Biomedical Research

Biomedical Research

• Definition• Study of the

processes of life; the prevention and treatment of disease; and the genetic lifestyle and environmentmental factors related to disease and health

Types of biomedical research

BASIC

APPLIED

CLINICAL

BASIC

• Research conducted to increase fundamental knowledge

• Not directed toward solving

any particular problem

Basic

• Focuses on understanding normal life processes and disease– Molecular– Cellular

BASIC

• Provides building blocks for other types of research –is the first stage

• Writing a research paper on a particular disease would be an example

APPLIED

Directed toward specific objectives, such as the development of a new drug, treatment or surgical procedure

Applied

• Conducted with:– Animals (primarily)– Tissue cultures– Computer models– And humans

Clinical• Usually last stage of

medical research• Used when other forms of

research have taken place – most clinical trials involve humans

• Used to treat potential drugs and treatments in humans

• Builds on what is done in basic and applied stages

CLINICAL

• Takes place :– Hospital – Clinical setting for

health care– Applies directly to:

• Prevention, diagnosis, or treatment of a specific disease in the individual or group of individuals or the rehabilation of the individual

Clinical

• Broad variety of activities and areas of study– Human clinical trials (Research study for a

new medicine or treatment)– Psychosocial and behavioral research– Disease control research (Research study for

a particular disease)

Clinical

• Edward Jenner – Inoculated son with cow pox– 6 weeks later- exposed son to smallpox– Son was resistant– “immunization”

Biomedical Research Methods

• 1. Chemical, mechanical, mathematical, and computer simulations

• 2. In vitro tests

• 3. Non-humans animal models

• 4. Human Studies

• 5. Epidemiological Studies

Strengths of Chemical, Mechanical, Mathematical, and Computer Simulations

• 1. Computers increase speed and efficiency with which data is used and processed

• 2.Pattern recognition programs enable scientists to compare characteristics of one compound to another

Strengths of Chemical, Mechanical, Mathematical, and Computer Simulations

• 3. Can extrapolate data• A. From high – dose

experimental exposure to low-dose

• B. From animals to humans

4. Reduces the numbers of animals needed for research

Using Computers as a Research Method

Limitations of Chemical, Mechanical, Mathematical, and Computer Simulations

• Limitations

• 1. Cannot replace laboratory testing

• 2. Computers do not generate data – they only process existing data

• 3. Computers equipment and software is expensive

In Vitro TestsIn Vitro – “in glass”

Takes place in an artificial environment (Laboratory)

Strengths of In Vitro Studies

• 1. Allow scientists to study a single effect in isolation

• 2. Less expensive, less time, more accurate, and easier to control than in vivo (whole animal) systems

Strengths of In Vitro Studies

• 3. More precise results as a result of ability to control temperature, acidity, oxygen levels and environmental conditions

• 4. Critical to the study of viruses which grow only in living cells

Limitations of In Vitro Studies

• 1. The time from chemcical exposure to toxic effect too complicated to be duplicated in vitro

• (Cancer as a multi-step process for example)

• 2. Cells grown in cultures are not exposed to other functions taking place in a living organism

Limitations of In Vitro Studies

• 3. Cells do not metabolize toxins in a culture the same way as in the whole body

• 4. Difficult to maintain differentiated cells in a culture

• 5. Cultures cannot tell us how a substance affects a complex system

Non-Human Animal Models

• Animals provide the best known surrogate for humans in the lab

• Similarities between animals and humans outweigh differences

Strengths of Animal Models

• 1.Ethical alternative to using humans

• 2.Animals provide a whole, integrated complex biological system

• 3. Animals share the same structures (cells, tissues, organs, and systems) as humans and function in much the same way

Strengths of Animal Models

• 4. Scientists can design experiments where they can control for more variables than with humans

Limitations of Animal Models

• 1. Animals are NOT humans so results must be extrapolated

• 2. Research animals are expensive to purchase, house, feed and provide with veterinary care

• 3. Use of animals are governed by federal regulations

Human Studies• Most often used in

developing prescription drugs

• Looking for the answers to the questions below:

• A. Is the drug biologically active in humans?

• B. Is the drug safe in humans?

Human Studies – Three Major Phases of Clinical Trials

• Phase I• 1. Determine drug’s

interaction with the human system

• 2. Involves a small number of healthy volunteers

• 3. Takes one year

Human Studies – Three Major Phases of Clinical Trials

• Phase II• 1. Controlled tests that help

determine a drug’s effectiveness on certain organs, etc.

• 2. 100-300 volunteer patients

• 3. Simultaneous animal and human tests to assess safety

• 4. Takes 4 years

Human Studies – Three Major Phases of Clinical Trials

• Phase III• Done to confirm

results of earlier tests and identify any adverse reactions

• 2. Clinical testing extensive – Need 1000 – 3000 volunteer patients

• 3. Takes 3 years

After Clinical Trails

• Firm files New Drug Application (NDA) with FDA

• Takes 2 ½ years to complete

• In all – 12 years from initiation of studies to FDA approval

• Each new medicine approved costs millions of dollars

Human Clinical Trials

Strengths

• Have actual human data (how it affect human)

Limitations

• 1. Ethical and moral considerations of using human volunteers as test subjects

• 2. Numerous variables, which may affect test data, are introduced when humans are used

To Be Continued ….