Expansin SlExp1 and endoglucanase SlCel2 synergistically promote fruit softening and cell wall disassembly in tomato.

Fruit softening, an irreversible process that occurs during fruit ripening, can lead to losses and waste during postharvest transportation and storage. Cell wall disassembly is the main factor leading to loss of fruit firmness, and several ripening-associated cell wall genes have been targeted for genetic modification, particularly pectin modifiers. However, individual knockdown of most cell wall-related genes has had minimal influence on cell wall integrity and fruit firmness, with the notable exception of pectate lyase. Compared to pectin disassembly, studies of the cell wall matrix, the xyloglucan-cellulose framework, and underlying mechanisms during fruit softening are limited. Here, a tomato (Solanum lycopersicum) fruit ripening-associated α-expansin (SlExpansin1/SlExp1) and an endoglucanase (SlCellulase2/SlCel2), which function in the cell wall matrix, were knocked out individually and together using clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9-mediated genome editing. Simultaneous knockout of SlExp1 and SlCel2 enhanced fruit firmness, reduced depolymerization of homogalacturonan-type pectin and xyloglucan, and increased cell adhesion. In contrast, single knockouts of either SlExp1 or SlCel2 did not substantially change fruit firmness, while simultaneous overexpression of SlExp1 and SlCel2 promoted early fruit softening. Collectively, our results demonstrate that SlExp1 and SlCel2 synergistically regulate cell wall disassembly and fruit softening in tomato.

Restoration of the Mucosal IgA Response by Improving CD4+ T Pyroptosis Fails to Attenuate Gut Bacterial Translocation and Organ Damage After LPS Attack.

BACKGROUND: Currently, the mechanisms of impaired gut mucosal immunity in sepsis remain unclear. Gut immunoglobulin A (IgA) is an important defense mechanism against invasive pathogens, and CD4+ T cells regulate the IgA response. AIM: We aimed to verify the hypothesis indicating that CD4+ T pyroptosis induced by lipopolysaccharide (LPS) leads to an impaired gut IgA response and subsequent bacterial translocation and organ damage. METHODS: Cultured CD4+ T cells and mice were manipulated with LPS, and pyroptosis was improved by A438079 or adoptive CD4+ T cell transfer. The changes demonstrated in pyroptosis-related molecules, cytotoxicity and CD4+ T cells were examined to determine CD4+ T pyroptosis. The changes demonstrated in IgA+ B cells, AID (key enzyme for immunoglobulins) and IgA production and function were examined to evaluate the IgA response. Serum biomarkers, bacterial colonies and survival analysis were detected for bacterial translocation and organ damage. RESULTS: LPS attack induced CD4+ T pyroptosis, as evidenced by increased expression of P2X7, Caspase-11 and cleaved GSDMD, which elevated cytotoxicity and decreased CD4+ T cells. Decreased CD4+ T subsets (Foxp3+ T and Tfh cells) influenced the IgA response, as evidenced by lower AID expression, which decreased IgA+ B cells and IgA production and function. A438079 or cell transfer improved the IgA response but failed to reduce the translocation of gut pathogens, damage to the liver and kidney, and mortality of mice. CONCLUSION: LPS attack results in CD4+ T pyroptosis. Improvement of pyroptosis restores the mucosal IgA response but fails to ameliorate bacterial translocation and organ damage.

A tomato LATERAL ORGAN BOUNDARIES transcription factor, SlLOB1, predominantly regulates cell wall and softening components of ripening.

Fruit softening is a key component of the irreversible ripening program, contributing to the palatability necessary for frugivore-mediated seed dispersal. The underlying textural changes are complex and result from cell wall remodeling and changes in both cell adhesion and turgor. While a number of transcription factors (TFs) that regulate ripening have been identified, these affect most canonical ripening-related physiological processes. Here, we show that a tomato fruit ripening-specific LATERAL ORGAN BOUNDRIES (LOB) TF, SlLOB1, up-regulates a suite of cell wall-associated genes during late maturation and ripening of locule and pericarp tissues. SlLOB1 repression in transgenic fruit impedes softening, while overexpression throughout the plant under the direction of the 35s promoter confers precocious induction of cell wall gene expression and premature softening. Transcript and protein levels of the wall-loosening protein EXPANSIN1 (EXP1) are strongly suppressed in SlLOB1 RNA interference lines, while EXP1 is induced in SlLOB1-overexpressing transgenic leaves and fruit. In contrast to the role of ethylene and previously characterized ripening TFs, which are comprehensive facilitators of ripening phenomena including softening, SlLOB1 participates in a regulatory subcircuit predominant to cell wall dynamics and softening.

