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The fate of the articular cartilage in intracapsular fracture of the femoral neck (articular cartilage in femoral neck fracture).

The fate of the articular cartilage of the hip joint with intracapsular neck fracture was studied by histological, histochemical and autoradiographic techniques and by using a polarized microscope and a scanning electron microscope. Cartilage specimens from 93 femoral heads and 7 acetabula were obtained from fractured hips 2 days to 4 1/3 years postfracture and from control hips with various disorders. The cartilage degeneration appeared 2 weeks after fracture and advanced steadily with time. The matrix was covered, invaded and ultimately replaced by the fibrous tissue. Chondrocyte viability, though it was lost from the surface, was recognized in the deep matrix even in the oldest fracture examined. It is concluded that the humoral factor directly caused by the injury as well as the biomechanical impairment, i.e. a loss of physical stress, may play an essential role in the pathogenesis of the degeneration. The possibility of regeneration was discussed.

Acetabulum↗

Immunological analysis of chick notochord and cartilage matrix development with antisera to cartilage matrix macromolecules.

Transverse frozen sections from the postcephalic region of stage 9-16 chick embryos and from the wing bud region of stage 17-31 embryos were stained with antibodies to the major extracellular matrix components of cartilage. These probes included unfractionated A1 and A2 antisera to the major cartilage proteoglycan, affinity-purified purified antibodies to the proteoglycan core protein and to Type II collagen, and a monoclonal antibody to keratan sulfate. In embryos as early as stage 10, notochord stained specifically with the keratan sulfate monoclonal antibody. At this stage the notochord, as well as surrounding tissues, were negative to cartilage proteoglycan and collagen antibodies. Positive staining with the latter probes was coordinately acquired by notochord cells and their accompanying sheath around stage 15, while surrounding tissues remained negative. At this stage, the ventral region of the perispinal cord sheath exhibited light staining with the proteoglycan and keratan sulfate antibodies though failing to react to Type II collagen antibodies. Positive staining of notochord and ventral spinal cord persisted through later developmental stages. As revealed by immunofluorescence, definitive vertebral chondroblasts first emerged at approximately stage 23 and definitive limb chondroblasts at stage 25. The results are discussed in terms of the possible multiple roles of notochord in early embryogenesis.

Animals↗

Calcification of cartilage matrix in chondrocyte cultures derived from rachitic rat growth plate cartilage.

Chondrocytes obtained from collagenase-digested epiphyseal growth plate cartilage of rachitic rats were grown in multilayer cultures. The cultured chondrocytes produced a metachromatic matrix and further electron microscopic examination revealed typical features of cartilage matrix collagen fibrils and matrix vesicles. The alkaline phosphatase activity in cultures was high during the entire 3-week culture period. Acid phosphatase showed a marked increase in activity during the first week of culture. The appearance of apatite crystals in the synthesized matrix was monitored by electron microscopy over a 3-week period. First crystals were consistently found to be associated with matrix vesicles, and in the older cultures calcification spread into the surrounding matrix. No collagen fibrils associated with mineralization were observed during the early culture period. This study clearly demonstrates that in chondrocyte cultures the first mineral crystals were found within or in close association with matrix vesicles. This gives further support to the hypothesis that matrix vesicles are the primary site of mineralization in cartilage. In addition to calcification studies it is suggested that this model is suitable for studying the effects of hormones or other agents on rachitic chondrocytes in vitro.

Animals↗

Columella lengthening using a cartilage graft in the bilateral cleft lip-associated nose: choice of cartilage according to age.

