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991.
Proinflammation represents a pathophysiological state on the early stage of a number of diseases, especially the infectious and immunological ones. In recent years, proinflammation has attracted much attention, and the term 損roinflammation factors?appears frequently in the literature. While investigating leukemia and leukemic cells from the angle of 損roinflammation state? we got some intriguing findings, e.g. we detected the significantly elevated expression of proinflammation factor IL-18 in patients with acute myeloid leukemia (AML), which could up-regulate matrix metalloproteinases (MMP) and specific tissue inhibitors (TIMPs). The increased MMP may play a role in the aggressiveness of myeloid leukemic cells, and be associated with a poor prognosis. This phenomenon reflects an ignored aspect of leukemia. Investigations from the angle of 損roinflammation state?have broaden the fields of tumor and leukemia study.  相似文献   
992.
The cardiac protective role of a novel erythro-cyte-derived depressing factor (EDDF) on spontaneous hy-pertensive rats (SHR), calcium overload (CaO) rats and Wistar rats and its mechanism was evaluated. Mean artery pressure (MAP), heart rate (HR) and LVdp/dtmax were measured by physiological recorder. The effect of EDDF on the Ca2+-ATPase activity in myocardial sarcoplasmic reticu-lum (SR) of CaO rats was determined by inorganic phos-phate assay. Calcium transport in myocytes was measured by 45Ca2+ radioactive isotope measurement. The phosphoryla-tion levels of extracellular signal-regulated protein kinases (ERK1/2) in myocardial tissue of SHR and CaO rats were measured by Western blot method. And the ultrastructures of cardiac muscle cells were observed with the transmission electron microscope. The results indicated that EDDF could significantly decrease MAP, HR and LVdp/dtmax in a dose dependent manner (P < 0.05). It seems that the mechanism might relate with activating the Ca2+-APTase, enhancing the uptake and release of Ca2+ from SR (P < 0.05), decreasing the phosphorylation levels of ERK1/2 of myocytes (P < 0.01) and lightening the ultrastructural lesion of cardiac muscle cells. In CaO rats, the Ca2+-ATPase activity decreased clearly com-pared to control (64.99 7.16 vs 94.48 7.68 nmol·min-1 ·mg-1 protein, P < 0.01), while EDDF (100 mg/mL) could significantly increase the activity (87.93 ?9.54 vs 64.99 ?7.16, P < 0.05, n = 7). Both uptake and release rate of Ca2+ (祄ol 45Ca2+/g protein/min) from myocardial SR of CaO rats re-markably decreased compared to control (32.40 ?2.70 and 15.46 ?1.49 vs 61.09 ?10.89 and 25.47 ?4.29, P < 0.05); EDDF (100 mg/mL) could significantly stimulate their activi-ties (50.48 6.76 and 21.76 2.75 vs 32.40 2.70 and 15.46 1.49, P < 0.05). EDDF could evidently down-regulate the phosphorylation of ERK1/2 in myocardial tissue from SHR and CaO rats (P < 0.01), lighten the ultrastructural lesion of cardiac muscle cells of SHR as well. It is concluded that EDDF seems to play protective roles on both structure and function of heart, which closely related with amelioration of Ca2+ transport and inhibition of Ca2+-MAP kinase pathway.  相似文献   
993.
