Bone Abstracts

Activins belong to the transforming growth factor-β superfamily, and they regulate bone formation by controlling both osteoclast and osteoblast behaviour. We have previously shown that activin-A strongly inhibited matrix mineralization in osteoblast cultures, and that activin A-signalling was most effective before the onset of mineralization.The aim of this study was therefore to investigate how an early activin-A pulse affected osteoblast mineraliz...

Background: Patients with differentiated thyroid cancer (DTC) are treated with L-thyroxine (L-T4) in relatively hight doses to suppress endogenous TSH levels. Very long-term effect of thyroid hormones supplementation on bone are controversial.Objetive: To study the possible negative effects on bone mineral density (BMD) and bone markers in DTC patients followed in our center.Methods: A 46 po...

Objective: Osteocalcin, an osteoblast-derived hormone, is among the most abundant proteins in bone and is involved in the regulation of whole-body metabolism, muscle adaptation, and reproduction. High bone turnover and low bone mass are clinical hallmarks of Osteogenesis Imperfecta (OI), a bone disease mainly caused by mutations in the collagen-I gene. Recently, we have shown that growing mice with a severe dominant form of OI, Col1a1Jrt/+ mice, displayed significantly elevate...

Vitamin D deficiency is common in older persons and non-western immigrants. Vitamin D is often started in loading doses of 50 000 IU/ml solution. Though, generally considered safe, this highly concentrated solution carries some risks as is illustrated by the following cases. A woman of >80 years old was admitted with hypercalcemia, calcium 3.27 mmol/l. She complained of nausea, thirst and polyuria for 3 months. History included cholecystitis, atrial fibrillation, myocardia...

The murine osteoprogenitor cell line, KS483 (Percuros, The Netherlands) is a well-established model for investigation of osteoblast differentiation and bone formation processes. The mesenchymal characteristics of this cell line allow it to differentiate into either adipocytes or mature, mineralizing osteoblasts. Various phases can be distinguished during osteoblast differentiation and maturation; namely proliferation, matrix formation, matrix maturation, and mineralization.</p...

Although trials have shown that exercise has positive effects on bone mineral density (BMD), not all exercise modalities are osteogenic and the majority of exercise trials have been conducted in older women. The aim of this study was to systematically review trials examining the effect of weight-bearing and resistance-based exercise modalities on the BMD of hip and lumbar spine of middle-aged and older men. Eight electronic databases were searched in August 2012. Only randomis...

Young transsexuals at a minimum age of 12 years are treated with GnRH-analogues (GnRHa) to suspend pubertal development until the addition of hormones of the desired sex is started at a minimum age of 16 years. The effect of this treatment on adult bone mineral density (BMD) is still unknown. We aimed to assess BMD at the age of 22, as this is near its peak in healthy individuals.In this prospective observational study 19 female to male (FtM) and 16 male...

Background: Long-term use of bisphosphonates has raised concerns about the association with Atypical Femur Fractures (AFFs) that have been reported mainly in postmenopausal women.Clinical case: An 18-year-old patient with juvenile osteoporosis based on X-linked osteoporosis due to a PLS3 mutation developed a low trauma femoral fracture after seven years of intravenous and two years of oral bisphosphonate use, fulfilling the revised ASBMR diagnostic crite...

Background: Weyers acrofacial dysostosis (WAD, OMIM 193530) is a rare autosomal dominant disease, characterized by mildly short stature, postaxial polydactyly, nail dystrophy and dental anomalies. WAD should be distinguished from Ellis-van Creveld syndrome (OMIM 225500), a similar but more severe disease, comprising chondrodysplasia, orofacial anomalies and, in a proportion of patients, cardiovascular malformations. Both diseases are caused by mutations in either EVC or EVC2<s...

see PP205....