Calcified Cartilage Matrix Research Articles

1206 ACROMESOMELIC DYSPLASIA, A HISTOCHEMICAL STUDY OF THE ENDOCHONRAL GROWTH PLATE

Endochondral growth plate cartilage from a patient with the typical clinical and radiographic features of acromesomelic dysplasia was studied histochemically and immunohistochemically. The investigation revealed many previously undescribed abnormalities. The cartilage was hypercellular in general. There were numerous small areas of matrix degeneration scattered through the resting zone and a few large islands of hypertrophic cartilage in the growth plate region. Staining indicated excessive amounts of chondroitin sulfate and an absence of collagen fibers in both of these areas. In the remaining cartilage, collagen fibers tended to aggregate around the cells. The resting chondrocytes were irregular in size and distribution, and many exhibited protein containing cytoplasmic inclusions. The growth plate per se was poorly organized; hypertrophic chondrocytes were randomly oriented. The provisional calcification of cartilage matrix was absent, but the mineralization of subchondral bone appeared normal except along the outer margin where bone formation extended into the perichondrial space. These abnormalities appear to be distinct for acromesomelic dysplasia. Moreover, they provide several clues regarding the pathogenesis of the disorder.

Fine structure of the nucleus of ossification in cartilage

Fine structure with endochondral ossification of the calcifying cartilage and bone matrix in the nucleus of ossification were investigated by a scanning electron microscope, using fracture surfaces of the nucleus in the cartilagious sternum of the fetus.The chondrocyte lacunar wall in the superficial layer of the nucleus of ossification was formed by numerous calcospherites, and its surface was rough. The longitudinal septa of the hypertrophic layer was strand-shaped and calcified. The calcifying cartilage matrix in the part of the center of the trabeculae of the layer of ossification was mostly formed by dense calcified matrix. The gap of the calcospherites was formed by collagen fibrils. The calcifying cartilage matrix of the layer of ossification was highly calcified. There were many osteocyte lacunae showing irregularly arranged in the bone matrix of the fracture surface. The osteocyte lacunar wall was formed with dense networks of collagen fibrils.

Effects of γ Irradiation on Cartilage Matrix Calcification

The effect of ..gamma.. irradiation on cartilage matrix calcification was studied in vitro. Metatarsal bones of 14- to 17-day-old embryonic mice were dissected and cultured under various conditions. Prior to culture, half of the metatarsal bones received absorbed doses of 1.0 to 30.0 Gy ..gamma.. radiation. Their paired counterparts served as controls. Irradiation inhibited longitudinal growth and calcification of the cartilage matrix during culture. In addition, a number of histological changes were noted. The inhibition of matrix calcification appeared to be due to an inhibition of the intracellular calcium accumulation. The formation of extracellular calcification foci and the growth of the calcified area already present at the moment of explanation were not inhibited during culture.

Bone formation in cartilage produced by transplanted epiphyseal chondrocytes.

Chondrocytes were isolated from rat epiphyseal cartilage, cultured in vitro, and exposed to exogenous tracers which accumulated in their lysosomes. The cells were then injected into the posterior tibial muscle of animals from the same outbred strain, where they reconstructed calcifying hyaline cartilage. The mineralization of the tissue was followed by ingrowth of blood capillaries from the host bed. Macrophage-like cells surrounding the vessels phagocytized degenerated chondrocytes and unmineralized matrix, whereas multinucleated chondroclasts removed some of the mineralized cartilage matrix. Mesenchyme-like cells accompanying the invading vessels attached to the remaining septa of calcified cartilage matrix and developed into osteoblasts depositing bone matrix on the surface of these septa. The apparent lack of inherent tracer labeling of the lysosomes in the different bone cells indicate that they were derived from the host. No signs of transformation of chondrocytes into bone cells were observed. When isolated rat epiphyseal chondrocytes were injected into the wall of the hamster cheek pouch, calcifying cartilage was reconstructed without signs of subsequent ossification. Transplantation of cartilage reconstructed in the hamster into the dorsal muscles of rats was, however, followed by formation of bone by a sequence analogous to that described above. Such an osteogenetic response was also obtained when the cartilage had been devitalized before transplantation. These experiments show that calcified cartilage, developing in or grafted into an intramuscular site, is able to induce and serve as a substrate for endochondral bone formation, similar to that occurring during normal development. They further indicate that bone induction by calcified cartilage does not require the presence of living chondrocytes.

