BdellaNea

Leeches and their Playmates

2012-02-06T19:12:00.000-08:00

Sometime before May of 2011, one-time Playboy Playmate Yvette Vickers passed away. Her mummified body was found at her home in Benedict Canyon, CA. Vickers was well known as the female lead in the Gene (not Roger, his brother) Corman cult classic Attack of the Giant Leeches.

Playboy Playmate Pamela Anderson has had her own experience with leeches, as she described to Colin Ferguson in 2008, blaming them for a series of scars on her left shoulder, but admitting that she's lied about it her whole life and she forgets.

A Different Pink "Ribbon" Campaign

2012-02-06T18:42:00.000-08:00

Healing Breast Cancer With Leeches?

Malaysian news reports that a Sumatran homeopath claims to have cured breast cancer in many women with the application of leeches.

A bit lacking in the scientific method I am afraid. "I have not kept a record of the numbers but I think I have treated hundreds of women over the years and most of them were cured," Ismail said.

While I am highly skeptical, there is a kernel of truth. Most leeches have an antistasin in their saliva. It is one of many anticoagulants. This particular protein acts by preventing factor Xa from converting prothrombin to thrombin (thus preventing thrombin from converting fibrinogen to fibrin, and so preventing clot formation). Turns out that almost all Xa inhibitors, even those from hookworms have anti-tumor-metastisis functionality because they prevent a new tumor from creating its new blood supply (angiogenesis).
There's even a published research paper demonstrating effectiveness against lung cancer metastasis.

Nasty MDR Aeromonas from a leech bite. It was only a matter of time.

2011-07-16T09:38:00.000-07:00

A 56 yr old man who had leeches applied following facial reconstructive surgery picked up from leeches that were applied an Aeromonas infection that proved to be multi-drug resistant. Ampicillin was used as the initial prophylaxis and later even cipro couldn’t beat the nasty bug back. The flap tissue graft went fully necrotic and failed requiring repeat of the surgery 8 months later.

Given the severity of the outcome for this patient, it is unfortunate that the report, no doubt, continues the insufferable errors regarding the identity of the leech and the diagnosis of the bacterium. The leeches came from a leech supplier. It's already been shown that the leeches universally supplied by commercial outfits are Hirudo verbana, not Hirudo medicinalis. And it's also recently been clear that while the resident crop bacteria in Hirudo medicinalis, is in fact Aeromonas hydrophila, those in in Hirudo verbana most certainly are not; they are Aeromonas veronii.

The implications of these taxonomic identity errors are not trivial. Anyone looking for MDR Aeromonas hydrophila and not finding it in the natural environment could end up scratching their heads – because they’re looking at the wrong bug – the causative agent in this nosocomial leech case was assuredly Aeromonas veronii.

Widespread global use of fluoroquinolones means these antibiotics have been put out there in natural water areas just through flushing. Aeromonas species in leeches are also found living freely in those habitats where they are being exposed to dribbling, but selection-effective quantities of the antibiotics. Since every commercial leech operation needs to replenish its supply of Hirudo verbana from Turkey (as implied in the report), they are all going to bring this nasty bug with them.

Sims Medieval

2011-04-13T12:15:00.000-07:00

The Sims Medieval now released for the gaming community by EA. Build kingdoms, create heroes, wizards and blacksmiths, battle a witch or... collect leeches if your Sim is a physician! You can look in the ocean and the river for green spots with bubbles and collect them yourself, or buy them from the village store.
I'll ignore, for now, that leeching was more of a post-Enlightenment phenom than it ever was a medieval one.

Biotherapy

2010-12-03T07:43:00.000-08:00

Mixed messages from science reporting on a whole bunch of news webpages that just blithely copy each other.
E.g.,
"A new study, which will feature in the International Conference on Biotherapy being held in Los Angeles, has established that using maggots, leeches, and intestinal worms as an alternative to the pills may cure infections and allergies."
"science is beginning to back up their anecdotal claims that maggots, leeches and intestinal worms may be effective in the fight against everything from irritable bowel disease to allergies and psoriasis"
"the use of leeches, maggots and parasitic worms can help cure everything from irritable bowel syndrome to common allergies"

Yes, yes... using percutaneous migrating nematodes might alleviate allergies and asthma.
Yes, yes... maggots do help debrade and disinfect skin wounds.

