BACKGROUND: Liver transplantation is so far the most effective therapeutic modality for end-stage liver diseases, but ischemia/reperfusion (I/R) injury represents a critical barrier to liver transplantation. Primary g...BACKGROUND: Liver transplantation is so far the most effective therapeutic modality for end-stage liver diseases, but ischemia/reperfusion (I/R) injury represents a critical barrier to liver transplantation. Primary graft dysfunction and small-for-size syndrome are closely associated with I/R injury. Ischemic preconditioning (IPC) is defined as a brief period of liver ischemia followed by reperfusion, and has demonstrated protections against a prolonged I/R injury and improved the capacity of regeneration. The article aimed to review IPC literatures for the understanding of the effects of IPC on I/R injury involving in the procurement of donor liver and protective mechanisms. DATA SOURCES: A literature search of MEDLINE and Web of Science databases using 'liver transplantation', 'liver regeneration', 'hepatectomy', 'ischemia/reperfusion' and 'ischemic preconditioning' was performed, and then a large amount of related data was collected. RESULTS: The literature search provided a huge amount of evidence for the protective effects of IPC on I/R injury in liver transplantation, including reduction of blood loss in hepatectomy, intraoperative hemodynamic stability and its significant role in liver regeneration. The mechanism involves in balancing inflammatory cytokines, enhancing energy status and mitigating microcirculatory disturbance. CONCLUSION: IPC plays an essential role in hepatectomy before and after harvest of living donor liver and implantation of liver graft.展开更多
BACKGROUND: Urinary trypsin inhibitor (UTI) inhibits the inflammatory response and protects against ischemia-reperfusion (I/R) injury. The inflammatory response is mediated by nuclear factor-kappa B (NF-kappa B) and i...BACKGROUND: Urinary trypsin inhibitor (UTI) inhibits the inflammatory response and protects against ischemia-reperfusion (I/R) injury. The inflammatory response is mediated by nuclear factor-kappa B (NF-kappa B) and its related target genes and products such as vascular endothelial cell adhesion molecule and CXC chemokines. We aimed to assess the roles of those mediators in a UTI-treated mouse model of hepatic I/R injury. METHODS: Treatment group 1 (UTI given 5 minutes prior to liver ischemia), treatment group 2 (UTI given 5 minutes after the anhepatic phase) and a control group were investigated. Blood and liver samples were obtained and compared at 1, 3, 6 and 24 hours after reperfusion. RESULTS: Attenuation of pathological hepatocellular damage was greater in the treatment groups than in the control group (P < 0.05). Compared with the control group, the UTI treatment groups showed significantly lower serum alanine aminotransferase and aspartate aminotransferase levels, decreased myeloperoxidase activity, and reduced NF-kappa B activation. Also downregulated was the expression of tumor necrosis factor-alpha, cytokine-induced neutrophil chemoattractant, and macrophage inflammatory protein-2 at the mRNA level. P-selectin protein and intercellular adhesion molecule-1 protein expression were also downregulated. In addition, the treatment group I showed a better protective effect against I/R injury than the treatment group 2. CONCLUSIONS: UTI reduces NF-kappa B activation and downregulates the expression of its related mediators, followed by the inhibition of neutrophil aggregation and infiltration in hepatic I/R injury. The protective role of UTI is more effective in prevention than in treatment.展开更多
BACKGROUND: With the development of hepatic surgery, especially liver transplantation, the pathophysiological processes of hepatic ischemia-reperfusion (I/R) injury have gained special attention. Controlling I/R injur...BACKGROUND: With the development of hepatic surgery, especially liver transplantation, the pathophysiological processes of hepatic ischemia-reperfusion (I/R) injury have gained special attention. Controlling I/R injury has become one of the most important factors for successful liver transplantation. This study aimed to investigate the effects of tumor necrosis factor-alpha (TNF-alpha) in rats with hepatic I/R injury and promote the recognition of I/R injury in the liver. METHODS: Thirty-two Sprague-Dawley rats were randomly divided into 2 groups. Rats in the sham-operated (SO) group served as controls. Rats in the hepatic ischemia-reperfusion (I/R) group underwent reperfusion after 30 minutes of liver ischemia. Rats were sacrificed at 1, 6 and 12 hours. The expression of TNF-alpha mRNA in the liver was measured by RT-PCR. Histological changes in the liver were assessed. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were measured. RESULTS: The expression of TNF-alpha mRNA in the SO group was decreased compared with that in the I/R group (P<0.05). TNF-a mRNA expression progressively increased in the I/R group. The serum levels of ALT and AST in the I/R group were higher than those in the SO group (P<0.01). The histological changes were in accord with hepatic I/R injury. CONCLUSION: ALT and AST in serum are closely related to hepatic I/R injury and inflammatory reaction. TNF-alpha production in the liver triggers hepatic I/R injury through a cascade.展开更多