Calcification of aging articular cartilage in man.

Calcification of the articular cartilage was studied ultrastructually using normal femoral heads obtained from necropsies of persons ranging in age from 11 months to 80 years. Mineral crystals which appeared during the initial stages of deposition were morphologically divided into two types. Type A crystals were slender, twisted and curved, measuring from 100 nm to 360 nm in length. Type B crystals were short, needle-like and slightly curved, measuring from 30 nm to 160 nm in length. Type A crystals were found mainly in the developing epiphysis during childhood. Type B crystals were generally found in the calcified zone of adult articular cartilage. Both types of crystals initially appeared in close proximity to extracellular membrane-invested electron dense particle called "matrix vesicles", and gradually increased in number to form calcified cartilage matrix. The morphological differences between type A and B crystals might be caused by biochemical alterations of the cartilage matrices and/or biomechanical changes in the joints of children and adults.

136: Ultrastructural analysis of growth zone architecture. A SEM study in rats

In the present study the architecture of the growth zone and its disturbance in various forms of metabolic bone disease were investigated. Epipyhses and metaphyses of rats were separated transversely by fracture or sectioned longitudinally. The specimens were prepared by critical point drying or (for the study of mineralized structures) by digestion with sodium hypochlorite. A stable functional system of epipyhseal bone plate growth cartilage and metaphyseal trabeculae is formed in a light weight construction by various collagen fiber systems, cell columns and a framework of calcified cartilage matrix. Individual cell columns are joined with the epipyhses by being inserted into holes of the lower surface of the epiphyseal bone plate. The columns are stabilized by a shroud like system of collagen fibers and connected with one another by other interchanging fiber systems. Other fibers run longitudinally into the metaphyseal bone. In the zone of calcification mineralized globules can be found within longitudinal and transverse septa, whereas the matrix plane in contact with the chondrocyte cell surface shows only a fine granular surface. It can be shown that metabollically induced disturbance of longitudinal growth (rickets, uremia) will distroy this functional system.

Resorption of calcified cartilage as seen in Meckel's cartilage of rats.

AbstractIn rats, a portion of Meckel's cartilage — that lying within the mandible but proximal to the rostral convergence of the bars — gives rise to no definitive structures. It offers especially favorable opportunity to study cartilage resorption. By the eighteenth fetal day it is established as a hyaline cartilage bar, and a thin perichondral bone shell starts to form on its lateral aspect, completing encirclement in the next two days. On day 19 cartilage within this bone shows chondrocyte hypertrophy, lacunar enlargement, and matrix calcification. Osteoclasts open a fenestra laterally in the bone and commence removal of calcified cartilage matrix. The erosion front expands rapidly, moving medially (preceded by cartilage hypertrophy and calcification) and extending proximally and distally along the segment. Chondroclasts (multinucleated cells identical with osteoclasts) dominate the erosion front. Capillaries and various mononucleated cells follow. Bone formation is much delayed except in the most rostral extremity, so that, contrary to the situation in endochondral osteogenesis, one is examining calcified cartilage resorption in uncomplicated form. This resorption, including the perichondral bone shell, is virtually complete by day 21, and intramembranous bony reorganization of the site is in progress at birth.Several features of chondroclasts, including some in dispute or not easily seen in vivo, are well displayed. These include ameboid form with pseudopodial extensions (sometimes filamentous), and fusion of some released chondrocytes with entering chondroclasts. Osteo/chondroclasts are often found in contact with perichondral bone at one extremity and calcified cartilage elsewhere on the same cell. There is evidence that matrix calcification is prerequisite to the chondroclastic activity.

The nature of endochondral ossification in the mandibular condyle of the mouse.

