The localization and secretion of type IV collagen in synovial capillaries by immunohistochemistry using a monoclonal antibody against human type IV collagen

The localization and the secretion of type IV collagen in synovial capillaries have been investigated by detecting the antigenic determinant of the major triple helix of human type IV collagen. Type IV collagen was indicated to be localized mainly in the lamina densa of basement membranes (BM) and to be secreted by both endothelial cells and pericytes. The pericytes secreted this collagen to both surfaces facing endothelial cells and the interstitial connective tissue. On the contrary, the direction of type IV collagen secretion by the endothelial cells was strictly confined to one side, namely towards the surface facing the BM. The absence of the antigenic determinant in rough endoplasmic reticulum and Golgi apparatus of the endothelial cells and pericytes indicated that the major triple helix of type IV collagen is mainly formed in the secretory vesicles after budding from the Golgi apparatus.

The role of fibronectin in the pathogenesis of antigen-induced arthritis in the rabbit

Fibronectin (FN), a high molecular weight glycoprotein, is present in plasma and is a normal structural component of the synovium in the rabbit, as it is in man. FN is also involved in the sequence of changes seen in synovium in experimental antigen-induced arthritis. Its widespread distribution in inflamed synovia in the initial acute phase of induced arthritis probably merely reflects the presence of FN of plasma origin in serous exudates. In established experimental arthritis, FN co-distributes with fibrin, while in synovia undergoing organisation, FN is present intracellularly in several types of mesenchymal cells (suggesting local synthesis) and is deposited on immature collagen fibrils. However, it is no longer present when mature collagen is formed. The persistence of FN, along with fibrin, in inflamed joints, and its involvement in fibrosis, suggest that it may play a significant part in determining the chronicity of this form of experimental arthritis.

Immunoelectron microscopic demonstration of fibronectin in rheumatoid pannus and at the cartilage-pannus junction

The presence of fibronectin (Fn) in rheumatoid pannus was investigated by an immunoelectron microscopic method using horseradish peroxidase-conjugated antibody to stain Fn. Large amounts of Fn were demonstrated in the interstitial collagenous tissue of invasive rheumatoid pannus. Fn was also observed on the surface of both fibroblast-like and macrophage-like pannus cells, suggesting that it was secreted by these cells and that the secreted Fn might facilitate the spreading of the pannus cells over the cartilage matrix. However, decreased amounts of Fn were observed in areas of contact between pannus cells and the cartilage matrix. The reduction in the amount of Fn demonstrable at the cartilage-pannus junction may be a consequence either of proteolysis of Fn by enzymes secreted at the junction, inhibition of Fn synthesis in cells in contact with cartilage matrix, or transfer of Fn from the pannus cell surface to collagen of the cartilage matrix.

An ultrastructural study of the marginal transitional zone in the rabbit knee joint

The ultrastructure of the marginal transitional zone of femoral articular cartilage has been studied in the rabbit knee. There is an abrupt boundary between the convex margin of the cartilage and the synovial membrane. This is due to the arrangement and amount of collagen and of cells, because cell ultrastructure changes gradually from synovium to cartilage. The densely fibrous marginal synovium contains scattered fibrocytic cells with sparse cytoplasm and long filopodia. Near the synovium/cartilage interface, oval boundary cells containing more abundant cytoplasm abut on the cartilage matrix. In the periphery of the cartilage, an edge-belt of collagen fibrils runs obliquely from articular surface to subchondral bone. Chondrocytes near the edge-belt, whatever their depth from the articular surface, ultrastructurally resemble middle zone (zone II) cells of articular cartilage generally. The synovial surface of the marginal zone is smooth and resembles articular cartilage surfaces. Most intimal cells contain plentiful granular endoplasmic reticulum and Golgi membranes and hence are intermediate between A and B synoviocytes commonly found elsewhere. Non-fenestrated (type I) capillaries lie in a superficial stratum beneath the synovial surface and in a deep stratum near the synovium/cartilage boundary, and are surrounded by pericytes. No mast cells, macrophages, lymph vessels or nerves could be identified in the marginal zone. Contrary to earlier accounts of collagen orientation in this zone, most of the fibrils in the marginal synovium appear to run around the perimeter of the cartilage and only a few bundles run radially from the synovium towards the cartilage. It is suggested that the circumferential collagen both contains the marginal cartilage and prevents displacement of synovial tissue on to the articular surface. The radial strata of collagen serve to anchor the circumferential collagen to the cartilage edge-belt. In agreement with earlier investigators, it is considered that the edge-belt withstands tensile stresses arising from deformation of the articular surface. The role of the marginal synovium is also discussed in relation to synovial fluid formation and cartilage nutrition.

