Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CARTILAGE, ARTICULAR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,279 records · Page 71Linked to original sources
PubMed1999

In vivo characterization of indentation stiffness of articular cartilage in the normal human knee.

Previous laboratory measurements showed topographical variation in the properties of articular cartilage in several animal species and in humans. In this study we characterize for the first time the topographical variation of the stiffness of the human knee articular cartilage in vivo using a novel arthroscopic indentation instrument. The instrument indicates the stiffness in the form of force (Newtons) by which the tissue resists the constant deformation (300 microm) produced by the small (1-mm diameter) cylindrical indenter. Measurements were carried out at eight sites in the knee joint of 20 persons who had intact cartilage in the arthroscopic examination. The stiffest cartilage (5.6 +/- 1.2 N, mean +/- SD) was located in the lateral condyle of the femur, whereas the softest cartilage (2.4 +/- 0.8 N) was in the medial plateau of the tibia. In general, the cartilage stiffness was higher in the femur than in the tibia (p < 0. 01) or in the patella (p < 0.01). In the femur, the condyles were stiffer than the patellar surface (p < 0.01). The stiffness variation was consistent with earlier biphasic indentation analyses of laboratory measurements with the knee joint cartilage of cadavers. This study provides baseline data for characterization of cartilage stiffness in pathological situations or follow-up of the cartilage quality after surgical interventions.

Adolescent↗
PubMed1991

Hypertrophic repair of canine articular cartilage in osteoarthritis after anterior cruciate ligament transection.

Transection of the anterior cruciate ligament in the dog is used frequently to produce a model of osteoarthritis (OA). Although it results in metabolic, biochemical, biomechanical and morphological changes in the articular cartilage of the unstable knee which resemble those in human OA, it rarely results in full thickness cartilage loss. The lack of progression of the cartilage lesions in this model has generally been attributed to stabilization of the joint by osteophytes and capsular fibrosis which develop following transection of the ligament. In our study transection of the anterior cruciate ligament of adult foxhounds and mongrels resulted in a progressive increase in the amount of articular cartilage in the unstable knee. In articular cartilage from the medial femoral condyle of the unstable knee the total amount of proteoglycan, as assessed by hexuronic acid analysis, and, often, the proteoglycan concentration were increased. Furthermore, the rate of proteoglycan synthesis was commonly elevated, in comparison with that from the contralateral knee. Thus, in these animals knee instability did not lead to loss of cartilage but to an active synthetic response by the chondrocytes resulting in hypertrophic cartilage repair which was sustained for up to 64 weeks of observation.

Animals↗
PubMed2000

Scratching the surface: articular cartilage disorders in the knee.

Powerful techniques with MR imaging are being developed for evaluating articular cartilage. Pharmaceutical and biotechnology development is driven largely by the search for novel therapeutic solutions to the growing problem of arthritis in our aging society. Accordingly, imaging tools that will be used to direct patients to specific therapies and then to monitor treatment effectiveness and safety presently are being refined and validated in rigorous multicenter and multinational clinical trials aimed at gaining regulatory approval. As trials approach completion, radiologists can anticipate an increased demand for expertise and experience in evaluating articular cartilage disorders. This article reviews this novel mechanism for evolving imaging techniques for clinical use through clinical drug trials, lists the most promising MR imaging markers available for evaluating cartilage integrity, and speculates on how these techniques will find their way into clinical practice.

Cartilage Diseases↗
PubMed2003

Anatomically shaped osteochondral constructs for articular cartilage repair.

Few successful treatment modalities exist for surface-wide, full-thickness lesions of articular cartilage. Functional tissue engineering offers a great potential for the clinical management of such lesions. Our long-term hypothesis is that anatomically shaped tissue constructs of entire articular layers can be engineered in vitro on a bony substrate, for subsequent implantation. To determine the feasibility, this study investigated the development of bilayered scaffolds of chondrocyte-seeded agarose on natural trabecular bone. In a series of three experiments, bovine chondrocytes were seeded in (1) cylindrical bilayered constructs of agarose and bovine trabecular bone, 0.53 cm2 in surface area and 3.2 mm thick, and were cultured for up to 6 weeks; (2) chondrocyte-seeded anatomically shaped agarose constructs reproducing the human patellar articular layer (area=11.7 cm2, mean thickness=3.4 mm), cultured for up to 6 weeks; and (3) chondrocyte-seeded anatomically shaped agarose constructs of the patella (same as above) integrated into a corresponding anatomically shaped trabecular bone substrate, cultured for up to 2 weeks. Articular layer geometry, previously acquired from human cadaver joints, was used in conjunction with computer-aided design and manufacturing technology to create these anatomically accurate molds. In all experiments, chondrocytes remained viable over the entire culture period, with the agarose maintaining its shape while remaining firmly attached to the underlying bony substrate (when present). With culture time, the constructs exhibited positive type II collagen staining as well as increased matrix elaboration (Safranin O staining for glycosaminoglycans) and material properties (Young's modulus and aggregate modulus). Despite the use of relatively large agarose constructs partially integrated with trabecular bone, no adverse diffusion limitation effects were observed. Anatomically shaped constructs on a bony substrate may represent a new paradigm in the design of a functional articular cartilage tissue replacement.