Establishment and Maintenance of Heat-Stress Memory in Plants.

Among the rich repertoire of strategies that allow plants to adapt to high-temperature stress is heat-stress memory. The mechanisms underlying the establishment and maintenance of heat-stress memory are poorly understood, although the chromatin opening state appears to be an important structural basis for maintaining heat-stress memory. The chromatin opening state is influenced by epigenetic modifications, making DNA and histone modifications important entry points for understanding heat-shock memory. Current research suggests that traditional heat-stress signaling pathway components might be involved in chromatin opening, thereby promoting the establishment of heat-stress memory in plants. In this review, we discuss the relationship between chromatin structure-based maintenance and the establishment of heat-stress memory. We also discuss the association between traditional heat-stress signals and epigenetic modifications. Finally, we discuss potential research ideas for exploring plant adaptation to high-temperature stress in the future.

Investigation of the Performance of Hastelloy X as Potential Bipolar Plate Materials in Proton Exchange Membrane Fuel Cells.

The phase, mechanical properties, corrosion resistance, hydrophobicity, and interfacial contact resistance of Hastelloy X were investigated to evaluate its performance in proton exchange membrane fuel cells (PEMFCs). For comparison, the corresponding performance of 304 stainless steel (304SS) was also tested. Hastelloy X exhibited a single-phase face-centered cubic structure with a yield strength of 445.5 MPa and a hardness of 262.7 HV. Both Hastelloy X and 304SS exhibited poor hydrophobicity because the water contact angles were all below 80°. In a simulated PEMFC working environment (0.5 M H2SO4 + 2 ppm HF, 80 °C, H2), Hastelloy X exhibited better corrosion resistance than 304SS. At 140 N·cm-2, the interfacial contact resistance of Hastelloy X can reach as low as 7.4 mΩ·cm2. Considering its overall performance, Hastelloy X has better potential application than 304SS as bipolar plate material in PEMFCs.

UPLC-Q-TOF/MS-Based Plasma and Urine Metabolomics Contribute to the Diagnosis of Sepsis.

In this study, we aimed to identify potential metabolic biomarkers that can improve the diagnostic accuracy of sepsis. Sixty-six patients including 30 septic and 36 nonsepsis patients from an intensive care unit were recruited. The global plasma and urine metabolomic profiles were determined by ultraperformance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry-based methodology. The risk factors, including both traditional physiological indicators and metabolic biomarkers, were investigated by binary logistic regression analysis and used to build a least absolute shrinkage and selection operator (Lasso) regression model to evaluate the ability of diagnosis. Fifty-five metabolites in plasma and 11 metabolites in urine were identified through orthogonal projections to latent structures discriminant analysis (OPLS-DA). Among them, ten (PE (20:4(5Z, 8Z, 11Z, 14Z)/P-18:0), harderoporphyrinogen, chloropanaxydiol, (Z)-2-octenal, N1,N8-diacetylspermidine, 1-nitroheptane, venoterpine, α-CEHC, LysoPE (20:0/0:0), corticrocin) metabolites were identified as risk factors. The Lasso regression model incorporating these ten metabolic biomarkers and five traditional physiological indicators displayed better differentiation than the traditional model, represented by the elevated area under receiver operating characteristic curve (AUROC) from 96.80 to 100.0%. Furthermore, patients with septic shock presented a significantly lower level of PE-Cer (d16:1(4E)/19:0). This study suggests that metabolomic profiling could be an effective tool for sepsis diagnosis.

An EjbHLH14-EjHB1-EjPRX12 module is involved in methyl jasmonate alleviation of chilling-induced lignin deposition in loquat fruit.

