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71.
Krumova E Dolashki A Pashova S Dolashka-Angelova P Stevanovic S Hristova R Stefanova L Voelter W Angelova M 《Archives of microbiology》2008,189(2):121-130
The present study aims to provide new information about the unusual location of Cu/Zn-superoxide dismutase (Cu/Zn-SOD) in
lower eukaryotes such as filamentous fungi. Humicola lutea, a high producer of SOD was used as a model system. Subcellular fractions [cytosol, mitochondrial matrix, and intermembrane
space (IMS)] were isolated and tested for purity using activity measurements of typical marker enzymes. Evidence, based on
electrophoretic mobility, sensitivity to KCN and H2O2 and immunoblot analysis supports the existence of Cu/Zn-SOD in mitochondrial IMS, and the Mn-SOD in the matrix. Enzyme activity
is almost equally partitioned between both the compartments, thus suggesting that the intermembrane space could be one of
the major sites of exposure to superoxide anion radicals. The mitochondrial Cu/Zn-SOD was purified and compared with the previously
published cytosolic enzyme. They have identical molecular mass, cyanide- and H2O2-sensitivity, N-terminal amino acid sequence, glycosylation sites and carbohydrate composition. The H. lutea mitochondrial Cu/Zn-SOD is the first identified naturally glycosylated enzyme, isolated from IMS. These findings suggest
that the same Cu/Zn-SOD exists in both the mitochondrial IMS and cytosol.
Ekaterina Krumova and Alexander Dolashki equally contributed to this work. 相似文献
72.
Distorted relation between mRNA copy number and corresponding major histocompatibility complex ligand density on the cell surface 总被引:4,自引:0,他引:4
73.
Great deal of work has been devoted to determine doses from alpha particles emitted by 222Rn and 220Rn progeny. In contrast, contribution of beta particles to total dose has been neglected by most of the authors. The present
work describes a study of the detriment of 222Rn and 220Rn progeny to the human lung due to beta particles. The dose conversion factor (DCF) was introduced to relate effective dose
and exposure to radon progeny; it is defined as effective dose per unit exposure to inhaled radon or thoron progeny. Doses
and DCFs were determined for beta radiation in sensitive layers of bronchi (BB) and bronchioles (bb), taking into account
inhaled 222Rn and 220Rn progeny deposited in mucus and cilia layer. The nuclei columnar secretory and short basal cells were considered to be sensitive
target layers. For dose calculation, electron-absorbed fractions (AFs) in the sensitive layers of the BB and bb regions were
used. Activities in the fast and slow mucus of the BB and bb regions were obtained using the LUNGDOSE software developed earlier.
Calculated DCFs due to beta radiation were 0.21 mSv/WLM for 222Rn and 0.06 mSv/WLM for 220Rn progeny. In addition, the influence of Jacobi room parameters on DCFs was investigated, and it was shown that DCFs vary
with these parameters by up to 50%. 相似文献
74.
Grafting of softwood kraft pulps fibers with fatty acids under cold plasma conditions 总被引:1,自引:0,他引:1
Popescu MC Totolin M Tibirna CM Sdrobis A Stevanovic T Vasile C 《International journal of biological macromolecules》2011,48(2):326-335
Cold plasma treatment is used to modify the cellulosic fibers for a variety of applications. The grafting of softwood unbleached (UBP) and bleached (BP) kraft pulp fibers has been performed under the action of cold plasma discharges, using different kinds of fatty acids. The grafted samples are characterized by FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), termogravimetry (TG-DTG) and X-ray diffraction (XRD). All these methods confirm the morphological and structural changes after plasma treatment which determines the modification in cellulosic fiber properties. The active centers created within the cellulose chains by plasma treatment were used to initiate grafting reactions with fatty acids. Such modification is useful to enhance the fibers properties such as softness and to change hydrophilic/hydrophobic balance. 相似文献
75.
Identification of an SSX-2 epitope presented by dendritic cells to circulating autologous CD4+ T cells 总被引:6,自引:0,他引:6
Ayyoub M Hesdorffer CS Metthez G Stevanovic S Ritter G Chen YT Old LJ Speiser D Cerottini JC Valmori D 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(11):7206-7211
Accumulating evidence supports the requirement for both tumor-specific CD8(+) and CD4(+) T cell responses for efficient tumor rejection to occur. Because of its expression in different tumor types, the cancer/testis Ag encoded by the synovial sarcoma X breakpoint 2 (SSX-2) gene is among the most relevant candidates for the development of generic cancer vaccines. The immunogenicity of SSX-2 has been previously corroborated by detection of specific humoral and CD8(+) T cell responses in cancer patients. In this study we report identification of the first CD4(+) T cell epitope encoded by SSX-2. The identified epitope mapped to the 19-34 region of the protein and was recognized by CD4(+) T cells from an Ag-expressing melanoma patient in association with HLA-DPB1*0101. The absence of detectable response in healthy donors and other patients suggests that SSX-2-specific CD4(+) T cells in the responder patient had been previously expanded in vivo in response to the autologous tumor. The epitope did not appear to be presented on the surface of tumor cells at levels sufficient to allow direct recognition. In contrast, it was efficiently presented by autologous dendritic cells, supporting the concept that processing by professional APC is the main pathway through which the CD4(+) T cell immunoresponse to tumor Ags occurs in vivo. 相似文献
76.
