Diet and asthma

AbstractThe role of food intolerance in asthma is well recognized, and where food avoidance measures are instituted considerable improvement in asthma symptoms and in reduction in drug therapy and hospital admissions can result. These benefits may have a greater impact in those patients with greater symptoms. However, the promise of such benefits should not result in an approach which ignores inhaled drug therapy, or in a dietary regime which is inappropriate in the face of mild symptoms. Whilst sub-optimal intake of dietary nutrients is also a recently recognized potential risk factor for asthma, available data are insufficient to implicate any as casual. A number of studies have sought to establish the role of the antioxidant vitamins, A, C and E and selenium, yet others of the elements sodium and magnesium. Sub-optimal nutrient intake may enhance asthmatic inflammation, consequently contributing to bronchial hyperreactivity. Prospective studies of supplementation therapy are needed to confirm this

Clinical efficacy and safety of fluticasone propionate 1 mg twice daily administered via a HFA 134a pressurized metered dose inhaler to patients with severe asthma

A randomized, double-blind, cross-over study was conducted to assess the efficacy and safety of fluticasone propionate 1 mg twice daily administered via a pressurized metered dose inhaler (pMDI) containing the new non-chlorofluorocarbon (CFC) propellant (HFA 134a), or the established CFC propellants 11 and 12 in patients with severe asthma. The study comprised a 2-week run-in period followed by two 6-week treatment periods, with no washout period in between. One hundred and nineteen symptomatic adult patients with severe asthma, who were receiving inhaled beclomethasone 2–4 mg day−1 or equivalent, were randomized to treatment.Patients were randomized to one of two sequence groups (sequence 1: HFA 134a pMDI then CFC pMDI or sequence 2: CFC pMDI then HFA 134a pMDI). The sequence groups differed with respect to mean peak expiratory flow (PEF) at baseline; however, the magnitude of the increase in PEF from baseline during treatment was similar in the two sequence groups. Mean PEF at baseline was 334 l min−1 in sequence group 1 (HFA 134a→CFC pMDI) and this increased to 357 l min−1 and 366 l min−1 during treatment with the HFA 134a and CFC pMDI, respectively. In sequence group 2 (CFC→HFA 134a pMDI) mean PEF at baseline was 297 l min−1 and this increased to 336 l min−1 and 328 l min−1 during treatment with the HFA 134a and CFC pMDI, respectively.Based on an overall analysis of the two treatment groups at week 6, equivalence was demonstrated; the mean treatment difference (HFA 134a-CFC pMDI) in morning PEF was 0 l min−1 (90% confidence interval (CI), for difference between groups: −7, 6 l min−1). There was a comparable improvement in secondary efficacy variables, including clinic lung function measurements, in the two treatment groups. The incidence and type of most adverse events were similar in the two treatment groups. There was no difference in the adjusted geometric mean morning serum cortisol levels after treatment with the HFA 134a and CFC pMDI.Therefore, the fluticasone propionate HFA 134a pMDI constitutes a suitable replacement for the established CFC pMDI at a microgram equivalent dose

The performance of Mini Wright peak flow meters after prolonged use

AbstractThe accuracy of 84 new and 35 old Mini Wright peak flow meters were tested using a servo-controlled pump system. The 95% confidence limits for flow measurement across the range of the new meters was between ± 151 min−1 at the lower end of the range and ± 281 min−1 at the top of the range. The readings for 22 (63%) of the old meters (age range 1–13 yr) were within these 95% confidence limits. For the remaining 13 old meters (age range 1–13 yr) whose readings were not within these limits, there were 11 meters with readings falling below and two meters with readings above these limits. Twelve of these old meters were washed and retested and there was no significant change in their readings. Twenty of the new meters were retested after 1 yr of continuous use and their readings were significantly higher with a median value of 51 min−1 across the range, although only two of these 20 meters had readings outside the 95% confidence limits set from the 84 new meters. It is concluded that whilst Mini Wright meters aged up to 14 yr can give readings which are as good as new meters, some meters demonstrate significant changes in readings after only 1 yr and washing did not correct this change. It is recommended that clinicians prescribing peak expiratory flow (PEF) meters should be responsible for checking the patient's meter as well as their PEF readings at clinic visits

