INTERNATIONAL JOURNAL OF RHEUMATIC DISEASES, Issue 2006
Article first published online: 6 JUL 200
No abstract is available for this article. [source]

THE FREE RADICAL-SCAVENGING PROPERTY OF CHONDROITIN SULFATE FROM PIG LARYNGEAL CARTILAGE IN VITRO

JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2007
SHUANG-LI XIONG
ABSTRACT This study compared the free radical-scavenging properties of chondroitin sulfate (ChS) from pig laryngeal cartilage and its reduced or sulfonated derivatives. The binding behavior between Cu2+ and ChS and its derivatives, and the interaction between superoxide radical and ChS were studied by fluorescence quenching, equilibrium dialysis, infrared spectra and thermal analysis. Purified ChS inhibited the generation of hydroxyl radical and scavenged superoxide radical in a concentration-dependent manner. Reduced ChS did not scavenge hydroxyl radical and superoxide radical. Sulfonated ChS had no hydroxyl radical scavenging activity but scavenged superoxide radical as strongly as purified ChS. ChS showed strong binding activity with Cu2+ in deionized water but not in 0.01-M HCl. Both reduced ChS and sulfonated ChS did not exhibit such chelating behavior. The structural basis of hydroxyl radical inhibiting of ChS was attributed to a complex of the Cu2+ with the carboxyl group of glucuronic acid residue. The reaction of superoxide radical with the sulfate ester and the carboxyl group may be the basis of superoxide radical scavenging activity of ChS. [source]

The Incidences of Chondritis and Perichondritis Associated With the Surgical Manipulation of Auricular Cartilage

DERMATOLOGIC SURGERY, Issue 1 2004
Andrew L. Kaplan MD
Background. The cartilage and soft tissues of the ear are frequently employed as donor sites for tissue used in the repair of defects of the nose and external ear after Mohs surgery. Enthusiasm for using these auricular donor sites is occasionally tempered by surgeons' concerns for the development of Pseudomonal suppurative chondritis, a complication that has been described to follow cartilage manipulation. Objective. To quantify the incidence of postoperative perichondritis and chondritis after Mohs reconstructions involving auricular cartilage manipulations. Methods. We retrospectively reviewed 341 Mohs reconstructions that involved cartilage and soft-tissue donor sites located on the ear. Procedures included full-thickness skin grafts (295) harvested from the conchal bowl and flap repairs (46) incorporating cartilage batten grafts from conchal or anthelix donor sites. When the perichondrium was compromised, patients were routinely prescribed perioperative prophylactic antibiotics with Pseudomonal coverage. Postoperative examinations were performed at 1 week and 4 to 12 weeks. Patients not seen in clinic were interviewed by telephone regarding complications. Results. Complete follow-up information was obtained in 337 of 341 (98.8%) cases. Inflammatory perichondritis was observed in 19 (5.6%) patients. There were no cases of suppurative chondritis. Conclusion. The incidence of inflammatory perichondritis is low after Mohs reconstructions involving auricular cartilage manipulation. When prophylactic antibiotics and appropriate operative technique are used, the historic concern for suppurative chondritis associated with these procedures is unwarranted. [source]

Fell-Muir Lecture: Cartilage 2010 , The Known Unknowns

INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 3 2010
Timothy E. Hardingham
Summary Over the past 40 years there have been giant steps forward in our understanding of cellular and molecular biology that have given us the framework by which to understand tissue organization and tissue function on a range of scales. However, although the progress has been great, the more we have discovered, the more we are aware of what we don't yet know. In this article, I would like to flag up some issues of cartilage biology, function and pathology where we still have significant ignorance. As scientists we all provide contributions to add to the greater understanding of science and progress is on a broad front, but gaps are left where particular difficulty is encountered and in life sciences it is no different. Progress is fast where new knowledge and techniques pave the way, but where study is complex and relevant techniques poorly developed the gaps are left behind. In cartilage research and matrix biology, the gaps can particularly be seen at interfaces between disciplines and where technology development has lagged behind and in the particular challenges of understanding how molecular properties can explain tissue macro properties. [source]

Collagen architecture and failure processes in bovine patellar cartilage

JOURNAL OF ANATOMY, Issue 4 2001
JACK L. LEWIS
Cartilage fails by fibrillation and wearing away. This study was designed to identify the microscopic failure processes in the collagen network of bovine cartilage using scanning electron microscopy. Cartilage samples from fibrillated cartilage from the bovine patella were removed from the bone, fixed, digested to remove proteoglycans, freeze-fractured, and processed for SEM. The architecture of the collagen network in the normal cartilage was first defined, and then the failure processes were identified by examining sites of fibrillation and at crack tips. The bovine patellar cartilage was organised with a superficial layer composed of 3,5 lamina, attached to a sub-superficial tissue by angled bridging fibrils. Collagen in the sub-superficial tissue was organised in lamina oriented in the radial direction up to the transition zone. Failure of the system occurred by cracks forming in superficial layer and lamina, creating flaps of lamina that rolled up into the larger ,fronds'. Larger cracks not following the laminar planes occurred in the transition, mid, and deep zones. Failure at the crack tips in the sub-superficial tissue appeared to be by peeling of collagen fibrils, as opposed to breaking of collagen fibrils, suggesting a ,glue' bonding the collagen fibrils in a parallel fashion. Cracks propagated by breaking these bonds. This bond could be a site of disease action, since weakening of the bond would accelerate crack propagation. [source]

