Risk stratification and survival time of patients with gram-negative bacillary pneumonia in the intensive care unit.

Introduction: Pneumonia is a common infection in the intensive care unit (ICU), and gram-negative bacilli are the most common bacterial cause. The purpose of the study was to investigate the risk factors for 30-day mortality in patients with gram-negative bacillary pneumonia in the ICU, construct a predictive model, and stratify patients based on risk to assess their short-term survival. Methods: Patients admitted to the ICU with gram-negative bacillary pneumonia at Fujian Medical University Affiliated First Hospital between January 2018 and September 2020 were selected. Patients were divided into deceased and survivor groups based on whether death occurred within 30 days. Multifactorial logistic regression analysis was used to identify independent risk factors for 30-day mortality in these patients, and a predictive nomogram model was constructed based on these factors. Patients were categorized into low-, medium-, and high-risk groups according to the model's predicted probability, and Kaplan-Meier survival curves were plotted to assess short-term survival. Results: The study included 305 patients. Lactic acid (odds ratio [OR], 1.524, 95% CI: 1.057-2.197), tracheal intubation (OR: 4.202, 95% CI: 1.092-16.169), and acute kidney injury (OR:4.776, 95% CI: 1.632-13.978) were identified as independent risk factors for 30-day mortality. A nomogram prediction model was established based on these three factors. Internal validation of the model showed a Hosmer-Lemeshow test result of X2=5.770, P=0.834, and an area under the ROC curve of 0.791 (95% CI: 0.688-0.893). Bootstrap resampling of the original data 1000 times yielded a C-index of 0.791, and a decision curve analysis indicated a high net benefit when the threshold probability was between 15%-90%. The survival time for low-, medium-, and high-risk patients was 30 (30, 30), 30 (16.5, 30), and 17 (11, 27) days, respectively, which were significantly different. Conclusion: Lactic acid, tracheal intubation, and acute kidney injury were independent risk factors for 30-day mortality in patients in the ICU with gram-negative bacillary pneumonia. The predictive model constructed based on these factors showed good predictive performance and helped assess short-term survival, facilitating early intervention and treatment.

Development of a nomogram for predicting in-hospital mortality in patients with liver cirrhosis and sepsis.

In this study, we aimed to investigate the risk factors associated with in-hospital mortality in patients with cirrhosis and sepsis, establish and validate the nomogram. This retrospective study included patients diagnosed with liver cirrhosis and sepsis in the Medical Information Mart for Intensive Care IV (MIMIC-IV). Models were compared by the area under the curve (AUC), integrated discriminant improvement (IDI), net reclassification index (NRI) and decision curve analysis (DCA). A total of 1,696 patients with cirrhosis and sepsis were included in the final cohort. Our final model included the following 9 variables: age, heartrate, total bilirubin (TBIL), glucose, sodium, anion gap (AG), fungal infections, mechanical ventilation, and vasopressin. The nomogram were constructed based on these variables. The AUC values of the nomograms were 0.805 (95% CI 0.776-0.833), which provided significantly higher discrimination compared to that of SOFA score [0.684 (95% CI 0.647-0.720)], MELD-Na [0.672 (95% CI 0.636-0.709)] and ABIC [0.674(95% CI 0.638-0.710)]. We established the first nomogram for predicting in-hospital mortality in patients with liver cirrhosis and sepsis based on these factors. This nomogram can performs well and facilitates clinicians to identify people at high risk of in-hospital mortality.

New Attempts to Inhibit Methicillin-Resistant Staphylococcus aureus Biofilm? A Combination of Daptomycin and Azithromycin.

