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461.
Interaction of amiodarone and its analogs with calmodulin 总被引:1,自引:0,他引:1
M R Deziel P J Davis F B Davis V Cody J Galindo S D Blas 《Archives of biochemistry and biophysics》1989,274(2):463-470
Benzofurans have important actions on the electrical properties of myocardium; the biochemical basis of those actions is not known. Crystallographic examination of these compounds has revealed that benzofurans share structural homologies with the traditional calmodulin antagonists N-(6-aminohexyl)-5-chloro-1-naphthalene and trifluoperazine. In the present study, the ability of amiodarone, desethylamiodarone, and benziodarone to displace the fluorescent ligand 8-anilino-1-naphthalene sulfonic acid (ANS) from calmodulin, to modulate the fluorescence emission of dansylcalmodulin, and to inhibit the activation by calmodulin of bovine brain cyclic nucleotide phosphodiesterase and human erythrocyte membrane Ca2+-ATPase were investigated at concentrations ranging from 10(-8) to 10(-6) M. These benzofurans displaced ANS from calmodulin with nearly equal efficiency upon forming a 1:1 complex with that protein. Each of these compounds also produced a decreased fluorescence emission of dansylcalmodulin, but with relative efficiencies being desethylamiodarone greater than amiodarone greater than benziodarone. Amiodarone and desethylamiodarone inhibited calmodulin-stimulable phosphodiesterase activity with similar potencies. Amiodarone and benziodarone inhibited calmodulin-stimulable Ca2+-ATPase activity equally, but desethylamiodarone had no effect. The observed differential effects of the amiodarone analogs suggest that calmodulin may possess multiple benzofuran-binding sites that are recognized by specific targets and ligands of this Ca2+-binding protein and that the cellular action of amiodarone and its analogs may reflect calmodulin antagonism. 相似文献
462.
Quantification of cell surface roughness; a method for studying cell mechanical and adhesive properties 总被引:1,自引:0,他引:1
J L Mege C Capo A M Benoliel C Foa R Galindo P Bongrand 《Journal of theoretical biology》1986,119(2):147-160
The presence on the surface of nucleated cells of a variety of asperities of different size and shape plays a prominent role in cell-cell and cell-substrate interaction. Also, the organization of these asperities is directly related to cellular cytoskeletal elements. In the present report, we describe a simple and objective method of studying electron micrographs to quantify the roughness of cell contours. Constant-length segments of cell boundaries are compared to reference circular segments with common extremities and enclosing the same area. This procedure was performed with a digitizer connected to a microcomputer, and it was used to analyse model contours or electron micrographs of (i) target tumour cells bound by cytotoxic T lymphocytes and (ii) thymocytes sticking to concanavalin A-coated surfaces. It is shown that this method allows precise quantification of cell deformation in adhesive zones, which may allow absolute evaluation of adhesive stimuli. 相似文献
463.
Miguel A. Galindo 《Inorganica chimica acta》2009,362(3):1027-7420
In this contribution, we discuss the use of simple pyrimidine derivatives and geometrically related heterocycles in combination with protected metal ions to build cyclic polynuclear coordination assemblies. The resulting assemblies range from conformationally rigid triangles to corrugated octagons with positively charged cavities and surfaces that can interact with anionic species in a supramolecular fashion. Special attention has been focussed to the supramolecular interaction of these systems towards mononucleotides and DNA as a possible novel interaction of DNA binding metallo-drugs. The results show that these systems efficiently interact with both mononucleotides and ds-DNA. The molecular recognition of ds-DNA leads to significant conformational changes, however, this interaction gives only rise to moderate cytotoxic effects towards tumour cell lines. 相似文献
464.
B. Witkind Davis Kelvin Alie William J. Fielding Michelle Morters Francisco Galindo 《Journal of applied animal welfare science : JAAWS》2013,16(2):141-151
The subject of sanctuaries for chimpanzees has lately become the topic of a great deal of discussion (Brent, Butler, &; Haberstroh, 1997; Committee on Long-Term Care of Chimpanzees, 1997; Dyke, Williams-Blangero, Mamelka, &; Goodwin, 1995; Peterson &; Goodall, 1993). In the United States, laboratories that use chimpanzees in research are facing a housing crisis. An increase in captive births caused by the initiation of the National Chimpanzee Breeding and Research Program in 1986 (Hobson, Graham, &; Rowell, 1991), coupled with the diminished use of chimpanzees as experimental subjects, have led to a large population of chimpanzees considered to be surplus to demand (Blood, Wolfle, &; Whitney, 1992). These chimpanzees, as well as an unknown number from the private sector, are candidates for what is currently being called retirement. 相似文献
465.
Silicone is proposed as an alternative binding substance in the production of D-L alanine pellets used in electron paramagnetic resonance (EPR) dosimetry of gamma rays. The dosimeters are manufactured at room temperature, making the production simple. Examination by EPR silicone-alanine pellets irradiated with 60Co gamma rays in the dose range 10 to 10(6) Gy shows that the proposed silicone binder does not affect typical alanine dose-response curves. Thermal stability of the pellets below 40 degrees C is good, but their pre-dose EPR signal amplitude is slightly higher than for nonirradiated alanine. 相似文献