Solute Carrier Transporters in Synovial Membrane and Hoffa's Pad of Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a complex autoimmune disease that leads to joint destruction. A number of immune cells that affect joint tissues are involved in the pathogenesis of this disease. This leads to the synthesis of many pro-inflammatory mediators. The transport of drugs, as well as many cytokines involved in the development of inflammation in RA patients, is mediated by membrane transporters. Membrane transporters are proteins that mediate the transfer of substrates across biological membranes. But to date there are no studies examining the expression of solute carrier (SLC) transporters in joint tissues. The aim of the study was to evaluate the expression of individual SLC family transporters in the synovial membranes (SMs) and infrapatellar fat pad (Hoffa's pad) of RA patients. The study included 20 patients with rheumatoid arthritis and 20 with osteoarthritis as the control group who were undergoing joint replacement surgery as a normal part of clinical care. In the SM and Hoffa's pad of RA patients the following 17 membrane transporters were defined at relevant expression levels for SLC transporter superfamily: SLC15A2, SLC16A3, SLC19A1, SLC2A9, SLC22A1, SLC22A3, SLC22A4, SLC22A5, SLC22A18, SLC33A1, SLC47A1, SLC51A, SLC7A5, SLC7A6, SLC01C1, SLC02B1, SLC04A1. The confirmed expression of these transporters in the SMs as well as Hoffa's pad of patients with RA and OA, and the differences in their expression between these groups, suggests the involvement of SLC transporters in both the maintenance of homeostasis under physiological conditions in the tissues of the joints, as well as in the inflammatory process in RA.

Case report: Equine metacarpophalangeal joint partial and full thickness defects treated with allogenic equine synovial membrane mesenchymal stem/stromal cell combined with umbilical cord mesenchymal stem/stromal cell conditioned medium.

Here, we describe a case of a 5-year-old show-jumping stallion presented with severe lameness, swelling, and pain on palpation of the left metacarpophalangeal joint (MCj). Diagnostic imaging revealed full and partial-thickness articular defects over the lateral condyle of the third metacarpus (MC3) and the dorsolateral aspect of the first phalanx (P1). After the lesion's arthroscopic curettage, the patient was subjected to an innovative regenerative treatment consisting of two intra-articular injections of equine synovial membrane mesenchymal stem/stromal cells (eSM-MSCs) combined with umbilical cord mesenchymal stem/stromal cells conditioned medium (UC-MSC CM), 15 days apart. A 12-week rehabilitation program was accomplished, and lameness, pain, and joint effusion were remarkably reduced; however, magnetic resonance imaging (MRI) and computed tomography (CT) scan presented incomplete healing of the MC3's lesion, prompting a second round of treatment. Subsequently, the horse achieved clinical soundness and returned to a higher level of athletic performance, and imaging exams revealed the absence of lesions at P1, fulfillment of the osteochondral lesion, and cartilage-like tissue formation at MC3's lesion site. The positive outcomes suggest the effectiveness of this combination for treating full and partial cartilage defects in horses. Multipotent mesenchymal stem/stromal cells (MSCs) and their bioactive factors compose a novel therapeutic approach for tissue regeneration and organ function restoration with anti-inflammatory and pro-regenerative impact through paracrine mechanisms.

3D in vitro synovial hyperplasia model on polycaprolactone-micropatterned nanofibrous microwells for screening disease-modifying anti-rheumatic drugs.

