232 research outputs found

    Extra-fine particles improve lung delivery of inhaled steroids in infants: a study in an upper airway model

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    BACKGROUND: The particles of a new hydrofluoroalkane-134a (HFA)-beclomethasone dipropionate (BDP) metered-dose inhaler (Qvar; 3M Pharmaceuticals; St. Paul, MN) are considerably smaller than those of chlorofluorocarbon (CFC)-BDP. This may improve lung deposition in infants who inhale nasally and have irregular breathing patterns and small airways. Aim: To compare the dose delivered to the lungs of HFA-BDP and CFC-BDP at different breathing patterns using an upper airway model of an infant. METHODS: An anatomically correct upper airway model of a 9-month-old child with an open nasal airway was connected to an impactor and breathing simulator. HFA-BDP, 100 microg, and CFC-BDP, 100 micro g, were delivered to the model through a detergent-coated, small-volume spacer. The total dose leaving the model (lung dose), its particle size distribution, and median mass aerodynamic diameter (MMAD) were assessed during simulated tidal breathing with tidal volumes (VTs) of 50 mL, 100 mL, and 200 mL, and 30 breaths/min. Dose was expressed as percentage of nominal dose. RESULTS: Lung doses for HFA-BDP were 25.4%, 26.5%, and 30.7% compared with 6.8%, 4.8%, and 2.1% for CFC-BDP at VTs of 50 mL, 100 mL, and 200 mL, respectively. The dose of particles < 2.1 microm to the lung for HFA-BDP was 23 to 28% compared with 0.6 to 0.8% for CFC-BDP. The lung dose of CFC-BDP mainly consisted of particles between 2.1 microm and 4.7 microm. MMAD for HFA-BDP was 1.2 microm, and 2.6 to 3.3 microm for CFC-BDP depending on VT. The lung dose for CFC-BDP decreased significantly with increasing VT. HFA-BDP lung dose did not alter significantly with VT. CONCLUSIONS: In this infant model study, the use of HFA-BDP with a high dose of particles < 2.1 microm improves the dose delivered to the lungs substantially. Furthermore, the large proportion of extra-fine particles in HFA-BDP results in lung doses less dependent on breathing pattern compared with CFC-BDP

    An in vivo magnetic resonance spectroscopy study of the effects of caloric and non-caloric sweeteners on liver lipid metabolism in rats

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    We aimed to elucidate the effects of caloric and non-caloric sweeteners on liver lipid metabolism in rats using in vivo magnetic resonance spectroscopy (MRS) and to determine their roles in the development of liver steatosis. Wistar rats received normal chow and either normal drinking water, or solutions containing 13% (w/v) glucose, 13% fructose, or 0.4% aspartame. After 7 weeks, in vivo hepatic dietary lipid uptake and de novo lipogenesis were assessed with proton-observed, carbon-13-edited MRS combined with13C-labeled lipids and13C-labeled glucose, respectively. The molecular basis of alterations in hepatic liver metabolism was analyzed in detail ex vivo using immunoblotting and targeted quantitative proteomics. Both glucose and fructose feeding increased adiposity, but only fructose induced hepatic lipid accumulation. In vivo MRS showed that this was not caused by increased hepatic uptake of dietary lipids, but could be attributed to an increase in de novo lipogenesis. Stimulation of lipogenesis by fructose was confirmed by a strong upregulation of lipogenic enzymes, which was more potent than with glucose. The non-caloric sweetener aspartame did not significantly affect liver lipid content or metabolism. In conclusion, liquid fructose more severely affected liver lipid metabolism in rats than glucose, while aspartame had no effect.</p

    Variability of aerosol delivery via spacer devices in young asthmatic children in daily life

