Custom Mentholation of Commercial Cigarettes for Research Purposes.
Ontology highlight
ABSTRACT:
SUBMITTER: MacGregor IC
PROVIDER: S-EPMC4303566 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Previous literature has shown that adding charcoal to cigarette filters can have varying effects on the delivery of toxic carbonyls depending on filter design, amount of charcoal, and puffing profiles. However, these studies have relied on either comparisons between commercially available charcoal and noncharcoal filtered cigarettes or experimental modification of filters to insert a charcoal plug into existing cellulose acetate filters. Make-your-own (MYO) cigarettes can help obviate many of the potential pitfalls of previous studies; thus, we conducted studies using commercial charcoal cigarettes and MYO cigarettes to determine the effects of charcoal on carbonyl delivery. To do this, we analyzed carbonyls in mainstream smoke by HPLC-UV after derivatization with 2,4-dinitrophenylhydrazine (DNPH). Charcoal was added in-line after the cigarettes or through the use of MYO charcoal cigarette tubes. MYO cigarettes had carbonyl deliveries similar to that of 3R4F research cigarette, regardless of tobacco type. The greatest effect on carbonyl delivery was observed with 200 mg of charcoal, significantly reducing all carbonyls under both methods tested. However, "on-tow" design charcoal filters, available on many commercially available charcoal brands, appeared to have a minimal effect on carbonyl delivery under intense smoking methods. Overall, we found that charcoal, when added in sufficient quantity (200 mg) as a plug, can substantially reduce carbonyl delivery for both MYO and conventional cigarettes. As carbonyls are related to negative health outcomes, such reductions may be associated with reductions in carbonyl-related harm in smokers.
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Project description:This paper presents data related to the article "A method for easily customizable gradient gel electrophoresis" (A.J. Miller, B. Roman, E.M. Norstrom, 2016) [1]. Data is presented on the rate of electrophoretic migration of proteins in both hand-poured and commercially acquired acrylamide gradient gels. For each gel, migration of 9 polypeptides of various masses was measured upon completion of gel electrophoresis. Data are presented on the migration of proteins within separate lanes of the same gel as well as migration rates from multiple gels.
| S-EPMC5007585 | biostudies-literature
Project description:We compared the accuracy of microarray measurements obtained with oligonucleotide arrays (GeneChip, Affymetrix) with a laboratory-developed cDNA array by assaying test RNA samples from an experiment using a paradigm known to regulate many genes measured on both arrays. We selected 47 genes represented on both arrays, including both known regulated and unregulated transcripts, and established reference relative expression measurements for these genes in the test RNA samples using quantitative reverse transcriptase real-time PCR (QRTPCR) assays. The validity of the reproducible (average coefficient of variation = 11.8%) QRTPCR measurements were established through application of a new mathematical model. The performance of both array platforms in identifying regulated and non-regulated genes was identical. With either platform, 16 of 17 definitely regulated genes were correctly identified, and no definitely unregulated transcript was falsely identified as regulated. Accuracy of the fold-change measurements obtained with each platform was assessed by determining measurement bias. Both platforms consistently underestimate the relative changes in mRNA expression between experimental and control samples. The bias observed with cDNA arrays was predictable for fold-changes <250-fold by QRTPCR and could be corrected by the calibration function F(c) = F(a(cDNA))(q), where F(a(cDNA)) is the microarray-determined fold-change comparing experimental with control samples, q is the correction factor and F(c) is the calibrated value. The bias observed with the commercial oligonucleotide arrays was less predictable and calibration was unfeasible. Following calibration, fold-change measurements generated by custom cDNA arrays were more accurate than those obtained by commercial oligonucleotide arrays. Our study demonstrates systematic bias of microarray measurements and identifies a calibration function that improves the accuracy of cDNA array data.
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Project description:The "Caparrona" bean is a landrace that was grown largely in Monzón, and for that reason, it is also known by the name of "Caparrona de Monzón." Historical references mention that in the thirties of the last century, Caparrona beans reached a production higher than 200,000 kg. Nevertheless, the increasing modernization of agriculture at the end of the 20th century enhanced its replacement by newer varieties. As a result, only a few local growers continued producing Caparrona beans mainly for family use. However, in recent years, the high demand for local products, grown with environmentally friendly farming techniques, has reawakened interest in this local bean. In order to recover the Caparrona bean crop, a study was conducted with the aim of assessing this landrace, along with all the processes, from collecting seeds to securing the in situ and ex situ conservation. Six bean samples were initially collected from local farmers and the traditional knowledge was also recorded. After the first seed-borne virus test, two samples were rejected because of the positive results for Bean Common Mosaic Virus (BCMV). The four remaining samples were evaluated in a randomized complete block design with three replications at two locations. All through the growth phase of the plants, samples were taken for a virus test. Two samples tested positive for BCMV and were discarded. Between the two healthy seed samples, regarding morphology, chemical composition, and agronomic data, no significant statistical differences were found. Therefore, both samples were selected for commercial production. The seeds obtained from the assays were transferred to a recently created producers' association, which registered a private label to commercialize the Caparrona beans as a gourmet product. Seeds are also available from the Spanish BGHZ-CITA public genebank.
