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A Swan

Publications and source records attributed to A Swan.

15 recordsLinked to original sources

Evidence for a causal relationship between the structure, size, and load of calcium pyrophosphate dihydrate crystals, and attacks of pseudogout.

OBJECTIVE: To investigate any relationship between the nature, size, and numbers of synovial fluid (SF) calcium pyrophosphate dihydrate (CPPD) crystals, and attacks of pseudogout. METHODS: Knee SF was aspirated from nine selected patients, first during an attack of pseudogout (acute sample) and again later when the attack had subsided (interval sample). CPPD crystals were extracted, weighed, examined by high resolution transmission electron microscopy (HRTEM), and characterised by size and crystal habit (monoclinic or triclinic). Structural analysis was carried out by x ray powder diffraction (XRD) and the proportions of monoclinic to triclinic CPPD were estimated from densitometric measurements of selected key reflections. RESULTS: The mean crystal size, by HRTEM, indicated that the crystals in the acute sample were larger than those in the interval sample. The ratio of monoclinic to triclinic CPPD, whether estimated from their morphological appearance by HRTEM, or from XRD, was greater in the acute than in the interval sample in all nine patients. The total amount of extracted mineral varied, but in every patient the concentration of CPPD per ml of fluid, and the total mineral per joint, were greater in the acute sample than in the interval sample. CONCLUSION: In this highly selected group of patients, the large numbers of CPPD crystals associated with attacks of pseudogout included a greater proportion of monoclinic crystals, and larger crystals, than those present when inflammation had subsided. A special, phlogistic population of crystals may exist, originating in different joint tissues, or cleared in a different manner, than the more common populations of smaller crystals with a greater proportion of triclinic CPPD, seen in chronic disease.

Acute Disease

Submicroscopic crystals in osteoarthritic synovial fluids.

OBJECTIVES: To investigate the hypothesis that synovial fluid (SF) from patients with osteoarthritis (OA) may contain calcium phosphate crystals that are either too small, or too few in number to be identified by conventional light microscopy techniques. METHODS: Twelve SF from 11 patients with established knee OA, five SF from patients with rheumatoid arthritis (RA), and two control samples of SF from patients with pseudogout were subjected to an enzyme/hypochlorite extraction procedure. The patients with OA and RA had no radiographic evidence of chondrocalcinosis, or SF crystals on polarised light microscopy. Extracted material was examined and analysed by analytical electron microscopy (AEM) and x ray powder diffraction (XRD). RESULTS: Mineral was found in 11 of 12 OA samples, ranging from 2-120 micrograms/ml SF. Analytical electron microscopy revealed calcium pyrophosphate dihydrate (CPPD) crystals in five (confirmed by XRD in three) and basic calcium phosphates (BCP) in eight (five on XRD). Two samples with confirmed CPPD contained some rods with a mean length below 100 nm. The majority of BCP clusters were also less than 100 nm in diameter. BCP was detected in 1/5 RA samples. Control samples contained CPPD crystals of the expected size range of 0.42-17.9 microns. CONCLUSIONS: The data indicate that many OA SF may contain CPPD or BCP crystals which are too small or too few in number to be identified by conventional techniques. Crystal deposition is not an 'on-off' phenomenon in OA.

Aged

Changes in cartilage metabolism in arthritis are reflected by altered serum and synovial fluid levels of the cartilage proteoglycan aggrecan. Implications for pathogenesis.

The metabolism of the cartilage proteoglycan aggrecan was studied in patients with osteoarthritis (OA, n = 83), rheumatoid arthritis (RA, n = 127), and in controls (n = 117) using monoclonal antibody-based radioimmunoassays for glycosaminoglycans in the serum and synovial fluid (SF) to detect epitope 846 on chondroitin sulfate (probably only on recently synthesized molecules) and a keratan sulfate (KS) epitope AN9PI, present on intact and degraded molecules. Epitope 846 levels were always elevated in SF over serum (mean 38-fold in OA and 8.6-fold in RA) being highest in OA patients with the longest disease duration and greatest loss of cartilage, and lowest in RA joints with high leucocyte counts. Serum levels were more often elevated in RA (56%) than in OA (19%) and probably reflect increased aggrecan synthesis in diseased joints. KS levels were higher in SF than in serum in 69% of patients (up to 2.3-fold); levels were inversely (OA) and directly (RA) related to SF leucocyte counts. Serum KS was reduced in both diseases and in RA was inversely related to both systemic and joint inflammation markers. SF 846 levels were inversely related to SF KS in both diseases. These epitopes may provide a measure of the balance between cartilage synthesis and degradation in these diseases.

