1.Research on the design and application of oxygen conversion adapter for respirator
Xiaochao LU ; Deju ZENG ; Wenbin LI
China Medical Equipment 2014;(1):60-61,62
Objective:Developed two kinds of oxygen conversion adapter in order to make the respirator be used rapidly in all of the hospital without changing the oxygen connecting device of respirator. Methods:Designed one double sleeve type structure with a socket and a plug on each side which was named oxygen conversion adapter. Results: The installation of oxygen conversion adapter only cost a few seconds who made the using of respirator have no obstacle. Conclusion:Oxygen conversion adapter not only solve the oxygen plug and socket mismatch problem but also saved money.
2.Comparison of MMP-9 Expression in Osteoclasts Obtained by Different Methods
Ming DU ; Bo HE ; Xiaochao ZHANG ; Xueting YANG ; Yiqin LU ; Peng CHEN ; Zhiqiang SHEN
Journal of Kunming Medical University 2013;(12):1-4,25
Objective To investigate the differences of protein and mRNA expression of matrix metalloproteinase 9 (MMP-9) in osteoclasts (OC) and osteoclast-like cells (OLC) obtained by mechanical and inducement methods. Methods Mechanical separation method was used to separate mature osteoclasts from long bones of SD rats aged one-day;and inducement culture method was applied to induce OLC by using RANKL (100 ng/mL) and M-CSF (100 ng/mL) . The protein expression of MMP-9 was measured by immunocytochemistry and mRNA expression of MMP-9 was assayed by in situ hybridization. Results The integral optical density (IOD) and average optical density (AOD) of positive cells in the visual field were higher in the 12-d group of inducement method as compared with the 3 d-group of mechanical method. Conclusions It is suggested that the protein and mRNA expression of MMP-9 in OLC obtained by 12 d inducement method is much high than in OC obtained by 3 d mechanical method. OLC obtained by inducement method can be applied in the study of osteoporosis.
3.Activation of PXR causes drug interactions with Paxlovid in transgenic mice.
Saifei LEI ; Alice GUO ; Jie LU ; Qian QI ; Aaron S DEVANATHAN ; Junjie ZHU ; Xiaochao MA
Acta Pharmaceutica Sinica B 2023;13(11):4502-4510
Paxlovid is a nirmatrelvir (NMV) and ritonavir (RTV) co-packaged medication used for the treatment of coronavirus disease 2019 (COVID-19). The active component of Paxlovid is NMV and RTV is a pharmacokinetic booster. Our work aimed to investigate the drug/herb-drug interactions associated with Paxlovid and provide mechanism-based guidance for the clinical use of Paxlovid. By using recombinant human cytochrome P450s (CYPs), we confirmed that CYP3A4 and 3A5 are the major enzymes responsible for NMV metabolism. The role of CYP3A in Paxlovid metabolism were further verified in Cyp3a-null mice, which showed that the deficiency of CYP3A significantly suppressed the metabolism of NMV and RTV. Pregnane X receptor (PXR) is a ligand-dependent transcription factor that upregulates CYP3A4/5 expression. We next explored the impact of drug- and herb-mediated PXR activation on Paxlovid metabolism in a transgenic mouse model expressing human PXR and CYP3A4/5. We found that PXR activation increased CYP3A4/5 expression, accelerated NMV metabolism, and reduced the systemic exposure of NMV. In summary, our work demonstrated that PXR activation can cause drug interactions with Paxlovid, suggesting that PXR-activating drugs and herbs should be used cautiously in COVID-19 patients receiving Paxlovid.