Objective:A three-dimensional (3D) finite element model of the ankle joint of marathon runners was constructed to simulate the changes of the lateral collateral ligament (LCL) injury on the stability of the ankle joint and the force distribution of talar talus cartilage during exercise.Methods:The 3D MRI images of the right ankle joint of one marathon runner were acquired and imported into Mimics software in DICOM format for preliminary 3D model reconstruction of the images. The boundary conditions and loads were loaded on the model using Ansys Workbench software, and the ankle joint forces were analyzed by Ansys Workbench for marathon runners in the sports condition, and four kinds of ankle LCL injury finite element models were established, i.e., the normal model of LCL, the injury model of anterior talofibular ligament (ATFL), the injury model of AFTL merged with the calcaneofibular ligament (CFL), and the injury model of AFTL merged with the CFL and the posterior talofibular ligament (PTFL). The peak talus slide cartilage stress and its distribution were observed under the four models, and one-way ANOVA was used to compare the values of talus advancement, and the SNK- q test was used for two-by-two comparisons. Results:In the LCL normal model, the maximum stress peak of the talar slide was 0.21 MPa, which was mainly distributed in the junction area of the anterior medial (MA) and anterior lateral (LA) parts and part of the LA region. In ATFL injury, the peak stress of talar cartilage increased compared with the normal model, with a maximum value of 0.65 MPa, which was mainly distributed in the MA region. In ATFL combined with CFL injury, the peak stress increased, and the peak was mainly distributed in the MA region, and was shifted from the MA to the LA region. In ATFL combined with CFL and PTFL injuries, the peak cartilage stress in the talus slide was up to 2.29 MPa, and the maximum stress was mainly distributed in MA and LA, which had a comparable range of distribution. The anterior talar displacement values were (3.2±0.4), (3.4±0.4), (3.7±0.5), and (6.5±0.7) mm for normal LCL, AFTL injury, AFTL combined with CFL injury, ATFL combined with CFL, PTFL injuries, respectively, with a statistically significant difference ( F=109.08, P<0.001). The anterior talar displacement of ATFL combined with CFL, PTFL injuries was larger than those of normal LCL, AFTL injury, and AFTL combined with CFL injury ( P<0.05). Conclusions:A 3D finite element model is successfully constructed based on 3D MRI of the ankle joint in marathon runners. The peak and range of cartilage stresses in the talar glide change during LCL injury, and the talar glide displaces anteriorly.

Objective:To evaluate the acute effects of different foot-strike patterns of running on knee cartilage in amateur marathon runners using the T 2* mapping technique. Methods:From November 2021 to February 2022, 29 amateur marathon runners were recruited in Hangzhou. The gait analysis was performed to determine their landing patterns, then the runners were divided into the fore-foot strike (FFS) group (11 cases) and the rear-foot strike (RFS) group (18 cases). The MRI of the knee joint of the dominant leg was performed before and 30 min after running, and the volume, thickness, and T 2* value of each division of knee cartilage were measured. Independent samples t-tests were used to compare the differences in baseline data before running between the groups, and paired samples t-tests were used to compare the differences before and after running within the groups. Results:The difference in knee cartilage volume and thickness between the FFS and RFS groups before running was not statistically significant ( P>0.05), and the T 2* value of the femur medial posterior in the RFS group was higher than that of the FFS group ( t=-2.47, P=0.020). Compared with pre-running, cartilage thickness of the tibia lateral posterior decreased in the FFS group after running ( t=-2.96, P=0.016), and cartilage thickness of the tibia lateral posterior and patella lateral central decreased in the RFS group ( t=-3.25, -3.02, P=0.004, 0.007). Cartilage volume of the tibia lateral posterior decreased in the FFS group after running ( t=-2.58, P=0.030), and the cartilage volume of the patella lateral central decreased in the RFS group ( t=-2.74, P=0.013). The differences in T 2* values of cartilage in each region before and after running were not statistically significant in the FFS group ( P>0.05), whereas in the RFS group, the cartilage T 2* values in the femur medial posterior, femoral trochanter central, femoral trochanter lateral, femur lateral central, tibia lateral anterior, tibia medial posterior, tibia medial central, and tibia medial anterior decreased ( P<0.05). Conclusions:After running, FFS showed changes in morphology and biochemical composition only in some subregions of tibial cartilage, whereas most of the femoral cartilage, patellar cartilage, and tibial cartilage regions were altered by RFS. The RFS pattern introduces greater acute changes in cartilage in the knee joint.

