[Study on antimicrobial susceptibility of Brucella in a city].

Objective: To investigate the antimicrobial susceptibility of Brucella and to provide a scientific basis for rational drug use and effective treatment of patients with brucellosis. Methods: A total of 41 Brucella strains were isolated from the blood of patients with brucellosis in 5 counties and 2 districts in Yuxi City, China from 2014 to 2016. The susceptibility to 23 antimicrobial drugs was tested using Kirby-Bauer (K-B) disk diffusion method and the sizes of antimicrobial rings were recorded. The susceptibility testing results were interpreted according to the Drug Susceptibility Testing Guideline (2009 version) . Results: The susceptibility rate of Brucella was 100.00% to ofloxacin, ciprofloxacin, levofloxacin, and amikacin and >90% to cefotaxime, cefepime, imipenem, doxycycline, cefoperazone, minocycline, tobramycin, rifampicin, cefoperazone/sulbactam, and chloramphenicol. The high resistance to aztreonam and ampicillin was observed (87.80% and 41.46%). Doxycycline-intermediate strains, rifampicin-intermediate strains, and rifampicin-resistant strains were identified. Conclusion: Doxycycline and rifampicin are commonly used in the treatment of brucellosis, but doxycycline/rifampicin-intermediate and-resistant strains have been identified. The susceptibility of Brucella to fluoroquinolones and cephalosporins was high, so the two drugs can be considered in the treatment of brucellosis.

Paclitaxel induces apoptosis in leukemia cells through a JNK activation-dependent pathway.

Paclitaxel (PTX) is a mitotic inhibitor widely used in chemotherapy for many types of cancers, including solid tumors and hematological malignancies. However, the molecular basis of the anti-proliferation activity of PTX is not fully understood. In this paper, we focused on the role of c-Jun N-terminal kinase (JNK) pathways in PTX-induced apoptosis and proliferation inhibition. The effects of PTX were examined in human leukemia cell lines and patients' chronic lymphocytic leukemia (CLL) cells in relation to mitochondrial events, apoptosis, and perturbation of JNK activation using flow cytometry, siRNA, mitochondrial membrane potential determination, and western blotting. Exposure of cells to PTX at concentrations ≥ 10 nM for 18 or 24 h resulted in a significant release of cytochrome c from mitochondria to the cytosol, cleavages of procaspase 3 and poly (ADP-ribose) polymerase (PARP), and JNK activation, leading to apoptosis. The pan-caspase inhibitor BOC-D-FMK blocked the PTX-induced apoptosis but had no effect on cytochrome c release, suggesting that cytochrome c had been released before caspase activation. Moreover, both pharmacological JNK inhibitors SP600125 and JNK siRNA dramatically blocked PTX-induced apoptosis, cytochrome c release, caspase 3, and PARP cleavage. These findings demonstrate that JNK activation plays a critical role in the induction of apoptosis mediated by PTX in human leukemia cell lines and CLL patient-derived primary cancer cells, and this event is upstream of cytochrome c release, caspase 3, and PARP cleavage.

Cloning, characterization and expression analysis of coagulation factor II gene in grass carp (Ctenopharyngodon idella).

Here, we characterized the structure and function of the coagulation factor II (FII) gene in grass carp and determined its role in coagulation mechanisms. The FII gene EST was obtained using a constructed splenic transcriptome database; the full-length FII gene sequence was obtained by 3' and 5' RACE. The open reading frame (ORF) of FII was cloned and the full-length gene was found to be 1718 bp, with an ORF of 1572 bp; the gene contained a 25 bp 5'-untranslated region (UTR) and 108 bp 3'-UTR. The ORF encoded 524 amino acids, including 74 alkaline amino acids (arginine and lysine) and 69 acidic amino acids (aspartic acid and glutamic acid). The theoretical pI was 6.22. The calculated instability index (II) was 39.81, indicating that FII was a stable protein; the half-life period was predicted to be approximately 30 h. Amino acid sequence comparisons indicated that grass carp FII showed most similarity (71%) to FII of Takifugu rubripes, followed by Oplegnathus fasciatus (48% similarity) and Larimichthys crocea (47% similarity). A real-time reverse transcription PCR analysis showed that under normal circumstances, FII was most highly expressed in the liver, followed by the gill, spleen, thymus, and head-kidney (P < 0.001). After injection of the grass carp reovirus 873 (GCRV873), the pattern of FII expression was significantly altered (P < 0.001); gene expression was high after injection, suggesting a response involving the initiation of the coagulation system and defense of the body in combination with the platelet and complement system.

