scholarly journals Assessment of the potential vaping-related exposure to carbonyls and epoxides using stable isotope-labeled precursors in the e-liquid

2021 ◽  
Author(s):  
Anne Landmesser ◽  
Max Scherer ◽  
Gerhard Scherer ◽  
Mohamadi Sarkar ◽  
Jeffery S. Edmiston ◽  
...  
Keyword(s):  
Clinical Study ◽  
Carboxylic Acid ◽  
Stable Isotope ◽  
Propylene Glycol ◽  
Urine Samples ◽  
Mainstream Smoke ◽  
High Background ◽  
Background Levels ◽  
Biomarkers Of Exposure ◽  
A Minor

AbstractThe formation of carbonyls and epoxides in e-cigarette (EC) aerosol is possible due to heating of the liquid constituents. However, high background levels of these compounds have inhibited a clear assessment of exposure during use of ECs. An EC containing an e-liquid replaced with 10% of 13C-labeled propylene glycol and glycerol was used in a controlled use clinical study with 20 EC users. In addition, five smokers smoked cigarettes spiked with the described e-liquid. Seven carbonyls (formaldehyde, acetaldehyde, acrolein, acetone, crotonaldehyde, methacrolein, propionaldehyde) were measured in the aerosol and the mainstream smoke. Corresponding biomarkers of exposure were determined in the user’s urine samples. 13C-labeled formaldehyde, acetaldehyde and acrolein were found in EC aerosol, while all seven labeled carbonyls were detected in smoke. The labeled biomarkers of exposure to formaldehyde (13C-thiazolidine carboxylic acid and 13C-N-(1,3-thiazolidine-4-carbonyl)glycine), acrolein (13C3-3-hydroxypropylmercapturic acid) and glycidol (13C3-dihydroxypropylmercapturic acid) were present in the urine of vapers indicating an EC use-specific exposure to these toxicants. However, other sources than vaping contribute to a much higher extent by several orders of magnitude to the overall exposure of these toxicants. Comparing data for the native (unlabeled) and the labeled (exposure-specific) biomarkers revealed vaping as a minor source of user’s exposure to these toxicants while other carbonyls and epoxides were not detectable in the EC aerosol.

scholarly journals Effect of arsenosugar ingestion on urinary arsenic speciation

1998 ◽  
Vol 44 (3) ◽  
pp. 539-550 ◽  
Author(s):  
Mingsheng Ma ◽  
X Chris Le
Keyword(s):  
Arsenic Speciation ◽  
Inorganic Arsenic ◽  
Sample Pretreatment ◽  
Arsenic Species ◽  
Urine Samples ◽  
Standard Reference Materials ◽  
Dimethylarsinic Acid ◽  
Urinary Arsenic ◽  
Biomarkers Of Exposure

Abstract We developed and evaluated a method for the determination of μg/L concentrations of individual arsenic species in urine samples. We have mainly studied arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) because these are the most commonly used biomarkers of exposure by the general population to inorganic arsenic and because of concerns over these arsenic species on their toxicity and carcinogenicity. We have also detected five unidentified urinary arsenic species resulting from the metabolism of arsenosugars. We combined ion pair liquid chromatography with on-line hydride generation and subsequent atomic fluorescence detection (HPLC/HGAFS). Detection limits, determined as three times the standard deviation of the baseline noise, are 0.8, 1.2, 0.7, and 1.0 μ/L arsenic for arsenite, arsenate, MMAA, and DMAA, respectively. These correspond to 16, 24, 14, and 20 pg of arsenic, respectively, for a 20-μL sample injected for analysis. The excellent detection limit enabled us to determine trace concentrations of arsenic species in urine samples from healthy subjects who did not have excess exposure to arsenic. There was no need for any sample pretreatment step. We used Standard Reference Materials, containing both normal and increased concentrations of arsenic, to validate the method. Interlaboratory studies with independent techniques also confirmed the results obtained with the HPLC/HGAFS method. We demonstrated an application of the method to the determination of arsenic species in urine samples after the ingestion of seaweed by four volunteers. We observed substantial increases of DMAA concentrations in the samples collected from the volunteers after the consumption of seaweed. The increase of urinary DMAA concentration is due to the metabolism of arsenosugars that are present in the seaweed. Our results suggest that the commonly used biomarkers of exposure to inorganic arsenic, based on the measurement of arsenite, arsenate, MMAA, and DMAA, are not reliable when arsenosugars are ingested from the diet.

