Gross medicine: hundreds of years ago, maggots and leeches were "medicine cabinet" staples. Now, old is new again: ready to try them? (Life science: circulatory system).

A dazed young man recently stumbled into Pensacola, Florida's Baptist Hospital, bleeding profusely from a gaping facial wound. "He'd lost a chunk off his nose," says plastic surgeon Dr. Ian Rogers. "It was dangling from this little flap of flesh." Rogers performed delicate microsurgery to suture (stitch together) the patient's delicate nerves, blood vessels, and skin tissue--reattaching the nose tip.

The operation seemed a success, until the nose grew swollen and turned purple as a grape. The problem: Blood flowed into the reattached flesh through vessels called arteries, but the veins didn't transport blood away from the area fast enough. The condition, known as venous congestion, often occurs after reconstructive surgery, because damaged veins are thin-walled and difficult to repair. To clear out the congested blood, "I decided we needed to put a leech on his nose," says Rogers.

Is he crazy??? No way. When venous congestion strikes, a doctor must restore circulation quickly or else tissue dies. Enter leeches, a type of bloodsucking worm. "We always keep about a half-dozen of the little guys on hand in a refrigerator," says Rogers. "If all else fails, we call in the worms."

It may turn your stomach, but up-to-date doctors across the nation are taking a new look at the healing power of "folk" remedies like leeches and maggots (caterpillar-like fly larvae). These creepy crawlies were standard medical fare for centuries, until scientific advances supplanted them: In the late 19th century the sepsis theory held that keeping wounds and instruments free from germs promotes healing. Twentieth-century breakthroughs--like antibiotics, or germ-killing medicines--all but banished folk cures from modern hospitals.

Now, "almost by chance we're relearning that nature's medicines--often called `gross'--are sometimes the best," says Michele Root-Bernstein, author of Honey, Mud, Maggots and Other Medical Marvels.

SLIMY SURGEONS

Today, as in the past, doctors use maggots to eat dead tissue and clean out infected wounds. In nature, some fly species lay eggs in dead animals (carcasses). When the eggs hatch into wormlike larvae, called maggots, they secrete chemical enzymes that break down large molecules into smaller, digestible ones.

Scientists don't yet understand how these enzymes work, but the substances dissolve rotting flesh into a liquid that maggots slurp up like soup. "The maggots are satiated [full] after 48 hours," says maggot-therapy expert Dr. Ronald Sherman at the University of California in Irvine. When full, the maggots instinctively squirm away from the carcass and bury themselves in the ground to pupate, or become a pupa. A pupa is the inactive stage in the metamorphosis, or transformation, of many insects; it follows the larval stage and precedes the adult stage. During the pupal stage, larvae transform into adult flies inside protective cocoons.

During the Civil War and World War I, flies were naturally drawn to battlefield hospitals and sometimes laid eggs in the rotting flesh of soldiers' wounds. Amazed military physicians observed that wounds infested with maggots tended to heal better than noninfested wounds. Maggot therapy was born.

Today, physicians at 280 U.S. medical centers prescribe maggots to treat infected pressure ulcers (bed sores), burns, leg and foot ulcers, stab wounds, and post-surgical wounds that refuse to heal. "Maggots work faster than any nonsurgical method for wound healing and aren't as likely to injure healthy tissue," says Sherman, who raises medicinal maggots in an "insectary."

There, blowflies (Phaenicia sericata) "blow" up to 2,000 eggs at a time onto slabs of raw liver. Technicians wash eggs in disinfectant and place them in a sterile (microbe-free) container, so that larvae hatch in an environment without bacteria. In nature, blowfly larvae hatch in rotting animal flesh full of bacteria. But only maggots fed on sterilized meat in a lab are clean enough for medical use.

LAST CHANCE

When a patient has, say, a large leg wound that doesn't heal despite surgery and months--or years--of treatment with antibiotic oinments and cleansers, two options remain: amputation or maggot therapy. Which would you choose?

Treatment begins when a doctor places sterile fly larvae--no more than 8 per square centimeter--directly in the wound and covers it with a sheer nylon mesh "cage" to prevent maggots from worming away. The doctor then layers absorbent gauze atop the cage to keep larvae moist and absorb any liquified dead flesh. Maggots act in three key ways on a wound, Sherman says: "They debride [remove dead, infected tissue], disinfect, and stimulate healthy tissue growth."

About 48 hours after application, a doctor picks off the maggots with a moist gauze pad and discards them with other infectious medical waste, which is usually incinerated (burned). In a recent study, researchers found that the average maggot-treated leg or foot wound displays healthy tissue growth within three weeks (see chart, p. 9).

Does the notion of maggot therapy make patients' skin crawl? "I've never had anyone freak out--not even those who are initially grossed out by the idea," says plastic surgeon Dr. Jane Petro at Westchester County Medical Center in Valhalla, New York.

CALLING ALL LEECHES

If the thought of writhing maggots on your body makes you cringe, how about bloodsucking leeches? For centuries, doctors applied leeches (Hirudo medicinalis) for bloodletting, or phlebotomy; they mistakenly thought blood loss healed the body by letting impurities and excess fluid escape.

Today, when it comes to restoring blood circulation after reconstructive surgery, "leeches are very effective," says Dr. Donald Mackay of Pennsylvania State University College of Medicine. Why? One slug-like worm can gorge on up to five times its own body weight in blood! The medicinal leech, one of 650 leech species, is a 10 centimeter (4 inch)-long carnivorous (flesh and blood-eating) worm, found naturally in European bogs and ponds. A leech has a sucker on each end; the smaller one features hundreds of teeth (see diagram, left). Surprisingly, a leech bite doesn't hurt. That's because the worm's saliva contains a natural anesthetic, or painkiller.

