Advanced Glycation End-products (AGEs) are the products of non-enzymatic glycation protein. It has been demonstrated that AGEs are closely correlated to a variety of diseases such as diabetes, vascular complications, aging and renal diseases, AGEs play important roles in the development of these diseases. They can effect the function of cells and tissues directly, and also mediate pathological reactions through binding with special receptors. The present paper reviews the procedures of AGEs production, action mechanism and pathology of AGEs.

AIMIn order to discover new inhibitors and enhancers of nitric oxide synthase (NOS), an in vitro assay to determine NOS activity was established for high throughput screening.

METHODSThe activity of NOS was detected based on the change of nicotinamide-adenine dinucleotide phosphate (NADPH) concentration in the reaction system by the fluorescence density. The enzyme was prepared from bovine brain by gradient centrifugation. The reaction performed in black 96 well micro-plate with a final volume of 90 microL. Every factor which would affect the results such as the concentration of NADPH, L-arginine (L-Arg, used as substrate) and enzyme protein was optimized in different conditions. At last, 5,600 samples (compounds and extracts) were screened by the method.

RESULTSThe test signal (fluorescence density) in the reaction system was influenced by many different factors such as temperature and concentration of substrates. The ideal system contains protein 1.50 mg.mL-1, L-Arg 1 mmol.L-1, NADPH 0.1 mmol.L-1 at 37 degrees C. In this method, there were about 2% samples which emit fluorescence, and about 0.5% samples which quench the fluorescence. So these samples were deleted from the sample library. The effects of these samples on activity of NOS were distributed in a normal manner. About 2% samples had potential effects on the NOS activity (including inhibitors and enhancers).

CONCLUSIONThe method can be performed by high throughput screening and gives the stable data, not only for inhibitors, but also for enhancers of NOS activity.

Animals ; Arginine ; pharmacology ; Cattle ; Drug Evaluation, Preclinical ; methods ; Enzyme Inhibitors ; isolation & purification ; pharmacology ; In Vitro Techniques ; NADP ; pharmacology ; Nitric Oxide Synthase ; antagonists & inhibitors ; metabolism ; Nitroarginine ; pharmacology

For a long time, the cultivation of medical students’ scientific research and innovation abilitymainly depends on scattered extracurricular scientific research activities. With limited students, unsystematic teaching and inadequate administrative guarantee, it often results in obvious weakness andinefficiency. Since 2002, the Biochemistry and Molecular Biology teaching team in Shantou UniversityMedical College has been working on a “3+X” model to nurture the scientific research and innovationability of medical students. Guided by the concepts of complementary development of science andeducation, student-centeredness, and Problem-based Learning, a model is established based on the‘HEART” professionalism courses and the academy culture specific to Shantou University. We also takefull advantage of the first-tier disciplines of biology, basic medicine and clinical medicine in ShantouUniversity and collaborate with other professional teaching teams. It is conceptualized in a framework thatembraces the comprehensive connotation of scientific research and innovation ability and adopts a corecurriculum system that runs through the 5-year medical undergraduate education. In this model, " 3" means " whole-person training", " whole-process training" and " omni-directional training" for medicalstudents; " X" refers to several confirmatory dimensions of the operational effectiveness of the " 3+X" model, including organizing medical students to participate in various forms of national college students’ innovative experimental research competitions, international college students’ academic seminars, writingand publishing academic papers by medical undergraduates as the first author, etc. The model proves tobe effective in cultivating the scientific research and innovation ability of medical students, hence settinga good example to solve the current problems in the cultivation of medical students’ scientific researchand innovation ability.