Human Excretion Research Articles

Pengaruh Pembelajaran Tgt (Teams Games Tournament) Dengan Media Explosion Box Pada Materi Sistem Ekskresi Manusia Terhadap Hasil Belajar Siswa

This reserch aims to determine the effect of TGT (Team Games Tounament) learning with the explosion box media on the human excretion system material on student learning outcomes of class XI MA Al-Mukhlishin Batu Bara. This type of research is quasi-experimental or quasi-experimental. The instrument in this study was in the form of an objective test or multiple choice of 20 questions. Data analysis in this study was a paired simple t-test with the help of Statistical Product and Service Solutions (SPSS) software version 22. By looking at the significance value, namely if Sig (2-tailed) <0.05. as for the results found is the sig value. 2-tailed 0.00 <0.05 with a value of t-count> t-table, namely 23.38> 2.01, which means that H0 is rejected, and Ha is accepted. This shows that there is an effect of TGT (team games tournaments) learning with the media explosion box on the human excretion system material on the learning outcomes of students of class XI IPA Ma Al-Mukhlishin Batu Bara.

Assessment of Human Mycotoxin Exposure in Hungary by Urinary Biomarker Determination and the Uncertainties of the Exposure Calculation: A Case Study.

Urinary biomarkers of mycotoxin exposure were evaluated in the case of healthy people (n = 41) and coeliac patients (n = 19) by using a multi-biomarker LC-MS/MS immunoaffinity based method capable to analyse biomarkers of nine mycotoxins, i.e., fumonisin B1 (FB1), fumonisin B2 (FB2), deoxynivalenol (DON), zearalenone (ZEN), ochratoxin A (OTA), Aflatoxin B1 (AFB1), T-2 toxin, HT-2 toxin and Nivalenol (NIV). Urinary biomarker concentrations were used to calculate the probable daily intake (PDI) of fumonisin B1, deoxynivalenol, zearalenone and ochratoxin A and compared with their tolerable daily intake (TDI). The human urinary excretion rate values reported in the literature and the 24 h excretion rate measured in piglets were used to estimate and compare the PDI values of the four mycotoxins. The highest mean biomarker concentrations were found for DON (2.30 ng/mL for healthy people and 2.68 ng/mL for coeliac patients). Mean OTA concentration was significantly higher (p < 0.001) in healthy people compared to coeliac patients. PDI calculated with piglets excretion data exceeded the TDI values by a much smaller percentage than when they were calculated from human data, especially for FB1. The uncertainties arising from the different calculations can be well perceived on the basis of these data.

Characterization of Clinical Absorption, Distribution, Metabolism, and Excretion and Pharmacokinetics of Velsecorat Using an Intravenous Microtracer Combined with an Inhaled Dose in Healthy Subjects.

This open-label, single-period study describes the human absorption, distribution, metabolism, excretion, and pharmacokinetics of velsecorat (AZD7594). Healthy subjects received inhaled velsecorat (non-radiolabeled; 720 µg) followed by intravenous infusion of carbon 14 (14C)-velsecorat (30 µg). Plasma, urine, and feces were collected up to 168 hours post-dose. Objectives included identification and quantification of velsecorat and its metabolites (i.e., drug-related material) in plasma and excreta, and determining the elimination pathways of velsecorat by measuring the rate and route of excretion, plasma half-life (t1/2), clearance, volume of distribution and mean recovery of radioactivity. On average, 76.0% of administered 14C dose was recovered by the end of the sampling period (urine = 24.4%; feces = 51.6%), with no unchanged compound recovered in excreta, suggesting that biliary excretion is the main elimination route. Compared with intravenous 14C-velsecorat, inhaled velsecorat had a longer t1/2 (27 versus 2 hours), confirming that plasma elimination is absorption-rate-limited from the lungs. Following intravenous administration, t1/2 of 14C-drug-related material was longer than for unchanged velsecorat, and 20% of the 14C plasma content was related to unchanged velsecorat. The geometric mean plasma clearance of velsecorat was high (70.7 l/h) and the geometric mean volume of distribution at steady state was 113 l. Velsecorat was substantially metabolized via O-dealkylation of the indazole ether followed by sulfate conjugation, forming the M1 metabolite, the major metabolite in plasma. There were 15 minor metabolites. Velsecorat was well tolerated, and these results support the progression of velsecorat to phase 3 studies. SIGNIFICANCE STATEMENT: This study describes the human pharmacokinetics and metabolism of velsecorat, a selective glucocorticoid receptor modulator, evaluated via co-administration of a radiolabeled intravenous microtracer dose and a non-radiolabeled inhaled dose. This study provides a comprehensive assessment of the disposition of velsecorat in humans. It also highlights a number of complexities associated with determining human absorption, distribution, metabolism, and excretion for velsecorat, related to the inhaled route, the high metabolic clearance, sequential metabolite formation and the low intravenous dose.

