Expired Air Samples Research Articles

Interrupting sitting acutely attenuates cardiometabolic risk markers in South Asian adults living with overweight and obesity.

This study examined the acute effects of interrupting sitting with light-intensity walking on postprandial cardiometabolic risk markers in South Asian adults. South Asians with overweight/obesity (n = 19; body mass index [BMI] > 23kg·m-2) and normal-weight (n = 8; BMI 18.0-22.9kg·m-2) aged 48.8 ± 5.6years completed two, 5-h conditions: (1) prolonged sitting (SIT), and (2) interrupted sitting with 5-min bouts of light-intensity walking every 30-min (INT-SIT). Blood samples and resting expired air samples were collected throughout each condition. Statistical analyses were completed using linear mixed models. In participants with overweight/obesity, postprandial glucose, triglycerides (TAG) and metabolic load index (MLI) over time were lower, whereas resting substrate utilisation and resting energy expenditure (REE) were higher, in INT-SIT than SIT (all p ≤ 0.05). Compared with SIT (0.18 [95% CI 0.13, 0.22] kcal.min-1), INT-SIT (0.23 [95% CI 0.18, 0.27] kcal.min-1) increased postprandial REE iAUC in participants with overweight/obesity (p = 0.04, d = 0.51). Postprandial TAG concentrations over time were lower in INT-SIT versus SIT (p = 0.01, d = 30) in normal-weight participants, with no differences in any other outcomes for this sample group. These findings suggest that interrupting sitting with 5-min bouts of light walking every 30-min acutely attenuates cardiometabolic risk markers among South Asians living with overweight/obesity, whereas limited effects may be seen in individuals with normal-weight.

Trajectories of Return to Cigarette Smoking Up to 1 Year Postpartum Among People Who Quit Smoking During Pregnancy.

Previous work has identified predictors of relapse to smoking postpartum among parenting people who quit during pregnancy, but less is known about the time course of postpartum relapse. The study goals were to document patterns and correlates of smoking resumption among people who quit smoking during pregnancy and were motivated to remain abstinent. We conducted a secondary analysis among participants in a randomized controlled trial of postpartum-specific smoking relapse prevention interventions who self-reported no smoking since the quit date to delivery (n = 280). Participants provided expired air samples of carbon monoxide, and completed self-report measures of mood, perceived stress, and demographic and pregnancy-related information. Timeline follow-back interviews were conducted at the end of pregnancy and 12-, 24-, and 52-weeks postpartum. The largest group (49.7% of participants) belonged to a trajectory reflecting abstinence across 1 year postpartum. Another 13% remained abstinent 5-6 months after delivery. However, one in five started to smoke consistently within 100 days after delivery, and 16% relapsed in a pattern that can be described as inconsistent smoking. Participants with more prior quit attempts and those who smoked more cigarettes prior to their quit attempt were more likely to relapse within 100 days of delivery. The first 3 months postpartum represent a critical window for relapse prevention, given that most individuals who relapsed did so in the first 100 days or so after delivery. Assessing prior smoking history can help identify pregnant people who will need additional support in the early postpartum period. Relapse to smoking during the year after childbirth is common, but the time course of relapse after delivery is poorly understood. This study provides evidence for 4 distinct trajectories of relapse, and highlights variables linked to early relapse that may improve efforts to target and time intervention efforts. Specifically, assessing age at initiation, quantity of tobacco use prior to quit attempt, and number of previous quit attempts will identify pregnant people at greatest risk of early relapse. These findings also suggest that additional support early in the postpartum period is crucial for most people in the postpartum who will relapse.

Influence of Fluid Delivery Schedule and Composition on Fluid Balance, Physiologic Strain, and Substrate Use in the Heat

