Epstein-Barr virus-positive mucocutaneous ulcer: A unique case occurring in association with cholelithiasis in a gallbladder.

Epstein-Barr virus (EBV)-positive mucocutaneous ulcer is a lymphoproliferative disorder occurring in patients due to iatrogenic or age-related immunosuppression confined to the oropharynx, skin, and gastrointestinal tract. Here, we report the first case to our knowledge of EBV-positive mucocutaneous ulcer occurring in a gallbladder.

A review of coccidiostats and the analysis of their residues in meat and other food.

Coccidiostats are used in the control of protozoan infections in different food producing animals. They are most widely used as feed additives in intensively reared species such as pigs and poultry to maintain animal health and in some cases enhance feed conversion. However, a number of these drugs are used in the control of infections in beef and lamb production. Coccidiostat residues have been frequently reported in meat and eggs in a number of countries since the late 1990s. This has prompted increased research and surveillance of coccidiostat residues in food. This paper reviews the various coccidiostat agents used in animal production, including their chemical properties, mode of action and activity. Legislation concerning coccidiostats, limits for residues in food, monitoring and occurrence of residues in food is discussed. Methods for residue determination in food, including screening and physicochemical methods are discussed in depth. The paper concludes with a synopsis of the current state of coccidiostat residue analysis and future perspectives.

Residue analyses and exposure assessment of the Irish population to nitrofuran metabolites from different food commodities in 2009-2010.

An exposure assessment to nitrofuran residues was performed for three human populations (adults, teenagers and children), based on residue analyses of foods of animal origin (liver, honey, eggs and aquaculture) covering the 2-year period 2009-2010. The occurrence of nitrofuran metabolites in food on the Irish market was determined for the selected period using the data from Ireland's National Food Residue Database (NFRD) and from results obtained from the analysis of retail samples (aquaculture and honey). Laboratory analyses of residues were performed by methods validated in accordance with Commission Decision 2002/657/EC regarding performance of the analytical method and interpretation of results. Semicarbazide (SEM) was the contaminant most frequently identified and its content ranged from 0.09 to 1.27 µg kg(-1). SEM is currently used as a marker of nitrofuran abuse, but it may also occur from other sources. The presence of nitrofuran metabolite 3-amino-2-oxazolidinone (AOZ) was detected in two aquaculture samples (prawns) at 1.63 and 1.14 µg kg(-1), but such a low number of positive cases did not present sufficient data for a full AOZ exposure assessment. Therefore, the evaluation of exposure was focused on SEM-containing food groups only. Exposure assessments were completed using a probabilistic approach that generated 10 iterations. The results of both the upper- and lower-bound exposure assessments demonstrate that SEM exposure for Irish adults, teenagers and children from selected food commodities are well below EFSA-estimated safe levels.

Design and implementation of an imprinted material for the extraction of the endocrine disruptor bisphenol A from milk.

This paper describes the determination of bisphenol A (BPA) in milk samples, using a novel molecularly imprinted polymer. The imprinted polymer was developed using a rational design approach, and pre-polymerization interactions were investigated using molecular dynamics simulations and X-ray crystallography. A hydroquinone-imprinted polymer was used for solid phase extraction (SPE) clean-up of samples. BPA was quantified by high performance liquid chromatography (HPLC) and fluorescence (FLD) detection. Following validation, the method described was capable of determining bisphenol A in milk down to a limit of detection of 1.32µgkg(-1). The method was applied to a survey (n=27) of commercial milk products; BPA was detected in one of the samples, at a level of 176µgkg(-1). Test results were confirmed by a parallel UHPLC-MS/MS analytical method. This demonstrates the utility of the hydroquinone-imprinted polymer for application to selective sample clean-up and analysis of bisphenol A in milk, avoiding possible detrimental affects associated with template bleeding and without the need for expensive or difficult-to-obtain template.

The use of ultra-high pressure liquid chromatography with tandem mass spectrometric detection in the analysis of agrochemical residues and mycotoxins in food - challenges and applications.

In the field of food contaminant analysis, the most significant development of recent years has been the integration of ultra-high pressure liquid chromatography (UHPLC), coupled to tandem quadrupole mass spectrometry (MS/MS), into analytical applications. In this review, we describe the emergence of UHPLC through technological advances. The implications of this new chromatographic technology for MS detection are discussed, as well as some of the remaining challenges in exploiting it for chemical residue applications. Finally, a comprehensive overview of published applications of UHPLC-MS in food contaminant analysis is presented, with a particular focus on veterinary drug residues.