Degradation of selected pharmaceuticals detected in wastewater systems using an enzyme-mediator system and identification of resulting transformation products

Pharmaceuticals are often found in municipal wastewater due to human excretion and disposal of drugs into sewerage systems. Conventional wastewater treatment plants were not designed for pharmaceutical removal and, hence, pharmaceutical concentrations ranging from ng L−1 to μg L−1 are often detected in treated wastewater, with additional treatment required for full removal. This study has investigated the potential of Trametes versicolour laccase enzyme and 2,2'-azino-bis-(3-ethyl-benzthiazoline-6-sulphonic acid) diammonium salt (ABTS) mediator system to degrade sulfamethoxazole, trimethoprim, metronidazole and phenytoin. The best degradation was observed at pH 5 for both sulfamethoxazole (97% in 12 hours) and trimethoprim (44% in 168 hours), using an initial micropollutant concentration of 100 µM, an enzymatic activity between 110–115 U L−1, and an ABTS concentration of 200 µM. Phenytoin and metronidazole were not degraded. Deamination followed by hydroxylation led to the formation of the two major sulfamethoxazole transformation products (TPs), whilst hydroxylation and hydroxylation/demethylation mechanisms formed the majority of the trimethoprim TPs. The sulfamethoxazole and trimethoprim TPs observed from the laccase-ABTS system were similar to the TPs obtained from degradation processes such as advanced oxidation or photodegradation. The laccase-ABTS system shows promise for control of emerging contaminants containing electron donating groups (such as amines and methoxy groups) on aromatic rings in wastewater systems.

Human Metabolism and Urinary Excretion Kinetics of Nonylphenol in Three Volunteers after a Single Oral Dose.

Nonylphenol (NP) is an endocrine-disrupting anthropogenic chemical that is ubiquitous in the environment. Human biomonitoring data and knowledge on internal NP exposure are still sparse, and its human metabolism is largely unknown. Therefore, in this study, we investigated human metabolism and urinary excretion of NP. Three male volunteers received a single oral dose of 1 mg 13C6-labeled NP (10.6-11.7 μg/kg body weight). Consecutive full urine voids were collected for 48 h. A metabolite screening identified nine ring- and/or side chain-oxidized metabolites. We chose the most promising hits, the alkyl chain-oxidized metabolites hydroxy-NP (OH-NP) and oxo-NP, for quantitative investigation next to the parent NP. For this purpose, we newly synthesized specific n - 1-oxidized monoisomeric analytical standards. Quantification of the polyisomeric metabolites was performed via online-solid phase extraction-LC-MS/MS with stable isotope dilution using a previously published consensus method. Alkyl chain hydroxylation (OH-NP) constituted the major metabolism pathway representing 43.7 or 62.2% (depending on the mass transition used for quantification) of the NP dose excreted in urine. The urinary excretion fraction (FUE) for oxo-NP was 6.0 or 9.3%. The parent NP, quantified via an analogous isomeric 13C6-NP standard, represented 6.6%. All target analytes were excreted predominately as glucuronic acid conjugates. Excretion was rather quick, with concentration maxima in urine 2.3-3.4 h after dosing and biphasic elimination kinetics (elimination half-times first phase: 1.0-1.5 h and second phase: 5.2-6.8 h). Due to its high FUE and insusceptibility to external contamination (contrary to parent NP), OH-NP represents a robust and sensitive novel exposure biomarker for NP. The novel FUEs enable to robustly back-calculate the overall NP intakes from urinary metabolite levels in population samples for a well-informed cumulative exposure and risk assessment.

