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排序方式: 共有407条查询结果,搜索用时 15 毫秒
1.
Impairment of the calcium pump of human erythrocytes by divicine 总被引:1,自引:0,他引:1
U Benatti L Guida G Forteleoni T Meloni A De Flora 《Archives of biochemistry and biophysics》1985,239(2):334-341
Divicine (2,6-diamino-4,5-dihydroxypyrimidine), an aglycone implicated in the pathogenesis of favism, produces a remarkable and consistent inactivation of the Ca2+-ATPase activity of the erythrocyte calcium pump. The patterns of inactivation are similar in normal and glucose-6-phosphate dehydrogenase (G6PD)-deficient erythrocytes. Inactivation of Ca2+-ATPase is apparently unrelated to the cellular GSH system, to the proteolytic machinery of mature erythrocytes, and to calmodulin, and also occurs in hemoglobin-free, unsealed erythrocytes membranes at 50-100 microM concentrations of divicine. Analysis of erythrocytes that have escaped destruction during the acute hemolytic crisis of a number of favic patients revealed a dramatic elevation of erythrocyte calcium and a significant decrease of Ca2+-ATPase activity. These results support the view that divicine plays a toxic role in the pathogenesis of favism and suggest that acute electrolyte imbalances, mostly affecting calcium homeostasis, are involved in the mechanisms of erythrocyte damage and destruction in this hemolytic disease. 相似文献
2.
3.
Cogoli-Greuter M Sciola L Spano A Meloni MA Pippia P Cogoli A 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》1995,2(1):P117-P118
Cell-cell contacts and the formation of aggregates play an important role in the mitogen induced in-vitro activation of lymphocytes. The fact that the formation of cell aggregates is only slightly reduced in microgravity suggests that cells are moving and interacting also in space. Direct evidence was obtained for the first time in an experiment performed on a sounding rocket flight, where the movements and interactions of free-floating, non activated cells could be observed in real time in microgravity. In an experiment performed on the IML-2 mission in July 1994, the movements and interactions of human lymphocytes during activation with the mitogen Con A were studied in real time in microgravity. 相似文献
4.
S. Martinoia M. Meloni M. T. Parodi M. Tedesco C. Ciccarelli M. Grattarola 《Cytotechnology》1993,11(Z1):S86-S88
A silicon microsensor (ISFET — Ion Sensitive Field Effect Transistor) has been used to detect the metabolism of a cell population cultured on a coverslip and positioned close to the sensor surface. The system output is analyzed as a function of cell density. 相似文献
5.
Byoung K. Choi Kwan H. Han Tea Y. Park 《Flexible Services and Manufacturing Journal》1996,8(2):159-182
Presented in the article is a method for constructing a graphical model of an FMS by using a new modeling tool called JR-net (Job Resource relation-net). JR-net is an object-oriented graphical tool for modeling automated manufacturing systems (AMSs), such as FMSs, FASs, and AS/RSs. As with the object-oriented modeling paradigm of Rumbaugh et al. (1991), the JR-net modeling framework supports the three stages of models: static layout model (object model); job flow model (functional model); and supervisory control model (dynamic model). In this article, the existing JR-net structure (Park 1992, Han et al., 1995) is extended further to make it a graphical tool for FMS modeling. Using the extended JR-net, a step-by-step procedure for constructing a graphical model of FMSs is presented. Also addressed are issues of classifying FMSs in terms of their generic functions and of utilizing the JR-net model of FMSs. 相似文献
6.
