Bone Abstracts

Mammalian target of rapamycin (mTOR) is a serine–threonine kinase that plays a central role in a number of key cellular pathways that have been previously implicated in bone formation. mTOR mediates these diverse roles by forming two multi-protein complexes, mTORC1 and mTORC2, each of which is defined by unique proteins raptor and rictor respectively.Studies from our laboratory have previously demonstrated that inhibition of mTORC1 increases the ost...

Objectives: To evaluate the clinical outcomes of intravenous bisphosphonate treatment in children with mild-moderate osteogenesis imperfecta (OI) who had progressed from active bisphosphonate treatment to maintenance therapy for >2 years.Methods: A retrospective review was conducted on 17 patients with mild-moderate OI. Clinical data, fracture history, biochemistry, dual energy X-ray absorptiometry (DXA) parameters, vertebral measurements, bone age a...

Objectives: Bisphosphonate infusions are associated with numerous adverse effects including acute systemic inflammatory reactions and electrolyte abnormalities. The aims of this study were to evaluate the safety and efficacy of a 3-day course of prednisone on children receiving their first dose of pamidronate or zoledronic acid.Methods: A retrospective cohort of 166 patients (85 males) were commenced on pamidronate (16%) or zoledronic acid (84%) for trea...

Glucocorticoid (GC)-induced osteoporosis (GIO) occurs in patients undergoing therapeutic intervention for inflammatory disorders such as rheumatoid arthritis and lupus. The effect of long-term GC administration on bone turnover was investigated in two frequently used mouse strains; C57BL/6 and CD1 in order to assess the influence of genetic background.GIO was induced in 12 weeks old female C57BL/6 and CD1 mice by s.c. insertion of long-term (60 days) rel...

Background: Parathyroid hormone-like hormone (PTHLH) is an important regulator of endochondral bone development. Mutations of the PTHLH gene can cause a variety of different skeletal dysplasias, with duplications of the PTHLH gene resulting in a phenotype characterized by endochrondomatosis, metaphyseal dysplasia and osteolysis.Presenting problem: Our patient presented at the age of 4 months, given concerns regarding lower limb deformit...

Background: Families of children with Osteogenesis Imperfecta (OI) make costly modifications to their home, lifestyle and employment and incur costs of rehabilitative, preventative and adaptive care for their child. While parents have readily identified that these costs are financially burdensome, the degree of financial burden has not yet been described in families of children with OI.Objectives: To evaluate the out of pocket, OI related expenses (ExpOI...

Hypogonadism is common in cardiac transplant (CTX) patients and exerts negative effects on bone but also on libido and quality of life.We investigated whether testosterone replacement therapy (TRT) has any positive effects on bone mass, fracture incidence, and quality of sex life when administered in addition to ibandronate (IBN) in hypogonadal CTX recipients. 52 male patients entered the study and received IBN (quarterly 2 μg i.v.). 60% of the pati...

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Here we identify the lipolytic enzyme hepatic lipase (HL, encoded by Lipc) as a novel cell-autonomous regulator of osteoblast function. In an unbiased genome-wide expression analysis, we find Lipc – which was formerly thought to be expressed almost exclusively by the liver – to be highly induced upon osteoblast differentiation, as verified by quantitative Taqman analyses of primary osteoblasts in vitro and of bone samples in vivo. ...

Introduction: Pubertal suppression with gonadotrophin releasing hormone (GnRH) analogue is introduced after onset of puberty in adolescents with gender dysphoria (GD). As puberty is a critical period for bone accrual and changes in body composition, alterations in body composition and bone mass may be observed during treatment.Methods: Thirty-eight adolescents (32/38 assigned females at birth) with GD had dual energy X-ray absorptiometry (DXA) prior to s...