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

A cell line, MCO-Y4, was established from a mammary gland osteosarcoma of a 16-year-old female mongrel dog. Histopathologically the tumor was composed of osteoblastic cells with an osteoid meshwork and chondroid matrix. The mean doubling time of the cells at the 93rd passage was 32.39+/-4.66 hr. Immunohistochemically, the osteoblastic and chondroblastic cells were positive for bone morphogenetic protein (BMP)-2/4 and BMP receptor (BMPR) II. The cultured cells were spindle in shape during the growth and the confluent phases. No tumor matrix was detected in the culture dish by alcian blue staining or von-Kossa silver impregnation. MCO-Y4 cells on the chamber slides showed intense immunoreactivity for BMP-2/4 and BMPR II. Noggin, an antagonist for BMP-2/4, showed the growth inhibition on MCO-Y4 cells. In addition, fibronectin might be potential for stimulating growth of MCO-Y4 cells. When transplanted into severe combined immunodeficiency mice, the cells formed tumors consisting of solid proliferation of osteoblastic and fibroblastic cells with woven-bone trabeculae. These tumor cells were intensely positive for BMP-2/4 and BMPR II. Our results suggested that the cell line might be useful for studying the role of BMPs in canine osteosarcoma and the mechanism of ossification.
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PMID:Establishment and characterization of a cell line, MCO-Y4, derived from canine mammary gland osteosarcoma. 1708 82

Purpose. The antimicrobial effect of a silver-coated tumor endoprosthesis has been proven in clinical and experimental trials. However, in the literature there are no reports concerning the effect of elementary silver on osteoblast behaviour. Therefore, the prosthetic stem was not silver-coated because of concerns regarding a possible inhibition of the osseointegration. The aim of the present study was to investigate the effect of 5-25 mg of elementary silver in comparison to Ti-6Al-4V on human osteosarcoma cell lines (HOS-58, SAOS). Methods. Cell viability was determined by measuring the MTT proliferation rate. Cell function was studied by measuring alkaline phosphatase (AP) activity and osteocalcine production. Results. In the HOS-58 cells, the AP activity was statistically significant (P < 0.05) higher at a supplement of 5-10 mg of silver than of Ti-6 Al-4V at the same doses. For both cell lines, a supplement above 10 mg of silver resulted in a reduced AP activity in comparision to the Ti-6 Al-4V group, but a statistically significant difference (P < 0.05) was observed at a dose of 25 mg for the SAOS cells only. At doses of 20-25 mg in the HOS-58 cells and 10-25 mg in the SAOS cells, the reduction of the proliferation rate by silver was statistically significant (P < 0.05) compared to the Ti-6 Al-4V supplement. Discussion. In conclusion, elementary silver exhibits no cytotoxicity at low concentrations. In contrast, it seems to be superior to Ti-6 Al-4V concerning the stimulation of osteogenic maturation at these concentrations, whereas at higher doses it causes the known cytotoxic properties.
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PMID:The influence of elementary silver versus titanium on osteoblasts behaviour in vitro using human osteosarcoma cell lines. 1768 31

Maxillary osteosarcomas are a relatively frequent malignant tumor of the oral cavity. Similarly to other skeletal osteosarcomas, they exhibit different cellular differentiation patterns, i.e. chondroblastic, osteoblastic, or fibroblastic. Although their histological features resemble those of osteosarcomas of the long bones, their pattern of evolution usually differs. Morphometric variations in silver stained Nucleolar Organizer Regions (AgNOR) have proved of value to study the biology of several tumors. However, information on the analysis of AgNOR in maxillary tumors is scarce. The aim of the present study was to analyze the variations of different morphological parameters related to AgNOR in a series of 32 cases of maxillary osteosarcoma. In each case we analyzed 100 nuclei corresponding to the prevalent cellular differentiation type, selecting the most aggressive area. We employed software previously developed at our laboratory that yields information on different AgNOR-related parameters. The results were compared with those previously reported in a study on 12 cases of osteosarcoma of long bones. Six cases of oral mucosa squamous cell carcinoma were also included for comparative purposes. Single AgNOR volume proved to be the most discriminatory and informative parameter. The value of single AgNOR volume was considerably lower in mandible osteosarcomas than in osteosarcomas of the upper maxilla (p=0.02). The values were significantly lower in maxillary osteosarcomas than in long bone osteosarcomas and in oral carcinomas. This finding would suggest a slower rate of cell activity in maxillary osteosarcomas, associated in turn to its known lower degree of aggressiveness. The present results suggest that the analysis of AgNOR is a valuable and easily applicable marker to determine the degree of malignancy and biology of maxillary osteosarcomas.
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PMID:Evaluation of nucleolar organizer regions in maxillary osteosarcoma. 1804 71