Leech saliva also contains hirudin, a substance that keeps blood from clotting. During a 30-minute feed, a leech can draw off 30 milliliters of blood--about 5 or 6 thimbles full. The leech then drops off to digest its meal. But, says Ian Rogers, "thanks to hirudin, the bite keeps bleeding and promoting circulation for 12 to 15 hours." Leeches also produce a vasodilator, or substance that opens blood vessels. "Leeches are like a mini-drugstore," says Anna Baldwin at the Biopharm Leech Center in Charleston, South Carolina.

What about patient squeamishness? When a reattached finger is swollen with blood due to venous congestion, the choice is simple, says Dr. Jeffrey Friedman, a plastic surgeon at Baylor College of Medicine in Houston: "We can cut your finger off again or use a leech." Adds Donald Mackay: "I've never had any patient refuse the treatment. One patient even gave the leeches names!"

HEALING WOUNDS: MAGGOTS VS ANTIBIOTICS

In a study of 103 patients, wounds treated with maggots healed and shrunk in size faster than antibiotic-treated wounds.

[ILLUSTRATION OMITTED]

MAGGOTS AT WORK

Necrotic (dead) tissue fills a patient's skin ulcers (left). The open sores didn't respond to IV (intravenous) antibiotics. Three months after maggot therapy (right), necrotic tissue is replaced by healthy new skin.

ANATOMY OF A LEECH

REAR SUCKER

BODY WALL

NERVOUS SYSTEM

CIRCULATORY SYSTEM

DIGESTIVE TRACT

BRAIN

FRONT SUCKER

MOUTH

JAWS

In nature, the medicinal leech lurks in European ponds, where it feeds on blood just once every 18 months.

LET IT FLOW: Scientists extract the drug orgelase from leech saliva. It widens blood vessels, increasing blood flow.

IT'S YOUR CHOICE

After reading the article, choose the correct answer to these questions:

1 Sepsis theory is

A the use of germ-killing
  medicines.
B an outdated form of physical
  therapy.
C the idea that keeping wounds
  and instruments free of germs
  promotes healing.
D the idea that blood loss
  promotes healing.

2 Hirudin is a substance that

A kills bacteria.
B keeps blood from clotting.
C eats dead tissue.
D relieves pain.

3 Which of the following
correctly lists the developmental
stages of a blowfly?

A egg, larva, pupa, fly
B egg, tadpole, maggot, fly
C maggot, egg, cocoon, fly
D microbe, egg, pupa, fly

4 The word phlebotomy means

A bloodletting.
B using maggots to clean out
  wounds.
C skin surgery.
D using leeches to restore
  circulation after surgery.

BETTER THAN THE REAL THING?

Many doctors agree: Nothing beats a leech to promote blood flow in damaged tissue. But not every patient relishes the idea, says University of Wisconsin surgeon Dr. Gregory Hartig. That's why Hartig, along with Michael Conforti and Nadine Connor, invented a tiny bloodsucking gadget that mimics a squirming leech. "In the case of leech medicine, we can improve on nature," says Connor. Has the leech met its mechanical match?

In addition to its sleek, clinical design, the mechanical leech never gets full and falls off, so it can remove far more blood than the real thing. Here's how it works:

A A teflon-coated cone, or "sucker," is inserted beneath a patient's skin. Holes in the sucker cone release a cleansing solution.

B A tube delivers an anti-clothing drug into the wound

C A suction tube draws blood and solution to promote circulation.

D A glass vacuum chamber maintains suction.

Life Science: Circulatory System

[ILLUSTRATION OMITTED]

Did You Know?

* Researchers at the Essen-Mitte Clinic in Germany recently applied leeches to 10 patients who had knee pain due to osteoarthritis (degenerative joint disease). The treatment relieved pain and inflammation, but U.S. doctors say further study is needed before they'd advocate leech therapy for arthritis.

* Medicinal leeches, which cost about $7.50 each, can survive for months in a refrigerated jar of saline solution.

* Maggots excrete a chemical similar to ammonia that kills bacteria in a wound.

Cross-Curricular Connection

History: Have students research and report on other unusual medicinal beliefs and practices in the Middle Ages.

Critical Thinking: snake and bee venom, white clay, even honey have current medical uses. Choose one and research what doctors use it for.

Resources

A companion Web site to the four-part PBS mini series Red Gold: The Epic Story of Blood looks at the facts and myths about blood and its impact on everything from religion and medicine to commerce and popular culture throughout history. www.pbs.org/wnet/redgold/

For eye-popping closeups of medicinal maggots, check out the images on forensic biologist Dr. Mark Benecke's Web site: www.benecke.com/eyeofscience.html

CHECK FOR UNDERSTANDING

Name: --

Directions: Read "Gross Medicine." Then study the line graph to answer
the questions below.

1. What was the approximate surface area of the patients'
wounds at the start of the study?

a. 8 [cm.sup.2]
b. 5 [cm.sup.2]
c. 6 [cm.sup.2]
d. 4 [cm.sup.2]

2. After 1 week, what was the average surface area of the
wounds that received maggot therapy?

3. After 3 weeks, how much smaller on average were the
maggot-treated wounds than those treated with
antibiotics?

a. about 3 [cm.sup.2] smaller
b. almost 2 [cm.sup.2] smaller
c. nearly 5 [cm.sup.2] smaller
d. less than 1 [cm.sup.2] smaller

4. How much had the wounds NOT treated with maggots changed in size
after 4 weeks? Answer in a complete sentence:

ANSWERS

Gross Medicine

1. c

2. They were about 4 [cm.sup.2].

3. a

4. The wounds' surface area grew in size from about 6 [cm.sup.2] to
almost 7 [cm.sup.2].

Gross Medicine
1. c 2. b 3. a 4. a