Objective:To gain insight into the constitution of juvenile rheumatic diseases, treatment outcome and trends of rheumatic inpatients in past 12 years, and to improve awareness of juvenile rheumatic diseases.Methods:The clinical data of 5 950 patients in rheumatology department of the affiliated pediatric hospital of Fudan University (from 2005 to 2016) were analyzed retrospectively, and the chi-square test was used to compare and analyze the incidence.Results:Disease changes: ① The top three rheumatic diseases were Kawasaki disease (KD) (44.3%), Henoch-schoniein purpura (HSP) (35.4%), juvenile idiopathic arthritis (JIA)(9.6%). ② The number of all constitution of juvenile rheumatic diseases in hospital increased other than HSP. ③ The rheumatic diseases were increased from 17 to 37 kinds in the past 6 years. ④ The number of systemic lupus erythematosus (SLE) increased year by year (112/2 348 vs 197/3 602, χ2=1.41, P=0.235), as well as the severe SLE (35/112 vs 55/197, χ2=0.38, P=0.536). ⑤ The rate of rheumatic diseases complicated with macrophage activation (MAS) was 7.2‰(43/5 950). 12.9%(26/201) of systemic juvenile idiopathic arthritis(sJIA) were complicated with MAS, which was accounted for 60.5%(26/43) of total number of MAS in rheumatic diseases. In the last 6 years, there was a significant increase in the number of patients with MAS in patients with rheumatic diseases ( χ2=14.1, P<0.01) and sJIA( χ2=11.2, P<0.01). ⑥ 1.1%(64/5 950) of rheumatic diseases patients had lung lesions, juvenile dermatomyositis (JDM) accounted for 24.4%(20/82). In the last 6 years, the number of patients with lung lesions associated with rheumatic diseases increased significantly ( χ2=5.66, P=0.017). ⑦ The mortality rate of juvenile rheumatic diseases was only 3.7‰(22/5 950), and 45.5% occurred in SLE (10/22). The mortality rate of SLE decreased in last 6 years (5/112 vs 5/197, χ2=0.34, P=0.558). Conclusion:The constitution of juvenile rheumatic diseases in our center is decreasing for systemic vasculitis (KD, HSP), JIA, SLE, JDM in last 6 years. The annual total number of patients is relatively stable. But rare, difficult and critically illed cases increase year by year. Although SLE is still the primary cause of death in juvenile rheumatic diseases in recent 6 years, the mortality rate has decreased year by year.

Objective To study the effects of half marathon loading on the T2* mapping assessment of knee joint cartilage. Methods Twenty male amateur marathon runners with more than three years of running age were enrolled. The T1WI, PDWI, 3D?DESS, and T2*mapping were performed on right knee joint before and after the half marathon within 3h and after a period of approximately 1 week. Cartilage was divided into 6 regions: medial and lateral femoral cartilage, medial and lateral tibial cartilage and patella and trochlea cartilage. Femoral cartilage was partitioned into central weight?bearing regions, posterior cartilage nonweight?bearing regions with the posterior boundary of the meniscus as the dividing mark. All cartilage was further divided into deep and superficial layers according to the thickness 1/2, and the ROI was delineated to obtain the T2* value of the corresponding area. One?way repeated measures analysis was performed to test the difference of T2*values pre?and post?marathon. LSD tests were used to estimate the different influences of physiological activities on each articular cartilage area. Results All cartilage areas of the knee joint did not show cartilage injury during the examination. The differences in the global T2*values of the superficial layers of the knee cartilage before and after the half?marathon marathon were statistically significant (t=5.145, P<0.05), but the global T2*value of the deep region were not (t=1.864, P>0.05). After a week, the T2* values of all cartilage areas were not statistically different from those before running (t=1.062, 0.309; P>0.05). Conclusion After a single half marathon, the changes of knee cartilage composition in male amateur marathon runners are reversible. In the absence of positive findings in conventional MRI, T2* mapping can indirectly reflect changes in biochemical composition of the articular cartilage during exercise.