Fibrin and fibronectin in rheumatoid synovial membrane and rheumatoid synovial fluid

Normal synovial membranes and synovial membranes from patients with classic rheumatoid arthritis were investigated for the presence of fibrin and fibronectin by an indirect immunoperoxidase technique. In normal synovial membranes, fibronectin was found around the monolayer of the synovial lining cells. Staining was most intense on the surface and beneath the lining cells, but not detectable in the cytoplasm. Fibronectin was also found in the cytoplasm of the endothelial cells. No staining for fibrin was found in the normal synovial membrane. In synovial membranes from patients with rheumatoid arthritis, large amounts of fibronectin were found around the multilayer of synovial lining cells, in the cytoplasm of the endothelial cells, and in argyrophilic fiber-rich connective tissue. In superficial areas denuded of synovial lining cells, high amounts of fibronectin were found incorporated in fibrin. In some areas with noninjured synovial lining cells, fibrin was also found, but in this case no fibronectin was incorporated. No fibronectin was found in connective tissue in areas with infiltration of inflammatory cells. After treatment of normal and rheumatoid synovial membranes with hyaluronidase, fibronectin was still present around the lining cells but the staining was found to be more distinct. This study relates the presence of fibrin and fibronectin in the rheumatoid synovial membrane to the high amount of these proteins, recently described, in rheumatoid synovial fluid. It also suggests that fibronectin present in the synovial membrane is produced and secreted by the endothelial cells.

Characterization of proteins from human synovium and mononuclear leucocytes that induce resorption of cartilage proteoglycan in vitro

Both human synovial tissue in culture and lectin-stimulated mononuclear leucocytes produced a protein that induced proteoglycan resorption in explants of bovine nasal cartilage and human articular cartilage. On gel filtration the protein had Mr 16000-20000 and on isoelectric focusing its pI was 5.2-5.3. The protein corresponded to catabolin, which has previously been identified as a product of cultured porcine synovial tissue and mononuclear leucocytes. The action of partially purified human catabolin was not inhibited by cortisol, although the activity of the leucocyte supernatants from which it had been isolated was inhibited. For this reason it is not possible to be sure that the active factor detected in the bioassay of the crude leucocyte culture supernatants is in fact catabolin.

An ultrastructural study of articular chondrocalcinosis in cases of knee osteoarthritis

A study was made by transmission electron microscopy of tissue specimens (cartilage, meniscus and synovial membrane) taken from 5 knees presenting radiological and anatomical signs of articular chondrocalcinosis and osteoarthritis. It was part of a broader study which included analysis of the same specimens by macroscopy and light microscopy as well as by X-ray diffraction of the mineral deposits. In cartilage and meniscus juxta-cellular calcium pyrophosphate dihydrate (CPPD) crystals of variable sizes were observed in the extracellular organic matrix, independent of the collagen fibrils. They occurred mainly in the superficial and middle zones but could also be seen intermingled with the apatite crystals in the cartilage calcified zone. In synovial membrane most of the CPPD crystals were extracellular but some of them could be seen in cytoplasmic phagocytic vacuoles. These observations are in agreement with those in the literature regarding the ultrastructural picture of chondrocalcinosis and support the thesis that the crystals originate in the cartilage and are phagocytized in the synovial membrane. Although the results of the present study do not provide direct evidence of a relationship between chondrocalcinosis and osteoarthritis, the data of the ultrastructural investigation appear nevertheless of great interest as a complement to the data furnished by light microscopy.

