BACKGROUND:Traditional imaging examinations have lower sensitivity in diagnosing articular cartilage injury, and the effects of biomarkers in body fluid on diagnosing severity of cartilage injury should be evaluated.OBJECTIVE: To investigate the significance of the biomarkers, including cartilage oligomeric matrix protein (COMP), matrix metalloproteinases-1 (MMP-1), matrix metalloproteinases-3 (MMP-3) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), in serum and synovial fluid in evaluating the early sports injury of articular cartilage.DESIGN: A randomized controlled trial.SETTING: the 105 Central Hospital of Chinese PLA.MATERIALS: Eighteen adult male hybrid dogs (15-25 kg, average 22.5 kg) were divided into three groups randomly: ①plain-running group (n =8): the dogs ran on the plain; ② slope-running group (n =8): the dogs ran on the slope of 10°; ③control group (n =2): the dogs could move freely.METHODS: Dogs in the plain-running group and slope-running group were trained daily, rurning for an hour in the morning and in the afternoon respectively(total two hours per day), 4 m/s, and the training lasted for 10 weeks. Serum and synovial fluid were collected on the dayof training, and at the 2nd, 4th, 8th and 10th weeks respectively in both the plain-running group and slope-running group, and the concentrations of COMP,MMP-1, MMP-3, TIMP-1 were detected with ELISA. Standard curves were built by the standard concentrations and A values, according to which corresponding concentrations of specimens were obtained. Knee joint MRI examination was performed, and the training was canceled on the day of examination. All the dogs were killed after 10 weeks, and the knee joint cartilages weight loading region of femur condyles were observed histologically.MAIN OUTCOME MEASURES: Concentrations of COMP, MMP-1, MMP-3, TIMP-1 in serum and synovial fluid on the day of training, and the 2, 4, 6, 8 and 10 weeks in each group; Results of MRI examination of knee joint; Results of the histological observation of knee joint cartilage after 10 weeks.RESULTS: All the 18 dogs were involved in the analysis of results. ① Results of examination in serum. ② Results of examination in synovial fluid: In the slope-running group, the COMP concentrations at 2, 4, 6, 8 and 10 weeks were obviously higher than those in the plain-running group (P ＜ 0.01), MMP-1 concentration at 2, 4 and 6 weeks were higher than those in the plain-running group (P ＜ 0.05-0.01), MMP-3 concentrations at 2, 4, 6 and 8 weeks were higher than those in the plain-running group (P ＜ 0.01);The MMP-3/TIMP-1 ratios at 2, 4 and 8 weeks were higher than those in the plain-running group(P ＜ 0.05-0.01).③ The concentrations of COMP,MMP-1,MMP-3 and TIMP-1 and the MMP-3/TIMP-1 ratio in serum were significantly correlated with the corresponding biomarkers in synovial fluid (r =0.631,0.502, 0.748, 0.651, 0.667, P＜ 0.01). ④ Results of histological observations: In both the plain-running group and slope-running group, obvious pathological changes of articular cartilage injury were observed at 10 weeks, the activity of articular chondrocytes in the surface layer was obviously decreased, which was severer in the latter group than in the former one. ⑤Results of MRI examination: Early sports injury changes of knee joint appeared at 2 weeks, and progressive aggravation occurred in both the plain-running group and slope-running group.CONCLUSION: Repetitive, impacted, torsional, shearing motions with long time and great intensity are easy to induce sports injury,even osteoarthritis.The sensitivity of these biomarkers is better than MRI in reflecting the pathological changes of articular cartilage.

