Bone Abstracts

As a bone-derived hormone that regulates phosphate homeostasis and renal 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] production, fibroblast growth factor (FGF)-23 has been postulated to indirectly control calcium and bone metabolism by modulating the levels of phosphate and 1,25(OH)2D3. However, the presence of FGF receptor-1 (FGFR-1) proteins in the intestinal epithelial cells suggests that the intestine may directly respond t...

A decrease or absence of beta-globin production in erythroid cells causes a hereditary anemic disorder known as beta-thalassemia, which is associated with ineffective erythropoiesis, iron overload, growth retardation, osteopenia, and osteoporosis. Our recent investigation revealed that beta-thalassemia led to osteoclast-mediated bone resorption and the impaired intestinal calcium absorption, the latter of which modestly responded to conventional 1,25-dihydroxyvitamin D3</...

Breastfeeding women resorb trabecular bone to supply much of the calcium content of milk. Few studies have examined the speed and extent of BMD recovery after weaning, or the factors that predict a greater post-lactation increase in BMD. We hypothesize that weight-bearing, nutrition, hormones, and other factors facilitate bone formation after lactation.The aims of the Factors Affecting Bone Formation After Breastfeeding Pilot Study (FABB-Pilot) were to d...

The biological relevance of Klotho in aging processes was impressively demonstrated in transgene and knock out mouse experiments and its impact on calcium, vitamin D and phosphate metabolism suggests multifunctional modes of action.The human alpha Klotho gene encodes two transcripts, one for a protein of 130 kDa with a short intracellular and a transmembrane region and the two extracellular domains KL1 and KL2. A second transcript exists due to alternati...

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...

Background: Sun exposure may be limited in Arctic populations and Greenland Inuit have adapted to the Arctic environment. The influence of chronic low vitamin D level on PTH to uphold a normal serum calcium remains to be elucidated.Objective: To describe the association between PTH and factors known to influence PTH-, including vitamin D (25OHD) and calcium, in Arctic populations.Methods: Inuit and non-Inuit in the capital city Nuu...

Introduction: Tumor-induced osteomalacia (TIO) is a rare acquired paraneoplastic syndrome which is usually induced by mesenchymal tissue tumor with excessive secretion of FGF23. The misdiagnosis of TIO is frequently seen in clinic. Therefore, this study is aimed to describe the misdiagnosed situation of TIO, explore the possible underlying reasons for missed diagnosis and misdiagnosis through the analysis of 144 TIO patients, and improve clinicians’ awareness of TIO.<...

Reduced peripheral serotonin (5HT) in mice lacking tryptophan hydroxylase (TPH1), the rate limiting enzyme for 5HT synthesis, was reported to be anabolic to the skeleton. However, in other studies, TPH1 deletion either had no bone effect or an age-dependent inhibition of osteoclastic bone resorption. The role of 5HT in bone therefore remains poorly understood. To address this issue, we used selective breeding to create rat sublines with constitutively high (high-5HT) and low (...

Recent studies suggest that the concentration and genotype of vitamin D binding protein are important factors that determine the bioavailability of 25OH Vit-D in blood. It has been suggested that measurement of free, non-protein bound 25OH Vit-D in serum, may provide more relevant diagnostic information than total 25OH Vit-D, for instance in chronic kidney disease, bladder cancer and pancreatic cancer, or in hemodialysis patients.To measure free 25OH Vit...

Background and objectives: Vitamin D deficiency causes calcium-depleted bone, which further weakens the bones and increases the risk of fractures. Also, It is known as related to obstetrics problem like gestational diabetes, infections, preeclampsia and incidence of caesarean section as well as glucose metabolism, immune system, cardiovascular diseases and cancer.Recently, the relationship between preterm birth and vitamin D deficiency becomes the main i...

TRPV4-associated skeletal dysplasias include: FDAB, ADBO, SMDK, SEDM, MD and Parastremmatic dysplasia. In this study, we recruited 3 families with congenital scoliosis and 1 family with localized digital osteopetrosis. We collected their clinical data and use the next-generation sequencing system, Sanger sequencing and RT-PCR to obtain the genetic diagnosis. Proband 1, 2, 3 all presented with early-onset kyphoscoliosis and short stature. X-ray showed platyspondyly, hemivertebr...

Background: It is well established that Asians have lower levels of vitamin D (25OHD) when compared to Caucasians. Vitamin D binding protein (DBP) levels are also lower in some races than in Caucasians.Objectives: i) To find out whether DBP is lower in Asians; ii) To find out whether free 25OHD is lower in Asians; iii) To find out whether PTH is increased in Asians and interpret this in relation to 25OHD levels and iv) To find out whether the increment i...