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71.
72.
Denis Monneret Jean-Louis Pepin Diane Godin-Ribuot Veronique Ducros Jean-Philippe Baguet Patrick Levy Patrice Faure 《Free radical biology & medicine》2010,48(4):619-625
Obstructive sleep apnea (OSA) is characterized by recurrent apnea during sleep that may unbalance oxidative stress, increasing atherosclerosis. Among oxidative stress markers, 15-F2t-isoprostane is considered one of the most sensitive and specific metabolites of lipid peroxidation. To explore the relationship between urinary 15-F2t-isoprostane with sleep apnea severity and carotid modifications in nonobese OSA patients, 31 nonobese sleep apnea patients were studied, along with 10 lean subjects without OSA. Patients were assessed by polysomnography, blood pressure measurement, and ultrasonography to determine the carotid intima–media thickness (IMT). Urinary 15-F2t-isoprostanes were measured by liquid chromatography–tandem mass spectrometry. Urinary 15-F2t-isoprostane concentrations were increased in severe OSA patients compared to control subjects (20.2 ± 7.3 vs 12.3 ± 2.8 ng/mmol creatinine; P = 0.020). Mean carotid IMT was correlated with 15-F2t-isoprostane (r = 0.532; P < 0.001) and with the apnea–hypopnea index (r = 0.345; P = 0.029). 15-F2t-Isoprostane level was related to the night time spent at SaO2 < 90% (r = 0.478; P = 0.002), the apnea–hypopnea index (r = 0.465; P = 0.003), and the mean nocturnal SaO2 (r = ? 0.424; P = 0.007). These results showed a relationship between lipid peroxidation, carotid intima–media thickness, and intermittent hypoxia in nonobese OSA patients, thus reinforcing the hypothesis that oxidative stress could be involved in the early atherosclerotic process. 相似文献
73.
Peter Veen Josef Fanta Ivan Raev Iovu-Adrian Biriş Jacques de Smidt Bert Maes 《Biodiversity and Conservation》2010,19(6):1805-1819
Despite extensive forest destruction in the Middle Ages and later intensive commercial forest management, remnants of virgin
forests remained spared in some Central, Eastern and South-Eastern European countries. These virgin forests are the last examples
of original forests in this part of Europe. That is why their protection becomes an important issue of current European forestry
and nature protection policy. But the knowledge about the location and the area of virgin forests in these countries is incomplete
up till now. This article has the prime goal to present a conceptual framework what virgin forests might be (“A conceptual framework for defining of virgin forests” section). Based on this framework, a working methodology has been tested in Bulgaria and Romania (“Results of the two national projects in Romania and in Bulgaria” section and further). For this reason two projects have been carried out by the Royal Dutch Society of Nature Conservation
(KNNV) in close co-operation with the Forestry Institutes in Romania and in Bulgaria. The results of these projects are described
in general terms and further analysis in the future is necessary to describe specific features like forest structure and spatial
heterogeneity of these forests. Based on the results of the inventory, principles of sustainable protection and management
of the mapped virgin forests were defined and described in the research reports. The usefulness of the inventory became evident
already during the EU pre-accession period of both countries while preparing the NATURA 2000 network. The remaining virgin
forests of temperate Europe are an inexhaustible source of ecological information about biodiversity, structure, natural processes
and overall functioning of undisturbed forest ecosystems. Their research will reveal information which can be used for ecological
restoration of man-made forests which are degraded through intensive forestry practices over the last centuries. The last
virgin forests of temperate Europe represent an irreplaceable part of the natural capital of Europe and are worth to be protected
by law. Their last remnants in South-Eastern and Eastern Europe are endangered by commercial activities. A full inventory
of remaining virgin forests in all countries of temperate Europe is a matter of highest urgency. A representative selection
of virgin forest sites should be declared by UNESCO as World Heritage Sites. 相似文献
74.
