[Time-dependent flow behavior and fibrinogen content of synovial fluid]

Normal bovine synovial fluid and synovial effusions in human non-inflammatory joint diseases do not show any decrease of viscosity for a long period of time during imposed shear loading, as is required for thixotropy. This observation is based on two different methods of measurement; the "hysteresis loop" method and the recording of the shear stress-time curve. Inflammatory synovial fluids--particularly from patients with rheumatoid arthritis and a high concentration of fibrinogen--form a visible gel after 6 to 20 hours of rest. Those gels show a hysteresis loop typical for thixotropy and a decrease of viscosity with the duration of shear loading. Due to the shearing in the rheometer precipitation occurs and fibrin clots appear. The appearance of fibrin clots induced by mechanical shear loading not known until now, can be discussed with regard to its possible participation in the symptom of morning stiffness, in the formation of rice bodies and in the destruction of joint cartilage in rheumatoid arthritis.

Increased frequency of HLA-Bw62 and Bw35 CREG antigens in HLA-B27 negative ankylosing spondylitis

67 patients with ankylosing spondylitis (AS) were tissue-typed for HLA-A, -B and -C antigens. HLA-Bw62 was found in 6 of 13 (46%) HLA-B27 negative patients, compared to 9% in HLA-B27 positive AS (p greater than 0.01) and 10% in healthy blood donors (p greater than 0.001). HLA-Bw62, a split of the previous HLA-B15, belongs to the HLA-Bw35 CREG antigens, 11 of 13 (85%) of HLA-B27 negative patients had an HLA-Bw35 CREG antigen. The present results are interpreted as an indication of a direct involvement of the HLA-B locus in the pathogenesis of AS.

[Effect of prostaglandins on in vitro electrolyte metabolism in human spongiosa]

Prostaglandins seem to be involved in the pathogenesis of juxtaarticular osteopenia in rheumatoid arthritis. Therefore the influence of prostaglandins on in vitro electrolyte metabolism of human trabecular bone was tested. Trabecular bone was prepared from femoral heads of patients who had undergone hip replacement surgery for coxarthrosis. 500 mg samples of trabecular bone were incubated in modified Eagle's minimal essential medium. Net electrolyte movements between bone and incubation medium were measured. PGE2 caused an increase in the release of calcium (Ca) and magnesium (Mg) from bone into incubation medium as compared to controls (PGE2 1 micrograms/ml: Ca = 0.87 +/- 0.09 mmol/l*, Mg = 0.44 +/- 0.03 mmol/l*; controls: Ca = 0.81 +/- 0.09 mmol/l, Mg = 0.41 +/- 0.05 mmol/l; n = 15, *p less than 0.001). The effect of PGE2 was dose-dependent and comparable to the effect of human parathyroid hormone 1-34 (hPTH 1-34). PGE2 turned out to be the most potent prostaglandin on human trabecular bone. PGE1 and PGF2 alpha had about 50% and PGF1 alpha about 40% of the potency of PGE2. PGA1 and PGA2 had no effect. The effect of PGE2 could be completely inhibited by human calcitonin (hCT), similar to the inhibition of the effect of hPTH 1-34 by hCT. The effect of PGE2 was not further enhanced by hPTH 1-34. Magnesium metabolism was affected in all experiments in the same way as calcium metabolism. Phosphate metabolism, release of alkaline phosphatase and hydroxyproline from bone into incubation medium were not affected by prostaglandins.

Circulating immune complexes in ankylosing spondylitis

Circulating immune complexes were determined in the sera of patients with ankylosing spondylitis using a polyethylene glycol precipitation laser nephelometer technique. Positive results were obtained in 52% of sera from patients with active disease, but only in 20% from those in inactive stages. The immunoglobulin/complement protein ratio differed from that seen in rheumatoid arthritis and in systemic lupus erythematosus, due to the relatively larger amounts of C3 and C4 present in the immune complexes. These findings indicate that circulating immune complexes in ankylosing spondylitis may not be of pathogenetic significance because of their degree of solubilization.

Auranofin and sodium aurothiomalate in the treatment of rheumatoid arthritis. A double-blind, comparative multicenter study

Auranofin (AF), a new gold compound, has been suggested as an alternative to parenteral gold in the treatment of rheumatoid arthritis (RA). This hypothesis has been tested within a double-blind comparative study and to date 103 patients have been enrolled. Forty-one RA patients have been treated for longer than 6 months. The patients were randomly allocated to treatment with either AF or sodium aurothiomalate (GSTM) and serial comparison of changes within the articular index, grip strength, pain, morning stiffness, and global assessment during treatment were measured. Improvement was noted within both treatment groups. Diarrhea as a side effect was most commonly seen during treatment with AF while rash often combined with pruritus was most commonly reported with GSTM; withdrawal from treatment as the result of this was nevertheless uncommon.