Maximum residue level validation of triclabendazole marker residues in bovine liver, muscle and milk matrices by ultra high pressure liquid chromatography tandem mass spectrometry.

Triclabendazole is the only anthelmintic drug, which is active against immature, mature and adult stages of fluke. The objective of this work was to develop an analytical method to quantify and confirm the presence of triclabendazole residues around the MRL. In this work, a new analytical method was developed, which extended dynamic range to 1-100 and 5-1000 µg kg(-1) for milk and tissue, respectively. This was achieved using a mobile phase containing trifluoroacetic acid (pK(a) of 0.3), which resulted in the formation of the protonated pseudomolecular ions, [M+H](+), of triclabendazole metabolites. Insufficient ionisation of common mobile phase additives due to low pK(a) values (<2) was identified as the cause of poor linearity. The new mobile phase conditions allowed the analysis of triclabendazole residues in liver, muscle and milk encompassing their EU maximum residue levels (MRL) (250, 225 and 10 µg kg(-1) respectively). Triclabendazole residues were extracted using a modified QuEChERS method and analysed by positive electrospray ionisation mass spectrometry with all analytes eluted by 2.23 min. The method was validated at the MRL according to Commission Decision (CD) 2002/657/EC criteria. The decision limit (CCα) of the method was in the range of 250.8-287.2, 2554.9-290.8 and 10.9-12.1 µg kg(-1) for liver, muscle and milk, respectively. The performance of the method was successfully verified for triclabendazole in muscle by participating in a proficiency study, the method was also applied to incurred liver, muscle and milk samples.

Darned in 2013: inclusion of model organisms and linking with Wikipedia.

DARNED (DAtabase of RNa EDiting, available at http://darned.ucc.ie) is a centralized repository of reference genome coordinates corresponding to RNA nucleotides having altered templated identities in the process of RNA editing. The data in DARNED are derived from published datasets of RNA editing events. RNA editing instances have been identified with various methods, such as bioinformatics screenings, deep sequencing and/or biochemical techniques. Here we report our current progress in the development and expansion of the DARNED. In addition to novel database features the DARNED update describes inclusion of Drosophila melanogaster and Mus musculus RNA editing events and the launch of a community-based annotation in the RNA WikiProject.

Determination of 20 coccidiostats in egg and avian muscle tissue using ultra high performance liquid chromatography-tandem mass spectrometry.

A quantitative, comprehensive multiresidue method which includes 20 coccidiostat residues has been developed. The method described uses a simple one-step liquid extraction with acetonitrile to isolate analytes from both the polyether ionophore and chemical classes of coccidiostats. Subsequent to a further concentration step, samples were analysed via UHPLC-MS/MS. The method was validated according to the Commission Decision 2002/657/EEC in egg and avian muscle. The method permitted quantitative confirmation for 13 compounds below target concentrations, and screening for a further 7 compounds. Within-laboratory repeatability gave accuracy values in the range of 68-129%, while reproducibility ranged between 75 and 123%. Calibration ranges were typically 1-50 µg kg⁻¹, although higher ranges were used for dinitrocarbanilide, imidocarb and toltrazuril residues. A regression coefficient (R²) value of greater than 0.98 was obtained for all analytes. Precision results ranged from 2.3 to 19.7% CV for egg and from 2.6 to 23.6% CV in muscle. CCα was in the range from 1.13 µg kg⁻¹ (clopidol) to 179 µg kg⁻¹ (lasalocid) in egg. In muscle, CCα ranged from 2.25 µg kg⁻¹ (aprinocid) to 4579 µg kg⁻¹ (dinitrocarbanilide). CCß was from 1.29 µg kg⁻¹ (clopidol) to 209 µg kg⁻¹ (lasalocid) in egg, and 2.58 µg kg⁻¹ (arprinocid) to 6060 µg kg⁻¹ (dinitrocarbanilide) in muscle. Limits of quantification were 1 µg kg⁻¹ for all compounds, except imidocarb and dinitrocarbanilide (10 µg kg⁻¹), and toltrazuril and metabolites (50 µg kg⁻¹).

Simultaneous detection of four nitrofuran metabolites in honey using a multiplexing biochip screening assay.