AIM:To make a retrospective analysis of endoscopy findings and clinicopathologic characteristics of colonic schistosomiasis in order to further improve our understanding of the disease and decrease its misdiagnosis. M...AIM:To make a retrospective analysis of endoscopy findings and clinicopathologic characteristics of colonic schistosomiasis in order to further improve our understanding of the disease and decrease its misdiagnosis. METHODS:Endoscopy findings and clinicopathologic characteristics of 46 intestinal schistosomiasis patients were retrospectively analyzed.All the patients underwent colonoscopy and all biopsy specimens stained with hematoxylin and eosin were observed under a light microscope. RESULTS:Of the 46 colonic schistosomiasis patients,1 was diagnosed as acute schistosomal colitis,16 as chronic schistosomal colitis and 29 as chronic active schistosomal colitis according to their endoscopic findings and pathology.Not all patients were suspected of or diagnosed as colonic schistosomiasis.Of the 12 misdiagnosed patients,4 were misdiagnosed as ulcerativecolitis,1 as Crohn's disease,and 7 as ischemic colitis.The segments of rectum and sigmoid colon were involved in 29 patients(63.0%) .Intact Schistosoma ova were deposited in colonic mucosa accompanying infiltration of eosinocytes,lymphocytes,and plasma cells in acute schistosomal colitis patients.Submucosal fibrosis was found in chronic schistosomal colitis patients.Among the 17 patients with a signal polyp,hyperplastic polyp,canalicular adenoma with a low-grade intraepithelial neoplastic change,tubulovillous adenoma with a highgrade intraepithelial neoplastic change were observed in 10,5,and 2 patients,respectively.Eight out of the 46 patients were diagnosed as colonic carcinoma. CONCLUSION:Endoscopy contributes to the diagnosis of colonic schistosomiasis although it is nonspecific. A correct diagnosis of colonic schistosomiasis can be established by endoscopy in combination with its clinicopathologic characteristics.展开更多
First, Wirsching's model, which is widely employed in fatigue reliability anlysis of marine and offshore structures, is analysed systematically. It is found that the very important random variable A in Wirsching&#...First, Wirsching's model, which is widely employed in fatigue reliability anlysis of marine and offshore structures, is analysed systematically. It is found that the very important random variable A in Wirsching's model can not be directly determined from fatigue experiment because of the irreversibility of fatigue test, and in fact, what Wirsching studied from testing results is not A but a of the statistical Miner's rule. Second, by use of the statistical Miner's rule, a modified Wirsching's model is proposed. Thirdly and more importantly, based on the two-dimensional probabilistic Miner's rule, a new model is established for fatigue reliability analysis of structural components subjected to specified cyclic loading of variable amplitude or stochastic time history. In the end, an example is presented, from which it will be seen that this new model is very convenient to use and feasible to engineering practice.展开更多
BACKGROUND: The ischemic-type biliary lesion (ITBL) is one of the most serious biliary complications of liver transplantation. This study aimed to investigate the effects of autologous bone marrow mononuclear cell (BM...BACKGROUND: The ischemic-type biliary lesion (ITBL) is one of the most serious biliary complications of liver transplantation. This study aimed to investigate the effects of autologous bone marrow mononuclear cell (BM-MNC) implantation on neovascularization and the prevention of intrahepatic ITBL in a rabbit model. METHODS: The rabbits were divided into control, experimental model, and cell implantation groups, with 10 in each group. The model of intrahepatic ITBL was established by clamping the hepatic artery and common bile duct. Autologous BM-MNCs were isolated from the tibial plateau by density gradient centrifugation and were implanted through the common hepatic artery. Changes in such biochemical markers as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyltranspeptidase, total bilirubin and direct bilirubin were measured. Four weeks after operation, cholangiography, histopathological manifestations, differentiation of BM-MNCs, microvessel density and the expression of vascular endothelial growth factor were assessed. RESULTS: Compared with the experimental model group, the BM-MNC implantation group showed superiority in the time to recover normal biochemistry. The microvessel density and vascular endothelial growth factor expression of the implantation group were significantly higher than those of the control and experimental model groups. The ITBL in the experimental model group was more severe than that in the implantation group and fewer new capillary blood vessels occurred around it. CONCLUSIONS: Implanted autologous BM-MNCs can differentiate into vascular endothelial cells, promote neovascularization and improve the blood supply to the ischemic bile duct, and this provides a new way to diminish or prevent intrahepatic ITBL after liver transplantation. (Hepatobiliary Pancreat Dis Int 2010; 9:593-599)展开更多
In quorum sensing （QS） process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 （AI-2）, a QS signaling mol...In quorum sensing （QS） process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 （AI-2）, a QS signaling molecule proposed to be involved in interspecies communication, is produced by many species of gram-negative and gram-positive bacteria. In Escherichia coil and Salmonella typhimurium, the extracellular AI-2 is imported into the cell by a transporter encoded by the lsr operon. Upstream of the lsr operon, there is a divergently transcribed gene encoding LsrR, which was reported previously to repress the transcription of the lsr operon and itself. Here, we have demonstrated for the first time that LsrR represses the transcription of the lsr operon and itself by directly binding to their promoters using gel shift and DNase I footprinting assays. The β-galactosidase reporter assays further suggest that two motifs in both the lsrR and lsrA promoter regions are crucial for the LsrR binding. Furthermore, in agreement with the conclusion that phosphorylated AI-2 can relieve the repression of LsrR in previous studies, our data show that phospho- AI-2 renders LsrR unable to bind to its own promoter in vitro.展开更多
Microbial transformation of diosgenin(1) by Syncephalastrum racemosum yielded five new polar metabolites,which wereidentified as(25R)-spirost-5-en-3β,7α,9α-triol-12-one(2),(25R)-spirost-5-en-3β,9α,12α-triol-7-on...Microbial transformation of diosgenin(1) by Syncephalastrum racemosum yielded five new polar metabolites,which wereidentified as(25R)-spirost-5-en-3β,7α,9α-triol-12-one(2),(25R)-spirost-5-en-3β,9α,12α-triol-7-one(3),(25R)-spirost-5-en-3β,9α-diol-7,12-dione(4),(25R)-spirost-4-en-9α,12β,14α-triol-3-one(5),and(25S)-spirost-4-en-9α,14α,25β-triol-3-one(6).Compounds 1-6 exhibited moderate cytotoxicity against K562 cells and among them compounds 2,3,and 6 were more potentthan the parent compound 1.展开更多
Chronic schistosome infection results in the suppression of host immune responses, allowing long-term schistosome survival and restricting pathology.Current theories suggest that Treg play an important role in this re...Chronic schistosome infection results in the suppression of host immune responses, allowing long-term schistosome survival and restricting pathology.Current theories suggest that Treg play an important role in this regulation.However, the mechanism of Treg induction during schistosome infection is still unknown.The aim of this study was to determine the mechanism behind the induction of CD4(+)CD25(+) T cells by Schistosoma japonicum HSP60(SjHSP60)-derived peptide SJMHE1 as well as to elucidate the cellular and molecular basis for the induction of CD4(+)CD25(+) T cells during S.japonicum infection.Mice immunized with SJMHE1 or spleen and LN cells from naive mice pretreated.with SJMHE1 in vitro all displayed an increase in CD4(+)CD25(+) T-cell populations.Release of IL-10 and TGF-beta by SJMHE1 stimulation may contribute to suppression.Adoptively transferred SJMHE1induced CD4(+)CD25(+) T cells inhibited delayed-type hypersensitivity in BALB / c mice.Additionally, SJMHE1-treated APC were tolerogenic and induced CD4(+) cells to differentiate into suppressive CD4(+)CD25(+) Treg.Furthermore, our data support a role for TLR2 in SJMHE1-mediated CD4(+)CD25(+) Treg induction.These findings provide the basis for a more complete understanding of the S.japonicum-host interactions that contribute to host homeostatic mechanisms, preventing an excessive immune response.展开更多
Two compounds, 12-deoxyphorbol-13-hexadecanoate 1 and 12-deoxyphorbol-13-acetate 2 were isolated from the roots of Euphorbia fischeriana. Compoound 1 was elucidated as a new diterpenoid. Compound 2 was discovered for ...Two compounds, 12-deoxyphorbol-13-hexadecanoate 1 and 12-deoxyphorbol-13-acetate 2 were isolated from the roots of Euphorbia fischeriana. Compoound 1 was elucidated as a new diterpenoid. Compound 2 was discovered for the first time from this plant and showed analgesic and sedative activities in preliminary experiment in mice.展开更多
In this paper,we introduce a novel way to solve thetradeoff problem about communication,storage,computation overhead of broadcast encryptionscheme.We construct a new scheme based on SubsetDifference(SD)scheme,use the ...In this paper,we introduce a novel way to solve thetradeoff problem about communication,storage,computation overhead of broadcast encryptionscheme.We construct a new scheme based on SubsetDifference(SD)scheme,use the concept of RSAaccumulator and the idea of separating the user-sidedevice into different function parts,take advantageof the public device’s functionality,minimize thestorage and computation overhead of the privatedevice,and make the broadcast encryption schememore implementation-oriented.展开更多
The paper proposes a new sequential digital multi-signature scheme based on Knapsack public-key cryptosystem,which is different from the existing scheme.The advantages of this scheme over the existing schemes are that...The paper proposes a new sequential digital multi-signature scheme based on Knapsack public-key cryptosystem,which is different from the existing scheme.The advantages of this scheme over the existing schemes are that it simplifies the signature generation process and speeds up the signature verification process.What’s more,the scheme reduces the cost of communication and redundancy operation, and improves efficiency,and can avoid cheating by signer efficiently,so the scheme has very broad application prospects.展开更多
In order to improve efficiency of developing customized artificial joint, a virtual enterprise is organized based on the manufacturing grid. The application-oriented framework of the virtual enterprise is created for ...In order to improve efficiency of developing customized artificial joint, a virtual enterprise is organized based on the manufacturing grid. The application-oriented framework of the virtual enterprise is created for organization of the virtual enterprise. The manufacturing system of the virtual enterprise is built up based on the exterior grid and manufacturing subsystems of member enterprises are set up based on the interior grid. Furthermore, according to characteristic matching of manufacturing resources, the scheduling flow is studied in detail and the related scheduling strategies are established. The scheduling procedure is divided into distributed scheduling stage and local scheduling stage.Based on the manufacturing grid, the organization of the virtual enterprise for customized artificial joint and the corresponding scheduling strategies can be utilized to shorten developing cycle and reduce produce cost.展开更多
Objective Using resting-state functional magnetic resonance imaging (rs-fMRI),we explored the changes in dynamic functional network connections (dFNC) in the brains of patients with first-episode schizophrenia (SZ)and...Objective Using resting-state functional magnetic resonance imaging (rs-fMRI),we explored the changes in dynamic functional network connections (dFNC) in the brains of patients with first-episode schizophrenia (SZ)and evaluated the potential clinical value of dFNC changes in combination with a machine learning model.展开更多
In this paper, we propose three gradient recovery schemes of higher order for the linear interpolation. The first one is a weighted averaging method based on the gradients of the linear interpolation on the uniform me...In this paper, we propose three gradient recovery schemes of higher order for the linear interpolation. The first one is a weighted averaging method based on the gradients of the linear interpolation on the uniform mesh, the second is a geometric averaging method constructed from the gradients of two cubic interpolation on macro element, and the last one is a local least square method on the nodal patch with cubic polynomials. We prove that these schemes can approximate the gradient of the exact solution on the symmetry points with fourth order. In particular, for the uniform mesh, we show that these three schemes are the same on the considered points. The last scheme is more robust in general meshes. Consequently, we obtain the superconvergence results of the recovered gradient by using the aforementioned results and the supercloseness between the finite element solution and the linear interpolation of the exact solution. Finally, we provide several numerical experiments to illustrate the theoretical results.展开更多
