| Brain Pacemakers
Brain pacemakers, created in the late 1980s to treat Parkinson’s and more
technically known as “deep brain stimulation” devices, deliver precisely
targeted electrical stimulation to the brain to treat behavioral, neurological,
and psychiatric disorders, with “promising results,” writes Rob Stein in the
Washington Post. Based on the accelerating advances in understanding
brain functions, precise imaging technologies, and the miniaturization of
implants, brain pacemakers are now most widely used for Parkinson’s and are
being tried on “cluster headaches” and other abnormalities. Large trials are
planned for epilepsy. Pilot studies have begun for depression and
obsessive-compulsive disorder, primate studies are underway for obesity
(appetite suppression and metabolic enhancement), and there is talk about using
them for addictions.
For the present, brain pacemakers are being implanted only in hopelessly ill
people and there are “layers of protections to ensure that all patients are
fully informed and shielded from abuse.” Nevertheless, its proponents —
especially those involved in studies producing beneficial effects in some
patients — think it is the beginning of a new era in the treatment of
neurological disorders.
Reference: Stein, Rob (2004). “The
Potential of ‘Brain Pacemakers’: Implanted Devices May Alter Treatment of Many
Disorders.” Washington Post, March 6.
Thought-controlled Prosthetics
The Duke University researchers who trained a monkey to move a mechanical arm
using thought have experimented with Parkinson’s disease patients in the process
of being given brain pacemaker implants. To optimally locate the implants,
surgeons temporarily implanted arrays of 32 microelectrodes, and gave the Duke
researchers five minutes to experiment with the arrays and the patients before
proceeding to implant the pacemakers.
During those five minutes, the patients (awake during surgery) played a video
game using a joystick. The electrodes picked up the brain’s signals, and a
computer quickly correlated the signals with the hand movements. It could then
predict the patients’ motions “quite well,” as one researcher put it.
The next step would be just a matter of sending the brain signals to, say, a
robotic arm pre-programmed with the correlations, which would know how to move
in response to a thought. The researchers are indeed thinking of developing a
robotic arm for quadriplegics, as well as a thought-controlled electric
wheelchair and a thought-operated keyboard. They are seeking US Food and Drug
Administration permission to do more experiments on human volunteers.
Reference: Unknown (2004). “Thought-controlled
robotic arm may work in people, say scientists.” Reuters, via New Zealand
Herald, March 24.
See also FDA
Approval Sought for Telerobotic Brain Implant Trial in the December 2003
issue of the Digest, and Brain-Computer
Interface in the September 2003 issue.
Convergence of Biotech and Medtech
A venture-funded startup originating out of MIT research and founded by top
scientists plans “to combine elements of tissue engineering and cell-based
therapy with the precision of medical devices to attack a variety of human
diseases,” reports Jeffrey Krasner in the Boston Globe. The company is
being cagey about its plans, but the following quotes he obtained from an
official tell some of the story:
“We’re addressing diseases that are orders of magnitude more complex than
what’s been done before. . . . It’s not a single target or pathogen. The
syndromes we’re attacking are not as trivial or one-dimensional as bacterial
pneumonia. . . . “We’re looking at an approach that does far more than just
overwhelm an injury site with a chemical. Our systems sense what’s going on and
regulate what they secrete. We are taking advantage of the natural healing
mechanism of the body. Cells are designed to adapt to their environment. They
sense what is happening and in a dynamic fashion secrete the full range of
factors needed to repair injury. For that reason we have created a cell-based
therapy.”
Reference: Krasner, Jeffrey (2004). “A
new attack on complex diseases.” Boston Globe, March 15.
Low Carb Cure for Cancer and Inflammatory
Diseases
GlycoMimetics is developing treatments for cancer, asthma, arthritis, and
other diseases by manipulating the behavior of cells. It has completed basic
research and is now working on a drug to prevent certain carbohydrates on the
surface of cells from binding to blood vessels, causing inflammation or tumors.