PURPOSE: This article describes the technique of columellar lengthening using a cartilaginous strut in patients with a severely deformed bilateral cleft lip-associated nose. MATERIALS AND METHODS: When the upper lip is not deficient, and especially when resection of lip scar tissue is indicated, the Millard forked flap technique is recommended. Advancement of the prolabium into the columella for lengthening, combined with an Abbé flap for upper lip reconstruction, is indicated when a deficient upper lip is unable to provide adequate donor tissue. A cartilaginous strut is inserted behind the forked flap or the advanced prolabium. According to the age of the patient, septal cartilage, costal cartilage, or ear cartilage is selected. Ten patients with a severely deformed bilateral cleft lip-associated nose underwent these procedures. RESULTS: In each case, the columella was lengthened satisfactorily. In four patients, the scar became hypertrophic at the base of the columella and scar revision was performed secondarily. CONCLUSIONS: A cartilaginous strut is the key to avoiding the tendency toward retraction or thickening of the lengthened columella. It gives a slight lift to the tip, provides more definition, and improves the columellar contour.

Adolescent↗

The head cartilage of cephalopods. II. Ultrastructure of isolated native collagen fibrils and of polymeric aggregates obtained in vitro: comparison with the cartilage of mammals.

Native collagen fibrils were isolated from cephalopod head cartilage and mammal hyaline cartilage. The analysis with TEM after positive and negative staining demonstrated that the fibrils have a periodic structure similar to that of fibrillar type I collagen of mammals. The banding pattern of polymeric forms (SLS, FLS) obtained in vitro from squid cartilage collagen was remarkably different from the analogous forms of mammal collagen types I and II.

Animals↗

Comparison of cartilage scoring and cartilage sparing otoplasty--A study of 203 cases.

UNLABELLED: The Edinburgh experience of different methods of otoplasty techniques in 203 patients (406 ears) over a five-year period is reviewed. MATERIALS AND METHODS: The patients were divided into three groups - Group A (anterior cartilage scoring), Group B (cartilage sparing in the fashion of posterior suturing) and Group C (posterior suturing refined with posterior fascial flap). Demographic details, operation technique, operation time, grade of the surgeon, suture materials, early and late complications, recurrence and revision rates, patients' and physicians' comments at the follow-up clinic were retrieved from the case notes. The pre- and the post-operative photographs were assessed by a blinded lay observer and a physician and scored on a visual analogue scale. Median follow-up was 11 months. RESULTS: The recurrence rate was 11.0%, 8.0% and 4.8% in Groups A, B and C, respectively (p = 0.0214). Complications were more common in Group A (8.8%) and Group B (7.9%) compared to Group C (1.2%) (p = 0.0208). The cosmetic result was judged best in Group C. In our experience, cartilage-sparing otoplasty refined with the post-auricular fascial flap results in significantly reduced complication rate and improved aesthetic outcome.

Adolescent↗

Magnetic resonance imaging for articular cartilage: cartilage-bone mismatch.

The authors studied the articular cartilage surface anatomy of the patellofemoral joint in the sagittal and axial planes. On sagittal and axial cryosections and on multiplanar MR arthrotomograms, biplanar contour differences of the retropatellar articular cartilage surfaces and curvatures with respect to the corresponding subchondral osseous contours of the patellofemoral joint were determined. On multiplanar arthrotomograms, the surface geometry of the articular cartilage of the patella and of the femoral trochlea were compared.

Adult↗

Delayed articular cartilage slough: two cases resulting from holmium:YAG laser damage to normal articular cartilage and a review of the literature.

We present two cases referred from other physicians with chondral damage and cartilage slough secondary to use of the holmium:YAG laser during knee arthroscopy. The first patient had a partial lateral meniscectomy, which was done with a 20-W Ho:YAG laser. The patient never fully recovered and underwent a second arthroscopy that revealed full-thickness cartilage defects of the lateral femoral condyle. The second patient had debridement of Outerbridge grade III changes of the lateral tibial plateau and patella, as well as a partial lateral meniscectomy using a Ho:YAG laser. The patient developed recurrent symptoms, and when a second arthroscopy was performed, new degenerative changes to the lateral femoral condyle were noted with large areas of cartilage loss. A careful look needs to be taken at the limited use of lasers until further randomized prospective studies are carried out comparing patient outcomes, cost, and long-term complications.

Adult↗

The effects of ascorbic acid on cartilage metabolism in guinea pig articular cartilage explants.

