(Photograph) - A lethal bacterium is providing many people with the illusion of eternal youth. Victoria Neumark explains
This is a computer-generated model of botulinum, a nerve toxin also known as Botox. It is a protein, a hugely complex building block of life.
Proteins contain upwards of more than 300 amino acids, which not only can be joined together in millions of ways but can also be multifariously twisted and folded. Different shapes of the same protein act in different ways: famously, the drug thalidomide which created birth defects in human beings when used in its right-handed spiral form, was entirely safe in its left-handed twist.
Before computers, the only way to represent these tiny units of the universe -molecules and atoms - was the kind of structure made by James Watson and Francis Crick in 1957 and now widely available in science stores: all plastic balls, steel rods and cardboard cut-outs. Scientists would logically work out what kind of physical structure could represent the bondings between different elements and basically junk-model the result. Now, with powerful calculators allied to x-ray crystallography, computers can not only do the maths to make the models, but also draw them out in a dazzling array of colours and motions.
Botulism is a form of food poisoning that occurs when someone eats something containing a neurotoxin produced by the bacterium Clostridium botulinum (it may be present in shellfish or tinned meat). Botox is a trade name for botulinum toxin A, one of the neurotoxins produced by this bacterium. How has it entered the cosmetic repertoire of today, with celebrities as diverse as presidential hopeful Senator John Kerry, pop star Madonna, actor Leslie Ash and comic Joan Rivers, all rumoured to be among its users?
The most serious effect of botulism is paralysis, in some cases fatal. The botulinum toxins (there are many, from A to F) attach themselves to nerve endings. Once this happens, acetylcholine, the neurotransmitter responsible for triggering muscle contractions, cannot be released, basically blocking the signals that normally tell your muscles to contract. For example, if chest muscles are attacked, you cannot breathe. This is why people die from paralysis, but it is also why careful shots of the toxin into selected face muscles prevent - or freeze out - wrinkles. It is particularly successful for "glabellar" or frown lines.
Botox, the trade-registered product of Allergan, was licensed by the US Food and Drug Administration for cosmetic use in April 2002. Its effects last three to six months, just long enough for a movie to be shot, but needing topping up for, say, a presidential campaign. Senator John Kerry denies that he has had any treatment to prevent him looking - Jas right-wing detractors have put it -like "Keith Richards' square brother who went to business school" - but Dr Rod Rohrick, a Dallas-based plastic surgeon and president of the American Society of Plastic Surgeons, has defended the procedure. "Botox makes people look more at ease. It doesn't affect their minds," he says. "Baby boomers don't want to age gracefully, they want to manage their age. And if they want to look more relaxed, that's perfectly OK."
For those in the red-carpet life, there is an additional bonus. About 12 injections into each arm-pit (ouch!) prevents them sweating and staining that borrowed frock. Injections have also been used for blepharospasm (eyelid twitch), neck and shoulder cramp and dystonias (muscle spasms) such as writer's cramp and head tremors. Side effects can include shakiness, headache, neck pain, bruising and ptosis (the eyelid-drooping condition from which Salman Rushdie used to suffer).
Though Botox parties are popular in the US, doctors frown on them. Alcohol, as well as increasing the chances of a botched jab, can worsen bruising, and an unskilled, perhaps unsteady, hand can overdo the dosage and produce a doll-like immobility of countenance. Repeated use can lead to side-effects like skin and muscle-thinning. None the less, more than a million people in the USuse Botox and it is fast catching on here: at approximately pound;200 a go, 50,000 injections were used in the UK last year. A neat wrinkle, by anyone's standards.