Practical Aspects of Designing and Conducting Validation Studies Involving Multi-study Trials.

This chapter focuses on practical aspects of conducting prospective in vitro validation studies, and in particular, by laboratories that are members of the European Union Network of Laboratories for the Validation of Alternative Methods (EU-NETVAL) that is coordinated by the EU Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM). Prospective validation studies involving EU-NETVAL, comprising a multi-study trial involving several laboratories or "test facilities", typically consist of two main steps: (1) the design of the validation study by EURL ECVAM and (2) the execution of the multi-study trial by a number of qualified laboratories within EU-NETVAL, coordinated and supported by EURL ECVAM. The approach adopted in the conduct of these validation studies adheres to the principles described in the OECD Guidance Document on the Validation and International Acceptance of new or updated test methods for Hazard Assessment No. 34 (OECD 2005). The context and scope of conducting prospective in vitro validation studies is dealt with in Chap. 4 . Here we focus mainly on the processes followed to carry out a prospective validation of in vitro methods involving different laboratories with the ultimate aim of generating a dataset that can support a decision in relation to the possible development of an international test guideline (e.g. by the OECD) or the establishment of performance standards.

Investigating the dependency of in vitro benchmark concentrations on exposure time in transcriptomics experiments.

There is increasing interest to employ in vitro transcriptomics experiments in toxicological testing, for example to determine a point-of-departure (PoD) for chemical safety assessment. However current practices to derive PoD tend to utilise a single exposure time despite the importance of exposure time on the manifestation of toxicity caused by a chemical. Therefore it is important to investigate both concentration and exposure time to determine how these factors affect biological responses, and as a consequence, the derivation of PoDs. In this study, metabolically competent HepaRG cells were exposed to five known toxicants over a range of concentrations and time points for subsequent gene expression analysis, using a targeted RNA expression assay (TempO-Seq). A non-parametric factor-modelling approach was used to model the collective response of all significant genes, which exploited the interdependence of differentially expressed gene responses. This in turn allowed the determination of an isobenchmark response (isoBMR) curve for each chemical in a reproducible manner. For 2 of the 5 chemicals tested, the PoD was observed to vary by 0.5-1 log-order within the 48-h timeframe of the experiment. The approach and findings presented here clearly demonstrate the need to take both concentration and exposure time into account when designing in vitro toxicogenomics experiments to determine PoD. Doing so also provides a means to use concentration-time-response modelling as a basis to extrapolate a PoD from shorter to longer exposure durations, and to identify chemicals of concern that can cause cumulative effects over time.

Building skills in cognitive behavioral supervision.

The purpose of supervision is to ensure that clients' needs are met and to monitor the effectiveness of therapeutic interventions and the therapeutic relationship. Cognitive behavioural therapy (CBT) supervision is the systematic cooperation of the supervisee with the supervisor, which aims at increasing the therapists' competencies when working with specific clients. The advantage of supervision is the possibility to shape and develop the therapist's practical skills through specific techniques. This paper aims to review currently available CBT supervision strategies that boost the development of therapists' skills and provide possible examples. Various techniques are discussed, including behavioural, cognitive, imagery and psychodrama methods that facilitate supervisors in enhancing therapists' skills. In addition, complementary approaches are discussed, such as role-playing, modelling, chaining, or imitation to present at a particular moment of the therapy, increase the insight into the client's perspective or the treatment itself, and search for an alternative approach to improve the therapeutic outcomes for the client. Overall, the article describes the supervisor's need to have a flexible variety of skills and know which learning methods might be most effective for boosting the supervisee's skill level and needs with a particular client.

Parallel process as a tool for supervision and therapy: A cognitive behavioral and schema therapy perspective.

INTRODUCTION: The parallel process is a psychosocial phenomenon where the relationship dynamics between the therapist and the client are repeated in the supervisory relationship between the therapist and the supervisor. The concept of the parallel process can be a useful tool for understanding and solving problems in therapy. However, it can induce supervision drift or block the supervision process. OBJECTIVE: This article aims to familiarize the reader with parallel processes in cognitive-behavioural therapy (CBT) and schema therapy supervision and discuss how to manage this phenomenon in supervision. METHOD: This article is a narrative review with illustrations of supervision interviews in which the parallel process unfolds. The text provides an overview of theoretical constructions and empirical studies related to the parallel process. We searched PubMed, PsycINFO, Web of Science, and Google Scholar for relevant resources using the keywords "parallel process," "cognitive behavioural therapy," "schema therapy," "transference," and "countertransference." Case vignettes were collected from trainees, training leaders and supervisors to provide real-life examples of how self-reflection and self-experience can enhance CBT and schema therapy training, practice, and supervision.

Problems in Cognitive-Behavioral Supervision: Theoretical Background and Clinical Application.

Cognitive-behavioural therapists and trainees are encouraged to undergo supervision when offering therapy to troubled clients and to process personal attitudes and events likely to affect their therapeutic work. We discuss common problems in cognitive behavioural therapy (CBT) supervision, which may arise at the client, supervisee, or supervisor level. These issues include difficulties with case formulation, therapeutic strategies, and the therapeutic relationship. A supervisor can help their supervisee deal with clients with multifaceted or particularly challenging problems, such as difficulties with compliance, complex psychosocial problems, or chronic mental disorders. We also discuss matters related to the supervision process, the supervisor's role, different supervisory styles, and issues affecting a supervisee's feelings of vulnerability and shame. Furthermore, we analyze distinct supervision styles and potential problems arising from the supervision of experienced CBT therapists.

