Avoiding a reproducibility crisis in regulatory toxicology-on the fundamental role of ring trials

The ongoing transition from chemical hazard and risk assessment based on animal studies to assessment relying mostly on non-animal data, requires a multitude of novel experimental methods, and this means that guidance on the validation and standardisation of test methods intended for international applicability and acceptance, needs to be updated. These so-called new approach methodologies (NAMs) must be applicable to the chemical regulatory domain and provide reliable data which are relevant to hazard and risk assessment. Confidence in and use of NAMs will depend on their reliability and relevance, and both are thoroughly assessed by validation. Validation is, however, a time- and resource-demanding process. As updates on validation guidance are conducted, the valuable components must be kept: Reliable data are and will remain fundamental. In 2016, the scientific community was made aware of the general crisis in scientific reproducibility-validated methods must not fall into this. In this commentary, we emphasize the central importance of ring trials in the validation of experimental methods. Ring trials are sometimes considered to be a major hold-up with little value added to the validation. Here, we clarify that ring trials are indispensable to demonstrate the robustness and reproducibility of a new method. Further, that methods do fail in method transfer and ring trials due to different stumbling blocks, but these provide learnings to ensure the robustness of new methods. At the same time, we identify what it would take to perform ring trials more efficiently, and how ring trials fit into the much-needed update to the guidance on the validation of NAMs.

The inter-laboratory validation study of EpiSensA for predicting skin sensitization potential

The Epidermal Sensitization Assay (EpiSensA) is a reconstructed human epidermis (RhE)-based gene expression assay for predicting the skin sensitization potential of chemicals. Since the RhE model is covered by a stratified stratum corneum, various kinds of test chemicals, including lipophilic ones and pre-/pro-haptens, can be tested with a route of exposure akin to an in vivo assay and human exposure. This article presents the results of a formally managed validation study of the EpiSensA that was carried out by three participating laboratories. The purpose of this validation study was to assess transferability of the EpiSensA to new laboratories along with its within- (WLR) and between-laboratory reproducibility (BLR). The validation study was organized into two independent stages. As demonstrated during the first stage, where three sensitizers and one non-sensitizer were correctly predicted by all participating laboratories, the EpiSensA was successfully transferred to all three participating laboratories. For Phase I of the second stage, each participating laboratory performed three experiments with an identical set of 15 coded test chemicals resulting in WLR of 93.3%, 93.3%, and 86.7%, respectively. Furthermore, when the results from the 15 test chemicals were combined with those of the additional 12 chemicals tested in Phase II of the second stage, the BLR for 27 test chemicals was 88.9%. Moreover, the predictive capacity among the three laboratories showed 92.6% sensitivity, 63.0% specificity, 82.7% accuracy, and 77.8% balanced accuracy based on murine local lymph node assay (LLNA) results. Overall, this validation study concluded that EpiSensA is easily transferable and sufficiently robust for assessing the skin sensitization potential of chemicals.

Severe COVID-19 and its cardiopulmonary effects 6 and 18 months after hospital discharge

Introduction

SARS-CoV-2 infection affects the cardiopulmonary system in the acute as well as long-term phase. The aim of the present study was to comprehensively assess symptoms and possible long-term impairments 6 and 18 months after hospitalization for severe COVID-19 infection.

Methods

This prospective registry included patients with PCR-confirmed COVID-19 infection requiring hospitalization. Follow-up approximately 6 months post discharge comprised a detailed patient history, clinical examination, transthoracic echocardiography, electrocardiogram, cardiac magnetic resonance imaging (cMRI), chest computed tomography (CT) scan, pulmonary function test (PFT), six-minute walk test (6MWT) and a laboratory panel. At the time of the second follow-up visit at 18 months, patients without pathologic findings during the first study visit were contacted by phone to inquire about the course of their symptoms. In all other patients all initial examinations were repeated.

Results

Two hundred Patients, who were hospitalized for COVID-19, were contacted by phone and were recruited for the study. Due to dropouts the second study visit was performed in 170 patients. A comparison between the two study visits at 6 and 18 months post discharge showed the following results: Six months after discharge, 73% and 18 months after discharge 52% fulfilled the criteria for Long COVID with fatigue being the most common symptom (49%). Echocardiography at 6 months post discharge showed an impaired left ventricular function in 8% of which 80% returned to normal. Six months post discharge, cMRI revealed pericardial effusion in 17% which resolved in 47% of the 15 patients who underwent a control cMRI. Signs of peri- or myocarditis were present in 5% of the patients and were resolved in all 4 patients who attended control studies. At 6 months, chest CT scans identified post-infectious residues in 24%. In the 25 repeated chest CT scans 20% showed full recovery. Length of in-hospital stay was identified as a significant predictor for persisting Long COVID (95% CI: 1.005-1.12, p = 0.03).

Conclusion

Comparing 6 to 18 months, the prevalence of Long COVID decreased over time, but a high symptom burden remained. Structural and functional abnormalities were less frequent than the portrayed symptoms, and it thus remains a challenge to substantiate the symptoms.

Comparison of toric intraocular lens alignment between femtosecond laser-assisted capsular marking and digital marking

PURPOSE

To compare the accuracy of toric intraocular lens (IOL) alignment between femtosecond laser-assisted capsular marking and digital marking.

SETTING

Ruhr University Eye Clinic, Bochum, Germany.

DESIGN

Prospective clinical trial.

METHODS

In this study, 28 eyes of 23 patients, who underwent femtosecond laser-assisted cataract surgery with implantation of a toric IOL, were included. Intraoperatively, both femtosecond laser-assisted capsular marking and digital marking were applied simultaneously and compared in every case. The toric IOL was aligned to the capsular markings. Postoperatively, the axis of the capsular markings and toric IOL alignment was examined. Visual acuity and refractive outcomes were evaluated.

RESULTS

Both alignment methods were performed without intraoperative complications in all cases. 25 eyes were included in the final analysis. Misalignment was significantly lower with femtosecond laser-assisted capsular marking than with digital marking (1.71 ± 1.25 degrees vs 2.64 ± 1.70 degrees, P = .016). Deviation from the target axis of the toric IOL was 1.62 ± 1.24 degrees 4 to 6 weeks postoperatively. Postoperative uncorrected distance visual acuity was 0.14 ± 0.13 logMAR, and residual astigmatism was 0.3 ± 0.23 diopter (D) with an astigmatism ≤0.5 D in 93% of eyes.

CONCLUSIONS

Both methods showed excellent results for the alignment of toric IOLs. However, femtosecond laser-assisted capsular marking was significantly more precise than digital marking and showed good refractive results. In addition, capsular marking offers the possibility to avoid parallax error and evaluating postoperative IOL rotation.

