Unit J: Biomedical Research

BT10.01:Discuss biomedical research. Biomedical research A.Definition – the area of science devoted to the study of the processes of life; the prevention and treatment of disease; and the genetic, lifestyle and environmental factors related to disease and health

B.Basic research 1.Research conducted to increase fundamental knowledge and understanding of the physical, chemical and functional mechanisms of life processes and disease 2.Not directed toward solving any particular problem in humans or animals 3.Provides building blocks upon which other types of research are based.

Basic research is often the hardest type of research to define because it is an area of science seeking to answer fundamental questions that are not necessarily focused on any specific disease or disorder. In most cases basic scientists are seeking to add to the primary storehouse of knowledge by explaining how processes in living organisms develop and function.

*****If we don’t know how a life process functions normally, we won’t know how to recognize and treat it when it functions abnormally. Ex: a scientist conducting basic research in the molecular structure of a virus BASIC HEART FACTS – ACTIVITY HEART THROBS

C.Applied research 1.Directed toward specific objectives – for example, development of new drug, treatment, or surgical procedure. It involves the application of existing knowledge, much of which is obtained through basic research, to a specific biomedical problem 2.Conducted with animals, non-animal methods (computer models or tissue cultures), and humans Ex: synthesis of new drugs to prevent Alzheimer’s

D.Clinical research 1. Used when other forms of research have taken place 2. Used to test potential drugs and treatments in humans 3. Builds on what is done in basic and applied stage 4. Broad variety of activities and areas of study a. Human clinical trials b. Psychosocial and behavioral research c. Disease control research

BT10.02:Outline biomedical research methods. A.Chemical, mechanical, mathematical, and computer simulations 1.Strengths of models – increase the speed and efficiency with which data can be studied and processed (may reduce the number of animals required for research)

2.Limitations of models – cannot replace laboratory testing. Computers do not “generate” data, they only “process” what has been entered. Rely on existing data. Sophisticated computer equipments and software are sometimes prohibitively expensive

B.In vitro tests “In glass” – takes place in an artificial environment (ex: laboratory container) 1.Strengths of in vitro studies – Allow scientists to study a single effect of a substance in isolation without the interference from other biological phenomena such as hormones, enzymes, & immune responses. Can be less expensive, require less time, and be more accurate & readily controlled than in vivo. Yield more precise results.

2.Limitations of in vitro studies Cells grown in a culture are not exposed to other functions taking place in a living organism (ex: no pumping of blood & interstitial fluid, etc.) It is also difficult to maintain differentiated cells in a culture, since the cells tend to become unspecialized after a short time, losing the characteristics of the organ or tissue from which they were taken Ex: Blood pressure medications cannot be tested without the presence of blood pressure.

C.Non-human models 1. Animals provide the best known surrogate for humans in the lab. Provide a whole, complex living system that can interact and react to stimuli much as humans do. 2. Similarities between animals and humans outweigh differences

3. Strengths of animal models – provide an ethical alternative to the use of humans in experimental studies in the search for treatment, cures & prevention of diseases & disabilities.

4. Limitations of animal models – because animals are not identical to humans, the results from experimental animal studies must be extrapolated to humans. Research animals are also expensive to purchase, house, feed and provide with veterinary care. ITCHY SLEEP DISEASE

ITCHY SLEEP 1. What was the same about the groups? –All showed symptoms, all infected with a germ, all mice, same # in each group 2. What was the purpose of giving different medicines? –To see what worked 3. Why didn’t mice in the control group receive any medicine? –Scientist needed them for comparison to see if they would have gotten better on their own

4. How did the scientists know their mice got better? –Stopped itching 5. What is the importance of observation in the research process? Observation –Watch for side effects –Watch control group –How quick is the recovery rate

Scientific Method 1.What causes the itchy sleep disease? 2.Medicine will improve symptoms? 3.Give sample of medication 4.Data Observers-observed & recorded 5.Red group was cured 6.Repeat experiment 7.Make reports

D.Human Studies (Clinical Studies) 1. Most often used in developing prescription drugs (to determine if the drug is biologically active in humans and is it safe for humans) 2. Three major phases of clinical trials (begin after a pharmaceutical firm files an Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA). The IND shows the results of laboratory testing and explains how the drug is made.

