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81.
Antonio Di Stefano Eleonora D'Aurizio Oriana Trubiani Rossella Grande Emanuela Di Campli Mara Di Giulio Soraya Di Bartolomeo Piera Sozio Antonio Iannitelli Antonia Nostro Luigina Cellini 《Microbial biotechnology》2009,2(6):634-641
The viscoelastic properties of mono‐microbial biofilms produced by ocular and reference staphylococcal strains were investigated. The microorganisms were characterized for their haemolytic activity and agr typing and the biofilms, grown on stainless steel surface under static conditions, were analysed by Confocal Laser Scanning Microscopy. Static and dynamic rheometric tests were carried out to determine the steady‐flow viscosity and the elastic and viscous moduli. The analysed biofilms showed the typical time‐dependent behaviour of viscoelastic materials with considerable elasticity and mechanical stability except for Staphylococcus aureus ATCC 29213 biofilm which showed a very fragile structure. In particular, S. aureus 6ME biofilm was more compact than other staphylococcal biofilms studied with a yield stress ranging between 2 and 3 Pa. The data obtained in this work could represent a starting point for developing new therapeutic strategies against biofilm‐associated infections, such as improving the drug effect by associating an antimicrobial agent with a biofilm viscoelasticity modifier. 相似文献
82.
Rosa Molfetta Francesca Gasparrini Giovanna Peruzzi Laura Vian Mario Piccoli Luigi Frati Angela Santoni Rossella Paolini 《PloS one》2009,4(5)
The best characterized role for ubiquitination of membrane receptors is to negatively regulate signaling by targeting receptors for lysosomal degradation. The high affinity receptor for IgE (FcεRI) expressed on mast cells and basophils is rapidly ubiquitinated upon antigen stimulation. However, the nature and the role of this covalent modification are still largelly unknown. Here, we show that FcεRI subunits are preferentially ubiquitinated at multiple sites upon stimulation, and provide evidence for a role of ubiquitin as an internalization signal: under conditions of impaired receptor ubiquitination a decrease of receptor entry is observed by FACS analysis and fluorescence microscopy. We also used biochemical approaches combined with fluorescence microscopy, to demonstrate that receptor endocytosis requires the integrity of specific membrane domains, namely lipid rafts. Additionally, by RNA interference we demonstrate the involvement of ubiquitin-binding endocytic adaptors in FcεRI internalization and sorting. Notably, the triple depletion of Eps15, Eps15R and Epsin1 negatively affects the early steps of Ag-induced receptor endocytosis, whereas Hrs depletion retains ubiquitinated receptors into early endosomes and partially prevents their sorting into lysosomes for degradation. Our results are compatible with a scenario in which the accumulation of engaged receptor subunits into lipid rafts is required for receptor ubiquitination, a prerequisite for efficient receptor internalization, sorting and delivery to a lysosomal compartment. 相似文献
83.
Bruno E. L. Cerabolini Guido Brusa Roberta M. Ceriani Rossella De Andreis Alessandra Luzzaro Simon Pierce 《Plant Ecology》2010,210(2):253-261
The general applicability of CSR classification (a methodology for applying CSR theory) has not been tested outside Britain.
We hypothesised that principal axes of trait variation for plant species native to southern European continental, sub-alpine
and alpine bioclimatic zones correlate with CSR classification scores. Functional traits were quantified in situ for 506 species
of 57 families. Multivariate analysis revealed three main modes in which plants invested biomass: (1) architectural extension
of individual ramets (tall canopies, large leaves), (2) durable tissues (high leaf dry matter contents and carbon contents,
low specific leaf areas) or (3) regenerative development (early, extensive flowering with delicate, nitrogen-rich leaves).
These were highly significantly correlated with the extent of competitive ability (C), stress-tolerance (S) and ruderalism
(R), respectively, determined by CSR classification. Despite being calibrated using only 43 British species, CSR classification
is consistent with trait variation in a phylogenetically broader sample of species native to a wider range of bioclimatic
zones. 相似文献
84.
