Inflamed Knee Research Articles

Thermal and Visual Imaging to Assist with Juvenile Idiopathic Arthritis Examination of the Knees

Juvenile idiopathic arthritis (JIA) causes inflammation of the joints, and it is frequently associated with their pain and stiffness. Its timely diagnosis is important to avoid its progressive damage to the bones and cartilage. Increases in the joint’s temperature and redness could be indicators of active JIA, hence their accurate quantification could assist with diagnosis. Thermal and visual images of the knees in 20 JIA participants (age: mean = 11.2 years, standard deviation = 2.3 years) were studied. The median temperature of knees with active inflammation was 3.198% higher than that of inactive knees. This difference, examined by a Wilcoxon signed-rank test, was statistically significant (p = 0.0078). In six out of the eight participants who had one active inflamed knee, thermal imaging identified the corresponding knee as warmer. In 16 out of 20 participants, the knee identified as warmer by thermal imaging was also identified as having a greater colour change by visual imaging as compared to their respective reference regions. The devised methods could accurately quantify the colour and temperature of the knees. It was concluded that thermal and visual imaging methods can be valuable in examining JIA. Further studies involving a larger number of participants and more detailed explorations would be needed prior to clinical application.

The two faces of the same medal… or maybe not? Comparing osteoarthritis and calcium pyrophosphate deposition disease: a laboratory and ultrasonographic study.

Osteoarthritis (OA) and calcium pyrophosphate deposition disease (CPPD) are frequently associated but the real relation between these diseases is not still understood. The aim of this paper is to investigate the characteristics in terms of inflammation, anatomical changes and synovial fluid (SF) features in knees of patients with OA and CPPD. Consecutive patients older than 55 years with knee pain and swelling were enrolled. All patients underwent a complete clinical examination, a US examination of the affected joint, arthrocentesis of the knee and analysis of synovial fluid, including dosing of inorganic ions and number of crystals. The gold standard for the diagnosis was the microscopic analysis of the SF. Sixty-seven patients were enrolled, 25 affected by OA and 42 by CPPD. At US, a significantly higher amount of effusion and synovitis was identified in patients with CPPD but there were no significant differences regarding structural changes. At the SF analysis, the white blood cell (WBC) count was higher in patients with CPPD who also presented a higher number of polymorphonuclear cells and a lower number of monocytes. Regarding the inorganic ion concentration, the statistical analysis did not reveal any differences. The number of crystals in the SF, correlated with a larger effusion, higher grade of synovitis and a higher WBC count. A higher degree of inflammation was found in patients with CPPD. The findings suggest that longitudinal studies would be useful to better understand the evolution of the diseases and highlight the need for different treatment strategies.

Effect of knee aspiration and intra-articular corticosteroid injection on gait biomechanics, strength, and patient-reported outcomes in patients with knee osteoarthritis

Purpose: Synovial inflammation is associated with pain and disease progression in knee OA and may adversely affect joint biomechanics. The presence of knee inflammation is associated with quadriceps avoidance gait (decreased external knee flexion moment) and decreased quadriceps and hamstring strength. The effect of decreasing knee inflammation on gait biomechanics and strength is unknown. Here, we investigate the effects of inflammation on gait biomechanics in patients with knee OA and inflammation on ultrasound (US), testing the effects of knee aspiration and intra-articular corticosteroid injection on gait, strength, and clinical outcomes. Methods: Forty-five patients with knee OA, synovitis and effusion underwent US, gait biomechanics and strength assessments, and completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), before and 3 weeks after receiving a knee aspiration and 40 mg triamcinolone injection under US guidance (Table 1). Ultrasound assessments were performed by a Canadian Rheumatology Ultrasound Society (CRUS) trained examiner using a 12 Hz linear probe. The suprapatellar recess was scanned in the long axis view medially, laterally and in the midline with the knee flexed to 30o. All US exams were graded using previously validated OMERACT grading criteria for synovitis, synovial hyperplasia, effusion, and power Doppler (6-point scale). Three-dimensional quantitative gait analysis was completed using a 12-camera motion capture system and floor mounted force plate and used to calculate knee angles and moments during walking. Strength testing was completed using an isokinetic dynamometer. Patients completed three maximal knee extension and flexion trials at 90 degrees per second. US, gait and strength tests were completed by the same examiner. Paired t-tests were used to assess mean differences in gait, strength and KOOS scores. Results: There was a significant (p < 0.05) increase in external knee flexion moment [mean change (95%CI)]: 0.32 %BW*ht (0.07, 0.57), peak quadriceps strength [5.95 Nm (0.99, 10.91)], and peak hamstring strength [4.03 Nm (0.56, 7.51)] 3 weeks after injection. There were significant (p < 0.05) improvements in US composite scores [-0.86 (-1.30, -0.42)], and KOOS Subscales for Symptoms [6.16 (1.63, 10.69)], Pain [6.43 (1.17, 11.69)], Function in Daily Living [5.61 (0.80, 10.42)] and Function in Sport and Recreation [9.37 (0.56, 18.18)]. There were no other significant changes in gait (Table 2). Conclusions: Patients undergoing aspiration and injection for knee synovitis and effusion experience increased knee flexion moments during walking and increased maximal quadriceps and hamstring strength. These results suggest a link between inflammation and joint biomechanics in patients with knee OA; interventions that induce changes in knee inflammation detectable by US can improve knee biomechanics during walking.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Synovial inflammation in anterior cruciate ligament injury knees in mice: surgical vs non-surgical models