Investigations into the elimination profiles and metabolite ratios of micro-dosed selective androgen receptor modulator LGD-4033 for doping control purposes

LGD-4033 (ligandrol) is a selective androgen receptor modulator (SARM), which is prohibited in sports by the World Anti-Doping Agency (WADA) and led to 62 adverse analytical findings (AAFs) in 2019. But not only deliberate doping with LGD-4033 constitutes a problem. In the past years, some AAFs that concerned SARMs can be attributed to contaminated dietary supplements (DS). Thus, the urgency to develop methods to differentiate between inadvertent doping and abuse of SARMs to benefit from the performance-enhancing effect of the compound in sports is growing. To gain a better understanding of the metabolism and excretion patterns of LGD-4033, human micro-dose excretion studies at 1, 10, and 50 µg LGD-4033 were conducted. Collected urine samples were prepared for analysis using enzymatic hydrolysis followed by solid-phase extraction and analyzed via LC-HRMS/MS. Including isomers, a total of 15 phase I metabolites were detected in the urine samples. The LC-HRMS/MS method was validated for qualitative detection of LGD-4033, allowing for a limit of detection (LOD) of 8 pg/mL. The metabolite M1, representing the epimer of LGD-4033, was synthesized and the structure elucidated by NMR spectroscopy. As the M1/LGD-4033 ratio changes over time, the ratio and the approximate LGD-4033 concentration can contribute to estimating the time point of drug intake and dose of LGD-4033 in doping control urine samples, which is particularly relevant in anti-doping result management.Graphical abstract

Review of digital PCR potential for surveillance of emerging disease from wastewater

Emerging infectious diseases (EID) such as COVID-19 had been widely caused massive impact for all countries in the world. The spreading of pathogens became uncontrolled and unpredictable to overcome this pandemic disease. Some non-waterborne EID also was discovered in wastewater in many countries of the world. Studies showed that digital PCR could become a powerful tool for environmental surveillance. It enables the performance of absolute quantification for nucleic acid with a high inhibitory sample, like wastewater, and potentially possibly detected a tiny quantity of pathogen residue and tracked the infectious diseases that originated from human excretions into sewage. Hopefully, with the development of this method and support of measurement and standardization, it is possible to become an effective method to overcome the digital PCR (dPCR) method challenge for surveillance of disease transmission from wastewater.

Exposure of adult zebrafish to androstenedione alters thyroid hormone levels and the transcriptional expression of genes related to the hypothalamus-pituitary-thyroid axis

Androstenedione (AED) is a naturally occurring androgen that is released into the environment through human and animal excretion. Several studies have shown that AED can interfere with the normal growth, development, and reproduction of organisms. However, studies examining the thyroid system, an important part of endocrine system of fish, are still lacking. This study examines thyroid hormone levels including T3 and T4, and transcriptional expression levels of genes associated with the hypothalamic-pituitary-thyroid axis (HPT axis) in adult zebrafish. Fish were exposed to a solvent control and three other concentrations of AED (0.2, 2.3, and 23.7 μg/L) for 60 days. Results indicated that AED significantly increased T4 levels but inhibited transcription of some HPT axis-related genes (nis, tpo, tg, dio1, dio2, sult1 st5, pax8, and nkx2.1) in female zebrafish. The adverse effects of AED on the thyroid system in males were very low, only affecting down-regulation of the tshb gene and up-regulation of the thrb gene. The overall results demonstrated that AED interferes with the thyroid endocrine system in fish.

Sewage Markers as Determinants to Differentiate Origins of Emerging Organic Pollutants in an Urban Sri Lankan Water Drainage Network

Urban sanitation is a major challenge during the rapid urbanization being experienced by developing countries, as a low sewerage infrastructure capacity and irregular onsite wastewater treatment raise the risk of surface water contamination. The application of specific sewage markers to characterize contaminant sources is therefore essential for managing urban sanitation issues. In this study, we investigated the concentrations of eight sewage markers (acetaminophen, caffeine, carbamazepine, cotinine, sulfamethoxazole, sulfapyridine, atenolol, and acesulfame) in various water sources within urban area of the Galle City, Sri Lanka. The total concentration of the eight markers was in the order of hospital discharge &gt; sewage treatment plant (STP) influent &gt; surface drainage system. Among the eight selected markers, acetaminophen was dominant in hospital discharge (70.2–123.6 µg/L) while caffeine was the largest contributor to STP influent (16.2–68.7 µg/L) and surface drainage (0.95–21.73 µg/L). We then proposed and tested a set of criteria for evaluating the applicability of markers, including removal efficiency, concentration magnitude, excretion rate, and wastewater burden. The labile markers caffeine and acetaminophen were suitable for characterizing domestic gray and black wastewater, respectively. These results imply that the city’s drainage system receives both domestic graywater and human excretion, likely due to insufficient on-site sanitation systems. The conservative marker carbamazepine was useful for tracking hospital residues over long distances; these results imply that hospital wastewater treatment was not working properly, accounting for pharmaceutical residues reaching surface water via a hidden discharges connected to the drainage system.

