UMLS:C0265264 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0265264 (HOS)
1,119 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Different types of calcium phosphates [hydroxyapatite (HA), fluorapatite (FA), tricalcium phosphate (TCP), and their composites (HA + FA, HA + TCP)] were coated on a zirconia (ZrO(2)) porous scaffold using a powder slurry method. The ZrO(2) porous scaffold was intended for a load-bearing implant, and the apatite layers were coated to improve osteoconductivity. The insertion of an FA intermediate layer between the coating layer and ZrO(2) scaffold effectively suppressed the reaction between the calcium phosphate and ZrO(2) and maintained the coating layer at the initial powder composition. The obtained coating layer, of a thickness of approximately 30 microm, was relatively microporous and firmly adherent to the ZrO(2) scaffold. Dissolution tests in physiological solution showed typical differences depending on the coating layers, with the dissolution rate increasing in the order TCP > HA + TCP > HA > HA + FA > FA. This result suggests the functional coating of the calcium phosphates in view of tailoring the solubility. Osteoblast-like cells, MG63 and HOS, responded similarly in terms of cell growth, morphology, and proliferation rate regardless of the coating types, indicating favorable and comparable cell viability. However, the alkaline phosphatase (ALP) activity of the cells on the pure HA and HA composite coatings (HA + FA and HA + TCP) expressed at higher levels compared to those on pure FA and pure TCP coatings for both MG63 and HOS cells, suggesting a selective cell activity depending on the coating types. All the calcium phosphate-coated-ZrO(2) scaffolds showed higher ALP levels compared to pure ZrO(2) scaffold.
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PMID:Dissolution control and cellular responses of calcium phosphate coatings on zirconia porous scaffold. 1476 32

The effects of six particulate metals (Al, Ti, Zr, Nb, Ta and Cr) on cell viability and alkaline phosphatase (ALP) activity were studied in vitro using two types of osteoblast-like cells, MG-63 and HOS cells. The cell viability in the presence of Al, Ti and Zr was depressed at lower concentrations than in the presence of Nb, Ta and Cr. The average sizes of the Al, Ti, Zr, Nb, Ta and Cr particulates were 6.48 microm, 16.99 microm, 5.07 microm, 14.18 microm, 8.32 microm and 23.27 microm respectively. The interaction of HOS cells with the particulates was more sensitive than that of MG-63 cells. ALP activity increased at higher concentrations only with the Al particulates; other experimental conditions did not exert an influence on ALP activity. These findings suggest that the cell viability of osteoblast-like cells might be influenced by particulate size and metal type, but ALP activity was not influenced by these factors.
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PMID:Effects of six particulate metals on osteoblast-like MG-63 and HOS cells in vitro. 1500 28

A double-layered coating, consisting of a hydroxyapatite (HA) outer film and a fluor-hydroxyapatite (FHA) inner film, was produced on a Ti substrate by a sol-gel route to improve the biocompatibility and functionality of the system. Dissolution behavior of and in vitro cellular responses to the layered film were investigated. Calcium nitrate and triethyl phosphite were used for calcium and phosphate precursors, respectively, and ammonium fluoride was added as a fluorine-ion source for FHA. The FHA layer was deposited on Ti by spin coating and subsequent heat treatment at 550 degrees C for 30 min in air, and then the HA layer was laid down over the FHA-coated Ti under the same conditions. After heat treatment, characteristic apatite structures and phases were developed on both FHA and HA films. The cross-section view of the HA/FHA film clearly showed a double-layered structure on Ti with each layer approximately 0.6-0.8-microm thickness. The coating layer was highly uniform and dense, and adhered to Ti substrate strongly with an adhesion strength of about 40 MPa. The in vitro solubility of the HA/FHA layered film in a physiological solution was between that of HA and FHA pure film, and the dissolution profile was quite biphasic, that is, an initial rapid period and a slowdown with increasing time, reflecting the gradient solubility of the fast HA outer structure/slow FHA inner structure. The human osteoblast-like HOS TE85 cells cultured on the HA/FHA layered film attached, spread, and grew favorably. The proliferation rate of the cells on the layered film was significantly higher (considered at p < 0.05 for n = 6) than that on Ti substrate and was similar to that on pure HA film. The alkaline phosphatase (ALP) activity and osteocalcin (OC) produced by the cells on the layered film were significantly higher (considered at p < 0.05 for n = 6) than those on Ti substrate. Moreover, the ALP and OC levels of cells on the layered film showed the trends of HA outer/FHA inner structure with respect to culture period, that is, HA initially and FHA later. These observations suggest that the HA/FHA layered film on Ti obtained by a sol-gel route possesses gradient functionality in terms of solubility and cellular responses, and find that those parameters can be tailored for specific use in hard-tissue implants.
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PMID:Hydroxyapatite and fluor-hydroxyapatite layered film on titanium processed by a sol-gel route for hard-tissue implants. 1536 29

