Characterisation of flucloxacillin and 5-hydroxymethyl flucloxacillin haptenated HSA in vitro and in vivo

Flucloxacillin is a synthetic penicillin used in the treatment of Staphylococcal infections. Adverse reactions to the drug are believed to arise through covalent modification of proteins, with tissue damage occurring secondary to an immune reaction. Serum proteins have been shown by adduct-specific antibodies to be modified by flucloxacillin, but the nature and sites of modification have not been characterised. Here, in vitro studies on HSA have shown by MS that the modification of protein lysine residues occurs in a dose-, time- and site-dependent manner. Affinity, cation exchange and reversed phase chromatography prior to MS revealed in vivo modification of HSA with flucloxacillin in tolerant patients, with up to nine modified lysine residues being detected in each patient, and with modification of Lys190 and Lys212 being detected in 8/8 patients. It was also revealed for the first time that plasma proteins could be modified with the 5-hydroxymethyl metabolite of flucloxacillin, and that essentially the same Lys residues were targeted by both the parent drug and its metabolite. This study provides a detailed characterisation of sites of chemical modification of an endogenous target and reveals candidate peptides for T-cell and antibody assays of flucloxacillin hypersensitivity.     

Advanced DNA- and Protein-based Methods for the Detection and Investigation of Food Allergens

Currently, food allergies are an important health concern worldwide. The presence of undeclared allergenic ingredients or the presence of traces of allergens due to contamination during food processing poses a great health risk to sensitized individuals. Therefore, reliable analytical methods are required to detect and identify allergenic ingredients in food products. The present review addresses the recent developments regarding the application of DNA- and protein-based methods for the detection of allergenic ingredients in foods. The fitness-for-purpose of reviewed methodology will be discussed, and future trends will be highlighted. Special attention will be given to the evaluation of the potential of newly developed and promising technologies that can improve the detection and identification of allergenic ingredients in foods, such as the use of biosensors and/or nanomaterials to improve detection limits, specificity, ease of use, or to reduce the time of analysis. Such rapid food allergen test methods are required to facilitate the reliable detection of allergenic ingredients by control laboratories, to give the food industry the means to easily determine whether its product has been subjected to cross-contamination and, simultaneously, to identify how and when this cross-contamination occurred.     

Recent developments in instrumental analysis for food quality

The definition of food quality has to be discussed in regard of changes of consumer expectations, legislative needs and new developments in instrumental analysis. The production process has to be controlled by fast new methods based on physical, chemical or increasingly biochemical/immunological principles. New chromatographic, immunological and mass-spectrometric methods allow the detection of trace amounts of residues/contaminants, allergens, trans-fatty acids and other undesired ingredients for food surveillance. Addition ally, analysis of new metabolic pathways in nutritional research is of increasing interest, giving evidence for positive health effects of minor food ingredients such as omega-3 fatty acids, isoflavones or conjugated linoleic acids. Most recent efforts in mass-spectrometric, biochemical and online/at-line methods for analysis of allergenicity, residues/contaminants, trans-fatty acid and for determination of identity and geographic origin of food are presented.     

Recent developments in instrumental analysis for food quality

The definition of food quality has to be discussed in regard of changes of consumer expectations, legislative needs and new developments in instrumental analysis. The production process has to be controlled by fast new methods based on physical, chemical or increasingly biochemical/immunological principles. New chromatographic, immunological and mass-spectrometric methods allow the detection of trace amounts of residues/contaminants, allergens, trans-fatty acids and other undesired ingredients for food surveillance. Additionally, analysis of new metabolic pathways in nutritional research is of increasing interest, giving evidence for positive health effects of minor food ingredients such as omega-3 fatty acids, isoflavones or conjugated linoleic acids. Most recent efforts in mass-spectrometric, biochemical and online/at-line methods for analysis of allergenicity, residues/contaminants, trans-fatty acid and for determination of identity and geographic origin of food are presented.     

Changes in the structure,digestibility and immunoreactivities of glycinin induced by the cross‐linking of microbial transglutaminase following heat denaturation

This study aimed to evaluate the effects of microbial transglutaminase (MTG)‐mediated modification on the structure, digestibility and immunoreactivities of glycinin. Glycinin was separated from soya bean and cross‐linked with MTG, and the sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) showed that the molecular weight of cross‐linked glycinin was higher than that of native glycinin. Individual MTG cross‐linking could maintain stable secondary structures and spatial structure. Sequential heat denaturation and MTG cross‐linking could promote the unfolding of protein structures and reduce their hydrophobicity. The digestibility of glycinin was decreased, and its immunoreactivities were increased because of MTG‐induced structural alteration, including primary and spatial structures.     

'EUROPART'. Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects

The relevance of particle mass, surface area or number concentration as risk indicators for health effects in non-industrial buildings has been assessed by a European interdisciplinary group of researchers (called EUROPART) by reviewing papers identified in Medline, Toxline, and OSH. Studies dealing with dermal effects or cancer or specifically addressing environmental tobacco smoke, house dust-mite, cockroach or animal allergens, microorganisms and pesticides were excluded. A total of 70 papers were reviewed, and eight were identified for the final review: Five experimental studies involving mainly healthy subjects, two cross-sectional office studies and one longitudinal study among elderly on cardiovascular effects. From most studies, no definite conclusions could be drawn. Overall, the group concluded that there is inadequate scientific evidence that airborne, indoor particulate mass or number concentrations can be used as generally applicable risk indicators of health effects in non-industrial buildings and consequently that there is inadequate scientific evidence for establishing limit values or guidelines for particulate mass or number concentrations.     

Building‐related health symptoms and classroom indoor air quality: a survey of school teachers in New York State

Most previous research on indoor environments and health has studied school children or occupants in non‐school settings. This investigation assessed building‐related health symptoms and classroom characteristics via telephone survey of New York State school teachers. Participants were asked about 14 building‐related symptoms and 23 classroom characteristics potentially related to poor indoor air quality (IAQ). Poisson regression analysis was used to assess the relationship between these symptoms and each classroom characteristic, controlling for potential confounders. About 500 teachers completed the survey. The most frequently reported classroom characteristics included open shelving (70.7%), food eaten in class (65.5%), dust (59.1%), and carpeting (46.9%). The most commonly reported symptoms included sinus problems (16.8%), headache (15.0%), allergies/congestion (14.8%), and throat irritation (14.6%). Experiencing one or more symptoms was associated most strongly with reported dust (relative risk (RR) = 3.67; 95% confidence interval (CI): 2.62–5.13), dust reservoirs (RR = 2.13; 95% CI: 1.72–2.65), paint odors (RR = 1.73; 95% CI: 1.40–2.13), mold (RR = 1.71; 95% CI: 1.39–2.11), and moldy odors (RR = 1.65 95% CI: 1.30–2.10). Stronger associations were found with increasing numbers of reported IAQ‐related classroom characteristics. Similar results were found with having any building‐related allergic/respiratory symptom. This research adds to the body of evidence underscoring the importance to occupant health of school IAQ.     

Effect of pasta drying temperature on gastrointestinal digestibility and allergenicity of durum wheat proteins

The effects of different drying temperatures (20, 60, 85, 110 and 180 °C) on digestibility and potential allergenicity of durum wheat proteins were studied in model pasta samples, cooked in boiling water (MPSs). Increasing the drying temperature resulted in increased protein denaturation and aggregation. In vitro treatment of MPSs with pepsin and pancreatin showed similar protein degradability up to a drying temperature of 110 °C, resulting in the disappearance of the main prolamin components. In contrast, the MPS treated at 180 °C was much less digestible, due to the presence of Maillard-type protein aggregates.