Human metabolism and urinary excretion of seven neonicotinoids and neonicotinoid-like compounds after controlled oral dosages

Few human data on exposure and toxicity are available on neonicotinoids and neonicotinoid-like compounds (NNIs), an important group of insecticides worldwide. Specifically, exposure assessment of humans by biomonitoring remains a challenge due to the lack of appropriate biomarkers. We investigated the human metabolism and metabolite excretion in urine of acetamiprid (ACE), clothianidin (CLO), flupyradifurone (FLUP), imidacloprid (IMI), sulfoxaflor (SULF), thiacloprid (THIAC) and thiamethoxam (THIAM) after single oral dosages at the currently acceptable daily intake levels of the European Food Safety Authority. Consecutive post-dose urine samples were collected up to 48 h. Suspect screening of tentative metabolites was carried out by liquid chromatography–high-resolution mass spectrometry. Screening hits were identified based on their accurate mass, isotope signal masses and ratios, product ion spectra, and excretion kinetics. We found, with the exception of SULF, extensive metabolization of NNIs to specific metabolites which were excreted next to the parent compounds. Overall, 24 metabolites were detected with signal intensities indicative of high metabolic relevance. Phase-I metabolites were predominantly derived by mono-oxidation (such as hydroxy-FLUP, -IMI, and -THIAC) and by oxidative N-desalkylation (such as N-desdifluoroethyl-FLUP and N-desmethyl-ACE, -CLO and -THIAM). IMI-olefin, obtained by dehydration of hydroxylated IMI, was identified as a major metabolite of IMI. SULF was excreted unchanged in urine. Previously reported metabolites of NNIs such as 6-chloronicotinic acid or 2-chlorothiazole-4-carboxylic acid and their glycine derivatives were detected either at low signal intensities or not at all and seem less relevant for human biomonitoring. Our highly controlled approach provides specific insight into the human metabolism of NNIs and suggests suitable biomarkers for future exposure assessment at environmentally relevant exposures.

Rekonstruksi LKPD untuk meningkatkan keterlibatan dan penguasaan konsep peserta didik pada materi sistem ekskresi

This research was aimed at investigating the information about the use of the Student Worksheet (LKPD) the results of reconstruction about the involvement and mastery of students' concepts in the material of human excretion system. Reconstruction of student worksheets was done because the previous research shows analysis results the component of diagram vee in the eksperiment students worksheet is low. Whereas, the diagram Vee's rubric is usually used for developing eksperiment students worksheet. This research is a descriptive research. The subject of the research are 28 students of grade XI IPA in senior high school Bandung. The instrument that used is the rubric of component of diagram Vee's existence, observation worksheet in students engagement and test of mastering concept that consist is multiple choice. The result of the research shows : (1) students engagement in the class is about 79,17%; (2) students' mastery of concepts based on categories is good, 96.43% of students achieve maximum completeness criteria (KKM), and an average N-gain of 0.72. This showed the influence of use reconstruction of student worksheets on the student engagement and mastery of student concepts.

Evaluation of the Influence of Zhenwu Tang on the Pharmacokinetics of Digoxin in Rats Using HPLC-MS/MS.

Digoxin (DIG) is a positive inotropic drug with a narrow therapeutic window that is used in the clinic for heart failure. The active efflux transporter of DIG, P-glycoprotein (P-gp), mediates DIG absorption and excretion in rats and humans. Up to date, several studies have shown that the ginger and Poria extracts in Zhenwu Tang (ZWT) affect P-gp transport activity. This study aimed to explore the effects of ZWT on the tissue distribution and pharmacokinetics of DIG in rats. The deionized water or ZWT (18.75 g/kg) was orally administered to male Sprague–Dawley rats once a day for 14 days as a pretreatment. On day 15, 1 hour after receiving deionized water or ZWT, the rats were given the solution of DIG at 0.045 mg/kg dose, and the collection of blood samples was carried out from the fundus vein or excised tissues at various time points. HPLC-MS/MS was used for the determination of the DIG concentrations in the plasma and the tissues under investigation. The pharmacokinetic interactions between DIG and ZWT after oral coadministration in rats revealed significant reductions in DIG Cmax and AUC0-∞, as well as significant increases in T1/2 and MRT0-∞. When coadministered with ZWT, the DIG concentration in four of the investigated tissues statistically decreased at different time points except for the stomach. This study found that combining DIG with ZWT reduced not only DIG plasma exposure but also DIG accumulation in tissues (heart, liver, lungs, and kidneys). The findings of our study could help to improve the drug's validity and safety in clinical applications and provide a pharmacological basis for the combined use of DIG and ZWT.

