Objective To investigate the method for isolating and identification exosomes from the HK-2 cells exposed to high oxalate.Methods HK-2 cells were cultured to serum-free culture medium and treated with oxalate at the concentration from 0 mmol/L to 10.00 mmol/L for 48 h.CCK-8 assays were performed to measure the cells proliferation.Combined the cell morphology,observed under inverted microscope with statistical analysis,we finally 2.00 mmol/L oxalic acid as the experimental concentration.The HK-2 cell was exposed to 2.00 mmol/L oxalate for 48 h.The supernatants were collected.Exosomes were isolated and purified from the supernatants by ultracentrifugation.Transmission electron microscopy (TEM) was used to observe the morphology of isolated exosomes.Particle size of exosomes were detected with Nanosight technology.Western blot analysis was used to examine the experession of HSP70,CD63.Results CCK-8 assay showed that the cell viability in each group,including (100.0 ± 4.0) ％ in 0 mmol/L group;(97.7 ± 1.5)％ in the 0.25 mmol/L group;(97.3 ±2.1)％ in the 0.50 mmol/L group;(87.7 ± 2.1) ％ in the 1.00 mmol/L group;(76.0 ± 1.0) ％ in the 2.00 mmol/L group;(58.1 ± 2.6) ％ in the 4.00 mmol/L group;(52.7 ± 1.5) ％ in the 5.00 mmol/L group;(37.7 ± 3.2) ％ in the 8.00 mmol/L group;(31.3 ±2.0)％ in the 10.00 mmol/L group.The isolated exosomes demonstrated round or oval shape under TEM.The peak particle size was 56 nm,which the overall mean particle size was 87 nm.Those and particles with a diameter between 30-150 nm accounted for 91.2％.In this experiment,The expression of HSP70,CD63 could be detected in the isolated exosomes.However,only the expression of HSP70 could be detected in the HK-2 cells.Conclusions Under the treatment of 2 mmol/l oxalate for 48 hours,Ultracentrifugation can be used to isolate and purify exosomes efficiently from the HK-2 cells.This is helpful for further study of exosome as mediator of cell-to-cell communication.

Objective:To explore the relationship between the psychological stress response of clinical nurses and hospital violence and ability empathy.Methods:Using the convenient sampling method, a total of 300 clinical nurses in Beijing Anzhen Hospital were selected as the research objects from March to June 2021. Nurses were surveyed using the Hospital Violence Incidents Inventory, Impact of Event Scale-Revised (IES-R) and Interpersonal Reactivity Index (IRI) . Pearson correlation analysis was used to explore the relationship between psychological stress response of clinical nurses and hospital violence and empathy ability. Stepwise regression analysis was used to explore the effect of hospital violence and empathy ability on predicting nurses' psychological stress response. A total of 300 questionnaires were distributed, 291 were recovered and 279 were valid.Results:The overall incidence of hospital violence among clinical nurses within 1 year was 58.1% (162/279) . There were statistically significant differences in scores of each dimension of psychological stress response of clinical nurses with different gender and education levels ( P<0.05) . The total score of psychological stress response was correlated with the total number of violent incidents, the number of verbal injuries and the number of threats in the past year ( P<0.05) . The severity of physical conflict, imagination, number of threats were positively correlated with psychological stress response ( P<0.01) , and females had more stress response ( P<0.01) . Opinion-taking was negatively correlated with psychological stress response ( P<0.05) . Conclusions:Clinical nurses may have a certain degree of psychological stress response after being subjected to hospital violence, which is more likely to occur in women, and empathy is a protective factor against this response.