HOWEVER... while leeches have been approved as a medical device by the FDA, it's got nothing to do with infection, allergy, IBS, or psoriasis. Their use is purely mechanical removal of congested blood in tissue that need time for the restoration of venous circulation. End of story. Nothing magic.

Yeeesh.

Leeches and the Opera

2010-11-01T07:45:00.001-07:00

There's been quite a lull in the availability of leeches in the news in recent months, but they have once again reared their awesome anecdotal heads in the story of famed blind tenor Andrea Bocelli.

I had the honor of an impromptu visit from Bocelli a few years back. He was in New York performing and was brought by my office in the course of a behind the scenes tour. Funny, though I knew of his work and stunning range of voice, it had escaped me that he is blind. Regardless, while his companion showed a keen interest in our wormy jars of live bloodsuckers, Mr. Bocelli expressed a revulsion (however mild) that I thought was a bit odd.

Now I get it.

A recent news article reveals that doctors tried to treat Bocelli's congenital blindness with leeches when he was about 12 years old. To no avail of course.

All is explained.

T. rex found alive, feeding on children in remote Amazonia!

2010-04-15T06:43:00.000-07:00

A new genus and species of leech, Tyrranobdella rex Phillips et al. 2010 with enormous teeth was described in the journal PloS ONE on Wednesday of this week. Found feeding from the nose of a 9 yr old child in the upper Amazon by Renzo Arouco-Brown of the School of Medicine at the Universidad Peruana Cayetano Heredia, this new T. rex is known from 3 nasopharyngeal cases, and may well be the first leech species for which Homo sapiens is the type-host.

Phylogenetic work in the publication demonstrates that T. rex is part of a larger evolutionary group of mammal-specific endoparasites, the Praobdellidae, which includes the terrible ferocious leech (Dinobdella ferox) from Asia as well as African and Mexican pests. Mucosal leech infestations by members of this family typically involve the naries, pharynx and hypopharynx, though more alarming mucosal infestation sites are noted by Anna Phillips of the American Museum of Natural History and her co-authors. While leeches are not typically thought to be significant parasites of humans, praobdellid leeches like T. rex have been known to cause life-threatening conditions that range from choking to severe anemia and even death.

In addition to Phillips and Arauco-Brown, authors of this new and formidable T. rex include Mark Siddall and Alejandro Oceguera-Figueroa, also of the American Museum of Natural History, Gloria P.Gomez of the Department of Microbiology at the Universidad Peruana Cayetano Heredia in Lima, María Beltrán of the Enteroparasitology Laboratory at the Peruvian Public Health Center, and Lai Y-Te of the National Taiwan University in Taipei. The research was funded by the the National Science Foundation (DEB-0640463), the Stavros Niarchos fund for Expeditionary Research, a
Theodore Roosevelt Memorial Grant, and a CUNY Science Fellowship.

Branchellion torpedinis - parasite of the day.

2010-01-25T06:35:00.000-08:00

In honor of the International Year of Biodiversity, my good friend and colleague Susan Perkins established a blog that designates a quaint quotidian critter as Parasite of the Day, for each and every day of 2010.

Today's entry is the enigmatic elasmobranch ectoparasite, Branchellion torpedinis (submitted by Al Dove of the Georgia Aquarium).

By way of adding to his contribution, please find below here two additional pics of the beautiful frilly leech:

Industrial Leech Husbandry

2010-01-11T06:54:00.001-08:00

A recent video piece from Reuters showcases the "International Leech Center" in Udelnaya, outside of Moscow. Alas, and uncritically, the piece gives voice to the local belief (and one that prevailed in European medicine the 1800s) that leeches are a cure-all. Among other things, we are told that they "boost the body's immune system" and "the level of endorphins". I can't find any scientific evidence of (or even studies on) the latter. And while it is true that leeches can induce an immune response, it typically is not a pleasant one. My own exposure to North American medicinal leeches induces what appears to be a delayed-type immune response leading to massive swelling in the afflicted extremity, peaking about 72 hrs after the bite.

