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Objective:To explore the effect of short-chain fatty acid (SCFA) on acute lung injury (ALI) in sepsis via macrophage polarization.Methods:① Clinical trial: 30 sepsis patients admitted to the intensive care unit (ICU) of General Hospital of Ningxia Medical University from January to December in 2022 and 10 non-sepsis patients in the same period were enrolled, stool samples were collected on the first day of admission, and SCFA butyric acid level in the two groups were studied by targeted metabolomics. ② Animal experiment: male C57BL/6J mice were selected and randomly divided into sham operation group (Sham group), sepsis caused by cecal ligation and perforation (CLP group) and SCFA intervention group (SCFA group, sodium butyrate 25 mg/kg was given by gavage 1 hour after CLP), with 6 animals in each group. Twenty-four hours after molding, the state of mice was evaluated by mouse sepsis score (MSS), the degree of pulmonary edema was evaluated by calculating the wet/dry ratio (W/D), and the pathological changes of lung tissue were observed by hematoxylin-eosin (HE) staining, and lung injury score was performed. The serum levels of tumor necrosis factor-α (TNF-α), interleukins (IL-1β, IL-6, IL-10), nuclear factor-κB (NF-κB), and transforming growth factor-β (TGF-β) were detected by enzyme-linked immunosorbent assay (ELISA). Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to measure the mRNA expressions of inflammatory factors TNF-α, IL-1β, IL-6 and antioxidant factor nuclear factor E2-related factor 2 (Nrf2) in lung tissue. The expressions of macrophage polarization markers arginin-1 (ARG-1), CD206, inducible nitric oxide synthase (iNOS) and IL-1β in lung tissue were detected by immunohistochemistry.Results:① Compared with non-sepsis patients, SCFA-butyric acid level was significantly reduced in patients with sepsis (μg/g: 34.56±6.61 vs. 1 150.67±381.90, P < 0.01). ② Compared with the Sham group, MSS, lung W/D ratio, lung injury score, the levels of serum inflammatory factors TNF-α, TGF-β, NF-κB, IL-10, IL-6, IL-1β, the mRNA expressions of lung tissue inflammatory factors and antioxidant factor Nrf2, M1 macrophage polarization markers ARG-1, CD206 and M2 macrophage polarization markers iNOS and IL-1β were significantly increased in the CLP group. Compared with the CLP group, MSS, lung W/D ratio, lung injury score, the levels of serum inflammatory factors TNF-α, TGF-β, NF-κB, IL-10, IL-6, IL-1β, the mRNA expressions of lung tissue inflammatory factors and antioxidant factors Nrf2, and M1 macrophage polarization markers ARG-1 and CD206 were significantly reduced [MSS: 14.50±3.16 vs. 20.00±1.55, lung W/D ratio: 4.60±0.18 vs. 5.51±0.59, lung injury score: 47.56±2.36 vs. 88.30±6.04, serum TNF-α (ng/L): 27.99±0.58 vs. 69.55±18.53, serum TGF-β (μg/L): 9.82±2.16 vs. 18.73±1.83, serum NF-κB (μg/L): 1.23±0.09 vs. 1.95±0.28, serum IL-10 (ng/L): 78.39±2.29 vs. 140.22±19.82, serum IL-6 (ng/L): 300.64±77.60 vs. 1 442.52±494.14, serum IL-1β (ng/L): 33.13±0.99 vs. 38.39±1.31, lung IL-1β mRNA expression (IL-1β/β-actin): 1.01±0.01 vs. 2.24±0.62, lung IL-6 mRNA expression (IL-6/β-actin): 0.63±0.09 vs. 1.46±0.31, lung TNF-α mRNA expression (TNF-α/β-actin): 0.81±0.33 vs. 2.57±0.64, lung Nrf2 mRNA expression (Nrf2/β-actin): 1.59±0.25 vs. 2.96±0.89, ARG-1 positive area: (36.27±2.89)% vs. (49.75±5.03)%, CD206 positive area: (20.02±3.26)% vs. (44.24±3.61)%, all P < 0.05]. However, there was no significant difference in M2 macrophage polarization markers iNOS and IL-1β expression [iNOS positive area: (18.32±2.23)% vs. (21.77±3.57)%, IL-1β positive area: (40.42±4.78)% vs. (42.14±4.22)%, both P > 0.05]. Conclusion:SCFA may alleviate ALI in sepsis by reducing M1 polarization of pulmonary macrophages.