Purification of Matrix Gla Protein From a Marine Teleost Fish, Argyrosomus regius: Calcified Cartilage and Not Bone as the Primary Site of MGP Accumulation in Fish,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2003
DC Simes
Abstract Matrix Gla protein (MGP) belongs to the family of vitamin K-dependent, Gla-containing proteins, and in mammals, birds, and Xenopus, its mRNA was previously detected in extracts of bone, cartilage, and soft tissues (mainly heart and kidney), whereas the protein was found to accumulate mainly in bone. However, at that time, it was not evaluated if this accumulation originated from protein synthesized in cartilage or in bone cells because both coexist in skeletal structures of higher vertebrates and Xenopus. Later reports showed that MGP also accumulated in costal calcified cartilage as well as at sites of heart valves and arterial calcification. Interestingly, MGP was also found to accumulate in vertebra of shark, a cartilaginous fish. However, to date, no information is available on sites of MGP expression or accumulation in teleost fishes, the ancestors of terrestrial vertebrates, who have in their skeleton mineralized structures with both bone and calcified cartilage. To analyze MGP structure and function in bony fish, MGP was acid-extracted from the mineralized matrix of either bone tissue (vertebra) or calcified cartilage (branchial arches) from the bony fish, Argyrosomus regius,, separated from the mineral phase by dialysis, and purified by Sephacryl S-100 chromatography. No MGP was recovered from bone tissue, whereas a protein peak corresponding to the MGP position in this type of gel filtration was obtained from an extract of branchial arches, rich in calcified cartilage. MGP was identified by N-terminal amino acid sequence analysis, and the resulting protein sequence was used to design specific oligonucleotides suitable to amplify the corresponding DNA by a mixture of reverse transcription-polymerase chain reaction (RT-PCR) and 5,rapid amplification of cDNA (RACE)-PCR. In parallel, ArBGP (bone Gla protein, osteocalcin) was also identified in the same fish, and its complementary DNA cloned by an identical procedure. Tissue distribution/accumulation was analyzed by Northern blot, in situ hybridization, and immunohistochemistry. In mineralized tissues, the MGP gene was predominantly expressed in cartilage from branchial arches, with no expression detected in the different types of bone analyzed, whereas BGP mRNA was located in bone tissue as expected. Accordingly, the MGP protein was found to accumulate, by immunohistochemical analysis, mainly in the extracellular matrix of calcified cartilage. In soft tissues, MGP mRNA was mainly expressed in heart but in situ hybridization, indicated that cells expressing the MGP gene were located in the bulbus arteriosus and aortic wall, rich in smooth muscle and endothelial cells, whereas no expression was detected in the striated muscle myocardial fibers of the ventricle. These results show that in marine teleost fish, as in mammals, the MGP gene is expressed in cartilage, heart, and kidney tissues, but in contrast with results obtained in Xenopus and higher vertebrates, the protein does not accumulate in vertebra of non-osteocytic teleost fish, but only in calcified cartilage. In addition, our results also indicate that the presence of MGP mRNA in heart tissue is due, at least in fish, to the expression of the MGP gene in only two specific cell types, smooth muscle and endothelial cells, whereas no expression was found in the striated muscle fibers of the ventricle. In light of these results and recent information on expression of MGP gene in these same cell types in mammalian aorta, it is likely that the levels of MGP mRNA previously detected in Xenopus, birds, and mammalian heart tissue may be restricted toregions rich in smooth muscle and endothelial cells. Our results also emphasize the need to re-evaluate which cell types are involved in MGP gene expression in other soft tissues and bring further evidence that fish are a valuable model system to study MGP gene expression and regulation. [source]

Collagen Metabolism Is Markedly Altered in the Hypertrophic Cartilage of Growth Plates from Rats with Growth Impairment Secondary to Chronic Renal Failure

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2001
Jesús Álvarez
Abstract Skeletal growth depends on growth plate cartilage activity, in which matrix synthesis by chondrocytes is one of the major processes contributing to the final length of a bone. On this basis, the present work was undertaken to ascertain if growth impairment secondary to chronic renal insufficiency is associated with disturbances of the extracellular matrix (ECM) of the growth plate. By combining stereological and in situ hybridization techniques, we examined the expression patterns of types II and X collagens and collagenase-3 in tibial growth plates of rats made uremic by subtotal nephrectomy (NX) in comparison with those of sham-operated rats fed ad libitum (SAL) and sham-operated rats pair-fed with NX (SPF). NX rats were severely uremic, as shown by markedly elevated serum concentrations of urea nitrogen, and growth retarded, as shown by significantly decreased longitudinal bone growth rates. NX rats showed disturbances in the normal pattern of chondrocyte differentiation and in the rates and degree of substitution of hypertrophic cartilage with bone, which resulted in accumulation of cartilage at the hypertrophic zone. These changes were associated with an overall decrease in the expression of types II and X collagens, which was especially marked in the abnormally extended zone of the hypertrophic cartilage. Unlike collagen, the expression of collagenase-3 was not disturbed severely. Electron microscopic analysis proved that changes in gene expression were coupled to alterations in the mineralization as well as in the collagen fibril architecture at the hypertrophic cartilage. Because the composition and structure of the ECM have a critical role in regulating the behavior of the growth plate chondrocytes, results obtained are consistent with the hypothesis that alteration of collagen metabolism in these cells could be a key process underlying growth retardation in uremia. [source]

Expression of the CD44 variant isoform 5 in the human osteoarthritic knee joint: Correlation with radiological, histomorphological, and biochemical parameters