Ascorbic acid has been associated with the slowing of osteoarthritis progression in guinea pig and man. The goal of this study was to evaluate transcriptional and translational regulation of cartilage matrix components by ascorbic acid. Guinea pig articular cartilage explants were grown in the presence of L-ascorbic acid (L-Asc), D-isoascorbic acid (D-Asc), sodium L-ascorbate (Na L-Asc), sodium D-isoascorbate (Na D-Asc), or ascorbyl-2-phosphate (A2P) to isolate and analyze the acidic and nutrient effects of ascorbic acid. Transcription of type II collagen, prolyl 4-hydroxylase (alpha subunit), and aggrecan increased in response to the antiscorbutic forms of ascorbic acid (L-Asc, Na L-Asc, and A2P) and was stereospecific to the L-forms. Collagen and aggrecan synthesis also increased in response to the antiscorbutic forms but only in the absence of acidity. All ascorbic acid forms tended to increase oxidative damage over control. This was especially true for the non-nutrient D-forms and the high dose L-Asc. Finally, we investigated the ability of chondrocytes to express the newly described sodium-dependent vitamin C transporters (SVCTs). We identified transcripts for SVCT2 but not SVCT1 in guinea pig cartilage explants. This represents the first characterization of SVCTs in chondrocytes. This study confirms that ascorbic acid stimulates collagen synthesis and in addition modestly stimulates aggrecan synthesis. These effects are exerted at both transcriptional and post-transcriptional levels. The stereospecificity of these effects is consistent with chondrocyte expression of SVCT2, shown previously to transport L-Asc more efficiently than D-Asc. Therefore, this transporter may be the primary mechanism by which the L-forms of ascorbic acid enter the chondrocyte to control matrix gene activity.

Aggrecans↗

Modulation of CD(4)(+) and CD(8)(+) tumor infiltrating lymphocytes by a fraction isolated from shark cartilage: shark cartilage modulates anti-tumor immunity.

Shark cartilage has proven to have some inhibitory effects on angiogenesis, metastasis, cell adhesion and proteolysis. In this study, we wanted to study some of the effects of shark cartilage on tumor immune response. Firstly, by means of chromatographic methods and delayed type hypersensitivity (DTH) test, we optimized a procedure for isolation and purification of a shark cartilage protein fraction with most immunostimulatory effects. Then, we examined its effect on the infiltration of CD(4)(+) and CD(8)(+) lymphocytes into a murine tumor model. Our fraction was composed of two major proteins with molecular weights (MWs) of about 14 and 15 kDa. This fraction highly increases DTH response against sRBC in mice. Furthermore, intraperitoneal injection of this fraction to tumor-bearing mice could increase T-cell infiltration into the tumor. Also, there was a significant increase in the CD(4)/CD(8) ratio in tumor infiltrating lymphocytes, but no such changes were found in the peripheral blood lymphocytes. According to these results, we suppose that this fraction is a good candidate for further studies in cancer therapy. Also, we concluded that this fraction, with previously proven anti-angiogenic effects, can augment cellular immune response and T-cell infiltration into the tumor and thus, there may be a direct relationship between angiogenesis inhibition and T-cell infiltration.

Adenocarcinoma↗

Reconstruction with composite nasal septal cartilage and auricular cartilage in extended partial laryngectomy.

Several reconstruction techniques have been employed following partial laryngectomy in order to improve laryngeal function. We report 12 cases in which composite nasal septal cartilage and auricular cartilage were used. We decannulated the patients in an average of 19 days. Following the reconstruction we obtained a satisfactory phonatory function and swallowing. Six patients completed a follow-up period of three years without presenting any recurrences or mortality. Our experience with reconstruction using composite nasal septal and auricular cartilage following partial laryngectomy proved effective.

Adult↗

Studies on the polydispersity and heterogeneity of cartilage proteoglycans. Identification of 3 proteoglycan structures in bovine nasal cartilage.