Loquat fruit are susceptible to chilling injuries induced by postharvest storage at low temperature. The major symptoms are increased lignin content and flesh firmness, which cause a leathery texture. Pretreatment with methyl jasmonate (MeJA) can alleviate this low-temperature-induced lignification, but the mechanism is not understood. In this study, we characterized a novel class III peroxidase, EjPRX12, and studied its relationship to lignification. Transcript levels of EjPRX12 were attenuated following MeJA pretreatment, consistent with the reduced lignin content in fruit. In vitro enzyme activity assay indicated that EjPRX12 polymerized sinapyl alcohol, and overexpression of EjPRX12 in Arabidopsis promoted lignin accumulation, indicating that it plays a functional role in lignin polymerization. We also identified an HD-ZIP transcription factor, EjHB1, repressed by MeJA pretreatment, which directly bound to and significantly activated the EjPRX12 promoter. Overexpression of EjHB1 in Arabidopsis promoted lignin accumulation with induced expression of lignin-related genes, especially AtPRX64. Furthermore, a JAZ-interacting repressor, EjbHLH14, was characterized, and it is proposed that MeJA pretreatment caused EjbHLH14 to be released to repress the expression of EjHB1. These results identified a novel regulatory pathway involving EjbHLH14-EjHB1-EjPRX12 and revealed the molecular mechanism whereby MeJA alleviated lignification of loquat fruit at low temperature.

Dexmedetomidine Alleviates Gut-Vascular Barrier Damage and Distant Hepatic Injury Following Intestinal Ischemia/Reperfusion Injury in Mice.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) challenge often results in gut barrier dysfunction and induces distant organ injury. Dexmedetomidine has been shown to protect intestinal epithelial barrier against I/R attack. The present study aims to investigate the degree to which intestinal I/R attack will contribute to gut-vascular barrier (GVB) damage, and to examine the ability of dexmedetomidine to minimize GVB and liver injuries in mice. METHODS: In vivo, intestinal ischemic challenge was induced in mice by clamping the superior mesenteric artery for 45 minutes. After clamping, the mice were subjected to reperfusion for either 2, 4, 6, or 12 hours. Intraperitoneal injection of dexmedetomidine 15, 20, or 25 µg·kg-1 was performed intermittently at the phase of reperfusion. For the in vitro experiments, the challenge of oxygen-glucose deprivation/reoxygenation (OGD/R) was established in cultured vascular endothelial cells, and dexmedetomidine (1 nM) was used to treat the cells for 24 hours. Moreover, in vivo and in vitro, SKL2001 (a specific agonist of ß-catenin) or XAV939 (a specific inhibitor of ß-catenin) was applied to determine the role of ß-catenin in the impacts provided by dexmedetomidine. RESULTS: The attack of intestinal I/R induced GVB damage. The greatest level of damage was observed at 4 hours after intestinal reperfusion. There was a significant increase in plasmalemma vesicle-associated protein-1 (PV1, a specific biomarker for endothelial permeability) expression (5.477 ± 0.718 vs 1.000 ± 0.149; P < .001), and increased translocation of intestinal macromolecules and bacteria to blood and liver tissues was detected (all P < .001). Liver damages were observed. There were significant increases in histopathological scores, serum parameters, and inflammatory factors (all P < .001). Dexmedetomidine 20 µg·kg-1 reduced PV1 expression (0.466 ± 0.072 vs 1.000 ± 0.098; P < .001) and subsequent liver damages (all P < .01). In vitro, dexmedetomidine significantly improved vascular endothelial cell survival (79.387 ± 6.447% vs 50.535 ± 1.766%; P < .001) and increased the productions of tight junction protein and adherent junction protein (all P < .01) following OGD/R. Importantly, in cultured cells and in mice, ß-catenin expression significantly decreased (both P < .001) following challenge. Dexmedetomidine or SKL2001 upregulated ß-catenin expression and produced protective effects (all P < .01). However, XAV939 completely eliminated the protective effects of dexmedetomidine on GVB (all P < .001). CONCLUSIONS: The disruption of GVB occurred following intestinal I/R. Dexmedetomidine alleviated I/R-induced GVB impairment and subsequent liver damage.

Hybrid imidazo[1,2-a]pyridine analogs as potent ATX inhibitors with concrete in vivo antifibrosis effect.