The localization of fibronectin in rheumatoid arthritis synovium by light and electron microscopic immunohistochemistry

The distribution of fibronectin in rheumatoid arthritis (RA) synovium has been investigated by light and electron microscopic immunohistochemistry using an antihuman fibronectin antibody. Heavy accumulation of fibronectin was observed in the lining layer and the areas of proliferation of fibroblasts. Rough endoplasmic reticulum (RER) and peripheral vesicles of proliferated type B lining cells and fibroblasts contained large amounts of fibronectin. Thus these cells seem to participate actively in the local synthesis and secretion of this glycoprotein. Type A lining cells and migrated mononuclear phagocytes contained many phagolysosomes in some of which dense accumulation of fibronectin was observed. Some of the materials in the phagolysosomes, with dense accumulation of fibronectin, resembled the fibrinous material-fibronectin complexes frequently seen in the pericellular spaces. Accordingly fibronectin seems to play a role in the clearance of fibrinous materials by these phagocytes. The proliferated capillaries and small vessels possessed multilamellated basement membranes with heavy accumulation of fibronectin. However, RER or Golgi apparatus of the endothelial cells contained no detectable amounts of fibronectin. This indicates that these cells do not actively participate in the synthesis of fibronectin and that the majority of this glycoprotein in the basement membranes originates in fibronectin from blood vessel exudate. Fibrinous material-fibronectin complexes were frequently seen on the endothelial cell surfaces. Circulating platelets and mononuclear cells occasionally came in contact with these complexes, suggesting an association of fibronectin with the formation and clearance of thrombi in the vascular lumina at the inflammatory sites of RA synovium.

Laboratory handling of crystals

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[The role of the alloy-specific elements iron, cobalt, chromium and nickel in aseptic loosening of total hip joint prosthesis]

The cause of aseptic loosening of total hip joint prostheses is still largely unexplained. In addition to mechanical forces, material factors may also be instrumental. In 16 patients with loosened hip prostheses who underwent re-operation (8 X Huggler-Weber, 8 X McKee-Farrar), the concentration of the alloy-specific elements cobalt, chromium, nickel and iron were determined in 58 tissue samples by means of neutron activation and emission spectrum analysis. An increase in the element concentrations was found in all the tissue samples, and this was unrelated to the time elapsed since implantation. The chromium concentration in particular was significantly elevated in all the tissue samples, in some patients with McKee-Farrar prostheses up to 10,000 times the norm. In view of the known toxicity of cobalt, chromium and nickel in high doses it seems that the presence of unphysiologically high concentrations of these elements in the vicinity of total hip joint prostheses represents an explanation of some of the loosened prostheses.

Monosodium urate crystals in asymptomatic knee joints

Monosodium urate (MSU) crystals were shown in synovial (SF) fluid taken from the asymptomatic knee joints of 11 out of 13 patients with tophaceous gout. Intracellular crystals were identified in some cases. Examination of synovial biopsies taken concurrently revealed MSU crystals in 2 out of 6 cases. The results show that MSU crystals can be found in SF and synovium in the absence of acute gout. This implies that additional factors are important in the pathogenesis of gouty inflammation.

The association of amyloid deposits and osteoarthritis

Ten of eighteen consecutive patients who underwent total knee or hip arthroplasty for osteoarthritis had amyloid present in the surgically removed articular tissues. It was found in 6 of 13 cartilage specimens, 4 of 18 articular capsules, and 2 of 16 synovial membranes. In 3 of the cartilage specimens, the amyloid was adjacent to focal deposits of calcium pyrophosphate dihydrate crystals. Therefore, deposits of amyloid are not uncommon in osteoarthritis and may be more than incidental findings.