Leeches for Learning

2010-01-11T06:41:00.000-08:00

Anna Phillips (my student working on medicinal leech diversity) continues her considerable efforts at educating the youth of this nation on the beauty of leeches. The Mount Airy News covered her visit to J.J. Jones Intermediate School in Anna's own home town. Locally she has been involved in the after school programs here at AMNH and she also teaches as a substitute in the science program at the Spence School.

Putting leeches on a tight leash

2009-12-18T10:14:00.000-08:00

Holly Tucker of Vanderbilt University writesa nice piece on our fine friends in the most recent New Scientist magazine. Check it out!

Forensic Leech Solves Oz Case

2009-10-21T07:44:00.000-07:00

Eight years ago Peter Cannon tied up a 71 year old woman in her remote Tasmanian home and stole several hundred dollars in cash. Unbeknownst to Cannon, a terrestrial leech (probably Philaemon grandis, endemic to the island) that had finished feeding on him, dropped off while he was in the midst of theiving.

The case remained unsolved until forensic experts extracted DNA from the leech gut contents, and matched fingerprinting profiles to those on record for Cannon. Cannon promptly plead guilty when faced with the incriminating match.

New Leech Species from Jersey

2009-10-14T06:24:00.000-07:00

Bill and Carol Ott found a huge leech in a ditch in their backyard in Alloway New Jersey, brought it inside and cared for it. That's a story enough in itself!! "We're just curious people," Carol Ott said.

Beth Wirchansky, a student of Dan Shain's at Rutgers, figured out it was a species new to science, and described it as Haemopis ottorum. Through molecular phylogenetic methods, Wirchansky and Shain corroborated its uniqueness and that its closest relative is Haemopis terrestris.

For the rest of the month, there is a display devoted to Haemopis ottorum, including live specimens, in the lobby of Rutgers-Camden's Science Building!

Congrats Beth.

Leeches in Creation Mythology

2009-10-07T08:10:00.000-07:00

Last year I posted the Osage Creation Myth in which Macrobdella decora is prominent.

Remarkably, leeches appear in a wide variety of creation myths.

In the Qu'ran:
“then of that fluid-drop (nutfa) We created a leech-like clot" (Quran 23:14)
"then did he become a leech-like clot; then did (Allah) make and fashion (him) in due proportion. And of him He made two sexes, male and female.”(Quran 75: 37-39).

In the creation myth of the Bengali Munda people in India, the benevolent Sun god Sing-Bonga is married to the Moon and brings forth a tortoise, a crab and a leech to create the land by bringing up soil from the sea bed. – Dalton (1872: Descriptive ethnology of Bengal, p 197). "SingBonga ordered them to bring a lump of clay (hasa) from the depth of ocean. The tortoise and the crab failed to do it. The leech went deep and deep to the ocean and finally found bit clay from the depths of the ocean and gifted it to the Supreme Sing Bonga. SingBonga by his power transformed the bit of clay into the earth. "

In Shinto creation mythology "After the sun and moon, the next child Izanagi no Mikoto and Izanami no Mikoto gave birth to was the leech-child. When this child had completed his third year, he was nevertheless still unable to stand upright." Alternatively: "The child which was born to them was Hiruko (the leech-child), which when three years old was still unable to stand upright. So they placed the leech-child in a boat of reeds and let it float away."

If PBS does it, I guess ABC will too!

2009-09-15T15:40:00.000-07:00

Just finished a morning live interview on ABC News Now

NOVA - Secret Life of Scientists - Kicks off with the Leech Man!

2009-09-02T04:45:00.000-07:00

The Great Leech Of Tlanusi'yï

2009-08-21T18:48:00.000-07:00

I recently had the opportunity to attempt a face-to-face encounter with the largest and most feared leech of North America.

As described by James Mooney (1891), in his accounts of the Cherokee myths and sacred formulas...

