The role of rcpA gene in regulating biofilm formation and virulence in Vibrio parahaemolyticus.

Vibrio parahaemolyticus (V. parahaemolyticus) is a common seafood-borne pathogen that can colonize the intestine of host and cause gastroenteritis. Biofilm formation by V. parahaemolyticus enhances its persistence in various environments, which poses a series of threats to food safety. This work aims to investigate the function of rcpA gene in biofilm formation and virulence of V. parahaemolyticus. Deletion of rcpA significantly reduced motility, biofilm biomass, and extracellular polymeric substances, and inhibited biofilm formation on a variety of food and food contact surfaces. In mice infection model, mice infected with ∆rcpA strain exhibited a decreased rate of pathogen colonization, a lower level of inflammatory cytokines, and less tissue damage when compared to mice infected with wild type strain. RNA-seq analysis revealed that 374 genes were differentially expressed in the rcpA deletion mutant, which include genes related to quorum sensing, flagellar system, ribosome, type VI secretion system, biotin metabolism and transcriptional regulation. In conclusion, rcpA plays a role in determining biofilm formation and virulence of V. parahaemolyticus and further research is necessitated to fully understand its function in V. parahaemolyticus.

Polygonatum sibiricum Saponin Prevents Immune Dysfunction and Strengthens Intestinal Mucosal Barrier Function in Cyclophosphamide-Induced Immunosuppressed BALB/c Mice.

The aim of this study was to explore the immunomodulatory effect of Polygonatum sibiricum saponin (PS) in a cyclophosphamide-induced (Cy) immunosuppression mice model. Oral administration of PS by gavage effectively alleviated weight loss caused by Cy and increased the index of immune organs. PS promoted the proliferation of splenic lymphocytes and T cell subsets (CD3+, CD355+, CD4+/CD8+) and relieved the xylene-induced inflammatory response and Cy-induced increase of serum hemolysin. Moreover, PS increased serum levels of lactate dehydrogenase and acid phosphatase. PS elevated serum level of cytokines and immunoglobulins (TNF-α, IFN-γ, IL-4, IL-6, IL-ß, SIgA, and IgG) and the expression of mRNA of IL-10, TNF-α, and IL-6 in the spleen. Increased mRNA expression of tight junction protein (ZO-1, Mucin2, Occludin) expression and protein expression of IL-6/MyD88/TLR4 in the small intestine showed that PS exhibited a restorative effect on intestinal mucosal injury caused by cyclophosphamide. Oral PS prevented Cy-induced decline in leukocytes, red blood cells, lymphocytes, hemoglobin concentrations, and neutrophils, providing evidence for alleviating hematopoietic disorders. In addition, PS increased SOD and NO levels, reduced MDA levels, and improved oxidative damage in the liver. These findings demonstrate that PS has the potential to be developed as a supplemental agent for alleviating immunosuppression caused by chemotherapeutic agents.

Anti-Biofilm Activity of Laurel Essential Oil against Vibrio parahaemolyticus.

Vibrio parahaemolyticus is a primary seafood-associated pathogen that could cause gastroenteritis. It can attach to various surfaces and form a biofilm, which poses serious threats to food safety. Hence, an effective strategy is urgently needed to control the biofilm formation of V. parahaemolyticus. Laurel essential oil (LEO) is used in food, pharmaceutical and other industries, and is commonly used as a flavoring agent and valuable spice in food industries. The potential antibiofilm effects of LEO against V. parahaemolyticus were examined in this study. LEO obviously reduced biofilm biomass at subinhibitory concentrations (SICs). It decreased the metabolic activity and viability of biofilm cells. Microscopic images and Raman spectrum indicted that LEO interfered with the structure and biochemical compositions of biofilms. Moreover, it also impaired swimming motility, decreased hydrophobicity, inhibited auto-aggregation and reduced attachment to different food-contact surfaces. RT-qPCR revealed that LEO significantly downregulated transcription levels of biofilm-associated genes of V. parahaemolyticus. These findings demonstrate that LEO could be potentially developed as an antibiofilm strategy to control V. parahaemolyticus biofilms in food industries.

