Spike (M.I.) Walker
English photomicrographer Spike (M.I.) Walker has been a consistent winner of the Nikon Small World competition for many years and has published many articles and a book about microscopy. Featured below is a photomicrograph of the antiviral drug idoxuridine (Herpid), as used for the treatment of Herpes, crystallized from aqueous solution.
Known by the brand names Herpid (UK) and Herplex (USA & Canada), idoxuridine is a topically applied drug that is often effective against viral infections. Available as eye drops or ointment it is used to treat herpes simplex infections of the inner eyelids or the cornea of the eye. It is also prescribed for infections of the cornea caused by vaccines. In the treatment of deep herpes simplex infections of the eye, for which corticosteroids are prescribed, idoxuridine may also be given to prevent the spread of any viral growth stimulated by the corticosteroid. When high doses or corticosteroids are administered orally or by eye drops for other disorders, idoxuridine is often given to prevent the flare-up of a previous herpes eye infection. The drug is also used on infected areas of skin and external genitalia. It may give some relief when used locally in shingles.
Idoxuridine is a nucleoside analog, similar to the nucleosides (building blocks) of DNA. The analog becomes incorporated into the new DNA being made by the virus, but -- since it is not the correct nucleoside - DNA synthesis is halted. Because viruses can only function within the cells of their hosts, it has been difficult. Fortunately, the majority of viral infections resolve spontaneously in most people and do not require specific medication. However, antiviral treatment may be life-saving in immunocompromised individuals, whose ability to fight infection is impaired because of drug therapy (e.g. immunosuppressants) or disease (e.g. AIDS).
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