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排序方式: 共有450条查询结果,搜索用时 15 毫秒
371.
Marinelli K Bagnarelli P Gaffi G Trappolini S Leoni P Paggi AM Della Vittoria A Scalise G Varaldo PE Menzo S 《The new microbiologica》2007,30(3):275-278
Testing for viral BKV-DNA in urine is a non-invasive early detection and monitoring tool in the diagnostic of BKV-related pathologies: quantitative analysis by Real-Time PCR can provide useful information in addition to cytologic analysis, although our study suggests that high BKV viruria is not necessarily associated with kidney or bladder damage. 相似文献
372.
Cirioni O Giacometti A Kamysz W Silvestri C Riva A Della Vittoria A Abbruzzetti A Lukasiak J Scalise G 《Peptides》2007,28(4):747-751
The in vitro activities of tachyplesin III were investigated against 20 multidrug-resistant Pseudomonas aeruginosa clinical isolates. Methods included minimal inhibitory concentrations, minimal bactericidal concentrations, time-kill studies, checkerboard titration method, endotoxin-binding activity and cytotoxicity assay. Overall the organisms were susceptible to the peptide at concentrations of 0.50-4 mg/l. Tachyplesin III completely inhibits the endotoxin procoagulant activity at 22.36 mg/l concentration. Fractional inhibitory concentration indexes demonstrated synergy between the peptide and betalactams or colistin. In conclusion, the intrinsic antibacterial and antiendotoxin activities and the synergistic interactions demonstrated with clinically used antibiotics make tachyplesin III valuable as potential candidate for new therapeutic strategies aimed to treat P. aeruginosa infection. 相似文献
373.
D-Aspartic acid and nitric oxide as regulators of androgen production in boar testis 总被引:2,自引:0,他引:2
D-Aspartic acid (D-Asp) and nitric oxide (NO) are two biologically active molecules playing important functions as neurotransmitters and neuromodulators of nerve impulse and as regulators of hormone production by endocrine organs. We studied the occurrence of D-Asp and NO as well as their effects on testosterone synthesis in the testis of boar. This model was chosen for our investigations because it contains more Leydig cells than other mammals. Indirect immunofluorescence applied to cryostat sections was used to evaluate the co-localization of D-Asp and of the enzyme nitric oxide synthase (NOS) in the same Leydig cells. D-Asp and NOS often co-existed in the same Leydig cells and were found, separately, in many other testicular cytotypes. D-Asp level was dosed by an enzymatic method performed on boar testis extracts and was 40+/-3.6 nmol/g of fresh tissue. NO measurement was carried out using a biochemical method by NOS activity determination and expressed as quantity of nitrites produced: it was 155.25+/-21.9 nmol/mg of tissue. The effects of the two molecules on steroid hormone production were evaluated by incubating testis homogenates, respectively with or without D-Asp and/or the NO-donor L-arginine (L-Arg). After incubation, the testosterone presence was measured by immunoenzymatic assay (EIA). These in vitro experiments showed that the addition of D-Asp to incubated testicular homogenates significantly increased testosterone concentration, whereas the addition of L-Arg decreased the hormone production. Moreover, the inclusion of L-Arg to an incubation medium of testicular homogenates with added D-Asp, completely inhibited the stimulating effects of this enantiomer. Our results suggest an autocrine action of both D-Asp and NO on the steroidogenetic activity of the Leydig cell. 相似文献
374.
375.
