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1.
Chem Res Toxicol ; 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38924487

RESUMO

In 2012, the U.S. Food & Drug Administration (FDA) published an established list of 93 harmful and potentially harmful constituents (HPHCs) targeting four tobacco product types (cigarettes, cigarette tobacco, roll-your-own tobacco, smokeless tobacco). In 2016, the FDA finalized the deeming rule to regulate electronic nicotine delivery systems (ENDS). However, knowledge gaps exist regarding whether certain HPHCs are present in ENDS e-liquids and aerosols. We identified and addressed these gaps by conducting literature searches and then experimentally quantifying HPHCs in the e-liquid and aerosol of 37 ENDS brands based on gaps in the literature. The literature searches identified 66 e-liquid HPHCs and 68 aerosol HPHCs that have limited to no information regarding the quantifiability of these constituents. A contracted ISO 17025 accredited laboratory performed the HPHC quantifications. The availability of validated analytical methods in the contracted laboratory determined the HPHCs included in the study scope (63/66 for e-liquids, 64/68 for aerosols). Combining the results from the quantifications and literature searches, 36 (39%) and 34 (37%) HPHCs were found quantifiable (≥limit of quantification [LOQ]) in ENDS e-liquids and aerosols, respectively, with 25 HPHCs being quantifiable in both matrices. Quantifiability results imply potential HPHC transfers between matrices, leaching from components, or formations from aerosol generation. The study results can inform the scientific basis for manufacturers and regulators regarding regulatory requirements for HPHC reporting. The HPHC quantities can also inform evaluations of the public health impact of ENDS and public communications regarding ENDS health risks.

2.
Chem Res Toxicol ; 36(1): 94-103, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36602460

RESUMO

This study used standard linear smoking machines and puffing protocols to generate data on carbonyl yields in mainstream smoke from 11 unfiltered sheet-wrapped cigars (SWC), seven leaf-wrapped cigars (LWC), and two Kentucky reference cigarettes (3R4F, 1R6F). Carbonyl yields in cigar and cigarette products were determined using three different smoking regimens: International Organization for Standardization (ISO), Canadian Intense (CI), and Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) Recommended Method (CRM) No. 64 (CRM64, Routine Analytical Cigar-Smoking Machine─Specifications, Definitions and Standard Conditions). Mainstream tobacco smoke was collected using a smoking machine fitted with an impinger containing 2,4-dinitrophenylhydrazine (DNPH) and carbonyl compounds quantified using liquid chromatography with an ultraviolet detector. Commercial SWC and LWC generated comparable formaldehyde yields (SWC, 9.4-28 µg/cigar [ISO], 8.2-43 µg/cigar [CI], 8.6-13 µg/cigar [CRM64]; LWC, 11-13 µg/cigar [ISO], 11-22 µg/cigar [CI], 16-21 µg/cigar [CRM64]) and acrolein yields; however, LWC generated higher acetaldehyde yields compared to SWC, using CI and CRM64 regimens. Reference cigarettes using standard puffing regimens generated carbonyl yields within reported ranges and 5-10% RSDs, whereas the CRM64 regimen generated lower carbonyl yields and 12-14% RSDs. Reference cigarettes generated higher formaldehyde yields using cigarette smoking regimens (21-28 µg/cigarette under ISO, 76-96 µg/cigarette under CI) but comparable formaldehyde yields under CRM64 (12-14 µg/cigarette). In addition, this study evaluated physical parameters (e.g., tobacco weight, length, diameter, circumference, tobacco rod density) that show the correlation between tobacco weight, tobacco rod density, and acetaldehyde yields under the three smoking regimens. Carbonyl yields in the mainstream smoke of cigar products using the three smoking regimens were highly variable; however, the CI smoking regimen may provide meaningful analytical information regarding cigar smoke constituents, with lower likelihood of self-extinguishment due to the short puffing intervals.


Assuntos
Fumar Cigarros , Produtos do Tabaco , Canadá , Produtos do Tabaco/análise , Nicotiana/química , Formaldeído , Acetaldeído
3.
ACS Omega ; 7(29): 25537-25554, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35910156