Cathepsin G, and not the asparagine-specific endoprotease, controls the processing of myelin basic protein in lysosomes from human B lymphocytes 总被引:2,自引:0,他引:2
Burster T Beck A Tolosa E Marin-Esteban V Rötzschke O Falk K Lautwein A Reich M Brandenburg J Schwarz G Wiendl H Melms A Lehmann R Stevanovic S Kalbacher H Driessen C 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(9):5495-5503
The asparagine-specific endoprotease (AEP) controls lysosomal processing of the potential autoantigen myelin basic protein (MBP) by human B lymphoblastoid cells, a feature implicated in the immunopathogenesis of multiple sclerosis. In this study, we demonstrate that freshly isolated human B lymphocytes lack significant AEP activity and that cleavage by AEP is dispensable for proteolytic processing of MBP in this type of cell. Instead, cathepsin (Cat) G, a serine protease that is not endogenously synthesized by B lymphocytes, is internalized from the plasma membrane and present in lysosomes from human B cells where it represents a major functional constituent of the proteolytic machinery. CatG initialized and dominated the destruction of intact MBP by B cell-derived lysosomal extracts, degrading the immunodominant MBP epitope and eliminating both its binding to MHC class II and a MBP-specific T cell response. Degradation of intact MBP by CatG was not restricted to a lysosomal environment, but was also performed by soluble CatG. Thus, the abundant protease CatG might participate in eliminating the immunodominant determinant of MBP. Internalization of exogenous CatG represents a novel mechanism of professional APC to acquire functionally dominant proteolytic activity that complements the panel of endogenous lysosomal enzymes. 相似文献
77.
78.
We simultaneously tested the transfection efficiency of NT2/D1 and HeLa cells with Lipofectamine (Life Technologies) and Effectene (Qiagen) transfection reagents using the pCH110 eukaryotic assay vector, which contains the lacZ reporter gene. Under our culture conditions for NT2/D1 and HeLa cells, Effectene transfection efficiency could be augmented by simply increasing the amount of plasmid DNA 1.5-3 times above the recommended concentration without any visible cytotoxicity. With the Lipofectamine reagent, optimal transfection efficiency was obtained for both cell lines within the recommended concentrations, but at the top of the range. The results indicate that optimization of the transfection process should include plasmid DNA concentrations above the levels suggested by the manufacturers, in order to accomplish the highest transfection efficiency. 相似文献
79.
Contribution of mass spectrometry-based proteomics to immunology 总被引:1,自引:0,他引:1
Antigen processing forwards various information about the cellular status and the proteome to the cell surface for scrutiny by the cellular immune system. Thus the repertoire of major histocompatibility complex (MHC)-bound peptides and the MHC ligandome, indirectly mirrors the proteome in order to make alterations instantly detectable and, if necessary, to oppose them. Mass spectrometry is the core technology for analysis of both proteome and MHC ligandome and has evoked several strategies to gain qualitative and quantitative insight into the MHC-presented peptide repertoire. After immunoaffinity purification of detergent-solubilized peptide-MHC complexes followed by acid elution of peptides, liquid chromatography-mass spectrometry is applied to determine individual peptide sequences and, thus, allow qualitative characterization of the MHC-bound repertoire. Differential quantification based on stable isotope labeling enables the relative comparison of two samples, such as diseased and healthy tissue. Targeted searches for certain natural ligands, such as the 'predict-calibrate-detect' strategy, include motif-based epitope prediction and calibration with reference peptides. Thus, various approaches are now available for exposing and understanding the intricacies of the MHC ligand repertoire. Analysis of differences in the MHC ligandome under distinct conditions contributes to our understanding of basic cellular processes, but also enables the formulation of immunodiagnostic or immunotherapeutic strategies. 相似文献
80.
Avulsion injuries of the thumb 总被引:1,自引:0,他引:1
M V Stevanovic C Vucetic M Bumbasirevic C Vuckovic 《Plastic and reconstructive surgery》1991,87(6):1099-1104
Avulsion amputations of the thumb are generally thought to have a worse prognosis after replantation than other amputations. We report the results of 17 thumbs that had an avulsion amputation and were replanted. Fourteen of the 17 survived (82 percent). Our experience indicated that the survival rate was improved by restoring continuity of at least two veins and two arteries, using a Y-shaped vein graft and the princeps pollicis artery for the source of arterial circulation. Nerve grafts were used to bridge defects in avulsed digital nerves. When possible, avulsed tendons were reattached to their muscle. Key pinch strength was 60 percent of normal, and grip strength was always less than that of the normal hand. The age of the patients and the cold ischemia time had no significant effect on either survival or function of the replanted thumb. When excellent venous backflow occurred immediately after the vessel repair and continued for at least 20 minutes, the thumb always survived without complications. 相似文献