Determination of layer-specific mechanical properties of human coronary arteries with nonatherosclerotic intimal thickening and related constitutive modeling

At autopsy, 13 nonstenotic human left anterior descending coronary arteries [71.5 +/- 7.3 (mean +/- SD) yr old] were harvested, and related anamnesis was documented. Preconditioned prepared strips (n = 78) of segments from the midregion of the left anterior descending coronary artery from the individual layers in axial and circumferential directions were subjected to cyclic quasi-static uniaxial tension tests, and ultimate tensile stresses and stretches were documented. The ratio of outer diameter to total wall thickness was 0.189 +/- 0.014; ratios of adventitia, media, and intima thickness to total wall thickness were 0.4 +/- 0.03, 0.36 +/- 0.03, and 0.27 +/- 0.02, respectively; axial in situ stretch of 1.044 +/- 0.06 decreased with age. Stress-stretch responses for the individual tissues showed pronounced mechanical heterogeneity. The intima is the stiffest layer over the whole deformation domain, whereas the media in the longitudinal direction is the softest. All specimens exhibited small hysteresis and anisotropic and strong nonlinear behavior in both loading directions. The media and intima showed similar ultimate tensile stresses, which are on average three times smaller than ultimate tensile stresses in the adventitia (1,430 +/- 604 kPa circumferential and 1,300 +/- 692 kPa longitudinal). The ultimate tensile stretches are similar for all tissue layers. A recently proposed constitutive model was extended and used to represent the deformation behavior for each tissue type over the entire loading range. The study showed the need to model nonstenotic human coronary arteries with nonatherosclerotic intimal thickening as a composite structure composed of three solid mechanically relevant layers with different mechanical properties. The intima showed significant thickness, load-bearing capacity, and mechanical strength compared with the media and adventitia.     

Laser capture-microarray analysis of Lim1 mutant kidney development

The Lim1 gene has essential functions during several stages of kidney development. In particular, a tissue-specific knockout in the early metanephric mesenchyme results in the formation of the earliest nephron precursor, the renal vesicle, but failure of this structure to progress to the next stage, the comma-shaped body. To better understand the molecular nature of this developmental arrest, we used a laser capture microdissection-microarray strategy to examine the perturbed gene expression pattern of the mutant renal vesicles. Among the genes found differently expressed were Chrdl2, an inhibitor of BMP signaling, the proapoptotic factor Bmf, as well as myob5, an atypical myosin that modulates chemokine signaling, and pdgfrl, which is important in epithelial folding. Of particular interest, the microarray data indicated that the Dkk1 gene, which encodes an inhibitor of Wnt signaling, was downregulated ninefold in mutants. This was confirmed by in situ hybridizations. It is interesting to note that Lim1 and Dkk1 mutant mice have striking similarities in phenoytpe. These results suggest that the Dkk1 gene might be a key downstream effector of Lim1 function.     

Laser capture microdissection for the analysis of gene expression during embryogenesis of Arabidopsis

It is during embryogenesis that the body plan of the developing plant is established. Analysis of gene expression during embryogenesis has been limited due to the technical difficulty of accessing the developing embryo. Here we demonstrate that laser capture microdissection can be applied to the analysis of embryogenesis. We show how this technique can be used in concert with DNA microarray for the large-scale analysis of gene expression in apical and basal domains of the globular-stage and heart-stage embryo, respectively, when critical events of polarity, symmetry and biochemical differentiation are established. This high resolution spatial analysis shows that up to approximately 65% of the genome is expressed in the developing embryo, and that differential expression of a number of gene classes can be detected. We discuss the validity of this approach for the functional analysis of both published and previously uncharacterized essential genes.     

