Konstantinos Poulas

Nicotine delivery to the aerosol of a heat-not-burn tobacco product: comparison with a tobacco cigarette and e-cigarettes.

Introduction The purpose was to measure nicotine levels to the tobacco and levels emitted to the aerosol of a heat-not-burn product (HnB, IQOS) compared to e-cigarettes (ECs) and a tobacco cigarette. Methods The HnB device and regular and menthol sticks were purchased from Italy. Three types of ECs (ciga-like, eGo-style, and variable wattage) and a commercially-available tobacco cigarette were also tested. A custom-made liquid containing 2% nicotine was used with ECs. Products were tested using Health Canada Intense puffing regime while HnB and ECs were additionally tested using a 4-second puff duration regime while maintaining the same puff volume. Results Nicotine content in HnB regular and menthol tobacco sticks was 15.2 ± 1.1 mg/g and 15.6 ± 1.7 mg/g tobacco respectively. The levels of nicotine to the aerosol were similar for regular and menthol HnB products (1.40 ± 0.16 and 1.38 ± 0.11 mg/12 puffs respectively) and did not change significantly with prolonged puff duration. The tobacco cigarette delivered the highest level of nicotine (1.99 ± 0.20 mg/cigarette), with levels being higher than HnB and ECs under Health Canada Intense regime but similar to eGo-style and variable wattage ECs at prolonged puff duration regime. Conclusions The HnB product delivers nicotine to the aerosol at levels higher than ECs but lower than a tobacco cigarette when tested using Health Canada Intense puffing regime. No change in HnB nicotine delivery was observed at prolonged puff duration with the same puff volume, unlike ECs which deliver more nicotine with longer puff duration. Implications Nicotine delivery to the smoker is expected to play an important role in the ability of any harm-reduction product to successfully substitute smoking. This study evaluated the content and nicotine delivery to the aerosol of a heat-not-burn tobacco product (IQOS) in comparison with e-cigarettes and a tobacco cigarette. The main findings were that the heat-not-burn tobacco sticks contained similar nicotine concentration to tobacco cigarettes, and that the levels of nicotine delivered to the aerosol of the heat-not-burn products were lower than tobacco cigarette, higher than e-cigarettes at low puff duration but lower than high-power e-cigarettes at longer puff duration.

A Single Nucleotide Polymorphism in the HBBP1 Gene in the Human β-Globin Locus is Associated with a Mild β-Thalassemia Disease Phenotype

The rs2071348 (g.5264146A>C) polymorphism on the HBB pseudogene, namely HBBP1, previously emerged as a variant significantly associated with a milder disease phenotype in Asian β0-thalassemia/hemoglobin (Hb) E (β0-thal/Hb E [β26(B8)Glu→Lys, GAG>AAG]) patients. In this study, we aimed to explore the possible association of rs2071348 with β-thalassemia (β-thal) disease severity in a group of β-thal major (β-TM) patients (severe phenotype) and β-thal intermedia (β-TI) patients (mild phenotype) of Hellenic origin and compare the results with normal (non thalassemic) individuals of the same origin. In addition, we explored whether this single nucleotide polymorphism (SNP) can be exploited as a pharmacogenomic marker to predict the outcome of Hb F-augmenting therapy in β-thal patients receiving hydroxyurea (HU). Our data suggest that the rs2071348 polymorphism is associated with higher Hb F levels and a milder β-thal disease phenotype. However, the rs2071348 polymorphism in the HBBP1 gene does not correlate with response to HU treatment.

Changes in Puffing Topography and Nicotine Consumption Depending on the Power Setting of Electronic Cigarettes

Introduction The study purpose was to evaluate changes in puffing topography of experienced electronic cigarette users (vapers) when changing power settings in electronic cigarette battery devices. Methods Experienced adult vapers (n = 21) were recruited. Participants used their own liquids and an atomizer and battery provided by the researchers. Two 30-minute sessions were performed, with the device power set at 6 W and 10 W, in a randomized, crossover, participant-blinded design. Puff number and duration (mean [SD]) were recorded in the provided electronic cigarette battery device, whereas the atomizers were weighted before and after use to determine liquid and nicotine consumption. Results Puff number and puff duration were lower at 10 W (46 [16] puffs and 3.8 [0.8] s) compared with 6 W (57 [20] puffs and 4.6 [1.0] s). Liquid and nicotine consumption was higher at 10 W (373 [176] mg and 4.2 [2.4] mg, respectively) compared with 6 W (308 [165] mg and 3.5 [2.3] mg, respectively). Vapers reported more aerosol volume and ease of use at 10 W compared with 6 W. Conclusions The study identified an attempt for compensatory puffing patterns and nicotine self-titration, with a change in puffing patterns (puff number and duration) observed when changing the power settings of an e-cigarette device. Implications Compensatory smoking behavior and nicotine self-titration is a well-established phenomenon. In electronic cigarettes, changing nicotine concentration in the liquid has been shown to trigger a compensatory puffing pattern. Herein, power setting of the electronic cigarette device was found to be a parameter associated with changes in puffing behavior, whereas higher power was preferable for the participants. These findings could contribute to the understanding of patterns of electronic cigarette use and could explain the preference of dedicated vapers to higher power devices. Additionally, laboratory studies evaluating aerosol emissions should consider using different puffing patterns according to the power settings tested.

