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PubMed2001

Biochemical characterization of cartilage affected by osteochondritis dissecans in the humeral head of dogs.

OBJECTIVE: To determine glycosaminoglycan (GAG) concentration and immunohistochemical staining characteristics of type-I, -II, and -X collagen from cartilage affected by osteochondritis dissecans (OCD) in dogs. ANIMALS: 31 dogs with OCD and 11 clinically normal purpose-bred dogs. PROCEDURE: Cartilage samples were evaluated microscopically, and GAG content was determined. Immunohistochemical staining was performed for type-I, -II, and -X collagen. Sections were subjectively evaluated for location and intensity of staining. RESULTS: Cartilage affected by OCD had a variety of pathologic changes and significantly lower GAG concentrations than did normal cartilage. Normal cartilage had no detectable type-I collagen. For dogs < 9 months of age, cartilage affected by OCD had significantly more type-I collagen but significantly less type-X collagen than did control cartilage. For dogs > 12 months of age, cartilage affected by OCD contained significantly more type-I collagen than did control cartilage. There was a significant negative correlation between immunoreactivity of type-I collagen and that of type-II and -X collagen. A significant positive correlation was found between immunoreactivity of type-II and -X collagen. CONCLUSIONS AND CLINICAL RELEVANCE: Cartilage affected by OCD contains less GAG, more type-I collagen, and less type-X collagen, compared with normal cartilage. A direct correlation between these changes and the etiopathogenesis of OCD was not established.

Animals↗
PubMed2003

Effects of dosage titration of methylprednisolone acetate and triamcinolone acetonide on interleukin-1-conditioned equine articular cartilage explants in vitro.

REASONS FOR PERFORMING STUDY: Osteoarthritis is a frequent sequela of joint disease, especially with severe injuries or if attempts at therapy are unsuccessful. Negative and positive effects of corticosteroid treatment of articular cartilage have been demonstrated by in vitro and in vivo studies. OBJECTIVES: To assess the metabolic effects of varying dosages of methylprednisolone acetate (MPA) and triamcinolone acetonide (TA) on interleukin-1alpha (IL-1) conditioned equine cartilage explants. Our hypothesis was that lower dosages of corticosteroids would be less detrimental to cartilage metabolism than higher dosages. TA would be less detrimental to cartilage metabolism than MPA. METHODS: Treatment groups included articular cartilage explants with no IL-1 (control), IL-1 alone, and IL-1 plus 10, 5, 1 and 0.5 mg/ml MPA or 1.2, 0.6, 0.12 and 0.06 mg/ml TA. Explants were labelled with 35SO4 prior to the beginning and end of the experiment to assess glycosaminoglycan (GAG) degradation and synthesis, respectively. Total GAG content in media and explants and total cartilage DNA were also analysed. RESULTS: MPA and TA reduced GAG synthesis compared to control and IL-1 alone. The highest dosage of MPA (10 mg/ml) reduced GAG synthesis less than lower dosages of MPA and all dosages of TA. Compared to IL-1 alone, all dosages of TA and lower dosages of MPA increased GAG degradation. MPA at 10 mg/ml reduced GAG degradation. Both MPA and TA increased media GAG content compared to control and IL-1 explants. Total cartilage GAGs were unchanged with MPA, but reduced with TA, compared with IL-1 alone. Total cartilage DNA was decreased with MPA and increased with TA compared to IL-1 and control explants. CONCLUSIONS: MPA and TA did not counteract the negative effects of IL-1 and did not maintain cartilage metabolism at control levels. Lower dosages of MPA and TA were not less detrimental to cartilage metabolism than higher dosages. TA did not appear to be less harmful than MPA on cartilage metabolism. The results of this study differ from the findings of comparable in vivo studies. POTENTIAL RELEVANCE: The low numbers of horses used in this study limits extrapolation of these findings to the equine population; however, this study also questions the clinical relevance of this in vitro model.

Animals↗
PubMed1989

Potential influences of ketoprofen on human healthy and osteoarthritic cartilage in vitro.

