Local hemodynamics, permeability, and oxygen metabolism during acute inflammation of innervated or denervated isolated equine joints

OBJECTIVES: To determine oxygen metabolism, permeability, and blood flow in isolated joints in response to interleukin 1beta (IL-1beta) and contribution of innervation. SAMPLE POPULATION: One metacarpophalangeal (MCP) joint of 24 adult horses. PROCEDURE: The MCP joint was isolated for 6 hours in a pump-perfused, auto-oxygenated, innervated or denervated preparation. Isolated joints were assigned to the following 4 groups: control, control-denervated, inflamed, and inflamed-denervated, and inflammation was induced by intra-articular injection of IL-1beta. Circuit arterial and venous pressures, flows, and blood gas tensions, synovial fluid production, and intra-articular pressure were measured. Total vascular resistance; oxygen delivery, consumption, and extraction ratio (ER); and permeability surface area product were calculated. Synovial membrane blood flow was determined at 0, 60, and 330 minutes. Synovial membrane wet-to-dry ratio was obtained, and permeability to macromolecules was determined by intra-articular injection of Evans blue albumin and fluorescein isothiocyanate-conjugated dextran. RESULTS: Oxygen delivery and synovial membrane blood flow progressively increased but were not different among groups. Oxygen consumption and ER significantly increased in inflamed joints, as did intraarticular pressure and synovial fluid production. Inflamed joints had greater wet-to-dry ratio. Albumin permeability significantly increased in the villous synovial membrane of the inflamed groups, and dextran permeability was increased in the innervated groups, with a trend toward increased permeability in inflamed groups. CONCLUSION: Inflammation significantly increased oxygen demand, which was initially met by increased ER. Permeability to small molecules was increased with inflammation; innervation increased permeability to large molecules. Use of an isolated joint model enabled documentation of the physiologic responses of the joint to acute inflammation.     

Evaluation of sodium hyaluronate therapy in induced septic arthritis in the horse

This study was conducted to determine the efficacy of sodium hyaluronate (SH) with antibiotic therapy and joint lavage for reducing acute inflammatory and degenerative changes induced by septic arthritis. Septic arthritis was induced in six adult horses by inoculating the tarsocrural joints with 1 x 10(4) colony-forming units of Staphylococcus aureus. When clinical signs appeared, trimethoprim-sulphamethoxazole (30 mg/kg bodyweight [bwt] daily) and phenylbutazone (4.4 mg/kg bwt sid) were administered and continued until termination of the study (Treatment Day 18). Twenty-four hours post inoculation, all joints were lavaged with sterile lactated Ringer's solution. Following lavage, one joint of each horse was injected with 10 mg of SH, and the contralateral joint served as the control. Sodium hyaluronate treated joints showed significant reductions in lameness, tarsal circumference and synovial fluid protein and WBC concentrations. The synovial membrane of the SH-treated joints contained less cellular infiltrate, less granulation tissue formation and retained a more normal villous structure compared with controls. The total glycosaminoglycan loss from the articular cartilage in the SH treated joints was consistently less than that from the control joints; however, this difference was not statistically significant. Sodium hyaluronate with joint lavage appears to be more beneficial than lavage alone for treatment of septic arthritis.     

Ceramide, a mediator of interleukin 1, tumour necrosis factor alpha, as well as Fas receptor signalling, induces apoptosis of rheumatoid arthritis synovial cells

OBJECTIVES: To examine the effects of ceramide, which is a lipid second messenger of cell surface receptors, including tumour necrosis factor alpha (TNF alpha), interleukin 1 (IL1), and Fas receptors, on rheumatoid arthritis (RA) synovial cells. METHODS: Synovial cells from RA patients and normal skin fibroblasts were cultured with cell permeable ceramide (C2-ceramide). Apoptosis was assessed by microscopic observation of morphological changes, nuclear staining, and DNA electrophoresis. DNA synthesis was examined by thymidine incorporation. RESULTS: C2-ceramide induced reversible morphological changes of synovial cells such as cell rounding within four hours. Subsequently, irreversible nuclear changes characteristic to apoptosis were observed at 48 hours. DNA synthesis was not promoted. The addition of ceramide exerted similar effects on cultured dermal fibroblasts. CONCLUSION: Ceramide induced apoptosis in RA synovial cells. Ceramide could be a second messenger specific for apoptosis of RA synovial cells.     