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2004
Susanne Fuchs
Abstract Purpose: The purpose of this study was to correlate expression of CD44v5 in osteoarthritic synovium, cartilage, and synovial fluid with radiographical, histomorphological, and biochemical data. Methods: Cartilage and synovia specimens of 27 patients with osteoarthritis were histomorphologically assessed according to Mankin and Pelletier, respectively. Extended weight-bearing antero-posterior radiographs were evaluated according to Kellgren and Ahlback. Expression of membrane-bound CD44v5 was analyzed by immunohistochemistry and levels of soluble CD44v5 were determined by ELISA. Results: Expression of CD44v5 in cartilage and synovia was detected in 67% and 59% of the patients, respectively. Immunohistochemical findings in cartilage correlated significantly with structural cartilage changes (p < 0.001), whereas no correlation was found between expression in synovia and inflammatory synovial changes. Additionally, no relationship was evident between CD44v5 expression and radiographical data, but expression in cartilage and synovium was significantly correlated with each other (p < 0.04). Surprisingly, expression of CD44v5 in both cartilage and synovia was negatively correlated with synovial fluid levels of TNF, (p < 0.03 and p < 0.02, respectively), and no association was evident with levels of IL-1,. Conclusions: The data demonstrate expression of CD44v5 in osteoarthritic cartilage and synovia, probably independent of joint inflammation. But more importantly, expression of this receptor variant in cartilage seems to be strongly related to the degree of cartilage destruction. © 2003 Published by Elsevier Ltd. on behalf of Orthopaedic Research Society. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]

Acceleration of cartilage repair by genetically modified chondrocytes over expressing bone morphogenetic protein-7

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2003
Chisa Hidaka
Background: Cartilage has a limited capacity to heal. Although chondrocyte transplantation is a useful therapeutic strategy, the repair process can be lengthy. Previously we have shown that over expression of bone morphogenetic protein-7 (BMP-7) in chondrocytes by adenovirus-mediated gene transfer leads to increased matrix synthesis and cartilage-like tissue formation in vitro. In this context we hypothesized that implantation of genetically modified chondrocytes expressing BMP-7 would accelerate the formation of hyaline-like repair tissue in an equine model of cartilage defect repair. Methods: Chondrocytes treated with adenovirus vector encoding BMP-7 (AdBMP-7) or as control, an adenovirus vector encoding an irrelevant gene (Escherichia coli cytosine deaminase, AdCD) were implanted into extensive (15 mm diameter) articular cartilage defects in the patellofemoral joints of 10 horses. Biopsies were performed to evaluate early healing at 4 weeks. At the terminal time point of 8 months, repairs were assessed for morphology, MRI appearance, compressive strength, biochemical composition and persistence of implanted cells. Results: Four weeks after surgery AdBMP-7-treated repairs showed an increased level of BMP-7 expression and accelerated healing, with markedly more hyaline-like morphology than control. Quantitative real-time polymerase chain reaction (PCR) analysis of the repair tissue 8 months after surgery showed that few implanted cells persisted. By this time, the controls had healed similarly to the AdBMP-7-treated defects, and no difference was detected in the morphologic, biochemical or biomechanical properties of the repair tissues from the two treatment groups. Conclusions: Implantation of genetically modified chondrocytes expressing BMP-7 accelerates the appearance of hyaline-like repair tissue in experimental cartilage defects. Clinical relevance: Rehabilitation after cell-based cartilage repair can be prolonged, leading to decreased patient productivity and quality of life. This study shows the feasibility of using genetically modified chondrocytes to accelerate cartilage healing. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]

Skeletal tissue engineering using embryonic stem cells

JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 3 2010
Jojanneke M. Jukes
Abstract Various cell types have been investigated as candidate cell sources for cartilage and bone tissue engineering. In this review, we focused on chondrogenic and osteogenic differentiation of mouse and human embryonic stem cells (ESCs) and their potential in cartilage and bone tissue engineering. A decade ago, mouse ESCs were first used as a model to study cartilage and bone development and essential genes, factors and conditions for chondrogenesis and osteogenesis were unravelled. This knowledge, combined with data from the differentiation of adult stem cells, led to successful chondrogenic and osteogenic differentiation of mouse ESCs and later also human ESCs. Next, researchers focused on the use of ESCs for skeletal tissue engineering. Cartilage and bone tissue was formed in vivo using ESCs. However, the amount, homogeneity and stability of the cartilage and bone formed were still insufficient for clinical application. The current protocols require improvement not only in differentiation efficiency but also in ESC-specific hurdles, such as tumourigenicity and immunorejection. In addition, some of the general tissue engineering challenges, such as cell seeding and nutrient limitation in larger constructs, will also apply for ESCs. In conclusion, there are still many challenges, but there is potential for ESCs in skeletal tissue engineering. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Collagen dynamics in articular cartilage under osmotic pressure

