Synovial fluid pH, cytologic characteristics, and gentamicin concentration after intra-articular administration of the drug in an experimental model of infectious arthritis in horses.

Chemical and cytologic effects and bactericidal activity of gentamicin in septic synovial fluid were evaluated in an experimental model of infectious arthritis in horses. Septic arthritis was induced by inoculation of approximately 7.5 X 10(6) colony-forming units of Escherichia coli into 1 antebrachiocarpal joint in each of 16 clinically normal adult horses. Clinical signs of septic arthritis were evident 24 hours after inoculation. Horses were allotted to 3 groups: group-1 horses (n = 5) each were given 150 mg of gentamicin (50 mg/ml; 3 ml) intra-articularly (IA); group-2 horses (n = 5) each were given 2.2 mg of gentamicin/kg of body weight, IV, every 6 hours; and group-3 horses (n = 6) each were given buffered gentamicin, consisting of 3 mEq of sodium bicarbonate (1 mEq/ml; 3 ml) and 150 mg of gentamicin (50 mg/ml; 3 ml), IA. Synovial fluid specimens were obtained at posttreatment hour (PTH) 0, 0.25, 1, 4, 8, 12, and 24 via an indwelling intra-articular catheter. Synovial fluid pH was evaluated at PTH 0, 0.25, and 24. Microbiologic culture and cytologic examination were performed on synovial fluid specimens obtained at PTH 0 and 24, and gentamicin concentration was measured in all synovial fluid specimens. At PTH 0, E coli was isolated from synovial fluid specimens obtained from all horses. Synovial fluid pH was lower (range, 7.08 to 7.16) and WBC count was higher (range, 88,000 to 227,200 cells/microliters) and predominantly neutrophilic (95 to 99%) at PTH 0 than before inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Importancia del sinovianálisis en reumatología / Importance of synovial fluid examination in rheumatology

El examen del líquido articular debe ser parte obligada de la investigación del derrame articular. Se describe la metodología de estudio del líquido sinovial que realizan los autores. Analizan los elementos normales, las alteraciones físicas y químicas, los cambios en la celularidad y la aparición de cristales correlacionando los cambios con las probables patologías que las determinan. Se desglosa en tres secciones de acuerdo a la forma de conservar la muestra, facilitando la comprensión de los procedimentos de estudio a los que se somete el líquido sinovial

Quantification of fluid changes in rat leg joints with adjuvant arthritis by a one-dimensional magnetic resonance imaging experiment.

A simple and reliable method for quantifying the fluid content and characterizing the tissue T2 relaxation properties of animal extremities has been devised. This one-dimensional magnetic resonance imaging experiment, applied to the adjuvant arthritis model in rats, provides a useful, noninvasive monitor of the course of the disease in vivo. Tissue is characterized through the analysis of the biexponential T2 decay of the NMR-active hydrogen in the rat leg joint tissue. Long and short T2 components are identified, both of which are sensitive to the arthritic process. The long component is suggested to come from edema and increases by a factor of ca. 9 during the course of the disease, whereas the short T2 component may represent cellular influx into the joint and increases by a factor of ca. 3. These changes correlate with the severity of the disease and can be used to monitor therapeutic response. The main advantage of the technique over the more traditional two-dimensional imaging approach is that only one spatial variable has to be resolved, resulting in shorter imaging time.

Synovial fluid tests. What should be ordered?