Rheumatoid arthritis (RA) is known to be caused by autoimmune disorders and can be partially alleviated through Disease-Modifying Antirheumatic Drugs (DMARDs) therapy. However, due to significant variations in the physical environment and condition of each RA patient, the types and doses of DMARDs prescribed can differ greatly. Consequently, there is a need for a platform based on patient-derived cells to determine the effectiveness of specific DMARDs for individual patient. In this study, we established an RA three-dimensional (3D) spheroid that mimics the human body's 3D environment, enabling high-throughput assays by culturing patient-derived synovial cells on a macroscale-patterned polycaprolactone (PCL) scaffold. Fibroblast-like synoviocytes (FLSs) from patient and human umbilical vein endothelial cells (HUVECs) were co-cultured to simulate vascular delivery. Additionally, RA characteristics were identified at both the genetic and cytokine levels using real-time polymerase chain reaction (RT-qPCR) and dot blot assay. The similarities in junctions and adhesion were demonstrated in both actual RA patient tissues and 3D spheroids. The 3D RA spheroid was treated with representative DMARDs, observing changes in reactive oxygen species (ROS) levels, lactate dehydrogenase (LDH) levels, and inflammatory cytokine responses to confirm the varying cell reactions depending on the DMARDs used. This study underscores the significance of the 3D drug screening platform, which can be applied to diverse inflammatory disease treatments as a personalized drug screening system. We anticipate that this platform will become an indispensable tool for advancing and developing personalized DMARD treatment strategies.

Correlation of the total superoxide dismutase activity between joint fluid and synovium in end-stage knee osteoarthritis.

Recently, we found significantly reduced total superoxide dismutase (SOD) activity in the cartilage of patients with end-stage knee osteoarthritis (OA). In this study, we aimed to evaluate the SOD activity in serum, joint fluid, cartilage, and synovial membrane samples collected from 52 patients with end-stage knee OA who underwent total knee arthroplasty. The relationship between the total SOD activity in each tissue was evaluated using Spearman's rank correlation coefficient. The joint fluid total SOD activity was used as the objective variable, and its association with the serum, cartilage, and synovial total SOD activities was evaluated using multiple linear regression analysis. Univariate analysis revealed that joint fluid total SOD activity was positively correlated with synovial total SOD activity. Multiple linear regression analysis using joint fluid total SOD activity as the objective variable showed a positive association with synovial total SOD activity (ß = 0.493, adjusted R2 = 0.172, P < 0.01). In patients with end-stage knee OA, the state of the synovial total SOD activity is better reflected by the total SOD activity in the joint fluid than that in the cartilage. Joint fluid total SOD activity may serve as a biomarker for the treatment and prevention of synovitis.

Effect of Chitosan on Synovial Membrane Derived Cells and Anterior Cruciate Ligament Fibroblasts.

Previously, chitosan reduces the senescence-related phenotypes in human foreskin fibroblasts through the transforming growth factor beta (TGF-ß) pathway, and enhances the proliferation and migration capabilities of these cells are demonstrated. In this study, we examined whether the senescence-delaying effect of chitosan could be applied to primary knee-related fibroblasts, such as human synovial membrane derived cells (SCs) and anterior cruciate ligament fibroblasts (ACLs). These two types of cells were obtained from donors who needed ACL reconstruction or knee replacement. We found that chitosan treatment effectively reduced aging-associated ß-galactosidase (SA-ß-gal)-positive cells, downregulated the expression of senescence-related proteins pRB and p53, and enhanced the 5-bromo-2'-deoxyuridine (BrdU) incorporation ability of SCs and ACLs. Moreover, chitosan could make SCs secret more glycosaminoglycans (GAGs) and produce type I collagen. The ability of ACLs to close the wound was also enhanced, and the TGF-ß and alpha smooth muscle actin (αSMA) protein expression decreased after chitosan treatment. In summary, chitosan not only delayed the senescence but also enhanced the functions of SCs and ACLs, which is beneficial to the application of chitosan in cell expansion in vitro and cell therapy.

Syndecans, Exostosins and Sulfotransferases as Potential Synovial Inflammation Moderators in Patients with Hip Osteoarthritis.

