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1.
Summary Starting from field investigations and experiments on mimetic butterfly populations a model for two mimetic species is developed. The model comprises various features such as the growth rates and carrying capacities of the two species, their unpalatability to predators, the recruitment and the training of the predators and, most important, the similarity of the two mimetic species. The model ranges from pure Batesian to pure Müllerian mimicry over a spectrum of possible cases. The mimetic gain is introduced as the relative increase in equilibrium density in a mimetic situation as compared to a situation where mimicry is not present. The dependence of this quantity on parameters as growth rate, carrying capacity, unpalatability, and similarity is investigated using numerical methods. 相似文献
2.
Kristina Zakharova Donatella Tesei Gorji Marzban Jan Dijksterhuis Timon Wyatt Katja Sterflinger 《Mycopathologia》2013,175(5-6):537-547
Black microcolonial fungi (MCF) and black yeasts are among the most stress-resistant eukaryotic organisms known on Earth. They mainly inhabit bare rock surfaces in hot and cold deserts of all regions of the Earth, but some of them have a close phylogenetic relation to human pathogenic black fungi which makes them important model organisms also with respect to clinical mycology. The environment of those fungi is especially characterized by extreme changes from humidity to long periods of desiccation and extreme temperature differences. A key to the understanding of MCF ecology is the question about metabolic activity versus dormancy in the natural environments. In this study, the time lag from the desiccated state to rehydration and full metabolic activity and growth was measured and defined in accordance with simulated environmental conditions. The ability to survive after desiccation and the speed of rehydration as well as changes of the whole cell protein pattern are demonstrated. Whereas both mesophilic strains—Exophiala jeanselmei and Knufia perforans (=Coniosporium perforans)—show a clear reaction toward desiccation by production of small proteins, Cryomyces antarcticus—the extremotolerant MCF—does not show any response to desiccation but seems just to down-regulate its metabolism. Data on intracellular sugar suggest that both trehalose and mannitol might play a cell protective role in those fungi. 相似文献
3.
Marina Allegrezza Silvia Montecchiari Cecilia Ottaviani Veronica Pelliccia Giulio Tesei 《Plant biosystems》2019,153(4):616-623
This study presents the results of a floristic vegetational study on Robinia pseudoacacia neoformation forests in the peri-Adriatic sector of central Italy. This has allowed the characterization of these coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These currently represent the southernmost syntaxa of the Robinietea class described for the Italian peninsula, and the first syntaxonomic contribution of this class in Europe for the Mediterranean biogeographical region. We propose here the new alliance Lauro nobilis–Robinion pseudoacaciae of the order Chelidonio–Robinietalia pseudoacaciae and class Robinietea, with two new associations: Melisso altissimae–Robinietum pseudoacaciae and Rubio peregrinae–Robinietum pseudoacaciae. The new alliance Lauro nobilis–Robinion pseudoacaciae (typus: Melisso altissimae–Robinietum pseudoacaciae) brings together neoformation forests and pre-forest dominated by R. pseudoacacia in those territories with a Mediterranean macroclimate of the peri-Adriatic sector of central Italy. The optimum is found for the alluvial plain and low-slope morphologies, on soils that are moist and rich in organic matter and in areas with anthropic disturbance. On the basis of comparisons with the European context, the alliance Bryonio–Robinion described for the temperate territories of northern Italy is here validated. 相似文献
4.
Rosetti M Tesei A Ulivi P Fabbri F Vannini I Brigliadori G Amadori D Bolla M Zoli W 《Apoptosis : an international journal on programmed cell death》2006,11(8):1321-1330
Although non steroidal antiinflammatory drugs (NSAIDs) have been shown to be effective as chemopreventive agents, important
side-effects limit their clinical use. A promising novel class of drugs, nitric oxide-donating NSAIDs (NO-NSAIDs), has been
found to be more active than classical NSAIDs. This study explored the effect of the NO-donating aspirin derivative, NCX 4040,
on three human pancreatic adenocarcinoma cell lines (Capan-2, MIA PaCa-2 and T3M4). NCX 4040 activity was compared with that
of NCX 4016 (an NO2-positional isomer of NCX 4040), SNAP (a standard NO-releasing molecule), NCX 4042 (denitrated analog of NCX 4040), and aspirin.