Objective To test the differences in diffusion properties?namely fractional anisotropy (FA) and apparent diffusion coefficient(ADC)?between amateur marathon runners and healthy volunteers′thigh muscles using diffusion tensor imaging (DTI) at rest. Methods Thirty amateur marathon runners(Group A) and 20 healthy volunteers (Group B) were recruited. All were males and their age was between 28 to 53 years. All subjects underwent both thigh DTI examination. DTI parameters FA and ADC were evaluated in thigh muscles(rectus femoris, vastus lateralis, vastus intermedius, vastus medialis, adductor longus, adductor magnus, biceps femoris long head, semitendinosus and semimembranosus)in all subjects. We tested the differences in diffusion properties between GroupA and B using independent sample t test. Results The average FA value of the thigh muscles measured in Group A was (0.24 ± 0.03), which was significantly lower than that in Group B=(0.27±0.03)(t=5.164,P<0.01). The average ADC value of the thigh muscles measured in Group A was (1.74±0.10)×10?3mm2/s, which was significantly higher than that in Group B=(1.70±0.09)×10?3mm2/s (t=2.060,P<0.05). The FA value of Group A was lower than that of Group B in the rectus femoris, vastus lateralis, vastus medialis, biceps femoris long head, semitendinosus and semimembranosus (P<0.05). The ADC value of Group A was higher than that of Group B in the vastus intermedius, vastus medialis and biceps femoris long head(P<0.05). Conclusions In the absence of positive findings from conventional MRI, DTI technique can non?invasively assess the subtle changes in the bilateral thigh muscles of amateur marathon runners at rest in the early stage of microscopic molecular level, providing important imaging evidence for early changes in skeletal muscle caused by marathon.

Objective: To study the effects of half marathon loading on the T₂* mapping assessment of knee joint cartilage. Methods: Twenty male amateur marathon runners with more than three years of running age were enrolled. The T₁WI, PDWI, 3D-DESS, and T₂* mapping were performed on right knee joint before and after the half marathon within 3h and after a period of approximately 1 week. Cartilage was divided into 6 regions: medial and lateral femoral cartilage, medial and lateral tibial cartilage and patella and trochlea cartilage. Femoral cartilage was partitioned into central weight-bearing regions, posterior cartilage nonweight-bearing regions with the posterior boundary of the meniscus as the dividing mark. All cartilage was further divided into deep and superficial layers according to the thickness 1/2, and the ROI was delineated to obtain the T₂* value of the corresponding area. One-way repeated measures analysis was performed to test the difference of T₂* values pre- and post-marathon. LSD tests were used to estimate the different influences of physiological activities on each articular cartilage area. Results: All cartilage areas of the knee joint did not show cartilage injury during the examination. The differences in the global T₂* values of the superficial layers of the knee cartilage before and after the half-marathon marathon were statistically significant (t=5.145, P<0.05), but the global T₂* value of the deep region were not (t=1.864, P>0.05). After a week, the T₂* values of all cartilage areas were not statistically different from those before running (t=1.062, 0.309; P>0.05). Conclusion After a single half marathon, the changes of knee cartilage composition in male amateur marathon runners are reversible. In the absence of positive findings in conventional MRI, T₂* mapping can indirectly reflect changes in biochemical composition of the articular cartilage during exercise.

Objective: To test the differences in diffusion properties-namely fractional anisotropy (FA) and apparent diffusion coefficient(ADC)-between amateur marathon runners and healthy volunteers′ thigh muscles using diffusion tensor imaging (DTI) at rest. Methods: Thirty amateur marathon runners(Group A) and 20 healthy volunteers (Group B) were recruited. All were males and their age was between 28 to 53 years. All subjects underwent both thigh DTI examination. DTI parameters FA and ADC were evaluated in thigh muscles(rectus femoris, vastus lateralis, vastus intermedius, vastus medialis, adductor longus, adductor magnus, biceps femoris long head, semitendinosus and semimembranosus)in all subjects. We tested the differences in diffusion properties between GroupA and B using independent sample t test. Results: The average FA value of the thigh muscles measured in Group A was (0.24±0.03), which was significantly lower than that in Group B=(0.27±0.03)(t=5.164,P<0.01). The average ADC value of the thigh muscles measured in Group A was (1.74±0.10)×10^-3mm²/s, which was significantly higher than that in Group B=(1.70±0.09)×10^-3mm²/s (t=2.060,P<0.05). The FA value of Group A was lower than that of Group B in the rectus femoris, vastus lateralis, vastus medialis, biceps femoris long head, semitendinosus and semimembranosus (P<0.05). The ADC value of Group A was higher than that of Group B in the vastus intermedius, vastus medialis and biceps femoris long head (P<0.05). Conclusions In the absence of positive findings from conventional MRI, DTI technique can non-invasively assess the subtle changes in the bilateral thigh muscles of amateur marathon runners at rest in the early stage of microscopic molecular level, providing important imaging evidence for early changes in skeletal muscle caused by marathon.

