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31.
Odile?Sergent Aldo?Tomasi Daniela?Ceccarelli Alberto?Masini Hans?Nohl Pierre?Cillard Josiane?Cillard Yuri?A.?Vladimirov Andrey?V.?KozlovEmail author 《Biometals》2005,18(6):567-575
Iron overload aggravates tissue damage caused by ischemia and ethanol intoxication. The underlying mechanisms of this phenomenon
are not yet clear. To clarify these mechanisms we followed free iron (“loosely” bound redox-active iron) concentration in
livers from rats subjected to experimental iron overload, acute ethanol intoxication, and ex vivo warm ischemia. The levels of free iron in non-homogenized liver tissues, liver homogenates, and hepatocyte cultures were
analyzed by means of EPR spectroscopy. Ischemia gradually increased the levels of endogenous free iron in liver tissues and
in liver homogenates. The increase was accompanied by the accumulation of lipid peroxidation products. Iron overload alone,
known to increase significantly the total tissue iron, did not affect either free iron levels or lipid peroxidation. Homogenization
of iron-loaded livers, however, resulted in the release of a significant portion of free iron from endogenous depositories.
Acute ethanol intoxication increased free iron levels in liver tissue and diminished the portion of free iron releasing during
homogenization. Similarly to liver tissue, the primary hepatocyte culture loaded with iron in vitro released significantly more free iron during homogenization compared to non iron-loaded hepatocyte culture. Analyzing three
possible sources of free iron release under these experimental conditions in liver cells, namely ferritin, intracellular transferrin-receptor
complex and heme oxygenase, we suggest that redox active free iron is released from ferritin under ischemic conditions whereas
ethanol and homogenization facilitate the release of iron from endosomes containing transferrin-receptor complexes. 相似文献
32.
33.
Steindler C Li Z Algarté M Alcover A Libri V Ragimbeau J Pellegrini S 《The Journal of biological chemistry》2004,279(41):43168-43177
Jamip1 (Jak and microtubule interacting protein), an alias of Marlin-1, was identified for its ability to bind to the FERM (band 4.1 ezrin/radixin/moesin) homology domain of Tyk2, a member of the Janus kinase (Jak) family of non-receptor tyrosine kinases that are central elements of cytokine signaling cascades. Jamip1 belongs to a family of three genes conserved in vertebrates and is predominantly expressed in neural tissues and lymphoid organs. Jamip proteins lack known domains and are extremely rich in predicted coiled coils that mediate dimerization. In our initial characterization of Jamip1 (73 kDa), we found that it comprises an N-terminal region that targets the protein to microtubule polymers and, when overexpressed in fibroblasts, profoundly perturbs the microtubule network, inducing the formation of tight and stable bundles. Jamip1 was shown to associate with two Jak family members, Tyk2 and Jak1, in Jurkat T cells via its C-terminal region. The restricted expression of Jamip1 and its ability to associate to and modify microtubule polymers suggest a specialized function of these proteins in dynamic processes, e.g. cell polarization, segregation of signaling complexes, and vesicle traffic, some of which may involve Jak tyrosine kinases. 相似文献
34.
An immobilization procedure for protein on surface plasmon resonance sensor (SPR) chips is described. The target protein, cyclophilin D, is thereby genetically linked to a mutant of the human DNA repair protein O6-alkylguanine-DNA-alkyltransferase (hAGT). The procedure includes the immobilization of an alkylguanine derivative on the surface by amine coupling and contact of the surface with a solution of the fusion protein (TCypD-hAGT). TCypD-hAGT could be immobilized using buffer solutions of purified protein or cell extracts. High densities of covalently linked proteins were achieved by either procedure. Binding experiments performed with the ligand cyclosporin A indicate relative binding activities close to 100%. The KD value (12 nM) and the kinetic rate constants kon (3 × 105 M−1s−1) and koff (4 × 10−3s−1) are given and compared to values determined for cyclophilin D linked to the surface by amide coupling chemistry. The KD value is in excellent agreement with the KD value determined in solution by fluorescence titration. 相似文献
35.
Josiane Silva Araújo Aristéa Alves Azevedo Luzimar Campos Silva Renata Maria Strozi Alves Meira 《Plant Systematics and Evolution》2010,286(1-2):117-131
This work describes the leaf anatomy of 16 species belonging to three genera of the Malpighiaceae family found in the Cerrado (Minas Gerais State, Brazil). The scope of this study was to support the generic delimitation by contributing to the identification of the species and constructing a dichotomous identification key that includes anatomical characters. The taxonomic characters that were considered to be the most important and used in the identification key for the studied Malpighiaceae species were as follows: the presence and location of glands; presence of phloem in the medullary region of the midrib; mesophyll type; presence and type of trichomes; and presence, quantity, and disposition of accessory bundles in the petiole. It was also possible to indicate promising characters for future taxonomic and phylogenetic studies in the Malpighiaceae family, especially for the Banisteriopsis, Byrsonima, and Heteropterys genera. 相似文献
36.
