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Many diseases don't develop noticeable symptoms until they've already done considerable damage. That's why doctors would like to get a closer look at the first signs of disease: tiny changes in the way our cells communicate with each other. In this Science Update, you’ll hear about an innovative plan to get closer to those early distress signals.
An early-warning system for the body. I'm Bob Hirshon and this is Science Update.
When a patient's life hangs in the balance, any infection or inflammation has to be squelched immediately. But according to Allen Rosenbloom, a research biologist at Carnegie Mellon University, the body's earliest distress signals are too subtle to detect, even with state-of-the-art medical equipment.
Currently even in the ICU where the patients are monitored intensely, we miss the development of disease processes such as pneumonia and other infections—bleeding, even heart attacks—until these are processes have gotten fairly far along.
That's why he and his colleagues are developing a microchip monitor, that could be implanted directly into the body. It would keep track of proteins that cells use to send signals to each other—signals indicating an infection flaring up, a new organ being rejected, or a breakdown of normal body functions.
Once the chip can sense these molecules, and their changes, this information will be relayed to an outside source.”
Rosenbloom says they're already working with prototypes, but the technology could take decades to perfect. For the American Association for the Advancement of Science, I'm Bob Hirshon.
Making Sense of the Research
In the intensive-care units of hospitals, patients are monitored extremely closely, with a variety of different instruments and machines. The goal is to be able to detect even the slightest sign of trouble.
But as Rosenbloom explains, even the most advanced medical technology can only detect so much. Infections, internal bleeding, and even heart attacks can be well underway before they trigger even a subtle change in heart rate or body temperature. Meanwhile, with every minute that goes by, the body’s cells can sustain damage that may take a long time to reverse, if it can be reversed at all.
If doctors could listen to individual molecules and cells, rather than the entire body, they might be able to spot signs of trouble much earlier. The hard part is figuring out how to do that in a living patient, in real time, in a way that’s sensitive enough to detect these tiny cellular changes but doesn’t get overwhelmed and confused by all the signals from the rest of the body.
That’s where the chip comes in. The goal is to design a tiny, implantable microchip that can detect the presence of chemicals and proteins that are released when dangerous inflammations are just beginning. (Examples include interleukins and interferons.)
To do this, the researchers first need to design a membrane for the chip that lets the chemicals they’re looking for pass through it, while filtering other chemicals out. That’s harder than it sounds. Rosenbloom says that most membranes available today are too flimsy and clog up easily. He and his colleagues are trying to build a membrane out of silicon carbide, which is almost as hard as diamond.
Next, they’ll need to put something on the chip that can detect the presence of the proteins they’re looking for. There might be hundreds of these sensors on a single chip. Then finally, the chip has to be able to report its results to the physician. Currently, they’re thinking of installing each chip with a tiny radio transmitter, that relays information to a computer in a hospital room.
This technology won’t come into being all at once. It has to be built in stages. For example, the first models will probably use portable pumps that the patients wear outside the body, which collect and test the body fluid in an external chamber. If they’re successful, fully implantable microchips will come later.
Now try and answer the following questions:
- What are the limitations of most intensive-care units in hospitals?
- How might the microchip improve the detection of disease?
- What are some of the challenges in developing a microchip detection system?
- Can you think of other medical situations in which early detection makes a big difference in prognosis?
Scientific American is one source for articles addressing cell communication and human disease, including Cell Communication: The Inside Story.
To learn more about human diseases, go to the Centers for Disease Control and Prevention (CDC), a large federal agency working to protect the health and safety of all people.