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MicroRNAs (miRNAs) are non-coding RNAs that regulate basic cellular processes and are associated with cancer characteristics. The aim of this review is to summarize the principles of miRNA biogenesis and function and to describe their contribution to tumor development, especially in uro-oncology. Therefore a PubMed search was conducted. Up to March 2009 approximately 4,500 miRNA-related articles were cited in this database. Studies of miRNA expression and functional analyses prove their impact in carcinogenesis and their potential as diagnostic or prognostic markers or as novel therapeutic targets. Only a few miRNA-related studies have been published in uro-oncology so far. Although tumor-specific miRNA expression has been shown for urological neoplasms, the contradicting data show that miRNA research is still in its infancy in this field. A systematic elucidation of characteristic miRNA abnormalities could decisively improve diagnostics as well as therapy of urological tumors.  相似文献   
23.
Inflammatory mechanisms play a key role in the pathogenesis of type 1 diabetes. Individuals who progress to type 2 diabetes display features of low-grade inflammation years in advance of disease onset. This low-grade inflammation has been proposed to be involved in the pathogenetic processes causing type 2 diabetes. Mediators of inflammation such as tumor necrosis factor-alpha, interleukin (IL)-1beta, the IL-6 family of cytokines, IL-18, and certain chemokines have been proposed to be involved in the events causing both forms of diabetes. IL-6 has in addition to its immunoregulatory actions been proposed to affect glucose homeostasis and metabolism directly and indirectly by action on skeletal muscle cells, adipocytes, hepatocytes, pancreatic beta-cells, and neuroendocrine cells. Here we argue that IL-6 action-in part regulated by variance in the IL-6 and IL-6alpha receptor genes-contributes to, but is probably neither necessary nor sufficient for, the development of both type 1 and type 2 diabetes. Thus, the two types of diabetes are also in this respect less apart than apparent. However, the mechanisms are not clear, and we therefore propose future directions for studies in this field.  相似文献   
24.
Mitropoulos  KA; Martin  JC; Reeves  BE; Esnouf  MP 《Blood》1989,73(6):1525-1533
The endogenous, negatively charged surface that induces activation of the contact coagulation factors was investigated in plasmas taken from women in late pregnancy and control subjects of child-bearing age. The plasmas from the two groups of subjects were incubated at 4 degrees C for 24 hours either in plastic or in glass tubes and the factor VII coagulant activity (VIIc) was assayed in the treated plasmas. The activation of factor VII under these conditions involves the generation of enzymes derived from factor XII (XIIa). The contact surface is rate- limiting for the activation of factor VII in the plasmas in both groups of subjects and can be supplemented by large multilamellar liposomal vesicles carrying the appropriate density of negative charge. The size of these vesicles is within the range of sizes of the large lipoprotein particles (chylomicrons, very low and intermediate-density lipoproteins). The relationship between the density of negative charge on the liposomal vesicles and VIIc was similar in the late pregnancy and the control plasmas incubated in plastic tubes. At a saturating density of negative charge the observed relative VIIc was similar in both sets of plasmas. The incubation of late pregnancy or control plasma in plastic tubes in the presence of sodium stearate caused VIIc to increase with increasing concentration of the added fatty acid. These results suggest that large lipoprotein particles carrying the appropriate free fatty acid at a sufficient density of negative charge could provide the contact surface that induces the generation of factor XIIa and the subsequent activation of factor VII. Moreover, plasmas from women in late pregnancy have a higher concentration of potential surface and a higher density of negative charge than the plasmas from nonpregnant women.  相似文献   
25.
<正>电子结肠镜检查是诊断和筛查肠道疾病常用、有效的检查方法之一,而进行结肠镜检查的基本条件是清洁良好的肠道准备。虽然近年来肠道清洁剂的商品化和肠道准备方法的标准化不断完善,但仍有约30%的患者肠道准备不充分[1-3]。不充分的肠道准备会导致检查时间延长、操作难度增加、病变检出率降低、漏诊及检查费用增加等。肠道准备的质量多与患者的依从性有关,加强对患者肠道准备相关知识的教育,增强患者对肠道准备方法的认识和理解,可以提高检查前的肠道准备质量[4  相似文献   
26.
