scholarly journals Characterisation of human articular cartilage link proteins from normal and osteoarthritic cartilage: a comment.

1982 ◽  
Vol 41 (6) ◽  
pp. 643-644
Author(s):  
D W Bullimore
Keyword(s):  
Articular Cartilage ◽  
Human Articular Cartilage ◽  
Osteoarthritic Cartilage

scholarly journals Immunolocalization of type III collagen in human articular cartilage prepared by high-pressure cryofixation, freeze-substitution, and low-temperature embedding.

1995 ◽  
Vol 43 (4) ◽  
pp. 421-427 ◽  
Author(s):  
R D Young ◽  
P A Lawrence ◽  
V C Duance ◽  
T Aigner ◽  
P Monaghan
Keyword(s):  
High Pressure ◽  
Articular Cartilage ◽  
Polyclonal Antibodies ◽  
Freeze Substitution ◽  
Immunogold Electron Microscopy ◽  
Type Iii Collagen ◽  
Human Articular Cartilage ◽  
Chemical Fixation ◽  
Osteoarthritic Cartilage ◽  
Type Iii

We localized Type III collagen by immunogold electron microscopy in resin sections of intact normal and osteoarthritic human articular cartilage. Comparisons of antibody staining between tissue prepared by high-pressure cryofixation and freeze-substitution without fixatives and that exposed to conventional mild chemical fixation with paraformaldehyde showed that dedicated cryotechniques yielded superior preservation of epitopes that are modified by chemical fixation, and simultaneously provided good ultrastructural preservation. Type III collagen was detected with two polyclonal antibodies, one against the triple-helical domain of the molecule and a second against the more antigenic, globular amino pro-peptide domain, which in this collagen is retained in the extracellular matrix after secretion. Positive labeling was seen in association with the major interstitial fibrils, suggesting co-polymerization of Types III and II collagen in cartilage. Type III collagen could not be detected in aldehyde-fixed normal cartilage. In fixed osteoarthritic cartilage, Type III was detectable only when the antibody to the amino pro-peptide was employed. In contrast, high-pressure cryofixation and freeze-substitution preserved epitopes for both antibodies, permitting immunodetection of Type III collagen in normal and osteoarthritic cartilage. Cryotechniques offer exciting possibilities for significantly improving the immunolocalization of collagens and other fixative-sensitive antigens in situ.

scholarly journals Ultrastructure of Chondrocytes in Osteoarthritic Femoral Articular Cartilage

2015 ◽  
Vol 11 (3) ◽  
pp. 221-225
Author(s):  
Nj Goya ◽  
M Gupta ◽  
K Joshi
Keyword(s):  
Electron Microscope ◽  
Articular Cartilage ◽  
Control Group ◽  
Human Articular Cartilage ◽  
Joint Motion ◽  
Age Group ◽  
Radiographic Evidence ◽  
Osteoarthritic Cartilage ◽  
Total Knee ◽  
Ultrastructural Findings

Background Osteoarthritis (OA) is a common problem in elderly, but it is not an inevitable feature of ageing. About 80-90% of individuals of both sexes have radiographic evidence of OA by the time they reach an age of 65. But not all of them have the symptoms like pain and decreased joint motion. Objective The objective of the present study was conducted to find out whether the osteoarthritic changes in human articular cartilage are similar to the ageing process or not. Methods Femoral articular cartilage specimens obtained from 13 osteoarthritic patients (52-80years) undergoing total knee replacement and 9 cadavers of same age group (50-80years) (control) were processed and studied under electron microscope. The ultrastructure of the cartilage from the two groups was compared with each other. Results Under the electron microscope, articular cartilage from control group had chondrocytes having a secretary cell characteristic with prominent nucleus and well developed organelles. In osteoarthritic cartilage, degenerating or necrotic chondrocytes were found. Nuclei of these chondrocytes appeared lobulated or indented. Chondrocytes below the fibrillated surface had dilated and irregular endoplasmic reticulum. Electron dense lipid deposits in the extracelluar matrix as well as intracytoplasmic glycogen deposits were much increased in osteoarthritic cartilage as compared to the control group. Amount of perinuclear intracytoplasmic fine filaments was also increased in the chondrocytes of osteoarthritic cartilage. Conclusion Ultrastructural findings of the osteoarthritic articular cartilage were much different from the ageing non-osteoarthritic cartilage. Hence, OA should be considered a specific process and not simply an inevitable feature of ageing. DOI: http://dx.doi.org/10.3126/kumj.v11i3.12507 Kathmandu Univ Med J 2013; 43(3):221-225

