researches on animal testing

Ethical care for research animals

WHY ANIMAL RESEARCH?

The use of animals in some forms of biomedical research remains essential to the discovery of the causes, diagnoses, and treatment of disease and suffering in humans and in animals., stanford shares the public's concern for laboratory research animals..

Many people have questions about animal testing ethics and the animal testing debate. We take our responsibility for the ethical treatment of animals in medical research very seriously. At Stanford, we emphasize that the humane care of laboratory animals is essential, both ethically and scientifically.  Poor animal care is not good science. If animals are not well-treated, the science and knowledge they produce is not trustworthy and cannot be replicated, an important hallmark of the scientific method .

There are several reasons why the use of animals is critical for biomedical research: 

••  Animals are biologically very similar to humans. In fact, mice share more than 98% DNA with us!

••  Animals are susceptible to many of the same health problems as humans – cancer, diabetes, heart disease, etc.

••  With a shorter life cycle than humans, animal models can be studied throughout their whole life span and across several generations, a critical element in understanding how a disease processes and how it interacts with a whole, living biological system.

The ethics of animal experimentation

Nothing so far has been discovered that can be a substitute for the complex functions of a living, breathing, whole-organ system with pulmonary and circulatory structures like those in humans. Until such a discovery, animals must continue to play a critical role in helping researchers test potential new drugs and medical treatments for effectiveness and safety, and in identifying any undesired or dangerous side effects, such as infertility, birth defects, liver damage, toxicity, or cancer-causing potential.

U.S. federal laws require that non-human animal research occur to show the safety and efficacy of new treatments before any human research will be allowed to be conducted.  Not only do we humans benefit from this research and testing, but hundreds of drugs and treatments developed for human use are now routinely used in veterinary clinics as well, helping animals live longer, healthier lives.

It is important to stress that 95% of all animals necessary for biomedical research in the United States are rodents – rats and mice especially bred for laboratory use – and that animals are only one part of the larger process of biomedical research.

Our researchers are strong supporters of animal welfare and view their work with animals in biomedical research as a privilege.

Stanford researchers are obligated to ensure the well-being of all animals in their care..

Stanford researchers are obligated to ensure the well-being of animals in their care, in strict adherence to the highest standards, and in accordance with federal and state laws, regulatory guidelines, and humane principles. They are also obligated to continuously update their animal-care practices based on the newest information and findings in the fields of laboratory animal care and husbandry.  

Researchers requesting use of animal models at Stanford must have their research proposals reviewed by a federally mandated committee that includes two independent community members.  It is only with this committee’s approval that research can begin. We at Stanford are dedicated to refining, reducing, and replacing animals in research whenever possible, and to using alternative methods (cell and tissue cultures, computer simulations, etc.) instead of or before animal studies are ever conducted.

Organizations and Resources

There are many outreach and advocacy organizations in the field of biomedical research.

• Learn more about outreach and advocacy organizations

Stanford Discoveries

What are the benefits of using animals in research? Stanford researchers have made many important human and animal life-saving discoveries through their work. 

• Learn more about research discoveries at Stanford

ADDRESS THE NHP CRISIS TODAY!

Immediate action needed.

DRUG DEVELOPMENT PIPELINE AT RISK

Advocating SOUND PUBLIC POLICY

in support of ethical and essential animal research.

PROTECTING VITAL ROLE ANIMALS PLAY

in biomedical research

FACILITATING DIALOGUE BETWEEN

our members and their congressional delegations on animal research issues

PRESERVING BIOMEDICAL RESEARCHERS'

abilities to use animals in ethical and responsible research

SUPPORTING HUMANE CARE & TREATMENT OF LABORATORY ANIMALS

in biomedical research, training, and education

PROVIDING OUR MEMBERS

with information and consultation on state and local issues

CREATING A FORUM FOR THE BIOMEDICAL COMMUNITY

to develop common positions on legislative and regulatory issues

PROTECTING THE ABILITY TO STUDY WHOLE LIVING ORGANISMS

in support of biomedical research

Founded in 1979, the National Association for Biomedical Research (NABR) is a 501(c)(6) non-profit association dedicated to sound public policy for the humane use of animals in biomedical research, education, and testing. NABR provides a unified voice for the scientific community on legislative, regulatory and legal matters affecting the responsible, humane, and ethical use of laboratory animals. Members include more than 340 universities, medical and veterinary schools, teaching hospitals, pharmaceutical and biotechnology companies, patient groups, and academic and professional societies who rely on humane and responsible animal research to advance global human and animal health. For more than 40 years, and as the only national, non-profit organization solely dedicated to advocating sound public policy for ethical and essential animal research, NABR has worked to safeguard the future of biomedical research. 

NABR Files Formal Petition Challenging the Listing of Long-Tailed Macaque by the IUCN 

Working with recognized, independent scientists, the National Association for Biomedical Research (NABR) filed an initial petition on June 15, 2023 with the International Union for Conservation of Nature (IUCN) challenging the recent designation of the long-tailed macaque ( Macaca fascicularis ) as endangered under IUCN listing criteria. This designation is a result of improperly used data that do not support the endangered species listing. NABR called for an immediate review. Read more by clicking here . 

After several weeks of discussions between NABR and the IUCN, on September 11, 2023, NABR filed a formal petition with the IUCN challenging its decision to uplist the status of the long-tailed macaque from “vulnerable” to “endangered.” Read NABR’s formal IUCN petition and the addendum  here.   Read NABR’s press release  here .

In October 2023, the IUCN formally accepted NABR’s petition. Read the press release  here . 

On February 1, 2024, NABR submitted an expanded petition to the IUCN concerning the long-tailed macaque status. The expanded petition can be found  here  and the press release about the expanded petition can be found  here .

Read NABR’s February 2024  response  to the authors of the study the IUCN relied on to uplist the status of long-tailed macaques to “endangered.”

NABR's IUCN Petition: Noteworthy Articles

Read  the August 1, 2023 article in the journal Science by Shanghai correspondent Dennis Normile about NABR’s IUCN petition. Normile also discusses a recent study in Biological Reviews according to which long-tailed macaques are hyperabundant in formerly wild environments where humans have started settling. He highlights the inherent contradiction between the IUCN’s “endangered” listing of long-tailed macaques on the one hand, and the scientific data presented in the Biological Reviews study and NABR’s petition on the other hand.

Read   the NABR press release announcing the December 21, 2023  American Journal of Primatology article that disputes information used to determine a faulty conservation status of long-tailed macaques the IUCN issued. You can also read the AJP article directly here . 

YOUR HELP NEEDED

The U.S. Fish and Wildlife Service is denying permits related to Cambodian origin nonhuman primates (NHPs) and samples. Roughly 60% of the preclinical animal models of the drug development process are Cambodian origin NHPs. This action has put the development of new drugs to treat thousands of diseases for which there is no treatment or cure at significant risk. Our message is simple: We are calling on the U.S. government to work with, not against, the biomedical research sector, to find solutions to remedy the disruption in the biomedical research supply chain. Thank you for helping us do that. 

Institutional Sign-on Letter

NABR is organizing an   institutional sign-on letter  to be sent to key members of Congress. The sign-on letter is   here , and we are asking as many organizations as possible to add their names. Some organizations have asked whether the U.S. Fish and Wildlife Service has issued any public notice regarding the denial of permits affecting Cambodian origin NHPs and samples. Unfortunately, there has been no public statement or public notice regarding this decision, which is one impetus for our correspondence to the government. At least 60% of the NHPs in the drug development pipeline are of Cambodian origin, which underscores the impact this decision has on the creation of new medications for thousands of diseases for which there is no treatment or cure.

If you would like to sign-on, please email   [email protected] .

 Individual Letters

NABR members have submitted more than 2,000 letters to Congress regarding the NHP crisis, so let’s keep the momentum going! Please broadly circulate the  link   [ speak4.app/lp/24d1d8/ ]  and encourage others at your organization to do the same. Alternately, you can click the "Take Action" bubble at the bottom right of your screen. The process is fast and easy, and it does make a difference. NABR is hearing from Capitol Hill staff who have taken an interest in this critical issue.

NHP Shortage News

March 1, 2024 Modern Approaches in Drug Designing :  https://crimsonpublishers.com/madd/pdf/MADD.000585.pdf  

December 26, 2023   The South Florida Sun Sentinel:  https://www.sun-sentinel.com/2023/12/26/international-organizations-monkey-business-will-slow-medical-research-opinion/   

September 4, 2023   The Washington Times :  www.washingtontimes.com/news/2023/sep/4/activists-are-trying-to-slow-down-lifesaving-medic/

August 4, 2023 BioSpace.com:  www.biospace.com/article/scientists-veterinarians-and-conservationists-offer-recommendations-to-address-the-shortage-of-long-tailed-macaques-required-for-continued-health-advancements-/

August 3, 2023 ScienMag.com: www.scienmag.com/scientists-veterinarians-and-conservationists-offer-recommendations-to-address-shortage-of-long-tailed-macaques-required-for-continued-health-advancements/

June 27, 2023   The San Joaquin Valley Sun : www.sjvsun.com/u-s/advocates-peta-pressuring-feds-to-bar-on-primate-use-for-dug-research/

June 15, 2023   The San Joaquin Valley Sun : www.sjvsun.com/business/report-false-designation-for-primate-could-block-ability-to-test-groundbreaking-drugs/

June 15, 2023   E&E News : www.subscriber.politicopro.com/article/eenews/2023/06/15/researchers-challenge-endangered-status-of-lab-primate-00102155

May 22, 2023   The Salina, Kansas Post : www.salinapost.com/posts/a5f331c8-afd1-49e0-b32c-f6e4ad0b2092

May 4, 2023   STAT+ :  www.statnews.com/pharmalot/2023/05/04/nih-primates-macaques-research-biomedical-animals-organs/  

May 4, 2023 NABR press release:   https://www.nabr.org/about-nabr/news/nas-report-affirms-necessity-nhp-models-and-highlights-shortage-crisis

May 4, 2023   The Wall Street Journal :  The U.S. Is Running Out of Research Monkeys

May 4, 2023  STAT+:   NIH systems for non-human primate research fall short, threatening biomedical research

May 4, 2023  AP News   Research monkey shortage undermines US readiness, panel says

March 27, 2023   www.openaccessgovernment.org :    https://www.openaccessgovernment.org/article/fostering-nonhuman-primate-nhp-brain-research-without-animal-sacrifice/155741/

March 20, 2023  UK Guardian : Fate of 1,000 trafficked lab monkeys at center of US investigation in limbo

March 6, 2023   Endpoints News :  Pharma industry lobbies Congress for solution to primate shortage after indictments for alleged smuggling

March 3, 2023  ScienceDirect:  Is biomedical research demand driving a monkey business?

March 3, 2023  STAT+:   As a U.S. agency denies permits to import monkeys for research, industry starts pushing back

March 3, 2023   The Wall Street Journal :  Monkey Business Threatens U.S. Drug Discovery

January 20, 2023  The Dispatch: America's Primate Problem

June 23, 2022  Mother Jones :  A Plane of Monkeys, a Pandemic, and a Botched Deal: Inside the Science Crisis You’ve Never Heard Of

September 28, 2022  Bloomberg News:   Lab Monkeys Are the Latest Covid Shortage

August 31, 2020  The Atlantic:  America Is Running Low on a Crucial Resource for COVID-19 Vaccines

FAQs  on the FDA Modernization Act

Does the fda modernization act 2.0 end animal testing.

No. The FDA Modernization Act 2.0 does not eliminate animal testing nor does it state or imply that animal testing is unnecessary. It simply clarifies the definition under the Food, Drug and Cosmetic Act of a nonclinical test or study to include adjunct and complementary testing methods like organs-on-a-chip, micro-physiological systems and computer simulations. Animal models continue to be highly relevant to test the safety and efficacy of a drug as part of the approval process. NABR supports the use of alternative models to animal testing when scientifically feasible and when scientifically validated, and remains confident in the ability of FDA scientific reviewers to determine the best data that should be submitted in new drug applications.

The FDA states that many procedures intended to reduce animal tests are still in various stages of development[1,2]. Adjunct and complementary tests have a purpose, but ultimately testing must progress to a whole intact, living system, including a rodent and non-rodent species during preclinical drug trials[3,4,5]. Not conducting animal tests, when necessary, would likely subject humans and other animals to unreasonable risks.

What is the FDA Modernization Act 2.0?

The FDA Modernization Act 2.0, passed as part of the Omnibus appropriations legislation in December of 2022, amends the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 355) to clarify methods manufacturers and sponsors can use to investigate the safety and efficacy of a drug by inserting language on “nonclinical tests,” where “nonclinical tests” are defined broadly as follows [6] :

• ·       A test or study that is most likely to predict human response based on scientific evidence and occurs before or during the clinical trial phase of the investigation of the safety and effectiveness of a drug. Such test or study may include the following:
• o   Cell-based assays
• o   Organ chips and microphysiological systems
• o   Sophisticated computer modeling
• o   Other human biology-based test methods
• o   Animal tests

It is important to note that the FDA previously had the authority to allow non-animal data to be considered during safety and efficacy reviews of new drugs and previously issued guidance regarding such. Ultimately, the FDA Modernization Act 2.0 may not materially change the current drug approval process at the FDA. In fact, a spokesperson for the FDA stated on the record that the new law does not change the regulatory process for drugs [7].

Why is animal testing important as part of the drug approval process?

The Food, Drug and Cosmetic Act was enacted in 1938 after the drug sulfanilamide, marketed for strep throat in the U.S. without human or animal research data establishing its safety or its efficacy, killed and sickened hundreds of people due to toxic levels of antifreeze it contained[8]. Additional animal research safety and efficacy data became required under the Act in 1963 to prevent incidents like the thalidomide incident in Europe and other parts of the world [9].

Animal testing followed by human clinical trials currently remains the best way to examine complex physiological, neuroanatomical, reproductive, developmental and cognitive effects of drugs to determine if they are safe and effective for market approval.

The overwhelming majority of drugs on the market today relied on safety and efficacy data from multiple animal models before being allowed to move to human clinical trials as demonstrated by the Foundation for Biomedical Research's Top 25 Drugs and Animal Model study [10].

NABR’s press statement on the FDA Modernization Act 2.0

NABR Files Expanded Petition Challenging the Listing of Long-Tailed Macaques by the IUCN

NABR April Webinar: “One Health and Animal Research: The Good, the Bad, and the Ugly”

NABR Press Release: LTM Conservation Status

The FY 2023 USDA Oversight Process

Nabr insights.

NABR contributes a great deal of time and resources towards developing and compiling industry relevant reports, webinars, and other informative documents for the benefit of its members. Please click the links below to access a variety of valuable resources and information in the   Member's Only  section.

Crisis Management Guide

Available for all NABR members. Download

Legal Resources for Managing Security at Private Residences

2022 NABR USDA Inspection Management Guide

Available for all NABR members. Explore

FOIA/Open Records

Available for all NABR members.

