Antibacterial mechanism of CO2 combined with low temperature against Shewanella putrefaciens by biochemical and metabolomics analysis.

To further reveal the inhibition mechanism of carbon dioxide (CO2) on Shewanella putrefaciens (S. putrefaciens), influence on metabolic function was studied by biochemical and metabolomics analysis. Accordingly, reduction of intracellular pH (pHi), depolarization of cell membrane and accumulation of reactive oxygen species (ROS) indicated that CO2 changed the membrane permeability of S. putrefaciens. Besides, adenosine triphosphate (ATP), ATPase, nicotinamide adenine dinucleotide (NAD+/NADH) and ratios of NADH/NAD+ were detected, indicating a role of CO2 in repressing respiratory pathway and electron transport. According to metabolomics results, CO2 induced differential expressions of metabolites, disordered respiratory chain and weakened energy metabolism of S. putrefaciens. Inhibition of respiratory rate-limiting enzymes also revealed that electron transfer of respiratory chain was blocked, cell respiration was weakened, and thus energy supply was insufficient under CO2 stress. These results revealed that CO2 caused disruption of metabolic function, which might be the main cause of growth inhibition for S. putrefaciens.

A Handle-Free, All-Protein-Based Optical Tweezers Method to Probe Protein Folding-Unfolding Dynamics.

Optical tweezers (OT) have evolved into powerful single molecule force spectroscopy tools to investigate protein folding-unfolding dynamics. To stretch a protein of interest using OT, the protein must be flanked with two double stranded DNA (dsDNA) handles. However, coupling dsDNA handles to the protein is often of low yield, representing a bottleneck in OT experiments. Here, we report a handle-free, all-protein-based OT method for investigating protein folding/unfolding dynamics. In this new method, we employed disordered elastin-like polypeptides (ELPs) as a molecular linker and the mechanically stable cohesin-dockerin (Coh-Doc) pair as the prey-bait system to enable the efficient capture and stretching of individual protein molecules. This novel approach was validated by using model proteins NuG2 and RTX-v, yielding experimental results comparable to those obtained by using the dsDNA handle approach. This new method provides a streamlined and efficient OT approach to investigate the folding-unfolding dynamics of proteins at the single molecule level, thus expanding the toolbox of OT-based single molecule force spectroscopy.

Subtype-based analysis of cell-in-cell structures in non-small cell lung cancer.

Lung cancer is ranked as the leading cause of cancer-related death worldwide, and the development of novel biomarkers is helpful to improve the prognosis of non-small cell lung cancer (NSCLC). Cell-in-cell structures (CICs), a novel functional surrogate of complicated cell behaviors, have shown promise in predicting the prognosis of cancer patients. However, the CIC profiling and its prognostic value remain unclear in NSCLC. In this study, we retrospectively explored the CIC profiling in a cohort of NSCLC tissues by using the "Epithelium-Macrophage-Leukocyte" (EML) method. The distribution of CICs was examined by the Chi-square test, and univariate and multivariate analyses were performed for survival analysis. Four types of CICs were identified in lung cancer tissues, namely, tumor-in-tumor (TiT), tumor-in-macrophage (TiM), lymphocyte-in-tumor (LiT), and macrophage-in-tumor (MiT). Among them, the latter three constituted the heterotypic CICs (heCICs). Overall, CICs were more frequently present in adenocarcinoma than in squamous cell carcinoma (P = 0.009), and LiT was more common in the upper lobe of the lung compared with other lobes (P = 0.020). In univariate analysis, the presence of TiM, heCIC density, TNM stage, T stage, and N stage showed association with the overall survival (OS) of NSCLC patients. Multivariate analysis revealed that heCICs (HR = 2.6, 95% CI 1.25-5.6) and lymph node invasion (HR = 2.6, 95% CI 1.33-5.1) were independent factors associated with the OS of NSCLC. Taken together, we profiled the CIC subtypes in NSCLC for the first time and demonstrated the prognostic value of heCICs, which may serve as a type of novel functional markers along with classical pathological factors in improving prognosis prediction for patients with NSCLC.

Phospholipase A2 induces acute kidney injury by complement mediated mitochondrial apoptosis via TNF-α/NF-κB signaling pathway.