The probable future of toxicology - probabilistic risk assessment

Both because of the shortcomings of existing risk assessment methodologies, as well as newly available tools to predict hazard and risk with machine learning approaches, there has been an emerging emphasis on probabilistic risk assessment. Increasingly sophisticated AI models can be applied to a plethora of exposure and hazard data to obtain not only predictions for particular endpoints but also to estimate the uncertainty of the risk assessment outcome. This provides the basis for a shift from deterministic to more probabilistic approaches but comes at the cost of an increased complexity of the process as it requires more resources and human expertise. There are still challenges to overcome before a probabilistic paradigm is fully embraced by regulators. Based on an earlier white paper (Maertens et al., 2022), a workshop discussed the prospects, challenges and path forward for implementing such AI-based probabilistic hazard assessment. Moving forward, we will see the transition from categorized into probabilistic and dose-dependent hazard outcomes, the application of internal thresholds of toxicological concern for data-poor substances, the acknowledgement of user-friendly open-source software, a rise in the expertise of toxicologists required to understand and interpret artificial intelligence models, and the honest communication of uncertainty in risk assessment to the public.

Establishing a health-based recommended occupational exposure limit for isoflurane using experimental animal data: a systematic review protocol

BACKGROUND

Isoflurane is used as an inhalation anesthetic in medical, paramedical, and veterinary practice. Epidemiological studies suggest an increased risk of miscarriages and malformations at birth related to maternal exposure to isoflurane and other inhalation anesthetics. However, these studies cannot be used to derive an occupational exposure level (OEL), because exposure was not determined quantitatively and other risk factors such as co-exposures to other inhalation anesthetics and other work-related factors may also have contributed to the observed adverse outcomes. The aim of this systematic review project is to assess all available evidence on the effects of isoflurane in studies of controlled exposures in laboratory animals to derive a health-based recommended OEL.

METHODS

A comprehensive search strategy was developed to retrieve all animal studies addressing isoflurane exposure from PubMed, EMBASE, and Web of Science. Title-abstract screening will be performed by machine learning, and full-text screening by one reviewer. Discrepancies will be resolved by discussion. We will include primary research in healthy, sexually mature (non human) vertebrates of single exposure to isoflurane. Studies describing combined exposure and treatments with >  = 1 vol% isoflurane will be excluded. Subsequently, details regarding study identification, study design, animal model, and intervention will be summarized. All relevant exposure characteristics and outcomes will be extracted. The risk of bias will be assessed by two independent reviewers using an adapted version of the SYRCLE's risk of bias tool and an addition of the OHAT tool. For all outcomes for which dose-response curves can be derived, the benchmark dose (BMD) approach will be used to establish a point of departure for deriving a recommended health-based recommended OEL for 8 h (workshift exposure) and for 15 min (short-term exposure).

DISCUSSION

Included studies should be sufficiently sensitive to detect the adverse health outcomes of interest. Uncertainties in the extrapolation from animals to humans will be addressed using assessment factor. These factors are justified in accordance with current practice in chemical risk assessment. A panel of experts will be involved to reach consensus decisions regarding significant steps in this project, such as determination of the critical effects and how to extrapolate from animals to humans.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022308978.

Protocol for designing INVITES-IN, a tool for assessing the internal validity of in vitro studies

This protocol describes the design and development of a tool for evaluation of the internal validity of in vitro studies, which is needed to include the data as evidence in systematic reviews and chemical risk assessments. The tool will be designed specifically to be applied to cell culture studies, including, but not restricted to, studies meeting the new approach methodology (NAM) definition. The tool is called INVITES-IN (IN VITro Experimental Studies INternal validity). In this protocol, three of the four studies that will be performed to create the release version of INVITES-IN are described. In the first study, evaluation of existing assessment tools will be combined with focus group discussions to identify how characteristics of the design or conduct of an in vitro study can affect its internal validity. Bias domains and items considered to be of relevance for in vitro studies will be identified. In the second study, group agreement on internal validity domains and items of importance for in vitro studies will be identified via a modified Delphi methodology. In the third study, the draft version of the tool will be created, based on the data on relevance and importance of bias domains and items collected in Studies 1 and 2. A separate protocol will be prepared for the fourth study, which includes the user testing and validation of the tool, and collection of users' experience.

Applying a next generation risk assessment framework for skin sensitisation to inconsistent new approach methodology information

Cosmetic products must be safe for their intended use. Regulatory bans on animal testing for new ingredients has resulted in a shift towards the use of new approach methodologies (NAM), such as in silico predictions and in chemico/in vitro data. Defined Approaches (DA) have been developed to interpret combinations of NAM to provide information on skin sensitisation hazard and potency, three having been adopted within OECD Guideline 497. However, the challenge remains as to how DA can be used to derive a quantitative point of departure for use in next generation risk assessments (NGRA). Here we provide an update to our previously published NGRA framework and present two hypothetical consumer risk assessment scenarios (rinse-off and leave-on) on one case study ingredient. Diethanolamine (DEA) was selected as the case study ingredient based upon the existing NAM information demonstrating differences with respect to the outcomes from in silico predictions and in chemico / in vitro data. Seven DA were applied, and these differences resulted in divergent DA outcomes and reduced confidence with respect to the hazard potential and potency predictions. Risk assessment conclusion for the rinse-off exposure led to an overall decision of safe for all DA applied. Risk assessment conclusion for the higher leave-on exposure was safe when based upon some DA but unsafe for others. The reasons for this were evaluated, as well as the inherent uncertainty from the use of each NAM and DA in the risk assessment, enabling further refinement of our NGRA framework.

Do family characteristics explain a social gradient in overweight in early childhood?

Background

Children's overweight is associated with many factors, including their living situation, in particular their family's socioeconomic position (SEP) and family characteristics. Research on the extent to which family characteristics account for a social gradient in overweight in early life is scarce. This study evaluated whether family characteristics explain SEP differences in the risk of overweight in early childhood.

Methods

The study used baseline data of 3-6 year-old children (n = 1,116) from the intervention ‘Ene mene fit’ conducted at kindergartens in Baden-Württemberg, Germany. Data included overweight (body mass index > 90 percentile) and parents’ reports on their education and family characteristics associated with overweight (child consumes: sweets in front of TV, soft drinks; family joined time: outdoor, breakfast, sports; cooking; child sets table; role model). Model-based single mediation analyses decomposed the total effect of highest parental education on overweight into direct (unmediated) and indirect (mediated) effects (OR, 95% CI).

Results

Girls and boys with low parental education had higher odds for overweight than children with high/medium education. Among boys, low education influenced the risk of overweight via indirect effects of i. ‘sweets consumption in front of TV’ (OR = 1.31, 1.05-1.59) and ii. ‘no joined sports’ (OR = 1.14, 1.00-1.44). The direct effect of low education only remained significant when ‘no joined sports’ was considered (OR = 2.19, 1.11-5.19). Among girls, family characteristics measured here did not explain SEP differences in overweight.

Conclusions

The family characteristics ‘sweets consumption in front of TV’ and ‘no joined sports’ contribute to inequalities in overweight among boys, but not among girls. Therefore, more gender-sensitive research is needed to identify family risk and protective characteristics that explain health inequalities among both boys and girls.

