| 1. |
- Lohmander, L. S., et al.
(författare)
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Stromelysin, tissue inhibitor of metalloproteinases and proteoglycan fragments in human knee joint fluid after injury
- 1993
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Ingår i: Journal of Rheumatology. - 0315-162X. ; 20:8, s. 1362-1368
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To determine in a cross sectional study the concentrations of stromelysin, tissue inhibitor of metalloproteinases (TIMP), and proteoglycan fragments in knee synovial fluid (SF) at different times after injury to cruciate ligament or meniscus. Methods. Joint fluid samples were obtained from patients with knee injury diagnosed by arthroscopy. Concentrations of stromelysin-1 and TIMP-1 were determined by immunoassay with monoclonal and polyclonal antibodies. Cartilage proteoglycan fragments were quantified by immunoassay with polyclonal antibodies or by dye precipitation. Results. Average concentrations of stromelysin increased 40-fold in association with injury, and after about 6 months decreased to a plateau level about 10-fold increased compared to a reference group with healthy knees. TIMP and proteoglycan levels also increased in similar temporal patterns, but less markedly. Increased average SF levels of these markers were maintained for at least 17 years after injury. SF from knees with injury contained a 1.5 to 2.5 molar excess of stromelysin over TIMP, while reference joint fluids contained a 2-fold molar excess of TIMP over stromelysin. Conclusion. The persistent changes in SF markers after joint injury may be associated with the cartilage destruction and frequent development of posttraumatic osteoarthritis in this group of patients.
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| 2. |
- Dahlberg, L., et al.
(författare)
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A longitudinal study of cartilage matrix metabolism in patients with cruciate ligament rupture-synovial fluid concentrations of aggrecan fragments, stromelysin-1 and tissue inhibitor of metalloproteinase-1
- 1994
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Ingår i: British Journal of Rheumatology. - : Oxford University Press (OUP). - 0263-7103. ; 33:12, s. 1107-1111
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Tidskriftsartikel (refereegranskat)abstract
- This is the first study which quantifies aggrecan fragments, stromelysin-1 and tissue inhibitor of metalloproteinases-1 (TIMP-1) in SF samples prospectively obtained from the same patient at different time intervals after a cruciate ligament injury of the knee. Aggrecan fragment concentrations were determined by dye precipitation with Alcian Blue. Stromelysin-1 and TIMP-1 were analysed by immunoassay. Ten healthy volunteers formed the reference group. Immediately after knee injury, all marker concentrations were higher as compared to the reference group. The high marker concentrations decreased gradually with time, and in samples obtained between 6 months and 6 years after the injury, median concentrations of some of the markers were not different compared to reference levels. This was in contrast to results from previous cross-sectional studies, where chronic phase median concentrations of all markers were consistently higher than reference levels. In previous cross-sectional studies, however, the samples were obtained at arthroscopy done because of knee complaints at different times after a knee injury. In the present study, the knee injured patients visited the orthopaedic outpatient ward only for SF sampling, and they had no or only minor knee symptoms. We conclude that the temporal changes of marker concentrations in joint fluid after knee injury, suggested from cross-sectional studies, have now been confirmed in a longitudinal, prospective cohort study. We further find that in patients with mild knee symptoms in the chronic phase after cruciate ligament injury, median SF levels of aggrecan fragments, stromelysin-1, and TIMP-1 are lower than in patients with significant knee complaints after the same type of injury. This suggests a possible relationship between joint fluid marker concentrations, joint pathology, and cartilage metabolism.
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| 3. |
- Dahlberg, L., et al.
(författare)
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Cartilage metabolism in the injured and uninjured knee of the same patient
- 1994
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967. ; 53:12, s. 823-827
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Lohmander, L. S., et al.