Objective To explore the significance of such biological markers as cartilage oligomeric matrix protein (COMP), matrix metalloproteinases-1(MMP-1), matrix metalloproteinases-3 (MMP-3) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) in serum and synovial fluid to evaluate early motional injury on knee joint cartilage induced by different modes of training. Methods Twenty adult dogs were randomly divided into three groups, i.e. common training group (n=8), short intensified training group (n=8) and control group (n=4). Magnetic resonance imaging (MRI) examinations were performed regularly (0, 2, 4, 6, 8, 10 weeks) to investigate the changes in the knee joint cartilage, while the concentrations of COMP, MMP-1, MMP-3 and TIMP-1 in serum and synovial fluid were measured by ELISA. Results It was revealed by MRI that the motional injury to knee joint cartilage occurred both in common training group and short intensified training group 2 weeks after training with different intensity, with severest injury occurring during 4~6 weeks after training, and then subsided gradually. The concentrations of COMP, MMP-1, MMP-3, TIMP-1 and MMP-3/TIMP-1 in serum and synovial fluid elevated in various degrees during training period with the lapse of time. Generally, the concentrations of MMP-1, MMP-3 and MMP-3/TIMP-1 in short intensified training group were lower, while that of COMP was higher, than that in common training group. The results suggested that the possibility of incurring articular injury in short intensified training group was lower than that in common training group, while the possibility of repairing the injury was on the contrary. Furthermore, the changes in levels of biomarkers in both serum and synovial fluid showed a close correlation. Conclusions Intensified training may result in moulding reconstruction better than the common training did. A combined determination of several biomarkers could be more sensitive than MRI examination on predicting the injury and repair of articular cartilage and on monitoring the course of illness. Therefore they are valuable for clinical application.

As a high-throughout technique after DNA chips in biomedical research, protein arrays are developing, with high sensitivity and veracity. They have drawn increasing attention because they can provide a new technological platform for life science studies. There has been no effective diagnosis instrument for common articular cartilage injuries when they are at an initial stage, but when the disorders progress into an advanced stage, visible functional disturbances often arise. Protein arrays may offer a solution to the lasting tough problem in orthopaedic field. In this paper, we review the development and research of protein arrays, the regulation of proteins, their biochemical functions and their potential interaction partners, as well as changes of cartilage biomarkers in body fluid after injury. In addition, the feasibility and rationality of using protein microarrays for diagnosing early articular cartilage injuries are discussed.

Objective To study the adaptation process and extent of changes in articular cartilage in the canine knee joint to the intensified training, in order to elucidate the influence of different movement training on remodeling and reconstruction of articular cartilage. Methods Twenty adult dogs were randomly divided into three groups. Eight dogs were assigned to the short training group, and they were allowed to run on a slope of 10? with the speed of 200m/min. Eight dogs were assigned to short intensified training group, and they were allowed to run on a slope of 10? with a speed of 300m/min. Four dogs served as controls, and they were allowed to have unrestricted activity in the cage. Dogs in training group and intensified group were asked to, run for an hour both in the morning and in the afternoon every day (tolally two hours per day). The training lasted for ten weeks. All the dogs were euthanized after ten weeks, and all the knee joints were harvested and examined histologically. Results Histological examination after ten weeks of exereises demonstrated that the signs of cartilage damage and repair were obvious in canine knee joint in training group and intensified group. Remodeling process was better promoted in the intensified group compared with training group, but there was no significant difference in Mankin score between these two groups. Conclusion Movements for a long time with great intensity are prone to induce sport injury. It is followed by repair process. Intensified training promotes a better remodeling reconstruction of articular cartilage than ordinary training.

Objective To establish clinical diagnostic criteria for zero-stage non-traumatic osteonecrosis of femoral head,and then to check the accuracy and value of the criteria in clinical application through combined intervention therapy including the administration of traditional Chinese medicine and physical therapy.Methods The clinical data of 258 patients suffering from non-traumatic osteonecrosis of femoral head were retrospectively analyzed.Clinical diagnostic criteria for zero-stage non-traumatic osteonecrosis of femoral head were established based on the analysis.Then a clinical comparative study concerning the criteria was performed,so as to verify its authority.Results The established criteria were proved to be satisfactory.The sensitivity,specificity and accuracy of the criteria were 93.7%,86.4% and 89.7%,respectively.The clinical comparative study showed that the prevalence of non-traumatic osteonecrosis of femoral head in the intervention group(34.2%)was obviously lower than that of the non-intervention group(84.9%,P

