425 research outputs found
Hepatitis C virus infection: A "liaison a trois" amongst the virus, the host, and chronic low-level inflammation for human survival
No full textThis review covers the various aspects of the immune system that allows the relationship between the hepatitis-C virus, the host and chronic low-level inflammation, to be highly flexible and able to defend the host from persistent infections. This ambiguity mainly stems from the property of the immune system that can be both protective and harmful. Immunity cannot be fully protective without producing a certain degree of damage (acute hepatitis resulting in resolving HCV infection). In addition, the balance between protection and tissue damage is critical for the development of chronic HCV infection. The establishment of a state of chronic low-level inflammation is instrumental to limit liver immunopathology, to limit viral spread, and ultimately to ensure a long-lasting survival of the host. It is dictated by a fine equilibrium maintained by multiple immunologic mechanisms, including: sensory perception of innate immunity, virus-specific T and B cell functions, control of immune responses, and finally the balance between immunity and immunopathology that has principally evolved to favor the survival of the species. (C) 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved
Application of differential scanning calorimetry-chemometric coupled procedure to the evaluation of thermo-oxidation on extra virgin olive oil
No full textIn this work, the opportunity of adopting a differential
scanning calorimetry (DSC)-principal component
analysis (PCA) coupled procedure to measure the degree of
thermal stress for extra virgin olive oil (EVOO) was presented.
Oil was subjected to thermal stress under convectional
or microwave heating treatments at different heating
times up to 1,440 and 15 min, respectively, and p-anisidine
values (PAV) were obtained on all samples to measure their
oxidative degradation. The entire DSC profiles obtained on
the oil upon cooling in the range from 30 °C to –80 °C and
subsequent re-heating to 30 °C at different times and under
cooking procedures have been subjected to PCA data analysis.
PCA discriminated samples by means of profile
changes in DSC transition both upon cooling and heating
not only according to treatment times (which accounted for
the degree of thermo-oxidation) but also considering
different heating process. The proposed procedure may be
useful to measure oil thermal stress and to select appropriate
heating condition to be applied for EVOO both in industrial
and/or in food-catering sectors
DSC characterization of different olive oil categories
No full textThe EC Council of Regulation (Regulation (EC) No 1513/2001) have recently redefined commercial categories of olive oil and olive-pomace oil to avoid misleading of consumers and operators and to preserve high-quality products. DSC has proven to be able to differentiate monovarietal extra virgin olive oil and good correlation between thermal properties and chemical composition has been reported.
The aim of this work was to characterize different commercial olive oils by means of DSC cooling and heating thermograms. Samples of extra virgin olive oil, refined olive oil, olive oil, refined olive-pomace oil and olive-pomace oil were analyzed by means of DSC (DSC Q100, TA Instruments, New Castle, DE). All samples were cooled from 30 to -80°C at 2°C/min, held at -80°C and heated from -80 to 30°C at 2°C/min. Enthalpy (H, J/g), onset (Ton), and offset (Toff) temperatures, as well as range of transitions, were obtained.
Crystallization profiles of all samples showed two well defined exothermic events, a minor one at about -15°C and a major one at about -39°C. Crystallization of pomace oils had significantly lower enthalpy that the other samples, starting at higher temperature and developing over a larger range of temperature.
Heating profiles exhibited more marked differences. Two well defined endothermic events were observed at about -6 and 7°C. Lineshapes of the melting event peaking at higher temperature, were found to be different for the various olive oil categories. An additional endothermic peak at lower temperature was found in the refined olive oil, while the other oils exhibited an exothermic event which was more pronounced in pomace samples. Both refined oils displayed higher melting enthalpy and larger range of transition than their corresponding blends with virgin oil
DSC evaluation of thermoxidative decomposition of extra virgin olive oil: effect of microwave and conventional heating
No full textThe aim of this work was to evaluate DSC thermal properties of extra virgin olive oil subjected to microwave and thermal heating. Fresh extra virgin olive oil was stored in dark bottles under nitrogen at room temperature before analysis. Sample were placed in a 250 ml open flask and either heated in an electric oven (with air convection) at 180°C for 30, 90, 120, 180, 360, 900 and 1440 min, or microwaved (at 2450 MHz, 0.72 kW) for 3, 6, 9, 12, 15 and 20 min. All samples were cooled at room temperature in the dark to 30°C and then analyzed. Thermograms were obtained by means of DSC, by cooling from 30 to -80°C at 2°C/min, holding 3 min at -80°C and heating from -80 to 30°C at 2°C/min. Enthalpy (H, J/g), onset (Ton), and offset (Toff) temperatures of the transitions were obtained.