scholarly journals Comparison of Compressive Stress-Relaxation Behavior in Osteoarthritic (ICRS Graded) Human Articular Cartilage

2017 ◽  
Author(s):  
Rajesh Kumar ◽  
David M. Pierce ◽  
Vidar Isaksen ◽  
Catharina de Lange Davies ◽  
Jon O. Drogset ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Stress Relaxation ◽  
Computational Models ◽  
Articular Surface ◽  
Significant Loss ◽  
Relaxation Behavior ◽  
Human Articular Cartilage ◽  
Osteoarthritic Cartilage ◽  
Human Cartilage ◽  
Stress Relaxation Behavior

Osteoarthritis (OA) is a common joint disorder found mostly in elderly people. The role of mechanical behavior in the progression of OA is complex and remains unclear. The stress-relaxation behavior of human articular cartilage in clinically defined osteoarthritic stages may have importance in diagnosis and prognosis of OA. In this study we investigated differences in the biomechanical responses among human cartilage of ICRS grades I, II and III using polymer dynamics theory. We collected 24 explants of human articular cartilage (eight each of ICRS grade I, II and III) and acquired stress-relaxation data applying a continuous load on the articular surface of each cartilage explant for 1180 s. We observed a significant decrease in Young’s modulus, stress-relaxation time, and stretching exponent in advanced stages of OA (ICRS grade III). The stretch exponential model indicated that significant loss in hyaluronic acid polymer might be the reason for the loss of proteoglycan in advanced OA. This work encourages further biomechanical modelling of osteoarthritic cartilage utilizing these data as input parameters to enhance the fidelity of computational models aimed at revealing how mechanical behaviors play a role in pathogenesis of OA.

Alterations in the Mechanical Properties of the Human Chondrocyte Pericellular Matrix With Osteoarthritis

2003 ◽  
Vol 125 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Leonidas G. Alexopoulos ◽  
Mansoor A. Haider ◽  
Thomas P. Vail ◽  
Farshid Guilak
Keyword(s):  
Articular Cartilage ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Theoretical Models ◽  
Significant Loss ◽  
Surface Zone ◽  
Human Articular Cartilage ◽  
Pericellular Matrix ◽  
Osteoarthritic Cartilage ◽  
Isolation Technique

In articular cartilage, chondrocytes are surrounded by a pericellular matrix (PCM), which together with the chondrocyte have been termed the “chondron.” While the precise function of the PCM is not known there has been considerable speculation that it plays a role in regulating the biomechanical environment of the chondrocyte. In this study, we measured the Young’s modulus of the PCM from normal and osteoarthritic cartilage using the micropipette aspiration technique, coupled with a newly developed axisymmetric elastic layered half-space model of the experimental configuration. Viable, intact chondrons were extracted from human articular cartilage using a new microaspiration-based isolation technique. In normal cartilage, the Young’s modulus of the PCM was similar in chondrons isolated from the surface zone (68.9±18.9 kPa) as compared to the middle and deep layers (62.0±30.5 kPa). However, the mean Young’s modulus of the PCM (pooled for the two zones) was significantly decreased in osteoarthritic cartilage (66.5±23.3 kPa versus 41.3±21.1 kPa, p<0.001). In combination with previous theoretical models of cell-matrix interactions in cartilage, these findings suggest that the PCM has an important influence on the stress-strain environment of the chondrocyte that potentially varies with depth from the cartilage surface. Furthermore, the significant loss of PCM stiffness that was observed in osteoarthritic cartilage may affect the magnitude and distribution of biomechanical signals perceived by the chondrocytes.

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