Effects of 0.2 T static magnetic field on human skin fibroblasts.

Human skin fibroblasts were exposed to 0.2 T static magnetic field generated by a magnetic resonance tomograph. After 1h exposure, cell morphology was modified in association with a concomitant decrease in the expression of some sugar residues of glycoconjugates. Study of cell proliferation and mitogenic signal transduction showed a decrease of thymidine incorporation and of second messenger formation. However, cell viability, assessed by colony forming assay, was unaffected. These results demonstrate that the static magnetic field generated by routinely used magnetic resonance tomograph induces alterations on human skin fibroblasts.

Association between atmospheric ozone levels and damage to human nasal mucosa in Florence, Italy.

We evaluated the effects of urban air pollutants on human nasal mucosa over an 8-month period on 102 subjects living in Florence, Tuscany, Italy. A group of subjects living in a city with a lower level of pollution (Sassari, Sardinia, Italy) was also analyzed. Nasal mucosa cells were harvested by brushing, a noninvasive procedure. Half of the cells were used for genotoxicity studies using the alkaline comet assay, and half for morphological studies. The levels of DNA damage in the nasal mucosa were considerably higher (+73%) in the subjects living in Florence than in Sassari. High levels of atmospheric ozone in Florence air correlated with DNA damage, and to the prevalence of inflammatory pathologies of the upper respiratory tract, although the ozone concentrations were below the Italian recommended attention level. Furthermore, higher levels of DNA damage were correlated with a dysfunction in the ability to maintain a normal epithelial cell structure. These data suggest an association between ozone air levels and damage in the upper respiratory tract. It remains unclear whether ozone itself or other associated pollutants are responsible for the observed alterations.

Stomal recurrence following total laryngectomy: clinical and molecular analysis of a series.

The aim of the present study was to analyze the risk features and to discuss the preventive measures and treatment of stomal recurrence (SR) after total laryngectomy (TL), and to investigate the clonal relationship between the primary and recurrent lesions. We reviewed a series of 25 patients affected by SR after TL for laryngeal squamous cell carcinoma. A subset of 7 coupled primary and recurrent carcinomas were examined for microsatellite alterations that were used as a marker of genetic lineage. The incidence of SR was higher in patients with initial subglottic lesions (subglottic, transglottic, or glottic-subglottic tumors) than in those with other locations of laryngeal cancer (p = .013). In addition, the frequency of SR was significantly higher in patients who underwent preoperative tracheotomy, performed 48 hours or more before the TL, than in the group of patients who did not receive preoperative tracheotomy (23.3% versus 0.46%, p < .001). According to microsatellite analysis, of the 5 informative patients, 2 demonstrated discordant alterations in the recurrent tumor indicative of clonal heterogeneity, 2 demonstrated identical alterations, and 1 showed an additional alteration in the recurrent tumor. Our analysis supports the hypothesis that a subset of SRs after TL may be second primary tumors, genetically unrelated to the primary laryngeal lesion.