1,996 research outputs found
Lipid-laden alveolar macrophages and pH monitoring in gastroesophageal reflux-related respiratory symptoms
Lipid-laden alveolar macrophages and pH monitoring have been used in the diagnosis of chronic aspiration in children with gastroesophageal reflux (GER). This study was conducted to prove a correlation between the detection of alimentary pulmonary fat phagocytosis and an increasing amount of proximal gastroesophageal reflux. It was assumed that proximal gastroesophageal reflux better correlates with aspiration than distal GER. Patients from 6 months to 16 years with unexplained recurrent wheezy bronchitis and bronchial hyperreactivity, or recurrent pneumonia with chronic cough underwent 24-hour double-channel pH monitoring and bronchoscopy with bronchoalveolar lavage (BAL). Aspiration of gastric content was determined by counting lipid laden alveolar macrophages from BAL specimens. There were no correlations between any pH-monitoring parameters and counts of lipid-laden macrophages in the whole study population, even when restricting analysis to those with abnormal reflux index expressing clinically significant GER. Quantifying lipid-laden alveolar macrophages from BAL in children with gastroesophageal-related respiratory disorders does not have an acceptable specificity to prove chronic aspiration as an underlying etiology. Therefore, research for other markers of pulmonary aspiration is needed
Airway responses and inflammation in subjects with asthma after four days of repeated high-single-dose allergen challenge
Background: Both standard and low-dose allergen provocations are an established tool in asthma research to improve our understanding of the pathophysiological mechanism of allergic asthma. However, clinical symptoms are less likely to be induced. Therefore, we designed a protocol for repetitive high-dose bronchial allergen challenges to generate clinical symptoms and airway inflammation.
Methods: A total of 27 patients aged 18 to 40âyears with positive skin-prick tests and mild asthma underwent repetitive high-dose allergen challenges with household dust mites for four consecutive days. Pulmonary function and exhaled NO were measured at every visit. Induced sputum was analysed before and after the allergen challenges for cell counts, ECP, IL-5, INF-Îł, IL-8, and the transcription factor Foxp3.
Results: We found a significant decrease in pulmonary function, an increased use of salbutamol and the development of a late asthmatic response and bronchial hyperresponsiveness, as well as a significant induction of eNO, eosinophils, and Th-2 cytokines. Repeated provocation was feasible in the majority of patients. Two subjects had severe adverse events requiring prednisolone to cope with nocturnal asthma symptoms.
Conclusions: Repeated high-dose bronchial allergen challenges resulted in severe asthma symptoms and marked Th-2-mediated allergic airway inflammation. The high-dose challenge model is suitable only in an attenuated form in diseased volunteers for proof-of-concept studies and in clinical settings to reduce the risk of severe asthma exacerbations.
Trial registration: ClinicalTrials.govNCT0067720
Methacholine challenge â Comparison of an ATS protocol to a new rapid single concentration technique
SummaryBronchial methacholine challenge is well established in asthma diagnostics and research. ATS guidelines propose a five step standard dosimeter (SDM) protocol with incremental concentrations of methacholine to calculate the concentration causing a 20% drop in FEV1 in an individual (PC20FEV1). In contrast, the aerosol provocation system (APS) by ViasysÂŽ automatically determines the administered dose of methacholine by measuring the effective nebulisation time and referring it to drug concentration and nebuliser power. Therefore, it offers a feasible and less time-consuming provocation procedure by applying incremental doses (PD20) of methacholine using a single concentration (16mg/mL methacholine, APS-SC). In this study we compared these two methods in 52 young adults (25Âą5.8 years). Following a screening visit, subjects were randomly assigned to undergo either SDM or APS-SC followed by the other method within 1 week. A close correlation between concentration and dosage causing a 20% fall of FEV1 was found (r=0.69, p<0.001).Using the ATS categorisation of bronchial responsiveness we interpreted the results of the APS-SC method as follows: PD20 methacholine<0.3mg as âmoderate to severe BHRâ, 0.3 â 0.6mg as âmild BHRâ, 0.6 â 1.0mg as âborderline BHRâ, and>1.0mg as ânormal bronchial responseâ.We conclude that the five-step APS-SC is a suitable method, providing reliable results. In clinical practice the APS-SC is a timesaving procedure and less prone to errors since only one dilution of methacholine is necessary compared to the SDM
The epidemiological impact of childhood influenza vaccination using live-attenuated influenza vaccine (LAIV) in Germany: predictions of a simulation study
Rose MA, Damm O, Greiner W, et al. The epidemiological impact of childhood influenza vaccination using live-attenuated influenza vaccine (LAIV) in Germany: predictions of a simulation study. BMC Infectious Diseases. 2014;14(1): 40.Background
Routine annual influenza vaccination is primarily recommended for all persons aged 60 and above and for people with underlying chronic conditions in Germany. Other countries have already adopted additional childhood influenza immunisation programmes. The objective of this study is to determine the potential epidemiological impact of implementing paediatric influenza vaccination using intranasally administered live-attenuated influenza vaccine (LAIV) in Germany.