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Objective:To investigate the microecological structure changes and correlation in blood, lung tissue and fecal intestine of mice with sepsis and acute lung injury.Methods:A total of 12 healthy male C57BL/6J mice were divided into the cecal ligation and perforation (CLP) group and sham operation (sham) group by random number table method, with six mice in each group. In the CLP group, acute lung injury model of sepsis mice was prepared by CLP method. In the sham group, only laparotomy but no perforation of cecal ligation was performed. Eye blood, lung tissue, and feces were collected from mice in each group 24 h after surgery. Lung tissue morphological changes were observed by HE staining, and 16s ribosome RNA sequencing was used to analyze the structural changes of microecology of the bacterial flora at each site in sepsis mice and find out the correlation.Results:(1) HE staining showed that mice in the CLP group had exudation into the alveolar cavity of the lung, disordered lung tissue structure, accompanied by a large number of inflammatory cell infiltration, and the lung histopathological score was significantly higher than that in the sham group ( P < 0.01). (2)α diversity analysis showed that there was no statistical significance in blood and fecal samples between the sham group and CLP group, while Ace index, Chao index and Simpson index in lung tissue samples were statistically significant ( P < 0.05). (3) β diversity analysis showed that the differences in blood and fecal samples were greater between the sham group and CLP group than that within the group, and analysis of Bray Curtis, weighted, and unweighted indexes were statistically significant ( P < 0.05). (4) At the phylum level, compared with the sham group, the abundance of Proteobacteria gradually increased, and the abundance of Firmicutes and actinobacteria was decreased in the CLP group. At the genus level, the sham group was dominated by Acinetobacter and Duchenne, while the CLP group was dominated by Escherichia coli and unclassified Enterobacter. Blood flora was more similar to lung tissue flora composition as compared with fecal flora. Conclusions:The distribution of bacterial flora in blood, lung tissue and intestine of sepsis mice with acute lung injury is partially overlapped.
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Objective:To analyze the clinical characteristics, risk factors and prognosis of early septic patients with bloodstream infection (BSI) in department of critical care medicine of Ningxia Medical University General Hospital.Methods:Patients with sepsis admitted to department of critical care medicine of Ningxia Medical University General Hospital from November 1, 2019 to August 31, 2021 were included in a prospective observational study. Blood samples were collected for culture within 24 hours of sepsis diagnosis. General information, laboratory test indicators and blood culture results within 24 hours of sepsis diagnosis were recorded. Patients were followed up and prognostic indicators [mechanical ventilation time, length of intensive care unit (ICU) stay, and 28-day survival] were observed. According to blood culture results, patients were divided into BSI group and non-BSI group. Univariate and multivariate Logistic regression analysis were performed on the general clinical characteristics of patients in the two groups to screen the risk factors of early BSI in septic patients. Receiver operator characteristic curve (ROC) was drawn to evaluate the predictive value of risk factors for early BSI in septic patients.Results:A total of 202 septic patients were included in this study, with 62 patients in BSI group and 140 patients in non-BSI group. The majority of patients in the BSI group were associated with abdominal infection (61.3%), and the majority of patients in the non-BSI group were associated with pulmonary infection (49.3%). A total of 76 strains were isolated from septic patients in BSI group, and the most common pathogens were Escherichia coli (26 strains, 34.2%), Klebsiella pneumoniae (11 strains, 14.4%), Enterococcus (7 strains, 9.2%), Bacteroides fragilis (6 strains, 7.9%) and Staphylococcus aureus (6 strains, 7.9%). There were no significant differences in mechanical ventilation time, the length of ICU stay and 28-day mortality between the BSI group and the non-BSI group. The difference of variables was statistically significant between two group according to Univariate analysis, which included body temperature, acute physiology and chronic health score Ⅱ (APACHEⅡ), use of antibiotics before admission to ICU, abdominal infection, hypersensitivity C-reactive protein (hs-CRP), serum creatinine (SCr), total bilirubin (TBil), platelet count (PLT), blood lactic acid (Lac) and hypercalcitonin (PCT). Multivariate analysis showed that low PLT [odds ratio ( OR) = 1.004, P = 0.019], high Lac ( OR = 1.314, P = 0.002), high body temperature ( OR = 1.482, P = 0.027), concomitant abdominal infection ( OR = 2.354, P = 0.040), no use of antibiotics before admission to ICU ( OR = 2.260, P = 0.049) were independent risk factors for early BSI in septic patients. The area under ROC curve (AUC) of PLT, Lac, body temperature, abdominal infection and no use of antibiotics before admission to ICU for predicting early BSI in septic patients were 0.711, 0.686, 0.594, 0.592 and 0.590, respectively. Youden index was used to calculate the optimal cut-off values, which was PLT 122.50×10 9/L, Lac 2.95 mmol/L, body temperature 39.45 ℃, respectively. The highest level of AUC was 0.754, the sensitivity was 75.8%, and the specificity was 68.8%, which were observed when the 5 items were combined. Conclusions:Early septic patients with BSI are more serious than those without BSI. Low PLT, high Lac, high temperature, concomitant abdominal infection and no use of antibiotics before admission to ICU are independent risk factors for early BSI in septic patients, and the combination of these five factors has good predictive value.