Mangiferin induces cell cycle arrest at G2/M phase through ATR-Chk1 pathway in HL-60 leukemia cells.

This study aimed to determine the effect of mangiferin on the cell cycle in HL-60 leukemia cells and expression of the cell cycle-regulatory genes Wee1, Chk1 and CDC25C and to further investigate the molecular mechanisms of the antileukemic action of mangiferin. The inhibitory effect of mangiferin on HL-60 leukemia cell proliferation was determined by the MTT assay. The impact of mangiferin on the HL-60 cell cycle was evaluated by flow cytometry. After the cells were treated with different concentrations of mangiferin, the expression levels of Wee1, Chk1 and CDC25C mRNA were determined by RT-PCR, and Western blot was used to evaluate the expression levels of cdc25c, cyclin B1, and Akt proteins. The inhibition of HL-60 cell growth by mangiferin was dose- and time-dependent. After treatment for 24 h, cells in G2/M phase increased, and G2/M phase arrest appeared with increased mRNA expression of Wee1, Chk1 and CDC25C. Mangiferin inhibited Chk1 and cdc25c mRNA expression at high concentrations and induced Wee1 mRNA expression in a dose-dependent manner. It significantly inhibited ATR, Chk1, Wee1, Akt, and ERK1/2 phosphorylation but increased cdc2 and cyclin B1 phosphorylation. Furthermore, mangiferin reduced cdc25c, cyclin B1, and Akt protein levels while inducing Wee1 protein expression. It also antagonized the phosphorylation effect of vanadate on ATR, and the phosphorylation effect of EGF on Wee1. These findings indicated that mangiferin inhibits cell cycle progression through the ATR-Chk1 stress response DNA damage pathway, leading to cell cycle arrest at G2/M phase in leukemia cells.

Screening of differentially expressed genes related to ischemic stroke and functional analysis with DNA microarray.

BACKGROUND: Prognostic blood biomarkers in the setting of acute ischemic stroke have become increasingly relevant for risk stratification, monitoring disease and response to therapies, developing targets for neuroprotective treatment and as surrogate end points for treatment trials. AIM: We aim to find the feature genes which can accurately detect acute ischemic stroke and perform function analysis of these crucial genes in peripheral blood mononuclear cells. MATERIALS AND METHODS: The gene expression profile GSE22255 was downloaded from Gene Expression Omnibus (GEO) database which includes 20 ischemic stroke patients and 20 controls. The differentially expressed genes between patients and controls samples were identified with packages in R language. The selected differentially expressed genes were further analyzed using bioinformatics methods. Software STRING (Search Tool for the Retrieval of Interacting Genes) was used to establish co-expression network. GOTM (General Ocean Turbulence Model) software was used to obtain differentially expressed gene enriched modules. The functions of genes in modules were analyzed by using software GeneCodis. RESULTS: A total of 37 genes were identified as differentially expressed genes by comparing peripheral blood mononuclear cells gene expression of ischemic stroke patients and 20 controls. A co-expression network was constructed within 30 differentially expressed genes, among which gene interleukin-8 (IL-8) and tumor necrosis factor (TNF) showed the highest node degree. Genes in the module containing IL-8 and TNF were significantly enriched in 6 biological functions, and the most significant function was respond to stimulation. CONCLUSIONS: Our results highlight that genes IL-8 and TNF have close relationship with acute ischemic stroke, and the expression patterns of these genes may be valid targets for new medications able to modify the ischemic stroke process.

Phase-conjugated XeCl laser resonator.

Self-Q switching of a XeCl laser fitted with a resonator containing a stimulated-Brillouin-scattering phase-conjugate reflector is demonstrated. Q-switched laser pulses of 0.2-mJ energy and 2.5-ns duration and with a divergence close to the diffraction limit were obtained. A spectral narrowing of the two strong lines at 307.98 and at 308.19 nm exhibited by the XeCl laser spectrum was also observed.