Socioeconomic position and self-rated health among adolescents: the mediating role of the family

Background

Although health inequalities in adolescence are well documented, the underlying mechanisms remain unclear. Few studies have examined the role of the family in explaining adolescents’ health inequalities. The study aimed to explore whether the association between socioeconomic position and self-rated health (SRH) was mediated by familial determinants.

Methods

Using data from wave 2 of the KiGGS study (1,838 female and 1,718 male 11- to 17-year-olds), linear regression analyses were conducted to decompose the total effects of parents’ education, occupation, income, socioeconomic position index, and adolescents’ subjective social status on SRH into direct effects and indirect effects through familial determinants (family cohesion, parenting styles, parental well-being, stress, obesity, smoking and sporting activity).

Results

A significant total effect of all socioeconomic position indicators on SRH was found, except for income in male adolescents. In female adolescents, more than 70% of the total effects of each socioeconomic position indicator were explained by familial mediators, whereas no significant direct effects remained. The most important mediator was parental well-being, followed by family cohesion, parental smoking and sporting activity. In male adolescents, the associations of parental education, the socioeconomic position index and subjective social status with SRH were also mediated by familial determinants (family cohesion, parental smoking and obesity). However, a significant direct effect of subjective social status remained.

Conclusions

The family appears to play an important role in explaining health inequalities, particularly in female adolescents. Reducing health inequalities in adolescence requires policy interventions, community-based strategies, as well as programs to improve parenting and family functioning.

Do regional characteristics predict developmental delay? Analyses of German school entry examination

Background

Children's health and development are strongly linked to their living situation, including their family's socioeconomic position (SEP) and living region. However, research on the impact of the living region on children's development beyond family SEP is scarce. This study evaluated whether rurality and regional socioeconomic deprivation (DEP) are associated with children's development independently of family SEP.

Methods

The study used population-based data of 5-6.5 years old children (n = 22,801) from mandatory school entry examinations (SEE) in the German federal state of Brandenburg, which were examined in 2018/2019. The SEE data have been linked with data on i. rurality that was defined by an inverted population density and ii. regional DEP that were provided by the German Index of Socioeconomic Deprivation. By binary multilevel models, the predictive values of rurality and regional DEP for global developmental delay (GDD) were evaluated, while adjusting for family SEP.

Results

Children with high family SEP showed reduced odds for GDD compared to medium family SEP (female: OR = 4.26, CI95=3.14-5.79, male: OR = 3.46, CI95=2.83-4.22) and low family SEP (female: OR = 16.58, CI95=11.90-23.09, male: OR = 12.79, CI95=10.13-16.16). Regional DEP additionally predicted GDD, with higher odds for children from more deprived regions (female: OR = 1.35, CI95=1.13-1.62, male: OR = 1.20, CI95=1.05-1.39). Rurality did not predict GDD beyond family SEP and regional DEP.

Conclusions

In addition to family SEP, the regional DEP has an effect on children's developmental delay. Hence, Public Health should take into account regional socioeconomic conditions as determinant of health over the life course in addition to family SEP.

Key messages

• Regional socioeconomic deprivation contributes to inequalities in children's development and health.

• Besides family SEP, regional socioeconomic circumstances are of particular interest to promote health over the life course.

A sport focus of ECEC centres appears especially health-promoting for boys from lower socio-economic background

Background

Pediatric overweight is considered one of the 21st century's most serious public health challenges. Many studies investigated individual level determinants of children's body mass index (BMI), yet studies measuring determinants at the meso- level are sparse. As there is a lack of theoretical and empirical knowledge about the role of child care facilities, the aim was to examine the combined effects of family socio-economic position (SEP) and the meso-level variable early childhood education and care (ECEC) centre with sport focus on the BMI of pre-schoolers.

Methods

We used data from the German National Educational Panel Study (NEPS) and included 1,891 children from 224 ECEC centre groups. Multilevel mixed-effects linear regressions were applied to calculate the main association of ECEC centre focus and family SEP, as well as their interaction on children's BMI. All analyses were adjusted for age, migration background, number of siblings, and employment status of parents and were stratified by gender.

Results

Boys attending an ECEC centre with a sport focus have on average a lower BMI than boys from ECEC centres not having this focus. Interactive effects between family SEP and ECEC centre focus were found. Considering predictive margins, boys with low family SEP not attending a sport focused ECEC centre had the highest BMI while boys with low family SEP attending a sport focused ECEC centre had the lowest BMI. For girls, no association regarding ECEC centre focus or interactive effects emerged. Girls in the high family SEP tertile had the lowest BMI in both ECEC centre types.

Conclusions

Our analysis shows the social gradient towards a higher BMI for children from lower SEP families. Considering meso-level factors, we provide evidence for the relevance of ECEC centre characteristics for BMI in boys, whereas for girls the association of family SEP with BMI remains. The ECEC centre focus appears to lower the association of family SEP with BMI for boys.

The impact of the school-to-work transition on self-rated health & subjective well-being in Germany

Background

During the school-to-work transition (STWT), young people enter different states as vocational training, university or unemployment that may have immediate or long-term effects on health. Since research has not paid much attention to this, we investigate the development of self-rated health (SRH) and subjective well-being (SWB) during the STWT.

Methods

We used data from Starting Cohort 4 of the German National Educational Panel Study (NEPS), a nationally representative cohort of 11,098 ninth graders (50.5% girls) followed over nine years. Linear panel regression analysis with fixed-effects (FE) was used to explore intra-individual changes in SRH and SWB when moving between different STWT states (school, prevocational program, vocational training, university, employment, unemployment, inactivity). FE impact functions were used to compare trajectories of SRH and SWB by states reached after school-leave. Time-varying control variables were age, household composition, and residential area.

Results

School-leave was linked to increases in SRH and SWB, whereas no impact was found for job entry after vocational training or university. Upward transitions (e.g. from a prevocational program to vocational training, from vocational training to university or from unemployment to employment) increased SRH or SWB, while downward transitions (e.g. from vocational training or employment to unemployment) were related to decreases. Over the years after school-leave, we found a decline in SRH and SWB, which was faster in case of transitions to unemployment or prevocational programs directly after school.

Conclusions

Findings suggest that a smooth STWT is key for good health in youth and adulthood. Health and labour market intervention programs should focus on the time after school-leave, especially on those who are not able to find an academic or vocational training position.

Does leg dominance influence anterolateral thigh flap perforators?

INTRODUCTION

Thorough knowledge of perforator anatomy can facilitate anterolateral thigh (ALT) free flap harvest. The selection of the right or left thigh as donor area may be supported by preoperative perforator imaging and practical considerations. The study aims to determine if the leg dominance should be taken into account, when choosing the donor thigh for ALT free flap harvest, as muscle mass and perfusion might influence perforator quantity.

METHODS

ALT perforators were localized by color-coded duplex sonography and dynamic infrared thermography on both thighs within a defined 250 × 80 mm area in 24 subjects. Perforator number and thickness of subcutaneous tissue and muscle layer were compared in dominant and nondominant legs.

