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3R in Toxicity Testing:

Fragen zur Abschlussklausur 2022

Test format: Open book exam

Date and time: Friday Sept 30, 8:45-9:45 h

Pleases email your answers to aswin.mangerich@uni-konstanz.deuntil 10 am.

If possible, please write your answers in red color.

 

Overview of toxicity testing and the 3 Rs concept: requirements, goals & status quo (Mangerich /Leist)

Question 1   [3 points]

Please name three advantages and limitations/disadvantages, respectively, of the use of animals in toxicity testing.

 

Question 2   [4 points]

Below, eight non-standard (3R) approaches to assess hazard are given (A-H). Decide for each approach whether it is based on the use of animals or not. Animal-based means that animals will or may be used. Non-animal means that live animals are not used. Mark your choice of the correct answer with a cross in either the 3rd or 4th column. Each correct answer gives 0.5 points. Wrong answers give 0.5 negative points. The maximum number of points is four, the minimum is zero.

Approach

Name

animaluse

noanimaluse

A

Reduction

X

 

B

Refinement

X

 

C

Replacement

 

x

D

In vitro NAM

 

x

E

In silico NAM

 

x

F

QSAR

 

x

G

Readacross

 

x

H

IATA

x

 

Introduction into test development for hazard and toxicokinetic predictions (Leist)

Question3 [5 points]

Below, five statements are made which are to be judged as TRUE or FALSE. Mark your choice of the correct answer with a cross in either the 2nd or 3rdcolumn. Each correct answer gives 1 point. Wrong answers give 1 negative point. The maximum number of points is five, the minimum is zero.

 

Statement

True

False

The PoD for a NAM (e.g. hepatotoxicity of chemical A) is given in mg/kg

 

x

The clearance of compound A in hepatocytes is determined usually by measuring the half-life of compound A, when incubated with hepatocytes

x

 

PBK models require parameters for the transition of chemicals between (body) compartments

x

 

A NAM is always setup to predict chemical hazard and it can therefore be used for hazard determination of any chemical

 

x

Each cell-based NAM has a defined test endpoint (e.g. ATP content)

x

 

 

The concept of adverse outcome pathways (AOPs) (Schildknecht)

Question 4   [2 points]

Provide a brief definition of the term“Adverse Outcome Pathway (AOP)”.

 

Question 5   [2 points]

What are 2 key requirements that qualify a biological state as “Key Event (KE)”

 

Validation concepts and test readiness criteria (Waldmann)

Question 6   [5 points]

Below, five statements are made which are to be judged as TRUE (T) or FALSE (F). Mark your choice of the correct answer with a cross in either the 2nd or 3rd column. Each correct answer gives 1 point. Wrong answers give 1 negative point. The maximum number of points is five, the minimum is zero.

 

Statement

True

False

The solvent control is the only negative control that is needed for validation of a test method

 

x

The endpoint-specific controls are used to gain confidence that pathways considered to be relevant for the endpoint are indeed affected.

x

 

The prediction model can be also a more complex decision tree to combine two endpoints or even several test methods

x

 

Acceptance criteria must be set before the first test runs for test method validation.

x

 

To define acceptance criteria historical data must be collected in order to learn about baseline variations and test performance.

x

 

 

 

Good in vitro method practices guidance; a tool to increase trust in data for (regulatory) decision making (Langezaal)

Question 7   [1 point]

Which action described below is recommended by GIVIMP. Please check the correct answer.

a)      In-house validation of the in vitro method, after the generation of data and publication of results.

b)      Inclusion of positive and negative controls, to demonstrate that the test system (e.g. cells, tissue or cellular fraction) responds as expected. -

c)      Setting cut-off limits for the test item results below the limit of detection.

d)      Use of fetal bovine serum and antibiotics to enhance cell attachment and suppress

microbiological infections, respectively.

 

Question 8   [1 point]

Which of the following elements is NOT part of an in vitro method

a)      the test system (e.g. a cell or tissue)

b)      positive and negative control items

c)      data analysis and data interpretation model

d)      the test item

 

New approach methodologies (NAMs) in hepatotoxicity testing (Hengstler)

Question 9   [4 points]

Please assign the cell types of the liver below to a typical function:

Cell type of the liver

(a)  Hepatocyte 2

(b)  Kupffer cell 3

(c)  Sinusoidal endothelial cell 1

(d)  Stellate cell 4

Function

1.    First contact with immune cells of the blood

2.    Metabolism

3.    Phagocytosis of bacterial fragments

4.    Secretion of extracellular matrix

 

 

History and state of the art of stem cell-based toxicity testing (Seeger)

Question 10 [2 points]

Which aspects make the fetus extremely sensitive to developmental toxicants?

