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991.

Background  

In insects, hemocyanin superfamily proteins accumulate apparently to serve as sources of amino acids during metamorphosis, reproduction and development. Storage hexamerins are important members of the hemocyanin superfamily. Although insects possess storage hexamerins, very little is known about the character and specific functions of hexamerin 1 and storage protein 1 in insect development.  相似文献   
992.

Background  

The search for naturally occurring nanocomposites with diverse properties for tissue engineering has been a major interest for biomaterial research. In this study, we investigated a nanofiber and nanoparticle based nanocomposite secreted from an insect-capturing plant, the Sundew, for cell attachment. The adhesive nanocomposite has demonstrated high biocompatibility and is ready to be used with minimal preparation.  相似文献   
993.

Introduction  

There is growing evidence that interleukin 17 (IL-17) producing T cells are involved in the pathogenesis of systemic lupus erythematosus (SLE). Previous studies showed that increased percentages of T-cell subsets expressing the costimulatory molecules CD80 and CD134 are associated with disease activity and renal involvement in SLE. The aim of this study was to investigate the distribution and phenotypical characteristics of IL-17 producing T-cells in SLE, in particular in patients with lupus nephritis, with emphasis on the expression of CD80 and CD134.  相似文献   
994.
Berberine, a plant alkaloid used in traditional Chinese medicine, has a wide spectrum of pharmacological actions, but the poor bioavailability limits its clinical use. The present aim was to observe the effects of sodium caprate on the intestinal absorption and antidiabetic action of berberine. The in situ, in vitro, and in vivo models were used to observe the effect of sodium caprate on the intestinal absorption of berberine. Intestinal mucosa morphology was measured to evaluate the toxic effect of sodium caprate. Diabetic model was used to evaluate antidiabetic effect of berberine coadministrated with sodium caprate. The results showed that the absorption of berberine in the small intestine was poor and that sodium caprate could significantly improve the poor absorption of berberine in the small intestine. Sodium caprate stimulated mucosal-to-serosal transport of berberine; the enhancement ratios were 2.08, 1.49, and 3.49 in the duodenum, jejunum, and ileum, respectively. After coadministration, the area under the plasma concentration–time curve of berberine was increased 28% than that in the absence of sodium caprate. Furthermore, both berberine and coadministration with sodium caprate orally could significantly decrease fasting blood glucose and improve glucose tolerance in diabetic rats (P?P?相似文献   
995.
秦岭南坡不同海拔林分凋落叶分解特征   总被引:1,自引:0,他引:1  
采用野外放置凋落物分解袋法,对秦岭南坡林区不同海拔华山松(Pinus armandii)、油松(P.tabulaeformis)、锐齿栎(Quercus aliena var.acuteserrata)和华北落叶松(Larix principis-rupprechtii)凋落叶分解过程中N、P、C、粗脂肪、粗纤维和热值的变化规律进行比较研究.结果表明:(1)处于不同海拔的同一树种新鲜凋落叶的N、P、C、粗脂肪含量及其热值差异不显著(P>0.05).(2)在一年的分解过程中,凋落叶N、P含量表现出逐渐富集的趋势,其中油松凋落叶N、P富集速度最快,分别达到165.60%和189.94%;凋落叶C、粗脂肪含量和热值、C/N、C/P、粗纤维/N在分解中逐渐下降,粗脂肪释放速率达到50.29%~77.82%.(3)分解一年后,不同海拔同一树种凋落叶N、P、C、C/N、C/P含量仍未表现出显著性差异(P>0.05),但不同海拔凋落叶粗脂肪分解表现出极显著差异(P<0.01),其中差距最大的锐齿栎凋落叶低海拔较高海拔粗脂肪释放率高19.38%;不同海拔华北落叶松和锐齿栎凋落叶粗纤维释放速率差异极显著(P<0.01),而不同海拔油松、华山松凋落叶粗纤维释放无显著差异;处于高低海拔的华北落叶松和锐齿栎凋落叶热值分别为17.12和15.68 kJ·g-1、17.74和13.51 kJ·g-1,表现出极显著差异(P<0.01),油松、华山松凋落叶表现出显著差异(P<0.05).研究发现,一年中海拔差异所造成的降水、温度等因素的变化对各树种凋落叶中N、P、C的释放无显著影响,但对凋落叶分解过程中粗脂肪、热值、粗纤维/N的变化影响显著.  相似文献   
996.
