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101.
Naloxone at doses of 200 micrograms X kg-1 increases cough, in experiments carried out on dogs. With stimuli of the same intensity, after naloxone, a significant increase in the number of coughs in each fit, is observed. Changes in the first cough burst, compared with spontaneous respiration at rest, are statistically significant and they contribute to define the characteristics of the cough burst. The increase of cough by naloxone blockade of endorphinic neurons of the respiratory center shows that usually the activity of these inhibitory neurons, tonically depresses the tussive response. The antitussive opiates would seem to operate by activating these inhibitory synapses. 相似文献
102.
J M Fernández M F Rubio-Arroyo M Soriano-García R A Toscano M C Pérez-César 《Steroids》1985,45(2):151-157
The synthesis and molecular structure of prolame, N-(3-hydroxy-1,3,5(10)-estratrien-17 beta-yl)-3-hydroxypropylamine, is described. It was characterized by ir, nmr, mass spectrometry and chemical analysis. The crystal structure of this compound was determined by single-crystal x-ray diffraction. Prolame belongs to space group P212121. Cell dimensions are: a = 8.356(2), b = 13.343(4) and c = 16.119(4) A. Z = 4; R = 4.1%. 相似文献
103.
A method is given to predict the unitary free energies of complexation between drug-like and nucleoside-like biomolecules in a range of mixed solvent compositions. A stability maximum for the actinomycin (A)-deoxyguanosine (D) complex at 8% MeOH (v/v) in methanol/water mixtures is correctly predicted by the theory in agreement with existing experimental data. The molecular surface areas of A and D exposed to the solvent are found to diminish by 36.4 A(2) upon association. The 'microthermodynamic differential surface tension' of the solvophobic theory obtained for nucleoside-like and organic molecules in contact with MeOH/H2O can be used to predict the solvent effect free energies in other such molecular or biopolymeric associations in solution. 相似文献
104.
Independent experiments have shown that both protein folding (G. Velicelebi and J.M. Sturtevant, Biochemistry 18 (1979) 1180) and drug-biomolecule complexation (D.M. Crothers and D.I. Ratner, Biochemistry 7 (1968) 1823) in a wide range of compositions of methanol/water mixed solvents exhibit a maximum at 8% (v/v) MeOH. This hitherto unexplained phenomenon is shown to be given a priori by the 'solvophobic theory' developed earlier by Sinanoglu which had related the solvent effects including water in biochemistry to the then introduced 'molecular surface areas' and to 'microthermodynamic cavity inner surface tensions' and in a different version to interfacial microtensions between side chains and the solvent. Both analyses carried out in the present paper in detail for MeOH/water mixtures show how the denaturation or complexation free energies are predicted for the entire range of MeOH/water compositions from only data at one point. The molecular surface area changes for the conformational processes are obtained as well as the free energies in the hypothetical but theoretically important in vacuo limits with no solvent present. 相似文献
105.
Javier G. Fernández Velasco Norma L. Pucheu Oscar Romero Norma L. Kerber Raúl A. Fernández Augusto F. García 《Archives of microbiology》1985,143(2):192-195
The conditions under which an oscillatory behaviour is observed during net hydrolysis or synthesis of ATP in chromatophores of Rhodospirillum rubrum FR1 are described. In the case of ATPase the oscillations are observed at low temperature (ca. 11°C) in the dark after an initial transient behaviour. These oscillations are attenuated or disappear by the addition of an uncoupler.Oscillations are also observed during ATP synthesis. At 3°C the oscillations appear spontaneously if photophosphorylation is measured during a sufficiently long time. At 30°C the mere intercalation of a dark period also at 30°C is sufficient to trigger the oscillations in the following light period.Abbreviations Bchl
Bacteriochlorophyll
- FCCP
carbonyl cyanide p-trifluoromethoxyphenyl hydrazone
- PMS
phenazine methosulfate
- TMPD, N,N,N,N
tetramethyl-1,4-phenylenediamine
Dedicated to Prof. Dr. Gerhart Drews as a homage for his permanent example as hard worker and careful scientist and also for his remarkable human quality 相似文献
106.
