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941.
近年来,因在退行性或遗传性等疾病中潜在的治疗前景,成体干细胞可塑性引起众多学者的广泛兴趣。有许多报道显示骨髓源干细胞植入体内可生成多种组织细胞,但到目前为止,成体干细胞可塑性尚存争议,尤其是关于成体干细胞体内分化成皮肤组织的报道较少且意见不一。本工作,自成年BALB/C小鼠的骨髓中分离获得并体外培养扩增多能间充质干细胞,将适量的供体BALB/C小鼠骨髓源多能间充质干细胞和一定量的C57BL/6小鼠骨髓细胞经尾静脉共同植入经致死量照射的成年C57BL/6小鼠。40天后,观察到受体C57BL/6小鼠背部出现白色毛发,逐渐扩展至3—4cm^2,同时还出现在颈部和腹部,取该部位的皮肤组织进行免疫组化检测及RT—PC汉检测。蛋白水平和基因水平的结果均显示受体C57BL/6小鼠出现白色毛发处的皮肤组织为BALB/C来源。首次直接证明了成体骨能源多能间充质干细胞体内在一定条件下可以分化成皮肤干细胞及皮肤组织。不仅为研究体内诱导皮肤分化的机制也为鉴定成体多能干细胞提供了一个模型,也为成体干细胞可塑性理论提供了新的依据。  相似文献   
942.
本文记述分布湖南省城步县的长柄茧蜂属Streblocera两新种,赵氏长柄茧蜂Streblocera chaoi You et Zhou,sp.nov.,何氏长柄茧蜂Strenlocera hei You et Xiao,sp.nov.,模式标本存于湖南农学院。  相似文献   
943.

Purpose

Elevated plasma fibrinogen levels are associated with tumor progression and poor outcomes in different cancer patients. The objective of this study was to investigate the clinical and prognostic value of preoperative plasma fibrinogen levels in patients with operable breast cancer.

Methods

Two hundred and twenty-three patients diagnosed with breast cancer were retrospectively evaluated in this study. Plasma fibrinogen levels were examined before treatment and analyzed along with patient clinicopathological parameters, disease-free survival (DFS) and overall survival(OS). Both univariate and multivariate analyses were performed to identify the clinicopathological parameters associated with DFS and OS.

Results

Elevated preoperative plasma fibrinogen levels were directly associated with age of diagnose (≤47 vs. >47, p<0.001), menopause (yes vs. no, p<0.001), tumor size (T1&T2 vs.T3&T4, p = 0.033), tumor stage (Ⅰvs.Ⅱvs.Ⅲ, p = 0.034) and lymph node involvement (N = 0 vs. 1≤N≤3 vs. N≥4, p<0.001), but not with histological grade, molecular type and other Immunohistochemical parameters(ER, PR, HER2 and Ki-67). In a univariate survival analysis, tumor stage, tumor size, lymph node involvement (p<0.001/ p<0.001)and plasma fibrinogen (p<0.001/ p<0.001) levels were associated with disease-free and overall survival, but just lymph nodes involvement (p<0.001, hazard ratio [HR] = 2.9, 95% confidence interval [CI] = 1.6–5.3/ p = 0.006, HR = 3.2, 95% CI = 1.4–7.3) and plasma fibrinogen levels (p = 0.006, HR = 3.4, 95% CI = 1.4–8.3/ p = 0.002, HR = 10.1, 95% CI = 2.3–44.6) were associated with disease-free and overall survival in a multivariate survival analysis, respectively.