目的:通过比较奥美拉唑和泮托拉唑对冠状动脉支架术(PCI)后患者血小板功能指标和主要不良心血管事件与出血并发症发生情况,探讨不同质子泵抑制剂对PCI后氯吡格雷联合阿司匹林抗血小板作用的影响。方法:60例实施PCI后常规联合抗血小板治疗(氯吡格雷75mg/d+阿司匹林100mg/d)患者随机分为奥美拉唑组(40mg/d,20例),泮托拉唑组(40mg/d,20例)和对照组(20例),连续用药30d。分别在服药前1d及服药15d,30d用血栓弹力图检测ADP途径诱导的血小板抑制率值和比浊法检测ADP途径诱导的血小板最大聚集率(MPAR)。并观察30d各组主要不良心血管事件和出血并发症的发生情况。结果:①奥美拉唑组和泮托拉唑组与对照组相比,服药前1d及服药15d,30d用血栓弹力图检测的血小板抑制率和比浊法检测的血小板最大聚集率(MPAR)均无明显变化;奥美拉唑与泮托拉唑组间比较,差异也无统计学意义。服药15d,30d与服药前1d相比,每组血小板抑制率明显升高,血小板最大聚集率明显下降,差异有统计学意义(P0.05);但15d和30d相比较,差异无统计学意义。②三组比较心血管事件发生率相近,差异无统计学意义(P0.05);奥美拉唑组和泮托拉唑组比较,心血管事件发生率也无统计学差异(P0.05)。③与对照组比较,奥美拉唑组和泮托拉唑组胃肠道出血发生率均明显减少,有统计学意义(P0.05),但两服药组间比较,出血发生率无明显区别,差异无统计学意义(P0.05)。结论:氯吡格雷联合阿司匹林具有增强血小板抑制,降低血小板凝聚的作用,而不同机制质子泵抑制剂奥美拉唑与泮托拉唑对PCI术后氯吡格雷联合阿司匹林抗血小板治疗患者的血小板功能无明显影响,不降低对心血管事件的预防效果,同时明显降低患者胃肠出血事件的发生率。  相似文献   
997.
目的:探讨低氧对大鼠骨骼肌成肌细胞(SkMs)增殖的影响及低氧诱导因子(HIF-1α)在低氧促成肌细胞增殖中的相关机制。方法:采用流式细胞仪观察了3、10%O2对SkMs细胞数量和增殖指数的影响;用RT-PCR方法检测了HIF-1αmRNA的表达,用Western blot方法检测了SkMs胞浆、胞核及总HIF-1α蛋白的水平。结果:低氧组较常氧组细胞数量和增殖指数增加(P0.05);HIF-1αmRNA、总蛋白水平在常氧组和低氧组中没有明显差异,常氧下胞浆中HIF-1α蛋白水平高于胞核内,低氧下HIF-1α蛋白水平在胞核内高于胞浆。结论:低氧能够促进SkMs增殖,HIF-1α可能是通过氧浓度调控的核转位的方式参与了低氧促SkMs的增殖。  相似文献   
998.
目的:本研究旨在探讨低糖低氧对大鼠神经干细胞增殖和代谢的影响。方法:实验采用不同葡萄糖浓度的培养基以及不同的氧浓度进行处理:高糖(4.5g/L)、低糖(1.4g/L);常氧(20%O2)、低氧(3%O2);神经干细胞(NSCs)来自孕13.5d的大鼠中脑,在不同糖浓度下培养至第三代进行低氧处理,分为低糖常氧(L+N)、低糖低氧(L+H)、高糖常氧(H+N)、高糖低氧(H+H)组。神经干细胞在上述四种条件下分别培养1、3、5d后,利用CCK-8检测神经干细胞的增殖情况;生化分析仪测定细胞培养上清液中葡萄糖、乳酸、丙酮酸浓度;RT-PCR方法检测葡萄糖转运蛋白4(GluT4)、葡萄糖激酶(GK)、丙酮酸激酶(PK)和乳酸脱氢酶(LDH)的表达变化。结果:在低糖低氧条件下培养3d时NSCs的数量增加最为明显;低糖低氧条件下,葡萄糖浓度降低最为显著;而丙酮酸浓度在低糖处理组均高于高糖处理组;同样地,在低糖低氧处理组培养上清中乳酸含量增加的幅度最大;此外,在低糖或低氧时Glut4和PK的表达也明显高于对照组。结论:低氧能促进NSCs的增殖,而以低氧和低糖共同作用时更为明显;在低氧低糖条件下,神经干细胞的代谢发生变化,葡萄糖的利用明显增加,主要通过糖酵解途径代谢产能。  相似文献   
999.
Simian immunodeficiency viruses of sooty mangabeys (SIVsm) are the source of multiple, successful cross-species transmissions, having given rise to HIV-2 in humans, SIVmac in rhesus macaques, and SIVstm in stump-tailed macaques. Cellular assays and phylogenetic comparisons indirectly support a role for TRIM5α, the product of the TRIM5 gene, in suppressing interspecies transmission and emergence of retroviruses in nature. Here, we investigate the in vivo role of TRIM5 directly, focusing on transmission of primate immunodeficiency viruses between outbred primate hosts. Specifically, we retrospectively analyzed experimental cross-species transmission of SIVsm in two cohorts of rhesus macaques and found a significant effect of TRIM5 genotype on viral replication levels. The effect was especially pronounced in a cohort of animals infected with SIVsmE543-3, where TRIM5 genotype correlated with approximately 100-fold to 1,000-fold differences in viral replication levels. Surprisingly, transmission occurred even in individuals bearing restrictive TRIM5 genotypes, resulting in attenuation of replication rather than an outright block to infection. In cell-culture assays, the same TRIM5 alleles associated with viral suppression in vivo blocked infectivity of two SIVsm strains, but not the macaque-adapted strain SIVmac239. Adaptations appeared in the viral capsid in animals with restrictive TRIM5 genotypes, and similar adaptations coincide with emergence of SIVmac in captive macaques in the 1970s. Thus, host TRIM5 can suppress viral replication in vivo, exerting selective pressure during the initial stages of cross-species transmission.  相似文献   
1000.
COMM domain-containing proteins are a group of recently discovered proteins; their biochemical characterization remains much limited. Here we demonstrate that a cDNA encoding Branchiostoma belcheri COMMD6, designated BbCOMMD6, codes for a protein of 203 amino acids, with a COMM domain at its C-terminal region and an extended N-terminal portion. BbCOMMD6 is mainly present in the cytosol. In contrast to COMMD1, the presence of Cu(II) cannot enhance recombinant BbCOMMD6 dimer formation. Both the pull-down and reverse pull-down assays reveal that BbCOMMD6 interacts with the creatine kinase (CK), an essential enzyme involved in energy metabolism, forming a heterodimer BbCOMMD6-CK. The enzymatic activity assays show that CK activities are inhibited by BbCOMMD6 in a dose-dependent manner. All these data suggest that BbCOMMD6 is involved in energy transduction, via binding to CK and inhibiting activities of CK, and offer first clues to its role as a regulator of CK activities.  相似文献   
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