Ketoprofen (Orudis, Rhône-Poulenc) is an anti-inflammatory drug with analgesic properties that is used in diseases such as rheumatoid arthritis and osteoarthritis (OA). It is therefore of interest to know whether ketoprofen has a direct influence on cartilage metabolism. We studied the effects of ketoprofen in therapeutic concentrations, on proteoglycan (PG) turnover in explants of human cartilage. The cartilage specimens were divided into three groups: healthy young (less than or equal to 3 yrs) n = 8, healthy old (mean 56 yrs) n = 13 and OA cartilage (greater than or equal to 65 yrs) n = 15. The rate of PG synthesis at day 4 of the culture was measured by the uptake of 35S sulphate. Cartilage PG content and PG release into the medium were determined over 8 days of culture. Ketoprofen stimulated the rate of PG synthesis of young cartilage, but not of old cartilage. In OA cartilage both stimulation and suppression occurred. Ketoprofen had no influence on cartilage PG content and PG release of healthy or OA cartilage during the 8 days of culture. The cartilage was examined histologically, and graded for severity of OA. There was no relation between the severity of OA and the effect of ketoprofen.

Adult↗
PubMedDate not supplied

Mechanobiology in the development, maintenance, and degeneration of articular cartilage.

During skeletal development, the establishment of a layer of cartilage at the ends of long bones is intimately linked to the process of endochondral ossification. Previous in vivo studies and computer models suggest that mechanobiological factors can play a key role in modulating cartilage growth and ossification. Specifically, intermittent hydrostatic pressure is thought to maintain cartilage, and shear stresses encourage cartilage destruction and ossification. In the present investigation we examined the combined effects of hydrostatic pressure and shear stress--in the form of an osteogenic index--on the development of a layer of articular cartilage, using an idealized finite element computer model. The results of our analyses provide further support for the view that mechanobiological factors play a key role in regulating the distribution of cartilage thickness and in maintaining a stable cartilage layer at maturity. The model predicts that joints that experience higher contact pressures will have thicker cartilage layers. These predictions are consistent with observations of cartilage thickness in both humans and animals. Variations in articular mechanical load are predicted to modulate cartilage thickness. These results are consistent with the view that the mechanobiological factors responsible for the development of diarthrodial joints eventually lead to cartilage degeneration and osteoarthritis (OA) with aging.

Aging↗
PubMed2000

Adhesion of transplanted chondrocytes onto cartilage in vitro and in vivo.

OBJECTIVE: The specific objectives of this study using organ culture were (1) to transplant chondrocytes onto an intact cartilage surface; (2) to genetically modify endogenous and transplanted chondrocytes; and (3) to assess the ability of these cells to continually express a gene product. The specific objective with in vivo experiments was to transplant chondrocytes with intraarticular injections to cartilage. METHODS: Fluorescent membrane and intracellular dyes were used in conjunction with confocal microscopy to observe the integration of transplanted chondrocytes into cartilage both in vitro and in vivo. The distribution and duration of binding of rat, canine, and bovine chondrocytes to cartilage explants and the duration of expression of genes transduced into the transplanted chondrocytes were also determined. We used the vector AdlacZ, an E1 and E3 deleted replication defective adenoviral vector that contains the beta-galactosidase gene driven by the beta-actin promoter and the cytomegalovirus enhancer. RESULTS: The transplanted chondrocytes had a patchy distribution after in vitro or in vivo transplantation and buried themselves within the cartilage over time. Chondrocytes infected with the adenoviral vector AdlacZ soon or well after transplant to cartilage explants were maintained on the cartilage and continued throughout the duration of each trial to produce beta-galactosidase coded by the adenoviral vector. The cartilage plugs were infected with AdlacZ at 2 days or one, 2, 5, or 8 weeks after the chondrocytes were transplanted. The cartilage slices were then cultured from 15 days for chondrocytes infected at 8 weeks to 60 days for chondrocytes infected at 2 days post-transplant before determining the expression of beta-galactosidase. CONCLUSION: These results support the possibility of repairing cartilage by intraarticular injections of chondrocytes. Transduction of chondrocytes with genes producing a variety of matrix promoting proteins should further enhance the reconstruction of osteoarthritic cartilage.

Animals↗
PubMed2000

[Study of mechanisms of lightening aspiration and increasing decannulation rate in anastomosis of cricoid cartilage and base of tongue (epiglottis)].

