Search results for "osteoclast"

Increased TNF-alfa, IL-6 and decreased IL-1beta immunohistochemical expression by the stromal spindle-shaped cells in the central giant cell granulom…

2010

Objectives: the exp ress ion of the osteoclastogenic cytokines TNF-α, IL-6 and IL-1β were immunohistochemically evaluated in periph eral (PGCG) and central (CGCG) giant cell granulomas of the jaws in order to determine diff erences between these two lesions and between the two distinct tumor cell populations (multinucleated giant cells, MGCs and stromal sp indle-sh aped cells). Study Design: Paraffin-embedd ed tiss ue sections from 40 PGCG and 40 CGCG were immunohistochemically stained using antibodies against TNF-α, IL-6 and IL-1β. The percentage of positively stained cells and the staining intensity were ass ess ed to provide a combined immunoreactivity score value. Results: TNF-α, IL-6 a…

Jaw osteonecrosis management around a dental implant inserted 2 years before starting treatment with zoledronic acid

2015

Journal Article; Bisphosphonates (BP) are a type of drug known to inhibit bone resorption through complex interventions. Their primary mechanism of action is aimed at the cellular level, inhibiting osteoclast activity and so bone resorption. BPs are widely used, with many patients receiving continuous treatment for years. But it is well known that these drugs can produce osteonecrosis of the jaw (ONJ). Zoledronic acid (ZA) is an intravenous BP used in the treatment and prophylaxis of bone disease in patients with malignant tumors with bone implication. ZA is the most potent BP in clinical development. This report describes the case of a 62-year-old woman with breast cancer antecedents which…

Inflammation in the Human Periodontium Induces Downregulation of the α1- and β1-Subunits of the sGC in Cementoclasts

2021

Nitric oxide (NO) binds to soluble guanylyl cyclase (sGC), activates it in a reduced oxidized heme iron state, and generates cyclic Guanosine Monophosphate (cGMP), which results in vasodilatation and inhibition of osteoclast activity. In inflammation, sGC is oxidized and becomes insensitive to NO. NO- and heme-independent activation of sGC requires protein expression of the &alpha

Experimental models of orthodontic tooth movement and their effects on periodontal tissues remodelling.

2021

Made available in DSpace on 2022-04-29T08:31:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Objectives: The present study aimed to compare two different models of orthodontic tooth movement (OTM) in rats by evaluating tooth movement efficiency and periodontal tissues remodelling. Design: Fifteen animals were randomly distributed into 3 groups: control group (untreated); ligature appliance (LA) as experimental OTM using a closed coil spring fixed around maxillary first molar by steel ligature; occlusal appliance (OA) as experimental OTM using a closed coil spring attached on the occlusal surface of the maxillary f…

Inorganic Polyphosphates: Biologically Active Biopolymers for Biomedical Applications

2013

Inorganic polyphosphate (polyP) is a widely occurring but only rarely investigated biopolymer which exists in both prokaryotic and eukaryotic organisms. Only in the last few years, this polymer has been identified to cause morphogenetic activity on cells involved in human bone formation. The calcium complex of polyP was found to display a dual effect on bone-forming osteoblasts and bone-resorbing osteoclasts. Exposure of these cells to polyP (Ca2+ complex) elicits the expression of cytokines that promote the mineralization process by osteoblasts and suppress the differentiation of osteoclast precursor cells to the functionally active mature osteoclasts dissolving bone minerals. The effect o…

Mechanisms of Disease: molecular insights into aseptic loosening of orthopedic implants

2007

Despite the success of treating rheumatic disorders with biologic therapies, joint replacement surgery still remains the final treatment option in many cases. Approximately 1.5 million joint arthroplastic operations are performed annually worldwide. Implant failure due to massive bone loss and aseptic loosening of prostheses, however, is a major complication of joint replacement, which can lead to high socioeconomic burdens both for the individual patient and for health-care systems. To date, there is no approved drug therapy to prevent or inhibit periprosthetic osteolysis, and aseptic loosening of prostheses can only be overcome by surgical revision. Research during the past decade, howeve…

Biosilica-loaded poly(ϵ-caprolactone) nanofibers mats provide a morphogenetically active surface scaffold for the growth and mineralization of the os…

2014

Bioprinting/3D cell printing procedures for the preparation of scaffolds/implants have the potential to revolutionize regenerative medicine. Besides biocompatibility and biodegradability, the hardness of the scaffold material is of critical importance to allow sufficient mechanical protection and, to the same extent, allow migration, cell–cell, and cell–substrate contact formation of the matrix-embedded cells. In the present study, we present a strategy to encase a bioprinted, cell-containing, and soft scaffold with an electrospun mat. The electrospun poly(e-caprolactone) (PCL) nanofibers mats, containing tetraethyl orthosilicate (TEOS), were subsequently incubated with silicatein. Silicate…

The Deep-Sea Natural Products, Biogenic Polyphosphate (Bio-PolyP) and Biogenic Silica (Bio-Silica), as Biomimetic Scaffolds for Bone Tissue Engineeri…

2013

Bone defects in human, caused by fractures/nonunions or trauma, gain increasing impact and have become a medical challenge in the present-day aging population. Frequently, those fractures require surgical intervention which ideally relies on autografts or suboptimally on allografts. Therefore, it is pressing and likewise challenging to develop bone substitution materials to heal bone defects. During the differentiation of osteoblasts from their mesenchymal progenitor/stem cells and of osteoclasts from their hemopoietic precursor cells, a lineage-specific release of growth factors and a trans-lineage homeostatic cross-talk via signaling molecules take place. Hence, the major hurdle is to fab…

Effects of exosomes released by NSCLC cells on osteoclasts differentiation.

Effects of exosomes released by NSCLC cells on osteoclasts differentiation Pucci M., Taverna S., Corrado C., Giallombardo M., Rolfo C. and Alessandro R. Non-small cell lung cancer (NSCLC) has a poorly 5-year survival rate, as a consequence of the delay in the detection of the disease. The majority of patients are diagnosed in an advanced disease stage. Bone metastasis is the most frequent complication in NSCLC resulting in osteolytic lesions. The perfect balance between bone-resorbing osteoclasts (OCs) and bone-forming osteoblasts (OBs) activity is lost in bone metastasis, inducing osteoclastogenesis. Most of the patients with lung cancer are treated with EGFR inhibitors (TKIs). Numerous st…

IL RANK LIGANDO QUALE TARGET TERAPEUTICO NEL TRATTAMENTO DELLE PAZIENTI ANZIANE CON OSTEOPOROSI

2013

Cortical and trabecular bone undergo a continuous and balanced remodeling process, which consists of a phase of resorption, mediated by osteoclasts, and a phase of neoformation mediated by osteoblasts. The activity of both, osteoblasts and osteoclasts, is regulated by the osteocytes, which are the most abundant cells in bone tissue. An imbalance of this process with an excessive resorption activity causes a loss of bone mass and microarchitectural deterioration of the skeleton, with consequent reduction of bone strength and increased risk of fractures. The ligand for the “Receptor Activator of Nuclear Factor Kappa- B” (RANK-L), a protein expressed by osteoblasts, plays a fundamental role in…