 intervertebral disc were recorded and compared.Results There was no significant difference in the average displacement of the spine between two-segment fusion patient and single-segment fusion patient without removal of pedicle screws.However,under all motion forms,the average displacement of the spine of single-segment fusion patient after removal of pedicle screws was significantly higher than that before removal of pedicle screws and that of two-segment fusion patient.The average Von Mises stress of T11-12 intervertebral discs of two-segment fusion patient was significantly higher than that of one-segment fusion patient.Moreover,the average Von Mises stress of T11-12 intervertebral discs of single-segment fusion patient before removal of pedicle screw was higher than that after removal of pedicle screw.Conclusion Under the premise of satisfactory interbody fusion,removal of pedicle screws after one-segment fusion can increase spinal motion,reduce the stress of the adjacent intervertebral discs and delay disc degeneration.

Objective:To investigate the effect of the intact parathyroid hormone (iPTH) on residual renal function (RRF). Methods: The relationship between iPTH and calcium, phosphorum, product Ca?P, hypertension, triglycende, cholesterol,left ventricular mass index(LVMI) and RRF in 120 hemodialysis patients with chronic renal failure. Results: The results showed that 95. 9% of the hemodialysis patients with chronic renal failure had secondary parathyroldism. It was found that iPTH was positively correlated with SBP,DBP, product Ca?P, triglycende and LVMI, and negatively correlated with endogenous creatinine clearance rate and KT/V. RRF had positive correlation with KT/V and SBP,DBP, calcium, product Ca?P, triglyceride, cholesterol and LVMI. Conclusion: iPTH level is elevated in hemodialysis patients, which may lead to RRF loss.

Objective To investigate the clinical significance.of thrombocytopenia in systemic lupus erythematosus (SLE).Methods One hundred and two SLE patients with thrombocytopenia who were admitted to Peking University People's Hospital were involved in the study.SLE patients without thrombocytopenia were controls.Clinical and laboratory characteristics were analyzed.T-test and Chi-square test were used for inter-group comparison.Results Patients with thrombocytopenia had more organ damage than those without,although the disease activities (SLEDAI) were not different between these two groups.Bone marrow characteristics were analyzed and 16 patients were amegakaryocytic.However,there were no differences observed between patients with amegakaryocytosis and normal megakaryocytes in organ damage,disease activity and response to therapy.Conclusion Lupus patients with thrombocytopenia usually have more organ damage.About 32％ of those patients are amegakaryocytosis.

Purpose To investigate the value of quantitative evaluation of upper urinary tract pump function after unilateral lower urinary tract obstruction using 640-slice dynamic volumetric CT. Materials and Methods Twenty-six healthy subjects (control group), thirty cases of acute upper urinary tract obstruction caused by unilateral ureteral calculi and thirty cases of chronic upper urinary tract obstruction were selected, all receiving dynamic volume scan of 640-slice dynamic volumetric CT during renal excretion. The value of contrast agent volume, volumetric difference, time difference correspondent to the difference, volumetric change rate, and flow rate in ureteropelvic and partial upper ureter were calculated and analyzed. Results Volumetric change rate of obstruction side of upper urinary tract in acute obstruction group was higher than that of contralateral upper urinary tract. Volumetric average value, volumetric difference and flow rate were increased with time difference value decreased, the difference of which were all statistically significant (P<0.001). Volumetric change rate, volumetric difference and flow rate of obstruction side of upper urinary tract in acute obstruction group was lower compared with those of contralateral upper urinary tract, while volumetric average value and time difference raised, the difference was statistically significant (P<0.001). The difference of five pump function values among acute obstruction group, obstruction side of chronic obstruction group and control group were statistically significant (P<0.001). Conclusion 640-slice dynamic volumetric CT can be used to quantitatively evaluate changes of urinary tract pump function in physiological and obstructive status.

Objective To evaluate the feasibility and safety percutaneous pulmonary vein intervention in patients with severe pulmonary vein stenosis (PVS) caused by fibrosing mediastinitis(FM). Methods This retrospective analysis included 5 FM patients (2 male, 3 female, 54-77 years old) confirmed by clinical presentation and chest computed tomography (CT) scan from January to June 2018 who were from Gansu Provincial Hospital and Shanghai Chest Hospital. CT pulmonary angiography (CTPA) further revealed severe PVS caused by fibrotic tissue compression in mediastinum. After selective pulmonary vein angiography, gradually balloon angioplasty was used to expand the pulmonary vein and then stents were implanted in the pre?dilated stenotic pulmonary veins. Evaluation of therapeutic effect was made at 6 months after the procedure. Results All of 11 serious compression PVS were treated with stent implantation (diameter: 7-10 mm, length: 17-27 mm). After stenting, degree of pulmonary vein stenosis decreased from (83 ± 16)% to (12 ± 4)% (P<0.01). The minimal diameter of the stenotic pulmonary vein was significantly increased from (0.8±0.5)mm to (7.5±0.8)mm (P<0.01). Trans?stenotic gradient decreased from (27.0±15.1) mmHg (1 mmHg=0.133 kPa) to (2.50±0.58)mmHg (P<0.05). Mean pulmonary pressure measured by cardiac catheter decreased from (45.0 ± 9.0)mmHg to (38.7 ± 8.4)mmHg (P<0.05). One patient experienced cardiac arrest due to vagal nerve reflex during big sizing balloon stent dilation and recovered after cardiopulmonary resuscitation. There were no other serious procedure related complications. During the follow?up, severe stenosis at end of proximal stent was evidenced in 1 patient due to fibrotic compression, and another patient developed in?stent thrombosis due to discontinuation of prescribed anticoagulant. Conclusion Percutaneous intervention for severe pulmonary vein stenosis caused by FM is feasible and safe, and can improve hemodynamic caused by the compression of mediastinal vascular structures in these carefully selected patients.