A chemiluminescence-based biochip array sensing technique has been developed and applied to the screening of honey samples for residues of banned nitrofuran antibiotics. Using a multiplex approach, metabolites of the four main nitrofuran antibiotics could be simultaneously detected. Individual antibodies specific towards the metabolites were spotted onto biochips. A competitive assay format, with chemiluminescent response, was employed. The method was validated in accordance with EU legislation (2002/657/EC, 2002), and assessed by comparison with UHPLC-MS/MS testing of 134 honey samples of worldwide origin. A similar extraction method, based on extraction of the analytes on Oasis™ SPE cartridges, followed by derivatisation with nitrobenzaldehyde and partition into ethyl acetate, was used for both screening and LC-MS/MS methods. The biochip array method was capable of detecting all four metabolites below the reference point for action of 1 µg kg(-1). The detection capability was below 0.5 µg kg(-1) for the metabolites AHD, AOZ and AMOZ; it was below 0.9 µg kg(-1) for SEM. IC(50) values ranged from 0.14 µg kg(-1) (AMOZ) to 2.19 µg kg(-1) (SEM). This biosensor method possesses the potential to be a fit-for-purpose screening technique in the arena of food safety technology.

Perianal dermatofibrosarcoma protuberans: a case report.

A 67-year-old man presented with a perianal lump that had increased in size. On examination he had a 3-cm irregular, mobile, elevated, red, polypoid lump at the edge of the anus at the 8-o'clock position. Biopsy results unexpectedly revealed a spindle cell lesion extending deep into the subcutaneous tissue with occasional mitoses. The lesion was positive for CD34 and negative for epithelial markers, consistent with dermatofibrosarcoma protuberans (DFSP). Magnetic resonance imaging of the pelvis showed the mass extending deep into the ischiorectal space with no involvement of the external or internal anal sphincter. He underwent excision of the lesion with circumferential margins of 1 cm and formation of a skin rotation flap to achieve primary closure. Histology confirmed DFSP. Both the deep and lateral resection margins were involved. He proceeded to have a wider excision of margins, which was free of any remaining tumor. Dermatofibrosarcoma protuberans is a rare lesion. It most commonly occurs on the trunk; the perianal presentation in this case is unique. Surgical excision and preservation of functionality with cosmesis was an issue in this case, as DFSP is a locally aggressive tumor with a high recurrence rate.

Current trends in sample preparation for growth promoter and veterinary drug residue analysis.

A comprehensive review is presented on the current trends in sample preparation for the isolation of veterinary drugs and growth promoters from foods. The objective of the review is to firstly give an overview of the sample preparation techniques that are applied in field. The review will focus on new techniques and technologies, which improve efficiency and coverage of residues. The underlying theme to the paper is the developments that have been made in multi-residue methods and particularly multi-class methods for residues of licensed animal health products, which have been developed in the last couple of years. The role of multi-class methods is discussed and how they can be accommodated in future residue surveillance.

Structure and dynamics of monomer-template complexation: an explanation for molecularly imprinted polymer recognition site heterogeneity.

We here present the first simulation of a complete molecularly imprinted polymer prepolymerization system. Molecular dynamics studies were performed for a system comprising a total of 1199 discrete molecules, replicating the components and concentrations employed in the corresponding polymer synthesis. The observed interactions correlate well with results obtained from (1)H NMR spectroscopic studies. Comparison with simulations performed in the absence of cross-linking agent (ethylene dimethacrylate) demonstrated its significance in the formation of ligand recognition sites. Moreover, the influence of events such as template-template (bupivacaine) and monomer-monomer (methacrylic acid) self-association, porogen-template interactions, and template conformational variability was revealed. The template recognition capacity of the modeled polymer system was verified by synthesis of imprinted and reference polymers and subsequent radioligand binding analysis. Collectively, through a series of statistical analyses of molecular trajectories in conjunction with spectroscopic data it was demonstrated that an ensemble of complex structures is present in the prepolymerization mixture and that this diversity is the basis for the binding site heterogeneity observed in molecularly imprinted polymers (MIPs) prepared using the noncovalent strategy.

Theoretical and computational strategies for rational molecularly imprinted polymer design.

The further evolution of molecularly imprinted polymer science and technology necessitates the development of robust predictive tools capable of handling the complexity of molecular imprinting systems. A combination of the rapid growth in computer power over the past decade and significant software developments have opened new possibilities for simulating aspects of the complex molecular imprinting process. We present here a survey of the current status of the use of in silico-based approaches to aspects of molecular imprinting. Finally, we highlight areas where ongoing and future efforts should yield information critical to our understanding of the underlying mechanisms sufficient to permit the rational design of molecularly imprinted polymers.