Tarik Gaamouche Carmem‐Lara de O. Manes Dorota Kwiatkowska Barbara Berckmans Rachel Koumproglou Sara Maes Tom Beeckman Teva Vernoux John H. Doonan Jan Traas Dirk Inzé Lieven De Veylder 《The Plant journal : for cell and molecular biology》2010,64(1):26-37
As the shoot apex produces most of the cells that comprise the aerial part of the plant, perfect orchestration between cell division rates and fate specification is essential for normal organ formation and plant development. However, the inter‐dependence of cell‐cycle machinery and meristem‐organizing genes is still poorly understood. To investigate this mechanism, we specifically inhibited the cell‐cycle machinery in the shoot apex by expression of a dominant negative allele of the A‐type cyclin‐dependent kinase (CDK) CDKA;1 in meristematic cells. A decrease in the cell division rate within the SHOOT MERISTEMLESS domain of the shoot apex dramatically affected plant growth and development. Within the meristem, a subset of cells was driven into the differentiation pathway, as indicated by premature cell expansion and onset of endo‐reduplication. Although the meristem structure and expression patterns of the meristem identity genes were maintained in most plants, the reduced CDK activity caused splitting of the meristem in some plants. This phenotype correlated with the level of expression of the dominant negative CDKA;1 allele. Therefore, we propose a threshold model in which the effect of the cell‐cycle machinery on meristem organization is determined by the level of CDK activity. 相似文献
75.
Limited reports are available on the growth response of Mycoplasma hyopneumoniae in Friis medium and the routinely used color changing units (CCU) assay has not yet been profoundly compared with other titration methods. Firstly, growth kinetics of 7 diverse M. hyopneumoniae isolates were followed by ATP luminometry in five Friis medium batches. Secondly, results of the CCU and ATP assays were compared hereby evaluating the methods.Growth curves of all isolates had log, stationary and senescence phases, and reached similar maximal titres when cultured in the same batch of Friis medium. Doubling times (Tds) of the isolates grown in slowly shaken cultures varied between 4.8 and 7.8 h. Maximal titres, Tds, growth phase in which the phenol red indicator turned from red to yellow due to acidification by mycoplasmal metabolism, and the length of the stationary phase varied depending on the Friis medium batch. The effect of static vs. shaking culture conditions on the Td depended on the isolate. ATP and CCU assays obtained similar growth curves, but when maximal levels were reached the CCU titre dropped earlier than the ATP titre. During log phase, CCU and ATP titres were strongly linearly linked. We developed a model enabling transformation of ATP into CCU titres or vice versa. The calculated amount of ATP per CCU (1.77 amol ATP/ml) indicated that the CCU assay likely underestimates the actual cell concentration. When titres were determined as means of 3 measurements, the ATP assay was 7 times more accurate and had 11-fold lower outliers than the CCU assay. Unlike the CCU assay, luminometry only requires one measurement to obtain sufficient accuracy.It was concluded that the ATP assay constitutes a valuable robust alternative for reproducible real-time titre assessment of freshly grown M. hyopneumoniae cultures. It is faster, more accurate and time, work and cost efficient compared to the CCU assay. The assay is preferred to better standardise and describe M. hyopneumoniae cultures used in various experiments. 相似文献
76.
Characterization of DNA reactive and non-DNA reactive anticancer drugs by gene expression profiling 总被引:2,自引:0,他引:2
Gene expression profiling technology is expected to advance our understanding of genotoxic mechanisms involving direct or indirect interaction with DNA. We exposed human lymphoblastoid TK6 cells to 14 anticancer drugs (vincristine, paclitaxel, etoposide, daunorubicin, camptothecin, amsacrine, cytosine arabinoside, hydroxyurea, methotrexate, 5-fluorouracil, cisplatin, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU), and bleomycin) for 4-h and examined them immediately or after a 20-h recovery period. Cytotoxicity and genotoxicity, respectively, were evaluated by cell counting and by in vitro micronucleus assay at 24h. Effects on the cell cycle were determined by flow cytometry at 4 and 24h. Gene expression was profiled at both sampling times by using human Affymetrix U133A GeneChips (22K). Bioanalysis was done with Resolver/Rosetta software and an in-house annotation program. Cell cycle analysis and gene expression profiling allowed us to classify the drugs according to their mechanisms of action. The molecular signature is composed of 28 marker genes mainly involved in signal transduction and cell cycle pathways. Our results suggest that these marker genes could be used as a predictive model to classify genotoxins according to their direct or indirect interaction with DNA. 相似文献
77.