[Histamine in rheumatic diseases]

Histamine, the decarboxylation product of histidine, was determined in serum, leucocytes, synovial fluid and synovial tissue rheumatic diseases. Histamine level was variable in most of the biological samples. In serum of patients with rheumatoid arthritis histamine was more frequent (50%) than in controls (10%). Leucocyte preparations containing basophile cells did not differ in their histamine concentration. Synovial fluid of rheumatoid arthritis patients showed histamine levels in the range of 1,0 to 23,4 ng/ml. The results were discussed by means of the pertinent literature.

The value of hyaluronidase treatment of different tissues before demonstration of fibronectin by the indirect immunoperoxidase technique

The influence of testicular hyaluronidase treatment on the immunohistochemical localization of fibronectin in different tissues (human articular cartilage, large intestine, synovial membrane and experimental granulation tissue) as well on frozen as on formaldehyde fixed, paraffin embedded tissue, has been studied using the indirect immunoperoxidase technique. Pretreatment with hyaluronidase is essential in demonstrating fibronectin in frozen sections of human articular cartilage. In the other tissues examined treatment with hyaluronidase was not essential, but gave a more optimal staining quality. The effect of hyaluronidase treatment was to some extent dependent on the duration of treatment. In formaldehyde fixed, paraffin processed tissue the improvement with hyaluronidase treatment was only seen when the hyaluronidase followed pepsin digestion of the deparaffinized tissue sections.

[Studies on degradation of cartilage proteoglycan by rheumatoid synovial tissue. Part I: On the degraded products of proteoglycan (author's transl)]

The degradation of MgCl2-extracted proteoglycans (PG) from bovine nasal and articular cartilage was performed by using human rheumatoid synovial tissue extract, and the products were compared with that of being degraded by different commercially available proteases. 2. Degradation of PG by crude synovial extract occurred under the wide range of pH, and the degradation products showed the changes as follows; 1) a decrease of viscosity, 2) a decrease of hydrodynamic size, 3) an increase of electrophoretic mobility, 4) no change of the length of glycosaminoglycan side chains, 5) an increase of chondroitin sulfate relative to keratan sulfate in precipitate with 1% cetylpyridinium chloride (CPC), and 6) an increase of serine content in precipitate with 1% CPC. 3. The average hydrodynamic size of degradation products by crude synovial extract was larger than that of degradation products by pronase or papain. 4. The results indicate that the proteases play the main role on the PG-degrading activity of rheumatoid synovial tissue extract but the glycosidase play no significant role.

The pathogenesis of chronic haemophilic arthropathy

Specimens of tissue from haemophilic synovium and articular cartilage were collected from 39 patients during reconstructive surgery. They were studied by histochemistry, electron microscopy and microprobe analysis. The detailed findings are presented and discussed. It is suggested that haemophilic arthropathy is the result of a number of mechanisms affecting the synovial lining which becomes progressively fibrotic and the hyaline cartilage which disintegrates and is eventually lost. Mechanical and chemical processes cause degeneration of cells but enzymatic processes appear to be primarily responsible for the degradation of the matrix of the articular cartilage.

Appearance of anti-HLA-DR-reactive cells in normal and rheumatoid synovial tissue

The reactivity of rabbit anti-HLA-DR antigen antibodies with cells in normal and rheumatoid synovial tissue was investigated by indirect immunofluorescence on frozen sections of tissue. The antibodies reacted with a significant proportion of the synovial lining cells of both normal and rheumatoid synovial tissue, with endothelial cells, and with a number of, most probably, migratory cells. After dispersion of cells from rheumatoid synovial tissue by digestion with collagenase and DNase, adherent cells of both a macrophage-like and a dendritic appearance reacted with the anti-HLA-DR antigen antibodies. The adherent cells were also found to be potent stimulators in the allogeneic MLR. In addition, it was found that a high percentage of T lymphocytes from both peripheral blood and synovial tissue of rheumatoid patients bound anti-HLA-DR antibodies. The present data suggest a role for synovial lining cells in HLA-D-locus-dependent events of importance in the pathogenesis of rheumatoid arthritis and other joint diseases and point to the need for further investigations on T lymphocytes derived from the site of inflammation in the study of rheumatoid arthritis.

