Rheumatoid factors(RFs) are the characteristic autoantibodies of rheumatoid arthritis. Recent researches in our laboratory showed that the immobilized single-stranded DNA(ss-DNA) immunoadsorbent can selectively remove...Rheumatoid factors(RFs) are the characteristic autoantibodies of rheumatoid arthritis. Recent researches in our laboratory showed that the immobilized single-stranded DNA(ss-DNA) immunoadsorbent can selectively remove RFs from the serum of patients. In the present paper are studied the modification of argininine, tryptophan, lysine residues and carboxyl terminus of IgGRF, which was separated from patients′ serum, with 1,2-cyclohexanedione(CHD), N-bromosuccinimide(NBS), pyridoxal 5′-phosphate(PP) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide(EDC) respectively, and their effects on the adsorption capacity of the immobilized ss-DNA immunoadsorbent for IgGRF. After the specific modification, the corresponding adsorption capacities of the adsorbents were changed from 48%, 46%, 44% and 54% to 84%, 14%, 21% and 81%, respectively. These results indicate that the electrostatic or ionic-bonding is essential for the interaction between ss-DNA and IgGRF.展开更多
Microencapsulated genetically engineered bac- teria cells are a novel approach of oral therapy for uremia. Klebsiella aerogenes urease genes (UreaDABCEFG) are transformed into E. coli DH5αcells through plasmid pKAU17...Microencapsulated genetically engineered bac- teria cells are a novel approach of oral therapy for uremia. Klebsiella aerogenes urease genes (UreaDABCEFG) are transformed into E. coli DH5αcells through plasmid pKAU17. The transformant can use urea or ammonia as its sole nitrogen source through strain training. The urease ge- netically engineered bacteria cells are entrapped in polyvinyl alcohol (PVA) microcapsules, which can be used to remove urea from uremia patients. The mechanical strength of PVA microcapsules is significantly higher than that of APA microcapsules. This suggests that the problem of friability of APA can be solved in this way. The optimal conditions for the preparation of PVA microencapsulated genetically engi- neered bacterial cells are: polyvinyl alcohol (PVA, 2450±50) used as the carrier at a concentration 6%, the pH value of boric acid as crosslinking reagent 6.5, crosslinking time 24 h, entrapment ratio of bacteria 8 %, air flow rate of the encap- sulate device 3 L/min and liquid flow rate at 1 mL/10 min. The average diameter of microcapsules prepared under these optimal conditions is 20—40 mesh. Experiments in vitro showed that one hundred milligrams of wet bacterial cells in PVA microcapsules could remove 18.4 mg of urea in 4 h.展开更多
基金Key Projectof National Basic Science and Developm ent(No.G19990 6 4 70 7) and Tianjin- Nankai U niversi-ty Co- Construction Foundation and China- UK Collaboration Project
文摘Rheumatoid factors(RFs) are the characteristic autoantibodies of rheumatoid arthritis. Recent researches in our laboratory showed that the immobilized single-stranded DNA(ss-DNA) immunoadsorbent can selectively remove RFs from the serum of patients. In the present paper are studied the modification of argininine, tryptophan, lysine residues and carboxyl terminus of IgGRF, which was separated from patients′ serum, with 1,2-cyclohexanedione(CHD), N-bromosuccinimide(NBS), pyridoxal 5′-phosphate(PP) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide(EDC) respectively, and their effects on the adsorption capacity of the immobilized ss-DNA immunoadsorbent for IgGRF. After the specific modification, the corresponding adsorption capacities of the adsorbents were changed from 48%, 46%, 44% and 54% to 84%, 14%, 21% and 81%, respectively. These results indicate that the electrostatic or ionic-bonding is essential for the interaction between ss-DNA and IgGRF.
文摘Microencapsulated genetically engineered bac- teria cells are a novel approach of oral therapy for uremia. Klebsiella aerogenes urease genes (UreaDABCEFG) are transformed into E. coli DH5αcells through plasmid pKAU17. The transformant can use urea or ammonia as its sole nitrogen source through strain training. The urease ge- netically engineered bacteria cells are entrapped in polyvinyl alcohol (PVA) microcapsules, which can be used to remove urea from uremia patients. The mechanical strength of PVA microcapsules is significantly higher than that of APA microcapsules. This suggests that the problem of friability of APA can be solved in this way. The optimal conditions for the preparation of PVA microencapsulated genetically engi- neered bacterial cells are: polyvinyl alcohol (PVA, 2450±50) used as the carrier at a concentration 6%, the pH value of boric acid as crosslinking reagent 6.5, crosslinking time 24 h, entrapment ratio of bacteria 8 %, air flow rate of the encap- sulate device 3 L/min and liquid flow rate at 1 mL/10 min. The average diameter of microcapsules prepared under these optimal conditions is 20—40 mesh. Experiments in vitro showed that one hundred milligrams of wet bacterial cells in PVA microcapsules could remove 18.4 mg of urea in 4 h.