Electronic cigarette use in Greece: an analysis of a representative population sample in Attica prefecture

BackgroundThe purpose was to assess prevalence and correlates of electronic cigarette (e-cigarette) use in Greece in 2017.MethodsA cross-sectional survey of a representative sample of 4058 adults living in Attica prefecture (35% of the Greek adult population) was performed in May 2017 through telephone interviews. Prevalence and frequency of e-cigarette use were assessed according to the smoking status, and logistic regression analysis was performed to identify correlates of use.ResultsCurrent smoking was reported by 32.6% of participants. Ever e-cigarette use was reported by 54.1% (51.4–56.8%) of current smokers, 24.1% (21.7–26.5%) of former smokers and 6.5% (5.3–7.7%) of never smokers. Past experimentation was the most prevalent pattern of e-cigarette use among ever users (P < 0.001). Almost 80% of ever and 90% of current e-cigarette users were using nicotine. Extrapolated to the whole Attica population (3.1 million), there were 1 million current smokers, 848,000 ever e-cigarette users and 155,000 current e-cigarette users. The majority of current e-cigarette users (62.2%) were former smokers. Only 0.2% of never smokers were current e-cigarette users. One out of 20 participants considered e-cigarettes a lot less harmful than smoking. Being current or former smoker were the strongest correlates current e-cigarette use (OR 30.82, 95%CI 10. 21–69.33 and OR 69.33, 95%CI 23.12–207.90 respectively).ConclusionsE-cigarette use in Greece is largely confined to current or former smokers, while current use and nicotine use by never smokers is extremely rare. The majority of current e-cigarette users were former smokers. Most participants overestimate the harmfulness of e-cigarettes relative to smoking.

Development and validation of analytical methodology for the quantification of aldehydes in e-cigarette aerosols using UHPLC-UV

Aldehydes are produced in e-cigarette aerosols, as a result of the thermal decomposition of vegetable glycerin, propylene glycerol and flavorings in the atomizer. These aldehydes were collected with derivatization into 2,4-dinitrophenylhydrazine using impinger trapping. A new methodology for simultaneous quantitative analysis of aldehydes in base liquids was developed and validated. Chromatographic separation was carried out on a Jupiter Proteo 90A column, with the mobile phase consisting of 0.1% formic acid in water and acetonitrile, at a flow rate of 0.4 mL/min. Linearity was demonstrated over the range of concentrations 0.025-10 μg/mL, with correlation of determination ≥ 0.999. Intra- and inter-day % relative standard deviation and relative error were ≤ 10%. The lower limit of detection and quantification were 0.008 and 0.025 μg/mL, respectively. This method was further used for the quantification of aldehydes emitted by different base liquids. It has been shown that vegetable glycerin produces the highest percentage of aldehydes after thermal decomposition compared to propylene glycerol. We propose that it can be used for future e-liquids emissions studies.

Detection and quantitative determination of heavy metals in electronic cigarette refill liquids using Total Reflection X-ray Fluorescence Spectrometry.

Electronic cigarettes are considered healthier alternatives to conventional cigarettes containing tobacco. They produce vapor through heating of the refill liquids (e-liquids) which consist of propylene glycol, vegetable glycerin, nicotine (in various concentrations), water and flavoring agents. Heavy metals may enter the refill liquid during the production, posing a risk for consumers health due to their toxicity. The objective of the present study was the development of a methodology for the detection and quantitative analysis of cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), arsenic (As) and chromium (Cr), employing Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) as an alternative technique to ICP-MS or ICP-OES commonly used for this type of analysis. TXRF was chosen due to its advantages, which include short analysis time, promptness, simultaneous multi-element analysis capability and minimum sample preparation, low purchase and operational cost. The proposed methodology was applied to a large number of electronic cigarette liquids commercially available, as well as their constituents, in order to evaluate their safety. TXRF may be a valuable tool for probing heavy metals in electronic cigarette refill liquids to serve for the protection of human health.