Epigenome-wide association study reveals CpG sites related to COG of neuroblastoma.

BACKGROUND: Neuroblastoma (NB) is the most common extracranial solid tumor in infants and children. Its variable location and complex pathogenesis make NB hard for early diagnosis and risk classification. METHODOLOGY: We analyzed the methylation data of 236 samples from patients with NB in Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Kaplan-Meier survival analysis was used for comparing overall survival of NB patients in different groups. Epigenome-wide association study (EWAS) was conducted to screen CpGs significantly associated with NB patients' Children's Oncology Group (COG). Logistic regression method was used for constructing a model to predict NB patients' COG. RESULTS: NB patients in low COG showed significantly superior prognosis than those in high COG. A total of seven CpG sites were found closely related to COG. Logistic regression model based on those CpGs showed superior performance in separating NB patients in different COGs. CONCLUSIONS: The present study highlights the important role of DNA methylation in NB development, which might provide evidence for treatment decisions for children NB.

[The relationship between plasma BNP level and the left ventricular dysfunction parameters in patients with acute myocardial infarction and it's value in diagonosing heart failure.].

OBJECTIVE: To explore the correlation between plasma BNP level and left ventricular dysfunction parameters in patients with acute myocardial infarction (AMI). METHODS: Plasma BNP level was determined in 230 consecutive inpatients with AMI and 111 normal controls. Patients were grouped according Killip grades, LVEF and LVEDd, respectively. BNP was transformed into lnBNP for the normal distribution. The receiver operator characteristic curve (ROC curve) was drawn to determine the best threshold and criteria for diagnosing heart failure. RESULTS: After AMI, lnBNP levels increased significantly in proportion with increasing Killip grades (I-III), and decreasing LVEF (all P < 0.05). lnBNP level was significantly higher in LVEDd > 55 mm group than in the LVEDd < 55 mm group (P < 0.01). lnBNP, LVEDd and LVEF all linearly correlated with Killip grades (P < 0.05) and the best correlation was shown between lnBNP and Killip grades (r = 0.53, P < 0.05). lnBNP also positively correlated with LVEDd (r = 0.17, P < 0.05) and negatively correlated with LVEF (r = -0.41, P < 0.01). Among the parameters, lnBNP level presented the largest AUC in their ROC curves (P < 0.01) for diagnosing decompensated heart failure and cardiogenic shock. The sensitivity, specifiticity and accuracy rates for diagnosing decompensated heart failure were 84.9%, 45.0% and 70.0% respectively by lnBNP at the cut point of 140 ng/L. The sensitivity, negative predicting value and accuracy rate for diagnosing cardiac shock were 82.8%, 66.7% and 67.4% respectively by BNP at the cut point of 400 ng/L. CONCLUSION: lnBNP level in hospitalized patients with AMI was positively correlated with Killip grades and LVEDd, negatively correlated with LVEF and could serve as a parameter for diagnosing the decompensated heart failure and excluding the cardiac shock.

Thermosensitive and pH-sensitive Au-Pd bimetallic nanocomposites.

The bimetallic nanoparticles were protected by a double stimuli-sensitive diblock copolymer, poly(N-isopropylacrylamide)-block-poly(4-vinylpyridine) (PNIPAM-b-P4VP), which was synthesized via the reversible addition-fragmentation chain transfer (RAFT) polymerization. The obtained nanocomposites were made up of bimetallic nanoparticles cross-linked P4VP core and PNIPAM shell. Energy-dispersive X-ray (EDX) spectra and UV-vis transmittance revealed the formed nanoparticles was truly bimetallic particles with incomplete core-shell structures, Au as core and Pd as shell, rather than the physical mixture of monometallic nanoparticles. Laser light scattering (LLS) demonstrated the nanocomposites exhibit both thermo and pH sensitivity. X-ray diffraction (XRD) clearly showed Au formed a high-ordered crystal while Pd fashioned amorphous aggregates. In addition, the bimetallic nanocomposites show special responsiveness for temperature and better catalytic activity than corresponding monometallic nanocomposites.