The gradual deterioration of articular cartilage was thought to be the central event in osteoarthritis (OA), but recent studies demonstrated the importance of low-grade synovitis in the progression of OA. The Syndecan (SDC) family of membrane proteoglycans is known to be involved in the regulation of inflammation, but there is limited evidence considering the role of syndecans in OA synovitis. Our study aimed to investigate the hip OA synovial membrane expression patterns of SDC1, SDC2 and SDC4, as well as exostosins and sulfotransferases (enzymes involved in the polymerisation and modification of syndecans' heparan sulphate chains). Synovial membrane samples of patients with OA (24) were divided into two groups according to their Krenn synovitis score severity. The immunohistochemical expressions of SDC1, SDC2, SDC4, EXT1, EXT2, NDST1 and NDST2 in synovial intima and subintima were then analysed and compared with the control group (patients with femoral neck fracture). According to our study, the immunoexpression of SDC1, NDST1 and EXT2 is significantly increased in the intimal cells of OA synovial membrane in patients with lower histological synovitis scores and SDC4 in patients with higher synovitis scores, in comparison with non-OA controls. The difference in the expression of SDC2 among the OA and non-OA groups was insignificant. SDC1, SDC4, NDST1 and EXT2 seem to be involved as inflammation moderators in low-grade OA synovitis and, therefore, should be further investigated as potential markers of disease progression and therapeutic goals.

[Establishment and evaluation of a rabbit model of frozen shoulder induced by persistent strain injuries and ice compression].

OBJECTIVE: To evaluate the rabbit modle of frozen shoulder induced by persistent strain injuries and ice compression. METHODS: Twelve clean, healthy male New Zealand rabbits with a mass of (2 500±500) g were selected and randomly divided into a blank group and a control group with 6 rabbits in each group. In the control group, the rabbits were modeled with persistent strain injuries and ice compression, the general conditions of the rabbits and the active and passive activities of the shoulder joint were observed and their body weights were recorded. MRI was performed on the affected shoulder joints at 6 d and 29 d after modelling to observe the fluid and soft tissue;HE staining was used to observe the morphology of the rabbit biceps longus tendon and the synovial membrane of the joint capsule;Masson staining was used to observe the fibrous deposits of the rabbit biceps longus tendon and the synovial membrane of the joint capsule, and the fibrous deposits were analysed semi-quantitatively by Image J software. RESULTS: Six days after the end of modeling, the active movement of the shoulder joints in the control group was limited, the passive movement was not significantly limited, and they walked with a limp;29 days after the end of the modeling, the active and passive movements of the shoulder joints in the model group were severely limited. Compared with the blank group (2.50±0.14) kg, the body weight of the model group (2.20±0.17) kg was significantly reduced(P<0.01). MRI showed that 6 days after modelling, the muscles around the shoulder joint were not smooth in shape, the joint capsule structure was narrowed and a large amount of fluid was seen in the joint cavity;29 days after modelling, the muscles around the shoulder joint were rough in shape, structure of the joint capsule was unclear and the fluid in the joint cavity was reduced compared with 6 days after modelling. Pathological staining showed that the long-headed biceps tendon fibres in the control group were disorganised, curled or even broken, and the synovial tissue of the joint capsule was heavily vascularised, with collagen fibre deposits and severe inflammatory cell infiltration. The fiber deposition of the long head of biceps brachii in the model group [(23.58±3.41)%, (27.56±3.70)%] and synovial tissue [(41.78±5.59)%, (62.19±7.54)%] were significantly higher than those in the blank group [(1.79±1.03) %, (1.29±0.63) %] at 7 and 30 days after modeling and synovial tissue fiber deposition [(8.15±3.61) %, (11.29±7.10) %], as shown by the semi-quantitative analysis of Masson staining results by Image J software. And the longer the time, the more severe the fibrosis (P<0.01). CONCLUSION: The behavioral, imaging and pathological findings showed that the rabbit frozen shoulder model with persistent strain injuries and ice compression is consistent with the clinical manifestations and pathogenesis of periarthritis, making it an ideal method for periarthritis research.

The effect of low dose intra-articular S(+) ketamine on osteoarthritis in rats: an experimental study.

