三醋酸纤维素膜与聚砜膜低通量透析器对细菌DNA片段的通透性研究

目的通过体外实验观察三醋酸纤维素膜和聚砜膜低通量透析器对细菌DNA片段的通透性,比较2种透析器对细菌DNA片段的截留能力。方法以透析器类型分为三醋酸纤维素膜/低通量(130G)和聚砜膜/低通量(F6hps)两组。体外模拟血液透析4小时,血液侧为无菌生理盐水500ml,流速200ml/min。透析液侧为无菌生理盐水1000ml。以大肠埃希氏菌分别为2.06×102,1.603×103,2.671×103,1.336×104cells/ml浓度的混悬液作为污染透析液,透析液流速200ml/min。采用鲎试剂动态比浊法检测透析液和血液侧样本内的内毒素浓度,以超微量分光光度计检测血液侧样本的细菌DNA浓度,并对两组透析器血液侧的细菌DNA浓度进行比较。结果①透析4h后,两组透析器的血液侧透后样本的内毒素检测均为阴性。但细菌DNA浓度升高,并随透析液中污染菌浓度增加呈现上升趋势。②在透析液细菌浓度在1.603×103,2.671×103,1.336×104cells/ml浓度时,130G组血液侧样本的细菌DNA浓度明显高于F6hps组,两组间比较,t值分别为7.982,4.264,10.499,P值分别为0.001,0.013,<0.001,差异显著性有统计学意义。结论①细菌DNA比内毒素对三醋酸纤维膜和聚砜膜透析器的穿透能力更强。②与聚砜膜透析器相比,三醋酸纤维素膜对细菌DNA有更高的通透性。

The in vitro study on transfer of bacteria DNA across dialyzers with different dialysis membranes

Objective To assess the transfer of bacteria DNA across the dialyzers with cellulose triac- etate （CTA, low-flux） and pol）sulfone （low-flux） membranes. Methods Two dialyzers equipped with CTA （low-flux, 130（3） membrane or with pol）sulfone （low-flux, F6hps） membrane were used in this study. The experiment was carried out in saline-saline model. The dial）sate was mixed with E. coli at 4 levels （2.06 × 102, 1.603 × 103, 2.671 × 103, 1.336× 104 cells/mt）, and the in vitro dialysis was performed under diffusive condi- tion for 4 hours. Ultraviolet spectrophotometry and LAL test were used to detect bacteria DNA and endotoxin, respectively, in blood side samples. Bacteria DNA concentrations in blood side sample and dial）sate were compared between the two kinds of dialyzers. Results After the dialysis for 4 hours, LAL in blood side samples from the two kinds of dialyzers remained negative, but E. coli DNA increased along with the increase of E. coil concentration in dialysate. When dialysate contained E. coli of 1.603 ×103, 2.671 ×103, 1.336 × 104 cells/ml, bacterial DNAin blood side samples from the dialyser with CTA membrane were sig- nificantly higher than those from the dial）ser with polysulfone membrane （P 〈 0.05）. Conclusion Under the identical conditions, both the two dialyzers have the permeability for bacteria DNA but not for endotoxin. CTA low-flux dialyzer has higher permeability for bacteria DNA than polysulfone low-flux dialyzer.