Legislation

Regulatory Comments

FY22 Appropriation Items

NABR Position Statement on Retirement/Adoption

DOT Secretary Pete Buttigieg on NABR’s complaint

Outgoing NIH Director Francis Collins Discusses Animal Research Ethics in Popular Podcast

FASEB Joins Partners to Support Biomedical Animal Research

Why Animal Research?

Animal research is a major contributor to almost all advances in human and animal health. The similarity in biological makeup between humans and some animals provides insight into diseases such as COVID-19, Diabetes, Cancer and many more. Animal testing also allows scientists to control factors such as temperature, lighting and diet, which is rather difficult and sometimes unethical during human trials. 

FAQ on Animal Research

Why is animal research necessary.

Modern medical research, including research using animals, is necessary to understanding disease and creating medicines to improve human and animal lives and reduce suffering.  Every known medical breakthrough known has a basis in animal research and all of the top 25 most prescribed drugs were developed with the assistance of animal models.  To learn more about the indispensable role of animal research, watch a brief PSA by the Foundation for Biomedical Research (FBR)  by clicking here .

Why is it even necessary to move animals?

Biomedical research is conducted in universities and commercial laboratories across the globe.  Important breakthroughs are typically dependent on collaborative efforts from different laboratories in many states and countries.

Successful research depends on a reliable source of healthy laboratory animals.  The best way of achieving this is through a global supply and transportation chain. Animals obtained from the same source have consistent genetics allowing scientists to better interpret data from animal studies.   Professional breeders with highly controlled environments produce disease free animals with special characteristics important in studying human disease.

A shared source of genetically defined and healthy animals dramatically reduces the total number of animals required for a research program.  A striking benefit of collaboration is the refinement of animal use.   By including collaborators with the highest expertise and the best modern methodology to conduct animal studies, better data is produced.

Without the ability to transport laboratory animals from licensed commercial breeders and between research facilities, each research site would have to breed its own animals.  This would be costly and would unnecessarily increase the number of animals for research.

How are animals transported?

Experienced and licensed professional transport companies are used to safely move laboratory animals. Animals are transported in vehicles equipped with temperature and humidity monitors and controls.  Travel routes are designed to take the shortest time reasonable to reduce travel stress.  To keep the journey as brief as possible, animals are frequently transported via airplane.

During transport, animals are provided with food, water and appropriate temperatures and conditions. Shipping containers are designed for proper ventilation and to protection animals from escape or injury.  Bedding materials are provided for comfort and are specific to the needs of each species.  Veterinarians specializing in the care of laboratory animals coordinate the shipping process, working with trained staff who monitor animals throughout the shipping process.

Why do we need to import nonhuman primates?

It is often in the best interests of an animal to be born and raised in areas with a climate well suited to the welfare of their species and where year-round outdoor housing is available.   Nonhuman primates most commonly used in research are native to tropical and subtropical regions, and breeding facilities in those regions can provide captive animals with a suitable environment.  These captive bred animals are reared to young adulthood before being moved to research facilities around the world.

Where do we get research animals?

The preferred source for research animals is a professional breeder. These producers are dedicated to supplying healthy, high quality animals to the research community.  Animals are obtained from licensed, inspected and accredited facilities that employ experienced handlers, caretakers, and veterinarians.  The research community demands high quality standards for food, water, sanitation and welfare for research animals, creating conditions that often exceed those of typical house pets.

Is it safe for animals?

The regulated transportation of laboratory animals is very safe.  Industry statistics show there is an error rate of less than 1% for either land or air transportation of animals.  Most of these errors do not impact the health or welfare of the shipment, so the actual impact on animal safety is even lower.

What would happen if we couldn’t transport animals in the future?

Without the ability to transport laboratory animals, research would be restricted to fewer locations and would lose the contributions of many talented scientists.  Further, scientists would not always be able to use the most appropriate model to study a disease or response to a medication, delaying or stopping much needed medical advances.

The development of new medicines would slow, or even stop, denying cures and treatments to the people who need them.  Research institutions would have to divert precious funding, manpower and laboratory space to breeding animals, taking resources away from important research.

Scientific collaboration across the world would be hampered by inconsistency in their research animals and difficulty interpreting data.  Without the ability to transport laboratory animals by air, the research community would be unable to provide the best possible conditions for shipping animals quickly and safely.  Without air transportation options, animals would often be subject to longer and more stressful transportation by land or sea.

Crisis Management

Read more about NABR's Crisis Management Guide.

Click to Open

Become part of a unified voice for the scientific community.

Congressional and Legislative Action

Learn more about NABR's advocacy efforts, like the passage of the AETA.

Research using animals: an overview

Around half the diseases in the world have no treatment. Understanding how the body works and how diseases progress, and finding cures, vaccines or treatments, can take many years of painstaking work using a wide range of research techniques. There is overwhelming scientific consensus worldwide that some research using animals is still essential for medical progress.

Animal research in the UK is strictly regulated. For more details on the regulations governing research using animals, go to the UK regulations page .

Why is animal research necessary?

There is overwhelming scientific consensus worldwide that some animals are still needed in order to make medical progress.

Where animals are used in research projects, they are used as part of a range of scientific techniques. These might include human trials, computer modelling, cell culture, statistical techniques, and others. Animals are only used for parts of research where no other techniques can deliver the answer.

A living body is an extraordinarily complex system. You cannot reproduce a beating heart in a test tube or a stroke on a computer. While we know a lot about how a living body works, there is an enormous amount we simply don’t know: the interaction between all the different parts of a living system, from molecules to cells to systems like respiration and circulation, is incredibly complex. Even if we knew how every element worked and interacted with every other element, which we are a long way from understanding, a computer hasn’t been invented that has the power to reproduce all of those complex interactions - while clearly you cannot reproduce them all in a test tube.

While humans are used extensively in Oxford research, there are some things which it is ethically unacceptable to use humans for. There are also variables which you can control in a mouse (like diet, housing, clean air, humidity, temperature, and genetic makeup) that you could not control in human subjects.

Is it morally right to use animals for research?

Most people believe that in order to achieve medical progress that will save and improve lives, perhaps millions of lives, limited and very strictly regulated animal use is justified. That belief is reflected in the law, which allows for animal research only under specific circumstances, and which sets out strict regulations on the use and care of animals. It is right that this continues to be something society discusses and debates, but there has to be an understanding that without animals we can only make very limited progress against diseases like cancer, heart attack, stroke, diabetes, and HIV.

It’s worth noting that animal research benefits animals too: more than half the drugs used by vets were developed originally for human medicine. 

Aren’t animals too different from humans to tell us anything useful?

No. Just by being very complex living, moving organisms they share a huge amount of similarities with humans. Humans and other animals have much more in common than they have differences. Mice share over 90% of their genes with humans. A mouse has the same organs as a human, in the same places, doing the same things. Most of their basic chemistry, cell structure and bodily organisation are the same as ours. Fish and tadpoles share enough characteristics with humans to make them very useful in research. Even flies and worms are used in research extensively and have led to research breakthroughs (though these species are not regulated by the Home Office and are not in the Biomedical Sciences Building).

What does research using animals actually involve?

The sorts of procedures research animals undergo vary, depending on the research. Breeding a genetically modified mouse counts as a procedure and this represents a large proportion of all procedures carried out. So does having an MRI (magnetic resonance imaging) scan, something which is painless and which humans undergo for health checks. In some circumstances, being trained to go through a maze or being trained at a computer game also counts as a procedure. Taking blood or receiving medication are minor procedures that many species of animal can be trained to do voluntarily for a food reward. Surgery accounts for only a small minority of procedures. All of these are examples of procedures that go on in Oxford's Biomedical Sciences Building. 

How many animals are used?

Figures for 2023 show numbers of animals that completed procedures, as declared to the Home Office using their five categories for the severity of the procedure.

# NHPs - Non Human Primates

Oxford also maintains breeding colonies to provide animals for use in experiments, reducing the need for unnecessary transportation of animals.

Figures for 2017 show numbers of animals bred for procedures that were killed or died without being used in procedures:

Why must primates be used?

Primates account for under half of one per cent (0.5%) of all animals housed in the Biomedical Sciences Building. They are only used where no other species can deliver the research answer, and we continually seek ways to replace primates with lower orders of animal, to reduce numbers used, and to refine their housing conditions and research procedures to maximise welfare.

However, there are elements of research that can only be carried out using primates because their brains are closer to human brains than mice or rats. They are used at Oxford in vital research into brain diseases like Alzheimer’s and Parkinson’s. Some are used in studies to develop vaccines for HIV and other major infections.

What is done to primates?

The primates at Oxford spend most of their time in their housing. They are housed in groups with access to play areas where they can groom, forage for food, climb and swing.

Primates at Oxford involved in neuroscience studies would typically spend a couple of hours a day doing behavioural work. This is sitting in front of a computer screen doing learning and memory games for food rewards. No suffering is involved and indeed many of the primates appear to find the games stimulating. They come into the transport cage that takes them to the computer room entirely voluntarily.

After some time (a period of months) demonstrating normal learning and memory through the games, a primate would have surgery to remove a very small amount of brain tissue under anaesthetic. A full course of painkillers is given under veterinary guidance in the same way as any human surgical procedure, and the animals are up and about again within hours, and back with their group within a day. The brain damage is minor and unnoticeable in normal behaviour: the animal interacts normally with its group and exhibits the usual natural behaviours. In order to find out about how a disease affects the brain it is not necessary to induce the equivalent of full-blown disease. Indeed, the more specific and minor the brain area affected, the more focussed and valuable the research findings are.

The primate goes back to behavioural testing with the computers and differences in performance, which become apparent through these carefully designed games, are monitored.

At the end of its life the animal is humanely killed and its brain is studied and compared directly with the brains of deceased human patients. 

Primates at Oxford involved in vaccine studies would simply have a vaccination and then have monthly blood samples taken.

How many primates does Oxford hold?

* From 2014 the Home Office changed the way in which animals/ procedures were counted. Figures up to and including 2013 were recorded when procedures began. Figures from 2014 are recorded when procedures end.

What’s the difference between ‘total held’ and ‘on procedure’?

Primates (macaques) at Oxford would typically spend a couple of hours a day doing behavioural work, sitting in front of a computer screen doing learning and memory games for food rewards. This is non-invasive and done voluntarily for food rewards and does not count as a procedure. After some time (a period of months) demonstrating normal learning and memory through the games, a primate would have surgery under anaesthetic to remove a very small amount of brain tissue. The primate quickly returns to behavioural testing with the computers, and differences in performance, which become apparent through these carefully designed puzzles, are monitored. A primate which has had this surgery is counted as ‘on procedure’. Both stages are essential for research into understanding brain function which is necessary to develop treatments for conditions including Alzheimer’s, Parkinson’s and schizophrenia.

Why has the overall number held gone down?

Numbers vary year on year depending on the research that is currently undertaken. In general, the University is committed to reducing, replacing and refining animal research.

You say primates account for under 0.5% of animals, so that means you have at least 16,000 animals in the Biomedical Sciences Building in total - is that right?

Numbers change daily so we cannot give a fixed figure, but it is in that order.

Aren’t there alternative research methods?

There are very many non-animal research methods, all of which are used at the University of Oxford and many of which were pioneered here. These include research using humans; computer models and simulations; cell cultures and other in vitro work; statistical modelling; and large-scale epidemiology. Every research project which uses animals will also use other research methods in addition. Wherever possible non-animal research methods are used. For many projects, of course, this will mean no animals are needed at all. For others, there will be an element of the research which is essential for medical progress and for which there is no alternative means of getting the relevant information.

How have humans benefited from research using animals?

As the Department of Health states, research on animals has contributed to almost every medical advance of the last century.

Without animal research, medicine as we know it today wouldn't exist. It has enabled us to find treatments for cancer, antibiotics for infections (which were developed in Oxford laboratories), vaccines to prevent some of the most deadly and debilitating viruses, and surgery for injuries, illnesses and deformities.

Life expectancy in this country has increased, on average, by almost three months for every year of the past century. Within the living memory of many people diseases such as polio, tuberculosis, leukaemia and diphtheria killed or crippled thousands every year. But now, doctors are able to prevent or treat many more diseases or carry out life-saving operations - all thanks to research which at some stage involved animals.

Each year, millions of people in the UK benefit from treatments that have been developed and tested on animals. Animals have been used for the development of blood transfusions, insulin for diabetes, anaesthetics, anticoagulants, antibiotics, heart and lung machines for open heart surgery, hip replacement surgery, transplantation, high blood pressure medication, replacement heart valves, chemotherapy for leukaemia and life support systems for premature babies. More than 50 million prescriptions are written annually for antibiotics. 

We may have used animals in the past to develop medical treatments, but are they really needed in the 21st century?

Yes. While we are committed to reducing, replacing and refining animal research as new techniques make it possible to reduce the number of animals needed, there is overwhelming scientific consensus worldwide that some research using animals is still essential for medical progress. It only forms one element of a whole research programme which will use a range of other techniques to find out whatever possible without animals. Animals would be used for a specific element of the research that cannot be conducted in any alternative way.

How will humans benefit in future?

The development of drugs and medical technologies that help to reduce suffering among humans and animals depends on the carefully regulated use of animals for research. In the 21st century scientists are continuing to work on treatments for cancer, stroke, heart disease, HIV, malaria, tuberculosis, diabetes, neurodegenerative diseases like Alzheimer's and Parkinson’s, and very many more diseases that cause suffering and death. Genetically modified mice play a crucial role in future medical progress as understanding of how genes are involved in illness is constantly increasing. 

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Social Sciences | 7.25.2019

From the Archives: Animal Research

Every year, scientists use millions of animals—mostly mice and rats—in experiments. the practice provokes passionate debates over the morality and efficacy of such research—and how to make it more humane..

Click image to see full cover: The original January-February 1999 issue that this article appeared in

Read the original article as it appeared in 1999.

The volume of biomedical research, and of trials of new therapies, has increased dramatically in recent decades, fueled by advances in understanding of the genome and how to manipulate it, methods of processing huge data sets, and fundamental discoveries such as targeted and immunological approaches to attacking cancer (see “Targeting Cancer,” May-June 2018). Greater Boston, and Harvard, are major participants in academic biomedical research, in close proximity to the biotech and pharmaceutical industries, which have set up shop locally to tap into the wealth of talent and ideas. Along the way, new research techniques that are driven by more sophisticated imaging, bioinformatics (see “Toward Precision Medicine,” May-June 2015), and “organ-on-a-chip” technology have made it possible to conduct science with less reliance on various kinds of animal-testing. Given rising social concern for and interest in animal welfare (see “Are Animals ‘Things’?” March-April 2016), these converging trends make rereading this in-depth 1999 report by John F. Lauerman on the use of animals in biomedical research still timely and important. ~The Editors

“What is man without the beasts? If the beasts were gone, man would die from a great loneliness of spirit. For whatever happens to the beasts soon happens to man.”

