Nicotine flux as a powerful tool for regulating nicotine delivery from e-cigarettes: Protocol of two complimentary randomized crossover clinical trials.

Introduction: Electronic cigarette (EC) use has increased rapidly in the last decade, especially among youth. Regulating nicotine delivery from ECs could help curb youth uptake and leverage EC use in harm reduction yet is complicated by varying device and liquid variables that affect nicotine delivery. Nicotine flux, the nicotine emission rate, is a parameter that incorporates these variables and focuses on the performance rather than the design of an EC.

Acute alcohol consumption alters the peripheral cytokines IL-8 and TNF-α.

Background: Acute alcohol consumption triggers release of cytokines, which are immune signaling molecules. Dysregulated cytokine levels are associated with impaired immune function, and peripheral cytokine levels may communicate with the brain to propagate drinking-related behaviors. This exploratory study aims to characterize the peripheral cytokine response to an alcohol challenge in a well-controlled laboratory setting.

Plasma Menthol Glucuronide as a Biomarker of Acute Menthol Inhalation.

Objectives: Menthol is often added to cigarettes and e-cigarette solutions for its cooling and anti-irritant effects, and may contribute to development of nicotine dependence, particularly in vulnerable populations such as adolescents, and among African Americans. Menthol is rapidly metabolized to menthol glucuronide (MG) with little or no unconjugated menthol measurable in venous blood. Human challenge studies of the effects of inhaled menthol, and of its interactions with nicotine, would benefit from a quantitative measure of acute menthol exposure.

The effects of alcohol-containing e-cigarettes on young adult smokers.

Background: The liquids (e-liquids) used in an electronic cigarette (e-cigarette) contain myriad chemicals without adequate human inhalation safety data. Furthermore, the absence of e-liquid labeling requirements poses a formidable challenge to understanding how e-liquid constituents may promote nicotine addiction and/or have independent or synergistic biological effects when combined with nicotine. Ethyl alcohol is such a constituent, but has received little scientific interest in this context.

Ethyl glucuronide and ethyl sulfate assays in clinical trials, interpretation, and limitations: results of a dose ranging alcohol challenge study and 2 clinical trials.

Background: The ethanol metabolites, ethyl glucuronide (EtG) and ethyl sulfate (EtS), are biomarkers of recent alcohol consumption that provide objective measures of abstinence. Our goals are to better understand the impact of cutoff concentration on test interpretation, the need for measuring both metabolites, and how best to integrate test results with self-reports in clinical trials.

Methods: Subjects (n = 18) were administered, 1 week apart, 3 alcohol doses calibrated to achieve blood concentrations of 20, 80, and 120 mg/dl, respectively.

Nicotine fails to attenuate ketamine-induced cognitive deficits and negative and positive symptoms in humans: implications for schizophrenia.

Background: The uncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist, ketamine, induces a range of symptoms resembling those seen in schizophrenia. Enhancement of nicotinic acetylcholine receptor (nAChR) function may have potential as a treatment for the cognitive deficits and negative symptoms of schizophrenia. Accordingly, we examined the modulatory effects of brain nAChR systems on NMDAR antagonist-induced effects.

Rapid nicotine clearance is associated with greater reward and heart rate increases from intravenous nicotine.

The ratio of nicotine metabolites (trans-3'-hydroxycotinine (3HC) to cotinine) correlates with nicotine clearance. In previous studies, high nicotine metabolite ratio (NMR) predicted poor outcomes for smoking cessation treatment with nicotine patch. The underlying mechanisms that associate NMR with treatment outcomes have not been fully elucidated.