PHASE I – researchers determine a drug’s interaction with the human system, including how it is absorbed, distributed, metabolized and excreted, and the likely duration of its therapeutic effect. This phase involves a small number of healthy volunteers and takes approximately one year (healthy volunteers will not exhibit any effects of therapy)

PHASE II Use controlled tests that help determine a drug’s effectiveness. Involve 100 – 300 volunteer patients. Simultaneous animal and human tests are also conducted at this stage as researchers continue to assess the safety of the drug. Takes approximately two years

PHASE III Conducted to confirm the results of earlier tests and further identify any adverse reactions. Clinical testing is extensive, involving 1,000 – 3,000 volunteer patients in medical clinics and hospitals. Takes approximately three years

3.After clinical trials are completed, firms file a New Drug Application (NDA) with the FDA. Provides info. on: 1. Drug structure 2. pre-clinical animal & other laboratory study results 3. Rationale & purpose of drug therapy 4. all human clinical testing results 5. drug formulation & production details, 6. the company’s proposed labeling. Takes approximately 2 ½ years to complete

Currently it takes approximately 12 years from initiation of animal and other laboratory studies through all phases of clinical trials and submission of data to the FDA for approval

4. Strengths of clinical trials –provide actual human data on the efficacy and safety of promising new drugs

5. Limitations of clinical trials Ethical & moral considerations limit the extent to which human volunteers can used as test subjects for a potential new drug. Require extensive pre-clinical testing before they can be conducted Numerous variables may affect the test data (genetic makeup, exposure to other chemicals, disease history, etc.)

E.Epidemiological Studies Epidemiology is the study of disease incidence and its distribution in a population

1.Experimental epidemiology – is the human equivalent of animal testing – providing or withholding a substance to determine its toxic or beneficial effects

2.Descriptive epidemiology – analyzes data on the distribution and extent of health problems or other conditions in various populations, trying to find correlations among characteristics such as diet, air quality and occupation. Frequently made between countries or smaller geographic regions.

3.Observational epidemiology – uses data derived from individuals or small groups that is evaluated statistically to determine the strength of association between a particular variable and disease.

4.Information gathering occurs after the fact (as in the case of cancer, can occur many years after exposure) 5.They do not demonstrate a direct cause and effect, but instead show a statistically significant association between exposure and disease

6.Strengths of epidemiological studies Offer scientists a direct opportunity to study, the effects in humans exposed to chemicals and disease-causing organisms. Useful in identifying patterns in disease or injury distribution. Patterns may be traced to causative factors.

7.Limitations of epidemiological studies Major disadvantage is that considerable human exposure can take place before a toxic effect is detectable, (particularly in the case of diseases like cancer that take many years to develop.) Difficult to demonstrate a direct cause-and-effect relationship between a specific exposure and disease. Difficulty in identifying control groups or “unexposed” populations who can provide the data necessary for comparison. Can be quite expensive to conduct. cholera epidemic activity & mystery disease

Did you or Will You Ever? 1. Drink tap water? 2. Have a dog? 3. Have a cat? 4. Fertilize your lawn? 5. Drink milk? 6. Eat a hamburger? 7. Call Poison Control? 8. Receive a vaccination? 9. Take an antibiotic for an infection such as strep throat or an ear infection? 10. Eat eggs? 11. Observe an endangered species at a zoo? 12. Eat bacon or NC barbecue? 13. See a guide dog? 14. Have a relative over the age of 45?

BT10.03: Analyze the benefits of biomedical research A.Contributions to human health – the public’s awareness of healthy lifestyle choices has helped reduce mortality rates and has become the best medicine in preventing needless disease and disabilities. *Parents who have grown up without disease are complacent about children under 2 y.o. getting immunized.

