Objective To investigate the effects of transient plateau factor on acute lung injury induced by phosgene poisoning in rabbits.Methods Forty New Zealand white rabbits of both sexes,aged 2.0-2.5 kg,were randomly divided into 4 groups (n =10 each) using a random number table:control group (group C),plateau factor group (group H),phosgene poisoning group (group P),and phosgene poisoning and plateau factor group (group HP).In group H,the rabbits were exposed to a simulated altitude of 33000 m for 2 h.In group P,the rabbits were exposed to phosgene for 3 min only.In group HP,the rabbits were exposed to phosgene for 33 min and then to a simulated altitude of 3000 m for 2 h.Respiratory rate (RR) was recorded and blood samples were taken before exposure to phosgene (T1),after exposure to phosgene (T2),and at 0,1 and 6 h after onset of exposure to a simulated altitude of 33000 m (T3-5) for determination of PaO2 and oxygenation index (OI) was calculated.The chests were opened at T5 and lungs removed for determination of lung water content (LC) and for microscopic examination.Lung coefficient (LC) was calculated.Results Compared with C group,RR was significantly increased at T3 in group H (P ＜ 0.05),and RR was increased and OI was decreased at T2-5 in P and HP groups (P ＜ 0.05 or 0.01).Compared with P group,RR was increased and OI was decreased at T3-5 in HP group (P ＜ 0.05 or 0.01).LW and LC were significantly higher in P and HP groups than in group C,and in HP group than in group P (P ＜ 0.05 or 0.01).The microscopic examination showed that pathological changes were observed in P and HP groups,however,the changes were severer in HP group.Conclusion Transient plateau factor can obviously aggravate the degree of acute lung injury induced by phosgene poisoning in rabbits.

Objective:To evaluate the feasibility and clinical value of pre-treatment non-enhanced chest CT radiomics features and machine learning algorithm to predict the mutation status and subtype (19Del/21L858R) of epidermal growth factor receptor (EGFR) for patients with non-small cell lung cancer (NSCLC).Methods:This retrospective study enrolled 280 NSCLC patients from first and second affiliated hospital of University of South China who were confirmed by biopsy pathology, gene examination, and have pre-treatment non-enhanced CT scans. There are 136 patients were confirmed EGFR mutation. Primary lung gross tumor volume was contoured by two experienced radiologists and oncologists, and 851 radiomics features were subsequently extracted. Then, spearman correlation analysis and RELIEFF algorithm were used to screen predictive features. The two hospitals were training and validation cohort, respectively. Clinical-radiomics model was constructed using selected radiomics and clinical features, and compared with models built by radiomics features or clinical features respectively. In this study, machine learning models were established using support vector machine (SVM) and a sequential modeling procedure to predict the mutation status and subtype of EGFR. The area under receiver operating curve (AUC-ROC) was employed to evaluate the performances of established models.Results:After feature selection, 21 radiomics features were found to be efffective in predicting EGFR mutation status and subtype and were used to establish radiomics models. Three types models were established, including clinical model, radiomics model, and clinical-radiomics model. The clinical-radiomics model showed the best predictive efficacy, AUCs of predicting EGFR mutation status for training dataset and validation dataset were 0.956 (95% CI: 0.952-1.000) and 0.961 (95% CI: 0.924-0.998), respectively. The AUCs of predicting 19Del/L858R mutation subtype for training dataset and validation dataset were 0.926 (95% CI: 0.893-0.959), 0.938 (95% CI: 0.876-1.000), respectively. Conclusions:The constructed sequential models based on integration of CT radiomics, clinical features and machine learning can accurately predict the mutation status and subtype of EGFR.