scholarly journals Methylmalonic acid quantification by stable isotope dilution gas chromatography-mass spectrometry from filter paper urine samples

1996 ◽  
Vol 42 (6) ◽  
pp. 910-914 ◽  
Author(s):  
M T McCann ◽  
M M Thompson ◽  
I C Gueron ◽  
B Lemieux ◽  
R Giguère ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Stable Isotope ◽  
Isotope Dilution ◽  
Filter Paper ◽  
Methylmalonic Acid ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Urinary Creatinine ◽  
Stable Isotope Dilution

Abstract A specific method for quantification of methylmalonic acid (MMA) from urine samples dried onto filter paper is described. The method involves stable isotope dilution gas chromatography-mass spectrometry with [methyl-2H3]-MMA as the internal standard. MMA is stable in dry paper samples stored at room temperature for at least 2 weeks. The extraction efficiency of MMA from paper was 56-58%. The concentration of urinary MMA in dried filter paper specimens from 190 normal controls was 1.21 +/- 1.34 (mean +/- SD) mmol/mol of urinary creatinine. Age-related reference values are also reported. The concentrations, normalized to the urinary creatinine concentration, decrease with age. The applicability of this method to rapid screening for cobalamin (vitamin B12)-related disorders and methylmalonic aciduria is demonstrated.

Clinical study of the effectiveness of a dual amplified immunoassay IDEIA PCE Chlamydia for the diagnosis of male urethritis

1998 ◽  
Vol 9 (7) ◽  
pp. 414-417
Author(s):  
T Hirose ◽  
A Iwasawa ◽  
T Satoh ◽  
N Itoh ◽  
T Tsukamoto ◽  
...  
Keyword(s):  
Clinical Study ◽  
Chlamydia Trachomatis ◽  
Nested Pcr ◽  
Patient Population ◽  
Antigen Detection ◽  
Dna Probe ◽  
Urine Samples ◽  
Increased Sensitivity ◽  
Probe Assay

A clinical study of patients with male urethritis n =316 was undertaken to determine the sensitivity potential for a new dual amplified immunoassay IDEIA PCE ChlamydiaTM . Increased sensitivity 98.8 , 84 85 was obtained for IDEIA PCE ChlamydiaTM compared to a conventional antigen detection test IDEIA ChlamydiaTM, 81.2 , 69 85 when testing urine samples. In a smaller patient population n =104 the positivity rate for the first void urine tested with IDEIA PCE ChlamydiaTM of 30.8 32 104 was similar to the 27.9 29 104 obtained from urethral swabs tested with a DNA probe assay PACE 2TM . The increased sensitivity of the test was confirmed with a commercial PCR kit AmplicorTM and nested PCR. The IDEIA PCE ChlamydiaTM kit has the sensitivity potential to be a clinically reliable alternative for detecting Chlamydia trachomatis .

