Objective To evaluate the efficacy and safety of a novel mutated recombinant tissue-type plas-minogen activator (rt-Pam) in a rat model of acute cerebral thrombosis. Method Eighty-seven adult Wister rats were randomly divided into control group, recombinant tissue-type plasminogen activator (rt-PA) group, low dose of rt-Pam group and routine dose of rt-Pam group. The rats of different groups were treated for 3 hours after thrombosis of middle cerebral artery. The size of infarction, neurological scores and severity of hemorrhage were observed 24 hours after treatment. The protective role of rt-Pam in the brain tissue was evaluated as per the infiltration of neutrophils and the concentration of plasminogen activator receptor-1 (PAR-1). Results Compared with control group, the sizes of infarction in the low dose of rt-Pam group and routine dose of rt-Pam group were significantly smaller [(108.5 ±27.3) mm3 and (68.3 ±17.2) mm3 vs. (323.4 ±42.3) mm3]. The neurological scores were evidently correlated with the size of infarction (r = 0.613, P<0.001), while the liability of cerebral hemorrhage in low dose of rt-Pam group was not significantly increased. The rt-Pam also reduced the production of myeloperox-idase, as well as the production of PAR-1 in comparison with rt-PA group [(13.8 ± 3.1) vs. (28.3±4.5), P <0.00l]. Conclusions The novel rt-Pam could be a better thrombolytic agent than rt-PA in treating acute stroke.

BACKGROUNDTo study the antibody against hepatitis C virus first envelope (HCV-E1) protein in the sera from patients with HCV and to evaluate the application of HCV-E1 antigen in detection of HCV antibody.

METHODSPurified E1 engineering protein was used as antigen to develop an ELISA for detecting E1 antibody in 80 national reference sera, 821 blood donors' sera and l20 sera from clinical patients with hepatitis.

RESULTSAnti-HCV E1 was positive in 70% (28/40) and negative in 100% (40/40) of 80 national reference sera, and 1.9% (16/821) was positive in blood of the sera donors' and 68% (492/720) positive in sera of patients with hepatitis. Most anti-HCV E1 positive sera were positive for core, NS 3 and NS 5A, but only a few sera were positive for E1 antigen. Of the sera from 218 clinical patients, 813 blood donors and 848 normal people that were anti-HCV negative tested by commercial anti HCV ELISA kit, 1.4%, 1.1% and 0.9% were anti-HCV E1 positive, respectively. Investigation of seroconversion on three patients showed that anti-E1 was first detectable.

CONCLUSIONSDetection of anti-HCV E1 by engineered E1 protein is sensitive and specific. The prevalence and early presence of E1 antibody in HCV infected patients reflect the active status of the disease to a certain extent. Detection of the antibody is useful in clinical diagnosis.

Enzyme-Linked Immunosorbent Assay ; Hepatitis C ; diagnosis ; Hepatitis C Antibodies ; blood ; Humans ; Viral Structural Proteins ; immunology