Quadriceps femoris activation changes in genu varum: a possible biomechanical factor in the pathogenesis of osteoarthrosis.

This study was designed to determine whether the presence of an alignment deformity of the lower leg, known as genu varum, causes abnormalities in individual- or group-activation of the surrounding knee extensors, a situation which might accelerate knee deterioration. Nine healthy women with normal tibial alignment were compared with nine age-matched healthy women with genu varum. The outcome measure of maximal quadriceps femoris activity was recorded during successive maximal concentric isometric and isokinetic contractions of the knee extensors performed on a dynamometer using surface electromyography. The results showed that, taken as a whole, the percentage utilization of quadriceps motor units was higher for those subjects with genu varum (p < 0.01). These findings demonstrate that the extensors surrounding a varus knee might function less efficiently than those surrounding a normally aligned knee. As such they suggest that pathological force generation across a varus knee might be caused, in part, by associated alterations in quadriceps tension generating capacity.

Comparison between the surface electromyogram of the quadriceps surrounding the knees of healthy women and the knees of women with osteoarthrosis.

The purpose of this study was to compare the electromyographic (EMG) activity of the quadriceps femoris (QF) muscles of women with osteoarthrosis (OA) of the knee with the EMG activity of the QF muscles of healthy women. To this end, a total of 14 subjects attended a single test session during which full-wave rectified surface electromyograms were recorded from the rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) muscles during maximum voluntary isometric quadriceps contractions performed at knee angles of 30 degrees and 60 degrees flexion. A comparison of the resultant normalized peak EMG ratios using independent t-tests demonstrated significantly higher composite QF muscle activation for the osteoarthrotic subjects (p < 0.05). A higher RF activation also differentiated the two groups. The findings raise the possibility of a direct correlation between abnormal activation of the QF and joint status. They also suggest that patients with knee OA may benefit functionally from rehabilitation designed to improve QF coordination and endurance, and not merely strength.

Quadriceps femoris activation in healthy women with genu varum and women with osteoarthrosis and genu varum.

This study was designed to determine whether abnormalities in individual or group activation of the knee extensors might be associated with the development of osteoarthrosis of the knee with varus deformity. The study consisted of nine healthy women with normal tibial alignment, nine agematched healthy women with genu varum and nine women with osteoarthrosis (OA) of the knee and genu varum. The outcome measures were normalized quadriceps femoris surface EMG amplitude parameters, recorded during maximal voluntary static and dynamic knee extension movements at 0° and 90° s(-1), expressed as a percentage and peak torque and rate of tension development at 0° s(-1). Under static conditions, the normalized EMG amplitudes, peak torque and rate of tension development of the knee extensors in those with OA differed significantly from the same parameters recorded for the healthy controls (P < 0.001). Although not significantly different under dynamic conditions (P = 0.1), there was a large effect size of f = 0.40 between the EMG amplitudes of the knee extensors of the two healthy groups, with a neglible effect size between the EMG amplitudes as well as a trend towards reduced tension-generating capacity of the knee extensors in those with varus deformity, irrespective of joint status. The latter findings suggest that the neural integration mechanisms governing the contractural pattern of the extensors surrounding a varus knee may abnormally reflect various aspects of the disease process of osteoarthrosis.

Detection of antiphospholipid antibodies by flow cytometry: rapid detection of antibody isotype and phospholipid specificity.

Laboratory diagnosis of antiphospholipid antibodies is important in patients with clinical features of the antiphospholipid syndrome, such as thrombosis and fetal loss. We have developed a novel method for the detection of antiphospholipid antibodies using flow cytometry. Anionic phospholipids cardiolipin, phosphatidylserine and phosphatidylinositol are coated onto polystyrene beads of different sizes, allowing detection and semiquantitation of their respective phospholipid antibody isotypes. The results of the flow cytometric method closely correlate those of the standardised anticardiolipin enzyme-linked immunosorbent assay (ELISA), but the method is quicker and is versatile in its ability to detect IgG, IgM and IgA antibody isotypes at the same time. The method promises to be useful in evaluating the significance of phospholipid specificity and antibody isotypes in patients with the antiphospholipid syndrome.

A comparative study of pain, sleep quality and pain responsiveness in fibrositis and myofascial pain syndrome.

Twenty patients with fibrositis and 19 patients with myofascial pain syndrome were compared with regard to pain levels, sleep quality, general pain threshold and localized pain responsiveness at fibrositic tender points. Patients with fibrositis had significantly lower pain responsiveness (p less than 0.01), lower pain threshold (p less than 0.05) and higher pain levels (p less than 0.05) than patients with myofascial pain syndrome when differences in age between the groups were controlled. No significant difference was found for sleep quality. Regional pain levels influenced local measures of pain sensitivity. A discriminant function, developed on the 4 main study variables, resulted in an almost 80% correct classification to groups.

Immunosuppression as initial treatment for gold induced aplastic anemia.

Three patients who received antithymocyte globulin therapy for severe aplastic anemia due to gold therapy are described. In 2 patients the hemoglobin, white blood cell count and neutrophils were normal and platelet counts exceeded 100 X 10(9)/1 more than 2 years after treatment. The 3rd patient did not respond to antithymocyte globulin or to cyclosporine therapy; subsequent allogeneic bone marrow transplantation resulted in satisfactory engraftment at 12 months. In all 3 patients the arthritis was improved after the episode of marrow aplasia and its treatment. Including these 3 patients, 12 reported patients with severe aplastic anemia due to gold have now been treated with antithymocyte globulin; 8 have shown significant improvement. These results are better than those reported for any other treatment. Antithymocyte globulin may be optimal initial treatment for this serious disorder.

