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In search for innovative therapeutic agents for children neuroblastoma, the oxygen therapy could be considered an alternative anti-tumoral treatment. Given the physiochemical properties of O(2/3) gas mixture including fairly low aqueous solubility and spreading, and the interesting perspective of hyperoxia, we analyzed the inhibitory effect of O(2/3) treatment on two human neuroblastoma cell lines (SK-N-SH and SK-N-DZ). In this study, we demonstrated that O(2/3) treatment was able to induce cell growth inhibition and cell cycle perturbation in both cell lines. We observed an arrest at G(2) phase, accompanied by an alteration in the expression and localization of cyclin B1/cdk1 complex and a reduction in its activity in SK-N-SH cells. This reduction was consistent with the increase in both Wee1 and chk1 protein levels. On the contrary, O(2/3) induced apoptosis in SK-N-DZ cells via caspase 3 activation and Poly ADP-ribose polymerase-1 (PARP) cleavage, associated with an increase in the pro-apoptotic Bax protein. Consequently, we considered the possibility of improving the responsiveness to chemotherapeutic agents such as Cisplatin, Etoposide, and Gemcitabine in combination with O(2/3) treatment. The combined treatments produced a stronger cell inhibitory effect than Cisplatin and Etoposide used alone in SK-N-SH cells. On the contrary, the combination data were not significantly different from O(2/3) treatment alone in SK-N-DZ cells, thus suggesting that the obtained changes in cell growth inhibition were due to the effect of O(2/3) alone.

Background: Particle size affects the performance of personal air samplers used to measure dust exposure in the workplace. Few field studies have been conducted for comparing the performance of personal inhalable samplers. Objective: To compare wood dust sampling with two inhalable samplers: IOM (Institute of Occupational Medicine) and Italian cone. Methods: 136 Italian cone/IOM paired samples and 136 passive IOM samples were collected in 30 Italian woodworking industries. The valid number of sample pairs was 114. Ultra-large particles were collected by passive IOM. The sampling membranes were weighed and the size particles were measured. Mass differences in active and passive IOM samples were calculated (IOM-Δ). Results: Statistical analysis of all 114 Italian cone/active IOM paired results showed a significant mass difference (P < 0.05) and no significant mass difference for sanding and cutting woodworking processes. The Italian cone/IOM-Δ paired results consistently showed no statistically significant mass differences in any woodworking processes. Both samplers performed similarly when ultra-large particles mass contribution was not considered. Conclusions: These findings confirm the presence of ultra-large particles in woodworking. The Italian cone and IOM samplers can be used interchangeably for personal wood dust exposure assessment, when the wood activities produce small-size particles.

Objective Biosolubility is an important parameter in the understanding of mechanisms involved in pulmonary toxicity of fibrous materials. It can be studied in vitro using models of simulated lung fluids and observing the loss of structural molecules, expressed as dissolution constant (K dis ). The aim of this paper was the study of dissolution behaviour of four wools belonging to high temperature insulation wools (HTIW) in saline solutions simulating lung fluids. Methods Four HTIW were studied in saline solutions at pH 7.4 (representative of the extracellular environment) and 4.5 (representative of the intracellular conditions): refractory ceramic fibers (RCF), two alkaline earth silicate wools (AES1 and AES2 with high calcium and magnesium content respectively), and polycrystalline wools (PCW). Size, morphological and chemical changes of fibers were observed by scanning electron microscopy (SEM) with energy-dispersive X-ray spectrometry (EDS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Results RCF, AES2 and PCW did not show statistically significant diameter changes. AES1 size distribution shifted to a larger mean diameter suggesting that through dissolution there was a preferential loss of thin fibers at acid pH after 14 days of treatment. Both AES wools showed selective leaching of alkali/alkali earth oxides (incongruent dissolution) at pH 7.4: a fast and extensive selective leaching of calcium for AES1 with complete dissolution of fibers already after 14 days of treatment and a moderate selective leaching of magnesium for AES2. PCW showed some transversal breakage of the fibers in both pH environments (low congruent dissolution). For RCF, the treatment produced uncorroded fibers in both pH environments without chemical changes and fiber fragmentation (no dissolution). The estimated K dis at physiological pH followed the sequence: AES1 > AES2 > PCW > RCF. All wools had a low K dis at acid pH suggesting a low dissolution rate of short fibers. Conclusion The leaching process and transverse fragmentation play an important role in the biopersistence mechanisms and pathogenicity of fibers and the K dis estimate is undoubtedly useful as a preliminary toxicological screening of fibers, especially for developing fibers.

The aim of this study is to identify the infrared absorption band suitable for quantifying tremolite in three powdered samples (fine, medium, and large size classes) coming from a quarry of ophiolitic friable rocks in the western part of the Calabria region of Italy. Three IR bands were considered: OH stretching band between 3700 and 3650 cm−1, the stretching bands of the Si-O-Si linkage between 1200 and 900 cm−1, and the absorbance band at 756 cm−1attributable to tremolite. The amount of tremolite in the test samples was quantified by using the curve parameters of the three analytical bands. The quantitative analysis of tremolite using the band due to OH stretchings (3700–3650 cm−1) and the bands attributed to the Si-O-Si stretchings (1200–900 cm−1) showed high values for all test samples. Their use overestimated the tremolite amount because both bands were affected at the interfering mineral silicates such as talc, kaolinite, chlorite, and serpentinites. The abundant presence of antigorite in studied samples mainly in medium size class sample had a key role in our findings. The band at 756 cm−1was not affected at the interfering minerals and can be used for quantitative analysis of tremolite in sample coming from ophiolitic deposits.