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1.
Diphasic ventilatory response to hypoxia in newborn lambs 总被引:2,自引:0,他引:2
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Gemma L. Moir-Meyer John F. Pearson Felicity Lose Rodney J. Scott Mark McEvoy John Attia Elizabeth G. Holliday Paul D. Pharoah Alison M. Dunning Deborah J. Thompson Douglas F. Easton Amanda B. Spurdle Logan C. Walker The Australian National Endometrial Cancer Study Group The Hunter Community Study Studies of Epidemiology Risk Factors in Cancer Heredity 《Human genetics》2015,134(3):269-278
4.
Interaction between the Effects of Inside and Outside Na and K on Bullfrog Skin Potential 总被引:2,自引:1,他引:1
Daniel E. Leb Charles Edwards Barry D. Lindley T. Hoshiko with the technical assistance of James A. Dugan 《The Journal of general physiology》1965,49(2):309-320
The composition of the solution bathing one border of the isolated frog skin affects the response of the potential across the skin to changes in the composition of the solution bathing the opposite border. Increasing the K concentration of the inside (corium) bathing solution decreased the sensitivity of the potential to a change in outside Na concentration. Decreasing the outside Na concentration decreased the sensitivity of the potential to a change in inside K concentration. Increasing the total ionic strength of the outside bathing solution or of both bathing solutions decreased the sensitivity of the potential to a change in outside Na concentration. 相似文献
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P Vago S Abdoukhil F Odier H Mion J P Bureau 《Comptes rendus des séances de la Société de biologie et de ses filiales》1987,181(6):658-665
Flow cytometric analysis of cell DNA content in the mouse C 57 BL/6 shows better results with fine needle aspiration than with mechanical dissociation of the tissues. There is no difference fresh and deep frozen stored tissues. In the liver, it has been found two cell populations with different DNA content including diploid and tetraploid cell lines. In the spleen and the thymus, only diploid cells are encountered with different cell cycles belonging to the organ. 相似文献
7.
Oryzalin,a dinitroaniline herbicide,binds to plant tubulin and inhibits microtubule polymerization in vitro 总被引:11,自引:0,他引:11
The effects of oryzalin, a dinitroaniline herbicide, on chromosome behavior and on cellular microtubules (MTs) were examined by light microscopy and immunogold staining, respectively, in endosperm cells from Haemanthus katherinae Bak. Brief treatments with 1.0·10-8 M oryzalin reduced markedly the migration rate of anaphase chromosomes and 1.0·10-7 M oryzalin stopped migration abruptly. Oryzalin (1.0·10-7 M) depolymerized MTs and prevented the polymerization of new MTs at all stages of the mitotic cycle. The chromosome condensation cycle was unaffected by oryzalin. Endothelial cells from the heart of Xenopus leavis showed no chromosomal or microtubular rearrangements after oryzalin treatment. The inhibition by oryzalin of the polymerization of tubulin isolated from cultured cells of Rosa sp. cv. Paul's scarlet was examined in vitro by turbidimetry, electron microscopy and polymer sedimentation analysis. Oryzalin inhibited the rapid phase of taxol-induced polymerization of rose MTs at 24°C with an apparent inhibition constant (K
i
) of 2.59·106 M. Shorter and fewer MTs were formed with increasing oryzalin concentrations, and maximum inhibition of taxol-induced polymerization occurred at approx. 1:1 molar ratios of oryzalin and tubulin. Oryzalin partially depolymerized taxol-stabilized rose MTs. Ligand-binding experiments with [14C]oryzalin demonstrated the formation of a tubulin-oryzalin complex that was time- and pH-dependent. The tubulin-oryzalin interaction (24°C, pH 7.1) had an apparent affinity constant (K
app) of 1.19·105 M-1. Oryzalin did not inhibit taxol-induced polymerization of bovinebrain MTs and no appreciable binding of oryzalin to brain tubulin or other proteins was detected. The results demonstrate pharmacological differences between plant and animal tubulins and indicate that the most sensitive mode of action of the dinitroaniline herbicides is the direct poisoning of MT dynamics in cells of higher plants.Abbreviations MT
microtubule
- SIB
sucrose isolation buffer
- TO
tubulin-oryzalin complex 相似文献
8.