OBJECTIVE: Acute kidney injury (AKI) is one of common complications of wasp/bee stings. Phospholipase A2 (PLA2) is a vital pathogenic composition of wasp/bee venom. We aimed to investigate the role of complement mediated mitochondrial apoptosis in PLA2 induced AKI. MATERIALS AND METHODS: PLA2 induced AKI model was established by injecting PLA2 into via tail vein on mice. The pathological changes and the microstructural changes of kidney, complement activation, inflammation and apoptosis were detected in vitro and in vivo respectively. RESULTS: The results showed that PLA2 induced AKI models were successfully established in vivo and vitro. Compared with control, serum creatinine and urea nitrogen levels were elevated. Complement system activation and mitochondrial damage were observed. Expressions of IL-6, TNF-α, cleaved caspase-3 and cleaved caspase-9, and Bax/Bcl-2 increased in PLA2 induced AKI models. TNF-α/NF-κB signaling pathway activation in AKI models. CONCLUSION: In the present study, PLA2 induced AKI model was first successfully established to our knowledge. The role of complement mediated mitochondrial apoptosis pathway in renal tubular epithelial cells in PLA2 induced AKI were verified in vitro and vivo.

Carbon dioxide can inhibit biofilms formation and cellular properties of Shewanella putrefaciens at both 30 °C and 4 °C.

Shewanella putrefaciens (S. putrefaciens), which is a common specific spoilage organism (SSO) of marine fish, has strong spoilage ability even under low-temperature conditions. Carbon dioxide (CO2) was widely applied to control microorganisms in aquatic products package. To explore the regulation mechanism of CO2 on biofilm formation and cell properties of S. putrefaciens, the dynamic formation process of biofilms, cellular surface properties, and cellular metabolic characteristics of S. putrefaciens at both 30 °C and 4 °C in pure CO2 gas were evaluated. As evidenced by the crystal violet staining method, confocal laser scanning microscopy (CLSM) analysis, and field emission scanning electron microscopy (FESEM) observation, dynamic formation process of S. putrefaciens biofilms was apparently delayed by CO2 with integral cellular morphology. The number and viability of sessile cells in S. putrefaciens biofilms was significantly lower than those in normal air composition. The changes in cellular surface properties, such as decreased auto-aggregation and hydrophobicity, might be one of the reasons why biofilms were inhibited by CO2. Inhibition of swimming and swarming motility ability by CO2 could also be observed with significantly shorter bacterial halo diameter. What's more, cellular metabolism was significantly decreased by CO2 according to the results of ATP content, ATPase activity and extracellular proteolytic activity. The influence of CO2 could be both observed whether combined with 30 °C or 4 °C. However, the inhibition produced by CO2 was more pronounced at the incubation temperature of 4 °C. In summary, it could be concluded that the dynamic formation process of S. putrefaciens biofilms and cellular metabolic properties could be inhibited by CO2. This research provided a theoretical basis for better application of CO2 to regulate spoilage microorganisms.

Effect of CO2 on the spoilage potential of Shewanella putrefaciens target to flavour compounds.

To investigate the regulation mechanism of CO2 (0% CO2, 20% CO2, 60% CO2, and 100% CO2) on the spoilage potential of S. putrefaciens target to flavour compounds, the metabolic activity of S. putrefaciens and the changes in flavour compounds extracted from inoculated large yellow croakers were evaluated. Results showed that CO2 significantly reduced biofilm formation capacity and suppressed synthesis of intracellular adenosine triphosphate (ATP). The production of unpleasant flavour compounds, such as total volatile basic nitrogen (TVB-N), trimethylamine (TMA), inosine (HxR), hypoxanthine (Hx), histidine, lysine, histamine, putrescine, 1-octen-3-ol, hexanal and benzaldehyde, was inhibited by CO2. The hydrolysis and oxidation of lipid in CO2-treated samples were alleviated and unsaturated fatty acids (UFAs) were in a higher percentage. In summary, CO2 efficiently reduced the spoilage potential of S. putrefaciens and contributed to better flavour quality of samples during 4 °C storage. A more effective inhibition by 100% CO2 was observed.

Early use of endotoxin absorption by oXiris in abdominal septic shock: A case report.