Examines the convection diffusion problems using domain decomposition method. Presentation of continuous and discrete convection diffusion equations; Kinds of multiplicative Schwarz algorithms; Optimal order error est...Examines the convection diffusion problems using domain decomposition method. Presentation of continuous and discrete convection diffusion equations; Kinds of multiplicative Schwarz algorithms; Optimal order error estimate results.展开更多
Objective To investigate the relationship between the brain-derived neurotrophic factor (BDNF) gene Tag SNPs(rs 11030101 and rs6265) and early-onset schizophrenia in the Chinese Han population. Methods The tag single ...Objective To investigate the relationship between the brain-derived neurotrophic factor (BDNF) gene Tag SNPs(rs 11030101 and rs6265) and early-onset schizophrenia in the Chinese Han population. Methods The tag single nucleotide polymorphisms (tag SNPs) rs11030101 and rs6265 in the BDNF gene were展开更多
基金supported by grants from the National Key Technology R&D Program in the Eleventh Five-Year Plan of China (No. 2008BAI60B02 and 2008BAI60B06)the National Natural Science Foundation of China (No. 30700769)
文摘BACKGROUND: Liver transplantation is so far the most effective therapeutic modality for end-stage liver diseases, but ischemia/reperfusion (I/R) injury represents a critical barrier to liver transplantation. Primary graft dysfunction and small-for-size syndrome are closely associated with I/R injury. Ischemic preconditioning (IPC) is defined as a brief period of liver ischemia followed by reperfusion, and has demonstrated protections against a prolonged I/R injury and improved the capacity of regeneration. The article aimed to review IPC literatures for the understanding of the effects of IPC on I/R injury involving in the procurement of donor liver and protective mechanisms. DATA SOURCES: A literature search of MEDLINE and Web of Science databases using 'liver transplantation', 'liver regeneration', 'hepatectomy', 'ischemia/reperfusion' and 'ischemic preconditioning' was performed, and then a large amount of related data was collected. RESULTS: The literature search provided a huge amount of evidence for the protective effects of IPC on I/R injury in liver transplantation, including reduction of blood loss in hepatectomy, intraoperative hemodynamic stability and its significant role in liver regeneration. The mechanism involves in balancing inflammatory cytokines, enhancing energy status and mitigating microcirculatory disturbance. CONCLUSION: IPC plays an essential role in hepatectomy before and after harvest of living donor liver and implantation of liver graft.
文摘BACKGROUND: Urinary trypsin inhibitor (UTI) inhibits the inflammatory response and protects against ischemia-reperfusion (I/R) injury. The inflammatory response is mediated by nuclear factor-kappa B (NF-kappa B) and its related target genes and products such as vascular endothelial cell adhesion molecule and CXC chemokines. We aimed to assess the roles of those mediators in a UTI-treated mouse model of hepatic I/R injury. METHODS: Treatment group 1 (UTI given 5 minutes prior to liver ischemia), treatment group 2 (UTI given 5 minutes after the anhepatic phase) and a control group were investigated. Blood and liver samples were obtained and compared at 1, 3, 6 and 24 hours after reperfusion. RESULTS: Attenuation of pathological hepatocellular damage was greater in the treatment groups than in the control group (P < 0.05). Compared with the control group, the UTI treatment groups showed significantly lower serum alanine aminotransferase and aspartate aminotransferase levels, decreased myeloperoxidase activity, and reduced NF-kappa B activation. Also downregulated was the expression of tumor necrosis factor-alpha, cytokine-induced neutrophil chemoattractant, and macrophage inflammatory protein-2 at the mRNA level. P-selectin protein and intercellular adhesion molecule-1 protein expression were also downregulated. In addition, the treatment group I showed a better protective effect against I/R injury than the treatment group 2. CONCLUSIONS: UTI reduces NF-kappa B activation and downregulates the expression of its related mediators, followed by the inhibition of neutrophil aggregation and infiltration in hepatic I/R injury. The protective role of UTI is more effective in prevention than in treatment.