Objective:To analyze the electrocardiographic characteristics of patients with chronic pulmonary artery stenosis (PAS), and to explore their relationship with disease severity indicators.Methods:The study was a retrospective case-series analysis. Patients with chronic PAS admitted to Gansu Provincial Hospital from January 2018 to July 2021 were enrolled. The clinical data and the results of electrocardiography, transthoracic echocardiography, right cardiac catheterization, N-terminal B-type natriuretic peptide (NT-proBNP) measurement and 6-min walking distance test of patients were analyzed. The linear regression model or logistic regression model was used to analyze the relationship between electrocardiographic characteristics and the disease severity in patients with chronic PAS.Results:Sixty-three patients aged (62.1±9.7) years including 43 females (68.3%) were enrolled in the study. Among them, 62 patients (98.4%) had (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ)<1.5 mV, and no patients had V 5lead R: S ratio to V 1 lead R: S<0.04 and V 6 lead R: S ratio<0.4. There were 55 patients (87.3%), with flat or inverted T-waves in V 1, and 10 patients (15.9%) with flat or inverted T-waves in all precordial leads (V 1-V 6). There were 18 patients (28.6%) with flat or inverted T-waves in inferior leads (Ⅱ, Ⅲ, aVF). Multiple liner regression analysis showed that Max R V1, 2+Max S I, aVL-S V1 combined with the number of flat or inverted T-waves in limb leads was independently correlated with atrial area ( R2=0.290, P=0.002); R V1+S V5 was independently correlated with right ventricular area ( R2=0.257, P=0.001); R peak V 1 combined with the number of flat or inverted T waves in precordial leads was independently correlated with tricuspid annular plane systolic excursion ( R2=0.407, P<0.001); (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ) combined with the number of flat or inverted T waves in precordial leads was independently correlated with NT-proBNP ( R2=0.504, P<0.001); Max R V1, 2+Max S I, aVL-S V1 were independently correlated with right atrial pressure ( R2=0.803, P=0.036); (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ) were independently correlated with mean pulmonary artery pressure ( R2=0.302, P<0.001); R aVRcombined with the number of flat or inverted T-waves in precordial leads was independently correlated with cardiac index ( R2=0.173, P=0.003); (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ) was independently correlated with pulmonary vascular resistance ( R2=0.173, P=0.002); R peak V 1 combined with the number of flat or inverted T-waves in precordial leads was independently correlated with mixed vein oxygen saturation ( R2=0.302, P<0.001). Conclusion:The vast majority of patients with chronic PAS have (R 1+S Ⅲ)-(S Ⅰ+R Ⅲ)<1.5 mV and flat or inverted T-wave in V 1 lead, and some characteristic electrocardiographic manifestations are correlated with indicators of disease severity.

Objective:To explore the clinical value of qualitative determination of C-reactive protein (CRP) in the differential diagnosis of benign and malignant pleural effusions or ascites .Methods :CRP in 3820 cases of pleural effusions and ascites were qualitatively examined by latex agglutination method .Specimen and latex reagent were added to the wells of the reaction plate successively .The result was observed after 2 minutes’ thorough mixing .The result was judged as positive if agglutination par-ticles were visible .Results:The positive rate of CRP in 672 cases of malignant pleural effusions and ascites was 6 .1% .The positive rate of CRP in pleural effusions and ascites was 75 .0% in 32 cases of hematopoietic and lymphoid tissue tumors ,and 2 .7% in 640 cases of epithelial malignant tumors .The positive rate of CRP in pleural effusions and ascites in 3148 cases of be-nign diseases was 21 .8% .The positive rate of CRP in benign pleural effusions and ascites was higher than that in malignant pleural effusions and ascites(P<0 .05) .The positive rate of CRP in pleural effusions and ascites of patients with hematopoietic and lymphoid tumors was higher than that of patients with epithelial malignant tumors .Conclusions :Qualitative determination of CRP in pleural effusions and ascites can be used to differentiate benign and malignant pleural effusions and ascites ,and to differentiate pleural effusions and ascites of hematopoietic and lymphoid tissue tumors and epithelial malignant tumors .

