Saturday, September 27, 2008

Leeches: The Fact Sheet

Biology

Leeches are annelids or segmented worms, and although closely related to the earthworms, are anatomically and behaviourally more specialised.

The bodies of all leeches are divided into the same number of segments (34), with a powerful clinging sucker at each end (although the anterior, or front sucker can be very small). Body shape is variable, but to some extent depends on the degree to which their highly muscular bodies are contracted. The mouth is in the anterior sucker and the anus is on the dorsal surface (top) just in front of the rear sucker.

Leeches usually have three jaws and make a Y-shaped incision. The Australian land leech has only two jaws and makes a V-shaped incision. Australian leeches can vary in size from about 7 mm long to as much as 200 mm when extended.

Different Types

Leeches are grouped according to the different ways they feed. One group (the jawed leeches or Gnatbobdellida) have jaws armed with teeth with which they bite the host. The blood is prevented from clotting by production of a non-enzymatic secretion called hirudin. The land leech commonly encountered by bushwalkers is included in this group.

A second group (the jawless leeches or Rhyncobdellida) insert a needle-like protrusion called a proboscis into the body of the host and secrete an enzyme, hemetin which dissolves clots once they have formed. Leeches which live on body fluids of worms and small freshwater snails possess such an apparatus.

A third group, (the worm leeches or Pharyngobdellida) have no jaws or teeth and swallow the prey whole. Its food consists of small invertebrates.

Respiration

Respiration takes place through the body wall, and a slow undulating movement observed in some leeches is said to assist gaseous exchange. Aquatic leeches tend to move to the surface when they find themselves in water of low oxygen content. As a fall in atmospheric pressure results in a small decrease in dissolved oxygen concentrations, rising leeches in a jar of water provided nineteenth century weather forecasters with a simple way of predicting bad weather.

Sense Organs

Sensory organs on the head and body surface enable a leech to detect changes in light intensity, temperature, and vibration. Chemical receptors on the head provide a sense of smell and there may be one or more pairs of eyes. The number of eyes and their arrangement can be of some use in Identification, however to properly identify a leech, dissection is required.

The Rhyncobdellids are capable of dramatic colour changes, and although not an attempt at camouflage, the significance of this behaviour is unknown.

Reproduction

As hermaphrodites, leeches have both male and female sex organs. Like the earthworms they also have a clitellum, a region of thickened skin which is only obvious during the reproductive period. Mating involves the intertwining of bodies where each deposits sperm in the others' clitellar area. Rhyncobdellids have no penis but produce sharp packages of sperm which are forced through the body wall.

The sperm then make their way to the ovaries where fertilisation takes place. The clitellum secretes a tough gelatinous cocoon which contains nutrients, and it is in this that the eggs are deposited.

The leech shrugs itself free of the cocoon, sealing it as it passes over the head.

The cocoon is either buried or attached to a rock, log or leaf and dries to a foamy crust. After several weeks or months, the young emerge as miniature adults. Studies show that the cocoons are capable of surviving the digestive system of a duck. Leeches die after one or two bouts of reproduction.

Feeding

Most leeches are sanguivorous, that is they feed as blood sucking parasites on preferred hosts. If the preferred food is not available most leeches will feed on other classes of host. Some feed on the blood of humans and other mammals, while others parasitise fish, frogs, turtles or birds. Some leeches will even take a meal from other sanguivorous leeches which may die after the attack.

Sanguivorous leeches can ingest several times their own weight in blood at one meal. After feeding the leech retires to a dark spot to digest its meal. Digestion is slow and this enables the leech to survive during very long fasting periods (up to several months).
Foraging - How does a leech go about searching for a blood meal?

A hungry leech is very responsive to light and mechanical stimuli. It tends to change position frequently, and explore by head movement and body waving. It also assumes an alert posture, extending to full length and remaining motionless. This is thought to maximise the function of the sensory structures in the skin.

In response to disturbances by an approaching host, the leech will commence "inchworm crawling", continuing in a trial and error way until the anterior sucker touches the host and attaches. Aquatic leeches are more likely to display this "pursuit" behaviour, while common land leeches often accidentally attach to a host.

The Bite

When a jawed leech bites it holds the sucker in place by making its body rigid. Using its semi circular and many toothed jaws like minute saws, it then makes an incision in the skin and excretes a mucous from the nephropores (external openings from the kidney-like organs). This helps the sucker to adhere. A salivary secretion containing the anticoagulant and a histamine floods the wound and the leech relaxes its body to allow the blood to be ingested. This mixture allows the blood to flow and also prevents clotting once inside the leech. A bacterium in the gut of the leech assists the digestion of the blood, and it has been shown that the type of bacterium varies with the type of host on which the leech feeds. The bacterium also prevents growth of other bacteria which may cause the ingested blood to putrefy.

Habitat

Most leeches are freshwater animals, but many terrestrial and marine species occur.

Land leeches are common on the ground or in low foliage in wet rain forests. In drier forests they may be found on the ground in seepage moistened places. Most do not enter water and cannot swim, but can survive periods of immersion.

In dry weather, some species burrow in the soil where they can survive for many months even in a total lack of environmental water. In these conditions the body is contracted dry and rigid, the suckers not distinguishable, and the skin completely dry. Within ten minutes of sprinkling with a few drops of water, these leeches emerge, fully active.

Freshwater leeches prefer to live in still or slowly flowing waters, but specimens have been collected from fast flowing streams.

Some species are considered amphibious as they have been observed in both terrestrial and aquatic habitats.

Uses in Medicine

For over 2000 years, leeches were needlessly applied for many ailments as an adjunct to blood letting. Their use in Europe peaked between 1830 and 1850, but subsequent shortages led to a decline in their use. Today there is a real clinical application in that they are of great value to plastic surgeons when venous congestion of skin and muscle flaps is a problem.

Leeches are treated in the same way as blood products and are reused only on the same patient.

Medical use of leeches also includes treatment of black eyes, and hirudin is used in the treatment of inflammation of the middle ear. Hirudin is also being developed for experimental use as a systemic anticoagulant, and may prove useful in invitro blood sampling.

Repellents

The most common enquiry regarding leeches concerns repellents. It is unknown whether a specific preparation is commercially available but there is a plethora of tried and tested, but unproven leech-protection ideas. These include a lather of bath soap smeared on exposed parts and left to dry, applications of eucalyptus oil, tropical strength insect repellent, lemon juice and impenetrable barriers of socks and pantyhose.

The Wound

The presence of hirudin in the wound following a leech bite may cause oozing to continue for several hours. Although inconvenient, blood loss is not significant.

Gut bacteria can cause wound infection. In the post-operative use of leeches this is closely monitored and dealt with by use of the appropriate antibiotic.

There may also be a delayed irritation and itching after a bite. There appears to be no support for the theory that mouthparts left behind after forced removal of the leech causes this reaction.

Can leeches transmit disease? There is no evidence to suggest that they do. The presence of trypanosomes, (malarial parasites), in the gut of jawless leeches has been noted, but jawed leeches do not appear to be hosts.

Allergy to leech bite has been reported. Medical opinion should be sought, depending on the severity of the reaction.

