Why do some people get sick and others stay healthy? Certainly genetics plays a large role. But is that all? What about the social determinants of health? Why does a child in rural Sub-Saharan Africa die from diarrhea, while a child in the rural United States doesn’t? Next on my reading list is The Upstream Doctors: Medical Innovators Track Sickness to its Source, by Rishi Manchanda. Read Paul Farmer’s review.
From my medical school graduation procession at the University of Pennsylvania, 2008
How is human engagement with biodiversity affecting emerging infectious diseases? Dr. Aaron Bernstein‘s fascinating lecture: Part 1 and Part 2
Lets go back to the basics of chemistry. Delta G is change in energy (or “Gibbs free energy”). If ΔG is positive, you need to add energy to make a reaction happen. Look at this flowering plant. Through photosynthesis, this plant is converting energy from the sun, and carbon dioxide, into chemical energy that the plant can use (in the form of carbohydrates). This process is “positive ΔG”– sunlight is needed for photosynthesis to occur.
Say you walk into your office’s break room at 4:30 PM and find some cake sitting on the table. This cake is full of fat and sugar, and if you eat it, your body will digest it. Through biochemical reactions, the cake’s energy will be stored as fat (adipose tissue). Adipose provides an enormous storage capacity of energy in the form of triglycerides. If you eat cake frequently, you will be in a stage of positive ΔG, and you will gain weight. Eventually, you may develop diabetes, like 26 million Americans.
But if you exercise, you burn that stored energy. Negative ΔG is good for our bodies!
Now think about the combustion of fossil fuels and the release of greenhouse gasses (negative ΔG). Human activities are filling up Earth’s atmosphere with carbon dioxide, leading to global warming.
It all comes down to ΔG.
It was 2005. I was between my first and second years of medical school, volunteering in a hospital in rural Guatemala. A young boy came in, breathing rapidly, in obvious respiratory distress. The doctors I was working with tried to transfer him to a larger hospital several hours away. Unfortunately, he died during the ambulance ride there. I will never forget the gut-wrenching feeling in my stomach when I learned of his death.
Many deaths in “resource-limited” (i.e. poor) areas of the world occur because of weak health systems. Well functioning laboratories are rarely available in such settings, and “point-of-care” diagnostic technology offers the promise of rapid diagnosis for infectious diseases. Dr. Ilesh Jani from Mozambique, and Dr. Trevor Peter have written an article in today’s New England Journal of Medicine, entitled “How Point-of-Care Testing Could Drive Innovation in Global Health. The main challenge from my perspective is one of implementation. How can these diagnostics be scaled up in the places which need them the most (the places with the least human resources and infrastructure)? How can we demonstrate impact? It’s time to advance the “science of delivery.” Learn more on the GHDonline website.
With colleagues at Hospitalito Atitlan, Guatemala, 2005
Atlanta isn’t known for being a city where public transportation is commonly used, like New York City. However, Atlanta’s MARTA actually offers reliable, economical service. Several train lines, and a number of bus routes, criss-cross the city. In order to use public transportation efficiently, however, I’ve learned several lessons.
First, I had to spend time learning the bus routes. That meant studying the maps and timetables on MARTA’s website. In particular, I needed to learn exactly what time the bus is expected to arrive, and plan accordingly. Second, I had to figure out how to refill my “Breeze Card” online, so I wouldn’t be caught without a bus fare. That wasn’t too hard. Finally, I had to learn to plan ahead, in terms of clothes and weather. It’s always best to be prepared, so I’m not stranded at the bus stop without an umbrella during a thunderstorm.
As Al Gore has said, we treat atmosphere an open sewer, dumping 90 million tons of global warming pollution each day into the atmosphere. It may be more convenient to hop in a car and drive to work, but walking, and taking public transportation, is worth it. It’s hard to change human behavior, but it’s possible.
Henry Molaison was born in 1926 in Connecticut, and became one of the most famous patients in the history of medicine. At the age of 7, Molaison was the victim of a bicycle accident, and as a result had severe traumatic brain injury, with intractable epileptic seizures. In 1953, he underwent brain surgery, and had his bilateral medial temporal lobes removed. As a result of the surgery, his epilepsy was cured, but he had severe anterograde amnesia. He could not remember any new experiences. For example, he was unable to recognize hospital staff he had just met; otherwise, he was normal. Researchers studying HM were therefore able to establish the link between the medial temporal lobes, hippocampus, and episodic memory.
Episodic memory (also known as “autographical memory”) is memory for prior events in our lives. It’s how we re-experience events in vivid detail, again and again. It’s not just “what” happened, but also “where” and “when” it happened. (Alzheimers disease injures the hippocampus, causing memory loss akin to HM’s).
Why bring up H.M.? I’m currently reading The New Digital Age: Reshaping the Future of People, Nations and Business, by Google CEO Eric Schmidt and Jared Cohen. The book focuses on dramatic changes in information technology and connectivity. The book has made me recall the story of Henry Molaison. What if Molaison had been born in 2013, wore “Google Glass,” and stored his experiences in the cloud?
With the rapid changes in technology and connectivity, how can we develop our own “External Hippocampi,” and exponentially improve our learning and retention?