The little suckers have made a comeback - leeches

On the afternoon of Aug. 16, 1985, a dog in Medford, Mass. attacked a five-year-nd bit off his right ear. A child's ear had never been surgically reattached (an adult's had been once). The technical difficulty of this procedure was daunting: it was easy enough reconnecting an artery to restore blood flow to the ear, but reattaching the veins was, says Joseph Upton, who performed the operation, ''like sewing together strands of wet toilet paper'' -- strands just a hundredth to two hundredths of an inch in diameter.

During ten hours of work through a surgical microscope, Upton,a hand and microvascular specialist at Children's Hospital in Boston, reconnected one artery and four veins. But within a few days the boy's ear began to discolor, turning blue and then purple as blood built up in it. What Upton needed was some means of gently relieving the congestion while the veins healed. He turned to leeches.

The leech, long ridiculed as a medicinal tool, was at that time attracting renewed interest among European microsurgeons. In fact, Upton had tried leeches himself some years earlier, as an army surgeon treating congested tissue grafts. Now, when he needed them again, he found them unavailable in the U.S. A series of calls led him to a company called Biopharm in

Swansea, Wales, where Lorna Sawyer agreed to drive a package of about 30 medicinal leeches (Hirudo medicinalis) the three hours to London's Heathrow Airport. Upton met the flight in Boston and was able to wangle the delivery past doubting customs agents.

The first leech quickly fastened itself to the upper crest of the boy's ear and arched its neck, which began to pulse subtly -- a sign that bloodsucking had begun. Eight leeches and some days afterward, the boy went home with his ear intact, and newspapers and television newscasters around the country were hailing the triumph of the leech.

The source of Upton's leeches -- and of most leeches used in medicine or research -- was a sort of leech ranch in a disused Welsh steel plant. There, in darkened, temperature-controlled rooms, silent except for the whir and bubble of aerator pumps, Biopharmers tend more than 50,000 head of leech of eight different species. Singly and in knotty, glistening clumps, the leeches cling to the sides of buckets, fish tanks, long, shallow vats, and a converted fiberglass dinghy. They have an alarming tendency to mosey off from these habitats, which explains the netting, held down by strips of Velcro, stretched across the top of each container. Biopharm, the brainchild of an eccentric but highly regarded American scientist named Roy Sawyer (Lorna's husband), isn't merely a leech breeder or supplier. It's at the center of the medicinal leech's extraordinary resurgence.

Leeches are held in higher scientific regard now than at any time since the leechmania of the early nineteenth century, when they were often applied 50 at a time to cure patients of every disorder from nosebleeds to obesity. But if the present interest in leeches is more restrained, it's also more promising in its potential for yielding new knowledge and new therapies.

Nowadays leeches don't merely rescue reattached ears, lips, fingertips, and other surgical grafts. They've also become a leading model for researchers seeking to understand how the nervous system works -- how, for instance, some nerve pathways regenerate after injury.

Leeches have provided researchers with what Sawyer calls ''a living pharmacopoeia.'' Several biochemicals evolved by the leech for obtaining and digesting blood have recently been marketed as research tools. Some of them may one day be used to treat circulatory and other disorders. ''Before I conk it,'' says Sawyer, his accent veering from that of South Carolina, where he was brought up, to that of south Wales, ''I want to develop one of them into a pharmaceutical drug.'' He predicts that secretions from leeches will eventually do for cardiovascular disorders what penicillin did for infections.

Sawyer, 44, is a mild man, soft-spoken, slightly distracted. He can turn any conversation to leeches, and his green eyes pop just perceptibly when he hits pay dirt. According to Lorna, he was ''born with a leech in his mouth.'' But he dates his obsession only as far back as his boyhood in the coastal swamps near Charleston, where every frog, turtle, and budding naturalist looked like dinner to a leech. Sawyer gathered leeches and studied them, and one of his high school reports included mention of several species previously unknown to science, among them a turtle leech (Placobdella translucens) that was three inches long.

Sawyer returned to the leech in the course of his graduate research at the University of Michigan, and his scholarly interest grew into monomania. One night during their courtship, says Lorna, he took her out in party clothes and rubber boots to search a Florida swamp for a species that hadn't been seen since the 1870s. They failed to find it, but in the morning she heard an ecstatic whoop: a specimen of the leech had turned up inside one of her boots. She married him anyway. On another evening some time later, she heard an agonized cry from their living room, where Sawyer was in the habit of admiring a pair of ornate Chinese leeches. They had escaped, and the Sawyers had to tear up the wall-to-wall carpeting to find them. His devotion to his subject (and her tolerance for it) is such that he was able to spend twelve years, five of them without gainful employment, compiling his definitive three-volume Leech Biology and Behaviour, published last year by Oxford University Press.