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41.
Pierleoni R Buffalini M Vallorani L Guidi C Zeppa S Sacconi C Pucci P Amoresano A Casbarra A Stocchi V 《Phytochemistry》2004,65(7):813-820
The formation of the fruit body represents the final phase of the ectomycorrhizal fungus T. borchii life cycle. Very little is known concerning the molecular and biochemical processes involved in the fructification phase. 2-DE maps of unripe and ripe ascocarps revealed different protein expression levels and the comparison of the electropherograms led to the identification of specific proteins for each developmental phase. Associating micropreparative 2-DE to microchemical approaches, such as N-terminal sequencing and 2-D gel-electrophoresis mass-spectrometry, proteins playing pivotal roles in truffle physiology were identified. 相似文献
42.
Targeted modification of homogalacturonan by transgenic expression of a fungal polygalacturonase alters plant growth
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Capodicasa C Vairo D Zabotina O McCartney L Caprari C Mattei B Manfredini C Aracri B Benen J Knox JP De Lorenzo G Cervone F 《Plant physiology》2004,135(3):1294-1304
Pectins are a highly complex family of cell wall polysaccharides comprised of homogalacturonan (HGA), rhamnogalacturonan I and rhamnogalacturonan II. We have specifically modified HGA in both tobacco (Nicotiana tabacum) and Arabidopsis by expressing the endopolygalacturonase II of Aspergillus niger (AnPGII). Cell walls of transgenic tobacco plants showed a 25% reduction in GalUA content as compared with the wild type and a reduced content of deesterified HGA as detected by antibody labeling. Neutral sugars remained unchanged apart from a slight increase of Rha, Ara, and Gal. Both transgenic tobacco and Arabidopsis were dwarfed, indicating that unesterified HGA is a critical factor for plant cell growth. The dwarf phenotypes were associated with AnPGII activity as demonstrated by the observation that the mutant phenotype of tobacco was completely reverted by crossing the dwarfed plants with plants expressing PGIP2, a strong inhibitor of AnPGII. The mutant phenotype in Arabidopsis did not appear when transformation was performed with a gene encoding AnPGII inactivated by site directed mutagenesis. 相似文献
43.
Verde C Howes BD De Rosa MC Raiola L Smulevich G Williams R Giardina B Parisi E Di Prisco G 《Protein science : a publication of the Protein Society》2004,13(10):2766-2781
The suborder Notothenioidei dominates the Antarctic ichthyofauna. The non-Antarctic monotypic family Pseudaphritidae is one of the most primitive families. The characterization of the oxygen-transport system of euryhaline Pseudaphritis urvillii is herewith reported. Similar to most Antarctic notothenioids, this temperate species has a single major hemoglobin (Hb 1, over 95% of the total). Hb 1 has strong Bohr and Root effects. It shows two very uncommon features in oxygen binding: At high pH values, the oxygen affinity is exceptionally high compared to other notothenioids, and subunit cooperativity is modulated by pH in an unusual way, namely the curve of the Hill coefficient is bell-shaped, with values approaching 1 at both extremes of pH. Molecular modeling, electronic absorption and resonance Raman spectra have been used to characterize the heme environment of Hb 1 in an attempt to explain these features, particularly in view of some potentially important nonconservative replacements found in the primary structure. Compared to human HbA, no major changes were found in the structure of the proximal cavity of the alpha-chain of Hb 1, although an altered distal histidyl and heme position was identified in the models of the beta-chain, possibly facilitated by a more open heme pocket due to reduced steric constraints on the vinyl substituent groups. This conformation may lead to the hemichrome form identified by spectroscopy in the Met state, which likely fulfils a potentially important physiological role. 相似文献
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45.
Maccaglia A Mallozzi C Minetti M 《Biochemical and biophysical research communications》2003,305(3):541-547
The protective effects of eating fruits and vegetables in the prevention of several degenerative pathologies have been attributed at least in part to the antioxidant and anti-inflammatory properties of polyphenols. In this study, we investigated the effects of two polyphenols, quercetin and resveratrol, on red blood cell Band 3 tyrosine phosphorylation signalling activated by peroxynitrite. Peroxynitrite is a physiological oxidant scavenged largely by the erythrocyte and formed by the reaction between nitrogen monoxide and superoxide anion. Quercetin and its structurally analogous (+)-catechin inhibited the peroxynitrite-dependent upregulation of Band 3 tyrosine phosphorylation. Quercetin was found to downregulate the activity of syk, which is upstream in the Band 3 tyrosine phosphorylation cascade, and partially prevented peroxynitrite-mediated phosphotyrosine phosphatase inhibition. Resveratrol and hydroxytyrosol, unexpectedly, amplified peroxynitrite-dependent upregulation of Band 3 tyrosine phosphorylation through the activation of lyn, a kinase of the src family. The present results clearly indicate that polyphenols may activate cell transduction pathways in different and sometimes opposite ways. 相似文献
46.
Romani R Antognelli C Baldracchini F De Santis A Isani G Giovannini E Rosi G 《Chemico-biological interactions》2003,145(3):321-329
The present study looks at possible changes in the activity of acetylcholinesterase (AChE) in tissues (brain and white muscle) of the Mediterranean bony fish Sparus auratus after a 20 days exposure to sublethal concentrations (0.1 or 0.5 ppm) of copper in the marine water and on control untreated animals. The trials also included measurements of Cu concentration in the tissues to evaluate possible metal accumulation. Moreover, sedimentation analysis as well as V(max) and K(m) determination were carried out in tissue extracts of Cu-exposed or control animals. V(max) and K(m) were also determined with or without addition of Cu(2+) in the assay. No Cu accumulation occurred in brain and muscle after Cu exposure. AChE showed in both tissues a molecular polymorphism with putative globular (G) and asymmetric (A) forms. Cu exposition led to an increased specific activity and improved catalytic efficiency of AChE in brain and muscle, seemingly regarding G forms. The increase in catalytic efficiency also resulted from the in vitro assay with tissue extracts and Cu(2+) addition. The higher AChE activity and catalytic efficiency in both tissues after Cu exposition and without metal accumulation, suggests an increase of free Cu aliquot into the cells, likely due to mechanisms of metal homeostasis. 相似文献
47.