NMR IN BIOMEDICINE, Issue 8 2006
Göran Zernia
Abstract Cartilage is a complex biological tissue consisting of collagen, proteoglycans and water. The structure and molecular mobility of the collagen component of cartilage were studied by 13C solid-state NMR spectroscopy as a function of hydration. The hydration level of cartilage was adjusted between fully hydrated (,80 wt% H2O) and highly dehydrated (,30 wt% H2O) using the osmotic stress technique. Thus, the conditions of mechanical load could be simulated and the response of the tissue macromolecules to mechanical stress is reported. From the NMR measurements, the following results were obtained. (i) Measurements of motionally averaged dipolar 1H,13C couplings were carried out to study the segmental mobility in cartilage collagen at full hydration. Backbone segments undergo fast motions with amplitudes of ,35° whereas the collagen side-chains are somewhat more mobile with amplitudes between 40 and 50°. In spite of the high water content of cartilage, collagen remains essentially rigid. (ii) No chemical shift changes were observed in 13C cross-polarization magic angle spinning spectra of cartilage tissue at varying hydration indicating that the collagen structure was not altered by application of high osmotic stress. (iii) The 1H,13C dipolar coupling values detected for collagen signals respond to dehydration. The dipolar coupling values gradually increase upon cartilage dehydration, reaching rigid limit values at ,30 wt% H2O. This indicates that collagen is essentially dehydrated in cartilage tissue under very high mechanical load, which provides insights into the elastic properties of cartilage collagen, although the mechanical pressures applied here exceed the physiological limit. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Proteomic analysis of mouse growth plate cartilage

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 24 2006
Daniele Belluoccio
Abstract Cartilage is a highly specialized load-bearing tissue with a small number of cells and a high proportion of extracellular matrix (ECM). The abundance of heavily sulfated proteoglycans and a poorly soluble collagenous ECM presents a major technical challenge to 2-DE. Here we report proteomic analysis of mouse growth plate cartilage using novel methodology for tissue dissection and sample prefractionation. We have successfully resolved cartilage tissue extracts by 2-DE for the first time and identified cartilage ECM proteins by Western blotting and MS/MS. [source]

Microanatomy of the Mandibular Symphysis in Lizards: Patterns in Fiber Orientation and Meckel's Cartilage and Their Significance in Cranial Evolution

THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2010
Casey M. Holliday
Abstract Although the mandibular symphysis is a functionally and evolutionarily important feature of the vertebrate skull, little is known about the soft-tissue morphology of the joint in squamate reptiles. Lizards evolved a diversity of skull shapes and feeding behaviors, thus it is expected that the morphology of the symphysis will correspond with functional patterns. Here, we present new histological data illustrating the morphology of the joint in a number of taxa including iguanians, geckos, scincomorphs, lacertoids, and anguimorphs. The symphyses of all taxa exhibit dorsal and ventral fibrous portions of the joints that possess an array of parallel and woven collagen fibers. The middle and ventral portions of the joints are complemented by contributions of Meckel's cartilage. Kinetic taxa have more loosely built symphyses with large domains of parallel-oriented fibers whereas hard biting and akinetic taxa have symphyses primarily composed of dense, woven fibers. Whereas most taxa maintain unfused Meckel's cartilages, iguanians, and geckos independently evolved fused Meckel's cartilages; however, the joint's morphologies suggest different developmental mechanisms. Fused Meckel's cartilages may be associated with the apomorphic lingual behaviors exhibited by iguanians (tongue translation) and geckos (drinking). These morphological data shed new light on the functional, developmental, and evolutionary patterns displayed by the heads of lizards. Anat Rec 293:1350,1359, 2010. © 2010 Wiley-Liss, Inc. [source]

Tissue-engineered trachea for airway reconstruction,

THE LARYNGOSCOPE, Issue 11 2009
Mark Weidenbecher MD
Abstract Objectives/Hypothesis: Scaffold-free cartilage has been used to engineer biocompatible and mechanically stable neotracheas in vivo. The purpose of this animal study was to determine if neotracheal constructs, implanted paratracheally, could successfully be used for segmental tracheal reconstruction. Study Design: Animal study. Methods: Culture-expanded auricular rabbit chondrocytes were used to engineer scaffold-free cartilage sheets. Cartilage and a strap muscle flap were wrapped around a tube and implanted paratracheally. At 12 to 14 weeks postimplantation neotracheas were used to reconstruct 20 mm tracheal defects. Surgical technique was modified several times in an attempt to decrease the amount of neotracheal obstruction and fibrosis. In one of the six rabbits, neotrachea with its intact strap muscle flap was dropped into the defect followed by an end-to-end anastomosis; in two animals the muscle flap was partially, and in one rabbit completely removed. In two animals the muscle flap was partially removed, the tube reinserted, and the construct reimplanted for 5 weeks to allow formation of a fibrous lining over the exposed cartilage followed by tracheal reconstruction. Results: All implants developed into vascularized and mechanically sound neotracheas. Following reconstruction, none of the animals showed immediate signs of respiratory distress; however, one died after 24 hours due to extensive endotracheal muscle flap edema, whereas rabbits who had undergone partial or complete muscle flap removal survived up to 39 days before developing cicatricial stenosis. Conclusions: Tissue-engineered neotracheas proved to have excellent biocompatibility and stability to function under physiologic conditions, but lacked adequate endotracheal lining resulting in neotracheal stenosis. Laryngoscope, 2009 [source]

Preparation Techniques for the Injection of Human Autologous Cartilage: An Ex Vivo Feasibility Study,