Country-specific life cycle inventories for human excretion of food products

Country-specific life cycle inventories for human excretion of food products

Effectiveness of Discovery Blended Learning on Concept Understanding and Student Motivation

This study aims to determine the effectiveness of discovery blended learning towards understanding concepts and learning motivation in the material of class VIII human excretion system in SMP Negeri 27 Semarang. This research is an experimental study with a true experimental design type posttest only control group design. Sampling was done by purposive sampling, with each experimental group and the control class. Data was collected using tests, observation sheets, and questionnaire sheets. The results showed that discovery blended learning was effective against the understanding of concepts and learning motivation of VIII grade students in SMP Negeri 27 Semarang which was seen from the percentage of conceptual understanding between the experimental class and the control class, there were significant differences between the average value of the experimental class concept understanding and the control class and the average learning motivation of the experimental classDiscovery Blended Learning, Concept Understanding, Learning Motivation

Composition of the Gut Microbiome Influences Production of Sulforaphane-Nitrile and Iberin-Nitrile from Glucosinolates in Broccoli Sprouts.

Isothiocyanates, such as sulforaphane and iberin, derived from glucosinolates (GLS) in cruciferous vegetables, are known to prevent and suppress cancer development. GLS can also be converted by bacteria to biologically inert nitriles, such as sulforaphane-nitrile (SFN-NIT) and iberin-nitrile (IBN-NIT), but the role of the gut microbiome in this process is relatively undescribed and SFN-NIT excretion in humans is unknown. An ex vivo fecal incubation model with in vitro digested broccoli sprouts and 16S sequencing was utilized to explore the role of the gut microbiome in SFN- and IBN-NIT production. SFN-NIT excretion was measured among human subjects following broccoli sprout consumption. The fecal culture model showed high inter-individual variability in nitrile production and identified two sub-populations of microbial communities among the fecal cultures, which coincided with a differing abundance of nitriles. The Clostridiaceae family was associated with high levels, while individuals with a low abundance of nitriles were more enriched with taxa from the Enterobacteriaceae family. High levels of inter-individual variation in urine SFN-NIT levels were also observed, with peak excretion of SFN-NIT at 24 h post broccoli sprout consumption. These results suggest that nitrile production from broccoli, as opposed to isothiocyanates, could be influenced by gut microbiome composition, potentially lowering efficacy of cruciferous vegetable interventions.

The occurrence and fate of microplastics in a mesophilic anaerobic digester receiving sewage sludge, grease, and fatty slurries

The mesophilic digester of a wastewater treatment plant serving 790,000 inhabitants was analyzed for incoming and outgoing microplastics (MPs). The annual MP load on the digester was 7326 kg y−1 and 1.20 × 1014 N y−1, while the digested sludge contained 4885 kg y−1 and 0.85 × 1014 N y−1. The corresponding mean reduction of approximately 30% was though within the variability of the analyzed samples, and size distributions and polymer composition before and after the digester could similarly neither confirm nor deny if MPs were lost in the digester. The load on the digester corresponded to a per capita load of 0.025 g capita−1 day−1 or 4.14 × 105 N capita−1 day−1. In terms of MP numbers, the values were high compared to most previous studies, which most likely was due to differences in analytical methods, where the present study applied FPA-μFTIR hyperspectral imaging with automatized MP recognition in the size range 10–500 μm and ATR-FTIR on all particles in the range 500–5000 μm. The polymer composition was quite diverse, with 15 identified polymer types, of which polyethylene and polyester were the most common in the sludge, while the variation in composition was larger in the grease that came from the plant's grease trap and the fatty slurries which came from grease traps in the drainage area. The load on the digester was finally used to demonstrate how especially the determined mass loads can be used to set upper boundaries for specific sources, for example human excretion.

Urinary soluble (pro)renin receptor excretion is associated with urine pH in humans.