Silver (or platinum)-containing calcium phosphate (hydroxyapatite (HA) and tricalcium phosphate (alpha-TCP)) coatings on titanium substrates were formed by micro-arc oxidation (MAO) and their in vitro antibacterial activity and in vitro cytotoxicity were evaluated. MAO was performed in an electrolytic solution containing beta-glycerophosphate disodium salt pentahydrate (beta-GP) and calcium acetate monohydrate (CA), and Ag and Pt were introduced in the form of AgNO(3) (or CH(3)COOAg) and H(2)PtCl(6), respectively. The MG63 and human osteosarcoma (HOS) cell lines were used to investigate the proliferation and differentiation behavior of the cells, respectively, whereas two strains of bacteria, Staphylococcus aureus and Escherichia coli, were used to evaluate the antibacterial activity of the coatings. The phase, morphology, and Ag content of the coatings were strongly dependent on the applied voltage and Ag precursor concentration. HA and alpha-TCP phases were detected in the coatings oxidized above 400 V and the presence of Ag was confirmed by EDS. While the coatings with a high content of Ag were cytotoxic and those obtained in the Pt-containing electrolyte had no apparent antibacterial activity, the calcium phosphate coatings obtained in the low Ag concentration electrolyte exhibited in vitro antibacterial activity but no cytotoxicity. Thus, biocompatible calcium phosphate coatings on Ti implants with antibacterial activity can be achieved by one-step MAO.
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PMID:Antibacterial properties of Ag (or Pt)-containing calcium phosphate coatings formed by micro-arc oxidation. 1828 18

To identify new biomarkers that facilitate the accurate early diagnosis of osteosarcoma and that may possibly include novel therapeutic candidates, we performed a proteomic approach to compare osteosarcoma cells and human primary cultured osteoblastic cells. Image analysis of silver-stained 2-DE gels revealed that the level of 12 protein spots was significantly different between the two groups of samples (p < .004). After mass spectroscopic identification and database searches, we found that in osteosarcoma cells, the level of HSP70, actin capping protein, ATP synthase, Mthsp75, UQCRC1, Ras-related nuclear protein, UCH-L1, and PRDX4 was elevated. However, the level of pyruvate dehydrogenase E1, Prohibitin, and Annexin V was decreased. Subsequent Western blot analyses of UQCRC1, UCH-L1, and PRDX4 in osteosarcoma tissues confirmed the results obtained by the proteomic analyses. These identified proteins may be potential molecular targets for osteosarcomatous diagnostics and therapeutics.
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PMID:Comparative proteomic analysis of osteosarcoma cell and human primary cultured osteoblastic cell. 1921 29

In this paper, we demonstrate how a simple fabrication route, i.e., pressureless sintering of mechanically mixed powders can be employed to develop hydroxyapatite (HAp, Ca(10)(PO(4))(6)(OH)(2))-silver (Ag) bioceramic composites with superior combination of physical (hardness, toughness), non-cytotoxicity, cytocompatiblity and anti-microbial property. The densification results show that such composites can be sintered at 1200 degrees C for 2 h near to theoretical density (>98% rho(th).) An important observation is that the dissociation of HAp phase can be prevented during sintering up to 1300 degrees C for 2 h in HAp-10 wt% Ag composites. The stability of HAp in presence of silver is discussed in reference to the results obtained using XRD, FTIR and Raman spectroscopy. The hardness values of the composites are comparable (approximately 6.5 GPa) to that of pure HAp, despite of the presence of softer Ag particles. The sintered composites exhibit modest crack growth resistance property and their toughness varies in the range of 0.9-1.2 MPa m(0.5), depending on sintering temperature. For selected samples, the in vitro characterization was performed using mouse fibroblast (L929) and human osteosarcoma (MG63) cell lines. The combination of biochemical assays (MTT, ALP and osteocalcin) confirm that HAp-10 wt% Ag biocomposites have comparable or even better cellular viability, osteogenic differentiation and bone mineralization as well as osteoinduction property. Antibacterial experiments involving gram-negative bacteria, Escherichia coli confirm excellent bactericidal property of HAp-10 wt% Ag composites, sintered using mechanically mixed powders.
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PMID:Densification, phase stability and in vitro biocompatibility property of hydroxyapatite-10 wt% silver composites. 1996 32