Objective To investigate the clinical effect and the prospect of Infliximab in treatment of intravenous immunoglobulin (IVIG)-resistant Kawasaki disease (KD) patients.Methods Clinical features,inflammatory markers and coronary changes were observed in 2 cases of IVIG-resistant KD patients hospitalized in Peking University First Hospital,who were treated effectively by Infliximab.Relevant researches on the mechanism and progress of the Infliximab treatment for IVIG-resistant KD in the last 10 years were reviewed at the same time.Results Two KD patients hospitalized in Peking University First Hospital had been treated with 2 g/kg IVIG for 2 times and followed by methylprednisolone treatment.However,fever and other clinical manifestations occurred again after 2 days and 6 days when temperature returned normal.They both defervesced and all the symptoms were improved after 1 dose of Infliximab (5 mg/kg) by laboratory examinations.Four published literatures of the basic research and 9 retrospective or prospective clinical researches of Infliximab treatment of KD showed that Infliximab alleviated the inflammatory level in the KD patients significantly.Complete remission was up to 72.73％-92.11％.Those KD patients defervesced within 12 h,with dramatic improvement of symptoms and signs.Arthralgia also disappeared in the patients with arthritis.Only 1 case was complicated with hepatitis in the acute phase and cholecystitis in recovery time.A phase 3 randomised,double-blinded,placebo-controlled trial had been done to assess the addition of Infliximab to the standard therapy.Conclusions Infliximab is a feasible choice for IVIG-resistant KD patients.Efficacy and safety of Infliximab for KD treatment have been proved in the literature.However,Infliximab for KD treatment has not been indicated in the drug instruction,so the informed consent from the guardians and Ethics Committee is needed.

Objective:To investigate the role of anaphylatoxin C 5 a in patients with asthma .Methods:A prospective study was performed between September 2006 and February 2007.A total of 33 patients with acute exacerbation of asthma and 13 healthy subjects were recruited into the study .The patients with acute exacerbation of asthma were also studied when they returned to the remission state .Levels of lung function, levels of C5a in induced sputum and cell differential count in induced sputum were determined . Results:The level of C5 a in induced sputum was significantly higher in patients with acute exacerbation of asthma [0.85(0.68-2.13) μg/L] than that in patients with stable asthma [0.45(0.26-0.88)μg/L, Z=-2.193, P=0.013];Sputum C5a levels in stable asthma patients were significantly higher than those in healthy controls [0.14(0.06-0.45) μg/L, Z=-2.141, P=0.015].The level of C5a in patients with severe exacerbation [2.21(1.27 -9.0) μg/L] was significantly higher than those in patients with mild exacerbation [0.34(0.17-0.63) μg/L] and moderate exacerbation [0.85(0.55-1.67) μg/L,χ2 =12.330, P=0.001].The level of C5a in induced sputum was positively correlated with the number of total cells count (r=0.797, P=0.004), neutrophils (r=0.504, P=0.032) and macrophages ( r =0.424, P=0.036 ) in acute exacerbation of asthma .Conclusion: C5a levels in induced sputum could be identified as an important prognostic biomarker , which involved in asthma ’ s pathogenesis .

Objective To investigate the clinical significance of anaphylatoxin C3a in induced sputum in patients with asthma. Methods The patients with acute exacerbation of asthma treated at our department between September, 2006 and February, 2007 were included in the study. The demographic data, medical history, levels of lung function and C3a levels in induced sputum were assessed. Results A total of 33 patients were included in the study. The level of C3a in induced sputum was significantly higher in patients with acute exacerbation of asthma (2.24 ng/ml, range 1.68-5.58 ng/ml) than that in patients with asthma remission (0.7 ng/ml, range 0.24-2.31 ng/ml, P<0.05). Sputum C3a levels in the remission patients were significantly higher than those in the healthy controls (0.12 ng/ml, range 0.07-0.39 ng/ml, P<0.05). The levels of C3a in patients with severe exacerbation (4.69 ng/ml, range 2.69-6.59 ng/ml) were significantly higher than those in patients with mild exacerbation (0.25 ng/ml, range 0.09-0.40 ng/ml) and moderate exacerbation (2.21 ng/ml, range 1.16-3.41 ng/ml) (P<0.01), and were significantly higher in patients with moderate exacerbation than in those in mild exacerbation (P<0.01). The level of C3a in induced sputum was positively correlated with the number of total cell count (r=0.718, P<0.05), eosinophils (r=0.495, P<0.05) and macrophages (r=0.600, P<0.05) in patients with acute exacerbation of asthma. Conclusion Induced sputum C3a level can serve as an important clinical biomarker for clinical asthma management.