Adult

Nail-patella syndrome associated with mixed crystal deposition arthropathy.

This report describes a case of nail-patella syndrome in a woman with a strong family history who presented with effusions in her shoulder and knees. Microscopic examination of the shoulder fluid suggested the presence of calcium pyrophosphate dihydrate (CPPD) crystals, and examination of the knee fluid suggested both hydroxyapatite (HAP) and CPPD crystals. To our knowledge, the coexistence of these two conditions has not been reported in the past. Moreover, it brings up a new element regarding the inflammatory origin of the nail-patella syndrome.

Arthritis

The effect of age on the inflammatory response to arthritis-associated crystals.

The effect of age on the inflammatory response to urate and hydroxyapatite crystals was examined using both in vivo (intradermal skin testing) and in vitro (neutrophil death following incubation with urate crystals) methods. No significant difference in crystal-induced inflammation was found between young (< 25 years) and elderly (> 75 years) subjects and there was no correlation between the in vivo and in vitro tests. There was good correlation (0.63, p < 0.001) between the intradermal responses to urate and hydroxyapatite, suggesting that subjects, regardless of their age, are consistent in their response to these two types of arthritis-associated crystal. Advanced age does not lead to a major alteration in the inflammatory response to arthritis-associated crystals.

Adolescent

Survival of calcium pyrophosphate crystals in stored synovial fluids.

Eleven synovial fluids containing calcium pyrophosphate dihydrate (CPPD) were examined repeatedly over an eight week period to assess whether storage conditions and duration influenced the number of crystals present. Aliquots of each fluid were stored at room temperature, 4 degrees C, and -70 degrees C. At -70 degrees C there was no change in crystal count after eight weeks' storage. At room temperature and 4 degrees C crystal counts declined slowly over the eight week period, though CPPD crystals were still readily apparent after eight weeks in 10/11 (4 degrees C) and 8/11 (room temperature) fluids. No change in crystal morphology was detected and, apart from one fluid kept at room temperature in which fungal hyphae were noted at six weeks, no new crystals were seen. Calcium pyrophosphate dihydrate crystals in synovial fluid can be maintained for prolonged periods by freezing.

Calcium Pyrophosphate

Trapping sheep blowflies using bait-bins.

A bait-bin designed to attract and kill sheep blowflies is described. It is composed of a garbage bin plus lid, attractant and insecticide-treated offal. Fly entry holes are covered with differentiator wire to increase selectivity of kill. Placing bait-bins in preferred habitats of blowflies to optimise kill is outlined and temporal insecticide strategies to increase effectiveness of kill and reduce blowfly resistance are suggested. Preliminary data supporting the effectiveness of bait-bins in reducing blowfly numbers and flystrike in combination with good management practices to reduce sheep susceptibility to flystrike in the arid zone of New South Wales are presented and cost-effectiveness of bait-bins is analysed.

Animals

A comparison of the effects of urate, hydroxyapatite and diamond crystals on polymorphonuclear cells: relationship of mediator release to the surface area and adsorptive capacity of different particles.

The ability of monosodium urate monohydrate (MSUM), hydroxyapatite and diamond crystals to stimulate phagocytosis, degranulation and secretion of cell movement factors (CMF) from polymorphonuclear leukocytes (PMN) was determined. The ability of each crystal to adsorb PMN derived enzymes and CMF was also compared. MSUM crystals stimulated greater enzyme release and generation of CMF than hydroxyapatite; in contrast, hydroxyapatite crystals exhibited greater adsorption of PMN products. This was partly due to the greater surface area (at a given concentration) of hydroxyapatite crystals. Diamond crystals clearly interacted with PMN, but they did not stimulate degranulation or CMF production.

