Bone Abstracts

Introduction: Collagen and glycosaminoglycans (GAGs) such as hyaluronan (HA) and chondroitin sulfate (CS) are basic elements of bone structure and collagen-GAG composites are currently developed for a wide range of applications. Here, we report on the molecular and cellular effects of GAGs and their sulfated derivatives on osteocytes, which are fundamental orchestrators of bone remodeling.Materials and methods: The effects of native and sulfate-modified ...

Osteocytes differentiate from osteoblasts, are embedded in mineralised matrix and are critical regulators of bone remodelling. In vitro osteocyte models are limited to cell lines in monolayer, which do not represent their 3D environment in vivo. We have shown that osteoblasts in 3D gels differentiate along the osteocytic pathway. Since IGF1 regulates osteoblasts, and is involved in osteocyte response to mechanical loading, we hypothesised that IGF1 modulates ...

Osteocytes make up >90% of bone cells, are embedded in mineralised matrix where they form a communication network. Osteocytes differentiate from osteoblasts, and are mechano-sensitive. They are very difficult to isolate with a dependence on cell lines for in vitro studies of osteocyte biology. Therefore new methods to study these cells are essential. Recent publications indicate that osteoblasts maintained in in vitro 3D collagen gels may differentiate to...

Introduction: Osteoporosis and fragility fractures are recognized complications of rheumatoid arthritis (RA). Previously Riches et al. described a patient with celiac disease and severe osteoporosis in whom neutralizing antibodies to osteoprotegerin (OPG) were present. The aim of this study was to determine if OPG autoantibodies were present in patients with RA and other rheumatic diseases and to relate these to clinical features.Methods: We dev...

Introduction: Osteocalcin (OC) is the noncollagenous protein of bone matrix produced by osteoblasts which play an important role in bone metabolism. In its carboxylated form (c-OC) osteocalcin binds to hydroxyapatite in bone and plays a regulatory role in bone formation and mineralization. In contrast, undercarboxylated OC (uc-OC) binds less effectively to hydroxyapatite and a significant association has been found between fracture incidence and uc-OC in elderly subjects. Unde...

Objectives: To investigate the possible relationship between neonatal anthropometric characteristics and bone turnover and growth markers in a sample of neonates and their mothers, taking into account the size for the gestational age.Methods: A sample which consisted of 20 small for the gestational age (SGA), appropriate for the gestational age (AGA), and large for the gestational age (LGA) randomly selected term neonates and their 20 mothers were analyz...

Objectives: A role for glucose-dependent insulinotropic polypeptide (GIP) in controlling bone mass and strength has previously been reported. However, the rapid degradation of GIP in the bloodstream by the dipeptidyl peptidase-4 enzyme precludes therapeutic use. To circumvent this problem, a series of N-terminally modified GIP agonists have been developed. The aim of the present study was to investigate the effects of 28-day treatment with N-AcGIP on bone microarchitecture and...

Objective: We investigated the effect of creatine administered in the diet for 10 weeks on bone turnover and bone quality in male Wistar rats.Methods: Rats were divided (after approval of Ethical committee 9814/2008–30 and 30793/2010–30) into four groups, ten animals in each group. G1 SLD-A group were fed a standard laboratory diet (SLD). G2 SLD-B group were fed SLD and 12 h before rats were sacrificed diet was removed. G3...

Objective: We investigated the effect of arginine administered for 10 weeks in diet on bone metabolism in male Wistar rats.Methods: Rats were divided (after approval of Ethical Committee 9814/2008-30 and 30793/2010-30) into four groups, ten animals in each group: G1 SLD-S group were fed a standard laboratory diet (SLD). G2 SLD-H group were fed SLD and 12 h before rats were sacrificed diet was removed. G3 ARG-S group was fed wit...

To evaluate the regeneration of alveolar bone after treatment with bone-resorption inhibitors in old acyclic rats that had been through a long period of low estrogen. Thirty-two female Wistar rats with 20 months old intact and ovariectomized (OVX at 4 months of age), were randomized into four groups (n=8/group): i) intact; ii) OVX/O (corn oil); iii) OVX/E2 (17β-estradiol, 400 μg) and iv) OVX/RLX (Raloxifene, 1 mg/kg per day). All treatments began ...