THE LARYNGOSCOPE, Issue 1 2008
J Pieter Noordzij MD
Abstract Objectives: To determine the optimum donor site and preparation technique for injecting human autologous cartilage as a potentially permanent implant material for vocal fold medialization. Study Design: Prospective ex vivo experimental model. Methods: Human nasal septal and auricular cartilage was obtained from eight surgical cases after institutional review board approval. The auricle and nasal septum were chosen as potential donor sites because of ease of accessibility, volume of cartilage potentially available, and minimal subsequent cosmetic deformity after the tissue harvesting procedure. Various preparation techniques readily available in most operating rooms were tested for their efficacy in generating an injectable cartilage slurry. The various cartilage slurries were injected through sequentially smaller needles and examined cytologically. Results: The best injection properties for both nasal septal and auricular cartilage were obtained by drilling the cartilage down with a 5 mm otologic cutting bur, which allowed free passage through an 18 gauge needle. Cytologic examination of drilled septal cartilage showed good uniformity of cartilage pieces with a mean largest dimension of 0.44 ± 0.33 mm, and 33% of lacunae contained viable-appearing chondrocytes. Cytologic examination of drilled auricular cartilage was similar, exceptonly 10% of lacunae were occupied by chondrocytes. Other techniques tested (knife, morselizer, and cartilage crusher) did not yield injectable cartilage slurries. Conclusions: Both nasal septal and auricular cartilage can be prepared for injection via an 18 gauge needle using a cutting otologic bur. Further testing of in vivo viability and long-term volume retention is needed. [source]

A Morphological Study of Age Changes in Adult Human Auricular Cartilage With Special Emphasis on Elastic Fibers

THE LARYNGOSCOPE, Issue 5 2001
Isamu Ito MD
Abstract Objective It is well known that the size of the human auricle increases after it has finished development. The reason why the size of the human auricle continues to enlarge until advanced age after reaching adulthood was investigated by observation of the ultrastructure of elastic fibers in human auricular cartilage. Methods A total of 1958 subjects (966 males and 992 females) were classified into 18 age groups from 0 to 5 years up to 85 years and above by 5-year intervals. Ear length, ear width, and length of ear attachment were measured with calipers. Human auricular cartilage was obtained from 26 subjects (16 males and 10 females) aged 14 to 79 years, stained by orcein, and examined by light and electron microscopy. Results Each item of measurement of human auricular size increased significantly with age in both males and females. On morphological examination by light and electron microscopy after orcein staining, elastic fibers in the cartilage were almost homogeneous in diameter and surrounded the cartilage lacuna in bundle-like fashion in young persons, whereas those in elderly persons were heterogeneous in thickness and had many fragments surrounding the territorial matrix. In elderly persons, collagen-like fibers and small vesicles with heterogeneous electron density were frequently observed near elastic bundles around the territorial matrix. Conclusion Structural changes of auricular cartilage associated with morphological age changes of elastic fibers may be one of the causes of expansion of the auricle after reaching adulthood. [source]

Hearing Results After Primary Cartilage Tympanoplasty,

THE LARYNGOSCOPE, Issue 12 2000
Matthew J. Gerber MD
Abstract Objectives/Hypothesis Cartilage,perichondrium grafting of the tympanic membrane has been used in an effort to reduce recurrence or progression of middle ear disease. The rigidity of cartilage has obvious benefit in preventing tympanic membrane retraction, but concern has been raised regarding its sound conduction properties. Few studies in the literature address hearing results after cartilage tympanoplasty. The purpose of this study was to investigate the hearing results after primary cartilage tympanoplasty and compare them with results after primary tympanoplasty with temporalis fascia. Study Design A retrospective review of all ear surgeries using cartilage between 1994 and 1999 was performed. Methods Only primary cases in which the ossicular chain was intact and no mastoid surgery was performed were included. Indications for surgery included tympanic membrane perforation, retraction, and cholesteatoma. Pre- and postoperative speech reception thresholds and air,bone gaps at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz were compared. Results Eleven patients comprised the cartilage study group, and there were 11 age- and temporally matched control subjects. The mean improvement in speech reception threshold for both the study group and the control group was 10 dB. The majority of patients in both groups had ABG closure to within 10 dB at all frequencies examined. There were no statistically significant differences in speech reception threshold improvement or air,bone gap closures between the two groups. Conclusions These results demonstrate that hearing results after cartilage tympanoplasty are comparable to those after temporalis fascia tympanoplasty. Therefore, when indicated, a cartilage,perichondrium graft can be used for prevention of disease recurrence or progression without fear of impairing hearing. [source]

Effects of Alendronate on A Disintegrin and Metalloproteinase with Thrombospondin Motifs Expression in the Developing Epiphyseal Cartilage in Rats

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2009
M. S. Kim
Summary A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) have been reported to play a role in the degradation of aggrecan, a major component of cartilage. This study was performed to examine the effects of alendronate on the expression of ADAMTS in developing femoral epiphyseal cartilage. Primary cultured chondrocytes from this cartilage were treated with alendronate in vitro and postnatal day 1 rats were injected subcutaneously with alendronate (1 mg/kg) every second day in vivo. The number of cultured chondrocytes and their aggrecan mRNA levels were unaffected by the alendronate treatment at 10,6 to 10,4 m concentrations. The mRNA levels of ADAMTS-1, -2 and -9 in chondrocytes were also unaffected. However, the levels of ADAMTS-5 and -4 were reduced significantly by the same treatment. The thickness of the proliferating chondrocyte layers and the aggrecan mRNA levels in the epiphysis were unaffected by the alendronate treatment in vivo. However, the hypertrophied chondrocyte layers became significantly thicker, and the size of the secondary ossification centre was reduced significantly by the same treatment (P < 0.05). Both ADAMTS-4 and -5 mRNA expressions were also reduced significantly in vivo. The immunoreactivity against ADAMTS-4 was seen in hypertrophied chondrocytes and reduced significantly by the alendronate treatment. These results suggested that alendronate can inhibit the degradation of aggrecan in the articular cartilage by downregulating the expression of matrix enzymes such as ADAMTS-4 and -5. [source]

