EURL-FA Control Proficiency test report: Determination of authorised coccidiostats in compound feed

The European Union Reference Laboratory for Feed Additives (EURL-FA), hosted by the Joint Research Centre (JRC), a Directorate General of the European Commission, has been mandated by the Directorate General for Health and Food Safety (DG SANTE) to organise a proficiency test (PT) among appointed National Reference Laboratories (NRLs) in the frame of its control activities (according to the Regulation (EC) No 882/2004 [1]). The aim of this PT was to assess the capacity of the NRLs to correctly determine selected authorised coccidiostats added to feed matrices at realistic authorised levels and at cross-contamination levels. Thirty-six European National and Official Control laboratories were invited and twenty-nine laboratories registered to the 2017 PT exercise. Twenty-five of the registered laboratories reported results for the analyses. The test items used in this exercise were produced by the JRC. Purchased commercial poultry compound feed, tested by the EURL-FA Control as being blank for the target analytes, was milled and ground and then spiked with the required coccidiostat standard solution or with the relevant authorised feed additive. The first item was spiked with a standard solution containing monensin, narasin and diclazuril, at cross-contamination level (MAT 1). The second test item (MAT 2) was spiked with an authorised feed additive Maxiban®, containing narasin (narasin AL) and nicarbazin, at additive level. MAT 1 and MAT 2 were subsequently homogenised and distributed in glass bottles. All bottles were labelled ensuring a random number encoding and dispatched to all registered participants on 27 June 2017. Laboratories were informed of the composition of the test material regarding the composition in coccidiostats for MAT 2 and had therefore only to quantify the content. For MAT 1 the laboratories had to screen for the presence of all 11 authorised coccidiostats and to quantify the detected ones. The assigned values (xpt) for the mass content of monensin, diclazuril and narasin in MAT 1 were calculated from the formulation as recommended by the IUPAC harmonized protocol [2]. The uncertainties for the assigned values (u(xpt)) were calculated according to the ISO Guide for the Expression of Uncertainty in Measurement (GUM) [3]. For narasin and nicarbazin in MAT 2, no assigned value was set since the criterion for sufficient homogeneity could not be met. Participants were invited to report their measurement uncertainties. This was done by twenty-three out of twenty-five reporting participants for monensin and narasin, seventeen for diclazuril, and twenty for narasin AL and nicarbazin. Laboratory results were rated using z and ζ (zeta) scores in accordance with ISO 13528:2015 [4]. The relative standard deviation for proficiency assessment (σpt) for each assigned value was calculated using the relevant Horwitz [5] or modified Horwitz equation [6]. The z scores obtained were considered satisfactory if their absolute values were equal to or below 2. The outcome of this PT exercise is mixed; the percentage of satisfactory results reported by the laboratories for MAT 1 is 88%, 80% and 57% for monensin, narasin and diclazuril respectively. For narasin AL and nicarbazin in MAT 2, no scoring was computed but the data reported by the laboratories were examined. In general, there was good agreement among the values of mass content of narasin and nicarbazin reported results. The laboratories also reported qualitative results as regards the presence of one or more of the other authorised coccidiostats. On the whole, the rate of false positive results was of 4% for robenidine, lasalocid, salinomycin and maduramicin; 5% for nicarbazin; 8% for decoquinate; and 0% for all the others. Two laboratories did not quantify diclazuril in MAT 1 while stating a limit of quantification of the method used lower than the assigned value, leading to a false negative rate of 9% for this analyte. One laboratory could not quantify diclazuril in MAT 1 due to the lack of sensitivity of the method used.JRC.F.5-Food and Feed Complianc

EURL-FA Control Proficiency Test Report: Determination of the mass fraction of the total cobalt in compound feed for rabbits

The European Union Reference Laboratory for Feed Additive Control (EURL-FA Control) organised a proficiency test (EURL-FAC 2017-2) for the determination of the mass fraction of total cobalt in compound feed, to support the Commission Implementing Regulation (EU) No 131/2014 concerning the authorisation of various cobalt(II) compounds as feed additives. This proficiency test was open to National Reference Laboratories (NRLs) and official feed control laboratories (OCLs). The material used as test item was a commercially available compound feed for rabbits (containing the coated granulated cobalt (II) carbonate, 3b304 ) which, after appropriate processing, was bottled, labelled and dispatched to participants on June 21, 2017. The homogeneity and stability of the test item were evaluated and the assigned values were derived from the results reported by the selected expert laboratories. Twenty one NRLs and two OCLs from 21 countries - representing EU Member States and Norway - registered to the exercise and reported results at the end of August 2017. Laboratory results were rated using z' and zeta scores in accordance with ISO 13528:2015. A relative standard deviation for proficiency assessment (σpt) of 16 % of the assigned value was set according to the modified Horwitz equation. Twenty (out of 23) laboratories reported satisfactory results (according to the z' score). This confirms the ability of most NRLs in monitoring maximum levels set by the Commission Implementing Regulation (EU) No 131/2014 in this type of animal feed. The majority (74 %) of the participating laboratories provided realistic estimates of their measurement uncertainties.JRC.F.5-Food and Feed Complianc

