| Blood Tests for Heart Problems
If an experimental new blood test works as expected, emergency room doctors
could quickly diagnose an imminent heart attack and family practitioners could
diagnose heart disease, saving potentially up to a million lives annually.
The test measures an enzyme made in white blood cells when arteries are
inflamed and develop plaque. It is simple and inexpensive, and appears to be
more accurate and reliable than existing tests for heart disease.
Reference: Sternberg, Steve (2003). “New test can
warn of heart attack Simple blood check could be a lifesaver.” USA TODAY,
October 23.
Neural Net Diagnoses Gastro-Intestinal
Problems
Two 12-month studies involving over 100 patients each have shown that an
artificial neural network is at least as accurate as other available methods in
predicting outcomes of patients with lower-gastrointestinal hemorrhage.
References: Hendry, Joene (2003). “Computer-Based
Artificial Neural Network Accurately Predicts Outcomes in Patients with
Lower-Gastrointestinal Haemorrhage.” Lancet 2003;362:1261-66 (summarized in
Doctor’s Guide, October 21.) Unknown (2003). “Artificial neural networks
aid decision making.” Lancet 362:9392, October 18.
Glutamate Sensor
University of Kentucky researchers have developed microsensor probes that
track concentrations of glutamate in a second — fast enough to aid in removing
the small amounts of tissue responsible for the high glutamate levels that can
lead to learning, memory, and motor problems. An enzyme and polymer coating on
the platinum tip of each micron-sized ceramic probe creates an electric current
when it comes into contact with glucamate. The sensors may be available in
commercial quantities in two years.
Reference: Unknown (2003). “Buckyball
Antibiotics.” Prototype, October.
Wearable Heart Monitors
Philips Electronics has developed sensors to monitor heart rate and other
vital signs that can be sown into underwear and transmit telemetry and alerts —
even call for an ambulance — wirelessly and automatically. Philips, Europe’s
largest consumer electronics maker, has reportedly identified personal
healthcare as a major business opportunity.
Reference: Unknown (2003). “Heart
Patients May Benefit from Sensors in Clothes.” Reuters, October
8.
Whole-genome and Diagnostic Gene Chips
At least four competitive “whole-genome” gene chips (a.k.a. microarrays) that
can be loaded with an entire human genome are being readied for market, some
immediately. They will enable researchers to rapidly scan all genes in a human
tissue sample to determine which genes are active, and will lower the cost and
increase the speed of a widely used test that has transformed biomedical
research in the last few years. One manufacturer called the creation of
whole-genome chips “a milestone event” and likened it to “an integrated circuit
[IC] of the genome.”
As a sort of IC, with fluidic gates analogous to transistor gates on computer
chips, gene chips are showing signs of obeying a variation of Moore’s law. Since
1990, the number of chips needed to process an entire genome has gone from five,
to two, and now to one. That alone is a major factor in reducing the cost of the
technology. Affymetrix is pricing its whole-genome chip at between $300 to $500,
depending on volume, or about half the price of the older two-chip set.
One expert points out, however, that whole-genome chips, while useful for
medical discovery, might be overkill for the potentially much bigger market of
diagnostic chips for the doctor’s office, and sees that market served by smaller
and cheaper chips containing only the genes relevant for a given diagnosis.
No sooner said than done. Singapore scientists are reportedly within a few
months of completing development of a chip that can diagnose SARS, flu, and
other respiratory diseases by analyzing nasal fluids dropped into it. The chip
will be able to instantly differentiate among flu, dengue fever, and SARS, all
of which exhibit similar early symptoms and are difficult to tell apart. An
unidentified U.S. medical device manufacturer is said to be collaborating in the
chip’s development.
Almost — but not quite — everyone seems to agree that being able to
pinpoint a precise diagnosis in a patient will enable drug companies to develop
precise drugs for that diagnosis, and that therefore the cost of developing the
drugs should come down, regulatory approval will come faster, and selling them
will be a no-brainer to patients known (from the precise diagnosis) for almost a
fact to benefit from a drug known for almost a fact to work in treating that
particular diagnosis.
Genetic and proteomic diagnostics is still in its infancy, therefore the
current debate is essentially academic. But the accelerating introduction of the
gene chips discussed above could soon settle the debate one way or the other.
Meanwhile, some drug companies — and some major device manufacturers — have made their bets firmly on
the side of a strong tie between diagnostics and successful drug development
going forward.
References: Pollack, Andrew (2003). “Human Genome on
Chip Offered by Rivals.” New York Times, October 2; Unknown (2003). “Singapore
Plans SARS-Detecting Microchip.” AP/Yahoo, October 5; Herper, Matthew
(2003). “The Diagnosis
For Medical Diagnostics.” Forbes, October 9.
DNA, Supersized
By inserting a ring of benzene into the genetic bases A, C, T, and G,
Stanford researchers are creating super-sized DNA molecules that glow. The size,
coloration, and enhanced stability of the “XDNA” could make DNA diagnostics
easier and more robust. DNA from a biopsy sample is expected to bind with, and
adopt the same larger structure as, XDNA, making it easier to detect the
presence of rogue DNA in the biopsy tissue. XDNA’s enhanced stability could also
aid in drug discovery.
The creation of XDNA also suggests that such a molecule could already have
arisen naturally elsewhere in the universe and could therefore be the stuff of
which some aliens are made. It shows that there is no reason why all life must
conform to the earthly genetic base structure.
Reference: Philipkoski, Kristen (2003). “DNA, Now in
XXX-Large.” Wired News, October 30. |
