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91.
Bonazzi M Spanò S Turacchio G Cericola C Valente C Colanzi A Kweon HS Hsu VW Polishchuck EV Polishchuck RS Sallese M Pulvirenti T Corda D Luini A 《Nature cell biology》2005,7(6):570-580
Membrane fission is a fundamental step in membrane transport. So far, the only fission protein machinery that has been implicated in in vivo transport involves dynamin, and functions in several, but not all, transport pathways. Thus, other fission machineries may exist. Here, we report that carboxy-terminal binding protein 3/brefeldin A-ribosylated substrate (CtBP3/BARS) controls fission in basolateral transport from the Golgi to the plasma membrane and in fluid-phase endocytosis, whereas dynamin is not involved in these steps. Conversely, CtBP3/BARS protein is inactive in apical transport to the plasma membrane and in receptor-mediated endocytosis, both steps being controlled by dynamin. This indicates that CtBP3/BARS controls membrane fission in endocytic and exocytic transport pathways, distinct from those that require dynamin. 相似文献
92.
93.
John Reap Felipe Roman Scott Duncan Bert Bras 《The International Journal of Life Cycle Assessment》2008,13(4):290-300
Background, aims, and scope Life cycle assessment (LCA) stands as the pre-eminent tool for estimating environmental effects caused by products and processes
from ‘cradle to grave’ or ‘cradle to cradle.’ It exists in multiple forms, claims a growing list of practitioners, and remains
a focus of continuing research. Despite its popularity and codification by organizations such as the International Organization
for Standards and the Society of Environmental Toxicology and Chemistry, life cycle assessment is a tool in need of improvement.
Multiple authors have written about its individual problems, but a unified treatment of the subject is lacking. The following
literature survey gathers and explains issues, problems and problematic decisions currently limiting LCA’s goal and scope
definition and life cycle inventory phases.
Main features The review identifies 15 major problem areas and organizes them by the LCA phases in which each appears. This part of the
review focuses on the first 7 of these problems occurring during the goal and scope definition and life cycle inventory phases.
It is meant as a concise summary for practitioners interested in methodological limitations which might degrade the accuracy
of their assessments. For new researchers, it provides an overview of pertinent problem areas toward which they might wish
to direct their research efforts.
Results and discussion Multiple problems occur in each of LCA’s four phases and reduce the accuracy of this tool. Considering problem severity and
the adequacy of current solutions, six of the 15 discussed problems are of paramount importance. In LCA’s first two phases,
functional unit definition, boundary selection, and allocation are critical problems requiring particular attention.
Conclusions and recommendations Problems encountered during goal and scope definition arise from decisions about inclusion and exclusion while those in inventory
analysis involve flows and transformations. Foundational decisions about the basis of comparison (functional unit), bounds
of the study, and physical relationships between included processes largely dictate the representativeness and, therefore,
the value of an LCA. It is for this reason that problems in functional unit definition, boundary selection, and allocation
are the most critical examined in the first part of this review.
相似文献
Bert BrasEmail: |
94.
Zhu J Drenjancevic-Peric I McEwen S Friesema J Schulta D Yu M Roman RJ Lombard JH 《American journal of physiology. Heart and circulatory physiology》2006,291(2):H929-H938
Male Sprague-Dawley rats were maintained on a low-salt (LS) diet (0.4% NaCl) or changed to a high-salt (HS) diet (4% NaCl) for 3 days. Increases in intracellular Ca2+ ([Ca2+]i) in response to methacholine (10 microM) and histamine (10 microM) were significantly attenuated in aortic endothelial cells from rats fed a HS diet, whereas thapsigargin (10 microM)-induced increases in [Ca2+]i were unaffected. Methacholine-induced nitric oxide (NO) production was eliminated in endothelial cells of aortas from rats fed a HS diet. Low-dose ANG II infusion (5 ng x kg(-1) x min(-1) iv) for 3 days prevented impaired [Ca2+]i signaling response to methacholine and histamine and restored methacholine-induced NO production in aortas from rats on a HS diet. Adding Tempol (500 microM) to the tissue bath to scavenge superoxide anions increased NO release and caused N(omega)-nitro-L-arginine methyl ester-sensitive vascular relaxation in aortas from rats fed a HS diet but had no effect on methacholine-induced Ca2+ responses. Chronic treatment with Tempol (1 mM) in the drinking water restored NO release, augmented vessel relaxation, and increased methacholine-induced Ca2+ responses significantly in aortas from rats on a HS diet but not in aortas from rats on a LS diet. These findings suggest that 1) agonist-induced Ca2+ responses and NO levels are reduced in aortas of rats on a HS diet; 2) increased vascular superoxide levels contribute to NO destruction, and, eventually, to impaired Ca2+ signaling in the vascular endothelial cells; and 3) reduced circulating ANG II levels during elevated dietary salt lead to elevated superoxide levels, impaired endothelial Ca2+ signaling, and reduced NO production in the endothelium. 相似文献
95.
