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PubMedDate not supplied

Isolation of Chlamydia trachomatis or Ureaplasma urealyticum from the synovial fluid of patients with Reiter's syndrome.

BACKGROUND: The aim of this study was to contribute to the insight of the role of the infectious agent in ethiopathogenesis of the Reiter's syndrome development, which could directly influence the choice of treatment of these patients. METHODS: Eighteen patients with urogenital form of the Reiter's syndrome and 16 controls (6 with rheumatoid arthritis and 10 with pigmented villonodular synovitis) were included in the study. In all patients standard laboratory analyses of the blood, urine and stool were made; antibody titer to Chlamydia trachomatis and Ureaplasma urealyticum was determined in synovial fluid and serum; isolation of Chlamydia trachomatis and Ureaplasma urealyticum in urethral, cervical and conjunctival swabs, as well as in prostatic and synovial fluid, was also made. HLA typing was done, too. Chlamydia was isolated in the McCoy cell culture treated with cycloheximide, while Ureaplasma was identified according to its biochemical properties grown on cell-free liquid medium. RESULTS: Chlamydia trachomatis was isolated from the synovial fluid of 4 patients with Reiter's syndrome (22.2%), while Ureaplasma urealyticum was isolated in 7 of them (38.9%). These microorganisms were not found in any synovial fluid of the control group patients. CONCLUSION: Presence of these bacteria in the inflamed joint might be an important factor in etiopathogenesis of this disease, and it supports the hypothesis that arthritis in Reiter's syndrome is probably of the infectious origin.

Adult↗
PubMed2001

Electron microscope and biochemical observations of the surface active phospholipids on the articular surfaces and in the synovial fluid of the temporomandibular joint: a preliminary investigation.

PURPOSE: The goal of this article is to investigate the surface-active phospholipids located on the articular surfaces and in the temporomandibular joint (TMJ) synovial fluid (SF) by means of electron microscopy and biochemical analysis. MATERIALS AND METHODS: Synovial fluids and articular cartilage samples taken from 6 normally functioning TMJs were studied. The osmiophilic lining of human TMJ articular surfaces has been studied by using special nondestructive fixation procedures. To study the SF, negative staining technique has been used. In addition, thin-layer chromatography has been used to identify the phospholipids extracted from synovial fluid of human TMJs. RESULTS: In the SF, granular bodies were identified with diameter of between 170 and 280 nm. Their diameter decreased dramatically when exposed to phospholipase-A(2). The amorphous and highly osmophilic material on the articular surface include membrane-bound vesicles (270 nm in diameter) with lamellated pattern surrounding the amorphous-dense core. Biochemical extraction revealed phosphatidylcholine as the major component of the polar lipids. CONCLUSIONS: This preliminary study presents findings that suggest that phospholipids present in the TMJ may provide an efficient boundary lubrication that enables the disc to slide down the slope of the eminence on joint function.

Chromatography, Thin Layer↗
PubMedDate not supplied

[The status of various indicators of the protease inhibitor system in blood and synovial fluid in rheumatoid arthritis].

Elastase-like activity, alpha 1-inhibitor of proteinases and acid stable antitryptic activity were studied in blood of 26 patients and in synovial fluid of 11 patients with rheumatoid arthritis during acute stage of the disease and after treatment with salase pyridasine and orthophene. The higher values of the elastase-like activity were detected in synovial fluid as compared with that of blood. In blood of these patients, hyperproduction of alpha 1-inhibitor of proteinases and acid stable inhibitors was observed, while deficiency of these substances occurred in synovial fluid. Distinct decrease in the patterns of the blood protease-inhibitory system studied simultaneously with clear positive clinical effect were observed after treatment with salase pyridasine together with orthophene; estimation of these patterns may be used in the evaluation of the therapy.

Adult↗
PubMed1975

Immunoglobulins and complement components in synovial fluid of patients with acute rheumatic fever.

Three components of complement and six other serum proteins were assayed in synovial fluid and serum samples from 25 patients with acute rheumatic fever in Trinidad. The resulting data indicate a relative decrease in both early and late components of complement within the synovial fluids which suggests local activation by immune complexes. Such activation of complement within the joint spaces may play a primary role in development of the inflammatory arthritis of acute rheumatic fever.

Adolescent↗
PubMed2001

Cartilage and bone biological markers in the synovial fluid of osteoarthritic patients after hyaluronan injections in the knee.

