OBJECTIVE: CRISPR-Cas protects bacteria from exogenous DNA invasion and is associated with bacterial biofilm formation and pathogenicity. METHODS: We analyzed the type I-F CRISPR-Cas system of Legionella pneumophila WX48, including Cas1, Cas2-Cas3, Csy1, Csy2, Csy3, and Cas6f, along with downstream CRISPR arrays. We explored the effects of the CRISPR-Cas system on the in vitro growth, biofilm-forming ability, and pathogenicity of L. pneumophila through constructing gene deletion mutants. RESULTS: The type I-F CRISPR-Cas system did not affect the in vitro growth of wild-type or mutant strains. The biofilm formation and intracellular proliferation of the mutant strains were weaker than those of the wild type owing to the regulation of type IV pili and Dot/Icm type IV secretion systems. In particular, Cas6f deletion strongly inhibited these processes. CONCLUSION The type I-F CRISPR-Cas system may reduce biofilm formation and intracellular proliferation in L. pneumophila.
Legionella pneumophila/pathogenicity* ; CRISPR-Cas Systems ; Biofilms/growth & development* ; Phenotype ; Bacterial Proteins/metabolism* ; Gene Deletion

OBJECTIVE: To investigate the mechanistic basis for the attenuation of bone degeneration by edible bird's nest (EBN) in ovariectomized rats. METHODS: Forty-two female Sprage-Dawley rats were randomized into 7 groups (6 in each group). The ovariectomized (OVX) and OVX + 6%, 3%, and 1.5% EBN and OVX +estrogen groups were given standard rat chow alone, standard rat chow +6%, 3%, and 1.5% EBN, or standard rat chow +estrogen therapy (0.2mg/kg per day), respectively. The sham-operation group was surgically opened without removing the ovaries. The control group did not have any surgical intervention. After 12 weeks of intervention, blood samples were taken for serum estrogen, osteocalcin, and osteoprotegerin, as well as the measurement of magnesium, calcium abd zinc concentrations. While femurs were removed from the surrounding muscles to measure bone mass density using the X-ray edge detection technique, then collected for histology and estrogen receptor (ER) immunohistochemistry. RESULTS: Ovariectomy altered serum estrogen levels resulting in increased food intake and weight gain, while estrogen and EBN supplementation attenuated these changes. Ovariectomy also reduced bone ER expression and density, and the production of osteopcalcin and osteorotegerin, which are important pro-osteoplastic hormones that promote bone mineraliztion and density. Conversely, estrogen and EBN increased serum estrogen levels leading to increased bone ER expression, pro-osteoplastic hormone production and bone density (all P<0.05). CONCLUSION EBN could be used as a safe alternative to hormone replacement therapys for managing menopausal complications like bone degeneration.

Background:Clinical outcomes of undifferentiated arthritis (UA) are diverse,and only 40 ％ of patients with UA develop rheumatoid arthritis (RA) after 3 years.Discovering predictive markers at disease onset for further intervention is critical.Therefore,our objective was to analyze the clinical outcomes of UA and ascertain the predictors for RA development.Methods:We performed a prospective,multi-center study from January 2013 to October 2016 among Chinese patients diagnosed with UA in 22 tertiary-care hospitals.Clinical and serological parameters were obtained at recruitment.Follow-up was undertaken in all patients every 12 weeks for 2 years.Predictive factors of disease progression were identified using multivariate Cox proportional hazards regression.Results:A total of 234 patients were recruited in this study,and 17 (7.3％) patients failed to follow up during the study.Among the 217 patients who completed the study,83 (38.2％) patients went into remission.UA patients who developed RA had a higher rheumatoid factor (RF)-positivity (42.9％ vs.16.8％,x2=8.228,P=0.008),anti-cyclic citrullinated peptide (CCP) antibodypositivity (66.7％ vs.10.7％,x2 =43.897,P ＜ 0.001),and double-positivity rate of RF and anti-CCP antibody (38.1％ vs.4.1％,x2 =32.131,P ＜ 0.001) than those who did not.Anti-CCP antibody but not RF was an independent predictor for RA development (hazard ratio 18.017,95％ confidence interval:5.803-55.938;P ＜ 0.001).Conclusion:As an independent predictor of RA,anti-CCP antibody should be tested at disease onset in all patients with UA.