Animals↗
PubMedDate not supplied

[The cellular mechanisms of articular cartilage differentiation].

The ways of structural-functional differentiation of chondrocytes and the characteristics of cytoarchitectonics of the articular cartilage were considered. The trophism of cells of the articular cartilage is realized from bone underlying it. Towards the articular surface, the degradation and elimination of chondrocytes were found.

Animals↗
PubMed1991

In vivo effects of interleukin-1 on articular cartilage. Prolongation of proteoglycan metabolic disturbances in old mice.

We investigated the effects of intraarticular injections of interleukin-1 alpha (IL-1 alpha) into the knee joints of young (3-month-old) and old (18-month-old) C57Bl/10 mice. In this in vivo study, 35S-sulfate incorporation and release were used to compare the effects of IL-1 on patellar cartilage proteoglycan metabolism. IL-1-induced stimulation of proteoglycan degradation was confined to the first 24 hours after injection in both young and old animals, and was only slightly lower in old cartilage than in young. In old patellar cartilage, IL-1-induced suppression of proteoglycan synthesis appeared to be more prolonged. Also, the amount of time needed to restore the cartilage matrix, characterized by proteoglycan synthesis above normal levels, was longer in old animals. Histologic analysis confirmed the retarded recovery in the cartilage of old mice. Autoradiography showed that the chondrocytes of the medial side of the femorotibial area were most vulnerable to IL-1-induced suppression of proteoglycan synthesis, especially the medial tibial plateau. As with the patellar cartilage, IL-1-induced suppression of proteoglycan synthesis in this area of articular cartilage was more prolonged in old animals. Our data indicated that the impact of IL-1 on articular cartilage is higher in old mice and that, consistent with certain loci found to be at risk in experimental osteoarthritis, there are sites at which IL-1 is more likely to act.

Aging↗
PubMed2005

[Repair of articular cartilage defects with "two-phase" tissue engineered cartilage constructed by autologous marrow mesenchymal stem cells and "two-phase" allogeneic bone matrix gelatin].

OBJECTIVE: To investigate the effect of "two-phase" tissue engineered cartilage constructed by autologous marrow mesenchymal stem cells(MSCs) and allogeneic bone matrix gelatin(BMG) in repairing articular cartilage defects. METHODS: Thirty-two New Zealand white rabbits were involved in the experiment. "Two-phase" allogeneic BMG scaffold (one side of porous cancellous bone and the other side of cortical bone; 3 mm both in diameter and in thickness) was prepared from iliac bone and limb bone of 5 rabbits by sequentially chemical method. The MSCs were separated from 18 New Zealand white rabbits and induced to express chondrocytic phenotype. The chondrocyte precursor cells were seeded onto "two-phase" allogeneic BMG to construct tissue engineering cartilage. Masson's trichrome staining, PAS staining and scanning electronic microscopic observation were carried out at 1, 3 and 5 weeks. The defects of full thickness articular cartilage (3 mm both in diameter and in depth) were made at both sides of femoral medial condyles in 27 rabbits (including 18 of separated MSCs and the remaining 9). The defects were repaired with the tissue engineered cartilage at the right side (group A, n = 18), with BMG at the left side (group B, n = 18), and without any implant at both sides in the remaining 9 rabbits as a control (group C, n = 18). After 1, 3 and 6 months, the 6 specimens of femoral condyles were harvested in 3 groups, respectively. Gross observation, Masson's trichrome and Alcian blue staining, modified Wakitani scoring and in situ hybridization of collagen type I were carried out to assess the repair efficacy of tissue engineered cartilage. RESULTS: The "two-phase" BMG consisted of the dense cortical part and the loose cancellous part. In cancellous part, the pore size ranged 100-800 microm, in which the chondrocyte precursor cells being induced from MSCs proliferated and formed the cell-rich cartilaginous part of tissue engineered cartilage. In cortical part, the pore size ranged 10-40 microm, on which the cells arranged in a layer and formed the hard part of subchondral bone. After 1 month of transplantation, the cartilage and subchondral bone were regenerated in group A; during observation, the regenerated cartilage gradually thinned, but defect was repaired and the structure of the articular surface and subchondral bone was in integrity. In groups B and C, defects were not repaired, the surrounding cartilage of defect was abrased. According to the modified Wakitani scoring, the indexes in group A were significantly higher than those in group B and C (P < 0.01) except the thickness of cartilage at 6 months. The positive cell rate of in situ hybridization for collagen type II in group A was also higher than those in groups B and C (P < 0.01). CONCLUSION: "Two-phase" allogeneic BMG is a prospective scaffold for tissue engineered cartilage, which combines with autologous chondrocyte precursor cells induced from MSCs to construct the tissue engineering cartilage. The tissue engineered cartilage can repair defects of articular cartilage and subchondral bone.

