ABSTRACT
Objective To establish and evaluate a rat model of inhalation lung injury induced by ship smog.Methods A rat model of inhalation lung injury was established by analyzing the composition of ship materials after combustion.Fortytwo healthy male Wistar rats were randomly divided into normal control group and 2,6,12,24,48 and 72h groups (6 each)after inhalation,these rats were killed at each time point,and the changes of arterial blood gas,coagulation function,the lung water content (％) were detected.Macroscopic and microscopic changes in lung tissues were observed to judge the degree of lung injury.Results The main components after combustion of 7 kinds of nonmetal materials on ship included CO,CO2,H2S,NOx and other harmful gases in this study,AIKE in one gas detector was used to monitor O2,CO,CO2 and H2S,and their concentrations remained relatively stable within 15 minutes,and the injury time was 15 minutes.The rats presented with shortness of breath and mouth breathing.Smoke inhalation caused a significant hypoxemia,the concentration of blood COHb reached a peak value 2h and the lung water content (％) did 6h after inhalation (P＜0.05).It is metabolic acidosis in the early stage after inhalation,but metabolic acidosis combined with respiratory acidosis in the later period.Histopathological observation showed diffuse hemorrhage,edema and inflammatory cell infiltration in the lung tissue as manifestations of lung injury,and the injury did not recover at 72h after inhalation,the change of blood coagulation function was not statistically significant.Conclusion A rat model of inhalation lung injury induced by ship smog has been successfully established,and has the advantages of easy replication,stability and reliability,thus can be used to research and treat inhalation lung injury induced by ship smog in naval war environment and other cases.
ABSTRACT
Objective To investigate the expression and variation of MIP 1β,MIP-2,and IL-12p70 in mice with bloodstream infection caused by 4 kinds of bacteria.Methods CD-1 (ICR) mouse models of bloodstream infection with Staphylococcus aureus (S.aureus),Enterococcus f aecalis (E.f aecalis),Escherichia coli (E.coli),and K lebsiella pneumoniae (K.pneumoniae) were established.After mice in each trial group and PBS control group were infected by bacteria for 0.5h,1h,3h,6h,12h,24h,and 48h,concentrations of MIP-1β,MIP-2,and IL-12p70 were detected by Luminex liquid suspension chip system.Results Concentrations of MIP-1β increased significantly 1h after bacteria was in blood,S.aureus,E.faecalis,E.coli,K.pneumoniae,and control groups were (134.5 ± 18.3),(61.5 ± 15.4),(3 354.0 ±809.0),(6 888.4 ± 1 100.2),and (28.9 ± 4.6) pg/mL respectively;the peak values of IL-12p70 were (389.3 ± 118.1),(127.6 ± 10.0),(42.2 ± 3.5),(62.8 ± 8.4),and (4.8 ± 0.3) pg/mL respectively.Concentrations of MIP-1β and MIP-2 in E.coli and K.pneumoniae groups were significantly higher than other trial groups and control group (all P＜0.01),while concentrations of IL-12p70 in S.aureus and E.faecalis groups were both significantly higher than E.coli,K.pneumoniae,and control groups (all P＜0.01).Conclusion Concentrations of MIP-1β and MIP-2 in E.coli and K.pneumoniae groups were both significantly higher than those in S.aureus and E.faecalis groups,while concentrations of IL-12p70 in S.aureus and E.faecalis groups were both significantly higher than those in E.coli and K.pneumoniae groups.The combination detection of multiple cytokines or chemokines are valuable in predicting gram-positive or gram-negative bacterial infection,and can provide basis for treatment of early infection.