Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high cataly...Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high catalytic performance,enhanced stabilities,improved enzyme-substrate affinities,and reusabilities.Many studies have been performed to investigate the efficient use of cellulose nanocrystals,polydopamine-based nanomaterials,and synthetic polymer nanogels for enzyme immobilization.Various nanobiocatalysts are highlighted in this review,with the emphasis on the design,preparation,properties,and potential applications of nanoscale enzyme carriers and nanobiocatalysts.展开更多
The histological hallmark of autoimmune hepatitis（AIH） is a dense portal mononuclear cell infiltrate that invades the surrounding parenchyma and comprises T and B lymphocytes,macrophages,and plasma cells.An unknown ...The histological hallmark of autoimmune hepatitis（AIH） is a dense portal mononuclear cell infiltrate that invades the surrounding parenchyma and comprises T and B lymphocytes,macrophages,and plasma cells.An unknown but powerful stimulus must be promoting the formation of this massive inflammatory cellular reaction that is likely to initiate and perpetuate liver damage.An autoimmune attack can follow different pathways to inflict damage on hepatocytes.Liver damage is likely to be orchestrated by CD4^＋ T lymphocytes recognizing an autoantigenic liver peptide.To trigger an autoimmune response,the peptide must be embraced by an HLA class Ⅱ molecule and presented to naive CD4^＋ T helper（Th0） cells by professional antigen presenting cells,with the co-stimulation of ligand-ligand fostering interaction between the two cells.Th0 cells become activated,differentiate into functional phenotypes according to the cytokines prevailing in the microenvironment and the nature of the antigen,and initiate a cascade of immune reactions determined by the cytokines produced by the activated T cells.Th1 cells,arising in the presence of the macrophage-derived interleukin（IL） -12,secrete mainly IL-2 and interferon-gamma（IFN-γ）,which activate macrophages,enhance expression of HLA classⅠ（increasing liver cell vulnerability to a CD8^＋ T cell cytotoxic attack）,and induce expression of HLA class Ⅱ molecules on hepatocytes.Th2 cells,which differentiate from Th0 if the microenvironment is rich in IL-4,produce mainly IL-4,IL-10,and IL-13 which favour autoantibody production by B lymphocytes.Physiologically,Th1 and Th2 antagonize each other.Th17 cells,a recently described population,arise in the presence of transforming growth factor beta（TGF-β） and IL-6 and appear to have an important effector role in inflammation and autoimmunity.Theprocess of autoantigen recognition is strictly controlled by regulatory mechanisms,such as those exerted by CD4^＋CD25^＋ regulatory T cells,which derive from Th0 in the presence of TGF-β,but in the absence of IL-6.If regulatory mechanisms fail,the autoimmune attack is perpetuated.Over the past three decades different aspects of the above pathogenic scenario have been investigated.In particular,a defect in immunoregulation affecting CD4^＋CD25^＋ regulatory T cells（T-regs） has been demonstrated in AIH,particularly at diagnosis or during relapse.Advances in the study of autoreactive T cells have occurred mostly in AIH type 2,since the knowledge that CYP2D6 is the main autoantigen has enabled the characterization of both CD4 and CD8 T cells targeting this cytochrome.CD4 T cells from patients with type 2 AIH positive for the predisposing HLA allele DRB10701 recognize seven regions of CYP2D6,five of which are also recognized by CD8 T cells.High numbers of IFN-γ producing CD4 T cells and CD8 T cells are associated with biochemical evidence of liver damage,suggesting a combined cellular immune attack.展开更多
Gastric cancer is one of the most common causesof cancer death worldwide. Surgery is the most widely utilizedtreatment for resectable gastric cancer. Evidence indicates thatlymph node involvement and depth of invasion...Gastric cancer is one of the most common causesof cancer death worldwide. Surgery is the most widely utilizedtreatment for resectable gastric cancer. Evidence indicates thatlymph node involvement and depth of invasion of the primarytumor are the most important prognostic factors for gastriccancer patients. Therefore, lymph node clearance is deemed akey procedure in gastric cancer surgery for the prognostic valueto patients. Although the appropriate lymphadenectomy duringgastrectomy for cancer still remains controversial, extendedlymph node dissection (D2 lymphadenectomy) should berecommended in high volume hospitals.展开更多