Reference: McCarthy, Ellen (2004). “GlycoMimetics’
Research Taps Troublesome Carbohydrates to Combat Diseases.” Washington
Post, March 15.
Brakes on Adult Stem Cell Therapy
Two attempts have failed to replicate a 2001 study in which stem cells taken
from the bone marrow of an adult mouse appeared to rebuild heart tissue
following a myocardial infarction. In the new studies, none of the cells turned
into heart tissue, and their authors conclude that the original results were
misinterpreted. Still, other clinical trials in progress suggest that blood or
bone marrow stem cells may have at least some modest therapeutic value in heart
disease, and the senior author of the 2001 paper says the replica studies may
have made subtle technical mistakes.
The enormous potential of such therapy makes it imperative that the issue be
thoroughly investigated and a definitive answer found.
Reference: Cook, Gareth (2004). “Report
challenges blood stem cell role in rebuilding heart.” Boston Globe, March
22.
Antibiotic Resistance
The Staphylococcus aureus (“staph”) bacteria responsible for many skin
infections and some internal organ infections have become increasingly resistant
to antibiotics. Resistant staph, said one doctor, are “more invasive and more
pervasive” than the strains most primary care doctors are used to treating.
Another said he was “very concerned about what we are seeing,” and a third said
“Most doctors are just not aware of this [increase in resistant staph].”
Resistant staph can still be treated with several common antibiotics such as
Bactrim, Vibramycin and Cleocin; just “not the ones doctors
are accustomed to using,” such as Keflex and Rocephin, writes
Abigail Zugler in the New York Times. The resistant staph are growing
more virulent and more deadly, therefore “heightening doctors’ awareness is
crucial to tracking and fighting the new staph.”
Reference: Zuger, Abigail (2004). “Bacteria Run
Wild, Defying Antibiotics.” New York Times, March 2.
Artificial Hearts on Exponential Roll
Twenty years after Barney Clark received the first artificial heart, an
expert panel has recommended that the US federal government grant general
approval for their use in heart transplant centers, albeit only as a temporary
measure to sustain hospitalized patients until a donor heart becomes available
for a transplant.
A medical ethicist questioned the value to society of keeping more people
alive in the hopes of getting a transplant, writes Rob Stein in the
Washington Post. “As long as there’s a shortage of organs, mechanical
hearts can’t change the number of patients who could benefit from a heart
transplant. It can only change the identity of who gets one, and increase the
cost to the health care system.”
Nevertheless, the decision is an historic one and, writes Stein, “comes amid
a flurry of activity to develop a new generation of gadgets to support or
replace failing hearts, including small auxiliary pumps that can be implanted
into the body to supplement organs damaged by disease and heart attacks, as well
as a complete, fully implantable device that could win limited government
approval by the end of the year.”
Reference: Stein, Rob (2004). “Artificial
Heart Gets FDA Panel Approval: Device Is Interim Before Transplant.”
Washington Post, March 18.
Children’s Heart Pump
A six-year-old Texas girl became the first to receive a DeBakey child
heart pump, a scaled-down model of the original LVAD (left ventricular assist
device), while she awaits a heart transplant that could take several months.
A European device called the Berlin Heart has already been implanted
in several American children, including a 22-month-old boy.
Several other pumps are available in the United States, including the
HeartMate and the Novacor. Both devices, says an Associated Press
report, are in thousands of patients and both are larger than the DeBakey pump.
Reference: Unknown (2004). “1st
DeBakey Heart Pump Is Used for Child.” Associated Press via Yahoo News,
March 27.
Biorobots, or MicroBioMechanical Systems
Silicon devices “smaller than a pencil dot,” powered by heart muscle tissue
and fueled by the glucose in the bloodstream, are “a critical first step in the
creation of part-human, part-artificial miniature robots,” writes Linda Marsa in
the New York Times. UCLA researchers have created these miniature
cyborgs, which could be used to stimulate nerves to make a paralyzed patient’s
diaphragm expand and contract, enabling the patient to breathe without a
ventilator, to diagnose and fix other ailments, and to permanently replace the
batteries in pacemakers and other implanted devices. “You can put it in and
forget about it — no more need to replace batteries, or worry about infections
from the external wiring,” one of the researchers told her.
