[Effects of water level variations on survival, morphological phenotype and responsiveness of tadpoles to phytohemagglutinin]. / æ°´ä½å˜åŒ–å½±å“èŒèšªå­˜æ´»ã€å½¢æ€è¡¨åž‹å’Œæ¤ç‰©è¡€å‡ç´ ååº”.

To investigate the responses of morphological and physiological characteristics in tadpoles of Pelophylax nigromaculatus to various water levels, a total of 480 tadpoles with similar sizes were treated with rapid, moderate and slow desiccation. Both the metamorphosis duration and average metamorphosis survival rate of specific developmental stages were counted. Their body and internal organ sizes, as well as the responsiveness to phytohemagglutinin (PHA-P) of froglets were measured after complete metamorphosis. The results showed that the metamorphosis duration of tadpoles in the control group was the longest. The average metamorphosis survival rate of different treatment groups ranged from 72.5% to 90.8%, which was the highest in the control group and the lowest in the rapid desiccation group. Body weight (BW) and body length (BL) of froglets in control and slow desiccation groups were significantly higher than those of moderate or rapid desiccation groups. Body width, ratio of BW to BL, carcass wet weight and the wet weight index of lung and fat body were the lowest in rapid desiccation group. There was no significant difference in the wet weight index of heart, spleen, kidneys and digestive organs, as well as the length index of different segments of whole digestive tract between groups. The maximal response value of froglets to PHA-P appeared at 3 h after injection in different treatments, which was significantly higher in moderate and slow desiccation groups than the control group. There was no significant difference between rapid desiccation group and any other groups. The tadpoles of P. nigromaculatus might accelerate the metamorphosis developmental process to cope with desiccation stress, accompanying with decreased atrophic body size and weakened cell-mediated immunity, which would harm tadpoles to successfully land.

[Application of time domain reflectometry for determination of wate content in Xiangsha Yangwei pills].

Xiangsha Yangwei pill was selected as a model drug in this research, and time domain reflectometry (TDR) was used to determine the water content in the pill. The effects of five factors including the number of pill layers, pill packing density, atmospheric moisture, ambient temperature and the ratio of pill formula were investigated on water content. The results showed that the number of pill layers and ambient temperature had significant effects on water content of pills, while the pill packing density, atmospheric moisture and pill formula ratio had little effect on the determination of water content in pills. The reflection value was stable when 6 layers of pills were used. Under the condition of 25 ℃ and 45% relative humidity, the water content of pills ranged from 4.01% to 22.38%, showing good linear relationship between water content and reflection value, and the model equation was as follows: Y=0.279X－21.670 (R²=0.997 0). Verification experiment was used to explain the feasibility of this prediction model. The precision of the method complied with the methodology standard. It is concluded that TDR can be used in determination of water content in Xiangsha Yangwei pills. Additionally, TDR, as a new way to quickly and efficiently determine the water content, has a prospect application in the processing of traditional Chinese medicine pharmacy, especially for concentrated pill.

Effect of soy extract administration on losartan pharmacokinetics in healthy female volunteers.

BACKGROUND: osartan is metabolized by CYP2C9 and CYP3A4 to an active metabolite, E-3174, which has greater antihypertensive activity than the parent compound. Soy extract has been shown to be an activator of CYP2C9 and CYP3A4 in vitro. Coadministration of soy extract and losartan may therefore alter the pharmacokinetics of losartan and E-3174. OBJECTIVE: To determine whether, when losartan was used in combination with soy extract, a significant pharmacokinetic interaction would be observed in healthy female volunteers. METHODS: Eighteen healthy Chinese female volunteers were recruited. In an open-label, 2-phase study, losartan 50 mg was given to each subject, with and without soy extract. Plasma concentrations of losartan and E-3174 were determined by liquid chromatography-tandem mass spectrometry for 12 and 24 hours, respectively. On day 8 through day 21 of the study, following a 7-day washout period, each subject consumed two 1000-mg Genistein Soy Complex tablets orally after meals, twice daily, for 14 days. On day 22, all volunteers received losartan 50 mg and blood samples were collected again. RESULTS: All subjects completed the study, without adverse drug effects. Over the 14-day pretreatment period, soy extract did not significantly influence the pharmacokinetics of losartan or E-3174. The ratio of the area under the curve of the drug and metabolite after losartan administration, with and without soy extract ingestion, was 0.21 +/- 0.05 and 0.23 +/- 0.05 (mean +/- SD), respectively. The difference was not statistically significant (p = 0.22). CONCLUSIONS: Our data indicate that a significant interaction between soy extract and losartan is unlikely to occur in females.