China ; Humans ; Streptococcus pneumoniae

Objective:To investigate the application value of metagenomic next-genera-tion sequencing (mNGS) in pathogenic diagnosis of suspected infected severe acute pancreatitis (SAP).Methods:The prospective study was conducted. The clinical data of 25 patients with suspected infected SAP who were admitted to the Xiangya Hospital of Central South University from May to September 2023 were collected. Upper limb venous blood samples of all the patients were collected for both of mNGS and routine pathogen microbial culture. Observation indicators: (1) grouping situations of the enrolled patients; (2) comparison of the diagnostic efficiency of mNGS and routine pathogen microbial culture; (3) results of peripheral blood pathogen microbial testing and peri-pancreatic effusion microbial culture; (4) testing time and cost. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3). Count data were expressed as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Results:(1) Grouping situations of the enrolled patients. A total of 25 patients were selected for eligibility. There were 18 males and 7 females, aged 48(40,59)years. The duration of hospital stay of 25 patients was 30(20,50)days. The etiologies of 25 patients included 14 cases of hyperlipidemic pancreatitis, 8 cases of biliary pancreatitis, 1 case of alcohol-induced acute pancreatitis, and 2 cases of pancreatitis caused by other causes. Of the 25 patients, there were 17 cases with infected pancreatic necrosis (IPN) including 7 cases of death, and 8 cases with sterile pancreatic necrosis including no death. (2) Comparison of the diagnostic efficiency of mNGS and routine pathogen microbial culture. The positive rates of mNGS and routine pathogen microbial culture in diagnosis of suspected infected SAP were 72.0%(18/25) and 32.0%(8/25), respectively, showing a significant difference between them ( χ2=8.01, P<0.05). The sensitivity and negative predic-tive value of mNGS and routine pathogen microbial culture in diagnosis of IPN were 94.1%(16/17), 35.3%(6/17) and 85.7%(6/7), 35.3%(6/17), showing significant differences between them ( χ2=12.88, 5.04, P<0.05). The specificity and positive predictive value of mNGS and routine pathogen microbial culture in diagnosis of IPN were 75.0%(6/8), 75.0%(6/8) and 88.9%(16/18), 75.0%(6/8), showing no significant difference between them ( χ2=0, 0.82, P>0.05). (3) Results of peripheral blood pathogen microbial testing and peripancreatic effusion microbial culture. Of the 17 patients with IPN, 36 strains of pathogenic bacteria were detected by mNGS, and 6 strains were detected by routine pathogen microbial culture. There were 16 of 17 patients with IPN showing positive mNGS pathogenic testing, of which 13 cases were consistent with the pathogenic testing results of peri-pancreatic effusion microbial culture, showing a consistency rate of 76.5%(13/17). There were 6 pati-ents with IPN showing positive routine pathogen microbial culture, with a consistency rate of 35.3%(6/17) to peripancreatic effusion microbial culture. (4) Testing time and cost. Testing time of mNGS and routine pathogen microbial culture were (43±17)hours and (111±36)hours, showing a signifi-cant difference between them ( t=9.31, P<0.05). Testing cost of mNGS was (2 267±0)yuan/case, accoun-ting for 1.7% of the hospitalization expenses of (133 759±120 744)yuan/case. Testing cost of routine pathogen microbial culture was (240±0)yuan/case, accounting of 0.2% of the hospitalization expenses. Conclusion:mNGS has important value for early pathogenic diagnosis of suspected infected SAP, and has a high timeliness.

Background and Aims:Accurate early pathogen diagnosis is a breakthrough for improving the prognosis of infectious pancreatic necrosis(IPN)patients.However,there is currently a lack of efficient methods for early identification of IPN in clinical settings.This study was performed to assess the application value of next-generation sequencing technology based on metagenomic capture(MetaCAP)in the pathogen diagnosis of IPN. Methods:A prospective study was conducted on 29 patients suspected of having acute necrotizing pancreatitis at Xiangya Hospital of Central South University between January and July 2024.Blood samples were tested using MetaCAP and conventional pathogen culture.The results of peritoneal fluid pathogen culture were used as the gold standard to compare the diagnostic efficacy of the two methods. Results:Due to three cases lacking peritoneal fluid culture results,a total of 26 cases were included in the final analysis.The overall mortality rate was 23.1％(6/26).During hospitalization,9 cases(34.6％)were diagnosed with IPN.The sensitivity and negative predictive value of MetaCAP for diagnosing IPN were significantly higher than those of conventional pathogen culture(77.8％vs.11.1％,P=0.031;86.7％vs.65.2％,P=0.032),while the differences in specificity(76.5％vs.88.2％,P=0.689)and positive predictive value(63.6％vs.33.3％,P=0.347)between the two methods were not statistically significant.The average detection time for MetaCAP was 33(20-49)h,while microbial culture took 125(45-142)h,with a significant difference(P＜0.001).The average cost for blood MetaCAP testing was 2 500 yuan per case,but it accounted for only 1.19％of the average hospitalization cost. Conclusion:MetaCAP has significant value in the early pathogen diagnosis of IPN,with a shorter detection time,good testing efficacy,and health-economic value,demonstrating a promising clinical application prospect.