Fibronectin in synovial fluid and tissue in rheumatoid arthritis

Fibronectin is a glycoprotein found in body fluids, loose connective tissue matrix and in basement membranes. Fibronectin in rheumatoid arthritis synovial fluid was immunologically indistinguishable from the plasma form, as shown by double-diffusion analysis. Fibronectin isolated from rheumatoid synovial fluid by affinity chromatography on gelatin--Sepharose had a polypeptide pattern similar to that of plasma fibronectin in SDS--polyacrylamide gel electrophoresis. In fifty-one patients with rheumatoid arthritis and related diseases fibronectin concentrations is synovial fluid were 445 +/- 103 micrograms/ml (mean +/- SD) and within normal range, 335 +/- 52 micrograms/ml, in plasma. Immunofluorescence staining showed a prominent increase of fibronectin in the proliferating synovial connective tissue in rheumatoid arthritis as compared to normal synovial membrane. The results suggest an increased local production of fibronectin in rheumatoid synovial tissue.

Clearance of calcium pyrophosphate dihydrate crystals in vivo. III. Effects of synovial hemosiderosis

Synthetic triclinic calcium pyrophosphate dihydrate crystals, uniformly labeled with 85Sr and 45Ca, were injected into the knee joints of 2 normal adult rabbits and 2 rabbits previously injected repeatedly with autologous blood. The "half clearance time" of the injected crystal mass was 20.4 and 19 days from control joints, nearly identical to previously reported values in 6 rabbits (19.1 +/- 1.4), and 28.8 and 34 days from the joints injected with blood, a significant difference (P less than 0.05). Iron stains showed hemosiderin granules in the superficial synovium in these joints. Electron microscopy showed crystals with a molar calcium/phosphorus ratio of 1.0 and particles containing iron within synovial cells. We hypothesize that the decreased clearance rate from hemosiderotic synovium is due to inhibition of one or more intracellular pyrophosphatases by iron.

"Milwaukee shoulder"--association of microspheroids containing hydroxyapatite crystals, active collagenase, ad neutral protease with rotator cuff defects. III. Morphologic and biochemical studies of an excised synovium showing chondromatosis

Synovial tissue excised from the unstable right shoulder joint of a patient with an absent rotator cuff, severe glenohumeral joint degeneration, and hydroxyapatite-containing microspherules, collagen types I, II, and III, active collagenase, and neutral protease in the joint fluid showed extensive osteochondromatosis histologically. Electronmicroscopy revealed calcific foci in microvilli which could easily escape into the adjacent joint space through areas denuded of synovial cells. Fibrocytes demonstrated intensive pinocytotic activity of unknown significance. Energy dispersive analysis showed elemental ratios consistent with hydroxyapatite. A literature review suggested some relationships between the various pathologic lesions present in this joint. Whether similar synovial changes exist in the opposite shoulder joint of this patient and in 3 other subjects with nearly identical clinical, radiographic, and joint fluid findings is not known.

Electron-probe x-ray analysis of granules and particles found in aurosomes produced by colloidal gold

Aurosomes produced in the rabbit synovial membrane after intraarticular injection of colloidal gold were found to contain large spherical electron-dense granules and fine electron-dense particles. Electron-probe x-ray analysis demonstrated the presence of gold in the granules and iron in the particles. Sulphur and phosphorus were not detected in these aurosomes produced by colloidal gold. This is in contrast to the aurosomes produced by the soluble gold salt sodium aurothiomalate where besides gold, sulphur and phosphorus are easily detected.

Comparative study of reticuloendothelial system pools of the normal and immunologically activated rabbit synovium with radiocolloids

A quantitative study of the uptake of radiocolloids by the joint synovium relative to other reticuloendothelial system organs was performed in the rabbit model. The radiocolloids of 198Au and 99mTc-sulfide colloid were administered intravenously and distribution in synovial pad, liver, spleen, bone marrow, blood, lung, and other tissues was determined in a gamma counter. The uptake of radiocolloids by both normal and immunologically activated synovial pad was very small in comparison with the reticuloendothelial cells in liver, spleen, and bone marrow.