Methods
A deterministic age-structured model is used to simulate the population-level impact of different vaccination strategies on the transmission dynamics of seasonal influenza in Germany. In our base-case analysis, we estimate the effects of adding a LAIV-based immunisation programme targeting children 2 to 17 years of age to the existing influenza vaccination policy. The data used in the model is based on published evidence complemented by expert opinion.
Results
In our model, additional vaccination of children 2 to 17 years of age with LAIV leads to the prevention of 23.9 million influenza infections and nearly 16 million symptomatic influenza cases within 10 years. This reduction in burden of disease is not restricted to children. About one third of all adult cases can indirectly be prevented by LAIV immunisation of children.
Conclusions
Our results demonstrate that vaccinating children 2â17 years of age is likely associated with a significant reduction in the burden of paediatric influenza. Furthermore, annual routine childhood vaccination against seasonal influenza is expected to decrease the incidence of influenza among adults and older people due to indirect effects of herd protection. In summary, our model provides data supporting the introduction of a paediatric influenza immunisation programme in Germany
Methacholine challenge in young children as evaluated by spirometry and impulse oscillometry
SummaryBackgroundIn young children, it is difficult to obtain a reproducible flow-volume curve throughout all stages of bronchial challenge. The forced oscillation technique (FOT) is especially established in paediatrics because this method does not require forced or maximal manoeuvres and is less cooperation-dependent than conventional spirometry.ObjectivesTo evaluate the association of spirometric and impulse oscillometric (IOS) indices in a short protocol for methacholine provocation.MethodsThe primary endpoint was the methacholine dose that caused a 20% decrease in FEV1 (PDâ20FEV1) compared to baseline. Changes in respiratory resistance (Rrs5) and reactance (Xrs5) acquired by IOS were compared with FEV1.ResultsForty-eight children (5.3 ¹ 0.9 years) were challenged. The mean maximal reduction in FEV1 was 29.8% ¹ 14.7 (p < 0.0001), the mean increase in Rsr5 was 55.3% ¹ 31.7, and the mean decrease in Xrs5 was 0.37 kPa s Lâ1 ¹ 0.23 (p < 0.001). An increase in Rrs5 of 45.2% and a decrease in Xrs5 of 0.69 kPa s Lâ1 showed the optimal combination of sensitivity and specificity to detect a 20% reduction in FEV1 (0.72 and 0.73; 0.80 and 0.76, respectively), and the area under the ROC curve was 0.76 and 0.81, respectively (p < 0.005). In 28 patients with significant changes in FEV1 and Rsr5, the PDâ20FEV1 was 0.48 mg methacholine Âą0.59 and the PD+40Rrs5 was 0.28 mg methacholine Âą0.45 (p = 0.03).ConclusionsA short protocol for methacholine challenge testing is feasible in young children. IOS detected 70â80% of patients who responded in spirometry. During the challenge, the Rrs5 response preceded the FEV1 response
Omega-3 polyunsaturated fatty acids and bronchial inflammation in grass pollen allergy after allergen challenge
SummaryRatioAsthma is a major public health problem, with bronchial inflammation as the therapeutic target. The role of dietary fish oil derived polyunsaturated fatty acids (PUFAs) in allergic inflammation is controversial. Most asthmatics suffer from mild disease and non-pharmacologic interventions are attractive. This study investigates the anti-inflammatory potential of nutritional PUFAs in an experimentally induced bronchial inflammation.MethodsWe examined 38 grass pollen allergic asthmatics and 19 controls. History of dietary PUFA intake was compared with levels of PUFAs in erythrocyte membranes, and stratified according to low (25th quartile; Q25) and high (75th quartile; Q75) ratios of omega-3 (n-3) to omega-6 (n-6) PUFAs as a surrogate for anti-inflammatory (Q75) or proinflammatory (Q25) effects. Bronchial inflammation was simulated with one-step inhalation of grass pollen. Bronchial response (exhaled nitric monoxide, eNO as surrogate for inflammation, decrease of FEV1) was correlated with levels of PUFAs in erythrocyte membranes.ResultsRatios of n-3/n-6 PUFA were significantly lower in asthmatics than in healthy controls. Levels of eNO were significantly higher in Q25 asthmatics than in Q75 asthmatics (p = 0.040). There was a trend of higher bronchial hyperreactivity in Q25 asthmatics (median PD20 0.27 vs. 0.14; n.s.), induced by specific bronchial challenge with grass pollen (FEV1 decrease 16.7 vs. 23.1%; n.s.).ConclusionWhen stratifying for erythrocyte membrane PUFA content as a surrogate for alimentary intake, we found mild effects on bronchial allergic inflammation. Future intervention studies with pharmacological PUFA doses appear suitable to clarify dietary PUFA role as an adjunctive intervention to the established treatment of asthma.ClinicalTrials.gov No. NCT00519740