Ewa Sewerynek Mitsushi Abe Russel J. Reiter Lornell R. Barlow-Walden Lidun Chen Timothy J. McCabe Linda J. Roman Beatriz Diaz-Lopez 《Journal of cellular biochemistry》1995,58(4):436-444
The protective effect of melatonin on lipopolysaccharide (LPS)-induced oxidative damage in phenobarbital-treated rats was measured using the following parameters: changes in total glutathione (tGSH) concentration, levels of oxidized glutathione (GSSG), the activity of the antioxidant enzyme glutathione peroxidase (GSH-PX) in both brain and liver, and the content of cytochrome P450 reductase in liver. Melatonin was injected intraperitoneally (ip, 4mg/kg BW) every hour for 4 h after LPS administration; control animals received 4 injections of diluent. LPS was given (ip, 4 mg/kg) 6 h before the animals were killed. Prior to the LPS injection, animals were pretreated with phenobarbital (PB), a stimulator of cytochrome P450 reductase, at a dose 80 mg/kg BW ip for 3 consecutive days. One group of animals received LPS together with Nw-nitro-L-arginine methyl ester (L-NAME), a blocker of nitric oxide synthase (NOS) (for 4 days given in drinking water at a concentration of 50 mM). In liver, PB, in all groups, increased significantly both the concentration of tGSH and the activity of GSH-PX. When the animals were injected with LPS the levels of tGSH and GSSG were significantly higher compared with other groups while melatonin and L-NAME significantly enhanced tGSH when compared with that in the LPS-treated rats. Melatonin alone reduced GSSG levels and enhanced the activity of GSH-PX in LPS-treated animals. Additionally, LPS diminished the content of cytochrome P450 reductase with this effect being largely prevented by L-NAME administration. Melatonin did not change the content of P450 either in PB- or LPS-treated animals. In brain, melatonin and L-NAME increased both tGSH levels and the activity of GSH-PX in LPS-treated animals. The results suggest that melatonin protects against LPS-induced oxidative toxicity in PB-treated animals in both liver and brain, and the findings are consistent with previously published observations related to the antioxidant activity of the pineal hormone. 相似文献
96.
Karthick Raja Muthu Raja Lucie Rihova Lenka Zahradova Maria Klincova Miroslav Penka Roman Hajek 《PloS one》2012,7(10)
Background
Regulatory T (Treg) cells play an important role in the maintenance of immune system homeostasis. Multiple myeloma (MM) is a plasma cell disorder frequently associated with impaired immune cell numbers and functions.Methods
We analyzed Treg cells in peripheral blood (n = 207) and bone marrow (n = 202) of pre-malignant and malignant MM patients using flow cytometry. Treg cells and their subsets from MM patients and healthy volunteers were functionally evaluated for their suppressive property. A cohort of 25 patients was analyzed for lymphocytes, CD4 T cells and Treg cells before and after treatment with cyclophosphamide, thalidomide plus dexamethasone (CTD).Results
We found elevated frequencies of Treg cells in newly diagnosed (P<0.01) and relapsed MM patients (P<0.0001) compared to healthy volunteers. Also, Treg subsets including naïve (P = 0.015) and activated (P = 0.036) Treg cells were significantly increased in MM patients compared to healthy volunteers. Functional studies showed that Treg cells and their subsets from both MM and healthy volunteers were similar in their inhibitory function. Significantly increased frequencies of Treg cells were found in MM patients with adverse clinical features such as hypercalcemia (>10 mg/dL), decreased normal plasma cell (≤5%) count and IgA myeloma subtype. We also showed that MM patients with ≥5% of Treg cells had inferior time to progression (TTP) (13 months vs. median not reached; P = 0.013). Furthermore, we demonstrated the prognostic value of Treg cells in prediction of TTP by Cox regression analysis (P = 0.045). CTD treatment significantly reduced frequencies of CD4 T cells (P = 0.001) and Treg cells (P = 0.018) but not Treg cells/CD4 T cells ratio compared to pre-treatment.Conclusions
Our study showed immune deregulation in MM patients which is evidenced by elevated level of functionally active Treg cells and patients with increased Treg cells have higher risk of progression. 相似文献97.