References
Mann, K.H. 1962. Leeches (Hirudinea) Their structure, Physiology, Ecology and Embryology. Pergamon Press Ltd
Williams, W.D.Australian Freshwater Life. Globe Press
Sawe, R.T. Leech Biology & Behaviour (reprint). Neurobiology of the Leech, 1981. Cola Spring Harbour Laboratory
Seliznev, K.G. et al. Use of the medicinal Leech in the treatment of ear diseases. Relat. Spec. (Switz) 1992 54 (1) 1-4
Wills, M.D. et al. The Medicinal Leech: an old treatment revisited. Microsurgery (US) 1993 14 (3) 183-6
Richardson, L.R. Observations on the Australian Land Leech, Chtonobdella Libbata (Grube, 1866). Aust. Zoologist V. XIV (3) 1968
Davies, R.W., Linton, L.R., Wrona, F.J. Passive dispersal of Four Species of Freshwater Leeches (Hirudinoidea) by ducks. Freshwater Invertebrate Biol. 1982 1(4) 40-44
Richardson, L.R. Trypanosomes in the crop of an Haemadipsid leech. 1968 Aust. Journal of Sci. vol 30 (9)

http://www.amonline.net.au/factsheets/leeches.htm

When modern medicine needs some help, surgeons call in mother nature's little helper - the leech

by Jack McClintock, Photography by Elinor Carucci
published online December 1, 2001
http://discovermagazine.com/2001/dec/featblood

"I was scalped by a box-making machine," says Christine Lippincott. She was working in a factory in Greensboro, North Carolina, and her attention wandered. "It caught my hair from behind and ripped it right off in a second, from the back of my neck to my eyebrows." Gushing blood, Lippincott fainted. Coworkers carefully extricated her scalp from the box machine, packed it in ice, and rushed it and her to the local hospital. A helicopter took her to Duke University Medical Center in Durham, where plastic surgeon L. Scott Levin sewed her scalp back on, meticulously reconnecting its blood supply in a six-hour operation.

But the crisis wasn't over. Levin could see that blood was flowing through the reattached arteries into Lippincott's replanted scalp. But it wasn't flowing out very well through her veins, which are vulnerable to clots and increased pressure. So Levin did what many up-to-date surgeons would do: He applied leeches.

"I had them on my neck and the back of my head," says Lippincott, who is 25. "There was a bucket of them in the room with me. Blood was pouring out of my scalp 24 hours a day for a week."

But that was the point. Bloodsucking worms maintained her circulation and probably saved her scalp. "It's a time-honored method that works extremely well in the right patients, the right clinical situation, the right application. It's a living drug therapy," says Levin, chief of plastic surgery and professor of orthopedic and plastic surgery at Duke's medical center.

Leeches aren't a surgeon's first option, of course. Other methods are tried first—trying to connect as many small veins as possible, redoing the surgery and, when a finger or toe is involved, removing the nail, scoring the nail bed with a scalpel, and putting the patient on heparin, an anticoagulant. But sometimes only a leech will do. That was the case with Lippincott. "If we hadn't done it," Levin says, "her replant might well have failed for lack of venous outflow."

The leech's peculiar talent is to create a wound that bleeds for hours. Substances in its saliva anesthetize the wound, prevent clotting, and dilate vessels to increase blood flow. Using them in surgery is simple: Poke the warm, blue, swollen, congested skin with a needle to start the flow of inviting, clot-dark blood. Apply a leech, and the voracious worm, having been stored unfed, will saw through the skin with the 300 teeth in its tripartite jaws. Its sucking mouth will draw out congested blood and maintain circulation until the patient's body creates new blood-flow channels. And when the leech has fed for 20 minutes to an hour, taken 15 to 30 milliliters of blood, and dropped off sated, its anticoagulant assures that the wound will ooze for 10 hours more. In Lippincott's case, Levin applied 30 to 40 leeches over six days.

Hirudo medicinalis, the European medicinal leech, is a four-inch-long carnivorous, hermaphroditic, segmented worm with a sucker on each end, five pairs of eyes, and 32 nerve bundles, or "brains," in the middle. It is one of 650 leech species and is found mostly in ponds and bogs. Some species are highly specialized—one, in fact, feeds only on earthworms. Another feeds on fish in freezing polar seas. One dwells in the nostrils of Saharan camels, another inside the rectum of the African hippopotamus. Another lives in New Guinea caves and sucks the blood of bats. Still another, the anaconda of leeches, inhabits the Amazon basin and grows up to 18 inches long.

For well over 2,000 years, humans have employed Hirudo for bloodletting, a practice thought to restore balance to the body's humors and heal everything from headaches to hemorrhoids. Leeches were so entwined with medicine that the words leech and doctor were synonymous in Anglo-Saxon English, and by the mid-19th century they had become the aspirin of their day—apply two leeches and call me in the morning. A French physician working in the early 19th century, François-Joseph-Victor Broussais, is said to have prescribed as many as 30 leeches at a time before he even saw his patients.

As medical science advanced, leeching died out, but with the advent of microvascular surgery and tissue transfer, surgeons rediscovered the creature's value. Two Slovenian surgeons pioneered modern medical leeching in the 1960s, describing how the worms assisted them in a tissue-flap transplantation. Then, in 1985, Harvard plastic surgeon Joseph Upton was called to care for a 5-year-old boy whose ear had been bitten off by a dog. Ears, which have very small blood vessels, had never been successfully replanted. Upton had no trouble with the boy's arteries, but as he worked through the night reconnecting the veins, clots began to form.

Upton had used maggots to clean severe infections while serving in the Army, so the idea of a natural remedy came easily to him. He phoned Biopharm, a company in Swansea, Wales, owned by zoologist Roy T. Sawyer, who breeds Hirudo on the world's only leech farm. A box of leeches arrived overnight, and the boy's ear was saved. When Upton published his results in the journal Plastic and Reconstructive Surgery, leech sales soared. Nine years later, in a memorably bizarre case, leeches saved a life. During an operation for congenital facial abnormalities, an 8-year-old Dutch boy developed swelling so severe that his tongue filled with blood and protruded from his mouth, blocking his airway. Steroids and antibiotics didn't help. But six hours and 27 leeches later, the boy was out of danger, and leeches had been firmly reestablished as good medical science.

Nobody knows how many lives, limbs, and appendages they have saved, but medical literature describes leeches being used to relieve severe postsurgical venous congestion after finger, toe, ear, and scalp replantation and penile surgery, after skin-flap plastic surgery, and to relieve engorgement of the nipple following breast augmentation or reduction surgery. And the creatures have turned out to be miniature pharmaceutical factories—researchers have isolated a dozen compounds from leech saliva to prevent blood clots, treat inflammation, dilate blood vessels, kill bacteria, and relieve pain.

Carl Peters, the leech-growth technician at Biopharm, removes the muslin cover from a plastic bucket, and leeches crawl out. He pokes one. It creeps across a visitor's hand, humping along with the suckers at its head and foot and arching its back like a Halloween cat. The creature feels wet and cool, like a chilled strand of fettuccine. Every few seconds, it stands on its rear sucker and waves its head around ominously, as if searching for something, which is just what it's doing. It's out for blood.

"It's like a cross between a slimy slug and a Velcro barracuda," Peters says with a grin and a glance toward the movie poster on the wall for The African Queen. In the movie, Humphrey Bogart's character says: "If there's anything in the world I hate, it's leeches. Oh, the filthy little devils!" Peters has worked with them for nine years and has been bitten five times. He says it doesn't hurt, "but I don't think I'd like to be plastered with leeches."

n nature, the medicinal leech inhabits the wetter environments of western and southern Europe. Sensing the warmth, motion, or shadow of possible prey, the leech cozies up, attaches itself with its suckers, injects an anesthetic so that its presence is not detected, and goes to work. The three jaws of its head sucker stiffen, protrude, and slice into the prey's skin with a sawing motion. Immature leeches feed on the thin-skinned bodies of amphibians and young fish; mature leeches can move on to larger prey, such as cattle, horses, ducks, and humans. The leech's natural anticoagulant, hirudin, keeps blood flowing for the 20 to 40 minutes it takes to feed, during which time the leech's body weight may increase 10 times, reaching up to 60 grams (about two ounces). The secretions of one leech can prevent up to half a cup of blood from coagulating. Blood sucked into its crop can take 18 months to digest. During this time, the leech does little but lie around in a stupor, rousing itself only to reproduce. The hermaphroditic leech copulates on land, wrapping around its partner using a kind of mucus, and later secretes a cocoon, which it deposits in damp soil near the shoreline. Within two to four weeks, about 15 to 25 leeches hatch. Under the right conditions, a leech can produce up to 1,200 young in a five-year lifetime. At Biopharm, leeches feed on pig blood poured into an artificial membrane that simulates the skin of natural prey. After rearing the leeches for six months at 80 degrees Fahrenheit, Peters transfers them to a room chilled to a growth-slowing 45 degrees. They can live there for a year without food.

