Objectives: To assess insulin dynamics to oral glucose tolerance testing in o bese children, denoting individual contributions of insulin hypersecretion versu s resistance to racial and etiopathogenetic specificity. S...Objectives: To assess insulin dynamics to oral glucose tolerance testing in o bese children, denoting individual contributions of insulin hypersecretion versu s resistance to racial and etiopathogenetic specificity. Study design: We perfor med 3- hour oral glucose tolerance testing in 113 nondiabetic obese children (a ge 13.6 ± 3.1 years; 41 male, 78 female; 37 black, 41 white; 35 with central n ervous system [CNS] insult). The corrected insulin response (CIRgp; measuring β - cell secretion) and the composite insulin sensitivity index (CISI) were comp uted and log- transformed, and each was modeled in terms of the other, plus rac e/etiology, age, sex, body mass index z score, glucose tolerance, pubertal statu s, and geographic location. Results: A scatterplot of logCIRgp versus logCISI sh owed that racial and etiopathogenetic groups plotted in different areas. CISI (c ontrolled for CIRgp and other variables) was only 13% lower in blacks than in whites (P = .32). Conversely, CIRgp (controlled for CISI and other variables) wa s 49% higher in blacks (P = .028). CNS insult exhibited a 40% higher CIRgp ( P = .054) and 11% higher CISI (P = .42) than intact white subjects. Conclusion s: Insulin hypersecretion and resistance are distinct phenomena in childhood obe sity. Insulin hypersecretion ap- pears to be the more relevant insulin abnormal ity both in obese blacks and in CNS insult.展开更多
文摘Objectives: To assess insulin dynamics to oral glucose tolerance testing in o bese children, denoting individual contributions of insulin hypersecretion versu s resistance to racial and etiopathogenetic specificity. Study design: We perfor med 3- hour oral glucose tolerance testing in 113 nondiabetic obese children (a ge 13.6 ± 3.1 years; 41 male, 78 female; 37 black, 41 white; 35 with central n ervous system [CNS] insult). The corrected insulin response (CIRgp; measuring β - cell secretion) and the composite insulin sensitivity index (CISI) were comp uted and log- transformed, and each was modeled in terms of the other, plus rac e/etiology, age, sex, body mass index z score, glucose tolerance, pubertal statu s, and geographic location. Results: A scatterplot of logCIRgp versus logCISI sh owed that racial and etiopathogenetic groups plotted in different areas. CISI (c ontrolled for CIRgp and other variables) was only 13% lower in blacks than in whites (P = .32). Conversely, CIRgp (controlled for CISI and other variables) wa s 49% higher in blacks (P = .028). CNS insult exhibited a 40% higher CIRgp ( P = .054) and 11% higher CISI (P = .42) than intact white subjects. Conclusion s: Insulin hypersecretion and resistance are distinct phenomena in childhood obe sity. Insulin hypersecretion ap- pears to be the more relevant insulin abnormal ity both in obese blacks and in CNS insult.
文摘为探索长期连作状态下烟草根系分泌物内含有的化感物质组成成分,设置石英砂栽培和连作土壤栽培2种烟草培养处理,对2种烟草不同生长时期的根系分泌物进行提取,利用超高效液相色谱串联质谱(ultra-high performance liquid chromatography tandem mass spectrometry,UHPLC-MS/MS)对提取的根系分泌物进行分析,通过数据库比对、差异分析和时间聚类分析等方法筛选连作烟草根系分泌物中潜在的化感物质。结果表明,共筛选出11类潜在化感物质,分别为生物碱、萜类、胺类、有机酸、苯酸及其衍生物、脂肪酸、酚类、氨基酸和多肽、香豆素、肉桂酸及其衍生物和其他。生物碱、萜类、胺类和有机酸4类化合物相对含量占所有化合物的73.3%。L-烟碱、熊果酸、β-氨基丙腈、5-羟基吲哚乙酸、早熟素Ⅱ、单乙基己基邻苯二甲酸、己内酰胺、姜酚、L-乳酸、邻苯二甲酸二乙酯和2,3-二氢-3,5-二羟基-2-氧代-3-吲哚乙酸甲酯是连作烟草根系分泌物中相对含量较高的潜在化感物质。研究结果为烟草根系化感物质的化感作用研究及缓解烟草连作障碍方法研究提供理论基础。