The composite structure of the mammalian skull, which forms predominantly via intramembranous ossification, requires precise pre- and post-natal growth regulation of individual calvarial elements. Disturbances of this process frequently cause severe clinical manifestations in humans. Enhanced DNA binding by a mutant MSX2 homeodomain results in a gain of function and produces craniosynostosis in humans. Here we show that Msx2-deficient mice have defects of skull ossification and persistent calvarial foramen. This phenotype results from defective proliferation of osteoprogenitors at the osteogenic front during calvarial morphogenesis, and closely resembles that associated with human MSX2 haploinsufficiency in parietal foramina (PFM). Msx2-/- mice also have defects in endochondral bone formation. In the axial and appendicular skeleton, post-natal deficits in Pth/Pthrp receptor (Pthr) signalling and in expression of marker genes for bone differentiation indicate that Msx2 is required for both chondrogenesis and osteogenesis. Consistent with phenotypes associated with PFM, Msx2-mutant mice also display defective tooth, hair follicle and mammary gland development, and seizures, the latter accompanied by abnormal development of the cerebellum. Most Msx2-mutant phenotypes, including calvarial defects, are enhanced by genetic combination with Msx1 loss of function, indicating that Msx gene dosage can modify expression of the PFM phenotype. Our results provide a developmental basis for PFM and demonstrate that Msx2 is essential at multiple sites during organogenesis.  相似文献   
994.
In most mammals, male development is triggered by the transient expression of the Y-chromosome gene, Sry, which initiates a cascade of gene interactions ultimately leading to the formation of a testis from the indifferent fetal gonad. Several genes, in particular Sox9, have a crucial role in this pathway. Despite this, the direct downstream targets of Sry and the nature of the pathway itself remain to be clearly established. We report here a new dominant insertional mutation, Odsex (Ods), in which XX mice carrying a 150-kb deletion (approximately 1 Mb upstream of Sox9) develop as sterile XX males lacking Sry. During embryogenesis, wild-type XX fetal gonads downregulate Sox9 expression, whereas XY and XX Ods/+ fetal gonads upregulate and maintain its expression. We propose that Ods has removed a long-range, gonad-specific regulatory element that mediates the repression of Sox9 expression in XX fetal gonads. This repression would normally be antagonized by Sry protein in XY embryos. Our data are consistent with Sox9 being a direct downstream target of Sry and provide genetic evidence to support a general repressor model of sex determination in mammals.  相似文献   
995.
996.
浅谈对电梯检验的认识   总被引:4,自引:0,他引:4  
分析了电梯的控制系统及安全部件在检验中的注意事项以及澄清电梯检验中容易混淆的概念。  相似文献   
997.
采用气相色谱-质谱联用技术,首次对木果楝叶子和果实挥发油进行了成分分析,从木果楝叶子和果实分别鉴定出了33和36种化合物,分别占挥发油的99.11%和97.63%.两个部位中挥发油化学组成各有异同,但其主要成分均是倍半萜类化合物b-桉叶烯和γ-桉叶烯.本研究结果可为木果楝的综合开发利用提供理论依据.  相似文献   
998.
马达 《科学之友》2007,(9B):168-169
通过对临汾段店工业园区控制性详细规划设计理念和功能布局的论述,提出以中、高技术产业为主,集科、工、贸于一体,多功能、综合性的现代化、花园式的城市功能区是工业园区发展的方向。  相似文献   
999.
一种基于星型子网的片上网络结构研究   总被引:2,自引:0,他引:2  
赵宏智  王景存  王沁  刘恩涛 《系统仿真学报》2007,19(22):5336-5338,5341
提出了一种基于星型子网的片上网络结构SSBM NoC(Star-Subnet-Based-MeshNoC),它在已有网格状结构的基础上引入了子网的概念,并在子网内使用星型拓扑结构来连接一个交换机与四个网络节点。OPNET仿真结果表明,在同等网络规模下SSBM结构较之单纯的二维网格状结构具有更少的端到端通信延时,并仅使用其1/4数目的交换机,而交换机的负载则不到其两倍。  相似文献   
1000.
Hardware system design for UHF surface velocities radar   总被引:1,自引:0,他引:1       下载免费PDF全文
UHF surface velocities radar is developed based on the successful ocean state measuring and analyzing radar system. The design method for UHF radar system is presented. It is designed to operate at UHF channel, and the transmit power is under 5W. Maximum range of field test over fresh water can be a kilometer. The field tests at Tangsun River and at Majiatan and Gaohazhou proved that USVR System can be used successfully.  相似文献   
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