Though “some formidable technical problems” remain, some formidable technical
problems have already been overcome, including getting the muscle cells to bind
to a synthetic material and still be able to contract and relax to produce
locomotion. “Now that we’ve established the basic technology,” said the
researcher, “with enough resources, we could have prototype devices within five
years.”
Anil Ananthaswamy provides additional information in New Scientist
(see reference).
Reference: Marsa, Linda (2004). “Big
idea in mini-robotics.” LA Times, March 15.
Reference: Ananthaswamy, Anil (2004). “First robot moved
by muscle power.” New Scientist, February 27.
Drug Addiction Drugs
Future drugs to treat drug addiction will prevent cocaine, nicotine,
methamphetamine, and other illegal drugs from reaching the brain’s “pleasure
receptors” that create the addict’s “high,” writes Kristen Philipkoski in
Wired. The hypothesis is that by taking the pleasure out of taking the
drug, the addiction will be cured. The lack of success in eliminating nicotine
and other addictions is proof that a new approach is needed.
Anti-addiction drugs in clinical trials employ a technique, commonly used in
vaccines, to train the immune system to quickly spot and destroy unwanted
organisms. Nicotine (say) is attached to a “carrier” substance such as a
detoxified cholera molecule, a synthetic peptide, or the bacterium exotoxin A,
so the antibodies will become primed to attack not only the carrier but also the
addictive substance. When a vaccinated addict takes a drug “hit,” antibodies
already circulating in the bloodstream attach to the drug molecules making them
too large to pass through the blood-brain barrier, and take all the fun out of
it.
Reference: Philipkoski, Kristen (2004). “Designing Drugs to
Swat Addiction.” Wired News, March 29.
Female Fertility Extender
Researchers have grown an embryo from an egg produced by ovarian tissue that
had been frozen for six years and re-implanted. Eventually, the procedure could
be available to any woman who wants to preserve her fertility, but initially it
would be intended for women whose fertility is threatened by radiation,
chemotherapy, or other medical treatments. The research is still in the early
stages.
Reference: Philipkoski, Kristen (2004). “Fertility Frozen
in Time.” Wired News, March 8.
Healthier Food?
California has approved the planting of a rice crop genetically modified to
produce two proteins present in breast milk that protect babies from ear
infections, diarrhea, respiratory tract infections, meningitis, and other
infections. Babies that stop breast feeding or are not breast-fed at all are
unprotected.
The theory is that it will be cheaper to develop drugs this way than by
building and maintaining expensive manufacturing plants. The downside is that
such crops could well find their way into the normal human food chain. “All you
need is one shipment of corn flakes that has a contraceptive in it and there’s a
real problem, obviously,” one critic told Wired‘s Kristen Philipkoski.
Caution is called for: contamination of normal crops has occurred in previous GM
crop experiments.
Reference: Philipkoski, Kristen (2004). “Waiter, There’s a
Drug in My Rice.” Wired News, March 30.
Old Drugs in New Bottles
The drug naltrexone, approved in 1984 to treat opiate addiction and in
1994 for alcohol addiction, worked — except for patients who stopped taking it,
as most did. An experimental injectable version that lasts one month takes away
the patient’s option to quit the therapy, at least for a month.
Many other pharmaceuticals are being rejuvenated through the burgeoning field
of “drug delivery” that is already helping schizophrenics stay on their
medication and alleviate sexual dysfunction “on demand” via nasal spray. As new
formulations, the techniques are also helping pharmaceutical companies extend
expiring drug patents.
An experimental drug-delivery system involving “nanoscale polymer devices”
being tested in animals could improve cancer therapy. The devices mimic viruses,
inserting themselves into targeted cells and releasing drugs, causing fewer side
effects than oral drugs. Also in animal testing is a removable small disk
implanted under the skin, to deliver schizophrenia medicine for one year. It
dissolves slowly to release medicine.
