Epidemiological studies have linked exposures to ambient fine particulate matter (PM
) and traffic with autonomic nervous system imbalance (ANS) and cardiac pathophysiology, especially in individuals ...with preexisting disease. It is unclear whether metabolic syndrome (MetS) increases susceptibility to the effects of PM
. We hypothesized that exposure to traffic-derived primary and secondary organic aerosols (P + SOA) at ambient levels would cause autonomic and cardiovascular dysfunction in rats exhibiting features of MetS. Male Sprague Dawley (SD) rats were fed a high-fructose diet (HFrD) to induce MetS, and exposed to P + SOA (20.4 ± 0.9 μg/m
) for 12 days with time-matched comparison to filtered-air (FA) exposed MetS rats; normal diet (ND) SD rats were separately exposed to FA or P + SOA (56.3 ± 1.2 μg/m
).
In MetS rats, P + SOA exposure decreased HRV, QTc, PR, and expiratory time overall (mean effect across the entirety of exposure), increased breathing rate overall, decreased baroreflex sensitivity (BRS) on three exposure days, and increased spontaneous atrioventricular (AV) block Mobitz Type II arrhythmia on exposure day 4 relative to FA-exposed animals receiving the same diet. Among ND rats, P + SOA decreased HRV only on day 1 and did not significantly alter BRS despite overall hypertensive responses relative to FA. Correlations between HRV, ECG, BRS, and breathing parameters suggested a role for autonomic imbalance in the pathophysiologic effects of P + SOA among MetS rats. Autonomic cardiovascular responses to P + SOA at ambient PM
levels were pronounced among MetS rats and indicated blunted vagal influence over cardiovascular physiology.
Results support epidemiologic findings that MetS increases susceptibility to the adverse cardiac effects of ambient-level PM
, potentially through ANS imbalance.
This study aimed to assess the effect of exposure to organic pollutants in adults with chronic kidney disease (CKD).
This was a cross-sectional and longitudinal analysis.
Forty adults enrolled in the ...Chronic Renal Insufficiency Cohort (CRIC).
Exposure at baseline and longitudinally to various organic chemical pollutants.
The outcomes were as follows: death; composite of congestive heart failure, myocardial infarction, and stroke; event-free survival from kidney failure or ≥50% decline in estimated glomerular filtration rate (eGFR); and longitudinal trajectory of eGFR.
We used high-performance liquid chromatography with tandem mass spectrometry to measure urinary concentrations of bisphenols, phthalates, organophosphate pesticides, polycyclic aromatic hydrocarbons, melamine, and cyanuric acid at years 1, 3, and 5 after enrollment in the CRIC. Univariate and multivariable logistic regression were used to examine the association of individual compounds and classes of pollutants with the outcomes. The Cox proportional hazards model and Kaplan-Meier method were used to calculate hazard ratios and 95% CIs for each class of pollutants.
Median baseline eGFR and urinary protein-to-creatinine ratio were 33 mL/min/1.73 m2 and 0.58 mg/g, respectively. Of 52 compounds assayed, 30 were detectable in ≥50% of participants. Urinary chemical concentrations were comparable in patients with CKD and healthy individuals from contemporaneous National Health and Nutrition Examination Survey cohorts. Phthalates were the only class with a trend toward higher exposure in patients with CKD. There was an inverse relationship between exposure and the eGFR slopes for bisphenol F, mono-(3-carboxypropyl) phthalate, mono-benzyl phthalate, mono-2-(carboxymethyl)hexyl phthalate, and melamine. There were no associations between organic pollutant exposure and cardiovascular outcomes.
Small sample size, evaluation of single rather than combined exposures.
Simultaneous measurement of multiple organic pollutants in adults with CKD is feasible. Exposure levels are comparable with healthy individuals. Select contaminants, especially in the phthalate class, may be associated with more rapid deterioration in kidney function.