AbstractThrough the application of histological and histochemical techniques, this study demonstrates that the ossification process of the mandibular condyle differs basically from that of other endochondral growth sites. In the epiphyseal plate of a typical long bone, the cartilage cells are known to undergo degenerative processes and death. In the mandibular condyle, however, the cartilage cells keep their vitality throughout the cartilage zones. In the lower border of the calcified cartilage, adjacent hypertrophic cartilage cells fuse after the dissolution of the intervening matrix to form multinuclear chondroclasts. These giant cells reveal marked positive reaction to mitochondrial and lysosomal enzymes. It is suggested that these enzymes are active in the resorption process of the calcified cartilage matrix, which is an integral phase of the ossification mechanism of the condylar growth center. It is believed that the mandibular condyle of the mouse demonstrates a specific type of endochondral ossification, in which the hypertrophic chondrocytes are not dying cells, but contribute actively to the process of bone formation.

Membranous particles in calcifying cartilage matrix.

Transactions of the New York Academy of SciencesVolume 32, Issue 5 Series II p. 619-630 MEMBRANOUS PARTICLES IN CALCIFYING CARTILAGE MATRIX*,† H. Clarke Anderson M.D., H. Clarke Anderson M.D. Department of Pathology State University of New York Downstate Medical Center Brooklyn, N.Y.Search for more papers by this authorTatsuji Matsuzawa M.D., Tatsuji Matsuzawa M.D. Department of Pathology State University of New York Downstate Medical Center Brooklyn, N.Y.Search for more papers by this authorStanley W. Sajdera Ph.D., Stanley W. Sajdera Ph.D. Rockefeller University New York, N.Y.Search for more papers by this authorS. Yousuf Ali Ph.D., S. Yousuf Ali Ph.D. Rockefeller University New York, N.Y. Recipient of a Sir Henry Wellcome Travelling Fellowship; on leave from the Institute of Orthopaedics, University of London, London, England.Search for more papers by this author H. Clarke Anderson M.D., H. Clarke Anderson M.D. Department of Pathology State University of New York Downstate Medical Center Brooklyn, N.Y.Search for more papers by this authorTatsuji Matsuzawa M.D., Tatsuji Matsuzawa M.D. Department of Pathology State University of New York Downstate Medical Center Brooklyn, N.Y.Search for more papers by this authorStanley W. Sajdera Ph.D., Stanley W. Sajdera Ph.D. Rockefeller University New York, N.Y.Search for more papers by this authorS. Yousuf Ali Ph.D., S. Yousuf Ali Ph.D. Rockefeller University New York, N.Y. Recipient of a Sir Henry Wellcome Travelling Fellowship; on leave from the Institute of Orthopaedics, University of London, London, England.Search for more papers by this author First published: May 1970 https://doi.org/10.1111/j.2164-0947.1970.tb02737.xCitations: 68 † This paper was presented at a meeting of the Section on February 26, 1970. ‡ Supported by United States Public Health Service grants nos. CA-10052 and CA-06081. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume32, Issue5 Series IIMay 1970Pages 619-630 RelatedInformation

The distribution of calcium in normal and tetracycline-modified bones of developing chick embryos.

The presence of calcium (GBHA technique) in the periosteal cells, osteoblasts, osteocytes and chondrocytes of developing chick embryo bone confirms the findings ofKashiwa (1966) in the rat. Modification of bone development by tetracycline administration indicates that there is a direct correlation between the amount of calcium within these cells and the degree of mineralization of the adjacent matrices. The calcium of the calcification front of bone and the abnormally calcified cartilage matrix resulting from tetracycline treatment appears to differ from that of the older bone and normally calcifying cartilage matrix in its ability to chelate with GBHA. The distribution of the GBHA positive material appears to correspond to that of a pyridine-resistant bound lipid previously reported.

Histochemistry of bone formation in normal and tetracycline-treated chick embryos—I: Lipids

The localization of lipid components in the developing femurs of normal and tetracycline-treated chick embryos has been described. A lipid component readily extractable with ethanol, possibly neutral fat, was found in the cytoplasm of osteoblasts and osteocytes, in bone matrix, and to a much lesser extent in osteoid. Phospholipids were found in the cytoplasm of the chondrocytes. A sudanophilic bound lipid, which is unmasked by ethanol but removed by pyridine extraction, was found in the calcified bone of both normal and experimental animals, and in the calcified cartilage matrix of the experimental femurs. A sudanophilic bound lipid, which is resistant to pyridine extraction with the techniques used, was found in the rapidly calcifying bone and cartilage matrix. It was reduced in amount in the older, less rapidly calcifying bone. A similar pyridine-resistant, sudanophilic, bound lipid was found in cytoplasmic granules of the chondrocytes, and those osteocytes situated in a calcified matrix. There appears to be a direct relationship between the size and possibly the number of these granules and the degree and rate of calcification of the surrounding matrix.

