Two sets of primers were designed according to the sequences of xynA and xynB from Aspergillus sulphureus, and the DNA fragments composed of 574 bp and 594 bp were amplified by polymerase chain reaction (PCR), respectively. The two PCR products respectively digested with EcoRⅠ/BamHⅠ and BglⅡ/HindⅢ were ligated into multiple cloning sites of pET-28a(+). The resulting plasmid is pET-xynAB, in which xylanase A and B are ligated by a 7-amino acid peptide (GlyGlyGlySerGlyGlyGly). E. coli BL21 transformed with pET-xynAB was induced by IPTG, and a special protein band about 50 ku was detected by SDS-PAGE. The protein purified with Ni-NTA column was denatured by 8 mol/L urea and dialyzed for refolding. The recombinant xylanase showed optimal activity at 50℃ and pH 4.4. The enzyme retained above 75% of its activity at the range of pH 2.4～5.4. The xylanase displayed about 50% retained acitivity after incubating at 80℃ for 30 min. Various metal ions have different effects on activity of the recombinant xylanase.

Objective To value the effect and safety of butyl phthalide sequential treatment in cerebral infarction of branch sclerosis of arterial congee appearance. Methods Sixty patients with acute cerebral infarction were randomly divided into treated group( n = 31)and control group( n = 29). According to the condition of illness,all patients were given aspirin,atorvastatin calcium,and the injection of ozagrel sodium intravenous;controlled the blood pressure,blood sugar,blood lipid,and treated complications posstively;take the early rehabilitation of nerve treatment afte the illness was in stable condition. Butyl phthalide was used in the patients of treated group(100 ml,twice per day,intravenous drip,during 14 days period therapy,and then 0. 2 g oral,third per day),besides the routine therapy. The degree of neural function defect score( NIHSS)and activities of daily living score(BI)between two groups were observed before and after treatment. Corresponding adverse consequences were recorded. Results Compared with pretreatment,the NIHSS of postreatment at the 14th day in treat and control groups were decreased(treated group:(4. 36 ± 3. 11)vs.(11. 42 ± 3. 20);control group:(6. 12 ± 2. 67)vs.(11. 64 ± 3. 43),P < 0. 05,and the treated group was significantly lower than control group(F inner groups = 2. 125,P < 0. 01;F between groups = 18. 63,P < 0. 01;F cross groups = 25. 34,P< 0. 01;P < 0. 05). The BI of postreatment in two group were increased(treated group:(86. 72 ± 8. 44)vs. (26. 54 ± 13. 36);control group:(75. 96 ± 9. 86)vs.(26. 38 ± 13. 02)),and the treated group was significantly lower than control group(F inner groups = 29. 27,P < 0. 01;F between groups = 32. 48,P < 0. 01;F cross groups= 42. 41,P < 0. 01;P < 0. 05). There was no the adverse reactions. Conclusion Butyl phthalide sequential treatment can improve the NIHSS and BI of cerebral infarction of branch sclerosis of arterial congee appearance and have a better therapy effect.