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    Pressurized metered dose inhalers (pMDI) are widely used together with spacers for the treatment of asthma in children. However, the variability of daily medication dose for pMDI/spacer combinations is not known. Electrostatic charge is a potential source of dose variability. Metal spacers have no static charge. This study assessed and compared within-subject variability of aerosol delivery of metal and plastic spacers. This was a randomized, crossover study in children with stable asthma aged 1-4 (group I, n=17) and 5-8 (group II, n=16) yrs. In both groups the amount of drug delivered to the mouth by a metal spacer (Nebuchamber) and one of two plastic (polycarbonate) spacers, i.e. Babyhaler in group I and Volumatic in group II was measured. The metal and plastic spacers were tested at home in a randomized order for 7 days each, using budesonide (200 microg b.i.d.). Aerosol was collected on a filter positioned between spacer and facemask or mouth. Budesonide on the filter was assessed by high performance liquid chromatography. The mean filter dose for each child (mean+/-SD) during the 7 days was expressed as a percentage of the nominal dose. Within-subject variability was expressed as coefficient of variation (CV). Mean filter dose in group I was 41.7+/-10.1% for Nebuchamber and 26.0+/-4.0% for Babyhaler (p<0.001). Mean filter dose in group II was 50.2+/-9.2% for Nebuchamber and 19.4+/-7.2% for Volumatic (p<0.001). Mean CV in group I was 34% for Nebuchamber and 37% for Babyhaler (p=0.44). Mean CV in group II was 23% for Nebuchamber and 34% for Volumatic (p=0.003). There was substantial within-subject dose variability in aerosol delivery in children using a pMDI/spacer at home. This variability was lower for the metal than for the plastic spacer in children 5-8 yrs of age. The dose delivered to the mouth was about two-fold higher fo

    Aerosol delivery from spacers in wheezy infants: a daily life study

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    The aims of this study were to assess and compare dose delivery and dose variability of pressurized metered dose inhalers (pMDI)/spacers in wheezy infants in daily life and to investigate factors influencing aerosol delivery. In an open randomized crossover study in 25 wheezy infants aged 5-26 months, a metal spacer (Nebuchamber), a detergent coated (DC) and a non-detergent coated (nonDC) plastic spacer (Babyhaler) were tested at home for 7 days each. Budesonide (200 microg b.i.d) was administered via a Nebuchamber or fluticasone (125 microg b.i.d) via a Babyhaler. Aerosol was trapped in filters, positioned between the spacer and face mask. Cooperation was scored on diary cards. Electrostatic charge (ESC) of the spacers was measured. Evaluations of the administration technique were made from video recordings. Median (range) dose delivery of the filters expressed as per cent (%) of nominal dose, was 34% (3-59), 23% (1-49), and 41% (12-55) for the Nebuchamber, nonDC-Babyhaler, and DC-Babyhaler respectively. Considerable dose variability was found, median (range) within-subject dose variability, expressed as coefficient of variation, for the Nebuchamber (49% (15-249)) was significantly higher when compared with both nonDC- (36% (12-325)) and DC-Babyhalers (27% (10-122)), for which dose variabilities were similar. Detergent coating was effective to reduce electrostatic

    Brand and generic use of inhalation medication and frequency of switching in children and adults: A population-based cohort study

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    Background: The expiration of patents of brand inhalation medications and the ongoing pressure on healthcare budgets resulted in a growing market for generics. Aim: To study the use of brand and generic inhalation medication and the frequency of switching between brand and generic and between devices. In addition, we investigated whether switching affected adherence. Methods: From dispensing data from the Dutch PHARMO Database Network a cohort aged ≥ 5 years, using ≥ 1 year of inhalation medication between 2003 and 2012 was selected. Switching was defined as changing from brand to generic or vice versa. In addition, we studied change in aerosol delivery device type (e.g., DPI, pMDI, and nebulizers). Adherence was calculated using the medication possession ratio (MPR). Results: The total cohort comprised 70,053 patients with 1,604,488 dispensations. Per calendar year, 5% switched between brand and generic inhalation medication and 5% switched between devices. Median MPRs over the first 12 months ranged between 33 and 55%. Median MPR over the total period was lower after switch from brand to generic and vice versa for formoterol (44.5 vs. 42.1 and 63.5 vs. 53.8) and beclomethasone (93.8 vs. 59.8 and 81.3 vs. 55.9). Conclusion: Per year, switching between brand and generic inhalation medication was limited to 5% of the patients, switching between device types was observed in 5% as well. Adherence to both generic and brand inhalation medication was low. Effect of switching on adherence was contradictory; depending on time period, medication and type, and direction of switching. Further research on reasons for switching and potential impact on clinical outcomes is warranted