OBJECTIVE: To evaluate synovial fluid levels of cartilage and bone biological markers after repetitive intra-articular injections of sodium hyaluronate (HA) in knee osteoarthritis (OA) patients. METHODS: Twenty patients with knee OA were evaluated before and after 5 weekly injections of HA. To study cartilage and bone biological markers, synovial fluid and urine samples were collected simultaneously with the first (FI=week 0) and before the last injection (LI=week 4) of HA. Not commercially available markers (cartilage oligomeric matrix protein (COMP), proteoglycan monomers and cyanogen bromide peptide 11 of the type II collagen chains (alpha (II) CA11B)) were determined by an indirect inhibition ELISA developed and standardized in our laboratory. RESULTS: We found a significant reduction in levels of proteoglycan monomers (30+/-16 vs. 22+/-10 microg/ml, p<0.05), an increase in COMP concentration (2.9+/-0.9 vs. 3.6+/-0.9 microg/ml, p<0.05) and osteocalcin (BGP) levels (8.7+/-8 vs. 11.9+/-9 ng/ml, p<0.05). No significant changes were observed in the levels of alpha (II)CB11B), metalloproteinase-1 (MMP-1) or pyridinium cross-link/creatinine (Pyr/Cr). CONCLUSIONS: HA could elicit an indirect response on the cartilage and bone metabolism due to the increased overuse of the joint caused by the analgesic effect of HA. However, a direct HA action on the metabolism of chondrocytes must not be ruled out.

Aged↗
PubMed1978

Antibiotic penetration of synovial fluid in infected and normal knee joints.

A spectrum of new and commonly used antibiotics was examined with regard to their ability to penetrate into joint fluid in normal and E. coli infected rabbit knee joints. In order to carry out this investigation a new, simple method of measuring antibiotics in very small amounts of synovial fluid was developed. Cephalothin, cefazolin, cefoxitin, carbenicillin, amikacin, and gentamicin all penetrated into synovial fluid effectively achieving peak concentrations within 30 minutes to one hour. Synovial fluid antibiotic concentrations at 2 hours were equal to or higher than simultaneous serum levels. This relationship persisted thereafter. Penetration of antibiotics into infected joints was dependent primarily on serum concentration and was not altered importantly by the presence of acute chronic or previous infection. Antibiotic doses employed were equivalent to clinical usage on a weight basis. Penetration of all antibiotics studied was satisfactory for use against their normally intended pathogens.

Amikacin↗
PubMed2006

Resistin in rheumatoid arthritis synovial tissue, synovial fluid and serum.

BACKGROUND: Resistin is a newly identified adipocytokine which has demonstrated links between obesity and insulin resistance in rodents. In humans, proinflammatory properties of resistin are superior to its insulin resistance-inducing effects. OBJECTIVES: To assess resistin expression in synovial tissues, serum and synovial fluid from patients with rheumatoid arthritis, osteoarthritis and spondylarthropathies (SpA), and to study its relationship with inflammatory status and rheumatoid arthritis disease activity. METHODS: Resistin expression and localisation in synovial tissue was determined by immunohistochemistry and confocal microscopy. Serum and synovial fluid resistin, leptin, interleukin (IL)1beta, IL6, IL8, tumour necrosis factor alpha, and monocyte chemoattractant protein-1 levels were measured. The clinical activity of patients with rheumatoid arthritis was assessed according to the 28 joint count Disease Activity Score (DAS28). RESULTS: Resistin was detected in the synovium in both rheumatoid arthritis and osteoarthritis. Staining in the sublining layer was more intensive in patients with rheumatoid arthritis compared with those with osteoarthritis. In rheumatoid arthritis, macrophages (CD68), B lymphocytes (CD20) and plasma cells (CD138) but not T lymphocytes (CD3) showed colocalisation with resistin. Synovial fluid resistin was higher in patients with rheumatoid arthritis than in those with SpA or osteoarthritis (both p<0.001). In patients with rheumatoid arthritis and SpA, serum resistin levels were higher than those with osteoarthritis (p<0.01). Increased serum resistin in patients with rheumatoid arthritis correlated with both CRP (r=0.53, p<0.02), and DAS28 (r=0.44, p<0.05), but not with selected (adipo) cytokines. CONCLUSION: The upregulated resistin at local sites of inflammation and the link between serum resistin, inflammation and disease activity suggest a role for resistin in the pathogenesis of rheumatoid arthritis.