Listeria monocytogenes is an important zoonotic foodborne pathogen that can tolerate a number of environmental stresses. RsbR, an upstream regulator of the sigma B (SigB) factor, is thought to sense environmental challenges and trigger the SigB pathway. In Bacillus subtilis, two phosphorylation sites in RsbR are involved in activating the SigB pathway and a feedback mechanism, respectively. In this study, the role of RsbR in L. monocytogenes under mild and severe stresses was investigated. Strains with genetic deletion (ΔrsbR), complementation (C-ΔrsbR), and phosphorylation site mutations in the rsbR (RsbR-T175A, RsbR-T209A, and RsbR-T175A-T209A) were constructed to evaluate the roles of these RsbR sequences in listerial growth and survival. SigB was examined at the transcriptional and translational levels. Deletion of rsbR reduced listerial growxth and survival in response to acidic stress. Substitution of the phosphorylation residue RsbR-T175A disabled RsbR complementation, while RsbR-T209A significantly upregulated SigB expression and listerial survival. Our results provide clear evidence that two phosphorylation sites of RsbR are functional in L. monocytogenes under acidic conditions, similar to the situation in B. subtilis.
Alanine/genetics* ; Bacillus subtilis ; Bacterial Proteins/metabolism* ; Binding Sites ; Gene Deletion ; Gene Expression Regulation, Bacterial ; Genetic Complementation Test ; Homeostasis ; Hydrogen-Ion Concentration ; Listeria monocytogenes/metabolism* ; Listeriosis/microbiology* ; Mutation ; Phenotype ; Phosphoproteins/metabolism* ; Phosphorylation ; Sigma Factor/metabolism* ; Stress, Physiological

OBJECTIVETo investigate the effects of evodiamine (Evo), a component of Evodiaminedia rutaecarpa (Juss.) Benth, on cardiomyocyte hypertrophy induced by angiotensin II (Ang II) and further explore the potential mechanisms.

METHODSCardiomyocytes from neonatal Sprague Dawley rats were isolated and characterized, and then the cadiomyocyte cultures were randomly divided into control, model (Ang II 0.1 μmol/L), and Evo (0.03, 0.3, 3 μmol/L) groups. The cardiomyocyte surface area, protein level, intracellular free calcium ([Ca]) concentration, activity of nitric oxide synthase (NOS) and content of nitric oxide (NO) were measured, respectively. The mRNA expressions of atrial natriuretic factor (ANF), calcineurin (CaN), extracellular signal-regulated kinase-2 (ERK-2), and endothelial nitric oxide synthase (eNOS) of cardiomyocytes were analyzed by real-time reverse transcriptionpolymerase chain reaction. The protein expressions of calcineurin catalytic subunit (CnA) and mitogen-activated protein kinase phosphatase-1 (MKP-1) were detected by Western blot analysis.

RESULTSCompared with the control group, Ang II induced cardiomyocytes hypertrophy, as evidenced by increased cardiomyocyte surface area, protein content, and ANF mRNA expression; increased intracellular free calcium ([Ca]) concentration and expressions of CaN mRNA, CnA protein, and ERK-2 mRNA, but decreased MKP-1 protein expression (P<0.05 or P<0.01). Compared with Ang II, Evo (0.3, 3 μmol/L) significantly attenuated Ang II-induced cardiomyocyte hypertrophy, decreased the [Ca] concentration and expressions of CaN mRNA, CnA protein, and ERK-2 mRNA, but increased MKP-1 protein expression (P<0.05 or P<0.01). Most interestingly, Evo increased the NOS activity and NO production, and upregulated the eNOS mRNA expression (P<0.05).

CONCLUSIONEvo signifificantly attenuated Ang II-induced cardiomyocyte hypertrophy, and this effect was partly due to promotion of NO production, reduction of [Ca]i concentration, and inhibition of CaN and ERK-2 signal transduction pathways.

Angiotensin II ; Animals ; Atrial Natriuretic Factor ; metabolism ; Calcineurin ; genetics ; metabolism ; Calcium ; metabolism ; Dual Specificity Phosphatase 1 ; genetics ; metabolism ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Hypertrophy ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Quinazolines ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley

Objective To develop a detergent for decontamination of Co2+ and Mn2+ on skin.Methods Single-factor experimental and orthogonal experimental designs were performed to study the formula composition of the decontaminant.The skin irritation experiment was performed and assessed according to the standard method.The detergent was prepared according the conventional process of showering gel.The pH,ethylenediaminetetraacetic acid (EDTA) level,total active substances of the detergent,and its stability were evaluated according to the chemical method recommended in the national standard GB/T 13173-2008.The decontamination efficiency on stable isotopes of Co2+ and Mn2+ contamination was measured on the back of hand skin of volunteers.Results The formula composition of the decontaminant was obtained through the orthogonal experiment.The pH value of the detergent was 6.99,total active substance was 20.49％ and the content of EDTA was 5.99％.After being kept at-5 ℃ and 40℃℃ for 24h,the decontaminant showed no strange smell,no precipitation,no discoloration and still kept transparent.The decontamination effects on Co2+ and Mn2+ contaminated on hand skin were 103.13％ ± 0.05％ and 100.62％ ± 0.09％,respectively,which was significantly higher than that of distilled water (81.77％ ± 0.23％ and 79.63％ ± 0.23％,P＜0.01,respectively).Conclusion The decontaminant has a high effect on decontamination of Co2+ and Mn2+ polluted on skin,and is hopeful to be developed as an effective detergent on radioactive isotopes contamination.

A one-step dual flow immunochromatographic assay (DICGA), based on a competitive format, was developed for simultaneous quantification of ochratoxin A (OTA) and zearalenone (ZEN) in corn, wheat, and feed samples. The limit of detection for OTA was 0.32 ng/ml with a detection range of 0.53‒12.16 ng/ml, while for ZEN it was 0.58 ng/ml with a detection range of 1.06‒39.72 ng/ml. The recovery rates in corn, wheat, and feed samples ranged from 77.3% to 106.3% with the coefficient of variation lower than 15%. Naturally contaminated corn, wheat, and feed samples were analyzed using both DICGA and liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the correlation between the two methods was evaluated using a regression analysis. The DICGA method shows great potential for simple, rapid, sensitive, and cost-effective quantitative detection of OTA and ZEN in food safety control.
Animal Feed ; Calibration ; Chromatography, Affinity ; Chromatography, Liquid ; Colloids ; Food Contamination/analysis* ; Food Safety ; Gold ; Immunoassay/methods* ; Inhibitory Concentration 50 ; Limit of Detection ; Metal Nanoparticles ; Ochratoxins/analysis* ; Regression Analysis ; Reproducibility of Results ; Sensitivity and Specificity ; Triticum ; Zea mays ; Zearalenone/analysis*

OBJECTIVETo study the immunologic function of dendritic cells (DCs) cultured in two kinds of hepatoma cell line's supernatant and the enhancing effects of carboxymethylpachymaran (CMP) on DCs.

METHODSDCs were harvested after stimulation by granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 from umbilical cord blood using density-gradient centrifugation method. Cultured supernatant of two hepatoma cell lines (HepG2 and HepG2.2.15) were collected for condition medium (CM) according to a volume ratio of supernatant to incomplete RPMI-1640 medium, which was 3:1. CMP was dissolved in incomplete RPMI-1640 medium. Experimental groups were divided according to the culture medium, either CM or with CMP in it. DCs subsets CD83, CD86, CD1a, and d-related human leukocyte antigens (HLA-DR) were analyzed by flow cytometry. The proliferation ability of allogeneic T cells in mixed lymphocyte reaction (MLR) stimulated by DCs was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. IL-12p70, interferon-γ (IFN-γ), and nuclear factor κB (NF-κB) were detected by enzyme-linked immunosorbent assay analysis.

RESULTSThe proliferation of lymphocytes and secreting level of IL-12 and expression of phenotype of DCs cultured in two kinds of CM were lower than those of normal group (P <0.01). Compared with the normal group, groups treated with CMP showed a higher expression level of DCs subsets, lymphocyte reproductive activity, as well as IL-12 and IFN-γ secretion levels. Groups treated with CMP also demonstrated higher levels of DCs phenotype expression and IL-12 and IFN-γ secretion in supernatant of MLR and higher lymphocyte reproductive activity compared with CM group (P <0.05). Compared with the normal group, the expression level of NF-κB in DCs nuclear was higher in CMP groups but lower in two CM groups (P <0.05). After CMP was added, the NF-κB expression levels of two CM groups were increased compared with levels before CMP was added (P <0.05). However, there was no significant difference between the two CM groups (P >0.05).

CONCLUSIONSTwo kinds of hepatoma cell line's supernatant can inhibit the immunologic function of DCs. This suppressive effect may be related to the inhibition of NF-κB/Rel pathway. CMP may up-regulate the DCs function by activating the NF-κB/Rel pathway.