In recent years, small-molecule inhibitors targeting the autotaxin (ATX)/lysophosphatidic acid axis gradually brought excellent disease management benefits. Herein, a series of imidazo[1,2-a]pyridine compounds (1-11) were designed as ATX inhibitors through a hybrid strategy by combining the imidazo[1,2-a]pyridine skeleton in GLPG1690 and the benzyl carbamate moiety in PF-8380. As indicated by FS-3-based enzymatic assay, the carbamate derivatives revealed moderate to satisfying ATX inhibitory potency (IC50 = 23-343 nM). Subsequently, the carbamate linker was altered to a urea moiety (12-19) with the aim of retaining ATX inhibition and improving the druglikeness profile. The binding mode analysis all over the modification process well rationalized the leading activity of urea derivatives in an enzymatic assay. Following further structural optimization, the diethanolamine derivative 19 exerted an amazing inhibitory activity (IC50 = 3.98 nM) similar to the positive control GLPG1690 (IC50 = 3.72 nM) and PF-8380 (IC50 = 4.23 nM). Accordingly, 19 was tested directly for in vivo antifibrotic effects through a bleomycin model (H&E staining), in which 19 effectively alleviated lung structural damage and fibrosis at an oral dose of 20 and 60 mg/kg. Collectively, 19 qualified as a promising ATX inhibitor for potential application in fibrosis-relevant disease treatment.

A comparison of paravertebral block, erector spinae plane block and the combination of erector spinae plane block and paravertebral block for post-operative analgesia after video-assisted thoracoscopic surgery: A randomised controlled trial.

BACKGROUND: This study was to determine the analgesic effect of ultrasound-guided erector spinae plane block (ESPB) and paravertebral block (PVB) as well as the combination of PVB and ESPB (P + E) after video-assisted thoracoscopic surgery (VATS). PATIENTS AND METHODS: Patients were randomly assigned to receive ESPB, PVB or PVB combined with ESPB with 0.5% ropivacaine (20 ml). The primary outcomes were cumulative hydromorphone consumption and Visual Analogue Scale (VAS) scores at rest and while coughing at 0 h, 12 h, 24 h, 48 h and 72 h postoperatively. The secondary outcomes were effective PCA usage count and rescue analgesia requirement at the same time points. RESULTS: The median (interquartile range) hydromorphone consumption, including converted oxycodone, was significantly different at 48 h postoperatively among the three groups (ESPB, 10.24 [9.53-11.71] mg; PVB, 9.94 [9.19-10.75] mg; P + E, 9.44 [8.96-9.97] mg; P = 0.011). Hydromorphone consumption in P + E group was lower compared with that in ESPB group at 12 h, 24 h and 48 h (P < 0.001, P = 0.004 and P = 0.003, respectively). VAS scores at rest were significantly higher for ESPB group compared to P + E group at 0 h postoperatively (P = 0.009). VAS scores while coughing were significantly higher for ESPB group compared to P + E group at 0 h and 12 h postoperatively (P = 0.015 and P < 0.001) and to the PVB group at 12 h postoperatively (P = 0.002). The effective PCA usage count in P + E group was lower than in ESPB group in 0-12 h (P < 0.001). More patients needed rescue analgesia in ESPB group compared to those in P + E group in 0-12 h, 0-24 h and 0-48 h (P = 0.022, 0.035 and 0.035, respectively). CONCLUSIONS: Ultrasound-guided PVB combined with ESPB provided superior analgesia to ESPB for VATS. The combination of PVB and ESPB had a similar analgesic effect compared with PVB alone.

UPLC-MS-Based Serum Metabolic Profiling Reveals Potential Biomarkers for Predicting Propofol Responsiveness in Females.

Although previous studies have shown that certain factors interfere with the sensitivity of propofol, the mechanisms for interindividual variability in response to propofol remain unclear. This study aimed to screen the metabolites to predict patients' sensitivity to propofol and to identify metabolic pathways to explore possible mechanisms associated with propofol resistance. Sera from 40 female patients undergoing elective hysteroscopic surgery in a prospective cohort propofol study were obtained before the administration of propofol. The patients' responsiveness to propofol was differentiated based on propofol effect-site concentration. Serum samples from two sets, a discovery set (n = 24) and an independent validation set (n = 16), were analyzed using ultraperformance liquid chromatography coupled with mass spectrometry based untargeted metabolomics. In the discovery set, 494 differential metabolites were screened out, and then 391 potential candidate biomarkers with the area under receiver operating characteristic curve >0.80 were selected. Pathway analysis showed that the pathway of glycerophospholipid metabolism was the most influential pathway. In the independent validation set, six potential biomarkers enabled the discrimination of poor responders from good and intermediate responders, which might be applied to predict propofol sensitivity. The mass spectrometry data are available via MetaboLights (http://www.ebi.ac.uk/metabolights/login) with the identifier MTBLS2311.