Transforming growth factor-beta 1 stimulates articular chondrocyte proteoglycan synthesis and induces osteophyte formation in the murine knee joint

BACKGROUND: High concentrations of active transforming growth factor-beta (TGF-beta) have been found in synovial fluids from arthritic joints. TGF-beta stimulates articular cartilage proteoglycan synthesis and suppresses proteoglycan degradation in vitro. In an earlier study, we found no effect on cartilage proteoglycan metabolism shortly after a single intra-articular injection of TGF-beta 1. In the present study, we used multiple intra-articular injections and a longer time-scale. EXPERIMENTAL DESIGN: TGF-beta 1 was injected into the murine knee joint to gain insight in the consequences of its overproduction in joint diseases. This was evaluated using histologic sections of the whole knee joint and measurements of articular cartilage proteoglycan synthesis and content. RESULTS: At 6 hours after a single TGF-beta 1 injection, recruitment of polymorphonuclear leukocytes (PMNs) was observed. After 24 hours, the amount of inflammatory cells had already decreased. Multiple TGF-beta 1 injections induced synovial hyperplasia and synovitis predominantly consisting of cells of the macrophage/monocyte lineage. Both single and multiple TGF-beta 1 injections induced strong and long-lasting stimulation of articular cartilage proteoglycan synthesis. This in vivo stimulation of proteoglycan synthesis was similar in cartilage of young (3 months) and old mice (18 months). Multiple TGF-beta 1 injections resulted in an increased GAG content in patellar cartilage. After triple TGF-beta 1 injections, impressive osteophyte formation was noted at specific sites. The size and the localization of osteophytes was identical in young and old mice. Interestingly, the localization of TGF-beta 1-induced osteophytes was very similar to that of osteophytes observed in experimental arthritis and osteoarthritis models, suggesting a role for endogenous TGF-beta in osteophyte formation during joint pathology. CONCLUSIONS: Our data indicate that TGF-beta 1 injection into a normal joint induces inflammation, synovial hyperplasia, osteophyte formation, and prolonged elevation of proteoglycan synthesis and content in articular cartilage.     

Glycosaminoglycan depletion greatly raises the hydraulic permeability of rabbit joint synovial lining

The hydraulic resistance of the synovial lining of a joint is important for retention of intraarticular lubricant. The resistance has been attributed to synovial interstitial glycosaminoglycans. This was tested by depletion of hyaluronan and chondroitin sulphates from synovium in five rabbit knees in vivo under anaesthesia, using testicular hyaluronidase. The enzyme raised synovial permeability to fluid 5- to 7-fold-substantially more, in fact, than predicted by a recent model. The results prove that hyaluronan and/or chondroitin sulphate are important sources of hydraulic resistance in synovium.     

New developments and applications in quantitative electron spectroscopic imaging of iron in human liver biopsies

The objective of this study was to determine the effects of intra-articularly administered triamcinolone acetonide (TA) in exercised equine athletes with carpal osteochondral fragmentation. Eighteen horses were randomly assigned to each of 3 groups. An osteochondral chip fragment was created in one randomly chosen intercarpal joint of each horse. Both intercarpal joints in the placebo control group (CNT) horses were injected with intra-articular administration (IA) of polyionic fluid. Both joints in the TA control group (TA CNT) horses were treated with 12 mg of TA in the intercarpal joint without an osteochondral fragment, and the opposite intercarpal joint was injected with a similar volume of polyionic fluid. The TA treated group (TA TX) horses were treated with 12 mg of TA in the joint that contained the osteochondral fragment and the opposite intercarpal joint was injected with a similar volume of polyionic fluid. All horses were treated IA on days 13 and 27 after surgery and exercised on a high speed treadmill for 6 weeks starting on Day 14. Horses in the TA TX group were significantly less lame than horses in the CNT and TA CNT groups. Horses in either TA CNT or TA TX groups had lower total protein, and higher hyaluronan, and glycosaminoglycan concentrations in synovial fluid than did those in the CNT group. Synovial membrane collected from subjects in TA CNT and TA TX groups had significantly less inflammatory cell infiltration, subintimal hyperplasia and subintimal fibrosis compared to the CNT group. Articular cartilage histomorphological parameters were significantly better from the TA CNT and TA TX groups compared to the CNT group. In conclusions, results from this study support favourable effects of TA on degree of clinically detectable lameness, and on synovial fluid, synovial membrane, and articular cartilage morphological parameters, both with direct intra-articular administration and remote site administration as compared to placebo treatment. The clinical use of IA administered TA in horses may be therapeutically beneficial in selected cases of osteochondral fragmentation and osteoarthritis.     