98.
99.
Papaioannou A Manos M Karkabounas S Liasko R Evangelou AM Correia I Kalfakakou V Pessoa JC Kabanos T 《Journal of inorganic biochemistry》2004,98(6):959-968
Reaction of one equivalent of vanadium(III) chloride with three equivalents of l-cysteine(H2Cys) in methyl alcohol affords a VIII-Cys compound that is formulated as [VIII(Hcys)3].2HCl.2.5H2O 1. The solid state characterization of 1 was performed by microanalysis, circular dichroism (CD) and infrared studies as well as room temperature magnetic susceptibility. These studies have shown coordination of each HCys- ligand to the VIII atom through an amine nitrogen and a carboxylate oxygen atoms. Solution studies of 1 were carried out in water and methanol by UV-visible, CD and electron paramagnetic resonance (EPR) spectroscopies. According to these studies, it was evident that despite the progressive oxidation of 1 to oxovanadium(IV) species, some V(III) species were also present in solution after several hours. Compound 1, VIVOSO4.5H2O and l-cysteine were examined for their total antioxidant capacity (TAC) and lag time. Compound 1 exhibited significantly greater total antioxidant capacity and lag time values than l-cysteine. VIVOSO4.5H2O did not show any total antioxidant capacity or lag time. The inhibition of neutral endopeptidase (NEP) activity caused by 1, VIVOSO4.5H2O and thiorphan was also measured. Compound 1, at a concentration of 10(-3) M, showed inhibition of NEP activity as potent as thiorphan at 10(-6) M, while VIVOSO4.5H2O in the same concentration exhibited less than 50% inhibitory activity than that of thiorphan at 10(-6) M. Moreover, the antimetastatic effects of compound 1, l-cysteine and VIVOSO4.5H2O were examined on Wistar rats, treated with 3,4-benzopyrene. The results revealed that 1 prevents significantly lung metastases (only 9.5% of animals treated with 1 showed metastases), whereas 47-52% of the rats of the control group and those treated with l-cysteine and VIVOSO4.5H2O exhibited metastases. 相似文献
100.
Chia-chen Chang Daniel T. C. Cox Qiao Fan Thi Phuong Le Nghiem Claudia L. Y. Tan Rachel Rui Ying Oh Brenda B. Lin Danielle F. Shanahan Richard A. Fuller Kevin J. Gaston L. Roman Carrasco 《PLoS biology》2022,20(2)
Nature experiences have been linked to mental and physical health. Despite the importance of understanding what determines individual variation in nature experience, the role of genes has been overlooked. Here, using a twin design (TwinsUK, number of individuals = 2,306), we investigate the genetic and environmental contributions to a person’s nature orientation, opportunity (living in less urbanized areas), and different dimensions of nature experience (frequency and duration of public nature space visits and frequency and duration of garden visits). We estimate moderate heritability of nature orientation (46%) and nature experiences (48% for frequency of public nature space visits, 34% for frequency of garden visits, and 38% for duration of garden visits) and show their genetic components partially overlap. We also find that the environmental influences on nature experiences are moderated by the level of urbanization of the home district. Our study demonstrates genetic contributions to individuals’ nature experiences, opening a new dimension for the study of human–nature interactions.Nature experiences have been linked to mental and physical health. This twin study reveals genetic influences on an individual’s orientation towards nature and nature experiences, opening a new dimension to understanding human-nature interactions. 相似文献