"The spot where Valley river joins Hiwassee, at Murphy, in North Carolina, is known among the Cherokees as Tlanusi'yï, 'The Leech place,' and this is the story they tell of it:

"Just above the junction is a deep hole in Valley river, and above it is a ledge of rock running across the stream, over which people used to go as on a bridge. On the south side the trail ascended a high bank, from which they could look down into the water. One day some men going along the trail saw a great red object, full as large as a house, lying on the rock ledge in the middle of the stream below them. As they stood wondering what it could be they saw it unroll--and then they knew it was alive--and stretch itself out along the rock until it looked like a great leech with red and white stripes along its body. It rolled up into a ball and again stretched out at full length, and at last crawled down the rock and was out of sight in the deep water. The water began to boil and foam, and a great column of white spray was thrown high in the air and came down like a waterspout upon the very spot where the men had been standing,. and would have swept them all into the water but that they saw it in time and ran from the place.

"More than one person was carried down in this way, and their friends would find the body afterwards lying upon the bank with the ears and nose eaten off, until at last the people were afraid to go across the ledge any more, on account of the great leech, or even to go along that part of the trail. But there was one young fellow who laughed at the whole story, and said that he was not afraid of anything in Valley river, as he would show them. So one day he painted his face and put on his finest buckskin and started off toward the river, while all the people followed at a distance to see what might happen. Down the trail he went and out upon the ledge of rock, singing in high spirits:

Tlanu'si gäe'ga digi'gäge
Dakwa'nitlaste'stï.
I'll tie red leech skins
On my legs for garters.

"But before he was half way across the water began to boil into white foam and a great wave rose and swept over the rock and carried him down, and he was never seen again.

"Just before the Removal, sixty years ago, two women went out upon the ledge to fish. Their friends warned them of the danger, but one woman who had her baby on her back said, 'There are fish there and I'm going to have some; I'm tired of this fat meat.' She laid the child down on the rock and was preparing the line when the water suddenly rose and swept over the ledge, and would have carried off the child but that the mother ran in time to save it. The great leech is still there in the deep hole, because when people look down they see something alive moving about on the bottom, and although they can not distinguish its shape on account of the ripples on the water, yet they know it is the leech. Some say there is an underground waterway across to Nottely river, not far above the mouth, where the river bends over toward Murphy, and sometimes the leech goes over there and makes the water boil as it used to at the rock ledge. They call this spot on Nottely 'The Leech place' also.

Leech Invasion in Atsugi Japan!!!!

2009-07-28T10:16:00.000-07:00

I love the dramatic music.

The Eyes Have it!!!

2009-07-28T07:00:00.000-07:00

As an undergraduate student taking Sherwin Desser's JZM252 parasitology course, I was fascinated by the nummber of "worm-in-the-eye" stories with which he regaled us. Loa loa, Onchocerca, Alaria, bot fly larvae, Toxocara (like Baylisascaris procyonis featured in an episode of House)... all potential eye parasites... ugh.
     I have often shown the image at right in public presentations about leeches. If you look closely you can see a Dinobdella ferox peeking out from behind someone's ~~lower~~ upper eyelid and it's back sucker holding onto the eyeball itself (the eye is upside down). This was sent to Gene Burreson by a physician in India many years ago, and it never fails to first confuse, and then disgust, a lunch-time scientific audience!
     The tribulations of people with leeches in their eyes continues. In regions of the world where the terrestrial leeches abound, like Australia and in the wet forests of Madagascar, leeches in the eyes and ears is all too common. Getting aquatic leeches in an eye, while less common, is perhaps more terrifying in light of the larger size of these "medicinal" leeches.
     The Australian story is remarkable for this misperception: "Dr Fogg says tweezers were not an option as simply pulling the leech off could leave its head lodged in the eyeball, leading to infection." Even if leeches had a head, which they do not, for this to be true, the head would have to embed, which it does not since the leech would be unable to suck blood without the seal it makes with its oral sucker.
     We might have Hollywood to blame for this. In The African Queen, Humphry Bogart's character Allnut (a Canadian, I might add), when he emerges from a swamp covered in leeches, declares to Rose (Katharine Hepburn), "No, no, don't touch 'em, don't! Salt, Rosie! ... You pull 'em off but their heads stay in! Poison the blood! Get the salt... If there's anything in the world I hate, it's leeches. Oooh, the filthy little devils."
     If you do get a leech in your eye, salt water will get it out. It will have to be saltier than your tears, so it's likely to sting, and you'll want to flush your eyeball with water afterwards.
     Every photograph of a leech in an eye is one where someone ran for a camera first instead of getting the thing out!

