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91.
In neutralizing heparin with intravenous protamine sulfate, hypotension may be prevented by administering the drug intraarterially. Forty patients underwent cardiac surgery with extracorporeal circulation in our hospital; each received a rapid injection of nondiluted protamine sulfate in the aortic root to reverse the effects of heparin. To maintain the blood volume at a constant level, volume expanders and inotropic drugs were avoided. The intraaortic injections ranged in duration from 0.2 min to 2.8 min, with a mean of 1.1 min. The mean systolic pressure only dropped from 92 mm Hg (SD +/- 21) before protamine injection to 85 mm Hg (SD +/- 23) after injection (p < 0.0001). In seven patients (18%), no hypotension was evident; in the remaining patients, the systolic pressure returned to preinjection values within a mean of 2.2 min. Coagulation was observed within 3 to 4 min (mean = 2.2 min) after the initiation of injection. This study indicates that intraaortic administration of protamine is a rapid and safe technique for heparin reversal after cardiopulmonary bypass. 相似文献
92.
Summary The effect of quinidine on Na and H+ transport by the turtle bladder and water transport by the toad bladder was examined. Quinidine inhibited the short-circuit current and the potential difference in a dose-dependent fashion. The effect of quinidine on the short-circuit was not dependent on extracellular calcium concentration and was not reversible with removal of the drug. Quinidine inhibited H+ secretion in a dose-dependent fashion. The effect of quinidine on H+ secretion also was not dependent on extracellular calcium concentration and was not reversible, either with removal of the drug or with stimulation of H+ secretion with 5% CO2. The effect of quinidine on Na or H+ transport could not be elicited by an equivalent dose of tetracaine, suggesting that the inhibitory effect of quinidine is not dependent on its anesthetic properties. Quinidine also inhibited vasopressin and cyclic AMP stimulated water flow in the toad bladder. Quinidine did not alter calcium uptake by the turtle bladder but increased calcium efflux by the turtle and toad bladders. These observations suggest that a rise in cytosolic calcium is responsible for the inhibitory effect of quinidine on Na, H+, and water transport. 相似文献
93.
Jose M. Gonzales-Ros Alexander Paraschos Mary C. Farach Marino Martinez-Carrion 《生物化学与生物物理学报:生物膜》1981,643(2):407-420
Non-ionic detergents used for the solubilization and purification of acetylcholine receptor from Torpedo californica electroplax may remain tightly bound to this protein. The presence of detergent greatly hinders spectrophotometric and hydrodynamic studies of the receptor protein. β-d-Octylglucopyranoside, however, is found to be effective in solubilizing the receptor from electroplax membranes with minimal interference in the characterization of the protein. The acetylcholine receptor purified from either octylglucopyranoside or Triton X-100-solubilized extracts exhibits identical amino acid compositions, α-Bungarotoxin and (+)-tubocurarine binding parameters, and subunit distributions in SDS-polyacrylamide gels. The use of octylglucopyranoside allows for the assignment of a molar absorptivity for the purified receptor at 280 nm of approx. 530 000 . Additionally, successful reconstitution of octylglucopyranoside-extracted acetylcholine receptor into functional membrane vesicles has recently been achieved (Gonzales-Ros, J.M., Paraschos, A. and Martinez-Carrion, M. (1980) Proc.Natl. Acad. Sci. U.S.A. 77, 1796–1799).Removal of octylglucopyranoside by dialysis does not alter the specific toxin and antagonist binding ability of the receptor or its solubility at low protein concentrations. Sedimentation profiles of the purified acetylcholine receptor in sucrose density gradients reveal several components. Sedimentation coefficients obtained for the slowest sedimenting species agree with previously reported molecular weight values. Additionally, the different sedimenting forms exhibit distinctive behavior in isoelectric focusing gels. Our results suggest that both the concentration and type of detergent greatly influence the physicochemical behavior of the receptor protein. 相似文献
94.
Jose A.L. Arruda Harry Lubansky Sandra Sabatini George Dytko C.Tyler Burt 《Biochemical and biophysical research communications》1981,100(4):1459-1463
The urinary bladder of the fresh water turtle is capable of acidification and Na transport, in vitro, and it has been extensively used as a model of distal nephron of the kidney. In the course of measuring intracellular pH of stripped turtle bladder mucosa with phosphorus nuclear magnetic resonance, we observed the consistent presence of two inorganic phosphorus resonances under aerobic conditions, indicating the existence of a pH gradient possibly between cytosol and mitochondrion. This pH gradient was collapsed by addition of N2 and could be restored by reintroduction of oxygen. These observations demonstrate the existence of a spontaneous pH gradient between cytosol and mitochondria of turtle bladder epithelial cells. 相似文献
95.