Identification of a lipase gene with a role in tomato fruit short-chain fatty acid-derived flavor volatiles by genome-wide association.

Fatty acid-derived volatile organic compounds (FA-VOCs) make significant contributions to tomato (Solanum lycopersicum) fruit flavor and human preferences. Short-chain FA-VOCs (C5 and C6) are among the most abundant and important volatile compounds in tomato fruits. The precursors of these volatiles, linoleic acid (18:2) and linolenic acid (18:3), are derived from cleavage of glycerolipids. However, the initial step in synthesis of these FA-VOCs has not been established. A metabolite-based genome-wide association study combined with genetic mapping and functional analysis identified a gene encoding a novel class III lipase family member, Sl-LIP8, that is associated with accumulation of short-chain FA-VOCs in tomato fruit. In vitro assays indicated that Sl-LIP8 can cleave 18:2 and 18:3 acyl groups from glycerolipids. A CRISPR/Cas9 gene edited Sl-LIP8 mutant had much lower content of multiple fruit short-chain FA-VOCs, validating an important role for this enzyme in the pathway. Sl-LIP8 RNA abundance was correlated with FA-VOC content, consistent with transcriptional regulation of the first step in the pathway. Taken together, our work indicates that glycerolipid turnover by Sl-LIP8 is an important early step in the synthesis of multiple short-chain FA-VOCs.

Terlipressin relieves intestinal and renal injuries induced by acute mesenteric ischemia via PI3K/Akt pathway.

Background: To date, the effect of vasopressin on organ damages after acute mesenteric ischemia (MI) remains poorly understood. Aims: To investigate the effect of terlipressin, a selective vasopressin V1 receptor agonist, versus norepinephrine on the intestinal and renal injuries after acute MI, and to explore the underlying mechanism of terlipressin. Methods: Acute MI model was produced by clamping the superior mesenteric artery for 1 hour. Immediately after unclamping, terlipressin or norepinephrine was intravenously administered for 2 hours. Meanwhile, in vitro, RAW264.7 cells were treated with lipopolysaccharide or lipopolysaccharide+terlipressin. In addition, wortmannin was used to determine the role of phosphoinositide 3-kinase (PI3K)/ protein kinase B (Akt) pathway in the potential impacts of terlipressin. Results: MI led to severe hypotension, caused notable intestinal and renal impairments and resulted in high mortality, which were markedly improved by terlipressin or norepinephrine. Terlipressin increased mean arterial pressure, decreased intestinal epithelial cell apoptosis, inhibited the generation of M1 macrophage in intestinal and renal tissues, and hindered the release of inflammatory cytokines after MI. Moreover, in cultured macrophages, terlipressin reduced the mRNA level of specific M1 markers and the release of inflammatory cytokines caused by lipopolysaccharide challenge. Wortmannin decreased the expression of PI3K and Akt induced by terlipressin in cells and in tissues, and abolished the above protective effects conferred by terlipressin. Conclusions: Terlipressin or norepinephrine could effectively improve organ damages and mortality after acute MI. Terlipressin elevates blood pressure and inhibits intestinal epithelial apoptosis and macrophage M1 polarization via the PI3K/Akt pathway.

An antifouling interface integrated with HRP-based amplification to achieve a highly sensitive electrochemical aptasensor for lysozyme detection.