BACKGROUND: This study aimed to investigate the analgesic impact of S(+)-ketamine on pain behavior and synovial inflammation in an osteoarthritis (OA) model. METHODS: Animals were grouped as follows: OA-Saline (n = 24) and OA-Ketamine (n = 24), OA induced via intra-articular sodium monoiodoacetate (MIA); a Non-OA group (n = 24) served as the control. On the 7th day post OA induction, animals received either saline or S(+)-ketamine (0.5 mg.kg-1). Behavioral and histopathological assessments were conducted up to day 28. RESULTS: S(+)-ketamine reduced allodynia from day 7 to 28 and hyperalgesia from day 10 to 28. It notably alleviated weight distribution deficits from day 10 until the end of the study. Significant walking improvement was observed on day 14 in S(+)-ketamine-treated rats. Starting on day 14, OA groups showed grip force decline, which was countered by S(+)-ketamine on day 21. However, S(+)-ketamine did not diminish synovial inflammation. CONCLUSION: Low Intra-articular (IA) doses of S(+)-ketamine reduced MIA-induced OA pain but did not reverse synovial histopathological changes. IRB APPROVAL NUMBER: 23115 012030/2009-05.

Treatment of Equine Tarsus Long Medial Collateral Ligament Desmitis with Allogenic Synovial Membrane Mesenchymal Stem/Stromal Cells Enhanced by Umbilical Cord Mesenchymal Stem/Stromal Cell-Derived Conditioned Medium: Proof of Concept.

Horses are high-performance athletes prone to sportive injuries such as tendonitis and desmitis. The formation of fibrous tissue in tendon repair remains a challenge to overcome. This impels regenerative medicine to develop innovative therapies that enhance regeneration, retrieving original tissue properties. Multipotent Mesenchymal Stem/Stromal Cells (MSCs) have been successfully used to develop therapeutic products, as they secrete a variety of bioactive molecules that play a pivotal role in tissue regeneration. These factors are released in culture media for producing a conditioned medium (CM). The aforementioned assumptions led to the formulation of equine synovial membrane MSCs (eSM-MSCs)-the cellular pool that naturally regenerates joint tissue-combined with a medium enriched in immunomodulatory factors (among other bioactive factors) produced by umbilical cord stroma-derived MSCs (eUC-MSCs) that naturally contribute to suppressing the immune rejection in the maternal-fetal barrier. A description of an equine sport horse diagnosed with acute tarsocrural desmitis and treated with this formulation is presented. Ultrasonographic ligament recovery occurred in a reduced time frame, reducing stoppage time and allowing for the horse's return to unrestricted competition after the completion of a physical rehabilitation program. This study focused on the description of the therapeutic formulation and potential in an equine desmitis treatment using the cells themselves and their secretomes.

Transmission electron microscopic study of the surface layer of surgical resected disc specimens in human temporomandibular joint.

In this study, we investigated specific and characteristic findings of the surface layer of surgical resected disc specimens in human temporomandibular joint osteoarthritis cases by transmission electron microscopy (TEM).Specimens were surgically removed from the TMJ of 5 cases (4 female patients: 5 cases) clinically osteoarthritis. Following findings were observed by TEM. Images were photographed on a JEM1400-Flash Electron microscope (JEOL, Japan) equipped with an EM-14661FLASH high-sensitivity digital complementary metal-oxide-semiconductor camera.Following findings were observed by TEM. 1) The surface is covered with plump fibroblastic and histiocytoid cells. 2) Collagen fiber bundles and collagenous matrix are exposed onto the eroded disc surface. 3) Fibrinous dense material is observed on the eroded disc surface. 4) Bundles of collagen fibers are densely observed. 5) Collagen bundles are rich around capillary vessels. 6) Synovial surface cells reveal features of activated macrophages with vacuole formation. Especially, plump fibroblastic and histiocytoid cells, and activated macrophages with vacuole, which were significant findings of the surface layer. These findings might have a significant effect on the regulation of synovial fluid.