Core-shell-corona au-micelle composites with a tunable smart hybrid shell.

Micelles having a core of polystyrene and a mixed shell of poly(ethylene glycol) and poly(4-vinylpyridine) were formed through self-assembly of a triblock copolymer poly(ethylene glycol)- block-polystyrene- block-poly(4-vinylpyridine) in acidic water (pH 2). Reducing the HAuCl(4)-treated micelle solution leads to the formation of the Au-micelle composites with a core of polystyrene, a hybrid shell of poly(4-vinylpyridine)/Au/poly(ethylene glycol), and a corona of poly(ethylene glycol). The gold nanoparticles with controlled sizes were anchored to poly(4-vinylpyridine) to form the physically cross-linked hybrid shell. In aqueous solution, the hybrid shell is swollen and the swollen degree is sensitive to the pH condition. Under basic conditions, the channel in the hybrid shells of the composite is produced, which renders the composites a good catalytic activity. In addition, the composites also show good stability, unchanged hydrodynamic diameter, and surface plasmon absorption under different pH conditions.

Formation and catalytic activity of spherical composites with surfaces coated with gold nanoparticles.

Micelle-supported gold composites with a polystyrene core and a poly(4-vinyl pyridine)/Au shell are synthesized using NaBH(4) to reduce a mixture of micelle and HAuCl(4) in acidic aqueous solution (pH approximately 2). The template micelle with a polystyrene core and a poly(4-vinyl pyridine) shell is formed by self-assembly of block copolymer polystyrene-block-poly(4-vinyl pyridine). The gold nanoparticles coated onto the surfaces of the composites possess an average diameter of about 15 nm. The composites are applied to catalyze the reduction of p-nitrophenol in the presence of NaBH(4), and the results indicate that the kinetic constant of the reaction increases when the composite concentration and the reaction temperature increase. In addition, research results also indicate that composites with high content of gold show higher catalytic activity and higher catalytic efficiency.

[The clinical value of B-type natriuretic peptide in the diagnosis of left heart failure].

OBJECTIVE: To evaluate the diagnostic value of B-type natriuretic peptide (BNP) in the diagnosis of left heart failure (HF) or left ventricular systolic dysfunction. METHODS: Samples of peripheral venous blood were collected from 243 consecutive patients with left HF and 111 normal controls (control group, CG) to measured BNP level with fluorescence immunoassay method. The patients with left HF were divided into 2 groups: those with the left ventricular ejection fraction (LVEF) 40% (n = 132) according to the level of LVEF; or into 2 groups: compensated heart failure group (CHF group, at NYHA grade I - II, n = 110) and decompensated heart failure group (DHF group, at NYHA grade III - IV, n = 133) according to the New York Heart Association (NYHA) functional class. RESULTS: The plasma level of BNP of the left HF group was 292.0 ng/L, significantly higher than that of the CG (17.9 ng/L, P < 0.001). The plasma BNP of the group with the LVEF 40% (138.5 ng/L, P < 0.001). The plasma BNP of the DHF group was 579.0 ng/L, significantly higher than that of the of the CHF group (84.8 ng/L, P < 0.001). The values of area under the curve (AUC) of receiver operator characteristic curve were all > 0.9 in the diagnosis of presence of HF (AUC = 0.927), HF with the LVEF 40% and compensated heart failure, the PPV were 88.0% and 84.7%, the NPV were 72.6% and 72.1% respectively. CONCLUSION: The diagnostic value of BNP is high for the diagnosis of more severely impaired LVEF and decompensated heart failure with 90.0 pg/ml as the cutoff value, and if 50.0 pg/ml is used as the cutoff value, the value is also good for the diagnosis of HF with the LVEF > 40% and compensated heart failure.