Untitled Quiz

Animal Models: Definition and Purpose

• An animal model is a living organism used to study diseases and test treatments.
• A specific aspect of the animal mimics aspects of a phenomenon/disease in humans.
• Animal models are used when human experimentation is unethical or impossible, aiding in the development and evaluation of new vaccines and treatments.
• Researchers study analogous mechanisms in animals and humans for comparisons.
• Animal models resemble human biology, making them valuable in disease research.

Animal Models: Biological Similarities

• Animal models share similar biological systems with humans.
• Diseases affecting humans frequently also affect other animal species.
• Many veterinary drugs are similar or analogous to those used in human medicine.
• This makes animal models valuable tools for studying human illnesses and treatments.

Animal Models: Anatomical and Physiological Similarities

• Anatomical and physiological similarities connect human and animal systems.
• Key organ systems (e.g., heart, lungs, brain) and their functions are comparable across species.
• This physiological similarity underlines the reliability of animal models in biomedical studies.

Animal Models: Applications and Successes

• Animal models contributed significantly to vaccine creation and treatment development.
• Animal models were pivotal in the discovery of insulin for diabetes treatment.
• Tissue engineering and various surgical methods were first tested in animal models before human applications.
• Animal models contribute vital information used in advancements of other fields of research.

Criteria for Selecting Animal Models

• Animal models must accurately mimic the desired disease or function.
• Data from animal studies should be readily transferable to humans.
• Models must be easily accessible to a wide range of researchers.
• The model should have a long enough lifespan to allow for thorough research.
• Appropriate housing will support successful methodology.
• The animals must be of a large enough size and number to yield sufficient study data.
• Multiple offspring per gestation is preferred.

Classification of Animal Disease Models: Induced Models

• Induced models involve healthy animals with experimentally induced disease.
• An example of an induced model is experimentally inducing diabetes with streptozotocin (STZ).
• Induced models are useful for studying the mechanisms of disease resistance and treatment development.

Classification of Animal Disease Models: Spontaneous Models

• Spontaneous models involve animals bred to conserve disease characteristics originating from genetic mutations.
• A prime example is the athymic nude mouse, lacking a thymus, vital to the immune system.
• Spontaneous models have preserved phenotypic characteristics of some human diseases/conditions, making them valuable models for research.

Classification of Animal Disease Models: Genetically Modified Models

• Genetically engineered models involve modifying existing genes to turn them off or replace with altered DNA.
• This approach allows researchers to study the function of specific genes and their role in human diseases.
• Examples include obesity models and models of various cancers.

Classification of Animal Disease Models: Negative/Non-reactive Models

• In negative/non-reactive models, the disease-causing agent doesn't affect the animal.
• These models help identify the mechanisms of disease resistance in other organisms.
• Models may be used study methods to prevent illnesses and how certain species are resistant to disease.

Classification of Animal Disease Models: Orphan Models

• These models involve diseases unknown in humans.
• They become valuable once similar human diseases are identified, assisting in human disease research.
• Examples include papillomavirus in animals, which yielded insights into its human equivalent.
• Additionally, bovine spongiform encephalopathy (BSE) led to research into Creutzfeldt-Jakob Disease (vCJD).

Extrapolation of Data from Animal Models

• Animal studies must be validated before applying them to humans.
• Extrapolable data allows the translation of animal findings into new treatments and therapies.
• Extrapolation does not always guarantee that animal study results correctly apply to humans.

Ethical Concerns in Animal Model Research

• Ethical concerns surrounding animals are major factors in research.
• Cruelty to Animals Act (1876) established guidelines for animal experimentation.
• The 3Rs Principle (Replacement, Reduction, Refinement) emphasizes ethical practices.
• Minimizing harm and maximizing ethical treatment of animals is crucial.