Search results for "OSTEOCLAST"

Reaction of 3-Amino-1,2,4-Triazole with Diethyl Phosphite and Triethyl Orthoformate: Acid-Base Properties and Antiosteoporotic Activities of the Prod…

2017

The reaction of diethyl phosphite with triethyl orthoformate and a primary amine followed by hydrolysis is presented, and the reaction was suitable for the preparation of (aminomethylene)bisphosphonates. 3-Amino-1,2,4-triazole was chosen as an interesting substrate for this reaction because it possesses multiple groups that can serve as the amino component in the reaction-namely, the side-chain and triazole amines. This substrate readily forms 1,2,4-triazolyl-3-yl-aminomethylenebisphosphonic acid (compound 1) as a major product, along with N-ethylated bisphosphonates as side products. The in vitro antiproliferative effects of the synthesized aminomethylenebisphosphonic acids against J774E m…

Effects of zoledronic acid and dexamethasone on early phases of socket healing after tooth extraction in rats : a preliminary macroscopic and microsc…

2018

Background The exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) is still unknown. The aim of this paper was to investigate the effects of zoledronic acid and dexamethasone on the early phases of socket healing in rats subjected to tooth extractions. Material and Methods Thirty male Sprague-Dawley rats were divided into 2 groups: pharmacologically treated group (T, n=20) and non-pharmacologically treated group (C, n=10). T group rats received 0.1 mg/Kg of zoledronic acid (ZOL) and 1 mg/Kg of dexamethasone (DEX) three times a week for 10 consecutive weeks. C group rats were infused with vehicle. After 9 weeks from the first infusion, first maxillary molars were extrac…

Generation and function of the soluble interleukin-6 receptor

1999

Profilin 1 negatively regulates osteoclast migration in postnatal skeletal growth, remodeling, and homeostasis in mice

2019

ABSTRACT Profilin 1 (Pfn1), a regulator of actin polymerization, controls cell movement in a context‐dependent manner. Pfn1 supports the locomotion of most adherent cells by assisting actin‐filament elongation, as has been shown in skeletal progenitor cells in our previous study. However, because Pfn1 has also been known to inhibit migration of certain cells, including T cells, by suppressing branched‐end elongation of actin filaments, we hypothesized that its roles in osteoclasts may be different from that of osteoblasts. By investigating the osteoclasts in culture, we first verified that Pfn1‐knockdown (KD) enhances bone resorption in preosteoclastic RAW264.7 cells, despite having a compa…

Role of pamidronate disodium in the treatment of metastatic bone disease.

1998

Aims and Background Bone metastases are a common feature of advanced neoplastic disease and are considered to be among the most frequent causes of pain and complications in oncologic patients. The main objective of the treatment of such patients is to control their symptoms and improve their quality of life. Pamidronate disodium is a second-generation bisphosphonate capable of inhibiting bone resorption (particularly osteoclast activity) without affecting bone reminerali-zation. After a brief introduction concerning the pathophysiology of bone metastases and neoplastic bone pain, we herein present data on the clinical pharmacology and toxicity of bisphosphonates in general, and pamidronate …

Simplifying the dental/periodontal management of patients with metabolic bone fragility receiving treatment with denosumab

2020

Denosumab (DNB) is a bone-targeted medication used to preserve structural integrity and minimise the risk of fragility fractures in metastatic cancer and metabolic bone disorders. DNB targets and binds RANK Ligand, inhibiting osteoclast maturation, function, and survival. In contrast with nitrogen-containing bisphosphonates (N-BPs), DNB does not bind to hydroxyapatite and incorporate into bone; thus, bone cellular remodelling recovers rapidly after drug suspension. Denosumab has benn linked to the occurrence of osteonecrosis of the jaw (MRONJ), a uncommon but severe oral side effect with a higher prevalence in metastatic cancer patients than in patients with metabolic bone fragility. Althou…

Pancreatic undifferentiated carcinoma with osteoclast-like giant cells is genetically similar to, but clinically distinct from, conventional ductal a…

2017

Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells (UCOGC) is currently considered a morphologically and clinically distinct variant of pancreatic ductal adenocarcinoma (PDAC). In this study, we report clinical and pathological features of a series of 22 UCOGCs, including the whole exome sequencing of eight UCOGCs. We observed that 60% of the UCOGCs contained a well-defined epithelial component and that patients with pure UCOGC had a significantly better prognosis than did those with an UCOGC with an associated epithelial neoplasm. The genetic alterations in UCOGC are strikingly similar to those known to drive conventional PDAC, including activating mutations in the…

Analgesic Treatment of Bone Metastases

2013

The presence of bone metastases predicts the presence of pain and is the most common cause of cancer-related pain. Although bone metastases do not involve vital organs, they may determine deleterious effects in patients with prolonged survival. Bone fractures, hypercalcaemia, neurologic deficits and reduced activity associated with bone metastases result in an overall compromise in the patient’s quality of life. A metastasis is a consequence of a cascade of events including a progressive growth at the primary site, vascularization phase, invasion, detachment, embolization, survival in the circulation, arrest at the site of a metastasis, extravasion, evasion of host defense and progressive g…

Involvement of multiple myeloma cell-derived exosomes in osteoclast differentiation

2015

Bone disease is the most frequent complication in multiple myeloma (MM) resulting in osteolytic lesions, bone pain, hypercalcemia and renal failure. In MM bone disease the perfect balance between bone-resorbing osteoclasts (OCs) and bone-forming osteoblasts (OBs) activity is lost in favour of OCs, thus resulting in skeletal disorders. Since exosomes have been described for their functional role in cancer progression, we here investigate whether MM cell-derived exosomes may be involved in OCs differentiation. We show that MM cells produce exosomes which are actively internalized by Raw264.7 cell line, a cellular model of osteoclast formation. MM cell-derived exosomes positively modulate pre-…

MMP-13 stimulates osteoclast differentiation and activation in tumour breast bone metastases

2011

INTRODUCTION: The increased bone degradation in osteolytic metastases depends on stimulation of mature osteoclasts and on continuous differentiation of new pre-osteoclasts. Metalloproteinases (MMP)-13 is expressed in a broad range of primary malignant tumours and it is emerging as a novel biomarker. Recent data suggest a direct role of MMP-13 in dissolving bone matrix complementing the activity of MMP-9 and other enzymes. Tumour-microenvironment interactions alter gene expression in malignant breast tumour cells promoting osteolytic bone metastasis. Gene expression profiles revealed that MMP-13 was among the up-regulated genes in tumour-bone interface and its abrogation reduced bone erosion…