A biomechanical analysis of the Ilizarov external fixator   总被引:8,自引:0,他引:8  
Five configurations of the Ilizarov fixator were analyzed in vitro. The overall stiffness, shear stiffness, and axial motion of the fracture site were determined. The data were compared with the results of eight conventional one-half frame fixators previously tested in the same manner. The Ilizarov fixator allowed significantly more axial motion at the fracture site during axial compression than the other fixators tested. The overall stiffness and shear rigidity of the Ilizarov external fixator were similar to those of the one-half pin fixators in bending and torsion. The stability of the Ilizarov fixator was a function of bone position within the fixator rings and fixation wire tension. The use of olive stop wires increased the shear resistance of the Ilizarov system.  相似文献   
27.
A practical, rapid, reliable and sensitive method for the isolation and determination of the allergens tuliposide A and α-methylene-γ-butyrolactone (tulipalin A), by reversed-phase high-performance liquid chromatography (RP-HPLC), has been developed in order to select Alstroemeria species for breeding purposes. From the aqueous extracts of flowers, stems and leaves, of several Alstroemeria species, the contents of 6-tuliposide A and tulipalin A were determined by isocratic RP-HPLC, using distilled water as mobile phase. The compounds were detected by an UV detector at 208 nm. Differences in 6–tuliposide A and tulipalin A content were found among the species investigated, with the highest concentrations in stems and flowers. The absence of other tuliposides (e.g., 1-tuliposide A, 1- and 6-tuliposide B) in extracts was proven by TLC, RP-HPLC, 1H- and 13C-NMR. 6-Tuliposide A and tulipalin A were identified by 1H- and 13C-NMR and comparison with authentic material, respectively. With this HPLC method, it is possible to investigate a large number of plants for their contents of tuliposide A and tulipalin A, within a minimum of time, and to isolate them directly from aqueous extracts.  相似文献   
28.
目的:验证二甲双胍治疗抗精神病药引起的血脂异常的疗效和安全性。方法:将两项随机、安慰剂的 对照研究纳入分析。共有201例服用抗精神病药物后出现血脂异常的首发精神分裂症患者,并将其分为1 000 mg/d 二甲双胍组(以下简称为二甲双胍组,n=103)和安慰剂组(n=98),观察24周。在基线、治疗后第12周和第24周进行 临床症状及体重、血糖、血脂等代谢指标的评估。结果:二甲双胍治疗后,二甲双胍组和安慰剂组之间低密度脂 蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)的平均差异从基线时的0.16 mmol/L,降低到第24周结束时的 –0.86 mmol/L,降低了1.02 mmol/L,差异有统计学意义(P<0.01)。而24周结束时,二甲双胍组LDL-C≥3.37 mmol/L的 患者有25.3%,显著低于安慰剂组24周结束时的64.8%(P<0.01)。与安慰剂组相比,二甲双胍组的体重、体重指数、 胰岛素、胰岛素抵抗指数、总胆固醇、三酰甘油和高密度脂蛋白胆固醇也有显著变化,差异均有统计学意义(均 P<0.05)。治疗对体重和胰岛素抵抗的影响出现在第12周,并且在第24周进一步改善,但对改善血脂异常的作用在第 24周结束时才出现。结论:二甲双胍治疗对于改善抗精神病药物引起的血脂异常和胰岛素抵抗是有效的,并且改善 抗精神病药物诱导的胰岛素抵抗出现的时间早于降低血脂异常的时间。  相似文献   
29.
Patients with hairy cell leukemia (HCL) and chronic lymphocytic leukemia (CLL) were treated with recombinant interferon alpha A (rIFN- alpha A). The binding of iodinated recombinant interferon-alpha to baseline samples of peripheral blood mononuclear cells (PBMCs) from the leukemia patients was compared with clinical responsiveness to rIFN- alpha A. HCL patients (8/10) responded to rIFN-alpha A therapy, whereas none (0/10) of the CLL patients studied responded. The PBMCs from the eight responsive HCL patients bound approximately twice as much iodinated interferon as the PBMCs from nonresponsive CLL patients. This difference was due to more high-affinity receptors per cell with no difference in the affinity of the interferon-receptor interaction. However, because PBMCs from HCL patients were larger than PBMCs from CLL patients, the cell surface receptor density was similar. The leukemic cells from one of the two nonresponsive HCL patients bound iodinated interferon similarly to the cells from the responsive HCL patients, whereas the leukemic cells from the other nonresponsive HCL patient bound considerably less. The rapidity of response of the HCL patients did not correlate with the level of binding of iodinated interferon. Our results suggest that the absolute number of interferon receptors per cell may be only one of several important parameters in the response to rIFN-alpha A therapy, and that the responsiveness of a particular lymphoproliferative disease or a particular patient to rIFN- alpha A therapy cannot be predicted or explained solely by the degree of interaction between IFN and its cell surface receptor.  相似文献   
30.
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