Lipid crystallization Ton of fresh extra virgin olive oil was at -11°C and developed over a 35–40 degrees range. Two well defined events (minor, peaking at -16 and major peaking at -40°C) were distinguishable. Heating thermograms of fresh sample showed a minor exothermic peak and successively a major endothermic event occurring over the -18°C/12°C temperature range, with the presence of a major endothermic peak (-5°C) and a small shoulder at 8°C.
Enthalpy of both crystallization and melting transition significantly decreased in all samples with increasing length of heating treatment; this effect was more pronounced for the microwaved sample. Crystallization peak line-shape dramatically changed with increasing heating time. The major crystallization peak decreased in height, and the transition spanned over a larger temperature range, because of a significant shift of Toff towards lower temperatures. Crystallization Ton remain constant in conventionally heated samples, whereas it significantly shifted towards higher temperature in samples microwaved for at least 12 min. Melting line-shapes also dramatically changed; in fact, the major endothermic peak flattened, decreased in height, and spanned over a larger temperature range, while the minor endothermic peak disappeared in the longest treated samples. An additional endothermic peak also appeared at lower temperature after 20 and 900 min of microwave and conventional treatment, respectively. Ton of the heating transition significantly shifted towards lower temperatures at increasing treatment time.
In conclusion, changes in all thermal properties were already evident in microwaved samples after 9 minutes of treatment, whereas similar values were reached after 360 min of air convection heating
Therapeutic Implications of Immunogenic Cell Death in Human Cancer
No full textDendritic cells (DCs) are central to the adoptive immune response, and their function is regulated by diverse signals in a context-specific manner. Different DCs have been described in physiologic conditions, inflammation, and cancer, prompting a series of questions on how adoptive immune responses, or tolerance, develop against tumors. Increasing evidence suggests that tumor treatments induce a dramatic change on tumor-infiltrating lymphocytes and, in particular, on some DC subtypes. In this review, we summarize the latest evidence on the role of DCs in cancer and preliminary evidence on chemotherapy-associated antigens identified in human cancers
Non-targeted, suspect and targeted High Resolution Mass Spectrometry (HRMS) approaches for the profiling of oenological matrices and different food commodities
No full textThe increasing number of foodomics studies based on non-targeted methods shows that this approach is considered by scientists to be an efficient way of evaluating food safety and quality. In the last few years, high resolution mass spectrometry (HRMS) has indeed gained wider acceptance thanks to the high selectivity and sensitivity achievable during analysis. In contrast to the classic unit-mass-resolution MS/MS approach, HRMS provides more information on sample composition through collection of full-scan spectra and thanks to the possibility of performing retrospective data analysis. Consequently, even without defining compound-specific tuning, HRMS data can be used for identification of suspect compounds or for structural elucidation of unknowns. HRMS can only compete with classic MS/MS methods using the targeted approach, even if it allows the simultaneous detection of a higher number of compounds. In contrast, HRMS is a more promising approach when suspect and non-targeted screening analysis is performed, not only because full-scan and retrospective analysis is feasible, but also because the accurate mass of both precursor and product ions and their isotope patterns are provided. Furthermore, a non-targeted approach leads to specific profiling of biological systems through a wide selection of chemical descriptors, and provides the fingerprint of the system under investigation, useful for more easily identifying potential adulteration.
