Objective To investigate the relationship between serum Leptin levels and insulin resistance.Methods During 2001-10~2002-08 fasting serum Leptin concentrations were measured with RIA in 196 cases(including 118 type 2 diabetes,78 controls),and height,body weight were measured to calculate body mass index(BMI).Results HbA_1c,SBP,TG,Leptin were correlated with ISI,Leptin concentration were higher in type 2 diabetes than in controls;Leptin concentration was significantly increased in obese subjects,whereas in type 2 diabetes serum Leptin concentration had no significant difference between obese subjects and non-obese subjects.Conclusion Most of obeses subjects have insulin resistance,whether obesity or not,the patients type 2 diabetes have some kind of insulin resistance.

Objective To construct a rating scale on the knowledge,attitude,and practice of geriatrics for 8-year clinical medical students and undergraduate nursing students,and to test the reliability and validity of the scale.Methods The Knowledge,Attitude,Practice(KAP)theory was used as a guided framework,relative literatures were reviewed,and topics for question answering were discussed by experts group.Then,a questionnaire was initially constructed.Five methods,including discrete trend method,Cronbach coefficient,t-test,correlation analysis,and factor analysis,were used to screen the attitude and practice items.The knowledge items were evaluated by experts.Items with over three exclusion criteria were deleted when combining the literal questions.The construct validity of the integrated scale was assessed by factor analysis.A pilot research was conducted by 100 eight-year medical students and nursing undergraduates selecting question entries,and the reliability and validity of the scale were examined.Results The scale consisted of three dimensions.A 43-item initiate questionnaire on the scale included 13 items for knowledge,11 for attitude,and 19 for practice.Two knowledge items were deleted according to expert evaluation.Seven items with more than three exclusion criteria were deleted after statistical analyses.Eventually,34 items were included in the questionnaire.The Cronbach α coefficient of the questionnaire was 0.702.And three common factors were extracted according to exploratory factor analysis.Conclusions The reliability and validity of Geriatrics Knowledge,Attitude and Practice scale for eight year medical students and nursing undergraduates are acceptable,but the knowledge items should be recomposed.

Triterpenoids are one of the most diverse compounds in plant metabolites, and they have a wide variety of physiological activities and are of important economic value. Oxidosqualene cyclases catalyze the cyclization of 2, 3-oxidosqualene to generate different types of sterols and plant triterpenoids, which is of great significance to the structural diversity of natural products. However, the mechanism of the diversified cyclization of 2, 3-oxidosqualene catalyzed by oxidosqualene cyclases remains unclear. This review summarized the research progress of oxidosqualene cyclases from the aspects of catalytic function, molecular evolutionary relationship between genes and proteins, protein structure, molecular simulation and molecular calculations, which may provide a reference for protein engineering and metabolic engineering of triterpene cyclase.
Intramolecular Transferases/metabolism* ; Metabolic Engineering ; Plants/genetics* ; Squalene/chemistry* ; Triterpenes

Limonene (C₁₀H₁₆) and bisabolene (C₁₅H₂₄) are both naturally occurring terpenes in plants. Depending on the number of C₅ units, limonene and bisabolene are recognized as representative monoterpenes and sesquiterpenes, respectively. Limonene and bisabolene are important pharmaceutical and nutraceutical products used in the prevention and treatment of cancer and many other diseases. In addition, they can be used as starting materials to produce a range of commercially valuable products, such as pharmaceuticals, nutraceuticals, cosmetics, and biofuels. The low abundance or yield of limonene and bisabolene in plants renders their isolation from plant sources non-economically viable. Isolation of limonene and bisabolene from plants also suffers from low efficiency and often requires harsh reaction conditions, prolonged reaction times, and expensive equipment cost. Recently, the rapid developments in metabolic engineering of microbes provide a promising alternative route for producing these plant natural products. Therefore, producing limonene and bisabolene by engineering microbial cells into microbial factories is becoming an attractive alternative approach that can overcome the bottlenecks, making it more sustainable, environmentally friendly and economically competitive. Here, we reviewed the status of metabolic engineering of microbes that produce limonene and bisabolene including microbial hosts, key enzymes, metabolic pathways and engineering of limonene/bisabolene biosynthesis. Furthermore, key challenges and future perspectives were discussed.