Objective:To analyze the epidemiological characteristics of acute paraquat(PQ)poisoning in children in southwest Shandong, and the risk factors for pulmonary interstitial fibrosis.Methods:This retrospective study was performed on the clinical data of children with acute PQ poisoning admitted from January 2013 to December 2017 in 12 hospitals in southwest Shandong.All participants were divided into pulmonary interstitial fibrosis group and no pulmonary interstitial fibrosis group on the basis of the chest CT 14 days after poisoning.The epidemiological characteristics and risk factors of pulmonary interstitial fibrosis were analyzed.Results:During the study period, a total of 307 children with acute PQ poisoning were admitted to 12 hospitals, of which 61 (19.87%) were suffering from acute PQ poisoning.Forty-nine cases with complete clinical data were analyzed, including 26 male and 23 female patients poisoned by oral.The age distribution ranged from 8 months to 14 years.Poisoning mainly occured from July to September of each year.The mortality of acute PQ poisoning was 8.2%(4/49), and the incidence of pulmonary interstitial fibrosis in survival patients was 44.4%(20/45). Statistical differences ( P<0.05) were found between the pulmonary interstitial fibrosis and no pulmonary interstitial fibrosis, with regard to the times of blood purification, the time from poison exposure to blood purification, the application rate of glucocorticoids, the concentration of PQ in urine, the pediatric critical illness score, the time from poison exposure to gastric lavage, the white blood count at admission, serum creatinine, arterial blood lactate, PaO 2, PaCO 2, and PaO 2/FiO 2; however, there was no significant difference in the proportion of blood purification treatment, the mode of blood purification treatment, alanine aminotransferase, aspartate aminotransferase, urea nitrogen, creatine kinase and troponin.Stepwise logistic regression analysis showed that the time from exposure to poison to gastric lavage( OR=0.683, 95% CI 0.210-2.222)and to blood purification( OR=0.0133, 95% CI 0.004-0.042), the times of blood purification( OR=2.862, 95% CI 1.450-5.648), concentration of PQ in urine( OR=1.435, 95% CI 1.085-1.898), and the use of glucocorticoids( OR=0.190, 95% CI 0.048-0.757) were the risk factors for pulmonary interstitial fibrosis( P<0.05). Conclusion:Early gastric lavage and blood purification, increasing the frequence of adminitrating purification appropriately, using low-dose glucocorticoids can reduce the incidence of pulmonary interstitial fibrosis of children with acute PQ poisoning.

Bacterial persisters are phenotypic variants that tolerate exposure to lethal antibiotics. These dormant cells are responsible for chronic and recurrent infections. Multiple mechanisms have been linked to persister formation. Here, we report that a complex, consisting of an extracellular poly(dC) and its membrane-associated binding protein RmlB, appears to be associated with persistence of the opportunistic pathogen Pseudomonas aeruginosa. Environmental stimuli triggers a switch in the complex physiological state (from poly(dC)/RmlB to P-poly(dC)/RmlB or RmlB). In response to the switch, bacteria decrease proton motive force and intracellular ATP levels, forming dormant cells. This alteration in complex status is linked to a (p)ppGpp-controlled signaling pathway that includes inorganic polyphosphate, Lon protease, exonuclease VII (XseA/XseB), and the type III secretion system. The persistence might be also an adaptive response to the lethal action of the dTDP-L-rhamnose pathway shutdown, which occurs due to switching of poly(dC)/RmlB.

[Objective] To study the effect of p-nitrophenol (PNP) on persisters of Escherichia coli and Pseudomonas aeruginosa and to analyze the transcriptome to illustrate the impact of PNP on persister formation.[Methods] Ofloxacin was used to determine the bacteria persisters number.Cell self-digestion assay was done and the effect of respiratory inhibitors carbonyl cyanide chlorobenzene hydrazone (CCCP) on bacteria persisters was studied as well.Based on analysis of bacterial transcriptome,two genes (cyoA and appC) associated with the formation of persistence were screened.Their expressions were confirmed by Real-time Fluorescence Quantitative Polymerase Chain Reaction (PCR).The association between the two genes and the formation of persistence was also checked by antisense oligodeoxynucleotide assay.[Results] PNP inhibited the respiration of E.coli and P.aeruginosa,thus increased the proportion of bacterial persisters.PNP concentration,PNP function time and the bacterial growth period affected the proportion of bacteria persisters.PNP and CCCP inhibited the self-digestion of E.coli and P.aeruginosa,including the changes in dissolved oxygen,protein degradation and cell size,and the integrity of RNA.The results from transcriptome analysis and Real-time fluorescent quantitative PCR showed that PNP addition decreased the expression of cyoA and appC in E.coli and P.aeruginosa.Through the antisense oligodeoxynucleotide inhibitory expression of cyoA and appC was found that bacteria persister proportion increased compared with the original strain.[Conclusion] PNP can increase the proportion of bacteria persisters by inhibiting the cellular respiration.