Acute Effects of Albuterol on Ventilatory Capacity in Children with Asthma.

BACKGROUND: Children with asthma may have a reduced ventilatory capacity, which could lead to symptoms and early termination of a cardiopulmonary exercise test (CPET). The purpose of this study was to examine the effects of short-acting beta agonist (albuterol) administration on estimated ventilatory capacity in children with asthma. METHODS: Fifteen children (eleven boys, 10.6 ± 0.9 years) completed spirometry at baseline, after 180 µg of albuterol, and after the CPET in this cross-sectional study. Ventilatory capacity was calculated from forced vital capacity (FVC) and isovolume forced expiratory time from 25 to 75% of FVC (isoFET25-75) as follows: FVC/2 × [60/(2 × isoFET25-75)]. Differences in outcome variables between baseline, after albuterol administration, and after the CPET were detected with repeated measures mixed models with Bonferroni post hoc corrections. RESULTS: Estimated ventilatory capacity was higher after albuterol (68.7 ± 21.2 L/min) and after the CPET (75.8 ± 25.6 L/min) when compared with baseline (60.9 ± 22.0 L/min; P = 0.003). Because forced vital capacity did not change, the increased ventilatory capacity was primarily due to a decrease in isoFET25-75 (i.e., an increase in mid-flows or isoFEF25-75). CONCLUSION: Albuterol administration could be considered prior to CPET for children with asthma with relatively well-preserved FEV1 values to increase ventilatory capacity pre-exercise and potentially avoid symptom-limited early termination of testing.

Comparisons between human and rodent hepatic glutathione S-Transferase activities reveal sex and species differences.

Glutathione S-transferases (GSTs) are conjugating enzymes involved in drug metabolism, antioxidant defence, and cell signalling. Herein, we investigated hepatic GST conjugation in several mouse and rat strains, including both sexes, with a direct comparison to humans.Using general and isoform-selective substrates, all mouse strains had significantly greater activities than humans for total cytosolic GST, GST-M, GST-T, and microsomal GST activities. Some strains had significantly greater GST-P activities compared to humans. Sex differences between males and females were evident in all strains for total cytosolic GST, GST-M, and GST-P, and sex differences in GST-T and microsomal GST activities within strains were noted.All rats had significantly greater activities than humans for GST-M and GST-T; only some strains were significantly greater than humans for GST-P, total cytosolic GST, and microsomal GST. Sex differences within strains showed significantly greater GST-M and GST-T activities in males compared to females. Select strains showed sex differences for total cytosolic and microsomal GST activities; there were no sex differences in GST-P activities.Significant differences in glutathione conjugation between humans and rodents exist, including sex differences. This highlights the need for careful animal selection in pre-clinical studies where GSTs are the primary metabolic pathway.

The Phytomanagement of PFAS-Contaminated Land.

Globally, several hundred thousand hectares of both agricultural and urban land have become contaminated with per- and polyfluoroalkyl substances (PFAS). PFAS compounds are resistant to degradation and are mobile in soil compared to other common contaminants. Many compounds have KD values (matrix/solution concentration quotients) of <10. PFAS compounds endanger the health of humans and ecosystems by leaching into groundwater, exposure via dust, and, to a lesser extent, through plant uptake. This review aims to determine the feasibility of phytomanagement, the use of plants, and the use of soil conditioners to minimize environmental risk whilst also providing an economic return in the management of PFAS-contaminated land. For most sites, PFAS combinations render phytoextraction, the use of plants to remove PFAS from soil, inviable. In contrast, low Bioaccumulation Coefficients (BAC; plant and soil concentration quotients) timber species or native vegetation may be usefully employed for phytomanagement to limit human/food chain exposure to PFAS. Even with a low BAC, PFAS uptake by crop plants may still exceed food safety standards, and therefore, edible crop plants should be avoided. Despite this limitation, phytomanagement may be the only economically viable option to manage most of this land. Plant species and soil amendments should be chosen with the goal of reducing water flux through the soil, as well as increasing the hydrophobic components in soil that may bind the C-F-dominated tails of PFAS compounds. Soil conditioners such as biochar, with significant hydrophobic components, may mitigate the leaching of PFAS into receiving waters. Future work should focus on the interactions of PFAS with soil microbiota; secondary metabolites such as glomalin may immobilize PFAS in soil.