Objective To investigate the serum level of free fatty acid (FFA) and explore its relationship with cytokines and atherosclerosis (AS) in chronic kidney disease (CKD).Methods The serum level of FFA was determined with enzymatic colorimetry.IL-1 β, IL-6 and TNFα were determined with ELISA.High-sensitivity C-reactive protein (hsCRP) was measured with immunoturbidimetry.Prevalence of atherosclerosis was detected with carotid ultrasonography.We evaluated the relationship between serum levels of FFA and IL-1β,IL-6, TNFα, hsCRP as well as the renal function in 130 adult patients with CKD, stratified according to the GFR ( based on the National Kidney Foundation/Kidney Dialysis Outcomes Quality Initiatives) and in 58 hemodialytic (HD) patients.The relationship between FFA level and cardiac geometry incidence in CKD patients was analyzed with logistic regression model.Results The serum level of FFA was significantly higher in CKD patients as compared with that in the healthy controls [(492.63 ± 143.59)vs (302.65 ± 142.18) μ mol/L, P ＜ 0.01], even in the early stage of CKD.The level of FFA increased with the progression of renal dysfunction.In the non-dialytic CKD group, the level of FFA was negatively related to GFR and positively related to the proteinuria (P ＜ 0.05), while in the HD group, it was positively correlated with dialysis duration ( P ＜ 0.05 ).The serum levels of FFA were higher in CKD patients with carotid artery atherosclerosis than those in patients without ( P ＜ 0.05 or ＜ 0.01 ).However, in both groups with impairment of renal function, the levels of FFA were positively correlated with hsCRP, IL-1 β, IL-6,TNFα and TG( all P ＜ 0.05 ).A positive correlation between the level of FFA and the clinical manifestations such as carotid intimal medial thickness (IMT) and AS was also found.A negative correlation was found between the level of FFA and the serum level of albumin and GFR( P ＜ 0.05).Conclusion Serum levels of FFA are significantly higher either in non-dialytic CKD or in HD patients and it is related with hsCRP, IL-1 β, IL-6, TNFα as well as carotid artery atherosclerosis, indicating that FFA is an independent risk factor of AS in CKD.

Objective To investigate the effects of levocarnitine combined with urimetazidine on left ventricular remodeling in maintenance hemodialysis(MHD)patients.Methods All of 86 MHD patients and 40 healthy volunteers(health control group)were involved in the study.all of 86 MHD patients were randomly divided into two groups,disease treatment group(46 cases)and disease control group(40 cases),who had undergone hemodialysis for at least 3 months before the study and were in a stable clinical status without signs of infection or disease activity.In disease treatment group,1.0 g of levocarnitine was infused at the end of each dialysis treatment and 20 mg of trimetazidine was taken orally 3 times each day for 6 months,while the parameters for free fatty acid(FFA),free carnitine(FC),inflammation and oxidative stress were studied before and after the treatmenL In disease control group these two drugs were not used.The left ventricular end-diastolic diameter(LVDd),left ventricuhr end-systolic diameter(LVDs),left atrial diameter (LAD),left ventricular posterior wall thickness(LVPWT),interventricular septal thickness(IVST)and left ventricular ejection fraction(LVEF)were detected by ultrasonic cardiography.Results Before treatment,the serum levels of FFA,high-sensitivity C-reactive protein(hs-CRP),intedeukin(IL)-1β,IL-6,tumor necrosis factor(TNF)-αand malondialdehyde(MDA)were higher in disease treatment group and disease control group than those in health control group(P<0.05 or<0.01),while the serum levels of FC,glutathione peroxidase(GSHPx)and superoxide dismutase(SOD)were lower in disease treatment group and disease control group than those in health control group(P<0.05 or<0.01).Compared with those before treatment,the serum levels of FFA,hs-CRP,IL-1β,IL-6,TNF-α,MDA were decreased(P<0.05 or<0.01),FC,GSHPx,SOD were increased(P<0.05 or<0101),the scores of LVDd,LAD,IVST,LVPWT,LVMI were also decreased significantly(P<0.05),while LVEF increased markedly after treatmem in disease treatment group(P<0.05).There were significant differences in all indexes between disease treatment group and disease control group(P<0.05 or<0.01).Conclusion Supplements of levocarnitine combined with trimetazidine in MHD patients appear to be associated with an improvement of left ventricular remodeling.