OBJECTIVE: To study laryngopharyngeal anastomosis and fixing methods of super-cricoid laryngectomy with reconstruction of functions in lightening aspiration and increasing decannulation rate. METHODS: Recovering conditions of laryngeal functions in 66 patients who underwent supracricoid laryngectomy and anastomosis of cricoid cartilage and base of tongue (epiglottis) in recent eight years were summarized. Some relevant caliber distances in 21 residual larynges were measured. RESULTS: All cases restored their phonation. In 36 cases that underwent anastomosis of cricoid cartilage and base of tongue, 15 cases without aspiration, 18 with mild aspiration, 3 moderates. Decannulation rate is 94.4%. In 30 cases who underwent anastomosis of cricoid cartilage and base of tongue, 10 with mild aspiration, 17 moderate, 3 serious. All cases overcame aspiration within 3 weeks. 7 cases were cannulated. 3, 5, 10 year survival rates were 80.3%, 74.4%, and 3/7. The longitudinal and transverse calibers of epiglottis were 1.5-2.0 times longer than that of the entrance of cricoid cartilage. After anastomosis of cricoid cartilage and base of tongue (epiglottis), the epiglottis can exactly cover the entrance of cricoid cartilage to prevent aspiration fully and increase decannulation rate. Previously the cricoid cartilage was anatomized and fixed under the hyoid bone. Because some spaces exist between cricoid cartilage, base of tongue and epiglottis, aspiration is likely to occur. That hyoid bone covers the entrance of cricoid cartilage will bring constriction of the new laryngeal orifice and make decannulation difficult. Hyoidectomy and anastomosis of cricoid cartilage and base of tongue (epiglottis) overcame the two shortcomings and had good effects. CONCLUSION: Cricoid-hyoid-anastomosis was the main reason of severe aspiration and low decannulation rate. The ideal methods to lighten aspiration and increase decannulation rate are hyoidectomy and anastomosis of cricoid cartilage and base of tongue (epiglottis).

Adult↗
PubMed2004

Zonal and directional variations in tensile properties of bovine articular cartilage with special reference to strain rate variation.

UNLABELLED: THE AIMS of this study were: (i) to investigate the variation in the tensile properties of articular cartilage with depth through cartilage thickness and fibre orientation; (ii) to determine the effect of strain rate on tensile properties of articular cartilage. MATERIALS AND METHOD: All experimental work was performed on cartilage specimens taken from two bovine knee joints. Osteochondral plugs 12 mm in diameter were harvested with a special reamer from the femur and the tibial plateaux of each knee. Slices (0.2 mm thick), of articular cartilage were cut from the plug with a microtome. The predominant orientation of the collagen fibres on the cartilage surface was determined using the pinpricking technique. Each specimen used for the tensile test was cut, so as to produce a dumbbell shape, with a gauge length of 6 mm. Uniaxial tensile tests were performed on each specimen in order to determine the tensile Young's modulus, and ultimate tensile strength (UTS). In this investigation, these tensile tests were carried out at different strain rate: 1, 20, 50 and 70%/sec. RESULTS: As regards the zonal properties, it was found that tensile stiffness was greater in the superficial layer than in deep layer. However, a few specimens from the deep layer displayed similar or greater stiffness compared to the superficial layer. With respect to the directional properties, the specimens oriented parallel to the predominant alignment of collagen, were stiffer than those, which were perpendicular to it in each layer. However, only the results regarding the deep layer can be considered statistically significant. In regard to the variation of modulus with the strain-rate, the results showed that there is no significant increase of the modulus with increasing strain rate from 20 to 50% per second. However, at 70% per second, articular cartilage stiffness considerably increased by up to one order of magnitude greater than that determined at lower strain rates in both the superficial and deep layer. Moreover, the UTS of cartilage specimens tested at 70% per second showed a significant rise, reaching values of four to five times that of those measured at 1, 20 or 50% per second. CONCLUSION: The steep increases in both the stiffness and ultimate tensile strength of cartilage at high strain rates point to the existence in cartilage of a mechanism for its protection from damage by stresses arising in trauma, which are usually applied at high rates. This mechanism needs to be elucidated. The reduced anisotropy found in the present study pointed out that collagen is likely to be less organized in bovine cartilage than in the human and therefore, a study of its ultra-structure would be appropriate.

Adaptation, Physiological↗
PubMed2006

The serine protease inhibitor trappin-2 is present in cartilage and synovial fluid in osteoarthritis.