Wildfire suppression is characterized by high total energy expenditure and water turnover rates. Hydration position stands outline hourly fluid intake rates. However, dose interval remains ambiguous. We aimed to determine the effects of microdosing and bolus-dosing water and microdosing and bolus-dosing carbohydrate-electrolyte solutions on fluid balance, heat stress (physiologic strain index [PSI]), and carbohydrate oxidation during extended thermal exercise. In a repeated-measures cross-over design, subjects completed four 120-min treadmill trials (1.3 m·s-1, 5% grade, 33°C, 30% relative humidity) wearing a US Forest Service wildland firefighter uniform and a 15-kg pack. Fluid delivery approximated losses calculated from a pre-experiment familiarization trial, providing 22 doses·h-1 or 1 dose·h-1 (46±11, 1005±245 mL·dose-1). Body weight (pre- and postexercise) and urine volume (pre-, during, and postexercise) were recorded. Heart rate, rectal temperature, skin temperature, and steady-state expired air samples were recorded throughout exercise. Statistical significance (P<0.05) was determined via repeated-measures analysis of variance. Total body weight loss (n=11, -0.6±0.3 kg, P>0.05) and cumulative urine output (n=11, 677±440 mL, P>0.05) were not different across trials. The micro-dosed carbohydrate-electrolyte trial sweat rate was lower than that of the bolus-dosed carbohydrate-electrolyte, bolus-dosed water, and microdosed water trials (n=11, 0.8±0.2, 0.9±0.2, 0.9±0.2, 0.9±0.2 L·h-1, respectively; P<0.05). PSI was lower at 60 than 120 min (n=12, 3.6±0.7 and 4.5±0.9, respectively; P<0.05), with no differences across trials. The carbohydrate-electrolyte trial's carbohydrate oxidation was higher than water trial's (n=12, 1.5±0.3 and 0.8±0.2 g·min-1, respectively; P<0.05), with no dosing style differences. Equal-volume diverse fluid delivery schedules did not affect fluid balance, PSI, or carbohydrate oxidation during extended thermal work.

Toilets dominate environmental detection of severe acute respiratory syndrome coronavirus 2 in a hospital

Respiratory and fecal aerosols play confirmed and suspected roles, respectively, in transmitting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). An extensive environmental sampling campaign of both toilet and non-toilet environments was performed in a dedicated hospital building for patients with coronavirus disease 2019 (COVID-19), and the associated environmental factors were analyzed. In total, 107 surface samples, 46 air samples, two exhaled condensate samples, and two expired air samples were collected within and beyond four three-bed isolation rooms. The data of the COVID-19 patients were collected. The building environmental design and the cleaning routines were reviewed. Field measurements of airflow and CO2 concentrations were conducted. The 107 surface samples comprised 37 from toilets, 34 from other surfaces in isolation rooms, and 36 from other surfaces outside the isolation rooms in the hospital. Four of these samples were positive, namely two ward door handles, one bathroom toilet seat cover, and one bathroom door handle. Three were weakly positive, namely one bathroom toilet seat, one bathroom washbasin tap lever, and one bathroom ceiling exhaust louver. Of the 46 air samples, one collected from a corridor was weakly positive. The two exhaled condensate samples and the two expired air samples were negative. The fecal-derived aerosols in patients' toilets contained most of the detected SARS-CoV-2 in the hospital, highlighting the importance of surface and hand hygiene for intervention.

Abstract A113: Mass balance and pharmacokinetics of an oral dose of 14C-napabucasin in healthy adult male subjects