Outpatient hysteroscopy is effective for uterine cavity evaluation following failed office-based endometrial biopsy.

BACKGROUND: Failure to obtain an office-based endometrial biopsy for abnormal uterine bleeding is not uncommon. Although operating room-based procedures are traditionally considered the gold standard assessment tool in these circumstances, outpatient hysteroscopy is a less invasive, more cost-effective, and safer alternative. However, there is no contemporary Canadian literature on the effectiveness of an outpatient approach for this specific population. OBJECTIVE: We aim to evaluate the effectiveness and outcomes of outpatient hysteroscopy for uterine cavity evaluation for patients who have failed an in-office endometrial biopsy attempt. METHODS: We conducted a retrospective cohort study of all patients referred to an academic outpatient hysteroscopy unit between January 2015 and January 2018, who underwent an outpatient hysteroscopy following failed endometrial biopsy. Data were collected from electronic medical records. RESULTS: Of the 407 consecutive patients who underwent an outpatient hysteroscopic procedure, 68 met inclusion criteria. Postmenopausal bleeding was the most common indication for initial biopsy, and most failures were attributed to cervical stenosis. Outpatient hysteroscopies were successfully completed in 96% of cases (n = 65/68). Failure resulted from either anxiety and discomfort (n = 2), or severe intrauterine adhesions (n = 1). Overall, 10% of patients subsequently required an operating room-based hysteroscopy, either to complete a myomectomy or polypectomy, or to allow general anesthesia. Outpatient hysteroscopy identified endometrial hyperplasia and cancer in 4.5% and 3% of patients, respectively. CONCLUSION: Outpatient hysteroscopy following unsuccessful office endometrial biopsy attempts appears to be a feasible, safe, and cost-effective investigation strategy that may prevent the need for an operating room-based procedure in 90% of cases.

Protective placental inflammatory and oxidative stress responses are attenuated in the context of twin pregnancy and chorioamnionitis in assisted reproduction.

PURPOSE: Assisted reproduction technologies (ART) are associated with increased risks of pregnancy complications and obstetric interventions. Here, we aimed to determine if ART affects placental inflammation and oxidative stress as a mechanism for unfavorable pregnancy outcomes. METHODS: The levels of six cytokines (IFN-γ, IL-1ß, IL-6, IL-8, IL-10, TNFα) were measured using multiplex ELISA. The activity of four antioxidant enzymes (glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase, superoxide dismutase) and levels of two antioxidants (GSH, vitamin E) were measured using commercial/in-house assays. Markers were compared between ART and unassisted pregnancies, and then groups were stratified using ICD9/10 codes to determine differences in specific clinical contexts. RESULTS: In unassisted twin pregnancies, there was a trend of decreased cytokine levels (IL-1ß, IL-6, IL-8, TNFα, p < 0.05), but cytokines in ART twins were the same or higher. Additionally, GST and GPx activities were lower in unassisted twins, and vitamin E levels were higher in ART twins (p < 0.05). In pregnancies complicated by chorioamnionitis, there was a trend of increased cytokine levels in unassisted pregnancies (IL-1ß, IL-6, and IL-8, p < 0.05). No increase was observed in ART, and IFN-γ and TNFα were decreased (p < 0.05). Placental GST and GPx activities were higher in unassisted pregnancies with chorioamnionitis compared to ART (p < 0.05). CONCLUSION: Attenuation of protective placental inflammatory and oxidative stress responses may play a role in the underlying pathogenesis of negative birth outcomes in ART, expanding our understanding of adverse pregnancy outcomes when ART is used to conceive.

