Relationships between the Nicotine Metabolite Ratio and a Panel of Exposure and Effect Biomarkers: Findings from Two Studies of U.S. Commercial Cigarette Smokers.

Background: We examined the nicotine metabolite ratio's (NMR) relationship with smoking intensity, nicotine dependence, and a broad array of biomarkers of exposure and biological effect in commercial cigarette smokers.

Methods: Secondary analysis was conducted on two cross-sectional samples of adult, daily smokers from Wave 1 (2013-2014) of the Population Assessment of Tobacco Use and Health (PATH) Study and baseline data from a 2014-2017 randomized clinical trial. Data were restricted to participants of non-Hispanic, white race.

Comparative analysis of the effect of IV administered acid suppressants on gastric pH in dogs.

Background: Upper gastrointestinal (GI) ulceration and bleeding in critically ill dogs can cause severe anemia and increase morbidity. Acid suppressants using proton pump inhibitors or histamine-2 receptor blockers administered IV is commonly recommended.

Hypothesis/objectives: To evaluate the efficacy of IV administered esomeprazole, pantoprazole, and famotidine constant rate infusion (CRI) on increasing the intragastric pH of dogs.

Covalent on-surface polymerization.

With the rapid development of scanning probe microscopy, it has become possible to study polymerization processes on suitable surfaces at the atomic level and in real space. In the two-dimensional confinement of a surface, polymerization reactions can give rise to the formation of unprecedented polymers with unique structures and properties, not accessible in solution. After a little over one decade since the discovery of covalent on-surface polymerization, we give an overview of the field, analyse the crucial aspects and critically reflect on the status quo.

Biomarkers of Exposure among Adult Smokeless Tobacco Users in the Population Assessment of Tobacco and Health Study (Wave 1, 2013-2014).

Background: Monitoring population-level toxicant exposures from smokeless tobacco (SLT) use is important for assessing population health risks due to product use. In this study, we assessed tobacco biomarkers of exposure (BOE) among SLT users from the Wave 1 (2013-2014) of the Population Assessment of Tobacco and Health (PATH) Study.

Methods: Urinary biospecimens were collected from adults ages 18 and older.

Simultaneous Optical Tuning of Hole and Electron Transport in Ambipolar WSe Interfaced with a Bicomponent Photochromic Layer: From High-Mobility Transistors to Flexible Multilevel Memories.

The interfacing of 2D materials (2DMs) with photochromic molecules provides an efficient solution to reversibly modulate their outstanding electronic properties and offers a versatile platform for the development of multifunctional field-effect transistors (FETs). Herein, optically switchable multilevel high-mobility FETs based on few-layer ambipolar WSe are realized by applying on its surface a suitably designed bicomponent diarylethene (DAE) blend, in which both hole and electron transport can be simultaneously modulated for over 20 cycles. The high output current modulation efficiency (97% for holes and 52% for electrons) ensures 128 distinct current levels, corresponding to a data storage capacity of 7 bit.

Enlightening Materials with Photoswitches.

Incorporating molecular photoswitches into various materials provides unique opportunities for controlling their properties and functions with high spatiotemporal resolution using remote optical stimuli. The great and largely still untapped potential of these photoresponsive systems has not yet been fully exploited due to the fundamental challenges in harnessing geometrical and electronic changes on the molecular level to modulate macroscopic and bulk material properties. Herein, progress made during the past decade in the field of photoswitchable materials is highlighted.

Resolution and Quantitation of Mercapturic Acids Derived from Crotonaldehyde, Methacrolein, and Methyl Vinyl Ketone in the Urine of Smokers and Nonsmokers.