A rapid, simple and reliable combined method for G-banding mammalian and human chromosomes 总被引:4,自引:0,他引:4
A simple and reliable method for G-banding chromosomes from human and mammalian cells is described. This rapid method combines hot saline and trypsin treatments and yields high quality G-bands in both bone marrow and cultured cells. 相似文献
107.
J. M. Guerrero J. R. Calvo M. R. Garrido P. Molinero C. Osuna J. Jiménez R. Goberna 《Bioscience reports》1986,6(1):39-44
A non-ionic detergent such as Lubrol-PX extracts in soluble form the VIP-binding structures of rat liver plasma membranes. Detergent-solubitized proteins bind specifically [125I]VIP and the complex tracer-protein is identified by the use of Sepharose 6B columns. The interaction is only possible in the absence of detergent (below 0.001%) and is inhibited by native peptide. A molecular weight of about 80,000 was estimated for VIP-binding proteins by reference to a series of globular markers of proteins. Binding to VIP soluble proteins is specific and dependent on time as studied by the Hummel and Dreyer (Biochim. Biophys. Acta
63:530–532, 1962) assay. 相似文献
108.
Representative conditional yeast secretory mutants, blocked in transport of secretory and plasma membrane proteins from the endoplasmic reticulum (sec 18), from the Golgi body (sec 7) and in transport of secretory vesicles (sec 1), accumulated exoglucanase, a constitutive yeast activity, when incubated at the restrictive temperature (37°C). Different proportions of the accumulated activity were released by mutant cells under permissive conditions. The presence or absence of cycloheximide during the secretion period made no differences in the results. More than 90% of the internal activity was bound to membrane in wild type cells. However, only the soluble pool underwent changes during the accumulation or secretion periods. The bulk of secretory invertase accumulated by sec 1 was also soluble. By contrast sec 7 and sec 18 accumulated membrane-bound as well as soluble invertase forms and both were secreted in similar proportions in each mutant. More than 90% of the accumulated invertase was secreted at the permissive temperature in sec 18 cells. That percentage was significantly lower for exoglucanase (<65%). Concomitantly, invertase accumulated by this mutant exited from the cells with a lower half time (t 1/2=150 min). These results may be interpreted assuming that exoglucanase is exported by a passive flow of the soluble pool.Non-standard abbreviations p-NPG
p-nitrophenyl--d-glucopyranoside
- Con A
concanavalin A
- Tris
tris(hydroxymethyl)-amino-methane 相似文献
109.
A J Fernández M A Sierra A Méndez E Mozos M C Moyano L Carrasco 《Cell structure and function》1986,11(4):379-382
Effects of septic shock by repeated inoculations with Escherichia coli on the ultrastructure of the folliculo-stellate cells and cavities of the adenohypophysis of the chicken were investigated in order to determine the function of these cavities. The principal morphological modifications were dilation of the Golgi apparatus, endoplasmic reticulum and autophagic vacuoles, and necrosis phenomena in the stellate cells. The follicular cavities showed dilation, and there was heterogeneous dense material and granular elements in the follicular lumen. Based on results reported in the literature, the observations reported here are evidence of a "cleaning-role", for the removal of cell debris, when there is endocrine disfunction. 相似文献
110.
The influence of surfactant micelles on the acid-base dissociation of the charged tertiary amino group of the local anesthetic, tetracaine, has been investigated. From measurements of tetracaine fluorescence as a function of bulk pH, apparent values of 6.88, 7.58 and 9.92 were found in the presence of cationic, neutral and anionic micelles, respectively, in 10 mM NaCl. These values are considerably displaced with respect to the in aqueous solution which is 8.26. Such large shifts can be attributed to the effect of the surface polarity and electrical potential on the dissociation behavior of the anesthetic bound to micelles. It can be expected that the acid-base dissociation of a local anesthetic adsorbed to nerve fibers will also be affected by the properties of the membrane surface. Thus, it is suggested that the influence of the interfacial region on the of surface-bound molecules should not be disregarded when estimating the proportion of charged and uncharged forms of local anesthetics interacting with axonal membranes. 相似文献