Influence of the substrate's hydrophilicity on the in vitro Schwann cells viability.

A series of polymeric biomaterials including poly (methyl acrylate) (PMA), chitosan (CHT), poly(ethyl acrylate) (PEA), poly(hydroxyethyl acrylate) (PHEA), and a series of random copolymers containing ethyl acrylate and hydroxyethyl acrylate monomeric units were tested in vitro as culture substrates and compared for their impact on the proliferation and expansion of Schwann cells (SCs). Immunocytochemical staining assay and scanning electron microscopy techniques were applied to perform a quantitative analysis to determine the correct maintenance of the cultured glial cells on the different biomaterials. The results strongly suggest that cell attachment and proliferation is influenced by the substrate's surface chemistry, and that hydrophobic biomaterials based on PMA, PEA, and the copolymers PEA and PHEA in a narrow composition window are suitable substrates to promote cell attachment and proliferation of SCs in vitro.

Copper content of grape and wine from Italian farms.

The copper content of grape and wine from 16 wine-farms in Italy was studied during the harvest of 2003. The influence of the number of copper applications, the period between the last application and harvest, and the total amount of copper applied was examined. Of the total number of samples analysed, 13% of grape samples and 18% of wine samples exceeded the maximum residue level (MRL). The total amount of copper applied and the number of days between the last application and harvest explained 44% of the concentration of copper in grape. This low correlation may be due to other influencing factors, such as meteorology and the application method. In 2003, conditions were unusually dry and the recommended safety interval for copper application (20 days) was not sufficient to guarantee a residue level in grape below the MRL (20 mg kg(-1)). In order to reduce the probability of copper residues being close to the MRL, a period of 40-50 days between the last application and harvest is suggested. Furthermore, the copper content of grape and wine was not dependent on the pest management strategy of the farm (conventional, integrated or organic). A more important factor influencing copper residue levels may be that copper applications are made in response to the prediction of a disease outbreak rather than being dependent on the pest management strategy in place. No difference in copper content was observed between red and white grape or wine.