Reliability of the AR-CALUX®In Vitro Method Used to Detect Chemicals with (Anti)Androgen Activity: Results of an International Ring Trial.

The AR-CALUX® in vitro method is a reporter gene-based transactivation method where endocrine active chemicals with androgenic or anti-androgenic potential can be detected. Its primary purpose is for screening chemicals for further prioritization and providing mechanistic (endocrine mode of action) information, as defined by the Organisation of Economic Cooperation and Development (OECD) conceptual framework for the testing and assessment of endocrine-disrupting chemicals. This article describes the conduct and results of an international ring trial with 3 EU-NETVAL laboratories and the test method developer. It was organized by EURL ECVAM to validate the method by testing 46 chemicals. A very good reproducibility within and between laboratories was concluded (94.7-100% and 100% concordance of classification) with low within and between laboratory variability (less than 2.5% CV on EC50 values). Moreover, the variability is within the range of other validated, mechanistically similar methods. In comparison to the AR-reference list compiled by ICCVAM, an almost 100% concordance of classifications was obtained. This method allows the detection of the agonist and antagonist properties of a chemical. A specificity control test was developed during the validation study and added to the antagonist assay rendering the assay more specific. A comparison is made with the mechanistically similar methods AR-EcoScreen™ and 22Rv1/MMTV GR-KO TA. The AR-CALUX® method was approved for inclusion in the recently updated OECD test guideline TG458 which incorporates all 3 methods.

Limitations and uncertainties of acute fish toxicity assessments can be reduced using alternative methods.

Information about acute fish toxicity is routinely required in many jurisdictions for environmental risk assessment of chem­icals. This information is typically obtained using a 96-hour juvenile fish test for lethality according to OECD test guideline (TG) 203 or equivalent regional guidelines. However, TG 203 has never been validated using the criteria currently required for new test methods including alternative methods. Characterization of the practicality and validity of TG 203 is important to provide a benchmark for alternative methods. This contribution systematically summarizes the available knowledge on limitations and uncertainties of TG 203, based on methodological, statistical, and biological consider­ations. Uncertainties stem from the historic flexibility (e.g., use of a broad range of species) and constraints of the basic test design (e.g., no replication). Other sources of uncertainty arise from environmental safety extrapolation based on TG 203 data. Environmental extrapolation models, combined with data from alternative methods, including mechanistic indicators of toxicity, may provide at least the same level of environmental protection. Yet, most importantly, the 3R advan­tages of alternative methods allow a better standardization, characterization, and an improved basic study design. This can enhance data reliability and thus facilitate the comparison of chemical toxicity, as well as the environmental classifi­cations and prediction of no-effect concentrations of chemicals. Combined with the 3R gains and the potential for higher throughput, a reliable assessment of more chemicals can be achieved, leading to improved environmental protection.

Validation of in vitro methods for human cytochrome P450 enzyme induction: Outcome of a multi-laboratory study.

CYP enzyme induction is a sensitive biomarker for phenotypic metabolic competence of in vitro test systems; it is a key event associated with thyroid disruption, and a biomarker for toxicologically relevant nuclear receptor-mediated pathways. This paper summarises the results of a multi-laboratory validation study of two in vitro methods that assess the potential of chemicals to induce cytochrome P450 (CYP) enzyme activity, in particular CYP1A2, CYP2B6, and CYP3A4. The methods are based on the use of cryopreserved primary human hepatocytes (PHH) and human HepaRG cells. The validation study was coordinated by the European Union Reference Laboratory for Alternatives to Animal Testing of the European Commission's Joint Research Centre and involved a ring trial among six laboratories. The reproducibility was assessed within and between laboratories using a validation set of 13 selected chemicals (known human inducers and non-inducers) tested under blind conditions. The ability of the two methods to predict human CYP induction potential was assessed. Chemical space analysis confirmed that the selected chemicals are broadly representative of a diverse range of chemicals. The two methods were found to be reliable and relevant in vitro tools for the assessment of human CYP induction, with the HepaRG method being better suited for routine testing. Recommendations for the practical application of the two methods are proposed.

Biomonitoring and Subsequent Risk Assessment of Combined Exposure to Phthalates in Iranian Children and Adolescents.

This study aimed to estimate the exposure and related health risks of phthalates, and to assess the health risks from combined exposure to three of the phthalates sharing the same mode of action (anti-androgenicity) in children. We determined the internal exposure of 56 Iranian children and adolescents aged 6 to 18 years by analyzing seven urinary metabolites of five phthalates. The estimated daily intake values derived from the biomonitoring data ranged from 0.01 µg/kg bw/day for butyl benzyl phthalate (BBP), to 17.85 µg/kg bw/day for di(2-ethylhexyl) phthalate (DEHP). The risk assessment revealed that not only the exposure to the individual phthalates, but also the combined exposure to the three anti-androgenic phthalates (DEHP, DBP, BBP) did not raise a safety concern (hazard index values averaged 0.2). The range of maximum cumulative ratio values varied from around 1 for most individuals to around 2 in some individuals, indicating that the combined exposures were dominated by one and in some cases by two of the three anti-androgenic phthalates, especially dibutyl phthalate (DBP) and/or DEHP. Based on biomonitoring data, the overall combined exposure of Iranian children to phthalates does not raise a concern, while reduction of exposure is best focused on DEHP and DBP that showed the highest hazard quotient.