AIMS To evaluate the effects of chronic alcohol abuse on the mucosal permeability to lipopolysaccharide in the colon in rats. METHODS Escherichia coil lipopolysaccharide (LPS,20 μg/ml) was injected into the colon of ...AIMS To evaluate the effects of chronic alcohol abuse on the mucosal permeability to lipopolysaccharide in the colon in rats. METHODS Escherichia coil lipopolysaccharide (LPS,20 μg/ml) was injected into the colon of chronic alcoholic rats (n=10) and the rats were supplied with Lieber diets every other day for 6 weeks. Before LPS injection and 5,10,20,30 minutes after injection, blood samples from the portal vein were obtained and contents of LPS in the blood were measured. The dis- tribution of LPS in the colon tissues was observed with a confocal laser scanning microscope by immunofluo- rescent technique using a monoclonal antibody specific to the lipid A region of LPS. Normal rats were used as controls (n=6). RESULTS Before LPS injection in the colon,LPS levels in the blood of portal vein of chronic alcoholic rats were significantly higher than those of normal con- trols (3.56±0.67 pg/ml,vs 2.45±0.15 pg/ml,P <0.01). At 5,10,20,30 minutes after injection of LPS,LPS contents were significantly higher than those before LPS injection (173.56±23.45 pg/ml,154.78 ±20.57 pg/ml,43.89±8.67 pg/ml,45.38± 7.89 pg/mls vs 3.56±0.67 pg/ml,P<0.01 respectively). Most mucosal cells showed strong posi- tive reactions to LPS in the rats of chronic alcohol abuse,but no significant changes of LPS contents in blood from the portal vein and fluorescent reactions to LPS in mucosal cells of normal rats were found after LPS injection. CONCLUSIONS Chronic alcohol abuse resulted in a significant increase of permeability to LPS in colon mu- cosal cells in rats.展开更多
Effects of Lycium barbarum polysaccharide(LBP),Astragalus polysaccharide (APS),polysaccharide of Acanthopanax senticosus(PAS)and polysaccharide of bacterial lipopolysaccharide(PS)on the induction of lymphokine-activat...Effects of Lycium barbarum polysaccharide(LBP),Astragalus polysaccharide (APS),polysaccharide of Acanthopanax senticosus(PAS)and polysaccharide of bacterial lipopolysaccharide(PS)on the induction of lymphokine-activated killer(LAK)cells from C57BL/6 murine splenocytes were studied using [^(125)I]UdR release assay.The four polysaccharides alone were shown to induce no cytotoxicity.When combined with human recombination interleukin-2(rlL-2),they augmented LAK cell activities in a dose-dependent manner,most markedly at 0.01～0.1 mg·ml^(-1)for LBP,0.01 mg·ml^(-1) for APS and PAS,and 0.01 μg·ml^(-1) for PS.They increased LAK cell activity in a short range of rIL-2 concentrations(250～1000U·ml^(-1)).They were shown to inhibit LAK cell activity when used beyond the suitable dosage.展开更多
Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heatstable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared...Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heatstable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared from the phage infecting Klebsiella K13. Treatment at 60℃ for 30 min could inactivate most of the K13 phage, with the titration decreasing from 6.4×10^8 PFU/mL to 1.6×10^6 PFU/mL. However, no obvious loss of phage enzyme activity was found after this treatment. The optimum hydrolytic temperature of phage enzyme was 60℃, with an activity 57 % higher than that at 30℃. The addition of phage enzyme could result in a rapid decrease of viscosity of exopolysaccharide （EPS） solution within minutes, indicating that K13 phage polysaccharide depolymerase acts as a kind of endo-glycanohydrolase. HPLC and reducing sugar analysis showed that the hydrolysis of EPS approached approximately the maxi-mum at 4h when the final concentration of phage was 6.0 x los PFU/mL. The results showed that K/eb-siella K13 phage depolymerase enzyme could be used as a good tool for the preparation of EPS oligosac- charide.展开更多
