Contents
Introduction..............................................................................................................................1
Animal models: choices and consequences..............................................................................2
Organ-on-a-chip........................................................................................................................6
Ethic aspects of animal experimentation..................................................................................9
The art of randomization........................................................................................................13
3Rs – Alternatives to animal experiments..............................................................................14
Anesthesia and euthanasia.....................................................................................................16
Microbiology and hygiene......................................................................................................19
Principles of analgesia.............................................................................................................22
View of Proefdiervrij on animal experiments.........................................................................26
Assessment of distress............................................................................................................27
Legislation...............................................................................................................................30
Nutrition of laboratory animals..............................................................................................33
Principles of surgery...............................................................................................................35
Labor ator y an im al scien ce
Introduction
LAS is a multidisciplinary science contributing to:
Quality of science and animal studies
Health and wellbeing of laboratory animals
Public acceptance of animal studies
Science is growing and there are more alternative to animal experiments still big
amount of data.
Same laws in all EU countries EU directive 2010/63/EU to harmonize practices,
implement 3Rs improve welfare, transparency and enforcement.
No legal base for education & training
- Education and training framework to promote harmonization, ensure
competence and facilitate free movement of personnel.
- Outcome based on general agreement, not binding.
- Interpretation is left to Member States
3R’s
Replacement is “any scientific method employing non-sentient material which
may replace methods which use conscious living vertebrates”.
, Reduction is a means of “lowering the number of animals used to obtain
information of a given amount and precision”.
Refinement is the set of measures undertaken to “decrease in the incidence or
severity of procedures applied to those animals which have to be used”.
Whether we have to use less animals with more discomfort or more animals with less
discomfort really depends on the situation.
1% can be collected from animals to prevent anemia.
Animal models are limited in their ability to translate to humans: of the drugs that
have proved promising in animal trials, 86-90% fail in human trials.
Animal models: choices and consequences
Why use animal models? research with animals contributes to more than half of
the significant discoveries, 75% of major advances.
Studies with bacteria, tissue culture and computer stimulation can provide very
helpful information but cannot fully mimic the human complexity.
Definition of laboratory animal model
“An animal model in which normative biology or behavior can be studied, or in which
a spontaneous or induced pathological process can be investigated, and in which the
phenomenon in one or more respects resembles the same phenomenon in humans or
other species of animal”.
Disease models
Induced (experimental) disease models (inducing obesity, tumor growth,
renal damage, etc.)
Spontaneous (genetic) disease models (nude mice, hypertensive rat, etc.)
Transgenic disease models (KO, KI (i.e. introducing a crippled version of a
GPCR), tissue selective, inducible)
Neutral models
Healthy animals from all species
Inbr ed
- Created by generations of crossing siblings, same genotype
- Inbred (isogenic) strains: produced by many (>20) generations of brother x
sister mating.
- Aim: Genetic homogeneity
- The same genotype can be reproduced indefinitely, though over a period of
time
- there may be some genetic drift due to the accumulation of new mutations.
Outbr ed
- Diverse population, more like humans
, - Breeding colonies in which there is (certain) degree of genetic variation.
- Aim: Genetically undefined outbred stocks
- The amount of genetic variation depends on the breeding history of the
particular colony
- Although outbred stocks are widely used, they are not ideal experimental
material because nothing is known about the genotype of any individual, and
no two individuals are alike.
- This means that a "control" and a "treated" animal will differ not only in
treatment, but also to an unknown extent in genotype. As a result, sample
sizes will need to be greater than if isogenic animals had been used.
- Genetic homogeneity leads to phenotypic uniformity, which means that
smaller numbers of animals are needed to achieve a given level of statistical
precision: ‘inbreds will have a higher statistical reproducibility’
Festing: Someone using an outbred stock generally knows nothing about the genetic
characteristics of individual animals, what genes they carry or how heterozygous they
are. Background data on characteristics will be unreliable because they can change
rapidly.
Scientists sometimes try to justify the use of outbred stocks on the grounds that the
aim is to model humans, and humans are genetically variable. True when studying
very fundamental processes, like reproduction. But scientists using outbreds are not
being very consistent.
