Study on molecular epidemiology of carbapenem resistant Pseudomonas aeruginosa and related genes of quorum sensing signal system.

This study aims to investigate the drug resistance, regulation mechanism of quorum sensing system, expression of related virulence genes, and epidemiological characteristics of carbapenem-resistant Pseudomonas aeruginosa (CRPA).In this study, Polymerase chain reaction amplification was performed to evaluate carbapenemase genes, OprD2 gene, quorum sensing system, and related virulence genes. Bacterial genotypes were analyzed using multilocus sequence typing and evolutionary analysis was conducted based on the goeBURST algorithm. The results demonstrated that a total of 47 CRPA strains were collected in this study, primarily from respiratory specimens in the ICU. Drug sensitivity results showed that the resistance rates of the 47 CRPA strains were highest for imipenem (97.87 %). The loss of OprD2 may be the main factor contributing to carbapenem resistance in our hospital's CRPA strains.All isolates tested positive for the quorum sensing system genes lasI and rhlI/R, and the virulence gene lasB was detected in all isolates, while the algD gene was detected in 19.15 % of the isolates. Among the 47 strains, 6 were untypeable, and the 41 strains with 28 different sequence types were clustered into three clonal complexes (BG1, BG2, and BG3).In conclusion, the CRPA isolates from our hospital exhibit high genetic diversity, with the deletion of the OprD2 gene possibly being the primary determinant of carbapenem resistance in Pseudomonas aeruginosa.Moreover, Las and RhI systems play a key role in quorum sensing signal system. Further research and development of drugs targeting quorum sensing signaling system may provide valuable guidance for the treatment of CRPA.

Postoperative infusion of dexmedetomidine via intravenous patient-controlled analgesia for prevention of postoperative delirium in elderly patients undergoing surgery.

BACKGROUND: Postoperative delirium (POD) is a common clinical complication in elderly patients after surgery and predicts poor outcomes. AIM: We researched whether postoperative infusion of dexmedetomidine (DEX) had prophylactic effect on POD in elderly patients. METHODS: A total of 236 patients over the age of 60 years undergoing thoracoabdominal tumor surgery were enrolled in Zhejiang Cancer Hospital from November 2016 to October 2020. The patients were randomly assigned into DEX group (group D) and control group (Group C). DEX was provided via PCIA pump 1-3 days after surgery, which consisted of 3 ug/kg sufentanil and 3 ug/kg DEX in group D, and 3 ug/kg sufentanil without DEX in group C. The PCIA parameters were programmed as follows: total amount 150 ml, 2 ml bolus dose with a lock-out of 10 min and background infusion rate 2 ml/h. The primary endpoint was the incidence of POD, assessed twice daily within 7 days after surgery by Richmond Agitation-Sedation Scale (RASS) and the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). The secondary endpoint was postoperative hospitalization days, ICU stay time, adverse events and non-delirium complications. RESULTS: The incidence of POD in all patients was 7%. The incidence of POD in group C was significantly higher than that in group D (10.1% vs 3.4%, P = 0.042). There were no significant differences in length of hospital stay after operation, ICU stay time, the percentage of patients discharged within 7 days after surgery, non-delirium complications, and 30-day all-cause deaths between the two groups. The incidence of hypertension in group D was lower than that in group C (P = 0.003), and there were no differences in other adverse events. CONCLUSION: Patients aged over 60 years received DEX in addition to intravenous patient-controlled analgesia (PCIA) for major thoracoabdominal surgery experienced less delirium.

An RNAi suppressor activates in planta virus-mediated gene editing.

RNA-guided CRISPR/Cas9 technology has been developed for gene/genome editing (GE) in organisms across kingdoms. However, in planta delivery of the two core GE components, Cas9 and small guide RNA (sgRNA), often involves time-consuming and labor-intensive production of transgenic plants. Here we show that Foxtail mosaic virus, a monocot- and dicot-infecting potexvirus, can simultaneously express Cas9, sgRNA, and an RNAi suppressor to efficiently induce GE in Nicotiana benthamiana through a transgenic plant-free manner.