Ion Cyclotron Resonance Studies of Alkylsilyl Ions. II. The Reactions of Ketones, Carboxylic Acids and Esters with the Trimethylsilyl Cation

1979 ◽  
Vol 32 (6) ◽  
pp. 1389 ◽  
Author(s):  
IA Blair ◽  
JH Bowie
Keyword(s):  
Carboxylic Acid ◽  
Transition State ◽  
Lewis Acid ◽  
Cyclotron Resonance ◽  
Nucleophilic Attack ◽  
Ion Cyclotron Resonance ◽  
Deuterium Isotope Effect ◽  
Trimethylsilyl Cation ◽  
A Minor ◽  
Membered Transition State

Nucleophilic attack of a ketone, carboxylic acid or ester at the electrophilic centre of the trimethylsilyl cation (Me,Si+) produces a 1:1 adduct. This adduct does not decompose in the case of ketones. Acid adducts decompose primarily by loss of methane, but a minor pathway exists which involves elimination of a ketene. Ester adducts fragment primarily by this latter process through a four-membered transition state. The transfer of hydrogen was shown to arise solely from the acyl group and was shown to proceed with a small deuterium isotope effect. Further decomposition of the resulting ion by loss of methane provides unequivocal proof that esters react predominantly through the alkyl oxygen with the Lewis acid Me3Si+.

Use of next-generation deep sequencing to improve FGFR3 mutation detection in the urine of patients with bladder cancer.

2012 ◽  
Vol 30 (5_suppl) ◽  
pp. 289-289
Author(s):  
John M. Millholland ◽  
Shuqiang Li ◽  
Cecilia A. Fernandez ◽  
Anthony P. Shuber
Keyword(s):  
Bladder Cancer ◽  
Deep Sequencing ◽  
Mutation Detection ◽  
Amplicon Sequencing ◽  
Urine Samples ◽  
Next Generation ◽  
High Background ◽  
Non Invasive ◽  
Fgfr3 Mutation ◽  
Fgfr3 Mutations

289 Background: FGFR3 mutations have been identified in ∼60-70% of low-stage, non-invasive tumors. Our group and others have developed assays to detect FGFR3 mutations in the urine of bladder cancer patients. However, urine-based assays have been limited by the technical ability to detect rare events in a dilute medium where there is a high background of normal DNA. In these assays, FGFR3 mutations are generally found in ∼30% of the urine samples, which is < 50% concordance with the expected detection in tissue. We have now developed an ultra-deep amplicon sequencing technique that increases FGFR3 mutation detection in urine to ∼67%, near the expected detection if every mutation found in tissue could be detected in urine. Methods: Amplicons were designed against FGFR3 exons 7, 10, and 15 using PCR primers containing the adapter sequences for unidirectional sequencing. Taqman probes were used to determine if sufficient DNA was present in each sample. Primary amplification was performed from DNA isolated from 4 ml of urine. The resulting PCR products were used as template for emulsion PCR and these were then sequenced using the Roche 454 GS Junior. Samples were analyzed for total DNA reads per sample and number of mutant sequencing reads to determine percent mutation. Results: Urine samples from 29 patients with stage Ta bladder cancer were analyzed by both our previously described qPCR method and the new ultra-deep sequencing approach. Of the 29 samples, 2 did not have sufficient DNA for analysis by sequencing. Using ultra-deep amplicon sequencing, 18 out of 27 (66.7%) were positive for FGFR3 mutations, while only 3 out of 27 (11.1%) were positive for mutations by qPCR. The urine samples from the 15 newly identified mutations using deep sequencing contained FGFR3 mutations as low as 0.05%. The sensitivity achieved using deep sequencing approximates the FGFR3 mutations observed in tissue. Conclusions: We have developed a highly sensitive non-invasive urine based assay that can detect FGFR3 mutant DNA when present at < 1% of the sample and suggests > 90% concordance with the expected mutations in Ta tumor tissues. To our knowledge, this is the first practical application of next generation sequencing technology for diagnostic use.