Objective To investigate the serum cystatin C (CysC) level and explore its relationship with cytokines and atherosclerosis (AS) in maintenance hemodialysis (MHD) patients.Methods A total of 110 stable MHD patients undergoing hemodialysis for at least six months and 60 healthy control people were enrolled in the study.Serum levels of CysC and high-sensitivity Creactive protein (hsCRP) were measured by immunoturbidimetry.The serum levels of total homocysteine (tHcy),IL-1β,IL-6 and TNF-α were determined by ELISA.Prevalence of atherosclerosis was detected by carotid ultrasonography.The relationship of CysC level and cardiac geometry incidence in MHD patients was analyzed by Logistic regression model.Results The serum CysC level was significantly higher in MHD patients as compared with healthy controls [(6.19±0.95) mg/L vs (0.76±0.21) mg/L,P＜0.01],and the serum levels of hsCRP,tHcy,IL-1β,IL-6,TNF-α were significantly higher in MHD patients than those in healthy control group (P＜0.05 or P＜0.01).The serum CysC level was higher in MHD patients with carotid artery atherosclerosis compared to patients without carotid artery atherosclerosis (P＜0.05).CysC was positively correlated with hsCRP,tHcy,IL-1β,IL-6,TNF-α respectively (P＜0.05 or P＜O.01),and was positively correlated with carotid intimal medial thickness (IMT) and AS.Besides,a negative correlation was found between the serum CysC level and the serum albumin level (P＜0.05),while CysC was positively correlated with dialysis duration,systolic pressure and iPTH (P ＜0.05).Conclusion Serum CysC level is significantly higher in MHD patients and is correlated with hsCRP,tHcy,IL-1β,IL-6,TNF-α as well as carotid artery atherosclerosis,which indicates that CysC is an independent risk factor of AS in MHD patients.

Objective To investigate the effect of L-carnitine on pathological changes of myocardium and the underlying mechanism in chronic renal failure rats (CRF). Methods A total of 55 male SD rats were randomly divided into sham group (n=10),model group (n=15),low dose (300 mg/kg),medium dose (600 mg/kg) and high dose (900 mg/kg) L-carnitine group(n=10,each).5/6 subtotal nephrectomy was performed in these rats without sham group.One week after the operation,normal saline or corresponding dose L-carnitine were intragastrically administrated to sham and model group or L-carnitine groups for 17 weeks.Transthoracic echocardiography,mean arterial pressure (MAP),heart rate (HR) and heart weight/body weight were assessed.Moreover,24h urine protein,renal function,SOD,MDA,IL-6,ATP,ADP were measured at the end of the study.Additionally,pathological changes in myocardium were detected by light microscope and transmission electron microscope. Results (1) ATP (μmol/g·wt)in L-carnitine groups (2.35±0.24,3.59±0.28,3.78±0.25) was significantly higher than that in model group (1.61±0.12) (all P＜0.01).(2) Thickness of posterior wall of left ventricle (mm) in high dose L-carnitine group was thinner than that in model group (3.74±0.23 vs 4.18±0.48,P＜0.05). (3) The ratios of heart weight to body weight in both medium dose and high dose L-carnitine groups (3.92±0.27,3.65±0.2) were significantly lower compared to model group (3.99±0.27) (all P＜0.01). (4) Under light microscopy,disarrangement and hypertrophy of cardiac myocytes,increased myocardial fibrosis were observed in model group, while these changes and the pathological scores were significantly improved in both medium dose and high dose L-carnitine groups (7.14±1.07,6.13±0.99),as compared with model group (9.88±1.13) (all P＜0.01).Under electron microscopy,typical changes in cardiac hypertrophy were observed,including dissolution of myocardial fibers,increasing and swelling of mitochondria,membrane rupture as well as matrix increase in model group,while these changes were ameliorated by L-carnitine in a dose-dependent manner. (5) Seventeen weeks after the treatment,both IL-6 and MDA were decreased in all L-carnitine-treated groups than those in model group [IL-6 (ng/L):261.86±13.18,240.12±18.7,233.34±36.88 vs 596.64±81.41; MDA (nmol/L):15.23±2.01,12.41±0.6.10.97±1.9 vs 21.84±2.71).Whereas,SOD (U/ml) were increased in L-carnitine-treated groups (51.2±6.11,58.51±5.52,60.63±6.94) than that in model group(32.01 ±5.69 )(all P＜0.05).(6) No significant differences of systolic,diastolic blood pressure or MAP were found among groups. Conclusion L-carnitine can improve energy metabolism,micro-inflammation and oxidative stress in myocardium of CRF rats,which may be associated with the amelioration of cardiac hypertrophy and fibrosis.

