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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ultrastructural findings from the cellular, early osteoid regions of 10 osteosarcoma lesions are described. The characteristic features included irregularity in nuclear shape, margination of the chromatin, a large number of nucleoli, normal-sized nuclear pores, undifferentiated cells, poorly differentiated osteoblasts with scanty rough endoplasmic reticulum in annular or lamellar conformation, and malignant osteoblasts characterized by large accumulations of dilated rough endoplasmic reticulum (often in the form of huge anastomosing lakes) and by intracellular filaments. Several of the lesions demonstrated prominent giant cells, most of which were similar ultrastructurally to uninuclear tumor cells rather than to mitochondrialaden giant cells or osteoclasts. Variable amounts of primarily collagenous intercellular matrix were present. Cross-banded collagen fibers with diameters from 30-90 nm were seen as were thinner non-cross-banded fibrils 12-18 nm wide.
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PMID:Ultrastructural observations on osteosarcoma tissue: a study of 10 cases. 657 1

Monkey periodontal ligament fibroblasts (MPLF cells), human gingival fibroblasts (HGF cells), rat embryonic calvaria cells (REC cells), porcine periodontal ligament epithelial cells (PPLE cells) and rat osteosarcoma 17/2 cells (ROS cells) were incorporated into 3-dimensional collagen gels plated in 60 mm Petri dishes in order: first, to measure the capacity of these cell types to contract; second, to investigate cell-collagen and intercellular relationships during contraction; and third, to define the cellular contribution to tissue contraction in an in vitro system. Measurements at times up to 72 h on 3 ml gels containing 5 x 10(5) cells and with a collagen concentration of 1.20 mg/ml showed that MPLF cells contracted the gels at a significantly greater rate (P less than 0.001) than did the other cell types. In addition, contraction started sooner and was of greater extent than with the other cells. HGF cells contracted the gels more rapidly than REC and PPLE cells, while ROS cells caused no contraction. Several stages of gel compaction could be defined: (1) the attachment of cells to collagen; (2) cellular spreading within the collagen fibre matrix; (3) organization and alignment of collagen fibres by cell processes; (4) cell migration; (5) establishment of intercellular contacts; and (6) the development of a cellular reticular arrangement within the gel and the extension of this arrangement into a 3-dimensional, tissue-like, honeycomb network. Electron microscopic observations on 0.1 ml gels containing MPLF cells showed that, in the early contractile phase, numerous cell processes attached to or enclosed collagen fibrils. These processes contained microfilamentous material and few organelles. In compacted gels, the cells contained an increased amount of distended rough endoplasmic reticulum and Golgi membranes. Since MPLF cells have the capacity for vigorous contraction of the collagen gels and since they develop a reticular, 3-dimensional structure in compacted gels that is reminiscent of the relationship of periodontal ligament fibroblasts to collagen fibres in vivo, it is suggested that they could provide the major force necessary for tooth eruption in vivo. This system also provides a well-defined in vitro model to study the sequential stages that occur during contraction processes.
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PMID:Contraction and organization of collagen gels by cells cultured from periodontal ligament, gingiva and bone suggest functional differences between cell types. 679 46

Six human osteosarcomas were transplanted subcutaneously in the back of nude mice and three of the six were found to be serially transplantable. Two of three transplantable solid tumors were called DOS tumor and KOS tumor. The 4th generation of DOS tumor and the 1st generation of KOS tumor grew to invade the peritoneum and tumor cells were spilt spontaneously into the abdominal cavity. These two cases were transformed to ascites tumor, called DOS-NM ascites tumor and KOS-NM ascites tumor. They were found to be serially transplantable by an intraperitoneal injection of free tumor cells (10-20 x 10(5) cells). DOS-NM and KOS-NM ascites tumor cells were analysed to have human karyotype and alkaline phosphatase activity. Ascites tumor cells were studied under light and electron microscopes. A large number of elongated and ballooned mitochondria were characteristically seen in the cytoplasm of two ascites tumor cells by electron microscope. Development of rough surfaced endoplasmic reticulum and Golgi's apparatus was poor, and no production of collagen fiber was seen in these materials. There is no report referring to ascites tumor of human osteosarcoma, therefore ascites tumor of osteosarcoma was made deliberately and the following results were obtained. 1) Several blocks of DOS tumor were implanted intraperitoneally into 5 nude mice, and only solid tumors grew in the abdominal cavity without ascites. 2) Minced DOS tumor was implanted subcutaneously close to the peritoneum and 2 out of 6 nude mice developed ascites tumor. 3) Cell suspension of DOS tumor was injected intraperitoneally and 3 out of 4 nude mice developed ascites tumors. As mentioned above, human osteosarcoma was successfully induced to ascites tumor (DOS-NM), which was established earlier compared with solid tumor (DOS). Characteristics of human osteosarcoma are easily examined with ascites tumor and in vivo screening test of anticancer drugs can be quantitatively done. Therefore ascites tumor is considered to be a valuable experimental model.
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PMID:[Experimental studies on ascites tumor of human osteosarcoma in nude mice (author's transl)]. 694 13