Abstract Introduction: Napabucasin is an NQO1-bioactivatable investigational agent hypothesized to affect multiple oncogenic cellular pathways including pSTAT3 through the generation of reactive oxygen species. The primary objectives of this phase 1, open-label study in healthy male subjects were to characterize the absorption, metabolism, and excretion of 14C-napabucasin and to determine the pharmacokinetics of 14C-napabucasin and relevant metabolites in plasma, urine, and feces. The secondary objective was to assess safety and tolerability of napabucasin. Methods: Healthy male adult (age 18–45 years) subjects were eligible to receive a single oral 240-mg dose of napabucasin containing ~100 μCi of 14C-napabucasin. Blood, urine, and feces were collected up to 264 hours (h; 11 days) postdose. Whole blood, plasma, urine, fecal, and expired air samples were assayed for total radioactivity (TR). Plasma, urine, and fecal samples were assayed for napabucasin and metabolites. Results: Overall, 8 subjects (mean [range] age 29 [23–39] years) were enrolled. The mean TR recovered was 81.1%. In general, elimination of 14C-napabucasin was predominantly via feces (57.2%), to a lesser extent via urine (23.8%), and was negligible in expired air. Most (76.0%) recovery was within 48 h postdose. 14C-napabucasin was rapidly absorbed (median time to peak concentration 2.8 h) and underwent extensive reductive metabolism to yield dihydro-napabucasin (M1), the sole major circulating metabolite. Systemic exposure to 14C-napabucasin was higher than M1, and M1 plasma concentration versus time profiles generally mirrored 14C-napabucasin. Similar arithmetic mean half-lives for 14C-napabuscasin and M1 (7.9 h and 7.1 h, respectively) suggest that the rate of formation of the reduced metabolite is rate limiting. The TR whole blood:plasma ratio of 0.4 indicated that circulating drug-related compounds were essentially confined to plasma. Four minor metabolites were identified but accounted for ≤7.0% of TR in plasma. Consistent with preclinical animal models, no uniquely human or disproportionate metabolite was quantified. Secondary glucuronide and sulfate conjugates were common urinary metabolites. These data suggest that 14C-napabucasin was mainly cleared by reductive metabolism and, to a lesser extent, by renal elimination. 14C-napabucasin and M1 recovered in urine accounted for 13.2% and 9.6% of the administered dose, respectively. Apparent renal clearance of 14C-napabucasin and M1 were 8.1 L/h and 7.9 L/h, respectively. All subjects experienced treatment-emergent adverse events (TEAEs). All TEAEs were mild (grade 1) and the majority were assessed as related to napabucasin. The most commonly reported TEAEs were gastrointestinal disorders and, of these, diarrhea was reported most frequently and generally started within 4.5–5.0 h postdose and resolved without treatment. There were no clinically significant laboratory, vital sign, electrocardiogram, or physical examination changes. Conclusions: 14C-napabucasin is primarily excreted through feces. 14C-napabucasin underwent extensive metabolism to yield M1 as the sole major circulating metabolite. No uniquely human or disproportionate metabolite was quantified. A single oral 240-mg dose of napabucasin was tolerated in healthy male subjects. Citation Format: Xiaoshu Dai, Michael D Karol, Matthew Hitron, Marjie Hard, J Evan Blanchard, Nicola Eraut, Natalie Rich, Brandon Gufford. Mass balance and pharmacokinetics of an oral dose of 14C-napabucasin in healthy adult male subjects [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A113. doi:10.1158/1535-7163.TARG-19-A113

Effect of medium-chain TAG and exercise on satiety, energy intake and energy balance.

The present study examined whether the combination of medium-chain TAG (MCT) along with exercise suppresses energy intake to a greater extent compared with either intervention alone. Twelve participants consumed a porridge breakfast containing 692·9 kJ of either vegetable or MCT oil on two separate occasions: one followed by rest for 240 min and another followed by rest broken up with 1 h of cycling at 65 % $\dot V$O2peak starting at 120 min. At 240 min, participants consumed a buffet lunch to satiation and recorded their food intake for the rest of the day. Expired air samples (for calculation of energy expenditure (EE)) and subjective ratings of appetite on visual analogue scales were taken every 30 min, and gastric emptying (GE) breath samples were taken every 15 min. No effect of either breakfast or exercise condition was observed on energy intake at any time point (P > 0·05) or no effect was observed on subjective appetite ratings (P > 0·05). Exercise trials resulted in significantly higher EE compared with resting trials (2960·6 kJ, 95 % CI 2528·9, 3392·2; P < 0·001), and MCT increased resting EE over 4 h compared with long-chain TAG (LCT) (124·8 kJ, 95 % CI 13·5, 236·0; P = 0·031). GE was accelerated by exercise, regardless of the breakfast consumed, but delayed by MCT in both resting and exercise trials. The results show that exercise causes energy deficits via increased EE without promoting dietary compensation. MCT has no effect on energy intake or satiety but increases EE under resting conditions. There is no additive effect of MCT and exercise on EE, intake or appetite ratings.

Microparticle Responses to Aerobic Exercise and Meal Consumption in Healthy Men.