Conclusions

This study demonstrates that elevated preoperative plasma fibrinogen levels are associated with breast cancer progression and are independently associated with a poor prognosis in patients with operable breast cancer.  相似文献   
944.
为了观察Nestin在新生SD大鼠中枢神经系统中的分布,探讨神经干细胞在新生鼠的分布.采用免疫荧光法,显示含神经干细胞特征性的标志物Nestin的阳性结构在新生SD大鼠中枢神经系统中的分布.结果表明在新生SD大鼠中枢神经系统中,Nestin在前脑、脑干和小脑的各个部位均有表达,阳性结构多为纤细的纤维状突起,分布密集,标记强度多为中等强度,分布相对比较均匀.在脊髓实质的Nestin免疫阳性产物明显减少,分布稀疏,染色也较浅,中央管Nestin免疫染色阳性的室管膜细胞很少,但在脊髓中央管的背侧(延髓见于腹侧和背侧)可见到“喷泉”状免疫强阳性纤维束垂直伸展,直达软膜.由此可得出结论:新生SD大鼠中枢神经系统的广泛脑区均存在大量的神经干细胞,而脊髓的神经干细胞数目较少,提示神经干细胞在生后从神经系统的尾端开始逐渐减少.  相似文献   
945.
The present study was carried out to observe the protective effects of αB-crystallin protein on hydrogen peroxide (H2O2)-induced injury in rat myocardial cells (H9c2) and to investigate the mechanisms of these protective effects at the cellular level, which could provide the experimental basis for future applications of αB-crystallin in the treatment of cardiovascular disease. Western blotting was used to measure the expression of αB-crystallin in cultured H9c2 cells in vitro. A αB-crystallin recombinant expression vector, pcDNA3.1-Cryab, was constructed to transfect H9c2 cells for the establishment of cells that stably expressed αB-crystallin. A tetrazolium-based colorimetric assay (MTT test) was used to measure changes in the viability of the H9c2 cells at 1, 2, 3 and 4 h after induced by 150 μM H2O2 to establish a model of H2O2 injury to cells. H2O2 was applied to H9c2 cells that were stably transfected with αB-crystallin, and the effect of αB-crystallin overexpression on the viability of myocardial cells subjected to H2O2-induced injury was measured by the MTT assay. The effect of αB-crystallin overexpression on the H2O2-induced injury of H9c2 cells was also analyzed by flow cytometry. The mitochondrial components and cytoplasmic components of H9c2 cells were separated, and western blotting was used to measure the effect of αB-crystallin overexpression on the release of cytochrome c from the mitochondria. Western blotting was also used to measure the effect of αB-crystallin overexpression on the expression of the anti-apoptosis protein Bcl-2 and components of the phosphatidylinositol 3-OH kinase (PI3K)/AKT pathway. The αB-crystallin recombinant expression vector pcDNA3.1-Cryab successfully transfected H9c2 cells, and H9c2 cells that were stably transfected with αB-crystallin were established after G418 selection. The measurements carried out by western blotting showed that αB-crystallin proteins are expressed in normal H9c2 cells, but the proteins’ expression was much higher in pcDNA3.1-Cryab transfected cells (P < 0.01). The MTT assays showed that 4 h of H2O2 treatment induced significant injury in H9c2 cells (P < 0.01), but αB-crystallin overexpression can effectively antagonize the H2O2-induced injury to H9c2 cells (P < 0.05). The results of flow cytometry analysis showed that αB-crystallin overexpression can significantly reduce apoptosis in H2O2-injured H9c2 cells (P < 0.05). The results of western blotting showed that αB-crystallin overexpression in myocardial cells can reduce the H2O2-induced release of cytochrome c from the mitochondria (P < 0.05), antagonize the H2O2-induced downregulation of Bcl-2 (P < 0.05) and magnify the decrease in phosphorylated AKT levels induced by H2O2 injury (P < 0.05). The overexpression of αB-crystallin has a protective effect on H2O2-injured H9c2 cells, and αB-crystallin can play a protective role by reducing apoptosis, reducing the release of cytochrome c from the mitochondria and antagonizing the downregulation of Bcl-2 expression. The protective effects of αB-crystallin may be related to the PI3K/AKT pathway.  相似文献   
946.
To combat the possibility of a zoonotic H5N1 pandemic in a timely fashion, it is necessary to develop a vaccine that would confer protection against homologous and heterologous human H5N1 influenza viruses. Using a replicating modified vaccinia virus Tian Tan strain (MVTT) as a vaccine vector, we constructed MVTTHA-QH and MVTTHA-AH, which expresses the H5 gene of a goose-derived Qinghai strain A/Bar-headed Goose/Qinghai/1/2005 or human-derived Anhui Strain A/Anhui/1/2005. The immunogenicity profiles of both vaccine candidates were evaluated. Vaccination with MVTTHA-QH induced a significant level of neutralizing antibodies (Nabs) against a homologous strain and a wide range of H5N1 pseudoviruses (clades 1, 2.1, 2.2, 2.3.2, and 2.3.4). Neutralization tests (NT) and Haemagglutination inhibition (HI) antibodies inhibit the live autologous virus as well as a homologous A/Xingjiang/1/2006 and a heterologous A/Vietnam/1194/2004, representing two human isolates from clade 2.2 and clade 1, respectively. Importantly, mice vaccinated with intranasal MVTTHA-QH were completely protected from challenge with lethal dosages of A/Bar-headed Goose/Qinghai/1/2005 and the A/Viet Nam/1194/2004, respectively, but not control mice that received a mock MVTTS vaccine. However, MVTTHA-AH induced much lower levels of NT against its autologous strain. Our results suggest that it is feasible to use the H5 gene from A/Bar-headed Goose/Qinghai/1/2005 to construct an effective vaccine, when using MVTT as a vector, to prevent infections against homologous and genetically divergent human H5N1 influenza viruses.  相似文献   
947.

