Methyl (S)-4-(6-amino-9H-purin-9-yl)-2-hydroxybutanoate (DZ2002) is a potent reversible inhibitor of S-adenosyl-L-homocysteine hydrolase (SAHH). Due to its ester structure, DZ2002 is rapidly hydrolyzed in rat blood to 4-(6-amino-9H-purin-9-yl)-2-hydroxybutyric acid (DZA) during and after blood sampling from rats; this hampers accurate determination of the circulating DZ2002 and its acid metabolite DZA in rats. To this end, a method for determining the blood concentrations of DZ2002 and DZA in rats was developed by using methanol to immediately deactivate blood carboxylesterases during sampling. The newly developed bioanalytical assay possessed favorable accuracy and precision with lower limit of quantification of 31 nM for DZ2002 and DZA. This validated assay was applied to a rat pharmacokinetic study of DZ2002. After oral administration, DZ2002 was found to be extensively converted into DZA. The level of systemic exposure to DZ2002 was significantly lower than that of DZA. The apparent oral bioavailability of DZ2002 was 90％–159％. The mean terminal half-lives of DZ2002 and DZA were 0.3–0.9 and 1.3–5.1 h, respectively. The sample preparation method illustrated here may be adopted for de-termination of other circulating ester drugs and their acid metabolites in rodents.

Hypertension is an important risk factor for cardiovascular and cerebrovascular diseases,which can damage structure and function of vital organs such as the heart,brain and kidney.Pseudo hypertension (PHT) refers to the blood pressure measured by ordinary cuffmanometry is higher than that of the arterial puncture,which is an essential factor of refractory hypertension.Recent findings have suggested that the elderly patients with concomitant history of atherosclerotic disease,renal insufficiency,and diabetes mellitus have the highest risk of pseudohypertension.The incidence rate ofpseudohypertension is about 1.7％-50％ in domestic and international studies.In the clinical treatment,the misdiagnosis of hypertension of patients with excessive blood pressure will lead to severe perfusion defects.In this review,we will focus on the diagnosis and pathogenesis of pseudohypertension.

Objective To analyze the number and quality of biomedical journals of different countries,so as to evaluate the situation of their biomedical research.Methods We searched and analyzed the Journal citation report published by Thomson Reuters. The information of biomedical journals of four countries:China,Japan,India,and South Korea,was collected,and was subjected to statistical analysis.Results It was found that China had the least number of biomedical journals,and it accounted for the lowest ratio of its total journals.However,the quality of Chinese biomedical journals was in the lead among the four countries.The impact factor of Chinese journals was obviously higher than those of the other three groups.Compared with Japan,the numbers of Chinese biomedical journals was less for different academic areas.Conclusion China has comparatively small number of SCI-indexed biomedical journals, and the situation should be improved from both number and quality aspects,so that our biomedical journal become a part of the interna-tional biomedical publishing community.

Angioplasty, Balloon, Coronary ; Coronary Thrombosis ; therapy ; Humans