Animals↗
PubMed1987

Ultrastructural localisation of fibronectin in human osteoarthritic articular cartilage.

A protein A-gold immunolocalisation technique has been used on sections of femoral head articular cartilage to localise fibronectin. Chondroitinase treatment enhanced gold staining, particularly when tissue samples were digested before fixation. The greatest accumulations of fibronectin were seen in the surface zone of osteoarthritic cartilage. Disease free cartilage contained very little fibronectin in this region. Cells which appeared to produce fibronectin were rare in normal specimens but common in the superficial region of osteoarthritic cartilage. These chrondrocytes appeared to release fibronectin as part of an amorphous material which accumulated in the pericellular region. This is the first ultrastructural demonstration of fibronectin synthesis by articular cartilage chondrocytes.

Adult↗
PubMed1995

Modification by oral doxycycline administration of articular cartilage breakdown in osteoarthritis.

Oral administration of doxycycline has been shown to reduce the severity of articular cartilage breakdown in various animal models of osteoarthritis (OA). This disease modifying effect is associated with reductions in the levels of active and total collagenase and gelatinase in extracts of articular cartilage from the involved joint. These observations appear to justify a clinical trial of doxycycline, a readily available, inexpensive antimicrobial that has been used therapeutically in humans with OA for years with an excellent safety record.

Administration, Oral↗
PubMed2005

Effects of low-intensity pulsed ultrasound in repairing injured articular cartilage.

OBJECTIVE: To investigate the effects of low-intensity pulsed ultrasound in repairing injured articular cartilage. METHODS: Ten adult New Zealand rabbits with bilateral full-thickness osteochondral defects on the cartilage surface of intercondylar fossas were used in this study. The wounds in the left knees were treated with low-intensity pulsed ultrasound as the experimental group. The right knees received no treatment as the control group. All the animals were killed at 8 weeks after injury and the tissues in the wounds were collected for gross appearance grading, histological grading and proteoglycan quantity. RESULTS: The scores of the gross appearance grades, histological grades and the optical density of toluidine blue of the tissues in the experimental group were significantly higher than those of the controls at 8 weeks after injury (P < 0.05). CONCLUSIONS: Low-intensity pulsed ultrasound can accelerate the repair of injured articular cartilage.

Animals↗
PubMed1999

Sulfation of chondroitin sulfate in human articular cartilage. The effect of age, topographical position, and zone of cartilage on tissue composition.

The chondroitin ABC lyase digestion products of normal human femoral condyle articular cartilage and of purified aggrecan were analyzed for their mono- and nonsulfated disaccharide composition. Changes in the total tissue chemistry were most pronounced during the period from birth to 20 years of age, when the -[GlcAbeta,3GalNAc6]- disaccharide content increased from approximately 50% to 85% of the total disaccharide content and there was a concomitant decrease in the content of the 4-sulfated disaccharide. In general, the disaccharide content of the deeper layers of immature cartilage were richer in the 4-sulfated residue than the upper regions of the tissue. As the tissue aged and decreased in thickness, the disaccharide composition became more evenly 6-sulfated. The newly synthesized chondroitin sulfate chains had a similar composition to the endogenous chains and also underwent the same age and zonal changes. The monoclonal antisera 3B3(+) and 2B6(+) were used to immunolocalize the unsaturated 6- and 4-sulfated residues generated at the reducing termini of the chondroitin sulfate chains by digestion with chondroitin ABC lyase, and these analyses indicated that the sulfation pattern at this position did not necessarily reflect the internal disaccharide composition of the chains. In summary, the sulfation pattern of chondroitin sulfate disaccharides from human normal articular cartilage varies with the age of the specimen, the position (topography) on the joint surface, and the zone of cartilage analyzed. Furthermore, these changes in composition are a consequence of both extracellular, post-translational processing of the core protein of aggrecan and changes in the sulfotransferase activity of the chondrocyte.

