A series of nonsecosteroidal vitamin D receptor agonists for osteoporosis therapy.

In an extension of our study on gamma hydroxy carboxylic acid analogs, we explored a series of nonsecosteroidal vitamin D receptor (VDR) agonists in which 1,3-diol of 1,25(OH)2D3 had been replaced by aryl acetic acid. These analogs showed very potent activity in vitro compared with 1,25(OH)2D3. An X-ray analysis of 8d showed that the inserted phenyl ring well mimicked the folded methylene linker of the gamma hydroxy carboxylic acid moiety but the carboxylic acid of 8d interacted with VDR in a different manner from gamma hydroxy carboxylic acids. Through our in vivo screening in an osteoporosis rat model using immature rats, we identified a potent active vitamin D3 analog, compound 7e. In mature rats of the same model, compound 7e also showed good PK profiling and excellent ability to prevent bone mineral density loss without severe hypercalcemia. Our nonsecosteroidal VDR agonist 7e (CH5036249) could be a possible new drug candidate for treating osteoporosis in human.

Novel nonsecosteroidal vitamin D3 carboxylic acid analogs for osteoporosis, and SAR analysis.

Novel vitamin D(3) analogs with carboxylic acid were explored, focusing on a nonsecosteroidal analog, LG190178, with a bisphenyl skeleton. From X-ray analysis of these analogs with vitamin D receptor (VDR), the carboxyl groups had very unique hydrogen bonding interactions in VDR and mimicked 1α-hydroxy group and/or 3ß-hydroxy group of 1α,25-dihydroxyvitamin D(3). A highly potent analog, 6a, with good in vitro activity and pharmacokinetic profiles was identified from an SAR study. Compound 6a showed significant prevention of bone loss in a rat osteoporosis model by oral administration.

Portable hyperspectral imager with continuous wave green laser for identification and detection of untreated latent fingerprints on walls.

Untreated latent fingerprints are known to exhibit fluorescence under UV laser excitation. Previously, the hyperspectral imager (HSI) has been primarily evaluated in terms of its potential to enhance the sensitivity of latent fingerprint detection following treatment by conventional chemical methods in the forensic science field. In this study however, the potential usability of the HSI for the visualization and detection of untreated latent fingerprints by measuring their inherent fluorescence under continuous wave (CW) visible laser excitation was examined. Its potential to undertake spectral separation of overlapped fingerprints was also evaluated. The excitation wavelength dependence of fluorescent images was examined using an untreated palm print on a steel based wall, and it was found that green laser excitation is superior to blue and yellow lasers' excitation for the production of high contrast fluorescence images. In addition, a spectral separation method for overlapped fingerprints/palm prints on a plaster wall was proposed using new images converted by the division and subtraction of two single wavelength images constructed based on measured hyperspectral data (HSD). In practical tests, the relative isolation of two overlapped fingerprints/palm prints was successful in twelve out of seventeen cases. Only one fingerprint/palm print was extracted for an additional three cases. These results revealed that the feasibility of overlapped fingerprint/palm print spectral separation depends on the difference in the temporal degeneration of each fluorescence spectrum. The present results demonstrate that a combination of a portable HSI and CW green laser has considerable potential for the identification and detection of untreated latent fingerprints/palm prints on the walls under study, while the use of HSD makes it practically possible for doubly overlapped fingerprints/palm prints to be separated spectrally.

Inspection of skin hemodynamics with hyperspectral camera.

Using hyperspectral imaging techniques, which enable us to simultaneously obtain spatial and wavelength information, we have improved upon the newly developed hyperspectral camera to develop a method of observing changes in skin melanin levels and hemodynamics over time. As an evaluation of this method, we measured the skin diffuse reflectance spectrum of the human middle finger in an experiment of blood flow blockage in the brachial region. The changes in skin hemodynamics observed through this method match the behavior expected based on clinical knowledge, and also show an extremely high correlation with results obtained by the Erythema Index, which is used to make similar calculations from a limited number of wavelengths.

A comparison between 1,25-dihydroxy-22-oxavitamin D(3) and 1,25-dihydroxyvitamin D(3) regarding suppression of parathyroid hormone secretion and calcaemic action.

BACKGROUND: Since Slatopolsky et al. (J Clin Invest 1984; 74: 2136-2143) reported the effect of active vitamin D, 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), on secondary hyperparathyroidism (2HPT) which accompanies chronic renal failure, there have been several studies of the therapeutic effects of 1,25(OH)(2)D(3) in this disease. Although parathyroid hormone (PTH) is suppressed by treatment with 1,25(OH)(2)D(3), long-term treatment with 1,25(OH)(2)D(3) tends to induce hypercalcaemia. Therefore, an analogue of 1,25(OH)(2)D(3), 1,25-dihydroxy-22-oxavitamin D(3) (22-oxacalcitriol, OCT) with less calcaemic activity, was developed for the treatment of 2HPT. METHODS: In order to clarify the differences between the effects of 1,25(OH)(2)D(3) and OCT on 2HPT associated with chronic renal failure, these compounds were administered by intermittent i.v. injection for 2 weeks in rats with mild to moderate uraemia. RESULTS: 1,25(OH)(2)D(3) markedly suppressed PTH levels, but increased serum calcium (Ca). OCT also markedly suppressed PTH levels, but induced only a slight increase in serum Ca. 1,25(OH)(2)D(3) caused a dose-dependent decrease in body weight, whereas OCT had no effect on body weight in uraemic rats. Based on those doses of OCT and 1,25(OH)(2)D(3), which resulted in a 60% suppression of PTH, and induced hypercalcaemia, we consider the relative ratios for efficacy and Ca-elevating activity between OCT and 1,25(OH)(2)D(3) to be 1 : 8 and 1 : 48, respectively. CONCLUSIONS: OCT suppressed PTH levels with a slight increase in serum Ca without changing the body weight in uraemic rats. This observation suggests that OCT might be a useful vitamin D analogue for 2HPT management in long-term clinical treatment.