RESULTS

We found no statistically significant difference comparing sonographically identified ALT perforator numbers and hot spot numbers in dominant and nondominant legs. Yet, we found high interindividual differences. The comparison of subcutaneous tissue and muscle thickness yielded no significant difference.

CONCLUSIONS

Our study yielded no evidence for preference of the dominant or nondominant leg in ALT free flap harvesting. As we found high interindividual differences in perforator number, we suggest to rely on preoperative perforator imaging when choosing the ALT free flap donor thigh.

Live-cell micromanipulation of a genomic locus reveals interphase chromatin mechanics

Our understanding of the physical principles organizing the genome in the nucleus is limited by the lack of tools to directly exert and measure forces on interphase chromosomes in vivo and probe their material nature. Here, we introduce an approach to actively manipulate a genomic locus using controlled magnetic forces inside the nucleus of a living human cell. We observed viscoelastic displacements over micrometers within minutes in response to near-piconewton forces, which are consistent with a Rouse polymer model. Our results highlight the fluidity of chromatin, with a moderate contribution of the surrounding material, revealing minor roles for cross-links and topological effects and challenging the view that interphase chromatin is a gel-like material. Our technology opens avenues for future research in areas from chromosome mechanics to genome functions.

Application of evidence-based methods to construct mechanism-driven chemical assessment frameworks

The workshop titled “Application of evidence-based methods to construct mechanism-driven chemical assessment frameworks” was co-organized by the Evidence-based Toxicology Collaboration and the European Food Safety Authority (EFSA) and hosted by EFSA at its headquarters in Parma, Italy on October 2 and 3, 2019. The goal was to explore integration of systematic review with mechanistic evidence evaluation. Participants were invited to work on concrete products to advance the exploration of how evidence-based approaches can support the development and application of adverse outcome pathways (AOP) in chemical risk assessment. The workshop discussions were centered around three related themes: 1) assessing certainty in AOPs, 2) literature-based AOP development, and 3) integrating certainty in AOPs and non-animal evidence into decision frameworks. Several challenges, mostly related to methodology, were identified and largely determined the workshop recommendations. The workshop recommendations included the comparison and potential alignment of processes used to develop AOP and systematic review methodology, including the translation of vocabulary of evidence-based methods to AOP and vice versa, the development and improvement of evidence mapping and text mining methods and tools, as well as a call for a fundamental change in chemical risk and uncertainty assessment methodology if to be conducted based on AOPs and new approach methodologies (NAM). The usefulness of evidence-based approaches for mechanism-based chemical risk assessments was stressed, particularly the potential contribution of the rigor and transparency inherent to such approaches in building stakeholders’ trust for implementation of NAM evidence and AOPs into chemical risk assessment.

The Role of CDK Pathway Dysregulation and Its Therapeutic Potential in Soft Tissue Sarcoma

Soft tissue sarcomas (STSs) are tumors that are challenging to treat due to their pathologic and molecular heterogeneity and their tumor biology that is not yet fully understood. Recent research indicates that dysregulation of cyclin-dependent kinase (CDK) signaling pathways can be a strong driver of sarcogenesis. CDKs are enzyme forms that play a crucial role in cell-cycle control and transcription. They belong to the protein kinases group and to the serine/threonine kinases subgroup. Recently identified CDK/cyclin complexes and established CDK/cyclin complexes that regulate the cell cycle are involved in the regulation of gene expression through phosphorylation of critical components of transcription and pre-mRNA processing mechanisms. The current and continually growing body of data shows that CDKs play a decisive role in tumor development and are involved in the proliferation and growth of sarcoma cells. Since the abnormal expression or activation of large numbers of CDKs is considered to be characteristic of cancer development and progression, dysregulation of the CDK signaling pathways occurs in many subtypes of STSs. This review discusses how reversal and regulation can be achieved with new therapeutics and summarizes the current evidence from studies regarding CDK modulation for STS treatment.

ISO 10993-23 In vitro irritation testing for medical devices: Substantiating applicability to mild irritants and non-extractables

Irritation testing is an integral part of the biocompatibility assessment of medical devices and has historically been conducted on animals, either by direct contact or with polar and non-polar solvent extracts. In 2018 an ISO-sponsored interlaboratory validation study demonstrated that two reconstituted human epidermis (RhE) based assays, which were adapted from validated methods used for industrial chemicals, produced results essentially equivalent to those obtained with in vivo tests. This led to the publication of the ISO 10993-23:2021 standard on irritation testing, which states that RhE-based assays are now the preferred method. The 2018 validation study evaluated strong irritants, so we tested nine mild irritants (GHS Category 3), neat and spiked at different concentrations into medical device extracts, per ISO 10993-23:2021. The results substantiated the applicability of RhE-based assays for evaluating mild irritants in medical device extracts. Moreover, the 2018 validation study tested solid extractable medical device materials but did not consider non-extractable medical device materials (e.g., creams, gels, or sprays). By testing nine marketed non-extractable materials, either neat or spiked with irritants, we also confirmed that RhE-based assays are readily applicable to such medical device materials.

Biological plausibility in environmental health systematic reviews: a GRADE concept paper

BACKGROUND

"Biological plausibility" is a concept frequently referred to in environmental and public health when researchers are evaluating how confident they are in the results and inferences of a study or evidence review. Biological plausibility is not, however, a domain of one of the most widely-used approaches for assessing the certainty of evidence (CoE) which underpins the findings of a systematic review, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) CoE Framework. Whether the omission of biological plausibility is a potential limitation of the GRADE CoE Framework is a topic that is regularly discussed, especially in the context of environmental health systematic reviews.

OBJECTIVES

We analyse how the concept of "biological plausibility", as applied in the context of assessing certainty of the evidence that supports the findings of a systematic review, is accommodated under the processes of systematic review and the existing GRADE domains.

RESULTS AND DISCUSSION

We argue that "biological plausibility" is a concept which primarily comes into play when direct evidence about the effects of an exposure on a population of concern (usually humans) is absent, at high risk of bias, is inconsistent, or limited in other ways. In such circumstances, researchers look toward evidence from other study designs in order to draw conclusions. In this respect, we can consider experimental animal and in vitro evidence as "surrogates" for the target populations, exposures, comparators and outcomes of actual interest. Through discussion of 10 examples of experimental surrogates, we propose that the concept of biological plausibility consists of two principal aspects: a "generalisability aspect" and a "mechanistic aspect". The "generalisability aspect" concerns the validity of inferences from experimental models to human scenarios, and asks the same question as does the assessment of external validity or indirectness in systematic reviews. The "mechanistic aspect" concerns certainty in knowledge of biological mechanisms and would inform judgements of indirectness under GRADE, and thus the overall CoE. While both aspects are accommodated under the indirectness domain of the GRADE CoE Framework, further research is needed to determine how to use knowledge of biological mechanisms in the assessment of indirectness of the evidence in systematic reviews.