CCAAT/ENHANCER binding protein , mediates expression of matrix metalloproteinase 13 in human articular chondrocytes in inflammatory arthritis

ARTHRITIS & RHEUMATISM, Issue 3 2009
Mitsumasa Hayashida
Objective To determine the function of CCAAT/enhancer binding protein , (C/EBP,) in the expression of matrix metalloproteinase 13 (MMP-13) in chondrocytes in inflammatory arthritis. Methods Cartilage obtained from patients with rheumatoid arthritis and osteoarthritis was immunostained for expression of C/EBP, or MMP-13. Interleukin-1,, or tumor necrosis factor , (TNF,),stimulated chondrocytes were subjected to Western blotting and real-time reverse transcriptase,polymerase chain reaction (RT-PCR). MMP-13 promoter assays were conducted, and the C/EBP, response element was characterized by deletion and mutation analysis. C-28/I2 cells were treated with TNF, and subjected to chromatin immunoprecipitation (ChIP) assays. Finally, C/EBP,,liver-enriched activator protein (LAP) was overexpressed in C-28/I2 cells or cartilage tissues, and MMP-13 expression was analyzed. Results C/EBP, and MMP-13 expression was colocalized in chondrocytes in arthritic cartilage. MMP-13 promoter activity was stimulated by C/EBP, overexpression in a dose-dependent manner. Luciferase assays revealed that a ,981-bp promoter had the greatest activity, while deletion to ,936 bp strongly diminished promoter activity. Luciferase activity was repressed to basal levels by mutations in potential C/EBP binding sites. The stimulatory effects of C/EBP, overexpression were diminished by mutation. ChIP assays revealed that TNF, treatment enhanced the binding of C/EBP, to the MMP-13 promoter. When C/EBP,-LAP was overexpressed in C-28/I2 cells, endogenous MMP-13 expression was stimulated up to 32-fold as detected by real-time RT-PCR. Furthermore, following adenoviral overexpression of C/EBP,-LAP in organ culture of articular cartilage, stimulation of MMP-13 was also detected by immunohistochemistry. Conclusion C/EBP, directly binds to the MMP-13 promoter region and stimulates the expression of MMP-13 in chondrocytes in inflammatory arthritis. [source]

Change in joint space width: Hyaline articular cartilage loss or alteration in meniscus?

ARTHRITIS & RHEUMATISM, Issue 8 2006
D. J. Hunter
Objective To explore the relative contribution of hyaline cartilage morphologic features and the meniscus to the radiographic joint space. Methods The Boston Osteoarthritis of the Knee Study is a natural history study of symptomatic knee osteoarthritis (OA). Baseline and 30-month followup assessments included knee magnetic resonance imaging (MRI) and fluoroscopically positioned weight-bearing knee radiographs. Cartilage and meniscal degeneration were scored on MRI in the medial and lateral tibiofemoral joints using a semiquantitative grading system. Meniscal position was measured to the nearest millimeter. The dependent variable was joint space narrowing (JSN) on the plain radiograph (possible range 0,3). The predictor variables were MRI cartilage score, meniscal degeneration, and meniscal position measures. We first conducted a cross-sectional analysis using multivariate regression to determine the relative contribution of meniscal factors and cartilage morphologic features to JSN, adjusting for body mass index (BMI), age, and sex. The same approach was used for change in JSN and change in predictor variables. Results We evaluated 264 study participants with knee OA (mean age 66.7 years, 59% men, mean BMI 31.4 kg/m2). The results from the models demonstrated that meniscal position and meniscal degeneration each contributed to prediction of JSN, in addition to the contribution by cartilage morphologic features. For change in medial joint space, both change in meniscal position and change in articular cartilage score contributed substantially to narrowing of the joint space. Conclusion The meniscus (both its position and degeneration) accounts for a substantial proportion of the variance explained in JSN, and the change in meniscal position accounts for a substantial proportion of change in JSN. [source]

Effect of oral glucosamine on cartilage and meniscus in normal and chymopapain-injected knees of young rabbits

ARTHRITIS & RHEUMATISM, Issue 9 2002
Theodore R. Oegema Jr.
Objective To determine if oral glucosamine (GlcN) improves joint biology after acute damage by a protease. Methods The effect of 8 weeks of dietary GlcN (20 or 100 mg/kg/day) on knee joint cartilage was evaluated in 2.2-kg male NZW rabbits with and without damage introduced by intraarticular injection of chymopapain (CP). Cartilage was evaluated histologically and scored according to the Mankin scale. Analyses of total hydroxyproline and glycosaminoglycan (GAG) contents and reverse transcription,polymerase chain reaction (RT-PCR) analysis of selected genes were performed. Results After 8 weeks, there was no effect of GlcN on the GAG content of normal cartilage. Both levels of GlcN treatment significantly increased the sulfated GAG content in the cartilage of the medial femoral condyle in damaged and contralateral knees, but did not change the collagen content. In CP-injected knees, there was still some loss of surface proteoglycan (PG) that was not completely corrected by dietary GlcN. Even after 8 weeks, levels of messenger RNA (mRNA) detected by RT-PCR showed changes indicative of damage and repair, such as elevated type II collagen mRNA, and these levels were not influenced by GlcN treatment. Meniscal GAG content was increased in the contralateral knee of rabbits receiving high-dose GlcN, but was decreased in those receiving no GlcN or low-dose GlcN. Neither diet nor treatment affected the meniscal collagen content. Conclusion These results suggest that oral GlcN treatment might be useful in a situation where GlcN is limiting, such as where there is a rapid replacement of cartilage PG. [source]

