Dov Michaeli
Posted 10/08/11 on The Doctor Weighs In
Yesterday Pat Salber treated us to a list of truly great innovations compiled by the Cleveland Clinic. Let me say at the outset: each one of the innovations on the list is really a gee-whiz invention, and each promises to transform a specific field of medicine. But some of the inventions provoked some thoughts about our basic attitudes and beliefs.
Take the #1 innovation, catheter-based renal denervation for resistant high blood pressure. This is brilliant; resistant high blood pressure is just that –resistant to treatment. Disrupting the renal nerve seems to solve this vexing problem. So what’s my problem? Knowing the history of seemingly focused treatment “metastasizing” to totally inappropriate treatments, I am a bit cynical. How long will it be before surgeons see hypertension as a “profit center”? Stomach banding was designed for treating the morbidly obese. It is rapidly evolving as a painless way around the more demanding way of diet and exercise for weight reduction. Can renal denervation be far behind?
Or what about concussion management for athletes? A great gizmo, no question about it. But did anybody dare to challenge the basic premise
that it’s O.K. for our gladiators to bash each other’s heads? Last time I checked, such games were played in Rome 2000 years ago, where the crowds were clamoring for blood. Haven’t we evolved a bit since? Couldn’t a simple change in the rules of the game obviate the necessity for such an innovation? It almost sounds un-American.
I plead guilty to having a bias for innovation #5, the rapid and cheap gene sequencing. This is truly going to revolutionize medicine. It ushers in the dream of many scientists and physicians –personalized medicine. Your treatment is going to be tailored for you. If you were diagnosed with
hypertension –a specific treatment will be prescribed based on your genetic makeup. If you’d have the misfortune of getting a diagnosis of malignant disease –no more carpet bombing your body with chemotherapy: your genes will tell where the cell biochemistry went awry, and which drugs can treat your specific problem. Now, this I call revolutionary. I think it deserves the #1 position.
The most intriguing to me is the release of radiation-sterilized male mosquitoes. Once they mate, the deluded female thinks that she was fertilized, and lays those useless eggs. Brilliant! This approach has actually been used about 40 years ago. Texas cattle suffered from blood-sucking blowflies. The female blowfly mates only once, so millions of male flies were radiologically-sterilized and released. The blowfly population gradually declined, and after several years of release it ceased to be a problem. One more detail: the program cost hundreds of millions of dollars to develop and maintain. And yes, it was a federally-financed program, and it saved the ranching industry of the lone star republic and its rugged individualists.
On the other side of the world, in East Africa, another fly, the tse-tse fly, transmitted a dread disease. The fly feeds on cattle blood and if that cattle happens to carry the parasite Trypanosoma brucei it will transmit it to humans when it feeds on their blood. The disease? Sleeping sickness. Nothing restful about that sleep; the parasite migrates to the brain, and the patient lapses into deep come and eventually dies. No
therapy is available once the parasite reaches the brain, and many thousands of people died every year in Kenya, Tanzania, Mozambique, Zimbabwe, Botswana. Now, the same solution of releasing radiation-sterilized males was contemplated for this scourge, but it was too expensive for the limited resources of those poor countries. So how was the problem solved? By using ingenuity and simple solutions. All over Eastern Africa you would see in the meadows where the cattle graze large hanging sheets painted brown, the color of cattle. The fly is attracted by the brown color and attempts to bite the sheet, but instead manages to get a lethal dose of an insecticide impregnated into the cloth. The endemic disease was essentially eradicated. The cost of the operaton –in the thousands of dollars, a pittance compared to the high-tech radiation used against the blowfly of Texas.
So why not use a similarly simple approach to tackle the mosquito-borne diseases? Drs. Yosef Schlein, a parasitologist at the Hebrew University and his research partner Günther Müller took advantage of the fact that mosquitoes feed on flower and fruit nectar. The female also feeds on warm-blooded animals like us because without a blood meal to provide iron and protein her eggs will not develop. So they concocted a solution of rotting nectarine juice (as an attractant), brown sugar solution (as bait) and added Sinosad, a bacterial insecticide that is safe for humans and most beneficial insects. They put the solution in empty soda bottles, placed them in socks, and added a wick to keep the socks wet with the delicious elixir. They tried it at an oasis near the Red Sea and reduced the mosquito population by 90%. They also checked the sex of the trapped mosquitoes, and they got a nice bonus-most of the insects were mature females, the ones that are ripe for laying eggs. They repeated the experiment around the water cisterns at a Greek monastery in the Judean hills. Again, over 90% reduction of the mosquito population, the female population totally collapsed, and the area remained mosquito-free at least one month. The Bill and Melinda Charitable Foundation took notice and awarded them the princely sum of$1million to try it in Mali, Africa. There they used juice of local fruits, Guava and melons with identical results –within one week the mosquito population dropped more than 90%, and the female count was essentially zero. In another area they sprayed the solution on tree branches, and had the same results.
So not to detract from the importance of innovation #10, I think this is a simpler and more elegant solution to the malaria and dengue fever problem. It’s also a hell of a lot cheaper.
Dov Michaeli MD, PhD is a basic researcher who writes at The Doctor Weighs In.
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