Objective To investigate the geographical distribution and seasonal fluctuations of visceral leishmaniasis vectors sandflies in Henan Province in 2023, so as to provide insights into the prevention and control of visceral leishmaniasis vectors. Methods A total of 23 counties (districts) were sampled from 18 cities of Henan Province from May to September, 2023 as sandfly surveillance sites, and sandflies were captured using human capture and light trapping methods. Following morphological identification, the changes in the sandfly density were calculated at different months and in different breeding habitats. Results A total of 406 light traps were set at sandfly surveillance sites in Henan Province from May to September, 2023, and a total of 3 137 female sandlies were captured, with an average density of 7.73 sandlies/(light·night). A total of 1 494 Phlebotomus chinensis sandflies were captured, including 1 222 female sandflies, with an average density of 3.01 sandflies/(light·night), and the highest density of P. chinensis was found in Gongyi City [17.00 sandflies/(light·night)]. A total of 5 544 sandflies were captured using the human capture method, including 230 P. chinensis, and the density of P. chinensis appeared a unimodal distribution, with a peak in early July [5.81 sandflies/(light·night)]. Among different breeding habitats, the highest P. chinensis density was detected in pigpens [4.50 sandflies/(light·night)]. Conclusions P. chinensis was predominantly distributed in hilly areas of northern and central-western Henan Province in 2023, and the sandfly density appeared a unimodal distribution. Intensified monitoring of visceral leishmaniasis vectors is recommended.

Objective:To investigate the physiological changes of people when advancing rapidly to the plateau, and to evaluate the performance of high-altitude simulation device.Methods:A total of 24 healthy volunteers were randomly divided into 4 groups with 6 individuals in each by the random number table method. The high-altitude simulation device was used to simulate the plateau in two stages. The first stage simulated an altitude of 3 500 m (equivalent to high altitude), and the second stage was performed after an interval of 24 hours from the first stage, which simulated an altitude of 5 000 m (equivalent to ultra-high altitude). During the two stages, for blood routine and blood gas analysis, blood samples were taken before entering the chamber of each stage, and at the simulated altitudes of 3 500 and 5 000 m in the chamber. Furthermore, ECG tests were also conducted before and after entering the chamber. In the case of cardiac abnormality, the cardiac enzyme test would be carried out. Meanwhile, one volunteer in each group was under ECG monitoring.Results:As the simulated altitude increased, the volunteers’ pulse rates increased gradually, while their saturation of periferal oxygen(SpO 2) decreased gradually. Comparing the pulse rate and SpO 2 at 3 500 m with those before entering the chamber, and comparing the pulse rate and SpO 2 at 5 000 m with those before entering the chamber; all the differences were statistically significant ( P<0.05, or P<0.01). The blood routine tests demonstrated a significant increase in the total counts of red blood cells, hemoglobin, platelets and white blood cells and other contents at the first stage, i. e., 3 500 m; and the differences were statistically significant compared with those before entering the chamber ( P<0.05, or P<0.01). Furthermore, the pH values increased gradually, whereas arterial partial pressure of oxygen (PaO 2), oxygen saturation (SaO 2), and arterial partial pressure of carbon dioxide (PaCO 2) decreased gradually. The significant decrease in HCO 3- showed at 5, 000 m, and the differences were statistically significant compared with those before entering the chamber ( P<0.05, or P<0.01). Conclusion:The plateau simulation can reflect physiological changes of the human body after advancing rapidly to the plateau under the premise of ensuring safety. It has laid a foundation for the further implementation of plateau acclimatization on plain area.

Objective:To investigate the physiological changes of people when advancing rapidly to the plateau, and to evaluate the performance of high-altitude simulation device.Methods:A total of 24 healthy volunteers were randomly divided into 4 groups with 6 individuals in each by the random number table method. The high-altitude simulation device was used to simulate the plateau in two stages. The first stage simulated an altitude of 3 500 m (equivalent to high altitude), and the second stage was performed after an interval of 24 hours from the first stage, which simulated an altitude of 5 000 m (equivalent to ultra-high altitude). During the two stages, for blood routine and blood gas analysis, blood samples were taken before entering the chamber of each stage, and at the simulated altitudes of 3 500 and 5 000 m in the chamber. Furthermore, ECG tests were also conducted before and after entering the chamber. In the case of cardiac abnormality, the cardiac enzyme test would be carried out. Meanwhile, one volunteer in each group was under ECG monitoring.Results:As the simulated altitude increased, the volunteers’ pulse rates increased gradually, while their saturation of periferal oxygen(SpO 2) decreased gradually. Comparing the pulse rate and SpO 2 at 3 500 m with those before entering the chamber, and comparing the pulse rate and SpO 2 at 5 000 m with those before entering the chamber; all the differences were statistically significant ( P<0.05, or P<0.01). The blood routine tests demonstrated a significant increase in the total counts of red blood cells, hemoglobin, platelets and white blood cells and other contents at the first stage, i. e., 3 500 m; and the differences were statistically significant compared with those before entering the chamber ( P<0.05, or P<0.01). Furthermore, the pH values increased gradually, whereas arterial partial pressure of oxygen (PaO 2), oxygen saturation (SaO 2), and arterial partial pressure of carbon dioxide (PaCO 2) decreased gradually. The significant decrease in HCO 3- showed at 5, 000 m, and the differences were statistically significant compared with those before entering the chamber ( P<0.05, or P<0.01). Conclusion:The plateau simulation can reflect physiological changes of the human body after advancing rapidly to the plateau under the premise of ensuring safety. It has laid a foundation for the further implementation of plateau acclimatization on plain area.

Objective To obtain the heavy chain variable region (VH) gene of monoclonal antibody 2F2 against Japanese encephalitis virus (JEV).Methods Total RNA was isolated with Trizol from hybridoma 2F2 cells,and cDNA of VH was amplified with reverse transcription polymerase chain reaction (RT-PCR) and sequenced.The putative VH gene was expressed in E.coli,and the expressed products was detected with enzyme linked immunosorbent assay (ELISA) to determine the activity to bind JEV.Results The VH gene was 354 bp in length which encodes 118 amino acids.Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the VH gene was successfully expressed and purified from inclusion bodies.ELISA result also demonstrated that VH gene expressed products bind purified JEV.Conclusions The VH gene of monoclonal antibody 2F2 against JEV had been cloned.