Adult↗
PubMed2002

In vivo effects of meloxicam and aspirin on blood, gastric mucosal, and synovial fluid prostanoid synthesis in dogs.

OBJECTIVE: To evaluate in vivo activity in dogs of meloxicam or aspirin, previously shown in vitro to be a selective cyclooxygenase-2 (COX-2) inhibitor (COX-1 sparing drug), or a nonselective COX inhibitor, respectively. ANIMALS: 12 male dogs with unilateral osteoarthritis of the stifle joint. PROCEDURE: Each dog was treated in a crossover design with aspirin or meloxicam for 21 days. Prostaglandin E2 (PGE2) concentrations were measured at days 0 (baseline), 7, and 21 of each treatment period in lipopolysaccharide (LPS)-stimulated blood, synovial fluid collected by arthrocentesis, and endoscopic gastric mucosal biopsy specimens. Thromboxane B2 (TXB2) was evaluated in blood on days 0, 7, and 21 of each treatment period. RESULTS: Aspirin administration significantly suppressed PGE2 concentrations in blood, gastric mucosa, synovial fluid, and suppressed TXB2 concentration in blood at days 7 and 21. Meloxicam administration significantly suppressed PGE2 concentrations in blood and synovial fluid at days 7 and 21, but had no effect on concentrations of TXB2 in blood or PGE2 in gastric mucosa. Suppression of LPS-stimulated PGE2 concentrations in blood and synovial fluid by aspirin and meloxicam administration is consistent with activity against the COX-2 isoenzyme. Suppression of concentrations of PGE2 in the gastric mucosa and TXB2 in blood by aspirin administration is consistent with activity against COX-1. Meloxicam, in contrast, had a minimal effect on functions mediated by COX-1. CONCLUSIONS AND CLINICAL RELEVANCE: Meloxicam acts in vivo in dogs as a COX-1 sparing drug on target tissues by sparing gastric PGE2 synthesis while retaining antiprostaglandin effects within inflamed joints.

Animals↗
PubMed1991

Differential synthesis of 5-lipoxygenase in peripheral blood and synovial fluid neutrophils in rheumatoid arthritis.

In order to investigate 5-lipoxygenase enzyme regulation in neutrophils during an inflammatory reaction, we studied 5-lipoxygenase mRNA levels, as well as de novo enzyme synthesis, in resting and activated neutrophils isolated from normal individuals and patients with rheumatoid arthritis. The approach used was to analyze these activities in resting peripheral blood neutrophils of normal individuals on the one hand and in peripheral blood and matched synovial fluid neutrophils isolated from patients with rheumatoid arthritis on the other hand. Our first observation was that resting peripheral blood neutrophils of either normal individuals or patients show detectable levels of 5-lipoxygenase mRNA and are able to synthesize the enzyme de novo. Our second observation was that inflammatory activated neutrophils from synovial fluid reveal lower 5-lipoxygenase mRNA levels and enzyme synthesis than do the patient-matched peripheral blood cells. This is in spite of the fact that, for other proteins, synovial fluid neutrophils are equally or more active than their peripheral blood counterparts. We conclude that peripheral blood neutrophils are capable of synthesizing the enzyme, thus ensuring the turnover of the protein. Furthermore, complex regulatory mechanisms appear to take place in response to inflammation as it occurs in synovial fluids of patients with rheumatoid arthritis, leading to decreased mRNA levels and enzyme synthesis. Possible mechanisms of regulation are discussed and are presently under investigation.

Arachidonate 5-Lipoxygenase↗
PubMed2001

Effect of intraarticular hyaluronan injection on synovial fluid hyaluronan in the early stage of canine post-traumatic osteoarthritis.

