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- Dahlberg, L., et al.
(author)
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Cartilage metabolism in the injured and uninjured knee of the same patient
- 1994
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In: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967. ; 53:12, s. 823-827
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Journal article (peer-reviewed)abstract
- Objective-To examine if unilateral knee injury affects the synovial fluid concentrations of aggrecan fragments, cartilage oligomeric matrix protein (COMP) fragments, stromelysin-l, and tissue inhibitor of metalloproteinases-l (TIMP-1) in the contralateral uninjured knee. Methods-Synovial fluids from the injured and uninjured knees were obtained at different times in a group of patients after unilateral knee trauma. Serum samples were obtained on the same occasion. Concentrations of aggrecan fragments were determined by precipitation with Alcian Blue; those of COMP fragments, stromelysin-l, and TIMP-1 were measured by immunoassay. Concentrations were compared with those in a reference group of 10 healthy volunteers. Results-Immediately after knee injury, concentrations of aggrecan fragments, COMP fragments, stromelysin-l and TIMP-1 were increased in the synovial fluid of the injured knee. However, concentrations of aggrecan and COMP fragments, and stromelysin-l increased also in the contralateral uninjured knee immediately after injury, but less than in the injured knee. Subsequently, the concentrations ofall markers decreased in the synovial fluid of the injured knee, but remained unchanged in the uninjured knee. The concentration of aggrecan fragments in the injured knee decreased to less than that in the uninjured knee in the chronic phase. Serum concentrations of COMP were much smaller than those in synovial fluid. Conclusions-The increased concentrations of aggrecan and COMP fragments and stromelysin-1 in the joint fluid of the contralateral, uninjured knee following unilateral knee injury, compared with concentrations in healthy reference knees, suggest changes in joint cartilage metabolism in both knees following unilateral knee injury. The mechanisms for these changes are unclear. The low serum concentration of COMP makes it less likely that there is any significant 'exchange' of molecular markers between the knees. A further consequence of these findings is that the contralateral knee cannot be recommended as the only control joint in studies of matrix metabolism in patients with unilateral knee injury.
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2. |
- Lohmander, L. S., et al.
(author)
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Release of cartilage oligomeric matrix protein (COMP) into joint fluid after knee injury and in osteoarthritis
- 1994
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In: Annals of the Rheumatic Diseases. - 0003-4967. ; 53:1, s. 8-13
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Journal article (peer-reviewed)abstract
- Objective - The release of fragments of cartilage oligomeric matrix protein (COMP) and aggrecan into knee joint fluid and serum after joint injury and in post-traumatic and primary osteoarthritis was monitored in a cross-sectional study. Methods - Samples of joint fluid and serum were obtained from healthy volunteers and from patients with arthroscopically verified injury to anterior cruciate ligament and or meniscus of the knee at different times after injury and with different degrees of post-traumatic osteoarthritis. Samples were also obtained from patients with primary osteoarthritis. Fragments of COMP were quantified in joint fluid and in serum by enzyme-linked immunoassay. Fragments of aggrecan were quantified in joint fluid by enzyme-linked immunoassay. Results - Concentrations of COMP and aggrecan fragments in joint fluid in the study groups were increased over the reference levels of 47 (range 10-109) and 34 (range 6-59) μg/mL, respectively, in the volunteers with healthy knees. The ratios (w/w) of aggrecan to COMP fragments in joint fluid were also increased in all study groups over that in the reference group. Average concentration of COMP in joint fluid were high shortly after injury and decreased with time but remained increased over reference levels for many years. Joint fluid COMP concentrations were also increased in early stage post-traumatic and primary osteoarthritis, but not in advanced osteoarthritis. Conclusion - Increased amounts of aggrecan and COMP fragments are released into joint fluid after joint injury and in early stage osteoarthritis. The ratios of aggrecan to COMP in joint fluid vary with time after injury and with osteoarthritis disease stage. Although both molecules are sensitive to the agents active in matrix breakdown in joint disease, differences may thus exist in the release mechanisms and attempted repair. The concentrations of the individual markers in body fluids and their ratios may serve to monitor treatment efficacy, disease progression and repair in osteoarthritis and other joint diseases.
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3. |
- Ståhl Hallengren, Christina, et al.
(author)
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An extra cysteine in one of the non calcium binding EGF-like motifs of the FBN1 polypeptide is connected to a novel variant of Marfan syndrome
- 1994
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In: Journal of Clinical Investigation. - 0021-9738. ; 94, s. 709-713
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Journal article (peer-reviewed)abstract
- We present here a family with a clinical phenotype resembling Marfan syndrome (MFS), and displaying joint contracture and episodes of knee joint effusions, but lacking the cardiovascular features of the syndrome. The phenotype of this family represents a unique mixture of connective tissue symptoms, some of which are found in classical MFS and some of which are typical of dominant ectopia lentis. Linkage analyses suggested a linkage (LOD score 2.4; theta = 0) between the phenotype of the family and a polymorphic marker in the vicinity of the fibrillin locus on chromosome 15 (FBN1). Furthermore, a novel transition mutation was identified in the FBN1 gene in all the affected members of the family. In contrast to the majority of fibrillin mutations reported so far, this mutation substitutes a cysteine for arginine, producing an extra cysteine in one of the non-calcium-binding EGF-like motifs of the fibrillin polypeptide, most probably disturbing the formation of one of the three disulfide bridges known to be essential for the normal conformation of this motif.
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