IgG RF analysis of synovial fluid of the knee joints in 35 patients with rheumatic disease

Rheumatoid arthritis (RA) is an autoimmune disease. IgG RF in the synovial fluid is a significant indicator for the pathogenesis and differential diagnosis of this disease. To now, RF tested by latex agglutination belongs to the IgM type whereas, in the rheumatoid synovial fluid, most of immunocomplex molecules are IgG which bind into a complex. IgG RF was determined by ELISA in the synovial fluid of 35 cases of joint disorders, including 12 cases of RA, 7 cases of reactive arthritis (ReA), 5 cases of osteoarthritis (OA) and 11 cases of non-synovitis (non-S) which were regarded as negative control. The upper limit of OD value +2s was 0.5. Using this standard 7 out of 12 cases of RA were positive. 2 of 5 cases of OA were weakly positive, and only one case of ReA was positive. This suggest that this test is valuable in the diagnosis of RA. We have also observed the relation between IgG RF in synovial fluid and X-ray and arthroscopic findings of the same knee joint. In 5 of 7 cases of positive RA, II-III X-ray changes and II-III cartilage destruction arthroscopic findings were noted, suggesting a relationship between IgG RF in synovial fluid and articular damage.     

Molecular lysis of synovial lining cells by in vivo herpes simplex virus-thymidine kinase gene transfer

Herpes simples virus thymidine kinase (HSV-TK) expression plasmid DNA was injected into the joint space of rabbits with antigen-induced arthritis (AIA). Purified plasmid DNA was able to mediate transfection of synovial lining cells and transient overexpression of HSV-TK in the context of active synovial inflammation. The pharmacodynamic distribution of intraarticular expression plasmid DNA was confined to the joint space. Arthritic rabbits treated with intraarticular expression plasmid DNA followed by intravenous ganciclovir (GCV, 5 mg/kg) twice daily for 3 days showed histologic evidence of synovial lining layer cytolysis when articular tissues were examined 21 days posttreatment. There was also a reduction in joint swelling in the TK-treated knees. No untoward clinical effects were observed in the rabbits and no evidence of cytolytic damage specific to the TK-GCV gene therapy was observed either in the articular cartilage or bone. The application of TK-GCV intraarticular gene therapy using purified expression plasmid DNA for the induction of synovial cytolysis may be applicable to the treatment of human inflammatory arthritis.     

Increased permeability for plasma components of the cerebral vessels during acute angiotensin hypertension in rats

Experimentally induced acute angiotensin hypertension has been shown to increase the permeability of cerebral arterioles, venules and veins to plasma components whthin a few hours. This increase in permiability was demonstrated by means of circulating homologous fluorescent serum proteins and colloidal carbon particles. The results support the view that an increased permeability of the cerebral vessels to plasma components is either a causal or an additional pathogenetic factor in the development of the hypertensive encephalopathy.     

Effects of pulse methylprednisolone on cell adhesion molecules in the synovial membrane in rheumatoid arthritis. Reduced E-selectin and intercellular adhesion molecule 1 expression

OBJECTIVE: To investigate the effects of a 1,000-mg intravenous pulse of methylprednisolone succinate (MP) on cell adhesion molecule expression on the synovial vascular endothelium in patients with rheumatoid arthritis (RA). METHODS: Sequential arthroscopic biopsy samples were taken before and 24 hours after MP administration (10 patients) and at the time of RA flare (2 patients) and after retreatment with MP (1 patient). Immunoperoxidase staining for E-selectin (CD62E), P-selectin (CD62P), intercellular adhesion molecule 1 (ICAM-1; CD54) and platelet-endothelial cell adhesion molecule (PECAM; CD31) was performed, and the staining was quantified by color video image analysis. RESULTS: MP caused a rapid (within 24 hours) and substantial decrease in the expression of E-selectin on the synovial vascular endothelium, with a smaller reduction in ICAM-1 expression on synovial vascular endothelium and the synovial lining. There were no similar effects on synovial membrane P-selectin or PECAM expression. CONCLUSION: A potential mechanism by which MP impairs neutrophil trafficking into inflamed RA joints might be by reducing E-selectin, and possibly, ICAM-1, expression in the synovial membrane.     

