Cross-correlation analysis to quantify relative spatial distributions of fat and protein in super-resolution microscopy images of dairy gels

The advent of super-resolution microscopy allows microstructures of foods to be explored in new depths, which when coupled with quantitative image analysis can provide a powerful analytical tool. Herein, a methodology is presented and applied to use a 2D spatial cross-correlation analysis to investigate the relative spatial arrangement of protein and fat in acid induced whole milk gels where the milk is either non-homogenised or has been homogenised at either 10 or 25 MPa. Two-channel images were taken using super-resolution Stimulated Emission Depletion (STED) microscopy and confocal microscopy. A term has been derived to extract the typical distance from the fat droplet surface and to the local maximum protein distribution. The fat droplet size is determined through 2D spatial autocorrelation analysis. Methods of analysis are applied to global images and to region specific analysis focussing on individual fat droplets. Cross-correlation analysis has been empirically validated using generated images with precise spatial features corresponding to the features of interest in true microscopy images, over appropriate length scales. The protein microstructure, fat droplet size and distances between the fat droplets and protein network are characterised. There are significantly different distances between the fat droplets and protein network in the homogenised samples compared to the non-homogenised sample. The extracted separation distances are below the diffraction limit of light, highlighting the utility of super-resolution imaging

Dynamic moisture loss explored through quantitative super-resolution microscopy, spatial micro-viscosity and macroscopic analyses in acid milk gels

Molecular interactions and dynamic changes at a range of length scales affect the structuring of food materials, as such it is essential to explore structure at a range of different length scales. Herein, four acid milk gel samples are produced from either fresh or reconstituted skim milk that either had no heat treatment or had undergone heat treatment at 85 °C for 10 min. Milk acid gels demonstrate complex structure on a range of length scales of interest in colloidal materials and exhibit different macroscopic and water binding properties. A method is presented to measure the dynamic moisture loss in these samples, without applying external force. Super-resolution microscopy images are quantitatively analysed to describe the gel microstructure with precise features. Fluorescent Lifetime Imaging Microscopy is used to spatially resolve differences in molecular confinement across the sample's microstructure, which is quantified for each sample. Moisture loss and microstructural analyses are correlated to bulk and macroscopic properties determined through rheological and texture analysis, pH and conductivity measurements. More severe thermal and processing treatments leads to a reduction in moisture loss over time. Differences in moisture loss and mechanical properties relate to different thermal processing histories, but are not fully explained by levels of denatured whey proteins, and appear related to changes in mineral balance. The methods presented provide a comprehensive and complementary overview of material properties across relevant length scales and relevant sample conditions

Early Lung Function Testing in Infants with Aortic Arch Anomalies Identifies Patients at Risk for Airway Obstruction

BACKGROUND: Aortic arch anomalies (AAA) are rare cardio-vascular anomalies. Right-sided and double-sided aortic arch anomalies (RAAA, DAAA) are distinguished, both may cause airway obstructions. We studied the degree of airway obstruction in infants with AAA by neonatal lung function testing (LFT). PATIENTS AND METHODS: 17 patients (10 RAAA and 7 DAAA) with prenatal diagnosis of AAA were investigated. The median (range) post conception age at LFT was 40.3 (36.6-44.1) weeks, median body weight 3400 (2320-4665) g. Measurements included tidal breathing flow-volume loops (TBFVL), airway resistance (R(aw)) by bodyplethysmography and the maximal expiratory flow at functional residual capacity (V'(max)FRC) by rapid thoracic-abdominal compression (RTC) technique. V'(max)FRC was also expressed in Z-scores, based on published gender-, age and height-specific reference values. RESULTS: Abnormal lung function tests were seen in both RAAA and DAAA infants. Compared to RAAA infants, infants with DAAA had significantly more expiratory flow limitations in the TBFVL, (86% vs. 30%, p<0.05) and a significantly increased R(aw) (p = 0.015). Despite a significant correlation between R(aw) and the Z-score of V'(max)FRC (r = 0.740, p<0.001), there were no statistically significant differences in V'(max)FRC and it's Z-scores between RAAA and DAAA infants. 4 (24%) infants (2 RAAA, 2 DAAA) were near or below the 10(th) percentile of V'(max)FRC, indicating a high risk for airway obstruction. CONCLUSION: Both, infants with RAAA and DAAA, are at risk for airway obstruction and early LFT helps to identify and to monitor these infants. This may support the decision for therapeutic interventions before clinical symptoms arise

Intestinal carriage of Staphylococcus aureus: How does its frequency compare with that of nasal carriage and what is its clinical impact?