To determine which synovial fluid tests are most useful, we prospectively analyzed the synovial fluid test results of 100 consecutive patients undergoing diagnostic arthrocentesis. Each patient's diagnosis was established independently of synovial fluid laboratory test results; in 69 patients a definite inflammatory or noninflammatory categorization could be made. Sensitivity and specificity were estimated for synovial fluid white blood cell count (sensitivity, 0.84; specificity, 0.84), percentage of polymorphonuclear cells (sensitivity, 0.75; specificity, 0.92), glucose (sensitivity, 0.20; specificity, 0.84), protein (sensitivity, 0.52; specificity, 0.56), and lactate dehydrogenase (sensitivity, 0.83; specificity 0.71). Receiver operating characteristic regression analysis indicated that both white blood cell count and percentage of polymorphonuclear cells were found to contribute independent diagnostic information but lactate dehydrogenase did not. In a separate, retrospective analysis of 19 patients with definite septic arthritis, similar results were observed. We conclude that synovial fluid white blood cell count and percentage of polymorphonuclear cells perform well as discriminators between inflammatory and noninflammatory disease. Ordering chemistry studies of synovial fluid should be discouraged because they are likely to provide misleading or redundant information.

Cartilage breakdown in equine osteoarthritis: measurement of keratan sulphate by an ELISA system.

Degradation of cartilage in osteoarthritis of man results in the release of sulphated glycosaminoglycans, particularly keratan sulphate, into tissue fluids. A study was made to evaluate these markers for osteoarthritis in the horse. Synovial fluid and serum levels of keratan sulphate, measured by an ELISA-inhibition technique, and sulphated glycosaminoglycans measured by specific dye binding assay, were found to be significantly increased (P less than 0.001) in joints from horses with osteoarthritis, compared with normal joints. Synovial fluids from joints with infective arthritis also showed high keratan sulphate levels, but statistically were not significantly different from osteoarthritis. Measurement of serum/synovial fluid levels of proteoglycan may enable cartilage degeneration to be detected and monitored and help more effective treatments to be developed in the equine species.

A rapid and highly sensitive method for the quantitative determination of dexamethasone in plasma, synovial fluid and tissues by combined gas chromatography/negative ion chemical ionization mass spectrometry.

A new, simple and highly sensitive assay is developed for the quantitative measurement of very low levels of dexamethasone in human plasma, synovial fluid and tissues following a topical administration of the drug. Dexamethasone and the internal standard, flumethasone, are measured by gas chromatography/negative ion chemical ionization mass spectrometry with methane as the reagent gas. After a three-step extraction procedure, the two compounds of interest are converted to their trimethylsilyl ether derivatives using trimethylsilylimidazole and formamide as the base catalyst. Under soft derivatization conditions only one chromatographic peak corresponding to the trisubstituted derivative is observed. The mass spectrometer is focused to monitor abundant and stable characteristic high-mass ions (m/z 446 and 464) which are generated in the ion source by an electron capture process. This assay requires only 1 ml of plasma or 0.5 ml of synovial fluid and the detection limit of the method is equal to 0.1 ng ml-1 with a relative standard deviation lower than 6%.

[Changes in the synovial medium in deforming gonarthrosis]. / Izmeneniia sinovial'noi sredy pri deformiruiushchem gonarthroze.

The authors have determined the changes in the synovial medium of the joint characteristic of various stages of severity of the disease in 248 patients with deforming gonarthrosis on the basis of arthroscopic and thermographic studies and investigation of the permeability of the synovial membrane in the complex with clinical and roentgenologic examinations. At the initial stages the signs of local reactive inflammation of the synovial membrane near the foci of degeneration of the articular cartilage prevail. For the late stages a trend to spreading of the reactive inflammation of the synovial membrane with the development of sclerotic changes in the previously affected areas is characteristic. A comparison of the results of arthroscopy, infra-red thermography and the permeability of the synovial membrane point at parallel changes in the synovial medium and in the microcirculatory and regional circulation of the knee joint. These findings may be used for working out the rational tactics of treatment of the patients with deforming gonarthrosis.

[Spectrophotometric study of synovial exudate in differential diagnosis of pigmented villonodular synovitis]. / Spektrofotometricheskoe issledovanie sinovial'nogo vypota v diagnostike pigmentnogo vorsinchato-uzelkovogo sinovita.