Fischer FM Borges FN Rotenberg L Latorre Mdo R Soares NS Rosa PL Teixeira LR Nagai R Steluti J Landsbergis P 《Chronobiology international》2006,23(6):1165-1179
This paper aims at identifying variables associated with inadequate work ability among nursing personnel at a public hospital, considering factors related to socio-demographic, lifestyles, working conditions, and health outcomes. A cross-sectional study was conducted in a university hospital in S?o Paulo, Brazil, as part of a larger research study on tolerance to 12 h night work. Nursing staff included registered nurses, nurse technicians, and nurse aides; in total, there were 996 healthcare workers (878 female; 118 male) at the time of the study. Some 696 workers (69.9%) of the population agreed to participate. Data collection (October 2004-July 2005) was based on a comprehensive questionnaire about living and working conditions (including incivility at work, work demands, work control, and support), mental and physical health symptoms (fatigue and sleep problems), and work ability. This report presents analyses of the adapted Brazilian version of the Work Ability Index (WAI) and associated variables. The study population worked one of the following shift schedules at this hospital: 12 h nights followed by 36 h off or 9 h or 6 h day (morning or afternoon) shifts. The mean age of the respondents was 34.9 (S.D.+/-10.4) years of age; 31.5% of the participants held two jobs. Statistical analyses using a hierarchical multiple logistic regression model were performed to evaluate the factors associated with inadequate (moderate and low scores) of the WAI. The significantly associated factors were socio-demographic (income responsibility, sole breadwinner, raising kids, age group), working conditions (thermal discomfort, organization of the workplace, and verbal abuse), and health outcomes (high body mass index, obesity, sleep problems, and fatigue). In spite of limitations of the study design, results indicate that the nursing profession is associated with stressful working conditions, contributing to inadequate WAI. This is in addition to bad living conditions and precarious work. Intervention measures, either at the workplace or at individual levels, are necessary to prevent a decrease in work ability, even in this quite young working population. 相似文献
37.
In this work, an alternative to conventional preparation procedures for scanning electron microscopy (SEM) analysis of Cryptococcus neoformans was performed. The cells were fixed directly in the agar culture. This method is simpler than others already reported and the morphology of the cells was well preserved. 相似文献
38.
A Chaillon T Wack M Braibant L Mandelbrot S Blanche J Warszawski F Barin 《Journal of virology》2012,86(19):10540-10546
It has been hypothesized that neutralizing antibodies (NAbs) should have broad specificity to be effective in protection against diverse HIV-1 variants. The mother-to-child transmission model of HIV-1 provides the opportunity to examine whether the breadth of maternal NAbs is associated with protection of infants from infection. Samples were obtained at delivery from 57 transmitting mothers (T) matched with 57 nontransmitting mothers (NT) enrolled in the multicenter French perinatal cohort (ANRS EPF CO1) between 1990 and 1996. Sixty-eight (59.6%) and 46 (40.4%) women were infected by B and non-B viruses, respectively. Neutralization assays were carried out with TZM-bl cells, using a panel of 10 primary isolates of 6 clades (A, B, C, F, CRF01_AE, and CRF02_AG), selected for their moderate or low sensitivity to neutralization. Neutralization breadths were not statistically different between T and NT mothers. However, a few statistically significant differences were observed, with higher frequencies or titers of NAbs toward several individual strains for NT mothers when the clade B-infected or non-clade B-infected mothers were analyzed separately. Our study confirms that the breadth of maternal NAbs is not associated with protection of infants from infection. 相似文献
39.
40.
Espiña DC Carvalho FB Zanini D Schlemmer JB Coracini JD Rubin MA Morsch VM Schetinger MR Leal DB Baiotto CR Jaques JA 《Cell biochemistry and function》2012,30(4):347-353
The aim of this study was to investigate the effect of the aqueous extract (AE) of Achyrocline satureioides on serum lipid profile, liver oxidative profile and Na(+),K(+)-ATPase activity of rats submitted to a hyperlipidic diet. The animals were divided into four groups: control (C), AE 10% (A(10)), hyperlipidic (H) and hyperlipidic/AE 10% (HA(10)). In serum, we measured the levels of total cholesterol (TC), high-density lipoprotein, very-low-density lipoprotein, low-density lipoprotein (LDL) and triglyceride (TG). In liver homogenates, we measured the thiobarbituric acid reactive substances, the carbonyl proteins, the non-protein thiols (NPSHs) and the activity of superoxide dismutase, catalase (CAT) and Na(+),K(+)-ATPase. We observed a significant increase in the TC and LDL levels in the H group. A. satureioides prevented these effects, decreased the TG levels in the HA(10) group and increased the NPSH levels in the A(10) and HA(10) groups. The H group showed an increase in the carbonyl protein level and a decrease in CAT and Na(+),K(+)-ATPase activities. With the use of this model, results show that increased levels of lipids are related to a redox imbalance in the liver, which is also related to the inhibition of Na(+),K(+)-ATPase activity, and that chronic administration of the AE of A. satureioides is capable of changing this profile. 相似文献