This Guidance describes how to perform hazard identification for endocrine‐disrupting properties by following the scientific criteria which are outlined in Commission Delegated Regulation (EU) ...2017/2100 and Commission Regulation (EU) 2018/605 for biocidal products and plant protection products, respectively.
This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2018.EN-1447/full
•Hepatocytes provide an in vitro model for predicting in vivo metabolic clearance.•Chemical concentration vs time allows calculation of depletion rate due to metabolism.•Six structural analogue short ...chain fatty acids, both aliphatic and branched, were used.•UPLC Mass spectrometry enabled precise quantitative analysis of chemical clearance.•Chain molecular structures were more biotransformed than their branched carbon analogues.
Laboratory measurements of intrinsic clearance support the development of TK models, with potential relevance to weight of evidence toxicity assessments of xenobiotics, including read-across, the concept of predictive estimation by data extrapolation between chemicals of similar structure (analogues).
In this work a procedure with analytical method for determination of in vitro hepatic metabolic clearance, relevant to biotransformation toxicokinetic (TK) modelling, is presented. Cryopreserved primary human hepatocytes represent a suitable cells, due to their biological characteristics, for providing an in vitro model for simulating in vivo metabolic clearance.
The experimental part considered an adequate sequential time-frame for collecting samples and controls for all chemicals tested, including centrifugation and aliquoting of the corresponding fractions until the instrumental session.
For the first time, in vitro hepatocyte intrinsic clearance was measured for six analogue test chemicals: valproic acid, 2-ethyl caproic acid, octanoic acid, valeric acid, 2-methyl butyric acid and 2-trans pentenoic acid, during incubated cell culture exposure up to 2 h or 3.5 h. The time dependence of any metabolism was determined from analysis of the supernatant at intervals using a new developed analytical method for UPLC coupled with QTOF mass spectrometer. The chemicals could then be ranked by their relative intrinsic clearance.
The analyses were reproducible, with coherence of the calculated in vitro intrinsic clearance between experiments.
Ethyl glucuronide (EtG) and ethyl sulphate (EtS) are minor metabolites of ethanol, and their presence in urine provides a strong indication of recent alcohol administration. In this study, we ...performed a drinking experiment to investigate the kinetics of EtG and EtS formation and elimination after the administration of two doses of alcohol.
Nineteen volunteers provided urine and serum (only 18) after administration of 4 and 8 units of alcohol (1 unit corresponds to 10 ml or ∼8 g of pure ethanol). The analysis was performed using a validated ultra-performance liquid chromatography-mass spectrometry (UPLC(®)-MS/MS) method.
After 4 units, the median EtG maximum concentration (C(max)) was 0.4 µg/ml and the interquartile range (0.3 µg/ml) in serum and 3.5 mg/h (1.2 mg/h) in urine and were reached (T(max)) after 2.0 h (0.8 h) and 3.0 h (1.0 h), respectively. EtS C(max) was 0.2 µg/ml (0.1 µg/ml) in serum and 1.3 mg/h (0.6 mg/h) in urine, and the corresponding T(max) were 1.0 h (1.0 h) and 2.0 h (0.5 h). After 8 units, EtG C(max) was 1.3 µg/ml (0.4 µg/ml) in serum and 10 mg/h (3.4 mg/h) in urine and was reached after 4.0 h (1.8 h) and 4.0 h (2.0 h), respectively. EtS C(max) was 0.6 µg/ml (0.1 µg/ml) in serum and 3.5 mg/h (1.1 mg/h) in urine, the corresponding T(max) were 3.0 h (1.0 h) and 3.0 h (1.0 h). The EtG/EtS ratio increased as a function of the time after alcohol administration in both serum and urine samples but to a lesser extent after 8 units than 4.
These results correlate with values obtained in previous studies. T(max) of EtG and EtS increased between 4 and 8 units. The EtG:EtS ratio increased in the serum and urine samples of all volunteers as a function of time at least up to 4 h after alcohol administration.
Hepatic metabolic clearance is one of the most important factors driving the overall kinetics of chemicals including substances used in various product categories such as pesticides, biocides, ...pharmaceuticals, and cosmetics. A large number of in vitro systems from purified isozymes and subcellular organelles to hepatocytes in simple cultures and in complex scaffold setups are available for measuring hepatic metabolic clearance for different applications. However, there is currently no approach for systematically characterising and comparing these in vitro methods in terms of their design, applicability and performance. To address this, existing knowledge in the field of in vitro human hepatic metabolic clearance methods was gathered and analysed in order to establish a framework to systematically characterise methods based on a set of relevant components. An analogous framework would be also applicable for non-human in vitro systems. The components are associated with the biological test systems used (e.g. subcellular or cells), the in vitro method (e.g. number of cells, test item solubility), related analytical techniques, data interpretation methods (based on substrate depletion/metabolite formation), and performance assessments (precision and accuracy of clearance measurements). To facilitate the regulatory acceptance of this class of methods, it is intended that the framework provide the basis of harmonisation work within the OECD.
