The effect of La^(3+) on formation of osteoclast-like cells in rabbit bone marrow cells induced by 1,25-dihydroxyvitamin D_3 and their bone-resorbing activity was evaluated by counting the number of tartrate resistant...The effect of La^(3+) on formation of osteoclast-like cells in rabbit bone marrow cells induced by 1,25-dihydroxyvitamin D_3 and their bone-resorbing activity was evaluated by counting the number of tartrate resistant-acid phosphatase-positive [TRAP(+)] multi-nucleated cells and measuring the number and surface area of bone resorption pits with photomicrography and image analysis. The formation and morphological characteristics of osteoclast-like cells and bone resorption pits were observed under a phase contrast inverted microscope. La^(3+) promotes the formation of osteoclast-like cells at the concentration of 1.00×10^(-8)mol·L^(-1) compared with the control group(P<(0.01)), whereas no significant change in cell number is observed at higher concentrations(1.00×10^(-5), (1.00×)10^(-6) and 1.00×10^(-7) mol·L^(-1))(P>0.05). La^(3+) at the concentration of 1.00×10^(-8)mol·L^(-1) also increases the number and surface area of the resorption pits(P<0.01), but inhibits the bone-resorbing activity dose-dependently(P<0.01)at higher concentrations(1.00×10^(-5), 1.00×10^(-6) and 1.00×10^(-7) mol·L^(-1)). These findings suggest that La^(3+) may promote or inhibit the formation and bone-resorbing activity of osteoclast-like cells depending on its concentration.展开更多
把维生素 B_1加入克山病病区粮中喂饲大鼠两个月左右,可明显改善大鼠的营养状态;心肌细胞色素 C 氧化酶活性明显升高;使亚硝酸钠所致大鼠死亡率及心肌坏死面积明显降低。而对全血及心肌内的谷胱甘肽过氧化物酶活性,血清 T_3、T_4和皮质...把维生素 B_1加入克山病病区粮中喂饲大鼠两个月左右,可明显改善大鼠的营养状态;心肌细胞色素 C 氧化酶活性明显升高;使亚硝酸钠所致大鼠死亡率及心肌坏死面积明显降低。而对全血及心肌内的谷胱甘肽过氧化物酶活性,血清 T_3、T_4和皮质酮含量没有影响。提示我们除硒等因素缺乏外,维生素 B_1相对不足可能参与了克山病的发病。展开更多
Synthesis of an optically active intermediate 4b for the A-ring of 1a,25-dihydroxyvitamin D3 analogs has been achieved in eight steps, starting from readily available, inexpensive D-(+)-xylose.
A polymer-bound photosensitizer was synthesized by the reaction of Merrifield resin with 9-anthracenemethanol in the presence of potassium hydride. The photoisomerization of trans-vitamin D3 to cis-vitamin D3 was car...A polymer-bound photosensitizer was synthesized by the reaction of Merrifield resin with 9-anthracenemethanol in the presence of potassium hydride. The photoisomerization of trans-vitamin D3 to cis-vitamin D3 was carried out with this polymer-bound photosensitizer in ethanol and toluene solutions. The experiment results demonstrate that this solid photosensitizer is efficient for the photoismerization and easy for separation from the reaction mixtures.展开更多
文摘The effect of La^(3+) on formation of osteoclast-like cells in rabbit bone marrow cells induced by 1,25-dihydroxyvitamin D_3 and their bone-resorbing activity was evaluated by counting the number of tartrate resistant-acid phosphatase-positive [TRAP(+)] multi-nucleated cells and measuring the number and surface area of bone resorption pits with photomicrography and image analysis. The formation and morphological characteristics of osteoclast-like cells and bone resorption pits were observed under a phase contrast inverted microscope. La^(3+) promotes the formation of osteoclast-like cells at the concentration of 1.00×10^(-8)mol·L^(-1) compared with the control group(P<(0.01)), whereas no significant change in cell number is observed at higher concentrations(1.00×10^(-5), (1.00×)10^(-6) and 1.00×10^(-7) mol·L^(-1))(P>0.05). La^(3+) at the concentration of 1.00×10^(-8)mol·L^(-1) also increases the number and surface area of the resorption pits(P<0.01), but inhibits the bone-resorbing activity dose-dependently(P<0.01)at higher concentrations(1.00×10^(-5), 1.00×10^(-6) and 1.00×10^(-7) mol·L^(-1)). These findings suggest that La^(3+) may promote or inhibit the formation and bone-resorbing activity of osteoclast-like cells depending on its concentration.
文摘Synthesis of an optically active intermediate 4b for the A-ring of 1a,25-dihydroxyvitamin D3 analogs has been achieved in eight steps, starting from readily available, inexpensive D-(+)-xylose.
文摘A polymer-bound photosensitizer was synthesized by the reaction of Merrifield resin with 9-anthracenemethanol in the presence of potassium hydride. The photoisomerization of trans-vitamin D3 to cis-vitamin D3 was carried out with this polymer-bound photosensitizer in ethanol and toluene solutions. The experiment results demonstrate that this solid photosensitizer is efficient for the photoismerization and easy for separation from the reaction mixtures.
