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Abstract: Four non-magnetic mutants of Magnetospirillum gryphiswaldense strain MSR-1 were isolated by transposon mutagenesis and found to contain interruption of either the mamO or mamE gene within the mamAB operon. Studies indicated that mamO and mamE genes are essential for magnetosome crystal biomineralization in MSR-1. This is the first report of a single gene (mamO or mamE) whose mutation affects crystal biomineralization in MSR-1. [ABSTRACT FROM AUTHOR]

AbstractIn order to improve the utilization value of the erythritol mother liquor, the separation and purification of the erythritol mother liquor was selected in this study. The selected chromatographic separation programme for erythritol crystallizing mother liquor is as follows: Firstly, erythritol is resolved from mannitol and arabitol with DTF-01Ca (Suqing Group) resin and then mannitol is resolved from arabitol with 99Ca/320 (Dowex) resin. At the same time, the chromatographic conditions of the DTF-01Ca (Suqing Group) and 99Ca/320 (Dowex) resins were optimized, resulting in an optimal separation temperature and mobile phase flow rate of 70 °C, 10 ml/min. On this basis, a single-column chromatographic model was used to calculate the TD model parameter (N) and the mass transfer coefficient (km ) of the separation of erythritol mother liquor by DTF-01Ca (Suqing Group) and 99Ca/320 (Dowex) resins. The adsorption isotherms, TD model parameter (N) and the mass transfer coefficient (km ) provides data references for the design and operation of the simulated moving beds (SMB) separation system for the industrial-scale separation of erythritol crystallizing mother liquor. [ABSTRACT FROM AUTHOR]

The β-cyclodextrin (β-CD) based high internal phase emulsions (HIPEs) were prepared as building blocks for engineering high-quality 3D shapes and achieving 4D color transformation. The increase of β-CD concentration, the decrease of pH value, and the addition of NaCl contributed to the adsorption of β-CD molecules at the oil-water interface and the improvement of the microstructure, rheological properties and printing quality of the Pickering HIPEs. Moreover, the 4D printing of Pickering HIPEs was achieved by introducing pH-sensitive curcumin and heat-labile NaHCO 3. With the increase in heating temperature, heating time and NaHCO 3 concentration, the decomposition of H C O 3 − to C O 3 2 − led to an elevation in pH, which induced the conformational change in curcumin, accompanied by a decrease in L* and b* values and an increase in a* value of the samples. These findings dramatically improve the pleasure of diet and take full advantage of the custom design benefits of 3D printing technology. • High internal phase emulsions prepared by β-CD exhibited viscoelastic behavior. • Microstructure, interfacial and rheological properties of emulsions were evaluated. • The printability of emulsions was regulated by β-CD concentrations and pH values. • The pH-triggered color change was achieved by heating emulsions containing curcumin. [ABSTRACT FROM AUTHOR]

Estrogens and androgens play important roles in regulating the hormone-secreting functions of the pituitary gland by binding to their corresponding receptors. However, the expression of estrogen receptors (ERs) and the androgen receptor (AR) and the cell types containing ERs and AR in the anterior pituitary gland of adult chickens have not been well-studied. In this study, the distribution of ERα, AR and their corresponding cell types in the anterior pituitary gland of adult cockerels was detected by immunohistochemistry. The results showed that ERα was expressed in 68.63 % of luteinizing hormone (LH) producing cells but was not found in thyrotropes, lactotropes, somatotropes, corticotropes and folliculo-stellate (FS) cells. Pituitary hormone and AR double labeling results showed that about 37 % of LH cells and 50 % of thyroid-stimulating hormone (TSH) producing cells expressed AR, respectively. In contrast, less than 1 % of the somatotropes had an AR positive signal and AR signals were not detected in lactotropes, corticotropes or FS cells. In addition, there were only a few AR and ERα dual-labeled cells observed. These novel results provide evidence for a cell-specific distribution of ERα and AR in the anterior pituitary from adult cockerels by immunohistochemistry. The different distributions of ERα and AR in the LH cells suggest that the feedback-regulating mechanisms of estrogen and androgen on the pituitary hormones secretion are different. The functions and related mechanisms still need to be elucidated further. [ABSTRACT FROM AUTHOR]

Androgens are known to modulate the skeletal muscle proliferation and differentiation processes. Recent in vitro studies have shown that dihydrotestosterone and anabolic steroids have functions in promoting the proliferation and differentiation of the mouse skeletal muscle myoblast C2C12 cell line through the classical androgen receptor (AR) signaling pathway. But there are contradictory reports that androgen plays its roles through the membrane signaling pathways. In the present study, we show that there is no expression of the classical AR in L6 cells both at gene and protein levels. We then investigated the effects of testosterone (T) on L6 cell proliferation and differentiation. The results show that T promotes L6 cell proliferation after a 24 h treatment, which followed by enhancing L6 cell differentiation, but these effects are not inhibited by flutamide (F), an antagonist of intracellular AR. Further, we tested the effect of testosterone covalently bounding to albumin (T-BSA), which does not cross the plasma membrane. The results demonstrate that T-BSA and free T have similar effects on L6 cell proliferation and differentiation, and that these effects involve G protein-coupled receptors and different downstream pathways. The L6 cell proliferation induced by T involves PKC and ERK1/2 signaling pathways and cell differentiation happens via the PKA signaling pathway. These results suggest that T promotes cell proliferation and differentiation via G protein-coupled receptors and different downstream pathways in the L6 cell line, although the related molecular mechanisms need to be elucidated in future studies. J. Cell. Physiol. 227: 98-107, 2012. © 2011 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

A fast and sensitive method was developed for the simutaneous quantitative determination of 16 sulfonamides in animal feeds using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC–MS–MS). With the developed method, a feed sample can be analyzed in less than 2 h. A solid phase extraction method using acetonitrile and basic alumina column was developed to extract and purify sulfonamides from animal feeds. The analysis time can be greatly reduced with this method compared with previous reports. A linear range of 0.2∼40 ng/mL (R2> 0.996) were obtianed for most of the compounds. The limits of quantification for all sulfonamides were in the range of 0.5∼20 μg/kg. The high precision and accuracy of this method were represented by average recoveries ranging from 80% to 120% and coefficients of variation of less than 10% for spiked animal feed samples. The method is suitable for fast determination of sulfonamides in concentrates, premixes, and complete feeds. [ABSTRACT FROM AUTHOR]

Abstract: Cimetidine (CIM) is a histamine H2 receptor inverse agonist used primarily as an anti-stomach acids drug, but recent studies showed that it may also modulate immune responses. To evaluate its potential usefulness as an adjuvant, we determined its immune modulating effects on subunit immunization using an HBV-derived recombinant protein antigen rHBsAg. CIM activated the PI3K-Akt signaling pathway in DCs. As an adjuvant, it activated immunogenic DCs, deactivated tolerogenic T cells (nTreg), and augmented both Th1- and Th2-polarlized immune responses to rHBsAg. As a result, it enhanced both antibody- and cytotoxic T cell-mediated immune responses. Importantly, in comparison with the FDA-approved human adjuvant alum, CIM is superior in its ability to block IL-10 up-regulation and potentiate Th1/Th2 dual polarization. These results suggest that CIM may be a better adjuvant for therapeutic vaccines against chronic viral infection, such as the HBV infection, where dual polarization should allow more effective elimination of infected host cells. [Copyright &y& Elsevier]