Predatory bacteriophages have evolved a vast array of depolymerases for bacteria capture and deprotection.These depolymerases are enzymes responsible for degrading diverse bacterial surface carbohydrates.They are expl...Predatory bacteriophages have evolved a vast array of depolymerases for bacteria capture and deprotection.These depolymerases are enzymes responsible for degrading diverse bacterial surface carbohydrates.They are exploited as antibiofilm agents and antimicrobial adjuvants while rarely inducing bacterial resistance,making them an invaluable asset in the era of antibiotic resistance.Numerous depolymerases have been investigated preclinically,with evidence indicating that depolymerases with appropriate dose regimens can safely and effectively combat different multidrug-resistant pathogens in animal infection models.Additionally,some formulation approaches have been developed for improved stability and activity of depolymerases.However,depolymerase formulation is limited to liquid dosage form and remains in its infancy,posing a significant hurdle to their clinical translation,compounded by challenges in their applicability and manufacturing.Future development must address these obstacles for clinical utility.Here,after unravelling the history,diversity,and therapeutic use of depolymerases,we summarized the preclinical efficacy and existing formulation findings of recombinant depolymerases.Finally,the challenges and perspectives of depolymerases as therapeutics for humans were assessed to provide insights for their further development.展开更多
目的:分离紫心甘薯的多糖(Polysaccharide of purple sweet potato,PPSP)组分,并对其组分的抑癌活性进行初步研究。方法:采用DEAE-Cellulose和CM-Cellulose离子交换柱分离紫心甘薯多糖,收集分离PPSP组分;MTT法检测PPSP各组分对肿瘤细胞...目的:分离紫心甘薯的多糖(Polysaccharide of purple sweet potato,PPSP)组分,并对其组分的抑癌活性进行初步研究。方法:采用DEAE-Cellulose和CM-Cellulose离子交换柱分离紫心甘薯多糖,收集分离PPSP组分;MTT法检测PPSP各组分对肿瘤细胞的体外抑制活性;薄层层析法分析PPSP各组分的单糖组成;利用傅里叶红外光谱技术检测PPSP组分的结构特征。结果:选用弱阴离子交换柱DEAE-Cellulose分离,并经NaCl溶液梯度分段洗脱,得到4个紫心甘薯多糖组分,分别命名为PPSPⅠ、PPSPⅡ、PPSPⅢ和PPSPⅣ;观察PPSPⅠ、PPSPⅡ、PPSPⅢ对Hela和HepG2肿瘤细胞的抑制作用,检测发现PPSPⅡ、PPSPⅢ组分有一定的抑癌活性。结构分析结果表明,PPSPⅠ主要由葡萄糖和半乳糖这两种单糖组成;PPSPⅡ由葡萄糖组成,并具有β-D-葡萄吡喃聚糖的红外特征吸收峰;PPSPⅢ具有蛋白吸收峰。结论:成功分离得到PPSP的4种多糖组分,其中检测到PPSPⅡ、PPSPⅢ组分对Hela和HepG2肿瘤细胞具有一定的体外抑制作用。推测PPSPⅡ、PPSPⅢ组分抑癌活性可能与其含有β-D-葡萄吡喃聚糖或糖蛋白的结构有关。展开更多
基金Supported by the Youth Natural Scientific Foundation of Shanxi Province No.93017,95013.
文摘AIMS To evaluate the effects of chronic alcohol abuse on the mucosal permeability to lipopolysaccharide in the colon in rats. METHODS Escherichia coil lipopolysaccharide (LPS,20 μg/ml) was injected into the colon of chronic alcoholic rats (n=10) and the rats were supplied with Lieber diets every other day for 6 weeks. Before LPS injection and 5,10,20,30 minutes after injection, blood samples from the portal vein were obtained and contents of LPS in the blood were measured. The dis- tribution of LPS in the colon tissues was observed with a confocal laser scanning microscope by immunofluo- rescent technique using a monoclonal antibody specific to the lipid A region of LPS. Normal rats were used as controls (n=6). RESULTS Before LPS injection in the colon,LPS levels in the blood of portal vein of chronic alcoholic rats were significantly higher than those of normal con- trols (3.56±0.67 pg/ml,vs 2.45±0.15 pg/ml,P <0.01). At 5,10,20,30 minutes after injection of LPS,LPS contents were significantly higher than those before LPS injection (173.56±23.45 pg/ml,154.78 ±20.57 pg/ml,43.89±8.67 pg/ml,45.38± 7.89 pg/mls vs 3.56±0.67 pg/ml,P<0.01 respectively). Most mucosal cells showed strong posi- tive reactions to LPS in the rats of chronic alcohol abuse,but no significant changes of LPS contents in blood from the portal vein and fluorescent reactions to LPS in mucosal cells of normal rats were found after LPS injection. CONCLUSIONS Chronic alcohol abuse resulted in a significant increase of permeability to LPS in colon mu- cosal cells in rats.
