脂肪酸结合蛋白4在小鼠子宫蜕膜中的表达

[目的]检测脂肪酸结合蛋白4(FABP4)在小鼠子宫蜕膜细胞中的表达。[方法]获取正常的小鼠子宫蜕膜组织和人工诱导蜕膜化组织,同时利用酶消化分离小鼠子宫内膜基质细胞,进行体外诱导蜕膜化,利用实时定量PCR检测脂肪酸结合蛋白4在子宫蜕膜组织细胞中的表达。[结果]FABP 4在小鼠正常子宫蜕膜组织、人工诱导蜕膜化组织及子宫内膜蜕膜化基质细胞中的表达水平均显著高于对照组。[结论]FABP4可能参与了小鼠子宫内膜蜕膜化过程,为研究蜕膜化机理奠定了基础。     

绿盲蝽化学感受蛋白基因AlucCSP1的克隆、表达谱分析及结合特征

 【目的】克隆、组织特异性表达以及荧光结合特征分析绿盲蝽 (Apolygus lucorum Meyer-Dür)化学感受蛋白（chemosensory protein,CSP）。【方法】设计特异性引物,用RT-PCR技术克隆绿盲蝽化学感受蛋白基因AlucCSP1,使用半定量RT-PCR和Real-time PCR技术对AlucCSP1组织特异性表达进行研究,在BL2（DE3）工程菌株中用pGEX-4T-1载体进行原核表达,并在GSTrap FF柱中纯化和去标签蛋白。使用bis-ANS作为荧光配基,研究AlucCSP1蛋白与58种气味标样和5种棉花次生代谢物质的结合特征。【结果】得到了绿盲蝽化学感受蛋白基因,命名为AlucCSP1（GenBank登录号：JN573217）。该序列阅读框全长393 bp,编码130个氨基酸残基,N端有一段长17个aa的信号肽,具有4个保守的半胱氨酸残基。绿盲蝽AlucCSP1几乎全部在雌虫触角中表达。构建pGEX/AlucCSP1原核表达载体,在BL21（DE3）工程菌株中表达出分子量约为39 kD的融合蛋白,用亲和层析法纯化、经凝血酶作用去除标签蛋白获得纯化的AlucCSP1蛋白,该蛋白与棉酚、单宁、槲皮素、芦丁水合物亲和力较强,结合常数分别为13.4、32.7、19.7、38.5 μmol•L-1。【结论】克隆得到绿盲蝽化学感受蛋白基因AlucCSP1,在雌性触角内特异表达,并进一步得到约13 kD的AlucCSP1纯蛋白。为研究AlucCSP1在绿盲蝽化学感器中的作用奠定了基础。     

浅谈混凝土结构加固方案的选择

介绍了混凝土加固的各种方法及技术特点、加固原理及其在各类混凝土结构构件加固中的机理作用,阐明在确定加固方案时应综合考虑各种因素,最终选择正确合理的加固方案至关重要。     

Effects of open- and closed-system temperature changes on blood O2-binding characteristics of Atlantic bluefin tuna (Thunnus thynnus)

We investigated the effects of open- and closed-system temperature changes on the O₂ affinity of Atlantic bluefin tuna (Thunnus thynnus) blood using in vitro methods essentially identical to those previously employed on tropical tuna species. Bluefin tuna blood has a general O₂ affinity (P ₅₀ = 2.6–3.1 kPa or 19–23 mm Hg at 0.5% CO₂) similar to that of skipjack tuna, yellowfin tuna, and kawakawa blood (P ₅₀ = 2.8–3.1 kPa at 0.5% CO₂) but significantly above that of bigeye tuna blood (P ₅₀ = 1.6–2.0 kPa at 0.5% CO₂). We therefore hypothesize that bluefin tuna are less tolerant of hypoxia than bigeye tuna. Further, we found the P ₅₀ of bluefin tuna blood to be slightly reduced by a 10°C open-system temperature increase (e.g., from 4.83 kPa at 15°C to 3.95 kPa at 25°C) and to be completely unaffected by a 10°C closed-system temperature change. Bluefin tuna blood, therefore, had a significantly reduced Bohr effect when subjected to the inevitable changes in P CO ₂ and plasma pH that accompany closed-system temperature shifts (0.04–0.09 Δlog P₅₀ΔpH⁻¹) compared with the effects of changes in plasma pH accomplished by changing P CO ₂ alone (0.81–0.94 Δlog P₅₀ Δ pH⁻¹). This response is similar to that of skipjack tuna blood, but different from yellowfin or bigeye tuna blood. During closed-system temperature changes at oxygen levels above P ₅₀, however, bluefin tuna blood showed a reversed temperature effect (i.e., P O ₂ decreased in response to an increase in temperature). Unlike in other tuna species, temperature effects on O₂ affinity of bluefin tuna whole blood were similar to those previously reported for hemoglobin solutions, suggesting that red cell-mediated ligand changes are not involved.     