Adsorption

A tissue kallikrein in the synovial fluid of patients with rheumatoid arthritis.

Tissue kallikrein is an enzyme that forms the vasoactive peptide kallidin from an endogenous substrate L-kininogen. Tissue kallikrein has been identified in joint fluids and in inflammatory infiltrates within synovial membranes. It is suggested that tissue kallikrein and kinins have an important role in synovitis and joint damage. Immunoreactive tissue kallikrein and amidase activity were both measured in the synovial fluid of 24 patients with rheumatoid arthritis (RA) and 12 with osteoarthritis (OA). Active enzyme concentrations were higher in RA than in OA and correlated well with the lysosomal enzymes beta-glucuronidase and lactate dehydrogenase. Both total immunoreactive tissue kallikrein and the proenzyme values were similar in RA and OA. Tissue kallikrein was localised by immunocytochemistry to the polymorphonuclear leucocytes present in the synovial fluid and membranes of patients with RA.

Adult

Detection of crystals in synovial fluids by light microscopy: sensitivity and reliability.

Polarised light microscopy of synovial fluid is an established diagnostic technique widely regarded as reliable for the detection of crystals. The threshold concentration of crystals which can be detected has been investigated and the sensitivity and specificity of six observers compared. Various concentrations of laboratory manufactured crystals of monosodium urate monohydrate (MSUM), calcium pyrophosphate dihydrate (CPPD), and basic calcium phosphates (BCP) were added to the synovial fluid. The threshold for reliable identification of MSUM and CPPD was in the range of 10-100 micrograms/ml. False positives were frequent. The mean sensitivity of the six observers for MSUM was 69% and for CPPD was 82%. The mean specificity for MSUM was 97% and for CPPD was 78%. There was much discrepancy in the results of the slides stained with alizarin red S. Thus the value of alizarin red S as a screening test for BCP is questioned. In view of the variable sensitivity and specificity of different observers for MSUM and CPPD and the concentration threshold for reliable crystal identification, greater caution in the interpretation of synovial fluid analysis is advised, and recommendations for increased quality control are supported.

Anthraquinones

A comparison of normal and pathological synovial fluid.

Synovial fluid from 16 normal subjects was compared with that from 149 patients with a variety of rheumatic disorders. Normal fluid had fewer cells and a lower content of beta-glucuronidase than osteoarthritic samples. Particles, including occasional birefringent crystals, were seen in normal fluids as well as pathological samples. Alizarin red staining particles (presumed to contain apatite) were seen in all diagnostic groups; their numbers showed some correlation with radiological calcification in and around the joints and with a hypertrophic subchondral bone response. Lactate levels were highest in septic arthritis. No assay showed disease specificity.

Adult

Cardiac lymphoscintigraphy following closed-chest catheter injection of radiolabeled colloid into the myocardium of dogs: concise communication.

A catheter technique for injection of radiolabeled colloids into the myocardium was developed and tested in a series of 15 dogs. A multipurpose angiographic catheter was modified to permit an inner core of PE-50 polyethylene tubing, tipped with a 23-gage needle, to pass through the lumen for intra-myocardial injection of radiocolloids. For injection of the left ventricle, the catheter is introduced through the femoral artery: for the right ventricle, the femoral vein. The catheter advanced under fluoroscopy until the desired surface for injection is reached. The inner core is then extended to lodge the needle in the endocardium. A mixture of Renografin (to confirm the endocardial injection site) and radiolabeled colloid was injected in 13 animals. Ten minutes after injection, scintigraphy was begun and continued for up to 6 hr. In three dogs the procedure was repeated 3 or 4 times. From two to five nodes were visible in all animals, irrespective of whether the right or left ventricular myocardium was injected. In two animals the injection was given intravenously, and no nodes were seen. These data suggest that cardiac lymphatic drainage can be studied with a catheter injection method.

Animals