The structure of the capsular polysaccharide from Klebsiella K26 has been determined by using the techniques of methylation, periodate oxidation, partial hydrolysis, and β-elimination. N.m.r. spectroscopy (1H and 13C) was used to establish the nature of the anomeric linkages and to identify oligosaccharides obtained by the different degradative techniques employed.The polysaccharide is comprised of repeating units of the heptasaccharide shown. 相似文献
96.
Jose A. Melero Jose Salas Maria L. Salas 《Biochimica et Biophysica Acta (BBA)/General Subjects》1976,437(2):462-476
The distribution between nuclei and cytoplasm of DNA-binding proteins from growing NIL cells was studied. To obtain the subcellular fractions, cell monolayers or cells previously detached from the culture dish were treated with the non-ionic detergent Nonidet P-40. Proteins with affinity for DNA were isolated from nuclear or cytoplasmic fractions by chromatography on DNA-cellulose columns and were further analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The results show that P8, one of the major components in the 0.15 M NaCl-eluted proteins, is found predominantly in the cytoplasmic fractions, whereas P6, the other main protein peak in this eluate, is more prominent in the nuclear fraction. Among the other proteins eluted at 0.15 M NaCl from the DNA-cellulose column, P5 and P5′ are detected in both nuclear and cytoplasmic fractions. All the other proteins in the 0.15 M NaCl eluate are present almost exclusively in the cytoplasmic fraction. On the other hand, most of the proteins with higher affinity for DNA, eluted from the column at 2 M NaCl, are present in the nuclear fraction, although they are also detected in the cytoplasm in amounts similar to those observed in the nuclei. 相似文献
97.
98.
Emilio Virgós Rafal Kowalczyk Atalya Trua Anna de Marinis Julián G. Mangas Jose M. Barea‐Azcón Eli Geffen 《Journal of Biogeography》2011,38(8):1546-1556
Aim To test the abundant centre hypothesis by analysing the physical and climatic factors that influence body size variation in the European badger (Meles meles). Location Data were compiled from 35 locations across Europe. Methods We used body mass, body length and condylo‐basal length (CBL) as surrogates of size. We also compiled data on latitude, several climatic variables, habitat type and site position relative to the range edge. We collapsed all continuous climatic variables into independent vectors using principal components analysis (PCA), and used a general linear model to explain the morphometric variation in badger populations across the species’ range. Results Body mass and body length were nonlinearly and significantly related to latitude. In contrast, CBL was linearly related to latitude. Body mass changed nonlinearly along the temperature (PC1) gradient, with the highest values observed at mid‐range. Furthermore, body mass, body length and CBL differed significantly among habitats, with badgers showing larger size in temperate habitats and core areas relative to peripheral zones. Main conclusions Our analysis supports the nonlinear pattern predicted by the abundant centre hypothesis only for body mass and body length. These results imply that individuals are largest and heaviest at the centre of the climatic range of badger distribution. Variation of CBL with latitude follows a linear trend, consistent with Bergmann’s rule. Our results provide mixed support for the abundant centre hypothesis, and suggest food availability/quality to be the main mechanism underlying body size clines in this species. 相似文献
99.
100.
About 150 species belonging to 14 families are mentioned in the scattered literature dealing with the land molluscs of Chile. However, the records of the Streptaxidae and Haplotrematidae are dubious and all those for the Limacidae, Zonitidae and Helicidae correspond to introduced species. The remaining 9 families are represented by endemic genera and subgenera present either in the oceanic islands (Fernandezia, Tornatellina, Ambrosiella) or in continental Chile (Bostryx (Ataxus), Chiliborus). A few are limited in their distribution to the southern part of South America (Austrodiscus, Stephadiscus, Macrocyclis) or are found both in the islands and along the continent (Amphiodoxa, Stephanoda). The majority of the other genera have a wider distribution in the Indo‐Pacific (Punctum, Ptychodon, Champa), in South America, the Americas in general and/or in the other parts of the world. The distribution of molluscan genera and species in continental Chile is discussed with regard to the biogeographic units proposed by various authors for plants and animals. Their probable relationships with the faunas of neighbouring countries and other biogeographic regions is briefly outlined. A taxonomic list of the species indicating the original reference, general distribution and the uncertain position of some of them within the different genera is given. Only about 120 species appear relatively well characterized. 相似文献