High Background Levels of Urinary Benzene Metabolites Found in a Volunteer Study

2007 ◽  
Vol 4 (8) ◽  
pp. D71-D77
Author(s):  
Dennis J. Paustenbach ◽  
Shannon H. Gaffney ◽  
Paul K. Scott ◽  
Jay L. Brown ◽  
Julie M. Panko
Keyword(s):  
High Background ◽  
Background Levels ◽  
Volunteer Study

Pretreatment of Urine Samples for the Analysis of 11-nor-Δ9-Tetrahydrocannabinol-9-Carboxylic Acid Using Solid-Phase Extraction

1990 ◽  
Vol 14 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Ritchard C. Parry ◽  
Lydia Nolan ◽  
Robert E. Shirey ◽  
George D. Wachob ◽  
Daryl J. Gisch
Keyword(s):  
Carboxylic Acid ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Urine Samples ◽  
Phase Extraction

scholarly journals Heat budget contribute rate in the Three Gorges Reservoir tributary bay between mainstream and tributary using stable isotope analysis

2018 ◽  
Vol 19 (2) ◽  
pp. 553-564 ◽  
Author(s):  
Yao Cheng ◽  
Yuchun Wang ◽  
Huaidong Zhou ◽  
Mingming Hu ◽  
Rong Jiang ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Three Gorges Reservoir ◽  
Heat Budget ◽  
Meteorological Data ◽  
Isotope Analysis ◽  
Three Gorges ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Using Data ◽  
A Minor

Abstract Understanding the interaction processes between the mainstream and its tributaries and detailing the rates of contribution of water and heat from two different water bodies in the tributary bay are essential for water management in the Three Gorges Reservoir (TGR). The stable isotope ratios of hydrogen (δD) and oxygen (δ18O) were applied to explore the interactions between the TGR mainstream and the tributary, Zhuyi River. A heat budget of the TGR tributary bay was constructed for the year 2014 using data for water temperature, meteorological data and water mixing ratio. The results showed that approximately 91% of the water in the tributary bay was from the TGR mainstream. And the heat budget reveals that the tributary bay net heat flux is dominated by the mainstream advective heat, and the average contribution rate is 87% during the whole year, while the tributary advective heat and atmosphere make a minor contribution to the tributary bay heat budget.

scholarly journals Sugar intake among German adolescents: trends from 1990 to 2016 based on biomarker excretion in 24-h urine samples

2020 ◽  
Vol 124 (2) ◽  
pp. 164-172
Author(s):  
Ines Perrar ◽  
Nicola Gray ◽  
Gunter G. Kuhnle ◽  
Thomas Remer ◽  
Anette E. Buyken ◽  
...  
Keyword(s):  
Linear Time ◽  
Epidemiological Studies ◽  
Urine Samples ◽  
Free Sugar ◽  
Study Cohort ◽  
Sugar Intake ◽  
Dietary Record ◽  
Biomarker Analysis ◽  
Age Trends ◽  
A Minor

AbstractTrend analyses based on dietary records suggest decreases in the intakes of total sugar (TS), added and free sugar since 2005 among children and adolescents in Germany. In terms of age trends, TS intake decreased with increasing age. However, self-reported sugar intake in epidemiological studies is criticised, as it may be prone to bias due to selective underreporting. Furthermore, adolescents are more susceptible to underreporting than children. We thus analysed time and age trends in urinary fructose excretion (FE), sucrose excretion (SE) and the sum of both (FE + SE) as biomarkers for sugar intake among 8·5–16·5-year-old adolescents. Urinary sugar excretion was measured by UPLC-MS/MS in 997 24-h urine samples collected from 239 boys and 253 girls participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study cohort between 1990 and 2016. Time and age trends of log-transformed FE, SE and FE + SE were analysed using polynomial mixed-effects regression models. Between 1990 and 2016, FE as well as FE + SE decreased (linear time trend: P = 0·0272 and P < 0·0001, respectively). A minor increase in excretion during adolescence was confined to FE (linear age trend: P = 0·0017). The present 24-h excretion measurements support a previously reported dietary record-based decline in sugar intake since 2005. However, the previously seen dietary record-based decrease in TS from childhood to late adolescence was not confirmed by our biomarker analysis, suggesting a constant sugar intake for the period of adolescence.

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