OBJECTIVE: Trappins are small serine protease inhibitors bound to extracellular matrix (ECM) through the actions of transglutaminase (TGase) enzymes. Trappin-2 is present in many tissues and is upregulated at sites of injury. In osteoarthritis (OA), serine proteases contribute to articular cartilage destruction, and TGase activity is increased. Yet little is known about matrix-bound serine protease inhibitors or TGase substrates in articular cartilage. Our purpose was to determine if trappin-2 was present in OA cartilage and synovial fluid (SF). METHODS: OA knee articular cartilage and SF were assayed for trappin-2 protein by Western blotting, ELISA, and immunohistochemistry. Trappin-2 mRNA was detected with RT-PCR. The ECM components bound to trappin-2 were identified by 2-D gel electrophoresis and peptide fingerprinting. RESULTS: Trappin-2 was detectable in OA articular cartilage extracts, cultured chondrocytes, conditioned media, and SF by Western blotting. OA cartilage protein extracts contained significantly higher quantities of trappin-2 than normal cartilage protein extracts (22.98 +/- 1.28 ng/mg wet weight vs 14.97 +/- 1.92 ng/mg wet weight; p < 0.01). RT-PCR confirmed the presence of trappin-2 mRNA in OA chondrocytes. Immunohistochemical studies of OA cartilage revealed trappin-2 protein in chondrocytes. Peptide mapping of trappin-2 binding partners showed that fibromodulin was bound to trappin-2 in cartilage. CONCLUSION: We confirmed the presence of trappin-2 in OA cartilage and SF. Elevated levels of TGase activity in OA cartilage may increase levels of this serine protease inhibitor in response to injury.

Adolescent↗
PubMed1991

[The distribution of S-100 protein positive chondrocytes in the human articular cartilages under aging or diseased conditions].

There have been few reports on the localization of S-100 protein positive chondrocytes in the human articular cartilages. We studied 59 articular cartilages of the aged subjects, 65 osteoarthritic (OA) and 39 rheumatoid arthritic (RA) articular cartilages, to detect the histological localization of S-100 protein using immunoperoxidase method (ABC). The results obtained from normal cartilages demonstrated strongly positive cells representing hypertrophic chondrocytes in the perivascular areas of the neonatal articular cartilage and in the deep zone of the infant articular cartilage. The moderately positive cells were found in the intermediate zone of infant and adult articular cartilages. In mild OA, there were many positive chondrocytes in the intermediate zone with erosion of the surface layer, while in moderate or severe OA many strongly positive cells were found in clusters. The hypertrophic cells in the metaplastic cartilage arising from bone marrow in subjects with severe OA, or from pannus after RA were also positive. It is therefore, suggested that S-100 protein may be correlated with the metabolic activity of the cartilage matrix such as collagen and proteoglycan, as reported in the literature. S-100 protein further, appears to be useful for evaluating histologically the activity of cartilage repair in the pathologic human articular cartilages.

Adolescent↗
PubMed1985

Lipids of normal and osteochondritic cartilage of the immature canine humeral head.

Specimens of cartilage removed from the shoulder joint of dogs with osteochondritis dissecans were compared with the articular-epiphyseal cartilage from the same location of healthy dogs. The pathologic cartilage lost the lamination pattern of articular-epiphyseal cartilage from healthy dogs. Chondrocytes of healthy and pathologic cartilage contained lipid inclusions. However, in pathologic samples, the lipid inclusions were more prominent, particularly in the superficial region of the presumptive articular cartilage. Lipids in the interterritorial matrix of the pathologic cartilage were observed. The pathologic cartilage contained large groups of chondrocytes and areas of mineralization of variable magnitude. Although lipid inclusions were found in the chondrocytes of cartilage of healthy dogs, the increase in magnitude of lipids in the cartilage from dogs with osteochondritis dissecans was considered to result from a metabolic response of the chondrocyte to an altered microenvironment. The loss of sudanophilic lipids in areas of chondrolysis may be used to explain the retardation of osteogenesis of chondrolytic cartilage.

Animals↗
PubMed1986

Investigations of low-temperature storage of articular cartilage for transplantation.

Isolated bovine articular cartilage chondrocytes and intact slices of cartilage were investigated to determine the effects of low-temperature cryopreservation on articular cartilage. Studies have focused on prefreezing conditions of cartilage, including the incubation medium and temperature of incubation, type and toxicity of the cryopreservative used, and the penetration of cryopreservative agents into cartilage cells. Cartilage freezing conditions were examined with respect to rate of freezing, controlled differential freezing rates, the ultimate storage temperature, and the time of storage. Cartilage thawing conditions were observed to ascertain the role of membrane osmotic stress during thawing and the effect of variable thawing rates on the viability of chondrocytes. Careful control of these variables can yield cartilage with cellular viability of over 50%. Optimum cryopreservation of viable cartilage should include prefreezing treatment with 7.5%-10% DMSO in nutrient medium, controlled slow freezing to -70 degrees, and rapid thawing in DMSO containing medium. A significant number of chondrocytes in deep-frozen cryopreserved articular cartilage can survive. The work recommends continued clinical use of deep-frozen cartilage.

