Mutations in the renal sodium-dependent phosphate co-transporters NPT2a and NPT2c have been reported in patients with renal stone disease and nephrocalcinosis, but the relative contribution of genotype, dietary calcium and phosphate to the formation of renal mineral deposits is unclear. We previously reported that renal calcium phosphate deposits persist and/or reappear in older Npt2a-/- mice s...

We previously described the discovery of a fetuin-matrix Gla protein (MGP)-mineral complex in the serum of rats treated with the bone-active bisphosphonate etidronate and showed that the appearance of this complex in serum correlates with the inhibition of bone mineralization by etidronate. In this study we show that the inhibition of bone resorption by treatment with the hormone calcitonin, th...

KOSTAS VERDELIS: Study Of Mineral And Matrix Maturation In Dentin (Under the direction of Adele L. Boskey and J. Timothy Wright) Spectroscopic analysis was used to study the patterns of changes in the mineral and matrix properties of dentin during maturation of the tissue. Fourier Transform Infrared Imaging (FTIRI) analyses on undecalcified semi-thin sections from fetal bovine incisors and deve...

Rat urine could inhibit not only the in vitro initial precipitation of calcium and phosphate/oxalate ions as mineral phase but also the subsequent growth of the preformed mineral phase. Oral administration of the aqueous extract of a commercially available Ayurvedic compound preparation to rats, was found to significantly increase the ability of the urine samples to inhibit both the initial min...

The strategy in biomineralization of initially depositing a less ordered mineral and then transforming it into a more crystalline mature phase is probably widespread among invertebrates. The report in this issue by N.J. Crane, V. Popescu, M.D. Morris, P. Steenhuis, M.A. Ignelzi, Raman spectroscopic evidence for octacalcium phosphate and other mineral species deposited during intramembraneous mi...

As renal function declines, the accumulation of phosphate adversely affects mineral homeostasis and bone turnover. The consequences of this imbalance include secondary hyperparathyroidism (2oHPT), osteodystrophy, and vascular calcification. High phosphate levels are a key factor in the pathogenesis of 2oHPT. Hyperphosphatemia is common in uraemic patients due to a reduced excretion of phosphate...

Liposome encapsulation technology has been used to entrap aqueous calcium salts within dipalmitoylphosphatidylcholine lipid vesicles, which were then used to form calcium phosphate minerals. The calcium encapsulation efficiency was found to depend upon a number of factors that included calcium salt concentration, vesicle size, lipid concentration, and method of vesicle preparation. Removal of u...