Correlated theoretical, spectroscopic and X-ray crystallographic studies of a non-covalent molecularly imprinted polymerisation system.

The correlation of the recognition properties of a molecularly imprinted polymer (MIP) with the recognition events in pre-polymerisation mixtures is of central importance to our understanding of the molecular imprinting technique. Using the NSAID naproxen as a model template, we have applied parallel theoretical (molecular dynamics) and practical ((1)H-NMR, X-ray crystallography, HPLC, radioligand binding) methods to examine the nature of template-functional monomer complexation. An effective imprint is achieved, despite the presence of only one site on the template which provides for the formation of effective electrostatic interactions with the functional monomer used, 4-vinylpyridine. This is attributed to the creation of a well-defined receptor site for the acidic terminus of the molecule and complementary van der Waals interactions, as described in preliminary simulations of the pre-polymerisation system, and as confirmed for the resultant MIP by HPLC data. Qualitative agreement is also observed between simulation and proton NMR data examining monomer self-association in the presence and absence of the template. On the basis of the data obtained, the role of a cross-linker appears to be more significant for this system than previously anticipated.

Mode of heavy meromyosin adsorption and motor function correlated with surface hydrophobicity and charge.

The in vitro motility assay is valuable for fundamental studies of actomyosin function and has recently been combined with nanostructuring techniques for the development of nanotechnological applications. However, the limited understanding of the interaction mechanisms between myosin motor fragments (heavy meromyosin, HMM) and artificial surfaces hampers the development as well as the interpretation of fundamental studies. Here we elucidate the HMM-surface interaction mechanisms for a range of negatively charged surfaces (silanized glass and SiO2), which is relevant both to nanotechnology and fundamental studies. The results show that the HMM-propelled actin filament sliding speed (after a single injection of HMM, 120 microg/mL) increased with the contact angle of the surfaces (in the range of 20-80 degrees). However, quartz crystal microbalance (QCM) studies suggested a reduction in the adsorption of HMM (with coupled water) under these conditions. This result and actin filament binding data, together with previous measurements of the HMM density (Sundberg, M.; Balaz, M.; Bunk, R.; Rosengren-Holmberg, J. P.; Montelius, L.; Nicholls, I. A.; Omling, P.; Tågerud, S.; Månsson, A. Langmuir 2006, 22, 7302-7312. Balaz, M.; Sundberg, M.; Persson, M.; Kvassman, J.; Månsson, A. Biochemistry 2007, 46, 7233-7251), are consistent with (1) an HMM monolayer and (2) different HMM configurations at different contact angles of the surface. More specifically, the QCM and in vitro motility assay data are consistent with a model where the molecules are adsorbed either via their flexible C-terminal tail part (HMMC) or via their positively charged N-terminal motor domain (HMMN) without other surface contact points. Measurements of zeta potentials suggest that an increased contact angle is correlated with a reduced negative charge of the surfaces. As a consequence, the HMMC configuration would be the dominant configuration at high contact angles but would be supplemented with electrostatically adsorbed HMM molecules (HMMN configuration) at low contact angles. This would explain the higher initial HMM adsorption (from probability arguments) under the latter conditions. Furthermore, because the HMMN mode would have no actin binding it would also account for the lower sliding velocity at low contact angles. The results are compared to previous studies of the microtubule-kinesin system and are also discussed in relation to fundamental studies of actomyosin and nanotechnological developments and applications.

Imprinted polymeric materials. Insight into the nature of prepolymerization complexes of quercetin imprinted polymers.

Molecular imprinting techniques have proved to be a highly accessible method for producing molecule-specific recognition materials for a variety of applications, ranging from sensing to catalysis and separations. In noncovalent imprinting, it is anticipated that polymerizable complexes are created in the prepolymerization solution via self-assembly of functional monomers and template molecules resulting from inherent chemical complementarity, which will ideally form binding sites within the cross-linked matrix after polymerization. On the basis of 1H NMR data and X-ray crystallographic evidence, we now infer a more important role for template self-association for the recognition properties of quercetin-imprinted polymers. While directly applicable to fundamental understanding of the molecular imprinting mechanism of this polyphenol, on a more generic scale, this work also demonstrates the utility of this strategy toward analyzing complex noncovalent interaction mechanisms between small molecules. These interactions are of particular interest for quercetin and other members of the flavone/flavonoid class of compounds, which are radical-scavenging polyphenols of substantial interest to biomedicine.

Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003.

Over 1450 references to original papers, reviews and monographs have herein been collected to document the development of molecular imprinting science and technology from the serendipitous discovery of Polyakov in 1931 to recent attempts to implement and understand the principles underlying the technique and its use in a range of application areas. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by papers dealing with fundamental aspects of molecular imprinting and the development of novel polymer formats. Thereafter, literature describing attempts to apply these polymeric materials to a range of application areas is presented.

Analyzing the mechanisms of selectivity in biomimetic self-assemblies via IR and NMR spectroscopy of prepolymerization solutions and molecular dynamics simulations.

Molecularly imprinted polymers (MIPs) for 2,4-dichlorophenoxyacetic acid were synthesized via a noncovalent approach with 4-vinylpyridine as functional monomer and ethylene glycol dimethacrylate as cross-linker in a methanol/water mixture. Templated polymers synthesized in this self-assembly approach rely on complex formation between the target analyte and functional monomers in porogenic solution prior to radical polymerization. Consequently, the achievable selectivity is governed by the nature and stability of these complexes. The nature of noncovalent interactions responsible for complex formation during imprinting of the template 2,4-dichlorophenoxyacetic acid (2,4-D) with the functional monomer 4-vinylpyridine has been investigated. Fourier transform infrared and 1H NMR spectroscopies provide the fundamental analytical basis for rationalizing the mechanisms of recognition during the imprinting process probing the governing interactions for selective binding site formation at a molecular level. Molecular modeling studies in explicit solvent (chloroform and water) corroborate the importance of hydrogen bonding in aprotic solvents and of hydrophobic interactions in protic media in agreement with the experimental spectroscopic investigations of prepolymerization solutions. Furthermore, chromatographic studies of the synthesized MIPs provided insight on the importance of size, shape, and functionality during selective 2,4-D rebinding processes confirming the results obtained during the prepolymerization studies.

Cognitive performance and liver function among recently abstinent alcohol abusers.

It has frequently been suggested that some of the enduring subtle cognitive impairments seen in sober alcohol-dependent persons may be a result of subclinical liver dysfunction. Cognitive performance and liver function among 85 recently abstinent alcohol-dependent persons were assessed by means of a neuropsychological examination and the GGT test of liver function. Unlike some previous studies, no relationships were found between the two areas of functioning. It is argued that lack of statistical power did not account for the failure to find an association between the two domains. The proposition that residual cognitive impairment in abstinent alcoholic persons is (partly) mediated by earlier liver dysfunction rests on slight empirical foundations and remains speculative.

Administration of analgesia for acute abdominal pain sufferers in the accident and emergency setting.

BACKGROUND: Recent trials suggest that the early administration of analgesia in patients with acute abdominal pain facilitates examination and does not delay diagnosis. We investigated current practice regarding analgesia for these patients. METHODS: All patients admitted via the accident and emergency department with abdominal pain were included. The main outcome measures evaluated were waiting time for analgesia and its relationship to subjective visual analogue pain scores and clinical diagnoses. RESULTS: Data from 107 consecutive patients were investigated; seven patients were excluded. Forty-two per cent were male. The mean age was 40.1 years (6-85). The mean overall waiting time for analgesia was 1.4 h (2 min to 14 h). Sixty-seven per cent received analgesia within one hour, although 22% waited 2-14 h after presentation. Those with mild pain waited significantly longer for analgesia (mean 247 min) than those with severe pain (mean 82 min; P=0.01). Those with moderate pain had intermediate waiting times (mean 111 min), although they were not statistically different from the severe group (P=0.43). Female patients had to wait longer (mean 129 min) than male patients (mean 69 min; P=0.09 analysis of variance). Of 64% who were general practitioner referrals, only 11% (all severe group, P=0.02) received analgesia in the community. Neither clinical diagnosis nor age influenced the timing of analgesia. Seventy-three per cent received analgesia in the casualty department (mean 0.5 h; range 0.02-3.2), whereas those admitted in the ward without receiving analgesia in casualty had to wait significantly longer for their pain relief (mean 5 h; 1.2-14). CONCLUSION: This study shows the need for standardized protocols for analgesia usage in patients presenting with acute abdominal pain.