Adolescent↗
PubMed1991

Osteoarthritic changes in canine articular cartilage, subchondral bone, and synovium fifty-four months after transection of the anterior cruciate ligament.

Anterior cruciate ligament transection (ACLT) in the dog results in osteophyte formation and in morphologic, metabolic, biochemical, and biomechanical changes in the articular cartilage of the unstable knee that mimic those of human osteoarthritis (OA). However, in dogs studied up to 2 years after ACLT, the changes have appeared to be self-limiting, which has led to the suggestion that this is a model of cartilage damage and repair, rather than of OA. To ascertain whether changes in articular cartilage and subchondral bone of dogs subjected to ACLT lead to progressive changes of OA, we studied 3 dogs for 54 months after ACLT. Arthrotomy was performed in the dogs to visualize and then transect the anterior cruciate ligament. When the dogs were killed, full-thickness ulceration of the articular cartilage was seen on the medial femoral condyle and tibial plateau of the unstable knee, while cartilage in other regions was thicker than that of the contralateral knee, consistent with hypertrophic cartilage repair. Synovial infiltration by mononuclear cells was not more severe than that seen in dogs killed at earlier intervals after ACLT, although gross fibrotic thickening of the capsule was apparent in each dog. Histomorphometric studies revealed a marked increase in subchondral bone volume and active bone formation. These findings show that the changes that develop in the canine knee joint after ACLT are progressive and are unambiguously those of OA.

Animals↗
PubMed1996

Development and ageing of the articular cartilage of the rabbit knee joint: distribution of the fibrillar collagens.

The development of the articular cartilage of the rabbit knee joint from the 17-day fetus to the 2-year adult rabbit has been examined. At 17 days, the developing femur and tibia are separated by the interzone. Cavitation occurs around 25 days; the cells of the intermediate layer flatten and move onto those of the chondogenous layers to create the articular surfaces. After birth, growth of the cartilage is mainly the result of matrix production. Ossification of the epiphyses is complete by 6 weeks postpartum. Horizontal zones can be distinguished in the articular cartilage; the superficial cells are aligned parallel to the surface, but in the deep layers the cells are in columns. The tidemark is first seen at 12-14 weeks. The matrix of the interzone in the 17-day fetus contains types I, III and V collagens, but no type II. After cavitation at 25 days, the surface layer of the articular cartilage still contains type I, but no type II collagen. From 6 weeks postnatal onwards, type II collagen is present throughout the cartilage and type I disappears. Type III collagen is initially in the inter-territorial matrix, but later it is mainly pericellular. Type V collagen is pericellular both in the chondrogenous layers and later in the articular cartilage, but is not present in the epiphyseal cartilage below. From 6 weeks onwards, types III and V collagens create a capsule around all the chondrocytes above the tidemark. The relationship of types V and XI collagens is discussed. It is concluded that the articular chondrocytes form a unique subset of cells from the earliest stages of joint formation in the fetal rabbit.

Aging↗
PubMed1994

Changes in the expression of decorin and biglycan in human articular cartilage with age and regulation by TGF-beta.

In chondrocytes isolated directly from human articular cartilage, without subsequent culture, biglycan mRNA levels decreased with the age of the donor, whereas those for decorin increased. In cultured chondrocytes in the presence of FCS, mRNA levels for biglycan remained similar to those in uncultured counterparts, while decorin transcription became depressed. The differential effect on decorin and biglycan mRNA expression was mimicked by the addition of TGF-beta. In the absence of exogenously added growth factors (TGF-beta or FCS) biglycan mRNA levels decreased, while those for decorin increased. In contrast, IGF-I showed no differential modulation of the relative abundance of the two messages. The opposite regulation of these two proteoglycans by TGF-beta was also reflected at the level of protein synthesis. It would appear that the need of articular cartilage for decorin is greatest in the adult, whereas the need for biglycan is greatest in the juvenile.

Adult↗