We report here a highly sensitive sandwich type electrochemical aptasensor for lysozyme (lys) detection by the integration of an antifouling interface with HRP-based signal amplification. The biosensing interface with antifouling ability is designed, consisting of a lys-binding aptamer (LBA), dithiothreitol (DTT) and mercaptohexanol (MCH). When lys is captured by the immobilized LBA due to the specific recognition of the aptamer, gold nanoparticles (AuNPs) functionalized with HRP and LBA (HRP-AuNP-LBA) are further conjugated to the surface-bound lys, forming a sandwich assay format. HRP catalyzes the chemical oxidation of hydroquinone (HQ) by hydrogen peroxide (H2O2) to produce benzoquinone (BQ) which results in a large electrochemical reduction signal of BQ. Therefore, this reduction signal measured by differential pulse voltammetry (DPV) is used to detect lys. The catalytic behavior of HRP toward the reaction between HQ and H2O2, together with the high loading of HRP on AuNPs, remarkably amplifies the signal. A linear relationship between the DPV response and the logarithm of lys concentration from 0.01 pg mL-1 to 105 pg mL-1 with a detection limit of 0.003 pg mL-1 (S/N = 3) is obtained. The proposed biosensing platform combines antifouling ability and signal amplification, resulting in high sensitivity, providing an effective way for ultrasensitive assay of protein biomarkers in complex media.

Activation of PD-1 Protects Intestinal Immune Defense Through IL-10/miR-155 Pathway After Intestinal Ischemia Reperfusion.

BACKGROUND: To date, mechanisms of intestinal immunoglobulin (Ig) dysfunction following intestinal ischemia/reperfusion (I/R) remain unclear. Programmed death 1 (PD-1) is associated with immune responses of lymphocytes. AIM: We aimed to verify the hypothesis that activation of PD-1 may improve intestinal immune dysfunction by regulating IL-10/miR-155 production after intestinal IR injury. METHODS: Intestinal I/R injury was induced in mice by clamping the superior mesenteric artery for 1 h followed by 2-h reperfusion. PD-L1 fusion Ig, anti-interleukin (IL)-10 monoclonal antibody (mAb), and microRNA (miR)-155 agomir were administered. PD-1 expression, IL-10 mRNA, and protein expression in Peyer's patches (PP) CD4+ cells were measured. MiR-155 levels, tumor necrosis factor (TNF)-α and IL-1ß concentration, and activation-induced cytidine deaminase (AID), a key enzyme for intestinal immune antibodies, in PP tissues were measured, respectively. Importantly, the production and cecal bacteria-binding capacity of IgA and IgM were detected. RESULTS: Intestinal I/R led to decreased PD-1 expression, imbalanced production, and impaired bacteria-binding capacity of IgA and IgM. Activating PD-1 by PD-L1 Ig facilitated IL-10 synthesis, then decreased miR-155 levels, and subsequently promoted AID expression and reduced TNF-α, IL-1ß concentration. Upregulation of AID improved the disruptions of intestinal immune barrier caused by IgA and IgM dysfunction. Anti-IL-10 mAb and miR-155 agomir abolished the protective effects of PD-L1 Ig on the intestinal immune defense. CONCLUSION: Activation of PD-1 with PD-L1 Ig relieves intestinal immune defensive injury through IL-10/miR-155 pathway following intestinal I/R attack. PD-1, IL-10, and miR-155 may be potential targets for the damages of intestinal barrier and immunity.

Propofol Does Not Reduce Pyroptosis of Enterocytes and Intestinal Epithelial Injury After Lipopolysaccharide Challenge.

BACKGROUND: To date, mechanisms of sepsis-induced intestinal epithelial injury are not well known. P2X7 receptor (P2X7R) regulates pyroptosis of lymphocytes, and propofol is usually used for sedation in septic patients. AIMS: We aimed to determine the occurrence of enterocyte pyroptosis mediated by P2X7R and to explore the effects of propofol on pyroptosis and intestinal epithelial injury after lipopolysaccharide (LPS) challenge. METHODS: A novel regimen of LPS challenge was applied in vitro and in vivo. Inhibitors of P2X7R (A438079) and NLRP3 inflammasome (MCC950), and different doses of propofol were administered. The caspase-1 expression, caspase-3 expression, caspase-11 expression, P2X7R expression and NLRP3 expression, extracellular ATP concentration and YO-PRO-1 uptake, and cytotoxicity and HMGB1 concentration were detected to evaluate enterocyte pyroptosis in cultured cells and intestinal epithelial tissues. Chiu's score, diamine oxidase and villus length were used to evaluate intestinal epithelial injury. Moreover, survival analysis was performed. RESULTS: LPS challenge activated caspase-11 expression and P2X7R expression, enhanced ATP concentration and YO-PRO-1 uptake, and led to increased cytotoxicity and HMGB1 concentration. Subsequently, LPS resulted in intestinal epithelial damage, as evidenced by increased levels of Chiu's score and diamine oxidase, and shorter villus length and high mortality of animals. A438079, but not MCC950, significantly relieved LPS-induced enterocyte pyroptosis and intestinal epithelial injury. Importantly, propofol did not confer the protective effects on enterocyte pyroptosis and intestinal epithelia although it markedly decreased P2X7R expression. CONCLUSION: LPS attack leads to activation of caspase-11/P2X7R and pyroptosis of enterocytes. Propofol does not reduce LPS-induced pyroptosis and intestinal epithelial injury, although it inhibits P2X7R upregulation.

