ABSTRACT
Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the ...effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS‐internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent‐resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome‐like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS‐exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.—Clunes, L. A., Davies, C. M., Coakley, R. D., Aleksandrov, A. A., Henderson, A. G., Zeman, K. L., Worthington, E. N., Gentzsch, M., Kreda, S. M., Cholon, D., Bennett, W. D., Riordan, J. R., Boucher, R. C., Tarran, R. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration. FASEB J. 26, 533–545 (2012). www.fasebj.org
The role of natural polyphenols in reducing oxidative stress and/or supporting antioxidant mechanisms, particularly relating to exercise, is of high interest. The aim of this study was to investigate ...OliPhenolia® (OliP), a biodynamic and organic olive fruit water phytocomplex, rich in hydroxytyrosol (HT), for the first time within an exercise domain. HT bioavailability from OliP was assessed in fifteen healthy volunteers in a randomized, double-blind, placebo controlled cross-over design (age: 30 ± 2 yrs; body mass: 76.7 ± 3.9 kg; height: 1.77 ± 0.02 m), followed by a separate randomized, double-blinded, cohort trial investigating the short-term impact of OliP consumption (2 × 28 mL∙d−1 of OliP or placebo (PL) for 16-days) on markers of oxidative stress in twenty-nine recreationally active participants (42 ± 2 yrs; 71.1 ± 2.1 kg; 1.76 ± 0.02 m). In response to a single 28 mL OliP bolus, plasma HT peaked at 1 h (38.31 ± 4.76 ng∙mL−1), remaining significantly elevated (p < 0.001) until 4 h. Plasma malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and HT were assessed at rest and immediately following exercise (50 min at ~75% V˙O2max then 10 min intermittent efforts) and at 1 and 24 h post-exercise, before and after the 16-day supplementation protocol. Plasma HT under resting conditions was not detected pre-intervention, but increased to 6.3 ± 1.6 ng·mL−1 following OliP only (p < 0.001). OliP demonstrated modest antioxidant effects based on reduced SOD activity post-exercise (p = 0.016) and at 24 h (p ≤ 0.046), and increased GSH immediately post-exercise (p = 0.009) compared with PL. No differences were reported for MDA and CAT activity in response to the exercise protocol between conditions. The phenolic compounds within OliP, including HT, may have specific antioxidant benefits supporting acute exercise recovery. Further research is warranted to explore the impact of OliP following longer-term exercise training, and clinical domains pertinent to reduced oxidative stress.
The incorporation of ammonia inside methane clathrate hydrate is of great interest to the hydrate chemistry community. We investigated the phase behavior of methane clathrate formed from aqueous ...ammonia solution. Ammonia's presence decreases methane occupancy in the large cages, without definitive Raman spectroscopic evidence for its incorporation inside the structure.
This study investigated the effect of decaffeinated green tea extract (dGTE), with or without antioxidant nutrients, on fat oxidation, body composition and cardio-metabolic health measures in ...overweight individuals engaged in regular exercise. Twenty-seven participants (20 females, 7 males; body mass: 77.5 ± 10.5 kg; body mass index: 27.4 ± 3.0 kg·m
; peak oxygen uptake (O
): 30.2 ± 5.8 mL·kg
·min
) were randomly assigned, in a double-blinded manner, either: dGTE (400 mg·d
(-)-epigallocatechin-3-gallate (EGCG),
= 9); a novel dGTE+ (400 mg·d
EGCG, quercetin (50 mg·d
) and α-lipoic acid (LA, 150 mg·d
),
= 9); or placebo (PL,
= 9) for 8 weeks, whilst maintaining standardised, aerobic exercise. Fat oxidation ('FAT
' and steady state exercise protocols), body composition, cardio-metabolic and blood measures (serum glucose, insulin, leptin, adiponectin, glycerol, free fatty acids, total cholesterol, high HDL-c and low-density lipoprotein cholesterol LDL-c, triglycerides, liver enzymes and bilirubin) were assessed at baseline, week 4 and 8. Following 8 weeks of dGTE+, maximal fat oxidation (MFO) significantly improved from 154.4 ± 20.6 to 224.6 ± 23.2 mg·min
(
= 0.009), along with a 22.5% increase in the exercise intensity at which fat oxidation was deemed negligible (FAT
; 67.6 ± 3.6%O
,
= 0.003). Steady state exercise substrate utilisation also improved for dGTE+ only, with respiratory exchange ratio reducing from 0.94 ± 0.01 at week 4, to 0.89 ± 0.01 at week 8 (
= 0.004). This corresponded with a significant increase in the contribution of fat to energy expenditure for dGTE+ from 21.0 ± 4.1% at week 4, to 34.6 ± 4.7% at week 8 (
= 0.006). LDL-c was also lower (normalised fold change of -0.09 ± 0.06) for dGTE+ by week 8 (
= 0.038). No other significant effects were found in any group. Eight weeks of dGTE+ improved MFO and substrate utilisation during exercise, and lowered LDL-c. However, body composition and cardio-metabolic markers in healthy, overweight individuals who maintained regular physical activity were largely unaffected by dGTE.
