鲤鱼发育早期HPG轴和GH/IGF轴相关因子的转录起始分析

采用RT-PCR的方法,以不同发育时期的鲤鱼胚胎和幼鱼为材料,研究了与鱼类生殖相关的HPG轴以及与生长相关的GH/IGF轴中GnRH、GtH以及GH、GHR和IGF重要信号分子的转录起始特征。结果显示,sGnRH、cGnRH、GtH-Iβ亚基和GHR于鲤鱼胚胎受精后20h开始转录,IGF-1于受精后23h开始转录,GtH-IIβ亚基于受精后26h开始转录,GtHα亚基于受精后46h开始转录,GH于1dph(孵出后第1天)开始转录。其中,GHR和IGF-1均早于GH开始转录,GtHα亚基和β亚基的转录起始时

Diversities in hepatic HIF-1, IGF-I/IGFBP-1, LDH/ICD, and their mRNA expressions induced by CoCl2 in Qinghai-Tibetan plateau mammals and sea level mice

Ochotona curzoniae and Microtus oeconomus are the native mammals living on the Qinghai-TibetanPlateau of China. The molecular mechanisms of their acclimatization to the Plateau-hypoxia remain unclear. Expressions of hepatic hypoxia-inducible factor (HIF)-1 alpha, insulin-like growth factor-I (IGF-I)/IGF binding protein (BP)-1(IGFBP-1; including genes), and key metabolic enzymatic genes [lactate dehydrogenase (LDH)-A/isocitrate dehydrogenase (ICD)] are compared in Qinghai-Tibetan- Plateau mammals andsea- level mice after injection of CoCl2 (20, 40, or 60 mg/ kg) and normobaric hypoxia (16.0% O-2, 10.8% O-2, and 8.0% O-2) for 6 h, tested by histochemistry, Western blot analysis, ELISA, and RT-PCR. Major results are CoCl2 markedly increased 1) HIF-1 alpha only in mice, 2) hepatic and circulatory IGF-I in M. oeconomus, 3) hepatic IGFBP-1 in mice and O. curzoniae, and 4) LDH-A but reduced ICD mRNA in mice (CoCl2 20 mg/kg) but were unchanged in the Tibetan mammals. Normobaric hypoxia markedly 1) increased HIF-1 alpha and LDH-A mRNA in mice and M. oeconomus (8.0% O-2) not in O. curzoniae, and 2) reduced ICD mRNA in mice and M. oeconomus (8.0% O-2) not in O. curzoniae. Results suggest that 1) HIF-1 alpha responsiveness to hypoxia is distinct in lowland mice and plateau mammals, reflecting a diverse tolerance of the three species to hypoxia; 2) CoCl2 induces diversities in HIF-1, IGF-I/IGFBP-1 protein or genes in mice, M. oeconomus, and O. curzoniae. In contrast, HIF-1 mediates IGFBP-1 transcription only in mice and in M. oeconomus (subjected to severe hypoxia); 3) differences in IGF-I/IGFBP-1 expressions induced by CoCl2 reflect significant diversities in hormone regulation and cell protection from damage; and 4) activation of anaerobic glycolysis and reduction of Krebs cycle represents strategies of lowland-animals vs. the stable metabolic homeostasis of plateau- acclimatized mammals.

Absence of association between SNPs in the promoter region of the insulin-like growth factor 1 (IGF-1) gene and longevity in the Han Chinese population

Previous studies have indicated that genetic variations in the factors of insulin/insulin-like growth factor 1 (IGF-1) signaling pathway could influence human life-span by affecting IGF-1 levels. The promoter region of the IGF-1 gene is an obvious candida

用NMR、FT-IR、DSC和AFM的方法研究PP-b-PE的结构与性能

聚丙烯是一种优异的高分子材料，但其低温抗冲击性能欠佳，因而限制了其应用范围。采用PP与PE嵌段共聚来改善PP的抗冲击性能是世界上目前行之有效的方法，因而引起人们的重视。由于聚丙烯嵌段共聚物（PP-b-PE）是由多组分组成的复杂体系，对其组成和链的结构仍不十分清楚。因此，本工作选取国外（6组）和国内（5组）共计11组PP-b-PE样品，分别对其结构、性能及其影响因素进行了研究，为实际应用提供了依据。为了保证能将PP-b-PE中的橡胶成分抽提出来，先将PP-b-PE样品用二甲苯溶解，之后加入甲醇沉淀、过滤、干燥，最后用正庚烷抽提，使得PP-b-PE样品中正庚烷的不可溶物与可溶物完全分离。其中，可溶物即为橡胶，不可溶物为塑料。再利用高温核磁共振谱仪（NMR）、示差扫描量热仪（DSC）和傅立汗卜变换红外谱仪（FT-IR）等先进的分析技术手段进行结构分析，并用原子力显微镜（AFM）观察生产过程中样品的形貌。实验和分析结果表明：在正庚烷可溶物中含有低熔点的聚丙烯和嵌段长度不同且能结晶的聚乙烯；并且还含有属于乙丙无规共聚物橡胶部分的n值小于4的（-CH2-）n结构，以及嵌有结晶性的丙烯和乙烯链节。正庚烷的不可溶物主要为聚丙烯，及少量聚乙烯。对于不同物性的PP-b-PE而言，正庚烷不可溶物决定了其刚性，正庚烷可溶物决定了其韧性，并由其粘度比决定了橡胶在聚丙烯中的分布情况。用AFM来研究PP-b-PE中的橡胶颗粒的分布情况是非常好的分析方法。PP-b-PE样品中橡胶的含量及其组成成分将对PP-b-PE的性能产生很大的影响。国内用浆液法生产的PP-b-PE样品中橡胶含量相对于用液一气相法和气相法生产的要少，但在其正庚烷不可溶物中含有较多的乙烯。从而可以用控制乙烯的含量来改善其抗冲击性能，这是浆液法与液一气相法和气相法的最大区别。液一气相法和气相法生产的PP-b-PE样品中的正庚烷可溶物的含量和结构十分接近。结果表明，本文采用多种不同的先进的分析方法和实验手段对PP-b-PE的结构与性能的研究是一条有效可行的实验途径。

Ni/Si,Pt/Si,Ir/Si系的As离子注入和退火

于2010-11-23批量导入