Low molecular weight kininogen binds to platelets to modulate thrombin-induced platelet activation 总被引:3,自引:0,他引:3
The kininogens, high molecular weight kininogen (HK) and low molecular weight kininogen (LK), are multifunctional, single-gene products that contain bradykinin and identical amino-terminal heavy chains. Studies were performed to determine if LK would bind directly to platelets. 125I-LK specifically bound to gel-filtered platelets in the presence of 50 microM Zn2+. HK effectively competed with 125I-LK for the same binding site (Ki = 27 +/- 9 nM, n = 5). Similarly, the Ki for LK inhibition of 125I-LK binding was 12 +/- 1 nM (n = 3). Albumin, fibrinogen, factor XIII, and kallikrein did not inhibit 125I-LK binding to unstimulated platelets. 125I-LK (66 kDa) was not cleaved upon binding to platelets. The binding of 125I-LK to unstimulated platelets was found to be fully reversible by the addition of a 50 molar excess of unlabeled LK at both 10 and 20 min. LK binding to platelets was saturable with an apparent Kd of 27 +/- 2 nM (mean +/- S.E., n = 9) and 647 +/- 147 binding sites/platelet. Both LK and HK at plasma concentrations inhibited thrombin-induced platelet aggregation. LK and HK at about 5% of plasma concentration also inhibited thrombin-induced secretion of both stirred and unstirred platelets. Both kininogens were found to be noncompetitive inhibitors of proteolytically active thrombin binding to platelets. The kininogens did not inhibit D-phenylalanyl-prolyl-arginine chloromethyl ketone-treated thrombin from binding to platelets. These studies indicated that both kininogens have a region on their heavy chain which allows them to bind to platelets. Further, kininogen binding by its heavy chain modulates thrombin activation of platelets since it prevents proteolytically active thrombin from binding to its receptor. 相似文献
7.
Amino acid sequence of k Sci, the Bence Jones protein isolated from a patient with light chain deposition disease 总被引:2,自引:0,他引:2
V Bellotti M Stoppini G Merlini M C Zapponi M L Meloni G Banfi G Ferri 《Biochimica et biophysica acta》1991,1097(3):177-182
Light chain Sci was isolated from the urine of a patient affected by light chain deposition disease with an apparent exclusive localization to the kidney. Sci protein is an intact light chain: it consists of 214 amino acid residues and has an Mr of 23.65. Its complete primary structure has been determined by sequence analysis of the corresponding tryptic peptides and by partially sequencing the intact protein. Sequence comparison shows that Sci protein is strictly related to the light chains of kIIIa family (88% structural identity) which are usually expressed in autoimmune rheumatoid syndromes. Computer graphics model suggests a perturbation in k Sci three-dimensional structure due to the unusual replacement of residues 53 and 77. 相似文献
8.
R Berni M Stoppini M C Zapponi M L Meloni H L Monaco G Zanotti 《European journal of biochemistry》1990,192(2):507-513
1. The primary structure of bovine plasma retinol-binding protein (RBP) has been determined and found to be more than 90% identical to human and rabbit RBPs, and more than 80% identical to rat RBP. Main changes in amino acid sequence are observed in two regions on the surface of the protein molecule (residues 138-148 and 169-183). 2. The interactions of bovine RBP with bovine and human transthyretins were investigated using the technique of fluorescence polarization. Bovine RBP was able to form high affinity complexes (K'd = 0.34 +/- 0.02 microM) with both bovine and human transthyretins, displaying a stoichiometry of approximately 2 molecules RBP/molecule transthyretin in both cases. The sites that participate in protein-protein interactions are thus very similar, and this tends to exclude the involvement of the superficial regions more significantly substituted in mammalian RBPs (residues 138-151 and 167-183) in the protein-protein recognition. 3. Bovine RBP has been crystallized (space group P2(1)2(1)2(1), with a = 4.61 nm, b = 4.91 nm, c = 7.61 nm) and the crystals are suitable for high-resolution X-ray diffraction studies. 相似文献
9.
New inhibitors of fungal 17β-hydroxysteroid dehydrogenase based on the [1,5]-benzodiazepine scaffold
Matej Živec Matej Sova Mojca Brunskole Roman Lenaršič Tea Lanišnik Rižner Stanislav Gobec 《Journal of enzyme inhibition and medicinal chemistry》2013,28(1):29-36
The synthesis and activity of a new series of non-steroidal inhibitors of 17β-hydroxysteroid dehydrogenase that are based on a 1,5-benzodiazepine scaffold are presented. Their inhibitory potential was screened against 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl), a model enzyme of the short-chain dehydrogenase/reductase superfamily. Some of these compounds are potent inhibitors of 17β-HSDcl activity, with IC50 values in the low micromolar range and represent promising lead compounds that should be further developed and investigated as inhibitors of human 17β-HSD isoforms, which are the enzymes associated with the development of many hormone-dependent and neuronal diseases. 相似文献
10.
Alessandra Vacca Roberta Montisci Pietro Garau Paolo Siotto Matteo Piga Alberto Cauli Massimo Ruscazio Luigi Meloni Sabino Iliceto Alessandro Mathieu 《Arthritis research & therapy》2013,15(1):R8