(författare)
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Temporal patterns of stromelysin-1, tissue inhibitor, and proteoglycan fragments in human knee joint fluid after injury to the cruciate ligament or meniscus
- 1994
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Ingår i: Journal of Orthopaedic Research. - 0736-0266. ; 12:1, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- Stromelysin-1, tissue inhibitor of metalloproteinases-1 (TIMP-1), and proteoglycan fragments were quantified in knee synovial fluid samples in a cross-sectional study of patients who had injury to the anterior cruciate ligament or the meniscus. The average concentrations of stromelysin-1 and TIMP-1 increased 25-fold and 10-fold within the first day after the trauma, respectively, and the concentration of proteoglycan fragments increased 4- fold. From approximately 1-6 months after injury, the levels of these markers were higher after injury to the cruciate ligament than after injury to the meniscus. From 6 months to 18 years after trauma, however, the levels of stromelysin-1 and TIMP-1 in patients who had an injury to the ligament were the same as the levels in patients who had a meniscal lesion, but the levels were increased compared with those for a reference group of healthy volunteers. The molar balance of stromelysin-1 to TIMP-1 in synovial fluid in both groups of injured joints changed from a balance representing an excess of free inhibitor in the normal joint to one representing an excess of free enzyme in the injured joint. The increased release of these markers to joint fluid both early and late after trauma may be caused by a change in the loading patterns in the knee with an injured ligament or meniscus or by synovitis induced by bleeding. The increased release may be associated with the frequent development of posttraumatic osteoarthritis in patients with these injuries.
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| 5. |
- Lorange, P., et al.
(författare)
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Building successful strategic alliances
- 1992
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Ingår i: Long range planning. - 0024-6301 .- 1873-1872. ; 25:6, s. 10-17
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we will discuss (1) why a firm would want to go into a strategic alliance, (2) the different types of alliance, and (3) guidelines to follow when forming an alliance. © 1992.
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| 6. |
- Roos, H., et al.
(författare)
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Proteoglycan fragments in knee joint fluid after exercise
- 1993
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Ingår i: Scandinavian Journal of Medicine & Science in Sports. - 0905-7188. ; 3:2, s. 127-130
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Tidskriftsartikel (refereegranskat)abstract
- The concentration of cartilage proteoglycan fragments in knee joint fluid was measured before and after one event of physical exercise in 33 healthy athletes. Nine athletes ran on a treadmill for 60 min, 16 ran on road for 80 min and 8 played one soccer game (90 min). Before exercise, the levels of proteoglycan fragments in the athlete joint fluid were lower than in a previously analyzed reference group. After exercise, the concentration of proteoglycan fragments increased in all of the 7 athletes that could be directly compared before and after exercise. This increased concentration of proteoglycan fragments in the joint fluid could be an effect of mechanical loading of the cartilage in combination with a possible high turn-over rate of the cartilage matrix in the athletes.
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| 7. |
- Roos, H., et al.
(författare)
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The prevalence of gonarthrosis and its relation to meniscectomy in former soccer players
- 1994
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Ingår i: The American journal of sports medicine. - 0363-5465. ; 22:2, s. 219-222
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of radiographic signs of gonarthrosis and its relation to knee injuries were studied in 286 former soccer players-215 nonelite and 71 elite players-and were compared with 572 age-matched controls with a mean age of 55 years. The prevalence of gonarthrosis among the nonelite players was 4.2%, among the elite players 15.5%, and among the controls 1.6%. Seven of the soccer players had known anterior cruciate ligament injuries, and 40 had had meniscectomies. Of the 32 nonelite players with knee injuries, 4 (13%) had gonarthrosis, and of the 183 without known knee injuries 5 (3%) had gonarthrosis. Among the elite players, the prevalence of gonarthrosis in knees without diagnosed injuries was 11%. We conclude that soccer, especially at an advanced level, is associated with an increased risk for gonarthrosis. After excluding subjects with known knee injuries, there was no difference between nonelite players and controls, but we found a higher rate of gonarthrosis among the elite players.
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| 8. |
- Roos, Johan, et al.
(författare)
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A case-study of equipment purchasing in Czechoslovakia
- 1992
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Ingår i: Industrial Marketing Management. - 0019-8501 .- 1873-2062. ; 21:3, s. 257-263
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Tidskriftsartikel (refereegranskat)abstract
- On the basis of interviews in Norway and Czechoslovakia, this article examines the changes in procurement decision making processes by organizations in Czechoslovakia as a result of the dramatic political and economic restructuring since 1989. The focus is on the area of environmental protection equipment where, in spite of the economic constraints, the strongly recognized need for action in Czechoslovakia to control pollution will result in many new market openings for Western companies. It was found that there has been a significant shift from the past pattern of a multistage, time-consuming, highly bureaucratized procurement process, over which the user organization had very little control. In the new model, the user has control over the purchasing process, thus cutting the time involved and leaving a number of past key actors in an advisory role. Past formal networks are being disrupted or broken and there are now opportunities for Western firms to form more direct relationships with user firms.
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