In toxicology:
- Outbred, because one doesn’t know what to expect?
- Inbred, ‘‘genetically defined’’ strains of mice and rats are more stable, more
uniform, more repeatable, and better defined than the ‘‘genetically undefined’’
outbred stocks used in most toxicity testing.
W hy use inbr ed : On average isogenic strains are more sensitive than outbred
stocks to experimental treatments, which also increases the power of experiments
which use them. - They are internationally distributed, so that work can be replicated
all over the world. - Searchable lists of inbred strains of mice and rats and their
characteristics are maintained by, for instance, The Jackson Laboratory.
To use when fundamental or undefined processes are to be evaluated
(reproduction, universal physiological processes, toxicology)
In such a way that the experiment can be repeated with similar (spread in)
genetic composition between animals;
No genetic difference between controls and experimental animals (requires
relatively large group sizes)
Responsibility and awareness
For a good preparation consultation of literature is needed. Helpful to see what has
been done previously. But there is more.
, After selecting a model, you need to think if the models is valid for the disease. Look
if the model has been used in the field of study. Use the lowest species possible
without compromising the study outcome (zebrafish over mice). Look where your
genes are more preserved in the case of genetic diseases.
New animal models are continually being identified and characterized. • Selection of
a species should not be based solely on availability, familiarity, or cost. The readily
available, familiar, or inexpensive species may not provide the genetic, physiologic or
psychological facets needed or wanted for the proposed project.
M ice:
Ideal for mammalian genetics
Small and easy to maintain
Great reproductive performance
Anatomy and physiology similar to humans
MODEL VALIDATION:
Best possible resemblance between model and research target
- face validity (resemblance in symptoms and signs)
- predictive validity (resemblance in reaction to current treatment)
- construct validity (resemblance in origin/mechanism)
Forced swim test: mouse or rat is put into water where the have to swim out. If not,
they will struggle and give up. Floating animals depict depression.
When you need to find a new model you don’t know the mechanism so you need to go
with the best model there is. If you know the mechanism you should choose models
where we do not see a construct validity.
B6 strain is the most well-characterized strain.
Introduction..............................................................................................................................1
Animal models: choices and consequences..............................................................................2
Organ-on-a-chip........................................................................................................................6
Ethic aspects of animal experimentation..................................................................................9
The art of randomization........................................................................................................13
3Rs – Alternatives to animal experiments..............................................................................14
Anesthesia and euthanasia.....................................................................................................16
Microbiology and hygiene......................................................................................................19
Principles of analgesia.............................................................................................................22
View of Proefdiervrij on animal experiments.........................................................................26
Assessment of distress............................................................................................................27
Legislation...............................................................................................................................30
Nutrition of laboratory animals..............................................................................................33
Principles of surgery...............................................................................................................35
Labor ator y an im al scien ce
Introduction
LAS is a multidisciplinary science contributing to:
Quality of science and animal studies
Health and wellbeing of laboratory animals
Public acceptance of animal studies
Science is growing and there are more alternative to animal experiments still big
amount of data.
Same laws in all EU countries EU directive 2010/63/EU to harmonize practices,
implement 3Rs improve welfare, transparency and enforcement.
No legal base for education & training
- Education and training framework to promote harmonization, ensure
competence and facilitate free movement of personnel.
- Outcome based on general agreement, not binding.
- Interpretation is left to Member States
3R’s
Replacement is “any scientific method employing non-sentient material which
may replace methods which use conscious living vertebrates”.
, Reduction is a means of “lowering the number of animals used to obtain
information of a given amount and precision”.
Refinement is the set of measures undertaken to “decrease in the incidence or
severity of procedures applied to those animals which have to be used”.
Whether we have to use less animals with more discomfort or more animals with less
discomfort really depends on the situation.
1% can be collected from animals to prevent anemia.
Animal models are limited in their ability to translate to humans: of the drugs that
have proved promising in animal trials, 86-90% fail in human trials.
Animal models: choices and consequences
Why use animal models? research with animals contributes to more than half of
the significant discoveries, 75% of major advances.
Studies with bacteria, tissue culture and computer stimulation can provide very
helpful information but cannot fully mimic the human complexity.
