Bis-butanediol-mercapturic acid (bis-BDMA) as a urinary biomarker of metabolic activation of butadiene to its ultimate carcinogenic species

Human carcinogen 1,3-butadiene (BD) undergoes metabolic activation to 3,4-epoxy-1-butene (EB), hydroxymethylvinyl ketone (HMVK), 3,4-epoxy-1,2-butanediol (EBD) and 1,2,3,4-diepoxybutane (DEB). Among these, DEB is by far the most genotoxic metabolite and is considered the ultimate carcinogenic species of BD. We have shown previously that BD-exposed laboratory mice form 8- to 10-fold more DEB–DNA adducts than rats exposed at the same conditions, which may be responsible for the enhanced sensitivity of mice to BD-mediated cancer. In the present study, we have identified 1,4-bis-(N-acetyl-l-cystein-S-yl)butane-2,3-diol (bis-BDMA) as a novel DEB-specific urinary biomarker. Isotope dilution high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was employed to quantify bis-BDMA and three other BD-mercapturic acids, 2-(N-acetyl-l-cystein-S-yl)-1-hydroxybut-3-ene/1-(N-acetyl-l-cystein-S-yl)-2-hydroxy-but-3-ene (MHBMA, from EB), 4-(N-acetyl-l-cystein-S-yl)-1,2-dihydroxybutane (DHBMA, from HMVK) and 4-(N-acetyl-l-cystein-S-yl)-1,2,3-trihydroxybutane (THBMA, from EBD), in urine of confirmed smokers, occupationally exposed workers and BD-exposed laboratory rats. Bis-BDMA was formed in a dose-dependent manner in urine of rats exposed to 0–200 p.p.m. BD by inhalation, although it was a minor metabolite (1%) as compared with DHBMA (47%) and THBMA (37%). In humans, DHBMA was the most abundant BD-mercapturic acid excreted (93%), followed by THBMA (5%) and MHBMA (2%), whereas no bis-BDMA was detected. These results reveal significant differences in metabolism of BD between rats and humans

Aerosol–cloud drop concentration closure for clouds sampled during the International Consortium for Atmospheric Research on Transport and Transformation 2004 campaign

This study analyzes 27 cumuliform and stratiform clouds sampled aboard the CIRPAS Twin Otter during the 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) experiment. The data set was used to assess cloud droplet closure using (1) a detailed adiabatic cloud parcel model and (2) a state-of-the-art cloud droplet activation parameterization. A unique feature of the data set is the sampling of highly polluted clouds within the vicinity of power plant plumes. Remarkable closure was achieved (much less than the 20% measurement uncertainty) for both parcel model and parameterization. The highly variable aerosol did not complicate the cloud droplet closure, since the clouds had low maximum supersaturation and were not sensitive to aerosol variations (which took place at small particle sizes). The error in predicted cloud droplet concentration was mostly sensitive to updraft velocity. Optimal closure is obtained if the water vapor uptake coefficient is equal to 0.06, but can range between 0.03 and 1.0. The sensitivity of cloud droplet prediction error to changes in the uptake coefficient, organic solubility and surface tension depression suggest that organics exhibit limited solubility. These findings can serve as much needed constraints in modeling of aerosol-cloud interactions in the North America; future in situ studies will determine the robustness of our findings

Activation of sodium azide in mammalian cells

Abstract not availabl

Advanced Collaborative Emissions Study Auxiliary Findings on 2007-Compliant Diesel Engines: A Comparison With Diesel Exhaust Genotoxicity Effects Prior to 2007

Since its beginning, more than 117 years ago, the compression-ignition engine, or diesel engine, has grown to become a critically important part of industry and transportation. Public concerns over the health effects from diesel emissions have driven the growth of regulatory development, implementation, and technological advances in emission controls. In 2001, the United States Environmental Protection Agency and California Air Resources Board issued new diesel fuel and emission standards for heavy-duty engines. To meet these stringent standards, manufacturers used new emission after-treatment technology, and modified fuel formulations, to bring about reductions in particulate matter and nitrogen oxides within the exhaust. To illustrate the impact of that technological transition, a brief overview of pre-2007 diesel engine exhaust biomarkers of genotoxicity and health-related concerns is provided, to set the context for the results of our research findings, as part of the Advanced Collaborative Emissions Study (ACES), in which the effects of a 2007-compliant diesel engine were examined. In agreement with ACES findings reported in other tissues, we observed a lack of measurable 2007-compliant diesel treatment–associated DNA damage, in lung tissue (comet assay), blood serum (8-hydroxy-2′-deoxyguanosine [8-OHdG] assay), and hippocampus (lipid peroxidation assay), across diesel exhaust exposure levels. A time-dependent assessment of 8-OHdG and lipid peroxidation also suggested no differences in responses across diesel exhaust exposure levels more than 24 months of exposure. These results indicated that the 2007-compliant diesel engine reduced measurable reactive oxygen species–associated tissue derangements and suggested that the 2007 standards–based mitigation approaches were effective

285 “Stages” of Hope: Theater as a Research and Outreach Modality for Generating Knowledge, Understanding, and Healing

OBJECTIVES/GOALS: Theater has always served as a means of reflecting and understanding the human condition. Participatory theater further offers the option for viewers to participate in and thus additionally benefit from the performance itself. We use Playback Theater for outreach and research, eliciting information to guide research, education, and engagement. METHODS/STUDY POPULATION: Playback Theater is a type of improvisation that involves audience members recounting personal experiences which are then enacted by a theater troupe. Playback has evolved to include storytelling as a means of expressing and understanding difficult life experiences such as violence, bullying, incarceration, disaster, illness, etc. While not intended as therapy, it has been found to provoke insight and catharsis when used by trained practitioners. We are conducting Playback theater with LGBTQ+ and African American women to elucidate health disparities related to HIV/AIDS. Black/African Americans accounted for 42.1% of cases in 2019, and African American females are 15 times more likely to develop AIDS than white females. We hope to elucidate barriers to screening and treatment to inform early intervention. RESULTS/ANTICIPATED RESULTS: In community engagement, we employ a variety of strategies involving storytelling, since this simple act fosters multiple positive outcomes. For example, by talking about their experiences participants might find clarity about a difficult experience, facilitating coping or healing, or even letting go. By sharing their stories, others (clinicians, researchers, other patients, or the public) can learn what it is like to go through a particular illness or event. This knowledge can be used to allay patient fears or help researchers or clinicians to develop programming that better responds to needs. This novel approach to knowledge sharing also allows communication that may not otherwise be possible. Discussions about sensitive topics are enabled, often leading to shared understanding and potential solutions. DISCUSSION/SIGNIFICANCE: Through Playback Theater, we hope to identify and thus be able to address barriers to early screening and treatment for African American women and the LGBTQ+ population. We are also planning an event with children with cancer and their families to better understand their experiences and needs in both the clinical and familial settings