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61.
Platelet-derived growth factor activates mitogen-activated protein kinase in isolated caveolae 下载免费PDF全文
Pingsheng Liu Yun-shu Ying Richard G. W. Anderson 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(25):13666-13670
The ability of a peptide hormone to affect many different intracellular targets is thought to be possible because of the modular organization of signal transducing molecules in the cell. Evidence for the presence of signaling modules in metazoan cells, however, is incomplete. Herein we show, with morphology and cell fractionation, that all the components of a mitogen-activated protein kinase pathway are concentrated in caveolae of unstimulated human fibroblasts. Addition of platelet-derived growth factor to either the intact cell or caveolae isolated from these cells stimulates tyrosine phosphorylation and activates mitogen-activated protein kinases in caveolae. The molecular machinery for kinase activation, therefore, is preorganized at the cell surface of quiescent cells. 相似文献
62.
通过期末考试成绩对实验班与参照班学生语言基础知识和应用能力2方面进行比较,分析产生差异的原因,以便更合理地利用现有教学资源,取得最佳教学效果。 相似文献
63.
Senile vascular dementia refers to organic loss of intellectual function due to cerebral damages caused by insufficient blood supply. The following is a summaryon achievements in its etiology, pathogenic mechanism, type identification and treatment in TCM, and the compound formulas, special formulas and drugs, and thepatent drugs used successfully for its treatment. 相似文献
64.
近年来的研究结果发现由Th1/Th2细胞分泌的淋巴因子与妊娠高血压综合征联系密切 ,可能参与了其病因及病理生理过程 ,对它的深入研究有利于妊娠高血压综合征诊断、治疗水平的提高 相似文献
65.
Prof. Shan Zhaowei ( 单兆伟 ), the author's teacher, has been engaged in TCM for more than 30 years, with profound knowledge in the treatment of diseases of the spleen and stomach, which are introduced in the following. 相似文献
66.
Role of mast cells and monoamines in the thrombocytopaenia and mortality elicited by tumour necrosis factor in mice. 下载免费PDF全文
We explored the thrombocytopaenia elicited by the i.v. injection of mouse recombinant tumour necrosis factor (TNF) in mice. Injection of 10 micrograms of TNF led to a thrombocytopaenia (evident after 0.5 hr) which was caused by decreased platelet survival, as seen by the injection of labelled platelets. TNF-induced thrombocytopaenia was not prevented by heparin, nor by depletion of either fibrinogen or C'. TNF-induced thrombocytopaenia was markedly attenuated in mice treated with reserpine, an agent that depletes monoamines from mast cells and other cells, and in the mast-cell-deficient WWv mice. In vitro, TNF elicited a modest release of monoamine from peritoneal mast cells and from a mast cell line. When mice are injected with 3H-serotonin (3H-5HT) before TNF, TNF injection increased the plasma 3H-5HT content 1 hr later, modifications absent in reserpine pretreated or mast-cell-deficient mice. 3H-5HT content of the small intestine was markedly depleted in TNF-injected mice, suggesting that this organ is the source of the plasma 3H-5HT. Drop in body temperature and mortality induced by TNF were also attenuated in mast-cell-deficient, and in reserpine pretreated mice. These results indicate that TNF can induce a release of monoamines from mast cells, mainly from those of the small intestine, a process that contributes to TNF-induced thrombocytopaenia and mortality. 相似文献
67.
N┐(4┐乙氧苯基)苯甲酰胺类化合物的合成及抗炎、抗变态反应活性研究周玉新1)党永红刘建飞2)徐颖刘百里(沈阳药科大学制药系,沈阳110015)郑文义(东北第六制药厂,沈阳110043)1981年,刘百里等〔1,2〕发现和研制的新药益肤酰胺,经药理实... 相似文献
68.
69.
目的 探讨超声刀在腹腔镜胆囊切除术中的应用价值。方法 将 86例腹腔镜胆囊切除术患者随机分为超声刀组 ( 3 4例 )与电刀组( 5 2例 ) ,分别使用超声刀与单极电刀完成手术 ,比较术中及术后的效果。结果 86例手术顺利完成 ,无中转开腹。手术时间分别为 ( 4 5±7)min和 ( 62± 9)min(P <0 0 1) ,术中出血量分别为 ( 5± 0 .8)ml和 ( 2 0± 5 )ml(P <0 .0 1) ,术后肠道功能恢复时间分别为 ( 2 0± 4)h和 ( 2 4±6)h(P <0 0 1) ,两组均无胆瘘发生。结论 超声刀在腹腔镜胆囊切除术中较电刀更快捷 ,出血更少 ,术后恢复更快 相似文献
70.
F. Debiais Dr. L. -G. Durand Z. Guo R. Guardo 《Medical & biological engineering & computing》1997,35(5):480-485
The basic parameters of the spectrogram, the Choi-Williams, and the Bessel distributions are adjusted to provide the best
time-frequency representations (TFRs) of the simulated murmur signals of mitral stenosis, mitral regurgitation, aortic stenosis,
aortic regurgitation, and of two musical murmurs. The initial adjustment of the parameters of each TFR technique is performed
by computing and minimising the relative averaged absolute error between the frequency contours at −3dB and −10dB of each
TFR of the simulated murmurs and those of the theoretical distribution of the same signals. The results show that the spectrogram
generally provides very good to excellent performance in representing the TFRs of stenotic and regurgitant murmurs. Improvements
provided by the Choi-Williams and the Bessel distributions are minor but not systematic for the two signal-to-noise ratios
tested (0 and 30 dB) and for the two frequency contours estimated. The Bessel and the Choi-Williams distributions provide
the best performance for the musical murmurs. The study shows that although a single technique cannot be optimal for all six
murmurs, the spectrogram using a Hamming window of 30 ms is an acceptable compromise to detect the six simutated heart murmurs. 相似文献