Effects of FTY720 on Lung Injury Induced by Hindlimb Ischemia Reperfusion in Rats.

BACKGROUND: Sphingosine-1-phosphate (S1P) is a biologically active lysophospholipid mediator involved in modulating inflammatory process. We investigated the effects of FTY720, a structural analogue of S1P after phosphorylation, on lung injury induced by hindlimb ischemia reperfusion (IR) in rats. METHODS: Fifty Sprague-Dawley rats were divided into groups SM, IR, F3, F5, and F10. Group SM received sham operation, and bilateral hindlimb IR was established in group IR. The rats in groups F3, F5, and F10 were pretreated with 3, 5, and 10 mg/kg/d FTY720 for 7 days before IR. S1P lyase (S1PL), sphingosine kinase (SphK) 1, and SphK2 mRNA expressions, wet/dry weight (W/D), and polymorphonuclear/alveolus (P/A) in lung tissues were detected, and the lung injury score was evaluated. RESULTS: W/D, P/A, and mRNA expressions of S1PL, SphK1, and SphK2 were higher in group IR than in group SM, while these were decreased in both groups F5 and F10 as compared to IR (p < 0.05). The lung tissue presented severe lesions in group IR, which were attenuated in groups F5 and F10 with lower lung injury scores than in group IR (p < 0.05). CONCLUSIONS: FTY720 pretreatment could attenuate lung injury induced by hindlimb IR by modulating S1P metabolism and decreasing pulmonary neutrophil infiltration.

Expression of overall survival-EMT-immune cell infiltration genes predict the prognosis of glioma.

This study investigates the crucial role of immune- and epithelial-mesenchymal transition (EMT)-associated genes and non-coding RNAs in glioma development and diagnosis, given the challenging 5-year survival rates associated with this prevalent CNS malignant tumor. Clinical and RNA data from glioma patients were meticulously gathered from CGGA databases, and EMT-related genes were sourced from dbEMT2.0, while immune-related genes were obtained from MSigDB. Employing consensus clustering, novel molecular subgroups were identified. Subsequent analyses, including ESTIMATE, TIMER, and MCP counter, provided insights into the tumor microenvironment (TIME) and immune status. Functional studies, embracing GO, KEGG, GSVA, and GSEA analyses, unraveled the underlying mechanisms governing these molecular subgroups. Utilizing the LASSO algorithm and multivariate Cox regression, a prognostic risk model was crafted. The study unveiled two distinct molecular subgroups with significantly disparate survival outcomes. A more favorable prognosis was linked to low immune scores, high tumor purity, and an abundance of immune infiltrating cells with differential expression of non-coding RNAs, including miRNAs. Functional analyses illuminated enrichment of immune- and EMT-associated pathways in differentially expressed genes and non-coding RNAs between these subgroups. GSVA and GSEA analyses hinted at abnormal EMT status potentially contributing to glioma-associated immune disorders. The risk model, centered on OS-EMT-ICI genes, exhibited promise in accurately predicting survival in glioma. Additionally, a nomogram integrating the risk model with clinical characteristics demonstrated notable accuracy in prognostic predictions for glioma patients. In conclusion, OS-EMT-ICI gene and non-coding RNA expression emerges as a valuable indicator intricately linked to immune microenvironment dysregulation, offering a robust tool for precise prognosis prediction in glioma patients within the OBMRC framework.

A Meta-analysis of Randomised Controlled Trials Comparing Combination Therapy as Second-line Treatment With Monotherapy in Advanced Non-small Cell Lung Cancer With Epidermal Growth Factor Receptor Mutation.