Animals↗
PubMed1985

Regenerating rib cartilage tentatively used as a source of chondrocytes for transplantation.

In search for cartilage which could serve as a source of chondrocytes for autogeneic transplantation in mature individuals we studied the morphological appearance and digestibility of normal rib cartilage and regenerated cartilage formed after subperichondrial removal of the former in adult dogs. Cells liberated after collagenase digestion were transplanted intramuscularly to see whether they will reconstruct cartilage similarly as it happens after transplantation of fetal chondrocytes. Chondrocytes in normal rib cartilage were arranged in three zones and lay in large isogenous groups. Collagenase dissolved only the peripheral zone. Isolated cells did not reconstruct cartilage after transplantation. No distinct zones could be seen in regenerated cartilage. Chondrocytes lay singly or in pairs but were not numerous. Regenerated cartilage could be completely dissolved by collagenase, but the yield of cells was low owing to their low content in digested material. After transplantation chondrocytes from regenerated cartilage reconstructed cartilage in one out of ten transplants. The possibility of increasing the cellularity of regenerated cartilage by stimulation of the perichondrium with factors known to promote chondrocyte growth in vitro is discussed.

Animals↗
PubMedDate not supplied

[Immune complexes: mediators for the formation of inflammatory granulation tissue? Immunohistologic studies of the hyaline articular cartilage in chronic polyarthritis].

Previous reports describe the presence of immunoglobulins and complement components within rheumatoid articular cartilage, thereby suggesting an effect of immune complexes on the formation of pannus. This hypothesis is reinvestigated in this paper. As confirmed in our work, the superficial layer of rheumatoid hyaline cartilage may fulfill the immunohistological criteria for the presence of immune complexes. In osteoarthritis, however, a noninflammatory disease not mediated by immunologic mechanisms, similar results can be obtained. The presence of immune-proteins within hyaline cartilage therefore requires a cautious interpretation. Hyaline cartilage in rheumatoid arthritis is replaced by granulation tissue growing not only at its surface (pannus), but also in subchondral bone. We therefore also thoroughly investigated deep layers of hyaline cartilage in the vicinity of such subchondral tissue, but could not obtain any evidence for the presence of immune complexes therein. The growth of subchondral granulation tissue and the accumulation of PMN in the region of its junction with hyaline cartilage therefore appear to be independent of immune complexes within rheumatoid hyaline cartilage. It is suggested on the basis of these data that immune complexes possibly present in hyaline cartilage do not play an essential role in the formation of granulation tissue replacing cartilage in rheumatoid arthritis. It is, however, not entirely excluded that during advanced stages of rheumatic cartilage degradation immune complexes are formed within the matrix or carried into it from the extra-cartilaginous environment, and that they may then contribute to further cartilage destruction by enzyme release during phagocytic processes.

Antigen-Antibody Complex↗
PubMed1983

Legg-Calvé-Perthes disease. Histochemical and ultrastructural observations of the epiphyseal cartilage and physis.

UNLABELLED: Biopsy specimens of the lateral aspect of the femoral head and neck were obtained from five children with Legg-Calvé-Perthes disease and were studied using histochemistry and electron microscopy. Beneath the normal articular cartilage there was a thick zone of hyaline (epiphyseal) cartilage containing sharply demarcated areas of hypercellular and fibrillated cartilage with prominent blood vessels. The fibrillated cartilage was strongly positive to alcian blue, weakly positive to periodic acid-Schiff, and positive to aniline blue. The interterritorial matrix in the hypercellular areas was weakly positive to both alcian blue and periodic acid-Schiff. Ultrastructural examination of these areas revealed many irregularly oriented large collagen fibrils and variable amounts of proteoglycan granules. These results suggest that in the fibrillar areas there are: (1) a high proteoglycan content, (2) a decrease in structural glycoproteins, and (3) a different size of collagen fibrils from that of normal epiphyseal cartilage. The hypercellular areas had a decrease in proteoglycans, glycoproteins, and collagen. The lateral physeal margin was often irregular, with a marked reduction of collagen and proteoglycan granules, and contained numerous large lipid inclusions. CLINICAL RELEVANCE: The abnormal areas in the epiphyseal cartilage of patients with Legg-Calvé-Perthes disease have different histochemical and structural properties from normal cartilage and from fibrocartilage. This suggests that the disease could be a localized expression of a generalized, transient disorder of epiphyseal cartilage that is responsible for delayed skeletal maturation. The cartilage lesions are similar to those seen in the vertebral plates in patients with juvenile kyphosis. Whether the epiphyseal cartilage abnormalities are primary or are secondary to ischemia remains uncertain; however, it appears that the collapse and necrosis of the femoral head could result from the breakdown and disorganization of the matrix of the epiphyseal cartilage, followed by abnormal ossification.