Detection of aluminum oxide and polyethylene wear particles from joint endoprostheses using cathodoluminescence and x-ray analysis in SEM

A highly sensitive method to localize aluminum oxide or polyethylene wear particles in biological tissues is presented. Using the scanning electron microscope (SEM) with a special cathodoluminescence detector system, small amounts of these foreign materials can be visualized in simple frozen sections by their bright luminescence, even at low magnifications (200X). At higher magnifications, a differentiation of free as well as phagocytized aluminum oxide and polyethylene particles can be made due to their different behavior in light emission. In addition, aluminum oxide such as other metals can be identified by x-ray microprobe analysis. This combination of SEM with microprobe analysis and with the highly sensitive cathodoluminescence mode enables to detect and identify wear products from all the materials, commonly used in manufacturing artificial joint replacements.

Purification and quantities of immunoglobulins of rheumatoid synovial tissues

Synovial tissue of rheumatoid arthritic origin was incubateed with radio-labelled amino acids and the immunoglobulin fraction of the products isolated using either a diethylaminoethyl (DEAE)-cellulose column or an affinity column of antihuman immunoglobulin coupled to Sepharose. The affinity column method provided a simple, one-step procedure for obtaining quantitative yields of substantially pure immunoglobulin. The elutions from the affinity columns utilized guanidine-HCl allowing the elutions to be performed quickly and under conditions which apparently did not denature the immunoglobulins except perhaps immunoglobulin M. Other solvent conditions for dissociating antibody-antigen complexes were shown to be not suitable and resulted in large volumes of eluates. The affinity columns could be reutilized many times without apparent loss of capacity to bind immunoglobulins.

Elevated levels of collagenase and prostaglandin E2 from synovium associated with erosion of cartilage and bone in a patient with chronic Lyme arthritis

A patient with chronic Lyme arthritis and roentgenographic evidence of bony erosion underwent a synovectomy; proliferative synovium (pannus), containing aggregates of small lymphocytes, was found adherent to eroded cartilage and bone. During 8 days in tissue culture, the synovial cells produced large amounts of collagenase and prostaglandin E2, but only low levels of both neutral and acid proteinases. Sixty-seven percent of the lymphocytes from the synovium were T cells; 19% were B cells. Attempts to identify agent/antigen in the synovial cells were unsuccessful. Thus, the synovium of this patient, whose disease appears to be tick-transmitted, resembles that of rheumatoid arthritis. This finding further supports the hypothesis that many possible agents, including infectious ones, trigger a common pathway in synovium, which leads to joint destruction.

Radioactivity studies on 2 synovial specimens after radiation synovectomy with yttrium-90 silicate

Synovial membranes surgically removed from the knees of 2 patients who had received radioactive yttrium-90 silicate have been examined. Autoradiographs showed that in both cases the activity was unevenly distributed over the synovium. One of the specimens, removed 7 weeks after administration of the isotope, was found to contain a slight degree of radioactivity, attributable in part to a long-lived radioactive contaminant.

[Value of synovial biopsy in the diagnosis of arthropathies associated with hyperlipoproteinemias]

In two patients suffering from hyperlipoproteinemias (HLP) type II and also having arthralgias, a biopsy of the synovial membrane of the knees was done. In both cases sodium urate crystals were found. On the basis of this data, the authors emphasize the need for systematic use of biopsy of the synovial membrane in all cases of HLP with articular manifestations. In this way, it was possible to establish the nosographic autonomy of arthropathies combined with HLP.