Microparticles (MP) are shed extracellular vesicles that express the prothrombotic tissue factor (TF). Aerobic exercise may reduce MP count and TF expression. This study investigated the impact of acute running or rest followed by standardized meal consumption on MP phenotypes and TF expression. Fifteen males (age, 22.9 ± 3.3 yr; body mass, 81.9 ± 11.4 kg; V˙O2max, 54.9 ± 6.5 mL·kg·min; mean ± SD) completed 1 h of running (70% V˙O2max) or rest at 9:00 AM and consumed a standardized meal (1170 kcal, 43% CHO, 17% PRO, 40% fat) at 10:45 AM. Venous blood samples were taken at 9:00 AM, 10:00 AM, and 11:30 AM. The MP concentration, diameter, phenotypes, and TF expression were assessed using nanoparticle tracking analysis and flow cytometry. Nanoparticle tracking analysis identified no changes in MP concentration or diameter in response to time or trial. Flow cytometry revealed total MP count increased from 9:00 AM to 10:00 AM (1.62 ± 2.28 to 1.74 ± 2.61 × 10 L, P = 0.016, effect size (η) = 0.105), but was unaffected by trial. TF platelet-derived MP % reduced from 9:00 AM to 10:00 AM (44.0% ± 21.2% to 21.5% ± 9.3%, P = 0.001, η = 0.582) after exercise only (control, 36.8% ± 18.2% to 34.9% ± 11.9%; P = 0.972). TF neutrophil-derived MP percentage reduced from 9:00 AM to 11:30 AM (42.3% ± 17.2% to 25.1% ± 14.9%; P = 0.048, η = 0.801) in the exercise trial only (control, 28.5% ± 15.7% to 32.2% ± 9.6%; P = 0.508). Running induced a significant reduction in %TF platelet and neutrophil MP, suggesting a transient reduction in cardiovascular risk via reduced TF-stimulated thrombosis. This requires further investigation over longer periods in cardiovascular disease populations.

New Zealand blackcurrant extract enhances fat oxidation during prolonged cycling in endurance-trained females

PurposeNew Zealand blackcurrant (NZBC) extract has previously been shown to increase fat oxidation during prolonged exercise, but this observation is limited to males. We examined whether NZBC intake also increases fat oxidation during prolonged exercise in females, and whether this was related to greater concentrations of circulating fatty acids.MethodsIn a randomised, crossover, double-blind design, 16 endurance-trained females (age: 28 ± 8 years, BMI: 21.3 ± 2.1 kg·m−2, VO2max: 43.7 ± 1.1 ml·kg−1·min−1) ingested 600 mg·day−1 NZBC extract (CurraNZ™) or placebo (600 mg·day−1 microcrystalline cellulose) for 7 days. On day 7, participants performed 120 min cycling at 65% VO2max, using online expired air sampling with blood samples collected at baseline and at 15 min intervals throughout exercise for analysis of glucose, NEFA and glycerol.ResultsNZBC extract increased mean fat oxidation by 27% during 120 min moderate-intensity cycling compared to placebo (P = 0.042), and mean carbohydrate oxidation tended to be lower (P = 0.063). Pre-exercise, plasma NEFA (P = 0.034) and glycerol (P = 0.051) concentrations were greater following NZBC intake, although there was no difference between conditions in the exercise-induced increase in plasma NEFA and glycerol concentrations (P > 0.05). Mean fat oxidation during exercise was moderately associated with pre-exercise plasma NEFA concentrations (r = 0.45, P = 0.016).ConclusionsIntake of NZBC extract for 7 days elevated resting concentrations of plasma NEFA and glycerol, indicative of higher lipolytic rates, and this may underpin the observed increase in fat oxidation during prolonged cycling in endurance-trained females.

Absorption, metabolism, and excretion of [14C]evogliptin tartrate in male rats and dogs

ABSTRACTThe objective of this study was to determine the absorption, excretion, and metabolism of a novel, oral antihyperglycemic drug, evogliptin, in male rats and dogs. Plasma, urine, feces, and expired air samples were collected after a single oral dose administration of [14C]evogliptin, samples were analyzed by measuring overall radioactivity levels using high-performance liquid chromatography (HPLC), and radioactivity levels were measured by utilizing LC-tandem mass spectrometry (LC-MS/MS). The total amounts of radioactivity excreted in urine, feces, and expired air up to 168 h after administration of [14C]evogliptin tartrate to rats (30 mg evogliptin/kg) and dogs (10 mg evogliptin/kg) were 96.7% and 96.8% of initial doses administered, respectively. The extent of urinary and fecal excretion in the rat up to 168 h constituted 29.7% and 66.5% of the given dose, respectively; and in dog was 43.3% and 53.5%, respectively. A total of 23 possible metabolites were detected with radiochromatograms of plasma, urinary, and fecal samples, but only the structures of 12 metabolites were identified via LC-MS/MS analysis. Evogliptin was the major component. Regarding the total radiochromatographic peak areas, peaks 9 (evogliptin acid) and 11 (hydroxyevogliptin) were the major metabolites in rats, and peaks 8 [4(S)-hydroxyevogliptin glucuronide], 15 [4(S)-hydroxyevogliptin], and 17 [4(R)-hydroxyevogliptin] were the predominant metabolites in dogs. Data demonstrated that evogliptin was the major component excreted in urine and feces of rats and dogs, but the metabolite profiles varied between species.

