Search results for "BONE"
showing 10 items of 2629 documents
Silicate modulates the cross-talk between osteoblasts (SaOS-2) and osteoclasts (RAW 264.7 cells): inhibition of osteoclast growth and differentiation
2012
It has been shown that inorganic monomeric and polymeric silica/silicate, in the presence of the biomineralization cocktail, increases the expression of osteoprotegerin (OPG) in osteogenic SaOS-2 sarcoma cells in vitro. In contrast, silicate does not affect the steady-state gene expression level of the osteoclastogenic ligand receptor activator of NF-κB ligand (RANKL). In turn it can be expected that the concentration ratio of the mediators OPG/RANKL increases in the presence of silicate. In addition, silicate enhances the growth potential of SaOS-2 cells in vitro, while it causes no effect on RAW 264.7 cells within a concentration range of 10-100 µM. Applying a co-cultivation assay system,…
Osteogenic differentiation of periodontal fibroblasts is dependent on the strength of mechanical strain
2012
Abstract Objective During orthodontic therapy the correct strength of mechanical strain plays a key role for bone remodelling during tooth movement. Aim of this study was to investigate the osteogenic differentiation of human periodontal ligament fibroblasts (HPdLF) depending on the applied strength of mechanical strain compared to osteoblasts (HOB). Design HPdLF and HOB were loaded with different strengths (1%, 5% and 10%) of static mechanical strain (SMS) for 12 h in vitro. Viability was verified by MTT and apoptosis by TUNEL assay. Gene expression of cyclin D1, collagen type-1 (COL-I), alkaline phosphatase (ALP), osteocalcin, osteoprotegerin (OPG) and receptor activator of the NF-κB liga…
In vitro comparison of the efficacy of two fractured implant-prosthesis screw extraction methods: Conventional versus mechanical.
2019
Abstract Statement of problem Implant-supported prostheses may be subject to esthetic, biological, or mechanical complications. Protocols for dealing with these mechanical problems are sparse. Purpose The purpose of this in vitro study was to compare the efficacy of a mechanical system for extracting fractured implant-prosthesis screws with the conventional method. Material and methods A total of 60 screws were divided into 2 groups according to their morphology (flat screws with a smooth shaft and threaded apical area and screws with a completely threaded body) and subjected to fatiguing and static load testing until fracture. The specimens were assigned to 3 operators with varying levels …
Posterior perilunate carpal dislocation associated with a multifragmentary distal radius fracture.
2009
Summary Dorsal perilunate wrist dislocations are rare. Associated carpal bones or radial styloid process fractures can occur and be included in the current classifications. The authors report an unusual association of dorsal perilunate wrist dislocation with a multifragmentary distal radius fracture. Such traumatic entity has never been previously described. Poor functional outcome may justify the inclusion of associated complex forearm bone fractures in wrist dislocation classifications.
Biomechanical testing of different posterior fusion devices on lumbar spinal range of motion.
2019
Abstract Background Recent minimal-invasive posterior fusion devices are supposed to provide stability and obtain fusion in combination with interbody cages in the instrumented segment. The aim of the present study is to evaluate the primary stability of two minimal-invasive posterior prototypes compared to an established spinous process plate and standard pedicle screw instrumentation. Methods Seven fresh frozen human cadaver lumbar spines (L2–L5) were tested in a spinal testing device with a moment of 7.5 Nm. Spinal stability was determined as mean range of motion (RoM) in the segment L3/L4 during extension-flexion, lateral bending and axial rotation. The RoM was measured during five cond…
Decreased serum levels of sex steroids associated with osteoporosis in a group of Romanian male patients
2016
Abstract Introduction. With age, sex hormone deficiency leads to reduced bone mineral density (BMD) in men. The aim of our research is to analyze the role of serum sex steroids in assessing BMD in the men included in this study. Materials and methods. This cross-sectional study included 146 men aged 65-85 years old with osteopenia or osteoporosis (study group) and 121 men with normal BMD (control group). Serum levels of total testosterone (Tt) and free testosterone (Tf) were measured by immunoassay, and estradiol (E2) levels were measured by the immunoenzymatic method. Femoral neck and lumbar spine BMD was examined by dual-energy X-ray absorptiometry. Results. Tf and E2 deficiency was signi…
Bone and cartilage characteristics in postmenopausal women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis
2015
Objectives: To evaluate the association between radiographically-assessed knee osteoarthritis and femoral neck bone characteristics in women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis. Methods: Ninety postmenopausal women (mean age [SD], 58 [4] years; height, 163 [6] cm; weight, 71 [11] kg) participated in this cross-sectional study. The severity of radiographic knee osteoarthritis was defined using Kellgren-Lawrence grades 0=normal (n=12), 1=doubtful (n=25) or 2=minimal (n=53). Femoral neck bone mineral content (BMC), section modulus (Z), and cross-sectional area (CSA) were measured with DXA. The biochemical composition of ipsilateral knee cart…
The campomelic syndrome: review, report of 17 cases, and follow-up on the currently 17-year-old boy first reported by Maroteaux et al in 1971.
1983
We report 17 cases of the campomelic syndrome (CS) and a follow-up of one of the original patients of Maroteaux et al who is now 17 years old. Our review is based on 97 patients, including our own. An infant with the CS presents at birth with spectacularly short and bowed femora and tibiae. The initial chest radiograph confirms the diagnosis by demonstrating extremely small bladeless scapulae and hypoplastic pedicles of many thoracic vertebrae. Ossification of the sternal segments, pubis, talus, and knee epiphyses is also retarded. Usually the hips are dislocated and talipes equinovarus deformities are present. There is a small chondrocranium and a disproportionately large neurocranium. The…
Significant interaction between high-dose methotrexate and high-dose piperacillin-tazobactam causing reversible neurotoxicity and renal failure in an…
2020
Introduction Pharmacokinetic interaction of high-dose methotrexate (MTX) and other concomitantly administered renally secreted medicinal products may lead to insufficient methotrexate serum level decrease and significant MTX toxicity. Case report We report the case of an 18-year-old male patient treated with high-dose MTX for an osteosarcoma and with high-dose piperacillin-tazobactam at the same time. MTX serum levels were severely elevated 24 hours after the MTX infusion and did not decrease in accordance with the specific calcium folinate rescue protocol. The patient experienced renal failure accompanied by neurological symptoms, most consistent with MTX-related renal and CNS toxicity. Ma…
COX-2 expression in chondrosarcoma: A role for celecoxib treatment?
2010
Chondrosarcomas are resistant to conventional chemo- and radiotherapy. A subset of chondrosarcomas arises secondarily in the benign tumour syndromes enchondromatosis (EC) and multiple osteochondromas (MO), and prevention of tumour development would greatly improve prognosis. We therefore investigated the effect of selective COX-2 inhibition on chondrosarcoma growth. COX-2 expression was studied in central- and peripheral cartilaginous tumours. The effect of COX-2 inhibition was assessed in four high-grade chondrosarcoma cell lines using celecoxib and NS-398 treatment. COX-2 activity (prostaglandin E-2 (PGE(2)) ELISA) and cell viability were measured. The (prophylactic) effect of celecoxib o…