Biochemical validation of self-reported electronic nicotine delivery system and tobacco heaviness of use

Research on tobacco use disorder relies on a combination of self-reported use (e.g., cigarettes per day) and biochemical validation to quantify heaviness of use. However, electronic nicotine delivery system (ENDS) users may be unaware of how much they have vaped per day. The aim of this study was to test the relationship between self-reported heaviness of ENDS/tobacco use and nicotine biomarkers. Young adults (n = 30) who currently use ENDS and other tobacco products completed a detailed tobacco use history, timeline follow-back, and an ENDS topography session. We evaluated the self-reports of own-brand ENDS use and tested correlations to determine which self-report measures of own-brand use, and which self-reported measures of puff topography, had the strongest correlations with urine and/or blood biomarkers of nicotine use. Participants reported using a variety of different ENDS devices and had a range of usage. The sum of the self-reported number of occasions or hours of ENDS use, along with the number of cigarettes and other tobacco products used, over the past 24 hr was significantly correlated with plasma cotinine levels. Puff topography measures correlated with increased nicotine concentrations, although participants underestimated the number of puffs they took during the topography session. This study provides preliminary evidence that summing together the hours of ENDS use, or the number of occasions of ENDS use, in addition to the number of other tobacco products used (i.e., cigarettes) based on self-report may be an accurate method of quantification. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Abstract PO-160: Associations between diet and food security with colorectal cancer-based health disparity among African Americans

Introduction. African Americans (AAs) have a colorectal cancer (CRC)-based health disparity. However, AAs had higher screening test usage than non-Hispanic whites (NHWs) in Arkansas in 2016. Additionally, CRC is of interest in Arkansas because geographic areas such as the Delta regions in Arkansas remain mortality hotspots. Also, certain lifestyle factors such as diet, alcohol and tobacco use, and physical activity have been associated with CRC risk. Our goal is to examine the association between colorectal health, diet, and sociodemographics related to access to adequate food, to understand the factors involved in the CRC health disparity among AAs. Method. We are recruiting participants who have recently (2019-2021) received a colonoscopy. These participants are filling out surveys related to their demographics, socioeconomic status, health, family history, lifestyle, and diet, as well as collecting a stool sample at home for our future untargeted metabolomic analysis. For this preliminary analysis, we have focused on self-report survey data to determine which factors are associated with colorectal health and race. Results. We used t-tests with Bonferroni correction and chi-square test with statistical significance at p<0.05. The comparisons were healthy vs. polyp(s), healthy vs. cancer, and polyp(s) vs. cancer. The cancer group had statistically lower percentages of having gone to or completed college, and of having hourly or salaried wages as well as higher percentages of $25,000/year or less in household income, overweight BMI of 25-30, family history of CRC, and ever smoked at least 100 cigarettes. In addition, all participants in the cancer group had ever used tobacco products and not lifted weights for physical activity in the last year. Also, the polyp(s) group had the highest percentage engaging in light physical activity, and the control group had the highest percentage of current use of cigarettes every day. We also compared the food- and nutrient-level data. Coumestrol was found to be significantly higher among the healthy group vs. polyp(s). Starch, starchy vegetables, phosphorous, zinc, and pinitol were found to be significant when comparing healthy vs. cancer, and all but pinitol were found to be higher among the cancer group. Also, starchy and total vegetables, trans-hexadecenoic acid, cis-9,trans-11 conjugated linoleic acid, and pinitol were found to be significant between polyp(s) vs. cancer, and all but pinitol were found to be higher among the cancer group. In addition, 37 food- and nutrient-level data points were significantly higher among NHW participants vs. AAs. Conclusion. CRC has minimal symptoms, and that is why routine CRC screening is important. From our findings, targeted education related to risk factors for CRC should be implemented among all people, especially on vegetable and fruit consumption, tobacco use, physical activity, and appropriate screening. Additional importance should be focused on high-risk individuals such as AAs and those with a family history of CRC.

Citation Format: Jonathan A. Laryea, Eryn K. Matich, Ping-Ching Hsu, Joseph Su. Associations between diet and food security with colorectal cancer-based health disparity among African Americans [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-160.

Association between pesticide exposure and colorectal cancer risk and incidence: A systematic review

BACKGROUND

Studies investigating the association between pesticide exposure and colorectal cancer (CRC) risk have been inconclusive.

OBJECTIVES

Investigate the association between pesticide exposure and CRC risk through a systematic literature review.

