Bone Abstracts

Background: DXA scan has for many years been gold standard when analyzing areal bone mineral density (aBMD) in osteoporotic patients. Risk of fractures increases as aBMD declines. However, although risk of fracture is highest in patients with osteoporosis, it is well known that the majority of fragility fractures actually occur in patients with osteopenia rather than osteoporosis. As aBMD is a projected two dimensional imaging technique it does not differentiate between cortic...

Background: Hypercalcemia in childhood is rare, can be of various origin and might go unrecognized until severe signs appear. We demonstrate hypercalcemia of different causes in two infants.Case no 1.: 5-month old girl with failure to thrive, constipation, muscle hypotonia, dehydration, where total calcaemia peaked to 4.25 mmol/l. Low calcium diet, application of glucocorticoids and furosemide resulted in a drop in calcaemia to values below 3 mmol/l and ...

Introduction: In spite of the frequent encounter of ‘asymptomatic’ primary hyperparathyroidism (PHPT), the patients often describe various relevant improvements postoperatively suggesting a subclinical biological effect of elevated PTH or hypercalcaemia.Materials and methods: To evaluate muscle function, postural stability, and quality of life (QoL) in untreated PHPT, we assessed maximal isometric muscle strength in upper and lower extremities,...

Purpose: To test whether bisphosphonates for osteoporosis reduce the risk of breast cancer.Background: Observational studies and meta-analyses find that women taking bisphosphonates have about a 1/3rd reduction in risk of breast cancer as soon as 1 year of treatment. This is plausible because bisphosphonates have in vitro anti-tumor activity and high doses of zoledronate reduce recurrence in women with breast cancer. However, observational studi...

Prolyl hydroxylase 2 (PHD2) regulates hypoxia-inducible factor α (HIFα) transcription factors and thus, erythropoietin (EPO) production. Under normoxic conditions, HIFα is constantly inactivated through hydroxylation by PHD2. Due to the embryonic lethality of PHD2 knock-out mice, its precise role in erythropoiesis and tissue homeostasis has long remained unknown. Recently, we generated a conditional knock-out (cKO) mouse lacking PHD2 in EPO-producing cells. Thes...

Type 2 diabetes mellitus impairs bone quality and increases fracture risk. We showed that diabetic ZDF rats have low bone mass due to impaired osteoblastogenesis, which can be partially reversed with an intermittent parathyroid hormone 1–84 (PTH) therapy. It remains unclear, why PTH treatment does not fully restore osteoblast (OB) function in diabetic conditions. Here, we tested if high glucose (HG) conditions lead to a partial PTH resistance in osteoblasts. Pre-osteoblas...

While the importance of interactions between bone and tumors is well-established, the mechanism by which the physical bone microenvironment regulates disease progression is limited by the lack of suitable in vitro models. We have designed 3D Tissue Engineered Constructs (TECs) using microCT imaging in tandem with inkjet 3D printing technology that recapitulate the mechanical and morphometric properties of trabecular bone. 3D-printed TECs exhibited no significant diffe...

It is well established that tumor expression of Gli2, a Hedgehog family transcription factor, contributes to tumor-induced bone disease. Our previous studies investigating genetic inhibition of Gli2 expression in tumor cells have shown promise for the development of therapeutics. While many groups have focused on developing upstream Hedgehog inhibitors for soft-tissue tumors that aberrantly express Gli proteins, we have previously demonstrated that the expression of Gli2 in tu...

Biallelic ENPP1 deficiency in humans induces hypophosphatemic rickets in children characterized by increased circulating FGF23 levels and renal phosphate wasting (‘Autosomal Recessive Hypophosphatemic Rickets Type 2’, or ARHR2), but osteopenia or osteoporosis has not been described in adults. Here, we describe three adult male patients (ages 43, 59, and 62) suffering from early-onset osteoporosis who presented to the Institute of Osteology and Biomechanics at the Uni...

Introduction: Vitamin D is known to be important for bone health. Still, the significance of serum 25-hydroxy vitamin D concentrations (s-25OHD) for hip fracture risk of the elderly is uncertain. Discordant findings may in part be explained by difficulties of RCTs or large cohort studies to reach both the frail and the healthy elderly. The objectives of this study were to determine the risk of hip fractures of the elderly related to s-25OHD, including both the frail and the he...