When leeches leave Biopharm—thousands a year—they are packed like Chinese takeout in little cardboard boxes. They go to such places as Carolina Biological Supply, in Burlington, North Carolina, where workers store them in buckets of icy spring water until a surgeon like Levin calls. "We maintain them so that when surgeons get one, it's a nice, clean, hungry leech," says Lawrence Wallace, the firm's director for live biological products. Hungry they are; sterile they are not. In the gut of every one, even those raised in sterile conditions, lives Aeromonas hydrophila, a bacterium that prevents putrefaction of the leech's blood meal and supplies enzymes crucial to its digestion. Studies have found that as many as 20 percent of leeched patients become infected by this bacterium, which increases the risk of serious wound infections. So preventive antibiotics are given to patients with weakened immune systems.

Aeromonas also kills other bacteria. Joerg Graf of the Institute for Infectious Diseases at the University of Bern, Switzerland, believes that a better understanding of Aeromonas could help researchers find a way to fight such bacteria as Staphylococcus aureus, which are becoming resistant to antibiotics. For some reason, staph cannot grow inside a leech. This may be the result of inhospitable conditions within the leech, says Graf, but it's also possible that Aeromonas produces something that inhibits staph growth. Finding such a substance could lead to a way of controlling staph growth in humans.

But leeches themselves may prove a direct source of antibiotics. Michel Salzet of the University of Science and Technology in Lille, France, has found infection-fighting peptides in leeches akin to those that have already been discovered in insects and other invertebrates. In leeches, these peptides are produced within 15 minutes of a bacterial infection. "These antimicrobial peptides diffuse quicker and easier than antibodies," he says, suggesting that such speed and potency might add up to a defense that can outbreed and outrun pathogens. "Antibacterial peptides from leeches may cure human diseases," Salzet says.

That wouldn't surprise Roy T. Sawyer. Courtly and soft-spoken, the North Carolinian escorts a visitor through his leech museum. It's a tidy room, bright and cheerful despite its display of bowls and knives for bleeding, leech jars with perforated lids, and oil paintings of patients with leeches stuck on their necks. He speaks of a "veritable pharmacy" of leech products, referring to potentially useful compounds he and his researchers have turned up. There's the enzyme orgelase, a "spreading factor" that quickly distributes chemicals in leech saliva around the wound. Sawyer believes it could help carry local anesthetic deep into tissues before surgery. And there's calin, which neutralizes the effects of collagen, a natural blood clotter. He calls it a "collagen-coating paint" that could help prevent blood clots following vascular surgery. Sawyer and others have isolated a dozen more active substances from Hirudo and nine other leech species. Among these is a local anesthetic that renders a leech bite painless. How it works is still not understood, and Sawyer has been unable to isolate the analgesic. "Common sense is telling me something is there. This is a potentially rich area," he says. Salzet, who recently found a morphinelike compound in Hirudo, agrees.

The anticoagulant extracted from leech saliva highlights the difficulties of developing drugs from the animal. In the marketplace, hirudin competes against heparin, which is easily derived from vertebrate immune cells and works with certain cofactors to inhibit thrombin, a clot-producing enzyme. Hirudin works more simply than heparin, binding directly to thrombin alone, but its dosage must be carefully measured to prevent excessive bleeding. Long-term studies of hirudin in humans have not been carried out, but a series of small studies suggests it may boost short-term heart attack survival by as much as 30 percent over heparin. Other studies suggest it may be more effective than heparin in reducing deep-vein clotting after hip surgery.

But to make enough hirudin from leeches for economical production, "you'd need a swimming pool of blood," says Maurice Moloney, professor of plant biotechnology at the University of Calgary in Alberta, Canada. So he tried another approach, altering Ethiopian brassica, a type of mustard, to contain the gene for hirudin. He planted five acres of the plant and produced 10 tons of seed, from which he extracted the drug.

Another candidate drug from leeches is hementin, derived from the 18-inch-long Amazon leech Haementaria ghilianii, which Sawyer brought back from French Guiana in 1977. He wondered if this leech, which lances large mammals with a six-inch-long proboscis, also produced anticoagulants to prolong its dinner. It did. But while hirudin prevents clot formation, hementin dissolves a particular kind of platelet-rich clot that can cause stroke and heart attack and against which clot busters like streptokinase and urokinase are ineffective. A German firm, says Sawyer, may decide to to clone the compound.

Other scientists are studying the leech's large, easily visible nerves. Figuring out how they work could help in promoting nerve regeneration in humans with spinal cord injuries. But the leech's future in science, like its past, will most likely stick close to its main interest: blood. "Secretions from bloodsucking animals could be to cardiovascular diseases what penicillin was to infectious disease in the past," Sawyer says. "Leeches are preadapted to human physiology. The secretions from their saliva cross the entire spectrum of physiology: blood clotting, digestion, connective tissue, disease, pain, inhibition of enzymes, anti-inflammation. You name it, the leech has it."

Leech Therapy

Leeches have been used in medicine for thousands of years. Leeches remove blood ("phlebotomize") from their host, and they release pain-killing (anesthetic) and blood-thining (anticoaggulant) substances with their saliva. Live leeches are currently used to treat blood-congested limbs, which otherwise might die or require amputation, if the pooling blood cannot be removed any other way. They are also sometimes used to provide pain relief, and for many other therapeutic effects.

History of Leech Therapy

Leech therapy has a long history. Records indicate that Egyptians used leech therapy 3,500 years ago. Leech treatments were very popular during the Middle Ages. Again leech therapy became was commonly practiced in the 1800's by American physicians treating a variety of diseases.

In the 1980, medicinal leech therapy got a big boost by plastic surgeons who used leeches to relieve venous congenstion, especially in transplant surgery. This use of leech therapy ("hirudotherapy") provides a good example of its current status. When appendages are re-attached following traumatic amputation, it is often possible to reconnect the largfer arterial blood vessels, but not the thinner, more delicate venous vessels. The body will eventually develop the necessary venous connections to drain the area of oxygen-depleted blood; but if this does not occur rapidly enough, the pooling venous blood can produce enough swelling and pressure that fresh arterial blood may no longer be able to enter the re-connected limb. In this situation, leeches are used to drain the local blood and decompress the pressure within the grafted limb, otherwise at risk of necrosis (death).

Today, Medicinal leeches are also used in the treatment of other veinous deseases such as thrombophlebitis, as well as angina pectoris, arthritis, hematomas, and even tinnitus.

Natural History of Leeches

The medicinal leech (Hirudo medicinalis) is a segmented worm (Phylum: Annelida). This phylum includes the Polychaetes, the Oligochaetes (earthworms) and the Hirudinea (leeches).

Leeches have two "suckers," one at each end. The caudal (back end) suction cup helps the leech to ambulate on dry surfaces, and to attach to its host; the rostral (front end) suction cup also contains the mouth with three sharp jaws that leave a Y-shaped bite.