METHODS

CRC has the fourth-highest rate of cancer-caused death in the US after lung cancer, breast cancer in women, and prostate cancer in men. Here we have conducted a systematic literature search on studies examining the association between any pesticide exposure and CRC risk using PubMed, MEDLINE via EBSCO host, and Embase according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

RESULTS

Following the review, 139 articles were included for qualitative evaluation. Study participants were farmers, pesticide applicators, pesticide manufacturers, spouses of pesticide applicators, farm residents, Korean veterans of the Vietnam War, rural communities, and those who consumed food with pesticide residues. The studies' results were split between those with significant positive (39 significant results) and inverse (41 significant results) associations when comparing pesticide exposure and CRC risk.

DISCUSSION

From our literature review, we have identified a similar number of significant positive and inverse associations of pesticide exposure with CRC risk and therefore cannot conclude whether pesticide exposure has a positive or inverse association with CRC risk overall. However, certain pesticides such as terbufos, dicamba, trifluralin, S-ethyl dipropylthiocarbamate (EPTC), imazethapyr, chlorpyrifos, carbaryl, pendimethalin, and acetochlor are of great concern not only for their associated elevated risk of CRC, but also for the current legal usage in the United States (US). Aldicarb and dieldrin are of moderate concern for the positive associations with CRC risk, and also for the illegal usage or the detection on imported food products even though they have been banned in the US. Pesticides can linger in the soil, water, and air for weeks to years and, therefore, can lead to exposure to farmers, manufacturing workers, and those living in rural communities near these farms and factories. Approximately 60 million people in the US live in rural areas and all of the CRC mortality hotspots are within the rural communities. The CRC mortality rate is still increasing in the rural regions despite the overall decreasing of incidence and mortality of CRC elsewhere. Therefore, the results from this study on the relationship between pesticide exposure and CRC risk will help us to understand CRC health disparities.

Abstract PO-038: Colorectal cancer health disparity among African Americans: A qualitative study at the community level, exploring the connection between low access to resources, diet, and colorectal health

Background: Colorectal cancer (CRC) is the third leading cause of cancer death in the United States (US) but can be prevented with routine screening. A significant racial disparity exists among African Americans (AAs) with higher CRC incidence and mortality rates than other races, in particular in some rural areas, such as the lower Mississippi Delta regions including 17 counties in Arkansas. However, this disparity cannot be explained solely by lack of screening. Previous studies have suggested that this health disparity may be related to limited access to healthy food, lack of physical activity, and lack of facilities for cancer screening. Additional research in Arkansas is needed on the determinants of these disparities to develop actionable prevention strategies. Methods: An engagement approach known as a community review board (CRB) was used in this study. A CRB is a one-time meeting with community member experts who have personal experience with the research issue, and these experts provide feedback on the study. Two CRBs consisting of AAs age 45-75 were conducted, in urban, central (Little Rock, n=6) and rural, lower Delta (Helena, n=10) Arkansas communities, to better understand these communities’ perspectives on CRC and screening. We also discussed the community members’ willingness to participate in a study to look at the association between diet and food security with CRC and the barriers to participate. Differences in the viewpoints of the two CRBs were compared and documented. Results: Both rural and urban CRB respondents indicated their willingness to believe and listen to other community members, and generally do not go to the doctor unless they are sick. A lower percentage of our rural CRB participants (30%) had been screened for CRC as compared to our urban CRB participants (83%). When invited to participate in research studies, rural CRB respondents preferred to learn about the results of the study in a public, community forum. These older AA community members, both rural and urban, thought communities could benefit from more information disseminated related to these topics. Additionally, the rural CRB participants were more comfortable discussing CRC incidence and mortality with family compared to urban CRB participants.

Conclusions: From this study, those in this rural community are more comfortable discussing CRC in the community-based discussion and with their family, and this may be related to the fact that they live in a CRC mortality hotspot in the Delta region. In addition, because members of these communities, both rural and urban, mentioned the need for more available information about CRC and screening we will hold virtual community forums with residents of Little Rock and Phillips County to discuss CRC, screening, and diet to inform and learn more from these Arkansas communities. We will also use the community members’ feedback to improve our research project in which we will analyze the association between food security, diet, and CRC.

Citation Format: Eryn K. Matich, Rachel Hale, Nicola Spencer, M. Kathryn Stewart, L. Joseph Su, Ping-Ching Hsu. Colorectal cancer health disparity among African Americans: A qualitative study at the community level, exploring the connection between low access to resources, diet, and colorectal health [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-038.

Applications of metabolomics in assessing ecological effects of emerging contaminants and pollutants on plants

Metabolomics, the global profiling of metabolite composition, is a powerful technique that can be applied to answer a diverse set of research questions concerning effects of toxicants on organisms. It has recently emerged as a tool to understand complex environmental perturbations in biological systems, especially at sub-lethal concentrations. Organisms can be affected by different stressors such as xenobiotics or increase in concentration of natural compounds such as nitrogen, phosphorous, and sulfur. Metabolomics has facilitated a better understanding of the effects of these perturbations on organisms such as plants, animals, and humans providing phenotypic and biological information in a high throughput manner. In this review, we will discuss recent applications of metabolomics to study the ecological effects of different environmental perturbations, including nanoparticles, pharmaceuticals and personal care products, pesticides, as well as the changes in natural compounds found in the environment with a focus on plant systems.