Recognition of dileucine-based sorting signals from HIV-1 Nef and LIMP-II by the AP-1 ÎłâĎ1 and AP-3 δâĎ3 hemicomplexes
The sorting of transmembrane proteins to endosomes and lysosomes is mediated by signals present in the cytosolic tails of the proteins. A subset of these signals conform to the [DE]XXXL[LI] consensus motif and mediate sorting via interactions with heterotetrameric adaptor protein (AP) complexes. However, the identity of the AP subunits that recognize these signals remains controversial. We have used a yeast three-hybrid assay to demonstrate that [DE]XXXL[LI]-type signals from the human immunodeficiency virus negative factor protein and the lysosomal integral membrane protein II interact with combinations of the Îł and Ď1 subunits of AP-1 and the δ and Ď3 subunits of AP-3, but not the analogous combinations of AP-2 and AP-4 subunits. The sequence requirements for these interactions are similar to those for binding to the whole AP complexes in vitro and for function of the signals in vivo. These observations reveal a novel mode of recognition of sorting signals involving the Îł/δ and Ď subunits of AP-1 and AP-3
1000 Norms Project: Protocol of a cross-sectional study cataloging human variation
Background Clinical decision-making regarding diagnosis and management largely depends on comparison with healthy or ânormalâ values. Physiotherapists and researchers therefore need access to robust patient-centred outcome measures and appropriate reference values. However there is a lack of high-quality reference data for many clinical measures. The aim of the 1000 Norms Project is to generate a freely accessible database of musculoskeletal and neurological reference values representative of the healthy population across the lifespan. Methods/design In 2012 the 1000 Norms Project Consortium defined the concept of ânormalâ, established a sampling strategy and selected measures based on clinical significance, psychometric properties and the need for reference data. Musculoskeletal and neurological items tapping the constructs of dexterity, balance, ambulation, joint range of motion, strength and power, endurance and motor planning will be collected in this cross-sectional study. Standardised questionnaires will evaluate quality of life, physical activity, and musculoskeletal health. Saliva DNA will be analysed for the ACTN3 genotype (âgene for speedâ). A volunteer cohort of 1000 participants aged 3 to 100 years will be recruited according to a set of self-reported health criteria. Descriptive statistics will be generated, creating tables of mean values and standard deviations stratified for age and gender. Quantile regression equations will be used to generate age charts and age-specific centile values. Discussion This project will be a powerful resource to assist physiotherapists and clinicians across all areas of healthcare to diagnose pathology, track disease progression and evaluate treatment response. This reference dataset will also contribute to the development of robust patient-centred clinical trial outcome measures
Recommended from our members
Biological, clinical and population relevance of 95 loci for blood lipids.
Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD
Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV
Results are presented from a search for physics beyond the standard model
based on events with large missing transverse energy, at least three jets, and
at least one, two, or three b-quark jets. The study is performed using a sample
of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS
detector at the LHC in 2011. The integrated luminosity of the sample is 4.98
inverse femtobarns. The observed number of events is found to be consistent
with the standard model expectation, which is evaluated using control samples
in the data. The results are used to constrain cross sections for the
production of supersymmetric particles decaying to b-quark-enriched final
states in the context of simplified model spectra.Comment: Submitted to Physical Review
- âŚ