ANALYSIS OF AGREEMENT BETWEEN EXPIRED-AIR CARBON MONOXIDE MONITORS.

The current study examined the level of agreement in expired-air carbon monoxide (CO) values, focusing especially on those confirming abstinence, between the two most commonly used CO monitors, the Vitalograph BreathCO and the Bedfont piCO+ Smokerlyzer. Expired-air samples were collected via both monitors from adult dependent smokers (44 M, 34 F) participating in studies using CO values to confirm abstinence durations of: 24 hours, 12 hours, or no abstinence. All met DSM-IV nicotine dependence criteria and had a mean (SD) Fagerström Test of Cigarette Dependence score of 5.1 (1.8). Paired data collected across multiple visits were analyzed by regression-based Bland-Altman method of Limits of Agreement. Analysis indicated a lack of agreement in CO measurement between monitors. Overall, the Bedfont monitor gave mean (±SEM) readings 3.83 (±.23) ppm higher than the Vitalograph monitor. Mean differences between monitors were larger for those ad lib smoking (5.65±.38 ppm) than those abstaining 12-24 hours (1.71±.13 ppm). Yet, there also was not consistent agreement in classification of 24 hour abstinence between monitors. Systematic differences in CO readings demonstrate these two very common monitors may not result in interchangeable values, and reported outcomes in smoking research based on CO values may depend on the monitor used.

Assessing a commercially available sports drink on exogenous carbohydrate oxidation, fluid delivery and sustained exercise performance

BackgroundWhilst exogenous carbohydrate oxidation (CHOEXO) is influenced by mono- and disaccharide combinations, debate exists whether such beverages enhance fluid delivery and exercise performance. Therefore, this study aimed to ascertain CHOEXO, fluid delivery and performance times of a commercially available maltodextrin/ fructose beverage in comparison to an isocaloric maltodextrin beverage and placebo.MethodsFourteen club level cyclists (age: 31.79 ± 10.02 years; height: 1.79 ± 0.06 m; weight: 73.69 ± 9.24 kg; VO2max: 60.38 ± 9.36 mL · kg·-1 min-1) performed three trials involving 2.5 hours continuous exercise at 50% maximum power output (Wmax: 176.71 ± 25.92 W) followed by a 60 km cycling performance test. Throughout each trial, athletes were randomly assigned, in a double-blind manner, either: (1) 1.1 g · min-1 maltodextrin + 0.6 g · min-1 fructose (MD + F), (2) 1.7 g · min-1 of maltodextrin (MD) or (3) flavoured water (P). In addition, the test beverage at 60 minutes contained 5.0 g of deuterium oxide (2H2O) to assess quantification of fluid delivery. Expired air samples were analysed for CHOEXO according to the 13C/12C ratio method using gas chromatography continuous flow isotope ratio mass spectrometry.ResultsPeak CHOEXO was significantly greater in the final 30 minutes of submaximal exercise with MD + F and MD compared to P (1.45 ± 0.09 g · min-1, 1.07 ± 0.03 g · min-1and 0.00 ± 0.01 g · min-1 respectively, P < 0.0001), and significantly greater for MD + F compared to MD (P = 0.005). The overall appearance of 2H2O in plasma was significantly greater in both P and MD + F compared to MD (100.27 ± 3.57 ppm, 92.57 ± 2.94 ppm and 78.18 ± 4.07 ppm respectively, P < 0.003). There was no significant difference in fluid delivery between P and MD + F (P = 0.078). Performance times significantly improved with MD + F compared with both MD (by 7 min 22 s ± 1 min 56 s, or 7.2%) and P (by 6 min 35 s ± 2 min 33 s, or 6.5%, P < 0.05) over 60 km.ConclusionsA commercially available maltodextrin-fructose beverage improves CHOEXO and fluid delivery, which may benefit individuals during sustained moderate intensity exercise. The greater CHOEXO observed when consuming a maltodextrin-fructose beverage may support improved performance times.