Simulation Opportunities by a Three-dimensional Calculation of Injection Moulding based on the Finite Element Method

The simulation of injection moulding is essential to meet quality requirements and to increase the efficiency of the design process. In this paper a 3D-finite element model for the simulation of injection moulding is presented. The model's capability comprises the calculation of velocity, pressure and temperature fields as well as the prediction of the flow front position. The numerical approach is mainly based on the Galerkin formulation. Special emphasis is placed on the handling of polymer compressibility in order to enable a realistic simulation of the packing phase. The numerical efficiency has been largely enhanced through the employment of an automatic time step control. In order to demonstrate the code's capabilities and outline advantages and disadvantages over other simulation systems, the calculation results are compared to experimental data and to results obtained from other numerical models.

Forensics in motion - Historic vehicles, genuine or fake?

In-depth forensic investigation and analysis of historic vehicles is a relatively new field of research. However, such examinations are becoming an important tool in the face of rising market values and the associated increase of manipulations and forgeries. We review various forensic approaches used in our interdisciplinary work in this field, including vehicle specialists, metallurgists, restorers, and archaeometry laboratories. The related investigations cover a general examination of the vehicle including detailed analysis of its materials and construction techniques, which are cross-referenced with the techniques and materials used in period. We illustrate our theoretical and analytical approach with practical examples from our work on collector vehicles. Finally, we consider methods and approaches currently under development.

How evidence-based methodologies can help identify and reduce uncertainty in chemical risk assessment

Evidence-based methodology, in particular systematic review, is increasingly being applied in environmental, public, and occupational health to increase the transparency, comprehensiveness, and objectivity of the processes by which existing evidence is gathered, assessed, and synthesized in answering research questions. This development is also changing risk assessment practices and will impact the assessment of uncertainties in the evidence for risks to human health that are posed by exposure to chemicals. The potential of evidence-based methodology for characterizing uncertainties in risk assessment has been widely recognized, while its contribution to uncertainty reduction is yet to be fully elucidated. We therefore present some key aspects of the evidence-based approach to risk assessment, showing how they can contribute to the identification and the assessment of uncertainties. We focus on the pre-specification of an assessment method­ology in a protocol, comprehensive search strategies, study selection using predefined eligibility criteria, critical appraisal of individual studies, and an evidence integration and uncertainty characterization process based on certainty of evi­dence frameworks that are well-established in health care research. We also provide examples of uncertainty in risk assessment and discuss how evidence-based methodology could address those. This perspective, which neither claims to be comprehensive nor complete, is intended to stimulate discussion of the topic and to motivate detailed exploration of how evidence-based methodology contributes to characterization of uncertainties, and how it will lead to uncertainty reduction in the conduct of health risk assessment.

Probabilistic risk assessment - the keystone for the future of toxicology

Safety sciences must cope with uncertainty of models and results as well as information gaps. Acknowledging this uncertainty necessitates embracing probabilities and accepting the remaining risk. Every toxicological tool delivers only probable results. Traditionally, this is taken into account by using uncertainty / assessment factors and worst-case / precautionary approaches and thresholds. Probabilistic methods and Bayesian approaches seek to characterize these uncertainties and promise to support better risk assessment and, thereby, improve risk management decisions. Actual assessments of uncertainty can be more realistic than worst-case scenarios and may allow less conservative safety margins. Most importantly, as soon as we agree on uncertainty, this defines room for improvement and allows a transition from traditional to new approach methods as an engineering exercise. The objective nature of these mathematical tools allows to assign each methodology its fair place in evidence integration, whether in the context of risk assessment, systematic reviews, or in the definition of an integrated testing strategy (ITS) / defined approach (DA) / integrated approach to testing and assessment (IATA). This article gives an overview of methods for probabilistic risk assessment and their application for exposure assessment, physiologically-based kinetic modelling, probability of hazard assessment (based on quantitative and read-across based structure-activity relationships, and mechanistic alerts from in vitro studies), individual susceptibility assessment, and evidence integration. Additional aspects are opportunities for uncertainty analysis of adverse outcome pathways and their relation to thresholds of toxicological concern. In conclusion, probabilistic risk assessment will be key for constructing a new toxicology paradigm – probably!

[Microsurgery Training with a Commercial Smartphone Kit - a new Device]

Microsurgical dissection and suturing techniques require persistent practice and perseverance. Rookies in particular often practice on the "dry model" in order to achieve a smooth transition to the application on the patient in the surgical theatre. Whether surgical glove, pig heart, with magnifying glasses, as a virtual reality tool, rat model with or without a training microscope - many different exercise models are described. For a number of years, self-made devices with smartphone cameras as a magnifying aid have also been known and are sometimes used. There is now a new commercial system from the US which allows the trainee to learn basic microsurgical techniques at any time and almost anywhere, or to perfect advanced knotting techniques such as the "through-the-loop" knot relatively easily and inexpensively. For this purpose, a conventional smartphone can be clamped in a 3 D swivel arm and anastomoses can be practiced on various vessel lumens. The smartphone therefor mimics a surgical microscope. There are prefabricated "cards" with built-in small plastic tubes of various diameters (1-3 mm) that can be used for practice.We believe that in the future such training kits can be part of the standard reporting in microsurgical training for interns and students in microsurgical centers.

Do families have moderating or mediating effects on early health inequalities? A scoping review

Background

During early childhood, families have a crucial impact on children's health behaviour, health, and development (bhd). However, a family's socioeconomic position (SEP) determines both the parental behaviour, living conditions, and child health. To understand how family characteristics may influence the development of health inequalities, this scoping review synthesised research on their mediating and moderating effects.

Methods

The review followed the guidelines of the PRISMA Extension for Scoping Reviews. The search included German and English peer-reviewed articles published between January 1st, 2000 and December 19th, 2019. The search in PubMed, PsycINFO, and Scopus used both free text terms in the title/abstract and index terms within linked keyword blocks: (1) family characteristics, (2) inequalities, (3) income, education, occupation, (4) bhd, (5) newborn, infant, toddler, preschooler. Two researchers independently examined eligibility for inclusion in two rounds (title/abstract; full-text).

Results

Of 7,089 articles identified, ten sources were included that studied family characteristics and health inequalities among 0-6 years olds. Parental rules, stress, and screentime, and TV in bedroom showed mediating effects on inequalities in behaviour problems or children's screentime. Families' negativity, single parenthood, and the number of children in the household moderated differences in impairment, health, behaviour problems, development or breastfeeding initiation.

Conclusions

The effect of family characteristics on early health inequalities has been sparsely investigated. The evidence supported models of family stress and investment. Further research is needed to comprehensively understand this association.

Key messages

Family characteristics contribute to health inequalities. Taking families’ stress and investment into account could improve targeted prevention efforts aimed at reducing health inequalities.