红光熊蜂卵黄原蛋白基因的cDNA全长序列克隆和表达分析

红光熊蜂Bombus ignitus Smith是许多经济作物和野生植物的重要授粉昆虫之一。卵黄原蛋白基因(vitellogenin,Vg)在昆虫的生殖调控中和行为方面起到重要的作用,本试验对Vg基因全长cDNA的克隆和测序及在蜂王、工蜂和雄性蜂三型蜂中的表达分析得出:Vg基因的全长cDNA为5 481 bp,GenBank中的登录号为FJ913883,有一个完整的开放阅读框(ORF),编码1 772个氨基酸,N-末端的前16个氨基酸为一个信号肽。接近C-末端区域存在保守的GL/ICG基元,其后含有9个半胱氨酸,而且DGXR位于GL/ICG基元上游18个氨基酸残基处。其氨基酸序列与韩国的熊蜂B.ignitus和B.hypocrita相似性高达95%,与西方蜜蜂Apis mellifera的相似性达到51%。Vg的mRNA首先在蜂王蛹期的白眼蛹(Pw)时期出现,其表达量在蜂王整个蛹期发育过程中呈上升趋势,且在黑眼蛹(Pbd)时期达到最高,在成年蜂的脂肪体中的表达量仍在升高,甚至更高。Vg也在工蜂蛹期的白眼蛹(Pw)时期被检测到,然后在整个蛹期发育过程中呈现上升趋势,在刚羽化出房时达到高峰,Vg的mRNA水平随着成年蜂日龄的增加而增加,到15日龄时达到最高,然后呈现下降趋势。对于雄性蜂,Vg的mRNA虽然卵黄原蛋白基因的mRNA水平几乎在整个蛹期发育阶段都表达,但是表达水平非常低,只有在刚羽化出房时期表达水平较高。     

人单个中性粒细胞IL-8RβmRNA丰度的相对半定量研究

目的：探讨单个中性粒细胞中白介素-8β型受体（IL-8Rβ）mRNA的表达丰度。方法：采用倍比稀释相对定量单细胞RT-PCR方法分离纯化人外周血中性粒细胞并提取总RNA,针对IL-8RβmRNA设计引物,进行RT—PCR确认IL-8Rβ在中性粒细胞中的基因表达并优化反应条件。收集单个中性粒细胞胞内容物或完整细胞,以相同引物进行RT反应,再将后者所得的cDNA倍比稀释后,与前者共同经过两轮PCR扩增,并将最终产物以BamHI内切酶酶切鉴定产物的特异性。结果：IL-8RβmRNA在人中性粒细胞中有大量表达,单个中性粒细胞中亦能扩增出特异性的IL-8Rβ目的条带,并且将单个细胞内mRNA稀释100倍后仍可扩增出目的条带,BamHI内切酶酶切反应证实为目的产物。结论：人中性粒细胞表达IL-8RβmRNA,mRNA倍比稀释单细胞RT—PCR方法确认其丰度远高于一般mRNA含量,且此方法可在单细胞水平比较细胞内mRNA的丰度。     

A piece-wise non-linear elastic stress expression of human and pig coronary arteries tested in vitro.

Eight human and nineteen pig unembalmed proximal left anterior descending and circumflex coronary arteries were subjected to linear volume changes (2 s ramp time) at three fixed axial extensions while immersed in a physiological saline bath at body temperature. Measured parameters included: lumen pressure, outside diameter, axial force, and axial extension. The deformations were measured using a video dimensional analyzer. The arteries were inflated to pressures well above the physiological range at each axial extension. A latex inner tube was placed inside of each specimen to prevent leakage, and its effects upon the measured stresses were corrected analytically. With this method, the average circumferential and axial stresses could be computed directly from the experimental data. In both directions the average stresses measured displayed two distinct regions: stresses occurring for small diameter changes (physiological pressures) and stresses occurring for large diameter changes (high pressures). The resulting average small strain and large strain stress components were curve-fit separately and, when reassembled, provided a piece-wise model of the stress response of coronary arteries over a wide range of inflation pressures and axial extensions.     