Objective: To investigate the antibacterial impact of daptomycin and azithromycin in vitro on methicillin-resistant Staphylococcus aureus (MRSA) biofilm. Methods: (1) Measure the strain growth curve and the biofilm formation curve. (2) Determine the minimum inhibitory concentrations (MICs) of daptomycin and azithromycin. (3) Investigate the antibacterial impact of the combination of daptomycin and azithromycin. (4) Perform the evaluation of the intervention impact of antimicrobial agents on MRSA biofilm. (5) Observe the biofilm after intervention with the antibacterial agent. Results: (1) MRSA exhibited three phases: lag phase (0-4 h), logarithmic growth (4-8 h) and stationary phase after 18 h; its biofilm began to form at 6 h, semi-matured at 24 h, and reached maturity after 48 h. (2) The MICs of daptomycin and azithromycin were 8 µg/mL and greater than 256 µg/mL, respectively. (3) The combination of daptomycin and azithromycin has an additive effect on MRSA (Fractional Inhibitory Concentration Index [FICI] 0.625) (FICI = MIC of drug A in combination/MIC of drug A alone + MIC of drug B in combination/MIC of drug B alone). Evaluation criteria: Synergistic effect is considered when FICI ≤ 0.5; additive effect is considered when 0.5 < FICI ≤ 1; irrelevant effect is considered when 1 < FICI ≤ 2; antagonistic effect is considered when FICI > 2). (4) Daptomycin or azithromycin at MICs inhibited not only the growth of planktonic bacteria but also the formation of biofilm. (5) The combination of both, in which group the ratio of live/dead bacteria is low and the biofilm morphology was incomplete, was more productive than monotherapy in against biofilm. Conclusion: Both daptomycin and azithromycin have anti-MRSA biofilm activity, and daptomycin is dominant. The fact that the combination of both can significantly inhibit the further maturation of MRSA biofilm and destroy already formed biofilm demonstrates the superiority of the combination over the monotherapy.

Risk model and validation of carbapenem-resistant Klebsiella pneumoniae infection in patients with cerebrovascular disease in the ICU.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an emerging global epidemic. The intention of this study was to explore the risk model and validation of CRKP infection in patients with cerebrovascular disease in the intensive care unit (ICU). The data of patients with cerebrovascular disease and Klebsiella pneumoniae infection were retrospectively collected. The patients were divided into the CRKP group and the carbapenem-susceptible Klebsiella pneumoniae (CSKP) group. There were significant differences (P < 0.05) between the CRKP group and the CSKP group for many variables. Multivariate binary logistic regression analysis showed that the number of types of antibiotics used, history of glucocorticoid use, and duration of mechanical ventilation before the occurrence of infectious bacteria are the independent risk factors for CRKP infection in patients with cerebrovascular disease in the ICU, and a nomogram risk model was constructed accordingly. The area under the ROC curve of the risk model was 0.868 (95% CI: 0.803-0.934).

Utility of methylene blue mixed with autologous blood in preoperative localization of pulmonary nodules and masses.

The value of CT-guided puncture with methylene blue mixed with autologous blood in preoperative localization of pulmonary nodules and masses was explored. A total of 113 patients with 146 nodules and masses were treated with methylene blue mixed with autologous blood for preoperative localization and thoracoscopic surgery in the Department of Thoracic Surgery, the First Affiliated Hospital of Fujian Medical University between October 2021 and October 2022. The localization effect, complications, and pathological conditions were observed. The localization success rate was 98.63% (144/146). The localization failed nodules and masses could still be located by looking for needle eyes and reading films. The whole group successfully completed thoracoscopic surgery. The average interval of operation after puncture was 22.16 ± 6.22 h. There was a small amount of suspicious hemothorax after puncture. There was no pneumothorax after puncture in the whole group. There were no hemoptysis, irritating dry cough, and other reactions. The overall complication rate was 2.65%, and no special treatment was given. It is safe and effective to use methylene blue mixed with autologous blood for CT-guided preoperative puncture and localization of small pulmonary nodules and masses.

Carbapenem-resistant gram-negative bacterial infection in intensive care unit patients: Antibiotic resistance analysis and predictive model development.

In this study, we analyzed the antibiotic resistance of carbapenem-resistant gram-negative bacteria (CR-GNB) in intensive care unit (ICU) patients and developed a predictive model. We retrospectively collected the data of patients with GNB infection admitted to the ICU of the First Affiliated Hospital of Fujian Medical University, who were then divided into a CR and a carbapenem-susceptible (CS) group for CR-GNB infection analysis. Patients admitted between December 1, 2017, and July 31, 2019, were assigned to the experimental cohort (n = 205), and their data were subjected to multivariate logistic regression analysis to identify independent risk factors for constructing the nomogram-based predictive model. Patients admitted between August 1, 2019, and September 1, 2020, were assigned to the validation cohort for validating the predictive model (n = 104). The Hosmer-Lemeshow test and receiver operating characteristic (ROC) curve analysis were used to validate the model's performance. Overall, 309 patients with GNB infection were recruited. Of them, 97 and 212 were infected with CS-GNB and CR-GNB, respectively. Carbapenem-resistant Klebsiella pneumoniae (CRKP), carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) were the most prevalent CR-GNB. The multivariate logistic regression analysis results of the experimental cohort revealed that a history of combination antibiotic treatments (OR: 3.197, 95% CI: 1.561-6.549), hospital-acquired infection (OR: 3.563, 95% CI: 1.062-11.959) and mechanical ventilation ≥ 7 days (OR: 5.096, 95% CI: 1.865-13.923) were independent risk factors for CR-GNB infection, which were then used for nomogram construction. The model demonstrated a good fit of observed data (p = 0.999), with an area under the ROC curve (AUC) of 0.753 (95% CI: 0.685-0.820) and 0.718 (95% CI: 0.619-0.816) for the experimental and validation cohort, respectively. The decision curve analysis results suggested that the model has a high practical value for clinical practice. The Hosmer-Lemeshow test indicated a good fit of the model in the validation cohort (p-value, 0.278). Overall, our proposed predictive model exhibited a good predictive value in identifying patients at high risk of developing CR-GNB infection in the ICU and could be used to guide preventive and treatment measures.

