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41.
Constantin A Constantinescu E Dumitrescu M Calin A Popov D 《Journal of cellular and molecular medicine》2005,9(3):683-691
In this study we investigated the effects of ageing on the carbonyl stress (protein carbonyls and 4-hydroxy-2-nonenal groups) and glutathione antioxidant defense in red blood cells (RBCs) of obese Type 2 diabetic patients with/without hypertensive complications. To this purpose the following methods were used: spectrophotometry (protein carbonyls, glutathione and glutathione peroxidase assays), immunofluorescence (4-hydroxy-2-nonenal localization), western blotting (immunodetection of carbonylated proteins). The results showed that compared to RBCs of healthy subjects, in obese Type 2 diabetics, ageing is associated with: (i) an increase in the concentration and expression of carbonylated proteins, a marker of oxidative stress; (ii) a decrease of both non-enzymatic and enzymatic endogenous glutathione defenses; (iii) a severely disturbed oxidant/antioxidant balance when obesity was associated with hypertension. The simultaneous insults of high blood pressure, obesity, and diabetes conducted to the highest carbonyl stress, exposure of 4-hydroxy-2-nonenal Michel adducts at the outer leaflet of RBCs plasmalemma, and the lowest glutathione antioxidant potential, particularly in elderly patients. These results can explain the gradual age-dependent diminishment of the detoxification potential of RBCs that at the old age can not overcome the deleterious effects of the high systemic oxidative stress. 相似文献
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Ramona Madalina Babes Roxana Gabriela Sandu Oana Elena Baran Vlad Cosoreanu Maria Teodora Ilie 《Cell cycle (Georgetown, Tex.)》2018,17(6):766-779
Human leukemia Jurkat T cells were analyzed for apoptosis and cell cycle by flow cytometry, using the Annexin V/propidium iodide (PI) standard assay, and a simple PI staining in Triton X-100/digitonin-enriched PI/RNase buffer, respectively. Cells treated with doxorubicin or menadione displayed a very strong correlation between the apoptotic cell fraction measured by the Annexin V/PI assay, and the weight of a secondary cell population that emerged on the forward scatter (FS)/PI plot, as well as on the side scatter (SS)/PI and FL1/PI plots generated from parallel cell cycle recordings. In both cases, the Pearson correlation coefficients were >0.99. In cell cycle determinations, PI fluorescence was detected on FL3 (620/30 nm), and control samples exhibited the expected linear dependence of FL3 on FL1 (525/40 nm) signals. However, increasing doses of doxorubicin or menadione generated a growing subpopulation of cells displaying a definite right-shift on the FS/FL3, SS/FL3 and FL1/FL3 plots, as well as decreased PI fluorescence, indicative of ongoing fragmentation and loss of nuclear DNA. By gating on these events, the resulting fraction of presumably sub-cycling cells (i.e. cells with cleaved DNA, counting sub-G0/G1, sub-S and sub-G2/M cells altogether) was closely similar to the apoptotic rate assessed by Annexin V/PI labeling. Taken together, these findings suggest a possible way to recognize the entire population of cells undergoing apoptotic DNA cleavage and simultaneously determine the cell cycle distribution of non-apoptotic cells in PI-labeled cell samples with various degrees of DNA fragmentation, using a simple and reproducible multiparametric analysis of flow cytometric recordings. 相似文献
43.
The role of intracellular Ca2+ as essential activator of the Na+---Ca2+ exchange carrier was explored in membrane vesicles containing 67% right-side-out and 10% inside-out vesicles, isolated from squid optic nerves. Vesicles containing 100 μM free calcium exhibited a 2-fold increase in the initial rate of Nai+-dependent Ca2+ uptake as compared with vesicles where intravesicular calcium was chelated by 2 mM EGTA or 10 mM HEDTA. The activatory effect exerted by intravesicular Ca2+ on the reverse mode of Na+---Ca2+ exchange (i.e. Nai+---Ca02+ exchange) is saturated at about 100 μM Cai2+ and displays an apparent K1/2 of 12 μM. Intravesicular Ca2+ produced activation of Nai+---Ca02+ exchange activity rather than an increase in Ca2+ uptake due to Ca2+---Ca2+ exchange. The presence of Cai2+ was essential for the Nai+-dependent Na+ influx, a partial reaction of the Na+---Ca2+ exchanger. In fact, the Na+ influx levels in vesicles loaded with 2 mM EGTA were close to those expected from diffusional leak while in vesicles containing Cai2+ an additional Na+---Na+ exchange was measured. The results suggest that in nerve membrane vesicles Ca2+ at the inner aspect of the membrane acts as an activator of the Na+---Ca2+ exchange system. 相似文献
44.
Madalina Duta-Mare Vinay Sachdev Christina Leopold Dagmar Kolb Nemanja Vujic Melanie Korbelius Dina C. Hofer Wenmin Xia Katharina Huber Martina Auer Benjamin Gottschalk Christoph Magnes Wolfgang F. Graier Andreas Prokesch Branislav Radovic Juliane G. Bogner-Strauss Dagmar Kratky 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2018,1863(4):467-478
Lysosomal acid lipase (LAL) is the only known enzyme, which hydrolyzes cholesteryl esters and triacylglycerols in lysosomes of multiple cells and tissues. Here, we explored the role of LAL in brown adipose tissue (BAT). LAL-deficient (Lal?/?) mice exhibit markedly reduced UCP1 expression in BAT, modified BAT morphology with accumulation of lysosomes, and mitochondrial dysfunction, consequently leading to regular hypothermic events in mice kept at room temperature. Cold exposure resulted in reduced lipid uptake into BAT, thereby aggravating dyslipidemia and causing life threatening hypothermia in Lal?/? mice. Linking LAL as a potential regulator of lipoprotein lipase activity, we found Angptl4 mRNA expression upregulated in BAT. Our data demonstrate that LAL is critical for shuttling fatty acids derived from circulating lipoproteins to BAT during cold exposure. We conclude that inhibited lysosomal lipid hydrolysis in BAT leads to impaired thermogenesis in Lal?/? mice. 相似文献
45.