In this study, a bio-composite scaffold containing chitosan/nano-hydroxyapatite/nano-silver particles (CS/nHAp/nAg) was developed by freeze drying technique, followed by introduction of silver ions in controlled amount through reduction phenomenon by functional groups of chitosan. The scaffolds were characterized using SEM, FT-IR, XRD, swelling, and biodegradation studies. The testing of the prepared scaffolds with Gram-positive and Gram-negative bacterial strains showed antibacterial activity. The scaffold materials were also found to be non-toxic to rat osteoprogenitor cells and human osteosarcoma cell line. Thus, these results suggested that CS/nHAp/nAg bio-composite scaffolds have the potential in controlling implant associated bacterial infection during reconstructive surgery of bone.
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PMID:Preparation, characterization and antimicrobial activity of a bio-composite scaffold containing chitosan/nano-hydroxyapatite/nano-silver for bone tissue engineering. 2154 47

The present work is aimed at the synthesis of antibacterial and bioactive silver/magnesium co-substituted hydroxyapatite (Ag/Mg-HAP) powders. For this purpose, firstly, different concentrations (0.5, 1.5, 2.5wt.%) of silver substituted HAP (Ag-HAP) powders were prepared by ultrasonic irradiation technique and were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Secondly, magnesium (Mg) is co-substituted as secondary material into Ag-HAP to offset the potential cytotoxicity of Ag, as higher concentration of Ag is toxic. The antibacterial activity of as-synthesized powders was evaluated by Escherichia coli (E. coli) and was found to be effectively high against bacterial colonization. Also, the in vitro cell-material interaction is evaluated with human osteosarcoma MG63 (HOS MG63) cells for cell proliferation. The results showed the evidence of cytotoxic effects of the higher concentration of Ag-HAP characterized by poor cellular viability whereas, Ag/Mg-HAP showed better cell viability indicating that co-substitution of Mg in Ag-HAP effectively offset the negative effects of Ag and improve performance compared with pure HAP. Thus, the as synthesized Ag/Mg-HAP will serve as a better candidate for biomedical applications with good antibacterial property and bone bonding ability.
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PMID:Synthesis and spectral characterization of silver/magnesium co-substituted hydroxyapatite for biomedical applications. 2463 37

We present a patient with dermal argyria as a cutaneous manifestation of a silver-coated megaprosthesis used for a distal femoral osteosarcoma. Histological and electron microscopic analyses also showed silver deposition in the dermis.
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PMID:Dermal argyria: Cutaneous manifestation of a megaprosthesis for distal femoral osteosarcoma. 2493 42

Optical microscopy modalities that achieve spatial resolution beyond the resolution limit have opened up new opportunities in the biomedical sciences to reveal the structure and kinetics of biological processes on the nanoscale. These methods are, however, mostly restricted to fluorescence as contrast mechanism, which limits the ultimate spatial resolution and observation time that can be achieved by photobleaching of the fluorescent probes. Here, we demonstrate that Raman scattering provides a valuable contrast mechanism for optical nanoscopy in the form of super-resolution structured illumination microscopy. We find that nanotags, i.e., gold and silver nanoparticles that are capable of surface-enhanced Raman scattering (SERS), can be imaged with a spatial resolution beyond the diffraction limit in four dimensions alongside and with similar excitation power as fluorescent probes. The highly polarized nature of super-resolution structured illumination microscopy renders these nanotags elliptical in the reconstructed super-resolved images, which enables us to determine their orientation within the sample. The robustness of nanotags against photobleaching allows us to image these particles for unlimited periods of time. We demonstrate this by imaging isolated nanotags in a dense layer of fluorophores, as well as on the surface of and after internalization by osteosarcoma cells, always in the presence of fluorescent probes. Our results show that SERS nanotags have the potential to become highly multiplexed and chemically sensitive optical probes for optical nanoscopy that can replace fluorophores in applications where fluorescence photobleaching is prohibitive for following the evolution of biological processes for extended times.
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PMID:Nanoparticles as Nonfluorescent Analogues of Fluorophores for Optical Nanoscopy. 2595 Sep 94


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