To evaluate the Plasmodium falciparum CTL epitope vaccines in HLA class I allele specific human cell lines that have high frequency among Chinese population. Methods. Synthesized oligonucleotides encoding for P.f. CTL...To evaluate the Plasmodium falciparum CTL epitope vaccines in HLA class I allele specific human cell lines that have high frequency among Chinese population. Methods. Synthesized oligonucleotides encoding for P.f. CTL epitope genes, constructed eukaryotic expression plasmids, transfected the minigenes into HLA class I allele specific human cell lines and identified endogenous expressing of the minigenes by RT- PCR and HLA stabilization assay. Results. Two mini- genes encoding Plasmodium falciparum CTL epitopes were designed and cloned, respectively, into an eukaryotic expressing vector to form TR26 which was restricted to HLA- B51, SH6 which was restricted to HLA- A2.1, and TS, which had the two aforementioned mini- genes fused in tandem. All of these CTL epitope genes were transfected and endogenously expressed in respective cell lines containing appropriate HLA molecules. The obviously increased expressions of HLA class I molecules were detected in the transfected cell lines. It was demonstrated that the two discrete Plasmodium falciparum epitope genes were effectively processed and presented, and the close proximity of the two epitope genes in one chain as in mini- gene TS did not interfere with the processing and presenting of each epitope gene in corresponding cell line. Conclusion. A successful expression and presentation of multiple CTL epitope mini- gene in MHC class I allele specific human cell lines were demonstrated by an in vitro assay, which could be corresponding to the vaccination of CTL vaccines in people with different MHC I molecules. This work also suggested the possibility of constructing a multiple CTL epitope plasmodium falciparum DNA vaccine that could cover most of Chinese population.展开更多
Let X1,X2(where N>m)be independent Nm(μ,∑) random vectors, and putwhere T is upper- triangular with positive diagonal elements. The author considers the problemof estimating ∑,and restricts his attention to the ...Let X1,X2(where N>m)be independent Nm(μ,∑) random vectors, and putwhere T is upper- triangular with positive diagonal elements. The author considers the problemof estimating ∑,and restricts his attention to the class of estimates is any diagonal matrix and b* is any nonnegative constant} because it has the following attractive features:(a) Its elements are all quadratic forms of the sufficient and complete statistics (X, T).(b) It contains all estimates of the form(and), which constructa complete subclass of the class of nonnegative quadratic estimates (where X = (X1,…, XN)') for any strict convex loss function.(c)It contains all invariant estimates under the transformation group of upper-triangularmatrices.The author obtains the Characteristics for an estimate of the formof ∑ to be admissible in when the loss function is chosed as tr(∑-1∑-Ⅰ)2, and shows,by an example, that(and)is admissible in can not imply itsadmissibility in .展开更多
基金supported by the National Natural Science Foundation of China(21336002,21222606,21376096)the Key Program of Guangdong Natural Science Foundation(S2013020013049)+2 种基金the Fundamental Research Funds for the Chinese Universities(2015PT002,2015ZP009)the Program of State Key Laboratory of Pulp and Paper Engineering(2015C04)the South China University of Technology Doctoral Student Short-Term Overseas Visiting Study Funding Project~~
文摘Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high catalytic performance,enhanced stabilities,improved enzyme-substrate affinities,and reusabilities.Many studies have been performed to investigate the efficient use of cellulose nanocrystals,polydopamine-based nanomaterials,and synthetic polymer nanogels for enzyme immobilization.Various nanobiocatalysts are highlighted in this review,with the emphasis on the design,preparation,properties,and potential applications of nanoscale enzyme carriers and nanobiocatalysts.