The present study describes the ultrastructural localization of two important circulating schistosome antigens--the circulating anodic antigen (CAA) and the circulating cathodic antigen (CCA)--in livers of mice at various time intervals after infection with Schistosoma mansoni. For the demonstration of these antigens at the electron microscope level use was made of a direct, double immunogold labeling procedure, in which CAA-specific monoclonal antibodies, labeled with 5-nm gold particles, and CCA-specific monoclonal antibodies, labeled with 15-nm gold particles, were used. Both antigens were localized in granules and in inclusion bodies of Kupffer cells and granuloma macrophages and it was found that in these compartments the degree of 5- and 15-nm gold labeling increased with the duration of the infection. Sometimes gold particles were also encountered on the cell surface and in endocytotic vesicles of these cells, in endothelial cells, and in the space of Disse. From these data it was concluded that in the liver CAA and CCA were primarily accumulated in granules and inclusion bodies of Kupffer cells and granuloma macrophages. It is discussed whether at these locations both antigens are degraded by lysosomal enzymes and whether these antigens are complexed with antibodies. 相似文献
9.
下丘脑外侧区注射TRH对大鼠胃酸分泌的影响 总被引:2,自引:2,他引:0
本文采用连续收集胃腔灌流法,观察下丘脑外侧区(LHA)注射促甲状腺激素释放激素(TRH)对大鼠胃酸分泌的影响,并分析TRH在LHA促进胃酸分泌的作用机制。结果表明:(1)LHA注射TRH(1μg)明显地刺激胃酸分泌;(2)预先向LHA注射酚妥拉明(10μg)、美多心安(5μg)及胃泌素抗体1μl(1:640)并不影响TRH的泌酸作用,如预先向LHA注射阿托品(5μg)则可消除TRH的泌酸效应;(3)垂体摘除及肾上腺切除均不影响TRH的泌酸作用;(4)隔下迷走神经切断后,LHA注入TRH的泌酸效应仍然出现,但持续时间显著缩短;腹腔交感神经节摘除后,TRH仍能促进胃酸分泌,但分泌量少而平稳。以上结果提示:LHA是TRH中枢泌酸效应的有关结构之一,其中枢机制是通过胆碱能M受体中介的,腹腔交感神经节和膈下迷走神经是TRH泌酸效应的传出途径。前者引起的泌酸反应出现较早且引起泌酸高峰,但持续时间短;后者则引起低平的持续分泌。 相似文献
10.
大量的研究表明,急性呼吸衰竭时多伴有心血管功能的损害,但有关急性呼吸衰竭对于左室心肌收缩性的影响所知甚少。本文对开胸麻醉犬在低通气引起呼吸衰竭时,左室心肌收缩性的变化进行了观测和分析。结果表明,在实验组(n=9)低通气呼吸(通气量小于160ml/min/kg,PaO_2小于60mmHg)时,心率(HR)、主动脉平均压(MOP)、左室收缩峰压(LV-SP)、左室内压最大上升速率(dP/dt_(max))、节段心肌发展张力(DT)及其最大发展速率(dT/dt_(max))均显著降低,心肌开始收缩至dp/dt_(max)的时间(t-dp/dt_(max))和至dT/dt_(max)的时间(t-dT/dt_(max))则显著增加,与低通气呼吸前比较均有统计学差异。而在对照组(n=5)保持正常通气(通气量大于450ml/min/kg,PaO_2大于70mmHg),观察45min,未见上述指标有明显改变。本研究表明,急性呼吸衰竭时左室心肌收缩性严重受损。 相似文献