RESUMO

The U.S. Food and Drug Administration established a list of 93 harmful and potentially harmful constituents (HPHCs) in tobacco products. While HPHCs are required to be submitted for tobacco products, knowledge gaps exist regarding which tobacco-containing tobacco product (TCTP, i.e., tobacco products that contain tobacco(s) as a component) types (cigarettes, cigars, roll-your-own tobaccos [RYOs], pipe tobaccos [pipes], smokeless tobacco products [STPs], waterpipe tobaccos [waterpipes]) and matrices (filler, smoke) contain which HPHCs. This study identified and addressed such gaps by conducting literature searches and measuring the amount of HPHCs in TCTP types and matrices. First, literature searches, performed for cigarettes, RYOs, and STPs for publications up to 2014 and for cigars, pipes, and waterpipes for publications up to 2016, identified knowledge gaps for the 93 HPHCs (or 119 HPHCs if cresols [o-, m-, p-cresol] are counted as 3 and chlorinated dioxins/furans as 25) across TCTP types and matrices. Then, three ISO 17025 accredited laboratories including two subcontracted laboratories performed the HPHC quantifications. Inclusion of the HPHCs, TCTP types, and matrices in the study scope was also determined by the availability of validated analytical methods in each laboratory. Eleven (9%) HPHCs are quantifiable in all brands for all TCTP types and matrices, 33 (28%) HPHCs are not quantifiable in any brands of any TCTP type and matrix, and 74 (63%) HPHCs are quantifiable only in some brands across TCTP types and matrices examined. Understanding the quantifiability of HPHCs in each TCTP type and matrix can inform the scientific basis for manufacturers regarding the regulatory requirements for reporting HPHCs. The quantity of HPHCs observed can also inform the evaluation of the public health impact of HPHCs and public communications regarding the health risks of tobacco products.

4.
J Pharm Sci ; 111(6): 1700-1708, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34861248

RESUMO

Portioned moist snuff and snus, two subcategories of smokeless tobacco products (STP) were dissolution tested as a quality control test. A USP Apparatus 4 was employed to develop and validate the method. The method was assessed based on time to reach nicotine dissolution plateau, percentage difference between two profiles at each time point, relative standard deviation (RSD), and f1 (similarity) and f2 (dissimilarity) values. Based on these criteria, 200 ml volume and 8 ml/min flow were found be discriminatory. The amount of nicotine dissolved from the nine products varied widely (2.0-3.4, 2.1-4.1, 3.3-4.6, 5.5-6.6, 6.9-9.1, 11.5-14.2, 12.5-14.6, 14.0-15.5, and 15.5-19.6 mg/pouch at 60 min). RSDs of the dissolution ranges were more than 20% at earlier time points and less than 20% at later timepoints. The developed method produced distinct profiles for all the tested products, which was further confirmed by f1>15 and f2<50 values. In conclusion, the developed method was discriminatory and can be employed as a quality control test and to differentiate among moist snuff and snus products.


Assuntos
Tabaco sem Fumaça , Nicotina , Solubilidade
5.
Artigo em Inglês | MEDLINE | ID: mdl-24970595

RESUMO

For aquaculture to become sustainable, there is a need to substitute fish oil [FO, rich in ω3 long chain polyunsaturated fatty acids (LC-PUFA) such as 20:5ω3 (EPA) and 22:6ω3 (DHA)] in aquafeed with plant oils such as camelina oil [CO, rich in C18 PUFA such as 18:3ω3 (ALA) and 18:2ω6 (LNA)]. The LC-PUFA are essential components in fish diets for maintaining optimal health, physiology and growth. However, most marine fish including Atlantic cod are inefficient at producing LC-PUFA from shorter chain precursors. Since elovl genes encode enzymes that play key roles in fatty acid biosynthesis, we hypothesized that they may be involved in Atlantic cod responses to diets rich in 18:3ω3 and 18:2ω6. Ten members of the cod elovl gene family were characterized at the mRNA level. RT-PCR was used to study constitutive expression of elovl transcripts in fifteen tissues. Some transcripts (e.g. elovl5) were ubiquitously expressed, while others had tissue-specific expression (e.g. elovl4a in brain and eye). Cod fed a CO-containing diet (100% CO replacement of FO and including solvent-extracted fish meal) had significantly lower weight gain, with significant up-regulation of elovl5 and fadsd6 transcripts in the liver as shown by QPCR analysis, compared with cod on a FO control diet after a 13-week trial. Multivariate statistical analyses (SIMPER and PCA) indicated that high 18:3ω3 and/or low ω3 LC-PUFA levels in the liver were associated with the up-regulation of elovl5 and fadsd6, which are involved in LC-PUFA biosynthesis in cod.


