Objective To demonstrate that heme oxygenase (HO) isoforms exist in rat spleen treated with hematin and phenylhydrazine and to confirm that the isolated cDNA actually encodes HO-1 by expressing cDNA in monkey kidney cells (COS-1 cells ) in order to prepare HO-1 mutant for inhibiting the natural enzyme.Methods The rat spleen microsomal fractions were first purified by diethylaminoethyl (DEAE)-Sephacel and hydroxylapatite. The activity of two isoforms (HO-1 and HO-2) of enzyme and their apparent molecular weight on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) were measured. Secondly, using the isolated HO-1 cDNA clone, the expression plasmid pcDNA3HO1 was constructed and transfected into cultured COS-1 cells. The transfected cells were collected and disrupted by sonication, and the microsomes were prepared by ultracentrifugation. The activity of HO-1 was measured.Conclusion The activity of expressed HO-1 in COS-1 cells is higher than that of purified enzyme from rat spleen tissue. It is suggested that this clone having an insert of 1030 base-pairs encodes HO-1 and that we can prepare HO-1 mutant by site-directed mutagenesis of HO-1 cDNA to prevent and treat hyperbilirubinemia.

Objective To evaluate the accuracy of measurements of atherosclerotic middle cerebral artery (MCA) stenosis with 3.0 T high-resolution magnetic resonance imaging (HR-MRI).Methods Forty patients with symptomatic atherosclerotic stenosis of middle cerebral artery (MCA) confirmed by digital subtraction angiography (DSA) in the Affiliated Hospital of Binzhou Medical College from September 2017 to May 2018 were enrolled in the study.Patients were scanned by HR-MRI sequence (including T1WI,T2WI,PDWI).The MCA M1 stenosis rate on HR-MR images was assessed by warfarin-aspirin symptomatic intracranial artery disease (WASID) method and area measurement algorithm,respectively,and based on the stenosis rate the degree of stenosis (semi-quantitative measurement) was determined.The accuracy of the two measurement methods was evaluated with DSA results as the gold standard.Results The HR-MRI images showed the structure of the vessel wall clearly in 30 patients meeting the measurement requirements.The inner edge of the vessel was clearly distinguishable and smooth,showing eccentric stenosis.The stenosis rate of MCA measured by DSA,WASID method and area measurement algorithm were (82± 17)％,(70± 12)％,(81 ± 16)％,respectively (P＞0.05).The result of area measurement algorithm was better correlated with DSA (r=0.893);and the coincidence of the stenosis degree rate of two measurement method was 90％(27/30).Conclusion The area measurement algorithm based on the HS-MRI has high accuracy in measuring the degree of MCA stenosis,which is of high clinical application value.