快猫短视频

THE fashion for cocaine may be causing a wave of heart disease among young
people. Besides its known effect of sending coronary arteries into spasm, the
drug also encourages the immune system to turn on healthy cardiac tissue,
researchers in Michigan have discovered.

The work comes as some doctors are complaining that the abuse of the drug is
causing a hidden drain on already stretched hospital resources. They believe
that cocaine is making large numbers of otherwise fit young people鈥攎ost of
them men鈥攔eport to emergency departments with chest pains.

The immunological study, led by Benedict Lucchesi of the University of
Michigan in Ann Arbor, suggests that cocaine activates a part of our immune
defences called the complement cascade. This system, which is usually triggered
by invading microorganisms, destroys cells by building complexes of proteins on
cell membranes, causing the cells to burst.

Working on rabbit hearts, the Michigan team has shown that cocaine boosts the
production of complement proteins, causing the deadly complexes to form on heart
muscle cells and the endothelial cells that line the heart鈥檚 blood vessels.

The complement cascade is already known to damage heart tissue in some
circumstances
(快猫短视频, 25 April 1998, p 20).
So, prompted by
Lucchesi鈥檚 findings, doctors at the University of Michigan鈥檚 hospitals are now
investigating whether drugs that block the cascade will help patients suffering
from cocaine overdoses.

Michael Davies of St George鈥檚 Hospital in London, a cardiovascular
pathologist and assistant medical director of the British Heart Foundation, says
the Michigan team鈥檚 research might explain why some young cocaine users develop
a form of heart failure in which the heart grows floppy and pumps blood less
efficiently. 鈥淭his would fit quite well with the idea that complement is
damaging blood vessels or heart tissue,鈥� he says.

Larry Alexander of Baylor Medical Center in Dallas, a drug abuse spokesman
for the American College of Emergency Physicians, agrees: 鈥淭he authorities
should be doing more to highlight the danger cocaine poses to people鈥檚
丑别补谤迟蝉.鈥�

Cocaine can also send coronary arteries into spasm. Alexander and other
specialists in emergency medicine believe this is the reason for a growing
number of young people turning up in hospital complaining of chest pain. The
vast majority are men, and they are usually discharged after doctors establish
that they are not suffering from a heart attack. Each case has to be thoroughly
investigated, however, which stretches hospitals鈥� resources.

鈥淎t the weekend I saw three young males in their early twenties with chest
pains, and all three were positive for cocaine,鈥� says Alexander. 鈥淣ormally it
just goes away. But occasionally it gets very serious and you鈥檒l see a heart
补迟迟补肠办.鈥�

The link between chest pain and cocaine abuse isn鈥檛 always clear, says
Alexander. And this could mean that statistics on the number of emergency
hospital visits caused by cocaine use
(see below) are seriously underestimated.
Alexander also fears that people who repeatedly send their cardiac arteries into
spasm may suffer long-term heart damage.

John Henry, an expert on drug abuse at St Mary鈥檚 Hospital in London, is
similarly concerned. He suspects that up to 10 per cent of people reporting to
hospital with chest pain owe their problems to cocaine abuse. Henry is seeking
ethical approval to carry out anonymous urine tests for cocaine on everyone
reporting to his hospital with chest pain.