~ Chief Seattle

Frederick Banting would never have begun his research without access to research animals. Before he had even spoken of his ideas, his first note to himself on the subject read: "Ligate the pancreatic ducts of dogs." The quiet Ontario doctor envisioned that severing the connection between the pancreas and the digestive system in a living animal would allow him to isolate the mysterious substance that would control diabetes.

During the first week in the laboratory, Banting and his assistant, Charles Best, operated on 10 dogs; all 10 died. Finally, in 1921, after months of experimentation, Banting and his colleagues isolated a material that kept a depancreatized dog named Marjorie alive for about 70 days. Exactly what information was gained from using dogs, and how many dogs were absolutely needed, is not clear. Work previous to Banting and Best’s, some of it in humans, had indicated the presence and importance of a hormone involved in glucose transport. Many more experienced scientists in the diabetes-research community believed that Marjorie had never been fully depancreatized, and thus may have never been diabetic. More likely, they said, the dog died of infection caused by her pancreatectomy. It’s possible that even the death of the famous Marjorie was unnecessary for the great discovery.

But the two Toronto researchers had isolated insulin, providing the first step toward producing it from pig and cow pancreas, available in bulk from slaughterhouses. The result—that Banting and Best "saw insulin"—appears to have justified all sacrifices. What’s the life of a dog, 10 dogs, a hundred? Before Banting and Best operated on dogs, we had no insulin; afterwards, we did.

Stories such as these are the reason our society and the vast majority of societies in the world accept the use of animals as a vital component of medical research.

Deeply entrenched traditions support the notion that animal welfare must bow to the best interests of humans. Animal domestication was among the first labor-saving devices. Humans have experimented with animal breeding, feeding, and disease control for thousands of years—not to benefit the animals themselves, but to insure that the owners obtained a maximum yield.

Today, those traditional practices have evolved into a scientific institution, the appropriateness of which is subject to perennial debate. In the United States alone, there are an estimated 17 million to 22 million animals in laboratory research facilities. To many people, animal research represents a doorway to the medical treatment of tomorrow. But to animal protectionists, and a growing number of other Americans, animal experimentation is a barbaric, outdated practice that—on the basis of a few notable past successes—has somehow retained its vestigial acceptability.

"Let’s say that it’s true, that animals were indispensable to the discovery of insulin," says Neal Barnard, M.D., of the Physicians Committee for Responsible Medicine, an animal-protection group. "That was a long time ago. I think to say, ‘It was done this way and there’s no other way it could have been done’ is a bit of a leap of faith, but let’s say that at the time there was no other way. You could also say that you couldn’t have settled the South without slavery. Would you still do it that way today? Just because something seemed necessary or acceptable at the time is not to say that we should do it in our time."

The Animal Debate

The legitimation of the animal-research debate challenges one of the most important and widely used scientific approaches to discovery about the human body and its diseases. Animal experimentation is often considered as much of a sine qua non to research as the Bunsen burner. But animal protectionists reply that the importance of animals to research is overrated, and that their pressure has exposed profligacy among experimenters.

In February 1997, a highly controversial collection of articles appeared in  Scientific American  on the subject of laboratory-animal research. The first, written by Barnard and Stephen Kaufman, M.D., of the Medical Research Modernization Committee, another protectionist group, advanced the view that data collected from animal experimentation are almost always redundant and unnecessary, frequently misleading, and by their very nature unlikely to provide reliable information about humans and their diseases. "Animal ‘models’ are, at best, analagous to human conditions," the authors wrote, "but no theory can be refuted or proved by analogy. Thus, it makes no logical sense to test a theory about humans using animals."

A rebuttal in support of animal research followed, by Jack Botting, Ph.D., former scientific adviser to the Research Defense Society in London, and Adrian Morrison, Ph.D., D.V.M., of the University of Pennsylvania School of Veterinary Medicine. Their reply cited examples of scientists from Louis Pasteur to John Gibbon, a twentieth-century pioneer in open-heart surgery, who made important breakthroughs in the treatment of human disease through animal research.

Many scientists—both supporters of animal research and advocates for its diminution—simply refused to discuss the difficult topic, recalls Madhusree Mukerjee, the editor who proposed that  Scientific American  explore the controversy and who wrote a third article, reporting on the overall state of animal research in the sciences. (Similar difficulties were encountered in researching the present article.) Mukerjee suspects that possible interviewees feared the criticism of their colleagues.

Reader response, on the other hand, was overwhelming, both pro and con. "We got a huge amount of flak for dealing with the subject at all," recalls Mukerjee. "Some of it was fairly frightening." To many animal-research supporters, it was as though the floodgates had been opened. "I am simply stunned that  Scientific American,  a paragon of promotion of scientific research, would actually offer up for debate whether animal research should occur," wrote one reader. "Please leave this question of animal research to animal-rights activists, and stop yourselves from turning into scientific wimps." "A lot of the scientific community felt [ Scientific American’ s editors] had overstepped their bounds and compromised their values by printing the Barnard-Kaufman article," says Joanne Zurlo, associate director of the Johns Hopkins School of Public Health Center for Alternatives to Animal Testing and a specialist in chemical carcinogenesis.

Those researchers who supported animal use and wrote in said the animal-protectionists’ side of the  Scientific American  debate was fraught with misstatements and scientific errors, although Mukerjee maintains that all the articles were painstakingly fact-checked. "We annoyed a lot of influential scientists," she says. "Our publication has spent more than a century describing advances in medical research, including some by fairly controversial figures. We’d never addressed the question of research on animals before, and in a sense it was a necessary thing to do. We probably lost some subscriptions because of it. But we are a bridge between the researchers who write for us and the public who read us, and we decided to let our readers decide for themselves."

Animal Welfare

Animal protectionists date their movement back to the times of Leonardo da Vinci and even Pythagoras, who are alleged to have been vegetarians. Numerous essayists and animal lovers have detailed their objections to the misuse of animals. Yet not long ago, virtually anyone who wanted to could conduct experiments on animals. In the 1960s, it was not uncommon to walk into a laboratory and find mice, dogs, cats, even monkeys, housed on the premises in whatever conditions researchers saw fit to provide. Banting himself frequently bought pound dogs and may even have caught dogs on his own; his collaborators recalled that he once arrived at the lab with a dog he had leashed with his tie.

Only in the nineteenth century did animal research begin to draw explicit objections from protectionists. A pivotal event occurred in England in 1874, when a lecturer at the University of Norwich demonstrated how to induce epileptic symptoms in a dog through the administration of absinthe. Objections were raised by students in the audience, and the dog was set free. Later, charges were filed against the lecturer under Dick Martin’s Act, an 1822 law that called for a fine of 10 shillings from anyone committing acts of cruelty against animals. Two years later, in 1876, Parliament passed the Cruelty to Animals Act, requiring a license for animal experimentation and placing restrictions on some painful forms of experimentation.

In the United States, minimal restrictions on animal experimentation prevailed until 1966, when the first federal Laboratory Animal Welfare Act (now known as the Animal Welfare Act, or AWA) was passed by Congress. In 1970 the AWA was broadened to require the use of appropriate pain-relieving drugs, and to include commercially bred and exhibited animals. Six years later, provisions were added covering animal transport and prohibiting animal-fighting contests. In 1985, Congress passed the Improved Standards for Laboratory Animals Act, which again strengthened the AWA by providing laboratory-animal-care standards, enforced by U.S. Department of Agriculture (USDA) inspectors, and also aimed to reduce unnecessarily duplicative animal-research experimentation.

In 1976, however, the AWA was amended in a rather curious way: rats, mice, birds, horses, and farm animals were specifically excluded from its purview for reasons that are not fully clear, although the USDA’s limited resources—along with political pressure from interested parties—are likely to be among them. Since rats and mice make up more than 95 percent of all research animals in this country, the amendment effectively put the vast majority of laboratory animals outside the reach of the USDA. Since then, at least one court has ruled the 1976 amendment "arbitrary and capricious."

The Mouse Warehouse

As associate professor of surgery Arthur Lage, D.V.M., walks through the doors of Harvard Medical School’s Alpert Building, people recognize him, smile, and let us pass without showing identification. He is director of the Center for Animal Resources and Comparative Medicine and the Center for Minimally Invasive Surgery at the medical school and director of the Office of Animal Resources for the Faculty of Arts and Sciences as well. We take an elevator down to a basement, where Lage swipes a card through a reader, unlocking a door to a hallway, where he speaks into a phone. A minute later, a young man clad in blue scrubs opens the door. Lage explains that he’s bringing a reporter in for a tour and that we’ll need keys to see certain rooms. The young man hands over the keys and closes the door.

At the other end of the short hallway are two doors, each leading to a sanitary changing room. When you turn the lights on in the changing rooms, the doors at either end lock automatically. After we’ve pulled blue scrubs over our clothes, Lage douses the lights and we step out of the room into another brightly lit hallway.

We’re in one of Harvard’s 16 animal facilities now, a moderately "clean" facility—meaning that it requires only minimal preparations for entry. Some laboratories would require us to remove our clothes and shower before entering; others don’t even stock scrubs. But this facility is full of mice—transgenic mice. A stray pathogen in one of the animal rooms could wipe out millions of dollars’ worth of experiments or, just as disastrous, infect a colony of mice with viruses or bacteria that might confound the results of a study.

Of course, the security isn’t intended only to repel microbes. Perhaps in frustration with perceived shortcomings in the oversight of animal experimentation, some animal-protection groups have gained a reputation for tactics that are rash and often destructive. On several occasions, animals have been "liberated" from laboratories, erasing potential results and sometimes careers. In 1989, the Animal Liberation Front took credit for the release of more than 1,200 laboratory animals, some of them infected with cryptosporidium, which can be harmful to infants and immunocompromised people. The total damage was estimated at $250,000. In 1987, a laboratory under construction at the University of California at Davis was burned; the loss was estimated at $3 million.

Although there is little evidence of violence toward animal researchers here in the United States, in Europe, where the animal- protection movement is more firmly entrenched, activists have taken aim at individuals, sometimes with disastrous results. In 1990, the infant daughter of a researcher was injured by a car bomb believed to have been set by animal protectionists. In separate, related incidents, a furrier and a breeder of cats used in experimentation were injured by letter bombs. Responsibility for the mail bombs was assumed by "The Justice Department," a militant, underground, animal-protection organization.

Even today, animal-protection groups find ways to gain access to research and testing facilities. In 1997, Michelle Rokke of People for the Ethical Treatment of Animals (PETA) infiltrated Huntingdon Life Sciences, a drug- and cosmetic-testing firm in East Millstone, New Jersey. Using a surveillance camera embedded in her eyeglasses, Rokke took hours of films that PETA claimed showed animals being slammed into cages and roughly handled. PETA president and co-founder Ingrid Newkirk said their investigation also revealed that young beagles’ legs were broken for another study at Huntingdon. Movie star Kim Basinger gave a press conference on Huntingdon’s lawn. In April 1998, the USDA fined Huntingdon $50,000 for AWA violations.

In the basement of the Alpert building, there is no evidence of such fury. Each room holds literally hundreds of mice in shoebox-sized cages, and there are so many of them it looks like a shoe warehouse. There are about 55,000 mice involved in research at Harvard at any one time, but that number is growing constantly. In 1997 it was closer to 50,000; by the end of 1998 it approached 58,000. By comparison, the numbers of other animals are almost negligible: about 1,300 rats, 145 rabbits, 115 hamsters, 70 guinea pigs, 67 primates, 35 pigs, 30 gerbils, 25 chicks, 20 dogs, 18 sheep, 6 cats, and 1 ferret. In addition, the New England Regional Primate Research Center in Southborough, Massachusetts, houses another 1,500 monkeys and other primates. Established at Harvard in 1966 with a grant from the National Institutes of Health, the NERPRC is one of seven such centers created by Congress in the early 1960s to serve as regional resources for scientists.

Surprisingly, there is no hint of animal smell within the basement facility. Temple Grandin of Colorado State University, a specialist in the behavior of captive animals, says that what mice really crave is some form of bedding—wood chips, paper, or shavings—which not all these animals have. Still, these laboratory animals, born and bred under fluorescent lights, are comfortable enough to live out lifespans they would never approach in the wild and, of course, to reproduce. And since almost all of them are involved in genetic studies, making sure they’re happy and healthy enough to reproduce is of vital importance. Keeping these buildings clean and free of infection is a triumph of research design. All the soiled animal cages are shuttled to one end of the laboratory where, before they re-enter, they pass through an enormous autoclaving machine that sanitizes the cages as well as the carts they sit on.

Amid the towers and technology of the medical area, animals one normally associates with a farm are a jarring sight. But Lage (pronounced lah-gee) led me through animal laboratories in the basement of the Seeley Mudd Building where we saw pigs, sheep, and rabbits held in small, clean pens. At one point, we watched eight sheep slated for experimental surgery frisk around a room that looked almost exactly like an office. If the straw were swept away, one could easily have moved in a desk and gone to work.

"We care for all these animals just as though they were covered by the [Animal Welfare] Act," Lage says proudly. "I think most of us believe that the act should cover rats and mice."

Although the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC), like the USDA, inspects laboratory-animal facilities, including those of rats and mice, AAALAC accreditation isn’t legally required to conduct animal research. "AAALAC conducts something like a ‘peer review’ assessment," Lage says. "It’s a voluntary process, subscribed to by many, many research organizations. If you decide not to go through accreditation, you have to describe your entire program every time you apply to the government for funding for animal research."

Many laboratories and commercial drug-testing companies that receive no funding from federal sources and use only rats and mice proceed with only minimal oversight from their own institutional animal care and use committees (IACUCs). But restrictions on animal research are, if anything, increasing, not abating. Not content with the level of state and federal regulation, for example, the city of Cambridge in 1989 passed its own law creating an inspector’s office with the power to make USDA-type inspections of all research facilities housing vertebrate animals, including rats and mice.

Cambridge’s current commissioner of laboratory animals, Julie Medley, D.V.M., annually inspects 34 laboratories, makes follow-up visits to some facilities (sometimes unannounced), and reviews "hundreds and hundreds" of research protocols to ensure that all experiments meet federal standards for pain control. Investigators readily comply with Medley’s suggestions for better animal care and pain control, she says, but she perceives an undercurrent among some researchers who chafe under what they perceive as excessive government intervention in their work. "I’m sure some of the principal investigators resent these regulations," she says. "It doesn’t happen that often, but there are rare occasions when I run into resistance from an investigator."

Still, for animal protectionists, the intentions of the Animal Welfare Act, AAALAC, and state inspectors are not enough. Sandi Larson, a scientific adviser to the New England Anti-Vivisection Society, who has a master’s degree in microbiology, concedes that "not all researchers are Dr. Frankensteins. But," she adds, "they have been trained to look at animals as tools. It’s ingrained in them to shut off their compassion and act like scientists. They think there’s no room for emotions." A significant portion of the animal-protection movement believes that most experimentation on animals is without merit. If animals are different enough from humans that we can dismiss their suffering as inconsequential, isn’t it just a little too convenient that they resemble us enough to be considered a source of reliable information about human physiology?

