Liraglutide increases FNDC5 expression in C2C12 myotubes via activa-tion of CAMKK2/AMPK signaling pathways / 中国病理生理杂志

AIM:To investigate the effect of liraglutide ( LG) on the expression of fibronectin type Ⅲdomain-containing protein 5 (FNDC5) in the C2C12 myotubes.METHODS:The C2C12 mouse myoblast cell line was induced to differentiation.Differentiated cells were stimulated with gradient concentrations (1 ~1000 nmol/L) of LG for different time (0 ~24 h).The effects of LG on the expression of FNDC5 and the activation of adenosine 5'-monophosphate ( AMP)-activated protein kinase ( AMPK) signaling pathway were determined .After pretreated with glucagon-like peptide-1 ( GLP-1 ) receptor antagonist exendin 9-39 , the inhibitor of Ca 2+/calmodulin-dependent protein kinase kinase 2 (CAMKK2), STO609, or the inhibitor of AMPK, Compound C, the LG-induced FNDC5 expression in C2C12 myotubes was examined.The expression of FNDC5 and the activation of AMPK were determined by Western blot .RESULTS: In C2C12 myotubes, LG promoted the expression of FNDC5 in a dose-and time-dependent manner .LG also activated AMPK signaling pathway .These effects of LG were partly abolished by exendin 9-39 , STO609 and Compound C .CONCLUSION:LG promotes the expression of FNDC5 via GLP-1 receptor in the C2C12 myotubes possibly through activation of the CAMKK2/AMPK signaling pathways .

Effects of hydrogen sulfide on impaired wound healing in ob/ob mice / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the role of hydrogen sulfide ( H2 S) on impaired wound healing in ob/ob mice and the underlying mechanism.METHODS:The ob/ob mice were randomly divided into 3 groups, including vehicle, in-sulin and NaHS for treatment.C57BL/6 mice were treated with vehicle as control.Full-thickness punch biopsy wounds were created on the mice.Firstly, H2 S concentrations in the skins and granulation tissues were measured.The mRNA ex-pression of cystathionineγ-lyase ( CSE) was detected by RT-qPCR.The protein expression of CSE and MMP-9 were deter-mined by Western blot.The neutrophil and monocyte/macrophage infiltration was analyzed by immunohistochemistry me-thod.The levels of tumor necrosis factor (TNF)-αand interleukin (IL)-6 were measured by ELISA.Collagen formation was measured by Masson staining.RESULTS:The H2 S levels in the skin and granulation were significantly decreased in ob/ob mice and increased in the NaHS-treated mice ( P to impaired wound healing in diabetes, which is alleviated by exogenous H2 S possibly through anti-inflammation.

3D semi-automatic segmentation of the cochlea and inner ear.

Though interactive direct volume rendering produces meaningful images with high quality, it cannot display separate inner ear labyrinth or cochlea only by adjusting imaging parameters to suppress the surrounding structures. Novel semi-automatic segmentation methods were presented to extract the cochlea and inner ear from spiral CT images. The cochlea was separated from the medical image volume by applying the 3D narrow band level set segmentation algorithm with user interaction introduced to locate the initial contour and adjust the parameters. The inner ear was extracted with a similar semi-automatic segmentation method: manual segmentation was first applied to remove several closely interconnected regions in boundary by viewing image volume slice by slice, then the 3D narrow band level set segmentation algorithm was used to complete fine segmentation on image volume. Generating 3D models of cochlea and inner ear structures with such methods not only takes advantage of the combination of 2D images with 3D volume but also saves much time of post-processing. The segmented results were rendered with the Marching Cubes surface rendering method. The correlation of the point on the resultant surface to the three orthogonal sections that intersect at that point on the surface was built to evaluate the segmented object and display the spatial relations of the anatomical structures. The performance of the presented semi-automatic segmentation methods is tested using spiral CT images of the temporal bone.

Application of weighted minimum-norm estimation with Tikhonov regularization for neuromagnetic source imaging / 生物医学工程学杂志

In magnetoencepholography(MEG) inverse research, according to the point source model and distributed source model, the neuromagnetic source reconstruction methods are classified as parametric current dipole localization and nonparametric source imaging (or current density reconstruction). MEG source imaging technique can be formulated as an inherent ill-posed and highly underdetermined linear inverse problem. In order to yield a robust and plausible neural current distribution image, various approaches have been proposed. Among those, the weighted minimum-norm estimation with Tikhonov regularization is a popular technique. The authors present a relatively overall theoretical framework Followed by a discussion of the development, several regularized minimum-norm algorithms have been described in detail, including the depth normalization, low resolution electromagnetic tomography(LORETA), focal underdetermined system solver(FOCUSS), selective minimum-norm(SMN). In addition, some other imaging methods, e.g., maximum entropy method(MEM), the method incorporating other brain functional information such as fMRI data and maximum a posteriori(MAP) method using Markov random field model, are explained as well. From the generalized point of view based on minimum-norm estimation with Tikhonov regularization, all these algorithms are aiming to resolve the tradeoff between fidelity to the measured data and the constraints assumptions about the neural source configuration such as anatomical and physiological information. In conclusion, almost all the source imaging approaches can be consistent with the regularized minimum-norm estimation to some extent.