Maria Fusaro Luca Dalle Carbonare Adriana Dusso Maria Vittoria Arcidiacono Maria Teresa Valenti Andrea Aghi Sabina Pasho Maurizio Gallieni 《PloS one》2015,10(8)
Background
Warfarin, a widely used anticoagulant, is a vitamin K antagonist impairing the activity of vitamin K-dependent Bone Gla Protein (BGP or Osteocalcin) and Matrix Gla Protein (MGP). Because dabigatran, a new anticoagulant, has no effect on vitamin K metabolism, the aim of this study was to compare the impact of warfarin and dabigatran administration on bone structure and vascular calcification.Methods
Rats with normal renal function received for 6 weeks warfarin, dabigatran or placebo. Bone was evaluated immuno-histochemically and hystomorphometrically after double labelling with declomycin and calcein. Aorta and iliac arteries were examined histologically.Results
Histomorphometric analysis of femur and vertebrae showed significantly decreased bone volume and increased trabecular separation in rats treated with warfarin. Vertebra analysis showed that the trabecular number was higher in dabigatran treated rats. Osteoblast activity and resorption parameters were similar among groups, except for maximum erosion depth, which was higher in warfarin treated rats, suggesting a higher osteoclastic activity. Therefore, warfarin treatment was also associated with higher bone formation rate/bone surface and activation frequency. Warfarin treatment may cause an increased bone turnover characterized by increased remodelling cycles, with stronger osteoclast activity compared to the other groups. There were no differences among experimental groups in calcium deposition either in aortic or iliac arteries.Conclusions
These findings suggest for the first time that dabigatran has a better bone safety profile than warfarin, as warfarin treatment affects bone by reducing trabecular size and structure, increasing turnover and reducing mineralization. These differences could potentially result in a lower incidence of fractures in dabigatran treated patients. 相似文献376.
Cutaneous phototype is considered mainly related to cutaneous pigmentation and to the eumelanin/pheomelanin ratio, which is mostly genetically determined by the melanocortin 1 receptor (MC1R) polymorphisms. However, data in literature indicate that, in addition to stimulation of eumelanin synthesis, the MC1R signalling activates antioxidant, DNA repair and survival pathways. New emerging aspects regarding photoprotection and skin phototypes are going beyond those features connected to the melanin content in the skin. Important new findings link the MC1R to nuclear receptors activation, shedding light on new extra‐melanogenic effects dependent on the α‐melanocyte‐stimulating hormone (α‐MSH) activity and new ways through which such functions are modulated. These evidences indicate that several factors including melanin play a part in defining the basis for individual sun sensitivity, suggesting that the cutaneous phototype represents a ‘biochemical fingerprint’. 相似文献
377.
Ana Ortiz-Espín Vittoria Locato Daymi Camejo Andreas Schiermeyer Laura De Gara Francisca Sevilla Ana Jiménez 《Annals of botany》2015,116(4):571-582
Background and Aims Reactive oxygen species (ROS), especially hydrogen peroxide, play a critical role in the regulation of plant development and in the induction of plant defence responses during stress adaptation, as well as in plant cell death. The antioxidant system is responsible for controlling ROS levels in these processes but redox homeostasis is also a key factor in plant cell metabolism under normal and stress situations. Thioredoxins (Trxs) are ubiquitous small proteins found in different cell compartments, including mitochondria and nuclei (Trxo1), and are involved in the regulation of target proteins through reduction of disulphide bonds, although their role under oxidative stress has been less well studied. This study describes over-expression of a Trxo1 for the first time, using a cell-culture model subjected to an oxidative treatment provoked by H2O2.Methods Control and over-expressing PsTrxo1 tobacco (Nicotiana tabacum) BY-2 cells were treated with 35 mm H2O2 and the effects were analysed by studying the growth dynamics of the cultures together with oxidative stress parameters, as well as several components of the antioxidant systems involved in the metabolism of H2O2. Analysis of different hallmarks of programmed cell death was also carried out.Key Results Over-expression of PsTrxo1 caused significant differences in the response of TBY-2 cells to high concentrations of H2O2, namely higher and maintained viability in over-expressing cells, whilst the control line presented a severe decrease in viability and marked indications of oxidative stress, with generalized cell death after 3 d of treatment. In over-expressing cells, an increase in catalase activity, decreases in H2O2 and nitric oxide contents and maintenance of the glutathione redox state were observed.Conclusions A decreased content of endogenous H2O2 may be responsible in part for the delayed cell death found in over-expressing cells, in which changes in oxidative parameters and antioxidants were less extended after the oxidative treatment. It is concluded that PsTrxo1 transformation protects TBY-2 cells from exogenous H2O2, thus increasing their viability via a process in which not only antioxidants but also Trxo1 seem to be involved. 相似文献
378.
