Objectives To establish a new transgenic mouse model for determining the function and role of human scavenger receptor A (SR-A) in atherosclerosis in vivo. Methods Human scavenger receptor minigene-driven mouse tie-1 promoter was constructed and confirmed by endonuclease digestion and sequence analysis. Transgenic mice were generated via the microinjection method. PCR and Southern blot were used to screen the positive transgenic mice. RT-PCR and immunohistochemical analysis were used to detect the level and location of human SR-A Ⅰ expression in transgenic mice. The activity of human SR-A Ⅰ was determined by morphologic observation of aortic endothelial cells of transgenic mice under transmission electron microscopy. Results The electrophoresis assay showed the expected 4 fragments of 0.9 kb, 1.1 kb, 1.2 kb and 4.2 kb in the Sma Ⅰ digest and 2 fragments of 0.8 kb and 6.7 kb in Bgl Ⅱ digest of plasmids pTie-1/hSR-A. The fragment sequence of tie-1 promoter and human SR-A cDNA in plasmids pTie-1/hSR-A was correct and no ATG before the translation initiation sites of human SR-A was found by sequence analysis. 561 injected and surviving embryos with the purified human SR-A minigene were implanted into the oviducts of 19 ICR pseudopregnant mice. Among the 54 surviving pups from 13 foster mothers, 7 were identified by PCR and Southern blot analysis. The results of RT-PCR and imrnunohistochemical analysis showed human SR-A was specifically expressed on vascular endothelial cells of the aorta and renal artery, as well as hepatic sinusoidal endothelial cells in transgenic mice. Transmmion electron microscope (TEM) of aorta of transgenic mice showed that a large number of vesicles, multivesicle bodies and swollen mitochondria filled the plasma of endothelial cells. Conclusions A transgenic mouse model with overexpression of human SR-A in endothelial cells was successfully established. The transgene was integrated and transmitted into the chromosome of transgenic mice. Tie-1 promoter controlled the transgene to express in endothelial cells in mice. Pinocytic activity of aortic endothelial cells in transgenic mice was higher than that of C57BL/6J mice. Our studies will provide a new transcgenic model for investigation of atherosclerosis and functions of human SR-A.

OBJECTIVE: To verify the accuracy of oxygen concentration (FiO₂) of modified oxygen treatment with Venturi and humidity system. METHODS: Patients just after ventilator weaning and before the removal of tracheal intubation/tracheotomy tube, who admitted to the intensive care unit (ICU) of Henan Provincial People's Hospital from May 1st to December 15th in 2017, were enrolled. All patients were given a modified oxygen treatment with Venturi and humidity system, and the oxygen flow rate (Flow) of the Venturi device and the oretical value of FiO₂ were adjusted according to the patient's condition. Patients were divided into five groups based on doctor's orders: Flow 3 L/min FiO₂ 0.24, Flow 3 L/min FiO₂ 0.26, Flow 6 L/min FiO₂ 0.28, Flow 6 L/min FiO₂ 0.30, Flow 9 L/min FiO₂ 0.35. The value of FiO₂ at the inhalation end of patients of each group was measured by TSI airflow analyzer, and the consistency between the measured value of FiO₂ at the inhalation end and the FiO₂ marked value of Venturi was compared and analyzed. RESULTS: When the FiO₂ theoretical value of Venturi were adjusted to 0.24, 0.26, 0.28, 0.30, and 0.35, the measured values of FiO₂ at the inhalation end of patients were 0.38±0.05, 0.38±0.05, 0.40±0.04, 0.41±0.04, and 0.77±0.11, respectively, which were all significantly higher than the theoretical value of FiO₂ (all P < 0.01). The difference between the measured value of FiO₂ at the inhalation side and the FiO₂ value of the Venturi annotated and the difference rate were both "V"-shaped, both of which decreased with the increase in theoretical value of FiO₂ to a Flow of 9 L/min and a theoretical value of FiO₂ 0.35, the accuracy was the worst, with the FiO₂ difference of 0.42±0.11, and the FiO₂ difference rate of (121.6±36.5)%. CONCLUSIONS There is a difference between the measured value and the theoretical value of FiO₂ at the inhalation end of the modified Venturi oxygen therapy humidification system, which needs to be paid attention to during clinical oxygen therapy.
Humans ; Humidity ; Oxygen/analysis* ; Oxygen Inhalation Therapy ; Respiration, Artificial ; Ventilator Weaning