Lutgarde Thijs Jan A Staessen Sonia Beleva Willem H Birkenhäger Christopher J Bulpitt Hilde Celis Astrid E Fletcher Rumjana Kermova Gastone Leonetti Tovio Laks Stefan Mantov Choudomir Nachev Cinzia Sarti Jaakko Tuomilehto Robert H Fagard 《Trials》2001,2(6):1-9
Background
The randomised, double-blind, placebo-controlled Systolic Hypertension in Europe trial (Syst-Eur 1) proved that blood pressure (BP) lowering therapy starting with nitrendipine reduces the risk of cardiovascular complications in elderly patients with isolated systolic hypertension. In an attempt to confirm the safety of long-term antihypertensive therapy based on a dihydropyridine, the Syst-Eur patients remained in open follow-up after the end of Syst-Eur 1. This paper presents the second progress report of this follow-up study (Syst-Eur 2). It describes BP control and adherence to study medications.Methods
After the end of Syst-Eur 1 all patients, treated either actively or with placebo, were invited either to continue or to start antihypertensive treatment with the same drugs as previously used in the active treatment arm. In order to reach the target BP (sitting SBP <150 mmHg), the first line agent, nitrendipine, could be associated with enalapril and/or hydrochlorothiazide.Results
Of the 3787 eligible patients, 3516 (93%) entered Syst-Eur 2. At the last available visit, 72% of the patients were taking nitrendipine. SBP/DBP at entry in Syst-Eur 2 averaged 160/83 mmHg in the former placebo group and 151/80 mmHg in the former active-treatment group. At the last follow-up visit SBP/DBP in the patients previously randomised to placebo or active treatment had decreased by 16/5 mmHg and 7/5 mmHg, respectively. The target BP was reached by 74% of the patients.Conclusion
Substantial reductions in systolic BP may be achieved in older patients with isolated systolic hypertension with a treatment strategy starting with the dihydropyridine calcium-channel blocker, nitrendipine, with the possible addition of enalapril and/or hydrochlorothiazide. 相似文献48.
Manfredini R Gallerani M Boari B Maraldi C la Cecilia O Rafael Ferreira AB Smolensky MH Portaluppi F 《Chronobiology international》2002,19(4):785-791
The aim of this study was to examine 24h patterning in the symptoms indicative of third-degree atrio-ventricular (AV) heart block. We found a total of 227 cases (126 men and 101 women) of third-degree AV block that had been diagnosed by the Emergency Medical Department of the St. Anna Hospital in Ferrara, Italy between 1990 and 2001. Determination of the hour of onset of symptomatic third-degree AV block, however, was possible and listed in the records of only 161 or 70.9% of the cases (92 men and 69 women). The onset time of every event was categorized into one of four 6h spans of the 24h: night (00:00-05:59h), morning (06:00-11:59h), afternoon (12:00-17:59h), and evening (18:00-23:59h). The onset of the symptoms of third-degree AV block in the sample of 161 cases was significantly greater in the morning between 06:00 and 11:59h than any other 6h span of the day and night (chi2-test; p < 0.001). The same phenomenon was substantiated in the subgroup of the 92 males (chi2; p < 0.0001), although it could not be detected for the smaller subgroup of 69 women. The 24h pattern, with morning preference, in the onset of symptomatic third-degree AV block is similar to the one in sudden cardiac death and cardiogenic cardiac arrest. The etiology of the 24h pattern in symptomatic AV block is unknown; it may be an expression of intrinsic biological rhythmicity within the heart tissue or its control system, and/or the timing of environmental triggers resulting in coronary ischemia. 相似文献
49.
50.
Brambilla G Civitareale C Ballerini A Fiori M Amadori M Archetti LI Regini M Betti M 《Redox report : communications in free radical research》2002,7(3):159-163
In pigs, the genetic selection for lean, large muscle blocks and fast growth has been linked to an increased prevalence of metabolic diseases such as porcine stress syndrome and mulberry heart disease. These diseases are associated with cardiovascular inadequacy, which may lead to oxidative stress. In the present study, reactive oxygen metabolites (ROMs) and the anti-oxidant power (OXY) in sera of different swine groups were investigated. The following groups were selected (each around 80 kg body weight): wild boars (WB), Cinta Senese (CS), and Landrace x Large White (LxLW), the latter as both specific pathogen-free (SPF) and intensively farmed animals. In addition, a group of LxLW agonic sows (AS) was also investigated; this group is known to be under oxidative stress. Two colorimetric micro-methods were used to measure ROMs and OXY; ROMs were expressed as mM H(2)O(2) and OXY as microM HOCl neutralised. Between groups, average ROM and OXY values were found to be significantly different by one-way ANOVA (P < 0.001). ROM levels were lower in WB (13.41 +/- 1.85) and CS (19.27 +/- 1.68), and highest in LxLW (42.00 +/- 1.36). OXY values ranged from 260.10 +/- 22.13 (WB) to 396.90 +/- 9.83 (LxLW). Only one swine group (the CS group) showed a significant, positive correlation between ROM and OXY values. The AS group even showed a negative correlation between ROM and OXY values. These results imply satisfactory environmental coping occurred only within the CS group. Results are discussed in the light of animal welfare legislation, food safety and consumers' protection. 相似文献