Bone Abstracts

The problem of early diagnosis of rheumatoid arthritis remains an important area of research in rheumatology. We investigated changes in bone metabolism, bone mineral density in early rheumatoid arthritis (ERA; up to 12 months). Data were compared with changes in the MRI study of the dominant hand.We observed 24 patients with ERA, the average age – 33.6±5.7 years. The men were 6 (25%), women – 18 (75%). Bone mineral density (BMD) was deter...

Fibroblast growth factor-23 (FGF23) is a hormone originating from osteocytes with suppressive actions on renal phosphate reabsorption and vitamin D synthesis. We recently identified FGF23 as a calcium-conserving hormone, regulating the membrane transport of the epithelial calcium channel TRPV5 in distal renal tubules. Here, we analyzed the long term sequelae of Fgf23 deficiency and renal calcium wasting on bone and mineral metabolism in 9-month-old mice lacking both Fgf23<...

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Pseudohypoaldosteronism type II (PHAII) is a hereditary disease characterized by hypertension, hypercalciuria and osteopenia. PHAII is caused by mutations in with-no-lysine kinase 1 (WNK1), WNK4, or the cullin RING ligase family members kelch-like 3 (KLHL3) or cullin 3 (CUL3). All mutations result in up-regulation of the WNK signalling pathway which activates thiazide-sensitive Na-Cl cotransporters (NCC) in renal distal tubules, leading to salt retention and hypertension in PH...

Lack of Klotho, the co-receptor for the bone-derived hormone fibroblast growth factor-23 (FGF23), leads to a severe impairment in bone mineralization in mice. However, the mechanisms underlying the Klotho deficiency-associated defects in bone mineralization are still poorly understood. Here, we sought to elucidate the vitamin D independent role of Klotho in bone mineralization. To ablate increased vitamin D signaling in Klotho knockout mice (Kl−/−), we c...

The aim of the work was to determine the influence of vitamin D deficiency on bone mineral density in schoolchildren.Methods: There were examined 304 children aged 10–18 years. The boys consisted 55.0%. The average age of boys was 12.9±0.2 and girls – 12.4±0.2 years old. Researches included ultrasound densitometry of calcaneus by SAHARA (Hologic), blood chemistry, 25(OH)D and intact parathyroid hormone (iPTH) in plasma were determined...