文摘BACKGROUND: With the development of hepatic surgery, especially liver transplantation, the pathophysiological processes of hepatic ischemia-reperfusion (I/R) injury have gained special attention. Controlling I/R injury has become one of the most important factors for successful liver transplantation. This study aimed to investigate the effects of tumor necrosis factor-alpha (TNF-alpha) in rats with hepatic I/R injury and promote the recognition of I/R injury in the liver. METHODS: Thirty-two Sprague-Dawley rats were randomly divided into 2 groups. Rats in the sham-operated (SO) group served as controls. Rats in the hepatic ischemia-reperfusion (I/R) group underwent reperfusion after 30 minutes of liver ischemia. Rats were sacrificed at 1, 6 and 12 hours. The expression of TNF-alpha mRNA in the liver was measured by RT-PCR. Histological changes in the liver were assessed. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were measured. RESULTS: The expression of TNF-alpha mRNA in the SO group was decreased compared with that in the I/R group (P<0.05). TNF-a mRNA expression progressively increased in the I/R group. The serum levels of ALT and AST in the I/R group were higher than those in the SO group (P<0.01). The histological changes were in accord with hepatic I/R injury. CONCLUSION: ALT and AST in serum are closely related to hepatic I/R injury and inflammatory reaction. TNF-alpha production in the liver triggers hepatic I/R injury through a cascade.
文摘AIM:To make a retrospective analysis of endoscopy findings and clinicopathologic characteristics of colonic schistosomiasis in order to further improve our understanding of the disease and decrease its misdiagnosis. METHODS:Endoscopy findings and clinicopathologic characteristics of 46 intestinal schistosomiasis patients were retrospectively analyzed.All the patients underwent colonoscopy and all biopsy specimens stained with hematoxylin and eosin were observed under a light microscope. RESULTS:Of the 46 colonic schistosomiasis patients,1 was diagnosed as acute schistosomal colitis,16 as chronic schistosomal colitis and 29 as chronic active schistosomal colitis according to their endoscopic findings and pathology.Not all patients were suspected of or diagnosed as colonic schistosomiasis.Of the 12 misdiagnosed patients,4 were misdiagnosed as ulcerativecolitis,1 as Crohn's disease,and 7 as ischemic colitis.The segments of rectum and sigmoid colon were involved in 29 patients(63.0%) .Intact Schistosoma ova were deposited in colonic mucosa accompanying infiltration of eosinocytes,lymphocytes,and plasma cells in acute schistosomal colitis patients.Submucosal fibrosis was found in chronic schistosomal colitis patients.Among the 17 patients with a signal polyp,hyperplastic polyp,canalicular adenoma with a low-grade intraepithelial neoplastic change,tubulovillous adenoma with a highgrade intraepithelial neoplastic change were observed in 10,5,and 2 patients,respectively.Eight out of the 46 patients were diagnosed as colonic carcinoma. CONCLUSION:Endoscopy contributes to the diagnosis of colonic schistosomiasis although it is nonspecific. A correct diagnosis of colonic schistosomiasis can be established by endoscopy in combination with its clinicopathologic characteristics.
基金This project was financially supported by the National Science Foundation of China(59605010)and the Postdoctoral Science Foundation of China
文摘First, Wirsching's model, which is widely employed in fatigue reliability anlysis of marine and offshore structures, is analysed systematically. It is found that the very important random variable A in Wirsching's model can not be directly determined from fatigue experiment because of the irreversibility of fatigue test, and in fact, what Wirsching studied from testing results is not A but a of the statistical Miner's rule. Second, by use of the statistical Miner's rule, a modified Wirsching's model is proposed. Thirdly and more importantly, based on the two-dimensional probabilistic Miner's rule, a new model is established for fatigue reliability analysis of structural components subjected to specified cyclic loading of variable amplitude or stochastic time history. In the end, an example is presented, from which it will be seen that this new model is very convenient to use and feasible to engineering practice.