Cartilage, Articular↗
PubMed1994

Binding characteristics of antitype II collagen antibody to the surface of diseased human cartilage as a probe for tissue damage.

OBJECTIVE: Studies have shown that collagen type II (CII) on the intact articular surface of cartilage is partially protected from binding to anti-CII antibodies by material proteinaceous in nature, not present in synovial fluid, synthesized by resident chondrocytes, and exquisitely sensitive to polymorphonuclear (PMN) attack and neutrophil elastase digestion. Thus, anti-CII antibody differential binding to articular cartilage surfaces before and after brief neutrophil elastase digestion may be used as a sensitive marker of cartilage damage. METHODS: We measured binding of anti-CII antibodies to the pannus-free articular surfaces of 4 normal, 11 rheumatoid (RA), and 10 osteoarthritic (OA) cartilage specimens, before and after brief digestion with PMN elastase. In addition, antibody binding was quantitated with an antiserum against a 4 M guanidine extract of human cartilage surface. RESULTS: Whereas anti-CII binding increased 59.0% +/- 2.8 after 1 h incubation of normal cartilage with elastase, both the RA and OA specimens failed to show significant increases (RA: 1.0 +/- 0.1; p < 0.001; OA: 27.2% +/- 1.6, p < 0.05). Moreover, anti-CII antibody binding to untreated cartilage specimens was highest for the RA group (Normal: 189.2.1 +/- 38.7 pg anti-lg/mg tissue; RA: 407.5 +/- 80.6, p < 0.05; OA: 243.6 +/- 50.6, NS). Concomitant binding studies with antiserum against cartilage surface material showed greater antibody binding to the articular surfaces than to the cut cartilage surfaces in normal and OA specimens. RA cartilage samples exhibited somewhat smaller antibody binding to the articular surfaces. CONCLUSION: Our studies suggest that in human inflammatory and noninflammatory arthritides the articular cartilage surface undergoes alterations that can be detected by differential binding with anti-CII antibodies, before and after brief digestion with PMN elastase.

Adolescent↗
PubMed1996

Chondrocyte matrix metalloproteinase-8: up-regulation of neutrophil collagenase by interleukin-1 beta in human cartilage from knee and ankle joints.

The loss of aggrecan from articular cartilage may lead to the development of osteoarthritis (OA). Degradation products of human aggrecan, generated in vivo by enzymatic cleavages, have been identified in synovial fluid of patients with rheumatoid arthritis and OA. One matrix metalloproteinase (MMP), stromelysin (MMP-3), and an unidentified proteinase called "aggrecanase" are believed to generate these products in pathologic conditions. Thus far, only one proteinase, neutrophil collagenase (MMP-8), has been shown in vitro to be capable of cleavage of the aggrecan molecule at the "aggrecanase" site. In this study, we compare the presence and distribution of MMP-3 and MMP-8 in cartilages from two different joints of normal human donors. We determined whether mRNA for MMP-8 is expressed in normal human articular cartilage from different joints. In addition, we compared differences in MMP-8 and MMP-3 gene expression between human ankle and knee cartilage after in vitro stimulation by interleukin (IL)-1 beta. These two joints were chosen because the incidence of symptomatic and radiographic OA varies between the different joints. The knee is the most frequently involved joint, whereas the ankle (talocrural) joint is relatively rarely affected. Message for MMP-8 was detected in untreated cartilage from normal knee joints, but not in untreated cartilage of normal ankle joints. Message for MMP-3 was detectable in most of the knee and ankle cartilages. Messenger RNA expression for both MMPs could be up-regulated by IL-1 beta. The highest doses of IL-1 beta appeared to be most effective in stimulation of mRNA for MMP-3, whereas MMP-8 expression was more sensitive to lower doses of IL-1 beta. The fact that ankle cartilage with a low incidence of OA does not express MMP-8, whereas knee cartilage with a high incidence of OA does not express MMP-8, whereas knee cartilage with a high incidence of OA does constitutively express MMP-8, suggests that MMP-8 might be one of the key enzymes in the pathogenesis of osteoarthritis. This is further supported by our finding that the earliest signs of cartilage degradation were very similar to those found in IL-1 beta-treated explants.