The aim of this work was to extend comprehension of the three different HRMS approaches (nontargeted, suspect and targeted screening), examining both their potential and limitations in relation to the analysis of the compounds of interest in different matrices. Initially, the objectives concerned the possibility of developing new methods – one for each HRMS screening approach – for the analysis of glycosides and phenolic compounds, in order to furnish innovative and well-performing analytical tools for food safety and quality control at all stages of food production, processing and distribution. Furthermore, they regarded the possibility of investigating the nature and occurrence of glycosides and phenolic compounds in widely consumed beverage and food commodities, such as grape, wine, spirits, cocoa and honeys.
The thesis, which includes both published and in litteris papers, describes newly developed analytical methods and their technological applications in the study of different matrices, focusing on:
- Investigation of Neutral Loss experiments as an instrument for non-targeted screening analysis of glycosides, and performance evaluation of this analytical approach in relation to the glycosidic profiling of international monovarietal wines;
- Investigation of the distribution of free and glycosylated low-molecular-weight phenolic compounds in skin and seeds of color-rich Vitis vinifera grapes cultivated in southern Uruguay, combining Neutral loss experiment and suspect screening analysis;
- Investigation of the selectivity and sensitivity of the HRMS approach for targeted analysis of free and glycosylated low-molecular-weight phenolic compounds and suspect screening analysis of the latter, together with evaluation of the best sample clean-up procedure for reducing matrix interference;
- Investigation of the distribution of free and glycosylated low-molecular-weight phenolic compounds in skin, pulp and seeds, focusing on both Vitis vinifera and hybrid grapes;
- Investigation of the impact of alcoholic fermentation on the free and glycosylated phenolic profile of wines produced from grapes of hybrid varieties;
- Study of the occurrence of glycosylated low-molecular-weight phenolic compounds in tannins of different botanical origin, in order to evaluate the alteration of the phenolic profile of wines after tannin addition;
- Study of the free phenolic composition of wood barrels, in order to evaluate phenolic enrichment during ageing, and investigation of the possible impact of different barrel sanitation treatments on the phenolic transfer from wood to wine;
- Study of the free and glycosylated low-molecular-weight phenolic profile in Primitivo di Manduria and Negroamaro wines of different vintages and evaluation of the effect of wine ageing;
- Investigation of the possibility of considering free or glycosylated low-molecular-weight phenolic compounds as new markers for beverages and food characterization and their geographical traceability, focusing on wine, spirits, vinegar, food tannins, cocoa beans and honeys;
- Implementation of investigative methods of suspect screening analysis using naturally rich matrices as available sources of compounds of interest. This approach was applied on plant products for alkaloid identification;
- Investigation of the selectivity and sensitivity of the HRMS approach for suspect screening analysis of flavonoids in flowering plant (C. pareira) extracts
Il ruolo fondamentale dei sistemi trascorrenti nella cinematica Plio-Quaternaria dell'Arco Calabro
No full textStrike-slip systems as the main tectonic features in the Plio-Quaternary kinematics of the Calabrian Arc
No full textThe oblique and diachronous collision of theApennine-Maghrebian Chain with the Apulian (in thenorth-east) and Pelagian (in the south) continental forelands,has determined the characteristic arcuate structure ofthis orogen. The effects of Plio-Pleistocene deformationof the Calabrian Arc have been analysed on the basis ofavailable reflection seismic profiles and using local timestructuralmaps reconstructed along the main structures.During this period, internal sectors of the Tertiary chainmigrated forward on the oceanic Ionian foreland, and werecut by important strike-slip systems. These last have anorientation approximately coincident with that of themigration of the front, allowing differential movement ofthe different sectors of the arc, towards the weakly buoyantIonian oceanic domain. The dataset suggests a clear connectionbetween the development of the strike-slip systemscutting the chain and the direction of tectonic transport,towards the East during Late Messinian/Early Pliocenetime, to the ESE during Late Pliocene/Early Pleistocenetime, finally to the SSE during the Middle/Late Pleistoceneto Present, showing a clockwise rotation in well definedstages during the kinematic evolution of the chain. Theorigin of the Strait of Messina during the different phases isalso interpreted in the context of the analysed regionaltectonic setting
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