Carcinoma, Hepatocellular ; pathology ; ultrastructure ; Cell Line, Tumor ; Cell Shape ; Dendritic Cells ; drug effects ; immunology ; Glucans ; pharmacology ; Humans ; Immunophenotyping ; Interferon-gamma ; metabolism ; Interleukin-12 ; metabolism ; Liver Neoplasms ; pathology ; ultrastructure ; Lymphocyte Culture Test, Mixed ; Signal Transduction ; drug effects ; Subcellular Fractions ; drug effects ; Transcription Factor RelA ; metabolism

OBJECTIVETo evaluate the efficacy and safety of nateglinide, a new antidiabetic agent, in the treatment of type 2 diabetes.

METHODSA total of 219 treatment-naïve patients with type 2 diabetes from 6 centers were enrolled in this study and blindly divided into nateglinide group (n = 105) and repaglinide group (n = 114). In all patients, the disease was confirmed for at least three months. The whole observation lasted for 12 weeks. The efficacy indicators measured include glycohemoglobin A1c (HbA1c), fasting blood glucose, and 2 hours postprandial blood glucose, and the safety parameters measured included renal and hepatic function, serum lipids, and blood and urea profiles.

RESULTSSimilar decreases in fasting blood glucose, 2 hours postprandial blood glucose, and HbA1 c were found in both nateglinide group and repaglinide group without significant differences. No severe adverse events were noted. The hypoglycemia event reports were not significantly different between these two groups.

CONCLUSIONNateglinide is an effective and safe drug in treating type 2 diabetes.

Blood Glucose ; drug effects ; Cyclohexanes ; administration & dosage ; adverse effects ; therapeutic use ; Diabetes Mellitus, Type 2 ; drug therapy ; Drug Administration Schedule ; Female ; Humans ; Hypoglycemic Agents ; administration & dosage ; adverse effects ; therapeutic use ; Male ; Middle Aged ; Phenylalanine ; administration & dosage ; adverse effects ; analogs & derivatives ; therapeutic use ; Treatment Outcome

Objective To explore the effect of dendritic cells (DC) modified with transforming growth factor β1 (TGF-β1) gene on the expressions of CD28/CTLA-4:B7 costimulatory molecules in peripheral blood mononuclear cells (PBMC) in the Lewis rats with experimental autoimmune myasthenia gravis (EAMG). Methods Thirty inbreeding line, healthy, female Lewis rats were divided randomly into 6 groups: normal group, EAMG group, DC treatment group, pcDNA3-TGF-β1-DCtreatment group, pcDNA3-DC control group and normal saline group. The rats were immunized with the AChR protein extracted from electric organ of Narcine timilei and CFA in the groups except normal group. 2×106 pcDNA3-TGF-β1-DCs/rat were injected subcutaneously into the backs of the rats which had been immunized 5 d earlier with AChR+CFA. The rats in DC treatment group, pcDNA3-DC control group and normal saline group were injected in parallel with untreated DC, pcDNA3-DC and normal saline, respectively. Seven weeks after the first immunization, the expressions of CD28 mRNA and CTLA-4 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR), and the levels of B7-1 and B7-2 on the surface of PBMC were examined using flow cytometry. Results (1)The low expression of CD28 mRNA and rare expression of CTLA-4 mRNA were found in the normal rats, and both expressions increased markedly in EAMG rats (P＜0.001). Compared to those in EAMG group, the expression of CD28 mRNA decreased and CTLA-4 mRNA was upregulated after the treatment with pcDNA3-TGF-β1-DC (P＜0.05). There was no significant difference in the expressions of CD28 mRNA and CTLA-4 mRNA among the EAMG group, DC treatment group, pcDNA3-DC control group and normal saline group (P＞0.05). (2) The expressions of CD28, CTLA-4, B7-1 and B7-2 on the surface of PBMC were rare in normal rats, which increased significantly in EAMG rats (P＜0.001). The levels of CD28, B7-1 and B7-2 in pcDNA3-TGF-β1-DC group were lower than those in EAMG group (P＜0.01), but the level of CTLA-4 was higher than that in EAMG group (P＜0.05). They showed no statistically difference among the EAMG group, DC treatment group, pcDNA3-DC control group and normal saline group (P＞0.05). Conclusions The expressions of CD28/CTLA-4:B7 costimulatory molecules are abnormal in the rats with EAMG. The regulation of CD28/CTLA-4:B7 costimulatory pathways may play a critical role in the mechanism of the treatment with DC transfected with pcDNA3-TGF-β1 in the incipient EAMG rats.