Real-time Monitoring of Force Response Measured in Mechanically Stimulated Tissue-Engineered Cartilage

ARTIFICIAL ORGANS, Issue 4 2009
Orahn Preiss-Bloom
Abstract:, Mechanical stimulation improves tissue-engineered cartilage development both in terms of biochemical composition and structural properties. However, the link between the compositional changes attributed to mechanical stimulation and the changing structural properties of the engineered cartilage is poorly understood. We hypothesize that transient events associated with construct stiffening can be documented and used to understand milestones in construct development. To do this, we designed and built a mechanical stimulation bioreactor that can continuously record the force response of the engineered construct in real time. This study documents the transient changes of the stiffness of tissue-engineered cartilage constructs over the first 14 days of their development under cyclic loading. Compressive strain stimulation (15%, 1 Hz) was applied to poly(ethylene glycol) (PEG) hydrogels seeded with primary articular chondrocytes. The average compressive modulus of strain-stimulated constructs was 12.7 ± 1.45 kPa after 2 weeks, significantly greater (P < 0.01) than the average compressive moduli of both unstimulated constructs (10.7 ± 0.94 kPa) and nonviable stimulated constructs (11.2 ± 0.91 kPa). The system was able to document that nearly all of the stiffness increase occurred over the last 2 days of the experiment, where live-cell constructs demonstrated a rapid 20% increase in force response. The system's ability to track significant increases in stiffness over time was also confirmed by Instron testing. These results present a novel view of the early mechanical development of tissue-engineering cartilage constructs and suggest that the real-time monitoring of force response may be used to noninvasively track the development of engineered tissue. [source]

Cryopreservation and in Vitro Expansion of Chondroprogenitor Cells Isolated from the Superficial Zone of Articular Cartilage

BIOTECHNOLOGY PROGRESS, Issue 1 2005
Juan M. Melero Martin
Understanding the proliferation mechanisms of chondroprogenitor cells and their influence on cell differentiation is crucial in order to develop large-scale expansion processes for tissue engineering applications. Proliferation control mechanisms were mainly attributed to substrate limitation and cell-cell contact inhibition. The limiting substrates were found to be components of the FCS, with an optimal proliferation rate achieved in the presence of 40% FCS. In addition, the medium supply rate was found to be essential in reducing substrate limitation. In terms of FCS, 10 ,L FCS cm,2 h,1 was the threshold feed rate required to prevent substrate limitation. Above this rate, maximum cell densities of 5.3 × 105 cells/cm2 were achieved, representing a 53-fold expansion. To reduce the need for high supply rates, the effect of specific growth factors was also investigated. Cell densities of 3.3 × 105 cells/cm2 were achieved in batch cultures using 40% FCS and 1 ng/mL TGF-,1. Chondroprogenitor cells were expanded in this medium up to three passages without compromising their ability to differentiate and produce cartilage-like matrix in pellet cultures. In addition to substrate limitation, cell-cell contact, even at very sparse subconfluent densities, appeared capable of exerting some degree of growth inhibition. The cells exhibited deceleratory growth kinetics, characterized by a decrease of specific growth rates over time. [source]

Benzo[d]isothiazol-3-yl-benzamidines: a Class of Protective Agents on Culture of Human Cartilage and Chondrocytes Stimulated by IL-1,

CHEMMEDCHEM, Issue 1 2007
Paola Vicini Prof.
Abstract New derivatives of N -benzo[d]isothiazol-3-yl-benzamidine 6,a were synthesized as nonacidic anti-inflammatory/antidegenerative agents. We investigated the influence of the amidines 6,a,j on the production of NO, PGE2, MMP-3, COX-2, ROS, and GAGs, key molecules involved in cartilage destruction in osteoarthritic diseases. The antidegenerative properties of the novel designed derivatives 6,b,j were improved with respect to N -benzo[d]isothiazol-3-yl-benzamidine 6,a. All of the compounds 6,a,j promoted the reduction of most of the IL-1,-induced harmful effects. Derivatives 6,d, 6,h, and 6,j were the most potent of all the tested compounds, particularly in the human chondrocyte culture model. [source]

Incidence and cytological features of pulmonary hamartomas indeterminate on CT scan

CYTOPATHOLOGY, Issue 3 2008
A. Saqi
Objective:, Pulmonary hamartomas have a characteristic heterogeneous radiological appearance. However, when composed predominantly of undifferentiated mesenchymal fibromyxoid component, their homogeneous appearance on computed tomography is indeterminate for malignancy. Rendering an accurate preoperative diagnosis in these cases can alter management. The aim of this study was to determine the incidence and accuracy of cytodiagnosis for hamartomas ,indeterminate' by imaging. Methods:, We retrospectively reviewed records for hamartomas diagnosed by transthoracic fine needle aspiration (FNA) including immediate impressions and final diagnoses. Cytological features evaluated included the presence of fibromyxoid stroma, bronchioloalveolar cell hyperplasia, fibroadipose tissue, cartilage and smooth muscle. Results:, Eighteen (1.3%) hamartomas were identified from 1355 transthoracic FNAs. The immediate impression was hamartoma in 13 (72%), carcinoid in one (6%), mucinous bronchioloalveolar carcinoma in two (11%) and non-diagnostic in two (11%). The final diagnosis of hamartoma in cases diagnosed as carcinoid, mucinous bronchioloalaveolar carcinoma and non-diagnostic on immediate impression was rendered following assessment of all cytological material. Conclusion:, Overall, FNAs are highly reliable for diagnosing hamartomas even when composed principally of undifferentiated mesenchymal fibromyxoid stroma, especially with the aid of all available preparations including Diff-Quik smears, Papanicolaou smears, ThinPreps and cell block material. [source]

