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排序方式: 共有677条查询结果,搜索用时 12 毫秒
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Huebner Lucas Schroeder Ines Kraft Eduard Gutmann Marcus Biebl Johanna Klamt Amrei Christin Frey Jana Warmbein Angelika Rathgeber Ivanka Eberl Inge Fischer Uli Scharf Christina Schaller Stefan J. Zoller Michael 《Der Anaesthesist》2022,71(10):795-800
Die Anaesthesiologie - Bei etwa 43?% aller Überlebenden der Intensivmedizin wird ein erworbenes Syndrom an Muskelschwäche beobachtet, welches Überleben und Lebensqualität... 相似文献
23.
Platelet-derived growth factor (PDGF) is a potent mitogen for many cultured connective tissue cells. It is present in concentrated form within the platelet alpha-granules and is believed to be released during platelet degranulation at sites of vascular injury. We have used a sensitive radioreceptor assay to measure PDGF levels in whole blood serum from normal humans [17.5 +/- 3.1 (SD) ng/mL] and baboons (2.7 +/- 1.2 ng/mL). PDGF was not detected in plasma from either species. In addition, plasma was found to substantially reduce the ability of added purified PDGF to bind to the cell surface PDGF receptor on cultured cells, suggesting that plasma may contain a PDGF-binding protein that would serve to inactivate PDGF released into plasma. Calculations of PDGF concentrations in serum have been corrected for the effects of the binding protein. 125I-PDGF injected intravenously into normal baboons was cleared rapidly from the plasma (t1/2 = two minutes). The rapid clearance of 125I-PDGF did not result from iodination damage, as purified unlabeled PDGF was cleared with comparable kinetics. The rapid clearance of purified and iodinated PDGF did not result from changes in PDGF structure during purification or from removal of PDGF-associated proteins during purification, as PDGF present in freeze-thaw lysates of fresh platelets was cleared equally rapidly. We conclude that release of PDGF at sites of vascular injury would greatly increase the local concentration of PDGF and that PDGF not localized to the site of injury would be rapidly cleared from the circulation. 相似文献
24.
Grard Eberl Christian Widmann Giampietro Corradin 《European journal of immunology》1996,26(9):1993-1999
The functional half-life (t1/2) of different complexes formed by major histocompatibility complex (MHC) class I molecules and antigen on the surface of target cells was measured using specific cytotoxic T lymphocyte (CTL) clones in cytolysis, and interferon-γ-production and Ca2+-mobilization assays. Functional t1/2 values of 5–10 h were obtained, which are in accordance with some previous estimations obtained from biochemical and immunochemical measurements. Moreover, these values were independent of the type of target cell, fixation of the target cells, or proteases able to degrade the peptides, suggesting that the unfolding of the peptide/MHC complexes at the cell surface alone determines the functional t1/2 of the CTL epitopes. 相似文献
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The synthetic, oxidized C-terminal fragment of the Plasmodium berghei circumsporozoite protein elicits a high protective response 总被引:2,自引:0,他引:2
Roggero MA Meraldi V López JA Eberl G Romero JC Matile H Betschart B Corradin G Renggli J 《European journal of immunology》2000,30(9):2679-2685
A polypeptide of 69 amino acids (PbCS 242-310) encompassing the C-terminal region of the circumsporozoite protein of Plasmodium berghei (PbCS) was generated using solid-phase peptide synthesis. The immunological and protective properties of peptide PbCS 242-310 were studied in BALB/c mice (H-2d). Two subcutaneous injections, in the presence of IFA at the base of the tail, generated (i) high titers of anti-peptide antibodies which also recognized the native P. berghei CS protein, (ii) cytolytic T cells specific for the Kd-restricted peptide PbCS 245-253 and (iii) partial CD8+-dependent protection against sporozoite-induced malaria. The same frequencies of peptide PbCS 245-253 specific CD8+ T cells were found by IFN-gamma ELISPOT in the draining lymph nodes of animals immunized with the short optimal CTL peptide 245-253 or with the polypeptide 242-310, indicating that the longer polypeptide can be processed and presented in vivo in the context of MHC class I as efficiently as the short CTL peptide. Interestingly, higher levels of IFN-gamma producing CD8 T cells and protection were observed when the four cysteine residues present in the C-terminal peptide were fully oxidized. These findings underline the potential importance of the chemical nature of the C-terminal fragment on the activation of the immune system and concomitant protection. 相似文献
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28.
Wang LM Zhang Q Zhu W He C Lu CL Ding DF Chen ZY 《第二军医大学学报》2005,26(11):1299-1299
Glial cell line-derived neurotrophic factor (GDNF) plays a critical role in neurodevelopment and survival of midbrain dopaminergic and spinal motor neurons in vitro and in vivo. The biological actions of GDNF are mediated by a two-receptor complex consisting of a glycosylphosphatidylinositol-linked cell surface molecule, the GDNF family receptor alpha 1 (GFR alpha 1), and receptor protein tyrosine kinase Ret. Although structural analysis of GDNF has been extensively examined, less is known about the structural basis of GFR alpha 1 function. In this study, based on evolutionary trace method and relative solvent accessibility prediction of residues, a set of trace residues that are solvent-accessible was selected for site-directed mutagenesis. A series of GFR alpha 1 mutations was made, and PC12 cell lines stably expressing different GFR alpha 1 mutants were generated. According to the survival and differentiation responses of these stable PC12 cells upon GDNF stimulation and the GDNF- GFR alpha 1-Ret interaction assay, residues 152NN153, Arg259, and 316SNS318 in the GFR alpha 1 central region were found to be critical for GFR alpha 1 binding to GDNF and eliciting downstream signal transduction. The single mutation R259A in the GFR alpha 1 molecule simultaneously lost its binding ability to GDNF and Ret. However N152A/N153A or S316A/N317A/ S318A mutation in the GFR alpha 1 molecule still retained the ability to bind with Ret. These findings suggest that distinct structural elements in GFR alpha 1 may be involved in binding to GDNF and Ret. 相似文献
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Kassiou M Eberl S Meikle SR Birrell A Constable C Fulham MJ Wong DF Musachio JL 《Nuclear medicine and biology》2001,28(2):165-175
To quantify changes in neuronal nAChR binding in vivo, quantitative dynamic SPECT studies were performed with 5-[(123)I]-iodo-A-85380 in baboons pre and post chronic treatment with (-)-nicotine or saline control. Infusion of (-)-nicotine at a dose of 2.0 mg/kg/24h for 14 days resulted in plasma (-)-nicotine levels of 27.3 ng/mL. This is equivalent to that found in an average human smoker (20 cigarettes a day). In the baboon brain the regional distribution of 5-[(123)I]-iodo-A-85380 was consistent with the known densities of nAChRs (thalamus > frontal cortex > cerebellum). Changes in nAChR binding were estimated from the volume of distribution (V(d) ) and binding potential (BP) derived from 3-compartment model fits. In the (-)-nicotine treated animal V(d) was significantly increased in the thalamus (52%) and cerebellum (50%) seven days post cessation of (-)-nicotine treatment, suggesting upregulation of nAChRs. The observed 33% increase in the frontal cortex failed to reach significance. A significant increase in BP was seen in the thalamus. In the saline control animal no changes were observed in V(d) or BP under any experimental conditions. In this preliminary study, we have demonstrated for the first time in vivo upregulation of neuronal nAChR binding following chronic (-)-nicotine treatment. 相似文献