The medicinal leech lives in clean waters. Leeches swim free in the water, with an undulating motion. When attached to its host for feeding, the leech remains in place for 30 minutes to 6 hours or more, as it fills with blood. During feeding, H. medicinalis can suck 5 - 15 mL of blood --- several times its own body weight.

Leech saliva contains several bioactive substances, including anti-cooaggulants, vaso-dilators, and anesthetics. Hirudin, a potent anticoagulant in leech saliva, inhibits the conversion of fibrinogen to fibrin, preventing blood from clotting. Indeed, a wound may continue to bleed for many hours after the leech has already detached.

The benefits of leech therapy are due, in large part, to the anti-coaggulant effects, vasodilatory effects, and anesthetic effects of these biochemicals, as well as the physical effects of blood letting (phlebotomy).

Like a snake, the leech periodically must shed its skin. The leech is hermaphtroditic, having both male and female elements. Fertilization and egg-laying usually occur during the spring, summer, and winter months. Young leeches feed on the blood of small water animals (frogs, toads or fish). Leeches may not be ready for medical application until they are several years old.

Clinical Practice of Leech Therapy

The application of leech therapy is simple: leeches are gently placed in the area needed, and allowed to attach and engorge for the next 6-12 hours, after which they will release. The entire course of treatment may require one to 6 treatments or more, depending upon the goals and rate of response.

For more details about the specific application procedures, readers are referred to the manufacturer's directions. A list of manufacturers can be found elsewhere on this site.

Leeches (Hirudo Medicinalis) have been used medically for more than 1500 years. Originally used to remove “bad blood,” the leech is now used extensively by reconstructive surgeons needing to remove stagnant blood from a flap or reattached limb. When the venous blood does not return to the heart, it pools in the wounded area, increasing pressure and preventing fresh arterial blood from entering the area with oxygen and nutrients. The venous blood must be removed and the pressure must be reduced in order to save the flap or limb. The leech is able to do this exceptionally well, because its saliva contains important biochemicals, including vasodilators, anticoagulants, and anesthetics.

The leech will withdraw approximately 5 ml (one teaspoon) of blood. Further therapeutic benefit of leech therapy comes after the leech is removed, during which up to 50 mls of blood will continue to ooze, for up to 48 hours. More leeches attached to the site mean more blood will be removed. After 3-7 days, the veins have usually reconnected themselves such that the blood is no longer pooling in the limb. Normal color and pressure should return to the area, as arterial blood circulates easily in the damaged zone. By that time, the wound will be able to heal, without further phlebotomy (leech therapy).

The application of leeches to the patient is relatively simple, but does require care. As few as one, or as many as 6 or more leeches may be required for a wound, depending upon its size and its clinical response. The greatest number of leeches should be applied to the area of maximal venous congestion.

The patient’s skin must be cleaned thoroughly with soap and water, and then rinsed with distilled, non-chlorinated water. A gauze barrier around the area intended for the leech will help prevent the leech from wandering away from the site where it’s attachment is desired. It can be carried to the site by hand, or it can be placed within a 5 cc plastic syringe (plunger removed) and then applied to the wound site, containing the leech until it is attached.

If the leech is reluctant to bite, it might be necessary to entice it with a tiny droplet of blood, drawn from the wound site with a needle prick.

Once the leech is attached, it will likely remain safely in place until fully distended. The gauze square can be removed and used elsewhere without disturbing the animal;however, it is important that the site be checked continuously to insure that the leech hasn't moved. The leech will let go of the patient (host) when it is finished (usually within an hour).

What's New in Leech Therapy

In June, 2004, the U.S. Food and Drug Administration cleared for medical leeches for marketting by Ricarimpex SAS, based in France.

http://www.bterfoundation.org/indexfiles/leechrx.htm

HIRUDOTHERAPY - The leech therapy

Is by its blood-diluting and container-extending effect the leech ideal Therapist for blood circulation disturbances. With multiplicity of diseases there is a connection with an unsatisfactory blood circulation. Clearly on the hand all diseases lie with our container system are connected like:
- Thrombose
- Cramp veins
- Haemorrhoiden
- Vardiac infarct
- Impact accumulations
- Calcifying the containers
- Tinnitus

At the same time it could be stated that the leech therapy can cause an improvement also with pain. Positive effects could be determined with:
- Rheumatism
- Arthrose
- Volume disk problems
- Pulling
- Bruises
- Muscular pains
- Muscle injuries

The preparation of the patient

The patient should not use showering gel, lotions, etc. on those skin portions, on which the leech are to be touched down. A cleaning of the skin before the treatment is possible with water, curd soap or alcohol. The alcohol as well as curd soap must be washed off before the beginning of the treatment. For the treatment the skin of the patient must be warm. Therefore use warm water.
How many leeches do I need for a therapy

The necessary number of leeches depends by the following factors: Age and weight of the patient, the kind of disease and the size of the leeches available. When chronic illnesses one sets fewer animals for it the therapy however in shorter time intervals is on repeated. With acute diseases one uses more leech and has a longer period up to the next treatment. For a normal adult with standard weight and no further medical treatment and in a healthy condition 10 leeches may be used for a therapy.

The leech therapy

The leech sucks approximately 30 minutes. One should let the animals in peace suck and under no circumstances when sucking disturb. Likewise should not be under any circumstances smoked in the environment. Sucking should not be artificially interrupted. At the end of sucking the leech drops off alone. Sometimes it happens that the leeches after sucking are so tired and slow acting, that they remain hanging on the patient. Into such a case it helps to drive with a putty under the front suction cup and take so the leech off. Please make sure that the leech will not be crimped, in order to avoid an infection. For this reason also no salt may be used for removing the leechs.

Subsequent treatment

The blood letting after the suction should not be prevented; it is increases the effectiveness of the therapy and has a cleaning effect. In addition thereby the wound is cleaned from the germs. The blood letting usually lasts up to 12 hours. During the day the treatment the patient should avoid physical efforts. The wounds should be controlled in the next days up to healing.

Medicinal leech - Hirudo medicinalis

Scientific interest in leeches date back to ancient India. However, the first Western citation is credited to the Greek, Nicander of Colophon (c 130 BC). These early references were accounts of the use of leeches for bloodletting. This therapeutic use of leeches, the medicinal leech in particular, reached a height between 1825 and 1840. A more contemporary use of leeches was dicovered in 1957 by Markwardt. The leech secretion hirudin was isolated and subsequently its anticoagulant properties with respect to the elucidation of blood clotting mechanisms were examined.

Today medicinal leeches are used as tools in tissue grafts and reattachment surgery. Not only do they secrete anitcoagulants to prevent blood clots and relieve pressure due to pooling blood. It appears that leech saliva has other therapeutic properties. Leech saliva helps reestablish blood flow to reattached body parts by means of a vasodilator, provides a numbing anesthetic, and lessens the risk of infection due to an antibiotic.

Although leech feeding may be the first behavior one associates with medicinal leeches, neurotologists have examined this species with particular interest in interneuronal oscillators. The advantage of this preparation stem from the simplicity of its central nervous system (CNS).

Leech therapy with eye diseases

In the literature numerous referring to the successful employment of the leech therapy are with the most different eye diseases.

Haematoma

Leeches are an excellent means to resorb Haematoma within the eye range. This characteristic also the boxer in the United States have themselves too use made around the so-called "blue eye" or also violet mentioned to heal. By the employment trauma tables swelling already mostly disappear to the leech therapy after few days.

Glaucoma

The acute accumulation with Glaucoma responds well to a leech therapy. The headache and the eye pain mostly omit after setting the leech relatively rapidly and the internal pressure of the eyes come again on a normal level. A eye-medicinal treatment however cannot be replaced by the leech therapy.

