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911.
912.
Martin Konvicka Jiri Benes Oldrich Cizek Frantisek Kopecek Ondrej Konvicka Lubomir Vitaz 《Journal of Insect Conservation》2008,12(5):519-525
We describe a rapid extirpation of a strong population of globally threatened butterfly, Colias myrmidone, from the White Carpathians, Czech Republic. The area is renowned for a high plant and insect diversity associated with savannah-like
Carpathian meadows, traditionally managed by mowing once a year and subsequent autumn grazing. Although many meadows fell
victim to land consolidation schemes in the 1970s and 1980s, over 2000 hectares have been preserved in a dense network of
reserves. The reserve management practised since the mid-1990s has consisted of uniform machine mowing of entire areas and
this was further accelerated after accession of the Czech Republic to the EU, when agri-environmental schemes (AES) required
two cuts per year. This starkly conflicted with the life history of C. myrmidone, because both spring and autumn cuts interfere with larval development. Despite intensive surveys, only five and then two
C. myrmidone individuals were seen in the area in 2005 and 2006, respectively, rendering the species effectively extinct. Conservation
authorities failed by neglecting early warning signals issued by amateur entomologists, and by ignoring the basic tenets of
conservation of insect diversity, such as the need to maintain heterogeneity of resources. Unless AES provide for this crucial
aspect of habitat suitability for invertebrates, they may turn from a great hope into a massive failure. 相似文献
913.
The removal of toluene and xylene from an artificial waste gaswas investigated in two laboratory scale biofilters filled withmixtures of peat, bark and wood. The packed beds differed in themixture of materials used, so that peat and then bark was thedominant constituent. The biofilters were operated in an upflowmode. Both biofilters showed relatively high removal efficienciesfor both pollutants (74–98%). The evaluation of the localelimination capacities in the peat-loaded biofilter revealed thatthe major part of pollutants was degraded in the middle layer.In this biofilter, larger differences in theremoval rates along the bed height were also observed. In thebiofilter with bark as dominant material, the major part ofpollutants was degraded at the inlet of the bed and also at arelative height of 0.7. Moisture contents of 71–80% and 65–78%were found for the biofilter with peat and bark respectively. Whenthe regular pouring of nutrient solution through the bed wasinterrupted for 1 month, a decrease in efficiency was observed inthe biofilter with bark, whilst the efficiency in the biofilter withpeat remained the same. 相似文献
914.
915.
916.
Kim JH Sedlak M Gao Q Riley CP Regnier FE Adamec J 《Omics : a journal of integrative biology》2010,14(6):689-699
Oxidative stress and protein carbonylation is implicated in aging and various diseases such as neurodegenerative disorders, diabetes, and cancer. Therefore, the accurate identification and quantification of protein carbonylation may lead to the discovery of new biomarkers. We have developed a new method that combines avidin affinity selection of carbonylated proteins with iTRAQ labeling and LC fractionation of intact proteins. This simple LC-based workflow is an effective technique to reduce sample complexity, minimize technical variation, and enable simultaneous quantification of four samples. This method was used to determine protein oxidation in an iron accumulating mutant of Saccharomyces cerevisiae exposed to oxidative stress. Overall, 31 proteins were identified with 99% peptide confidence, and of those, 27 proteins were quantified. Most of the identified proteins were associated with energy metabolism (32.3%), and cellular defense, transport, and folding (38.7%), suggesting a drop in energy production and reducing power of the cells due to the damage of glycolytic enzymes and decrease in activity of enzymes involved in protein protection and regeneration. In addition, the oxidation sites of seven proteins were identified and their estimated position also indicated a potential impact on the enzymatic activities. Predicted 3D structures of peroxiredoxin (TSA1) and thioredoxin II (TRX2) revealed close proximity of all oxidized amino acid residues to the protein active sites. 相似文献
917.