Purpose: Anterior-cruciate-ligament (ACL) rupture is one of the most common knee injuries, resulting in pain, disability, and increased risk of developing OA. However, only ∼50% of individuals with ACL rupture develop OA, and the factors underlying this variable risk remain unclear. Changes in joint stability as a result of ACL deficiency drive mechanobiological dysfunction and the development of OA. However, specific factors are known to increase OA risk such as concurrent injury to the meniscus, cartilage, and subchondral bone. Also, the degree of initial joint inflammation and its resolution are implicated in long-term outcomes. Surgical and nonsurgical models of ACL rupture in mice result in similar joint instability but distinct risks or trajectories of OA. We used these two models to investigate if differences in synovial inflammatory response are associated with this risk of OA disease progression Methods: Ten-week-old, male C57BL/6 mice were randomly assigned to ACL transection (ACLT), ACL rupture (ACLR), sham-surgery or uninjured groups. Mice in the ACLT and sham-operated groups were subjected to anaesthesia, right unilateral medial arthrotomy, patella luxation, and fat-pad elevation to visualise the ACL, at which time the surgeon was informed to transect or spare the ACL before joint closure. Uninjured and ACLR animals were anaesthetised, the latter having a single compressive load (9-12N) to posteriorly displace the femur and traumatically rupture the ACL. Animals were housed in mixed injury groups (up to 5/cage) and allowed unrestricted activity. At 1, 2, 4 and 8 weeks post-injury, mice were euthanised and joints harvested for fixation, paraffin embedding, sectioning and OA histopathology scoring (n=7/group/timepoint); or synovial tissue (en bloc fat-pad, synovial lining and joint capsule anterior to the collateral ligaments) isolation for RNA extraction and quantitative RT-PCR analysis of cytokines (IL1, IL6, TNF), inflammatory cell markers (CD11b, CD4, CD8), and enzymes implicated in OA pathophysiology (ADAMTS4, ADAMTS5, MMP3, MMP9, MMP13) (n=6/group/time point). Results: ACL injury resulted in progressive OA pathology with cartilage pathology significantly greater in ACLR compared with ACLT at 2 and 4 weeks (p<0.001), but by 8 weeks was equivalent in the two models; posterior osteochondral erosion significantly worse in ACLR than ACLT at 4 and 8 weeks (p<0.01); and osteophyte size (p<0.001) and maturity (p<0.01) greater at 1 and 2 weels in ACLR compared with ACLT. Synovitis was increased acutely in both ACL-injuries and then decreased with time, with ACLT>ACLR (p=0.003) at week-1 but similar thereafter; both still greater than uninjured joints through to week 8 (p<0.001). Sham and ACLT had similar synovitis scores until week 8 when the latter was more severe. Despite histomorphological similarities in synovitis in ACLT and ACLR, there were differences in gene expression patterns. Synovial expression of TNF, CD11b and CD8 was unchanged at any time when comparing between groups. Surgery alone (ACLT and Sham) increased synovial IL6 (week-1: ACLT p=0.02, Sham p<0.001 vs uninjured) while ACLR did not. While CD4 was also increased by surgery (week-1 and -2: ACLT p<0.01, Sham p<0.05 vs uninjured), it was also increased in ACLR versus uninjured at these times (p<0.05; Figure 1). ADAMTS5 expression was not detected in synovial tissue, and MMP9 mRNA did not differ between groups. In contrast, ADAMTS4, MMP3, and MMP13 expression were increased by surgery (ACLT/Sham) and ACLR at week-1 and -2 compared with uninjured joint, although both surgeries>ACLR (Table 1). Conclusions: While both models caused joint instability, OA trajectory and ultimate severity were greater in ACLR. In contrast, surgery induced greater histo-pathological synovitis acutely but was similar in both injuries thereafter. There was a difference in the “phenotype” of the synovial inflammation in the two injury models. In ACLT there was upregulation of IL6 not evident in ACLR but similar to Sham, suggesting this was a response to surgery and wound healing. While helper T-cell (CD4) increase was greater in ACLT and Sham, this also occurred in ACLR suggesting a role of adaptive immunity in OA after nonsurgical injury. Expression of ADAMTS4, MMP3 and MMP13 were similarly increased acutely in both injury models, suggesting synovial tissues as a source of these enzymes implicated in the structural pathology of OA. While their expression was not correlated with ultimate pathological severity they may be broad-spectrum target across varying phenotypes of post-traumatic OA. Our data suggest that synovitis severity per se was not associated with differential OA risk with ACL injury; it likely still contributes to long-term OA structural pathology.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Reliability and sensitivity to change of bone marrow lesion scores using the knee inflammation MRI scoring system (KIMRISS) before and after high tibial osteotomy