Inflammations of the eyes

The following inflammations of the eyes are mentioned in the literature, with which the leech therapy may be helpful:
- Chorioiditis
- Chorioretinitis
- Iridochorioiditis
- Iridozyklitis
- Keratoiritis
- Retrobulbaerneuritis
- Skleritis

http://www.cliniccolonic.com/en/hirudo.htm

An African leech for use in microsurgery in Africa!

After being one of the mainstays of medical practice in Europe since the time of Hippocrates, use of the medicinal leech, Hirudo medicinalis, fell into disrepute in the second half of the 19th century but it has made a dramatic comeback in recent years! So popular was the use of H. medicinalis for draining blood ("leeching") as a cure for different kinds of disease, that over-collecting for hundreds of years in western and central Europe drove the species almost to extinction. Not surprising in view of the old hospital records cited by Adams (1988) that during 1829 and 1836 for example, between 5 million and 6 million leeches were used annually in hospitals in Paris, drawing nearly 85 000 kg of blood from patients each year! There are many similar records of incredible numbers of medicinal leeches being used across Europe. Indeed individual patients were often bled by 50-60 leeches at the same time and on consecutive days! The effects of this exploitation are seen in many parts of Europe today where the medicinal leech is still rare and was included in the "near threatened" category in the IUCN's 1996 Red Data List.

The "new found" use for H. medicinalis is in plastic and reconstructive surgery! These annelids have become valuable tools for saving transplanted skin flaps or grafts that have become congested with blood, i.e. the blood hasn't drained away because the necessary capillaries have not joined or formed as the case may be. This will cause the death of the flap - and happens in about 10% of procedures. Enter the leech! If hungry leeches are allowed to suck up the excess blood and so relieve the congestion and accompanying swelling - the flap can often be saved. A single leech will remain attached for 30-40 minutes and suck up 10-15ml of blood in that time. Their value lies in the fact that their saliva, which is introduced into the tissue as they bite, contains an anticoagulant, hirudin, which prevents clotting and therefore allows fresh, oxygenated blood into the wound area until capillaries have grown and proper circulation is established. In this way, leeches have helped save what in surgical jargon are called "pedicled skin flaps" on many different parts of the body, e.g. ears, noses, lips, eyebrows, scalp, fingers, hips and legs.

In South Africa however H. medicinalis is not available and has to be hurriedly imported when needed - often for an emergency. There are "leech farms" in the UK, Europe and the United States who will supply leeches but at considerable cost and of course a delay of a day or two which might make the difference between saving or losing a flap. We need a local source of supply and we have several indigenous species of blood-sucking leeches to choose from. One of these, Aliolimnatis buntonensis, was investigated and tested at a Durban hospital as a local alternative. It was successful! This leech is common in the lakes and marshes from KwaZulu-Natal northwards into Mpumalanga and Northern Province and is one of seven southern African species of large, brown leeches with alternating dark and light stripes running down their backs. It grows up to about 85mm in length and can be recognized by its central stripe being light and not dark brown. They swim well and while hippos are probably their natural hosts, they do not hesitate to attack people if they get the chance.

All bloodsucking leeches have a set of three sharp jaws with which they puncture their victim's skin leaving marks that resemble the Mercedes Benz star and a powerful, muscular pharynx to suck up the blood as it oozes out. In addition the intestine has many branches each of which fills with blood, allowing the leech to take in a bloodmeal large enough to last it many months.

There are however problems associated with the use of leeches in this way. One is the possibility that, if used on more than one patient, they could transmit pathogens like the hepatitis B virus and HIV from one patient to another. Research done on A. buntonensis in Durban by Glenn Wilken suggests that if a leech is fed on hepatitis B +ve blood, the virus may persist in its bloodmeal for several months while digestion takes place. Although we know nothing about the fate of HIV under such conditions, such "mechanical" transmission will be avoided by the general policy of using a leech only once.

Another problem is that probably all blood-sucking leeches harbour symbiotic bacteria, Aeromonas hydrophila, in their intestines. This bacterium helps with the digestion of its bloodmeal and also produces an antibiotic that limits the growth of other bacteria such as those that cause damaged tissue to become necrotic and die. It has been argued that allowing an A. hydrophila-infected leech to feed on a patient may expose that patient to infection by this bacterium too. Indeed cases of A. hydrophila infections have been reported in people after undergoing microsurgery in which leeches were used. The best way to avoid infections of this kind from A. buntonensis is to apply antibiotics such as gentamicin, amikacin, chloramphenicol and tetracycline to the wound immediately after the leech has released itself.

To date only wild-caught A. buntonensis have been used in microsurgery South Africa. It would be ideal if it could be bred in captivity, especially since leeches are often needed in emergency situations when time is of the essence. An example occurred two years ago when a small boy was caught in a combine harvester in the KwaZulu-Natal midlands. Both his feet were severed and although one had been re-attached successfully, the other was failing. Leeches were seen as the best option for saving it but unfortunately none were available. As far as I know, there are no laboratory colonies in the country. An attempt to do so in Durban was partially successful but showed that we do not know enough about the animal's reproductive biology to set up breeding colonies. More research is required on the breeding behaviour of A. buntonensis and also on methods for artificially feeding juveniles and discarded adults - each leech should only be used once and then used for breeding purposes.

We know that A. buntonensis breeds in summer when water temperatures are around 25°C. Gravid adults crawl out the water at night to lay cocoons containing an average of about 14 eggs each beneath vegetation on damp mud. Laboratory observations suggest that A. buntonensis is long-lived but grows slowly, its weight increasing 2.9 - 3.8 fold after a bloodmeal. Analysis of data from laboratory feeding experiments over 9½ months allowed Glenn to estimate that it will take about four years for A. buntonensis to reach the minimum suggested weight of 2.4g for use in microsurgery (H. medicinalis takes about 2½ years). This may however be an over-estimate since the interplay between the leeches' breeding cycle, nutritional state and temperature is complex and needs to be investigated before the optimal conditions for establishing breeding colonies can be determined.

by Prof. Chris Appleton

Leech Theraphy Videos

Bloodsuckers' banquet - leech therapy back in fashion



Leech Cures

Leech therapy may be useful in penile replantation

August 1st, 2004

Leech therapy may be useful in penile replantation.

"Penile amputation is a rare urologic trauma for which immediate surgical replantation is indicated," surgeons in the United States explained. "Microsurgical techniques can reduce skin and graft loss complications; nonetheless, such complications are still highly prevalent."

M. Mineo and colleagues at the University of Texas described "a case of self-inflicted penile amputation" and a "nonmicrosurgical technique for replantation."

"To improve postoperative edema due to venous congestion, we applied medicinal leeches to the penis," according to the report.

Leeches: An Ancient Therapy Is Revived

In the classic film The African Queen, Humphrey Bogart noted, "If there's anything in the world I hate, it's leeches — filthy little devils!" Why has the U.S. Food and Drug Administration approved the use of these lowly and much maligned creatures?

Leeches (Hirudo medicinalis) have been used in medicine for over 2,000 years. Syrian physicians began using leeches for blood removal (called bloodletting) as early as 100 B.C. Over the years, bloodletting likely harmed more people than it helped. In fact, George Washington is said to have lost over three quarts of blood in his last days as a result of the use of leeches. Many historians credit the loss of blood as the cause of his death. The use of leeches as a way of bloodletting gave way to other methods, and the medical leech became a historical curiosity. Fortunately, blood letting by any means has also been abandoned. That is, until recently. Plastic and vascular surgeons are turning to the use of leeches with increasing frequency.

