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H. Notbohm H. Hollandt J. Meissner E. Harbers 《International journal of biological macromolecules》1979,1(4):180-184
Low-angle X-ray scattering curves of isolated calf thymus chromatin, dissolved in 0.2 mm EDTA, 0.2 mm MgCl2 or 0.5 m NaCl, have been analysed by comparison with simulated scattering curves of models from chromatin subunits and higher order structure. The results provided additional data based on established models. Assuming the protein core as a cylinder of 5.9–6.0 nm diameter and 5.9-2.0 nm height, the centre to centre distance of the cores in tightly packed chromatin was found to be 6.7 nm. Computer simulation of X-ray scattering of chromatin was fitted to experimentally derived data for estimating the ratios of quaternary and tertiary structure. Slight differences of the quaternary structures of 0.15 m NaCl adn in 0.2 mm MgCl2 were observed. 相似文献
615.
Liquid diffraction analysis of sarcoplasmic reticulum. II. Solvent electron contrast variation. 总被引:3,自引:1,他引:2
Intensities of x-ray scattering from rabbit muscle sarcoplasmic reticulum membrane have been measured over the range of s = 0.05-0.25, at solvent densities varying between p0 = 0.335 and 0.389 electrons/A3. Analysis of the results shows agreement with the elements of structure deduced earlier by a different technique, based on the variation of the lipid-protein concentration ratio. In addition, the present work extends the analysis to allow isolation of the lipid contribution to the total scattering, from which a profile of the lipid electron density normal to the membrane face is evaluated. The scattering arising from electron correlations within the plane of the bilayer has also been identified. 相似文献
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S Lopaciuk A J Meissner J M Ziemski A Tokarz P Psuja K Zawilska S G?owiński Z Wo?czyński E Czestochowska W Tymiński 《Polski tygodnik lekarski (Warsaw, Poland : 1960)》1991,46(37-39):704-707
In a multicenter randomized trial, the efficacy and safety of two streptokinase (SK) dosage regimens have been evaluated in patients with proximal deep vein thrombosis of inferior limbs. Twenty-nine patients received SK by a continuous intravenous infusion (250,000 IU as initial dose, 100,000 IU/h as maintenance dose), and 26 patients were treated with intermittent SK administration (500,000 IU as initial dose, followed by 250,000 IU every 12 h). Thrombolytic therapy was continued for 4 days, then the patients received heparin for 5 days and oral anticoagulant for 3 months. The results of treatment as judged by phlebographic examinations were similar in the two groups. Complete, substantial or partial thrombolysis was achieved in 52% of patients in the continuous infusion group and in 58% of patients in the intermittent treatment group. During SK administration, major bleeding complications occurred in 6 patients treated by continuous infusion and in 2 of the second group. The results showed that the intermittent SK administration is as effective and safe as the method of continuous SK infusion in the treatment of deep vein thrombosis. 相似文献
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Vesicle-45Ca2+ ion flux and planar lipid bilayer single-channel measurements have shown that the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum (SR) is activated by micromolar concentrations of Cibacron Blue F3A-G (Reactive Blue 2) and Reactive Red 120. Cibacron Blue increased the 45Ca2+ efflux rate from heavy SR vesicles by apparently interacting with both the adenine nucleotide and caffeine activating sites of the channel. Dye-induced 45Ca2+ release was inhibited by Mg2+ and ruthenium red. In single channel recordings with the purified channel protein complex, Cibacron Blue increased the open time of the Ca2+ release channel without an apparent change in the conductance of the main and subconductance states of the channel. 相似文献
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