Animal Liberation 

Peter Singer was an Oxford philosophy student who had little interest in animals, domesticated or otherwise, until he had lunch with a vegetarian friend one day and they began talking about the use and abuse of animals. Singer was quickly converted to the cause, and within a few years became its champion. One of the pivotal events in the treatment of laboratory animals in this country and throughout the world was the publication of his manifesto,  Animal Liberation,  in 1975.

Just 25 years ago, some proponents of animal experimentation still held that animals’ intellectual inferiority to humans meant that they could not be accorded the same rights as humans. Some argued that animals had no consciousness or memory, that they did not think as humans did. The quality and intensity of the pain felt by animals was still subject to debate. Singer, recently appointed DeCamp professor of bioethics at Princeton University’s Center for Human Values, refuted the assertion of animals’ inequality, pointing out that our society grants equal rights to all humans without regard to IQ or ability to function. "If the demand for equality were based on the actual equality of all human beings, we would have to stop demanding equality," he wrote. "...[T]he claim to equality does not depend on intelligence, moral capacity, physical strength, or similar matters of fact."

As for consciousness and the ability to feel pain, Singer pointed out that we have no reason to believe animals lack either one. Some of the experiments he recounts make their emotional vulnerability all too clear. In the late 1950s, for instance, psychologist Harry Harlow of the University of Wisconsin embarked on a series of experiments in which he deprived young rhesus monkeys of contact with their mothers. Young monkeys who were most completely deprived of parental contact developed very bizarre behavior, and would cling to objects that supplied the most minimal comfort, such as a scrap of terrycloth. Many of his fellow researchers considered Harlow a genius for having established the importance of interpersonal contact to normal childhood development. Singer, on the other hand, pointed out that the experiments demonstrated just how much like us monkeys really are, and he condemned the inhumanity of torturing them to obtain information that could have been elucidated in many other ways, perhaps through epidemiological studies of children who had been separated from their mothers at critical periods of development.

"You can’t have it both ways," says biochemist Karin Zupko ’77, an animal-rights advocate formerly with the New England Anti-Vivisection Society. "You can’t say that animals are different enough from people so that it’s acceptable to experiment on them, but enough like people so that the results of the experiments are valid."

Models for Medicine

Scientists, however, counter that you can, in fact, gather useful information about humans from animals that seem vastly different from us. They point to the many surgical experiments performed on pigs, dogs, and monkeys that have led to advances in transplantation, heart-valve replacement, and coronary artery bypass graft surgery.

"Research on live organisms is essential for medical advance," asserts Francis D. Moore ’35, M.D. ’39, S.D. ’82, Moseley professor and surgeon-in-chief emeritus at Harvard Medical School and Brigham and Women’s Hospital, respectively. As Moore has pointed out in testimony to the Massachusetts legislature and in his autobiographical book,  A Miracle and A Privilege,  the first successful human kidney transplant, in which Moore played a pivotal role in 1963, would not have been possible at that time without an understanding of immunology based on experiments in rats and mice. Important aspects of the surgery were developed in larger animals. "There’s no substitute for it," says Moore. "Some people say you can set up a computer program to act like a dog. Well, forget it. All animals have responses that we don’t understand, and there’s no way to set that up on a computer."

A great deal of our understanding of basic human physiology comes from experiments in large animals, like dogs and chimpanzees. Harvard physiologist Walter B. Cannon, A.B. 1896, M.D. ’00, S.D. ’37, for example, performed experiments on dogs for many years to understand the basic dynamics of digestion. Different animals may be selected for different purposes. A dog’s prostate differs from that of a human in having only two lobes, yet dogs, like humans, can develop benign prostatic hyperplasia.

"Not all animal models are ideal, but some cases are a perfect fit," says Arthur Lage. "Mice are certainly a very good model for studying human genes. Much of the genetic makeup of the mouse is very similar to that of a human; there are large regions of shared identity." That’s why, Lage explains, Harvard will probably double its use of mice over the next five years—to about 100,000 mice annually. The chief reason for this is transgenic-mouse technology—which allows the insertion and deletion of key disease genes into the mouse genome. These techniques allow researchers to study the impact of both subtle and drastic changes in the genome, and to make key predictions about how similar changes would affect humans. Mice can be bred, for example, with varying ability to express the  p53  gene, which has been implicated in a wide variety of cancers. Understanding how the activity of such genes affects cancer development promises to vastly increase our knowledge of treatment and prevention.

Philip Leder ’56, M.D. ’60, Andrus professor of genetics and head of the medical school’s department of genetics, who pioneered the technology, points out that transgenic mice have been used to test the safety and efficacy of new therapeutics; to detect biohazards; and to advance our knowledge of cancer. Yet he concedes this widely embraced methodology has yet to produce new therapies itself. "It’s impossible as yet to bring it home to lives of patients," he says, "because the development of diagnostics and therapeutics takes time."

There are many areas, however, where a direct connection between animal research and patient welfare can be argued. In the field of AIDS, for instance, research on animals has been making important contributions to the basic understanding, prevention, and treatment of this life-threatening disease.

In 1981, Norman Letvin ’71, M.D. ’75, received a call that would change his life. It concerned an epidemic of mysterious deaths, all caused by unusual pathogens and cancers, such as pneumocystis carinii pneumonia, cytomegalovirus, and rare lymphomas. But the patients suffering from these infections were not humans, but laboratory monkeys.

We now recognize these so-called "opportunistic infections" as signals of the presence of the human immunodeficiency virus (HIV) that causes AIDS. But at that time, the disease was just being recognized in humans, the term "AIDS" itself was unknown, and the cause of all these infections was still a frightening mystery.

Letvin, now professor of medicine at Harvard, says HIV probably began as a relatively harmless virus that infected some species of African monkeys. When it crossed species lines, it did so in several directions, spreading simultaneously into both human and additional non-human primate populations. In these new populations, the infection had much more serious consequences than in the African monkeys: it was lethal. But to Letvin, the realization that a parallel syndrome was occurring in man and monkeys was a tremendous opportunity.

"A great deal of effort has been expended on trying to find rodent and rabbit models for studying HIV infections, but they have not proven terribly useful," Letvin notes. "The only way we can see what happens in the first few minutes, hours, and days after infections—questions that are essential to answer in order to develop an HIV vaccine—is by working in animal models. We are forced to work in these models if we want to answer these questions." (The number of monkeys needed for such an experiment, he hastens to point out, is relatively small: usually about six.)

In Letvin’s experiments, monkeys are inoculated with candidate vaccines against HIV. After a brief period during which the vaccine draws a response from the host monkeys’ immune system, the animals are inoculated with a strain of immunodeficiency virus that brings on an AIDS-like disease. Periodic blood samples are taken to monitor their white blood cell counts and viral replication. An experimental model that causes the monkeys to get sick is more informative, Letvin explains, because even if the vaccine doesn’t prevent infection, it may slow the course of the disease enough to be useful.

"There’s little question that exciting animal data is a major drive for the initiation of human studies," Letvin says. "It’s not a gatekeeper, but an important piece of a complex puzzle we use to determine whether to go forward with the long march into humans. There are hundreds of approaches one could take. If a strategy does look promising, an animal trial makes it easier to determine whether it’s worth spending millions of dollars to measure its safety and efficacy in humans."

Letvin points out that an AIDS vaccine would save millions of human lives, particularly in populations where expensive treatment is not available. Thus the use of animals in research on diseases such as AIDS seems fated to continue for years to come. If the past is any indication, it will probably yield a rich crop of new medical information.

Perhaps the more accurate question then—under the circumstances—is, how much do we care about animal suffering? Is it worthwhile to consider that issue in our quest for better treatment for diseases?

The Three R’s

Since Peter Singer formulated his ideas, the animal-protection movement has gone from a series of staccato eruptions to a steady influence on the course of medical research. Everyone involved in the animal-research debate admits that the situation has changed considerably during the last 25 years. Ernie Prentice, a nationally recognized expert in the regulation and ethics of animal research and a member of the institutional animal care and use committee at the University of Nebraska Medical Center, can remember a time when animals were routinely subjected to painful measures without pain control. In one well-publicized experiment, pigs were burned without anesthetic; in another long-running research project, monkeys were subjected to traumatic blows to the head without analgesics. Animals progressed to the end stages of artificially induced malignancies, renal failure, and heart disease, all without any form of pain control.

"Those kinds of projects would not be permitted now. They would be unacceptable for at least two reasons," says Prentice. "One is that we now have regulations that clearly ban this kind of experimentation, and those regulations are adequately enforced to make sure that they’re followed. At the same time, there is heightened ethical sensitivity among both researchers and IACUCs. If you had sat in on a meeting of an IACUC in 1985 and were able to compare the level of discussion back then with what goes on today, you would see a tremendous difference."

Increasingly, members of the protection community are taking legal steps to gain input into animal-treatment guidelines, and have found more conventional ways to exert pressure. Marc Jurnove, a member of the Animal Legal Defense Fund (ALDF), is suing the USDA for "aesthetic and recreational injuries" that he suffered when seeing the living conditions of chimpanzees and apes at a Long Island zoo. Jurnove charged that the USDA failed to adopt and enforce adequate standards for the animals’ well-being, as is required by the AWA. This past September, the U.S. Court of Appeals for the District of Columbia Circuit, the nation’s most influential circuit court, upheld Jurnove’s right to sue. Recently, the ALDF also led animal-rights groups in successfully suing the National Academy of Sciences for access to records and to committee meetings pertaining to a guide on the care and use of laboratory animals.

Some major funding organizations have also embraced the animal-rights movement. The Doris Duke Charitable Foundation, with assets of $1.25 billion, is one of the 25 wealthiest philanthropies in the country. Although it funds medical research, one of its restrictions is that animals not be used as subjects. This creates a sticky situation for the board, which hopes to fund research on AIDS, cancer, heart disease, and sickle-cell anemia, areas heavily dependent on animal research in the past.

But the effort to occupy a middle ground, supporting the principles of reduction, replacement, and refinement of animal research while acknowledging its necessity, has been extremely frustrating.

Several research institutions have established centers of animal-rights advocacy. The Center for Animals and Public Policy at Tufts University and the Center for Alternatives to Animal Testing at Johns Hopkins University, for example, have tried to establish liaisons with both protectionists and researchers. "I wasn’t running around throwing bombs," says Andrew Rowan, Ph.D., former director of the Tufts Center and now senior vice president of the Humane Society of the United States. "I was engaging colleagues in scientific debate without being obstreperous. People were shouting past each other." Veterinarian Peter Theran, vice president of the health and hospitals division of the Massachusetts Society for the Prevention of Cruelty to Animals and director of the MSPCA’s Center for Laboratory Animal Welfare, says that his group has had to walk a fine line. "We try to maintain a rapport with both sides," he stresses. "I have to say that we often don’t agree with some of the more aggressive groups, like PETA. But there’s a tendency to paint the animal-welfare community with a broad brush. And that makes dialogue extremely difficult."

"When you say you’re for animal welfare, you’re perceived as rabid," says Joanne Zurlo of the Johns Hopkins center. "At the same time, we can’t deal with groups like PETA because they believe in abolition of animal use. When we organized the first World Congress on Alternatives and Animal Use in the Life Sciences in 1993, we invited representatives from every organization to sit at the table. PETA would not join. Even the American AntiVivisection Society sent a representative, but members of the hard-line groups who were picketing outside hounded her and called her a murderer."

Human Lives, Humane Experiments

The growth of the animal-protection debate has been fraught with acrimony. The results, however, go beyond the additional credibility that has been afforded animal protectionists. Scientists, too, find that they can be more open about the feelings they have or may have had for the creatures in their care, and are more free to explore alternative methods of experimentation.

"All of us, whether we’re doing research on animals or not, recognize that this is something that is not optimal," Andrew Rowan says. "If society didn’t feel that we needed the information, we wouldn’t do research on animals. But society feels we do, and so do scientists. There’s a tension between our concern about causing pain and distress and killing animals and our need for new knowledge. No one would say that the animals in research benefit from it, and in a world that was perfect we wouldn’t be doing this. We’re engaged in encouraging people to make animal welfare a higher priority without compromising their ability to gather information."

Neal Barnard, of the Physicians Committee for Responsible Medicine, argues that the route away from animal research should carry us toward population-based efforts like the Framingham Heart Study, in which heart researchers have closely followed the health habits and outcomes of 5,000 adults for just over 50 years. That study was a key factor in galvanizing current national efforts to lower cholesterol, combat hypertension, and encourage proper diet and exercise to reduce mortality from heart disease.

"Those areas where we struggle the most, clinically, are those where we haven’t exploited good clinical research and are relying on animal models," Barnard says. "Look at cardiac defects. We don’t know how they’re caused because no one has done the equivalent of the Framingham study for heart defects, even though it’s quite feasible. The Centers for Disease Control and organizations study these congenital abnormalities only in a very haphazard way.

"Of course," he continues, "there have been some brilliant exceptions, such as the research on neural tube defects. It was found through observation of humans that these defects were associated with deficiencies in folic acid, and that by taking vitamin supplements you can reduce the risk. The same with fetal alcohol syndrome: the breakthroughs came in studying humans, not animals."

Politics frequently obscures our view of research bias, Barnard says. He has called for a Framingham-style study of the health implications of cow’s milk consumption, which has been implicated in some studies as a possible cause of Type 1 diabetes in children. Barnard believes that the political strength of the dairy industry has kept such a study from becoming a reality even though some 700,000 Americans suffer from Type 1 diabetes.

Even within the scientific community, there is an increasing willingness to admit that current research methods can be improved upon. A wide variety of in vitro tests have been proposed (among them, the use of human tissue culture and in vitro cell-culture assays), as well as increased reliance on computer modeling and the creative application of human epidemiological studies. Both government and industry experts agree that if new techniques eliminate or reduce the use of animals, so much the better. "[T]he current rodent bioassay for assessing carcinogenicity costs $1 million to $3 million and requires at least 3 years to complete," reads the summary of a January 1997 meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals. The main topic of the meeting was the development of alternatives to animal research, and the report continues, "More efficient testing methods may reduce the time required to bring new products to the marketplace and increase the amount of useful information that can be obtained."

Most researchers recognize that the humane treatment of animals isn’t only compassionate—it’s also good science. Imagine trying to measure the effect of blood-pressure medication on a dog that hasn’t been walked in days. We now know that animals’ feelings, behavior, and emotions have a profound effect on their physiological functioning—as is the case with humans. Consequently, after strong initial opposition to the Animal Welfare Act, most researchers have come to support it.

The Humane Society of the United States represents one example of how animal protectionists can set reasonably limited goals that promote animal welfare in ways that better serve both animals and humans. "We’ve contacted animal care and use committees and asked them to work with us to identify techniques that cause pain and distress and figure out ways to share ways to eliminate that in research," says HSUS’s Andrew Rowan. "Some of the committees are rather suspicious; they see a hidden attempt to stop all animal research. The response has been slight so far. But we think that most researchers are bright people and will understand that our primary goal is just to eliminate animal suffering wherever possible."

