Introduction Recently, the Food and Drug Administration (FDA) authorized the marketing of IQOS Tobacco Heating System as a Modified Risk Tobacco Product (MRTP) based on an electronic heat-not-burn technology that purports to reduce the risk. Methods Sprague-Dawley rats were exposed in a whole-body mode to IQOS aerosol for 4 weeks. We performed the chemical characterization of IQOS mainstream and we studied the ultrastructural changes in trachea and lung parenchyma of rats exposed to IQOS stick mainstream and tissue pro-inflammatory markers. We investigated the reactive oxygen species (ROS) amount along with the markers of tissue and DNA oxidative damage. Moreover, we tested the putative genotoxicity of IQOS mainstream through Ames and alkaline Comet mutagenicity assays. Results Here, we identified irritating and carcinogenic compounds including aldehydes and polycyclic aromatic hydrocarbons in the IQOS mainstream as sign of incomplete combustion and degradation of tobacco, that lead to severe remodelling of smaller and largest rat airways. We demonstrated that IQOS mainstream induces lung enzymes that activate carcinogens, increases tissue reactive radical concentration; promotes oxidative DNA breaks and gene level DNA damage; and stimulates mitogen activated protein kinase (MAPK) pathway which is involved in the conventional tobacco smoke-induced cancer progression. Conclusions Collectively, our findings reveal that IQOS causes grave lung damage and promotes factors that increase cancer risk. Implications IQOS has been proposed as a safer alternative to conventional cigarettes, due to depressed concentration of various harmful constituents typical of traditional tobacco smoke. However, its lower health risks to consumers have yet to be determined. Our findings confirm that IQOS mainstream contains pyrolysis and thermogenic degradation by-products, the same harmful constituents of traditional cigarette smoke, and, for the first time, we show that it causes grave lung damage and promotes factors that increase cancer risk in the animal model.
Since 1993, strains of Entamoeba histolytica sensu lato have been assigned to 2 species on the basis of clinical, biochemical, immunological and genetic evidence: the pathogenic strains to E. histolytica sensu stricto, the non-pathogenic strains to Entamoeba dispar. Analysis of the gene encoding for the small subunit ribosomal RNA (SSU rDNA) supports the existence of 2 species. However, while 3 whole SSU rDNA sequences are available in the data bases for E. histolytica, only a partial sequence has been published for E. dispar. Here we report a SSU rDNA sequence for E. dispar. Compared to those of E. histolytica, this sequence shows 1.7% nucleotide substitutions. On the basis of our rDNA data, 2 primers were designed to produce polymerase chain reaction (PCR) amplification from both E. histolytica and E. dispar. Primer specificity for the 2 amoebae was assessed both theoretically against the data bases, and experimentally against a collection of eukaryotic and prokaryotic DNAs. The amplified stretch encompasses a polymorphic Dde I restriction site which allows, after cleavage of the fragment, E. histolytica and E. dispar to be distinguished. The reliability of this method of identification was assessed comparing the results with those based on classic isoenzyme analysis.
This essay explores the fictional representations of objects in Richard Marsh's Curios: The Strange Adventures of Two Bachelors (1898), a collection of tales in which things come alive in many ways, calling for a more nuanced approach than that allowed by commodity criticism. Marsh's objects are in fact sites of intersection between issues of identity, professional expertise, and relations between individuals. In my essay, I focus on three main aspects, all deeply informed by the author's exploration of the importance of sensorial perception in human-thing relations: the issue of evidence, the assessment of value, and the concepts of ownership and circulation. My point is to demonstrate that Marsh's stories foreground a mixed attitude towards collectors, and deploy a way of representing objects that emphasises the uncanny power they can exert on humans, but also the wealth of imaginative and sensorial possibilities they offer. Although much stress is given to the elusiveness of specific objects, these tales also show an amused awareness that material things will always escape us, but this very quality is what makes them interesting and worth pursuing.
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