Additional file 1: of Disparities in tobacco use by adolescents in southeast, Nigeria using Global Youth Tobacco Survey (GYTS) approach

Adapted GYTS students’ core questionnaire. Questionnaire used to collect information about students’ socio-demographic characteristics, use of smoked and smokeless tobacco, and susceptibility to smoking initiation. (PDF 364 kb

ENDS e-liquids their trade name, flavor, and manufacturer information obtained from local retailers used in this study.

<p>ENDS e-liquids their trade name, flavor, and manufacturer information obtained from local retailers used in this study.</p

State of the refillable ENDS heating element and its influence over successive use to generate OX/ROS in a cell-free ROS assay.

<p>State of the refillable ENDS heating element and its influence over successive use to generate OX/ROS in a cell-free ROS assay.</p

Refillable ENDS and Blu e-cigarettes.

<p>(A) Refillable ENDS and Blu e-cigarettes (B) Clearomizer removed, outer wick shown covering top of heating element coil (Upper panel). Used wick removed showing darkened region that contacted heating coil (Middle panel). Heating coil wrapped around second wick (Lower panel). (C) Activating heating element on refillable ENDS with Clearomizer removed. Less than 1 second activation (Upper panel), 2 seconds activation (Middle panel), greater than 2 second’s activation (Lower panel). (D) Cartomizer casing removed after previous use (Upper panel). Poly-fill material with partially absorbed e-liquid wrapped around the core. Outer material removed exposing inner absorbent material tightly wrapped around heating element (Middle panel). Heating element exposed showing coil wrapped wick secured perpendicular to longer woven polymer tubing. A long thin fiber that was wrapped around the heating coil shows points of contact with coil wire (Lower panel).</p

Intracellular glutathione levels in mouse lung following acute e-cigarette aerosol exposure.

<p>Mice were exposed to e-cig aerosol exposure (200 mg/m³ TPM) for 3 days and sacrificed immediately after the last exposure (3^rd day after 5 hrs exposure). Levels of (A) Total glutathione. (B) glutathione disulfide GSSG. (C) Total glutathione to GSSG ratio and (D) GSSG to total glutathione ratio were measured in lung homogenates. Data are shown as mean ± SD (n = 3/group).<i>* P</i> < 0.05 compared to air group mice (C57BL/6J).</p

Inflammatory mediators secreted by human lung fibroblasts (HFL-1) treated with e-liquids/humectants and human epithelial airway cells (H292) treated by air-liquid interface with e-cigarette aerosols.

<p>(A) Levels of IL-8 release in conditioned media from HFL-1 cells treated for 24 hrs with 1% humectants or e-liquids or CSE were measured by ELISA. Data are shown as mean ± SD of n = 3. <i>*** P</i> < 0.001 compared to control cells maintained in media with 0.5% FBS. (B) H292 cells were exposed to Blu e-cigarette aerosols with a puff of 3–4 sec for 5, 10 and 15 min. After exposure, H292 cells were incubated at 37°C in 5% CO₂ incubator for 16 hrs and levels of IL-8, and (C) IL-6 release in conditioned media were measured by ELISA. Data are shown as mean ± SD. <i>*P</i> < 0.05; <i>**P</i> < 0.01; and <i>*** P</i> < 0.001 as compared to air group (cells maintained in incubator).</p

DCF fluorescence of refillable e-liquids with different flavors and nicotine concentrations after addition of DCFH solution analyzed by a cell-free ROS assay.

<p>DCF fluorescence of refillable e-liquids with different flavors and nicotine concentrations after addition of DCFH solution analyzed by a cell-free ROS assay.</p

DCF fluorescence values obtained for refillable ENDS aerosols or ambient air alone drawn through DCFH in cell-free ROS assay.

<p>DCF fluorescence values obtained for refillable ENDS aerosols or ambient air alone drawn through DCFH in cell-free ROS assay.</p