Frequency of goose and duck down causation of hypersensitivity pneumonitis within an 80-patient cohort.

BACKGROUND: A variety of antigens have been identified as causative of hypersensitivity pneumonitis (HP), which is characterized by inflammation to the lung parenchyma that is induced by exposure. Goose and duck down (GDD) bedding is often overlooked by physicians as a potential cause, yet the use of GDD has markedly increased in recent years, paralleling an increased frequency of reports of GDD-induced HP. OBJECTIVE: To determine the frequency of GDD as the causative antigen in patients with HP who use bedding that contains GDD. METHODS: Patients referred with a working diagnosis of HP underwent a detailed environmental history. Those who were using GDD were asked to remove it as an avoidance procedure. Signs, symptoms, spirometry, and inflammatory markers were followed up at weekly intervals for up to 1 month to determine the effect of remediation. RESULTS: Eighty patients with HP were seen during an 8-year period. Thirty-two patients (40%) were using GDD bedding. Of these 32 patients, 12 (37.5% of those exposed and 15% of the total HP population experienced remission (or nonprogression) of disease by simply avoiding GDD bedding. Eleven (92%) of these 12 patients were female. In patients with GDD-induced HP, lung biopsy patterns were varied. CONCLUSION: Approximately one-third of patients with HP, who slept with GDD, had persistent improvement or remission with simple avoidance. The higher incidence of GDD-induced HP in females may be hormonal and/or sociocultural related. Lung biopsy findings were across the spectrum of histopathologic patterns. Avoidance-challenge techniques were effective in confirming diagnoses and causation and mitigating the need for additional remediation.

Assessment of Antifouling Potential of Novel Transparent Sol Gel Coatings for Application in the Marine Environment.

In recent years, there has become a growing need for the development of antifouling technology for application in the marine environment. The accumulation of large quantities of biomass on these surfaces cause substantial economic burdens within the marine industry, or adversely impact the performance of sensor technologies. Here, we present a study of transparent coatings with potential for applications on sensors or devices with optical windows. The focus of the study is on the abundance and diversity of biofouling organisms that accumulate on glass panels coated with novel transparent or opaque organically modified silicate (ORMOSIL) coatings. The diatom assessment was used to determine the effectiveness of the coatings against biofouling. Test panels were deployed in a marine environment in Galway Bay for durations of nine and thirteen months to examine differences in biofilm formation in both microfouling and macrofouling conditions. The most effective coating is one which consists of precursor, tetraethyl orthosilicate (HC006) that has a water contact angle > 100, without significant roughness (43.52 nm). However, improved roughness and wettability of a second coating, diethoxydimethylsilane (DMDEOS), showed real promise in relation to macrofouling reduction.

Probing skin physiology through the volatile footprint: Discriminating volatile emissions before and after acute barrier disruption.

Volatile organic compounds emitted by human skin were sampled before and after acute barrier disruption of the volar forearm to investigate the significance of this approach to skin physiology research. A small wearable housing integrating a solid-phase micro-extraction fibre permitting rapid enclosed headspace sampling of human skin volatiles is presented, enabling non-invasive sample collection in 15 minutes, in a comfortable wearable format. Gas chromatography-mass spectrometry was utilised to separate and identify the volatile metabolites. A total of 37 compounds were identified, with aldehydes (hexanal, nonanal, decanal), acids (nonanoic, decanoic, dodecanoic, tetradecanoic and pentadecanoic acids) and hydrocarbons (squalane, squalene) predominant within the chemical profile. Acute barrier disruption was achieved through tape stripping (TS) of the stratum corneum to determine the impact on the volatile signature. Principle component analysis demonstrated there to be a discriminating volatile signature before and after TS. The dysregulation of significant features was examined. Several compounds derived from sebaceous components and their oxidation products were altered following barrier disruption, including squalane, squalene, octanal and nonanal. The upregulation of glycine was also observed, which may indicate a perturbation to the skin's natural moisturising factor production. TS impacted the hydro-lipid film that functions within the skin barrier, resulting in a differing volatile signature from affected skin. This provides a valuable non-invasive approach for scientific and clinical studies in dermatology, particularly around dermatological disorders associated with compromised barrier function.

