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J. Donald Capra    immunologist
"One word which summarizes my creative process is 'daring'. I am not afraid to be wrong."
How were you originally motivated to become an immunologist?

In the late 1950s, when I was in medical school, two things struck me about immunology that may not have been obvious to all:

a) Vaccination (teatanus, whooping cough, diptheria, small pox, polio) had essentially eradicated various diseases, while treatments of diseases were making little headway. I wanted to be associated with a "prevention" approach rather than a "treatment" approach to medicine.

b) At this time, immunologists were in a few departments, but it was clear to me that soon these physicians would branch into all areas of medicine. I loved medicine and I wanted to keep my options open, so I chose immunology, knowing I could practice in medicine, pediatrics, pathology, microbiology, biochemestry, or many other areas.

Therefore, I chose the field of immunology because I wanted to focus on the preventative side of medicine addressing problems before an illness stuck. Immunology also exposed me to numerous disciplines within the medical field.

What can you share about your creative process?

One word which summarizes my creative process is "daring." I am not afraid to be wrong. Most successful scientists differ from people in other walks of life because in our profession, we are often wrong. In science, the definition of the "creative process" is thinking of an idea, testing it, and finding that your hypothesis is wrong most of the time. Trial and error is a daily part of science. However, if one equates being wrong to failing, his or her science will be dull and mundane; one must be daring enough to explore a new path, but confident enough to be wrong. We often learn as much from our mistakes as from our successes. I pride myself in having been wrong often, but right enough of the time to make my life very exciting and fulfilling.

What ideas do you have for a future colony on Mars?

My ideas about a future Mars colony can be divided into two categories: Preparations and Experiments. The scientific community would gain useful and valuable information from both the groundwork prior to a Mars colony as well as the actual experiments performed on the planet.

Preparations and Precautions:

1. Prior to colonizing on Mars, the plan should establish an artificial environment, similar to the Biosphere 2 experiment in Arizona. What kind of controlled environments would be required to grow plants and recycle water? Can one mimic Earth's atmosphere and humidity?

2. Screen the space-shuttle/equipment/personnel for environmental pathogens (e.g., bacterial, viral, fungal, retroviruses) before take-off to decrease exposure to known organisms upon arrival;

3. Mission should include an immunologist among the early colony members in order to assist with infectious outbreaks and to devise vaccines for previously unknown organisms;

4. Consider testing all initial colony members for known disease susceptibility genes due to high degree of required "inbreeding" to perpetuate the species;

5. Consider issues of fertility testing and in-vitro fertilization.

6. Discuss and determine most important medications, hospital equipment, and health personnel needed for the mission and specify the ideal number and ages of colonists to send to Mars.

7. There is a T cell suppression (or at least a decrease in peripheral blood T cells) with weightlessness. The months or years required to get to Mars could leave travelers immunosuppressed and susceptible to endogenous infections. This consideration must be addressed and precautions taken before embarking on a Mars colonization effort.

8. Harold Muchmore, the recently decreased member of the Infectious Diseases Section, studied colonists in Antarctica. Interestingly, these people developed upper respiratory infections that swept through the colony on a periodic basis throughout the winter. Apparently, some viruses are carried by the colonists reactivate and become infectious again in a carrier. They are then spread through contact. While our friends on Mars are likely to be spared the yearly bout of influenza, they are almost certain to develop infections with other viruses which will make their stay there similar to our experience here on Earth.

Experiments: What can we learn from Mars?

1. There is much less sunlight on Mars, so sunburn will be much more difficult and the frequency of melanoma should be lower. However, the lack of an ozone layer could actually raise the rate. Determining whether immune suppression is important in melanoma is one undertaking which could be learned from Mars. Fortunately, a spacesuit can easily protect the user against UV radiation.

2. Mars' gravity must be different from ours: how will this affect maintaining muscle tone or even internal organ functions of the human colonists?

3. What are the implications of introducing E. coli and other organisms carried by the colonists in Mars? Will they take root but develop in different ways?

4. The allergens on Mars should be interesting. Dust organics and inorganics might have chemical compositions not found on Earth and be new antigens for our immune systems. Colonists might need an antihistamine and nasal steroids. If there ever was life on Mars, then it is very likely that allergens never seen on Earth would be prevalent and poised to cause problems.

5. If there is life on Mars, are there pathogens for which we have no natural immunity? Previously unencountered pathogens had a major impact during colonization of the world; the colonists introduced germs that decimated most native peoples, and occasionally the reverse occurred. Are we prepared to address unknown pathogens? Are we capable of using known methods to combat unknown germs?

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