Purpose: Bone marrow lesions (BMLs) are an important feature of knee osteoarthritis (OA) and are associated with increased risk of cartilage damage and pain. The Knee Inflammation MRI Scoring System (KIMRISS) is a semi-quantitative grading tool used to evaluate measures of inflammation in patients with knee OA. The KIMRISS allows for readers to record scoring decisions in a rapid manner, on a convenient web-based interface. The objectives of this study were to investigate: 1. Inter-rater reliability of KIMRISS BML scores including expert readers and a trainee reader, and 2.

Effect of phenolic compounds from Oenothera rosea on the kaolin-carrageenan induced arthritis model in mice

Ethnopharmacological relevanceOenothera rosea (Onagraceae), commonly known as “hierba del golpe” in Mexico, is an herbaceous plant widely used in Mexican traditional medicine for the treatment of pain and inflammation. Aim of the studyThe aim of this study was to assess the effect of extracts and compounds isolated from O. rosea in kaolin-carrageenan induced arthritis. Materials and methodsHydroalcoholic extract from aerial parts of O. rosea was obtained and chemically separated in order to obtain OrEA and isolated compounds using column chromatography, HPLC, UPLC and NMR analysis. O. rosea extract and derivatives were tested on the kaolin/carrageenan (K/C) induced arthritis model on ICR mice. Knee inflammation and paw withdrawal threshold were assessed following intraarticular administration of kaolin and carrageenan (4% and 2%, respectively) and subsequent oral administration of O. rosea. TNF-α, IL-1β, IL-6 and IL-10 levels from synovial capsule were measured using ELISA kits. NF-κB activity was also measured using the RAWBlue™ cell line. Finally, spleen and lungs were dissected to investigate body index. ResultsOral administration of the O. rosea ethyl acetate fraction (25, 50 and 100 mg/kg) and isolated compounds (2 mg/kg) reduced the edema induced by kaolin/carrageenan, similar to the effect of methotrexate (1 mg/kg). Hyperalgesia but not allodynia was observed during this experiment. O. rosea derivatives reduced this behavior. The quantification of cytokines showed a reduction in TNF-α, IL-1β and IL-6, as well as an increase of IL-10. NF-κB production was also reduced by administering O. rosea derivatives. Chemical analysis of O. rosea derivatives showed that the major compounds present in the ethyl acetate fraction were phenolic compounds. Gallic acid, quercetin glucoside and quercetin rhamnoside were separated and identified by UPLC-UV-MS, and myricetin glycoside and tamarixetin glucoside using 1H and 13C NMR. ConclusionsO. rosea produces different phenolic compounds capable of reducing the inflammation and secondary mechanical hyperalgesia produced by K/C administration. They also reduced proinflammatory cytokines and increased anti-inflammatory cytokines. Finally, NF-κB modulation was reduced by the administration of O. rosea. Therefore, O. rosea could be considered of interest in inflammatory and painful diseases.

Anti-inflammatory and anti-arthritic activity in extract from the leaves of Eriobotrya japonica.

The Eriobotrya japonica (EJ) is a Chinese medicinal plant that is currently grown in Brazil. E. japonica leaves infusion is traditionally used in the treatment of inflammation; however, there are few scientific studies showing the effects of these properties on joint articular and persistent experimental inflammation. The present research had objective investigation of the effect of infusion obtained from leaves of E. japonica (EJLE) on acute and persistent experimental articular inflammation. The Swiss mice were treated orally with EJLE and analyzed for acute pleural inflammation (30, 100, and 300mg/kg), paw edema induced by carrageenan (100mg/kg), acute knee inflammation induced by zymosan (100mg/kg), and persistent inflammation induced by Complete Freund's Adjuvant (CFA) (30 and 100mg/kg). Mechanical hyperalgesia, cold and edema were analyzed. The chromatographic analysis of EJLE revealed the presence of corosolic acid, oleanolic acid, and ursolic acid. EJLE presented anti-inflammatory activity in the pleurisy model, inhibiting leukocyte migration, protein extravasation and nitric oxide production. In the articular inflammation model, EJLE reduced the number of leukocytes in the joint cavity, paw edema and hyperalgesia (4h after induction). In the persistent inflammation model induced by CFA, the extract reduced paw edema after 11 days of mechanical and cold hyperalgesia on day 6. The EJLE has anti-inflammatory and antihyperalgesic potential in models of acute and persistent experimental articular inflammation, making this infusion a new possibility for complementary treating acute or chronic articular inflammatory diseases.