1. Three chondroitin sulphate components were isolated from adult bovine nasal cartilage after treatment with alkaline NaB3H. Average molecular weights of 13000, 18 600 and 28 000 were obtained for chondroitin sulphate species representing 10, 52 and 38% (w/w) of the total chondroitin sulphate respectively. Each chondroitin sulphate pool has a narrow molecular-weight distribution. 2. A proteoglycan subunit preparation, isolated from one nasal cartilage by extraction and density-gradient fractionation in dissociative solvents, partitioned on a CSCl density gradient according to size and composition. Variation of proteoglycan molecular weight across the gradient was directly related to the average chondrotin sulphate chain length, which in turn reflected the relative proportion of the three chondroitin sulphate pools in each proteoglycan fraction. Consideration of proteoglycan molecular parameters, compositions and behaviour on sedimentation leads to a proposal that nasal cartilage contains 3 distinct proteoglycan pools, each of which has a constant number of chondroitin sulphate side chains of different average molecular weight. 3. Molecular-weight distribution parameters for these proteoglycan preparations indicate that all serine residues on the protein core capable of initiating chondroitin sulphate biosynthesis are occupied and that proteoglycan polydispersity results directly from the polydispersity of the attached chondroitin sulphate component.

Amino Acids↗

Cartilage repair using new polysaccharidic biomaterials: macroscopic, histological and biochemical approaches in a rat model of cartilage defect.

OBJECTIVE: The present study aims at evaluating, in a rat model of cartilage defect, the potential of various polymers as filling and repair biomaterials. The macroscopic and histological observations are compared to biochemical parameters in order to appreciate the pertinence of the latter as suitable criteria in tissue engineering. METHODS: A hydrogel, consisting of hyaluronic acid (HA), covalently substituted by hydrophobic alkyl chains (HA12, HA18) and an alginate sponge, alone (Asp) or combined with HA (AHAsp) or combined with HA and chondrocytes (HYBsp) were evaluated. Cartilage lesions were drilled in femoral trochlea of rats. The analyses were performed on trochlea as well as on patella and condyles. RESULTS: Repairs achieved with hydrogels had a similar macroscopic appearance than those afforded by AHAsp and HYBsp. Best macroscopic and histological scores were obtained with HA18 and HYBsp in comparison with alginate group (P< 0.01 and P< 0.02 respectively). Biochemical evaluations confirmed the presence of similar amounts of proteoglycans in the repaired zones and in the controls, though with different DeltadiC4S/DeltadiC6S ratios and enhanced HA levels. CONCLUSIONS: Hydrogels or sponges proved to be colonized by cells synthesizing a matrix with a high HA content. The matrix obtained eventually turns hyaline and takes over the scaffold. The addition of HA and/or chondrocytes to Asp significantly improves the macroscopic and histological scores (P< 0.05 and P< 0.02 respectively). However, biochemical parameters are significantly different of those evaluated in native cartilage. The present study shows that only biochemical parameters allow to discriminate between various biomaterials in tissue engineering and are essential informations which should be taken into account in addition to macroscopic and histological observations.

Alginates↗

Bipolar and monopolar radiofrequency treatment of osteoarthritic knee articular cartilage: acute and temporal effects on cartilage compressive stiffness, permeability, cell synthesis, and extracellular matrix composition.

The cellular, biochemical, biomechanical, and histologic effects of radiofrequency-generated heat on osteoarthritic cartilage were assessed. Articular cartilage explants (n=240) from 26 patients undergoing total knee arthroplasty were divided based on Outerbridge grade (I or II/III) and randomly assigned to receive no treatment (controls) or monopolar or bipolar radiofrequency at 15 or 30 W. Both potentially beneficial and harmful effects of radiofrequency treatment of articular cartilage were noted. It will be vital to correlate data from in vitro and in vivo study of radiofrequency thermal chondroplasty to determine the clinical usefulness of this technique.

Biomechanical Phenomena↗

[Use of cartilage transplants in middle ear surgery. A histologic long-term study of cartilage implants].