Effects of gold compounds on leukotriene B4, leukotriene C4 and prostaglandin E2 production by polymorphonuclear leukocytes.

The effects of auranofin (AF) and sodium aurothiomalate (GSTM) on the production of specific arachidonic acid metabolites by chemotactic tripeptide activated polymorphonuclear leukocytes has been investigated using radioimmunoassay techniques. AF insignificantly enhanced the production of leukotrienes B4 and C4 at a concentration of 0.5 microgram Au/ml. However, at increasing concentrations, this drug suppressed the production of these metabolites in a dose dependent manner. In contrast, GSTM did not affect the production of either leukotriene at the concentrations tested. Of particular interest, prostaglandin E2 production was not affected by either gold compound. Both leukotrienes and prostaglandins are metabolized from arachidonic acid and are potent mediators of inflammation. The inhibition of leukotriene production may be another mechanism by which AF manifests its antiinflammatory effects in patients with rheumatoid arthritis.

Ankylosis of the temporomandibular joint from psoriatic arthritis.

A review of 27 cases of temporomandibular joint arthritis in patients with psoriasis reveals the main pathologic features to be condylar erosions, condylar osteoporosis, calcification of the articular disc, and subchondral cyst formation. We present another pathological process, temporomandibular joint bony ankylosis in a patient with psoriasis. Surgical management consisted of a high condylectomy, with a silastic implant to maintain the vertical dimension of the ramus. A very good functional result was obtained and 21/2 years later her incisive distance is 44 mm.

Investigation of sacroiliac disease: comparative evaluation of radiological and radionuclide techniques.

An attempt has been made to improve diagnostic precision in a group of diseases associated with inflammation of the sacroiliac joints by using a 99mtechnetium stannous pyrophosphate bone scan. Inflammation of these joints is associated with osteoblastic activity and is reflected by an increase in the uptake of radionuclide, which can be precisely quantitated. The uptake was markedly above the range of normal in patients with active ankylosing spondylitis (AS), and also in a number of patients with possible AS, psoriasis, and Reiter's syndrome. However, patients with Grade 4 radiological changes of the sacroiliac joints frequently had normal scans. This technique may be useful in the early diagnosis of sacroiliitis, and the nosological implications of the changes in patients with Reiter's syndrome and psoriasis are of interest.

Genetic markers for acute anterior uveitis.

One hundred and sixty-nine patients, 82 with acute anterior uveitis (AAU) only, 48 with AAU and ankylosing spondylitis (AS), and 39 with AS only were studied. The HLA antigen A2 was present in 44/82 AAU only, 31/48 AAU + AS, and 23/39 AS only. Where haplotype analysis was possible by virtue of family studies, A2 B27 was present in 7/16 AAU only, 9/15 AAU and AS and 14/29 AS only. These figures do not differ significantly from the expected values of control populations. Alpha-1-antitrypsin (alpha-1-AT) phenotypes were obtained on 30/82 AAU only, 29/48 AAU + AS, and 27/39 AS only patients. The MZ phenotype appeared in 8/86 patients tested; 4/30 with AAU only and 4/29 AAU + AS patients. This is higher than the expected value for control populations. Therefore, MZ alpha-1-AT phenotype but not HLA-A2 appears increased in patients with AAU.

Hypoxemic respiratory failure in rheumatoid arthritis: gold related?

This report describes a patient with rheumatoid arthritis, treated with gold salts, that led to hypoxemic respiratory failure and rapid death, in an otherwise healthy adult with no cardiopulmonary history. The unique clinical, radiologic, pathologic, and therapeutic aspects of this case are discussed.

Liver dysfunction associated with gold therapy for rheumatoid arthritis.

Hepatic toxicity is rarely associated with gold therapy. Three patients with rheumatoid arthritis who developed jaundice during the course of chrysotherapy are described. Jaundice occurred both early and late in the course of therapy. differing grades of severity of dysfunction were encountered. Liver biopsy revealed intrahepatic cholestasis. Significance of jaundice occurring during gold therapy is discussed.

Gold therapy in rheumatoid arthritis. Interim report of the Canadian multicenter prospective trial comparing sodium aurothiomalate and auranofin.

One hundred and twelve patients with classical or definite rheumatoid arthritis (RA) were randomly assigned to receive either sodium aurothiomalate (GSTM) or auranofin (AF). Monthly clinical assessments (morning stiffness, grip strength, articular index, pain, quality of life) and concurrent hematological, biochemical, and urine studies were performed to monitor the efficacy/toxicity (E/T) ratio. Ninety-two patients have completed 3 months; 65, 6 months; 47, 9 months; and 30, 12 months. The groups were numerically balanced at each time period. Analysis of the 0-6 month period suggests that both drugs were equally and significantly beneficial after 3 months and that this was maintained at 6 months. Toxicity was as frequent in both groups but more serious in the GSTM group. The main side effects were gastrointestinal (diarrhea) in the AF group and mucocutaneous in the GSTM group. Half of the withdrawals (14 in each group) were because of side effects in the GSTM group and for inadequate therapeutic efficacy in the AF group. This study suggests that after 6 months of treatment the E/T ratio of AF is greater than or equal to that of GSTM. These conclusions will need to be confirmed during the ongoing longer observation period. A significant clinical difference between the 2 drugs is that in a given patient treated with GSTM, the onset of toxicity coincides with a good therapeutic effect. This relationship does not appear to exist during AF treatment.