The bacterial species Staphylococcus aureus, including its methicillin-resistant variant (MRSA), finds its primary ecological niche in the human nose, but is also able to colonize the intestines and the perineal region. Intestinal carriage has not been widely investigated despite its potential clinical impact. This review summarizes literature on the topic and sketches the current state of affairs from a microbiological and infectious diseases' perspective. Major findings are that the average reported detection rate of intestinal carriage in healthy individuals and patients is 20% for S. aureus and 9% for MRSA, which is approximately half of that for nasal carriage. Nasal carriage seems to predispose to intestinal carriage, but sole intestinal carriage occurs relatively frequently and is observed in 1 out of 3 intestinal carriers, which provides a rationale to include intestinal screening for surveillance or in outbreak settings. Colonization of the intestinal tract with S. aureus at a young age occurs at a high frequency and may affect the host's immune system. The frequency of intestinal carriage is generally underestimated and may significantly contribute to bacterial dissemination and subsequent risk of infections. Whether intestinal rather than nasal S. aureus carriage is a primary predictor for infections is still ill-defined

The role of epigenetic dysregulation in the epidemic of allergic disease

The epidemic of allergic disease in early life is one of the clearest indicators that the developing immune system is vulnerable to modern environmental changes. A range of environmental exposures epidemiologically associated with allergic disease have been shown to have effects on the foetal immune function in pregnancy, including microbial burden, dietary changes and environmental pollutants. Preliminary studies now suggest that these early effects on immune development may be mediated epigenetically through a variety of processes that collectively modify gene expression and allergic susceptibility and that these effects are potentially heritable across generations. It is also possible that rising rates of maternal allergy, a recognised direct risk factor for infant allergic disease, may be further amplifying the effects of environmental changes. Whilst effective prevention strategies are the ultimate goal in reversing the allergy epidemic, the specific environmental drivers, target genes, and intracellular pathways and mechanisms of early life immune programming are still unclear. It is hoped that identifying genes that are differentially regulated in association with subsequent allergic disease will assist in identifying causal pathways and upstream contributing environmental factors. In this way, epigenetic paradigms are likely to provide valuable insights into how the early environment can be modified to more favourably drive immune development and reverse the allergic epidemic

Prevalence and early-life risk factors of school-age allergic multimorbidity: The EuroPrevall-iFAAM birth cohort.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: Coexistence of childhood asthma, eczema and allergic rhinitis is higher than can be expected by chance, suggesting a common mechanism. Data on allergic multimorbidity from a pan-European, population-based birth cohort study have been lacking. This study compares the prevalence and early-life risk factors of these diseases in European primary school children. Methods: In the prospective multicentre observational EuroPrevall-iFAAM birth cohort study, we used standardized questionnaires on sociodemographics, medical history, parental allergies and lifestyle, and environmental exposures at birth, 12 and 24 months. At primary school age, parents answered ISAAC-based questions on current asthma, rhinitis and eczema. Allergic multimorbidity was defined as the coexistence of at least two of these. Results: From 10,563 children recruited at birth in 8 study centres, we included data from 5,572 children (mean age 8.2 years; 51.8% boys). Prevalence estimates were as follows: asthma, 8.1%; allergic rhinitis, 13.3%; and eczema, 12.0%. Allergic multimorbidity was seen in 7.0% of the whole cohort, ranging from 1.2% (Athens, Greece) to 10.9% (Madrid, Spain). Risk factors for allergic multimorbidity, identified with AICc, included family-allergy-score, odds ratio (OR) 1.50 (95% CI 1.32-1.70) per standard deviation; early-life allergy symptoms, OR 2.72 (2.34-3.16) for each symptom; and caesarean birth, OR 1.35 (1.04-1.76). Female gender, OR 0.72 (0.58-0.90); older siblings, OR 0.79 (0.63-0.99); and day care, OR 0.81 (0.63-1.06) were protective factors. Conclusion: Allergic multimorbidity should be regarded as an important chronic childhood disease in Europe. Some of the associated early-life factors are modifiable and may be considered for prevention strategies. Keywords: allergic multimorbidity; allergic rhinitis; asthma; children; eczema.European Commission under the 6th Framework Programme within the collaborative research initiative 'EuroPrevall' European Commission under 7th Framework Programme (FP7-KBBE-2012-6) within the collaborative project 'iFAAM' Icelandic birth cohort centre from Landspitali University Hospital Iceland Science Fund GlaxoSmithKline UK birth cohort centre from the UK Food Standards Agenc

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 × 10−8), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution