Chitosan composites and derivatives have gained wide attentions as effective biosorbents due to their low costs and high contents of amino and hydroxyl functional groups.They have showed significant potentials of remo...Chitosan composites and derivatives have gained wide attentions as effective biosorbents due to their low costs and high contents of amino and hydroxyl functional groups.They have showed significant potentials of removing metal ions,dyes and proteins from various media.Chemical modifications that lead to the formation of the chitosan derivatives and chitosan composites have been extensively studied and widely reported in literatures.The aims of this review were to summarize the important information of the bioactivities of chitosan,highlight the various preparation methods of chitosan-based active biosorbents,and outline its potential applications in the adsorption of heavy metal ions,dyes and proteins from wastewater and aqueous solutions.展开更多
In this article, a spherical chitosan gel crosslinked by epichlorohydrin was prepared. It was then loaded with copper ions to produce a metal chelate affinity adsorbent for protein. The uptake of bovine serum albumin ...In this article, a spherical chitosan gel crosslinked by epichlorohydrin was prepared. It was then loaded with copper ions to produce a metal chelate affinity adsorbent for protein. The uptake of bovine serum albumin (BSA) by the affinity adsorbent was investigated, and the adsorption capacity for BSA as high as 40 mg/g-wet beads was observed. The adsorption equilibrium data was well correlated by the Langmuir equation. The adsorption was considerably affected by pH. In addition, the amount of BSA adsorbed onto the beads decreased with the increasing of aqueous phase ionic strength, so adsorbed BSA can be desorbed by adjusting pH or ionic strength of the solution.展开更多
AIM： To evaluate the diagnostic values of serum autoan tibodies against matrix metalloproteinase-7 （MMP-7） in patients with esophageal squamous cell carcinoma （ESCC）. METHODS： The MMP-7 cDNA was cloned from ESCC...AIM： To evaluate the diagnostic values of serum autoan tibodies against matrix metalloproteinase-7 （MMP-7） in patients with esophageal squamous cell carcinoma （ESCC）. METHODS： The MMP-7 cDNA was cloned from ESCC tissues, and MMP-7 was expressed and purified from a prokaryotic system. MMP-7 autoanUbodies were then measured in sera from 50 patients with primary ESCC and 58 risk-matched controls, using a reverse capture enzyme-linked immunosorbent assay （ELISA） in which autoantibodies to MMP-7 bound to the purified MMP-7 proteins. In addition, MMP-7 autoantibody levels in sera from 38 gastric cancer patients and from control serum samples were also tested. RESULTS： The optimum conditions for recombinant MMP-7 protein expression were determined as 0.04 mmol/L Isopropyl-13-D-Thiogalactopyranoside （IPTG）induction at 37℃ for four hours. The levels of serum autoantibodies against MMP-7 were significantly higher in patients with ESCC than in the matched-control samples （OD450 = 1.69 ±0.08 vs OD450 = 1.55 ± 0.10, P 〈 0.001）. The area under the receiver operating character- istic （ROC） curve was 0.87. The sensitivity and specificity for detection of ESCC were 78.0% and 81.0%, respectively, when the OD450 value was greater than 1.65. Although the levels of autoantibodies against MMP-7 were also significantly higher in patients with gastric cancer compared to control samples （OD450 = 1.62± 0.06 vs OD450 = 1.55±0.10, P 〈 0.001）, the diagnostic accuracy was less significant than in ESCC patients. The area of ROC curve was 0.75, whereas the sensitivity and specificity were 60.5% and 71.7%, respectively, when the cut-off value of OD450 was set at 1.60. CONCLUSION： Serum autoantibody levels of MMP-7 may be a good diagnostic biomarker for esophageal squamous cell carcinoma,展开更多
Objective To study the effect of transforming growth factor-α (TGF-α) on early stage of embryo implantation.Methods Mouse blastocysts were cultured in vitro in medium containing various concentrations of TGF-α. Bla...Objective To study the effect of transforming growth factor-α (TGF-α) on early stage of embryo implantation.Methods Mouse blastocysts were cultured in vitro in medium containing various concentrations of TGF-α. Blastocyst implantation capacity was evaluated by calculating the percentage of embryos with attachment or outgrowth. Matrix metalloproteinases (MMPs) secretion of blastocysts was observed using gelatin zymography. Results There was no significant difference in the percentage of attachment between control and TGF-α treated groups, but the percentage of outgrowth of TGF-α treated groups was significantly higher than that of the control group after 24h culturing. Gelatin zymography showed that blastocysts cultured in TGF-α treated groups started secreting MMPs earlier than those in the control group.Conclusion TGF-α is involved in regulating the mouse embryo implantation process by promoting blastocyst outgrowth and secreting matrix matalloproteinases.展开更多