    Real and Virtual Compton Scattering: the nucleon polarisabilities

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    We give an overview of low-energy Compton scattering (gamma^(*) p --> gamma p) with a real or virtual incoming photon. These processes allow the investigation of one of the fundamental properties of the nucleon, i.e. how its internal structure deforms under an applied static electromagnetic field. Our knowledge of nucleon polarisabilities and their generalization to non-zero four-momentum transfer will be reviewed, including the presently ongoing experiments and future perspectives.Comment: 20 pages, 12 figures. Minireview/Proceedings of "Many-Body Structure of Strongly Interacting Systems", Mainz, Germany, Feb. 23-25 2011 . V2: typos corrected. version to appear in EPJ Special Topic

    γ spectroscopy of states in Cl 32 relevant for the S 31 (p,γ) Cl 32 reaction rate

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    Background: The S31(p,γ)Cl32 reaction becomes important for sulfur production in novae if the P31(p,α)Si28 reaction rate is somewhat greater than currently accepted. The rate of the S31(p,γ)Cl32 reaction is uncertain, primarily due to the properties of resonances at Ec.m.=156 and 549 keV. Purpose: We precisely determined the excitation energies of states in Cl32 through high-resolution γ spectroscopy including the two states most important for the S31(p,γ)Cl32 reaction at nova temperatures. Method: Excited states in Cl32 were populated using the B10(Mg24,2n)Cl32 reaction with a Mg24 beam from the ATLAS facility at Argonne National Laboratory. The reaction channel of interest was selected using recoils in the Fragment Mass Analyzer, and precise level energies were determined by detecting γ rays with Gammasphere. Results: We observed γ rays from the decay of six excited states in Cl32. The excitation energies for two unbound levels at Ex=1738.1 (6) keV and 2130.5 (10) keV were determined and found to be in agreement with a previous high-precision measurement of the S32(He3,t)Cl32 reaction [1]. Conclusions: An updated S31(p,γ)Cl32 reaction rate is presented. With the excitation energies of important levels firmly established, the dominant uncertainty in the reaction rate at nova temperatures is due to the strength of the resonance corresponding to the 2131-keV state in Cl32

    Dynamic moment of inertia of the 192Hg superdeformed band at high rotational frequencies

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    The superdeformed band in 192Hg has been extended to higher transition energies from a new analysis of a large set of double and triple coincidence data. Contrary to the results of cranked shell model calculations including monopole pairing, the dynamic moment of inertia I(2) is found to continue to increase with rotational frequency

    Multiple excitation modes in Hf 163

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    Excited states of Hf163 were populated using the Zr94(Ge74,5n) reaction and the decay γ rays were measured with the Gammasphere spectrometer. Two previously known bands were extended to higher spins, and nine new bands were identified. In addition to bands associated with three- and five-quasiparticle configurations, two γ-vibrational bands coupled to the i13/2 excitation were also observed. The lowest level of a newly identified, negative-parity band is proposed to be the ground state of the nucleus. A systematic delay of the high-spin proton crossing frequency with increasing quadrupole deformation from Hf162 to Hf172 was established. Extensive band searches failed to reveal a triaxial, strongly deformed structure in Hf163 similar to the one observed in several nuclei around A∼165
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