文摘BACKGROUND: The ischemic-type biliary lesion (ITBL) is one of the most serious biliary complications of liver transplantation. This study aimed to investigate the effects of autologous bone marrow mononuclear cell (BM-MNC) implantation on neovascularization and the prevention of intrahepatic ITBL in a rabbit model. METHODS: The rabbits were divided into control, experimental model, and cell implantation groups, with 10 in each group. The model of intrahepatic ITBL was established by clamping the hepatic artery and common bile duct. Autologous BM-MNCs were isolated from the tibial plateau by density gradient centrifugation and were implanted through the common hepatic artery. Changes in such biochemical markers as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyltranspeptidase, total bilirubin and direct bilirubin were measured. Four weeks after operation, cholangiography, histopathological manifestations, differentiation of BM-MNCs, microvessel density and the expression of vascular endothelial growth factor were assessed. RESULTS: Compared with the experimental model group, the BM-MNC implantation group showed superiority in the time to recover normal biochemistry. The microvessel density and vascular endothelial growth factor expression of the implantation group were significantly higher than those of the control and experimental model groups. The ITBL in the experimental model group was more severe than that in the implantation group and fewer new capillary blood vessels occurred around it. CONCLUSIONS: Implanted autologous BM-MNCs can differentiate into vascular endothelial cells, promote neovascularization and improve the blood supply to the ischemic bile duct, and this provides a new way to diminish or prevent intrahepatic ITBL after liver transplantation. (Hepatobiliary Pancreat Dis Int 2010; 9:593-599)
基金We thank our colleagues J Zang and X Liu for their technical assistance in protein purification. This work was supported by the One Hundred Talent Project of the Chinese Academy of Sciences and the National Natural Science Foundation of China （50738006）.
文摘In quorum sensing （QS） process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 （AI-2）, a QS signaling molecule proposed to be involved in interspecies communication, is produced by many species of gram-negative and gram-positive bacteria. In Escherichia coil and Salmonella typhimurium, the extracellular AI-2 is imported into the cell by a transporter encoded by the lsr operon. Upstream of the lsr operon, there is a divergently transcribed gene encoding LsrR, which was reported previously to repress the transcription of the lsr operon and itself. Here, we have demonstrated for the first time that LsrR represses the transcription of the lsr operon and itself by directly binding to their promoters using gel shift and DNase I footprinting assays. The β-galactosidase reporter assays further suggest that two motifs in both the lsrR and lsrA promoter regions are crucial for the LsrR binding. Furthermore, in agreement with the conclusion that phosphorylated AI-2 can relieve the repression of LsrR in previous studies, our data show that phospho- AI-2 renders LsrR unable to bind to its own promoter in vitro.
基金supported by National Natural Science Foundation of China(No.30730109)Shandong Provincial Foundation for Scientific Research(No.2006GG1102023).
文摘Microbial transformation of diosgenin(1) by Syncephalastrum racemosum yielded five new polar metabolites,which wereidentified as(25R)-spirost-5-en-3β,7α,9α-triol-12-one(2),(25R)-spirost-5-en-3β,9α,12α-triol-7-one(3),(25R)-spirost-5-en-3β,9α-diol-7,12-dione(4),(25R)-spirost-4-en-9α,12β,14α-triol-3-one(5),and(25S)-spirost-4-en-9α,14α,25β-triol-3-one(6).Compounds 1-6 exhibited moderate cytotoxicity against K562 cells and among them compounds 2,3,and 6 were more potentthan the parent compound 1.
文摘Chronic schistosome infection results in the suppression of host immune responses, allowing long-term schistosome survival and restricting pathology.Current theories suggest that Treg play an important role in this regulation.However, the mechanism of Treg induction during schistosome infection is still unknown.The aim of this study was to determine the mechanism behind the induction of CD4(+)CD25(+) T cells by Schistosoma japonicum HSP60(SjHSP60)-derived peptide SJMHE1 as well as to elucidate the cellular and molecular basis for the induction of CD4(+)CD25(+) T cells during S.japonicum infection.Mice immunized with SJMHE1 or spleen and LN cells from naive mice pretreated.with SJMHE1 in vitro all displayed an increase in CD4(+)CD25(+) T-cell populations.Release of IL-10 and TGF-beta by SJMHE1 stimulation may contribute to suppression.Adoptively transferred SJMHE1induced CD4(+)CD25(+) T cells inhibited delayed-type hypersensitivity in BALB / c mice.Additionally, SJMHE1-treated APC were tolerogenic and induced CD4(+) cells to differentiate into suppressive CD4(+)CD25(+) Treg.Furthermore, our data support a role for TLR2 in SJMHE1-mediated CD4(+)CD25(+) Treg induction.These findings provide the basis for a more complete understanding of the S.japonicum-host interactions that contribute to host homeostatic mechanisms, preventing an excessive immune response.