Synovium as a source of increased amino-terminal parathyroid hormone-related protein expression in rheumatoid arthritis. A possible role for locally produced parathyroid hormone-related protein in the pathogenesis of rheumatoid arthritis

Proinflammatory cytokines, including tumor necrosis factor (TNF) and interleukin 1 (IL-1), mediate the joint destruction that characterizes rheumatoid arthritis (RA). Previous studies have shown that parathyroid hormone-related protein (PTHrP) is a member of the cascade of proinflammatory cytokines induced in parenchymal organs during lethal endotoxemia. To test the hypothesis that NH2-terminal PTHrP, a potent bone resorbing agent, could also be a member of the synovial cascade of tissue-destructive cytokines whose expression is induced in RA, PTHrP expression was examined in synovium and synoviocytes obtained from patients with RA and osteoarthritis (OA). PTHrP production, as determined by measurement of immunoreactive PTHrP(1-86) in tissue explant supernatants, was increased 10-fold in RA versus OA synovial tissue. Synovial lining cells and fibroblast-like cells within the pannus expressed both PTHrP and the PTH/PTHrP receptor, findings that were confirmed by in vitro studies of cultured synoviocytes. TNF-alpha and IL-1beta stimulated PTHrP expression in synoviocytes, while dexamethasone and interferon-gamma, agents with some therapeutic efficacy in the treatment of RA, inhibited PTHrP release. Treatment of synoviocytes with PTHrP(1-34) stimulated IL-6 secretion. These results suggest that proinflammatory cytokine-stimulated production of NH2-terminal PTHrP by synovial tissue directly invading cartilage and bone in RA may mediate joint destruction through direct effects on cartilage or bone, or, indirectly, via the induction of mediators of bone resorption in the tumor-like synovium.     

Analog vs. digital photogrammetry for optic cup analysis

Fourteen heparinized dogs were autotransfused from 1-5 to 6 times calculated blood volume. Five animals retransfused 12 litres from an intraperitoneal bleed had marked decreases in all cellular elements, haematuria and a large (82 percent) drop in fibrinogen. All these animals died within 12 hours and post-mortem examination revealed evidence of disseminated intravascular coagulopathy. The dogs in which a smaller volume (3-6 litres) was recycled showed similar, but less devastating, changes. Haematocrit and platelet count dropped by a half and fibrinogen by 20 per cent. A leucocytosis of about 30 000/mm3 occurred within 24 hours. Autotransfusion of salvaged blood which was not allowed extravascular tissue contact significantly lessened these adverse effects. We conclude that the risk of cellular destruction and defibrination in large volume intra-operative autotransfusion is significant and must be weighed against its potential benefits in each case, and that red cell and platelet damage results primarily from extravascular tissue contact and is therefore unavoidable.     

Effects of 6alpha-methylprednisolone acetate on an equine osteochondral fragment exercise model

OBJECTIVE: To determine effects of intra-articularly administered 6alpha-methylprednisolone acetate (MPA) in exercised horses with carpal osteochondral fragmentation. ANIMALS: 18 horses: 3 groups of 6 each. PROCEDURE: An osteochondral (chip) fragment was created in 1 randomly chosen middle carpal joint of each horse. Polyionic fluid (PF) was injected into both middle carpal joints of horses in the control group. In horses of the MPA-control group, MPA was injected into the middle carpal joint without an osteochondral fragment; a similar volume of PF was injected into the contralateral middle carpal joint. In the MPA-treated group of horses, 100 mg of MPA was injected into the middle carpal joint containing the osteochondral fragment; a similar volume of PF was injected into the contralateral joint. Injections were administered on postsurgical days 14 and 28, and horses were exercised on a high-speed treadmill for 8 weeks, starting on postsurgical day 15. RESULTS: Clinical improvement in degree of lameness was not associated with MPA administration. Joints that contained an osteochondral fragment and were treated with MPA had lower prostaglandin E2 concentration in synovial fluid, and lower scores for intimal hyperplasia and vascularity in synovial membrane, compared with PF-treated joints. However, articular cartilage erosion and morphologic lesions suggested possible deleterious effect of intra-articular MPA administration. CONCLUSIONS: Some beneficial effects of MPA administration on synovial fluid and synovial membrane were identified; however, the deleterious findings contrast with those associated with triamcinolone acetonide used in a similar model, but agree with other results of MPA administration in normal and abnormal joints.     