Marshal Brain - HowStuff(doesn't)Works

2009-07-23T13:28:00.000-07:00

Marshall Brain, creator of HowStuffWorks (now a subsidiary of Discovery), which purports to be a clearing house of accurate technological information, badly mangles the truth about leeches in two podcasts: one on what is a medical [sic] leech and the other on how to remove a leech. In these uncited, apparently non-fact-checked articles (none of the leech biologists I know got a call), beyond the preposterous assertion that leeches look like slugs, Mr. Brain claims:
1) that leeches merely double in size when they feed (they can increase 5 times their weight or more).
2) that leeches raised in captivity are "sterile to a certain degree" (all leeches, wild or farm raised harbour Aeromonas in their crop; a course of antibiotics is recommended during post-operative leech therapy)
3) that they quickly attach and start feeding (far from true, especially in North America)
4) that leeches hold on with rows of tiny teeth (they hold on with their suckers, the teeth, far too small for holding onto anything, and which do not meet in any kind of bite, are used only for making incisions)
5) that removal of leeches requires one "to rip the teeth away from your skin" (in fact all that is needed is to gently break the suction seal made by the oral sucker at the smaller end of the leech, once that seal is broken, the leech cannot hold on and can be readily removed by detaching the posterior sucker)
6) that is will not hurt "because the leech has injected a numbing agent" (see my previous post about this unsubstantiated myth)

This is all timely in light of Carl Zimmer taking to task George Will and the Washington Post for failure to fact check on science. Alas, some science writers too fail to fact check. Please note that Discover Magazine where Carl is a columnist has no relationship with Discovery Communications where Brain blogs about "stuff", like ~~medical~~ medicinal leeches.

Injury in Iowa - Leeches score another win.

2009-07-14T06:28:00.000-07:00

When Eric Poore looked at his finger, there wasn’t much left. Wedding ring smashed, skin, muscle and blood vessels stripped away... nothing but bare bone and the tendons holding the mangled mass together. Paramedics snipped off Eric’s gold wedding band and rushed him to the hospital. Fully four trauma centers declined to treat Poore’s poor finger until Greg Yanish rushed to fix it some hours later. Yanish describes the blood flow in a delicately reattached finger “like the drain in the bathtub is slow, but the faucet is on full blast”. Once more, leeches to the rescue! Application of several (prob. H. verbana) to the reconstructed finger both immediately and over several days and it looks like Eric Poore will get to keep his finger. (As an aside... my EMT friends remind me this is an excellent argument against titanium wedding bands... can’t be snipped off). Here's the full article from the Des Moines Register.

The Rehabilitation of Princess Caraboo

2009-04-02T07:06:00.000-07:00

The sensational story of Princess Caraboo regards a young lady arriving in Almondsbury, England (just North of Bristol) in 1817, speaking a strange tongue and sporting various tattoos. When it was determined that she was a Princess of Javasu, kidnapped by pirates from her Indian Ocean home, she was taken in by the local dignitaries and feted for some 2 months as visiting royalty. Her scam was exposed in short order. There is no Island of Javasu. She was, in truth, one Mary Baker from Witheridge near Exeter, who, unable to find continued employment as a servant, had hit upon this rather novel method for achieving food and shelter. After being shipped off to the US by her duped, and now chastened, benefactors, the Worralls, Mary eventually returned to Bristol and by 1839 was more gainfully and respectably employed... selling leeches, of course.