Adolescent↗
PubMed1997

[Histological study on the using of autogenous costal perichondrium graft to repair the cartilage of condylar process of mandible].

In order to observe the histological changes of the autogenous perichondrium graft from rib in the repair of injured articular cartilage of the condylar process of mandible, 50 rabbits were used, in which 15 were served as control. The articular cartilage with its subchondral bone were resected and an autogenous graft of costal perichondrium was sutured onto the raw surface of the condylar process, and in the controls, only the articular portion of the condylar process was resected without the application of autogenous costal perichondrium graft. The morphological changes of the newly formed cartilage during the process of its development were investigated by hiostological and autoradiog aphic techniques. The result revealed that 10 days after operation, the graft had increased in thickness and was richly populated form the proliferation of mesenchyme-like cells. Twenty to thirty days later, the chondrocytes were matured and the newly formed cartilage had covered the bony surface of mandibular condyle. At 60 days, the newly formed cartilagenous joint surface became glossy, and the morphology and arrangement of cells tended to be regular simulating the morphology of normal articular cartilage. From the experiment, it could be concluded that (1) The autogenous perichondrium graft placed on the condylar surface of mandible could form new articular cartilage which was similar in tissue morphology to the normal condylar cartilage. (2) The process of development of newly formed cartilage was similar to that of the normal cartilage. (3) The motion and loading on the joint could promote the formation of new cartilage and undergo biological reformation, gradually resulting in normal joint morphology. On this basis, the clinical application of autogenous perichondrium graft to repair injured cartilage of the condylar process of the mandible was feasible.

Animals↗
PubMed2006

Evaluation of the articular cartilage of the knee joint with vastly undersampled isotropic projection reconstruction steady-state free precession imaging.

PURPOSE: To determine the feasibility of the vastly undersampled isotropic projection reconstruction steady-state free precession (VIPR-SSFP) sequence for evaluating the articular cartilage of the knee joint. MATERIALS AND METHODS: A magnetic resonance (MR) examination of the knee was performed on 33 subjects using a GE 1.5T scanner and a phased-array extremity coil. VIPR-SSFP, proton density-weighted fast spin-echo (PD-FSE), fat-suppressed T2-weighted fast spin-echo (T2-FSE), and three-dimensional fat-suppressed spoiled gradient recall-echo (SPGR) sequences were performed on three asymptomatic volunteers and 10 patients with osteoarthritis of the knee joint. Signal-to-noise efficiency, and contrast-to-noise ratio (CNR) measurements were calculated for all sequences and compared with the use of paired t-tests. The VIPR-SSFP sequence was then performed on 20 consecutive patients who were undergoing a routine MR examination of the knee. RESULTS: The cartilage signal-to-noise efficiency of the VIPR-SSFP sequence was not significantly different from that of the PD-FSE and SPGR sequences. The cartilage signal-to-noise efficiency of the VIPR-SSFP sequence was significantly higher (P < 0.05) than that of the T2-FSE sequence. The VIPR-SSFP sequence produced images with significantly higher (P < 0.05) CNR between cartilage and synovial fluid than the PD-FSE and SPGR sequences, and significantly higher (P < 0.05) CNR between cartilage and subchondral bone than the T2-FSE sequence. The VIPR-SSFP sequence allowed excellent visualization of the articular cartilage of the knee joint in all subjects. All articular cartilage defects identified on the PD-FSE, T2-FSE, and SPGR images were well visualized on the VIPR-SSFP images. CONCLUSION: VIPR-SSFP images had high cartilage signal-to-noise efficiency and high CNR between cartilage and adjacent synovial fluid and subchondral bone; therefore, the sequence is well suited for evaluating the articular cartilage of the knee joint.

Adult↗