Leeches are well designed for their task, bloodletting. They have sharp teeth to cut through skin and their saliva contains both a local anesthetic and blood thinner. The bacteria in their digestive tract help to digest blood, and they are capable of drinking several times their own weight at one meal. After eating, they can survive for months without another meal.

Some interesting leech facts:
- There are over 650 different species of leech.
- The largest leech is over 18 inches long.
- The leech has 32 brains.
- The medicinal leech has three jaws and 300 teeth.
- The bite mark of a leech looks like the emblem for the German carmaker Mercedes.
- A derivative of the blood thinner in leech saliva is used to treat and prevent blood clots.

To understand why anyone would use a leech today, you need to have an understanding of the limitations of surgery. When a surgeon reattaches a severed ear, finger, lip or other body part, it is relatively easy to put large blood vessels back together. So blood flow to the body part can usually be resumed. Unfortunately, blood flow in needs to be matched by blood flow out. If blood flow out is reduced, the finger or other reattached body part will swell and can become rather painful. This is what happens if you tightly wrap an elastic band around a finger. Blood flow out requires a fine drainage system that is interrupted and really cannot be sewn back together very well. If the problem is not fixed, the reattached part can be lost. Doctors sometimes resorted to “stabbing” the reattached body part dozens of times with a needle to let the blood that was collecting drain out. This process is both painful and not very successful. In 1960, two Slovenian surgeons reported on their use of leeches to help in the attachment of a large tissue flap. Since then hundreds of patients have been helped by the use of leeches.

Leeches usually don't need much coaxing to bite and draw blood. In the hospital, a nurse cuts a hole in the center of a piece of gauze and places it where he or she wants the leech to draw blood. The leech is placed in the center and allowed to bite. The bite is painless; leech saliva may have a local anesthetic effect (leech experts don't all agree that this is real). If the leech isn’t hungry enough, the nurse may make a pinprick using a sterile needle to draw a small amount of blood. That is usually enough of a lure to coax even the most difficult leech to bite. Once the leech makes its bite, it will usually stay attached until it is full. Even after it detaches, a blood thinner in the leech's saliva provides additional oozing from the site. Leeches have a habit of moving to warm moist places when they are full, so keeping an eye on them or restricting their ability to move around is a good idea. Once they are full, they will not bite again for months. Leeches are only used once and then destroyed, usually by first putting them to sleep with alcohol and then killing them.

The medicinal leech has made its way back as a useful therapy. Maybe they aren't such "filthy little devils" after all.

Last reviewed and revised on August 2, 2006
By Harold J. DeMonaco, M.S.
Massachusetts General Hospital

Harold J. DeMonaco, M.S., is senior clinical associate in the Decision Support and Quality Management Unit at the Massachusetts General Hospital and is currently a Visiting Scholar at the MIT Sloan School of Management. He is author of over 20 publications in the pharmacy and medical literature and routinely reviews manuscript submissions for eight medical journals.

Leech therapy ‘cures’ paralysis, osteo-arthritis

LUCKNOW, Uttar Pradesh (AsianAge), July 18, 2008

There is new hope for those suffering from diseases like paralysis, osteo-arthritis, hair-fall and skin disorders. The "Kaya Chikitsa" department of the Faculty of Ayurveda in the Institute of Medical Sciences at the Banaras Hindu University (BHU) now offers treatment of these diseases through the leech therapy. Ayurveda experts at the BHU have been successfully using blood-sucking leeches to treat human ailments, including paralysis and osteo-arthritis.

"We have treated many complex cases of osteo-arthritis, skin disorders like leucoderma, alopecia (type of baldness), paralysis induced by brain thrombosis, besides filarial and diabetic wounds which usually take time to heal," says Dr O.P. Singh, an expert in the leech-based prick and suck therapy.

The leeches, that often feared by humans for their blood sucking power, embody chemical enzymes which can work as catalyst in treatment of human ailments, by diluting blood clots in the infected body part, reducing the pain of the diseased part and ultimately improving the blood circulation in the problematic body area.

"Once the leech is allowed to prick and suck blood from infected body part of the patient, it not only sucks away the infected blood, but also salivates the treating attributes of the chemical enzymes into the patient’s body,’’ Dr Singh explained.

Giving the details of the procedure of the treatment process, Dr Singh said the leeches, before being administered on the patient’s body, were kept in a bowl of turmeric water that act as disinfectant and activating agent for the disease-treating leeches. The leeches are then set upon the infected part of the patient’s body to prick and suck blood.

A leech can suck up to 10 ml blood within a span of 40 to 60 minutes after which it automatically detaches from the body of the host. While the infected body part of the patient is bandaged properly and also dusted with "mulhathi" powder, the blood sucking leech is also dusted with turmeric powder and then cleaned with turmeric water to enable it to vomit the diseased human blood sucked from host’s body.

The leeches are then taken to the aquariums in bottles to be kept at room temperatures varying between 15 and 25ºC. Every bottle containing the leeches is assigned a unique identification code to ensure they are used only for the concerned patient for the remaining five weeks. Once the six-week treatment is over the leeches are destroyed.

The patients undergoing the prick and suck therapy are administered sufficient doses of immunity boosters like "Guruti Choorna" and "Ashwagandha Choorna" for the success of the side-effect free treatment.

Patients, mostly from rural areas, who come to the BHU for treatment, bring along non-poisonous medium sized leeches collected from village ponds.

According to Dr Singh, this type of therapy finds mention in ancient scriptures like Charak Samhita and Sushuruta Samhita. Besides, this technique of treating human disorders had been used to success in villages since centuries.

"BHU is the only centre in the northern region using the therapy termed Jalauka therapy (Jalauka means leech) since last year. Central Research Institutes in Orissa, Andhra Pradesh and Kerala are also using the leech therapy for curative purposes," the doctor added.

Source: Howrah News Service

BHU - Hair Loss Treatment

Experts at the Benares Hindu University in Uttar Pradesh successfully use non-poisonous leeches to treat ailments, ranging from paralysis to osteoarthritis. Patients have successfully been treated for skin diseases, arthritis, leukoderma and hair loss, as well. Successfully treated patients motivate others with similar problems to come here for treatment.

Patients are turning to leech therapy at the Benares Hindu University to cure them of ailments ranging from paralysis to hair loss.

Demi Moore Swears by Leeches Too!

The David Letterman Show, Demi Moore said the following: “I feel like I’ve always been someone looking for the cutting edge of things that optimize your health and healing… I was in Austria doing a cleanse and part of the treatment was leech therapy… These aren’t just swamp leeches though - we are talking about highly trained medical leeches. These are not some low level scavengers - we’re talking high level blood suckers… They have a little enzyme that when they are biting down in you it gets released in your blood and generally you bleed for quite a bit - and your health is optimized… It detoxifies your blood - I’m feeling very detoxified right now. I did it in some woman’s house laying on her bed. We did a little sampler first, which is in the belly button… It crawls in and you feel it bite down on you and you want to go, ‘You bastard.’ Then you relax and work on your Lemaze breathing just to kind of relax… You watch it swell up on your blood, watching it get fatter and fatter - then when its super drunk on your blood it just kind of rolls over like it is stumbling out of the bar.”

Hollywood celebrities are trying their hand at Rakta Moksha detox techniques too. While most people squirm at the thought of blood sucking leeches, celebrities like Demi Moore are swearing by leech therapy to keep themselves toxin free and youthful. According to US Magazine, leeches are Demi Moore’s secret to looking sexy at the age of 45.

“I feel like I’ve always been someone looking for the cutting edge of things that optimize your health and healing,” she told David Letterman when she appeared as a guest on his show a few months ago. Demi describes how four leeches got drunk on her blood, starting from her bellybutton, and how they don’t like hair and prefer waxed or shaved skin.