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Objective:To explore the value of bedside lung ultrasound in the early diagnosis and severity assessment of ventilator-associated pneumonia (VAP).Methods:A prospective observational study was conducted in 60 patients with VAP (VAP group) and 62 patients without VAP (control group) who were admitted to department of intensive care unit of General Hospital of Ningxia Medical University from September 2018 to July 2020. The gender, age and underlying diseases of non-VAP group were matched with VAP group. The general clinical data such as gender, age, underlying diseases, department source of the patient, acute physiology and chronic health evaluationⅡ(APACHEⅡ) score, sequential organ failure assessment (SOFA) score were recorded. The body temperature, white blood cell count (WBC), procalcitonin (PCT), oxygenation index (PaO 2/FiO 2), alveolar artery oxygen differential pressure (P A-aDO 2) were recorded. During mechanical ventilation, the patient's body temperature, WBC, sputum characteristics, and the change of the lung ultrasound were dynamically observed. With or without dynamic air bronchogram, lung ultrasound was considered to be positive as long as there were small subpleural consolidation or tissue-like sign. Ventilator-associated pneumonia lung ultrasound score (VPLUS) and lung ultrasound score (LUSS) were performed, and chest CT scan was completed on the same day. Use positive chest CT scan as the standard to evaluate the diagnostic efficacy of lung ultrasound, VPLUS score, and the combination of the two with PCT for VAP. LUSS was used to assess the severity of disease in patients with VAP. The correlation between LUSS and PaO 2/FiO 2, P A-aDO 2, APACHEⅡscore and SOFA score were analyzed. Results:① General information: compared with non-VAP group, VAP group had more emergency surgery patients [51.7% (31/60) vs. 33.9% (21/62), P = 0.047], APACHEⅡ score and SOFA score were significantly higher (APACHEⅡscore: 15.4±5.7 vs. 13.4±3.4, P = 0.021; SOFA score: 8.8±4.2 vs. 6.3±3.3, P < 0.001), body temperature tended to rise (℃: 38.3±0.8 vs. 38.0±0.9, P = 0.054), more patients had airway purulent secretions [65.0% (39/60) vs. 41.9% (26/62), P = 0.011], and mechanical ventilation time and length of ICU stay were longer [mechanical ventilation time (days): 10.5 (6.6, 15.0) vs. 4.3 (3.0, 6.0), P < 0.001; length of ICU stay (days): 14.8 (9.0, 18.0) vs. 6.0 (4.0, 9.1), P < 0.001], 28-day mortality rate was higher [31.7% (19/60) vs. 9.7% (6/62), P = 0.003].② Diagnostic efficacy evaluation: when lung ultrasound was positive, VPLUS≥3 and PCT > 0.5 μg/L were used separately for the diagnosis of VAP, the sensitivity was 73.3%, 75.0%, 61.7%, respectively; the specificity was 80.6%, 58.1% and 59.7%, respectively; the 95% confidence interval (95% CI) was 0.685-0.842, 0.574-0.748, 0.514-0.694, respectively, all P < 0.05, positive lung ultrasound had good sensitivity and specificity. When positive lung ultrasound or VPLUS≥3 were combined with PCT > 0.5 μg/L for tandem test, the specificity of VAP diagnosis was increased to 95.2% and 83.9%, respectively; but the specificity of VAP diagnosis of positive lung ultrasound combined with PCT > 0.5 μg/L was higher than VPLUS ≥3 combined with PCT > 0.5 μg/L (95.2% vs. 83.9%, P < 0.05).③ Correlation analysis: LUSS showed a significant positive correlation with APACHEⅡ and SOFA score ( r values were 0.407, 0.399, P values were 0.001, 0.002, respectively), LUSS had no relation with PaO 2/FiO 2 and P A-aDO 2 ( r values were 0.189, -0.064, P values were 0.629, 0.149, respectively). Conclusions:Lung ultrasound can early detect VAP , and its diagnostic specificity is significantly improved when combined with PCT > 0.5 μg/L. LUSS is closely related to the severity of disease in VAP patients, therefore, lung ultrasound may be an effective method for early diagnosis and efficacy evaluation of VAP patients.
