The ethics of research involving animals - Nuffield Council on ...
The ethics of research involving animals - Nuffield Council on ...
The ethics of research involving animals - Nuffield Council on ...
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T h e e t h i c s o f r e s e a r c h i n v o l v i n g a n i m a l s<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> use <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>animals</str<strong>on</strong>g> in the study <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
human disease<br />
Introducti<strong>on</strong><br />
6.1 In this chapter, we c<strong>on</strong>sider some <str<strong>on</strong>g>of</str<strong>on</strong>g> the principles and rati<strong>on</strong>ales <str<strong>on</strong>g>of</str<strong>on</strong>g> using <str<strong>on</strong>g>animals</str<strong>on</strong>g> as disease<br />
models. We examine in more detail two areas <str<strong>on</strong>g>of</str<strong>on</strong>g> recent medical advance: new therapeutic<br />
strategies for rheumatoid arthritis (RA), which also illustrates the c<strong>on</strong>tributi<strong>on</strong> and use <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
n<strong>on</strong>-animal models <str<strong>on</strong>g>of</str<strong>on</strong>g> disease, and the development <str<strong>on</strong>g>of</str<strong>on</strong>g> the scientific understanding <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
transmissible sp<strong>on</strong>giform encephalopathies (TSEs), including bovine sp<strong>on</strong>giform<br />
encephalopathy (BSE) and variant Creutzfeld–Jakob disease (vCJD). We also describe the<br />
role <str<strong>on</strong>g>of</str<strong>on</strong>g> animal <str<strong>on</strong>g>research</str<strong>on</strong>g> in the implementati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> public health policies for protecting<br />
humans from exposure to TSE agents. <str<strong>on</strong>g>The</str<strong>on</strong>g>se examples are followed by brief discussi<strong>on</strong>s <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
historically important animal disease models for hepatitis C and polio. We then c<strong>on</strong>sider<br />
two cases <str<strong>on</strong>g>of</str<strong>on</strong>g> diseases that have proved difficult to treat and cure, despite the availability <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
animal models: Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome<br />
(HIV/AIDS) and cancers.<br />
<str<strong>on</strong>g>The</str<strong>on</strong>g> pathogenesis <str<strong>on</strong>g>of</str<strong>on</strong>g> disease<br />
6.2 <str<strong>on</strong>g>The</str<strong>on</strong>g> study <str<strong>on</strong>g>of</str<strong>on</strong>g> the causes <str<strong>on</strong>g>of</str<strong>on</strong>g> disease is known as etiology. <str<strong>on</strong>g>The</str<strong>on</strong>g> mechanisms by which a disease<br />
develops, causes tissue damage and spreads within the body are known as pathogenesis.<br />
Understanding the etiology and pathogenesis <str<strong>on</strong>g>of</str<strong>on</strong>g> a disease is usually necessary in order to<br />
develop strategies to either prevent or limit disease. For example, a disease may be prevented<br />
by vaccinati<strong>on</strong> or the use <str<strong>on</strong>g>of</str<strong>on</strong>g> antibiotics. <str<strong>on</strong>g>The</str<strong>on</strong>g> effects <str<strong>on</strong>g>of</str<strong>on</strong>g> a disease may be limited by means <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
therapies and therapeutics that reduce inflammati<strong>on</strong> or stop further tissue degenerati<strong>on</strong>.<br />
6.3 Most diseases are complex and involve dynamic interacti<strong>on</strong>s between molecular and cellular<br />
systems, which influence the development <str<strong>on</strong>g>of</str<strong>on</strong>g> the disease process. 1 Biologists who study a<br />
particular disease <str<strong>on</strong>g>of</str<strong>on</strong>g>ten use a variety <str<strong>on</strong>g>of</str<strong>on</strong>g> methods, both animal and n<strong>on</strong>-animal, to<br />
investigate its mode <str<strong>on</strong>g>of</str<strong>on</strong>g> acti<strong>on</strong>. For example, pathogenesis studies with animal models are<br />
generally complemented by clinical, epidemiological and imaging studies using humans.<br />
While all <str<strong>on</strong>g>of</str<strong>on</strong>g> these areas are very important, <str<strong>on</strong>g>research</str<strong>on</strong>g>ers whose work involves living <str<strong>on</strong>g>animals</str<strong>on</strong>g><br />
c<strong>on</strong>sider that their <str<strong>on</strong>g>research</str<strong>on</strong>g> plays a special role in the study <str<strong>on</strong>g>of</str<strong>on</strong>g> the pathogenesis <str<strong>on</strong>g>of</str<strong>on</strong>g> diseases<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>animals</str<strong>on</strong>g> and humans, because it is <str<strong>on</strong>g>of</str<strong>on</strong>g>ten the most effective method <str<strong>on</strong>g>of</str<strong>on</strong>g> studying the<br />
complex interacti<strong>on</strong>s between molecules, cells and organs that occur in disease processes. For<br />
example, transferring a disease from <strong>on</strong>e animal to another is comm<strong>on</strong>ly held to be the most<br />
reliable way to establish that a disease is caused by an infectious agent. This principle was<br />
first dem<strong>on</strong>strated in the 19th century when mice were injected with blood from cows<br />
infected with anthrax. <str<strong>on</strong>g>The</str<strong>on</strong>g> <str<strong>on</strong>g>research</str<strong>on</strong>g> showed clearly that the mice subsequently developed<br />
the disease. 2<br />
CHAPTER 6 THE USE OF ANIMALS IN THE STUDY OF HUMAN DISEASE<br />
1 Examples include diseases in which high levels <str<strong>on</strong>g>of</str<strong>on</strong>g> antibodies and microbial or tissue antigens form immune complexes (a<br />
complex <str<strong>on</strong>g>of</str<strong>on</strong>g> antigen and antibodies in the blood circulati<strong>on</strong>). <str<strong>on</strong>g>The</str<strong>on</strong>g>se complexes can activate powerful inflammatory systems (the<br />
complement or coagulati<strong>on</strong> cascades) that recruit different molecular and cellular systems into the process <str<strong>on</strong>g>of</str<strong>on</strong>g> pathogenesis.<br />
Effects include widespread damage to blood vessels (vasculitis), the kidney (nephritis), skin (dermatitis) or brain (meningitis).<br />
2 <str<strong>on</strong>g>The</str<strong>on</strong>g> Nobel Foundati<strong>on</strong> (1967) Nobel Lectures, Physiology or Medicine 1901–1921 (Amsterdam: Elsevier Publishing Company), see<br />
Robert Koch – Biography, available at: http://nobelprize.org/medicine/laureates/1905/koch-bio.html. Accessed <strong>on</strong>: 12 Apr 2005.<br />
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