Organophosphorous (OP) compounds are pesticides frequently released into the environment because of extensive use in agriculture. Among these, methyl parathion (mPT) recently received attention as a consequence of illegal use. The predominant route of human exposure to mPT is via inhalation, but inadvertent consumption of contaminated foods and water may also occur. The goal of this study was to investigate the in vitro effects of mPT on cells in the oral cavity and evaluate the potential protective role of epigallocathechin-3-gallate (EGCG) on these effects. Human gingival fibroblasts (HGF) were exposed to 10, 50, or 100 μg/ml mPT for 24 h and assessed for oxidative stress, as evidenced by reactive generation of oxygen species (ROS), induction of apoptotic cell death, DNA damage (comet assay and cytochinesis-block micronucleus test), and nitric oxide (NO) production. The results showed that mPT produced significant oxidative stress, cytotoxicity, and genotoxicity and increased NO levels through stimulation of inducible NO synthase expression. Finally, data demonstrated that EGCG (10, 25, or 50 μM) was able to inhibit the pesticide-induced effects on all parameters studied. Data indicate that cytotoxic and genotoxic effects may be associated with oxidative stress induced by mPT observed in HGF cultures and that EGCG plays a protective role via antioxidant activities.

Single-wall carbon nanotubes (SWCNTs) are one of the most extensively produced carbon materials and the environmental, public and professional exposure is therefore dramatically increasing. Consequently the studies on bio-effects and safety of SWCNTs are highly needed. The goal of this study was investigate the effects in vitro of SWCNTs in cells of the oral cavity, never employed in this research field. We exposed human gingival fibroblasts to 50, 75, 100, 125, 150 μg/ml SWCNTs for 24 h and we investigated genotoxicity (Comet assay and micronucleus test), cytotoxicity, oxidative stress, as reactive oxygen species (ROS) generation, and stress response, as Heat shock protein 70 (Hsp70) expression. SWCNTs produced genotoxic effects at all doses, even if detected with different sensitiveness by the two tests, and at the two highest doses induced a strong decrease of the cell proliferation and cell survival, causing apoptosis too. Furthermore, we proved the ability of these nanomaterials to induce oxidative stress and Hsp70 expression. Finally, by inhibition of Hsp70 expression, we demonstrated that this heat shock protein conferred protection against SWCNT geno-cytotoxicity.

Activated single wall carbon nanotubes have been used for biomedical purposes as carriers for drugs, peptides, proteins and nucleic acids. A large volume of data speaks to their suitability to act as a carrier. The ability of two differently activated SWNTs (with carboxyl groups or with carboxyl groups and polyethylenimine (PEI)) to form a complex with the hepatitis A virus was evaluated. Both types of activations permitted the formation of a virus-SWNT complex. However, their patterns were different. The carboxyl-activated nanotubes had a somewhat low adsorptive capacity that was related inversely to the concentrations of the SWNTs and viruses. Statistical analysis, using the chi(2)-test, showed no significant differences between the SWNT-PEI ratios of 1:2.5, 1:1 and 1:0.5. The addiction of PEI improved the adsorption, probably because of the electropositive charge of the molecule. Adsorption was optimal between 100 mu g and 10 ng with a SWNTs-PEI weight ratio of 1:0.2 up to an inoculum of 10(5) genome equivalents of hepatitis A virus. Reducing or increasing this weight ratio reduced the adsorptive capacity of the PEI, and this adsorption activity was time and contact-dependent. Thus, SWNTs coated with PEI are able to complex with viruses, and they might be used in the future to transfect non-permissive cell lines. (C) 2010 Elsevier B.V. All rights reserved.

Nanotechnologies hold considerable promise of advances in many sectors especially the biomedical field, since the materials used are of the appropriate dimensions to interact with important biological matter such as proteins, DNA and viruses. In this field the use of nanotechnologies will probably be second in importance only to biotechnologies. However many characteristics of nanomaterials that make them so promising from a technological point of view may also lead to negative effects on the environment and human health. It is important therefore that the environmental and work-related exposure effects to these materials be evaluated. In this article the potential uses, toxic effects and public health implications of nanobiotechnologies are discussed.

