US: Smoking not only causes cancer it may also speed up the growth of existing tumours.
Research by scientists at the Oregon National Primate Research Centre in Beaverton suggests that nicotine in cigarette smoke could stimulate the production of a molecule which can make lung cancer cells more aggressive and encourages them to divide and grow.
"Smoking may boost the growth of existing tumours as well as triggering cancer," New Scientist magazine said on Wednesday.
The molecule, called acetylcholine, is a neurotransmitter, or message-carrying chemical, in the brain and nerves. Mr Eliot Spindel and his colleagues found that some cancerous cells have receptors, or molecular doorways into cells, for the molecule.
They also discovered that fast-growing cells make large amounts of the molecule and have a feedback loop so that the acetylcholine they make encourages them to divide and grow.
But when the scientists cut the loop by blocking the receptors with the nerve gas antidote atropine the cells stopped growing.
"Our discovery reveals the little extra push by nicotine," said Mr Spindel, who reported his research in the journal Life Sciences.
He believes it may be possible, though not easy, to adapt drugs such as atropine to treat lung cancer, but added that the correct dose and making sure it doesn't affect the nervous system would be crucial.
"This loop can be revved up by smoking," Mr Spindel said, "so there's no question that not smoking is the best thing you can do." - (Reuters)
On the stroke of midnight on Saturday, the bars and restaurants of New York will, with a handful of exceptions, become smoke-free zones.
Penalties for establishments which don't comply range from $200 to $400 for a first violation, $500 to $1,000 for repeat offenders and up to $2,000 for a third breach. Three offences within a 12-month period would give health officials the right to close a bar or restaurant down.
The ban will expand to cover the whole of New York state in June. - (AFP)