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Objective To investigate the characteristics of gut microbiota dysbosis in septic and non-septic patients in ICU.Methods A prospective observational research was conducted.Ten septic patients(septic group),ten patients without sepsis(non-septic group) were admitted to Department of Critical Care Medicine of General Hospital of Ningxia Medical University from February 2017 to June 2017 were enrolled.And ten healthy persons was enrolled as control group.Stool samples were collected from septic and non-septic patients within two days following admission to the intensive care unit (ICU);healthy persons' was random.High throughput 16S rRNA gene sequencing technology was used to detect fecal bacterium of three groups.Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score,Sequential Organ Failure Assessment (SOFA) score of patients were recorded on the first day after admission to ICU.Results Compared with the control group,the α diversity of gut microbiota in non-septic and septic groups showed a downward trend,the [3 diversity showed that the structure of gut microbiota in non-septic and the septic groups was significant different,and the individual differences were more obvious.At the level of phylum,compared with the control group,the proportion of Firmicutes+Bacteroidetes in non-septic and septic groups decreased significantly(P=0.013,0.028),and the proportion of Proteobacteria increased(P=0.017,0.026),while the proportion of Fusobacteria just increased in the non-septic group(P < 0.01).At the level of genus,compared with the control group,the proportion of beneficial symbiotic genus in non-septic and septic groups can be seen decreased,such as Ruminococcus(P=0.045,0.026),Pseudobutyrivibrio(P=0.009,< 0.01),Anaerostipes(P=0.011,0.003),Coprococcus(P=0.045,0.011),Phascolarctobacterium(P=0.008,0.022),Subdoligranulum(P=0.006,0.026).The proportion of Lactobacillus,Dorea,Faecalibacterium,Roseburia and Blautia showed downward trend in non-septic and septic groups,but only the decline of Lactobacillus in non-septic group had statistical difference(P=0.005),and the decline of Dorea,Faecalibacterium,Roseburia and Blautia in septic group had statistical differences(P=0.037,0.038,0.002 and 0.017,respectively).The proportion of conditional pathogenic Fusobacterium,Actinomyces,Peptstreptococcus,Streptococcus increased in non-septic group(P=0.001,0.019,0.011 and 0.014,respectively),the proportion of pathogenic Staphylococcus(P=0.035,0.006),Enterococcus(P=0.001,0.001),Anaerococcus(P=0.006,0.006) and Bacillus(both P < 0.01) increased in non-septic and septic groups.Conclusions Gut microbiota dysbiosis occured in septic and non-septic patients in the ICU,and showed that diversity decreased,structure of intestinal flora changed,obligate anaerobic bacteria decreased,facultative anaerobic bacteria increased,benefical symbiotic bacteria decreased,pathogenic bacteria increased and can be the dominate genus.
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Objective To observe differential expressions of microRNA-127-5p (miR-127-5p) in bronchoalveolar lavage fluid (BALF) of patients with severe pneumonia and the value of miR-127-5p in the diagnosis of severe pneumonia. Methods Thirty severe pneumonia patients and 10 non-respiratory infection patients who needed mechanical ventilation after surgery admitted to Department of Critical Care Medicine of General Hospital of Ningxia Medical University from January to December in 2015 were enrolled, whose specimens of BALF were collected. The differential expressions of miRNA in BALF of patients in both groups were screened by miRNA chip technique to preliminarily establish miRNA differential expression profiles in BALF of severe pneumonia, and the miRNAs which were up-regulated and down-regulated were screened out. The expression levels of miR-127-5p were determined using a real-time fluorescent quantitative polymerase chain reaction (PCR). The value of miR-127-5p expression in the diagnosis of severe pneumonia was evaluated with receiver-operating characteristic curve (ROC). Results All of the 40 patients were enrolled in the final analysis. Differential expression spectrum of miRNA in severe pneumonia patients was initially built, in which 40 miRNAs were up-regulated and 113 miRNAs were down-regulated. Compared with non-respiratory infection patients, the expressions of miR-127-5p were significantly lowered in severe pneumonia patients (2-ΔΔCT: 0.578±0.226 vs. 1.004±0.337) with statistical difference (t = 4.552, P = 0.000). ROC curve analysis showed that the area under ROC curve (AUC) of miR-127-5p for diagnosis of severe pneumonia was 0.855 [95% confidence interval (95%CI) = 0.721-0.989, P = 0.001], with the optimal sensitivity and specificity of 86.7%and 70.0% respectively with 0.840 as the critical value, and the positive likelihood ratio was 2.89, the negative likelihood ratio was 0.19. Conclusion miR-127-5p in BALF could be used as a new biomarker for the diagnosis of severe pneumonia.