Characterization of a proteoglycan of high electrophoretic mobility.

Proteoglycans from articular cartilage of young baboons (Papio papio) were fractionated on an associative density gradient. Material from the top of the gradient was shown to contain a proteoglycan of high electrophoretic mobility on large porosity gels. Associated and/or contaminating proteins were removed by ion-exchange chromatography on DEAE-cellulose and subsequent gel filtration on Sepharose 4B in the presence of 0.1% SDS. The electrophoretically homogeneous proteoglycan (Kd 0.43 on Sepharose 4B SDS) contained 39.7% protein, was rich in aspartate, glutamate, leucine and glycine and had a GalN : GluN molar ratio of 3.87.

An oligosaccharide component in proteoglycans of articular cartilage.

Two types of sialic acid-containing component are released from articular cartilage proteoglycan monomer (D1) treated with 0.05 M NaOH containing 1 M NaBH4. The smaller component, which has not been described before, contains galactosamine, glucosamine, galactose and sialic acid (Molar ratio 1:1:1:2). It is eluted from ECTEOLA-cellulose with low molarity (0.4 M) sodium formate and has Kav of 0.70 on Bio-gel P30. Its presence on the proteoglycan monomer was demonstrated at all stages of foetal and adult life.

Biochemical changes in intervertebral disc degeneration.

The distribution of the principal matrix components, collagen, proteoglycans and water, across the diameter of human normal and degenerate intervertebral discs was compared. Little difference in collagen distribution was noted between normal and degenerate tissue but water and proteoglycan content decreased with degeneration, particularly in the centre of the disc. Proteoglycans of the nucleus pulposus and annulus fibrosus of normal and degenerate intervertebral discs were examined. In comparison with monomers of normal tissues, degenerate disc proteoglycans were of larger average hydrodynamic size and had a higher glucosamine to galactosamine ratio. Proteoglycans were digested with chondroitinase ABC and passed over an HS-Sepharose 2B affinity column. A greater proportion of the keratan sulphate-protein cores from degenerate disc were capable of interaction with the immobilized hyaluronate. Loss of aggregating ability was associated with diminution in size of the core. It is suggested that a large proportion of proteoglycans from normal disc have undergone a degree of degradation in the hyaluronate binding region and that proteoglycan synthesis in this tissue is slower than in degenerate tissue.

Glycosaminoglycans and proteoglycans of human chondrosarcoma.

The glycosaminoglycans and proteoglycans of a human chondrosarcoma have been studied. Glycosaminoglycans were fractionated and identified by cetylpirdium chloride (CPC) cellulose chromatography, ECTEOLA cellulose ion-exchange chromatography and electrophoresis on cellulose acetate. Proteoglycans were extracted by low ionic strength solutions and by 4 M guanidinium chloride and fractioned by equilibrium density-gradient centrifugation and gel chromatography on Sepharose 2B. The tumour matrix contained both the 4- and 6-sulphate isomers of chondroitin sulphate and a high concentration (12% of hexosamine) of hyaluronic acid. Proteoglycans were poor in carbohydrate moieties and proportion were capable of aggregation. Amino acid analysis of the fractionated proteoglycans suggested the presence of a single protein core. A substance with the characteristic amino acid composition of glycoprotein link was recovered from the top of the dissociative density gradient.

Regional distribution of water and glycosaminoglycan in immature articular cartilage.

The distribution of water and glycosaminoglycan in different functional regions of bovine immature articular cartilage were studied. There was always more water in each articulating than in the corresponding growing zone, but there was less water in both zones in the areas of maximum contact. There was more hyaluronate and much more keratan sulphate in the articulating areas of maximum contact than in the minimum contact areas. In the growing zone the distribution of these two glycosaminoglycans did not vary as significantly but there was slightly more keratan sulphate in the area of maximum contact. Regional variations in chondroitin sulphate content were also present although not as striking as those of keratan sulphate. The results suggest that some keratan sulphate may be synthesized as a reaction to load.

Histomorphometric analysis of osteopenia associated with endemic osteoarthritis (Mseleni joint disease).

Mseleni Joint Disease (MJD), a polyarticular osteoarthritis of uncertain etiology is endemic among the Tonga-Zulu tribe. The traditional diet is deficient in calcium, and palm wine (2-4% alcohol) is drunk widely. Patients with MJD are reported to be more osteopenic than those without. Iliac bone biopsies of 19 arthritic patients were examined by routine histomorphometry and revealed decreased trabecular bone volume (p less than 0.0005), increased resorption surfaces (p less than 0.01), decreased bone formation rate at the BMU (p less than 0.01) level and increased mineralization lag time (p less than 0.01). Six of the 19 patients (31.6%) had features of osteomalacia and six (31.6%) signs of osteoblast failure. The most likely cause of the bone disorder is calcium deficiency, but inanition, inactivity and alcohol abuse may have contributed. Although the joint disorder may have contributed to the bone disorder, the converse is unlikely the case.

Transverse fracture through the body of the axis.