Giovanna Bosi Michael Herchenbach Fabrizio Buldrini Rossella Rinaldi Marta Bandini Mazzanti 《Economic botany》2017,71(2):133-146
Diospyros lotus L. is an arboreal species native to the Balkans and Caucasus and ranging to the Far East. In Italy, it has been cultivated for centuries and has reverted to the wild state in some regions. During archaeological excavations carried out in the historical center of Modena (northern Italy), two floral calyxes of D. lotus were discovered in a layer dating from the first century ce. These are the first and only remains of D. lotus found in an archaeological context in Italy thus far. The first historical mention of this species as an arboreal plant in Italy occurs in the 1565 edition of Dioscorides’ Commentarii de Medica materia by Pietro Andrea Mattioli. Our research allowed us to establish that the first three Italian herbaria containing samples of D. lotus, dating to the 1551–1570 period, are the Erbario B of the Biblioteca Angelica of Rome, the Erbario Aldrovandi (Bologna) and the Erbario Cesalpino (Florence). However, archaeobotanical remains reveal that the fruits of this species were known during the Roman period, probably arriving in northern Italy as a luxury food owing to their exceptional flavor. 相似文献
85.
Wilson C Venditti R Rega LR Colanzi A D'Angelo G De Matteis MA 《The Biochemical journal》2011,433(1):1-9
Remarkable advances have been made during the last few decades in defining the organizational principles of the secretory pathway. The Golgi complex in particular has attracted special attention due to its central position in the pathway, as well as for its fascinating and complex structure. Analytical studies of this organelle have produced significant advances in our understanding of its function, although some aspects still seem to elude our comprehension. In more recent years a level of complexity surrounding this organelle has emerged with the discovery that the Golgi complex is involved in cellular processes other than the 'classical' trafficking and biosynthetic pathways. The resulting picture is that the Golgi complex can be considered as a cellular headquarters where cargo sorting/processing, basic metabolism, signalling and cell-fate decisional processes converge. 相似文献
86.
Natoli M Leoni BD D'Agnano I D'Onofrio M Brandi R Arisi I Zucco F Felsani A 《Journal of cellular physiology》2011,226(6):1531-1543
The human intestinal Caco-2 cell line has been extensively used as a model of the intestinal barrier. However, it is widely reported in literature that culture-related conditions, as well as the different Caco-2 cell lines utilized in different laboratories, often lead to problems of reproducibility making difficult to compare results. We developed a new cell-maintenance protocol in which Caco-2 cells were subcultured at 50% of confluence instead of 80% of confluence, as usually suggested. Using this new protocol, Caco-2 cells retained a higher proliferation potential resulting in a cell population, which, on reaching confluence, was able to differentiate almost synchronously, forming a more homogeneous and polarized cell monolayer, as compared to that obtained using a high cell growing density. This comparison has been done by analyzing the gene expression and the structural characteristics of the 21-days differentiated monolayers by microarrays hybridization and by confocal microscopy. We then investigated if these differences could also modify the effects of toxicants on 21-days-differentiated cells. We analyzed the 2 h-acute toxicity of CuCl(2) in terms of actin depolymerization and metallothionein 2A (MT2A) and heat shock protein 70 (HSPA1A) genes induction. Copper treatment resulted in different levels of actin depolymerization and gene expression induction in relationship with culture protocol, the low-density growing cells showing a more homogeneous and stronger response. Our results suggest that cell growing density could influence a number of morphological and physiological properties of differentiated Caco-2 cells and these effects must be taken in account when these cells are used as intestinal model. 相似文献
87.
88.