The (pro)renin receptor [(P)RR] binds to renin and its precursor prorenin to activate the tissue renin-angiotensin system. It is cleaved to generate soluble (P)RR and M8–9, a residual hydrophobic truncated protein. The (pro)renin receptor also functions as an intracellular accessory protein of vacuolar-type H+-ATPase, which plays an essential role in controlling the intracellular vesicular acid environment. Thus, in the kidney, (P)RR may play a role in transporting H+ to urine in the collecting duct. Although blood soluble (P)RR has been recognized as a biomarker reflecting the status of the tissue renin-angiotensin system and/or tissue (P)RR, the significance of urinary soluble (P)RR excretion has not been determined. Therefore, this study aimed to investigate the characteristics of urinary soluble (P)RR excretion. Urinary soluble (P)RR excretion was measured, and its association with background factors was investigated in 441 patients. Relationships between changes in urine pH due to vitamin C treatment, which reduce urine pH, and urinary soluble (P)RR excretion were investigated in 10 healthy volunteers. Urinary soluble (P)RR excretion was 1.46 (0.44–2.92) ng/gCre. Urine pH showed a significantly positive association with urinary soluble (P)RR excretion, independent of other factors. Changes in urine pH and urinary soluble (P)RR excretion due to vitamin C treatment were significantly and positively correlated (ρ = 0.8182, p = 0.0038). These data showed an association between urinary soluble (P)RR excretion and urine pH in humans, suggesting that (P)RR in the kidney might play a role in urine pH regulation.

Application of Augmented Reality Technology for Human Excretion System as Android-Based Learning Media

The excretion system is a process of removing metabolic waste that is no longer used by the body. These remnants of metabolism in the form of compounds that are toxic (poison) so that if not removed can cause disruption of the function of organs in the body. Organs that play a role in the excretion system are the kidneys, lungs, skin and liver. Kidney is the main component making up the human excretion system, namely urine. The lungs produce residual respiratory processes in the form of gas CO2 (carbon dioxide) and H2O (water vapor). The skin is able to produce residual substances in the form of sweat. The liver produces waste products in the form of bile sap from an overhaul of red blood cells that have been damaged and destroyed in the spleen. Augmented Reality Human Excretion System is an application that can facilitate teachers and class XI MA Tanwiriyyah students in learning about the human excretion system. This application is made based on Android by applying augmented reality technology in its implementation. In this application the teacher and students can see 3D objects and know the process of removing residual substances in the excretory system organs. The design of this application uses the MDLC method and also uses UML diagrams, navigation structures and application interface design.

Determination of hydroxytyrosol and tyrosol in human urine after intake of extra virgin olive oil produced with an ultrasounds-based technology

Extra virgin olive oil (EVOO) is a known source of antioxidants, such as phenolic compounds, useful in the prevention of non-infectious diseases (atherosclerosis, diabetes, cancer, and other diseases). In the present study, EVOO obtained using an innovative ultrasounds-based technology was found richer in total polyphenols, hydroxytyrosol and tyrosol, than EVOO obtained using a conventional mechanical technology. The urinary excretion in humans of hydroxytyrosol and tyrosol, after the administration of ultrasounds and mechanical EVOOs, respectively, was assessed and compared. The analytes were determined in urine samples, collected for 24 h, of six healthy people (3 men and 3 women, age 22–70 years and body mass index <30 kg/m2) who ingested 20 g of oil for six consecutive days. A commercial refined olive oil was also used in the study to determine the baseline excretion levels of the two metabolites. High correlation coefficients (≥0.9311) were found between the amounts of the analytes ingested daily with EVOOs and those determined in the 24-h urines. The results clearly indicated that the EVOO obtained with the ultrasound process was characterized by the highest concentration of biophenols which were consequently available in greater quantities after ingestion, indicating that it represents a high-quality product containing high levels of beneficial compounds such as biophenols readily assimilable by the human body.

3-Ethenylpyridine Measured in Urine of Active and Passive Smokers: A Promising Biomarker and Toxicological Implications.

In studies of tobacco toxicology, including comparisons of different tobacco products and exposure to secondhand or thirdhand smoke, exposure assessment using biomarkers is often useful. Some studies have indicated that most of the toxicity of tobacco smoke is due to gas-phase compounds. 3-Ethenylpyridine (3-EP) is a major nicotine pyrolysis product occurring in the gas phase of tobacco smoke. It has been used extensively as an environmental tracer for tobacco smoke. 3-EP would be expected to be a useful tobacco smoke biomarker as well, but nothing has been published about its metabolism and excretion in humans. In this Article we describe a solid-phase microextraction (SPME) GC-MS/MS method for determination of 3-EP in human urine and its application to the determination of 3-EP in the urine of smokers and people exposed to secondhand smoke. We conclude that 3-EP is a promising biomarker that could be useful in studies of tobacco smoke exposure and toxicology. We also point out the paucity of data on 3-EP toxicity and suggest that additional studies are needed.