The Effects of 10-Day Exogenous Ketone Consumption on Repeated Time Trial Running Performances: A Randomized-Control Trial.

INTRODUCTION: The effects of ketone salt supplementation on repeated short-distance running time trial (TT) performance in well-trained subjects remain unknown. PURPOSE: To determine the effects of 10-day exogenous ketone salt supplementation on two consecutive 800 m running TTs in endurance-trained subjects. METHODS: Male and female subjects were randomly allocated to one of the following groups: Ketone (KET) (n = 16) or placebo (CON) (n = 16) (8 m, 8f per group). Subjects underwent two consecutive 800 m TTs before and after a 10-day treatment on a self-propelled treadmill. Time-to-completion of the first (TT1) and second (TT2) TT, the average time-to-completion (TTAVG), and blood lactate response during each TT was measured pre-post-treatment. Changes in blood ketone levels in response to a single dosing were measured pre- and post-treatment. Data was analyzed with a mixed factorial ANOVA with significance set to p < 0.05. RESULTS: KET demonstrated a faster TTAVG from pre- to post-treatment (-6.1 ± 8.9 s; p = 0.02) while CON showed no change. At pre- and post-treatment, CON showed no acute changes in blood ketones after a single-dosing while KET demonstrated a significant increases (Pretreatment = +0.4 ± 0.3 mmol/L; p < 0.001; Post-Treatment = +0.4 ± 0.4 mmol/L; p < 0.001). These acute single-dosing responses in blood ketone levels for KET did not change between pre- and post-treatment. There were no interactions for blood lactate response to exercise or fatigue index. CONCLUSIONS: In trained subjects, 10 days of ketone salt supplementation does not affect performance in an initial bout of short-distance running, such as during TT1. However, ergogenic effects may be observed under fatigue conditions for example during a repeated running bout.

Respiratory and Perceptual Responses to High-Intensity Interval Exercise in Obese Adults.

PURPOSE: Although high-intensity interval exercise (HIIE) has emerged as an attractive alternative to continuous exercise (CE), the effects of HIIE on ventilatory constraints and dyspnea on exertion have not been studied in obese adults, and thus, tolerability of HIIE in obese adults is unknown. The purpose of this study was to examine differences in respiratory and perceptual responses between HIIE and CE in nonobese and obese adults. METHODS: Ten nonobese (5 men; 24.1 ± 6.2 yr; body mass index, 23.0 ± 1.3 kg·m-2) and 10 obese (5 men; 24.2 ± 3.8 yr; body mass index, 37 ± 4.6 kg·m-2) adults participated in this study. Respiratory and perceptual responses were assessed during HIIE (eight 30-s intervals at 80% maximal work rate, with 45-s recovery periods) and two 6-min sessions of CE, completed below and above ventilatory threshold (Vth). RESULTS: Despite similar work rate, HIIE was completed at a higher relative intensity in obese when compared with nonobese participants (68.8% ± 9.4% vs 58.9% ± 5.6% maximal oxygen uptake, respectively; P = 0.01). Expiratory flow limitation and/or dynamic hyperinflation was present during HIIE in 50% of the obese but in none of the nonobese participants. Ratings of perceived breathlessness were highest during HIIE (5.3 ± 2.4), followed by CEaboveVth (2.5 ± 1.6), and CEbelowVth (0.9 ± 0.7; P < 0.05) in obese participants. Unpleasantness associated with breathlessness was higher in obese (4.2 ± 3.0) when compared with nonobese participants (0.6 ± 1.3; P = 0.005) during HIIE. CONCLUSIONS: HIIE, when prescribed relative to maximal work rate, is associated with greater ventilatory constraints and dyspnea on exertion when compared with CE in obese adults. CE may be more tolerable when compared with HIIE for obese adults.

Parameterization of Microsomal and Cytosolic Scaling Factors: Methodological and Biological Considerations for Scalar Derivation and Validation.