Marco Di Tola Rachele Amodeo Mariacatia Marino Fabio Tabacco Rossella Casale Maurizio Bove Alfredo Rossi Patrizia Cardelli Antonio Picarelli 《Biological trace element research》2014,159(1-3):81-86
Nickel (Ni) exposure through the intestinal mucosa may cause a hypersensitivity reaction recently defined as allergic contact mucositis (ACM). This condition is identifiable by the oral mucosa patch test (omPT), a qualitative and subjective examination that requires clinical expertise. Our aim was to evaluate if a peripheral blood lymphocyte typing performed before and after the omPT for Ni may be able to objectify this examination for diagnostic purposes. Thirty patients with symptoms referable to the ingestion of Ni-rich foods were subjected to omPT for Ni. Before and after the omPT, each patient underwent blood sampling for the typing of total lymphocytes and their subsets (T, T helper or Th, T cytotoxic or Tc, B, natural killer or NK). Statistical analysis was performed by Student t test and receiver operating characteristic (ROC) curve analysis. According to the omPT outcomes, 18 patients were defined as Ni-sensitive and the remaining 12 as controls. In Ni-sensitive patients, the number of total, T, Th, Tc, and B lymphocytes/μL whole blood increased after the omPT (p?<?0.0001 for the first three, p?=?0.0004 and p?=?0.0001 for the last two lymphocyte types). No omPT-dependent lymphocyte increase was observed in controls. The post/pre omPT cell ratio, especially if calculated for Th lymphocytes, appears to be an effective index for diagnostic purposes (sensitivity?=?100 %, specificity?=?83.3 %, Youden index?=?0.833, area under curve (AUC)?=?0.926, p?<?0.0001). In conclusion, the peripheral blood lymphocyte typing with calculation of post/pre omPT cell ratio has the potential to support the omPT in diagnosing ACM, with the advantage of providing quantitative and objective data. 相似文献
89.
Chiral dehydroamino acid building blocks are versatile starting materials for the preparation of optically active unusual amino acids and other compounds of pharmacological interest. Herein we disclose the expedient preparation of dehydroalanines (ΔAla) equipped with oxazolidin-2-one (Oxd) chiral auxiliaries, Ts-Oxd-ΔAla-OMe. These compounds have been obtained in high yields from dipeptides Ts-Ser/Thr/phenylSer-Ser-OMe by the one-pot cyclization–elimination reaction with N,N-disuccinimidyl carbonate and catalytic DIPEA. To test the efficacy of the chiral auxiliaries in controlling asymmetric transformations, the Friedel–Crafts alkylations of indoles carrying diverse substituents were performed in the presence of Lewis and Brønsted acids. The reactions proceeded with good to excellent diastereomeric ratios giving (S)- or (R)-tryptophan derivatives, isolated very conveniently by simple flash chromatography. To verify the utility of this approach, optically pure (S)-2-methyltryptophan and (S)-5-fluorotryptophan were obtained and utilized to prepare analogues of endogenous opioid peptide endomorphin-1, H-Tyr-Pro-Trp-PheNH2. 相似文献
90.
Michela Marignani Gianluigi Bacchetta Simonetta Bagella Maria Carmela Caria Francesco Delogu Emmanuele Farris Giuseppe Fenu Rossella Filigheddu Carlo Blasi 《Biodiversity and Conservation》2014,23(2):421-431
The collection and organization of distributional data is the first crucial stage of any conservation planning action: therefore the decline in field research has implications in both the systematic, floristic and conservation fields. The aim of this paper is to analyze the effects of data updating on conservation planning and priorities. Focusing on the short time frame ranging from 2006 to 2011, we present a case study showing the rate of increase of collected data (taxa and records) and the consequential effects on the definition of areas of priority interest for plant conservation (Important Plant Areas—IPAs). We gathered data on a total of 193 taxa and 849 records with a mean rate of increase of +97 % for taxa and +166 % for records (2006/2011). This increase caused a positive rate of change in high ranking cells (+78 %) defining IPAs, while the number of low ranking cells and no data cells slightly decreased (?12 and ?8 %, respectively). Our results suggest that specific investment to complete the knowledge on the distribution of selected taxa (e.g. 193 taxa represent the 7.5 % of the total vascular flora of Sardinia) would dramatically reduce both the Linnean and Wallacean shortfalls and would allow robust conservation programs to preserve the diversity of the island. Updating the IPAs on a regular basis is a good example of a process that has a low impact as well as a big potential gain especially when field research can only be performed with low intensity and small monetary investments. 相似文献