40
mg/dL
HDL below this level
linked to more heart
disease in men
50
mg/dL
HDL below this
level linked to
disease in women
60
mg/dL
HDL above this
level is considered protective
Quality may trump quantity in HDL
Good cholesterol’s effectiveness at clearing fats is crucial
By Tina Hesman Saey
How much good cholesterol a person
has is not as important as how well the
beneficial substance works to stop heart
disease, a new study suggests.
High-density lipoprotein — also
known as HDL, or “good” cholesterol — is
healthy for the heart, previous studies
have indicated. Higher blood levels of the
molecule tend to decrease risk of developing heart disease.
But a new study indicates that HDL
levels may not be the most important fac-
tor in protecting against clogged arteries
and cardiovascular disease. The study,
published January 13 in the Ne w England
Journal of Medicine, shows that HDL’s
efficiency at removing fats from arteries
is a better predictor of who will develop
heart disease than its levels in the blood.
Cocaine vaccine
looks promising
Injections raise antibodies
to limit drug’s effects in mice
in people. The new report will appear in
the March Molecular Therapy.
“When someone takes cocaine … you
don’t have much time,” says study
coauthor Ronald Crystal, a pulmonary
physician at Weill Cornell Medical
College in New York City. “It takes about
six seconds to pass from the lungs to the
blood to the brain.”
A vaccine would need to elicit a stand-
ing army poised to intercede. In the new
study, Crystal and his colleagues gave
mice three injections over six weeks.
Some of the animals received a placebo
while the others got the experimental
vaccine, which combines a cocainelike
substance with noninfectious portions
of an adenovirus that stimulate an
immune response but don’t cause dis-
ease. Four weeks later, all the mice were
By Nathan Seppa
Antibodies generated in response to a new
vaccine can capture cocaine molecules in
the seconds before the drug reaches the
brain, a study in mice shows. Although
the antibody brigade doesn’t snag all
the cocaine, it seems to collar enough to
greatly subdue the agitation that mice
usually exhibit when given the drug.
With these findings in hand, researchers are moving on to studies in rats and
monkeys in hopes of testing the vaccine
Calming influence Mice vaccinated against cocaine exhibit less agitated behavior when
exposed to the drug than do unvaccinated mice on the drug, as shown by the average time the
animals spend on various activities.
Anticocaine vaccine’s effect on mouse behavior
27%16%
6%
16%
9%
42%
78%
75%
Running
Repetitive motions
Resting/
other activities
31%
No cocaine and
no vaccine
Given cocaine
after vaccination
Given cocaine
without vaccination
source: M. HIcKs
et al/Molecular
therapy 2011
Antibodies elicited by the vaccine
kept about two-fifths of the cocaine from
reaching the brain in vaccinated animals,
according to examinations of the mice.
This effect translated into behavioral
changes: Cocaine makes mice hyperactive, Crystal says, and in this study the
unvaccinated mice spent a good portion
of their time running around. In contrast, vaccinated mice ran one-third as
much and performed repetitive motions
half as much, behavior similar to that of
mice that were not given cocaine at all.
Crystal says the vaccine might be
ready to test in people in a year or two.
“The most obvious strategy is to use it in
people who are addicted but who want to
stop and have enrolled in a program,” he
says. “This would help them.”
About 40 percent of cocaine users
are in denial about their addiction, and
another 40 percent are not yet willing
to take on the challenge of quitting, says
Stephen Ross, an addiction psychiatrist
at New York University. “The other
20 percent are ready to make a change,”
he says. Such people need behavioral
therapy and all available support. “The
more tools we have, the better,” Ross
says. “A vaccine could be part of that
arsenal.”
T. DubÉ
www.sciencenews.org
