A novel and efficient assay for identification and quantification of Acidithiobacillus ferrooxidans in bioleaching samples

Acidithiobacillus ferrooxidans is a Gram-negative, acidophilic, and chemolithotrophic bacterium that is active in bioleaching. The leaching efficacy is directly influenced by the biomass changes of this specie in bioleaching microbial community. In order to perform a simple and sensitive assay on A. ferrooxidans from mixed strains in this process, a novel assay was developed based on sandwich hybridization assay with the aid of S1 nuclease treatment and fluorescent labeling. In the work, a designed DNA probe complementary to the conservative region of its 16S rRNA was synthesized, which showed high accuracy for distinguishing homologous species with the exclusion of even-only two base pairs difference. The specificity of this assay was verified in different systems with mixed strains, and the quantitative result was proved by comparison of microscopic cell counting. The detection sensitivity was about 8 × 10(2) cells/ml and the inter-assay coefficient of variation of three independent assays was from 3.8 to 7.7 %, respectively. In addition, the cycle of assay was about 3-4 h when the cost estimated was less than $0.5 per sample. This assay method might be applied for identifying and monitoring any kind of bacterial strain from a mixed microbial flora in bioleaching or other areas.     

Over-expression of human carcinoma-associated antigen in intrahepatic cholangiocellular carcinoma

Objective: To investigate the expression status of human carcinoma antigen (HCA) in human cholangiocellular carcinomas, and to determine the relationship between HCA and clinical features. Methods: Tissues from 60 intrahepatic cholangiocellular carcinoma (ICC) patients, and normal liver tissues from 20 hepatic hemangioma patients selected randomly were assayed for the expression of HCA by immunohistochemistry, and Western blots. Areas of poorly differentiated (n = 20), moderately-well differentiated (n = 30), highly differentiated tumors (n = 10) from different cases were evaluated. Results were recorded as positive (?5% of cells staining and staining intensity 2+ or 3+) or negative (<5% of cells staining and staining intensity <2+) and analyzed using the χ² test. Results: BCE075 and BDD048 antibodies showed similar staining patterns. The positive immunostaining of BCE075 was mainly localized in the cytoplasm and cell secretions. The staining was positive in 15% of poorly differentiated ICC, 72% of moderately-well differentiated, 100% of highly differentiated tumors. But, staining was not detected in adjacent normal tissue. The differences in HCA expression among these tissues were statistically significant. Also, we found expression of HCA to be closely associated with the degree of differentiation of ICC and tumor cell morphology. There was a correlation between expression of HCA and serum CA19-9. Conclusion: The data suggest that HCA is a potential marker for the diagnosis of cholangiocellular carcinoma.     

1H, 13C, and 15N resonance assignments of a general stress protein GSP13 from Bacillus subtilis

GSP13 encoded by gene yugI is a general stress protein in Bacillus subtilis. The NMR assignments of the protein are essential for its structure determination.     

Genome sequence of duck pathogen Mycoplasma anatis strain 1340

Mycoplasma anatis, a member of the class Mollicutes, is the causative agent of a contagious infectious disease of domestic ducklings, wild birds, and eggs. Increasing reports show that coinfection of M. anatis with Escherichia coli results in substantial economic impacts on the duck farms in China. Here, we announce the first genome sequence of M. anatis.     

Direct activation of Transient Receptor Potential Vanilloid 1(TRPV1) by Diacylglycerol (DAG)

Voltage-gated sodium channels play important roles in modulating dorsal root ganglion (DRG) neuron hyperexcitability and hyperalgesia after peripheral nerve injury or inflammation. We report that chronic compression of DRG (CCD) produces profound effect on tetrodotoxin-resistant (TTX-R) and tetrodotoxin-sensitive (TTX-S) sodium currents, which are different from that by chronic constriction injury (CCI) of the sciatic nerve in small DRG neurons. Whole cell patch-clamp recordings were obtained in vitro from L₄ and/or L₅ dissociated, small DRG neurons following in vivo DRG compression or nerve injury. The small DRG neurons were classified into slow and fast subtype neurons based on expression of the slow-inactivating TTX-R and fast-inactivating TTX-S Na⁺ currents. CCD treatment significantly reduced TTX-R and TTX-S current densities in the slow and fast neurons, but CCI selectively reduced the TTX-R and TTX-S current densities in the slow neurons. Changes in half-maximal potential (V_1/2) and curve slope (k) of steady-state inactivation of Na⁺ currents were different in the slow and fast neurons after CCD and CCI treatment. The window current of TTX-R and TTX-S currents in fast neurons were enlarged by CCD and CCI, while only that of TTX-S currents in slow neurons was increased by CCI. The decay rate of TTX-S and both TTX-R and TTX-S currents in fast neurons were reduced by CCD and CCI, respectively. These findings provide a possible sodium channel mechanism underlying CCD-induced DRG neuron hyperexcitability and hyperalgesia and demonstrate a differential effect in the Na⁺ currents of small DRG neurons after somata compression and peripheral nerve injury. This study also points to a complexity of hyperexcitability mechanisms contributing to CCD and CCI hyperexcitability in small DRG neurons.     