OBJECTIVE: To determine how the quantity and molecular weight of synovial fluid hyaluronan (HA) within the synovial fluid (SF) of osteoarthritis (OA) joints is affected by intraarticular injection of HA. METHODS: Dogs in which OA was induced by transection of the anterior cruciate ligament received 5 weekly injections of HA (1.5 x 10(6) Da) in saline (10 mg/0.67 ml) or an equal volume of saline into the operated knee, beginning the day after surgery. Immediately before each injection, SF was aspirated and the volume of SF and the concentration of HA was measured (uronic acid), and the molecular weight of the HA in each sample was estimated by electrophoresis in agarose. RESULTS: The volume of SF in the unstable knee increased after surgery, and the molecular weight decreased from approximately 2.5 x 10(6) Da to approximately 2 x 10(6) Da. Injection of HA did not affect the volume of SF or average molecular weight of HA in samples obtained immediately before each injection or at the end of the experiment, 12 weeks after surgery. The SF HA concentration fell from a baseline value of 2.3 +/- 0.1 mg/ml to 1.1 +/- 0.2 mg/ml the day after surgery and remained low throughout the course of injections. The HA concentration 12 weeks after surgery in the HA injected knees was approximately 40% lower than the preoperative value, although it increased slightly relative to saline injected knees (1.4 +/- 0.3 vs 1.1 +/- 0.01 mg/ml, respectively; p = 0.04). CONCLUSION: Intraarticular injection of HA did not alter the volume of SF or molecular weight of HA in SF of OA canine knees, nor did it restore the HA concentration to that of normal canine SF.

Adjuvants, Immunologic↗
PubMed1996

Intra-articular morphine and saline injections induce release of large molecular weight proteoglycans into equine synovial fluid.

Both morphine and physiologic saline injected intra-articularly into healthy equine tarsocrural joints induced a release of large molecular size proteoglycan (PG) subunits into the synovial fluid (SF) analysed 24 h postinjection. High-performance liquid chromatography (HPLC) with a size-exclusion column was used to assess the high molecular weight proteoglycans in equine synovial fluid (SF). The PG peaks of SF samples eluated separately from SF hyaluronate and other molecular components of the SF in the HPLC chromatographies indicating no interaction between hyaluronate and PG in the SF. Individual elution profiles varied between joints and horses. The amount of PG release was measured by relative area index from the HPLC chromatograms. The synovial fluid PG content was significantly increased (P < 0.05) after morphine but not in saline injected joints compared with pretreatment but there were no significant differences between the two groups. It was concluded that intra-articular injections of both morphine and physiologic saline are able to elicit a marked PG release into the SF from articular cartilage within 24 h of injection.

Animals↗
PubMed1995

Sensitivities of PCR, MicroTrak, ChlamydiaEIA, IDEIA, and PACE 2 for purified Chlamydia trachomatis elementary bodies in urine, peripheral blood, peripheral blood leukocytes, and synovial fluid.

Routine microbiological diagnosis of Chlamydia-induced reactive arthritis is based mainly on the detection of Chlamydia trachomatis with urogenital swabs or in urine. Because chlamydial antigen, rRNA, and DNA are present in low quantities in the inflamed joint, highly sensitive assays are needed to detect C. trachomatis not only at the primary site of infection but also in peripheral blood and peripheral blood leukocytes, which are suspected carriers for dissemination, and in synovial fluid. To evaluate possible tools for this purpose, the sensitivities of PCR, MicroTrak, Chlamydia EIA, IDEIA, and PACE 2 for the detection of defined numbers of purified C. trachomatis elementary bodies (EB) in urine, peripheral blood, peripheral blood leukocytes, and synovial fluid were determined. In urine, PCR detected 2, MicroTrak and ChlamydiaEIA detected 2 x 10(3), and PACE 2 and IDEIA detected 2 x 10(4) EB per ml. In peripheral blood, only PCR and MicroTrak detected C. trachomatis, with detection limits of 100 and 2 x 10(7) EB per ml, respectively. For peripheral blood leukocytes, the detection limits were 2 EB per ml for PCR and 2 x 10(4) EB per ml for MicroTrak, ChlamydiaEIA, IDEIA, and PACE 2. In synovial fluid, PCR detected 200, MicroTrak and IDEIA detected 2 x 10(5), and PACE 2 detected 10(6) EB per ml. ChlamydiaEIA was unable to detect 2 x 10(6) EB per ml in synovial fluid. In summary, PCR was found to be the most sensitive method. The sensitivities of the other methods tested were at least 1,000 times lower than that of PCR. PCR should therefore be considered a most promising tool for routine diagnosis of Chlamydia-induced arthritis.

Antigens, Bacterial↗
PubMed1981

T gamma lymphocytes of peripheral blood and synovial fluid in rheumatoid arthritis: quantitative determination and qualitative analysis.