Assuntos
Acetiltransferases/genética , Ácidos Graxos Insaturados/metabolismo , Gadus morhua/metabolismo , Fígado/metabolismo , Óleos de Plantas , Acetiltransferases/metabolismo , Sequência de Aminoácidos , Animais , Brassicaceae/química , Dieta , Elongases de Ácidos Graxos , Ácidos Graxos Insaturados/biossíntese , Gadus morhua/crescimento & desenvolvimento , Expressão Gênica , Linoleoil-CoA Desaturase/metabolismo , Fígado/enzimologia , Dados de Sequência Molecular , Filogenia , RNA Mensageiro/metabolismo
7.
Mol Immunol ; 47(4): 763-84, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19923001

RESUMO

NR-13, Mcl-1, and BCL-X(L), are conserved anti-apoptotic proteins that belong to the anti-apoptotic Bcl-2 sub-family, which inhibits cell death by preventing mitochondrial membrane permeabilization (MMP). Given the anti-apoptotic functions of these proteins in vertebrates (e.g. human, mouse, and zebrafish) and the involvement of apoptotic regulation in immune responses, we studied the sequences of these genes and their transcript expression in Atlantic cod (Gadus morhua) during innate immune responses to viral and bacterial stimuli. Based on previously generated Atlantic cod expressed sequence tags (ESTs), we identified partial cDNA sequences of putative orthologues of Atlantic cod NR-13, Mcl-1, and Bcl-X, and obtained the full-length cDNA, genomic, and promoter region sequences for these genes. The analyses of Atlantic cod cDNA sequences, and comparisons of the cod deduced amino acid sequences to putative orthologues in other species, revealed the presence of highly conserved Bcl-2 homology (BH) and transmembrane (TM) domains in the Atlantic cod sequences. Analysis of gene structure revealed conserved intron/exon boundaries within the coding regions of human and Atlantic cod putative orthologues. We found that an intron/exon boundary immediately following the codon for the 8th residue (tryptophan) of the BH2 domain exists in all anti-apoptotic Bcl-2 sub-family genes regardless of vast evolutionary distance. We also identified a non-coding exon in the Atlantic cod NR-13-like gene, which appears to be absent in its putative mammalian orthologues. Quantitative reverse transcription-polymerase chain reaction (QPCR) was used to study constitutive gene expression in six tissues (blood, brain, gill, head kidney, pyloric caecum, and spleen) of non-stressed juvenile cod; NR-13 and Bcl-X2 were most highly expressed in gill, whereas Mcl-1 and Bcl-X1 were most highly expressed in blood. In cod challenged with intraperitoneal (IP) injections of the viral mimic polyriboinosinic polyribocytidylic acid (pIC), (1) NR-13 mRNA expression was significantly up-regulated (compared to both 0h pre-injection and timed saline injected controls) in spleen at 6h post-injection and in head kidney at both 6 and 24h post-injection (HPI), and (2) both Mcl-1 and Bcl-X2 were significantly up-regulated (compared to both 0h pre-injection and timed saline injected controls) in spleen at 6 HPI. QPCR was used to show that, in cod challenged with IP injections of formalin-killed, atypical Aeromonas salmonicida (ASAL), only NR-13 appeared to be responsive (significantly up-regulated in spleen at 6 HPI compared to 0h pre-injection controls). Interestingly, QPCR showed that saline injection had a mild (less than 3-fold) but significant inductive effect (compared to 0h pre-injection controls) on both NR-13 and Mcl-1 transcript expression in spleen at 2 HPI. Although we only obtained partial cDNA and genomic sequences for Bcl-X2, sufficient evidence was accumulated to show that two Bcl-X paralogues exist in Atlantic cod, possibly due to the teleost-specific genome duplication event. Promoter regions for NR-13, Mcl-1, and Bcl-X1 were obtained and analyzed for the first time in fish, and potential regulatory sites (e.g. putative NF-kappaB binding sites) that were found in the promoter regions of NR-13 and Mcl-1 may account for their transcriptional activation by pIC.


Assuntos
Proteínas de Peixes/genética , Gadus morhua/genética , Regulação da Expressão Gênica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína bcl-X/genética , Processamento Alternativo/genética , Sequência de Aminoácidos , Animais , Antígenos de Bactérias/imunologia , Antígenos Virais/imunologia , Oceano Atlântico , Sequência de Bases , Clonagem Molecular , Sequência Conservada , Éxons/genética , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Gadus morhua/microbiologia , Gadus morhua/virologia , Perfilação da Expressão Gênica , Humanos , Íntrons/genética , Dados de Sequência Molecular , Proteína de Sequência 1 de Leucemia de Células Mieloides , Fases de Leitura Aberta/genética , Regiões Promotoras Genéticas/genética , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNA , Baço/microbiologia , Baço/virologia , Proteína bcl-X/química , Proteína bcl-X/metabolismo
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