Dr. Bortrum
11/01/2014
Blood, Zombies and a Walker
CHAPTER 50 Medical Potpourri
Back in December 1990, just a few weeks before my 63rd birthday, I had major internal bleeding and had a transfusion of 5 units of blood! In all likelihood, some or perhaps all of that donated blood would have been from younger individuals. Years later, as I approached my 69th birthday, I was a bit apprehensive. My mother and her three siblings had all died at the age of 69, not a good omen for my own longevity. Fortunately, as I approach my 87th birthday next month, I seem to have taken more after my father, who lived into his nineties. Or, rather than a genetic influence or relatively clean living, could the fact I'm still here have been partly due to that blood from younger individuals?
I bring this up after reading an article titled "Young Blood" by Stephen S. Hall in the September 12 issue of the journal Science. The article focuses on the work of Harvard stem cell scientist Amy Wager and others who have been working on blood transfusions in mice. The very surprising result of Wager and coworkers' research is that circulating the blood of young mice in old mice has resulted in some of the properties of aging in the senior citizen mice have been slowed, repaired, or even reversed! Weakened muscles got stronger, the architecture of the heart was rejuvenated, as was the vasculature of the brain. Needless to say, this work has generated a huge amount of interest and stimulated work on the possibility of either slowing the aging process or prolonging life in us humans.
Ideally, one would hope to find a compound or compounds in the young blood that promote the repair or slowing of maladies associated with aging. Wager and her colleagues have isolated one compound they call growth differentiation factor 11 (GDF11) that does appear to fit the bill. However, Wager is quick to point out that GDF11 does not explain everything and tries to damp down enthusiasm about a quick solution to addressing the aging problem. Harvard has patented GDF11 and some trials are in the planning stage such as transfusing young blood into Alzheimer's patients at Stanford.
These days the medical topic grabbing most of the headlines isn't aging, but Ebola, which has made its way to our metropolitan New York area with an Ebola patient in a New York City hospital and a very outspoken nurse who was quarantined briefly here in New Jersey. Among the concerns expressed in various media articles and reports is the possibility that Ebola might evolve to be communicated via the air rather than just by contact with bodily fluids. Not likely, say some experts. Another possibility is that the virus could evolve to be less virulent and toxic if it becomes controlled so well that it finds a dead end in humans. In other words, it could evolve to stop killing us, but just make us sick; however, not so sick that we stop it by dying.
Speaking of evolution and disturbing microbes, I was intrigued by an article by Carl Zimmer in the November issue of National Geographic appropriate for Halloween. The magazine's cover was a picture of a ladybug with the caption "Real Zombies, The Strange Science of the Living Dead". The article deals with how various parasites ranging from wasps to viruses have evolved to not only live on or in the host (sometimes devouring it) but also to affect the mind and actions of the host in a manner that enhances the parasite's reproduction.
The ladybug pictured on the cover had the misfortune to be stung by a type of wasp that leaves behind a single egg, which hatches and the larva feasts on the insides of the ladybug. Later, the larva emerges from inside the bug and spins a cocoon between the ladybug's legs. You would think the ladybug would do everything possible to rid itself of the cocoon but no, it just stands over the cocoon, protecting the developing wasp from predators. Birds or other predators that fancy ladybugs soon find that the ladybug excretes poison from its legs and the predators learn to avoid bugs with orange and black coverings. So the wasp in its cocoon benefits from the outward appearance of its host. The parasitic wasp has somehow affected the mind of the ladybug to actually protect the parasite residing on its belly. It will actually flap its wings to scare away any predator interested in the contents of the cocoon! Most ladybugs die soon after the wasp leaves its cocoon but a few actually survive the ordeal.
The Geographic article discusses other cases where the parasite affects the behavior of its host so as to maximize the parasite's survival and reproduction. For example, a virus, the Baculovirus, will infect a gypsy moth caterpillar. In the caterpillar, the virus dines on the caterpillar, which outwardly appears normal, chewing away at the leaves as usual. But the food it imbibes goes to making more viruses. When the viruses are ready to leave, the caterpillar starts climbing, not its normal behavior. The viruses also produce something that turns the caterpillar into "goo". When the caterpillar has climbed up the tree and turns to goo the viruses rain down below to infect new caterpillars. Scientists have actually found a gene the virus carries that spurs climbing and when they make viruses with that gene inactivated, sure enough, the caterpillars don't climb.
Back to the poor ladybug. It's been found that when the wasp injects that egg into the bug, it also injects a mix of various chemicals and stuff, including a virus that reproduces in the wasp's ovaries. There's the possibility that the virus is the agent that causes the ladybug to be so docile and protect the wasp. If so, is it the virus parasite controlling the wasp's behavior to maximize its own, the virus's reproductive abilities?
But let's end on an upbeat note. In what could be the medical breakthrough of the century, Darek Fidyka, in Poland, is walking with the assistance of a frame. I first heard the news of this achievement on a TV news program but found details of the story in an article by Carl Engelking on the Discover magazine Web site. In 2010, a knife attack paralyzed Fidyka from the chest down, leaving him unable to walk and with the loss of feeling and body functions in his lower extremities.
An operation on Fidyka was performed in Poland by a team of researchers from University College London headed by Professor Geoffrey Raisman. What they did was take cells from the olfactory bulb in Fidyka's nose and culture them in a Petri dish. Why cells from the nose? It seems that these nasal cells are one of the few types of cells that regenerate throughout a person's lifetime. The hope was that by injecting the cells into the spinal cord they would regenerate more cells and fill in the gap in the severed spinal cord. I was intrigued by the fact that the surgeons not only injected the nasal cells but also transplanted four nerve fibers taken from the patient's ankles to bridge the 8-millimeter gap in the spinal cord and provide a path for the nasal cells to regenerate. Remarkably, three months later, Fidyka not only was walking with a frame but also had regained not only feeling in his extremities but also bladder, bowel and sexual functions!
The Discover article says that the team of researchers plans to perform this operation on other patients in Poland. With the apparent success and safety of the unusual procedure demonstrated in one individual, I would be amazed if there isn't a flurry of other surgeons trying this procedure on paralyzed patients all around the globe. I can't help thinking how Christopher Reeve would have felt if he had lived to see this possibility of a cure for millions of paralyzed individuals.
Finally, I have to take note of the Nobel Prize in Physics that has just been awarded to three Japanese researchers for their work leading to gallium nitride-based blue light-emitting diodes. Their achievement of blue LEDs paved the way for the white light LED light bulbs that are replacing the inefficient incandescent bulbs of Thomas Edison. As one who worked at Bell Labs on the first LEDs incorporated in telephones in the Bell System, may it rest in peace, I applaud the three who shared the prize. At Bell Labs, we had red and green LEDs but didn't pursue the blue, which for years remained the Holy Grail for producing white light. Our LEDs were made using gallium phosphide. If only we had gone on to substitute nitrogen for phosphorus, would we have gotten the Nobel? Oh well, as I end this column, I'm about to turn off the white light LED bulb we've had lighting our hallway for 10-12 hours every night for the past couple of years. Also, next week I'm taking my little white light LED flashlight to my Old Guard meeting, where I use it to read the instrument panel of some of our poorly lit audio equipment. Thank you, Nobel laureates.
Next column will be posted, hopefully, on or about December 1, 2014.
Allen F. Bortrum