We report a case of transverse fracture through the body of the axis. This fracture was unstable, had been produced by extension forces and was managed conservatively. The classification of such fractures is discussed.

Fractured neck of femur in black patients: a prospective study.

We explored the role of iron overload, deficiency of vitamin C and alcohol abuse in the aetiology of cervical and intertrochanteric fractures of the neck of the femur as a result of minor trauma. We studied prospectively 72 patients (45 men, 27 women). Levels of serum iron markers, vitamin C and alcohol markers were measured. Consumption of alcohol was estimated using questionnaires. The findings were compared with those of an age- and gender-matched control group. The mean age of the men was 59.5 years and of the women 66.9 years, with a male predominance. In the men, iron overload, as shown by high levels of serum ferritin (p < 0.001) and deficiency of vitamin C (p < 0.03), as well as abuse of both Western and the traditional type of alcohol, appear to be important aetiological factors. In women, alcohol abuse was also common, but iron markers and levels of vitamin C did not differ significantly from the control group.

External fixation for intra-articular fractures of the distal radius.

In a prospective study of 132 patients with an average age of 35 years, unstable intra-articular fractures of the distal radius were treated by external fixator. Only 15 cases required limited open reduction. Follow-up was for a mean of 42 months. There were few complications and 83% of patients had good or excellent results. There was a statistically significant correlation between the severity of the fracture and the clinical outcome, irrespective of radiological restoration. Articular and soft-tissue damage following violent compressive forces may lead to a degree of functional impairment.

Long-term results of revision total hip arthroplasty.

A total of 138 revision hip arthroplasties in 134 patients, all operated upon by one surgeon, were followed for an average of 7.4 years. The overall results were reasonable, with good to excellent Mayo hip scores in 62% and little or no pain in 86%. These results were independent of body weight, age, primary diagnosis and type of arthroplasty used. The incidence of radiological loosening was alarming, though comparable to that found in other series. Our findings indicate that it may be wise to replace both components even when, after careful assessment before and during operation, one of them seems to be securely fixed.

Radiographic features of the spine in fluoride therapy for osteoporosis.

In the search for a simple method of assessing the therapeutic efficacy of sodium fluoride, a prospective study of vertebral radiography during such treatment was carried out. Treatment of osteoporosis with sodium fluoride, calcium and vitamin D was found to enhance the vertical markings of the vertebral trabecular pattern in 69% of patients. This response was graded 1 (failure), 2 (good) and 3 (excellent); Grade 2 or 3 was attained after a mean treatment period of 31.7 months. Subsequent analysis of the vertebral fracture rate revealed that new vertebral fractures had occurred only in patients with Grade 1 and not in those with Grade 2 or 3. We recommend that treatment should aim at increasing the vertebral trabecular pattern to Grade 2 or 3 and that the duration of therapy should be approximately 30 months.

Radiological signs of loosening of the femoral stem in cementless total hip arthroplasty.

The radiological evaluation of cementless stem hip arthroplasty has received scant attention in medical publications. A retrospective analysis of 34 patients who underwent RM iso-elastic hip arthroplasty indicated the existence of a reproducible series of radiological features visible on plain radiography, which correlated both with clinical failure and with arthrographic evidence of loosening in 10 cases. In addition, there was correlation with scintinographic results and findings at revision surgery. The radiological signs were as follows: radio-opaque lines within radiolucent zones, the 'pedestal' sign, stem shift, localised cortical hypertrophy, and proximal bony overgrowth.

Circulating keratan sulfate: a marker of cartilage proteoglycan catabolism in osteoarthritis.

The serum level of a highly sulfated epitope present on long keratan sulfate chains provides a direct measure of the rate of catabolism of cartilage proteoglycans. Levels of the keratan sulfate epitope are elevated in patients with generalized osteoarthritis (OA), indicating these individuals have elevated rates of cartilage proteoglycan catabolism. In the Pond-Nuki model of canine OA, the serum level of the keratan sulfate epitope rises rapidly after the transection of the anterior cruciate ligament, long before OA lesions can be detected, and remains high for at least 13 weeks.

Cellular hypersensitivity in rheumatoid arthritis, ankylosing spondylitis, and anterior nongranulomatous uveitis.

The humoral and cellular responses to normal human ocular and joint tissue antigens were studied in rheumatoid arthritis, ankylosing spondylitis, and anterior non-granulomatous uveitis. No free-circulating autoantibodies could be detected by hemagglutination, immunodiffusion, and immunofluorescence. Uvea-retina, synovial membrane, and articular cartilage antigen preparations inhibited the migration of leukocytes from patients with rheumatoid arthritis. In ankylosing spondylitis inhibition could be induced only by synovial membrane antigens. Patients with anterior nongranulomatous uveitis were hypersensitive to uvea-retina antigens alone.

Isolated traumatic posterior dislocation of the radial head.

Only 4 cases of isolated posterior dislocation of the radial head in adults have been reported in the English-language literature. We describe 2 cases with a clear mechanism of injury and present a concise review of the literature.