Objective To determine the effects of trimetazidine (TMZ) on pathology and energy metabolism of myocardium in chronic renal failure(CRF) rats.Methods CRF models were built in Sprague-Dawley (SD) rats with 5/6 subtotal nephrectomy, and animals were randomyly divided into sham group, control group and three groups treated with different doses of TMZ (3 mg/kg,6 mg/kg or 9 mg/kg).TMZ was intragastrically administrated to CRF rats for 17 weeks, while physiologicalsalinewasusedascontrol. Transthoracicechocardiographywasperformedand myocardial morphosis was observed.Left ventricular weight/body weight(LVW/BW) and heart weight/body weight (HW/BW) were measured, and heart rate, and mean arterial pressure (MAP)were detected at the end of the study, while several parameters were detected, including urea nitrogen (BUN), creatinine(Scr), triphosaden(ATP), adenosine diphosphate(ADP), superoxide dismutase (SOD), malondialdehyde (MDA), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α).Results (l)Left ventricle end-systolic dimensions, anterior wall end-diastolic and end-systolic thicknesses, and posterior wall end-diastolic thickness were significantly lower in rats treated with either medium dose or high dose of TMZ, as compared with control group(P＜0.05).(2)LVW/BW and HW/BW in rats treated with either medium dose or high dose of TMZ were significantly lower than those in control group(P＜0.05). (3)Various pathological changes were observed in control group, such as irregular arrangement and hypertrophy of the cardiomyocytes, myocardial fibrosis,mitochondrial swelling, focal muscle fiber dissolution, etc.However, all these pathological changes were apparently ameliorated in TMZ-treated groups, while the beneficial effects of TMZ therapy were dose-dependent. (4)No difference was observed in heart rate among all the groups.Although no difference existed in all the CRF rats, concerning on the systolic/diastolic blood pressure and mean arterial pressure (P＞0.05), these parameters were elevated in CRF rats, as compared with sham-operated group(P＜0.01). (5)ATP and ADP in TMZ-treated rats were significantly higher as compared with control(P＜0.05), moreover, medium dose and high dose of TMZ were superior to low dose (P＜0.05).(6)SOD was significantly increased in TMZ-treated rats (P＜0.05), while IL-6,TNF-α and MDA were significantly decreased in medium dose and high dose of TMZ, as compared with control(P＜0.05).Conclusion TMZ may prevent myocardial fibrosis and left ventricular hypertrophy in chronic renal failure via ameliorating myocardial energy metabolism and alleviating inflammatory reaction and oxidative stress.