Using improved HPLC analysis conditions, we report the separation of three isomers of mercapturic acid conjugates previously assigned in the literature only to 3-hydroxy-1-methylpropylmercapturic acid (HMPMA-1), a human urinary metabolite of crotonaldehyde. The new conditions, employing a biphenyl column cooled to 5 °C and eluted with a gradient of formic acid, acetonitrile, and methanol, allow the analysis of human urinary mercapturic acids derived not only from crotonaldehyde but also from its isomers methacrolein (3-hydroxy-2-methylpropyl mercapturic acid, HMPMA-2) and methyl vinyl ketone (3-hydroxy-3-methylpropyl mercapturic acid, HMPMA-3). The mercapturic acids were detected and quantified by LC-ESI-MS/MS using the corresponding stable isotope labeled mercapturic acids as internal standards.

Multivalency in Heteroternary Complexes on Cucurbit[8]uril-Functionalized Surfaces: Self-assembly, Patterning, and Exchange Processes.

The spatial confinement of multivalent azopyridine guest molecules mediated by cucurbit[8]urils is described. Fluorescent dye-labelled multivalent azopyridine molecules were attached to preformed methyl viologen/cucurbit[8]uril inclusion complexes in solution and at surfaces. The formation of the resulting heteroternary host-guest complexes was verified in solution and on gold substrates.

Effects of 6-Week Use of Very Low Nicotine Content Cigarettes in Smokers With Serious Mental Illness.

Introduction: The US Food and Drug Administration is considering implementing a reduced-nicotine standard for cigarettes. Given the high rate of smoking among people with serious mental illness (SMI), it is important to examine the responses of these smokers to very low nicotine content (VLNC) cigarettes.

Methods: This trial compared the effects of VLNC (0.

A Randomized Clinical Trial Examining the Effects of Instructions for Electronic Cigarette Use on Smoking-Related Behaviors and Biomarkers of Exposure.

Introduction: Electronic cigarettes (e-cigarettes) have the potential to significantly reduce exposure to harmful constituents associated with cigarette smoking when smokers completely substitute cigarettes with e-cigarettes. This study examined patterns of e-cigarette and cigarette use, and extent of toxicant exposure, if smokers were instructed and incentivized to completely switch to e-cigarettes compared to instructions to use the product ad libitum.

Aims And Methods: US adult daily smokers (n = 264; 49.

Neurofibromatosis-1 and Rhabdomyosarcoma: An Unusual Recurrence.

Neurofibromatosis-1 has a known increased risk of malignancy with rhabdomyosarcoma occurring in up to 6% of patients. Here we report on an 8-year-old male with a history of Neurofibromatosis-1 and previously treated stage 3, group III bladder/prostate embryonal rhabdomyosarcoma (diagnosed at 18 months old) who presented with penile swelling concerning for priapism. Imaging and subsequent biopsy confirmed embryonal rhabdomyosarcoma of the penile corporal bodies.

Effects of 2-Phenethyl Isothiocyanate on Metabolism of 1,3-Butadiene in Smokers.

2-Phenethyl isothiocyanate (PEITC) is a natural product found as a conjugate in cruciferous vegetables. It has been reported to have preventative properties against lung cancer and to inhibit metabolic activation of tobacco carcinogens. In this study, we evaluated the ability of PEITC to influence the metabolism of the human carcinogen 1,3-butadiene in current smokers in a phase II clinical trial with a crossover design.

FEMA GRAS assessment of natural flavor complexes: Cinnamomum and Myroxylon-derived flavoring ingredients.

In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a program for the re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavor ingredients. This publication, third in the series, considers NFCs composed primarily of constituents with the 3-phenyl-2-propenyl or a cinnamyl functional group, using the procedure outlined in 2005 and updated in 2018 to evaluate the safety of naturally-occurring mixtures for their intended use as flavor ingredients. The procedure relies on a complete chemical characterization of the NFC intended for commerce and organization of each NFC's chemical constituents into well-defined congeneric groups.

Isolated Pure Malignant Rhabdoid Tumor (MRT) of the Bladder: Case Report and Lessons Learned.

Pediatric extrarenal malignant rhabdoid tumors (MRTs) are rare, aggressive tumors with a poor prognosis (20% 5-year survival). There are currently fewer than 10 published case reports of primary MRT of the bladder. We report the case of an 18-month-old female with an isolated MRT of the bladder which was initially misdiagnosed as an inflammatory myofibroblastic tumor on biopsy.