T1\u03c1-mapping for assessing knee joint cartilage in children with juvenile idiopathic arthritis \u2014 feasibility and repeatability

BackgroundOngoing arthritis in children with juvenile idiopathic arthritis (JIA) can result in cartilage damage.ObjectiveTo study the feasibility and repeatability of T1ρ for assessing knee cartilage in JIA and also to describe T1ρ values and study correlation between T1ρ and conventional MRI scores for disease activity.Materials and methodsThirteen children with JIA or suspected JIA underwent 3-tesla (T) knee MRI that included conventional sequences and a T1ρ sequence. Segmentation of knee cartilage was carried out on T1ρ images. We used intraclass correlation coefficient to study the repeatability of segmentation in a subset of five children. We used the juvenile arthritis MRI scoring system to discriminate inflamed from non-inflamed knees. The Mann-Whitney U and Spearman correlation compared T1ρ between children with and without arthritis on MRI and correlated T1ρ with the juvenile arthritis MRI score.ResultsAll children successfully completed the MRI examination. No images were excluded because of poor quality. Repeatability of T1ρ measurement had an intraclass correlation coefficient (ICC) of 0.99 (P<0.001). We observed no structural cartilage damage and found no differences in T1ρ between children with (n=7) and without (n=6) inflamed knees (37.8 ms vs. 31.7 ms, P=0.20). However, we observed a moderate correlation between T1ρ values and the juvenile arthritis MRI synovitis score (r=0.59, P=0.04).ConclusionThis pilot study suggests that T1ρ is a feasible and repeatable quantitative imaging technique in children. T1ρ values were associated with the juvenile arthritis MRI synovitis score.

Sex differences in the relationship between individual systemic markers of inflammation and pain in knee osteoarthritis

There are suggestions that the relationship between inflammation and pain in osteoarthritis (OA) may differ by sex, yet studies have been limited. We investigated whether the relationship between knee-specific OA pain and systemic inflammatory markers differs by sex. 196 patients scheduled for knee arthroplasty for OA were included. Questionnaires were completed and blood samples drawn pre-surgery. Questionnaire data: knee pain (WOMAC), sex, age, height, weight, comorbidities, depressive symptoms, and symptomatic joint count. Systemic inflammatory markers (cytokines IL-6, IL-8, IL-10, IL-1β and TNF-α) were measured by multiplex ELISA. A series of regression models with interaction terms between sex and ln-transformed inflammatory markers were estimated with pain score as the outcome. The adjusted relationship between pain and inflammatory markers, by sex, were presented graphically. Mean age was 64 years (range 43-89); females comprised 58.7% of the sample. In adjusted analyses, similar relationships between knee pain and lnIL-10 (negative: β​=​-1.28, 95%CI (-1.97, -0.58)) and lnTNF-α (positive: β​=​0.92, 95%CI (0.11, 1.76)) were found for females and males. In contrast, relationships between knee pain and lnIL-1β, lnIL-6 and lnIL-8 differed in direction for females and males. Specifically, for lnIL-1β and lnIL-8 they were positive for males, negative for females. The opposite was found with lnIL-6, negative for males, positive for females. These findings provide some evidence of sex-specific relationships between individual inflammatory markers and knee OA pain. They expose a need for further exploration of sex-differences in this context, with potential future implications for treatment or drug development in OA.

Pain-Relieving Effect of 4.4 MHz of Pulsed Radiofrequency on Acute Knee Arthritis in Rats.