[Synovial membrane changes in early rheumatoid arthritis. I. Histological studies]

The histological and histochemical findings in synovial membranes of 13 patients with early rheumatoid arthritis (duration not more than 6 months; clinical follow-up at least 2 years) have been compared with 16 late cases of definite RA (ARA criteria). The authors intended to investigate the dynamic evolution of rheumatoid synovitis and to analyze the full-fledged changes with reference to diagnosis and pathogenesis of RA. Although the basic pattern of reaction is the same, the following peculiarities are found in early RA: 1) A band-like mucoid swelling of the synovial adventitia, histochemically with increase of acid glucosaminoglycans; 2) more frequent occurrence of vasculitis; 3) less marked infiltration with lymphocytes and plasma cells; 4) absence of gross fibrin insudation and granulocyte infiltration; 5) absence of diffuse fibrosis and hyalinosis. For diagnostic purposes it is also important that proliferative reactions can be found but are much less marked than in late cases. In conclusion, the early morphological findings do not allow more than the suspicion of RA. The combined mucoid swelling of the ground substance and vasculitis together with further signs of proliferation and exsudation are most important. With reference to the pathogenesis of RA, the authors insist on the frequent vasculitic changes and the early occurrence of immuno-competent cells which are the cytological condition of immunological reactions.

Synovial origins of Rice bodies in joint fluid

Rice bodies and synovia obtained from knee joints of rheumatoid arthritis patients were solubilized by limited pepsin treatment. The quantity of each type of collagen in both tissues was determined by differential salt precipitation, cyanogen bromide peptide analysis, and SDS polyacrylamide gel electrophoresis. Rice bodies and synovial membrane contained equal proportions of Type I and III collagens with trace amounts of Type "A-B" collagen.

Amyloid arthropathy in myelomatosis--intracytoplasmic synovial deposition

An unusual case is described of a West Indian man who presented with symptoms of an acute polyarthritis and who was found to have myelomatosis. At necropsy, generalized amyloidosis was found with particular involvement of synovial tissue. Myelomatosis presenting as an acute polyarthritis resembling rheumatoid arthritis is an uncommon, although well recognized entity, whereas an arthritic picture produced by amyloidosis is exceptional. The occurrence of joint pathology in myelomatosis and amyloidosis is discussed and the unique feature of intracytoplasmic amyloid deposition seen in this case is stressed.

Synovial membrane in rheumatoid arthritis: determination of glycosaminoglycans and age-dependent correlations

From 16 synovial membranes patients with rheumatoid arthritis morphological parameters as well as the GAG distribution pattern have been determined using 2 methods each. The results were checked by discriminant and regression analysis: The total GAG concentration of the synovialis was significantly correlated with the sum of the parameters "fibrin in organization", "granulocytes" "nad "necroses" (acute activity). A highly significant correlation between the age of patients and the severity of chronic morphological alterations (basic activity, especially proliferation) was found. The percentage of CS plus DS was positively correlated with the age of patients as well as with the basic activity of the disease, especially with the proliferation. - Contrary to this, HA was significantly decreased when related to the "chronic" parameters. No correlation could be demonstrated between the GAG components and criteria of the acute activity. The evaluating system of STIEHL and GEILER is to be preferred for obtaining morphologic-biochemical correlations. Furthermore, a diagram is proposed demonstrating the cumulative progression of rheumatoid arthritis in the synovialis as related to the GAG pattern. Its combination with morphological data (scars, proliferation, exudation) may help to describe the development of the disease more acurately.

Iron content of pigmented villonodular synovitis detected by computed tomography

Pigmented villonodular synovitis is a rare lesion in which iron is accumulated. A CT scan performed on one such lesion demonstrated significantly increased attenuation values. We have calculated the amount of iron which would have to be added to muscle tissue in order to produce this increase in density. We have also measured the iron content directly. The close agreement of these two figures suggests that the observed density increase is due to the iron content of the lesion.

A cartilage catabolic factor from synovium

Porcine synovium in organ culture produces a factor that causes chondrocytes to degrade their matrix. A quantitative assay for the factor, for which the cartilage of bovine nasal septum is used, is described. Evidence is presented that the catabolic factor is a protein.

