头孢克洛在健康人体内的药物动力学研究

采用ＨＰＬＣ测定健康志愿者血浆中头孢克洛的浓度。方法简便快速，结果准确。平均回收率为１０２．１８±４．０１％，日间及日内ＲＳＤ均小于６％。血药浓度－时间曲线符合一室模型。     

Adhesion and growth of Serratia marcescens on artificial closed eye tears soaked hydrogel contact lenses

The adhesion to hydrogel contact lenses and growth of Serratia marcescens on artificial tear fluid (ATF) soaked lenses was investigated. Results indicated that a corneal ulcer isolate adhered more avidly to lenses; ATF increased adhesion for all strains tested. The contact lens induced acute red eye (CLARE) isolate adhered poorly; however; it grew to a larger extent on ATF-coated lenses. The ability of the corneal ulcer isolate to adhere to lenses may be an important factor in its pathogenicity whereas the ability of the CLARE isolate to grow on the lens in the presence of antimicrobial tear proteins may be important in the development of inflammation.     

豨莶脂溶性成分的研究

从豨莶(Siegesbeckia orientalis L.)的地上部分,分离出八个化合物,其中I和I根据理化性质和光谱数据确定其结构为ent-17-acetoxy-18-isobutyryloxy-16(α)-kauran-19-oicacid(I)和ent-17-ethoxy-16(α)-kauran-19-oicacid(II),均为新化合物,分别被命为豨莶酯酸(siegesesteric acid,I)和豨莶醚酸(siegesetheric acid,I)。其余化合物分别鉴定为腺梗豨莶萜醇酸(ent-16β,17-dihydroxy-kauran-19-oicacid,II),奇任醇(kirenol,IV,β-谷甾醇葡萄糖甙(β-sitosterolglucoside,V),二十一醇(heneicosanol,VI),花生酸甲酯(methyl arachidate,VII)和β-谷甾醇(β-sitosterol,VII)。除奇任醇和β-谷甾醇外,均为首次从该植物中分得。     

Early developmental 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure decreases chick embryo heart chronotropic response to isoproterenol but not to agents affecting signals downstream of the beta-adrenergic receptor.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes cardiovascular toxicity in laboratory animals, including alteration in several processes in which beta-adrenergic receptor (beta-AR) signaling plays important roles. Thus, our laboratory investigated the effects of TCDD on beta-AR expression and signal transduction. Fertile chicken eggs were injected with vehicle (corn oil), 0.24 or 0.3 pmol TCDD/g egg on incubation day 0 (D0) or D5. On D10, heart function was assessed by ECG in ovo. Exposure to TCDD increased the incidence of arrhythmias and decreased the positive chronotropic responsiveness of the heart to isoproterenol. The reduced beta-AR responsiveness was, in part, independent of any overt morphological changes in the heart as chick embryos exposed to TCDD on D5 displayed an intermediate responsiveness to beta-AR agonist in the absence of the dilated cardiomyopathy observed in chick embryos exposed to TCDD on D0. TCDD did not decrease the chronotropic response of the heart to agents that stimulate signals downstream of the beta-AR. In fact, TCDD-exposed embryos were more sensitive than controls to forskolin, increasing heart rates (HR) 21.8 +/- 3.5 beats per min (bpm) above baseline versus control values at 6.3 +/- 2.7 bpm above baseline. TCDD exposure also augmented the negative chronotropic response of the heart to verapamil, decreasing HR -23.2 +/- 7.4 bpm relative to baseline versus control embryos at -12.7 +/- 5.9 bpm below baseline. Finally, the mean cardiac beta1-AR mRNA expression in D10 embryos was not significantly altered by exposure to TCDD on D0. These findings establish that a functional end point of the developing chick heart is sensitive to TCDD exposure and that the TCDD-induced reduction in beta-AR responsiveness may result from alterations in signal transduction upstream of adenylyl cyclase.