Drug injections and surgery are popular treatments for knee joint osteoarthritis. However, these treatments are invasive, and new noninvasive treatments with similar or better efficacy are needed. Here, we evaluated the application of 4.4 MHz of pulsed radiofrequency (PRF) as a new treatment. Acute arthritis was induced by injection of carrageenan into the intra-articular space of the knee in male rats. At 4.5 hours after arthritis induction, PRF with the treatment protocol of three seconds on and off was applied to the affected knee joint for 20 minutes. The changes in pain behavior were evaluated by comparing the peak weight load values of both hind paws at pretreatment and four, six, seven, eight, and 24 hours after treatment. And we also used Western blotting and immunohistochemistry to measure the inflammatory changes in the synovial membrane of the inflamed knee. We found that the 20-minute application of PRF with the treatment protocol significantly recovered the weight load reduction at six-, seven-, and eight-hour time points after carrageenan injection. COX-2 and IL-1β levels were significantly reduced in the inflamed rats after PRF application at six and eight hours post-carrageenan injection. Immunohistochemistry showed that PRF significantly reduced inflammatory cell infiltration at six hours post-carrageenan injection. . Our results indicate that noninvasive PRF application inhibited pain-related behavior and decreased inflammatory cytokine expression in the inflamed knee joints of rats. Accordingly, PRF application can serve as a potential therapeutic treatment to relieve pain associated with peripheral joint/tissue damage or inflammation.

Intra-articular Injection of Kartogenin-Incorporated Thermogel Enhancing Osteoarthritis Treatment.

To provide a vehicle for sustained release of cartilage-protective agent for the potential application of osteoarthritis (OA) treatment, we developed a kartogenin (KGN)-incorporated thermogel for intra-articular injection. We fabricated a poly(lactide-co-glycolide)-block-poly(ethylene glycol)-block-poly(lactide-co-glycolide) (PLGA–PEG–PLGA) thermogel as a KGN carrier for IA injection. OA chondrocytes were cultured in thermogel with or with no KGN to investigate the effect of KGN thermogel on cartilage matrix. The in vivo effect of KGN thermogel on OA was examined in a rabbit OA model. The KGN thermogel showed a sustained in vitro release of KGN for 3 weeks. OA chondrocytes proliferated well both in thermogel and KGN thermogel. In addition, OA chondrocytes produced higher amount of [type 2 collagen (COL-2) and glycosaminoglycan (GAG)], as well as lower level of matrix metalloproteinase 13 (MMP-13) in KGN thermogel that those in thermogel with no addition of KGN. The gene analysis supported that KGN thermogel enhanced expression of hyaline-cartilage specific genes Col 2 and AGC, and inhibited the expression of MMP-13. Compared with intra-articular injection of saline or thermogel containing no KGN, KGN thermogel can enhance cartilage regeneration and inhibit joint inflammation of arthritic knees in a rabbit ACLT-induced OA model at 3 weeks after the injection. Therefore, the KGN-incorporated PLGA–PEG–PLGA thermogel may provide a novel treatment modality for OA treatment with IA injection.

Effectiveness of Non-Animal Chondroitin Sulfate Supplementation in the Treatment of Moderate Knee Osteoarthritis in a Group of Overweight Subjects: A Randomized, Double-Blind, Placebo-Controlled Pilot Study.

Osteoarthritis (OA) is the most common form of arthritis in the world and is characterized by pain, various disabilities and loss of quality of life. Chondroitin sulfate (CS) is recommended as first-line therapy. CS of non-animal origin is of great interest for safety and sustainability reasons. This study aims to investigate the anti-inflammatory effects, anti-pain and ability-enhancement of a short-term supplementation with non-animal CS in overweight subjects with OA. In a randomized, double-blind, placebo-controlled pilot study, 60 overweight adults with symptomatic OA were allocated to consume 600 mg of non-animal CS (n = 30) or a placebo (n = 30) daily for 12 consecutive weeks. The assessment of knee-pain, quality of life, related inflammation markers and body composition was performed at 0, 4 and 12 weeks. The Tegner Lysholm Knee Scoring (TLKS) scale of the experimental group showed a statistically significant increase (+10.64 points; confidence interval (95% confidence interval (CI) 5.57; 15.70; p < 0.01), while the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score decreased (−12.24 points; CI 95% −16.01; −8.38; p < 0.01). The results also showed a decrease in the C-reactive protein (CRP) level (−0.14 mg/dL, CI 95% −0.26; −0.04; p < 0.01) and erythrocyte sedimentation rate (ESR) level (−5.01 mm/h, CI 95% −9.18; −0.84, p < 0.01) as well as the visual analogue scale (VAS) score in both knees. In conclusion, this pilot study demonstrates the effectiveness of non-animal CS supplementation in overweight subjects with knee OA in improving knee function, pain and inflammation markers.

Evaluation iontophoretic delivery of a cationic ketoprofen prodrug for treating nociceptive symptoms in monosodium iodoacetate induced osteoarthritic rat model.

