Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics

The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, measuring 1,600 compounds. Cabbage was sampled in 2 years from one conventional and two organic farming systems in a rigidly controlled long-term field trial in Denmark. Using Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA), we found that the production system leaves a significant (p = 0.013) imprint in the white cabbage metabolome that is retained between production years. We externally validated this finding by predicting the production system of samples from one year using a classification model built on samples from the other year, with a correct classification in 83% of cases. Thus, it was concluded that the investigated conventional and organic management practices have a systematic impact on the metabolome of white cabbage. This emphasizes the potential of untargeted metabolomics for authenticity testing of organic plant products

Helicobacter pylori Adapts to Chronic Infection and Gastric Disease via pH-Responsive BabA-Mediated Adherence

International audienceThe BabA adhesin mediates high-affinity binding of Helicobacter pylori to the ABO blood group antigen-glycosylated gastric mucosa. Here we show that BabA is acid responsive-binding is reduced at low pH and restored by acid neutralization. Acid responsiveness differs among strains; often correlates with different intragastric regions and evolves during chronic infection and disease progression; and depends on pH sensor sequences in BabA and on pH reversible formation of high-affinity binding BabA multimers. We propose that BabA's extraordinary reversible acid responsiveness enables tight mucosal bacterial adherence while also allowing an effective escape from epithelial cells and mucus that are shed into the acidic bactericidal lumen and that bio-selection and changes in BabA binding properties through mutation and recombination with babA-related genes are selected by differences among individuals and by changes in gastric acidity over time. These processes generate diverse H. pylori subpopulations, in which BabA's adaptive evolution contributes to H. pylori persistence and overt gastric disease

Variance Reduction in Analytical Chemistry : New Numerical Methods in Chemometrics and Molecular Simulation

This thesis is based on five papers addressing variance reduction in different ways. The papers have in common that they all present new numerical methods. Paper I investigates quantitative structure-retention relationships from an image processing perspective, using an artificial neural network to preprocess three-dimensional structural descriptions of the studied steroid molecules. Paper II presents a new method for computing free energies. Free energy is the quantity that determines chemical equilibria and partition coefficients. The proposed method may be used for estimating, e.g., chromatographic retention without performing experiments. Two papers (III and IV) deal with correcting deviations from bilinearity by so-called peak alignment. Bilinearity is a theoretical assumption about the distribution of instrumental data that is often violated by measured data. Deviations from bilinearity lead to increased variance, both in the data and in inferences from the data, unless invariance to the deviations is built into the model, e.g., by the use of the method proposed in paper III and extended in paper IV. Paper V addresses a generic problem in classification; namely, how to measure the goodness of different data representations, so that the best classifier may be constructed. Variance reduction is one of the pillars on which analytical chemistry rests. This thesis considers two aspects on variance reduction: before and after experiments are performed. Before experimenting, theoretical predictions of experimental outcomes may be used to direct which experiments to perform, and how to perform them (papers I and II). After experiments are performed, the variance of inferences from the measured data are affected by the method of data analysis (papers III-V)

Self-perception after hypospadias repair in young men's perspective

Twenty-one males underwent an interview, clinical investigation, and measurement of urine flow and residual volume 15-25 years after surgery. Although surgical techniques have been improved during recent decades, the results of hypospadias repair made 20 years ago are nethertheless acceptable and most patients regard the outcome as satisfactory

HIV infection reduces skin graft survival in burn injuries: a prospective study

Impaired survival of skin grafts has been noted in human immunodeficiency virus (HIV) infected patients, but the reason is not known. Alterations in inflammatory response, which might be recorded as an imbalance in cytokine production, have been implicated. The aim of this study was to determine the impact of HIV infection in patients with burn injuries by comparison of split skin graft survival, T lymphocyte count and cytokine levels in HIV-infected and non HIV-infected patients in relation to healthy and HIV-infected nonburnt volunteers. Fifty-four patients with deep dermal burns were included. Fifteen patients' were HIV-infected. Thirteen healthy and 15 HIV-infected, volunteers were recruited as controls. The burnt surface area was traced on a transparent plastic sheet and converted to area. Graft survival on day of discharge/regraft for non HIV-infected patients was 69%, and in HIV-infected 22%, (p < 0.05). The median length of hospital stay for early excision among non HIV-infected patients was 21 (12-53) days and for HIV-infected, 41 days (p < 0.05). Serum protein levels in HIV-infected patients were elevated compared to non HIV-infected patients (p < 0.05). CD4+ Lymphocytes were depressed in HIV-infected volunteers and HIV-infected burn patients compared to healthy volunteers (p < 0.05). CD8+ lymphocytes were elevated in HIV-infected volunteers compared to non HIV-infected burn patients. Pro-inflammatory cytokine levels of Interleukin-2 (IL-2), Interteukin-6 (IL-6), Interferon-gama (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) were depressed in HIV-infected volunteers compared to healthy volunteers and non HIV-infected burn patients. The pro-inflammatory cytokine IFN-gamma did not increase after burn injury in HIV-infected burns patients as did IL-2, IL-6 and TNF-alpha (p < 0.05). Antiinflammatory cytokine levels of IL-4 were elevated in HIV-infected volunteers compared to healthy volunteers and burn patients (p < 0.05). Conclusion: Graft survival after split skin grafting of burn wounds in HIV-infected patients is impaired and hospital stay is prolonged. HIV infection. result in immune dysregulation, which might be related to impaired skin graft survival. (C) 2003 The British Association of Plastic Surgeons. Published by Elsevier Ltd. ALL rights reserved