In this article we describe the expansion of in vitro osteogenic capability of human osteoblasts (HOS cells) after sorting by fluorescence-activated cell sorting (FACS) with the osteoblastic marker of human bone alkaline phosphatase (AP) monoclonal antibody. After culturing for 7 days, the HOS cells were incubated with fluorescein isothiocyanate (FITC)-labeled AP monoclonal antibody. The antibody recognized the cells with high AP activity (high AP cells), which were about 76% of the total cells. After the HOS cells were sorted, the high AP cells could be recovered, and almost all of them reacted strongly with the AP antibody. Therefore, we were able to condense the high AP cells about 1.3 times. We further cultured the sorted cells as well as the unsorted control cells. After the initial seeding, the culturing periods for both groups of cells were 20 days. At the end of this period, we measured AP activity per DNA and osteocalcin contents. In contrast to the low condensation ratio of the high AP cells in the sorted fraction, the AP activity and osteocalcin contents were about nine times and four times greater than those of the unsorted cells, respectively. These results demonstrated that using the sorting technique to isolate the high AP cells might be a useful method for applications in bone tissue engineering.
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PMID:Enhancement of in vitro osteoblastic potential after selective sorting of osteoblasts with high alkaline phosphatase activity from human osteoblast-like cells. 1546 79

Titanium (Ti) surface was coated with hydroxyapatite (HA) films via the sol-gel method. The coating properties, such as crystallinity and surface roughness, were controlled and their effects on the osteoblast-like cell responses were investigated. The film crystallinity was controlled with different heat treatment temperatures (400, 500, and 600 degrees C): Also the surface roughness was changed by using different heating rates (1 and 50 degrees C/min). The obtained sol-gel films had a dense and homogeneous structure with a thickness about 1 mum. The film heat-treated at higher temperature had enhanced crystallinity (600>500>>400 degrees C), while retaining similar surface roughness. When heat-treated rapidly (50 degrees C/min), the film became quite rough, with roughness parameters being much higher (4-6 times) than that obtained at a low heating rate (1 degrees C/min). The dissolution rate of the film decreased with increasing crystallinity (400>>500>600 degrees C), and the rougher film had slightly higher dissolution rate. The attachment, proliferation, and differentiation behaviors of human osteosarcoma HOS TE85 cells were affected by the properties of the films. On the films with higher crystallinity (heat treated over 500 degrees C), the cells attached and proliferated well and expressed alkaline phosphatase (ALP) and osteocalcin (OC) to a higher degree as compared to the poorly crystallized film (heat treated at 400 degrees C). On the rough film, the cell attachment was enhanced, but the ALP and OC expression levels were similar as compared to the smooth films.
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PMID:Sol-gel-modified titanium with hydroxyapatite thin films and effect on osteoblast-like cell responses. 1601 54

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during tissue remodeling. MMPs, VEGF, Ki-67 (proliferative protein), and constituents of ECM play a critical role in angiogenesis and underlie neoplastic invasion and metastasis. This prompted us to investigate the effect of a diet containing lysine, proline, arginine, ascorbic acid, and green tea extract (NM) on the growth of tumors induced by implanting human osteosarcoma MNNG in athymic nude mice and the expression of MMPs, VEGF, Ki-67 and fibronectin in these tumors, as well as the production of mucin (by PAS staining). We also investigated the effect of the supplemented diet on serum ascorbic acid, total protein content, alkaline phosphatase activity, and liver enzymes. Athymic male nude mice (n = 12) were inoculated with 3 x 10(6) osteosarcoma cells MNNG-HOS and randomly divided into group A (fed a regular diet) and group B (fed a regular diet supplemented with 0.5% NM). Four weeks later, the mice were sacrificed. Results showed that NM inhibited the growth and reduced the size of tumors in nude mice. Histological evaluation revealed increased mitotic index, MMP-9, and VEGF secretion in the control group tissues. Results demonstrate that the nutrient mixture of lysine, proline, arginine, ascorbic acid, and green tea extract tested strongly suppressed the growth of tumors without adverse effects in nude mice, suggesting potential as an anticancer agent.
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PMID:Effect of ascorbic acid, lysine, proline, and green tea extract on human osteosarcoma cell line MNNG-HOS xenografts in nude mice: evaluation of tumor growth and immunohistochemistry. 1701 99