Norman Letvin, who frequently debates animal protectionists, knows that there are many who would like to end the practice of animal research for good. Although he is ready and willing to discuss the morality and ethics of his work, he thinks that calling an end to the practice would hurt society enormously.

"It is very easy to take an absolutist position and say it is wrong to cause the death of another living animal," Letvin says. "The difficulty in what [researchers] do comes in saying, ‘I understand that what I’m doing is causing the death of a limited number of animals, but I’m making a judgment that the information gained from this limited, focused experiment will yield results that will justify doing the study.’ Many humans infected with viruses or suffering from cancer or heart disease enter into studies that allow the development of new therapeutics. Every day, thousands of humans say, ‘It is worth it for me to be involved in those studies because, even though I probably won’t benefit, others will.’ In the end, the decisions I’m making with respect to experimental animals are not dissimilar."

As we walked to a new facility on Longwood Avenue, Arthur Lage reminded me that it was the former site of Angell Memorial Animal Hospital, which has since moved to Huntington Avenue in Jamaica Plain. He points out where horses were tethered in the courtyard as they waited to be seen by a veterinarian. He indicates a barely visible tower protruding from the rear roof where distempered dogs were once quarantined. "It was hard work," he recalls, somewhat wistfully, of the internship and residency he served at Angell. "But it was rewarding. You might sit up all night with a sick dog or cat, trying to save its life."

Today, Lage cannot devote as much time to saving animals’ lives. Instead, as he says, he’s helping save human lives through animal research, while ensuring that animals are used humanely. Embodied in his work are many of the contradictions that many of us feel when we consider the millions of animals—from mice to monkeys—that annually give their lives for human health. The use of animals in research will not end today, nor tomorrow, but opinions on the matter appear to be evolving, perhaps toward a better life for animals in the laboratory, and toward better science.

John Lauerman used to write the magazine’s " Harvard Health " column. He is coauthor of a book on diabetes and, with Thomas Perls, M.P.H. ’93, M.D., and Margery H. Silver, Ed.D. ’82, of  Living to 100,  forthcoming from Basic Books in March.

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About Animal Testing

Humane Society International / Global

What is animal testing?

The term “animal testing” refers to procedures performed on living animals for purposes of research into basic biology and diseases, assessing the effectiveness of new medicinal products, and testing the human health and/or environmental safety of consumer and industry products such as cosmetics, household cleaners, food additives, pharmaceuticals and industrial/agro-chemicals. All procedures, even those classified as “mild,” have the potential to cause the animals physical as well as psychological distress and suffering. Often the procedures can cause a great deal of suffering. Most animals are killed at the end of an experiment, but some may be re-used in subsequent experiments. Here is a selection of common animal procedures:

• Forced chemical exposure in toxicity testing, which can include oral force-feeding, forced inhalation, skin or injection into the abdomen, muscle, etc.
• Exposure to drugs, chemicals or infectious disease at levels that cause illness, pain and distress, or death
• Genetic manipulation, e.g., addition or “knocking out” of one or more genes
• Ear-notching and tail-clipping for identification
• Short periods of physical restraint for observation or examination
• Prolonged periods of physical restraint
• Food and water deprivation
• Surgical procedures followed by recovery
• Infliction of wounds, burns and other injuries to study healing
• Infliction of pain to study its physiology and treatment
• Behavioural experiments designed to cause distress, e.g., electric shock or forced swimming
• Other manipulations to create “animal models” of human diseases ranging from cancer to stroke to depression
• Killing by carbon dioxide asphyxiation, neck-breaking, decapitation, or other means

What types of animals are used?

Many different species are used around the world, but the most common include mice, fish, rats, rabbits, guinea pigs, hamsters, farm animals, birds, cats, dogs, mini-pigs, and non-human primates (monkeys, and in some countries, chimpanzees). Video: Watch what scientists have to say about alternatives to animal testing .

It is estimated that more than 115 million animals worldwide are used in laboratory experiments every year. But because only a small proportion of countries collect and publish data concerning animal use for testing and research, the precise number is unknown. For example, in the United States, up to 90 percent of the animals used in laboratories (purpose-bred rats, mice and birds, fish, amphibians, reptiles and invertebrates) are excluded from the official statistics, meaning that figures published by the U.S. Department of Agriculture are no doubt a substantial underestimate.

Within the European Union, more than 12 million animals are used each year, with France, Germany and the United Kingdom being the top three animal using countries. British statistics reflect the use of more than 3 million animals each year, but this number does not include animals bred for research but killed as “surplus” without being used for specific experimental procedures. Although these animals still endure the stresses and deprivation of life in the sterile laboratory environment, their lives are not recorded in official statistics. HSI believes that complete transparency about animal use is vital and that all animals bred, used or killed for the research industry should be included in official figures. See some animal use statistics .

What’s wrong with animal testing?

For nearly a century, drug and chemical safety assessments have been based on laboratory testing involving rodents, rabbits, dogs, and other animals. Aside from the ethical issues they pose—inflicting both physical pain as well as psychological distress and suffering on large numbers of sentient creatures—animal tests are time- and resource-intensive, restrictive in the number of substances that can be tested, provide little understanding of how chemicals behave in the body, and in many cases do not correctly predict real-world human reactions. Similarly, health scientists are increasingly questioning the relevance of research aimed at “modelling” human diseases in the laboratory by artificially creating symptoms in other animal species.

Trying to mirror human diseases or toxicity by artificially creating symptoms in mice, dogs or monkeys has major scientific limitations that cannot be overcome. Very often the symptoms and responses to potential treatments seen in other species are dissimilar to those of human patients. As a consequence, nine out of every 10 candidate medicines that appear safe and effective in animal studies fail when given to humans. Drug failures and research that never delivers because of irrelevant animal models not only delay medical progress, but also waste resources and risk the health and safety of volunteers in clinical trials.

What’s the alternative?

If lack of human relevance is the fatal flaw of “animal models,” then a switch to human-relevant research tools is the logical solution. The National Research Council in the United States has expressed its vision of “a not-so-distant future in which virtually all routine toxicity testing would be conducted in human cells or cell lines”, and science leaders around the world have echoed this view.

The sequencing of the human genome and birth of functional genomics, the explosive growth of computer power and computational biology, and high-speed robot automation of cell-based (in vitro) screening systems, to name a few, has sparked a quiet revolution in biology. Together, these innovations have produced new tools and ways of thinking that can help uncover exactly how chemicals and drugs disrupt normal processes in the human body at the level of cells and molecules. From there, scientists can use computers to interpret and integrate this information with data from human and population-level studies. The resulting predictions regarding human safety and risk are potentially more relevant to people in the real world than animal tests.

But that’s just the beginning. The wider field of human health research could benefit from a similar shift in paradigm. Many disease areas have seen little or no progress despite decades of animal research. Some 300 million people currently suffer from asthma, yet only two types of treatment have become available in the last 50 years. More than a thousand potential drugs for stroke have been tested in animals, but only one of these has proved effective in patients. And it’s the same story with many other major human illnesses. A large-scale re-investment in human-based (not mouse or dog or monkey) research aimed at understanding how disruptions of normal human biological functions at the levels of genes, proteins and cell and tissue interactions lead to illness in our species could advance the effective treatment or prevention of many key health-related societal challenges of our time.

Modern non-animal techniques are already reducing and superseding experiments on animals, and in European Union, the “3Rs” principle of replacement, reduction and refinement of animal experiments is a legal requirement. In most other parts of the world there is currently no such legal imperative, leaving scientists free to use animals even where non-animal approaches are available.

If animal testing is so unreliable, why does it continue?

Despite this growing evidence that it is time for a change, effecting that change within a scientific community that has relied for decades on animal models as the “default method” for testing and research takes time and perseverance. Old habits die hard, and globally there is still a lack of knowledge of and expertise in cutting-edge non-animal techniques.

But with HSI’s help, change is happening. We are leading efforts globally to encourage scientists, companies and policy-makers to transition away from animal use in favour of 21st century methods. Our work brings together experts from around the globe to share knowledge and best practice, improving the quality of research by replacing animals in the laboratory.

Are animal experiments needed for medical progress?

It is often argued that because animal experiments have been used for centuries, and medical progress has been made in that time, animal experiments must be necessary. But this is missing the point. History is full of examples of flawed or basic practices and ideas that were once considered state-of-the-art, only to be superseded years later by something far more sophisticated and successful. In the early 1900’s, the Wright brothers’ invention of the airplane was truly innovative for its time, but more than a century later, technology has advanced so much that when compared to the modern jumbo jet those early flying machines seem quaint and even absurd. Those early ideas are part of aviation history, but no-one would seriously argue that they represent the cutting-edge of design or human achievement. So it is with laboratory research. Animal experiments are part of medical history, but history is where they belong. Compared to today’s potential to understand the basis of human disease at cellular and molecular levels, experimenting on live animals seems positively primitive. So if we want better quality medical research, safer more effective pharmaceuticals and cures to human diseases, we need to turn the page in the history books and embrace the new chapter—21st century science.

Independent scientific reviews demonstrate that research using animals correlates very poorly to real human patients. In fact, the data show that animal studies fail to predict real human outcomes in 50 to 99.7 percent of cases. This is mainly because other species seldom naturally suffer from the same diseases as found in humans. Animal experiments rely on often uniquely human conditions being artificially induced in non-human species. While on a superficial level they may share similar symptoms, fundamental differences in genetics, physiology and biochemistry can result in wildly different reactions to both the illness and potential treatments. For some areas of disease research, overreliance on animal models may well have delayed medical progress rather than advanced it. By contrast, many non-animal replacement methods such as cell-based studies, silicon chip biosensors, and computational systems biology models, can provide faster and more human-relevant answers to medical and chemical safety questions that animal experiments cannot match.

“The claim that animal experimentation is essential to medical development is not supported by proper, scientific evidence but by opinion and anecdote. Systematic reviews of its effectiveness don’t support the claims made on its behalf” (Pandora Pound et al. British Medical Journal 328, 514-7, 2004).

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Imagine a syringe being forced down your throat to inject a chemical into your stomach, or being restrained and forced to breathe sickening vapours for hours. That’s the cruel reality of animal testing for millions of mice, rabbits, dogs and other animals worldwide.

We’re giving the beauty industry a cruelty-free makeover with a wave of animal testing bans supported by hundreds of companies and millions of caring consumers worldwide.

We all dream of the day when cancer is cured and AIDS is eradicated, but is the continued use of mice, monkeys and other animals as experimental “models” of human disease actually holding us back from realizing the promise of 21st century science?

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Animal behavior research is getting better at keeping observer bias from sneaking in – but there’s still room to improve

Professor and Associate Head of Psychology, University of Tennessee

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Todd M. Freeberg does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

University of Tennessee provides funding as a member of The Conversation US.

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Animal behavior research relies on careful observation of animals. Researchers might spend months in a jungle habitat watching tropical birds mate and raise their young. They might track the rates of physical contact in cattle herds of different densities. Or they could record the sounds whales make as they migrate through the ocean.

Animal behavior research can provide fundamental insights into the natural processes that affect ecosystems around the globe, as well as into our own human minds and behavior.

I study animal behavior – and also the research reported by scientists in my field. One of the challenges of this kind of science is making sure our own assumptions don’t influence what we think we see in animal subjects. Like all people, how scientists see the world is shaped by biases and expectations, which can affect how data is recorded and reported. For instance, scientists who live in a society with strict gender roles for women and men might interpret things they see animals doing as reflecting those same divisions .

The scientific process corrects for such mistakes over time, but scientists have quicker methods at their disposal to minimize potential observer bias. Animal behavior scientists haven’t always used these methods – but that’s changing. A new study confirms that, over the past decade, studies increasingly adhere to the rigorous best practices that can minimize potential biases in animal behavior research.

Biases and self-fulfilling prophecies

A German horse named Clever Hans is widely known in the history of animal behavior as a classic example of unconscious bias leading to a false result.

Around the turn of the 20th century , Clever Hans was purported to be able to do math. For example, in response to his owner’s prompt “3 + 5,” Clever Hans would tap his hoof eight times. His owner would then reward him with his favorite vegetables. Initial observers reported that the horse’s abilities were legitimate and that his owner was not being deceptive.

However, careful analysis by a young scientist named Oskar Pfungst revealed that if the horse could not see his owner, he couldn’t answer correctly. So while Clever Hans was not good at math, he was incredibly good at observing his owner’s subtle and unconscious cues that gave the math answers away.

In the 1960s, researchers asked human study participants to code the learning ability of rats. Participants were told their rats had been artificially selected over many generations to be either “bright” or “dull” learners. Over several weeks, the participants ran their rats through eight different learning experiments.

In seven out of the eight experiments , the human participants ranked the “bright” rats as being better learners than the “dull” rats when, in reality, the researchers had randomly picked rats from their breeding colony. Bias led the human participants to see what they thought they should see.

Eliminating bias

Given the clear potential for human biases to skew scientific results, textbooks on animal behavior research methods from the 1980s onward have implored researchers to verify their work using at least one of two commonsense methods.

One is making sure the researcher observing the behavior does not know if the subject comes from one study group or the other. For example, a researcher would measure a cricket’s behavior without knowing if it came from the experimental or control group.

The other best practice is utilizing a second researcher, who has fresh eyes and no knowledge of the data, to observe the behavior and code the data. For example, while analyzing a video file, I count chickadees taking seeds from a feeder 15 times. Later, a second independent observer counts the same number.

Yet these methods to minimize possible biases are often not employed by researchers in animal behavior, perhaps because these best practices take more time and effort.

In 2012, my colleagues and I reviewed nearly 1,000 articles published in five leading animal behavior journals between 1970 and 2010 to see how many reported these methods to minimize potential bias. Less than 10% did so. By contrast, the journal Infancy, which focuses on human infant behavior, was far more rigorous: Over 80% of its articles reported using methods to avoid bias.

It’s a problem not just confined to my field. A 2015 review of published articles in the life sciences found that blind protocols are uncommon . It also found that studies using blind methods detected smaller differences between the key groups being observed compared to studies that didn’t use blind methods, suggesting potential biases led to more notable results.

In the years after we published our article, it was cited regularly and we wondered if there had been any improvement in the field. So, we recently reviewed 40 articles from each of the same five journals for the year 2020.

We found the rate of papers that reported controlling for bias improved in all five journals , from under 10% in our 2012 article to just over 50% in our new review. These rates of reporting still lag behind the journal Infancy, however, which was 95% in 2020.

All in all, things are looking up, but the animal behavior field can still do better. Practically, with increasingly more portable and affordable audio and video recording technology, it’s getting easier to carry out methods that minimize potential biases. The more the field of animal behavior sticks with these best practices, the stronger the foundation of knowledge and public trust in this science will become.