While Moore actually appeared on Letterman’s show to promote her movie Flawless, most of the conversation focused on how leech therapy has kept her health flawless. Check out the video for yourself:



Watch from this minute: 03:30 Demi Moore explain about Leech Theraphy in the show with David Letterman.

Could you ever imagine purposefully letting leeches suck on your blood? Yeah, me neither. But Demi Moore does, as a way to detox, according to this interview she had with Letterman a couple of weeks back. According to Demi, "I was in Austria doing a cleanse and part of the treatment was leech therapy. These aren't just swamp leeches though - we are talking about highly trained medical leeches." And does she feel better after the cleanse? She answers with a resounding yes, though she admits she didn't feel very good immediately following the procedure.

Using leeches for medical reasons was considered a legitimate, trustworthy cure ... in medeval times. But back then, redheads and people with freckles and people were thought to be witches too. So why revert back to that ancient way of thinking? I can't see any way this could possibly be healthy. Can you?

Ayurvedic Detox: Leeches Help You Live Longer

While most people squirm at the thought of blood sucking leeches, Ayurvedic medicine has had an obsession with these creatures for centuries. Leeches are a critical player in an age old form of Ayurvedic detoxification known as Rakta Moksha i.e. the letting of toxic blood. The technique, drawn from ancient Ayurvedic scriptures such as the Charak Samhita and the Sushrut Samhita has been a stronghold of Indian village medicine for centuries, says Dr. O.P. Singh of Banaras Hindu University, India’s renowned Ayurvedic educational institution.

The practice of rakta moksha using leeches has diminished considerably in Ayurvedic education and practice. Although university level courses are required to teach the theoretical aspects of this therapy, many do not offer practical education. But this is not a method that can be taught via chalk and blackboard; it takes dedicated time and patience to become well versed with species of leeches that not only suck infected blood but also salivate an enzyme called hirudin which has a therapeutic effect on toxic blood clots.

While interning at Vaidya Paranjpe’s clinic in Mumbai, I was trained to care for the leeches as much as for the patient. Identifying the species was a challenge in itself: it took months to learn how to distinguish between low-lying swamp varieties versus the specific medicinal varieties used for therapy. Disinfecting the leeches in in turmeric water was an essential precursor to applying them onto the patient’s infected body part. The application in itself was easier said than done; on one hand I had to deal with the temperament of the patient and on the other hand with the temperament of the leeches. I remember struggling in vain one day to attach a ’stubborn’ leech to a patient but no amount of coaxing could convince the particular leech to do so!

Once attached, a leech can suck approximately 10 ml of blood in approximately 30 minutes to an hour after which it automatically detaches from the body of the host. The infected body part of the patient is dusted with Mulhathi powder while the blood sucking leech is cleansed in turmeric once again to allow the organism to ‘vomit’ the diseased human blood sucked from host’s body.

Traditional Ayurvedic doctors who practice this form of detox are sometimes difficult to seek out as even today they tend to reside in rural India. The good news is that there is a renaissance in leech therapy is some of the more established Ayurvedic institutions. Banaras Hindu University is using leech therapy to cure diseases associated with aging including paralysis, hair loss and osteo-arthritis. And if that’s not hip enough, then consider the fact that celebrities like Demi Moore are swearing by leech therapy to keep themselves toxin free and youthful.

Now did you ever fathom that blood-sucking worms could meet your style and anti-aging needs?

History of Refludan

The name hirudin is derived from Hirudo medicinalis, the medicinal leech used since antiquity in the practice of blood-letting, or phlebotomy. As the leech fastens onto the patient's skin, its salivary glands secrete a powerful anticoagulant that prevents the blood clotting that would deprive the leech of its meal.

In 1884, John Haycraft, who was working in a pharmacology laboratory in Strasbourg, was able to demonstrate that leeches contained a substance with anticoagulant properties. Until the discovery of heparin, this substance was the only means physicians had to prevent blood from clotting.

Finally, in the late 1950s, attempts to isolate the anticoagulant agent in leech saliva were successful, and hirudin was named and classified as a thrombin inhibitor. In 1976, the primary chemical structure of hirudin was established. A number of difficulties arose, however, in isolating hirudin from medicinal leeches. A limited number of leeches was available due to the failure of breeding trials, and leeches were placed on the endangered species list.

Because of the shortage of leeches—and the potential value of hirudin for therapeutic purposes—hirudin was an appropriate candidate for production using genetic engineering. The development of recombinant technology has enabled production of large amounts or r-hirudin—now called lepirudin—which has many physicochemical characteristics and biochemical properties identical to those of the natural product.

Refludan injection contains the active ingredient lepirudin, which is a type of medicine called a hirudin. It is an anticoagulant medicine used to treat and prevent blood clots. Lepirudin is a synthetic version of the substance that leeches inject into flesh when biting to prevent blood clotting.

Blood clots normally only form to stop bleeding that has occurred as a result of injury to the tissues. Sometimes, however, a blood clot can form abnormally within the blood vessels. This is known as a thrombus. It can be dangerous because the clot may detach and travel in the bloodstream, where it becomes known as an embolus. The embolus may eventually get lodged in a blood vessel, thereby blocking the blood supply to a vital organ such as the heart, brain or lungs. This is known as a thromboembolism.

When blood begins to clot, a complicated cascade of chemicals is activated within the body. This results in the formation of a protein called thrombin. Thrombin is central to the complete process of blood clotting.

Lepirudin works by binding to thrombin and directly inhibiting its action, so interfering with the blood clotting.

Abnormal blood clots in the blood vessels are usually treated with an injectable anticoagulant medicine called heparin. Heparin is also used to prevent blood clots in people at risk, for example in people having orthopaedic surgery who are going to be immobile for a long period of time. However, in some people, heparin can cause the number of platelets in the blood to drop (a condition called heparin-associated thrombocytopenia). People who develop this condition cannot continue to have heparin treatment and lepirudin is used as an alternative.

Refludan is given as an injection or drip into a vein (intravenous infusion)

REFLUDAN is a bivalent direct thrombin inhibitor proven to significantly reduce the risk of serious consequences of heparin-induced thrombocytopenia (HIT). It is indicated for anticoagulation in patients with HIT and associated thromboembolic disease in order to prevent further thromboembolic complications.

(http://www.refludan.com/index.jsp)

The International Centre for Medicinal Leeches, Russia

BUSINESSMEN investing in Russia are constantly warned about "bloodsuckers" in the government, mafia and commerce, but in the town of Rodniki they are part of a global business worth millions of pounds.

The International Centre for Medicinal Leeches breeds the slug-like creatures for doctors and beauty treatments. Women will pay big money for eye cream manufactured from them, and it is believed Moscow gangsters reluctant to go to hospitals with bullet wounds are among those who visit private clinics where leeches are used to clean up messy injuries.

Gennadi Nikonov, whose business now turns over £20m a year, said: "It always has been a normal reaction for someone to think leech and go ‘yuck’, but the tide is turning. There is a worldwide trend to use them in all forms of medicine and cosmetics. There are many mysteries of this creature yet to unravel."

The leech has 60 kinds of proteins which can improve the immune system and reduce inflammation.

And now, with contracts in Ukraine and France, the eye cream made from dead leeches could turn into a £10m industry within 18 months. The cream, called Antonia, is currently selling 500,000 units a year. Two million jars have been ordered by an American importer based in Dallas, Texas.

"Antonina" cream is designed for the care of skin of any type. Due to medicinal leech bioactive complex NM1 and olive oil the regular usage of the cream relieves the feeling of skin dryness, face shrinkage after washing, takes out irritation and necrosis. The skin after cream usage becomes more smooth and elastic. The skin gets extant shade. The small mimic wrinkles are disappearing due to this cream. It has signified anti-inflammatory, antiseptic and tonic action.