ObjectiveTo examine the clinical features of fractures and related risk factors in patients with rheumatoid arthritis(RA) in China.MethodsSix hundred and eighty-one RA patients were randomly selected from department of rheumatology of 18 hospitals of China.Data were obtained from the questionnaire,including age,sex,disease duration,the involvement of joints,treatment regimen,features of fractures etc.The possible risk factors of fracture in patients with RA were analyzed with a multi-variate Logistic regression analysis.Results① In 681 RA patients of the survey,48 patients had 54 fractures,and the incidence of fractures was about 8％.② Fractures occurred at various sites.Foot/ankle,femur,spine and wrist were the mostfrequent sites.③ The Logistic regression analysis showed that several factors increased the risk of fracture in RA patients,including long disease duration (OR:1.245,95％CI:0.987-1.570,P=0.065),male gender(OR:0.433,95％CI:0.199-0.942,P=0.035),more deformed joints(OR:1.042,95％CI:1.006-1.079,P=0.023),family history of RA (OR:2.201,95％CI:0.984-4.923,P=0.055),and high scores of SF-36(OR:1.017,95％CI:1.002-1.033,P=0.028).④ According to the degree of correlation from strong to weak,the risk factors of fracture were disease duration,SF-36,sex,number of deformed joints and family history of rheumatoid arthritis.ConclusionThe incidence of fracture is high in patients with rheumatoid arthritis.Several factors could increase the risk of fractures in RA patients,including long disease duration,male gender,more deformed joints,and family history of RA.In order to prevent the occurrence of fractures,cautions should be taken to prevent the development of fractures and treat the disease aggressively to suppress the disease activity of RA.

Objective To describe the distribution of medication costs of rheumatoid arthritis patients, and to analyze the factors that may affect the costs. Methods Data were obtained from a 12-month retrospective investigation of patients with rheumatoid arthritis (RA) across China. Department of Rheuma-tology of 18 hospitals were randomly selected. The data about their social conditions, clinical conditions, medications associated with RA such as disease-modifying antirheumatic drugs (DMARDs), non -steroidal anti -inflammtory drugs (NSAIDs), steroids, biologic agents were collected, and the costs of drugs were calculated. A non-parameter test and multivariate logistic regression analysis were performed. Results Six hundred and forty six patients were enrolled into the study, 435 completed data were chosen for analysis. The results demonstrated that the average costs per patient for medications in the past year was 8018 . The total medication costs were further subdivided into the following parts: DMARDs, (represented 20% of the total costs), biologic drugs (49%), NSAIDs (4%), herbal drugs (22%), steroids (1%). Data analysis showed that patients with higher education and higher incomes, with medical insurance,better health function status and outpatients paid more on DMARDs. Extra-articular manifestations increased the odds of the high-cost group (OR: 2.180, 95%CI: 1.335～3.558, P=0.002), while poor health function status increased the probability of paying high costs (OR: 1.373, 95%CI: 1.012～1.863, P=0.041). Conclusion High medication costs in RA do exist in RA patients. The costs of medication is associated with health function status and the presence of extra-articular manifestations.

Objective: To evaluate the feasibility and safety percutaneous pulmonary vein intervention in patients with severe pulmonary vein stenosis (PVS) caused by fibrosing mediastinitis(FM). Methods: This retrospective analysis included 5 FM patients (2 male, 3 female, 54-77 years old) confirmed by clinical presentation and chest computed tomography (CT) scan from January to June 2018 who were from Gansu Provincial Hospital and Shanghai Chest Hospital. CT pulmonary angiography (CTPA) further revealed severe PVS caused by fibrotic tissue compression in mediastinum. After selective pulmonary vein angiography, gradually balloon angioplasty was used to expand the pulmonary vein and then stents were implanted in the pre-dilated stenotic pulmonary veins. Evaluation of therapeutic effect was made at 6 months after the procedure. Results: All of 11 serious compression PVS were treated with stent implantation (diameter: 7-10 mm, length: 17-27 mm). After stenting, degree of pulmonary vein stenosis decreased from (83±16)% to (12±4)% (P<0.01). The minimal diameter of the stenotic pulmonary vein was significantly increased from (0.8±0.5)mm to (7.5±0.8)mm (P<0.01). Trans-stenotic gradient decreased from (27.0±15.1)mmHg (1 mmHg=0.133 kPa) to (2.50±0.58)mmHg (P<0.05). Mean pulmonary pressure measured by cardiac catheter decreased from (45.0±9.0)mmHg to (38.7±8.4)mmHg (P<0.05). One patient experienced cardiac arrest due to vagal nerve reflex during big sizing balloon stent dilation and recovered after cardiopulmonary resuscitation. There were no other serious procedure related complications. During the follow-up, severe stenosis at end of proximal stent was evidenced in 1 patient due to fibrotic compression, and another patient developed in-stent thrombosis due to discontinuation of prescribed anticoagulant. Conclusion Percutaneous intervention for severe pulmonary vein stenosis caused by FM is feasible and safe, and can improve hemodynamic caused by the compression of mediastinal vascular structures in these carefully selected patients.