Topical nonsteroidal anti-inflammatory drugs have been used in treatment of osteoarthritis but their efficacy is marginal. One major reason is because of limited drug direct penetration to affected joint and muscle tissues from the topical application. The main purpose of this study was to evaluate a new topical treatment through enhancing the direct drug penetration to local muscle and joint tissues for improving topical treatment of osteoarthritis. A cationic prodrug, ketoprofen choline chloride (KCC) was synthesized for iontophoretic topical delivery. Anodal iontophoretic delivery of KCC and cathodal iontophoretic delivery of ketoprofen to the knee of live hairless rats were evaluated and the drug concentrations in the joint and muscle tissues over the time were determined. In addition, a knee osteoarthritis rat model was induced with intra-articular injection of monosodium iodoacetate solution. Anodal iontophoretic delivery of KCC, cathodal iontophoretic delivery of ketoprofen, or anodal iontophoretic delivery of sodium chloride were applied to the affected knee joint of each rat group, respectively. Knee joint pain was evaluated through a hind paw weight bearing study and knee joint inflammation was evaluated through measuring of the knee diameter. Iontophoretic delivery of KCC showed much higher drug concentration in the knee joint and muscle tissues, compared to iontophoretic delivery of ketoprofen. Treatment of rat knee joint with anodal iontophoresis of KCC also showed significant pain relief and knee inflammation reduction comparing to the control group, while treatment results from cathodal iontophoresis of ketoprofen were mostly not significantly different from the control group.

Classification of Collegiate Athletes Based on Their Injury History

Sports-related injuries can have a significant impact on an athlete’s performance and career. While some injuries are inevitable, many can be prevented. Cluster analysis is a useful statistical technique that can assign individuals into groups (i.e., latent subgroups) based on common characteristics. PURPOSE: To utilize cluster analysis to 1) identify the latent subgroups based on athletes’ injury history; and 2) examine the characteristics of latent subgroups among athletes. METHODS: A total of 1,538 college athletes competing in the South Eastern Conference in NCAA division I were segmented by three criteria; 1) Injury parts indicate the body part sustaining the injury, 2) Injury types describe the detail of their injury status such as strain, contusion or tendonitis. 3) Injury duration refers to how long the athlete was unable to participate in training. K-means clustering analysis with the Euclidean similarity of injury log vectors was conducted to label players. The number of groups(k) was determined by applying the average silhouette method. The characteristics of clusters were analyzed descriptively, and the sports were allocated to each group followed by the athlete clusters. RESULTS: Five clusters were identified by the maximum average silhouette coefficient (0.153) among coefficients for randomly drawn k’s between 2 to 20. The first group, mainly baseball, men’s basketball, and men’s tennis, had injury to their ankle, arm, and hamstring for contusion and strain for a few weeks. The second group was mostly from football, with injury to their ankle, knee, and shoulder with the most extended injury durations. The third group, mostly football or track and field, were the athletes likely to have knee inflammation, and the duration was nearly half of a year. The injured body parts of the fourth group were back, finger, and hamstring, and the types of injuries were fracture and tendonitis. This cluster was mainly women’s basketball and track and field athletes. The members of the last group had head injury (e.g., concussion), and were soccer, softball or volleyball athletes. CONCLUSION: This study may help practitioners in recognizing the likelihood of an athletes’ injury according to their sport. Additionally, coaches could also consider this information in daily practices.

IL-1β-Mediated Activation of Adipose-Derived Mesenchymal Stromal Cells Results in PMN Reallocation and Enhanced Phagocytosis: A Possible Mechanism for the Reduction of Osteoarthritis Pathology

Background: Injection of adipose-derived mesenchymal stromal cells (ASCs) into murine knee joints after induction of inflammatory collagenase-induced osteoarthritis (CiOA) reduces development of joint pathology. This protection is only achieved when ASCs are applied in early CiOA, which is characterized by synovitis and high S100A8/A9 and IL-1β levels, suggesting that inflammation is a prerequisite for the protective effect of ASCs. Our objective was to gain more insight into the interplay between synovitis and ASC-mediated amelioration of CiOA pathology.Methods: CiOA was induced by intra-articular collagenase injection. Knee joint sections were stained with hematoxylin/eosin and immunolocalization of polymorphonuclear cells (PMNs) and ASCs was performed using antibodies for NIMP-R14 and CD271, respectively. Chemokine expression induced by IL-1β or S100A8/A9 was assessed with qPCR and Luminex. ASC-PMN co-cultures were analyzed microscopically and with Luminex for inflammatory mediators. Migration of PMNs through transwell membranes toward conditioned medium of non-stimulated ASCs (ASCNS-CM) or IL-1β-stimulated ASCs (ASCIL-1β-CM) was examined using flow cytometry. Phagocytic capacity of PMNs was measured with labeled zymosan particles.Results: Intra-articular saline injection on day 7 of CiOA increased synovitis after 6 h, characterized by PMNs scattered throughout the joint cavity and the synovium. ASC injection resulted in comparable numbers of PMNs which clustered around ASCs in close interaction with the synovial lining. IL-1β-stimulation of ASCs in vitro strongly increased expression of PMN-attracting chemokines CXCL5, CXCL7, and KC, whereas S100A8/A9-stimulation did not. In agreement, the number of clustered PMNs per ASC was significantly increased after 6 h of co-culturing with IL-1β-stimulated ASCs. Also migration of PMNs toward ASCIL-1β-CM was significantly enhanced (287%) when compared to ASCNS-CM. Interestingly, association of PMNs with ASCs significantly diminished KC protein release by ASCs (69% lower after 24 h), accompanied by reduced release of S100A8/A9 protein by the PMNs. Moreover, phagocytic capacity of PMNs was strongly enhanced after priming with ASCIL-1β-CM.Conclusions: Local application of ASCs in inflamed CiOA knee joints results in clustering of attracted PMNs with ASCs in the synovium, which is likely mediated by IL-1β-induced up-regulation of chemokine release by ASCs. This results in enhanced phagocytic capacity of PMNs, enabling the clearance of debris to attenuate synovitis.