BACKGROUND: Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors are standard therapy for patients with non-small cell lung cancer (NSCLC) with EGFR mutation; however, resistance is common. Combinatorial strategies have been explored to improve survival. This meta-analysis assesses the efficacy and safety of combination therapy versus monotherapy in patients with advanced NSCLC who failed first-line EGFR-tyrosine kinase inhibitor treatment. METHODS: We searched randomized controlled trials from PubMed, Web of Science, Google Scholar, Cochrane Library, and ClinicalTrial.gov. The efficacy and toxicity of combination treatment groups were assessed in terms of progression-free survival (PFS), overall response rate (ORR), disease control rate (DCR), and adverse events (AEs). RESULTS: This meta-analysis included 6 randomized controlled trials covering 785 participants. The results showed that the combined regimen arm had no significant improvement of PFS (log hazard ratio = -0.228, 95% CI: -0.543 to 0.087, P = 0.157), ORR (odds ratio = 1.147 [95% CI: 0.577, 2.281], P = 0.695), DCR (odds ratio = 1.578 [95% CI: 0.428, 5.821], P = 0.493), and AEs, including fatigue and diarrhea (odds ratio = 0.833 [95% CI: 0.297, 2.333], P = 0.728 for fatigue and odds ratio = 2.268 [95% CI: 0.544, 9.448], P = 0.261 for diarrhea). CONCLUSIONS: Combination therapy may not provide a significant improvement in PFS, ORR, DCR, and incidence of AEs compared with monotherapy in patients with advanced NSCLC with EGFR mutations. Further research is needed to investigate the optimal sequencing of combination therapy in patients with NSCLC with different molecular targets to determine the most effective treatment strategy that can improve outcomes and quality of life for these patients.

Comparison of Remimazolam-Flumazenil versus Propofol for Rigid Bronchoscopy: A Prospective Randomized Controlled Trial.

Background: Remimazolam is a novel ultrashort-acting intravenous benzodiazepine sedative−hypnotic that significantly reduces the times to sedation onset and recovery. This trial was conducted to confirm the recovery time from anesthesia of remimazolam-flumazenil versus propofol in patients undergoing endotracheal surgery under rigid bronchoscopy. Methods: Patients undergoing endotracheal tumor resection or stent implantation were randomly allocated into a remimazolam group (Group R) or a propofol group (Group P). The primary outcome was the recovery time from general anesthesia. The secondary outcomes were the time to loss of consciousness (LoC), hemodynamic fluctuations, and adverse events. Results: A total of 34 patients were screened, and 30 patients were enrolled in the study. The recovery time was significantly shorter for Group R (140 ± 52 s) than for Group P (374 ± 195 s) (p < 0.001). The times to LoC were 76 ± 40 s in Group R and 75 ± 25 s in Group P and were not significantly different. There were also no significant differences in hemodynamic fluctuations or adverse events between the two groups. Conclusions: The recovery time from general anesthesia in rigid bronchoscopy patients was shorter using remimazolam-flumazenil than with propofol, with no dramatic hemodynamic fluctuations and adverse events or differences between the agents. Remimazolam-flumazenil allows for faster recovery from anesthesia than propofol.

Ropivacaine suppresses tumor biological characteristics of human hepatocellular carcinoma via inhibiting IGF-1R/PI3K/AKT/mTOR signaling axis.

Ropivacaine, a common local anesthetic in the clinic, has anti-proliferative and pro-apoptotic effects in numerous cancers, however, the underlying regulatory mechanism of ropivacaine in hepatocellular carcinoma remains unclear. In the current study, human HepG2 cells were stimulated with different ropivacaine concentrations. Cell Counting Kit-8 assay, cell colony formation, and cell cycle were used to monitor cell viability. Cell apoptosis, migration, and invasion were determined by flow cytometry and transwell assays. Tumor xenograft experiments were performed to prove the anti-cancer effect of ropivacaine in vivo. A high dose of ropivacaine inhibited proliferation and promoted apoptosis of HepG2 cells in a dose-dependent manner. Ropivacaine challenge also arrested cells in the G2 phase, followed by a decline in the protein expression of cyclin D1 and cyclin-dependent kinase 2, and an increase in p27 levels in HepG2 cells. Additionally, different ropivacaine doses suppressed cell migration and invasion by upregulating E-cadherin expression and downregulating N-cadherin expression. Mechanically, ropivacaine challenge gradually restrained insulin-like growth factor-1 receptor (IGF-1 R) expression and the activities of phosphorylated-PI3K, AKT, and mTOR in HepG2 cells with increased ropivacaine doses. In the tumor xenograft experiment, ropivacaine was confirmed to inhibit tumor growth, accompanied by inhibition of the IGF-1 R/PI3K/AKT/mTOR signaling axis. In conclusion, ropivacaine suppressed tumor biological characteristics and promoted apoptosis, resulting in the suppression of hepatocellular carcinoma progression by targeting the IGF-1 R/PI3K/AKT/mTOR signaling pathway. It is possible that ropivacaine-mediated local anesthesia may be developed as a novel surgical adjuvant drug for treating hepatocellular carcinoma.

