Colin Salter - Science Is Beautiful: Disease and Medicine: Under the Microscope

Cocaine crystals (scanning electron micrograph)
Indigenous South Americans had been chewing the leaves of the coca plant medicinally and recreationally for a thousand years before cocaine was isolated in a German laboratory in 1855. Now cocaine is the second most widely used illicit drug in the world after cannabis. It has a medical application as a local or topical anaesthetic for eye, nose and mouth surgery, although its function is often replaced nowadays by less toxic drugs.
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In the first book in this series, Science Is Beautiful: The Human Body Under The Microscope, we looked in close-up detail at how the body works. We live in bodies which are masterpieces of complex machinery, a network of interacting, finely tuned systems which in normal use work so well that we dont even have to think about their operation. Our lungs breathe, our hearts beat, our faces crease with sadness or laughter, without any conscious instruction from us, the machines owner-occupiers.

In this book were turning our attention to what happens when things go wrong. Specifically we are looking at how bacteria, viruses and other disruptive forces manage to outwit the sophisticated defence mechanisms of our immune system. We look too at how science fights back, counter-attacking the invading diseases with ingenious medicines to prevent or cure disease. Remarkably, disease itself can sometimes be harnessed in the service of health. Doctors may deploy a so-called Trojan virus, which invades cells but prevents the spread of a more virulent infection. Vesicular stomatitis virus, for example, is used in this way to treat sufferers of HIV, cancer and ebola. Vaccination is another approach which actually gives us a small dose of a disease; this triggers the bodys defence against a larger dose. The first vaccine, devised in 1796, has been so successful that the disease it protected us from, smallpox, has been completely eradicated from the world.

Medicine is big business. It takes a long time for a new drug to be approved for public use, a process which requires significant investment long before any prospect of a financial return. Suppose theres a disease that youd like to find a cure for: first you have to understand the science of the disease. What does it affect? Where is it acquired? How is it transmitted? Only then can you begin your search for treatment. Once youve found something you think might work, you may start laboratory tests on cultured, infected cells. Only if the data from those tests looks promising can you start to do clinical trials on actual patients.

If after all that the drug seems to be effective, with side effects which are acceptable when compared to the medical benefits, you can start to produce and advertise your new miracle. Even then, everything has to be tested from the means of production and safety of packaging to the clarity of the leaflet telling you how to take the drug. And at every stage you are regulated by your countrys medical authority for example the Food and Drug Administration (FDA) in the US and the National Institute for Health and Care Excellence (NICE) in the UK.

It all costs a fortune, which is why pharmaceutical companies seek to protect their investment with patents giving them exclusive rights to manufacture and market new drugs. What seems like a high price for a medicine has to cover the costs not just of the pills and the bottle they come in but of years of research and development. But such high prices naturally discriminate against poor people and poor countries who may need the drugs most of all.