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She worked in animal research. Now she’s blocked from commenting on it.

An animal rights activist is embroiled in a court fight with the National Institutes of Health for blocking her online comments on NIH research using monkeys.

For a long time, Madeline Krasno didn’t tell other animal rights advocates that she had worked in a monkey research lab as a college student. It had taken her years to understand her nightmares and fragmented memories as signs of post-traumatic stress disorder. And some activists could be vicious to former lab workers.

But four years after she graduated from the University of Wisconsin at Madison, Krasno started posting online about her experiences. Eventually, she started tagging the school in those posts and then commenting on its pages.

Many of those comments disappeared. As she would later learn, it was not a mistake or a glitch. Both the university and the National Institutes for Health were blocking her comments. Now with support from free speech and animal rights organizations, she is suing both institutions.

“They’re suppressing any kind of conversation on the issue,” Krasno said in an interview while walking her dog, Millie. (She said she thinks of Millie as a person — and a soul mate — not a pet.) “You can’t tell me that’s not a free speech violation.”

Two courts have told her that it’s not a violation, that the blocking of keywords such as “animal testing” and related hashtags is a legal way of managing online conversations — the same way a local government can avoid chaotic town halls by deciding who speaks and on what topics. Both rulings are now on appeal and could go to the U.S. Supreme Court.

“Courts are just starting to dig into the parameters of free speech online,” said lawyer Stephanie Krent of the Knight First Amendment Institute, who argued NIH’s case in front of the U.S. Court of Appeals for the D.C. Circuit last week. Courts have said officials — including former president Donald Trump — can’t muzzle criticism online. But they haven’t said what the limits are when the government is allowed to moderate.

The lab in Madison where Krasno worked was named after Harry Harlow, a pioneering psychologist whose work upended harmful beliefs that too much tenderness would soften children’s minds. On the contrary, he found , neglect and isolation were liable to make children grow up angry and violent; mothers who had been traumatized were liable to became neglectful or abusive toward their children.

He came to those conclusions through experiments on rhesus monkeys . Some were separated early from their mothers and given a choice between a doll made of cloth or one made of wire. Some were left for months in a box he called the “pit of despair”; female monkeys were forced to copulate by being tied to a device he called “the rape rack.”

Harlow’s name, along with that of a scientist who worked with him, are on NIH’s list of banned words. So are “animals,” “cruelty,” “monkeys,” “revolting,” “testing” and “torture.” After Krasno’s lawsuit was filed, “PETA,” “#stopanimaltesting,” “#stoptesting” and “#stoptestingonanimals” were taken off the list of banned words.

NIH said it chose those words because they were the ones most commonly used in off-topic, repetitive comments. For example, an Instagram post on sickle-cell anemia prompted more than five dozen comments that were variations on “#animalabuser,” although the research highlighted did not involve animal testing.

Krasno, now 33, worked in the Harlow lab decades after his death and was never directly involved in research. She was a student caretaker for the hours when scientists and their assistants were off-duty. Immediately, she says, she had some awareness that what she was seeing was wrong. On her first day at the lab, she was taken to the one cage that housed multiple macaques. Her supervisor gave her some peanuts and showed her how to hand the treats through the bars.

“They were so excited,” she said. “They’re living in basically dungeons — windowless rooms where the lighting half the time wasn’t working, where the drains weren’t working. A peanut is all they have to live for.”

Other monkeys were caged alone, she said. While mothers were not separated from their babies the way Harlow’s test subjects had been, Krasno said the mothers often rejected their offspring or failed to properly nurse them because they had not learned from older monkeys in the wild. Though they weren’t tied down, she said, female monkeys were clearly traumatized by being put into cages with unfamiliar males for breeding: “You would hear screaming.”

A spokesman for the school said that they have no evidence of mistreatment during Krasno’s time in the lab and that federal agencies provide oversight of animal research. The school settled an investigation with the U.S. Agriculture Department over alleged violations of the Animal Welfare Act in 2020 by paying a $74,000 fine, saying safety measures had been improved.

“Monkeys in the university’s facilities receive regular attention and care from specialized veterinarians” and “are housed socially with other monkeys … as research and safety allow,” said Chris Barncard, the spokesman. “Studying animals is an important way — in many cases, the only way — to answer crucial questions about basic biological processes and to ethically study diseases with often devastating consequences for humans and animals.”

Krasno had planned to go into primate conservation. Instead, after graduation she began working in animal sanctuaries. She would dream about being back in the lab, taking photographs — something she had never done when she worked there. She started going to therapy and was eventually diagnosed with PTSD, she said.

In 2017, Krasno posted on Instagram a photo of a tattoo she had gotten that said: “for patrick” — the name of the first baby monkey she cared for in the lab. And she started intermittently describing her experiences.

At first, it was her ideological allies who responded negatively, saying she was a psychopath for having worked in animal research. “Some of the worst things that have been said to me have come from animal rights activists,” Krasno said. But she noticed that when she tagged her alma mater in posts, the school removed the notation. Feeling she had hit a nerve, she started commenting on the school’s Facebook and Instagram pages. The comments disappeared. So did her comments on NIH’s pages.

A friend in she met through a vegan University of Wisconsin alumni Facebook group tried posting similar comments; they also disappeared. They filed Freedom of Information Act requests and learned that certain words were being automatically blocked. When those filters didn’t work, the university was manually removing Krasno’s comments.

With help from a friend at the Animal Legal Defense Fund, she sued the school and NIH; People for the Ethical Treatment of Animals (PETA), joined the NIH suit. In response, both institutions said that they were simply trying to keep their social media feeds from being overwhelmed by repetitive, irrelevant comments and that Krasno and other animal rights activists just happened to be the ones leaving them.

It’s “a seemingly coordinated campaign to flood [NIH’s] social media pages with off-topic commentary related to animal testing,” Justice Department attorney Jennifer Utrecht said during last week’s oral argument at the D.C. Circuit. “The people who are repeatedly violating the off-topic policy all have a particular viewpoint.” She said followers of an online chat on brain health and a social media campaign on retina issues were confused and annoyed by the repeated posts on animal rights.

Other posts blocked by NIH included external links, profanity, strings of numbers, the mention of cannabis and “#believemothers,” used by anti-vaccine activists.

But Krasno’s side argues that animal testing is so common that almost any scientific research can be linked to it, and any comment on it is arguably relevant. For example, as the animal advocates pointed out in their court filings , the sickle cell researcher has done work on rats .

“Most people would agree that a comment that the coronavirus vaccine was tested on animals would be on-topic,” attorney Caitlin Foley of the Animal Legal Defense Fund said. “But if that’s filtered out, they wouldn’t know speech was being censored.”

Appellate judges seemed to be divided over how to handle the comments.

If banning certain keywords violates the First Amendment, then content moderation would be “extremely difficult,” Judge Brad Garcia said. Judge Patricia Millett said having humans, rather than a computer program, read and curate threads was “unrealistic.” But Millett was also skeptical that the government had proved the bans are necessary. “I would not consider dozens, on internet threads, which can go on forever, flooding,” she said, adding, “I really am struggling with how ‘test’ is just clearly off-topic for NIH.”

Krasno said that if the lawsuits succeed, she plans to sue other universities that have engaged in similar deletion of animal rights advocacy.

“These are our tax dollars,” she said. “To say you can’t even talk about it in ways that most people are discussing issues — that’s just not fair.”

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April 30, 2024

Synthetic platelets stop bleeding in animal studies

At a glance.

• Synthetic blood platelets stopped bleeding and sped wound healing in animals with internal injuries.
• The synthetic platelets didn’t accumulate in other organs and were rapidly excreted, indicating that they’re likely safe for testing in people.

Uncontrolled bleeding after trauma—whether from an accident, injury, or during surgery—can prove fatal. Transfusions of donated platelets, the tiny blood cells that promote clotting, are often used to help stop emergency bleeding. But platelets don’t last long outside the body, are difficult to store, and are sometimes contaminated with bacteria. Consequently, they’re often in short supply or unavailable in emergency settings like an ambulance.

Engineered compounds that promote clotting have been developed to replace platelet transfusions. But these compounds have drawbacks, including high costs. And biocompatible glues can be used on the skin, but not for internal bleeding. To overcome these shortfalls, researchers have been working to develop synthetic platelet-like particles, or PLPs.

A research team led by Dr. Ashley Brown from North Carolina State University has developed one such PLP. It consists of an ultrasoft microgel particle linked to a piece of an antibody that binds to fibrin. Fibrin is a protein found in wounds that helps blood clot. Targeting fibrin allows the PLPs to home in on wounds. The ultrasoft nature of the particles lets the PLPs change shape and compress their size. Such traits might let them mimic the behavior of real platelets and speed the healing process.

In previous studies, the researchers showed that clots formed by their PLPs mimicked properties of clots formed by natural platelets. In a new study, funded in part by NIH, they optimized PLP binding to fibrin and tested several versions of their synthetic platelets in mice, rats, and pigs with internal injuries. Results were published on April 10, 2024, in Science Translational Medicine .

In mice with traumatic liver injury, the PLPs collected at the injury sites. In contrast, the top synthetic platelet candidate wasn’t found in substantial numbers in other organs such as the heart, lung, and kidneys. Compared to mice given normal platelets or a control solution of saline, mice with liver injury given the PLPs had the lowest levels of blood loss. At seven days after injury, mice given the PLPs also had the smallest wounds, a sign of improved healing.

A similar reduction in blood loss was seen in rats given the PLPs after injury to a blood vessel. In additional studies in mice, the team found that the PLPs rapidly cleared from the body through urine in the absence of an active injury.

Finally, the researchers tested their top PLP candidate in pigs, an animal model closer to people. When given immediately after a liver injury, the PLPs traveled to the site of injury and reduced blood loss. They didn’t cause any measurable allergic or immune system reactions, and began to be excreted by the kidneys as soon as two hours after injection.

“In the mouse and pig models, healing rates were comparable in animals that received platelet transfusions and synthetic platelet transfusions,” Brown says. “And both groups fared better than animals that did not receive either transfusion."

While the PLPs bound to fibrin at the wound sites, the current versions don’t have all the functions of natural platelets. The team plans to develop next-generation synthetic platelets with additional features like the ability to clump together and to send signals to immune cells. They also hope to begin human studies within the next several years.

—by Sharon Reynolds

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• Blood Donation
• Blood Safety (CDC)

References:  Ultrasoft platelet-like particles stop bleeding in rodent and porcine models of trauma. Nellenbach K, Mihalko E, Nandi S, Koch DW, Shetty J, Moretti L, Sollinger J, Moiseiwitsch N, Sheridan A, Pandit S, Hoffman M, Schnabel LV, Lyon LA, Barker TH, Brown AC. Sci Transl Med . 2024 Apr 10;16(742):eadi4490. doi: 10.1126/scitranslmed.adi4490. Epub 2024 Apr 10. PMID: 38598613.

Funding:  NIH’s National Heart, Lung, and Blood Institute (NHLBI), National Institute of General Medical Sciences (NIGMS), and Office of the Director (OD); U.S. Department of Defense; North Carolina Biotechnology Translational Research Grant; North Carolina State University Research and Innovation Seed Funding; National Science Foundation; North Carolina State University Chancellor’s Innovation Fund; U.S. Department of Veterans Affairs; American Heart Association.

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https://www.nist.gov/news-events/news/2024/02/heart-chip-microfluidic-marvel-shaping-future-cardiovascular-research

Heart-on-a-Chip: A Microfluidic Marvel Shaping the Future of Cardiovascular Research

• NIST is developing a “heart-on-a-chip” system that captures aspects of human heart function for studying cardiovascular disease.
• NIST has surveyed the state of the technology, which includes efforts across the scientific community, in a review article.
• An organ-on-a-chip suite, which would include heart-on-a-chip, could ensure safer, faster and more precise drug development and reduce the need for animal testing.

Editor’s Note (May 2, 2024): This news article has been updated to clarify that the heart-on-a-chip system at NIST is still in development and that the Lab on a Chip article referenced is a review of work on this technology across the scientific community.

Researchers at the National Institute of Standards and Technology (NIST) have developed bioelectronic devices capable of real-time measurements of cell behavior. Researchers are integrating these components into their version of a system known as heart-on-a-chip (HoC). This technology seeks to address the limitations of conventional cardiovascular drug development, which relies heavily on animal testing. By capturing key aspects of the human cardiovascular system in a laboratory setup, the HoC holds the possibility of helping to replace animal testing with a more accurate representation of the human body, thus shortening drug development timelines and reducing costs. 

NIST researchers recently surveyed the state of the technology, which includes efforts across the science community, in a review article in the journal Lab on a Chip . NIST’s work on HoC is part of a larger organ-on-a-chip suite being developed at the agency, including a “body cube,” which mimics the human body’s organ functions in a 3D arrangement.

The HoC is a device that captures the intricate interactions of cells within the heart on a small chip. The actual design of the heart-on-a-chip varies, but it is typically a small, transparent or semi-transparent chip consisting of a network of microchannels printed on a layer of polymer. These microchannels are intricately designed to imitate the blood vessels found in the human heart. Researchers place human heart cells within these microchannels to manipulate and observe their behavior. Researchers can independently stimulate them or observe their behavior under different conditions, such as the introduction of a drug.

According to NIST researcher Darwin Reyes, who leads the development of this system, the heart-on-a-chip NIST is designing aims to mimic the conditions of a real heart. The goal is to manipulate the environment to change stem cells into heart cells and make them contract and relax, as they do in a body to produce a heartbeat. 

The “heart” of the organ-on-a-chip system lies in something called microfluidics, which is essentially a miniature plumbing system in which researchers can precisely control and manipulate tiny amounts of liquids. Researchers use microfluidics to create advanced models of organs and tissues on small chips in the lab. 

According to Reyes, the bioelectronic device could be used with many different cell types. For the HoC project, the researchers are using heart cells, but a customized version of the system has been used with other cells to monitor their behavior visually and electronically. 

Researchers can create chips that mimic the conditions of various organs in addition to the heart, and these chips can even be interconnected to form a multi-organ system. For example, you could have a heart-on-a-chip connected to a liver-on-a-chip to simulate how the heart and liver interact in response to certain drugs or medical conditions. This approach provides a more comprehensive understanding of how different organs function together in the human body. NIST works to understand sources of uncertainty in these devices and develop the design and fabrication techniques to realistically represent human physiology on the microscale.

Rethinking Animal Testing

In traditional drug development, animals are often used as test subjects. However, animal physiology does not perfectly match human physiology. A drug may pass a test on an animal subject but may then fail in human testing. This not only delays the drug testing process but also puts human test subjects at risk of adverse effects from the drug. Additionally, there is ongoing debate about the ethical considerations of animal testing.

“The ultimate goal is to, if possible, be able to skip the animal testing altogether,” said Reyes. “This would also shorten the time it takes to test drugs, which would hopefully make the medications cost less.”