M Maftei F Thurm VM Leirer CA von Arnim T Elbert M Przybylski IT Kolassa M Manea 《PloS one》2012,7(9):e44516
Physiological β-amyloid autoantibodies (Aβ-autoantibodies) are currently investigated as potential diagnostic and therapeutic tools for Alzheimer's disease (AD). In previous studies, their determination in serum and cerebrospinal fluid (CSF) using indirect ELISA has provided controversial results, which may be due to the presence of preformed Aβ antigen-antibody immune complexes. Based on the epitope specificity of the Aβ-autoantibodies, recently elucidated in our laboratory, we developed (a) a sandwich ELISA for the determination of circulating Aβ-IgG immune complexes and (b) an indirect ELISA for the determination of free Aβ-autoantibodies. This methodology was applied to the analysis of serum samples from healthy individuals within the age range of 18 to 89 years. Neuropsychological examination of the participants in this study indicated non-pathological, age-related cognitive decline, revealed especially by tests of visual memory and executive function, as well as speed-related tasks. The ELISA serum determinations showed significantly higher levels of Aβ-IgG immune complexes compared to free Aβ-autoantibodies, while no correlation with age or cognitive performance of the participants was found. 相似文献
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47.
SCF (Fbxl17) ubiquitylation of Sufu regulates Hedgehog signaling and medulloblastoma development 下载免费PDF全文
Madalina Raducu Ella Fung Sébastien Serres Paola Infante Alessandro Barberis Roman Fischer Claire Bristow Marie‐Laëtitia Thézénas Csaba Finta John C Christianson Francesca M Buffa Benedikt M Kessler Nicola R Sibson Lucia Di Marcotullio Rune Toftgård Vincenzo D'Angiolella 《The EMBO journal》2016,35(13):1400-1416
48.
Namhee Kim Prem K. Goel Madalina E. Tivarus Ashleigh Hillier David Q. Beversdorf 《PloS one》2010,5(8)
L-dopa, which is a precursor for dopamine, acts to amplify strong signals, and dampen weak signals as suggested by previous studies. The effect of L-dopa has been demonstrated in language studies, suggesting restriction of the semantic network. In this study, we aimed to examine the effect of L-dopa on language processing with fMRI using Independent Component Analysis (ICA). Two types of language tasks (phonological and semantic categorization tasks) were tested under two drug conditions (placebo and L-dopa) in 16 healthy subjects. Probabilistic ICA (PICA), part of FSL, was implemented to generate Independent Components (IC) for each subject for the four conditions and the ICs were classified into task-relevant source groups by a correlation threshold criterion. Our key findings include: (i) The highly task-relevant brain regions including the Left Inferior Frontal Gyrus (LIFG), Left Fusiform Gyrus (LFUS), Left Parietal lobe (LPAR) and Superior Temporal Gyrus (STG) were activated with both L-dopa and placebo for both tasks, and (ii) as compared to placebo, L-dopa was associated with increased activity in posterior regions, including the superior temporal area (BA 22), and decreased activity in the thalamus (pulvinar) and inferior frontal gyrus (BA 11/47) for both tasks. These results raise the possibility that L-dopa may exert an indirect effect on posterior regions mediated by the thalamus (pulvinar). 相似文献
49.
I. Diculescu C. T. Dragomir M. Condrescu-Guidi M. Popescu 《Histochemistry and cell biology》1970,21(1):9-16
Summary Some incubation media were elaborated to demonstrate tissue activity of L-amino acid tetrazolium reductase. These media had as substrate a L-amino acid to which a small amount of L-glutamate was added, well below the concentration used to demonstrate glutamic-dehydrogenase.The specifity of the reactions was assessed by incubations in control media and by studying the effects of some inhibitors. The work was concerned both with the actual pattern of the reaction and with changes initiated in the medium by tissue incubation.It became obvious that in this way an actual visualisation of an enzymatic oxido-reductive activity of various degrees in tissues and organs was possible. 相似文献
50.
An isoconversional method is proposed in order to calculate the kinetic parameters of enzyme inactivation. The method provides an efficient and low-cost procedure to describe both operational and thermal inactivation. Unlike the ordinary kinetic assays performed at constant enzyme concentration and at various substrate concentrations, the isoconversional method requires several extended kinetic curves for constant initial substrate concentration and different enzyme concentrations. The procedure was tested and validated using simulated data obtained for several kinetic models frequently discussed in the literature. After the validation, the isoconversional method was used for the investigation of the thermoinactivation of urease during urea hydrolysis in self buffered medium and the operational inactivation (destructive oxidation by excess peroxide) of catalase at high concentration of hydrogen peroxide. The results showed that the isoconversional method gives good results of global inactivation constant for both simple and more complex models. 相似文献