Bone Abstracts

Mammalian target of rapamycin (mTOR) functions mainly in the form of two complexes, namely mTORC1 and mTORC2, which are distinct in their unique components, raptor and rictor. Here, we focused on bone phenotypes in mice with a specific deletion of rictor using a Cre recombinase gene whose expression was driven by the promoter of osteocalcin. All procedures involving mice were approved by the Institutional Animal Care and Use Committee of the local admin. DXA analysis showed a ...

Study design: Prospective study.Objectives: The risk factors correlated with actual falls were assessed in patients with lumbar spinal stenosis.Materials and methods: In 201 patients (M:F 65:136) with symptomatic lumbar spinal stenosis, falls history within recent one year was investigated. The factors which were expected correlation with actual falls were evaluated together. Blood chemistry was performed to evaluate serum Vitamin ...

Pseudovitamin D-deficiency rickets (PDDR) is a rare autosomal recessive disorder resulting from a defect in renal 25-hydroxyvitamin D 1α-hydroxylase, which is encoded by the CYP27B1 gene. To our best knowledge, 48 mutations of the CYP27B1 gene have been identified so far. In the present study, we investigated CYP27B1 mutations in seven individuals from six separate families and identified nine different mutations: two novel missense mutations (G194R, R259L), three novel a...

Irisin is a hormone-like myokine secreted from skeletal muscle in response to exercise. Considering that an intimate relationship between skeletal muscle and bone has been well established and that physical exercise physiologically stimulates the skeleton strengthening, we explored the involvement of Irisin on bone metabolism.Our findings demonstrated that the myokine Irisin improves cortical bone mass and geometry in vivo, supporting the idea t...

Low levels of 25-hydroxyvitamin D have been documented among inhabitants of the wider Middle East and North African countries. Sunlight has long been recognized as a major provider of vitamin D. In this study we aimed to determine the optimum time for sun exposure in the Central region of Riyadh, Saudi Arabia. Ampoules containing 7-dehydrocholesterol in ethanol were exposed to sunlight every hour starting from sunrise until sunset in July and December. Our results demonstrated...

Objective(s): We aimed to determine the prevalence of osteoporosis and risk factors for bone demineralization in the Italian population.Material and methods: 3090 consecutive subjects were screened for osteoporosis by using calcaneal quantitative ultrasounds (QUS) in 16 Italian cities (women: 2635; men: 455) during the extension of the FIRMO study carried out in 2011 on about 7000 people. Anamnestic data were collected to assess the presence of recognize...

Objectives: To assess the vitamin D nutrition status of healthy children in the age group 2–5 years and to assess the daily dietary calcium intake of these children.Methods: A total of 100 healthy children (age group 2–5 years) were studied in this cross sectional study. Dietary calcium and energy intake was estimated using 24 h dietary recall method. Average sun exposure over last 3 days was assessed by calculating u.v. score. Biochemical para...

Vitamin D deficiency is common within Europe and the Middle East, especially in risk groups. While treatment is simple, there is no consensus on the diagnostic threshold for deficiency and the required dose. The Institute of Medicine and the Endocrine Society have established guidelines on the required 25-hydroxyvitamin D (25(OH)D) levels, supplementation doses and (extra)skeletal effects of vitamin D, coming to very different conclusions. The European Calcified Tissue Society...

The Rickets is a disease which disturbs normal bone formation through different methods, like vitamin D deficiency, malabsorption, chronic renal disease, metaphisary dysplasia, low phosphorus and resistant rickets.The peak age at which rickets is most prevalent is usually 3–18 months, and the characteristic clinical features of this metabolic bone disease include enlargement of the epiphyses of the long bones and rib cage, bowing of the legs, bendin...

Objectives: To estimate the status of 25-hydroxyvitamin D in healthy Mexican children and to describe factors related to vitamin D deficiency.Methods: A cross-sectional study was conducted in children 2–14 years old in Mexico City and Toluca Edo de Mexico. Trained interviewers applied a questionnaire including all relevant demographics, medical history, sun exposure, sunblock use and skin phototype. Morning fasting blood was collected in all subject...