Dietary starch source influences in growing goats: the intestinal losses of endogenous nitrogen and amino acids.

Four goats (20 (SD 2.5) kg) fitted with ruminal, duodenal and ileal cannulae were used in a 4 x 4 Latin square design to estimate the effects of a dietary starch source on the duodenal and ileal flows of endogenous N (EN) and endogenous amino acids (EAA) in growing goats. Goats were fed total mixed rations containing four starch sources (mainly from maize (MR), wheat (WR), paddy (PR) and sorghum (SR) treatments). There were no significant (P>0.05) effects of the dietary starch source on the intestinal flows of EN and EAA. The duodenal flows of EN were 2.40, 2.39, 2.18 and 1.56 g/d for the MR, WR, PR and SR treatments, respectively, as determined by the difference method, and the duodenal flows of EAA were 10.76, 11.29, 10.95 and 10.96 g/d by estimation with the amino acid profile method. The flows of EN and EAA at the ileum were 1.17, 1.12, 1.01, 0.70 and 4.87, 4.95, 4.94, 4.99 g/d, respectively, as estimated by the water-soluble method. The average intestinal reabsorption of EN and EAA was 57.5 %, and the endogenous Leu by the MR treatment was significantly (P < 0.05) lower than that of the other three treatments. The present results indicate that losses of endogenous protein in the intestine were not affected by the dietary starch source.

Comparison of different methods for determination of the duodenal and ileal flows of endogenous nitrogen and amino acids in growing goats.

The objective of the present study was to compare the isotope dilution, the difference and the amino acid profile (AAP) methods for the quantification of duodenal and ileal flows of endogenous nitrogen (N) and amino acids (AA) in growing goats. Nine growing goats were fed the same diet containing maize stover, ground corn and soybean meal. The duodenal flow of endogenous N determined by the isotope dilution method was significantly (p < 0.01) higher than that determined by the difference and AAP methods, while there was no difference between the difference and the AAP methods. The duodenal flows of individual endogenous AA determined by the isotope dilution method exceed those determined by the difference and the AAP method by 10 to 106%. The endogenous flow at the ileum determined by the isotope dilution method was not significantly different to those determined by the water-soluble method, but tended to be lower for N and all amino acids. It is concluded that the difference method and AAP method underestimate the duodenal flow of endogenous N and AA compared to the isotope dilution method.

Experimental investigation on the migration of leachate under flowing conditions through laboratory ERT.

With an increase of service time of landfills, a great amount of old landfills begin to leak and the leachate impairs the surrounding environment severely. Defining the flow of leachate is significant to the monitoring and restoration of the landfill. Field tests and laboratory tests are often used to investigate the leachate flow. However, many uncontrollable factors may affect the accuracy of field tests, and the application of field test results is usually limited. At the same time, it is difficult to simulate and monitor the migration process of leachate in real time in laboratory. To address this problem, a new physical simulating device is created to simulate the leachate migration under flowing conditions, and improved ERT device is designed to monitor the migration in laboratory tests. The results show that the improved ERT could delineate the migration range well in laboratory tests, providing a new method to investigate the leachate migration in laboratory test and providing a reference to the application of ERT in field tests. The relative variation rate of resistivity could reduce the influence of background, and is very suitable for time-lapse ERT. In addition, the effect of flowing rate, leakage rate, and time on the leachate migration is also investigated. The results show that the horizontal migration rate increases with an increase of flowing rate. The leakage rate has a significant influence on the vertical migration, but has limited effect on the horizontal migration. The curvature of migration front increases with an increase of flowing rate and time.