The Incidences of Chondritis and Perichondritis Associated With the Surgical Manipulation of Auricular Cartilage

Dermal fibroblasts contribute to multiple tissues in the accessory limb model

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 4 2010
Ayako Hirata
The accessory limb model has become an alternative model for performing investigations of limb regeneration in an amputated limb. In the accessory limb model, a complete patterned limb can be induced as a result of an interaction between the wound epithelium, a nerve and dermal fibroblasts in the skin. Studies should therefore focus on examining these tissues. To date, however, a study of cellular contributions in the accessory limb model has not been reported. By using green fluorescent protein (GFP) transgenic axolotl tissues, we can trace cell fate at the tissue level. Therefore, in the present study, we transgrafted GFP skin onto the limb of a non-GFP host and induced an accessory limb to investigate cellular contributions. Previous studies of cell contribution to amputation-induced blastemas have demonstrated that dermal cells are the progenitors of many of the early blastema cells, and that these cells contribute to regeneration of the connective tissues, including cartilage. In the present study, we have determined that this same population of progenitor cells responds to signaling from the nerve and wound epithelium in the absence of limb amputation to form an ectopic blastema and regenerate the connective tissues of an ectopic limb. Blastema cells from dermal fibroblasts, however, did not differentiate into either muscle or neural cells, and we conclude that dermal fibroblasts are dedifferentiated along its developmental lineage. [source]

Sox genes regulate type 2 collagen expression in avian neural crest cells

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 8 2006
Takashi Suzuki
Neural crest cells give rise to a wide variety of cell types, including cartilage cells in the cranium and neurons and glial cells in the peripheral nervous system. To examine the relationship of cartilage differentiation and neural crest differentiation, we examined the expression of Col2a1, which encodes type 2 collagen often used as a cartilage marker, and compared it with the expression of Sox transcription factor genes, which are involved in neural crest development and chondrogenesis. We found that Col2a1 is expressed in many neural crest-derived cell types along with combinations of Sox9, Sox10 and LSox5. Overexpression studies reveal the activation of Col2a1 expression by Sox9 and Sox10, and cross-regulation of these Sox genes. Luciferase assay indicates a direct activation of the Col2a1 enhancer/promoter both by Sox9 and Sox10, and this activation is further enhanced by cAMP-dependent kinase (PKA) signaling. Our study suggests that the regulatory mechanisms are similar in cartilage and neural crest differentiation. [source]

Long-term culture of Xenopus presumptive ectoderm in a nutrient-supplemented culture medium

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 5-6 2003
Yasuto Fukui
Animal cap assay is a useful experimental model for investigating the activity of inducers in amphibian development. This assay has revealed that activin A is a potent mesoderm-inducing factor. However, it has been very difficult to induce highly differentiated tissues such as cartilage in a 3,4 day culture period. It was recently reported that jaw cartilage was induced in vitro in an animal cap that had been cultured for 14 days in Steinberg's solution using the sandwich culture method and activin A. Under these conditions, necrosis was occasionally observed in the explants. In this study, we have achieved long-term animal cap cultures in a nutrient-supplemented culture medium designated RDX. This medium was made by modifying the saline concentration of the RD medium previously developed as a basal medium for the serum-free culture of various kinds of mammalian cells. The explants cultured in RDX grew more vigorously compared with those in Steinberg's solution. RDX medium promoted a wider variety of tissue induction and gene expression in the animal caps than Steinberg's solution, and also increased the frequency of cartilage induction. Therefore, the supplemental nutrients may support and promote the differentiation of cartilage. This long-term culture method using RDX medium is useful for studying the differentiation of tissues or organs such as cartilage in vitro. [source]

Retinoic acid controls expression of tissue remodeling genes Hmgn1 and Fgf18 at the digit,interdigit junction

DEVELOPMENTAL DYNAMICS, Issue 2 2010
Xianling Zhao
Abstract Previous studies on retinoic acid receptor (RAR) mutants suggested that retinoic acid (RA) is required for loss of interdigital mesenchyme during digit formation. Here, we report that the RA-generating enzyme retinaldehyde dehydrogenase-2 (Raldh2) is expressed in the interdigital mesenchyme whereas Cyp26b1, controlling RA degradation, is expressed in digits, limiting autopodal RA action to the interdigital zones. Embryonic day 13.5 Raldh2,/, mouse embryos lose expression of the RARE-lacZ RA-reporter transgene and matrix metalloproteinase-11 (Mmp11) throughout the interdigital mesenchyme, while expression of RARb, Fgf18, and high mobility group N1 (Hmgn1) is lost at the digit,interdigit junction. Raldh2,/, autopods exhibit reduced interdigital apoptosis associated with loss of Bmp7 expression, but Bmp2, Bmp4, Msx2, and Fgf8 were unaffected. Although interdigital expression of Hmgn1 was greatly down-regulated in Raldh2,/, autopods, complementary expression of Sox9 in digit cartilage was unaffected. Regulation of Hmgn1 and Fgf18 at the digit,interdigit junction suggests RA controls tissue remodeling as well as apoptosis. Developmental Dynamics 239:665,671, 2010. © 2009 Wiley-Liss, Inc. [source]