不同时期的铁丝绞缢对光皮树幼树早花早实的促进效果

采用铁丝绞缢法对4年生光皮树幼树主枝进行处理,处理时间分别为6月、7月、8月、9月每月5日和20日。结果表明：不同时期的铁丝绞缢处理均抑制了树高生长,7月份两次处理与对照达到差异显著;不同时期处理均促进了地径的生长,其中7月5日处理与对照达到差异显著;不同时期处理均抑制了冠幅的生长,但与对照未达到差异显著;不同时期处理促进开花效果显著,其中6月20日、7月5日、7月20日三次处理均与对照达到差异极显著。铁丝绞缢法促进光皮树早花早实最佳处理时间为6月底至7月中旬。     

Time-dependent changes of calbindin D-28K and parvalbumin immunoreactivity in the hippocampus of rats with streptozotocin-induced type 1 diabetes

The hippocampus is affected by various stimuli that include hyperglycemia, depression, and ischemia. Calcium-binding proteins (CaBPs) have protective roles in the response to such stimuli. However, little is known about the expression of CaBPs under diabetic conditions. This study was conducted to examine alterations in the physiological parameters with type 1 diabetes induced with streptozotocin (STZ) as well as time-dependent changes in the expression of two CaBPs changes of were being evaluated. Rats treated with STZ (70 mg/kg) had high blood glucose levels (>21.4 mmol/L) along with increased food intake and water consumption volumes compared to the sham controls. In contrast, body weight of the animals treated with STZ was significantly reduced compared to the sham group. CB-specific immunoreactivity was generally increased in the hippocampal CA1 region and granule cell layer of the dentate gyrus (DG) 2 weeks after STZ treatment, but decreased thereafter in these regions. In contrast, the number of PV-immunoreactive neurons and fibers was unchanged in the hippocampus and DG 2 weeks after STZ treatment. However, this number subsequently decreased over time. These results suggest that CB and PV expression is lowest 3 weeks after STZ administration, and these deficits lead to disturbances in calcium homeostasis.     

Freezing mouse blastocysts

Summary

A good survival rate in culturing mouse blastocysts can be obtained in Ovum Culture Medium, enriched with 20 per cent inactivated Foetal Bovine Serum or Sheep Serum under air. The transfer of fresh blastocysts gives the best results if the recipients are on day 3 of the pseudo‐pregnancy, but with 20 hours’ cultured blastocysts it is better to use recipients on day 4.

Exposure to 1.5 M DMSO has no harmful effect, provided that the DMSO is added at 5° C in 6 steps and is removed, again in 6 steps, at 35° C. The crystallization of the medium containing the embryos at ‐5° C to ‐6° C doet not appear te have a harmful influence on culture results of the blastocysts.     

Hepatitis in dogs. An indexed bibliography of journal articles (1994–2004)

Transmissible spongiform encephalopathies (TSEs) or prion diseases are unique disorders that are not caused by infectious micro-organisms (bacteria or fungi), viruses or parasites, but rather seem to be the result of an infectious protein. TSEs are comprised of fatal neurodegenerative disorders affecting both human and animals. Prion diseases cause sponge-like degeneration of neuronal tissue and include (among others) Creutzfeldt–Jacob disease in humans, bovine spongiform encephalopathy (BSE) in cattle and scrapie in sheep. TSEs are characterized by the formation and accumulation of transmissible (infectious) disease-associated protease-resistant prion protein (PrP^Sc), mainly in tissues of the central nervous system. The exact molecular processes behind the conversion of PrP^C into PrP^Sc are not clearly understood. Correlations between prion protein polymorphisms and disease have been found, however in what way these polymorphisms influence the conversion processes remains an enigma; is stabilization or destabilization of the prion protein the basis for a higher conversion propensity? Apart from the disease-associated polymorphisms of the prion protein, the molecular processes underlying conversion are not understood. There are some notions as to which regions of the prion protein are involved in refolding of PrP^C into PrP^Sc and where the most drastic structural changes take place. Direct interactions between PrP^C molecules and/or PrP^Sc are likely at the basis of conversion, however which specific amino acid domains are involved and to what extent these domains contribute to conversion resistance/sensitivity of the prion protein or the species barrier is still unknown.     

烟夜蛾气味结合蛋白的同源模建

[目的]预测烟夜蛾(Helicoverpa assulta)的气味结合蛋白。[方法]用同源模建的方法构建烟夜蛾(Helicoverpa assulta)气味结合蛋白的三维结构,并用Procheck、Verify_3D、Errat、ProSa2003等程序进行评价。[结果]程序评价结果表明模建结构是可靠的。模建结构显示烟夜蛾的气味结合蛋白由6个α-螺旋和连接这些螺旋的回折构成,底物结合口袋成锥形;6个保守的半胱氨酸形成3个对结构起稳定作用的二硫键。[结论]预测结构可靠,为烟夜蛾的研究及虫害的防治提供了理论依据。