RATIONALE: Septic shock leads to multiple organ failure and increases mortality rate. We reported a critical patient with abdominal septic shock, which was the first case successfully treated with continuous renal replacement therapy (CRRT) and a newly designed endotoxin removal device oXiris in mainland China. PATIENT CONCERNS: A 51-year-old man developed gastric ulcer perforation after resection of a benign peritoneal tumor and had a second abdominal surgery. His blood pressure decreased to 70/40 mm Hg with oliguria, requiring large doses of noradrenaline and intravenous fluid for resuscitation. The abdominal cavity was not sutured after the second open surgery due to severe abdominal infection and distention. His leukocyte count was over 30109/L, while the blood lactic acid was 12.5 mmol/L and procalcitonin (PCT) was >100 ng/mL. DIAGNOSIS: Since the bacterial culture of peritoneal exudate showed positive with Enterobacter aerogenes and Pseudomonas aeruginosa after the second surgery, and the patient had severe low blood pressure, hyoxemia and oliguria, combined with the laboratory tests results, he was diagnosed with Gram-negative related septic shock, acute kidney injury, and multiple organ dysfunction. INTERVENTIONS: CRRT with oXiris membrane was performed for 80hours and followed by AN69 ST membranes during the subsequent 27 days. Antibiotics together with other medical treatment were applied to the patient in the meantime. OUTCOMES: At the end of 80 hours treatment with oXiris, PCT of the patient had decreased to 14.52 ng/mL and lactic acid decreased to 4.2 mmol/L. The total sequential organ failure assessment (SOFA) score decreased from 15 to 11. Urine output steadily increased to 250 mL/h, and vital signs and blood pressure were stable without noradrenaline. At the end of the 27 days of conventional CRRT, his kidney function had completely recovered with a total sequential organ failure assessment score (SOFA score) of 6. LESSONS: oXiris, with its enhanced endotoxin adsorption, appeared to accelerate improvement in organ dysfunction and ultimate survival in our patient. In critical patients with abdominal septic shock, oXiris is an important adjunctive consideration to supplement definitive source control and antimicrobial therapy.

Timing of initiation of renal replacement therapy in acute kidney injury: an updated meta-analysis of randomized controlled trials.

Purpose: The results from randomized controlled trials (RCTs) concerning the timing of initiation of renal replacement therapy (RRT) for patients with acute kidney injury (AKI) are still inconsistent.Materials and methods: We searched for RCTs, as well as relevant references, focusing on the timing of RRT for AKI patients in the Medline, Embase, Cochrane Library, Google Scholar and Chinese databases from their inception to December 2018.Results: We included 18 RCTs from 1997 to 2018 involving 2856 patients. Pooled analyses of all RCTs showed no significant difference in mortality between early initiation and delayed initiation of RRT (RR 0.98, 95% CI: 0.89 to 1.08, p = .7) (I2 = 2%), and similar results were found in critically ill and community-acquired AKI patients, as well as in a subgroup of patients with sepsis and in cardiac surgery recipients. There was also no difference in the incidence of dialysis independence (RR 0.75, 95% CI: 0.47 to 1.2, p = .2) (I2 = 0). However, an early RRT strategy was associated with a significantly higher incidence of the need for RRT for AKI patients (RR 1.24, 95% CI: 1.13 to 1.36, p < .01) (I2 = 34%).Conclusions: As no life-threatening complications occurred, there was no evidence to show any benefit of an early RRT strategy for critically ill or community-acquired AKI patients; in contrast, a delayed strategy might avert the need for RRT.

Understanding the gut-kidney axis among biopsy-proven diabetic nephropathy, type 2 diabetes mellitus and healthy controls: an analysis of the gut microbiota composition.

AIMS: Type 2 diabetes mellitus (T2DM) has a rising prevalence and gut microbiota involvement is increasingly recognized. Diabetic nephropathy (DN) is a major complication of T2DM. The aim of the study was to understand the gut-kidney axis by an analysis of gut microbiota composition among biopsy-proven DN, T2DM without kidney disease, and healthy control. METHODS: Fecal samples were collected from 14 DNs, 14 age/gender-matched T2DMs without renal diseases (DM), 14 age and gender-matched healthy controls (HC) and household contacts (HH) of DM group. The microbiota composition was analyzed by 16sRNA microbial profiling approach. RESULTS: Substantial differences were found in the richness of gut microbiota and the variation of bacteria population in DM compared to HC, and DN compared to DM, respectively. DM could be accurately distinguished from age/gender-matched healthy controls by the variable of genus g_Prevotella_9 (AUC = 0.9), and DN patients could be accurately distinguished from age/gender-matched DM by the variables of two genera (g_Escherichia-Shigella and g_Prevotella_9, AUC = 0.86). The microbiota composition of HH group was close to that of HC group, and was different from DM group. Under the same diet, DM could be more accurately detected by the same genus (g_Prevotella_9, AUC = 0.92). CONCLUSION: Gut microbiota composition was explored to be related to the occurrence of biopsy-proven DN from DM. DM could be distinguished from HC by detecting g_Prevotella_9 level in feces, while DN was different from DM by the variables of g_Escherichia-Shigella and g_Prevotella_9, which potentially contributed to the physiopathological diagnosis of DN from DM.

