ScienceCache
Vol. 195
Feb. 18, 2005
GENE THERAPY CONVERTS DEAD BONE GRAFT TO NEW, LIVING TISSUE
Researchers have created a way to transform the dead bone of a transplanted
skeletal graft into living tissue in an experiment involving mice.
The advance, which uses gene therapy to stimulate the body into treating
the foreign splint as living bone, is intended to eventually aid people
with various cancers or injuries whose treatment involves the replacement
of large sections of bone. To make the transplanted bone more robust,
a team led by Edward M. Schwarz, associate professor of orthopedics
and
of microbiology and immunology, looked into the activity of the genes
and proteins that govern its health. His team replaced sections of
bones in dozens of mice, using both healthy and dead segments, then
scanned
the surrounding inflammatory tissue for differences in the levels of
the active genes. He discovered that the genes that create two key
proteins in living bone, called RANKL and VEGF, were barely expressed
around the
dead bone. He then modified a harmless virus to carry these genes,
devised a method of freeze-drying a paste containing the virus so
it could be
easily handled, and painted it directly onto a bone graft during surgery.
Numerous tests in mice confirmed that the virus permeated the inflammatory
tissue around the dead bone and turned on the genes. The findings were
posted online this week and will appear in the March 1 issue of Nature
Medicine.
Full story
PCBS, FUNGICIDE OPEN BRAIN CELLS TO PARKINSON'S ASSAULT
Scientists investigating the link between PCBs, pesticides and Parkinson's
disease have demonstrated new and intricate reactions that occur in certain
brain cells, making them more vulnerable to injury after exposures. In
two papers published in the journal Neurotoxicology, the group describes
how polychlorinated biphenyls (PCBs) disrupt dopamine neurons, which
are the cells that degenerate during the course of Parkinson's disease.
Researchers also show that low levels of maneb, a fungicide commonly
used in farming, can injure the antioxidant system in those same types
of cells. Environmental contaminants might make dopamine cells more vulnerable
to damage from normal aging, infection, or subsequent exposure to pollutants,
researchers say. “If we can identify the mechanisms by which PCBs
or pesticides perturb dopamine neuron function, it may lead to the development
of therapies that can prevent, slow or stop the progression of Parkinson's," says
Lisa Opanashuk, assistant professor of environmental medicine, who led
the work. Her studies focus on oxidative stress and antioxidant responses
to PCBs in dopamine neurons. She showed that just as in exposure to PCBs,
cells treated with low levels of maneb also undergo changes that disturb
the balance in the antioxidant defense system.
Full story
RESEARCHERS EYE LINK BETWEEN CHEMOTHERAPY AND SLEEP PATTERNS
Fatigue is a common complaint from people undergoing chemotherapy treatment
for cancer. And it couldn’t come at a worse time – because
that’s when they need the most energy to endure the emotional and
physical challenges of beating the disease. Oncologists encourage patients
to get more sleep at night and take naps during the day. But many people
are still exhausted, which has cancer and sleep researchers wondering
if chemotherapy drugs alter sleep rhythms. “The fatigue persists
long after their treatment for many people, no matter how much they sleep,” says
Michael Perlis, associate professor of psychiatry and director of the
URMC Sleep Research Laboratory. “This suggests to us that factors
beyond the disease, or the side effects of treatment, may mediate the
chronic fatigue that occurs with breast cancer. Part of the goal of this
study is to identify these factors and determine what treatments might
best bring relief.” A research team from the sleep lab and the
James P. Wilmot Cancer Center suspects the difficulties may lie in the
quality, not quantity, of sleep that patients get. They’ve secured
a $729,000 grant from the American Cancer Society to study patients with
lymphomas or breast or colon cancers. “If the chemotherapy prevents
people with cancer from reaching the most restful, healing phase of sleep,
it’s not a surprise that they are fatigued and exhausted,” says
Joseph Roscoe, research assistant professor of radiation oncology and
the principal investigator of the study.
Full story
|