30 autogenic and allogenic (homologous) cartilage grafts removed from the middle ear after an average time of 9 years and a maximal time of 25 years were studied by light microscopy. Half of the grafts showed signs of cellular vitality. Degeneration and avital cells are predominant in all grafts. Persisting residual vitality does not influence resorption and matrix necrosis in other areas of the graft. More than two thirds show structural changes by cellular resorption, infraction and vascularisation. These changes appear mainly independent of the time elapsed after transplantation. 5 grafts show bone new formation. Circumscript necrosis of the cartilage matrix was seen in 12 grafts. The study indicates that in comparison to ossicles or alloplastic material cartilage is less advisable to be used for the reconstruction of the ossicular chain due to the unpredictable degradation and loss of form stability.

Cartilage↗

Somatomedin-like peptide(s) isolated from fetal bovine cartilage (cartilage-derived factor): isolation and some properties.

Fetal bovine cartilage contains a polypeptide(s) that has somatomedin-like effects on rat and rabbit costal chondrocytes in culture. This factor, named the cartilage-derived factor, was extracted from fetal bovine cartilage, fractionated with acetone, and purified by gel filtration on Toyopearl HW 55-F in 4 M guanidine hydrochloride, preparative isoelectric focusing, and subsequent gel filtration on Toyopearl HW 55-F in 1 M formic acid. The resulting preparation, which focused in the neutral pH region and eluted from a Toyopearl column in a fraction with apparent Mr 10,000--11,000, appeared homogenous by NaDodSO4 gel electrophoresis. The purified preparation markedly enhanced not only proteoglycan synthesis but also DNA synthesis in rabbit costal chondrocytes and, on a protein basis, it was 1000 times more active than insulin and 1,000,000 times more active than fetal calf serum in stimulating proteoglycan synthesis.

Animals↗

Physiological role of vitamin A in growth cartilage cells: low concentrations of retinoic acid strongly promote the proliferation of rabbit costal growth cartilage cells in culture.

We have demonstrated that high concentrations of retinoic acid (RA) inhibit expression of the differentiated phenotypes of rabbit costal chondrocytes in culture [M. Takigawa et al. (1980) Proc. Natl. Acad. Sci. U.S. 77, 1481-1485]. In this study we examined the effects of low concentrations of RA on rabbit costal chondrocytes cultured in medium containing vitamin A-deficient serum. In vitamin A-deficient medium, chondrocytes isolated from growth cartilage (GC) proliferated only very slowly, and RA strongly stimulated their proliferation. This stimulatory effect was observable at a concentration of 10(-10) M RA and maximal at a concentration of 10(-8) M. RA at 10(-8) M did not change GC cells from a typical polygonal shape to fibroblast-like cells or inhibit their synthesis of type II collagen. Moreover, RA-treated cells did not synthesize type I collagen. RA inhibited glycosaminoglycan (GAG) synthesis by the cells dose-dependently, but did not change the distribution profile of proteoglycan monomers as determined by glycerol gradient centrifugation. The inhibitory action of RA on GAG synthesis was reversible: after removal of RA from the culture, the rate of GAG synthesis increased within 2 days. In contrast, resting cartilage (RC) cells proliferated well in vitamin A-deficient medium without addition of RA, and RA (10(-8) M) stimulated their proliferation only slightly. Furthermore, the inhibitory effect of RA on GAG synthesis in RC cells was much weaker than that in GC cells. These observations suggest a physiological role of RA in cartilage in stimulating the proliferation of GC cells without causing drastic change in their differentiated phenotypes.

Animals↗

Sibling pair analysis shows no linkage of generalized osteoarthritis to the loci encoding type II collagen, cartilage link protein or cartilage matrix protein.

Generalized OA (GOA) is a well-characterized subset of primary OA which is strongly associated with the occurrence of Heberden's nodes. Using gene-specific highly polymorphic markers and affected sib pair (ASP) analyses, we have investigated genetic linkage between GOA and three cartilage matrix genes: COL2A1 which encodes type II collagen; CRTL1 which encodes the cartilage link protein and CRTM which encodes the cartilage matrix protein. The analyses showed no linkage between GOA and the three genes in the 38 sib pairs examined. Since we examined a relatively modest number of sib pairs, our results can only exclude COL2A1, CRTL1 and CRTM as major susceptibility loci for GOA.

Alleles↗