Effect of gestational age on in-vitro responses of pregnant rat aorta

The hypothesis that the changes in vascular reactivity seen during pregnancy are determined by the gestational age was examined. Experiments were designed to investigate changes in vascular responses with progression of pregnancy. The contractile responses to potassium and phenylephrine (in the presence and absence of N(omega)-nitro-L- arginine methyl ester, a nitric oxide synthase inhibitor) and the relaxant responses to acetylcholine and sodium nitroprusside were measured in isolated aortic rings from pregnant rats at various stages of gestation and from non-pregnant female rats. Potassium-evoked contractile response was higher early in pregnancy and was decreased at term (P < 0.05). The contractile response to phenyllephrine was decreased and the relaxant response to acetylcholine was increased in early pregnancy (P < 0.05). Inhibition of nitric oxide synthase caused an increase in the contractile response to phenylephrine in all the groups, but the attenuation of the response in early pregnancy was maintained (P < 0.05). There was a small decrease in the maximal relaxant response to sodium nitroprusside at term (P < 0.05). It was concluded that the effects of pregnancy on the responses of rat aorta in vitro vary at different stages of gestation. Vascular resistance may be lowered by changes in vascular reactivity in early gestation and by a decrease in the contractile potential of the vasculature during the later stages.      

美白牙膏去除牙齿外源性色斑的临床效果观察

目的：与仅含有0．321％氟化钠的牙膏相比,评价含有0．321％氟化钠及20％高清洁二氧化硅（HCS）的牙膏减少外源性牙色斑的效果,方法：采用双盲,分层,二单位平行观察的临床研究方法,根据Lobene色斑指数均数（色斑指数包括染色部位及染色程度）,性别,将158名年龄为18－65岁的研究对象平衡地分为两组,随机地分配使用试验或对照牙膏,于基线,第4周及第8周固定由一名检查者完成研究对象的色斑指数测定,结果：4周时,使用美白牙膏的研究对象较对照组的牙齿色斑面积减少17．4％,染色程度减少19．2％（P＜0．01）,8周时,使用美白牙膏的研究较对照组的牙齿色斑面积减少38．6％,染色程度减少39．6％（P＜0．01）,结论：与对照组牙膏相比,使用含有0．321％氟化钠及20％HCS的牙膏可以有效地减少外源性牙色斑。     

Three new asterosaponins from the starfish Culcita novaeguineae and their bioactivity

Bioassay-guided fractionation of the active n-BuOH extract of the starfish Culcita novaeguineae resulted in the isolation of three new sulfated steroidal glycosides （asterosaponins） 1, 2 and 3, as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Compounds 1-3 possess the same pentasaccharide moiety, beta-D-fucopyranosyl-（1→2）-alpha-L-arabinopyranosyl- （ 1 → 4 ）-[- beta-D- quinovopyranosyl- （ 1 →2 ） ]-beta-D-xylopyranosyl- （ 1 → 3 ）-beta-D-quinovopyranosyl, linked to C-6 of 3beta-sulfated steroidal aglycones and differ from each other in the side chains.     

5-乙基-5-对氟苯甲酰丙基巴比妥酸在兔体内的代谢产物研究

用高效液相色谱法对5-乙基-5-对氟苯甲酰丙基巴比妥酸在家兔体内的代谢物进行了分离,用二极管阵列检测器测定了原药及代谢物紫外图谱,得出代谢物的紫外吸收性质;同时测试了原药及代谢物的质谱,推测出代谢物的可能结构,并用化学方法合成了代谢物对照品,通过核磁和质谱的测定进一步确证了结构。     

HPLC法测定血瘀证兔血清中游离阿魏酸

建立了一个用于测定正常及血瘀证兔血清中游离阿魏酸(FA)浓度的反相高效液相色谱法,此法简便、快速、灵敏而准确。以香豆素为内标,取0.2mlFA的血清,加入含有内标的乙腈沉淀蛋白,上清液挥干,残渣定容于60μl乙腈中。以DuPontZorbox C₁₈为分析柱,流动相为乙腈-0.10mol·L^-1磷酸缓冲液(pH2.5)(3:7v/v),紫外检测波长320nm,最小检出量和平均回收率分别为1ng和97.0±1.8%,血清中FA的线性范围20～800ng·ml^-1(r=0.9986),日内及日间相对标准差均小于7%。本法被用于正常及血瘀证兔体内FA的药代动力学研究。通过本实验发现FA在正常及血瘀证兔体内的药代动力学参数有显著差异,与证治药效学假说基本相符。     

丁基苯酞对氯化钾及 N-甲基-D-门冬氨酸诱导的大鼠皮质神经细胞损伤的保护作用

用原代培养大鼠皮质神经细胞的方法，观察ｌ丁基苯酞（ｌＮＢＰ）和ｄ丁基苯酞（ｄＮＢＰ）对ＫＣｌ及Ｎ甲基Ｄ门冬氨酸（ＮＭＤＡ）诱导的大鼠皮质神经细胞损伤的保护作用。结果表明：ｌＮＢＰ和ｄＮＢＰ能剂量依赖性地抑制ＮＭＤＡ诱导的大鼠皮质神经细胞内乳酸脱氢酶的释放，降低细胞死亡率，改善受损细胞的形态；此外ｌＮＢＰ和ｄＮＢＰ还能明显减轻ＫＣｌ诱导的神经细胞损伤。提示：ｌＮＢＰ和ｄＮＢＰ对ＫＣｌ及ＮＭＤＡ诱导的大鼠皮质神经细胞损伤有明显保护作用。     

Bioactive asterosaponins from the starfish Culcita novaeguineae

Two new sulfated steroidal pentaglycosides （asterosaponins）, novaeguinosides Ⅰ （2） and Ⅱ（3）, along with the known regularoside B （1） were isolated from the starfish Culcita novaeguineae. Their structures were elucidated by extensive NMR techniques as well as chemical evidence. The new asterosaponins showed marginal in vitro cytotoxicity against two human tumor cell lines.