Definition of laboratory animal model
“An animal model in which normative biology or behavior can be studied, or in which
a spontaneous or induced pathological process can be investigated, and in which the
phenomenon in one or more respects resembles the same phenomenon in humans or
other species of animal”.
Disease models
Induced (experimental) disease models (inducing obesity, tumor growth,
renal damage, etc.)
Spontaneous (genetic) disease models (nude mice, hypertensive rat, etc.)
Transgenic disease models (KO, KI (i.e. introducing a crippled version of a
GPCR), tissue selective, inducible)
Neutral models
Healthy animals from all species
Inbr ed
- Created by generations of crossing siblings, same genotype
- Inbred (isogenic) strains: produced by many (>20) generations of brother x
sister mating.
- Aim: Genetic homogeneity
- The same genotype can be reproduced indefinitely, though over a period of
time
- there may be some genetic drift due to the accumulation of new mutations.
Outbr ed
- Diverse population, more like humans
, - Breeding colonies in which there is (certain) degree of genetic variation.
- Aim: Genetically undefined outbred stocks
- The amount of genetic variation depends on the breeding history of the
particular colony
- Although outbred stocks are widely used, they are not ideal experimental
material because nothing is known about the genotype of any individual, and
no two individuals are alike.
- This means that a "control" and a "treated" animal will differ not only in
treatment, but also to an unknown extent in genotype. As a result, sample
sizes will need to be greater than if isogenic animals had been used.
- Genetic homogeneity leads to phenotypic uniformity, which means that
smaller numbers of animals are needed to achieve a given level of statistical
precision: ‘inbreds will have a higher statistical reproducibility’
Festing: Someone using an outbred stock generally knows nothing about the genetic
characteristics of individual animals, what genes they carry or how heterozygous they
are. Background data on characteristics will be unreliable because they can change
rapidly.
Scientists sometimes try to justify the use of outbred stocks on the grounds that the
aim is to model humans, and humans are genetically variable. True when studying
very fundamental processes, like reproduction. But scientists using outbreds are not
being very consistent.
In toxicology:
- Outbred, because one doesn’t know what to expect?
- Inbred, ‘‘genetically defined’’ strains of mice and rats are more stable, more
uniform, more repeatable, and better defined than the ‘‘genetically undefined’’
outbred stocks used in most toxicity testing.
W hy use inbr ed : On average isogenic strains are more sensitive than outbred
stocks to experimental treatments, which also increases the power of experiments
which use them. - They are internationally distributed, so that work can be replicated
all over the world. - Searchable lists of inbred strains of mice and rats and their
characteristics are maintained by, for instance, The Jackson Laboratory.
To use when fundamental or undefined processes are to be evaluated
(reproduction, universal physiological processes, toxicology)
In such a way that the experiment can be repeated with similar (spread in)
genetic composition between animals;
No genetic difference between controls and experimental animals (requires
relatively large group sizes)
Responsibility and awareness
For a good preparation consultation of literature is needed. Helpful to see what has
been done previously. But there is more.
, After selecting a model, you need to think if the models is valid for the disease. Look
if the model has been used in the field of study. Use the lowest species possible
without compromising the study outcome (zebrafish over mice). Look where your
genes are more preserved in the case of genetic diseases.
New animal models are continually being identified and characterized. • Selection of
a species should not be based solely on availability, familiarity, or cost. The readily
available, familiar, or inexpensive species may not provide the genetic, physiologic or
psychological facets needed or wanted for the proposed project.
M ice:
Ideal for mammalian genetics
Small and easy to maintain
Great reproductive performance
Anatomy and physiology similar to humans
MODEL VALIDATION:
Best possible resemblance between model and research target
- face validity (resemblance in symptoms and signs)
- predictive validity (resemblance in reaction to current treatment)
- construct validity (resemblance in origin/mechanism)
Forced swim test: mouse or rat is put into water where the have to swim out. If not,
they will struggle and give up. Floating animals depict depression.
When you need to find a new model you don’t know the mechanism so you need to go
with the best model there is. If you know the mechanism you should choose models
where we do not see a construct validity.
B6 strain is the most well-characterized strain.