A patient advocate worries that a year-long medication is going too far.
“This is the road to involuntary medicating. . . . It could be used in prisons,
in hospitals, wherever.”
Reference: Zimmerman, Rachel (2004). “New Ways to
Take Old Drugs Help Patients, Extend Patents.” Wall Street Journal, March
15.
Pharmaceuticals: Deceleration?
More and more biotechnology start-ups are eschewing risky avant-garde
research in favor of “scrounging around for existing drugs to license, . . .
reformulate, . . . and repurpose,” writes Andrew Pollack in the New York
Times. This may be at the expense of innovation in new compounds, but
innovation is not likely to dry up completely, given that there are thousands of
biotech companies and some continue to pursue new compounds and drug classes. In
any case, the definition of innovation ought rightly to embrace reformulation
and repurposing of existing compounds. Eventually, though, without a pipeline of
brand new compounds, there won’t be any old ones left to recycle.
Reference: Pollack, Andrew (2004). “Is
Biotechnology Losing Its Nerve?” New York Times, February 29.
Prostate Cancer Device
A US company has launched a high intensity ultrasound device in Europe to
treat prostate cancer. It is claimed to be 88 percent effective in reducing PSA
(prostate specific antigen, thought to be an indicator of the cancer) levels to
below 1.0 within a year of treatment.
Reference: Unknown (2004). “Misonix
shares soar on prostate device launch.” Reuters via Forbes, March 31.
RNAi Breakthrough for Cancer
Greek scientists may have found a way to lower cancer-cell resistance to
chemotherapy, making the treatment more effective at significantly reduced
dosages and eliminating many of its side effects. The method uses RNA
interference (RNAi) to switch off the expression of a protein used by all
cells — including cancer cells — as a shield against toxins.
In animal tests, the researchers reported “spectacular results even when
using a tenth of the usual [chemotherapy] dosage.”
Reference: Unknown (2004). “Greeks Go After
Cancer Cells.” Reuters via Wired News, March 1.
Laparoscopic Surgery Enhancement
A technology tinkerer has developed a clamp he claims gives surgeons a better
laparoscopic view inside the patient, obviates the need for insufflation, and
reduces risk from “visual misperception,” which a study found to be a cause of
bile duct injuries inflicted during laparoscopic gallbladder surgery.
The invention is like a miniature surgical clamp but has blades that splay
the incision open beneath the surface of the skin. “By dialing a little knob,
the surgeon or nurse makes the blades slowly swing open, like shutters on a
window,” is how Teresa Riordan describes it in the New York Times. “As
the blades open, they push flesh, fat and viscera out of the way, giving the
surgeon a clear window on the organ under scrutiny.”
The device has been used in about 1,500 surgeries and has been approved by
the US Food and Drug Administration, but it appears — reading between the lines
of Riordan’s report — that its inventor is having trouble licensing or selling
his patent-pending invention to device manufacturers.
Reference: Riordan, Teresa (2004). “Improving
Laparoscopic Surgery.” New York Times, March 29.
Robot Brain Surgeon
Canadian scientists are about to begin testing a prototype brain surgery
robot called the neuroArm. Like the well-known Da Vinci surgical robot,
the neuroArm eliminates the surgeon’s hand tremors and scales down hand
motions to allow greater precision. Safety switches prevent sudden accidental
movements from being transmitted to the robot arm.
The neuroArm actually has two independent arms. Each can be fitted
with special surgical tools to perform such procedures as soft tissue
manipulation, needle insertion, blunt dissection, suturing, cauterizing, and
cutting. The hand controllers include force sensors to provide the surgeon with
tactile feedback, something the Da Vinci lacked last time we looked.
The surgeon’s control panel incorporates three-dimensional MRI scans of the
patient’s brain, including the position of the tool currently being used; a
video view of the brain through a surgical microscope; and monitors displaying
system data and control settings.
Reference: Romain, Gabe (2004). “Testing of Robot
Brain Surgeon Begins: “NeuroArm” claimed to be more accurate and precise.”
Betterhumans, March 1. |
