[60]Fullerene-porphyrin [n]pseudorotaxanes: self-assembly, photophysics and third-order NLO response.

By means of different spectroscopic techniques, we investigate a novel series of porphyrin derivatives (H2TPP), connected to dibenzo-24-crown-8 (DB24C8) moieties, which undergo self-assembly with different methano[60]fullerene units bearing dibenzylammonium (DBA) cations. The formation of both [2] and [3]pseudorotaxanes was proved by means of NMR, UV-Vis-NIR absorption and emission spectroscopies. With the support of molecular modelling studies, spectroscopic investigations showed the presence of a secondary interaction between the porphyrin and the C60 chromophores leading to the formation of different types of "face-to-face" assemblies. Remarkably, investigations of the non-linear optical response of these supramolecular systems showed that individual porphyrin and fullerene derivatives exhibit significantly lower second hyperpolarizability values when compared to their pseudorotaxanes functionalised counterparts. This proves that this class of supramolecular materials possesses relevant NLO response, which strongly depends on the structural arrangement of the chromophores in solution.

Occurrence of enteric viruses in shellfish and relation to climatic-environmental factors.

AIMS: To investigate the presence of enteric viruses [hepatitis A (HAV) and norovirus (NoV)] in shellfish harvested from the deltaic area of the Po river in relation to environmental factors. METHODS AND RESULTS: Fortnightly sampling of shellfish was carried out in two lagoon areas (category B production areas) and one sea area (category A). Environmental parameters in the lagoon and hydrometric level of the tributary river were monitored throughout the sampling period. Samples (n = 120) were analysed for bacterial (E. coli and Salmonella) and viral (HAV and NoV) contamination; samples from category B areas were analysed before and after purification treatment. All the samples were negative for HAV whereas 10 samples (8.3%), all harvested in the lagoon areas, were positive for NoV. Sequencing identified the strains as genotypes II.4 and II.b. None of the samples was found to be contaminated after depuration. CONCLUSIONS: The monitoring showed a low frequency of NoV presence; viral contamination, detected exclusively in shellfish collected from the deltaic area (category B), could be influenced by the flow of the tributary river. The data collected are useful for the design of targeted prevention strategies and for the modulation of control plans after meteorological events.

Occurrence of hepatitis A and E and norovirus GI and GII in ready-to-eat vegetables in Italy.

Fresh vegetables and their ready-to-eat (RTE) salads have become increasingly recognized as potential vehicles for foodborne diseases. The EU Reg. 1441/2007 establishes microbiological criteria for bacterial pathogens for products placed on the market during their shelf-life (i.e. Salmonella spp., Listeria monocytogenes) for pre-cut fruits and vegetables (RTE) whilst it does not address the problem of contamination by enteric viruses. In this study we investigated the contamination by hepatitis A virus (HAV), hepatitis E virus (HEV) and norovirus (NoV) in 911 ready-to-eat vegetable samples taken from products at retail in Apulia and in Lombardia. The vegetable samples were tested using validated real-time PCR (RT-qPCR) assays, ISO standardized virological methods and ISO culturing methods for bacteriological analysis. The total prevalence of HAV and HEV was 1.9% (18/911) and 0.6% (6/911), respectively. None of the samples analysed in this study was positive for NoV, Salmonella spp. or Listeria monocytogenes. The detection of HAV and HEV in RTE salads highlights a risk to consumers and the need to improve production hygiene. Appropriate implementation of hygiene procedures is required at all the steps of the RTE vegetable production chain and this should include monitoring of emerging viral pathogens.

[Integrate cell culture--PCR (ICC/PCR) in viruses researches in environmental and food samples. Note I]. / L'integrazione colture cellulari--PCR (ICC/PCR) nella ricerca di virus in campioni ambientali e in alimenti. Nota I.

We carried out an experimental work integrating cell-culture and PCR to follow the HAV replication, to verify the PCR positiveness times and to confirm infectious viral particles presence. In tests HAV strain H59-175 was used. We proceeded to an initial valuation of the lowest viral concentration detectable by PCR. With viral titres between 10(5)-10(7) PFU/ml, the highest positive dilution resulted 10(-4)-10(-5). Then the 1 log lower dilution was inoculated in cell culture. At fixed times we proceeded to take surnatant and lisate samples for PCR test. After cell culture integration, positiveness was obtained in 72-120 hours against the 10-18 days necessary for CPE appearance.

Hepatitis E virus in wild boar in the central northern part of Italy.