NCX 4040 showed a striking cytocidal activity in all cell lines, already inducing significant percentages of apoptotic cells
at 10 μM in Capan-2 cell lines. This study focused on the biological mechanisms of sensitivity and resistance to NCX 4040,
highlighting that the cytotoxic action of this drug may be due to the hyperexpression of Bax, its translocation to the mitochondria,
the release of Cytochrome C, and the activation of caspases-9 and -3, overall in a p53-independent manner. Moreover, the use
of a specific COX-2 inhibitor (NS 398) in the experimental models showed that COX-2 hyperexpression could partially explain
the resistance mechanisms to NCX 4040.
This study was supported by Istituto Oncologico Romagnolo, Forlì, and by the Italian, Ministry of Health, 2004. 相似文献
5.
Rock inhabiting fungi are among the most stress tolerant organisms on Earth. They are able to cope with different stressors determined by the typical conditions of bare rocks in hot and cold extreme environments. In this study first results of a system biological approach based on two-dimensional protein profiles are presented. Protein patterns of extremotolerant black fungi – Coniosporium perforans, Exophiala jeanselmei – and of the extremophilic fungus – Friedmanniomyces endolithicus – were compared with the cosmopolitan and mesophilic hyphomycete Penicillium chrysogenum in order to follow and determine changes in the expression pattern under different temperatures. The 2D protein gels indicated a temperature dependent qualitative change in all the tested strains. Whereas the reference strain P. chrysogenum expressed the highest number of proteins at 40 °C, thus exhibiting real signs of temperature induced reaction, black fungi, when exposed to temperatures far above their growth optimum, decreased the number of proteins indicating a down-regulation of their metabolism. Temperature of 1 °C led to an increased number of proteins in all of the analysed strains, with the exception of P. chrysogenum. These first results on temperature dependent reactions in rock inhabiting black fungi indicate a rather different strategy to cope with non-optimal temperature than in the mesophilic hyphomycete P. chrysogenum. 相似文献
6.
Alice Pasini Giulia Paganelli Anna Tesei Wainer Zoli Emanuele Giordano Daniele Calistri 《Translational oncology》2012,5(6):461-468
Five-year survival rate for lung cancer is limited to 10% to 15%. Therefore, the identification of novel therapeutic prognostic factors is an urgent requirement. The aim of this study is thus to highlight specific biomarkers in chemoresistant non-small cell lung cancer cell lines. Therefore, we checked—in the control condition as well as after short-term pharmacological treatment with either docetaxel or gemcitabine—the expression of genes such as tumor suppressor genes (CDKN2A, DAPK, FHIT, GSTP1, MGMT, RARβ2, RASSF1A, and TIMP3), genes associated with drug resistance (BRCA1, COX2, ERCC1, IGFBP3, RRM1, and TUBB3), and stemness-related genes (CD133, OCT4, and SLUG) in two cellular models of squamous carcinoma (CAEP) and adenocarcinoma (RAL) of the lung originally established. Their promoter methylation profile was also evaluated. Drug-related genes were upregulated. Cisplatin resistance matched with high levels of BRCA1 and ERCC1 in both cell lines; docetaxel sensitivity of CAEP cells was associated to levels of TUBB3 lower than RAL cells. Although CAEP cells were more sensitive to gemcitabine, both cell lines showed high levels of RRM1. Stemness-related genes were downregulated in the control condition but became upregulated in docetaxel-resistant cells, indicating the selection of a population with stemness features. We did not find an unequivocal correspondence between gene expression and respective DNA promoter methylation status, suggesting the involvement of additional mechanisms of gene expression regulation. These results highlight specific biomarkers consistent with the different responses of the two cell lines to standard pharmacological treatments and indicate specific molecular traits for their chemoresistance. 相似文献
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8.
