Publications by authors named "Stephen S Hecht"

Article Synopsis
  • The FDA plans to lower the nicotine content in combustible cigarettes to make them less addictive, prompting this study on the impact of very low nicotine content cigarettes (VLNCCs) and electronic cigarettes (ECs) on adult smokers.
  • 213 adult combustible cigarette users participated in a study across four phases, where they initially smoked their usual brands, then switched to VLNCCs, and later used both VLNCCs and ECs with different nicotine levels and flavors.
  • Results showed participants used fewer usual brand cigarettes during the VLNCC and dual-product phases, but most remained dual users, experiencing less product satisfaction and more withdrawal symptoms compared to their usual smoking habits.
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Article Synopsis
  • - Tobacco use is linked to various cancers and causes about 25% of cancer-related deaths, primarily due to harmful substances in tobacco smoke, including tobacco-specific nitrosamines like NNN and NNK that create damaging DNA adducts.
  • - The study identified new mutational patterns induced by these DNA adducts, particularly in certain cancer cell lines and rat tumors, indicating specific mutations that occur in the DNA from exposure to these harmful compounds.
  • - Analyzing 2,780 cancer genomes revealed that these mutational patterns were present in around 180 tumors from types of cancer not typically associated with smoking, suggesting that the damage caused by the POB pathway could play a unique role in various cancers, including hematological
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Cigarette smoking is the acknowledged major cause of cancers of the lung and oral cavity and is an established important risk factor for multiple other cancers. DNA addition products (DNA adducts) caused by cigarette smoking are critical factors in its mechanism of carcinogenesis. However, most DNA adducts detected to date in humans cannot be specifically ascribed to smoking but rather have multiple exogenous and endogenous sources.

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Background: Reducing cigarette addictiveness has the potential to avert millions of yearly tobacco-related deaths worldwide. Substantially reducing nicotine in cigarettes decreases cigarette consumption, but no large clinical trial has determined the effects of reduced-nicotine cigarettes when other nicotine-containing products are available. The aim of this study was to examine the effects of reduced-nicotine cigarettes in the context of the availability of alternative nicotine delivery systems.

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Background: After accounting for smoking history, lung cancer incidence is greater in African Americans than Whites. In the multiethnic cohort, total nicotine equivalents (TNE) are higher in African Americans than Whites at similar reported cigarettes per day. Greater toxicant uptake per cigarette may contribute to the greater lung cancer risk of African Americans.

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Exposure to polycyclic aromatic hydrocarbons (PAHs), byproducts of incomplete combustion, and their effects on the development of cancer are still being evaluated. Recent studies have analyzed the relationship between PAHs and tobacco or dietary intake in the form of processed foods and smoked/well-done meats. This study aims to assess the association of a blood biomarker and metabolite of PAHs, -1,-2,3,-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT), dietary intake, selected metabolism SNPs, and pancreatic cancer.

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The tobacco-specific nitrosamines N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are considered 'carcinogenic to humans' by the International Agency for Research on Cancer (IARC) and are believed to be important in the carcinogenic effects of both smokeless tobacco and combusted tobacco products. This short review focuses on the results of recent studies on the formation of NNN and NNK in tobacco, and their carcinogenicity and toxicity in laboratory animals. New mechanistic insights are presented regarding the role of dissimilatory nitrate reductases in certain microorganisms involved in the conversion of nitrate to nitrite that leads to the formation of NNN and NNK during curing and processing of tobacco.

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Article Synopsis
  • The study investigates how tobacco exposure impacts health differently across various racial and ethnic groups, focusing on the internal nicotine dose as a key factor in carcinogen uptake.
  • Researchers conducted an epigenome-wide association study (EWAS) using blood samples to examine the relationship between urinary total nicotine equivalents (TNEs) and DNA methylation patterns in nearly 2,000 individuals from the Multiethnic Cohort Study.
  • The findings revealed 408 significant changes in DNA methylation associated with TNEs, identifying novel genetic sites linked to smoking, with variations noted among different racial and ethnic groups, indicating a complex relationship between nicotine exposure and health outcomes.
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Tobacco use is a major cause of preventable morbidity and mortality globally. Tobacco products, including smokeless tobacco (ST), generally contain tobacco-specific -nitrosamines (TSNAs), such as '-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK), which are potent carcinogens that cause mutations in critical genes in human DNA. This review covers the series of biochemical and chemical transformations, related to TSNAs, leading from tobacco cultivation to cancer initiation.

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Cigarette smoking is an established cause of chronic obstructive pulmonary disease (COPD). Numerous studies implicate acrolein, which occurs in relatively high concentrations in cigarette smoke and reacts readily with proteins, as one causative factor for COPD in smokers. Far less is known about the possible roles in COPD of the related α,β-unsaturated carbonyl compounds of cigarette smoke crotonaldehyde, methacrolein, and methyl vinyl ketone.

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In recent years, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) has conducted a program to re-evaluate the safety of natural flavor complexes (NFCs) used as flavor ingredients. This publication, twelfth in the series, details the re-evaluation of NFCs whose constituent profiles are characterized by alicyclic or linear ketones. In its re-evaluation, the Expert Panel applies a scientific constituent-based procedure for the safety evaluation of NFCs in commerce using a congeneric group approach.