| S-EPMC6209639 | biostudies-other
Project description:INTRODUCTION:Research on electronic cigarettes is an emerging field, with the number of articles in this field noted to have grown exponentially over recent years. We used a bibliometric analysis method (co-word analysis) to analyze the emerging trends and research hotspots in this field. METHODS:Publication data on electronic cigarettes from 2010 to 2018 were retrieved and downloaded from the PubMed database. Theme trends and knowledge structures were analyzed on the relevant research fields of electronic cigarettes by using a biclustering analysis, strategic diagram analysis, and social network analysis methods. Research hotspots were extracted and compared from three periods. RESULTS:Core topics that have continuously develop between the years 2010 and 2018 include: tobacco use cessation devices; tobacco products; tobacco use cessation devices/adverse effects; smoking prevention and adverse effects; electronic nicotine delivery systems/economics; and public health. Some currently undeveloped topics that could be considered as new future research directions include: tobacco use disorder/therapy; tobacco use disorder/epidemiology; students/psychology; students/statistics and numerical data; adolescent behavior/psychology; nicotine/toxicity; nicotinic agonists/administration and dosage; and electronic nicotine delivery systems/legislation and jurisprudence. CONCLUSIONS:Results suggest that some currently immature topics in strategic coordinates and emerging hotspots in social network graphs can be used as future research directions.
| S-EPMC7107908 | biostudies-literature
Project description:Electronic cigarettes (e-cigarettes) have gained their popularity as a substitute for cigarettes or cigars. Despite the widespread use of flavoring chemicals in e-cigarettes, the health impacts of the flavoring compounds, in particular their effects on critical cellular function in the lung, remain largely unknown. The goal of this study was to identify transcriptomic changes and impacted biological pathways in primary human bronchial epithelial cells (HBECs) exposed to flavoring chemicals (diacetyl or 2,3-pentanedione) and to flavored e-cigarette smoke. An airway-liquid interface culturing method was used to differentiate primary human bronchial epithelial cells (HBECs) into mature epithelial cells, which were then treated with 25 ppm diacetyl, 100 ppm 2,3 pentanedione, or e-cigarette smoke solution containing 2 ppm diacetyl. Poly(A)-selected RNA-Seq libraries were prepared with the PrepX RNA-Seq for Illumina Library kit. An Illumina HiSeq 2500 instrument was used to generate 50 base pair single-end reads. STAR was used to align sequencing reads to the hg38 reference genome, and HTSeq was used to quantify transcript levels. DESeq2 was used to perform differential expression analysis.
2019-08-21 | GSE118431 | GEO
Project description:IntroductionThe tobacco control community has raised some concerns about whether studies on electronic cigarettes (e-cigarettes) published in scientific journals hide conflicts of interest (COI) and whether such reports are biased. This study assessed potential COI in the e-cigarette scientific literature.MethodsCross-sectional study was conducted on e-cigarette publications indexed in PubMed up to August 2014. We extracted information about the authors (affiliations, location, etc.), publication characteristics (type, topic, subject, etc.), results and conclusions, presence of a COI statement, and funding by and/or financial ties to pharmaceutical, tobacco, and/or e-cigarette companies. An algorithm to determine the COI disclosure status was created based on the information in the publication. Prevalence ratios (PRs) and confidence intervals (CIs) were calculated to identify associations with COI disclosure, controlling for several independent variables.ResultsOf the 404 publications included in the analysis, 37.1% (n=150) had no COI disclosure statement, 38.6% declared no COI, 13.4% declared potential COI with pharmaceutical companies, 3.0% with tobacco companies, and 10.6% with e-cigarette companies. The conclusions in publications with COI, which were mainly tied to pharmaceutical companies, were more likely to be favourable to e-cigarette use (PR=2.23; 95% CI: 1.43-3.46). Publications that supported the use of e-cigarettes for both harm reduction (PR=1.81; 95%CI: 1.14-2.89) and smoking cessation (PR=2.02; 95% CI: 1.26-3.23) were more likely to have conclusions that were favourable to e-cigarettes.ConclusionsOne-third of the publications reporting studies on e-cigarettes did not have a COI disclosure statement, and this proportion was even higher in news articles, editorials and other types of publications. Papers with conclusions that were favourable to e-cigarette use were more likely to have COI. Journal editors and reviewers should consider evaluating publications, including funding sources, to determine whether the results and conclusions may be biased.
