Biomedical subjects
Publications and source records attributed to Shinichi Saito.
Conjugated diynes undergo dimerization in the presence of acetic acid and catalytic amounts of Pd(PPh3)4. The unprecedented reaction gives a novel chromophore containing the (E)-1,2-divinyl-1.2-diethynylethene (DVDEE) module, which is a potentially viable building block for acetylenic scaffolding.
Oral administration of active vitamin D3 can reduce the loss of bone mass and the incidence of fractures in patients with osteoporosis in Japan. We conducted a prospective study to confirm the effects of 1 alpha(OH)D3 (Alfacalcidol, Alfarol Chugai Tokyo) on bone and calcium metabolism in elderly women with osteoporosis. Enrolled in the present study were 16 elderly osteoporosis women aged 72.6 +/- 4.5 years to whom 1 microgram of 1 alpha(OH)D3 was administered daily. Fasting blood and urine were obtained at baseline, 1 week, 4 weeks, 12 weeks and 24 weeks after the treatment. Monitored parameters were vitamin D metabolites, intact-PTH, bone alkaline phosphatase (BAP), osteocalcin (OC), deoxypyridinoline (DPD) and pyridiuium crosslinked type I collagen telopeptides (CTx). Serum 1 alpha, 25(OH)2D and PTH levels were significantly increased (p < 0.01) and decreased (p < 0.05), respectively at 1 week after commencing administration. There was a significant decrease of DPD (p < 0.05) at 12 weeks after commencing administration compared to the baseline levels. Serum levels of BAP and OC were found elevated at 1 week, and decreased at 12 weeks. In conclusion, the present study clinically confirmed that 1 alpha(OH)D3 stimulates bone formation in vitro. Long-term administration of 1 alpha(OH)D3 indirectly suppressed bone resorption through the suppression of parathyroid function in the elderly.
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Benzaldehydes bearing an electron-withdrawing group reacted with 2 equiv of benzene in the presence of a superacid, trifluoromethanesulfonic acid, to give substituted triphenylmethane in good yields. On the other hand, benzaldehydes bearing an electron-donating or a neutral group reacted under the similar conditions to give unsubstituted diphenylmethane and triphenylmethanol, together with substituted benzene. We propose a new mechanism of this reaction, which involves transalkylation as the key step.