Laura Costarelli Elisa Muti Marco Malavolta Catia Cipriano Robertina Giacconi Silvia Tesei Francesco Piacenza Sara Pierpaoli Nazzarena Gasparini Emanuela Faloia Giacomo Tirabassi Marco Boscaro Angela Polito Beatrice Mauro Francesca Maiani Anna Raguzzini Fiorella Marcellini Cinzia Giuli Roberta Papa Monica Emanuelli Eugenio Mocchegiani 《The Journal of nutritional biochemistry》2010,21(5):432-437
Overweight and obesity are associated with low grade of inflammation and chronic inflammatory response characterized by abnormal production and activation of some pro-inflammatory signalling pathways. Taking into account that obesity is the direct result of an imbalance between energy intake and energy expenditure, the nutritional factors in the diet, with particular focus on zinc, may play a pivotal role in the development of obesity-associated comorbidities. Considering the potential interactions among zinc nutritional status, inflammation, overweight/obesity and insulin secretion, the aim of the present work was to clarify the influence of zinc dietary intake on some metabolic, inflammatory and zinc status parameters in adult overweight/obese subjects. We found a close interrelationship between nutritional zinc and obesity. In particular, subjects with a lower zinc dietary intake display a deeper inflammatory status, general impairment of the zinc status, an altered lipid profile and increased insulin production with respect to obese subjects with normal zinc dietary intake. Moreover, in the presence of low dietary zinc intake, the obese subjects are less capable to respond to oxidative stress and to inflammation leading to the development of obesity or to a worsening of already preexisting obesity status. In conclusion, a possible zinc supplementation in obese subjects with a deeper inflammatory status and more altered zinc profile may be suggested in order to limit or reduce the inflammation, taking also into account that zinc supplementation normalizes “inflammaging” as well as zinc profile leading to a correct intra- and extracellular zinc homeostasis. 相似文献
9.
Robertina Giacconi Stavroula Kanoni Patrizia Mecocci Marco Malavolta Dimitris Richter Sara Pierpaoli Laura Costarelli Catia Cipriano Elisa Muti Francesca Mangialasche Francesco Piacenza Silvia Tesei Roberta Galeazzi Eirini V. Theodoraki Fabrizia Lattanzio George Dedoussis Eugenio Mocchegiani 《The Journal of nutritional biochemistry》2010,21(10):1008-1014
Metallothioneins (MT), the antioxidant zinc-binding proteins, seem to mediate cardioprotection. It has been postulated that zinc homeostasis and MT function may be altered, as a consequence of oxidative stress, in cardiovascular disease (CVD), with a potential implication of MT genetic polymorphisms. The present study explores the role of +647A/C and +1245A/G MT1A polymorphisms on the susceptibility to CVD, zinc status and enzyme antioxidant activity, in the Greek and Italian populations. The country selection was based on the lower zinc status and the reduced zinc dietary intake in Greece than in Italy despite the similar Mediterranean dietary pattern. A total of 464 old, healthy control subjects and 369 old CVD patients more than 70 years of age were studied. Logistic regression model indicated that +1245 MT1A G+ genotype significantly increased the risk of CVD in Greece (34.4% vs. 23.2%; odds ratio=1.88, 95% confidence interval=1.14–3.08; P=.013) but not in Italy. Haplotype analysis showed an increment of CG haplotype frequency in CVD Greek patients (17.4% vs. 10.6%, P<.05). Differential country-related frequency distribution was also recorded. Applying a multivariate regression model, +647/+1245 MT1A haplotype was associated with a modulation of enzyme antioxidant activities in both countries. Decreased plasma zinc and reduced intracellular Zn release, as well as increased enzyme antioxidant activity, were more apparent in Greek healthy donors than in Italy. In conclusion, +1245 MT1A polymorphism and +647/+1245 MT1A haplotype are implicated in CVD in Greece but not in Italy, suggesting a role of gene–diet interaction in the disease predisposition. 相似文献
10.
Filippo Piccinini Anna Tesei Chiara Arienti Alessandro Bevilacqua 《Biological procedures online》2017,19(1):8