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951.
OBJECTIVE: To study the correlation of development and survival with amplification of c-erbB2 oncogene in endometrial carcinoma. METHODS: The amplification and expression of c-erbB2 oncogene were determined from formalin-fixed, paraffin-embedded tissues of 25 normal, 31 hyperplastic, and 72 malignant samples of the endometrium in 128 patients, using differential polymerase chain reaction (DPCR) and an immunohistochemical technique. RESULTS: Amplified c-erbB2 (2 to 12 copies) were found in two of 25 (8.0%) normal, 15 of 31 (48.4%) hyperplastic, and 45 of 72 (62.5%) malignant samples. When the results of DPCR were compared with those of the immunohistochemical method, the negative findings concide well with one another, i.e., nonamplification was associated with the absence of immunoreactivity. It was noted that the amplified c-erbB2 was found more significantly in complex and a typical hyperplasias than in simple hyperplasias. The high-level c-erbB2 amplification (at least five copies) was significantly correlated with the histological grade of endometrial carcinoma and vascular or lymphatic invasion. No correlation was seen between c-erbB2 amplification and overall survival in the present group of patients. CONCLUSIONS: The amplified c-erbB2 may play a potential role in the early development of some endometrial carcinomas. The high-level c-erbB2 amplification may identify a subset of aggressive endometrial carcinoma that involves vascular or lymphatic invasiveness and poor cell differentiation playing the role of a marker for clinical prognosis. 相似文献
952.
强度调制型光纤传感器信号补偿技术的现状与应用 总被引:8,自引:2,他引:6
简要地介绍了强度调制光纤传感器的特点,着重分析和比较目前国内外五种有代表性的强度调制型光纤传感器信号补偿方法及其应用状况. 相似文献
953.
Na_2O-Al_2O_3-SiO_2系统霞石微晶玻璃机械强度的研究 总被引:1,自引:0,他引:1
霞石微晶玻璃是一种高强度的新型无机非金属材料.本文以Na2O-Al2O3-SiO2系统为基础,引入晶核剂和复合澄清剂,经高温熔制和两步热处理制备的霞石微晶玻璃,具有较高的抗压和抗折强度.结果表明,霞石微晶玻璃的机械强度与霞石晶体及试样的结构有关,也与微晶化热处理的时间有关。 相似文献
954.
955.
氧化铈对改善ZTM陶瓷性能的作用 总被引:5,自引:0,他引:5
工业用电熔莫来石原料中含有钾、钠等杂质,而化学法制备的高纯莫来石中这些杂质含氏,因而以氧化锆增韧这两种莫来石制备陶瓷,发现其力学性能温度的变化趋势有较大差异。后者随温度升高力学性能反而有所增长。研究发现这一变化与原料中杂质含量有关。 相似文献
956.
本文介绍了用αβ谱仪系统同时测量αβ谱、实现Rn/Th子体补偿、确定超铀α核素气溶胶体积活度及人工放射性气溶胶总β体积活度的技术途径。利用RaA、RaC′a峰的二段时间计数可确定空气中RaA、RaB、RaC的气溶胶体积活度,相应的,也能给出RaB、RaC对总β计数的贡献。根据一般环境条件下的平衡比,用ThC′的。计数修正Th子体对αβ测量的影响。 ̄[239]pu或/和 ̄[241]Am人工核素的α计数,可通过两段时间分别扣除RaA、RaC′拖尾的方法确定;β计数分别扣除Rn/Th子体β贡献即可确定。在本文规定的测量条件下,对室内天然Rn子体水平在15Bq/m ̄3以下,超铀α核素气溶胶体积活度的测量下限可达到0.1Bq/m ̄3;即使在75Bq/m ̄3环境下,人工核素总β的测量下限也可达lBq/m ̄3以下。 相似文献
957.
Nucleoside-diphosphate kinase (NDP kinase), a key enzyme in nucleotide metabolism, is also known to be involved in growth and developmental control and tumor metastasis suppression. Interestingly, we find that coexpression of NDP kinase with Taz1, a Tar/EnvZ chimera, in the absence of its native signal, can activate a porin gene ompC-lacZ expression in Escherichia coli. Further studies show that NDP kinase can act as a protein kinase to phosphorylate histidine protein kinases such as EnvZ and CheA which are members of the His-Asp phosphorelay signal transduction systems in E. coli. Instead of ATP, the exclusive phosphodonor for histidine kinases, GTP can be utilized in vitro in the presence of NDP kinase to phosphorylate EnvZ and CheA, which then transfer the phosphoryl group to OmpR and CheY, the respective response regulators. The direct involvement of GTP for the phosphorylation of EnvZ through NDP kinase was further demonstrated by the use of a mutant EnvZ, which lost ability to be autophosphorylated with ATP. Phospho-OmpR thus formed can bind specifically to an ompF promoter sequence. These results suggest that NDP kinase may play a physiological role in signal transduction. 相似文献
958.
根据锆钛酸铅压电陶瓷的逆压电效应。设计了以8031单片机为核心的压电陶瓷堆微位移器提高了PZT的线性,从而满足了在天文自适应系统中所要求的精确微位的应用。 相似文献
959.
We studied the long-term clinical course of five patients with chronic manganese intoxication. The mean scores of the King's College Hospital Rating Scale for Parkinson's disease increased from 15.0 +/- 4.2 in 1987 to 28.3 +/- 6.70 in 1991 and then to 38.1 +/- 12.9 in 1995. The deterioration was most prominent in gait, rigidity, speed of foot tapping, and writing. Tissue concentrations of manganese in blood, urine, scalp hair, and pubic hair returned to normal. Follow-up MRIs did not show paramagnetic high-signal intensity on T1-weighted images. The data indicate that clinical progression in patients with manganese parkinsonism continues even 10 years after cessation of exposure. 相似文献
960.
AIM: To study the effect of the angiotensin-converting enzyme (ACE) inhibitors perindopril (Per) and enalaprilat (Ena) on the reactivity of the endothelium in normal rats. METHODS: Male rats were treated intragastrically with Per (2 mg.kg-1.d-1) or placebo (n = 18) for 6 wk. Aorta was isolated for experiment. Another set of isolated aortic rings with and without endothelium were incubated with Ena (0.1 mumol.L-1) for 30 min. Responses to acetylcholine, serotonin, phenylephrine, sodium nitroprusside (SN), and nitroglycerin (Nit) were observed. RESULTS: Endothelium-dependent relaxation to acetylcholine was augmented in aortic rings from rats treated with Per in comparison with control. The IC50 value (95% confidence limits) decreased from 3.8 (0.56-26.1) mumol.L-1 (control group) to 0.98 (0.28-3.41) mumol.L-1 (Per-treated group). The maximal relaxation was augmented from 62 +/- 9% to 78 +/- 10% (P < 0.01). However, the responses to the endothelium-independent vasodilators, SN and Nit, were similar. Serotonin- and phenylephrine-induced contractions were decreased, which were influenced by basal release of endothelium-derived relaxing factor (EDRF). EC50 values was 6.1 (2.6-14.4) nmol.L-1 vs 8.3 (3.6-18.8) nmol.L-1 in comparison with control group and Per-treated group. The maximal contraction was decreased from 2.42 +/- 0.29 g (control group) to 1.96 +/- 0.25 g (treated group) (P < 0.01). Similar results were found in incubation with Ena. CONCLUSION: Ena and Per enhanced the basic release of EDRF from vascular endothelium. 相似文献