文摘Two compounds, 12-deoxyphorbol-13-hexadecanoate 1 and 12-deoxyphorbol-13-acetate 2 were isolated from the roots of Euphorbia fischeriana. Compoound 1 was elucidated as a new diterpenoid. Compound 2 was discovered for the first time from this plant and showed analgesic and sedative activities in preliminary experiment in mice.
基金support from Asia Media Research Center Foundation (AM0551)Foundation of the State Administration of Radio Film and Television (SARFT) (NO.2005-02-1 and NO.2005-02-2).
文摘In this paper,we introduce a novel way to solve thetradeoff problem about communication,storage,computation overhead of broadcast encryptionscheme.We construct a new scheme based on SubsetDifference(SD)scheme,use the concept of RSAaccumulator and the idea of separating the user-sidedevice into different function parts,take advantageof the public device’s functionality,minimize thestorage and computation overhead of the privatedevice,and make the broadcast encryption schememore implementation-oriented.
基金supported by the National Key Lab.of Integrated Service Networks of Xidian University(No.ISN7-01)National Natural Science Foundation of China(No.60642008)
文摘The paper proposes a new sequential digital multi-signature scheme based on Knapsack public-key cryptosystem,which is different from the existing scheme.The advantages of this scheme over the existing schemes are that it simplifies the signature generation process and speeds up the signature verification process.What’s more,the scheme reduces the cost of communication and redundancy operation, and improves efficiency,and can avoid cheating by signer efficiently,so the scheme has very broad application prospects.
文摘In order to improve efficiency of developing customized artificial joint, a virtual enterprise is organized based on the manufacturing grid. The application-oriented framework of the virtual enterprise is created for organization of the virtual enterprise. The manufacturing system of the virtual enterprise is built up based on the exterior grid and manufacturing subsystems of member enterprises are set up based on the interior grid. Furthermore, according to characteristic matching of manufacturing resources, the scheduling flow is studied in detail and the related scheduling strategies are established. The scheduling procedure is divided into distributed scheduling stage and local scheduling stage.Based on the manufacturing grid, the organization of the virtual enterprise for customized artificial joint and the corresponding scheduling strategies can be utilized to shorten developing cycle and reduce produce cost.
文摘Objective Using resting-state functional magnetic resonance imaging (rs-fMRI),we explored the changes in dynamic functional network connections (dFNC) in the brains of patients with first-episode schizophrenia (SZ)and evaluated the potential clinical value of dFNC changes in combination with a machine learning model.
基金supported by National Natural Science Foundation of China (Grant No. 10625106)the National Basic Research Program of China (Grant No. 2005CB321701)+1 种基金supported by Graduate School Visit Project of Peking UniversityHunan Provincial Innovation Foundation for Postgraduate (Grant No. S2008yjscx05)
文摘In this paper, we propose three gradient recovery schemes of higher order for the linear interpolation. The first one is a weighted averaging method based on the gradients of the linear interpolation on the uniform mesh, the second is a geometric averaging method constructed from the gradients of two cubic interpolation on macro element, and the last one is a local least square method on the nodal patch with cubic polynomials. We prove that these schemes can approximate the gradient of the exact solution on the symmetry points with fourth order. In particular, for the uniform mesh, we show that these three schemes are the same on the considered points. The last scheme is more robust in general meshes. Consequently, we obtain the superconvergence results of the recovered gradient by using the aforementioned results and the supercloseness between the finite element solution and the linear interpolation of the exact solution. Finally, we provide several numerical experiments to illustrate the theoretical results.
基金National Natural Science Foundation of China (No. 10071044) and Major Basic Researches Program of China.
文摘Examines the convection diffusion problems using domain decomposition method. Presentation of continuous and discrete convection diffusion equations; Kinds of multiplicative Schwarz algorithms; Optimal order error estimate results.
文摘Objective To investigate the relationship between the brain-derived neurotrophic factor (BDNF) gene Tag SNPs(rs 11030101 and rs6265) and early-onset schizophrenia in the Chinese Han population. Methods The tag single nucleotide polymorphisms (tag SNPs) rs11030101 and rs6265 in the BDNF gene were