In 2022, President Joe Biden signed into law the FDA Modernization Act 2.0 . The bill essentially revises the Federal Food, Drug, and Cosmetics Act of 1938, which mandated animal testing for every new drug development protocol. While for the past century, the mandate was intended to ensure certain quality and safety standards for drugs and medical devices, recent advancements in science have begun to offer increasingly viable alternatives to animal testing, including organ-on-a-chip systems.

Global Collaboration for Standardizing Organ-on-a-Chip Technology

Developing this new technology is not done in a vacuum. Researchers across the world are working on similar microfluidic devices to usher in a new era of drug development. However, to make this a reality, there's a need for standardization — establishing consistent guidelines and rules for these technologies. This not only helps in gaining regulatory approvals but also ensures better acceptance in the scientific, industrial and medical communities. NIST is an active participant, along with scientific organizations across the globe, in developing standards for this technology.

“The more collaborative research there is outside of what is currently being done and where we're heading, the better this technology is going to be,” said Reyes.

Expanding Horizons Beyond Cardiovascular Focus

While HoC is focused on cardiovascular drug development, the OoC capabilities extend beyond a specific organ. The system can be applied to various cell types, including those relevant to cancer research. 

“We are in the test phase of understanding how we can track the movement and aggressiveness of cancer cells in real time,” shared Reyes. “Our hope is, in the future, with more testing, the system may be able to provide measurements of cancer cell aggressiveness that could help with diagnosis.”

Developing this new technology, underpinned by rigorous standards, marks an important step toward a future where drug development is characterized by precision, efficiency and heightened ethical considerations.

Paper: Derrick Butler and Darwin R. Reyes. Heart-on-a-Chip System: Disease Modeling and Drug Screening Applications. Lab on a Chip. Published online Feb. 6, 2024. DOI: 10.1039/D3LC00829K

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USDA Actions to Protect Livestock Health From Highly Pathogenic H5N1 Avian Influenza

Federal Order to assist with developing a baseline of critical information and limiting the spread of H5N1 in dairy cattle

WASHINGTON, April 24, 2024 – To further protect the U.S. livestock industry from the threat posed by highly pathogenic H5N1 avian influenza, USDA is sharing a number of actions that we are taking with our federal partners to help us get ahead of this disease and limit its spread.

Today, USDA’s Animal and Plant Health Inspection Service (APHIS) announced a Federal Order requiring the following measures, effective Monday, April 29, 2024:

Mandatory Testing for Interstate Movement of Dairy Cattle

• Prior to interstate movement, dairy cattle are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory.
• Owners of herds in which dairy cattle test positive for interstate movement will be required to provide epidemiological information, including animal movement tracing.
• Dairy cattle moving interstate must adhere to conditions specified by APHIS.
• As will be described in forthcoming guidance, these steps will be immediately required for lactating dairy cattle, while these requirements for other classes of dairy cattle will be based on scientific factors concerning the virus and its evolving risk profile.

Mandatory Reporting

• Laboratories and state veterinarians must report positive Influenza A nucleic acid detection diagnostic results (e.g. PCR or genetic sequencing) in livestock to USDA APHIS.
• Laboratories and state veterinarians must report positive Influenza A serology diagnostic results in livestock to USDA APHIS.

USDA has identified spread between cows within the same herd, spread from cows to poultry, spread between dairies associated with cattle movements, and cows without clinical signs that have tested positive. On April 16, APHIS microbiologists identified a shift in an H5N1 sample from a cow in Kansas that could indicate that the virus has an adaptation to mammals. Centers for Disease Control and Prevention (CDC) conducted further analysis of the specimen sequence, which did not change their overall risk assessment for the general public, because the substitution has been seen previously in other mammalian infections and does not impact viral transmission. Additionally, APHIS’ National Veterinary Services Laboratories found H5N1 in a lung tissue sample from an asymptomatic cull dairy cow that originated from an affected herd and did not enter the food supply.

The novel movement of H5N1 between wild birds and dairy cows requires further testing and time to develop a critical understanding to support any future courses of action. This Federal Order is critical to increasing the information available for USDA. Requiring positive test reporting will help USDA better under this disease and testing before interstate movement will limit its spread.

While we are taking this action today, it is important to remember that thus far, we have not found changes to the virus that would make it more transmissible to humans and between people. While cases among humans in direct contact with infected animals are possible, our partners at the U.S. Centers for Disease Control and Prevention (CDC) believe that the current risk to the public remains low.

Additionally, we continue to see affected cows recover after supported care with little to no associated mortality. We also continue to work with our partners in the states and industry to emphasize the critical importance biosecurity plays in limiting disease spread for all livestock and poultry.

You may view the Federal Order , which is effective on Monday, April 29, 2024.

Further, in an effort to maximize understanding and research on H5N1 in dairy cattle, on April 21, APHIS made publicly available 239 genetic sequences from the U.S. H5N1 clade 2.3.4.4b influenza virus recently found in samples associated with the ongoing HPAI outbreak in poultry and wild birds, and the recent H5N1 event in dairy cattle. APHIS has also offered virus samples to interested researchers to facilitate epidemiological study. Increasing our understanding of this disease and how it spreads is critical to stopping it. This is why APHIS is urging dairy cattle producers and those who work in or with the industry to share epidemiological information from affected farms, even if they are not planning to move cattle interstate. APHIS further urges producer participation in public health assessments to continue to confirm worker safety and monitor for any potential changes in the virus that could impact transmissibility.

In addition, our partners in the U.S. Food and Drug Administration released an update on the ongoing work to ensure continued effectiveness of the federal-state milk safety system. It is important to emphasize that, based on the information and research available to us at this time, the U.S. Food and Drug Administration and USDA believe that our commercial milk supply is safe because of both the pasteurization process and the required diversion or destruction of milk from sick cows. Pasteurization has continuously proven to inactivate bacteria and viruses in milk. The FDA and USDA continue to work closely to collect and evaluate additional data and information specific to avian influenza in dairy cattle and to support state counterparts as this emerging disease in dairy cattle is managed.

As USDA continues to take steps to protect the health of livestock, the Department continues to work closely with federal partners at the CDC on protecting the health of people and FDA on protecting the safety of the food supply. The U.S. government is committed to addressing this situation with urgency.

To learn more about USDA’s response to HPAI in dairy cattle, visit www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock .

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National Research Council (US) and Institute of Medicine (US) Committee on the Use of Laboratory Animals in Biomedical and Behavioral Research. Use of Laboratory Animals in Biomedical and Behavioral Research. Washington (DC): National Academies Press (US); 1988.

Use of Laboratory Animals in Biomedical and Behavioral Research.

• Hardcopy Version at National Academies Press

3 Benefits Derived from the Use of Animals

Animal studies have been an essential component of every field of medical research and have been crucial for the acquisition of basic knowledge in biology. In this chapter a few of the contributions of such studies in biomedical and behavioral research will be chronicled. These descriptions should be viewed within the context of the vast improvements in human health and understanding that have occurred in the past 150 years. For example, since 1900 the average life expectancy in the United States has increased by 25 years (U.S. National Center for Health Statistics, 1988). This remarkable increase cannot be attributed solely to animal research, as much of it is the result of improved hygiene and nutrition, but animal research has clearly been an important contributor to improved human health.

Despite the many advances and the projected results that will come through the use of animals, some individuals question the value of using animal models to study human disease, contending that the knowledge thus gained is insufficiently applicable to humans. Although experiments performed on humans would provide the most relevant information (and are used in clinical research conducted on humans when appropriate), it is not possible by commonly accepted ethical and moral standards or by law to perform most experiments on humans initially. It is true that not every experiment using animals yields immediate and practical results, but the advances that will be described in this chapter provide evidence that this means of research has contributed enormously to the well-being of humankind.

As a result of the acquisition of information and the development of techniques achieved through the use of animals, poliomyelitis is no longer a major threat to health in the United States. The number of cases of paralytic polio in the United States has declined as a result of vaccinations from 58,000 in 1952 to only 4 in 1984 (Office of Technology Assessment, 1986). Unfortunately, polio is still a major threat to health where the vaccine is not used. Indeed, in a number of African, Asian, and South American countries, the incidence of the disease has been rising, despite the availability of the vaccine (Cockburn and Drozdov, 1970). An estimated 500,000 cases occur around the world each year (Salk, 1983).

The use of rhesus monkeys for the study of polio began when Landsteiner and Popper (1909) showed that injection of spinal cord material from patients dying of polio caused paralysis in the animals. Flexner and Lewis (1909) promptly confirmed this result. To learn how to immunize monkeys to protect them against infection, researchers first used live virus, then formalin-inactivated virus from infected brain suspensions, and eventually modified live virus. A major breakthrough occurred when Enders, Weller, and Robbins (1949) showed that the virus could be propagated in cultured cells of non-neural origin. That set the stage for mass production of viruses that could be made into formalin-inactivated Salk vaccine or the modified live-virus Sabin vaccine (Salk, 1983).

Although the use of monkeys in polio research has decreased considerably, they are still essential to the production of both live and killed polio vaccines, which are routinely produced in monkey kidney cell cultures. The live vaccine is tested for neurovirulence in monkeys, and the killed vaccine is routinely tested for safety in monkeys.

• Acquired Immune Deficiency Syndrome

The recent emergence of acquired immune deficiency syndrome (AIDS) as a major health threat exemplifies not only the unpredictability of research needs, but also the criticality of animals in research. The similarity of simian AIDS, identified in rhesus monkeys at two primate centers, to human AIDS has allowed the disease in monkeys to serve as a model for the human disease. In monkeys, the virus that causes the disease has been isolated, infectibility studies have been conducted, and some experiments have provided preliminary indications of the possibility of vaccine development. This animal model might prove useful for testing the efficacy and safety of vaccines and therapeutic agents developed to prevent or treat the human disease (Institute of Medicine, 1986).

Recently, a new virus called feline T-lymphotropic lentivirus has been discovered. It resembles morphologically the human immunodeficiency virus (HIV) that causes AIDS, although differing antigenically, and causes a disease naturally in cats similar to AIDS. Thus, infected cats might prove useful as animal models for the study of certain aspects of human AIDS (Pedersen et al., 1987).

• Transplantation

The transplantation of skin, corneas, and various internal organs could not have become a safe and standard procedure without the knowledge of the biology of transplantation immunology acquired through the use of experimental animals. Some 30,000 Americans now alive have transplanted kidneys, and others survive with transplanted hearts and livers or retain their sight because of corneal transplants.

The treatment of burn victims was of particular importance to the British during World War II, and British biologist P. B. Medawar (1944) undertook to find relief for them through the transplantation of skin. For one of his models, he used freemartin cattle. A freemartin is a sexually maldeveloped female calf that is born as a twin of a normal male calf; male hormones that reach it through placental vessels usually make it sterile (Lillie, 1917). Experimentation showed that skin and other tissues could be transplanted with good, lasting success between the male and freemartin twins at any stage in their lives (Anderson et al., 1961). They were "tolerant" of each other's tissues because of prenatal exposure to each other's tissue antigens. Medawar and his colleagues sought to induce such tolerance in newborn mice. When newborns received skin transplants or received bone marrow from unrelated animals, they became forever "tolerant" of the new tissue (Brent et al., 1976). That discovery signaled a new era in immunology, with wide ramifications for health and the treatment of disease not only in humans, but also in animals.

Through a systematic study of the surface immune markers of specially bred strains of mice, Snell and Benacerraf provided the basis for much of the understanding that has led to the success of organ transplantation (Benacerraf, 1981).

In the past, young women with chronic pyelonephritis, patients with genetic polycystic disease, and people suffering from the aftermath of streptococcal infections were all vulnerable to chronic renal failure and death. Those people benefited from the invention of "artificial kidneys," which periodically washed blood and removed poisonous substances from it. The recipients of the benefit, however, had to undergo frequent, laborious, and uncomfortable procedures and had to rely on hospitals and mechanical devices.

The first extensive work with renal transplantation was reported in 1955 (Hume et al., 1955). At first, transplanted kidneys were rejected unless they were exchanged between identical twins. However, studies in dogs showed that administration of the drug 6-mercaptopurine after transplantation would prolong the survival of a transplanted organ from an unrelated person. This use of immunosuppressants ushered in the modern era of transplantation (Starzl and Holmes, 1964). These compounds, having been studied first in animals and proved to be effective, are now used in human transplant recipients.

The study of tissue antigens proceeded at the same time as transplantation work, first in mice and then in humans. Inbred (isogeneic) strains of mice had been created by repeated brother-sister matings. Ultimately, these strains became genetically identical, and the exchange of tissues and organs became possible. In the study of minor genetic differences between such strains, it became clear that some genes specify the cell-surface structures responsible for tissue recognition and rejection. "Transplantation antigens" can now be identified by tissue typing, and the most appropriate donors can be chosen for transplantation in both humans and animals.

A second revolution in transplantation was ushered in by the development of cyclosporin. This immunosuppressive agent was first used successfully in humans in 1983, after five years of toxicity and efficacy testing in mice, rats, and other animals. Since it became available for heart transplantation, survival after transplantation has improved significantly (Kupiec-Weglinski et al., 1984). Further progress is now occurring with monoclonal antibodies that seem to immobilize the cell-surface markers responsible for recognition and rejection. The hope is that such monoclonal antibodies, which have been developed and maintained in animals, will make it unnecessary to resort to complete immunosuppression of a transplant recipient. This would reduce the occurrence of infection and increase the rates of survival of transplanted organs.

• Cardiovascular-Renal Systems

Dogs have traditionally been used in cardiovascular-renal studies because of their relatively large size, which facilitates experimental procedures. For example, an early model of hypertension was produced by partially occluding the renal artery in dogs. Studies of renal function that use clearance techniques in unanesthetized animals are most often done in dogs. In the last two decades, however, some mutant rats have proved exceedingly valuable as animal models of human disease. The Brattleboro rat is an excellent example. It has diabetes insipidus and must drink 70 percent of its body weight in water each day. It cannot produce vasopressin, a hormone that plays an essential role in the kidneys' ability to regulate water excretion and blood pressure. Research on the Brattleboro rat has greatly increased our understanding of vasopressin's role in kidney and cardiovascular function, and that understanding might lead to the development of better drugs (and drugs with fewer side effects) for the treatment of clinical disorders (Sokol and Valtin, 1982).

The development of open-heart surgery is but one of many examples of the value of using laboratory animals. Working with cats and dogs, Gibbon built the forerunner of the present-day heart-lung machine (Deaton, 1974), which makes open-heart surgery possible. His research in the early 1930s included clamping off more and more of an animal's vasculature and detouring its blood through the heart-lung machine. The machine was further improved by the incorporation of a roller pump developed by DeBakey (DeBakey and Henly, 1961), which allowed the entire circulation to be shunted through the machine, which added oxygen to the animal's blood. The pump was first used and perfected in the animal laboratory and is now a standard, essential component of the heart-lung machine. As a result of these developments, more than 80 percent of infants born with congenital cardiac abnormalities now can be treated surgically and can lead normal lives.

