Vital Signs
New Hope for Preventing Blindness?
Gene therapy may one day be able to halt or even prevent
blindness caused by macular degeneration and diabetic
retinopathy, according to promising new animal studies led
by researchers at Hopkins's Wilmer Eye Institute.
Both conditions are caused by an overgrowth of blood
vessels in the eye. Current therapies include laser
treatment or surgery, both of which fail to attack the
underlying stimuli for blood vessel growth. "As a result,
the blood vessels tend to come back. Even with initially
successful treatments, many patients still end up with
severe loss of vision," says professor of
ophthalmology and
neuroscience Peter A. Campochiaro, senior author of the
studies.
Campochiaro's team injected two different genes into
the tail veins or eyes of lab mice with conditions similar
to macular degeneration and diabetic retinopathy. One gene
is for endostatin, which inhibits blood vessel growth; the
other is a substance that increases cell survival. The
therapy reduced new blood vessel growth by up to 90 percent.
Campochiaro calls initial results "very exciting."
A Rice-Based Solution to Diarrhea
A rice-based oral rehydration solution (ORS) has
outperformed the standard treatment for children suffering
from cholera and life-threatening diarrheas, according to a
study conducted by researchers at the Hopkins
Bloomberg
School of Public Health.
In the randomized study of children living in
Bangladesh, those who received a new prepackaged rice-based
ORS had 20 percent less stool output within the first eight
hours of treatment compared to children given the standard
glucose-based ORS. The findings appear in the May 2001 issue
of Acta Paediatrica.
Hospitals in Bangladesh have been using freshly ground
rice in ORS for some time, reports Hopkins
international
health professor David Sack. But fresh rice spoils quickly
and requires expertise to prepare, he notes, problems the
prepackaged solution surmounts.
Earlier Detection for Melanoma
When it comes to treating melanoma, the deadliest form of
skin cancer, early detection is crucial. But "telling the
difference between precancerous moles and early-stage
melanoma can be very difficult," notes Rhoda Alani, Hopkins
assistant professor of
oncology,
dermatology,
molecular
biology, and genetics.
In the August 15 issue of Cancer Research, Alani and
collaborators from Sloan-Kettering and New York University
Medical Center reported a link between two genes that
trigger skin cancers and could serve as early diagnostic
markers for the disease.
The researchers found that in melanomas, a cell growth
regulatory gene known as Id1 deactivates an important tumor
suppressor gene (p16/Ink4a), allowing cancer cells to grow
uncontrollably. High levels of Id1 proteins are found only
in the first stages of melanoma--a potentially life-saving
warning sign for doctors. Says Alani, "If it's melanoma, you
want to catch it very early and treat it aggressively by
removing as much tissue as possible to cure the disease."
--Compiled by SD
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