ScienceCache
Vol. 158
Jan. 28, 2004
HOW THE CELLULAR “GARBAGE DISPOSAL” GRINDS TO A HALT
TO CAUSE DISEASE
Scientists have discovered just how a genetic defect disrupts the cellular “garbage
disposal” of a cell, resulting in a horrific childhood disease
that kills most patients before the age of 25. For nine years researchers
have known the precise genetic flaw that causes Batten disease. But understanding
how a straightforward mistake in life’s blueprint translates to
a disease that ravages roughly 1,000 children in the United States each
year has been a challenge. Now, in a paper in the Proceedings of the
National Academy of Sciences, a team from the Center for Aging and Developmental
Biology lays out the sequence of biochemical steps that results in the
disease. The team led by David A. Pearce found that the genetic defect
is linked to a protein that regulates the amino acid arginine in and
out of a yeast organelle called the vacuole. The vacuole in yeast is
much like the lysosome in human cells, slicing and dicing up cellular
waste and then disposing or recycling the material. In Batten disease
and other lysosomal storage disorders, the lysosomes don’t work
correctly and cells swell up with gunk that eventually kills them. Pearce’s
team found that the trouble with arginine levels is critical to throwing
the pH levels of cells in lysosomes out of whack, affecting a range of
processes and ultimately ruining a cell’s ability to get rid of
its own waste. “It’s a little bit like getting sugar in your
gas tank,” Pearce says. “Once you change the mix just a little,
it has drastic repercussions throughout the system.”
Full story
MOVING TO THE NEXT PHASE OF WTC DUST INVESTIGATION
Scientists are beginning an investigation into the effects of World Trade
Center dust on the body’s immune system. The research is part of
an ongoing, collaborative effort that began in the months after Sept.
11, 2001, to assess the short- and long-term health implications of the
terrorism. So far, two years of scientific analysis shows that dust collected
from Manhattan immediately after the collapse of the twin towers is probably
no more harmful to the lungs than common dust. Research completed in
2003 measured the immediate and latent affects of the WTC dust on both
young and old rats, and showed minimal lung inflammation, says Alison
Elder, research assistant professor of environmental medicine. However,
many questions remain unanswered, such as the long-term effects of exposure
on emergency responders who inhaled large amounts of debris. Scientists
hypothesize, for example, that exposure to WTC dust may harm the body’s
ability to fight influenza or other respiratory viruses more than common
dust particles. Researchers in environmental medicine will study the
immune response to influenza in mice in collaboration with David Topham
of the Center for Vaccine Biology & Immunology. Questions will focus
on whether the WTC dust harms the body’s natural immunologic memory,
reducing a person’s ability to resist flu when infections recur.
Full story
DRUG HELPS PATIENTS WITH ADVANCED ALZHEIMER’S
A study in last week’s Journal of the American Medical Association
(JAMA) indicates that there is good reason for the recent attention surrounding
the drug memantine for the treatment of Alzheimer’s disease. A
multi-center study directed by Pierre Tariot, professor of psychiatry,
concluded that memantine, when taken with the commonly prescribed Alzheimer’s
drug donepezil, helped moderate to severe Alzheimer’s patients
maintain or in some cases improve their memory and other intellectual
functions. This represents the first medication approved by the FDA to
treat advanced Alzheimer’s patients, as well as a new category
of medication to treat the disease. Tariot says the study is significant
not only because it validates a new class of drugs for the treatment
of Alzheimer’s, but also because it is the first time positive
results have been seen combining two Alzheimer’s drugs. “To
find a new medication that can provide substantial benefit to patients
at this stage of the disease, either alone or in combination with another
Alzheimer’s drug, is certainly good news,” Tariot says.
Full story
THREE LOCAL TEENS MAKE SEMI-FINALS IN NATIONAL SCIENCE COMPETITION
Three local teens have earned recognition in the prestigious Intel Science
Talent Search for research projects they carried out last summer at the
Laboratory for Laser Energetics (LLE). Rohan Kekre of McQuaid Jesuit
High School, Nadine Lippa of Byron-Bergen High School, and Anthony Noto
of Greece Athena High School are among the 300 semifinalists nationwide
chosen from the record number of 1,652 who entered the competition. Kekre
worked out a new method for tuning the frequency conversion crystals
on the 60-beam Omega laser at LLE. Lippa carried out an experimental
project dedicated to developing a single-photon source with applications
to quantum cryptography, and Noto performed complex computer calculations
of chiral dye molecules of relevance both to optics and to pharmaceutical
design. “Our program provides a unique educational opportunity
for talented high-school students. They’re amazingly motivated,
and it’s exciting to see them recognized as among the best in the
nation,” said Stephen Craxton, LLE physicist and high-school program
director. Students working at the laboratory have made up the large majority
of Rochester-area Intel semifinalists honored during the past decade.
Full story
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