Temperature profile guided segmentation for detection of early subclinical inflammation in arthritis knee joints from thermal images

In arthritis, subclinical inflammation referred to the clinical condition when rheumatologists are in confusion about the presence of inflammation using clinical and pathological observations. Application of Thermal imaging in detection of subclinical inflammation is highlighted in this literature. Segmentation of the hotspot area from the thermal image is the initial step for further analysis of the hotspot. Analysis of the hotspot will help in prediction of the subclinical inflammation, impact of inflammation. Methodologies reported in existing literature for segmentation of hotspot or inflamed knee region in medical thermal images suffer from over and under extraction.In the present scope, we try to overcome this limitation by extending the conventional region growing segmentation technique with stronger similarity criteria and stopping rule. In this method, hotspot or inflamed region is generated by taking the intersection of two independent regions produced by two different version of Region growing algorithm using a separate set of parameters. An automatic multiseed selection procedure ensures prevention of missed segmentation. We validate our technique by experimentation on various thermal image datasets like a newly created inflammatory thermal knee-joint-Database of 50 images, DBT-TU-JU Dataset, and DMR-IR Dataset. The effectiveness of the proposed technique is established compared to the performance of state-of-the-art competing methodologies.

Relationships between systemic inflammatory markers and osteoarthritis knee pain differ by sex

Relationships between systemic inflammatory markers and osteoarthritis knee pain differ by sex

Detection of proteinase activated receptor stimulating enzymes in human arthritic knee joint fluids

Purpose: Osteoarthritis (OA) is a major health care burden worldwide. OA can affect all joints but is manifest most often in the knees, hips, big toe hands and spine, and results in joint inflammation, pain and stiffness. There is currently no effective cure or therapeutic interventions for OA. Therefore, there is a need for further studies into mechanisms underlying disease progression and for the identification of novel therapeutic targets. A key feature of OA is the progressive degradation of the cartilage. It is well established that there is an increase in proteolytic enzyme activity that is linked to this damage. We hypothesized that in addition to degrading the extracellular matrix, increased proteolytic activity in the arthritic joint could also signal through the enzymatically activated Proteinase Activated Receptor (PAR) family of G-protein coupled receptors. Methods: To study the hypothesis, twenty human knee joint synovial fluid samples derived from OA patients undergoing realignment osteotomy were screened for PAR cleavage/activity in CHO cells stably transfected with genetically encoded PAR1 or PAR2 sensors (nluc-hPAR1-eYFP and nluc-hPAR2-eYFP). The N-terminal nano-luciferase released upon proteolytic cleavage of the receptor was measured as a luminescence signal in the presence of the substrate furimazine in a 96-well microplate reader. To determine the class/type of enzymes, the test samples were pretreated with enzyme inhibitors and the receptor cleavage was measured using the PAR sensors. In addition, fluorogenic enzyme substrates were used to identify the class of enzymes using a fluorescence microplate reader. Results: PAR activating enzymes were identified at significant levels in the OA synovial fluid samples derived from twenty patients. Through the use of class/type selective enzyme inhibitors and fluorogenic substrates it was found that serine protease class enzymes including thrombin and trypsin-like, and matrix metalloproteinases are present in the inflamed knee joint samples. Further work aimed at identifying the specific enzymes is underway using activity-based probes and mass-spectrometry analysis. Conclusions: It is known that PAR activation is pro-inflammatory and inhibition of these receptors with specific antagonists may be beneficial in treating OA. A better understanding of PAR activators and the pathological signaling pathways triggered by these receptors will guide development of novel therapies to treat joint diseases.