A single‐dose, microtracer study to determine the mass balance of orally administered, 14C‐labeled sweetener in healthy adult men (LB450)

The objective of this study was to determine the mass balance recovery of a rare sugar, through measurement of absorption, metabolism, and elimination using 14C radio‐labeled tracer with quantification via liquid scintillation counting and accelerator mass spectrometry (AMS). AMS measures isotope ratios to achieve low detection limits, providing quantification of 14C labeled compounds to low attomole levels. Eight healthy male subjects were housed within a metabolic ward for 1 week. The orally administered 776 nCi [14C(U)]‐rare sugar (99% purity), in a beverage containing 15g of unlabeled sweetener was consumed following a light breakfast. Blood, urine, fecal and expired air samples were collected at baseline and at various time points through168 hr for detection of the radiotracer and potential metabolites. Plasma Cmax occurred ~1.5 hours after dosing. Urinary total radioactivity (TRA) was 48.02‐90.25 % of dose over 168hr of collection. There was one subject with a low urine recovery (48.02%) within the first 12hr, possibly due to a missed collection. Fecal TRA (0‐120hr) was 1.79‐5.65 % of dose. Expired air 14C detection over 6hrs was only 0‐0.05% of dose and considered negligible. Overall, TRA 14C recovery was approximately 90%. High performance liquid chromatographic fractions analyzed with AMS showed the majority of the radiotracer was intact (TRA 80.3% plasma; 83.6% urine; 16% fecal). The 14C‐rare sugar was the most abundant compound in the plasma and excreta, demonstrating that this novel sugar is absorbed, but not metabolized.Grant Funding Source: Research supported by Tate &amp; Lyle, Health and Nutrition Sciences.

A mobile-phone-based breath carbon monoxide meter to detect cigarette smoking.

Mobile phones hold considerable promise for delivering evidence-based smoking cessation interventions that require frequent and objective assessment of smoking status via breath carbon monoxide (Breath CO) measurement. However, there are currently no commercially available mobile-phone-based Breath CO meters. We developed a mobile-phone-based Breath CO meter prototype that attaches to and communicates with a smartphone through an audio port. We then evaluated the reliability and the validity of Breath CO measures collected with the mobile meter prototype and assessed the usability and acceptability of the meter. Participants included 20 regular smokers (≥10 cigarettes/day), 20 light smokers (<10 cigarettes/day), and 20 nonsmokers. Expired air samples were collected 4 times from each participant: twice with the mobile meter and twice with a commercially available Breath CO meter. Measures calculated by the mobile meter correlated strongly with measures calculated by the commercial meter (r = .96, p < .001). Additionally, the mobile meter accurately distinguished between smokers and nonsmokers. The area under the receiver-operating characteristic curve for the mobile meter was 94.7%, and the meter had a combined sensitivity and specificity of 1.86 at an abstinence threshold of ≤6 ppm. Responses on an acceptability survey indicated that smokers liked the meter and would be interested in using it during a quit attempt. The results of our study suggest that a mobile-phone-based Breath CO meter is a reliable, valid, and acceptable device for distinguishing between smokers and nonsmokers.

The Effect of Acute Rhodiola rosea Ingestion on Exercise Heart Rate, Substrate Utilisation, Mood State, and Perceptions of Exertion, Arousal, and Pleasure/Displeasure in Active Men.

The aim of this study was to examine the effect of acute Rhodiola rosea (R. rosea) ingestion on substrate utilisation, mood state, RPE, and exercise affect. Ten males (mean age ± S.D. = 26 ± 6 years) completed two 30-minute cycling trials at an intensity of 70% of following ingestion of either 3 mg·kg−1 body mass of R. rosea or placebo using a double-blind, crossover design. During exercise, heart rate and RPE were recorded. Participants completed measures of mood state and exercise affect before and after exercise. Expired air samples were taken during exercise to determine substrate utilisation. Repeated measures analysis of variance indicated that RPE was significantly lower at 30 minutes into exercise versus placebo (P = 0.003). Perceptions of arousal (P = 0.05) and pleasure were significantly higher after exercise with R. rosea compared to placebo (P = 0.003). Mood state scores for vigor were also higher in R. rosea condition compared to placebo (P = 0.008). There were no significant differences in energy expenditure, carbohydrate, or fat oxidation between conditions (P > 0.05). Ingestion of R. rosea favourably influenced RPE and exercise affect without changes in energy expenditure or substrate utilization during 30-minute submaximal cycling performance.

