Objective:To develop an HPLC method for the determination of nintedanib in rabbit plasma and study the pharmacoki-netics of nintedanib in rabbits. Methods:The separation was performed on an Agilent ZORBAX SB-C18 column. A mixture of acetoni-trile-0. 1% trifluoroacetic acid-water (35∶ 20∶ 45) was used as the mobile phase at a flow rate of 1. 0 ml·min-1. The detection wavelength was set at 286 nm. Carbamazepine was used as the internal standard and nintedanib was extracted by ethyl acetate from plasma under basic condition. Totally 6 rabbits were given 20 mg·kg-1 nintedanib with intravenous administration. The blood samples were collected from the auricular vein at different time points after the administration. The concentration of nintedanib in plasma was detected by the HPLC method. The pharmacokinetics parameters were analyzed by DAS program. Results: An excellent linear rela-tionship was obtained within the range of 0. 05-10. 00 μg·ml-1(r=0. 999 8). The intra-day RSD was 5. 55%, 4. 53% and 2. 74%and inter-day RSD was 6. 15%, 5. 45% and 3. 15%, respectively for the three concentrations(0. 10, 2. 50 and 7. 50μg·ml-1), and the relative recovery was (98. 50 ± 5. 47)%, (100. 25 ± 4. 54)% and (99. 94 ± 2. 74)%, respectively. The main pharmacokinetics parameters of nintedanib were as follows: Cmaxwas (3.01 ±0.35) μg·ml-1, t1/2 was (4.38 ±1.53) h and AUC0-t was (11.67 ± 1. 71) μg·h·ml-1 . Conclusion:The method is simple, rapid and accurate, and can be used to determine the nintedanib concentra-tion in rabbit plasma and study its pharmacokinetics. Nintedanib is fitted the first-order elimination kinetics in rabbits.

Objective To investigate the clinical value of serum insulin-like growth factor-1 (IGF-1),insulin-like growth factor-binding protein-3 (IGFBP-3) and mean height standard deviation score(HtSDS) in recombinant human growth hormone (rhGH)-treated small for gestational age (SGA) children.Methods 32 cases of SGA failed of catch-up growth were subcutaneously injected with rhGH every night before bed at a dose of 0.15-0.20u· kg-1 · d-1.And the variation of serum IGF-1,IGFBP-3,HtSDS,body height and growth velocity (GV) were monitored at 3,6,9 and 12 months of the treatment and compared.Results The GV (cm/years) increased to (12.4 ± 3.2),(11.0 ± 2.3),(10.1 ± 3.5),(9.4 ± 1.8) versus (4.1 ± 0.5) before treatment,suggesting a significant catch-up growth after treatment (F =51.35,P ＜ 0.01).Accordingly,HtSDS increased to (-2.55 ± 0.73),(-2.39 ± 0.65),(-2.21 ± 0.58),(-2.09 ± 0.94) versus (-2.81 ± 0.64),suggesting that height gaps were reduced compared to the normal children of the same age and sex after rhGH treatment (F =4.99,P ＜0.01).The serum levels of IGF-1,IGFBP-3 were significantly increased compared to pre-treatment (F =34.52,14.04,all P ＜ 0.01),especially for serum IGF-1,which maintained at a high level after 3 months of treatment and up to peak after 6 months.However,the ratio of IGF-1/IGFBP-3 showed no increase after treatment (F =1.82,P ＞ 0.05).There was a significant positive correlation between the serum level of IGF-1 and △HtSDS after the rhGH treatment within six months (r3 =0.72,r6 =0.91),while there was no correlation between them after 9 months (r9 =0.26,r12 =0.33).There were no serious adverse events during the rhGH treatment.Conelusion The serum levels of IGF-1,IGFBP-3 were significantly increased after the rhGH treatment,especially for serum IGF-1.There was a significant positive correlation between the serum level of IGF-1 and △HtSDS within six months,but not after 9 months.The rhGH treatment could be a safe and effective strategy for SGA children.

Stomatal density is important for crop yield. In this paper, we studied the epidermal pattern factors (EPFs) related to stomatal development. Prokaryotic expression vectors were constructed to obtain EPFs. Then the relationship between EPFs and hydrogen sulfide (H2S) was established. First, AtEPF1, AtEPF2 and AtEPFL9 were cloned and constructed to pET28a vectors. Then recombinant plasmids pET28a-AtEPF1, pET28a-AtEPF2 and pET28a-AtEPFL9 were digested and sequenced, showing successful construction. Finally, they were transformed into E. coli BL21(DE3) separately and induced to express by isopropyl β-D-galactoside (IPTG). The optimized expression conditions including IPTG concentration (0.5, 0.3 and 0.05 mmol/L), temperature (28 °C, 28 °C and 16 °C) and induction time (16 h, 16 h and 20 h) were obtained. The bands of purified proteins were about 18 kDa, 19 kDa and 14.5 kDa, respectively. In order to identify their function, the purified AtEPF2 and AtEPFL9 were presented to Arabidopsis thaliana seedlings. Interestingly, the H2S production rate decreased or increased compared with the control, showing significant differences. That is, EPFs affected the production of endogenous H2S in plants. These results provide a foundation for further study of the relationship between H2S and EPFs on stomatal development, but also a possible way to increase the yield or enhance the stress resistance.
Arabidopsis ; genetics ; metabolism ; Arabidopsis Proteins ; genetics ; isolation & purification ; metabolism ; Escherichia coli ; genetics ; Genetic Vectors ; genetics ; Hydrogen Sulfide ; metabolism ; Plasmids ; genetics ; Seedlings ; metabolism