Mechanism by which miR-34a-5p/PLCD3 axis regulates osteoarthritis progression / 中国组织工程研究

BACKGROUND:Molecular mechanisms targeting the miRNA/mRNA axis to regulate osteoarthritis disease process have been studied.We identified the mRNA:phospholipase C delta 3(PLCD3)and its target miRNA(miR-34a-5p)with clinical predictive value through previous bioinformatics studies,while experiments to verify their specific roles and mechanisms in regulating osteoarthritis are still lacking. OBJECTIVE:To investigate the regulatory role and mechanism of miR-34a-5p/PLCD3 axis on osteoarthritis progression. METHODS:The synovium of 15 patients with knee osteoarthritis was selected as the osteoarthritis group,and the synovium of 15 young patients with internal fixation of patellar fracture caused by trauma during the same period was selected as the control group.The expression of PLCD3 and miR-34a-5p in the synovium was detected by real-time PCR.Human fibroblast like synovial cells-osteoarthritis(HFLS-OA)cells were treated by cell transfection and divided into miR-34a-5p mimic group,pCDH-PLCD3 group,miR-34a-5p mimic+pCDH-PLCD3 group,miR-34a-5p inhibitor group,si-PLCD3 group,and miR-34a-5p inhibitor+si-PLCD3 group.The relationship between PLCD3 and miR-34a-5p expression was detected by real-time PCR.The effects of HFLS-OA cell viability and cell migration in each group were detected by CCK-8 assay and cell scratch test.Western blot assay was used to detect the expression level of apoptosis marker protein.The expression of inflammatory factors was detected by ELISA. RESULTS AND CONCLUSION:(1)PLCD3 was a direct target of miR-34a-5p,and the expression levels of PLCD3 and miR-34a-5p were negatively correlated.(2)Upregulation of PLCD3 promoted proliferation of HFLS-OA cells and inhibited cell migration.The up-regulation of miR-34a-5p significantly inhibited the activity of HFLS-OA cells and enhanced cell migration.Overexpression of miR-34a-5p significantly increased the levels of Casp3 and Casp9 proteins in HFLS-OA cells,while overexpression of PLCD3 showed the opposite trend.(3)PLCD3 overexpression significantly increased the expression of interleukin 6 and tumor necrosis factor alpha in HFLS-OA cells,while miR-34a-5p mimics showed protective activity.(4)The miR-34a-5p/PLCD3 axis may affect the progression of osteoarthritis by regulating the inflammatory process or apoptosis of synovial cells.

The comparative study on the extraction methods of exosomes from synovial fibroblasts in patients with rheumatoid arthritis / 中华风湿病学杂志

Objective:To compare the efficiency and purity of exosomes extracted from synovial fibroblasts of patients with rheumatoid arthritis by ultracentrifugation, size exclusion chromatography and modified polymer precipitation.Methods:The exosomes were extracted from human synovial fibroblasts by ultracentrifugation, size exclusion chromatography and modified polymer precipitation. Transmission electron microscopy, particle size detection and western Blot were used to identify the morphological characteristics, particle size distribution, concentration, and expression of marker proteins. One-way analysis of variance (ANOVA) was used for comparison among the three groups, and LSD- t test was used for pairwise comparison. P<0.05 was considered statistically significant. Results:Exosomes could be successfully obtained with all three extraction methods. The typical "saucer-like" structure could be observed under transmission electron microscope. The marker proteins of exosomes TSG101, Syntenin-1 and CD63 were all detectable by western blot. The peaks of main particle size were located within 30~150 nm. As for purity, the exosomes obtained by ultracentrifugation showed the highest purity, while modified polymer precipitation was the worst, with a large number of polymer particles and impurities protein. The purity of exosomes obtained by size exclusion chromatography was the moderate. For extraction efficiency, concentrations of exosomes particles obtained by the three methods were different ( F=9.61, P=0.049), and modified polymer precipitation was significantly higher than ultracentrifugation in terms of concentration of exosomes particles [(98.0±17.0)×10 10 particles/ml vs (11.6±7.7)×10 10 particles/ml, t=-4.34, P=0.023]. Conclusion:Human synovial fibroblasts derived exosomes canbe obtained by three methods. Ultracentrifugation is time-consuming, but can produce high-purity exosomes, which may be considered in the situation when high purity requirement with large volume samples are needed. Size exclusion chromatography is a good choice with high yield and purity exosomes, and suitable for small volume samples. Modified polymer precipitation is not recommended due to production of lowest purity exosomes.