Mark your choice of the correct answer with a cross in either the 2nd or 3rd column. Each correct answer gives 0.5 points. Wrong answers give 0.5 negative points. The maximum number of points is 2 points, the minimum is zero points.

 

 

Statement

Yes

No

Most rapid cell growth/organ differentiation

x

 

Organs are fully differentiated

 

x

High degree of epigenetic plasticity

x

 

Tight blood brain barrier

 

x

 

 

Question 11 [           1 point]

Which would be the perfect culture method for stem cells concerning Good Cell Culture Practice (one answer is correct)? c

 

a) feeder-dependent, xenogenic, chemically undefined

b) feeder-independent, xenogenic, chemically undefined

c) feeder-independent, xenofree, chemically defined

d) feeder-dependent, xenofree, chemically defined

 

Read-across for the prediction of toxiceffects of chemicals (vomBrocke)

Question 12             [4 points]

Name four aspects that belong to every read-across approach?

 

 

Computational toxicology methods for prediction of preclinical safety endpoint (Anger)

Question 13             [2 points]

What does the fundamental “Similarity principle” in Computational Toxicology mean?

 

Question 14             [1 point]

Bacterial mutagenicity, an endpoint for which many reliable in silico prediction models exist, is mainly driven by...


a) by physico-chemical properties

b) through primary (on-)target protein activity

c) by reactive chemical substructures

d) through secondary (off-)target protein activity

 

Use of zebrafish as a model organism in the context of 3Rs (Scholz)

Question 15             [1 point]

Why are zebrafish embryos considered as an alternative model and 3R-compliant?

 

 

Question 16 [1 point]

For which mode of action the zebrafish has reduced sensitivity in mortality if compared to adult fish?

 

 

 

Non-animal approaches in genetic toxicology and carcinogenicity testing(Martus/Mangerich)

Question 17 [2 points]

Which 2 key strategies are followed in order to further reduce animal numbers in genotoxicity testing?

 

 

Question 18 [2 points]

What are the advantages of using transgenic animals as opposed to wildtype animals? Please check the correct answer(s)

 

A1: shorter treatment duration

A2: higher sensitivity

A3: higher relevance of tumor findings

A4: less animals

 

Microphysiological systems (MPS) and organ on a chip (OoaC)Technologies (Loskill)

Question 19 [2 points]

Which of these aspects are basic principles of Organ-on-Chip models? Please check the correct answers.

 

a.         Physiological microenvironment

b.         Culture of microorganisms

c.         Integration of electrodes

d.         Vacuum channels

e.         Microfluidic perfusion

 

 

Question 20 [3 points]

What are advantages of organoid models? Please check the correct answers.

a.         Human genetic background

b.         Cell polarization

c.         Physiological biochemical and biophysical cues

d.         Static culture

e.         Cell heterogeneity

 

 

New approach methodologies (NAMs) in (developmental)neurotoxicity (DNT) testing (Fritsche)

Question 21 [3 points]

Name at least three cellular readouts for DNT.

 

 

New developments in reduction & refinement of animal experiments (Würbel)

Question 22 [3 points]

What do the 3Vs stand for and what is their role in a proportionality test of animal research?

 

European regulatory landscape of 3 Rs:Why Non-Animal Methods are controversial in EU policies? (Busquet)

Question 23 [4 points]

Name (a) the institutions involved in EU policy making and (b) at least 2 directorates-general (DG) involved in EU policies on the use of laboratory animals.

 

Relevance of new approach methodologies (NAMs) for the chemical industry - today and tomorrow (Birk)

Question 24[3 points]

What are critical requirements on NAMs during the development process – please list at least three requirements?

 

Development of OECD-approved test guidelines for new approach methods for skin sensitization (Kolle)

Question 25 [3 points]

Borderline range around prediction cut-offs. Check all answers that are correct.