文摘The histological hallmark of autoimmune hepatitis（AIH） is a dense portal mononuclear cell infiltrate that invades the surrounding parenchyma and comprises T and B lymphocytes,macrophages,and plasma cells.An unknown but powerful stimulus must be promoting the formation of this massive inflammatory cellular reaction that is likely to initiate and perpetuate liver damage.An autoimmune attack can follow different pathways to inflict damage on hepatocytes.Liver damage is likely to be orchestrated by CD4^＋ T lymphocytes recognizing an autoantigenic liver peptide.To trigger an autoimmune response,the peptide must be embraced by an HLA class Ⅱ molecule and presented to naive CD4^＋ T helper（Th0） cells by professional antigen presenting cells,with the co-stimulation of ligand-ligand fostering interaction between the two cells.Th0 cells become activated,differentiate into functional phenotypes according to the cytokines prevailing in the microenvironment and the nature of the antigen,and initiate a cascade of immune reactions determined by the cytokines produced by the activated T cells.Th1 cells,arising in the presence of the macrophage-derived interleukin（IL） -12,secrete mainly IL-2 and interferon-gamma（IFN-γ）,which activate macrophages,enhance expression of HLA classⅠ（increasing liver cell vulnerability to a CD8^＋ T cell cytotoxic attack）,and induce expression of HLA class Ⅱ molecules on hepatocytes.Th2 cells,which differentiate from Th0 if the microenvironment is rich in IL-4,produce mainly IL-4,IL-10,and IL-13 which favour autoantibody production by B lymphocytes.Physiologically,Th1 and Th2 antagonize each other.Th17 cells,a recently described population,arise in the presence of transforming growth factor beta（TGF-β） and IL-6 and appear to have an important effector role in inflammation and autoimmunity.Theprocess of autoantigen recognition is strictly controlled by regulatory mechanisms,such as those exerted by CD4^＋CD25^＋ regulatory T cells,which derive from Th0 in the presence of TGF-β,but in the absence of IL-6.If regulatory mechanisms fail,the autoimmune attack is perpetuated.Over the past three decades different aspects of the above pathogenic scenario have been investigated.In particular,a defect in immunoregulation affecting CD4^＋CD25^＋ regulatory T cells（T-regs） has been demonstrated in AIH,particularly at diagnosis or during relapse.Advances in the study of autoreactive T cells have occurred mostly in AIH type 2,since the knowledge that CYP2D6 is the main autoantigen has enabled the characterization of both CD4 and CD8 T cells targeting this cytochrome.CD4 T cells from patients with type 2 AIH positive for the predisposing HLA allele DRB10701 recognize seven regions of CYP2D6,five of which are also recognized by CD8 T cells.High numbers of IFN-γ producing CD4 T cells and CD8 T cells are associated with biochemical evidence of liver damage,suggesting a combined cellular immune attack.
文摘Gastric cancer is one of the most common causesof cancer death worldwide. Surgery is the most widely utilizedtreatment for resectable gastric cancer. Evidence indicates thatlymph node involvement and depth of invasion of the primarytumor are the most important prognostic factors for gastriccancer patients. Therefore, lymph node clearance is deemed akey procedure in gastric cancer surgery for the prognostic valueto patients. Although the appropriate lymphadenectomy duringgastrectomy for cancer still remains controversial, extendedlymph node dissection (D2 lymphadenectomy) should berecommended in high volume hospitals.
基金This project was supported by the National Natural Sciences Foun-dation of China, grant# 39770670 and China Medical Bo
文摘To evaluate the Plasmodium falciparum CTL epitope vaccines in HLA class I allele specific human cell lines that have high frequency among Chinese population. Methods. Synthesized oligonucleotides encoding for P.f. CTL epitope genes, constructed eukaryotic expression plasmids, transfected the minigenes into HLA class I allele specific human cell lines and identified endogenous expressing of the minigenes by RT- PCR and HLA stabilization assay. Results. Two mini- genes encoding Plasmodium falciparum CTL epitopes were designed and cloned, respectively, into an eukaryotic expressing vector to form TR26 which was restricted to HLA- B51, SH6 which was restricted to HLA- A2.1, and TS, which had the two aforementioned mini- genes fused in tandem. All of these CTL epitope genes were transfected and endogenously expressed in respective cell lines containing appropriate HLA molecules. The obviously increased expressions of HLA class I molecules were detected in the transfected cell lines. It was demonstrated that the two discrete Plasmodium falciparum epitope genes were effectively processed and presented, and the close proximity of the two epitope genes in one chain as in mini- gene TS did not interfere with the processing and presenting of each epitope gene in corresponding cell line. Conclusion. A successful expression and presentation of multiple CTL epitope mini- gene in MHC class I allele specific human cell lines were demonstrated by an in vitro assay, which could be corresponding to the vaccination of CTL vaccines in people with different MHC I molecules. This work also suggested the possibility of constructing a multiple CTL epitope plasmodium falciparum DNA vaccine that could cover most of Chinese population.
文摘Let X1,X2(where N>m)be independent Nm(μ,∑) random vectors, and putwhere T is upper- triangular with positive diagonal elements. The author considers the problemof estimating ∑,and restricts his attention to the class of estimates is any diagonal matrix and b* is any nonnegative constant} because it has the following attractive features:(a) Its elements are all quadratic forms of the sufficient and complete statistics (X, T).(b) It contains all estimates of the form(and), which constructa complete subclass of the class of nonnegative quadratic estimates (where X = (X1,…, XN)') for any strict convex loss function.(c)It contains all invariant estimates under the transformation group of upper-triangularmatrices.The author obtains the Characteristics for an estimate of the formof ∑ to be admissible in when the loss function is chosed as tr(∑-1∑-Ⅰ)2, and shows,by an example, that(and)is admissible in can not imply itsadmissibility in .
