Objective To study absorption characteristic of dioscin from Dioscorea nipponica Makino extract in rat intestine.Methods Single-pass intestinal perfusion (SPIP) model was used for rat in situ and HPLC was used to determine the concentrations of dioscin.The effects of different intestinal segments,drug concentration and P-glycoprotein (P-gp) inhibitor on intestinal absorption were investigated.Results Dioscin could be absorbed in the whole intestine,the absorption rate constant (Ka) and the apparent coefficient (Papp) of dioscin decreased following the sequence of ileum > duodenum =jejunum > colon.Absorption parameters of dioscin had no significant difference at different concentrations (40,80,120 mg·L-1).There were significant differences in Ka and Papp values between P-gp inhibitor group and no P-gp inhibitor group(P<0.05).Conclusion The saturate phenomena was not observed under the test range of drug concentration,and the absorption mechanism may be passive diffusion transport.Dioscin in Dioscorea nipponica Makino extract may be the substrate of P-gp.

Objective To investigate the change rules and its significance of erythrocytes surface molecule CD35 , CD58 and CD59 expression in recipients infected with cytomegalovirus (CMV)after renal transplantation. Methods Eighty-two recipients undergoing allogeneic renal transplantation were selected and divided into the negative (n=21 )and positive CMV groups (n=61 )based on the qualitative detection of CMV-pp65 antigen in peripheral blood. According to the results of CMV-pp65 (+)leucocyte count,all 61 patients in positive CMV group were further divided into low (n=55)and high active infection subgroups (n =6 ). Healthy adults were recruited into the normal control group (n =30 ). The expression levels of CMV-pp65 antigen,erythrocytes surface molecule CD35,CD58 and CD59 were measured by flow cytometry. Results Compared with normal control group,the expression levels of erythrocytes surface molecule CD35 , CD58 and CD59 in the positive CMV group were significantly down-regulated,and the CD35 and CD59 expression in the negative CMV group were considerably down-regulated (all P<0. 05 ). Compared with negative CMV group,the expression levels of CD58 and CD59 in the positive CMV group were significantly down-regulated (both P<0. 05 ). The expression levels of CD35 and CD59 in the high active infection subgroup were significantly lower than those in the low active infection subgroup (both P<0. 05 ). Conclusions The more severe active CMV infection after renal transplantation,the lower expression of erythrocytes surface molecule CD35,CD58 and CD59,hinting that red cell immune dysfunction is probably involved with active CMV infection.