Defining and investigating difficult asthma: Developing quality indicators

SummaryBackgroundThere is no agreed definition of ‘difficult asthma’ or what investigations should be available to investigate these patients. Patients with difficult asthma remain symptomatic on high levels of treatment and are high users of medical resources.AimTo develop a set of quality indicators for the definition and investigation of difficult asthma.MethodModified RAND Appropriateness Method was used. An expert panel composed of nine hospital asthma specialists who run ‘difficult’ asthma clinics and were identified from a shortlist of key workers in the field. Indicators were rated as necessary to define and investigate difficult asthma.ResultsDifficult asthma was defined as ‘symptoms persisting beyond therapy consistent with step 4 of the British Thoracic Society (BTS) guidelines’ (high dose inhaled corticosteroids and long acting β2-agonists). Eighty-three indicators were identified (40 relating to definition and 43 relating to investigations). Of these 32 (39%) were rated as necessary: 7 out of 40 (18%) for defining difficult asthma and 23 out of 43 (53%) for investigations. Indicators of high medical resource usage were characteristic of the ‘difficult’ nature of the management of patient with difficult asthma. A framework for the investigation of these patients was created.ConclusionThe listed performance indicators identify a range of requirements that are necessary to define difficult asthma. Targeting of real needs in this group of patients will lead to better patient care and reduction of ‘waste’ in provision of healthcare

Atmospheric Heating and Wind Acceleration: Results for Cool Evolved Stars based on Proposed Processes

A chromosphere is a universal attribute of stars of spectral type later than ~F5. Evolved (K and M) giants and supergiants (including the zeta Aurigae binaries) show extended and highly turbulent chromospheres, which develop into slow massive winds. The associated continuous mass loss has a significant impact on stellar evolution, and thence on the chemical evolution of galaxies. Yet despite the fundamental importance of those winds in astrophysics, the question of their origin(s) remains unsolved. What sources heat a chromosphere? What is the role of the chromosphere in the formation of stellar winds? This chapter provides a review of the observational requirements and theoretical approaches for modeling chromospheric heating and the acceleration of winds in single cool, evolved stars and in eclipsing binary stars, including physical models that have recently been proposed. It describes the successes that have been achieved so far by invoking acoustic and MHD waves to provide a physical description of plasma heating and wind acceleration, and discusses the challenges that still remain.Comment: 46 pages, 9 figures, 1 table; modified and unedited manuscript; accepted version to appear in: Giants of Eclipse, eds. E. Griffin and T. Ake (Berlin: Springer

Patterns of domestic exposure to carbon monoxide and particulate matter in households using biomass fuel in Janakpur, Nepal

Household Air Pollution (HAP) from biomass cooking fuels is a major cause of morbidity and mortality in low-income settings worldwide. In Nepal the use of open stoves with solid biomass fuels is the primary method of domestic cooking. To assess patterns of domestic air pollution we performed continuous measurement of carbon monoxide (CO) and particulate Matter (PM2.5) in 12 biomass fuel households in Janakpur, Nepal. We measured kitchen PM2.5 and CO concentrations at one-minute intervals for an approximately 48-h period using the TSI DustTrak II 8530/SidePak AM510 (TSI Inc, St. Paul MN, USA) or EL-USB-CO data logger (Lascar Electronics, Erie PA, USA) respectively. We also obtained information regarding fuel, stove and kitchen characteristics and cooking activity patterns. Household cooking was performed in two daily sessions (median total duration 4 h) with diurnal variability in pollutant concentrations reflecting morning and evening cooking sessions and peak concentrations associated with fire-lighting. We observed a strong linear relationship between PM2.5 measurements obtained by co-located photometric and gravimetric monitoring devices, providing local calibration factors of 4.9 (DustTrak) and 2.7 (SidePak). Overall 48-h average CO and PM2.5 concentrations were 5.4 (SD 4.3) ppm (12 households) and 417.6 (SD 686.4) μg/m3 (8 households), respectively, with higher average concentrations associated with cooking and heating activities. Overall average PM2.5 concentrations and peak 1-h CO concentrations exceeded WHO Indoor Air Quality Guidelines. Average hourly PM2.5 and CO concentrations were moderately correlated (r = 0.52), suggesting that CO has limited utility as a proxy measure for PM2.5 exposure assessment in this setting. Domestic indoor air quality levels associated with biomass fuel combustion in this region exceed WHO Indoor Air Quality standards and are in the hazardous range for human health

New games, new rules: big data and the changing context of strategy

Big data and the mechanisms by which it is produced and disseminated introduce important changes in the ways information is generated and made relevant for organizations. Big data often represents miscellaneous records of the whereabouts of large and shifting online crowds. It is frequently agnostic, in the sense of being produced for generic purposes or purposes different from those sought by big data crunching. It is based on varying formats and modes of communication (e.g., texts, image and sound), raising severe problems of semiotic translation and meaning compatibility. Crucially, the usefulness of big data rests on their steady updatability, a condition that reduces the time span within which this data is useful or relevant. Jointly, these attributes challenge established rules of strategy making as these are manifested in the canons of procuring structured information of lasting value that addresses specific and long-term organizational objectives. The developments underlying big data thus seem to carry important implications for strategy making, and the data and information practices with which strategy has been associated. We conclude by placing the understanding of these changes within the wider social and institutional context of longstanding data practices and the significance they carry for management and organizations