Leech Barometer

2009-01-27T06:05:00.000-08:00

The notion that leeches can predict inclement weather achieved its zenith with the creation of the Tempest Prognosticator (at left) by Yorkshireman inventor George Merryweather, and which he put on display at the first World's Fair (the Great Exhibition at London's Crystal Palace in 1851). The idea seems to trace back to the (occasionally insane) William Cowper (1731-1800) who wrote

"I have a leech in a bottle that foretells all these prodigies and convulsions of nature. Not... by articulate utterances ... but by a variety of gesticulations, which here I have not room to give an account of. Suffice it to say, that no change of weather surprises him, and that, in point of the earliest and most accurate intelligence, he is worth all the barometers in the world"

(letter to Lady Hesketh, 1789). Edward Jenner, to whom we owe the smallpox vaccine, was also an accomplished poet. In at least one (but not all) version of his Signs of Rain, the final lines read

"The leech, disturbed, is newly risen/Quite to the summit of his prison."

Merryweather cited these lines as inspiration for his Tempest Prognosticator. The device required a leech in each of 12 jars. The glass was to be transparent so that the leeches could "see each other" and so agree amongst themselves as to their prognostication. If any leech climbed up and into the escape tube, its weight would dislodge a piece of whalebone, releasing a hammer that would ring the bell thus announcing the onset of inclement weather. The Great Exhibition's jury rendered no verdict on this, imaginative, device. Nor did the Admiralty or the Board of Trade show much interest in Merryweather's storm warning system. Who needs doppler radar anyway?

Worst Science Jobs?

2009-01-22T14:30:00.000-08:00

The February 2009 issue of Popular Science magazine has listed a suite of 2009's worst jobs in science. Among them is Leech Researcher. Amusing and well-written article by Jason Daley. I must say though... I really think I've got the best job in the world (maybe next to Carl Zimmer).

Leech Meeting in Washington DC

2008-11-13T04:09:00.000-08:00

Friday November 14th,2008.
Waldo Schmitt Room
Natural History Museum

This event, gathering the country's leech biologists in one place, is becoming an annual affair as a premeeting to the Neurobiology meetings.

Morning session
8:45 am Welcome by Bill Moser and Otto Friesen
9:00 – 10:00 am Research talks John Hackett, moderator
Mark Siddall "Evolution of anticoagulation: Comparative salivary EST libraries from 3 leeches on 3 continents"
Eduardo Macagno "Application of MALDI imaging to study leech proteomics"
10:30 am – 12:00 pm Research talks (15’ each) Otto Friesen, moderator
Angela Wenning "News from our (leech) hearts"
John Hackett "Probing swim maintenance with drugs"
Peter Brodfuehrer "Swimming, glutamate and cell 204"
William Kristan"Leech decision-making"
Karen Mesce "Picking up the pace on what we know about the crawling motor pattern in the leech"
Afternoon Session
Posters

Leeches, Hirudin and Life Saving Dialysis

2008-10-02T07:06:00.000-07:00

Approximately 1 in 10,000 people in Western industrialized countries relies on dialysis to replace impaired kidney function or kidney failure. The more than 300,000 Americans, and 30,000 Canadians, who have their blood cleaned of toxins and metabolic waste, can thank leeches for the invention of this life-saving treatment. Georg Haas pioneered experimental dialysis treatments on animals at the University Hospital of Internal Medicine in Geising Germany. Preventing blood from clotting in the dialysis tubes was (and still is) critical to the success of the procedure. All of Haas' early experimental work was accomplished using crude leech extracts to prevent clotting. Unfortunately, the unpurified extracts proved toxic and leeches were hard to come by in light of over-exploitation during the latter half of the 19th century. Haas suspended his experiments during WWI until he learned, from the Father of American Pharmacology, John J. Abel at Johns Hopkins in Baltimore, of the availability of purified hirudin (the anti-thrombin from Hirudo medicinalis seen at right here). Haas performed the first human dialysis treatment in 1924 using this newly available purified hirudin. Expensive, hirudin would be supplanted by the wide availability of heparin in the next 3 years. Heparin is still used in dialysis treatments. Recently, at least 80 people were killed as a result of world heparin supplies being intentionally contaminated with cheaper chondroitin sulfate. It was another 20 years after Haas' bold move before Willem Kolff invented the first dialysis machine and 20 more before Belding Scribner opened the world’s first outpatient dialysis facility at the University of Washington Medical School.