Evaluation of the respiratory elimination kinetics of selenate and Se-methylselenocysteine after oral administration in lambs

Sheep can be acutely poisoned by selenium (Se) accumulating forages which often contain selenate or Se-methylselenocysteine as their predominant forms. Excess Se can be eliminated via respiration. Sheep were given a single oral dose of 0, 1, 2, 3, 4, or 6mg Se/kg BW as sodium selenate and Se-methylselenocysteine or 6mg Se/kg BW as sodium selenite or selenomethionine. Expired air samples were collected and analyzed for Se. The Se concentration of the expired air reflected a dose-dependent increase at individual time points for both Se-methylselenocysteine and sodium selenate, however, Se content was greater and eliminated more rapidly from sheep receiving Se-methylselenocysteine. The mean Se concentration in respired air from sheep administered 6mg Se/kg BW of different selenocompounds was greatest in sheep dosed Se-methylselenocysteine>selenomethionine>sodium selenate>sodium selenite. The Se concentration in respired air of acutely poisoned sheep is significantly different for different chemical forms of Se.

Using expired air carbon monoxide to determine smoking status during pregnancy: Preliminary identification of an appropriately sensitive and specific cut-point

BackgroundMeasurement of carbon monoxide in expired air samples (ECO) is a non-invasive, cost-effective biochemical marker for smoking. Cut points of 6ppm–10ppm have been established, though appropriate cut-points for pregnant woman have been debated due to metabolic changes. This study assessed whether an ECO cut-point identifying at least 90% of pregnant smokers, and misidentifying fewer than 10% of non-smokers, could be established. MethodsPregnant women (N=167) completed a validated self-report smoking assessment, a urine drug screen for cotinine (UDS), and provided an expired air sample twice during pregnancy. ResultsHalf of women reported non-smoking status early (51%) and late (53%) in pregnancy, confirmed by UDS. Using a traditional 8ppm+cut-point for the early pregnancy reading, only 1% of non-smokers were incorrectly identified as smokers, but only 56% of all smokers, and 67% who smoked 5+ cigarettes in the previous 24h, were identified. However, at 4ppm+, only 8% of non-smokers were misclassified as smokers, and 90% of all smokers and 96% who smoked 5+ cigarettes in the previous 24h were identified. False positives were explained by heavy second hand smoke exposure and marijuana use. Results were similar for late pregnancy ECO, with ROC analysis revealing an area under the curve of .95 for early pregnancy, and .94 for late pregnancy readings. ConclusionsA lower 4ppm ECO cut-point may be necessary to identify pregnant smokers using expired air samples, and this cut-point appears valid throughout pregnancy. Work is ongoing to validate findings in larger samples, but it appears if an appropriate cut-point is used, ECO is a valid method for determining smoking status in pregnancy.

Abstract 3367: Massbalance, excretion and metabolism of [14C]-Pralatrexate (PDX) incancer patients in a phase I trial.