Josef DVORAK Bohuslav MELICHAR Jiri PETERA Karel KABELAC Milan VOSMIK Pavel VESELY Igor SIRAK Zdenek ZOUL Ales RYSKA Pavel JANDIK 《Reports of Practical Oncology and Radiotherapy》2009,14(5):169-175
Aims and BackgroundTo evaluate toxicity and the radical resection rate in gastric adenocarcinoma treated with preoperative neoadjuvant chemoradiation.Materials & Methods32 patients, 22 males and 10 females with gastric adenocarcinoma, were treated with chemoradiation and hyperthermia.ResultsThe neoadjuvant regimen was completed as planned in 19/32 (59 %) patients; in the remaining patients the intensity of chemotherapy had to be reduced because of haematological and gastrointestinal toxicity. Surgical stage was as follows: 2 patients pathologically complete response, 3 patients AJCC stage I.A, 5 patients stage I.B, 7 patients stage II, 7 patients stage III.A, 1 patient stage III.B, 7 patients stage IV. R0 resection was achieved in 19/32 (59%) patients, R1 in 2/32 (6%) patients and R2 in 11 (34%) patients. Downstaging after neoadjuvant chemoradiotherapy was achieved in 17/32 (53%) patients. At the date of evaluation (31 March 2009), 4 patients were still alive 58, 81, 86 and 98 months from the date of diagnosis. Median survival was 18 months (95% confidence interval: 13–38 months). One-year survival was 69% (95% confidence interval: 53%–85%). Four-year survival was 19% (95% C.I.: 5%–34%).ConclusionsPreoperative neoadjuvant chemoradiotherapy has acceptable toxicity, and can lead to a high rate of R0 resections. 相似文献
918.
Ajay Singh Maradumane L. Mohan Alfred Orina Isaac Xiu Luo Jiri Petrak Daniel Vyoral Neena Singh 《PloS one》2009,4(2)
Converging evidence leaves little doubt that a change in the conformation of prion protein (PrPC) from a mainly α-helical to a β-sheet rich PrP-scrapie (PrPSc) form is the main event responsible for prion disease associated neurotoxicity. However, neither the mechanism of toxicity by PrPSc, nor the normal function of PrPC is entirely clear. Recent reports suggest that imbalance of iron homeostasis is a common feature of prion infected cells and mouse models, implicating redox-iron in prion disease pathogenesis. In this report, we provide evidence that PrPC mediates cellular iron uptake and transport, and mutant PrP forms alter cellular iron levels differentially. Using human neuroblastoma cells as models, we demonstrate that over-expression of PrPC increases intra-cellular iron relative to non-transfected controls as indicated by an increase in total cellular iron, the cellular labile iron pool (LIP), and iron content of ferritin. As a result, the levels of iron uptake proteins transferrin (Tf) and transferrin receptor (TfR) are decreased, and expression of iron storage protein ferritin is increased. The positive effect of PrPC on ferritin iron content is enhanced by stimulating PrPC endocytosis, and reversed by cross-linking PrPC on the plasma membrane. Expression of mutant PrP forms lacking the octapeptide-repeats, the membrane anchor, or carrying the pathogenic mutation PrP102L decreases ferritin iron content significantly relative to PrPC expressing cells, but the effect on cellular LIP and levels of Tf, TfR, and ferritin is complex, varying with the mutation. Neither PrPC nor the mutant PrP forms influence the rate or amount of iron released into the medium, suggesting a functional role for PrPC in cellular iron uptake and transport to ferritin, and dysfunction of PrPC as a significant contributing factor of brain iron imbalance in prion disorders. 相似文献
919.
920.
Witting PK Liao WQ Matthew J Harris Neuzil J 《Biochemical and biophysical research communications》2006,348(2):485-493
Hydrogen peroxide (H2O2) is implicated in cardiac myocyte (CM) damage during myocardial ischemia-reperfusion (IR) injury. Myoglobin (Mb) is present in CM at significant concentrations and reacts with H2O2 to yield one- and two-electron oxidants that may promote myocardial injury. Paradoxically, hearts from mice lacking Mb are more susceptible to H2O2-induced dysfunction than the corresponding controls [U. Flogel, A. Godecke, L.O. Klotz, J. Schrader, Role of myoglobin in the anti-oxidant defense of the heart, FASEB J. 18 (2004) 1156-1158]. We have overexpressed wild-type or Y103F variant of human Mb in cultured CMs to test whether Mb protects against H2O2 insult. Contrary to expectation, cells expressing WT or the Y103F Mb show increased mitochondrial dysfunction and apoptosis, and decreased ATP in response to H2O2 that follows the order native < Y103F Mb < WT human Mb consistent with the increasing pro-oxidant activity for these proteins. These data indicate that (i) Mb promotes oxidative damage to cultured CM and (ii) Mb may be a useful target for the design of inhibitors of myocardial IR injury. 相似文献