Mass spectrometry based detection of common vitellogenin peptides across fish species for assessing exposure to estrogenic compounds in aquatic environments

The identification of myriad of chemicals in the environment that mimic hormones and affect the endocrine functions of exposed organism is a daunting analytical challenge for environmental scientists and engineers. Many of these endocrine disrupting chemicals (EDCs) are present at very low concentrations in the aquatic systems, but yet affect the metabolic, developmental, and reproductive functions in exposed fish and wildlife. Vitellogenin (VTG) protein is a widely used biomarker in fish for assessing exposure to EDCs, and is commonly measured using species-specific immunochemical techniques. In this study, we developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) method that can measure common peptides from digested VTG in multiple fish species. In the initial experiments using high resolution mass spectrometry, two peptides (ALHPELR and FIELIQLLR) were identified as common fragments in the digested VTG protein isolated from three different fish species (Pimephales promelas, Micropterus salmoides, and Fundulus heteroclitus). Then, a quantitative analysis using LC-MS/MS under selected reaction monitoring mode was developed for the detection of these two peptides in trypsin-digested plasma from female fish (positive control), estrogen-exposed male fish (test sample), and unexposed male fish (negative control) using two of the same species used for identifying the common peptides (P. promelas, and M. salmoides) and one new species (Ameiurus nebulosus) that was not included during the selection of peptides. Results from this study demonstrate the potential of LC-MS/MS as an effective cross-species method to detect VTG in fish, which can be an alternative analytical technique for assessing endocrine disruption in multiple fish species.

Thioglycosides Are Efficient Metabolic Decoys of Glycosylation that Reduce Selectin Dependent Leukocyte Adhesion

Metabolic decoys are synthetic analogs of naturally occurring biosynthetic acceptors. These compounds divert cellular biosynthetic pathways by acting as artificial substrates that usurp the activity of natural enzymes. While O-linked glycosides are common, they are only partially effective even at millimolar concentrations. In contrast, we report that N-acetylglucosamine (GlcNAc) incorporated into various thioglycosides robustly truncate cell surface N- and O-linked glycan biosynthesis at 10-100 μM concentrations. The >10-fold greater inhibition is in part due to the resistance of thioglycosides to hydrolysis by intracellular hexosaminidases. The thioglycosides reduce β-galactose incorporation into lactosamine chains, cell surface sialyl Lewis-X expression, and leukocyte rolling on selectin substrates including inflamed endothelial cells under fluid shear. Treatment of granulocytes with thioglycosides prior to infusion into mouse inhibited neutrophil homing to sites of acute inflammation and bone marrow by ∼80%-90%. Overall, thioglycosides represent an easy to synthesize class of efficient metabolic inhibitors or decoys. They reduce N-/O-linked glycan biosynthesis and inflammatory leukocyte accumulation.

Type I collagen self-assembly: the roles of substrate and concentration

Collagen molecules, self-assembled into macroscopic hierarchical tissue networks, are the main organic building block of many biological tissues. A particularly common and important form of this self-assembly consists of type I collagen fibrils, which exhibit a nanoscopic signature, D-periodic gap/overlap spacing, with a distribution of values centered at approximately 67 nm. In order to better understand the relationship between type I collagen self-assembly and D-spacing distribution, we investigated surface-mediated collagen self-assembly as a function of substrate and incubation concentration. Collagen fibril assembly on phlogopite and muscovite mica as well as fibrillar gel coextrusion in glass capillary tubes all exhibited D-spacing distributions similar to those commonly observed in biological tissues. The observation of D-spacing distribution by self-assembly of type I collagen alone is significant as it eliminates the necessity to invoke other preassembly or postassembly hypotheses, such as variation in the content of collagen types, enzymatic cross-linking, or other post-translational modifications, as mechanistic origins of D-spacing distribution. The D-spacing distribution on phlogopite mica is independent of type I collagen concentration, but on muscovite mica D-spacing distributions showed increased negative skewness at 20 μg/mL and higher concentrations. Tilted D-spacing angles were found to correlate with decreased D-spacing measurements, an effect that can be removed with a tilt angle correction, resulting in no concentration dependence of D-spacing distribution on muscovite mica. We then demonstrated that tilted D-spacing is uncommon in biological tissues and it does not explain previous observations of low D-spacing values in ovariectomized dermis and bone.