Search for viral nucleic sequences in rheumatoid cells

DNA and RNA were extracted from synovial membranes, synovial fibroblast cells, peripheral blood lymphocytes, and synovial fibroblast cells strains derived from patients with rheumatoid arthritis and other joint conditions. They were hybridised after immobilisation on nitrocellulose filters with iodinated viral nucleic acids extracted from measles, rubella virus, SV--40, and a retrovirus, RD--114. In addition, in situ-hybridisation was carried out on sections of synovial membranes by means of iodinated measles and rubella virus RNA. In no case did any hybridisation occur. Positive control systems included synovial fibroblast strains transformed with SV--40, LLC--MK2 cells chronically infected with rubella virus and RD cells infected with RD--114. It was concluded tht the synovial cells did not contain viral genomes of measles, rubella virus, SV--40, or RD--114, or at least at a level equivalent to the positive control cells.

Lipid composition of the tissues of human knee joints. I. Observations in normal joints (articular cartilage, meniscus, ligaments, synovial fluid, synovium, intra-articular fat pad and bone marrow)

The composition and lipid profiles of the following tissues of the human knee joint were determined: articular cartilage, meniscus, ligaments, synovial fluid, synovium, intra-articular fat pad and bone marrow. The tissues were obtained from fresh cadavers and from surgical specimens. The lipid profiles of articular cartilage, meniscus and ligaments were similar to reported analyses of other tissues that are also rich in collagen. The lipid profiles for the remaining tissues were more like the profiles found in the fat depots and fatty tissues of the human body. Both the phospholipid and fatty acid patterns of these tissues were similar within statistical deviation. These results suggest that the per cent compositions of fatty acids and the phospholipid family profile ratios have limited range variability in the "normal" tissues of the human knee. On the other hand, the per cent neutral lipid compositions and their individual profiles showed great variations among the different tissue tissues of the knee.

[Fourier transform analysis of glycolipid depots in Fabry's disease]

An application of the Fourier Transform Process to the Fabry inclusion study has been made. The study, which rests upon five tissues and eight persons, brings out a new low frequency stratification. Various degrees of freedom exist for the basic molecule association. The periods are given for the three fundamental directions of the inclusion.

[The synovial membrane in articular chondrocalcinosis. Clinico-pathological data]

The study of 25 samples of synovial membrane taken from 118 subjects with articular chondrocalcinosis makes it possible to identify three histological aspects : the complete forms showing a crystalline deposit of calcium pyrophosphate of variable volume and alterations of an inflammatory or degenerative type ; incomplete forms showing no calcium deposit, but in which one can observe two sorts of modifications : forms of chondroid metamorphism or inflammatory stigmatas causing an indeterminate chronic synovitis ; finally, forms of superficial fibrosis of the chorion are sometimes encountered. In all, the synovial membrane in articular chodrocalcinosis is often little different from an arthrosic or senile one. However, the presence of crystalline deposits rich in calcium and phosphorous and varying in size can, in the face of certain articular manifestations of uncertain cause, point to the existence of an articular chondrocalcinosis.

Long-term effects of myochrysine on the synovial membrane and aurosomes

Mysochrysine injected into the rabbit knee joint produced regressive and destructive changes in the synovial membrane, ultimately leading to fibrosis. Aurosomes, containing characteristic electron-dense deposits indicating the presence of gold, formed in the synovial intimal cells and subsynovial macrophages. The number of aurosomes decreased with the passage of time but some were found even 2 yr after the injection of Myochrysine. Electron-probe X-ray analysis showed that the aurosomes contain gold, sulphur and phosphorus. A comparison was made between the atomic ratios of these elements in 3-day and 18-mth-old aurosomes but no significant difference was detected.

Nuclei of cultured synovial fibroblasts studied by immunofluorescence and microdensitometry

Two techniques which might be expected to detect alterations in DNA have been used in a comparison of cultured non-rheumatoid and rheumatoid synovial fibroblasts. Microdensitometry showed no alteration in staining affinity for methyl green when two pairs of cultures were compared. There was, however, a minor difference in the predominant staining pattern to a fluorescein conjugated anti-IgM serum when five rheumatoid cultures were compared with five non-rheumatoid cultures after exposure to a serum containing anti-nuclear antibodies.