Raffaele Iennaco Giulio Formenti Camilla Trovesi Riccardo Lorenzo Rossi Chiara Zuccato Tiziana Lischetti Vittoria Dickinson Bocchi Andrea Scolz Cristina Martínez-Labarga Olga Rickards Michela Pacifico Angelica Crottini Anders Pape Mller Richard Zhenghuan Chen Thomas Francis Vogt Giulio Pavesi David Stephen Horner Nicola Saino Elena Cattaneo 《Cell death and differentiation》2022,29(2):293
379.
Regulation of sucrose and starch metabolism in potato tubers in response to short-term water deficit 总被引:24,自引:0,他引:24
Peter Geigenberger Ralph Reimholz Michael Geiger Lucia Merlo Vittoria Canale Mark Stitt 《Planta》1997,201(4):502-518
To investigate the effect of water stress on carbon metabolism in growing potato tubers (Solanum tuberosum L.), freshly cut and washed discs were incubated in a range of mannitol concentrations corresponding to external water potential
between 0 and −1.2 MPa. (i) Incorporation of [14C]glucose into starch was inhibited in water-stressed discs, and labeling of sucrose was increased. High glucose overrode
the changes at low water stress (up to −0.5 MPa) but not at high water stress. (ii) Although [14C]sucrose uptake increased in water-stressed discs, less of the absorbed [14C]sucrose was metabolised. (iii) Analysis of the sucrose content of the discs confirmed that increasing water deficit leads
to a switch, from net sucrose degradation to net sucrose synthesis. (iv) In parallel incubations containing identical concentrations
of sugars but differing in which sugar was labeled, degradation of [14C]sucrose and labeling of sucrose from [14C]glucose and fructose was found at each mannitol concentration. This shows that there is a cycle of sucrose degradation and
resynthesis in these tuber discs. Increasing the extent of water stress changed the relation between sucrose breakdown and
sucrose synthesis, in favour of synthesis. (v) Analysis of metabolites showed a biphasic response to increasing water deficit.
Moderate water stress (0–200 mM mannitol) led to a decrease of the phosphorylated intermediates, especially 3-phosphoglycerate
(3PGA). The decrease of metabolites at moderate water stress was not seen when high concentrations of glucose were supplied
to the discs. More extreme water stress (300–500 mM mannitol) was accompanied by an accumulation of metabolites at low and
high glucose. (vi) Moderate water stress led to an activation of sucrose phosphate synthase (SPS) in discs, and in intact
tubers. The stimulation involved a change in the kinetic properties of SPS, and was blocked␣by protein phosphatase inhibitors.
(vii) The amount of ADP-glucose (ADPGlc) decreased when discs were incubated on 100 or 200 mM mannitol. There was a strong
correlation between the in vivo levels of ADPGlc and 3PGA when discs were subjected to moderate water stress, and when the
sugar supply was varied. (viii) The level of ADPGlc increased and starch synthesis was further inhibited when discs were incubated
in 300–500 mM mannitol. (ix) It is proposed that moderate water stress leads to an activation of SPS and stimulates sucrose
synthesis. The resulting decline of 3PGA leads to a partial inhibition of ADP-glucose pyrophosphorylase and starch synthesis.
More-extreme water stress leads to a further alteration of partitioning, because it inhibits the activities of one or more
of the enzymes involved in the terminal reactions of starch synthesis.
Received: 26 August 1996 / Accepted: 5 November 1996 相似文献
380.
Philip E. Thompson Vittoria Cavallaro Milton T. W. Hearn 《Letters in Peptide Science》1995,1(6):263-268
Summary Experimental conditions which influence the formation of -aminosuccinimide (Asu) structures in Fmoc-based SPPS have been examined as part of our work on the synthesis of the hypoglycaemic peptide, Asu11-hGH[6–13] amide, and its analogues. Based on these investigations, experimental conditions for the acid- and base-catalysed cyclization of the corresponding protected aspartyl-containing peptides have been optimized to provide improved yields and reduced side product formation of these -aminosuccinimide-containing peptides. 相似文献