The effect of exposure to organic pollutants has not been studied in adults with chronic kidney disease. (CKD). To fill this gap, we measured the exposure to a wide range of chemicals that are found in plastics, personal care products, and food preparation. Overall, the exposure was similar to that noted in the healthy population living in the United States. Only select compounds, mainly phthalates, demonstrated a trend with a more rapid decline in kidney function. These findings provide a useful reference for future studies that aim to evaluate organic pollutant exposure in patients with CKD. This is significant because these exposures represent a modifiable risk factor for disease progression through alterations in diet or lifestyle.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
There is an emerging understanding that coronavirus disease 2019 (COVID-19) is associated with increased incidence of pneumomediastinum. We aimed to determine its incidence among patients ...hospitalised with COVID-19 in the United Kingdom and describe factors associated with outcome.
A structured survey of pneumomediastinum and its incidence was conducted from September 2020 to February 2021. United Kingdom-wide participation was solicited
respiratory research networks. Identified patients had SARS-CoV-2 infection and radiologically proven pneumomediastinum. The primary outcomes were to determine incidence of pneumomediastinum in COVID-19 and to investigate risk factors associated with patient mortality.
377 cases of pneumomediastinum in COVID-19 were identified from 58 484 inpatients with COVID-19 at 53 hospitals during the study period, giving an incidence of 0.64%. Overall 120-day mortality in COVID-19 pneumomediastinum was 195/377 (51.7%). Pneumomediastinum in COVID-19 was associated with high rates of mechanical ventilation. 172/377 patients (45.6%) were mechanically ventilated at the point of diagnosis. Mechanical ventilation was the most important predictor of mortality in COVID-19 pneumomediastinum at the time of diagnosis and thereafter (p<0.001) along with increasing age (p<0.01) and diabetes mellitus (p=0.08). Switching patients from continuous positive airways pressure support to oxygen or high flow nasal oxygen after the diagnosis of pneumomediastinum was not associated with difference in mortality.
Pneumomediastinum appears to be a marker of severe COVID-19 pneumonitis. The majority of patients in whom pneumomediastinum was identified had not been mechanically ventilated at the point of diagnosis.
The Antarctic plateau contains the best sites on earth for many forms of astronomy, but none of the existing bases was selected with astronomy as the primary motivation. In this article, we try to ...systematically compare the merits of potential observatory sites. We include South Pole, Domes A, C, and F, and also Ridge B (running northeast from Dome A), and what we call “Ridge A” (running southwest from Dome A). Our analysis combines satellite data, published results, and atmospheric models, to compare the boundary layer, weather, aurorae, airglow, precipitable water vapor, thermal sky emission, surface temperature, and the free atmosphere, at each site. We find that all Antarctic sites are likely to be compromised for optical work by airglow and aurorae. Of the sites with existing bases, Dome A is easily the best overall; but we find that Ridge A offers an even better site. We also find that Dome F is a remarkably good site. Dome C is less good as a thermal infrared or terahertz site, but would be able to take advantage of a predicted “OH hole” over Antarctica during spring.
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BFBNIB, NMLJ, NUK, PNG, UL, UM, UPUK
It has been hypothesized that vegetation phenology may play an important role for the midlatitude climate. This study investigates the impact of interannual and intraseasonal variations in phenology ...on European climate using regional climate model simulations. In addition, it assesses the relative importance of interannual variations in vegetation phenology and soil moisture on European summer climate.
It is found that drastic phenological changes have a smaller effect on mean summer and spring climate than extreme changes in soil moisture (roughly ¼ of the temperature anomaly induced by soil moisture changes). However, the impact of phenological anomalies during heat waves is found to be more important. Generally, late and weak greening has amplifying effects and early and strong greening has dampening effects on heat waves; however, regional variations are found. The experiments suggest that in the extreme hot 2003 (western and central Europe) and 2007 (southeastern Europe) summers the decrease in leaf area index amplified the heat wave peaks by about 0.5°C for daily maximum temperatures (about half of the effect induced by soil moisture deficit). In contrast to earlier hypotheses, no anomalous early greening in spring 2003 is seen in the phenological dataset employed here. Hence, the results indicate that vegetation feedbacks amplified the 2003 heat wave but were not responsible for its initiation. In conclusion, the results suggest that phenology has a limited effect on European mean summer climate, but its impact can be as important as that induced by soil moisture anomalies in the context of specific extreme events.