Does Respiratory Variation in Inferior Vena Cava Diameter Predict Fluid Responsiveness in Mechanically Ventilated Patients? A Systematic Review and Meta-analysis.

BACKGROUND: We performed a systematic review and meta-analysis of studies investigating the diagnostic accuracy of respiratory variation in inferior vena cava diameter (ΔIVC) for predicting fluid responsiveness in patients receiving mechanical ventilation. METHODS: MEDLINE, EMBASE, the Cochrane Library, and Web of Science were screened from inception to February 2017. The meta-analysis assessed the pooled sensitivity, specificity, diagnostic odds ratio, and area under the receiver operating characteristic curve. In addition, heterogeneity and subgroup analyses were performed. RESULTS: A total of 12 studies involving 753 patients were included. Significant heterogeneity existed among the studies, and meta-regression indicated that ventilator settings were the main sources of heterogeneity. Subgroup analysis indicated that ΔIVC exhibited better diagnostic performance in the group of patients ventilated with tidal volume (TV) ≥8 mL/kg and positive end-expiratory pressure (PEEP) ≤5 cm H2O than in the group ventilated with TV <8 mL/kg or PEEP >5 cm H2O, as demonstrated by higher sensitivity (0.80 vs 0.66; P = .02), specificity (0.94 vs 0.68; P < .001), diagnostic odds ratio (68 vs 4; P < .001), and area under the receiver operating characteristic curve (0.88 vs 0.70; P < .001). The best ΔIVC threshold for predicting fluid responsiveness was 16% ± 2% in the group of TV ≥8 mL/kg and PEEP ≤5 cm H2O, whereas in the group of TV <8 mL/kg or PEEP >5 cm H2O, this threshold was 14% ± 5%. CONCLUSIONS: ΔIVC shows limited ability for predicting fluid responsiveness in distinct ventilator settings. In patients with TV ≥8 mL/kg and PEEP ≤5 cm H2O, ΔIVC was an accurate predictor of fluid responsiveness, while in patients with TV <8 mL/kg or PEEP >5 cm H2O, ΔIVC was a poor predictor. Thus, intensivists must be cautious when using ΔIVC.

TGF-ß1 improves mucosal IgA dysfunction and dysbiosis following intestinal ischaemia-reperfusion in mice.

Intestinal ischaemia/reperfusion (I/R) severely disrupts gut barriers and leads to high mortality in the critical care setting. Transforming growth factor (TGF)-ß1 plays a pivotal role in intestinal cellular and immune regulation. However, the effects of TGF-ß1 on intestinal I/R injury remain unclear. Thus, we aimed to investigate the effects of TGF-ß1 on gut barriers after intestinal I/R and the molecular mechanisms. Intestinal I/R model was produced in mice by clamping the superior mesenteric artery for 1 hr followed by reperfusion. Recombinant TGF-ß1 was intravenously infused at 15 min. before ischaemia. The results showed that within 2 hrs after reperfusion, intestinal I/R disturbed intestinal immunoglobulin A class switch recombination (IgA CSR), the key process of mucosal IgA synthesis, and resulted in IgA dysfunction, as evidenced by decreased production and bacteria-binding capacity of IgA. Meanwhile, the disruptions of intestinal microflora and mucosal structure were exhibited. Transforming growth factor-ß1 activated IgA CSR as evidenced by the increased activation molecules and IgA precursors. Strikingly, TGF-ß1 improved intestinal mucosal IgA dysfunction, dysbiosis and epithelial damage at the early stage after reperfusion. In addition, SB-431542, a specific inhibitor of activating mothers against decapentaplegic homologue (SMAD) 2/3, totally blocked the inductive effect of TGF-ß1 on IgA CSR and almost abrogated the above protective effects on intestinal barriers. Taken together, our study demonstrates that TGF-ß1 protects intestinal mucosal IgA immunity, microbiota and epithelial integrity against I/R injury mainly through TGF-ß receptor 1/SMAD 2/3 pathway. Induction of IgA CSR may be involved in the protection conferred by TGF-ß1.