Mathematical models that can predict the kinetics of compounds have been increasingly adopted for drug development and risk assessment. Data for these models may be generated from in vitro experimental systems containing enzymes contributing to metabolic clearance, such as subcellular tissue fractions including microsomes and cytosol. Extrapolation from these systems is facilitated by common scaling factors, known as microsomal protein per gram (MPPG) and cytosolic protein per gram (CPPG). Historically, parameterization of MPPG and CPPG has employed the use of recovery factors, commonly benchmarked to cytochromes P450 which work well in some contexts, but could be problematic for other enzymes. Here, we propose absolute quantification of protein content and supplementary assays to evaluate microsomal/cytosolic purity that should be employed. Examples include calculation of microsomal latency by mannose-6-phosphatase activity and immunoblotting of subcellular fractions with fraction-specific markers. Further considerations include tissue source, as disease states can affect enzyme expression and activity, and the methodology used for scalar parameterization. Regional- and organ-specific expression of enzymes, in addition to differences in organ physiology, is another important consideration. Because most efforts have focused on the liver that is, for the most part, homogeneous, derived scalars may not capture the heterogeneity of other major tissues contributing to xenobiotic metabolism including the kidneys and small intestine. Better understanding of these scalars, and how to appropriately derive them from extrahepatic tissues can provide support to the inferences made with physiologically based pharmacokinetic modeling, increase its accuracy in characterizing in vivo drug pharmacokinetics, and improve confidence in go-no-go decisions for clinical trials.

Detection and quantitation of non-steroidal anti-inflammatory drug use close to the time of birth using umbilical cord tissue.

BACKGROUND: Nonsteroidal anti-inflammatory drugs are contraindicated in the third trimester of pregnancy due to negative effects including alteration of uteroplacental blood flow, premature ductus arteriosus closure, and adverse effects on the fetal kidney. However, many women are unaware of these risks, and commonly report their use in pregnancy. We aimed to determine if umbilical cord was a reliable matrix for detecting NSAID use, determine incidence of use close to labour, and uncover associations with obstetric/neonatal outcomes. METHODS: We developed a UHPLC-MS/MS method to simultaneously detect diclofenac, ibuprofen, indomethacin, naproxen, and salicylic acid in plasma and umbilical cord lysate. Using this method, we screened 380 lysates to determine the prevalence of NSAID use. Results were compared to the clinical outcomes in pregnancy using ICD9/10 chart codes (n = 21). RESULTS: The UHPLC-MS/MS method has excellent linearity, accuracy, and precision in solvent and plasma, but lower sensitivity in umbilical cord lysate. We report a 3 % rate of NSAID ingestion within days of labour - the pharmacokinetically-determined window for active ingestion. There were no significant differences observed for maternal, obstetric, or neonatal outcomes between the NSAID positive group (n = 11) and NSAID negative group (n = 369). CONCLUSIONS: Because NSAID use in third trimester is contraindicated, even a 3% usage rate is alarmingly high. Based on UHPLC-MS/MS performance of umbilical cord lysate, 3% is likely a conservative estimate. Recent adoption of NSAIDs under clinical supervision to support in vitro fertilisation and prevent pre-eclampsia indicates future work should focus on determining safe dosages of NSAIDs and the correct therapeutic window in pregnancy.

Homology Modeling of Human Uridine-5'-diphosphate-glucuronosyltransferase 1A6 Reveals Insights into Factors Influencing Substrate and Cosubstrate Binding.

The elimination of numerous endogenous compounds and xenobiotics via glucuronidation by uridine-5'-diphosphate glycosyltransferase enzymes (UGTs) is an essential process of the body's chemical defense system. UGTs have distinct but overlapping substrate preferences, but the molecular basis for their substrate specificity remains poorly understood. Three-dimensional protein structures can greatly enhance our understanding of the interactions between enzymes and their substrates, but because of the inherent difficulties in purifying and crystallizing integral endoplasmic reticulum membrane proteins, no complete mammalian UGT structure has yet been produced. To address this problem, we have created a homology model of UGT1A6 using I-TASSER to explore, in detail, the interactions of human UGT1A6 with its substrates. Ligands were docked into our model in the presence of the cosubstrate uridine-5'-diphosphate-glucuronic acid, interacting residues were examined, and poses were compared to those cocrystallized with various plant and bacterial glycosyltransferases (GTs). Our model structurally resembles other GTs, and docking experiments replicated many of the expected UGT-substrate interactions. Some bias toward the template structures' protein-substrate interactions and binding preferences was evident.

Coexpression of Human Hepatic Uridine Diphosphate Glucuronosyltransferase Proteins: Implications for Ontogenetic Mechanisms and Isoform Coregulation.

Uridine diphosphate glucuronosyltransferases (UGTs) catalyze glucuronidation to facilitate systemic and local clearance of numerous chemicals and drugs. To investigate whether UGT expression is coregulated in human liver, we analyzed the protein expression of UGTs 1A1, 1A3, 1A4, 1A6, 1A9, 2B7, 3A1, and 3A2 using western blots from 164 healthy human liver samples, comparing expression with age and sex. UGT1A6 levels were significantly higher in children than adults, and UGT3A1 and 3A2 expression significantly increased with age from childhood to age >65 yearas. In children aged <18 years, UGT1A4/1A9 protein expression was significantly correlated, but not for adults aged >18 years. UGT1A3 expression was always significantly correlated with other UGT1A isoforms in all adults aged >18 years. In individuals aged ≥12 years, expression of UGT1A1/1A4, UGT1A1/1A6, UGT1A1/1A9, and UGT1A4/1A6 significantly correlated, which was not observed in children aged <12 years. In contrast, UGT1A4/2B7 showed significant correlation in children aged <12 years, but not in individuals aged ≥12 years, and this was observed in female but not male individuals. Expression of UGT1A6/1A9 and UGT3A1/3A2 correlated in the entire sample population, but UGT3As did not correlate with other UGTs. These correlations were sex dependent, as UGT1A3/1A1, UGT1A4/2B7 and UGT3A1/3A2 correlated more highly in male than female individuals, while UGT1A4/1A6 protein correlated more significantly in female than male individuals. This is the first report on the ontogeny of UGT3A isoforms, showing maximal expression in the elderly, and is the first demonstration that UGT isoforms commonly coexpress in vivo, in both age-dependent and sex-dependent manners.

The Effects of a Multi-Ingredient Performance Supplement Combined with Resistance Training on Exercise Volume, Muscular Strength, and Body Composition.

The effects of a multi-ingredient performance supplement (MIPS) incorporating a mixture of branched chain amino acids, beta-alanine, glutamine, creatine, and piperine on resistance training (RT)-induced adaptations remains unclear. Therefore, the purpose of this study was to investigate the effects of this investigational MIPS during six weeks of RT on performance and body composition. Thirty recreationally trained males and females were recruited for this pair-matched, double-blind, placebo-controlled investigation. Subjects were assigned to consume either an experimental MIPS (MIPS) (n = 15) or a placebo (PLA) (n = 15) concurrently with a six-week periodized RT program. Body composition, one-repetition maximum (1RM), and muscular power were assessed at pre- and post-training. Weekly relative volume load was compared between groups. The MIPS and PLA groups demonstrated a significant increase in total body mass (MIPS = +2.9 ± 1.3%; PLA = +2.5 ± 1.7%) and lean mass (MIPS = +5.0 ± 2.1%; PLA = +3.1 ± 1.9%) (p < 0.001) with no changes in fat mass. There were no group × time interactions for any of the body composition measures. Both groups demonstrated similar improvements in maximum strength for the back squat, bench press, and deadlift as well as lower body power from pre- to post-training (p < 0.001). Within the limitations of the current investigation, results failed to demonstrate the benefits of the experimental MIPS for muscular strength and body composition across six weeks of RT compared to PLA.

Modified Pluronic F127 Surface for Bioconjugation and Blocking Nonspecific Adsorption of Microspheres and Biomacromolecules.

Many experiments and applications require the chemical coupling of target molecules to surfaces, during which the elimination of nonspecific interactions presents a difficult challenge. We report on a technologically accessible surface passivation and chemical conjugation method based on an NHS end-labeled F127 Pluronic block copolymer (F127-NHS). To quantify interactions between the F127-NHS surface and magnetic microspheres, we developed a simple assay: the microsphere adhesion by gravity, inversion, then counting, or "MAGIC" assay. To improve blocking of microspheres while maintaining the ability to chemically couple additional molecules, we implemented a pH-dependent two-step chemical modification process for amine microspheres. This process achieves an extremely high level of blocking nonspecific interactions (less than 2% nonspecific adhesion) for a variety of microsphere surface charges and chemical functionalities. We also demonstrate the ability to specifically tether magnetic microspheres to an F127-NHS surface, using single DNA molecules. Using the DNA microspheres, we establish the applicability of the surface for force spectroscopy (stable with an applied load >30 pN) via the massively parallel technique of centrifuge force microscopy. Finally, we demonstrate that the surface can be used in fluorescence studies with a fluorogenic peptide cleavage assay, with high levels of blocking achieved for both the fluorogenic peptide and trypsin. These results suggest applications including, but not limited to, single-molecule force spectroscopy and fluorescence, biosensors, medical implants, and anti-biofouling, which could make use of the F127-NHS surface.

Plant uptake and availability of antimony, lead, copper and zinc in oxic and reduced shooting range soil.

Shooting ranges polluted by antimony (Sb), lead (Pb), copper (Cu) and zinc (Zn) are used for animal grazing, thus pose a risk of contaminants entering the food chain. Many of these sites are subject to waterlogging of poorly drained soils. Using field lysimeter experiments, we compared Sb, Pb, Cu and Zn uptake by four common pasture plant species (Lolium perenne, Trifolium repens, Plantago lanceolata and Rumex obtusifolius) growing on a calcareous shooting range soil under waterlogged and drained conditions. To monitor seasonal trends, the same plants were collected at three times over the growing season. Additionally, variations in soil solution concentrations were monitored at three depths over the experiment. Under reducing conditions, soluble Sb concentrations dropped from ∼50 µg L-1 to ∼10 µg L-1, which was attributed to the reduction of Sb(V) to Sb(III) and the higher retention of the trivalent species by the soil matrix. Shoot Sb concentrations differed by a factor of 60 between plant species, but remained at levels <0.3 µg g-1. Despite the difference in soil solution concentrations between treatments, total Sb accumulation in shoots for plants collected on the waterlogged soil did not change, suggesting that Sb(III) was much more available for plant uptake than Sb(V), as only 10% of the total Sb was present as Sb(III). In contrast to Sb, Pb, Cu and Zn soil solution concentrations remained unaffected by waterlogging, and shoot concentrations were significantly higher in the drained treatment for many plant species. Although showing an increasing trend over the season, shoot metal concentrations generally remained below regulatory values for fodder plants (40 µg g-1 Pb, 150 µg g-1 Zn, 15-35 µg g-1 Cu), indicating a low risk of contaminant transfer into the food chain under both oxic and anoxic conditions for the type of shooting range soil investigated in this study.

Single-Molecule Assay for Proteolytic Susceptibility: Force-Induced Collagen Destabilization.

Force plays a key role in regulating dynamics of biomolecular structure and interactions, yet techniques are lacking to manipulate and continuously read out this response with high throughput. We present an enzymatic assay for force-dependent accessibility of structure that makes use of a wireless mini-radio centrifuge force microscope to provide a real-time readout of kinetics. The microscope is designed for ease of use, fits in a standard centrifuge bucket, and offers high-throughput, video-rate readout of individual proteolytic cleavage events. Proteolysis measurements on thousands of tethered collagen molecules show a load-enhanced trypsin sensitivity, indicating destabilization of the triple helix.