•Promote the use of toxicokinetic (TK) data to support chemical risk assessment•Hepatic metabolic clearance often used as major TK process in chemical risk assessment.•Develop a framework to characterise in vitro hepatic metabolic clearance methods•Facilitate the regulatory acceptance of in vitro hepatic metabolic clearance data
In people suffering from schizophrenia, major areas of everyday life are impaired, including independent living, productive activities and social relationships. Enhanced understanding of factors that ...hinder real‐life functioning is vital for treatments to translate into more positive outcomes. The goal of the present study was to identify predictors of real‐life functioning in people with schizophrenia, and to assess their relative contribution. Based on previous literature and clinical experience, several factors were selected and grouped into three categories: illness‐related variables, personal resources and context‐related factors. Some of these variables were never investigated before in relationship with real‐life functioning. In 921 patients with schizophrenia living in the community, we found that variables relevant to the disease, personal resources and social context explain 53.8% of real‐life functioning variance in a structural equation model. Neurocognition exhibited the strongest, though indirect, association with real‐life functioning. Positive symptoms and disorganization, as well as avolition, proved to have significant direct and indirect effects, while depression had no significant association and poor emotional expression was only indirectly and weakly related to real‐life functioning. Availability of a disability pension and access to social and family incentives also showed a significant direct association with functioning. Social cognition, functional capacity, resilience, internalized stigma and engagement with mental health services served as mediators. The observed complex associations among investigated predictors, mediators and real‐life functioning strongly suggest that integrated and personalized programs should be provided as standard treatment to people with schizophrenia.
A retrospective cumulative risk assessment of dietary exposure to pesticide residues was conducted for chronic inhibition of acetylcholinesterase. The pesticides considered in this assessment were ...identified and characterised in a previous scientific report on the establishment of cumulative assessment groups of pesticides for their effects on the nervous system. The exposure assessments used monitoring data collected by Member States under their official pesticide monitoring programmes in 2016, 2017 and 2018, and individual food consumption data from 10 populations of consumers from different countries and from different age groups. Exposure estimates were obtained by means of a two‐dimensional probabilistic model, which was implemented in SAS® software. The characterisation of cumulative risk was supported by an uncertainty analysis based on expert knowledge elicitation. For each of the 10 populations, it is concluded with varying degrees of certainty that cumulative exposure to pesticides contributing to the chronic inhibition of acetylcholinesterase does not exceed the threshold for regulatory consideration established by risk managers.
The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State the United Kingdom and co‐rapporteur Member ...State Germany for the pesticide active substance thiacloprid are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative uses of thiacloprid as an insecticide on oilseed rape foliar use and maize seed treatment. The peer review also provided conclusions on whether exposure of humans to thiacoprid can be considered negligible, taking into account the European Commission's draft guidance on this topic. Confirmatory data following the review of existing maximum residue levels (MRLs) according to Article 12 of Regulation (EC) No 396/2005 were also assessed in this conclusion. The reliable end points, appropriate for use in regulatory risk assessment are presented. An evaluation of data concerning the necessity of thiacloprid as an insecticide to control a serious danger to plant health which cannot be contained by other available means, including non‐chemical methods is presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.
Lactulose to mannitol ratio (L/M) in urine is used as a non invasive assay to measure intestinal permeability. We describe here a rapid, specific and sensitive LC–MS/MS method for the measurement of ...these compounds in urine of children affected by abdominal recurrent pain (ARP).
The study has been performed on 50 children from the Pediatric Unit. The chromatographic separation was accomplished by using an NH
2-column, the detection with a Q-Trap 2000 system.
Multiple calibration curve exhibited consistent linearity and reproducibility. Linear responses were observed in the concentration range 0–400 μg/mL for both mannitol and lactulose. Limits of detection were 12.5 mg/L for lactulose and 1.25 mg/L for mannitol with a signal-to-noise ratio of 10.
The comparison of L/M values of healthy children with those found in children affected by idiopathic ARP demonstrates that in the latter subjects an alteration of intestinal permeability occurs. The method can represent a useful tool to monitor the intestinal functionality in children with ARP conditions and help for an accurate patient discrimination for diet restrictions.
The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State the United Kingdom and co‐rapporteur Member ...State Greece for the pesticide active substance mancozeb are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative uses of mancozeb as a fungicide on wheat (winter/spring), grapevine, potatoes and tomatoes. The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.
The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Germany, and co‐rapporteur Member State, ...Denmark, for the pesticide active substance Bacillus amyloliquefaciens strain QST 713, formerly Bacillus subtilis strain QST 713, are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of Bacillus amyloliquefaciens strain QST 713 as a fungicide on strawberry (field and greenhouse uses) and grapes (field use). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.
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