A simple bioscore improves diagnostic accuracy of sepsis after surgery.

BACKGROUND: Rapid and accurate prediction for sepsis remains a challenge in surgical intensive care units. Detection of individual biomarkers is often of marginal usefulness, and several biomarkers are difficult to measure in the clinical setting. The aim of this study was to evaluate the diagnostic and prognostic performance of three routine biomarkers, procalcitonin (PCT), B-type natriuretic peptide (BNP), and lymphocyte percentage, as individual or in combination for sepsis in surgical critically ill patients. MATERIALS AND METHODS: Circulating PCT, BNP, and lymphocyte percentage were measured in surgical patients on admission to the intensive care unit. A bioscore system combining these biomarkers was constructed. All studied variables were analyzed according to the diagnosis and clinical outcomes of sepsis. RESULTS: A total of 320 consecutive patients were included in the analysis. One hundred fifty-six patients presented with sepsis. In the patients with sepsis, levels of PCT and BNP increased and lymphocyte percentage decreased. For individual biomarkers, PCT achieved the best area under the curve for the diagnosis of sepsis, whereas the diagnostic performance of the bioscore was better than that of each individual biomarker (area under the curve, 0.914 [95% confidence interval, 0.862-0.951]). Levels of BNP and bioscore increased in nonsurvivors in the entire cohort, but the accuracy of these two variables for mortality prediction was lower than that shown by Acute Physiology and Chronic Health Evaluation II score. Furthermore, bioscore failed to predict outcomes in septic patients. CONCLUSIONS: A simple bioscore combining PCT together with BNP and lymphocyte percentage improves the diagnostic accuracy for sepsis in surgical critically ill patients but fails to predict outcomes in surgical patients with sepsis.

[Clinical value of lung ultrasound in the late goal-directed fluid removal in critically ill patients underwent fluid resuscitation].

OBJECTIVE: To investigate the clinical value of lung ultrasound in the late goal -directed fluid removal in critically ill patients underwent fluid resuscitation. METHODS: A prospective study was conducted. Forty patients underwent fluid resuscitation were enrolled in the Department of Surgical Intensive Care Unit of The First Affiliated Hospital of Sun Yat-sen University from Jan 2015 to June 2015. Lung and heart ultrasound were conducted for lung B-lines and left ventricular ejection fraction (EF). Serum amino-terminal pro-brain natriuretic peptide (NT-proBNP), central venous pressure (CVP) and serum creatinine were also measured and fluid balance was recorded in all patients enrolled. RESULTS: Among the 40 patients enrolled, 35 patients survived and 5 died. In patients survived, B-lines reached its peak at 12(30)h after admitted to ICU. It started to decrease instantly after the peak and reached zero at (39±34) h. A higher peak was followed with more fluids to be removed later and longer ICU stay (P<0.01). Moreover, when compared with the survivors, B-lines in death reached a higher peak[7(8) vs 3(4), P<0.01]and without the tendency to drop down. EF was lower in death than in survivor (44.5%±3.5% vs 69.2%±11.0%, P<0.05). A lower EF was found to be followed with a higher peak of B-lines. The peak time of NT-proBNP and clinical dehydration treatment were later than the peak time of B-lines in survivors. CONCLUSIONS: Fluid overloading occurs in late stage after resuscitation in critically ill patients. Lung ultrasound B-lines, which is more sensitive than the NT-proBNP and CVP, could help to monitor the patient's fluid status and guide the late goal-directed fluid removal.