| S-EPMC6659563 | biostudies-literature
Project description:BackgroundAs social media are increasingly used worldwide, more and more scientists are relying on them for their health-related projects. However, social media features, methodologies, and ethical issues are unclear so far because, to our knowledge, there has been no overview of this relatively young field of research.ObjectiveThis scoping review aimed to provide an evidence map of the different uses of social media for health research purposes, their fields of application, and their analysis methods.MethodsWe followed the scoping review methodologies developed by Arksey and O'Malley and the Joanna Briggs Institute. After developing search strategies based on keywords (eg, social media, health research), comprehensive searches were conducted in the PubMed/MEDLINE and Web of Science databases. We limited the search strategies to documents written in English and published between January 1, 2005, and April 9, 2020. After removing duplicates, articles were screened at the title and abstract level and at the full text level by two independent reviewers. One reviewer extracted data, which were descriptively analyzed to map the available evidence.ResultsAfter screening 1237 titles and abstracts and 407 full texts, 268 unique papers were included, dating from 2009 to 2020 with an average annual growth rate of 32.71% for the 2009-2019 period. Studies mainly came from the Americas (173/268, 64.6%, including 151 from the United States). Articles used machine learning or data mining techniques (60/268) to analyze the data, discussed opportunities and limitations of the use of social media for research (59/268), assessed the feasibility of recruitment strategies (45/268), or discussed ethical issues (16/268). Communicable (eg, influenza, 40/268) and then chronic (eg, cancer, 24/268) diseases were the two main areas of interest.ConclusionsSince their early days, social media have been recognized as resources with high potential for health research purposes, yet the field is still suffering from strong heterogeneity in the methodologies used, which prevents the research from being compared and generalized. For the field to be fully recognized as a valid, complementary approach to more traditional health research study designs, there is now a need for more guidance by types of applications of social media for health research, both from a methodological and an ethical perspective.International registered report identifier (irrid)RR2-10.1136/bmjopen-2020-040671.
| S-EPMC8193478 | biostudies-literature
Project description:Tobacco-specific nitrosamines (TSNAs) are N-nitroso-derivatives of pyridine-alkaloids (e.g., nicotine) present in tobacco and cigarette smoke. Two TSNAs, N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are included on the Food and Drug Administration's list of harmful and potentially harmful constituents (HPHCs) in tobacco products and tobacco. The amounts of four TSNAs (NNK, NNN, N-nitrosoanabasine (NAB), and N'-nitrosoanatabine (NAT)) in the tobacco and mainstream smoke from 50 U.S. commercial cigarette brands were measured from November 15, 2011 to January 4, 2012 using a validated HPLC/MS/MS method. Smoke samples were generated using the International Organization of Standardization (ISO) and Canadian Intense (CI) machine-smoking regimens. NNN and NAT were the most abundant TSNAs in tobacco filler and smoke across all cigarette brands, whereas NNK and NAB were present in lesser amounts. The average ratios for each TSNA in mainstream smoke to filler content is 29% by the CI smoking regimen and 13% for the ISO machine-smoking regimen. The reliability of individual TSNAs to predict total TSNA amounts in the filler and smoke was examined. NNN, NAT, and NAB have a moderate to high correlation (R2 = 0.61-0.98, p < 0.0001), and all three TSNAs individually predict total TSNAs with minimal difference between measured and predicted total TSNA amounts (error < 7.4%). NNK has weaker correlation (R2 = 0.56-0.82; p < 0.0001) and is a less reliable predictor of total TSNA quantities. Tobacco weight and levels of TSNAs in filler influence TSNA levels in smoke from the CI machine-smoking regimen. In contrast, filter ventilation is a major determinant of levels of TSNAs in smoke by the ISO machine-smoking regimen. Comparative analysis demonstrates substantial variability in TSNA amounts in tobacco filler and mainstream smoke yields under ISO and CI machine-smoking regimens among U.S. commercial cigarette brands.
| S-EPMC5318265 | biostudies-literature