The distribution of T gamma lymphocytes in the peripheral blood of one group of rheumatoid patients and in the synovial fluid in a second group was determined. The results were compared to those found for peripheral blood (PB) lymphocytes of normal subjects and for synovial fluid lymphocytes of osteoarthrosis and meniscitis patients. Besides recording percentage and absolute number, we also used cytofluorographic analysis to determine individual capacity of PB T gamma cells to bind heat-aggregated IgG (agg-IgG). The following results were found: 1) there is no significant difference between the percentage and absolute number of PB T gamma lymphocytes of rheumatoid arthritis (RA) patients and those of controls, 2) individual RA PB T gamma cells had a greater number and/or avidity of Fc receptor for IgG than those cells of controls, and 3) the percentage of RA T gamma lymphocytes in synovial fluid, revealed by IgG-EA ox rosetting, is significantly lower than that found in control patients. The factors that may determine a similar lymphocyte picture in RA are discussed.

Arthritis, Rheumatoid↗
PubMed2005

MMP protein and activity levels in synovial fluid from patients with joint injury, inflammatory arthritis, and osteoarthritis.

OBJECTIVE: To determine protein and activity levels of matrix metalloproteinases 1 and 3 (MMP-1 and MMP-3) in synovial fluid of patients with knee joint injury, primary osteoarthritis, and acute pyrophosphate arthritis (pseudogout). METHODS: Measurements were done on knee synovial fluid obtained in a cross sectional study of cases of injury (n = 283), osteoarthritis (n = 105), and pseudogout (n = 65), and in healthy controls (n = 35). Activity of MMP-1 and MMP-3 in alpha(2) macroglobulin complexes was measured using specific low molecular weight fluorogenic substrates. ProMMP-1, proMMP-3, and TIMP-1 (tissue inhibitor of metalloproteinase 1) were quantified by immunoassay. RESULTS: Mean levels of proMMP-1, proMMP-3, and TIMP-1 were increased in injury, osteoarthritis, and pseudogout compared with controls. MMP-1 activity was increased in pseudogout and injury groups over control levels, whereas MMP-3 activity was increased only in the pseudogout group. The increase in MMP-1 activity coincided with a decrease in TIMP-1 levels in the injury group. CONCLUSIONS: Patients with joint injury have a persistent increase in proMMP-1 and proMMP-3 in synovial fluid and an increase in activated MMPs, which are not inhibited by TIMP. The differences in activation and inhibition patterns between the study groups are consistent with disease specific patterns of MMP activation and/or inhibition in joint pathology.

Acute Disease↗
PubMed2002

Analysis of cartilage-derived retinoic-acid-sensitive protein (CD-RAP) in synovial fluid from patients with osteoarthritis and rheumatoid arthritis.

We have measured the concentration of cartilage-derived retinoic-acid-sensitive protein (CD-RAP) in synovial fluid (SF) from the knees of 49 patients with osteoarthritis (OA) and 79 with rheumatoid arthritis (RA) in order to investigate the correlation between the type of joint disease and level of CD-RAP. The mean concentration of CD-RAP in synovial fluid was significantly higher in OA than in RA. The level of CD-RAP in the group of patients with mild OA was significantly higher than in the moderate or severe groups and that in the group with mild RA was also significantly higher than in the other RA groups and decreased with progression of the disease. Immunohistochemical studies showed expression of CD-RAP in the cytoplasm of chondrocytes in newly-formed fibrocartilage. Since CD-RAP is mainly produced in young and proliferating chondrocytes, our results suggest that the level of CD-RAP in synovial fluid reflects remodelling of articular cartilage and may be used as a marker to estimate objectively the restorative reaction of chondrocytes.

Aged↗
PubMed2001

Cross-sectional comparison of synovial fluid biochemical markers in equine osteoarthritis and the correlation of these markers with articular cartilage damage.