Replacement of heart valves and segments of large arteries in the treatment of valvular heart disease was made feasible by dog studies done in the late 1940s and early 1950s (Gay, 1984). Before diseased heart valves could be replaced in patients, scientists had to study their design and use in animals. As with so many other drugs and operations, physicians and surgeons would not consider applying them to patients until they had proved safe and effective in animals, nor would the public accept them until their safety was proved. Each decade since then has seen improvements in the design, installation, and performance of these valves and other prosthetic devices. Because the ideal valve has not yet been developed, research is still in progress in many laboratories to further improve its capacities.

• Nervous System

The human brain is a structure of extraordinary complexity. Each of its 200 billion neurons (nerve cells) makes a few thousand to several hundred thousand connections with other neurons, muscles, or glands. Neurons use large amounts of metabolic energy to carry out a host of functions: the generation and conduction of impulses; the synthesis, transport, secretion, and uptake of transmitters; and the modification of structure and synaptic efficacy in response to activity and environmental perturbations (Kandel and Schwartz, 1985).

Many basic aspects of neuronal development can be studied in cell and tissue cultures, in brain slices, and in simple invertebrate neuronal systems. Computer simulations and noninvasive human studies can also provide important data on fundamental mechanisms of learning and memory. Yet there is no adequate substitute for animal studies in attempts to understand the complex behavioral and cognitive functions of the brain in health and disease.

Movement and Function

Our understanding of the nervous system and approaches to rational therapy of its disorders could not have come about without animal studies initiated by the physiologist Charles Sherrington (Eccles and Gibson, 1979). His studies on reflex mechanisms of the spinal cord in cats were continued by Eccles (1957), who described how excitatory and inhibitory processes work in the central nervous system. Today, neurosurgeons can remove some brain tumors with minimal damage to the motor system in part because scientists such as Sherrington discovered that localized electrical stimulation of the exposed brain of the dog could elicit discrete movements of the limbs.

Neurologists and neurosurgeons now examine electrical signals from the brain to diagnose and treat epilepsy, study levels of consciousness, localize brain tumors, diagnose multiple sclerosis, and study learning disabilities in children. Moreover, the applications of such essential tools for diagnosis and therapy as computed axial tomographic (CAT) scans and magnetic resonance imaging (MRI) were developed with research animals (Kandel and Schwartz, 1985).

The study of the nervous system and behavior is one of the major frontiers of modern science. A good deal is known about the anatomy and physiology of the brain and nervous system, but much remains to be learned about it as an organized assemblage of neurons and about how it is affected by environmental stimulation. The following examples provide an idea of how animals are used in studies of such subjects.

Postnatal Development of the Visual Cortex and the Influence of Environment

Hubel and Wiesel shared the Nobel Prize in 1981 for their studies of vision in cats and monkeys, including the development of visual functions in young animals (Barlow, 1982). The visual cortex of monkeys is not fully developed at birth; nerve cells are still growing and making connections with other nerve cells. In this process, normal development depends on visual stimulation during a critical period in early postnatal life.

As in humans, each eye of a monkey sees a slightly different view of the same object; normal binocular vision gives the impression of depth. If early in postnatal life one eye is occluded, the nerve cells for that eye in the visual cortex do not develop normally. Most of the nerve cells become responsive only to the open eye, as shown in recordings from cells of the visual cortex of anesthetized animals. In normal development, the visual cortex consists of alternating bands of reactive neurons from the right and left eyes; but in a monkey with an occluded eye, the regular alternation is weakened, and most neurons react only to the normal eye. These anatomical and physiological changes are the basis of blindness in the occluded eye.

Children with congenital cataracts or clouding of the ocular media for other reasons demonstrate a similar dependence of human vision on visual stimulation. Testing after restoration of normal vision has shown that the acuity of the previously occluded eye is reduced; the earlier in life the eye was occluded, the greater the degree of deficit. Animal experiments have also shown that correction of strabismus (squint) by surgery should be performed early in, or certainly before the end of, the critical period of eye-brain development to ensure normal vision (Wiesel, 1982).

The close correlation between the effects of visual deprivation observed in animals and the effects observed in the clinic suggests that they are based on similar physiological mechanisms. This correlation has been helpful in developing appropriate measures of prevention and treatment of neural eye disorders.

Another subject of behavioral research is memory. An estimated 5 percent of people over the age of 65 have severe limitations or even failures of memory and cognition; another 10 percent of the people over 65 have mild to moderate cognitive problems (Coyle et al., 1985). Specific conditions, such as Korsakoff's syndrome and Alzheimer's disease, affect mental functions and can cause extreme memory loss. Research on animals is improving the understanding of the mechanisms of such losses. In turn, this increased understanding has led to the discovery of some drugs that show promise of counteracting the losses. Most of the knowledge about the neurotransmitters involved in these diseases has also been derived from studies of the brains and nervous systems of animals.

Primates are phylogenetically closer to humans than are other mammals. Their behavioral capabilities are in keeping with the greater development and complexity of their brains. Primates also have age-related decrements in memory function. Generally, memory impairment with advancing age first appears as a failure of immediate memory, the recall of events that have just occurred. Transmitter chemicals of the α-adrenergic class, like clonidine, were first found to improve memory performance in macaques and aged rodents. Clonidine has now also proved effective in improving the memory of patients with Korsakoff's syndrome. Those findings suggest a new approach to the treatment of patients with memory disorders, and they have provided a new option for clinical trials with patients suffering from Alzheimer's disease (Arnsten and Goldman-Rakic, 1985).

Pain is a common symptom of disease in humans and animals. It is important that medical science develop more effective methods of pain management than are now available. Much pharmacological research has focused on the production of drugs with potent analgesic properties, and much research on pain—particularly that concerned with analgesics, acupuncture efficacy, hypnosis, and so on—has been carried out on human subjects for over a century. Research using animals is necessary, however, if unsolved problems are to be adequately addressed.

Although many experiments that study pain must involve pain for the animal, researchers have developed methods that are as humane as possible within the context of the experiment. For example, the slightest reflex movement of the tail of a rat or mouse is objective evidence that a noxious stimulus applied to the skin of the tail has attained threshold intensity. Reflex behavior, such as the tail-flick, is a useful index of the comparative effectiveness of analgesics, as well as of the effects of manipulating chemical messengers in the central pain pathways (Willis, 1985).

The understanding of intrinsic brain mechanisms of pain and its modification will require the use of modern techniques for cell marking and pathway tracing, immunocytochemical and microphysiological methods, and sophisticated behavioral studies. Paradoxically, many investigations of pain can be explored in anesthetized animals. Thanks to psychophysical studies in humans that were replicated in animals, neuroscientists have been able to trace the nerve fibers from skin, muscle, and internal organs that are specific carriers of ''pain signals.'' With such a powerful handle on the input end of the pain system, the passage and transformation of pain signals can be explored in complex neuronal organizations in anesthetized animals. It is also possible to study the central systems that control the passage of pain signals to higher levels of the central nervous system. Finally, isolation and identification of the transmitters, structure, and other components of the neurochemical machinery of the brain involved in pain perception and its modification can be elucidated (Willis, 1985).

Increasing recognition that behavioral factors play a significant role in many current health problems—for example, drugs and alcohol abuse, eating disorders, effects of stress, cardiovascular disease, and mental and psychiatric ailments—has led to the development of animal models for experimental and biological analysis as part of the emerging field of behavioral medicine (Hamburg et al., 1982).

• Other Benefits for Humans

The preceding examples provide a sampling of the contributions that research using animals has made to the improvement of human health and the acquisition of knowledge. Many others could be cited—for example, the development of medicinals such as the sulfonamides (Hubbard, 1976); the development of life-support systems for premature infants (Coalson et al., 1982; deLemos et al., 1985; Escobedo et al., 1982); and the increase in understanding of learning (Miller, 1985; Pavlov, 1927; Skinner, 1938; Thorndike, 1898), nonlinguistic communication (Gardner and Gardner, 1969; Romski et al., 1984), drug abuse (Deneau et al., 1969; National Institute of Drug Abuse, 1984; Seevers, 1968), and nervous system regeneration. Many examples of such benefits are also chronicled in publications such as those by Gay (1986), Leader and Stark (1987), and Paton (1984).

• Benefits for Animals

One might have the impression that animal research is conducted only with the aim of alleviating human suffering. The conduct of extensive research in veterinary schools and other institutions indicates that that is not the case. Most research on domestic farm animals is undertaken to increase the productivity and quality of animal products. Research is also undertaken to reduce the suffering and increase the overall well-being of animals, particularly companion animals. Examples include current research on Potomac fever in horses, the development of ivermectin to eradicate parasitic diseases in a variety of animals, and the development of vaccines for feline leukemia virus and canine parvovirus.

Research aimed at human illnesses has also had immeasurable benefits for animals. A host of immunizations and antibiotics have proven applicable to the therapy of animal diseases (Paton, 1984). Kidney transplantation, cardiovascular treatments, chemotherapeutics, and narcotics are widely applicable, as are the insights gained from genetic research (Gorman, 1988).

One example of the benefits of biomedical research for animals can be found in the propagation of endangered species. The ability to transfer embryos, eliminate parasitism, treat illnesses, and use anesthetic advances has improved the health and survival of many species. The knowledge gained from genetic studies has allowed appropriate management of species that are endangered or have disappeared in the wild. For example, the ability to identify the sex of birds has been essential in the management of the whooping crane and the California condor. Research into obstacles to successful breeding in captivity has markedly reduced the need for importation of many species, especially monkeys. For example, among nonhuman primate species used in research, there were 7,908 births in 1984 in the United States, compared with 2,198 in 1973 (Johnsen and Whitehair, 1986).

Animal research has resulted in enormous benefits for humans and animals. The searching and systematic methods of scientific inquiry have greatly reduced the incidence of human disease and have substantially increased life expectancy. Those results have come largely through experimental methods based in part on the use of animals, as illustrated by the many examples cited in this chapter.

At the same time, much obviously remains to be learned. Further studies in such areas as cancer, heart disease, diabetes, AIDS, dementias, and the development of vaccines and chemotherapeutic agents will continue to require the use of animals.

• Cite this Page National Research Council (US) and Institute of Medicine (US) Committee on the Use of Laboratory Animals in Biomedical and Behavioral Research. Use of Laboratory Animals in Biomedical and Behavioral Research. Washington (DC): National Academies Press (US); 1988. 3, Benefits Derived from the Use of Animals.
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Environmental Factor

Your online source for niehs news, niehs shares research to identify chemicals’ effects on development.

At two international meetings, NIEHS scientists addressed challenge of screening chemicals for adverse effects on developing nervous system.

By Catherine Sprankle

NIEHS scientists met with researchers from around the world at two April meetings focused on improving developmental neurotoxicity (DNT) testing, which is the process of testing chemicals to determine whether they may interfere with nervous system development in humans.

The Fifth International Conference on Developmental Neurotoxicity Testing (DNT5) was held April 7-10 in Konstanz, Germany. Following the DNT5 meeting, a group of experts working to advance such testing in vitro met, thanks to support from the Organisation for Economic Co-operation and Development (OECD).

Helena Hogberg, Ph.D., attended both meetings and served on the organizing committee for DNT5. Environmental Factor spoke with Hogberg about the meetings in the context of NIEHS activities related to DNT.

EF : What were the goals of these meetings, and who attended?

Hogberg : Both meetings were focused on new approach methodologies (NAMs) to replace animal experiments for testing chemicals that might cause DNT. Specifically, they focused on what needs to be done to advance NAMs so they can be used for regulatory testing of chemicals, pesticides, and consumer products.

About 80 people, representing academia, regulatory agencies, and industry from all over the world, attended the public DNT5 meeting. The OECD meeting was smaller with the goal of identifying action items from DNT5 for the expert group. We also discussed planned revisions to last year’s OECD guidance document “ Initial Recommendations on Evaluation of Data from the Developmental Neurotoxicity (DNT) In-Vitro Battery .”

EF : Why is DNT of interest to NIEHS, and what are our activities in that area?

Hogberg : There is concern that chemical exposure contributes to neurodevelopmental disorders. However, few chemicals have been tested for DNT using traditional animal tests because these tests are very resource-intensive in cost, time, and number of animals. They also provide limited information on how chemicals induce DNT at the cellular level. Applying NAMs based on human biology to DNT testing would be more efficient and support a better understanding of how chemicals cause DNT in humans.

DNT is a complex endpoint, and there are a lot of ways a chemical can induce it. The OECD guidance document I mentioned identifies 17 different assays, which are types of lab tests, that could be used in combination to identify chemicals that could cause DNT. Data from multiple assays are needed to inform on a chemical’s hazard potential, and more testing of different kinds of chemicals is needed to know how to best combine these assays. The NIEHS Division of Translational Toxicology (DTT) is doing this testing, in coordination with the European Food Safety Authority and the U.S. Environmental Protection Agency.

EF : What did you learn at these meetings that might affect NIEHS activities going forward?

Hogberg : Most of the assays described in the guidance document need transferability studies done to show that labs — other than the labs that developed the assays — can perform them and get similar results. A lot of the conversations at these meetings focused on who might conduct these studies and how they might be done.

Here at NIEHS, the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) has experience coordinating transferability studies. NICEATM also interacts regularly with U.S. federal agencies that would be interested in participating in or sponsoring such studies.

EF : Tell us about some of the NIEHS work presented at DNT5.

Hogberg : I gave a talk about DTT’s use of NAMs to screen chemicals and prioritize them for future DNT testing, as well as the development of integrated approaches to testing and assessment case studies for regulatory application. Jui-Hua Hsieh described how adding data from the zebrafish embryo behavior assay can complement data from the DNT In-Vitro Battery. Two posters presented by Jason Stanko and Chris McPherson described ongoing DNT work within the DTT. NICEATM also presented two posters, one describing a chemical set proposed for use in the transferability studies, and the other describing an approach to put in vitro chemical activity data into a human exposure context.

(Catherine Sprankle is a communications specialist for Inotiv, the contractor supporting NICEATM.)

International meetings advance non-animal testing methods

Approaches to replace animal testing were also considered at last month’s annual meeting of the OECD Working Group of National Coordinators (WNT). NICEATM Director Nicole Kleinstreuer, Ph.D., represented the United States at that meeting, along with Charles Kovatch of the U.S. Environmental Protection Agency.

The WNT coordinates development of test guidelines that are used by government, industry, and independent laboratories of the 38 OECD member countries to assess chemical safety. Some methods the WNT considered at its April 16-19 meeting could reduce animal use for eye irritation, skin sensitization, and ecotoxicity testing.

The WNT is also considering changing procedures that would streamline consideration and acceptance of non-animal testing approaches like those discussed at the DNT5 meeting. Kleinstreuer attended a workshop following the WNT meeting that will consider changes to OECD’s " Guidance Document on the Validation and International Acceptance of New or Updated Test Methods for Hazard Assessment ."

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