Hepatitis E virus (HEV) is responsible for sporadic acute hepatitis in developed countries, where the infection is acquired probably through ingestion of contaminated food, in addition to travel-related cases. In this study, the circulation of HEV in wild boar from nine Italian provinces was evaluated. An overall seroprevalence of 10.2% was found, although there were differences among the provinces, while no samples were positive for HEV RNA detection. This study indicates an active circulation of HEV in the Italian wild boar populations and suggests to consider the zoonotic risk in handling and eating meat from this animal.

Microbiological survey of raw and ready-to-eat leafy green vegetables marketed in Italy.

The presence of foodborne pathogens (Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7, thermotolerant Campylobacter, Yersinia enterocolitica and norovirus) in fresh leafy (FL) and ready-to-eat (RTE) vegetable products, sampled at random on the Italian market, was investigated to evaluate the level of risk to consumers. Nine regional laboratories, representing 18 of the 20 regions of Italy and in which 97.7% of the country's population resides, were involved in this study. All laboratories used the same sampling procedures and analytical methods. The vegetable samples were screened using validated real-time PCR (RT-PCR) methods and standardized reference ISO culturing methods. The results show that 3.7% of 1372 fresh leafy vegetable products and 1.8% of 1160 "fresh-cut" or "ready-to-eat" (RTE) vegetable retailed in supermarkets or farm markets, were contaminated with one or more foodborne pathogens harmful to human health.

[Set up of in vitro methods able to detect the safety of astringent liquids]. / Messa a punto di metodi in vitro per la valutazione dell'innocuità dei liquidi astringenti.

AIM: Most of dental operators agree about a gengival retraction impregnated cord in order to obtain an accurate and overwide dental impression. Hemostatic agents allow the formation of the primary coagulum that determines/causes the retraction of gum connective. Sometimes these astringent liquids cause local inflammation reaction as reported in literature. Aim of this work was the evaluation of the cytotoxic and inflammatory action of the most common astringent liquid on human gum primary cells by in vitro tests. METHODS: For this purpose primary cultures of normal human oral keratinocytes were established, following used either as monolayer or as reconstituted model. All dental preparations were dissolved in CEC medium, diluted to the designed concentrations and applied to the cultured cells. The cytotoxicity was determined by using MTT test, able to evaluate the succinate dehydrogenase activity and therefore the cell viability. Control cultures were treated with CED alone, whereas sodium dodecyl sulphate (SDS) was used as a positive control. Furthermore, the inflammatory response, determined by measuring TNF-alpha and IFN-gamma release, was evaluated on a reconstituted multilayer human oral epidermis model. RESULTS: All agents tested showed a dose-dependent increase in the cytotoxicity to normal human gingival keratinocytes over the dose range examined. In particular the results obtained suggest the higher toxicity of the Astringedent X compound. CONCLUSION: The results obtained from the present studies not only provide useful estimates of relative toxicities of these preparations to human oral mucose, but also can be useful as a standard for cytotoxic and inflammatory assessment of newly developed dental preparations to be topically applied to the oral mucosa. It is important to note, however, that the interpolation of these findings to in vivo conditions remains to be done.

In vitro comparison of the antimycotic activity of a miconazole-HP-beta-cyclodextrin solution with a miconazole surfactant solution.

The antimycotic activity of a new parenteral solution containing miconazole was compared with that of a marketed solution (Daktarin IV solution). This solution has been withdrawn from the Belgian market, probably because of toxic effects related to the presence of polyoxyl 35 castor oil. We propose a new formulation containing miconazole (10 mg/mL) (like the marketed solution), in combination with hydroxypropyl-beta-cyclodextrin and lactic acid. The MICs of these two solutions were determined by a broth microdilution method (based on NCCLS guidelines) for 67 yeasts and 50 filamentous fungi isolates. This study shows that the MICs obtained with these two solutions are not significantly different.

Evaluation of the protective effects of alpha-tocopherol and retinol against ochratoxin A cytotoxicity.

Ochratoxin A (OTA), a mycotoxin frequently present in food and feedstuffs, produces a wide range of toxic effects, including cell death via lipid peroxidation. In one human and four animal cell lines we determined the half lethal concentration (LC50) of OTA, its effect on reactive oxygen species (ROS) production, and its ability to induce cytochrome p450 activity. We also examined the protective effect of alpha-tocopherol and all-trans-retinol in the most sensitive cell lines (i.e. bovine mammary epithelia, for which LC50 was 0.8 microg/ml (24 h), and Madin Darby canine kidney, for which LC50 was 4.3 microg/ml (48 h)). Pre-incubation for 3 h with either antioxidant significantly (P<0.05) ameliorated the OTA-induced reduction in cell viability and significantly decreased (P<0.05) ROS production. These findings indicate that oxidative stress is an important factor in OTA cytotoxicity. Supplementation with antioxidant molecules may counteract the short-term toxicity of this mycotoxin.