RELATION OF EFFECTIVE THICKNESS AND REFRACTIVE INDEX TO PERMEABILITY OF TISSUE COMPONENTS IN FIXED SECTIONS.

SYNOPSISAccurate and reproducible interference microscopy of unstained sections requires (a) the use of a shearing system, preferably with a half‐shade eye‐piece; (b) complete removal of embedding wax from the section; (c) complete replacement of one mounting medium by any successive medium; (d) accurate measurement of the refractive index (RI) of the mounting media at the temperature and wave‐length used for microscopy. The optical path through a specimen mounted in water is consistently lower than expected from measurements in non‐polar fluids—this is attributed to swelling of the tissues in water. Cellulose, glycogen and some mucins have a relatively low RI, and secretory granules and cytoplasmic chromidial substance a relatively high one. The highest RI observed was in calcified cartilage matrix. The “effective thickness” of tissue components, especially certain mucins, is often considerably less than the geometrical thickness of the section. This is attributed to the presence in the tissues of substantial spaces containing mounting medium.The relation of the RI and the effective thickness of tissue components in sections to their permeability to histological dyes is discussed. It is concluded that both the RI and the effective thickness may be of some value in predicting the ease with which dye particles of a given size can penetrate the tissue.

The restoration of articular surfaces after joint excision; an experimental study with cartilage implants.

The experiments were performed to answer three main questions. These and our answers may be summarised as follows. What is the precise mechanism of healing of a raw bony surface in a joint? What cells are involved? Where do they originate?—In all the implant experiments and in the control series the fundamental mechanism of healing was similar. 1. A massive proliferation of fibroblasts occurred from the cut periosteum, from the cut joint capsule, and to a lesser extent from the medullary canal. 2. Fibroblasts grew centripetally in the first few weeks after operation, attempting to form a "fibroblast cap" to the cut bone end. 3. Fibroblasts of this cap near the cut bone spicules metamorphosed to become prechondroblasts, chondroblasts laying down cartilage matrix, and hypertrophied (alkaline phosphatase-secreting) chondrocytes lying in a calcified matrix. 4. This calcified cartilage matrix was invaded by dilated capillaries probably bearing osteoblasts which laid down perivascular (endochondral) bone. 5. Some of the cells of projecting bone spicules died and their matrix was eroded in the presence of many osteoclasts. 6. In the control experiments of simple excision of the radial head new bone was produced at the periphery only by processes (3) and (4). This sealed off the underlying peripheral cortical bone from the superficially placed peripheral articular surface of fibrocartilage. At about a year from operation the central portion of the articular surface was still formed of bare bone, or of bone spicules covered by a thin layer of irregularly arranged collagen fibres. The opposite capitular articular cartilage was badly eroded. Does the introduction of a dead cartilage implant over the raw bone end affect in any way the final constitution of the new articular surface?—In the implant experiments the new bone produced by processes (3) and (4) formed, after about a year, a complete cortical plate which entirely sealed off the cut end of the radius and left a superficially placed articular covering of smooth fibrocartilage, closely resembling a normal joint surface. The opposite capitular articular surface was normal. What is the final fate of such an implant?—Whale cartilage implants underwent replacement by fibroblasts and collagen fibres, and took about nine months to disappear. The cartilage of fixed autotransplants and homotransplants underwent similar gradual replacement, and took about the same time in each case. The dead bone, implanted in association with the cartilage in both cases, acted as a nidus for hyaline cartilage production by chondrocytes derived from fibroblasts. This cartilage underwent endochondral ossification. This observation suggests that induction by non-cellular osseous material is a factor in chondrification and ossification. All the implants functioned as temporary articular menisci or in some cases as temporary radial articular surfaces. They were always replaced by a permanent fibrocartilaginous meniscus, or a fibrocartilaginous articular surface. An implant did, in fact, always act as a temporary protecting cap and mould for the subjacent growth offibroblasts which was necessary for the production of a satisfactory new joint surface.