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

Silk fibroin protein, isolated from cocoons of the domesticated mulberry silkworm, Bombyx mori, finds extensive application in biomaterial design. In this study, poly(ethylene glycol) (PEG) 4000 has been used for blending fibroin from both B. mori and Antheraea mylitta, the wild tropical non-mulberry silkworm. PEG-blended films have shown marked changes from the pure fibroin films with respect to thermal properties and mechanical properties. FT-IR spectroscopy confirmed incorporation of new functional groups like quinone oximes. Pure fibroin and PEG-blended fibroin films showed biocompatibility with the HOS osteosarcoma cell line. Von Kossa staining confirmed nodule formation due to mineralization and differentiation of osteoblasts on pure and blended matrices. On account of increased surface roughness, higher elongation percentage, higher thermostability and better activity of osteoblasts in terms of intracellular alkaline phosphatase production, PEG-blended A. mylitta fibroin film shows better potential than PEG-blended B. mori fibroin film for use as potential biomaterial.
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PMID:Characterization of fibroin and PEG-blended fibroin matrices for in vitro adhesion and proliferation of osteoblasts. 1932 75

Osteosarcoma is the most common malignant bone tumour, with a peak incidence in children and young adolescents, suggesting a role of rapid bone growth in its pathogenesis. The Wnt/beta-catenin pathway plays a crucial role in skeletal development and is indispensable for osteoblasts' lineage determination. Previous studies suggesting an oncogenic role for the Wnt/beta-catenin pathway in osteosarcoma were based on cytoplasmic staining of beta-catenin or the detection of one component of this pathway. However, those approaches are inappropriate to address whether the Wnt/beta-catenin pathway is functionally active. Therefore, in this study, we examined nuclear beta-catenin expression in 52 human osteosarcoma biopsies, 15 osteoblastomas (benign bone tumours), and four human osteosarcoma cell lines by immunohistochemistry. Furthermore, we modulated Wnt/beta-catenin pathway activity using a GIN (GSK3beta inhibitor) and evaluated its effect on cell growth and osteogenic differentiation. Absence of nuclear beta-catenin staining was found in 90% of the biopsies and all osteosarcoma cell lines, whereas strong nuclear beta-catenin staining was observed in all osteoblastomas. Wnt-luciferase activity was comparable to the negative control in all osteosarcoma cell lines. GIN stimulated the Wnt/beta-catenin pathway, as shown by translocation of beta-catenin into the nucleus and increased Wnt-luciferase activity as well as mRNA expression of AXIN2, a specific downstream target gene. Stimulation of the Wnt/beta-catenin pathway by GIN significantly reduced cell proliferation in the cell lines MG-63 and U-2-OS and enhanced differentiation in the cell lines HOS and SJSA-1, as shown by an increase in alkaline phosphatase (ALP) activity and mineralization. In contrast with the oncogenic role of the Wnt/beta-catenin pathway in osteosarcoma as previous studies suggested, here we demonstrate that this pathway is inactivated in osteosarcoma. Moreover, activation of the Wnt/beta-catenin pathway inhibits cell proliferation or promotes osteogenic differentiation in osteosarcoma cell lines. Our data suggest that loss of Wnt/beta-catenin pathway activity, which is required for osteoblast differentiation, may contribute to osteosarcoma development.
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PMID:Inactive Wnt/beta-catenin pathway in conventional high-grade osteosarcoma. 1989 Aug 90

HOS cell is a model strain of human osteoblasts derived from human osteosarcoma. We cultured the HOS cells on both the conventional collagen gel (neutral gel), and the gamma-crosslinked collagen gel without collagen fibrils (acidic gel). The shape of HOS cells on the neutral gel was similar to that on the culture dish. However, HOS cells on acidic gel had an elongated shape and attached each other to form a mesh-like pattern. The cells attached to the surface of both gels but scarcely penetrated their depths. We measured the biochemical markers for osteogenic differentiation in the HOS cells cultured on both the neutral gel and the acidic gel. The expressions of alkaline phosphatase and osteocalcin were detected in the HOS cells on both types of collagen gel. Deposition of the calcium also occurred on both gels although it was higher in the neutral gel than the acidic one. These results indicate the importance of collagen for the differentiation of HOS cells, but it is not dependent on the molecular structure (fibril formation) of collagen.
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PMID:In vitro osteogenic differentiation of HOS cells on two types of collagen gels. 2054 62

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