Abstract Background: PDX is a novel 10-deaza-aminopterin analogue of methotrex[[Unsupported Character - Codename &amp;shy;]]ate consisting of a mixture of R- and S-diastereomeric folate derivatives. PDX inhibits folate metabolism by binding to and inhibiting the enzyme dihydrofolate reductase (DHFR). PDX is the first drug approved by the US Food and Drug Admin[[Unsupported Character - Codename &amp;shy;]]istration (FDA) specifically for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma. Mass balance studies in animals and humans with radiolabeled compounds represent a standard part of the development process for new drugs. Isotopically labeled analogs of a drug or its metabolites play an important role in understanding the absorption, distribution, metabolism and excretion profiles of a compound. The objectives of this study were to determine the pharmacokinetics (PK), metabolism and routes of excretion of [14C]-PDX and to characterize its metabolites in human plasma and urine. Methods: Four patients were administered intravenously with a mixture of 50 μCi of [14C]-PDX (0.5 mg) and 224.5 mg of non radioactive PDX over a 3-5 minute infusion. Serial blood and plasma samples were drawn at: 0 (before PDX infusion), and up to 144 h after the start of infusion. Urine and fecal samples were collected for up to 168 h after the start of infusion. Expired air samples were collected up to 24 hours after administration. The radioactivity measurement in biological fluids was performed using liquid scintillation counting. Results: Mass balance was achieved with a mean recovery radioactivity in excreta= 82.9 % ± 20.0 % for the four patients. The mean recovery of radioactivity in urine, feces, and expired air were 34.1%, 38.7% and 10.1%, respectively, indicating renal and fecal excretions were the major route of elimination of [14C]-PDX. A three-compartment open model adequately described [14C]-PDX time radioactivity-concentration courses. The AUC0-∞, and clearance values for total radioactivity in plasma were 18.1 nCi.h/mL, and 3.95 L/h, respectively. Metabolite profiling will be performed using HPLC with beta radiation detector. Conclusions: This study quantified the mass balance of PDX and defined its substantial excretion in both urine and feces after IV administration. The PK of [14C]-PDX was best described by a three compartment open model. The metabolite profiling of PDX is ongoing. Citation Format: Elodie Odore, Keyvan Rezaï, Olivier Madar, Sophie Weill, Ahmad Awada, Bert Pronk, Esteban Cvitkovic, Francois Lokiec. Massbalance, excretion and metabolism of [14C]-Pralatrexate (PDX) incancer patients in a phase I trial. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3367. doi:10.1158/1538-7445.AM2013-3367

Chemotherapy control by breath profile with application of SPME‐GC/MS method

Chemotherapy used as a treatment against lung cancer has influence on metabolic processes occurring in healthy cells. The changes of biochemical pathways proceeded inside cells might be observed in expired air. In the experiment, breath analysis was carried out before and after anticancer therapy. Expired air samples were collected from 22 patients with a biopsy confirmed lung cancer. Volatile organic compounds present in breath were analyzed by gas chromatography/mass spectrometry. For enrichment of analytes solid-phase microextraction technique was applied. Eight fibers covered by different sorbents were tested. Carboxen-polydimethylsiloxane fiber revealed the highest extraction efficiency in relation to analytes in breath. The data showed that cytostatic drugs increase the concentration of acetone and isoprene in the breath collected after chemotherapy. Volatile metabolites of administrated drugs were not identified in expired air.

Acute Effect of Fatmax Exercise on the Metabolism in Overweight and Nonoverweight Girls

Acute exercise can reduce postprandial insulin concentrations and increase fat oxidation in adults, which may have important implications for insulin resistance and weight control. However, similar studies with young people or comparing overweight (OW) and nonoverweight (NO) individuals are sparse. Therefore, the acute effect of Fatmax exercise on glucose, insulin, and fat oxidation was examined in 12 OW and 15 NO girls. Participants completed two 2-d conditions in a counterbalanced order. On day 1, participants either expended 2.09 MJ (500 kcal) during treadmill exercise at individual Fatmax (EX) or 0.47 MJ (112 kcal) during rest (CON). On day 2, capillary blood and expired air samples were taken in the fasting state and at regular intervals for 2 h after high-glycemic-index breakfast consumption. Subsequently, blood glucose and plasma insulin concentrations were determined, and fat oxidation was estimated. Blood glucose was similar between conditions in both groups (P > 0.05). Fasting plasma insulin (P = 0.047) and total area under the 2-h curve (P = 0.049) were reduced for EX compared with CON in the NO, but not OW girls (P > 0.05). Fasting fat oxidation was higher for EX than for CON in the NO girls (P = 0.036) and fat oxidation total area under the 2-h curve was higher for EX in both groups of girls (P ≤ 0.05). A bout of Fatmax exercise performed ~16 h before high-glycemic-index breakfast consumption reduced fasting and postprandial insulin concentrations in NO girls and increased fat oxidation in both OW and NO girls. The higher postintervention energy and CHO intake in the OW compared with the NO girls or differences in metabolism between the two groups may have compromised potential exercise-induced reductions in insulin the OW girls.

Estimate of expired air samples of patients with the pulmonary tuberculosis using laser photoacoustic spectroscopy technique

Estimate of expired air samples of patients with the pulmonary tuberculosis using laser photoacoustic spectroscopy technique