Resistance to apoptosis is essential for cancer survival and plays a critical role in carcinogenesis. Growing evidence suggests that nicotine can act as a tumor promoter, impairing apoptotic process in certain types of human cancer cell lines. Our previous study revealed in human gingival fibroblasts (HGFs) a concomitant antiapoptotic and genotoxic effect of nicotine, manifested by the attenuation of staurosporine (STP)-induced apoptosis and the increase of micronucleus frequency. The present report provides evidence that nitric oxide (NO) is critically involved in these actions. In vitro treatment with sodium nitroprusside as NO donor showed that NO produced similar effects as those observed with nicotine: it caused DNA damage and partially prevented apoptosis induced by staurosporine. Exposure of HGFs to nicotine, at concentrations similar to those found in the blood of habitual smokers, leads to the production of NO associated with the induction of inducible nitric oxide synthase (iNOS) expression. Experiments using an inhibitor of iNOS, N-monomethyl-L-arginine (NMA), together with nicotine confirmed the involvement of NO in the drug action, abrogating completely cell death and a good part of the genotoxicity. Finally, we show by different approaches that the inhibition of cell death by nicotine through NO release is related to modulation of caspase-1 activation.

The mismatch repair (MMR) system and p53 protein play a pivotal role in maintaining genomic stability and modulate cell chemosensitivity. Aim of this study was to examine the effects of either MMR-deficiency or p53 inactivation, or both, on cellular responses to bleomycin. The MMR-deficient colon carcinoma cell line HCT116 and its MMR-proficient subline HCT116/3-6, both expressing wild-type p53, were transfected with an expression vector encoding a dominant-negative p53 mutant, or with the empty vector. Four transfected clones, having the following phenotypes, MMR-proficient/p53 wild-type, MMR-proficient/p53 mutant, MMR-deficient/p53 wild-type, MMR-deficient/p53 mutant, were subjected to treatment with bleomycin. Loss of MMR function alone was associated with increased resistance to apoptosis, chromosomal damage and inhibition of colony formation caused by bleomycin. Loss of p53 alone resulted in abrogation of G1 arrest and increased sensitivity to apoptosis and chromosomal damage induced by the drug, but did not affect clonogenic survival after bleomycin treatment. Disabling both p53 and MMR function led to abrogation of G1 arrest and to a moderate impairment of drug-induced apoptosis. Chromosomal damage was reduced in the MMR-deficient/p53 mutant clone with respect to the MMR-proficient/p53 wild-type one, when evaluated 48 h after bleomycin treatment, but was comparable in both clones 96 h after drug exposure. Clonogenic survival of the MMR-deficient/p53 mutant clone was similar to that of the MMR-deficient/p53 wild-type one. The effects of MMR-deficiency on cellular responses to bleomycin were confirmed using the MMR-proficient lymphoblastoid cell line TK6 and its MMR-deficient subline MT1, both expressing wild-type p53. In conclusion, our data show that loss of MMR and p53 function exerts opposite and independent effects on apoptosis and chromosomal damage induced by bleomycin. Moreover, inactivation of MMR confers resistance to the cytotoxic activity of the anticancer agent in cells expressing either wild-type or mutant p53.

Isolated chondrocytes from mouse ribs have been put in culture and maintained for several weeks, till confluence. They retain differentiation, and preliminary data of cells characterization and growth are reported. Electron microscope observations of the cellsin vitro grown are superimposable to those performed on chondrocytes derived from live animals. Mouse chondrocytes, grownin vitro, represent a promising system for the study of bone differentiation, growth and regeneration, also considering the several mutations affecting skeleton formation known in mice, like cn/cn (achondroplasia).

Pgm allele frequencies of 383 individuals were determined in a sample of Drosophila melanogaster from three laboratory Sardinian populations, using the techniques of standard electrophoresis, heat denaturation, and isoelectric focusing. The analysis of the progeny obtained from informative crosses showed that the isoelectric focusing patterns segregate in a Mendelian way. The Pgm1.00 and Pgm0.70 electrophoretic alleles displayed different isoelectric points, whereas the Pgm1.00,tr and Pgm1.00,ts isoelectrophoretic alleles could not be differentiated when tested by isoelectric focusing. Moreover, the Pgm0.70,ts allele was split into two classes, with isoelectric points of pH 6.4 and pH 6.6.

In 6 species of mosquitoes of the generaAedes andCuliseta (Culicidae, Diptera) the frequency of phosphoglucomutase (PGM) heat sensitivity alleles is inversely correlated with the temperature of the environment where larvae develop. These data suggest that different selective values are associated with the PGM thermoresistant and thermosensitive genotypes in the different habitats.