1.Treatment for heart disease – heart-lung machine developed in 1953 (heart surgery was unthinkable before because it was impossible to see inside a beating heart)

2.Treatment for cancer- tx. to prevent the spread of cancer throughout the body. New drugs & research of gene therapy & understanding of the disease itself. Greater understanding could lead to modifications in our environment or lifestyle in order to reduce the risk of developing cancer.

3.Treatment for diabetes Third leading cause of death in the U.S. Describes either a deficiency of insulin or a decreased ability of the body to use insulin Human insulin is manufactured by bacteria (ecoli) using genetic engineering techniques. New blood sugar monitoring equipment uses very little blood to sample, so finger sticks are almost painless (new technology is working toward a “bloodless” monitoring system)

4.Bone marrow transplants Were introduced in the 1970’s as part of a tx. plan for patients diagnosed with leukemia. Method of destroying leukemia cells in bone marrow was developed before it is returned to the child. In time, the treated bone marrow begins to produce normal, healthy blood components. In the 1950’s nearly every child with leukemia died within 6 months of dx. Today survival rate is 75%

5. EARLY VACCINES 1794 Edward Jenner developed a vaccine against smallpox 1967 – WHO launched a global campaign, the success of which has led to the eradication of smallpox A cholera vaccine was developed by Louis Pasteur in the 19 th century.

6.Polio vaccine 5-10 cases annually in U.S. and ¼ million people worldwide Jonas Salk developed first vaccine Albert Sabin’s vaccine was administered orally and was made from live virus that was weakened or “attenuated”, but not killed. Could be dispensed easily on sugar cubes rather than by injection

Vaccine loses potency if not refrigerated. Difficult to deliver to Third World Countries.

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7.Chicken pox (Varicella) A vaccine became available in 1995 and is recommended for children 12 months or older who have not had the disease.

8.Hepatitis Hepatitis B vaccine became available in 1989 and infants are now routinely vaccinated against the disease. Since the virus can cause liver cancer, the hepatitis B vaccine is our first anti-cancer vaccine! Hepatitis A available since 1995 and is given to people traveling to developing countries.

9.Fluoride – many countries add to water to decrease tooth decay Less tooth decay in areas where the water naturally contains small amounts of fluoride.

10.Penicillin and other antibiotics Louis Pasteur uncovered the underlying principle of antibiotics. Alexander Fleming made the discovery now known as penicillin

Cyclosporine A primary cause of the failure of transplantation procedures is rejection of transplanted organs by the patient’s immune system. Cyclosporine treatment suppresses a patient’s immune system enough to accept transplanted organs.

Monoclonal Antibodies Cloning means to create a population of cells from a single ancestor cell Researchers are designing monoclonal antibodies that can target particular antigens on the surfaces of tumor cells. As a result, cancerous cells will be destroyed while other cells nearby will survive

B.AIDS research continues (acquired immunodeficiency syndrome) 1.Began in early 1980s 2.Caused by a virus 3.HIV infection progresses to AIDS when immune system is impaired and individual becomes susceptible to opportunistic infection

4.Animals important part of AIDS research 5.Anti-HIV drugs available 6.Number of possible vaccines have been developed and are being tested in humans 7.Common sense preventive measures best way to prevent AIDS

C. Multiple benefits for animal health Orthopedic surgery, pacemakers, vaccines, preventative medicine help prolong animals’ lives

Animal activists claim most advances in life span & health are attributed to improvements in nutrition, public health & sanitation. Objection of animal rights activists are behavioral tests are conducted merely to confirm obvious & do not produce meaningful responses. Vivisection (dissection of a live organism) – most animal rights activists opposed to it

95% of all animals used in medical research are rats, mice or other for rodents specifically bred for research. Most animals used in medical research are specifically bred for research. For each dog or cat used in research, 100 abandoned animals are killed in pounds and shelters.

Laws, Regulations and Guidelines governing animal research have improved the care & environment of lab animals. Copy and paste to internet address space.