Commercial Leech Farming in China

Kekang Biotechnology Co.,Ltd is the biggest company in China that industrialize extraction of natural hirudin market. They use Hirudinaria Manillensis as raw material to extract natural hirudin. Crude hirudin is firstly extracted repeatedly from living Hirudinaria Manillensis by using a self-owned patented technology and then purified to obtain refined natural hirudin. As a result, it takes the lead to realize the industrialization of hirudin in domestic market. As the most potent natural anticoagulant known up to now, hiirudin has been proved to exert a strong effect on prevention and cure of cardiocerebral vascular disease. In view of these virtues, hirudin has been used widely in medical, cosmetics and healthcare food industries and has great market potential.

Natural hirudin is widely used in cosmetics and healthcare foods in China. The sales amount hit 60 billion Yuan for 2003, increasing at an average rate of 15% annually. Experts have made a prediction that the sales amount of cosmetics in China will reach 100 billion Yuan by the year 2010. With the improvement of people’s living standard, requirement for the quality of cosmetics become higher and higher, making it gradually become the mainstream of market the cosmetics that contain natural elements. Healthcare industry is a worldwide sun-rise industry, and the market develops very fast. While in 1984 domestic consuming amount for healthcare products was only 2.0 billion Yuan, in 1990 it hit 10.0 billion Yuan. While in 1994 it was only 30.0 billion Yuan, in 1999 it hit 45.0 billion Yuan.

By 2003, it hit a breakthrough of 50.0 billion Yuan, finishing up 52.0 billion Yuan. That turns out to become a new growth of China’s industry in the new century. The core technologies of the project —repetitious extraction technology of hirudin from the living object of hirudinaria manillensis, technology of artificially breeding hirudinaria manillensis and renovated technology of hirudin products series, have been developed technologies with the company’s exclusive and independent intellectual property right, first of its kind at home. Applications for the following technologies have been submitted for the national patents for invention: the breeding method of hirudinaria manillensis and the extraction technique of hirudin (paten number: 031135668); hirudin extract cosmetics and its preparation method (paten number: 03140487.1). Generally speaking, the project has a mature technology and has begun mass production of the products.

The Natural Hirudin Properties from the Medicinal Leech

Natural hirudin is extracted from the salivary gland and saliva of Hirudinaria manillensis. It is a kind of single strand low molecular polypeptide containing 65 ~ 66 amino acid, universally known as the strongest natural anti-thrombin matter in the known matters in the world so far as well as the best drug for treatment of cardiovascular and cerebrovascular diseases. Statistics from the WHO show that about 17.00 million people die of cardiovascular and cerebrovascular diseases and the diseases, together with high blood pressure, have become the number one killer in China. In 2003, drugs sales amount totalled US$ 492 billion in the world (the sales amount concerning drugs for treatment of cardiovascular and cerebrovascular diseases was about US$ 45 billion, making up 12%), increasing by 9% over 2002. North America, Europe and Japan accounted for 4/5, becoming the main consuming area.

At present, foreign recomposed hirudin drug, which has been developed by way of gene engineering technology, has come into the market. Although recomposed hirudin is very similar to natural hirudin in the amino acid series and in the structure, 63-digit tyrosine residue has not been sulfated, making the inhibiting constant of recomposed hirudin against thrombin 90% less than natural hirudin. With another side effect of easily causing hemorrhage, recomposed hirudin is far beyond the natural one. Still with other defects such as short biological half-life period, high cost for treatment, it is difficult to promote the recomposed hirudin in clinic. Nonetheless, because of huge demand in the cardiovascular and cerebrovascular diseases market, recomposed hirudin products are still widely needed in the international market: Refludan of HMR Germany was permitted to go into the European market first in 1997. In 1998 and 1999, Refludan hit a big sale of US$ 9.00 million and US$ 14.00 million respectively in the worldwide market with an annual growth of 43%. According to the anticipation of HMR Germany, the potential sales amount for Refludan may reach US$ 235 million.

Natural hirudin has an obvious advantage on the anticoagulation drugs for it has the double functions of anticoagulation and anti-thrombus simultaneously. And what’s more, it seldom causes hemorrhage. So far, there is a tendency that the worldwide anti-thrombus drugs market is growing at a rate of 37%, for example, from US$ 6.7 billion in 1998 to US$ 9.3 billion in 2003.

Leech..... An Overview

Leeches are annelids comprising the subclass Hirudinea. There are fresh water, terrestrial, and marine leeches. Like their near relatives, the Oligochaeta, they share the presence of a clitellum. Like earthworms, leeches are hermaphrodites. There are 650 known species of leeches.

MEDICINAL LEECHES

Medicinal leeches are any of a group of several species of leeches but most commonly Hirudo medicinalis or the European Medical Leech. Other species sometimes referred to as Medical Leeches include (but are not limited to): Hirudo verbana, Macrobdella decora (North American Medical Leech), Hirudo troctina, Hirudo orientalis and Hirudinaria manillensis (Asian Medicinal Leech).

CLINICAL USE OF MEDICINAL LEECHES

Today, doctors use leeches for treating abscesses, painful joints, glaucoma, myasthenia, and to heal venous diseases and thrombosis. Medical leeches are used in plastic surgery, for improving blood circulation and for curing infertility.

The general indications for hirudotherapy are:

Inflammatory Reactions, Heart Diseases, Rheumatic Diseases, Tendovaginitis and Tendinitis, Venous Disease and Varicose Veins, Arthrosis, Arthritis, Muscle Tension, Antidyscratic therapy (blood purification and regeneration) of toxicoses and mental illnesses, Thrombosis and embolism, Passive congestions and spastic conditions, Vertebrogenic Pain Syndromes, Transudates and exudates.

A simple principle lies at the heart of all hirudo-miracles. During the process of feeding, leeches secrete a complex mixture of different biologically and pharmacologically active substances into the wound. Hirudin is the best known component of leech saliva. Hirudin is sometimes used to describe all active substance in leech saliva. In reality, Hirudin refers only to one specific active substance in leech saliva.

VETERINARY MEDICINE

The job of the leeches in veterinary medicine is spread since ancient time but it seems that the lack of material on the definite job of the annelidas is partly at the origin of their weak use in this domain. However the applications of the leech could be similar to those of human medicine.

The majority of the applications of the leech in human medicine are also valid in veterinary medicine. So they are similarly pointed out in the treatment of thromboses, phlebitis, furuncles, haemorrhoids, haematomata, enemata, tendinitis they can also be used in surgery in cases of tissulaires transplants.

COSMETICS AND PHARMACOLOGY

There are lots of bioactive substances in Medicinal Leeches and Leech Powder. These bioactive substances are used in Cosmetics and Pharmacies. Bioactive substances of the Medicinal Leeches:

1. Hirudin
2. Hyaluronidase
3. Pseudohirudin
4. Destabilase
5. Apyrase
6. Bdellines
7. Eglines
8. Kininases
9. Histamine-like substances
10. Collagenase
11. Leech prostanoids
12. Inhibitor of kallikrein of the blood plasma
13. Proteases
14. Lipolytic enzymes
15. Intibitor of Xa factor of the blood coagulation
16. Triglyceridase
17. Cholesterol esterase
18. Lipase

Although medicinal leeches have been successfully bred in laboratories for some time, we know little about their requirements for breeding, particularly for egg-laying in the wild. The medicinal leech leaves the water to lay its eggs, which are coated in a spongy protective cocoon. Cocoons must be deposited in a place where they will not dry out nor become waterlogged, and from where the young can easily reach the water after hatching.