Eldecalcitol is more effective in promoting osteogenesis than alfacalcidol in Cyp27b1-knockout mice.

Calcium (Ca) absorption from the intestinal tract is promoted by active vitamin D (1α,25D3). Vitamin D not only promotes Ca homeostasis, but it also inhibits bone resorption and promotes osteogenesis, thus playing a role in the maintenance of normal bone metabolism. Because 1α,25D3 plays an important role in osteogenesis, vitamin D formulations, such as alfacalcidol (ALF) and eldecalcitol (ELD), are used for treating osteoporosis.

Nongenomic effects of 1α,25-dihydroxyvitamin D on cartilage formation deduced from comparisons between Cyp27b1 and Vdr knockout mice.

The active form of vitamin D, 1α,25-dihydroxyvitamin D (1α,25D), plays an important role in the maintenance of calcium (Ca) homeostasis, bone formation, and cell proliferation and differentiation via nuclear vitamin D receptor (VDR). It is formed by the hydroxylation of vitamin D at the 1α position by 25-hydroxyvitamin D 1α-hydroxylase (CYP27B1) in the kidney. However, Cyp27b1 mice, deficient in CYP27B1, and VDR-deficient mice (Vdr) have not been extensively examined, particularly in a comparative framework.

Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes.

Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes.

Process development for the practical production of eldecalcitol by linear, convergent and biomimetic syntheses.

Eldecalcitol [1α,25-dihydroxy-2β-(3-hydroxypropoxy)vitamin D(3)], an analog of calcitriol (1α,25-dihydroxyvitamin D(3)), possesses a hydroxypropoxy substituent at the 2β-position of calcitriol. Eldecalcitol has potent biological effects on bone disease such as osteoporosis. The marketing of eldecalcitol has very recently started in Japan.

[Frontiers in vitamin D; basic research and clinical application. Exploratory research, biological characteristic and pharmacokinetics of eldecalcitol, a new active vitamin D derivative].

In 1981 when a clinical application of alfacalcidol, a prodrug of active vitamin D, started, differentiation inducing properties of active vitamin D were found at the same year. This indicated the diversity of the physiological actions of active vitamin D, which initially had been thought only to contribute to bone and calcium metabolism. Because these physiological actions were clinically useful, the discovery revealed opportunities for the development of drugs appropriate to specific purpose by synthesizing derivatives to separate biological effects.