Search results for "osteoclast"
showing 10 items of 77 documents
Otite media atelettasica, adesiva, timpanosclerotica: update medico e chirurgico
2011
Otitis media secretive is one of the most common ear diseases characterized by frequent sequelae and complications; in particular the authors describe middle ear atelectasis with pocket retraction of tympanic membrane, pocket retraction limited to pars tensa or to pars flaccida, adhesive otitis media, partial or total myringosclerosis and tympanosclerosis. For each disease the Authors comment the best surgical approaches to preserve and restore conductive hearing loss. As for middle ear atelectasis, adhesive otitis media, myringosclerosis and partial tympanosclerosis it was evidenced a significant hearing gain while in total tympanosclerosis there was an initial hearing improvement in a sho…
Desarrollo de sistemas mesoporosos con puertas moleculares para el transporte y la liberación selectiva y controlada de fármacos
2019
La presente tesis doctoral titulada “Desarrollo de sistemas mesoporosos con puertas moleculares para el transporte y la liberación selectiva y controlada de fármacos” se centra en la síntesis de materiales híbridos orgánico-inorgánicos. Estos materiales están compuestos por un material mesoporoso inorgánico que actúa como reservorio (en el cual introducir un colorante o un fármaco) y por una puerta molecular, que es una estructura química de naturaleza orgánica que permite la liberación selectiva y controlada de las moléculas presentes en el interior de las partículas porosas, y que puede adoptar dos posiciones, abierta o cerrada, siendo el cambio de estado inducido por un estímulo externo.…
Efectos inmunomoduladores y antirresortivos de osteostatina en artritis experimental y en células humanas
2021
La artritis reumatoide es una enfermedad inflamatoria y autoinmune crónica que afecta principalmente a las articulaciones. Se produce una inflamación articular que daña las diferentes estructuras deformándolas, llegando a incapacitar al paciente. Se caracteriza por inflamación de la membrana sinovial con infiltración de células inmunes, degradación del cartílago, con muerte de condrocitos, y destrucción del hueso por desregulación del mecanismo de degradación-reparación. La activación aberrante de las células presentadoras de antígeno frente a antígenos propios modificados inicia una cascada inflamatoria que lleva a la activación linfocitaria contra este antígeno, la proliferación de linfoc…
Synovial giant cells in rheumatoid arthritis: Expression of cystatin C, but not of cathepsin B
2000
This study was designed to investigate the expression of the matrix degrading proteinase cathepsin B and its endogenous inhibitor cystatin C in rheumatoid arthritis (RA) with special regard to multinucleated synovial giant cells (SGC). We applied an immunohistochemical double-labeling technique. SGC strongly expressed cystatin C and CD68, but were negative for cathepsin B. This staining pattern occurred in osteoclasts as well. Our findings support the idea that in RA matrix destruction by cathepsin B is not mediated by SGC or osteoclasts, but by mononuclear synoviocytes.
Osteoclast Immunosuppressive Effects in Multiple Myeloma: Role of Programmed Cell Death Ligand 1
2018
Immunomodulatory drugs and monoclonal antibody-based immunotherapies have significantly improved the prognosis of the patients with multiple myeloma (MM) in the recent years. These new classes of reagents target malignant plasma cells (PCs) and further modulate the immune microenvironment, which prolongs anti-MM responses and may prevent tumor occurrence. Since MM remains an incurable cancer for most patients, there continues to be a need to identify new tumor target molecules and investigate alternative cellular approaches using gene therapeutic strategies and novel treatment mechanisms. Osteoclasts (OCs), as critical multi-nucleated large cells responsible for bone destruction in >80% …
Dose-dependent osteoinductive effects of bFGF in rabbits.
2009
Growth factors lead to the induction of tissue regeneration in bone healing when coated on biomaterials. Basic fibroblast growth factor (bFGF) combines osteoinduction and neoangiogenesis. This study evaluated bFGF-coated hydroxylapatite implants in two experimental groups with 10 or 100 microg (n = 5 per group) compared with uncoated control implants in the rabbit patellar groove model. We observed an unexpected ineffectiveness compared to the control groups with no significant difference of bone growth after 35 days. However, all samples from the 100 microg experiment (control and coated implant) showed significantly stronger 19-25 day label than both 10 microg groups (control and coated i…
Tartrate-Resistant Acid Phosphatase 5b: A Novel Serum Marker of Bone Resorption
2000
Human serum contains two forms of tartrate-resistant acid phosphatase (TRAP), 5a and 5b. Of these, 5a contains sialic acid and 5b does not. We show here that antigenic properties and pH optimum of TRAP purified from human osteoclasts are identical to those of serum TRAP 5b and completely different from those of serum TRAP 5a, suggesting that 5b would be derived from osteoclasts and 5a from some other source. We developed a novel immunoassay specific for 5b using a monoclonal antibody O1A as capture antibody. O1A did not bind acid phosphatase derived from platelets and erythrocytes. Western analysis showed that O1A was specific for TRAP in both human bone and serum. We measured bound TRAP ac…
Alendronate-associated osteonecrosis of the jaws: a review of the main topics
2013
Bisphosphonates is a group of inorganic pyrophosphates analogues that suppress bone resorption by inducing osteoclast inactivation, being frequently used for management of diseases affecting bone metabolism, bone metastases and bone tumors. However, since 2003 many cases describing the presence of necrotic bone exposures in the jaws have been described in patients receiving these drugs, what represent a significant complication of bisphosphonates treatment. The overall incidence of bisphosphonate-related osteonecrosis of the jaws is low, ranging from 0.7% to 12%, mainly observed in those patients receiving intravenously treatment. Osteonecrosis of the jaws associated to oral bisphosphonate,…
Progestogens and risk of breast cancer: a link between bone and breast?
2015
This article reviews the data supporting the role of receptor activator of the nuclear factor kappa (RANK) and its ligand, RANKL, in progestogen-induced breast cancer. Both experimental and clinical studies have been included. The expression of both RANK and RANKL has been described in epithelial cells of both mice and humans. Experiments of gain and loss of function in mice have shown that RANK/RANKL mediate alveologenesis during pregnancy or the estrous cycle. Moreover, the participation of the RANK/RANKL has been detected in models of breast carcinogenesis associated with progestogens-like medroxyprogesterone acetate. Recent clinical studies have found that the expression of RANK is asso…
An approach to a biomimetic bone scaffold: increased expression of BMP-2 and of osteoprotegerin in SaOS-2 cells grown onto silica-biologized 3D print…
2012
Three-dimensional printed (3D printed) bone material is needed to close the shortage and to avoid the potential health risks associated with autografts and allografts, in the treatment of bone fractures/nonunions or bone trauma. Here we describe the fabrication of 3D printed scaffold, initially prepared form Ca-sulfate that has been impregnated/biologized with Ca-phosphate or with silica. The 3D printed grids had a size mesh of 200 μm; the chemical composition was determined by energy dispersive X-ray spectroscopy or conventional chemical analysis. Using human SaOS-2 cells (human osteogenic cells) it is shown that both the Ca-sulfate, and the Ca-phosphate or the silica impregnated Ca-sulfat…