Silibinin ameliorates Aβ<Subscript>25-35</Subscript>-induced memory deficits in rats by modulating autophagy and attenuating neuroinflammation as well as oxidative stress

Alzheimer’s disease (AD) is a progressive, neurodegenerative disease. Accumulating evidence suggests that inflammatory response, oxidative stress and autophagy are involved in amyloid β (Aβ)-induced memory deficits. Silibinin (silybin), a flavonoid derived from the herb milk thistle, is well known for its hepatoprotective activities. In this study, we investigated the neuroprotective effect of silibinin on Aβ_25-35-injected rats. Results demonstrated that silibinin significantly attenuated Aβ_25-35-induced memory deficits in Morris water maze and novel object-recognition tests. Silibinin exerted anxiolytic effect in Aβ_25-35-injected rats as determined in elevated plus maze test. Silibinin attenuated the inflammatory responses, increased glutathione (GSH) levels and decreased malondialdehyde (MDA) levels, and upregulated autophagy levels in the Aβ_25-35-injected rats. In conclusion, silibinin is a potential candidate for AD treatment because of its anti-inflammatory, antioxidant and autophagy regulating activities.     

Anthraquinone G503 Induces Apoptosis in Gastric Cancer Cells through the Mitochondrial Pathway

G503 is an anthraquinone compound isolated from the secondary metabolites of a mangrove endophytic fungus from the South China Sea. The present study elucidates the anti-tumor activity and the underlying mechanism of G503. Cell viability assay performed in nine cancer cell lines and two normal cell lines demonstrated that the gastric cancer cell line SGC7901 is the most G503-sensitive cancer cells. G503 induced SGC7901 cell death via apoptosis. G503 exposure activated caspases-3, -8 and -9. Pretreatment with the pan-caspase inhibitor Z-VAD-FMK and caspase-9 inhibitor Z-LEHD-FMK, but not caspase-8 inbibitor Z-IETD-FMK, attenuated the effect of G503. These results suggested that the intrinsic mitochondrial apoptosis pathway, rather than the extrinsic pathway, was involved in G503-induced apoptosis. Furthermore, G503 increased the ratio of Bax to Bcl-2 in the mitochondria and decreased the ratio in the cytosol. G503 treatment resulted in mitochondrial depolarization, cytochrome c release and the subsequent cleavage of caspase -9 and -3. Moreover, it is reported that the endoplasmic reticulum apoptosis pathway may also be activated by G503 by inducing capase-4 cleavage. In consideration of the lower 50% inhibitory concentration for gastric cancer cells, G503 may serve as a promising candidate for gastric cancer chemotherapy.     

Determination of zeranol and its metabolites in bovine muscle and liver by a chemiluminescence enzyme immunoassay: compared to an ultraperformance liquid chromatography tandem mass spectroscopy method

A chemiluminescent enzyme immunoassay (CLEIA) was compared to an ultraperformance liquid chromatography tandem mass spectroscopy (UPLC‐MS/MS) procedure for the analysis of zeranol and its metabolites in bovine tissue samples. Apparent recoveries from fortified samples by both methods were comparable at 0.5–4.0 µg/kg and a significant correlation was obtained. For CLEIA analysis, hapten mimicking the analyte was first synthesized and conjugated with the carrier protein bovine serum albumin as the immunogen to produce monoclonal antibody. The obtained antibody showed extensive cross‐reactivity toward zeranol metabolites (zearalanone). The limit of detection of CLEIA and UPLC‐MS/MS was 0.05 µg/kg and 0.5 µg/kg, respectively. Recoveries of both methods for fortified samples were higher than 75.0% with the coefficient of variation less than 15%. These results indicated that the combination of screening with CLEIA and confirmation with UPLC‐MS/MS for zeranol and its metabolites would be a reliable method for a large number of bovine samples. Copyright © 2013 John Wiley & Sons, Ltd.