Effects of continuous passive motion and immobilization on synovitis and cartilage degradation in antigen induced arthritis

OBJECTIVE: To determine the effects of continuous passive motion (CPM) and immobilization on synovitis and cartilage degradation in an experimental model of chronic inflammatory, antigen-induced arthritis. METHODS: After bilateral arthritis induction of knee joints in 22 NZW rabbits, one knee was immobilized with a flexion splint while the opposite knee received CPM. RESULTS: After 2 weeks (n = 10), the CPM treated knees had significantly greater joint swelling, synovial effusion, and histologic synovitis scores compared to its opposite immobilized knees. However, the total cartilage degradation score showed no statistically significant difference between the two treatments. When the treatments were discontinued after 2 weeks and animals were allowed intermittent active motion of both knees in cages for 4 weeks (n = 12), no statistically significant difference in joint swelling, synovial effusion, and histologic synovitis score was observed between the 2 treatments. The articular cartilage degradation, however, was significantly greater in the immobilized knees compared to its opposite CPM treated knees. Five of 12 immobilized knees had articular surface erosion compared to none in the CPM treated knees. Loss of cellularity was also significantly greater in the immobilized knees. CONCLUSION: Although CPM produced greater synovitis at 2 weeks, articular cartilage was better preserved in the knees treated with CPM than immobilization at 6 weeks.     

Breastfeeding twins and higher-order multiples

OBJECTIVE: To evaluate, in a pilot, open clinical trial on 40 patients with knee osteoarthritis, the structural changes in the synovial membrane and cartilage following treatment with intra-articular hyaluronic acid (HA-Hyalgan). METHODS: The structural effects of HA given as 5 weekly injections (20 mg/2 ml once a week for 5 weeks), were evaluated by microarthroscopy and morphological analysis of biopsy samples taken at baseline and after 6 months, under blind conditions. Clinical efficacy was also evaluated using visual analogue scales for pain and functional parameters. RESULTS: At 6 months, the microarthroscopic evaluation indicated that the majority of the patients (60%) showed no changes compared to baseline, while 32.5% of the patients showed improvement in the grading and/or extension of cartilage lesions and 7.5% showed a worsened condition. These changes were accompanied by a statistically significant reduction in the synovial inflammation (p = 0.001). The results were confirmed by morphological examination of the cartilage and synovial membrane. At 6 months compared to baseline, a statistically significant reconstitution of the superficial amorphous layer of the cartilage (p = 0.0039), an improvement in the chondrocyte density (p = 0.0023) and vitality (p = 0.05), and a statistically significant reduction in synovial inflammation (p = 0.0001) accompanied by a significant increase in the synovial repair process (p = 0.0001) were observed. Significant and long lasting improvement in pain and joint mobility were also seen after HA treatment. Joint effusion, when present, was reduced. The treatment was well tolerated. CONCLUSION: Hyalgan represents a useful therapy for knee OA, with long-lasting symptomatic efficacy and potential positive effects on joint tissues. Other studies, in particular placebo-controlled studies, are warranted to confirm these promising results observed on joint tissues.     

Aortoesophageal fistula: recognition and diagnosis in the emergency department

Synovium is an essential component of the joint and plays a critical role in maintaining a balance between physiological processes and pathological changes in the joint. Recurrent intra-articular bleeding as occur in haemophilia induce pathological synovial changes in the joint. From a certain point on, synovitis inevitably plays a major role in joint destruction, although in the early phase of haemophilic arthropathy its role may be secondary to cartilage damage as a result of the direct effects of blood on cartilage. The changed haemosiderotic, synovial tissue produces catabolic cytokines and enzymes harmful for cartilage.     

Immunocytochemical demonstration of the synovial membrane in experimentally induced arthritis of the rat temporomandibular joint

The present study is first to report an experimental model of adjuvant-induced arthritis in the rat temporomandibular joint (TMJ). Arthritis was induced by simultaneous intradermal administrations of Freund's complete adjuvant, one at the parietal scalp and the other at the base of the tail. In this model, we demonstrated responses of the synovial membrane by immunocytochemistry using antibodies to OX6 and ED1 which recognize Ia antigen in MHC class II antigen-expressing cells and the macrophage/monocyte lineage, respectively. Three weeks after administration, no remarkable signs of inflammation were macroscopically recognizable in the TMJ, but microscopically the synovial membrane in the TMJ revealed marked changes such as enhanced vascularization and hemostasis in the sublining layer and a thickening in the synovial lining cell layer. Intense OX6-immuno-reactivity was found in the synovial lining cells at lesions in the experimental group but not in the control group. Immunoelectron microscopy revealed that these OX6-immunopositive synovial lining cells developed dense cytoplasmic processes and numerous vacuoles and vesicles, resembling type A cells. Part of the type A cells also showed ED1-immunoreactivity. The expression of OX6 or ED1 immunoreactivity in the synovial lining cells might be involved in the initial immune responses in this arthritis model because the synovial membranes are exposed to the synovial fluids which have been believed to contain antigenic substances.