Biochemical validation of self-reported electronic nicotine delivery system and tobacco heaviness of use

An electron paramagnetic resonance time-course study of oxidative stress in the plasma of electronic cigarette exposed rats

The long-term consequences of electronic cigarette (Ecig) use in humans are not yet known, but it is known that Ecig aerosols contain many toxic compounds of concern. We have recently shown that Ecig exposure impairs middle cerebral artery (MCA) endothelial function and that it takes 3 days for MCA reactivity to return to normal. However, the sources contributing to impairment of the endothelium were not investigated. We hypothesized that the increased levels of oxidative stress markers in the blood are correlated with impaired MCA reactivity. We used electron paramagnetic resonance (EPR) spectroscopy to examine plasma from 4-month-old male Sprague-Dawley rats that were exposed to either air (n = 5) or 1 h Ecig exposure, after which blood samples were collected at varying times after exposure (i.e., 1-4, 24, 48 and 72 h postexposure, n = 4 or 5 in each time group). The EPR analyses were performed using the redox-sensitive hydroxylamine spin probe 1-hydroxy-3-carboxymethyl-2,2,5,5-tetramethyl-pyrrolidine (CMH) to measure the level of reactive oxidant species in the plasma samples. We found that EPR signal intensity from the CM• radical was significantly increased in plasma at 1-4, 24 and 48 h (P < 0.05, respectively) and returned to control (air) levels by 72 h. When evaluating the EPR results with MCA reactivity, we found a significant negative correlation (Pearson's P = 0.0027). These data indicate that impaired cerebrovascular reactivity resulting from vaping is associated with the oxidative stress level (measured by EPR from plasma) and indicate that a single 1 h vaping session can negatively influence vascular health for up to 3 days after vaping. HIGHLIGHTS: What is the central question of this study? Does the time course of oxidative stress triggered by electronic cigarette exposure follow the cerebral vascular dysfunction? What is the main finding and its importance? Electron paramagnetic resonance analysis shows that the oxidative stress induced after a single 1 h exposure to electronic cigarette aerosol takes ≤72 h to return to normal, which mirrors the time course for vascular dysfunction in the middle cerebral artery that we have reported previously.

Associations between Smoking and Smoking Cessation during Pregnancy and Newborn Metabolite Concentrations: Findings from PRAMS and INSPIRE Birth Cohorts

Newborn metabolite perturbations may identify potential biomarkers or mechanisms underlying adverse, smoking-related childhood health outcomes. We assessed associations between third-trimester smoking and newborn metabolite concentrations using the Tennessee Pregnancy Risk Assessment Monitoring System (PRAMS, 2009-2019) as the discovery cohort and INSPIRE (2012-2014) as the replication cohort. Children were linked to newborn screening metabolic data (33 metabolites). Third-trimester smoking was ascertained from birth certificates (PRAMS) and questionnaires (INSPIRE). Among 8600 and 1918 mother-child dyads in PRAMS and INSPIRE cohorts, 14% and 13% of women reported third-trimester smoking, respectively. Third-trimester smoking was associated with higher median concentrations of free carnitine (C0), glycine (GLY), and leucine (LEU) at birth (PRAMS: C0: adjusted fold change 1.11 [95% confidence interval (CI) 1.08, 1.14], GLY: 1.03 [95% CI 1.01, 1.04], LEU: 1.04 [95% CI 1.03, 1.06]; INSPIRE: C0: 1.08 [95% CI 1.02, 1.14], GLY: 1.05 [95% CI 1.01, 1.09], LEU: 1.05 [95% CI 1.01, 1.09]). Smoking cessation (vs. continued smoking) during pregnancy was associated with lower median metabolite concentrations, approaching levels observed in infants of non-smoking women. Findings suggest potential pathways underlying fetal metabolic programming due to in utero smoke exposure and a potential reversible relationship of cessation.

Del consumo ocasional del tabaco a la adicción a la nicotina

Introducción. El consumo ocasional de nicotina puede generar una dependencia o adicción, siendo detectable mediante modificaciones en los mecanismos neurobiológicos. Objetivo. Contextualizar del consumo a la adicción e identificar teóricamente el  mecanismo neurobiológico de transición del consumo regular del tabaco a la adicción de la nicotina. Metodología. Se realizó una búsqueda de artículos en inglés y español usando diferentes bases de datos y combinaciones de palabras clave, se seleccionaron los artículos que describieran las características de los procesos neurobiológicos implicados en el uso o consumo intermitentedel tabaco a la adicción a la nicotina como el tema principal. Resultados. El número de investigaciones relacionados a este tema es reducido, aún más en relación con la descripción de los procesos y cambios neurales de la adicción a la nicotina. La adicción a las drogas es un proceso neuroconductual complejo que altera los circuitos del sistema de motivaciónrecompensa del cerebro, por la disminución de la dopamina y la afectación en la regulación del glutamato en los ganglios basales y extensión de la amígdala se asocia con el craving, la anticipación y el déficit en la función ejecutiva. Conclusiones. El tabaco está considerado como una droga legal, por lo que su consumo pareciera ser inofensivo. Sin embargo, las evidencias muestran que su consumo a largo plazo tiene consecuencias graves en la salud de los individuos. El entender cómo cambia el hábito de fumar ocasionalmente al consumocrónico nos hace más conscientes sobre las adaptaciones en el cerebro.