文摘【背景】orf3位于猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)s基因与e基因之间,是目前发现的PEDV唯一一个附属基因,编码附属蛋白(ORF3蛋白)。我们前期研究初步发现ORF3蛋白对PEDV诱导的细胞凋亡有影响。【目的】研究ORF3蛋白在PEDV侵染复制过程中的毒力作用机制。【方法】实验用3种PEDV:rDR13att-∆ORF3(orf3基因全部敲除)、DR13-ORF3att(携带有C端截短orf3)、rDR13att-ORF3wt(携带全长orf3基因)感染Vero细胞,观察病变情况,再用活细胞成像仪、流式细胞仪、DNA断裂的原位末端标记法[terminal deoxynucleotidyl transferase(TDT)-mediated dUTP nick end labeling,TUNEL]等方法检测不同感染时间点的细胞凋亡情况,然后用蛋白质印迹方法分析PEDV感染宿主细胞中主要凋亡相关蛋白(如Caspase-3)的活化或裂解,最后进行转录组测序研究病毒感染细胞中差异基因的表达情况,再用荧光定量PCR验证转录组结果。【结果】rDR13att-∆ORF3引起较多的细胞病变,活细胞成像仪的动态观察结果显示,3种病毒侵染的细胞凋亡水平随着时间的延长均高于正常阴性细胞,但敲除orf3的病毒感染细胞后细胞凋亡率比其他两种病毒更高;敲除orf3病毒感染细胞凋亡率显著高于其他两种病毒;病毒rDR13att-∆ORF3感染细胞后TUNEL阳性细胞数比DR13-ORF3att和rDR13att-ORF3wt更多;表达ORF3蛋白的重组PEDV可以抑制Caspase-3的活化;ORF3蛋白对受感染细胞Heat shock 70 kD protein 1B(HSP70)基因转录有促进作用,荧光定量PCR结果表明rDR13att-ORF3wt感染细胞的HSP70表达量高于rDR13att-∆ORF3感染细胞。【结论】PEDV通过ORF3蛋白抑制细胞凋亡,而且这种作用可能是通过抑制Caspase-3的活化或增加HSP70的产生来完成的。
基金financially supported by Ocean Public Welfare Scientific Research Special Appropriation Project(201005020)Fundamental Research Funds for the Central Universities and Program for Changjiang Scholars and Innovative Research Team in University(IRT1188)
文摘Chitosan composites and derivatives have gained wide attentions as effective biosorbents due to their low costs and high contents of amino and hydroxyl functional groups.They have showed significant potentials of removing metal ions,dyes and proteins from various media.Chemical modifications that lead to the formation of the chitosan derivatives and chitosan composites have been extensively studied and widely reported in literatures.The aims of this review were to summarize the important information of the bioactivities of chitosan,highlight the various preparation methods of chitosan-based active biosorbents,and outline its potential applications in the adsorption of heavy metal ions,dyes and proteins from wastewater and aqueous solutions.
基金National Natural Science Foundation of China (Grant No. 20025617)
文摘In this article, a spherical chitosan gel crosslinked by epichlorohydrin was prepared. It was then loaded with copper ions to produce a metal chelate affinity adsorbent for protein. The uptake of bovine serum albumin (BSA) by the affinity adsorbent was investigated, and the adsorption capacity for BSA as high as 40 mg/g-wet beads was observed. The adsorption equilibrium data was well correlated by the Langmuir equation. The adsorption was considerably affected by pH. In addition, the amount of BSA adsorbed onto the beads decreased with the increasing of aqueous phase ionic strength, so adsorbed BSA can be desorbed by adjusting pH or ionic strength of the solution.
基金Supported by Science and Technology Projects of Hebei Province, #10396107DNIH Grant CA137570 (Zhong L)
文摘AIM： To evaluate the diagnostic values of serum autoan tibodies against matrix metalloproteinase-7 （MMP-7） in patients with esophageal squamous cell carcinoma （ESCC）. METHODS： The MMP-7 cDNA was cloned from ESCC tissues, and MMP-7 was expressed and purified from a prokaryotic system. MMP-7 autoanUbodies were then measured in sera from 50 patients with primary ESCC and 58 risk-matched controls, using a reverse capture enzyme-linked immunosorbent assay （ELISA） in which autoantibodies to MMP-7 bound to the purified MMP-7 proteins. In addition, MMP-7 autoantibody levels in sera from 38 gastric cancer patients and from control serum samples were also tested. RESULTS： The optimum conditions for recombinant MMP-7 protein expression were determined as 0.04 mmol/L Isopropyl-13-D-Thiogalactopyranoside （IPTG）induction at 37℃ for four hours. The levels of serum autoantibodies against MMP-7 were significantly higher in patients with ESCC than in the matched-control samples （OD450 = 1.69 ±0.08 vs OD450 = 1.55 ± 0.10, P 〈 0.001）. The area under the receiver operating character- istic （ROC） curve was 0.87. The sensitivity and specificity for detection of ESCC were 78.0% and 81.0%, respectively, when the OD450 value was greater than 1.65. Although the levels of autoantibodies against MMP-7 were also significantly higher in patients with gastric cancer compared to control samples （OD450 = 1.62± 0.06 vs OD450 = 1.55±0.10, P 〈 0.001）, the diagnostic accuracy was less significant than in ESCC patients. The area of ROC curve was 0.75, whereas the sensitivity and specificity were 60.5% and 71.7%, respectively, when the cut-off value of OD450 was set at 1.60. CONCLUSION： Serum autoantibody levels of MMP-7 may be a good diagnostic biomarker for esophageal squamous cell carcinoma,
文摘Objective To study the effect of transforming growth factor-α (TGF-α) on early stage of embryo implantation.Methods Mouse blastocysts were cultured in vitro in medium containing various concentrations of TGF-α. Blastocyst implantation capacity was evaluated by calculating the percentage of embryos with attachment or outgrowth. Matrix metalloproteinases (MMPs) secretion of blastocysts was observed using gelatin zymography. Results There was no significant difference in the percentage of attachment between control and TGF-α treated groups, but the percentage of outgrowth of TGF-α treated groups was significantly higher than that of the control group after 24h culturing. Gelatin zymography showed that blastocysts cultured in TGF-α treated groups started secreting MMPs earlier than those in the control group.Conclusion TGF-α is involved in regulating the mouse embryo implantation process by promoting blastocyst outgrowth and secreting matrix matalloproteinases.