Minimum reporting standards based on a comprehensive review of the zebrafish embryo teratogenicity assay

Reproductive toxicity chemical safety assessment involves extensive use of vertebrate animals for regulatory testing purposes. Although alternative methods such as the zebrafish embryo teratogenicity assay (identified in the present manuscript by the acronym ZETA) are promising for replacing tests with mammals, challenges to regulatory application involve lack of standardization and incomplete validation. To identify key protocol aspects and ultimately support improving this situation, a comprehensive review of the literature on the level of harmonization/standardization and validation status of the ZETA has been conducted. The gaps and needed advances of the available ZETA protocols were evaluated and discussed with respect to its applicability as an alternative approach for teratogenicity assessment. Based on the review outcomes, a set of minimum reporting standards for the experimental protocol is proposed. Together with other initiatives towards implementation of alternative approaches at the screening and regulatory levels, the application of minimum reporting requirements is anticipated to support future method standardization and validation, as well as identifying potential improvement aspects. Present findings are expected to ultimately support advancing the ongoing validation initiatives towards the regulatory acceptance of the ZETA.

A health-based recommended occupational exposure limit for nitrous oxide using experimental animal data based on a systematic review and dose-response analysis

BACKGROUND

Nitrous oxide (N₂O) is a common inhalation anaesthetic used in medical, paramedical, and veterinary practice. Since the mid 1950's, concerns have been raised regarding occupational exposure to N₂O, leading to many epidemiological and experimental animal studies. Previous evaluations resulted in the classification of N₂O as a possible risk factor for adverse reproductive health outcomes based on animal data. Human data were deemed inadequate primarily because of simultaneous co-exposures to other risk factors for adverse reproductive and developmental outcomes, including other anaesthetic gases. Since previous evaluations, controversies regarding N₂O use remained and new approaches for dose response modelling have been adopted, calling for an update and re-evaluation of the body of evidence. This review aims to assess available animal evidence on N₂O reproductive and developmental outcomes to inform a health-based recommended occupational exposure limit (OEL) for N₂O with a benchmark dose-response modelling (BMD) approach.

METHODS

Comprehensive searches in PubMed, EMBASE, and Web of Science were performed to retrieve all relevant studies addressing reproductive and developmental outcomes related to inhalation of N₂O in animals. The articles retrieved were screened based on title-abstract and full text by two independent reviewers. After data extraction, an overview of all studies was created for the different endpoints, namely foetal outcomes (e.g., resorption), female outcomes (e.g. implantations), and male outcomes (e.g. sperm count). A subset of studies reporting on exposure relevant to workplace settings and with a sufficient number of tested doses were included in dose-response modelling using the BMD approach.

RESULTS

In total, 15.816 articles were retrieved, of which 47 articles were finally included while 4 of those were used for the quantitative data synthesis. The overall risk of bias was judged to be probably high (using OHAT risk of bias tool) and unclear (using SYRCLE's risk of bias tool). From eligible rat studies, three studies provided an acceptable result by fitting a Hill model to the dose-response data. The resulting benchmark dose lower bounds (BMDLs) from three studies converged to an average (±sd) exposure level of 925 ± 2 mg/m³ at an additional risk of one standard deviation of implantation losses above those observed in the control group (i.e. reduced number of live foetuses/mother). For extrapolation from rats to humans, an uncertainty factor of 10 was used and an additional factor of 5 was applied to account for interindividual variability within the population of workers.

CONCLUSION

With this systematic review, all available evidence for reproductive toxicity and adverse developmental outcomes in animals resulting from inhalation exposure to N₂O was used to derive a health-based OEL recommendation of 20 mg/m³ as 8-h time-weighted average.

A Systematic Review to Compare Chemical Hazard Predictions of the Zebrafish Embryotoxicity Test With Mammalian Prenatal Developmental Toxicity

Originally developed to inform the acute toxicity of chemicals on fish, the zebrafish embryotoxicity test (ZET) has also been proposed for assessing the prenatal developmental toxicity of chemicals, potentially replacing mammalian studies. Although extensively evaluated in primary studies, a comprehensive review summarizing the available evidence for the ZET's capacity is lacking. Therefore, we conducted a systematic review of how well the presence or absence of exposure-related findings in the ZET predicts prenatal development toxicity in studies with rats and rabbits. A two-tiered systematic review of the developmental toxicity literature was performed, a review of the ZET literature was followed by one of the mammalian literature. Data were extracted using DistillerSR, and study validity was assessed with an amended SYRCLE's risk-of-bias tool. Extracted data were analyzed for each species and substance, which provided the basis for comparing the 2 test methods. Although limited by the number of 24 included chemicals, our results suggest that the ZET has potential to identify chemicals that are mammalian prenatal developmental toxicants, with a tendency for overprediction. Furthermore, our analysis confirmed the need for further standardization of the ZET. In addition, we identified contextual and methodological challenges in the application of systematic review approaches to toxicological questions. One key to overcoming these challenges is a transition to more comprehensive and transparent planning, conduct and reporting of toxicological studies. The first step toward bringing about this change is to create broad awareness in the toxicological community of the need for and benefits of more evidence-based approaches.

Validation of the 3D reconstructed human skin micronucleus (RSMN) assay: an animal-free alternative for following-up positive results from standard in vitro genotoxicity assays

In vitro test batteries have become the standard approach to determine the genotoxic potential of substances of interest across industry sectors. While useful for hazard identification, standard in vitro genotoxicity assays in 2D cell cultures have limited capability to predict in vivo outcomes and may trigger unnecessary follow-up animal studies or the loss of promising substances where animal tests are prohibited or not desired. To address this problem, a team of regulatory, academia and industry scientists was established to develop and validate 3D in vitro human skin-based genotoxicity assays for use in testing substances with primarily topical exposure. Validation of the reconstructed human skin micronucleus (RSMN) assay in MatTek Epi-200™ skin models involved testing 43 coded chemicals selected by independent experts, in four US/European laboratories. The results were analysed by an independent statistician according to predefined criteria. The RSMN assay showed a reproducibly low background micronucleus frequency and exhibited sufficient capacity to metabolise pro-mutagens. The overall RSMN accuracy when compared to in vivo genotoxicity outcomes was 80%, with a sensitivity of 75% and a specificity of 84%, and the between- and within-laboratory reproducibility was 77 and 84%, respectively. A protocol involving a 72-h exposure showed increased sensitivity in detecting true positive chemicals compared to a 48-h exposure. An analysis of a test strategy using the RSMN assay as a follow-up test for substances positive in standard in vitro clastogenicity/aneugenicity assays and a reconstructed skin Comet assay for substances with positive results in standard gene mutation assays results in a sensitivity of 89%. Based on these results, the RSMN assay is considered sufficiently validated to establish it as a ‘tier 2’ assay for dermally exposed compounds and was recently accepted into the OECD’s test guideline development program.