Characterisation of blood and synovial fluid lymphocytes from patients with rheumatoid arthritis and other joint diseases by monoclonal antibodies (OKT series) and acid alpha-naphthyl esterase staining

Mononuclear cell preparations from peripheral blood (PBL) and synovial fluid (SFL) of 27 Patients with rheumatoid diseases (15 patients with definite rheumatoid arthritis (RA), 10 with other inflammatory joint diseases (OJD), 1 with sarcoid arthritis (SA) and 1 with traumatic arthritis (TA) were examined for lymphocyte subpopulations determined by monoclonal antibodies of the OKT series and by the dot-like, acid alpha-naphthyl esterase staining (ANAE) activity. In patients with classic, active RA, blood T cells carrying the OKT8+ (suppressor/killer) phenotype were significantly reduced leading to an elevated OKT4/OKT8 ratio of 4.1 +/- 0.4 compared with 2.1 +/- 0.1 in healthy controls. In 10 patients with OJD this diminution of OKT8+ cells in peripheral blood was less pronounced or absent. As regards SFL subpopulations, patients with RA and OJD exhibited a similar distribution pattern with an elevation of OKT8+, Ia+ and ANAE negative cells and a similar OKT4/OKT8 ratio of 1.5 +/- 0.3 and 1.6 +/- 0.4, respectively. Similar results were also obtained in the only patient with TA, whereas the patient with SA and one RA patient with relapse after surgical synovectomy exhibited high OKT4/OKT8 ratios, both in synovial fluid and peripheral blood. Neither the OKT markers nor the dot-like ANAE staining pattern were significantly correlated to parameters of systemic or local disease activity as estimated by erythrocyte sedimentation rate and a local disease activity index.

HLA-B27 in possible ankylosing spondylitis with peripheral arthritis

Among 86 patients selected as possibly having ankylosing spondylitis because of clinical symptoms and radiologically normal sacroiliac joints. HLA-B27 was positive in 41%. Four years later a representative sample of 38 individuals were re-examined and radiographed. HLA-B27 positive patients developed sacroiliitis as defined by radiological criteria twice as often (P less than 0.05). They also showed increased uptake of technetium 99 m upon quantitative scintigraphy with a region of interest method and more often probable or definite ankylosing spondylitis as defined by the New York criteria. Further differences between the HLA-B27 positive and negative follow-up groups concerned the frequency of clinical symptoms and peripheral arthritis. It is suggested that HLA-B27 typing may be helpful both in diagnosis and in judging the prognosis of possible or abortive ankylosing spondylitis.

[Histopathology of nephroblastomas (author's transl)]

Nephrectomy specimens from 42 patients with nephroblastoma were investigated. With the exception of one specimen (the patient had been treated preoperatively), all of the tumors were suitable for grading procedures. When the tumors were classified by the grading procedure of Lawler et al. (1975), the moderately tubulus-rich type++ was the most common (22 out of 41 patients). When the classification of Beckwith and Palmer (1978) was applied, the mixed type of nephroblastoma dominated correspondingly (19 out of 41 patients). Patients with an increased risk can be identified particularly well with the classification of Beckwith and Palmer. The following histologic features are indications of an unfavourable prognosis: focal or diffuse "anaplasia" of the tumor tissue, or a sarcomatous component in a stroma-rich nephroblastoma. The children with sarcomatous nephroblastoma (5 patients) were remarkably young (the oldest was 16 months of age), whereas the children with anaplastic nephroblastoma (3 patients) were much older (62, 67, and 72 months). In five children equivalents of the nephroblastomatosis complex (nodular renal blastema in all 5 patients, sclerosing metanephric hamartoma in 2 patients, and Wilms' tumorlet in one patient) were found in the non-infiltrated tissue of the same kidney.

[Rheology and hyaluronic acid in inflammatory joint effusions (author's transl)]

The Weissenberg rheogoniometer was used to measure viscosity, normal force and the number of molecular entanglements, calculated from a shear modulus obtained by prestationary experiments, in inflammatory and non-inflammatory synovial fluid effusions. The rheological properties show greater pathological change in the inflammatory synovial fluid samples than in the non-inflammatory. Variation in the hyaluronic acid concentration is only partly responsible for the pathological rheology. Initial experiments with a normalization method for the viscosity flow curves suggest the possibility of determining changes in polymerization or structure of the hyaluronic acid by rheological measurements.

[Xeroradiography and its value in the diagnosis of chondrocalcinosis (author's transl)]

Conventional x-ray and xeroradiographic technique were compared in a modified blind study in order to evaluate its efficiency to detect calcifications of the cartilage. Using both techniques knees, hands, and pelvic joints were examined in 16 patients with proven chondrocalcinosis. Three different radiologists evaluated radiological films and xeroradiograms independently. Their results were classified in correct, false negative, and false positive groups. All examiners achieved the best results with xeroradiography. Due to special characteristic features in xeroradiography even fine calcifications were recognized in most cases. By this method the "false negative" results were reduced to almost zero. On the other hand, the twenty percent "false positive" results in conventional radiological technique was eliminated by xeroradiography.

[Psychological tests of patients with chronic rheumatoid arthritis(author's transl)]

27 women with rheumatoid arthritis had elevated depression and social introversion scores in the Minnesota multiple phasic personality inventory (MMPI) tests, whereas their somatic activity appeared reduced. Age of the patient at time of investigation apparently had no influence on the degree of psychological changes, but was reflected in an increased social introversion. Most important for the degree of psychological impairment was the height of the ARA index, which correlated positively with the neurotic triad as well as the psychasthenia scale in the MMPI. An elevation of the neurotic triad is common in many somatic disease. Patients with rheumatoid arthritis had an additional, introversion and depression, and decreased somatic activity.