T2 Black Synovitis in Musculoskeletal MRI: Disease Spectrum and Imaging Characteristics of Joint Diseases

The synovium may be affected by a wide spectrum of disorders, including inflammatory, infectious, degenerative, traumatic, hemorrhagic, and tumorous conditions. Magnetic resonance imaging (MRI) is a valuable imaging modality to characterize synovial disorders. Most abnormal lesions appear as areas of nonspecific high signal intensity on T2-weighted images (T2-WI) due to high water content or increased perfusion. However, T2 hypointensity can be attributed to blood components of varying ages, calcification, inorganic crystals, fibrosis, caseous necrosis and/or amyloid deposition. Hypointense lesions on T2-WI are infrequent and additional clinical and imaging characteristics can help to limit the list of differential diagnoses, which may include tenosynovial giant cell tumor, synovial chondromatosis, rheumatoid arthritis, tuberculous arthritis, chronic tophaceous gout, amyloid arthropathy, synovial hemangioma, lipoma arborescens and hemosiderotic synovitis. Recently, susceptibility weighted imaging has been developed and may contribute to more accurate diagnosis for deoxygenated blood and calcium. We review the MRI features of hypointense synovial lesions on MRI and emphasize the characteristic findings that suggest a correct diagnosis.

The effect of low dose intra-articular S(+) ketamine on osteoarthritis in rats: an experimental study

Abstract Background: This study aimed to investigate the analgesic impact of S(+)-ketamine on pain behavior and synovial inflammation in an osteoarthritis (OA) model. Methods: Animals were grouped as follows: OA-Saline (n = 24) and OA-Ketamine (n = 24), OA induced via intra-articular sodium monoiodoacetate (MIA); a Non-OA group (n = 24) served as the control. On the 7th day post OA induction, animals received either saline or S(+)-ketamine (0.5 mg.kg-1). Behavioral and histopathological assessments were conducted up to day 28. Results: S(+)-ketamine reduced allodynia from day 7 to 28 and hyperalgesia from day 10 to 28. It notably alleviated weight distribution deficits from day 10 until the end of the study. Significant walking improvement was observed on day 14 in S(+)-ketamine-treated rats. Starting on day 14, OA groups showed grip force decline, which was countered by S(+)-ketamine on day 21. However, S(+)-ketamine did not diminish synovial inflammation. Conclusion: Low Intra-articular (IA) doses of S(+)-ketamine reduced MIA-induced OA pain but did not reverse synovial histopathological changes. IRB approval number: 23115 012030/2009-05.

General joint hypermobility in temporomandibular joint disease; clinical characteristics, biomarkers, and surgical aspects.

Objectives: This study aimed at identifying biomarkers in the temporomandibular joint (TMJ) synovial tissue analysing 28 extra cellular matrix proteins in TMJ diseased patients, classified with either general joint hypermobility (GJH) or normal joint mobility (NJM), and to compile clinical and protein characterisation to reveal potential surgical predictive factors. Study design: A prospective observational cohort study including 97 consecutive patients scheduled for TMJ surgery was performed. Joint mobility and several other predefined clinical variables were recorded. Synovial tissue was harvested during surgery followed by examination using multi-analytic profiling. A multivariate quantile regression model was used for analysis purposes. Results: The GJH/NJM ratio was 2:5. The GJH cohort were younger (P = 0.001) and more likely to be women (P = 0.026) compared to the NJM cohort. None of the protein concentrations could be correlated to joint mobility in the multivariate regression model, but often to the variable TMJ diagnosis. The surgical outcome after the six-month follow-up were equal between GJH and NJM patients. Conclusions: GJH was more common in the study cohort compared to general population frequencies, but GJH was not a negative factor for surgical outcome. Young age and female gender correlated to GJH. No TMJ biomarkers were GJH specific, and the results suggested that TMJ diagnosis more strongly correlated to the protein profile compared to GJH and the other investigated variables.

Increased n-6 Polyunsaturated Fatty Acids Indicate Pro- and Anti-Inflammatory Lipid Modifications in Synovial Membranes with Rheumatoid Arthritis.