Applying evidence-based methods to the development and use of adverse outcome pathways

The workshop “Application of evidence-based methods to construct mechanistic frameworks for the development and use of non-animal toxicity tests” was organized by the Evidence-based Toxicology Collaboration and hosted by the Grading of Recommendations Assessment, Development and Evaluation Working Group on June 12, 2019. The purpose of the workshop was to bring together international regulatory bodies, risk assessors, academic scientists, and industry to explore how systematic review methods and the adverse outcome pathway framework could be combined to develop and use mechanistic test methods for predicting the toxicity of chemical substances in an evidence-based manner. The meeting covered the history of biological frameworks, the way adverse outcome pathways are currently developed, the basic principles of systematic methodology, including systematic reviews and evidence maps, and assessment of cer­tainty in models, and adverse outcome pathways in particular. Specific topics were discussed via case studies in small break-out groups. The group concluded that adverse outcome pathways provide an important framework to support mechanism-based assessment in environmental health. The process of their development has a few challenges that could be addressed with systematic methods and automation tools. Addressing these challenges will increase the transparency of the evidence behind adverse outcome pathways and the consistency with which they are defined; this in turn will increase their value for supporting public health decisions. It was suggested to explore the details of applying systematic methods to adverse outcome pathway development in a series of case studies and workshops.

In vitro methodology for medical device material thrombogenicity assessments: A use condition and bioanalytical proof-of-concept approach

Device manufacturers and regulatory agencies currently utilize expensive and often inconclusive in vivo vascular implant models to assess implant material thrombogenicity. We report an in vitro thrombogenicity assessment methodology where test materials (polyethylene, Elasthane™ 80A polyurethane, Pebax®), alongside positive (borosilicate glass) and negative (no material) controls, were exposed to fresh human blood, with attention to common blood-contact use conditions and the variables: material (M), material surface modification (SM) with heparin, model (Mo), time (T), blood donor (D), exposure ratio (ER; cm2 material/ml blood), heparin anticoagulation (H), and blood draw/fill technique (DT). Two models were used: (1) a gentle-agitation test tube model and (2) a pulsatile flow closed-loop model. Thrombogenicity measurements included thrombin generation (thrombin-antithrombin complex [TAT] and human prothrombin fragment F1.2), platelet activation (β-thromboglobulin), and platelet counts. We report that: (a) thrombogenicity was strongly dependent (p < .0001) on M, H, and T, and variably dependent (p < .0001 - > .05) on Mo, SM, and D (b) differences between positive control, test, and negative control materials became less pronounced as H increased from 0.6 to 2.0 U/ml, and (c) in vitro-to-in vivo case comparisons showed consistency in thrombogenicity rankings on materials classified to be of low, moderate, and high concern. In vitro methods using fresh human blood are therefore scientifically sound and cost effective compared to in vivo methods for screening intravascular materials and devices for thrombogenicity.

Recommendations for the conduct of systematic reviews in toxicology and environmental health research (COSTER)

BACKGROUND

There are several standards that offer explicit guidance on good practice in systematic reviews (SRs) for the medical sciences; however, no similarly comprehensive set of recommendations has been published for SRs that focus on human health risks posed by exposure to environmental challenges, chemical or otherwise.

OBJECTIVES

To develop an expert, cross-sector consensus view on a key set of recommended practices for the planning and conduct of SRs in the environmental health sciences.

METHODS

A draft set of recommendations was derived from two existing standards for SRs in biomedicine and developed in a consensus process, which engaged international participation from government, industry, non-government organisations, and academia. The consensus process consisted of a workshop, follow-up webinars, email discussion and bilateral phone calls.

RESULTS

The Conduct of Systematic Reviews in Toxicology and Environmental Health Research (COSTER) recommendations cover 70 SR practices across eight performance domains. Detailed explanations for specific recommendations are made for those identified by the authors as either being novel to SR in general, specific to the environmental health SR context, or potentially controversial to environmental health SR stakeholders.

DISCUSSION

COSTER provides a set of recommendations that should facilitate the production of credible, high-value SRs of environmental health evidence, and advance discussion of a number of controversial aspects of conduct of EH SRs. Key recommendations include the management of conflicts of interest, handling of grey literature, and protocol registration and publication. A process for advancing from COSTER's recommendations to developing a formal standard for EH SRs is also indicated.

A genetic memory initiates the epigenetic loop necessary to preserve centromere position

Centromeres are built on repetitive DNA sequences (CenDNA) and a specific chromatin enriched with the histone H3 variant CENP‐A, the epigenetic mark that identifies centromere position. Here, we interrogate the importance of CenDNA in centromere specification by developing a system to rapidly remove and reactivate CENP‐A (CENP‐A^OFF/ON). Using this system, we define the temporal cascade of events necessary to maintain centromere position. We unveil that CENP‐B bound to CenDNA provides memory for maintenance on human centromeres by promoting de novo CENP‐A deposition. Indeed, lack of CENP‐B favors neocentromere formation under selective pressure. Occasionally, CENP‐B triggers centromere re‐activation initiated by CENP‐C, but not CENP‐A, recruitment at both ectopic and native centromeres. This is then sufficient to initiate the CENP‐A‐based epigenetic loop. Finally, we identify a population of CENP‐A‐negative, CENP‐B/C‐positive resting CD4⁺ T cells capable to re‐express and reassembles CENP‐A upon cell cycle entry, demonstrating the physiological importance of the genetic memory.

The impact of the family on health inequalities in children – A systematic scoping review

Background

Health inequalities in school-aged children and adolescents were repeatedly reported across Europe but less is known about the contextual and compositional factors of families that might influence and reproduce those health inequalities. In this systematic scoping review we aim to provide a comprehensive overview of the available international literature on the mediating and moderating influence of the family on health inequalities in children and adolescents in Europe and North America.

Methods

This review follows the PRISMA guidelines for scoping reviews. After defining the research question a search strategy was developed in cooperation with a scientific librarian and the study protocol was registered. A search of three databases (Pubmed, Scopus, PsycINFO) was conducted to identify relevant literature in English or German published between the year 2000 and 2019. A qualitative data charting process was used to extract the relevant data.

Results

In total 11.838 records were identified through the multi database search (Pubmed n = 6370, PsycINFO n = 3505, Scopus n = 1963). After elimination of duplicates and records from excluded countries, 8862 abstracts were screened by two researchers independently. Different cluster of evidence of family influences on health inequalities were identified: Parental behaviors and children's obesity, parents' smoking and drinking habits and adolescents' risk behaviors, parenting style and children's common mental disorders, parental resources and children's quality of life.

Conclusions

There are different aspects of family's contextual and compositional characteristics on health inequalities identifiable in the international literature. These characteristics might be new targets for family-focused health promotion strategies.

Key messages

A systematic scoping review found different family aspects that influence health inequalities in children and adolescents. The identified family traits are promising targets for family-focused health promotion strategies to reduce health inequalities.

Independent Risk Factors for Impaired Early Outcome after Isolated Ankle Fracture - A Multivariate Analysis and Prognostic Models

BACKGROUND

Ankle fractures are common operative indications in orthopedic surgery. Their incidence is increasing.