Community Reference Laboratory for Feed Additives Authorisation: Annual Report 2006

The objective of this report is to present the activities of the Community Reference Laboratory for Feed Additives Authorisation in 2006 (CRL-FAA). The report shows that besides the evaluation of dossiers, the CRL-FAA carried out many other tasks. Important additional matters were the successful accreditation of the laboratory according to ISO 17025, the support of the European Commission regarding the drafting of the new guidelines for the applicants, further improvement of informatics tools and the organisation of two workshops to discuss these topics with the National Reference Laboratory.JRC.D.8-Food safety and qualit

Development and validation of a rapid multiplex ELISA for pyrrolizidine alkaloids and their N-oxides in honey and feed

Pyrrolizidine alkaloids (PAs) are a group of plant secondary metabolites with carcinogenic and hepatotoxic properties. When PA-producing plants contaminate crops, toxins can be transferred through the food chain and cause illness in humans and animals, most notably hepatic venoocclusive disease. Honey has been identified as a direct risk of human exposure. The European Food Safety Authority has recently identified four groups of PAs that are of particular importance for food and feed: senecionine-type, lycopsaminetype, heliotrine-type and monocrotaline-type. Liquid or gas chromatography methods are currently used to detect PAs but there are no rapid screening assays available commercially. Therefore, the aim of this study was to develop a rapid multiplex ELISA test for the representatives of three groups of alkaloids (senecionine, lycopsamine and heliotrine types) that would be used as a risk-management tool for the screening of these toxic compounds in food and feed. The method was validated for honey and feed matrices and was demonstrated to have a detection capability less than 25 μg/kg for jacobine, lycopsamine, heliotrine and senecionine. The zinc reduction step introduced to the extraction procedure allows for the additional detection of the presence of N-oxides of PAs. This first multiplex immunoassay for PA detection with N-oxide reduction can be used for the simultaneous screening of 21 samples for >12 PA analytes. Honey samples (n =146) from various origins were analysed for PA determination. Six samples were determined to contain measurable PAs >25 μg/kg by ELISAwhich correlated to >10 μg/kg by LC-MS/MS.JRC.D.5-Standards for Food Bioscienc

Assessment of dietary exposure to some persistent organic pollutants in the Republic of Karakalpakstan of Uzbekistan.

A 1999 study heightened long-standing concerns over persistent organic pollutant contamination in the Aral Sea area, detecting elevated levels in breast milk and cord blood of women in Karakalpakstan (western Uzbekistan). These findings prompted a collaborative research study aimed at linking such human findings with evidence of food chain contamination in the area. An international team carried out analyses of organochlorine and organophosphate pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) on samples of 12 foods commonly produced and consumed in Karakalpakstan. Analysis consistently detected long-lasting organochlorine pesticides and their metabolites in all foods of animal origin and in some vegetables such as onions and carrots--two low-cost components of many traditional dishes. Levels of PCBs were relatively low in all samples except fish. Analyses revealed high levels of PCDDs and PCDFs (together often termed "dioxins") in sheep fat, dairy cream, eggs, and edible cottonseed oil, among other foodstuffs. These findings indicate that food traditionally grown, sold, and consumed in Karakalpakstan is a major route of human exposure to several persistent toxic contaminants, including the most toxic of dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). Intake estimations demonstrate that consumption of even small amounts of locally grown food may expose consumers to dioxin levels that considerably exceed the monthly tolerable dioxin intake levels set by the World Health Organization. Data presented in this study allow a first assessment of the risk associated with the consumption of certain food products in Karakalpakstan and highlight a critical public health situation