The Effect of Serum Neutrophil Gelatinase-Associated Lipocalin on the Discontinuation of Continuous Renal Replacement Therapy in Critically Ill Patients with Acute Kidney Injury.

BACKGROUND: To determine the optimal time for discontinuing continuous renal replacement therapy (CRRT) by evaluating serum neutrophil gelatinase-associated lipocalin (NGAL) in critically ill patients with acute kidney injury (AKI). METHODS: A prospective observational study was conducted from September 2015 to March 2018. AKI patients treated with CRRT for at least 24 h were divided into "success" and "failure" groups according to their RRT requirement within 7 days after the initial discontinuation of CRRT. The prefilter and effluent NGAL concentrations were measured to calculate the sieving coefficient (SC) of NGAL in all included subjects from 0 to 72 h. RESULTS: In total, 110 patients were divided into success (n = 78) and failure groups (n = 32). The mean SC of NGAL during CRRT was less than 0.05. The patients in the failure group were associated with higher mortality compared with patients in the success group (37.5 vs. 12.8%, respectively, p = 0.013). There were significant differences in serum NGAL, creatinine, and urine output at discontinuation. In patients without sepsis (n = 70), serum NGAL and urine output were significant predictors of successful cessation. The area under the receiver operating characteristic to predict the successful discontinuation of CRRT was 0.88 for NGAL and 0.86 for urine output. An NGAL level of 403 ng/mL had the highest sensitivity (81%) and specificity (89%) and a urine output of 695 mL/day had the highest sensitivity (83%) and specificity (88%). However, in septic patients (n = 40), urine output but not serum NGAL (OR 0.999, p = 0.69) was a significant variable (OR 1.002, p = 0.005), with a cutoff of 796 mL/day (sensitivity 83%, specificity 88%). CONCLUSIONS: Serum NGAL was a significant factor for predicting successful CRRT discontinuation in nonseptic AKI patients. However, urine output, rather than serum NGAL, was a significant predictor in septic AKI patients.

Plasma alkylresorcinol metabolite, a biomarker of whole-grain wheat and rye intake, and risk of ischemic stroke: a case-control study.

Background: Epidemiologic studies on whole grains and risk of stroke have reported inconsistent results, with some suggesting a protective effect but others showing a null association. Objectives: The aim of this study was to examine whether plasma 3-(3,5-dihydroxyphenyl)-1-propanoic acid (DHPPA), a biomarker of whole-grain wheat and rye intake, is associated with risk of ischemic stroke. Methods: A hospital-based case-control study was conducted between March 2011 and May 2016. Cases (n = 990) with first ischemic stroke were matched to controls (n = 990) by sex and age. Concentrations of plasma DHPPA were determined by high-performance liquid chromatography-tandem mass spectrometry. We calculated ORs for the association of plasma DHPPA concentrations with ischemic stroke risk through the use of logistic regression. Results: Plasma DHPPA was inversely associated with ischemic stroke risk. After adjustment for potential confounding factors, the ORs for ischemic stroke across increasing quartiles of plasma DHPPA concentrations were 1 (referent), 0.76 (95% CI: 0.58, 0.99), 0.71 (95% CI: 0.54, 0.92), and 0.59 (95% CI: 0.45, 0.77), respectively (P-trend = 0.001). The inverse association was also observed in all subgroups of participants according to sex, age, body mass index, smoking status, alcohol consumption, history of hypertension, and history of diabetes. Conclusions: Our study showed that higher plasma DHPPA concentrations were associated with lower risk of ischemic stroke. This finding provides further evidence to support the health benefits of whole-grain consumption.

Analysis of serum metabolomics among biopsy-proven diabetic nephropathy, type 2 diabetes mellitus and healthy controls.