A prospective double blind randomized study comparing the need for blood transfusion with terlipressin or a placebo during early excision and grafting of burns

Introduction: Early excision and skin grafting has become the standard of good burn management, but it is associated with major blood loss. Aim: To determine the haemostatic effect of terlipressin compared with placebo. Material and methods: Fifty-one patients with bums of 10-20% total body surface area had early excision and split skin grafting of deep burns. The surface area of the bum wound and of the heated graft were measured by planimetry. The patients were randomly allocated to medication, either terlipressin or placebo. Blood loss and number of transfused units of blood were recorded. Results: Twenty-one patients received terlipressin, 13 received terlipressin late (cross-over) and 17 received placebo. Six out of 21 patients exposed to terlipressin were transfused with eleven units of packed red blood cells. Seven out of 13 patients crossed over from placebo to terlipressin (late terlipressin) were transfused with 17 units of blood. Eight out of 17 patients exposed to the placebo were transfused with 22 units of blood (P < 0.05). Graft healing was 1055 +/- 609 cm(2) out of 1452 +/- 1811 cm(2) in terlipressin and 914 +/- 633 cm(2) out of 1288 720 cm 2 in the placebo group (n.s.). Conclusion: Terlipressin reduced the need for blood transfusion by a factor of 2.5 compared to a placebo without impairment of graft healing

TracMass 2A Modular Suite of Tools for Processing Chromatography-Full Scan Mass Spectrometry Data

In untargeted proteomics and metabolomics, raw data obtained with an LC/MS instrument are processed into a format that can be used for statistical analysis. Full scan MS data from chromatographic separation of biological samples are complex and analyte concentrations need to be extracted and aligned so that they can be compared across the samples. Several computer programs and methods have been developed for this purpose. There is still a need to improve the ease of use and feedback to the user because of the advanced multiparametric algorithms used. Here, we present and make publicly available, TracMass 2, a suite of computer programs that gives immediate graphical feedback to the data analyst on parameter settings and processing results, as well as producing state-of-the-art results. The main advantage of TracMass 2 is that the feedback and transparency of the processing steps generate confidence in the end result, which is a table of peak intensities. The data analyst can easily validate every step of the processing pipeline. Because the user receives feedback on how all parameter values affect the result before starting a lengthy computation, the user’s learning curve is enhanced and the total time used for data processing can be reduced. TracMass 2 has been released as open source and is included in the Supporting Information. We anticipate that TracMass 2 will set a new standard for how chemometrical algorithms are implemented in computer programs

IgE responses to multiple allergen components among school-aged children in a general population birth cohort in Tokyo

Background: Response patterns to allergen components among Japanese children have not been studied extensively. Objective: Our aim was to examine the differences in sensitization patterns at ages 5 years and 9 years to identify longitudinal changes in the degree and patterns of sensitization in a birth cohort of Japanese children. Methods: Our study enrolled 984 children at aged 5 years between 2008 and 2010, and 729 children aged 9 years between 2012 and 2014. Allergic diseases were assessed using the ISAAC and UK Working Party's Diagnostic Criteria. Serum-specific IgE titers to allergen components were measured by multiplex array ImmunoCAP ISAC when the children were aged 5 and 9 years. Principal component analysis (PCA) was performed to characterize IgE sensitization to allergen components. Results: The prevalence of allergic rhinitis increased considerably over time (10.6%-31.2%). Furthermore, the sensitization prevalence to allergen-specific IgE (sIgE) also increased from 57.8% at age 5 years to 74.8% at age 9 years. IgE sensitization prevalence to Der f 1 (mites) was 42.1% at age 5 years and 54.3% at age 9 years. Furthermore, children were highly sensitized to Cry j 1 (Japanese cedar) (32.8% at age 5 years and 57.8% at age 9 years). Principle component analysis showed that sensitization to PR-10 cross-reactive components was independent of sensitization to mite and that no children acquired sensitization to pollen before acquiring sensitization to mite. Conclusions: The prevalence of allergic rhinitis and related allergen components increased from age 5 years to age 9 years in Japanese children

Understanding InP Nanowire Array Solar Cell Performance by Nanoprobe-Enabled Single Nanowire Measurements

III-V solar cells in the nanowire geometry might hold significant synthesis-cost and device-design advantages as compared to thin films and have shown impressive performance improvements in recent years. To continue this development there is a need for characterization techniques giving quick and reliable feedback for growth development. Further, characterization techniques which can improve understanding of the link between nanowire growth conditions, subsequent processing, and solar cell performance are desired. Here, we present the use of a nanoprobe system inside a scanning electron microscope to efficiently contact single nanowires and characterize them in terms of key parameters for solar cell performance. Specifically, we study single as-grown InP nanowires and use electron beam induced current characterization to understand the charge carrier collection properties, and dark current-voltage characteristics to understand the diode recombination characteristics. By correlating the single nanowire measurements to performance of fully processed nanowire array solar cells, we identify how the performance limiting parameters are related to growth and/or processing conditions. We use this understanding to achieve a more than 7-fold improvement in efficiency of our InP nanowire solar cells, grown from a different seed particle pattern than previously reported from our group. The best cell shows a certified efficiency of 15.0%; the highest reported value for a bottom-up synthesized InP nanowire solar cell. We believe the presented approach have significant potential to speed-up the development of nanowire solar cells, as well as other nanowire-based electronic/optoelectronic devices