Crystalline arrays of coated parallel tubules (CPT) were observed by electron microscopy within dilated cisternae of the rough endoplasmic reticulum of pleomorphic mononuclear cells in a human osteosarcoma. The wall of the peculiar intracisternal tubules consisted of an electron-dense thin membrane-like envelope which appeared to be composed of granular subunits. The electron-lucent tubular core together with the limiting envelope was approximately 15 nm in diameter. A coat of fuzzy material, approximately 10 nm thick, tightly surrounded the membrane-like wall of the tubules. Cross sections of accumulations of CPT showed the tubules to be arranged in a hexagonal crystalline array. The nature and significance of the intracisternal CPT are unknown.
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PMID:Intracisternal crystalline arrays of coated parallel tubules in cells of a human osteosarcoma. 694 45

The collagenous matrix of human osteosarcoma was characterized biochemically and ultrastructurally. The highly cellular regions of the tumors contained many osteoblast-like cells filled with dilated rough endoplasmic reticulum. The extracellular matrix displayed a random weave of banded collagen fibrils (30--90 nm in diameter) interspersed with thinner, unbanded fibrils (15 nm in diameter). Tumors from 9 patients were analyzed for collagen composition. All gave a similar collagen profile. Three main molecular species of collagen were abundant: type I, type III, and type V, which occurred in the approximate proportions of 65:25:10. A high ratio of alpha 1(I) to alpha 2(I) chains suggested that one-third of the type I collagen was present as a type I trimer molecule. In contrast, normal bone matrix consisted almost exclusively of type I collagen. The fibrillar collagens in the soft tumor seemed unusually rich in hydroxylysine and hydroxylysine glycosides; type I collagen had two to three times the hydroxylysine content of normal bone collagen.
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PMID:Collagen polymorphism in extracellular matrix of human osteosarcoma. 695 47

Ten cases of osteosarcoma were studied by electron microscopy. The tumors consisted of six cell types: fibroblastic, myofibroblastic, chondroblastic, osteoblastic, unclassified and histiocytic cells. Disturbed structure of dilated endoplasmic reticulum was a common feature. The neoplastic character of myofibroblastic and histiocytic cells is controversial. Myofibroblastic differentiation was most abundant in parosteal osteosarcoma and in fibrosarcomatous intraosseal osteosarcoma. The malignant cells sometimes formed giant cells and many aggregates of these cells were seen. Osteoclasts and other reactive cells were encountered and this may indicate host reaction against the tumor cells. Formation of collagenous and cartilaginous ground substance was poor, and the capacity of collagen to mineralize was decreased. It is concluded that osteosarcoma is the malignancy of a multipotential connective tissue cell which forms callus in normal osteogenesis.
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PMID:Ultrastructure of human osteosarcoma. Malignant transformation of a multipotential connective tissue cell. 695 51

Six cases of osteosarcoma, 5 cases of chondrosarcoma, and 6 cases of giant cell tumor of bone were studied by electron microscopy. The cells comprising osteosarcoma were basically osteoblasts and in addition to them, malignant chondrocytes, myofibroblasts and undifferentiated cells. The ratio of number of these cells were variable according to the portions designated microscopically as osteoblastic, chondroblastic and fibroblastic. Previous ultrastructural studies on osteosarcoma have scarcely revealed the presence of myofibroblasts. It is likely that osteosarcoma arises from undifferentiated mesenchymal cells capable of differentiating into various cells such as osteoblasts, chondroblasts, and fibroblasts; especially capable of differentiating into osteoblasts. On the other hand, chondrosarcoma was composed of the cells in the series of maturation from undifferentiated cells to chondrocytes. In high-grade malignant cases, glycogen particles and rough endoplasmic reticulum became less conspicuous, and occasionally malignant multinucleated cells were seen. In one case, endoplasmic reticular inclusions which were thought to be viral nucleocapsid by some authors were found. They, however, seemed to be formed by condensation of intracisternal granular material secreted by the rough endoplasmic reticulum. The cells comprising giant cell tumor of bone were multinucleated giant cells and stromal cells classified into four types. In a malignant case, giant cells showed no remarkable morphological change while stromal cells underwent an atypical change. This finding suggests that the mononuclear stromal cells are the principal tumor cells and the establishment of histological grading should mainly depend on the atypism of stromal cells. The tumor is likely to originate from undifferentiated mesenchymal cells which have the tendency of histiocytic and fibroblastic differentiation. The morphogenesis of multinucleated giant cells is not clarified in this study. Although the possibility that stromal cells are the origin of giant cells is still remained, it could also be speculated that giant cells are somehow related to immune response to the tumor having macrophage-related origin.
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PMID:Electron microscopy of bone tumors--osteosarcoma, chondrosarcoma, giant cell tumor of bone. 696 Jan

Two rat osteosarcoma cell lines, YROS-1 and YROS-2, were established from two experimental osteosarcomas and induced by internal irradiation with radioactive phosphorus. Both cell lines formed a monolayer cell sheet in vitro with focal piling. The YROS-1 cells were refractile and spindle or polygonal in shape, whereas the YROS-2 cells were flat, spread and polygonal in shape. Ultrastructurally, the YROS-1 cells had well-developed rough-surfaced endoplasmic reticulum with focal pericellular deposition of calcified matrix, whereas YROS-2 had abundant polysomes and intracytoplasmic filaments. Both cell lines grew stably with population doubling times of 23 and 39 h, respectively. Flow cytometry revealed that YROS-1 was rich in proliferating cells compared to YROS-2, with a higher colony-forming efficiency. YROS-1 showed high alkaline phosphatase activity, while YROS-2 possessed low activity. When subcutaneously transplanted into lumbodorsal area of athymic nude mice, only YROS-1 formed tumors with frequent lung metastasis.
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PMID:Establishment of two rat osteosarcoma cell lines (YROS-1 and YROS-2) induced by radioactive phosphorus. 747 67

A new cell line has been established directly from a spontaneous osteosarcoma on the femur of a 1.5-year-old male mongrel dog and named POS. Doubling time of the cells was approximately 33 hr. Morphologically, spherical cells, fibroblast-like cells, large or small polygonal cells and multinucleated giant cells seemed to be the major component of this cell line. The transmission electron microscopic feature of most of the cells was abundant dilated rough endoplasmic reticulum. Alkaline phosphatase activity as one of the osteoblastic properties was high in this cell line. The tumor tissue produced by the inoculation of the cells into nude mice was histologically identical to the original osteosarcoma.
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PMID:Establishment and characterization of a new cell line from a canine osteosarcoma. 769 11

Sequence information for aspartyl beta-hydroxylase (AspH), which specifically hydroxylates one Asp or Asn residue in certain epidermal growth factor (EGF)-like domains of a number of proteins, is so far only described for bovine species. We have isolated a 4.3-kb cDNA encoding the human AspH (hAspH) by immunoscreening of a human osteosarcoma (MG63) cDNA library in lambda ZAP with an antiserum raised against membrane fractions of these cells. Northern blot analyses revealed two transcripts with lengths of 2.6 and 4.3 kb. The deduced amino acid (aa) sequence of this cDNA encodes a protein of 757 aa (85 kDa). Comparison with the deduced bovine AspH (bAspH) aa sequence showed striking differences in the N-terminal portion of this protein. In vitro transcription and translation in the presence of canine pancreas microsomes yielded a 56-kDa protein. Western blot analyses of membrane fractions from MG63 cells with AspH-specific antibodies revealed a protein of the same M(r). These results suggest a posttranslational cleavage of the catalytic C terminus in the lumen of the endoplasmic reticulum.
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PMID:Cloning and characterization of the human gene encoding aspartyl beta-hydroxylase. 782 14


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