OBJECTIVE: To investigate the relationship between biochemical markers in the synovial fluid of osteoarthritic and contralateral equine joints and gross articular cartilage pathology. DESIGN: Twenty-two horses underwent bilateral arthroscopy of their carpal or metacarpophalangeal joints following recent onset lameness. The degree of cartilage damage in each joint was scored and synovial fluid, from both the clinically affected and the contralateral joint, was collected. Bone specific alkaline phosphatase (BAP), 5D4 epitope of keratan sulphate (KS), total glycosaminoglycans (GAG) and hyaluronan (HA) were measured. RESULTS: The mean age of the horses was 4.1 years and the maximum duration of lameness was three months. Joints examined were midcarpal, antebrachiocarpal and metacarpophalangeal. The median concentration (semi-interquartile range) of BAP was significantly higher in the clinically active joint than in the contralateral joint, 21.75 (6.22) vs. 12.35 (4.07) units, while the other biomarkers measured were significantly lower in the clinically active joint than in the contralateral joint, i.e. KS 8.79 (1.96) microg/ml vs. 16.39 (5.65) microg/ml, KS:GAG ratio 0.19 (0.04) vs. 0.31 (0.10) and HA 741.6 (222) microg/ml vs. 1061.75 (325) microg/ml. BAP was positively (R=0.57), and KS (R=-0.57) and KS:GAG ratio (R=-0.49) were negatively correlated to the degree of cartilage damage within the joint. CONCLUSION: The correlation between articular cartilage damage and synovial fluid BAP and KS imparts validity to their potential use as non-invasive diagnostic aids in equine osteoarthritis (OA). The positive correlation between BAP and cartilage damage suggests that there is a link between bone turnover and cartilage damage in OA.

Alkaline Phosphatase↗
PubMed1994

Disappearance kinetics of solutes from synovial fluid after intra-articular injection.

1. Five rheumatoid patients with a knee joint effusion participated in the study. An aqueous solution (0.1 to 0.2 ml) containing paracetamol, salicylate, diclofenac and [125I]-albumin was injected into a given joint to yield target concentrations of approximately 20 micrograms ml-1 for diclofenac, salicylate and paracetamol and 10(8) counts ml-1 for [125I]-albumin. 2. Paracetamol, salicylate and diclofenac were analysed in synovial fluid by h.p.l.c. [125I]-albumin was analysed using gamma counting. 3. The clearances (+/- s.d.) obtained for the solutes were [125I]-albumin (0.0053 +/- 0.0019 l h-1), diclofenac (0.0096 +/- 0.0061 l h-1), salicylate (0.024 +/- 0.022 l h-1) and paracetamol (0.055 +/- 0.041 l h-1). The corresponding fractions unbound of these solutes in synovial fluid were 0.0, < or = 0.01, 0.34 +/- 0.09 and 0.85 +/- 0.10, respectively. 4. Diffusion of unbound solute through the synovium is estimated to account for (+/- s.d.) 0.52 +/- 0.08, 0.87 +/- 0.06 and 0.99 +/- 0.01 of the total clearance of diclofenac, salicylate and paracetamol from the joint space, respectively. The remaining proportion of clearance is accounted for by efflux of solute bound to albumin. 5. An expression for the ratio of synovial fluid to total plasma concentrations after systemic administration was developed to include both diffusion of unbound solute and albumin flux. Most solutes appear to satisfy the conditions in which this expression reduces to the limiting case where the unbound concentration of the solute is identical in the synovial fluid and plasma under steady state conditions.

Acetaminophen↗
PubMed1996

Synovial surfactant: lamellar bodies in type B synoviocytes and proteolipid in synovial fluid and the articular lining.

Previous studies have shown that synovial surfactant could have beneficial roles in the joint, especially as a very effective boundary lubricant capable of high load bearing. This study is aimed at further characterization and identification of the source. Known to be an important minor component of pulmonary surfactant, proteolipid has now been detected in appreciable quantities in bovine synovial fluid and bound to the articular surface. Using standard procedures to separate it from the major component [surface-active phospholipid (SAPL)] by column chromatography, proteolipid: phospholipid ratios were found to be comparable to those in the lung or in lamellar bodies (LBs). LBs are the unequivocal source of surfactant in the lung and we have confirmed an earlier study demonstrating their presence in Type B synoviocytes. Using a fixation procedure specifically designed to preserve the graphite-like structure of SAPL deposited as oligolamellar layers, or coiled as lamellar bodies, we were able to demonstrate these structures in equine joints adjacent to the Golgi apparatus associated with the secretory mechanism of the cell. These results indicate that proteolipid could be facilitating the deposition of the graphite-like surface lining of SAPL providing efficient boundary lubrication just as it promotes surfactant adsorption in the lung and in the formation of myelin. Any deficiency in synovial surfactant, compromising its roles in the joint, is discussed in relation to osteoarthritis and the possible administration of exogenous SAPL to the degenerating joint.

Animals↗