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The tobacco-specific nitrosamine '-nitrosonornicotine (NNN) and its close analogue 4-(-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK) are classified as "carcinogenic to humans" (Group 1) by the International Agency for Research on Cancer. The currently used biomarker to monitor NNN exposure is urinary total NNN (free NNN plus its -glucuronide). However, total NNN does not provide information about the extent of metabolic activation of NNN as related to its carcinogenicity.

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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, eleventh in the series, evaluates the safety of NFCs characterized by primary alcohol, aldehyde, carboxylic acid, ester and lactone constituents derived from terpenoid biosynthetic pathways and/or lipid metabolism. The scientific-based evaluation procedure published in 2005 and updated in 2018 that relies on a complete constituent characterization of the NFC and organization of the constituents into congeneric groups.

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DNA alkylating drugs have been used as cancer chemotherapy with variable outcomes. The establishment of predictive biomarkers to identify patients who will effectively respond to treatment would allow for the development of personalized therapies. As the degree of interaction of alkylating drug with DNA plays a key role in their mechanism of action, our hypothesis is that the measurement of the DNA adducts formed by alkylating drugs could be used to inform patient stratification.

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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 flavoring ingredients in food. In this publication, tenth in the series, NFCs containing a high percentage of at least one naturally occurring allylalkoxybenzene constituent with a suspected concern for genotoxicity and/or carcinogenicity are evaluated. In a related paper, ninth in the series, NFCs containing anethole and/or eugenol and relatively low percentages of these allylalkoxybenzenes are evaluated.

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The FEMA Expert Panel program to re-evaluate the safety of natural flavor complexes (NFCs) used as flavoring ingredients in food has resulted in the publication of an updated constituent-based procedure as well as publications on the safety evaluation of many botanical-derived NFCs. This publication, ninth in the series and related to the ninth publication, describes the affirmation of the generally recognized as safe (GRAS) status for NFCs with propenylhydroxybenzene and allylalkoxybenzene constituents under their conditions of intended use as flavoring ingredients added to food. The Panel's procedure applies the threshold of toxicological concern (TTC) concept and evaluates relevant data on absorption, metabolism, genotoxic potential and toxicology for the NFCs themselves and their respective constituent congeneric groups.

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We developed a liquid chromatography-nanoelectrospray ionization-high-resolution tandem mass spectrometry (LC-NSI-HRMS/MS) method for simultaneous quantitative analysis of 5 oral cell DNA adducts associated with cigarette smoking: (8/)-3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-]purine-10(3)-one (γ-OH-Acr-dGuo, ) from acrolein; (6,8 and 6,8)-3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxy-6-methylpyrimido[1,2-]purine-10(3)-one [(6,8)γ-OH-Cro-dGuo, ; and (6,8)γ-OH-Cro-dGuo, ] from crotonaldehyde; 1,-etheno-dAdo () from acrylonitrile, vinyl chloride, lipid peroxidation, and inflammation; and 8-oxo-dGuo () from oxidative damage. Oral cell DNA was isolated in the presence of glutathione to prevent artifact formation. Clear LC-NSI-HRMS/MS chromatograms were obtained allowing quantitation of each adduct using the appropriately labeled internal standards.

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The Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) applies its procedure for the safety evaluation of natural flavor complexes (NFCs) to re-evaluate the safety of Asafetida Oil (Ferula assa-foetida L.) FEMA 2108, Garlic Oil (Allium sativum L.) FEMA 2503 and Onion Oil (Allium cepa L.

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Background: While cigarette smoking is the leading cause of lung cancer, the majority of smokers do not develop the disease over their lifetime. The inter-individual differences in risk among smokers may in part be due to variations in exposure to smoking-related toxicants.

Methods: Using data from a subcohort of 2,309 current smokers at the time of urine collection from the Multiethnic Cohort Study, we prospectively evaluated the association of ten urinary biomarkers of smoking-related toxicants [total nicotine equivalents (TNE), a ratio of total trans-3'-hydroxycotinine (3-HCOT)/cotinine (a phenotypic measure of CYP2A6 enzymatic activity), 4-(methylnitrosamino)-1-3-(pyridyl)-1-butanol (NNAL), S-phenylmercapturic acid (SPMA), 3-hydroxypropyl mercapturic acid (3-HPMA), phenanthrene tetraol (PheT), 3-hydroxyphenanthrene (PheOH), the ratio of PheT/PheOH, cadmium (Cd), and (Z)-7-(1R,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-1-enyl]cyclopenyl]hept-5-enoic acid (8-iso-PGF2α)] with lung cancer risk (n = 140 incident lung cancer cases over an average of 13.

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Introduction: The FDA proposed rule-making to reduce nicotine in cigarettes to minimally addictive levels. Research suggests decreasing nicotine levels (i.e.

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The use of electronic cigarettes (e-cigarettes) has increased rapidly in the United States, especially among high school students. e-Cigarettes contain some recognized carcinogens and may induce DNA damage in oral cells. The aim of this review is to summarize studies reporting DNA adducts or other types of DNA damage in oral cells in vitro or in vivo upon exposure to e-cigarette vapor and to evaluate the possible connections between e-cigarette exposure and oral cancer.

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