RESUMEN
The use of electronic cigarettes has dynamically increased over the last few years. Meanwhile, the knowledge regarding their safety has been rapidly changing, which could be a challenge for a medical practitioner. The purpose of this review is to summarize the latest reports and to verify statements on e-cigarettes' influence on health, including in the context of the ongoing SARS-CoV-2 pandemic. Awareness of the benefits of e-cigarettes can provide vital support for doctors caring for patients who smoke tra-ditional cigarettes. Nevertheless, attention should be paid to the dangers of the medically unjustified use of electronic cigarettes. Despite the idea of releasing e-cigarettes into the market as a harmless alternative to traditional cigarettes, this product also has a negative impact on health. Replacing traditional cigarettes with e-cigarettes provides well-documented benefits to patients with certain indications such as hypertension and asthma, as well as to smokers who intend to minimize the negative effects of passive smoking on their environment. Moreover, it could be valuable for patients who are willing to permanently overcome a nicotine addiction, especially when previous attempts to quit smoking with nicotine replacement therapy (NRT) monotherapy were unsuccessful. Electronic cigarettes are a rapidly developing technology and an innovative form of a well-known addiction, so it is essential for practitioners to stay informed.
Asunto(s)
COVID-19/epidemiología , Sistemas Electrónicos de Liberación de Nicotina/estadística & datos numéricos , Cese del Hábito de Fumar/estadística & datos numéricos , Dispositivos para Dejar de Fumar Tabaco/estadística & datos numéricos , Humanos , Polonia , Fumar/epidemiología , Prevención del Hábito de FumarRESUMEN
Replication of the mitochondrial genome depends on the single DNA polymerase (pol gamma). Mutations in the POLG gene, encoding the catalytic subunit of the human polymerase gamma, have been linked to a wide variety of mitochondrial disorders that show remarkable heterogeneity, with more than 200 sequence variants, often very rare, found in patients. The pathogenicity and dominance status of many such mutations remain, however, unclear. Remarkable structural and functional conservation of human POLG and its S. cerevisiae ortholog (Mip1p) led to the development of many successful yeast models, enabling to study the phenotype of putative pathogenic mutations. In a group of patients with suspicion of mitochondrial pathology, we identified five novel POLG sequence variants, four of which (p.Arg869Ter, p.Gln968Glu, p.Thr1053Argfs*6, and p.Val1106Ala), together with one previously known but uncharacterised variant (p.Arg309Cys), were amenable to modelling in yeast. Familial analysis indicated causal relationship of these variants with disease, consistent with autosomal recessive inheritance. To investigate the effect of these sequence changes on mtDNA replication, we obtained the corresponding yeast mip1 alleles (Arg265Cys, Arg672Ter, Arg770Glu, Thr809Ter, and Val863Ala, respectively) and tested their effect on mitochondrial genome stability and replication fidelity. For three of them (Arg265Cys, Arg672Ter, and Thr809Ter), we observed a strong, partially dominant phenotype of a complete loss of functional mtDNA, whereas the remaining two led to partial mtDNA depletion and significant increase in point mutation frequencies. These results show good correlation with the severity of symptoms observed in patients and allow to establish these variants as pathogenic mutations.