Antigen‐Induced Arthritis Leads to Depression‐Like Behavior in Mice Mediated by Central TNFα

Rheumatoid arthritis (RA) is a relapsing inflammatory condition of the joints. There are many debilitating neurological and psychological manifestations associated with RA, including chronic pain, and depression. These symptoms contribute to a reduction of quality of life, particularly because they are often present when the peripheral disease is in remission. While progress has been made in the treatment of joint inflammation, mechanisms that underlie the central neural manifestations of RA have yet to be characterized and treatment options identified.Using a mouse model of RA, we sought to demonstrate depression‐like behaviour in the absence of joint inflammation and determine a mechanism for this condition. We hypothesized that inflammation would lead to depression‐like behaviour mediated by central cytokines. To test the hypothesis, we used the antigen‐induced arthritis (AIA) model in mice. C57Bl/6 male mice (8–10 wk) were sensitized with methylated bovine serum albumin (mBSA) 14 days prior to the immune challenge. Knee intra‐articular injection of mBSA was performed to induce joint inflammation. After 1 or 13 days, mice were subjected to the tail suspension test to evaluate the presence of depression‐like behavior and pain was assessed with a Von Frey apparatus. To evaluate the inflammatory state of the brain, multiplex cytokine analysis (32 cytokines) were performed in hippocampal specimens and microglial staining was performed using anti‐Iba‐1 antibodies. Anti‐TNFα injections were performed intracerebroventricularly (icv) to evaluate to role of this cytokine on behaviour.One day after immune challenge, joint inflammation was observed in the knee. After 13 days, no neutrophil infiltration was observed, suggesting a basal, non‐inflamed state. We observed high levels of pain on day 1, which persisted until day 13. Depression‐like behaviour was only seen on day 13, suggesting an alteration in behavior in the absence of knee inflammation. To validate this result, mice with AIA were treated with the antidepressant imipramine (30 mg/kg). We saw a reduction in the depression‐like behavior previously observed. Moreover, to rule out joint pain on the behavior reported, we treated AIA mice locally with the non‐opioid analgesic dipyrone. Reducing joint pain did not influence the depression‐like behavior. Microglia analysis on the hippocampus showed no overt activation of microglia at either time point. Cytokine analysis showed an increase in KC, MCP‐1, and TNFα (p=0.08) in the hippocampus of AIA mice after day 1, but no changes at day 13. In order to test if TNFα may be involved in the depression behaviour, we injected anti‐TNFα icv on day 0. At day 13, we observed a reduction of depression‐like behaviour in AIA mice, suggesting a role for TNFα on this outcome.We conclude that depression‐like behaviour in a mouse model of RA is mediated by central cytokines. The mechanism of how TNFα is modulating this behavior remains to be determined.Support or Funding InformationThis work was supported by Canadian Institutes of Health Research (CIHR) and National Counsel of Technological and Scientific Development (CNPq – Brazil).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Investigation of the phytochemical composition and antioxidant properties of chinar (Platanus orientalis L.) leaf infusion against ethanol-induced oxidative stress in rats.

Chinar (Platanus orientalis L.) is used in folk medicine against tooth and knee pain, wounds, inflammation, and stomach discomfort; however, the effects of P. orientalis leaf (PO-leaf) infusion on the liver and kidney are unknown. The aim of this study was to investigate the phytochemical composition and antioxidant properties of an infusion obtained from dried P. orientalis leaves against ethanol-induced oxidative stress (OS) in rats. After a toxicity test, thirty male Wistar rats were divided into five groups: Control, Ethanol 20%, Ethanol 20% + Silymarin (10mg/kg), Ethanol 20% + PO-20mg/mL infusion, and Ethanol 20% + PO-60mg/mL infusion. The PO-leaf infusion doses were given ad libitum during 28days to test the biochemical and antioxidant enzyme levels. According to the results, the PO-leaf contained rich compounds such as benzaldehyde, palmitic acid, 2,4-ditert-butylphenol, stearic acid, octadecanoic acid, linoleic acid, linolenic acid, kaempferol, and kaempferol derivatives. In the Ethanol group, AST, ALT, LDH, GGT, UA, and urea in the serum and GST and malondialdehyde (MDA) in the liver and erythrocyte tissues showed a significant increase compared to the Control group. AST, LDH, GGT, UA, and LDL-C levels in the serum and MDA (all tissues) significantly decreased in the Ethanol + PO-60mg/mL group compared to the Ethanol group. SOD, GPx, and CAT activities in the kidney tissue of the Ethanol group showed a significant decrease compared to the Control group, whereas the GPx activity in kidney tissue in all of the treatment groups increased significantly compared to the Ethanol group. These findings suggest that the administration of the determined PO-leaf infusion doses might have a protective role against ethanol-induced liver and kidney damage in rats.