EURL-FA Control: Proficiency Test Report

The European Union Reference Laboratory for Feed Additive Control (EURL-FA Control) organised a proficiency test (PT) for the determination of the mass fraction of total selenium in compound feed, to support the Commission Directive 86/403/EEC concerning additives in feeding stuffs. This proficiency test was open to National Reference Laboratories (NRLs) and official feed control laboratories (OCLs). The material used as test item was a commercially available compound feed for rabbits (containing, among others, selenium as sodium selenite) which, after appropriate processing, was bottled, labelled and dispatched to participants on May 22, 2018. The homogeneity and stability of the test item were evaluated and the assigned values were derived from the results reported by the selected expert laboratories. Twenty one NRLs and four OCLs from 20 countries - representing several EU Member States, Norway and Switzerland - registered to the exercise and reported results at the end of June 2018. Laboratory results were rated using z' and ζ (zeta) performance scores in accordance with ISO 13528:2015. The relative standard deviation for proficiency assessment (σpt) of 15 % of the assigned value was derived from the reproducibility standard deviation reported in the CEN standard EN 16159:2012. Twenty three (out of 25) laboratories reported satisfactory results (according to the z' score). This confirms the ability of most NRLs in monitoring maximum levels set by the Commission Directive 86/403/EEC concerning additives in feeding stuffs.JRC.F.5-Food and Feed Complianc

Sleep disturbances in highly stress reactive mice: Modeling endophenotypes of major depression

<p>Abstract</p> <p>Background</p> <p>Neuronal mechanisms underlying affective disorders such as major depression (MD) are still poorly understood. By selectively breeding mice for high (HR), intermediate (IR), or low (LR) reactivity of the hypothalamic-pituitary-adrenocortical (HPA) axis, we recently established a new genetic animal model of extremes in stress reactivity (SR). Studies characterizing this SR mouse model on the behavioral, endocrine, and neurobiological levels revealed several similarities with key endophenotypes observed in MD patients. HR mice were shown to have changes in rhythmicity and sleep measures such as rapid eye movement sleep (REMS) and non-REM sleep (NREMS) as well as in slow wave activity, indicative of reduced sleep efficacy and increased REMS. In the present study we were interested in how far a detailed spectral analysis of several electroencephalogram (EEG) parameters, including relevant frequency bands, could reveal further alterations of sleep architecture in this animal model. Eight adult males of each of the three breeding lines were equipped with epidural EEG and intramuscular electromyogram (EMG) electrodes. After recovery, EEG and EMG recordings were performed for two days.</p> <p>Results</p> <p>Differences in the amount of REMS and wakefulness and in the number of transitions between vigilance states were found in HR mice, when compared with IR and LR animals. Increased frequencies of transitions from NREMS to REMS and from REMS to wakefulness in HR animals were robust across the light-dark cycle. Detailed statistical analyses of spectral EEG parameters showed that especially during NREMS the power of the theta (6-9 Hz), alpha (10-15 Hz) and eta (16-22.75 Hz) bands was significantly different between the three breeding lines. Well defined distributions of significant power differences could be assigned to different times during the light and the dark phase. Especially during NREMS, group differences were robust and could be continuously monitored across the light-dark cycle.</p> <p>Conclusions</p> <p>The HR mice, i.e. those animals that have a genetic predisposition to hyper-activating their HPA axis in response to stressors, showed disturbed patterns in sleep architecture, similar to what is known from depressed patients. Significant alterations in several frequency bands of the EEG, which also seem to at least partly mimic clinical observations, suggest the SR mouse lines as a promising animal model for basic research of mechanisms underlying sleep impairments in MD.</p

Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research

Altres ajuts: Max Planck Society (Germany).The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes

A protocol for the validation of qualitative methods of detection

This paper presents a draft protocol for analyzing the results of validation studies for qualitative methods of detection which is designed to meet three competing goals: (1) to give correct answers, (2) have a broad scope of application, and (3) be accessible to a wide range of users. The draft protocol can be applied to the validation of methods by collaborative trial or to single-laboratory studies. The protocol produces an estimate of the probability of a positive response with a prediction interval within which 95% of laboratories (or analytical runs) are expected to fall when the method is applied in practice. The interval is calculated from the observed reproducibility (or within-laboratory reproducibility) standard deviation. Then a simple plot of prediction intervals for the probability of detection against the concentration of analyte, where the concentration is known, is used to provide an estimate of the range of limits of detection and false positive probability that we can expect to see when the validated method is applied in practice. The use of the draft protocol is demonstrated using results produced by three collaborative trials. A simulation study showed that a conclusion that a method is fit for purpose that is generated by the draft protocol is likely to be safe.JRC.D.5-Standards for Food Bioscienc

Challenges and Needs for Food Measurements

Abstract is not availableJRC.D.8-Food safety and qualit