Central Venous Catheter Management in High-risk Children With Bloodstream Infections.

Background: National guidelines recommend removal of central venous catheters (CVCs) for central line-associated bloodstream infections (CLABSIs) caused by Staphylococcus aureus, Pseudomonas aeruginosa, and fungi. Data regarding guideline compliance and rates of associated treatment failures in pediatric patients with attempted CVC salvage are limited.

Methods: We performed a retrospective analysis of high-risk children (age ≤ 21 years) hospitalized from 1/2009 to 12/2015 with a long-term CVC and CLABSI due to S.

Isolation of Anti-Hapten Antibodies by Fluorescence-Activated Cell Sorting of Yeast-Displayed B-Cell Receptor Gene Repertoires.

Anti-hapten antibodies are widely used as specific immunochemical detection tools in a variety of clinical and environmental analyses. The sensitivity, however, is limited due to the resulting antibody affinities to the haptens which, in turn, leads to a high demand for specific affinity reagents. A well-established path for the generation of high-affinity antibodies is the immunization of animals with the target antigen.

Cigarette Smokers Versus Cousers of Cannabis and Cigarettes: Exposure to Toxicants.

Introduction: Cannabis and tobacco couse is common and could expose users to higher levels of toxicants. No studies have examined biomarkers of toxicant exposure in cousers of cannabis and cigarettes, compared with cigarette smokers (CS).

Aims And Methods: Adult daily CS were recruited from 10 US sites for a study of reduced nicotine cigarettes.

FEMA GRAS assessment of natural flavor complexes: Mint, buchu, dill and caraway derived flavoring ingredients.

In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavor ingredients. NFC flavor materials include a variety of essential oils and botanical extracts. The re-evaluation of NFCs is conducted based on a constituent-based procedure outlined in 2005 and updated in 2018 that evaluates the safety of NFCs for their intended use as flavor ingredients.

Biochemical Verification of Tobacco Use and Abstinence: 2019 Update.

Background: The changing prevalence and patterns of tobacco use, the advent of novel nicotine delivery devices, and the development of new biomarkers prompted an update of the 2002 Society for Research on Nicotine and Tobacco (SRNT) report on whether and how to apply biomarker verification for tobacco use and abstinence.

Methods: The SRNT Treatment Research Network convened a group of investigators with expertise in tobacco biomarkers to update the recommendations of the 2002 SNRT Biochemical Verification Report.

Results: Biochemical verification of tobacco use and abstinence increases scientific rigor and is recommended in clinical trials of smoking cessation, when feasible.

Oral Health Effects of Combusted and Smokeless Tobacco Products.

The oral cavity is usually the first part of a consumer's body exposed to the constituents of tobacco products or their emissions. Consequently, the oral cavity is a frequent site for carcinogenic, microbial, immunologic, and clinical effects of tobacco use. This article summarizes 5 presentations on various aspects of oral health affected by combusted or noncombusted tobacco products from a recent conference, "Oral Health Effects of Tobacco Products: Science and Regulatory Policy," sponsored by the American Association for Dental Research and the Food and Drug Administration.

Incompressible limit of a continuum model of tissue growth with segregation for two cell populations.

This paper proposes a model for the growth of two interacting populations of cells that do not mix. The dynamics is driven by pressure and cohesion forces on the one hand and proliferation on the other hand. Contrasting with earlier works which assume that the two populations are initially segregated, our model can deal with initially mixed populations as it explicitly incorporates a repul-sion force that enforces segregation.

Multifunctional radical quenchers as potential therapeutic agents for the treatment of mitochondrial dysfunction.

Mitochondrial dysfunction is associated with a wide range of human diseases, including neurodegenerative diseases, and is believed to cause or contribute to the etiology of these diseases. These disorders are frequently associated with increased levels of reactive oxygen species. One of the design strategies for therapeutic intervention involves the development of novel small molecules containing redox cores, which can scavenge reactive oxygen radicals and selectively block oxidative damage to the mitochondria.