Type 2 diabetes mellitus (T2DM) has a rising prevalence and diabetic nephropathy (DN) is a major complication of T2DM. Metabolomics could provide novel insights into the pathogenesis, so we aimed to explore serum metabolomic profiles from DN to T2DM. Serum samples were collected from 14 biopsy-proven DNs, 14 age/gender-matched T2DMs without renal diseases (DM), 14 age/gender-matched healthy controls (CTRL) and household contacts of DM group (HH). Serum metabolomics was analyzed by untargeted liquid chromatography-tandem mass spectrometry (LC/MS) assays. There were a total of 1470 metabolites identified from all serum samples. 45 metabolites with significantly different intensity were found between DN and DM, e.g., biliverdin and taurine were reduced while l-arginine was increased in DN comparing to DM. DN could be distinguished from age/gender matched DM patients by l-arginine (AUC = 0.824) or taurine levels (AUC = 0.789). The metabolic pathways affected by metabolite distinctions between DN and DM also existed, among which taurine and hypotaurine metabolism exhibited the highest pathway impact. l-Methionine, deethylatrazine, l-tryptophan and fumaric acid were reduced in DM comparing with those of CTRL, but had no different intensity in DM and HH groups. The changes were demonstrated in the metabolomic profiles of biopsy-proven DN compared to DM. Biopsy-proven DN patients could be distinguished from age/gender matched DM by l-arginine or taurine levels in serum metabolomic profiles. Taurine and hypotaurine metabolism pathway had the highest impact in pathway set enrichment analysis, which potentially affected the pathogenesis of DN from T2DM.

Procyanidins Extracted from Lotus Seedpod Ameliorate Amyloid-ß-Induced Toxicity in Rat Pheochromocytoma Cells.

Alzheimer's disease (AD) is a progressive neurodegenerative disease, which is characterized by extracellular senile plaque deposits, intracellular neurofibrillary tangles, and neuronal apoptosis. Amyloid-ß (Aß) plays a critical role in AD that may cause oxidative stress and downregulation of CREB/BDNF signaling. Anti-Aß effect has been discussed as a potential therapeutic strategy for AD. This study aimed to identify the amelioration of procyanidins extracted from lotus seedpod (LSPC) on Aß-induced damage with associated pathways for AD treatment. Rat pheochromocytoma (PC12) cells incubated with Aß 25-35 serve as an Aß damage model to evaluate the effect of LSPC in vitro. Our findings illustrated that LSPC maintained the cellular morphology from deformation and reduced apoptosis rates of cells induced by Aß 25-35. The mechanisms of LSPC to protect cells from Aß-induced damage were based on its regulation of oxidation index and activation of CREB/BDNF signaling, including brain-derived neurotrophic factor (BDNF) and phosphorylation of cAMP-responsive element-binding (CREB), protein kinase B (also known as AKT), and the extracellular signal-regulated kinase (ERK). Of note, by high-performance liquid chromatography-tandem mass spectroscopy (LC-MS/MS), several metabolites were detected to accumulate in vivo, part of which could take primary responsibility for the amelioration of Aß-induced damage on PC12 cells. Taken together, our research elucidated the effect of LSPC on neuroprotection through anti-Aß, indicating it as a potential pretreatment for Alzheimer's disease.

Plasma Alkylresorcinol Metabolite, a Biomarker of Whole-Grain Wheat and Rye Intake, and Risk of Type 2 Diabetes and Impaired Glucose Regulation in a Chinese Population.

OBJECTIVE: To examine the association of plasma alkylresorcinol metabolite 3-(3,5-dihydroxyphenyl)-1-propanoic acid (DHPPA), a biomarker of whole-grain wheat and rye intake, with type 2 diabetes (T2D) and impaired glucose regulation (IGR) in a Chinese population. RESEARCH DESIGN AND METHODS: A total of 1,060 newly diagnosed T2D patients, 736 newly diagnosed IGR patients, and 1,443 control subjects with normal glucose tolerance were recruited in the case-control study. Plasma DHPPA concentrations were determined by high-performance liquid chromatography-tandem mass spectroscopy. Multivariate logistic regression analysis was used to evaluate the independent association of plasma DHPPA concentrations with the likelihood of T2D and IGR. RESULTS: After adjustment for age, sex, BMI, and family history of diabetes, the odds ratios (95% CI) of T2D and IGR were 0.57 (0.45, 0.73) and 0.66 (0.50, 0.85), respectively, comparing the lowest with the highest quartile of plasma DHPPA concentrations. Further adjustment for current smoking status, current alcohol consumption, physical activity, history of hypertension, and educational level did not change the observed association materially. Similar results were also obtained in T2D and IGR groups combined. The inverse association of plasma DHPPA with T2D persisted in stratified analyses according to age, sex, BMI, current smoking status, current alcohol consumption, physical activity, family history of diabetes, and history of hypertension. CONCLUSIONS: These findings suggested that higher plasma DHPPA concentrations were associated with lower odds of T2D and IGR. Further studies are warranted to confirm these findings in prospective cohorts.