Hydralazine-Associated Vasculitis and Pulmonary Hemorrhage.

Hydralazine is a potent vasodilating medication used as adjunctive therapy for the treatment of hypertension. Rarely, hydralazine may cause the development of antineutrophil cytoplasmic antibody vasculitis with the pulmonary-renal syndrome. We are presenting a case of hydralazine-associated vasculitis and pulmonary hemorrhage.

Assessment of anthropogenic pollution by monitoring occurrence and distribution of chemicals in the river Liffey in Dublin.

This paper evaluates for the first time the spatial distribution of a wide group of organic (phthalates, nitro, aliphatic, halogen, aromatic, phenol and amino compounds) and inorganic pollutants along the Liffey river in Dublin city. The work takes into account the effect of short-term weather conditions on the occurrence of these contaminants. The results showed that rainfall conditions affect the levels of pollutants along the river in the days following a rainfall event. In addition, the tributaries entering the river Liffey were not found to impact its water quality. In relation to organic pollutants, 2,4,6-trichlorophenol, 2-nitrophenol and phthalate compounds were found in many water samples between concentrations of 0.21 and 2.17 µg L-1. On the other hand, dimethyl phthalate was present in certain samples at levels around 100 µg L-1. The levels of these contaminants in the river were lower than the toxicity values reported in the literature. Regarding inorganic pollutants, nitrates were detected from 0.59 to 6.81 mg L-1 increasing from upstream to downstream. Based on the chemical nature and applications of detected pollutants, the river contamination can be mainly related to agricultural, industrial activities as well as diffuse urban contributions. These vary with location within a short distance and have the potential to impact aquatic biodiversity as the chemical composition changes with rainfall events.

Differential Scanning Calorimetry to Quantify Heat-Induced Aggregation in Concentrated Protein Solutions.

Differential scanning calorimetry (DSC) is an important technique to measure the thermodynamics of protein unfolding (or folding). Information including the temperature for the onset of unfolding, the melt transition temperature (Tm), enthalpy of unfolding (ΔH), and refolding index (RI) are useful for evaluating the heat stability of proteins for a range of biochemical, structural biology, industrial, and pharmaceutical applications. We describe a procedure for careful sample preparation of proteins for DSC measurements and data analysis to determine a range of thermodynamic parameters. In particular, we highlight a measure of protein refolding following complete thermal denaturation (RI), which quantifies the proportion of protein lost to irreversible aggregation after thermal denaturation.

Fluorescence Correlation Spectroscopy for Particle Sizing in Highly Concentrated Protein Solutions.

Highly concentrated solutions of biomolecules play an increasingly important role in biopharmaceutical drug development. In these systems, the formation of reversible aggregates by self-association creates a significant analytical challenge, since dilution is often required for techniques such as HPLC/liquid chromatography and analytical ultracentrifugation. There is a growing demand for methods capable of analyzing these assemblies, ideally under formulation conditions (i.e., in the presence of excipients). One approach that addresses this need is based on fluorescence correlation spectroscopy (FCS), which is a flexible and powerful technique to measure the diffusion of fluorescently labeled particles. It is particularly suited to measuring the size distribution of reversible aggregates of proteins or peptides in highly concentrated formulations, since it overcomes some of the challenges associated with other methods. In this protocol, we describe state-of-the-art measurement and analysis of protein self-assembly by determination of particle size distributions in highly concentrated protein solutions using FCS.

Evaluation of a miniaturised single-stage thermal modulator for comprehensive two-dimensional gas chromatography of petroleum contaminated soils.