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BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
: Striking a balance between maximizing performance and preventing injury remains elusive in many professional sports. The purpose of this study was to assess the relative risk of non-contact ...injuries in professional basketball players based on predictive cut scores on the Functional Movement Screen™ (FMS).
: Thirty-two professional basketball players from the National Basketball Association (NBA) and Women's National Basketball Association (WNBA) participated in this study. This observational pilot cohort study assessed and scored each participant using the FMS during training camp. Each athlete was then tracked throughout the season while recording the number, type, and time lost due to injuries. Possible exposures, actual exposures, and exposures missed due to non-contact injury (NCI) for each athlete were calculated and then used to determine the crude and specific incident rates for exposures missed due to NCI per 1000 exposures.
: Linear regression models were used to evaluate the predictive ability of the FMS score for total missed exposures, NCI, and CI missed exposures. In all models, the FMS total score failed to attain significance as a predictor (
> 0.05). FMS scores ranged from 5 to 18. The recommended cut score of 14 showed a sensitivity of 0.474 and a specificity of 0.750. The cut score of 15 showed the best combination, exhibiting a sensitivity of 0.579 and specificity of 0.625. A total of 5784 exposures to NCI were possible for the men and women combined, and 681 possible exposures were missed. Of these, 23.5% were due to NCI, 16.5% were due to contact injuries (CI), and 60% were due to illnesses and personal reasons.
: The FMS proved to be a measure that was not associated with any injury measure in this sample of professional basketball players, suggesting the instrument lacks predictive validity in this population.
To evaluate the association between maternal blood pressure (BP) below 130/80 mm Hg compared with 130-139/80-89 mm Hg and pregnancy outcomes.
We conducted a planned secondary analysis of CHAP ...(Chronic Hypertension and Pregnancy), an open label, multicenter, randomized controlled trial. Participants with mean BP below 140/90 mm Hg were grouped as below 130/80 mm Hg compared with 130-139/80-89 mm Hg by averaging postrandomization clinic BP throughout pregnancy. The primary composite outcome was preeclampsia with severe features, indicated preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The secondary outcome was small for gestational age (SGA).
Of 2,408 patients in CHAP, 2,096 met study criteria; 1,328 had mean BP 130-139/80-89 mm Hg and 768 had mean BP below 130/80 mm Hg. Participants with mean BP below 130/80 mm Hg were more likely to be older, on antihypertensive medication, in the active treatment arm, and to have lower BP at enrollment. Mean clinic BP below 130/80 mm Hg was associated with lower frequency of the primary outcome (16.0% vs 35.8%, adjusted relative risk 0.45; 95% CI 0.38-0.54) as well as lower risk of severe preeclampsia and indicated birth before 35 weeks of gestation. There was no association with SGA.
In pregnant patients with mild chronic hypertension, mean BP below 130/80 mm Hg was associated with improved pregnancy outcomes without increased risk of SGA.
ClinicalTrials.gov , NCT02299414.
The severity of Clostridium difficile-associated infection depends on the virulence factors of the organism and host factors, including intestinal barrier function. The intestinal mucus layer has ...recently been recognized as the first line of defense against enteric pathogens. Its interaction with mucosal humoral immunity provided by secretory immunoglobulin A (SIgA) is unknown as it relates to C. difficile disease severity. This was studied in vitro.
Confluent HT29 (non-mucus-producing) and HT29-MTX (mucus-producing) intestinal epithelial cells (IECs) with and without transcytosed SIgA were exposed to C. difficile toxin A (6 hours), and IEC toxin internalization, permeability (fluorescein isothiocyanate dextran), and necrosis (propidium iodide staining) were determined. In other experiments, colostral SIgA was added to the apical surface of IEC, and cleavage was determined by measurement of intact SIgA and secretory component fractions by enzyme-linked immunosorbent assay. Tumor necrosis factor α and interleukin 6 were measured from basal chamber culture supernatants by enzyme-linked immunosorbent assay.
Toxin A uptake and subsequent enterotoxic effects on IEC were decreased by both the mucus layer and SIgA. Similar findings were noted with the effects of toxin A on IEC monolayer permeability, cytoskeleton changes, and proinflammatory cytokine release. The combination of the mucus layer and SIgA afforded the best protection against the adverse effects on IEC by toxin A. It seems that the mucus layer was also protective against SIgA cleavage, resulting in reduced protease activity by HT29 cells exposed to toxin A.
Both intestinal mucus and SIgA were important in limiting C. difficile-associated disease severity in this model. A synergistic effect of mucus and IgA was also noted and may be due to protection of SIgA from proteolytic cleavage.
Obesity is a chronic low-grade inflammatory condition associated with the elaboration of proinflammatory cytokines and adipokines from adipose tissue. Gender dimorphism (in part due to sex hormones) ...has been identified after injury and hemorrhagic shock. We hypothesized that the sex hormones estrogen (E2) and testosterone (DHT) have disparate effects on inflammatory mediator production from adipose tissue under stress conditions. This was studied in an in vitro model.
Mature adipocytes differentiated from adipose-derived stem cells were cocultured (2:1) with macrophages (RAW 264.7) and subjected to hypoxia/reoxygenation (H/R) and/or incubation with physiologic (10 μM) or stress (10 μM) concentrations of epinephrine (epi). Estrogen or DHT was added in a range of physiologic concentrations, and culture supernatants were obtained 12 hours after incubation, and tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and adiponectin levels were measured by enzyme-linked immunosorbent assay.
Basal TNF-α and IL-6 release from cocultures was significantly increased in response to epi and/or H/R conditions. Estrogen decreased cytokine release to basal levels, whereas DHT had no effect. Of note, varying the concentration of epi had no effect on cytokine release. Basal levels of adiponectin release were significantly decreased in response to epi and/or H/R conditions. Estrogen exposure returned adiponectin levels to basal levels, whereas DHT had no effect. The inverse of this relationship was observed in regard to the sex hormones effect on leptin release. Estrogen returned leptin release to basal levels, whereas DHT had no effect.
Stress levels of epi and H/R increased proinflammatory cytokine production and decreased adiponectin levels in adipocyte cocultures. Estrogen at physiologic concentrations decreased TNF-α, IL-6, and preserved adiponectin levels following epi and/or H/R conditions. There was no effect of DHT on mitigating the proinflammatory response. Our results suggest a gender dimorphism in adipose tissue under stress conditions that may explain the conflicting data in the literature.
Single-site supported organometallic catalysts bring together the favorable aspects of homogeneous and heterogeneous catalysis while offering opportunities to investigate the impact of metal–support ...interactions on reactivity. We report a ( dm Phebox)Ir(III) ( dm Phebox = 2,6-bis(4,4-dimethyloxazolinyl)-3,5-dimethylphenyl) complex chemisorbed on sulfated zirconia, the molecular precursor for which was previously applied to hydrocarbon functionalization. Spectroscopic methods such as diffuse reflectance infrared Fourier transformation spectroscopy (DRIFTS), dynamic nuclear polarization (DNP)-enhanced solid-state nuclear magnetic resonance (SSNMR) spectroscopy, and X-ray absorption spectroscopy (XAS) were used to characterize the supported species. Tetrabutylammonium acetate was found to remove the organometallic species from the surface, enabling solution-phase analytical techniques in conjunction with traditional surface methods. Cationic character was imparted to the iridium center by its grafting onto sulfated zirconia, imbuing high levels of activity in electrophilic C–H bond functionalization reactions such as the stoichiometric dehydrogenation of alkanes, with density functional theory (DFT) calculations showing a lower barrier for β-H elimination. Catalytic hydrogenation of olefins was also facilitated by the sulfated zirconia-supported ( dm Phebox)Ir(III) complex, while the homologous complex on silica was inactive under comparable conditions.
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IJS, KILJ, NUK, PNG, UL, UM
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