Emerging evidence suggests that fatty acids (FAs) and their lipid mediator derivatives can induce both beneficial and detrimental effects on inflammatory processes and joint degradation in osteoarthritis (OA) and autoimmune-driven rheumatoid arthritis (RA). The present study characterized the detailed FA signatures of synovial membranes collected during knee replacement surgery of age- and gender-matched OA and RA patients (n = 8/diagnosis). The FA composition of total lipids was determined by gas chromatography and analyzed with univariate and multivariate methods supplemented with hierarchical clustering (HC), random forest (RF)-based classification of FA signatures, and FA metabolism pathway analysis. RA synovium lipids were characterized by reduced proportions of shorter-chain saturated FAs (SFAs) and elevated percentages of longer-chain SFAs and monounsaturated FAs, alkenyl chains, and C20 n-6 polyunsaturated FAs compared to OA synovium lipids. In HC, FAs and FA-derived variables clustered into distinct groups, which preserved the discriminatory power of the individual variables in predicting the RA and OA inflammatory states. In RF classification, SFAs and 20:3n-6 were among the most important FAs distinguishing RA and OA. Pathway analysis suggested that elongation reactions of particular long-chain FAs would have increased relevance in RA. The present study was able to determine the individual FAs, FA groups, and pathways that distinguished the more inflammatory RA from OA. The findings suggest modifications of FA elongation and metabolism of 20:4n-6, glycerophospholipids, sphingolipids, and plasmalogens in the chronically inflamed RA synovium. These FA alterations could have implications in lipid mediator synthesis and potential as novel diagnostic and therapeutic tools.

Proliferative tenosynovitis in Brazilian Mangalarga Marchador horses.

Proliferative tenosynovitis (PT) is an inflammatory and proliferative disorder of the synovial membrane of the tendon sheath that is rare in animals. The histological alterations are characterized by multinodular neovascularization, with infiltration of histiocytic and multinucleated giant cells and haemosiderin deposition. We reviewed necropsy and biopsy records of horses submitted to the Setor de Anatomia Patológica of the Universidade Federal Rural do Rio de Janeiro from January 2017 to December 2020 to select cases of PT. We identified PT in three adult Brazilian Mangalarga Marchador horses with nodular lesions on the metacarpophalangeal, metatarsophalangeal or carpal joints. The three horses were under 6 years of age and presented with lameness and pain on palpation. There were recurrences in two horses after surgical removal. Radiographic and ultrasound examinations detected masses in the flexor or extensor tendons and subtendinous bursa. Histological study of synovial membrane and tendon sheath revealed an increased number of vessels, fibroplasia, osseous metaplasia and infiltration of lymphocytes, plasma cells and siderophages. This is the first description of PT in horses, which should be included as an orthopaedic differential diagnosis, especially in Mangalarga Marchador horses with lameness.

[Particle disease and its effects on periarticular tissue]. / Abrieberkrankungen und deren Effekte auf das umliegende Gewebe.

Particle disease is the condition caused by wear debris on surrounding tissues and influences the well-being of arthroplasty patients. This condition is multifactorial due to the type of bearing couple, head size and implant position. Subsequent periprosthetic osteolysis and soft tissue reactions, can lead to revision THA surgery. The periprosthetic synovial membrane (synovial-like interface membrane, SLIM) is used in diagnostics when the cause of implant failure is uncertain. Detailed analysis of synovial fluid and bone marrow could improve the diagnostic procedure and strengthen the cases for revision surgery and the underlying biology. A large number of research approaches on this topic have evolved and continue to be utilized in the clinic.

Temporomandibular Joint: Review of Anatomy and Clinical Implications.

Temporomandibular joints (TMJ) are one of the most complex joints. Each one is located on one side of the face, and are composed of mandibular fossa, joint tubercle, and condylar process of mandible, separated by an articular disk. To these structures are attached ligaments and muscles, which will provide stability and movement. When TMJs work properly, jaw movements can be performed without pain or discomfort. It is important to mention that the complex formed by both TMJs will confront the maxillary with the mandibular bone and therefore will be related to the occlusion, linking these structures during growth and development.