OBJECTIVES

To identify independent risk factors and to develop prognostic models for the prediction of prolonged length of hospital stay (LOS) and the onset of postoperative complications.

MATERIALS AND METHODS

This is a single-center, retrospective, observational study analyzing data of 154 consecutive, isolated, surgically treated ankle fractures. Multivariate binary logistic regression analysis was applied to identify significant independent risk factors. The validity and clinical applicability of the developed prognostic models was assessed with ROC-curve analysis (ROC: Receiver Operating Characteristic). Internal validation of prognostic models was performed with randomized backwards bootstrapping.

RESULTS

The median LOS was 7 days. 50 patients (33%) had a longer LOS. 13% of operated patients had a postoperative complication (n = 20). Independent preoperative risk factors for prolonged length of stay were leukocytosis (p = 0.020; OR: 1.211), an increased CRP-level (p = 0.005; OR: 1.901), as well as a bi- (p = 0.002; OR: 15.197) or trimalleolar (p = 0.001; OR: 10.678) fracture type. Immediate operative therapy was an independent beneficial factor (p < 0.001; OR: 0.070). The onset of complications was associated significantly with diabetes mellitus (p = 0.004; OR: 9.903) and an elevated ASA score (p = 0,004; OR: 3.574). The developed prognostic models for the prediction of prolonged LOS (AUROC: 0.736) and postoperative complications (AUROC: 0.724) had a good clinical validity and were internally validated.

CONCLUSION

The current data pronounce the importance of preoperative laboratory works. Furthermore, co-morbidities play a major role in the prognosis of outcome. The developed prognostic models are able to reliably predict the outcome and enable the preoperative identification of high-risk patients.

The GOLIATH Project: Towards an Internationally Harmonised Approach for Testing Metabolism Disrupting Compounds

The purpose of this project report is to introduce the European "GOLIATH" project, a new research project which addresses one of the most urgent regulatory needs in the testing of endocrine-disrupting chemicals (EDCs), namely the lack of methods for testing EDCs that disrupt metabolism and metabolic functions. These chemicals collectively referred to as "metabolism disrupting compounds" (MDCs) are natural and anthropogenic chemicals that can promote metabolic changes that can ultimately result in obesity, diabetes, and/or fatty liver in humans. This project report introduces the main approaches of the project and provides a focused review of the evidence of metabolic disruption for selected EDCs. GOLIATH will generate the world's first integrated approach to testing and assessment (IATA) specifically tailored to MDCs. GOLIATH will focus on the main cellular targets of metabolic disruption-hepatocytes, pancreatic endocrine cells, myocytes and adipocytes-and using an adverse outcome pathway (AOP) framework will provide key information on MDC-related mode of action by incorporating multi-omic analyses and translating results from in silico, in vitro, and in vivo models and assays to adverse metabolic health outcomes in humans at real-life exposures. Given the importance of international acceptance of the developed test methods for regulatory use, GOLIATH will link with ongoing initiatives of the Organisation for Economic Development (OECD) for test method (pre-)validation, IATA, and AOP development.

Ex vivo limb perfusion for traumatic amputation in military medicine

BACKGROUND

Limb loss has a drastic impact on a patient's life. Severe trauma to the extremities is common in current military conflicts. Among other aspects, "life before limb" damage control surgery hinders immediate replantation within the short post-traumatic timeframe, which is limited in part by the ischemic time for successful replantation. Ex vivo limb perfusion is currently being researched in animal models and shows promising results for its application in human limb replantation and allotransplantation.

PRESENTATION OF THE HYPOTHESIS

The current lack of replantation possibilities in military operations with high rates of amputation can be addressed with the development of a portable ex vivo limb perfusion device, as there are several opportunities present with the introduction of this technique on the horizon. We hypothesize that ex vivo limb perfusion will enable overcoming the critical ischemic time, provide surgical opportunities such as preparation of the stump and limb, allow for spare-part surgery, enable rigorous antibiotic treatment of the limb, reduce ischemia-reperfusion injuries, enable a tissue function assessment before replantation, and enable the development of large limb transplant programs.

TESTING THE HYPOTHESIS

Data from in vivo studies in porcine models are limited by the relatively short perfusion time of 24 h. In the military setting, notably longer perfusion times need to be realized. Therefore, future animal studies must focus especially on long-term perfusion, since this represents the military setting, considering the time for stabilization of the patient until evacuation to a tertiary treatment center.

IMPLICATIONS OF THE HYPOTHESIS

The development and clinical introduction of ex vivo limb perfusion in the military setting could lead to a drastic reduction in the number of limb amputations among service members. Ex vivo limb perfusion enables replantation surgery in Role 4 facilities and changes the clinical setting from a highly urgent, life-threatening situation to a highly methodical, well-prepared starting point for optimal treatment of the wounded service member. With its introduction, the principle of "life before limb" will change to "life before limb before elective replantation/allotransplantation after ex vivo limb perfusion".

Comorbidity, family history and personality traits in pathological gamblers compared with healthy controls

Background

While DSM-5 classified pathological gambling as an addictive disorder, there is debate as to whether ICD-11 should follow suit. The debate hinges on scientific evidence such as neurobiological findings, family history of psychiatric disorders, psychiatric comorbidity, and personality variables.

Methods

In the “Baden-Württemberg Study of Pathological Gambling”, we compared a group of 515 male pathological gamblers receiving treatment with 269 matched healthy controls. We studied differences in sociodemographic characteristics, gambling-related variables, psychiatric comorbidity (lifetime), family history of psychiatric conditions, as well as personality traits such as impulsivity (Barratt Impulsiveness Scale), sensation seeking (Zuckerman's Sensation Seeking Scale) and the NEO-FFI big five. Personality traits were validated in an age- and ethnicity-matched subsample of “pure” gamblers without any psychiatric comorbidity (including nicotine dependence). Data were analyzed using two-sample t-tests, Chi2 analyses, Fisher's exact test and Pearson correlation analysis, as appropriate. Bonferroni correction was applied to correct for multiple comparisons.

Results

Only 1% of the gamblers had been diagnosed with an impulse control disorder other than gambling (ICD-10). Notably, 88% of the gamblers in our sample had a comorbid diagnosis of substance dependence. The highest axis I comorbidity rate was for nicotine dependence (80%), followed by alcohol dependence (28%). Early age of first gambling experience was correlated with gambling severity. Compared to first-degree relatives of controls, first-degree relatives of pathological gamblers were more likely to suffer from alcohol dependence (27.0% vs. 7.4%), pathological gambling (8.3% vs. 0.7%) and suicide attempts (2.7% vs. 0.4%). Significant group differences were observed for the NEO-FFI factors neuroticism, agreeableness and conscientiousness. Gamblers were also more impulsive than controls, but did not differ from controls in terms of sensation seeking.

Conclusions

Our findings support classifying pathological gambling as a behavioural addiction in the ICD-11. This decision will have a significant impact on the approaches available for prevention (e.g. age limits) and treatment.