A novel miniaturised single-stage resistively heated thermal modulator was investigated as an alternative to cryogenic modulation for use in comprehensive two-dimensional gas chromatography (GC×GC). The single-stage thermal modulator described herein yielded average retention time relative standard deviations (RSD) of ≤0.2% RSD (first-dimension) and ≤3.4% RSD (second-dimension). The average peak widths generated by the modulator were 72±3ms, and the peak area precision was better than 5.3% RSD for a range of polar and non-polar test analytes. GC×GC analysis can be performed using this modulator without the requirement for cryogenic cooling or additional pressure control modules for flow modulation. The modulator and associated electronics are compact and amenable towards field analysis. The modulator was used for qualitative and quantitative characterisation of petroleum-contaminated soils derived from a sub-Antarctic research station at Macquarie Island. The limit of detection compared to standard 1D GC analysis was improved from 64 to 11mgkg(-1). An automated method of analysing and categorising samples using principal component analysis is presented.

Back-flushing and heart cut capillary gas chromatography using planar microfluidic Deans' switching for the separation of benzene and alkylbenzenes in industrial samples.

Planar microfluidic devices coupled with modern electronic pressure control have allowed gas chromatography (GC) practitioners to easily manipulate chromatographic systems to achieve heart cut and back-flushing configurations. These planar microfluidic devices have enhanced the connectivity between different components of GC instrumentation and have improved the inertness and minimised system dead volumes compared to classical chromatographic unions and valves. In the present contribution the setup and configuration of two multidimensional GC (MDGC) platforms is described for achieving the separation and quantification of trace level target C6-C8 alkylbenzenes in styrene monomer and Isoparaffin™ solvents, using flame ionisation detection (FID). The performance of these MDGC platforms indicated excellent retention time (0.2% relative standard deviation, RSD) and peak area repeatability (1% RSD) for all analytes of interest. The limit of detection (LOD) was 0.8 mg kg(-1) for benzene in styrene monomer, and 2.4-2.8 mg kg(-1) for C6-C8 alkylbenzenes such as benzene, toluene, ethylbenzene and xylene in Isoparaffin™ solvent.

Multiplexed dual first-dimension comprehensive two-dimensional gas chromatography-mass spectrometry with contra-directional thermal modulation.

A multiplexed dual-primary column comprehensive two-dimensional gas chromatography-mass spectrometry approach (2GC×GC-MS) is introduced. The approach splits injected samples into two first-dimension columns with different stationary phases, and recombines the two streams into one second-dimension column that terminates at a single detector. The approach produces two two-dimensional chromatograms for each injection, and is made possible by using a dual-stage modulator operated in contra-directional modulation mode. The dual two-dimensional chromatograms produced by this single detector system provide complementary information due to selectivity differences between the three separation columns used in the column ensemble. An aged Australian tea tree (Melaleuca alternifolia) essential oil was analyzed to demonstrate the 2GC×GC-MS approach. The number of compounds separated by each of the GC×GC separations in the 2GC×GC experiment is comparable to conventional GC×GC experiments with matching column configurations. Robust peak assignment was possible for this sample based on the combination of MS library matches and multiple linear retention index searching. Forty-nine components (22 unique) were identified using a non-polar×mid-polar column combination and 34 components (7 unique) were positively identified using a polar×mid-polar column combination. Twenty-seven peak assignments were corroborated by positive identification in both of the multiplexed separations.

Applications of resistive heating in gas chromatography: a review.

Gas chromatography is widely applied to separate, identify, and quantify components of samples in a timely manner. Increasing demand for analytical throughput, instrument portability, environmental sustainability, and more economical analysis necessitates the development of new gas chromatography instrumentation. The applications of resistive column heating technologies have been espoused for nearly thirty years and resistively heated gas chromatography has been commercially available for the last ten years. Despite this lengthy period of existence, resistively heated gas chromatography has not been universally adopted. This low rate of adoption may be partially ascribed to the saturation of the market with older convection oven technology, coupled with other analytical challenges such as sampling, injection, detection and data processing occupying research. This article assesses the advantages and applications of resistive heating in gas chromatography and discusses practical considerations associated with adoption of this technology.