The surface temperature of an active lava flow is an important physical property to measure. Through its influence on lava crystallinity, cooling exerts a fundamental control on lava rheology. ...Remotely sensed thermal radiance data acquired by multispectral sensors such as Landsat Thematic Mapper and the Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer are of insufficient spectral and radiometric fidelity to allow for realistic determination of lava surface temperatures from Earth orbit. This paper presents results obtained from the analysis of active lava flows using hyperspectral data acquired by NASA's Earth Observing‐1 Hyperion imaging spectrometer. The contiguous nature of the measured radiance spectrum in the 0.4–2.5 μm region means that, although sensor saturation most certainly occurs, unsaturated radiance data are always available from even the hottest, and most radiant, active lava flow surfaces. The increased number of wave bands available allows for the assumption of more complex flow surface temperature distributions in the radiance‐to‐temperature inversion processes. The technique is illustrated by using a hyperspectral image of the active lava lake at Erta Ale volcano, Ethiopia, a well‐characterized calibration target, a time series of three Hyperion images of an active lava flow acquired during a 4 day period at Mount Etna, Sicily, as well as a lava flow erupted at Nyamuragira, Democratic Republic of Congo. The results provide insights into the temperature–radiance mixture modeling problem that will aid in the analysis of data acquired by future hyperspectral remote sensing missions, such as NASA's proposed HyspIRI mission.
The masses, atmospheric makeups, spin-orbit alignments, and system architectures of extrasolar planets can be best studied when the planets orbit bright stars. We report the discovery of three bodies ...orbiting HD 106315, a bright (V = 8.97 mag) F5 dwarf targeted by our K2 survey for transiting exoplanets. Two small transiting planets are found to have radii and and orbital periods 9.55 days and 21.06 days, respectively. A radial velocity (RV) trend of 0.3 0.1 m s−1 day−1 indicates the likely presence of a third body orbiting HD 106315 with period 160 days and mass 45 M⊕. Transits of this object would have depths 0.1% and are definitively ruled out. Although the star has v sin i = 13.2 km s−1, it exhibits a short-timescale RV variability of just 6.4 m s−1. Thus, it is a good target for RV measurements of the mass and density of the inner two planets and the outer object's orbit and mass. Furthermore, the combination of RV noise and moderate v sin i makes HD 106315 a valuable laboratory for studying the spin-orbit alignment of small planets through the Rossiter-McLaughlin effect. Space-based atmospheric characterization of the two transiting planets via transit and eclipse spectroscopy should also be feasible. This discovery demonstrates again the power of K2 to find compelling exoplanets worthy of future study.
Titan, Saturn’s largest satellite, is the only icy moon with a dense atmosphere that is composed mainly of N2. Methane, the second most abundant constituent, would be depleted in only 30–100 million ...years by active photochemistry, suggesting replenishment from Titan’s interior. Under Titan’s near-surface conditions, clathrate hydrates are the stable form of methane and ice together, making them a likely methane reservoir. Cassini–Huygens observations suggest that ammonia is the main source of Titan’s atmospheric N2. Ammonia is known to decrease the melting point of water ice and some clathrate hydrates, such as those of tetrahydrofuran. The present study investigates the interaction of ammonia with cyclopentane clathrate hydrates (atmospheric analogue for methane clathrates) via a detailed examination of phase behavior using micro-Raman spectroscopy, differential scanning calorimetry, and X-ray diffraction. The results show that ammonia has the same effect on the stability of the cyclopentane clathrate as on tetrahydrofuran clathrate and ice by lowering the dissociation temperature by several tens of degrees and inducing incongruent melting. Ammonia does not interact directly with cyclopentane and does not appear to be incorporated into the cyclopentane clathrate structure, whether in the lattice or within the cages. A similar effect could be expected for methane clathrates. The presence of ammonia in Titan’s crust would thus destabilize methane clathrates, resulting in outgassing and replenishment of atmospheric methane.
Understanding the characteristics of volcanic thermal emissions and how they change with time is important for forecasting and monitoring volcanic activity and potential hazards. Satellite ...instruments view volcanic thermal features across the globe at various temporal and spatial resolutions. Thermal features that may be a precursor to a major eruption, or indicative of important changes in an on-going eruption can be subtle, making them challenging to reliably identify with satellite instruments. The goal of this study was to explore the limits of the types and magnitudes of thermal anomalies that could be detected using satellite thermal infrared (TIR) data. Specifically, the characterization of sub-pixel thermal features with a wide range of temperatures is considered using ASTER multispectral TIR data. First, theoretical calculations were made to define a “thermal mixing detection threshold” for ASTER, which quantifies the limits of ASTER's ability to resolve sub-pixel thermal mixing over a range of hot target temperatures and % pixel areas. Then, ASTER TIR data were used to model sub-pixel thermal features at the Yellowstone National Park geothermal area (hot spring pools with temperatures from 40 to 90
°C) and at Mount Erebus Volcano, Antarctica (an active lava lake with temperatures from 200 to 800
°C). Finally, various sources of uncertainty in sub-pixel thermal calculations were quantified for these empirical measurements, including pixel resampling, atmospheric correction, and background temperature and emissivity assumptions.
The Jovian InfraRed Auroral Mapper (JIRAM) on board the NASA Juno spacecraft is a dual-band imager and spectrometer, primarily designed to study the Jovian atmosphere and aurorae. In addition to its ...primary goal, JIRAM has been used to obtain images and spectra of the Galilean satellites, Jupiter's largest moons, when the spacecraft attitude was favourable to achieve this goal. Here we present JIRAM's first images and spectra of Io. These observations are used to characterize the location and possible morphology, and some temperatures, of Io's volcanic thermal sources; the identification of SO2 and the possible identification of other materials. A new hot spot/volcano is identified close to the South Pole of Io, and others are seen in lower latitude regions, which were previously unmapped. Images of the same region taken 2 months apart also show variations of hot spot intensity, possibly due to new lava flows or to lava flow breakouts.
•Juno's JIRAM investigation reveals new volcanic hot spots.•Identification of spectral signatures in the dayside-averaged I/F•Thermal characterization of Io's hot spots
PDF