Effects of overexpression of carbapenem OXA-48 on drug resistance,adaptability of bacterial strain and Toll-like receptor signaling pathway of host cell / 中国生物制品学杂志

@#Objective To investigate the effects of overexpression of OXA-48 on drug resistance,adaptability of bacterial strain and Toll-like receptor(TLR)signaling pathway of host cells. Methods The recombinant plasmid pET32a(+)-OXA-48was transformed into E.coli BL21(DE3),and the recombinant strain pET32a(+)-OXA-48-BL21(DE3)was identified by colony PCR and sequencing. Taking A_(600)(0. 3,0. 5 and 0. 7),IPTG final concentration(0. 4,0. 6 and 0. 8mmol/L)and induction time(2,4 and 6 h)as variables and mRNA transcription level as response value,an orthogonal experiment with three factors and three levels was designed to optimize the induced expression conditions of the plasmid. The drug resistance of recombinant strain pET32a(+)-OXA-48-BL21(DE3)to Imipenem(IPM),Meropenem(MEM),Ceftriaxone(CRO)and Cefepime(FEP)was detected by disk diffusion method;The adaptability was detected by biofilm formation test and serum resistance test. Mouse alveolar macrophages(MH-S)were infected with pET32a(+)-OXA-48-BL21(DE3),pET32a(+)-BL21(DE3)and E.coli BL21(DE3)strains,respectively. The mRNA transcription levels of TLR2,TLR4 and NF-кB(p65)genes were detected by qRT-PCR method,and the expressions of Interleukin-6(IL-6),IL-10,tumor necrosis factor-α(TNF-α)and transforming growth factor-β(TGF-β)were detected by ELISA. Results The recombinant strain pET32a(+)-OXA-48-BL21(DE3)was constructed correctly as identified by colony PCR and sequencing. The optimum induction conditions were as follows:A_(600)of 0. 3,IPTG final concentration of 0. 6 mmol/L and induction time of 2 h. Compared with pET32a(+)-BL21(DE3)strain,the resistance of recombinant strain pET32a(+)-OXA-48-BL21(DE3)to IPM,MEM,CRO and FEP significantly decreased(t = 7. 14～22. 32,P < 0. 05),the biofilm formed significantly increased(t = 15. 69,P < 0. 05),and the survival rate in serum significantly increased(t = 10. 60,P < 0. 05);The mRNA transcription level of TLR2 gene in MH-S cells infected with pET32a(+)-OXA-48-BL21(DE3)significantly increased 24 h after infection(t = 5. 77,P < 0. 05),while the mRNA transcription level of TLR4 and NF-кB(p65)genes(t = 3. 71～10. 06,P < 0. 05)and the expression level of IL-6 significantly increased 12 and 24 h after infection. Compared with the normal group,the expression of IL-6and TNF-α in MH-S cells infected with pET32a(+)-OXA-48-BL21(DE3)increased significantly at 6,12 and 24 h after infection(t = 7. 90 ～ 13. 44 and 5. 40～6. 32 respectively,each P < 0. 01),while the expression of IL-10 decreased significantly(t = 3. 15～4. 08,each P < 0. 05). There was no significant difference in the expression of TGF-β(t = 0. 013～1. 41,each P > 0. 05). The expression of IL-6 was significantly higher than that in pET32a(+)-BL21(DE3)group at 12 and 24 h after infection(t = 2. 92 and 3. 79 respectively,each P < 0.05) Conclusion Overexpression of OXA-48 can reduce bacterial drug resistance,improve bacterial adaptability and the transcription level of factors related to TLR signaling pathway in host cells,and affect the expression level of downstream cytokines in host cells.