定量分析诱导山羊体细胞重编程过程中端粒酶的表达变化

动物体细胞重编程为诱导多能干细胞(iPS)是目前干细胞生物学研究的热点。文中重点对山羊体细胞重编程过程中端粒酶(TERT)基因的相对表达量进行了检测,探讨了山羊重编程细胞的形成与端粒酶基因表达的关系。从关中奶山羊胎儿皮肤分离得到的胎儿成纤维细胞(GEF),其增殖能力较强,核型正常(60条XY),通过转录因子在体外诱导得到山羊重编程细胞。利用Real-timeRT-PCR方法首先对关中奶山羊胎儿各种组织的TERT表达进行了检测,结果表明睾丸组织中TERT的表达显著高于上皮组织(P0.01),在山羊胎儿的其他组织中TERT也有不同程度的表达。对原代重编程细胞和4株不完全重编程细胞株的TERT表达检测结果发现,碱性磷酸酶(AP)阳性的重编程细胞端粒酶表达量要显著高于AP阴性的重编程细胞(P0.01)。这一结果揭示,激活端粒酶活性并使其保持较高的表达水平对体细胞的重编程至关重要。     

Construction of EGFP-tagged rBCG of E.tenella and distribution in chickens

Chicken coccidiosis is a major parasitic disease with substantial economic burden to the poultry industry. Enhanced green fluorescent protein (EGFP) tagged recombinant Bacille Calmette-Guerin (rBCG), as a fusion protein with coccidian rhomboid antigen was constructed to track rBCG in vivo in chickens in this study. Immunization of chickens with one dose of rBCG pMV361-Rho/EGFP induced humoral immune response. The colonization of rBCG in liver, spleen, lung, kidney and caecum was observed by laser confocal microscopy. Real-time quantitative RT-PCR showed a rise expression level of rhomboid protein on the 7th day and a peak on the 14th day and disappearance on the 28th day after immunization. These results have significant implications for the development of rBCG vaccines against avian coccidiosis. Supported by Grants from the Foundation of the Jilin Provincial Science and Technology Department of China (Grant No. 20050211-2) and the National Natural Science Foundation of China (Grant No.30170696, 30500370 and 30671580).     

Evaluation of deleted in malignant brain tumors 1 (DMBT1) gene expression in bladder carcinoma cases: preliminary study

This study was undertaken to evaluate the expression of DMBT1 in bladder cancer and its correlation with clinico-pathological parameters analyzed in bladder carcinoma patients. We investigated DMBT1 in 56 paraffin embedded specimens of transitional cell carcinoma of the urinary bladder. We assessed DMBT1 gene expression at mRNA level by RT-PCR. Our results show 100% expression of DMBT1 in bladder carcinoma samples. Due to this preliminary results; gene expression was compared to tumor grade, and a significant difference was detected between grade 1 and 3 (p?=?0.028). The down-regulation of DMBT1 gene expression in carcinomas suggests the possible role in bladder cancer.     

野桑蚕谷胱甘肽-S-转移酶（GSTs）基因的诱导表达定量分析

谷胱甘肽-S-转移酶（GSTs）在机体的解毒代谢和抗氧化中起重要作用。为了从分子水平上探究野桑蚕Bombyx mandarina对杀虫剂抗性的产生机理,本研究采用实时荧光定量RT-PCR方法,对GSTs基因在正常饲养野桑蚕5龄幼虫及用敌敌畏和溴氰菊酯处理5龄幼虫不同组织中的转录水平进行检测,并采用Actin3内源参照基因对检测结果进行归一化处理。结果表明：用敌敌畏和溴氰菊酯处理5龄幼虫24 h后,GSTs基因在各组织中的诱导转录水平存在差异,但GSTs基因在脂肪体中的诱导转录水平最高,其次为中肠,可能与这2种组织是野桑蚕主要的解毒器官有关。其中,GSTe2和GSTe5基因诱导转录水平相对较高,推测这2个基因可能主要参与野桑蚕对外源物质的解毒代谢。