Highly selective and sensitive probes for the detection of Cr(vi) in aqueous solutions using diglycolic acid-functionalized Au nanoparticles.

In this study, a variety of diglycolic acid-functionalized gold nanoparticle (Au NP) probes are reported, which are highly sensitive for the detection of chromium ions, Cr(vi) ions, at low concentrations in aqueous solutions based on the application of surface plasmon resonance (SPR) theory. Due to its outstanding affinity for Cr(vi) ions, the capped diglycolic acid would induce the aggregation of the NP probes upon encountering them; this was evidenced by the obvious red-shifting of the SPR peak and the enlarged size of the NPs. For the same reason, the selectivity of the probe for Cr(vi) against other heavy metal ions was found to be remarkable. Under optimized conditions, the probe showed the limit of detection (LOD) of 0.32 ppb for Cr(vi) and a linear detection scale ranging from 0.32 ppb to 0.1 ppm. To the best of our knowledge, this is probably the lowest LOD reported for Cr(vi) detection among those of the methods based on SPR.

Preparation of elastic diglycolamic-acid modified chitosan sponges and their application to recycling of rare-earth from waste phosphor powder.

Inspired by the phenomenon of sponges soaking up water, a novel syringe-like adsorption device used diglycolamic-acid modified chitosan sponges (CSs-DGAA) as adsorbents is reported for recycling of rare-earth elements (REEs) by Squeezing & Soaking (S&S) operation. Integrating the elasticity of sponges and selective extraction ability of diglycolamic acid groups, the new device can efficiently recycle REEs from aqueous solutions. This device only needs 10 min to achieve adsorption equilibrium; squeezing the water from the sponges achieves solid-liquid separation. This syringe-like adsorption method not only solves the pollution problem caused by the organic solvents used during liquidliquid extractions, but also improves the time needed to achieve adsorption equilibrium and uses significantly less energy than energy intensive solid-phase extractions of solid-liquid separations. Moreover, the environment-friendly adsorbents effectively recycle yttrium and europium from waste phosphor powders. These experimental results demonstrated that the S&S method based on polymeric sponges has potential application in hydrometallurgy and environmental remediation.

Effect of fluoride exposure on mRNA expression of cav1.2 and calcium signal pathway apoptosis regulators in PC12 cells.

This study investigated the effects of fluoride exposure on the mRNA expression of Cav1.2 calcium signaling pathway and apoptosis regulatory molecules in PC12 cells. The viability of PC12 cell receiving high fluoride (5.0mM) and low fluoride (0.5mM) alone or fluoride combined with L-type calcium channel (LTCC) agonist/inhibitor (5umol/L FPL6417/2umol/L nifedipine) was detected using cell counting kit-8 at different time points (2, 4, 6, 8, 12, 10, and 24h). Changes in the cell configuration were observed after exposing the cells to fluoride for 24h. The expression levels of molecules related to the LTCC were examined, particularly, Cav1.2, c-fos, CAMK II, Bax, and Bcl-2. Fluoride poisoning induced severe cell injuries, such as decreased PC12 cell activity, enhanced cell apoptosis, high c-fos, CAMKII, and Bax mRNA expression levels. Bcl-2 expression level was also reduced. Meanwhile, high fluoride, high fluoride with FPL64176, and low fluoride with FPL64176 enhanced the Cav1.2 expression level. In contrast, low fluoride, high fluoride with nifedipine, and low fluoride with nifedipine reduced the Cav1.2 expression level. Thus, Cav1.2 may be an important molecular target for the fluorosis treatment, and the LTCC inhibitor nifedipine may be an effective drug for fluorosis.