78.
There is now evidence that chronic fatigue syndrome (CFS) is accompanied by an increased translocation of endotoxins from gram-negative enterobacteria through the gut wall, as demonstrated by increased prevalences and median values for serum IgM and IgA against the endotoxins of gram-negative enterobacteria. This condition can also be described as increased gut permeability or leaky gut and indicates intestinal mucosal dysfunction (IMD). Here we report a case of a 13 year old girl with CFS who showed very high values for serum IgM against the LPS of some enterobacteria and signs of oxidative and nitrosative stress, activation of the inflammatory response system, and IgG3 subclass deficiency. Upon treatment with specific antioxidants and a "leaky gut diet", which both aim to treat increased gut permeability, and immunoglobins intravenously, the increased translocation of the LPS of gram negative enterobacteria normalized and this normalization was accompanied by a complete remission of the CFS symptoms. 相似文献
79.
Immune activation is accompanied by induction of indoleamine (2,3)-dioxygenase (IDO), an enzyme which degrades tryptophan, a phenomenon which plays a role in the pathophysiology of major depression and post-natal depression and anxiety states. TRYCATs - tryptophan catabolites along the IDO pathway - such as kynurenine, kynurenic acid, xanthurenic acid, and quinolinic acid, have multiple effects, e.g. apoptotic, anti- versus pro-oxidant, neurotoxic versus neuroprotective, and anxiolytic versus anxiogenic effects. The aim of the present study was to study the immune effects of the above TRYCATS. Toward this end we examined the effects of the above TRYCATs on the LPS + PHA-induced production of interferon-gamma (IFNgamma), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNFalpha) in 18 normal volunteers. We found that the production of IFNgamma was significantly decreased by all 4 catabolites. Xanthurenic acid and quinolinic acid decreased the production of IL-10. Kynurenine, kynurenic acid, and xanthurenic acid, decreased the IFNgamma/IL-10 production ratio, whereas quinolinic acid increased this ratio. Kynurenic acid significantly reduced the stimulated production of TNFalpha. It is concluded that kynurenine, kynurenic acid, and xanthurenic acid have anti-inflammatory effects trough a reduction of IFNgamma, whereas quinolinic acid has pro-inflammatory effects in particular via significant decreases in IL-10. Following inflammation-induced IDO activation, some TRYCATs, i.e. kynurenine, kynurenic acid, and xanthurenic acid, exert a negative feedback control over IFNgamma production thus downregulating the initial inflammation, whereas an excess of quinolinic acid further aggravates the initial inflammation. 相似文献
80.
Major depression and chronic fatigue syndrome (CFS) are accompanied by signs of oxidative and nitrosative stress (O&NS) and an inflammatory response. Phosphatidyl inositol (Pi) is thought to play a role in depression. The aim of the present study is to examine whether depression and CFS are characterized by an IgM-mediated immune response directed against Pi. Toward this end, this study examines the serum IgM antibodies directed against Pi in 14 patients with major depression, 14 patients with CFS, 14 subjects with partial CFS, and in 11 normal controls. We found that the prevalence and mean value for the serum IgM levels directed against Pi were significantly greater in patients with major depression and CFS than in normal controls and patients with partial CFS. There were significant and positive correlations between serum IgM levels directed against Pi and two symptoms of the FibroFatigue Scale, i.e. fatigue and depression. The results show that an IgM-related immune response directed against Pi may occur in both depression and CFS and may play a role in the pathophysiology of the key symptom of CFS and major depression. It is suggested that the above disorders in Pi result from increased O&NS in both depression and CFS. Autoanti-Pi antibodies may have biological effects, for example, by changing inositol 1,4,5-triphosphate (IP3), phosphatidylinositol-4,5-bisphosphate (PIP2), diacylglycerol and phosphatidylinositol-3,4,5-triphosphate (PIP3) production, thus interfering with intracellular signalling processes. Future research in major depression and CFS should focus on the functional consequences of the immune responses directed against Pi. 相似文献