The authors have studied the spectrophotometric characteristics of the synovial exudates in the patients with diseases of the knee joint of various etiology. The presence of two main maximums of the absorption spectra has been revealed in the wave frequencies of 280 and 460-465 nm. It has been determined that with regard to the optical densitys in the protein component (280 nm) and the pigments (460 nm) absorption area it is possible to differentiate very precisely pigmented villondular synovitis and other pathologies.

Abnormal osteocalcin binding in rheumatoid arthritis.

Studies of osteocalcin in the serum and synovial fluid of patients with rheumatoid arthritis (RA) and osteoarthritis (OA) showed the presence of significant amounts of osteocalcin in synovial fluid and that the values in RA synovial fluid were significantly lower than in OA synovial fluid. In addition, the osteocalcin in OA synovial fluid bound almost completely to hydroxyapatite, whereas a significant proportion of the osteocalcin in RA synovial fluid did not. These studies suggest that patients with severe RA produce low amounts of active osteocalcin and higher than expected amounts of inactive osteocalcin in the synovial fluid. They provide some evidence that osteoblast function may be abnormal in the osteoporosis of RA.

Comparison of ultrasonically applied vs. intra-articular injected hydrocortisone levels in canine knees.

Phonophoresis of hydrocortisone is a commonly performed treatment for a wide variety of soft-tissue as well as intra-articular musculoskeletal disorders. There have been no previously reported studies indicating the degree of hydrocortisone penetration into joints achieved by means of phonophoresis. Twenty-four purebred greyhounds were used to compare intra-articular levels of hydrocortisone resulting from intra-articular injection, phonophoresis, and external application of hydrocortisone. A total of 40 samples from canine knees were analyzed by means of fluorescence polarization. Intra-articular hydrocortisone levels obtained with phonophoresis were extremely low in comparison with those obtained with intra-articular injection. There were no statistically significant differences in intra-articular hydrocortisone levels between the phonophoresis and external application treatments, or between either of these and placebo control measurements taken from knees of untreated dogs and from shoulders of treated dogs. It appears that phonophoresis is an ineffective method of obtaining hydrocortisone penetration into a joint in the canine model.

Cellular fibronectin in rheumatoid synovium and synovial fluid: a possible factor contributing to lymphocytic infiltration.

Mouse monoclonal antibodies against ED sequence-containing cellular fibronectin (cFn) were used to show that Fn in the inflamed synovium is distinct from the major form of plasma Fn (pFn). An accumulation of cFn was seen at sites of hyperplasia of the rheumatoid synovial membrane and in the walls of small vessels in the synovium by immunofluorescence microscopy. cFn was also found in rheumatoid synovial fluid by immunoblotting. Approximately one-fifth of the T lymphocytes from rheumatoid synovial fluid bound to Fn. The binding of synovial fluid T cells was always higher than that from peripheral blood. These results have two implications. On the one hand, the cellular type of Fn may be an indicator of synovial inflammation. On the other hand, the deposition of Fn may be a factor contributing to the infiltration of mononuclear cells into the synovium.

Injections for joint and soft tissue disorders: when and how to use them.

Joint and soft tissue injections may be the only way to differentiate various arthritic disorders, accurately identify a septic joint, and apply focused treatment. Certain considerations can make these injections safer and more effective. This article reviews the principles of diagnostic and therapeutic use of joint and soft tissue injections and makes specific recommendations for common injection sites. Also described are appropriate aseptic techniques for aspirating and injecting joints, bursae, and soft tissue, as well as the judicious use of corticosteroid injections in this age group.

Leukotriene B4 and prostaglandin E2-like activity in synovial fluid in osteoarthritis.

LTB4 and PGE2-like activity in synovial fluid samples from patients with osteoarthritis of the knee joint were determined and found to be significantly higher than in samples obtained from normal patients. The results suggest that leukotrienes and prostaglandins may have a role in the pathogenesis of osteoarthritis.