Background

Hemorrhagic fever with renal syndrome (HFRS) is highly endemic in mainland China, where human cases account for 90% of the total global cases. Zibo City is one of the most serious affected areas in Shandong Province China with the HFRS incidence increasing sharply from 2009 to 2012. However, the hotspots of HFRS in Zibo remained unclear. Thus, a spatial analysis was conducted with the aim to explore the spatial, spatial-temporal and seasonal patterns of HFRS in Zibo from 2009 to 2012, and to provide guidance for formulating regional prevention and control strategies.

Methods

The study was based on the reported cases of HFRS from the National Notifiable Disease Surveillance System. Annualized incidence maps and seasonal incidence maps were produced to analyze the spatial and seasonal distribution of HFRS in Zibo City. Then spatial scan statistics and space-time scan statistics were conducted to identify clusters of HFRS.

Results

There were 200 cases reported in Zibo City during the 4-year study period. One most likely cluster and one secondary cluster for high incidence of HFRS were identified by the space-time analysis. And the most likely cluster was found to exist at Yiyuan County in October to December 2012. The human infections in the fall and winter reflected a seasonal characteristic pattern of Hantaan virus (HTNV) transmission. The secondary cluster was detected at the center of Zibo in May to June 2009, presenting a seasonal characteristic of Seoul virus (SEOV) transmission.

Conclusion

To control and prevent HFRS in Zibo city, the comprehensive preventive strategy should be implemented in the southern areas of Zibo in autumn and in the northern areas of Zibo in spring.  相似文献   
948.
Guided by co-crystal structures of compounds 15, 22 and 30, an SBDD approach led to the discovery of the 6-methyl pyridone series as a novel class of GKAs that potently activate GK in enzyme and cell assays. Anti-diabetic OGTT efficacy was demonstrated with 54 in a mouse model of type 2 diabetes.  相似文献   
949.
蛋白质的非酶糖化(non-enzymatic glycation)在糖尿病及其并发症的发生发展中起着重要作用。糖化血红蛋白(hemoglobin Alc,HbAlC)已作为糖尿病患者血糖控制的“金标准”。相对而言,同为血红素蛋白的肌红蛋白(myoglobin,Mb),其非酶糖化的研究相对较少。研究发现:非酶糖化能改变Mb的空间构象,且对Mb血红素活性中心产生一定的影响,从而导致Mb各种生物学功能发生一定程度的改变。本文综述非酶糖化对Mb结构与功能的影响的研究现状,旨在阐明Mb非酶糖化后的结构.性质-功能之间的关系及其生物学意义,为糖尿病及其并发症的发病机制研究提供新的线索。  相似文献   
950.
中国特有种大卫鼠耳蝠线粒体D-loop区串联重复序列以81bp为重复单元,重复3~7次。54%的个体具有4个串联重复序列,与5~7个串联重复序列的现有模式具有较大的差异。重复单元的遗传差异受所在位次影响,具有明显的家族性或区域性特点。串联重复序列和相对保守的第一重复单元构建的ML树均形成了3个明显的分支,分别定名为东南区、西南区和南方区。线粒体重复序列区域间的差异暗示其可能经历了多次进化,并以东南区变异最为显著。  相似文献   
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