 

a) Any toxicological test result can clearly be assigned to the effect or no effect side.

b) A borderline result can come from two major sources including experimental variability or inherent properties of the item tested.

c) Using binary “hazardous/non-hazardous” information may lead to ambiguous classifications of substances

d) Quantifying the area where such ambiguous results are likely to occur, i.e. the borderline range, can be used to document a testing method’s limited precision

 

3Rs in the context of food safety (Kass)

Question 26 [2 points]

What are the main perceived obstacles to the use of NAMs in regulatory risk assessment for food safety?

 

 

(Neue) Fragen zur Abschlussklausur 2023

The concept of adverse outcome pathways (AOPs) (Schildknecht)

Question 4 [4 points]

Please give a brief definition of the AOP terms:

 

“Key Event”

 

 

“Key Event Relationship”

 

 

Good in vitro method practice guidance, test readiness criteria and validation concepts (Langezaal)

Question 5 [1 point]

Which of the following is true:

a)    The use of test readiness criteria is obligatory to confirm that a method is ready for validation

b)    The use of test readiness criteria is helpful to understand if method development is complete

c)    Test readiness criteria are an official tool of GD34, used by peer-reviewers, to confirm validation is complete

d)    None of the above

 

Question 6 [1 point]

What needs to be ensured, before a NAM will be used for regulatory decisions?

a)      All data generated during validation meet the acceptance criteria.

b)      The method developer confirms that the method is fit for purpose, biologically relevant and technically characterized.

c)      Chemicals that trigger the mode of action cannot be identified.

d)      Biological relevance, robustness, accuracy, reproducibility, and fitness for a specific purpose.

 

 

Systems Toxicology (Hartung)

Question 7 [2 point]

Which omics technologies are mainly used in systems toxicology?

 

 

History and state of the art of stem cell-based toxicity testing (Seeger)

Question 8 [3 points]

Name three types of stem cells. Give information in bullet points about the source and potency of each type.

 

 

Use of zebrafish as a model organism in the context of 3Rs (Scholz)

Question 10 [1 point]

Which mode of action can be detected by assessment of embryonic movements?

 

 

Computational toxicology methods for prediction of preclinical safety endpoint (Anger)

Question 13 [2 points]

What's the goal of applying Computational Toxicology methods in the early stages of drug discovery?

a) Risk assessment

b) High throughput

c) Prediction of toxic potential ("hazard")

d) Low throughput

 

 

New approach methodologies (NAMs) in (developmental) neurotoxicity (DNT) testing

(Fritsche)

Question 17 [4 points]

The DNT in vitro battery...

 

1. Consists of in vitro assays that cover basic neurodevelopmental processes.

2. Is a collaborative approach involving regulators and the OECD.

3. Only contains human cell systems.

4. Has been scientifically validated.

5. Is a continuing effort that takes novel developments into account.

 

Please mark the correct answers.

 

3Rs from the Pharma perspective (Moretti)

Question 19 [2 points]

Can you name two reasons behind using alternative methodologies in investigative toxicology?

 

 

European regulatory landscape of 3 Rs: Why Non-Animal Methods are controversial in EU policies? (Busquet)

Question 21 [2 points]

List min two reasons why NAMs are controversial?

 

 

Relevance of new approach methodologies (NAMs) for the chemical industry - today and tomorrow (Kolle)

Question 22 [3 points]

Industry use NAMs for different purpose. Please name three examples.

 

 

3Rs from the BfR perspective (Schönfelder)

Question 23 [1 point]

PARERE has a number of roles to fulfil: (Please mark the correct answer)

 

1.         To provide upstream input on potential regulatory relevance and suitability of proposed test methods and testing strategies.

2.         Facilitate information flow between OECD and regulators regarding the development and validation of methods and to identify areas that need specific attention.

3.         Identification of specifically industry partners to participate in specific EURL ECVAM project groups (e.g. ITS design, validation management groups, expert workshops etc.).

4.         Provide comments on draft EURL ECVAM recommendations following OECD peer review of validation studies.

5.         Support and promote the role of OECD laboratories to facilitate their participation as a testing and/or lead laboratory in EURL ECVAM led validation studies.

 

 

Read-across for the prediction of toxic effects of chemicals (vom Brocke)

Question 24 [3 points]

What are potential advantages of read-across over other test and non-test methods? Mention at least three:

 

 

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Last Update: 12. Oktober 2023