Establishment of in vivo mice inverted two-photon laser scanning microscope microvascular blood flow imaging / 解剖学报

Objective To establish a method of in vivo microvascular imaging and blood flow calculation with better continuous imaging quality. Methods Anesthetized mice with dye injection through tail vein were placed in the center of a 37 ℃ hot plate holder. The stripped tissues were placed in a self￣made low edge confocal dish and immersed in normal saline. The exposed tissues were pressed with self￣made circular metal pads of different weights and sizes. The microvascular blood flow in the liver and hind limb of pregnant mice (n = 3) and normal female mice (n = 3) were measured by the improved device. Results This method can accomplish stable and continuous imaging. The blood flow velocity of liver and hind limb of pregnant mice were faster than that of normal female mice. Conclusion This method can be used for three￣dimensional imaging of microvessels and detection of blood flow velocity in organs.

Design and Experimental Research of Portable Extracorporeal Circulation Pipeline Performance Testing System / 中国医疗器械杂志

Aiming at the current situation of performance testing of hemodialysis extracorporeal circulation tubing, which has slow efficiency, inaccurate measurement, and inconvenient testing, a portable detection system for testing the performance of hemodialysis extracorporeal circulation tubing is designed. The system mainly includes a hardware system and a software system. The hardware system uses STM32F407 single-chip microcomputer as the core to design the driving control of the roller pump; the software system uses the C++ real-time operating system, and the flow detection data is transmitted to the upper computer through RS485 communication and displayed. Experimental showed that the system detects the accuracy and the stability of the flow rate. It has the characteristics of stability and high precision. The relative error of the experimental measurement is within the range of ±10%. The weight of the whole machine is 2 kg, which improves the efficiency by 50% compared with the traditional detection method.

Development of a Recombinase-aided Amplification Combined With Lateral Flow Dipstick Assay for the Rapid Detection of the African Swine Fever Virus / 生物医学与环境科学（英文）

OBJECTIVE@#To establish a sensitive, simple and rapid detection method for African swine fever virus (ASFV) B646L gene.@*METHODS@#A recombinase-aided amplification-lateral flow dipstick (RAA-LFD) assay was developed in this study. Recombinase-aided amplification (RAA) is used to amplify template DNA, and lateral flow dipstick (LFD) is used to interpret the results after the amplification is completed. The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid. In addition, 30 clinical samples were tested to evaluate the performance of the RAA assay.@*RESULTS@#The RAA-LFD assay was completed within 15 min at 37 °C, including 10 min for nucleic acid amplification and 5 minutes for LFD reading results. The detection limit of this assay was found to be 200 copies per reaction. And there was no cross-reactivity with other swine viruses.@*CONCLUSION@#A highly sensitive, specific, and simple RAA-LFD method was developed for the rapid detection of the ASFV.

Establishment and application of a drug screening model targeting somatostatin receptor 2 / 中国药理学通报

Aim To establish a cell model to detect the activity of somatostatin (SST) by targeting somatostatin receptor 2 (SSTR2), and to provide a simple and stable evaluation method for the drug screening of SSTR2 agonists and somatostatin analogues (SSTA). Methods The target gene of SSTR2 was integrated into the pEGFP-N3 vector, and the recombinant plasmid was constructed and transfected into HEK293 cells. After G418 screening, positive clone was selected and the stable cell lines were obtained by expanding culture. The stable cell lines were identified by fluorescence cell imaging, Western blot and qPCR. A calcium flow detection system was established to optimize cell number, fluorescence dye concentration and incubation time. Finally, the screening model was used to detect the different batches of the marketed somatostatin preparation Stilamin. Results SSTR2 stable cell lines were successfully constructed, and the receptors were mainly distributed on the cell membrane. The optimal conditions for calcium flow detection were determined as follows; 30 000 cells/Well, Fluo-4/AM indicator concentration was 3 p,mol • L -1 ~5 u,mol • L-1 , incubation time was 45 min. Under this condition, EC50 value of Stilamin in different batches was stable. Conclusions SSTR2 overexpressed stable cell lines are successfully constructed and calcium flow detection method is optimized to provide a simple and stable model for the screening of somatostatin receptor agonists.