Time filter

Source Type

Wang W.,Zunyi Medical College Zhuhai Campus | Li W.,Yantai University | Li Q.,Yantai University
International Journal of Quantum Chemistry

The lithium bond between HMgH and LiNH2 has been predicted and characterized with quantum chemical calculations at the MP2/6-311++G(d,p) level. Upon formation of the lithium bond, both the Mg-H and Li-N bonds are stretched. The Li-N bond undergoes a red shift, whereas the Mg-H bond exhibits a blue shift. The lithium-bonded complex is controlled mainly by electrostatic and polarization interactions. The binding energy of HMgH with LiNH2 is computed to be 12.47 kcal/mol. The binding of the two molecules is enhanced by the substitution with the methyl group in the Li acceptor, whereas it is weakened by the replacement with whether the electron-withdrawing group such as F, Cl, CN, NC, or the electron-donating group (OH and HN2). A negative cooperativity is present in the ternary system of 2LiNH2 and HMgH. The polarization interaction plays an important role in the negative cooperativity. © 2009 Wiley Periodicals, Inc. Source

Lei S.-J.,Zunyi Medical College Zhuhai Campus | Shen Y.-X.,Interventional Imaging | Lou M.-W.,Interventional Imaging
Chinese Journal of Medical Imaging Technology

MRI is noninvasive imaging technique that can display cerebral information. In recent years, there were many experimental reports about pathophysiological process of Wallerian degeneration after cerebral infarction, but these studies lacked visibility. The combination of various MR techniques can make the course of Wallerian degeneration visualization. The application of various MRI techniques on Wallerian degeneration after cerebral infarction, from imaging principle and pathogenesis, were reviewed in this article. Source

Chen H.-X.,Zunyi Medical College Zhuhai Campus | Jiang X.-P.,Shenzhen Childrens Hospital | Cao J.,Shenzhen Childrens Hospital
Medicine (United States)

In the traditional view, muscle atrophy and interstitial fibrosis were regarded as the basic pathological features of congenital muscular torticollis (CMT). But in the ultrastructure study, the mesenchyme- like cells, myoblasts, myofibroblasts, and fibroblasts were found in the proliferation of interstitium of CMT. To investigate the characteristics of pathological features and the mechanisms of muscle atrophy in CMT, we retrospectively reviewed the medical records of 185 CMT patients from July 2009 to July 2011 in Shenzhen Children's Hospital in China and performed pathological studies. According to age, the 185 CMT patients were divided into 4 groups. All resected surgical specimens were processed for hematoxylin and eosin staining and Masson trichromic staining. Sudan III staining was used for frozen sections, whereas immunohistochemical staining for S-100, calpain-1, ubiquitin, and 20S proteasome was carried out on 40 CMT specimens. Eight adductor muscle specimens from 8 patients with development dysplasia of the hip were taken as control group in the immunohistochemical staining. By Masson trichromic staining, the differences in the percent area of fibrous tissue in each CMT groups were significant. In Sudan III staining and immunostaining for S-100, adipocyte hyperplasia was the pathological feature of CMT. Moreover, compared with controls, most atrophic muscle fibers in CMT specimens were found to show strong immunoreactivity for calpain-1, ubiquitin, and 20S proteasome. With increasing age, fibrosis peaked at both sides and it was low in middle age group. Adipocytes increased with age. The characteristics of pathological features in CMT are changeable with age. The calpain and the ubiquitin-proteasome system may play a role in muscle atrophy of CMT. In the CMT, adipogenesis, fibrogenesis, and myogenesis may be the results of mesenchyme-like cells in SCM (sternocleidomastoid muscle). In conclusion, the present study furthermore supports maldevelopment of the fetal SCM theory for etiology of CMT. © 2014 Wolters Kluwer Health. Source

Liu K.S.,Border Armed Police Central Hospital of Guangdong Province | Fan X.Q.,Jinan University | Zhang L.,Zunyi Medical College | Wen Q.N.,Central Peoples Hospital of Zhanjiang | And 4 more authors.
Molecular Medicine Reports

The current study aimed to investigate the rejection and survival time of grafted skin, and the changes of Treg cells, interleukin 10 (IL-10) and transforming growth factor-β (TGF-β) in peripheral blood following skin transplantation with recombinant human interleukin-10 (rhIL-10) or cyclosporin A (CsA), as well as the role of IL-10 in immunological rejection mechanisms. A total of 36 rabbits were divided into two groups. The skin of a donor rabbit was transplanted onto the back of one receptor rabbit. Receptors were randomly divided into six groups, including rhIL-10 low-dose (5 μg/kg/d), rhIL-10 high-dose (10 μg/kg/d), CsA low-dose (5 mg/kg/d), CsA high-dose (10 mg/kg/d), rhIL-10 (5 μg/kg/d) and CsA (5 mg/kg/d) and negative control normal saline (NS; 1 ml/d). All groups received intramuscular drug injection for ten days, beginning one day prior to skin transplantation surgery. Following transplantation, each rabbit's peripheral blood was collected at different times. The changes of CD4+CD25+ regulatory T cells, IL-10 and TGF-β were determined by flow cytometry and enzyme-linked immunosorbent assay. When compared with the control group, the rejection and survival times of the experimental groups were longer following skin graft. Compared with the two CsA groups and the control group, the proportion of CD4+CD25+ regulatory T cells of rhIL-10 groups was significantly upregulated on the 4th and 7th days following surgery. However, TGF-β levels were not significantly different. Data suggested that the concentration of IL-10 was positively correlated with the proportion of CD4+CD25+ regulatory T cells. In addition, IL-10 may delay the rejection time of rabbit skin transplantation and prolong the survival time. Thus, the role of IL-10 in inhibited allograft rejection may be associated with CD4+CD25+ regulatory T cells and IL-10, and may be independent of TGF-β. Source

Yang Y.,South China University of Technology | Yang Y.,Zhejiang University | Yang Y.,Zunyi Medical College Zhuhai Campus | Huang L.,Zhejiang University | And 2 more authors.
Enzyme and Microbial Technology

An FAD-dependent glucose dehydrogenase (FAD-GDH) from Aspergillus terreus NIH2624 was expressed in Escherichia coli with a yield of 228±16U/L of culture. Co-expression with chaperones DnaK/DnaJ/GrpE and osmotic stress induced by simple carbon sources enhanced productivity significantly, improving the yield to 23883±563U/L after optimization. FAD-GDH was purified in two steps with the specific activity of 604U/mg. Using d-glucose as substrate, the optimal pH and temperature for FAD-GDH were determined to be 7.5 and 50°C, respectively. Activity was stable across the pH range 3.5-9.0, and the half-life was 52min at 42°C. Km and Vmax were calculated as 86.7±5.3mM and 928±35U/mg, and the molecular weight was approximately 65.6kDa based on size exclusion chromatography, indicating a monomeric structure. The 3D structure of FAD-GDH was simulated by homology modelling using the structure of A. niger glucose oxidase (GOD) as template. From the model, His551, His508, Asn506 and Arg504 were identified as key residues, and their importance was verified by site-directed mutagenesis. Furthermore, three additional mutants (Arg84Ala, Tyr340Phe and Tyr406Phe) were generated and all exhibited a higher degree of substrate specificity than the native enzyme. These results extend our understanding of the structure and function of FAD-GDH, and could assist potential commercial applications. © 2014 Elsevier Inc. Source

Discover hidden collaborations