Novel genetic risk variants for pediatric celiac disease

BackgroundCeliac disease is a complex chronic immune-mediated disorder of the small intestine. Today, the pathobiology of the disease is unclear, perplexing differential diagnosis, patient stratification, and decision-making in the clinic.MethodsHerein, we adopted a next-generation sequencing approach in a celiac disease trio of Greek descent to identify all genomic variants with the potential of celiac disease predisposition.ResultsAnalysis revealed six genomic variants of prime interest: SLC9A4 c.1919G>A, KIAA1109 c.2933T>C and c.4268_4269delCCinsTA, HoxB6 c.668C>A, HoxD12 c.418G>A, and NCK2 c.745_746delAAinsG, from which NCK2 c.745_746delAAinsG is novel. Data validation in pediatric celiac disease patients of Greek (n = 109) and Serbian (n = 73) descent and their healthy counterparts (n = 111 and n = 32, respectively) indicated that HoxD12 c.418G>A is more prevalent in celiac disease patients in the Serbian population (P < 0.01), while NCK2 c.745_746delAAinsG is less prevalent in celiac disease patients rather than healthy individuals of Greek descent (P = 0.03). SLC9A4 c.1919G>A and KIAA1109 c.2933T>C and c.4268_4269delCCinsTA were more abundant in patients; nevertheless, they failed to show statistical significance.ConclusionsThe next-generation sequencing-based family genomics approach described herein may serve as a paradigm towards the identification of novel functional variants with the aim of understanding complex disease pathobiology.

Evidence for association of STAT4 and IL12RB2 variants with Myasthenia gravis susceptibility: What is the effect on gene expression in thymus?

Myasthenia gravis (MG) is an autoimmune disease mediated by the presence of autoantibodies that bind mainly to the acetylcholine receptor (AChR) in the neuromuscular junction. In our case-control association study, we analyzed common variants located in genes of the IL12/STAT4 and IL10/STAT3 signaling pathways. A total of 175 sporadic MG patients of Greek descent, positively detected with anti-AChR autoantibodies and 84 ethnically-matched, healthy volunteers were enrolled in the study. Thymus samples were obtained from 16 non-MG individuals for relative gene expression analysis. The strongest signals of association were observed in the cases of rs6679356 between the late-onset MG patients and controls and rs7574865 between early-onset MG and controls. Our investigation of the correlation between the MG-associated variants and the expression levels of each gene in thymus did not result in significant differences.

TA-GC cloning: A new simple and versatile technique for the directional cloning of PCR products for recombinant protein expression

During the last few decades, the recombinant protein expression finds more and more applications. The cloning of protein-coding genes into expression vectors is required to be directional for proper expression, and versatile in order to facilitate gene insertion in multiple different vectors for expression tests. In this study, the TA-GC cloning method is proposed, as a new, simple and efficient method for the directional cloning of protein-coding genes in expression vectors. The presented method features several advantages over existing methods, which tend to be relatively more labour intensive, inflexible or expensive. The proposed method relies on the complementarity between single A- and G-overhangs of the protein-coding gene, obtained after a short incubation with T4 DNA polymerase, and T and C overhangs of the novel vector pET-BccI, created after digestion with the restriction endonuclease BccI. The novel protein-expression vector pET-BccI also facilitates the screening of transformed colonies for recombinant transformants. Evaluation experiments of the proposed TA-GC cloning method showed that 81% of the transformed colonies contained recombinant pET-BccI plasmids, and 98% of the recombinant colonies expressed the desired protein. This demonstrates that TA-GC cloning could be a valuable method for cloning protein-coding genes in expression vectors.

E-cigarette use in the European Union: millions of smokers claim e-cigarettes helped them quit

Sir—We read with interest the paper written by Farsalinos and colleagues suggesting a role for e-cigarettes in smoking cessation and reduction among Europeans based on a cross-sectional survey [1]. They claim: ‘Extrapolating to the whole European Union (EU) population, an estimated 6.1 million European have quit smoking with the use of e-cigarettes, while a further 9.1 million have reduced their smoking consumption’ [1]. This could be interpreted easily as a causal statement, and indeed this is how it has been construed in news outlets [2]. However, neither the cross-sectional nature of the study nor the way that survey questions were formulated support such statements. First of all, it is impossible to know how many of those who claim that they have stopped with the aid of e-cigarettes would have stopped anyway, and how many of those who used an e-cigarette but failed to stop would have stopped had they used another method. That is why researchers go to great lengths to compare quitting rates in randomized controlled trials (RCTs) and observational studies. Secondly, the studys key question (‘Did the use of electronic cigarettes or any similar device help you to stop or reduce your tobacco consumption?’) is overly crude and can lead to mislabeling of short cessation periods as cessation. Some of the heavier smokers may count short periods of non-smoking as total success, while the more occasional smokers may underestimate the difficulty of remaining quit longer term, both contributing potentially to higher reporting of quitting success. Moreover, given the charged atmosphere about e-cigarette regulations in the EU [3–5], such a leading question can persuade some e-cigarette users to report a positive effect on cessation/ reduction in the hope of less strict regulations of e-cigarettes [6,7]. This question, furthermore, excludes those who use e-cigarettes for reasons other than quitting or reducing smoking (e.g. smoking where conventional cigarettes are not allowed), thus contributing to the selectiveness of certain responders/responses and subsequently biased conclusions based on these responses. Unsubstantiated claims based on weak evidence can lead only to more confusion about the potential role of e-cigarettes in tobacco control.