文摘Effects of Lycium barbarum polysaccharide(LBP),Astragalus polysaccharide (APS),polysaccharide of Acanthopanax senticosus(PAS)and polysaccharide of bacterial lipopolysaccharide(PS)on the induction of lymphokine-activated killer(LAK)cells from C57BL/6 murine splenocytes were studied using [^(125)I]UdR release assay.The four polysaccharides alone were shown to induce no cytotoxicity.When combined with human recombination interleukin-2(rlL-2),they augmented LAK cell activities in a dose-dependent manner,most markedly at 0.01～0.1 mg·ml^(-1)for LBP,0.01 mg·ml^(-1) for APS and PAS,and 0.01 μg·ml^(-1) for PS.They increased LAK cell activity in a short range of rIL-2 concentrations(250～1000U·ml^(-1)).They were shown to inhibit LAK cell activity when used beyond the suitable dosage.
基金the National Natural Science Foundation of China(No40506027 and No30771646)the Doctoral Foundation of Shandong Province(No2005BS02015)
文摘Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heatstable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared from the phage infecting Klebsiella K13. Treatment at 60℃ for 30 min could inactivate most of the K13 phage, with the titration decreasing from 6.4×10^8 PFU/mL to 1.6×10^6 PFU/mL. However, no obvious loss of phage enzyme activity was found after this treatment. The optimum hydrolytic temperature of phage enzyme was 60℃, with an activity 57 % higher than that at 30℃. The addition of phage enzyme could result in a rapid decrease of viscosity of exopolysaccharide （EPS） solution within minutes, indicating that K13 phage polysaccharide depolymerase acts as a kind of endo-glycanohydrolase. HPLC and reducing sugar analysis showed that the hydrolysis of EPS approached approximately the maxi-mum at 4h when the final concentration of phage was 6.0 x los PFU/mL. The results showed that K/eb-siella K13 phage depolymerase enzyme could be used as a good tool for the preparation of EPS oligosac- charide.
基金This work was supported by the University Grants Committee,Hong Kong SAR Government(No.14112921,China).The support of HKPFS from the University Grants Committee to HonglanWang was greatly acknowledged.
文摘Predatory bacteriophages have evolved a vast array of depolymerases for bacteria capture and deprotection.These depolymerases are enzymes responsible for degrading diverse bacterial surface carbohydrates.They are exploited as antibiofilm agents and antimicrobial adjuvants while rarely inducing bacterial resistance,making them an invaluable asset in the era of antibiotic resistance.Numerous depolymerases have been investigated preclinically,with evidence indicating that depolymerases with appropriate dose regimens can safely and effectively combat different multidrug-resistant pathogens in animal infection models.Additionally,some formulation approaches have been developed for improved stability and activity of depolymerases.However,depolymerase formulation is limited to liquid dosage form and remains in its infancy,posing a significant hurdle to their clinical translation,compounded by challenges in their applicability and manufacturing.Future development must address these obstacles for clinical utility.Here,after unravelling the history,diversity,and therapeutic use of depolymerases,we summarized the preclinical efficacy and existing formulation findings of recombinant depolymerases.Finally,the challenges and perspectives of depolymerases as therapeutics for humans were assessed to provide insights for their further development.
文摘目的:分离紫心甘薯的多糖(Polysaccharide of purple sweet potato,PPSP)组分,并对其组分的抑癌活性进行初步研究。方法:采用DEAE-Cellulose和CM-Cellulose离子交换柱分离紫心甘薯多糖,收集分离PPSP组分;MTT法检测PPSP各组分对肿瘤细胞的体外抑制活性;薄层层析法分析PPSP各组分的单糖组成;利用傅里叶红外光谱技术检测PPSP组分的结构特征。结果:选用弱阴离子交换柱DEAE-Cellulose分离,并经NaCl溶液梯度分段洗脱,得到4个紫心甘薯多糖组分,分别命名为PPSPⅠ、PPSPⅡ、PPSPⅢ和PPSPⅣ;观察PPSPⅠ、PPSPⅡ、PPSPⅢ对Hela和HepG2肿瘤细胞的抑制作用,检测发现PPSPⅡ、PPSPⅢ组分有一定的抑癌活性。结构分析结果表明,PPSPⅠ主要由葡萄糖和半乳糖这两种单糖组成;PPSPⅡ由葡萄糖组成,并具有β-D-葡萄吡喃聚糖的红外特征吸收峰;PPSPⅢ具有蛋白吸收峰。结论:成功分离得到PPSP的4种多糖组分,其中检测到PPSPⅡ、PPSPⅢ组分对Hela和HepG2肿瘤细胞具有一定的体外抑制作用。推测PPSPⅡ、PPSPⅢ组分抑癌活性可能与其含有β-D-葡萄吡喃聚糖或糖蛋白的结构有关。