Leech Cocoons

2008-09-03T12:00:00.000-07:00

In a series of papers, recently, Dan Shain (Rutgers University) and his colleagues have been carefully examining the structural and chemical properties of leech cocoons. As background, these cocoons are egg-cases that are secreted by the clitellum of leeches and they show some striking diversity. Brooding glossiphoniid leeches have a membraneous cocoon, erpobdellids and fish-leeches (below) cement their hardened cocoons to surfaces, and the medicinal leech cocoons (above) are pretty spongy looking. If you think about it, the material that goes into making these eggs cases must be pretty strange. First, whatever is secreted must adhere and polymerize quickly underwater and without any light or heat. Secondly, there's eveidence that leech cocoons are highly
resistant to denaturation or degredation; so much so that they seem to be showing up in Jurassic and Triassic deposits (e.g., Manum et al., 1991. Zoologica Scripta 20: 347-366; Jansson, et al. In Press, Early Jurassic leech cocoons from eastern Australia. Alcheringa). The work led by Shain has covered a variety of perspectives including the molecular composition of the proteins involved (one seems to belong to the same family as the factor Xa anticoagulants!), the structure of the cocoons and their biophysical properties.

Leeches clear a blocked carotid stent?

2008-08-08T07:47:00.000-07:00

The Sydney Morning Herald reports that a Mehdi Jaffari (at left here) managed to clear his 80%-blocked carotid artery by self-treatment with an Australian medicinal leech, Richardsonianus australis. Mr. Jaffari had had 4 heart attacks last year, and had a stent put in his carotid, only to be told in January that he had "advanced cardiovascular damage, with his left carotid artery almost 80 per cent blocked". Five days of leech therapy and the next angiogram showed it cleared. Hmm. Regardless of the veracity of the (as yet unrepeated) claim, the article contains an untruth: "while hirudin was known to dissolve blood clots, it was not known to dissolve plaque". In fact, hirudin only prevents clots. It does not dissolve them.

Leeches - PBS Wednesday - NOVA ScienceNOW

2008-07-21T14:15:00.000-07:00

Anoher reminder about our leech segment on NOVA this coming Wednesday (typically 9 pm). The NOVA website already has a few items up online. Including an accompany us in the field hunt for the Giant Amazonian leech, as well as an ask the expert interactive. A nice video podcast, distinct from the broadcast episode has been up on youtube:

Macrobdella the Mimic

2008-07-18T04:32:00.000-07:00

McCallum and colleagues, in an article just published in the Southeastern Naturalist, convincingly demonstrate that the rather striking colors of Macrobdella species, the North American medicinal leeches, the dorsal polka-dots, ventral orange with black specks, represent a case of Batesian or Müllerian mimicry.

Leeches in the Osage Creation Myth

2008-07-17T13:19:00.001-07:00

The North American native Osage Nation's creation legend concerns their ancestors' spirits ("the little ones") arriving on Earth but finding it totally covered in water. Eventually, the Great Elk manages to make the land appear by throwing himself down on the water, but not before the little ones have consulted a variety of animals, such as Macrobdella decora...

The Wi'-gi-e
The Sho'-ka hastened to the Red-breasted leech
And quickly returned with him
To the Red-breasted leech the people spake, saying: O, grandfather,
It is not possible for the little ones to dwell upon the surface of the water.
We ask that you make a search for a way out of our difficulty.
The Leech replied: You say it is not possible for the little ones to dwell upon the surface of the water.
You ask me to a search for a way out of your difficulty
I shall make search for a way.
Thereupon he pushed forth even against the current
Pulling himself repeatedly as he pushed on.
He came to a fourth bend in the current
Where he paused and spake, saying: It is not possible, O, my grandchildren.
Although it is not possible for me to give you help,
I will tell you: My walk in life is on the surface of the water.
The little ones shall make of me their bodies.
When the little ones make of me their bodies,
They shall be free from all causes of death.
When the little ones make of me their bodies,
They shall cause themselves to be difficult to overcome by death.
When the little ones make of me their bodies,
They shall enable themselves to live to see old age as they travel the path of life.
The days that are calm and beautiful
The little ones shall also enable themselves to live and see.

Francis La Flesche, 1922, Annual report of the Bureau of American Ethnology #36

Thanks to Peter Whiteley for informing me about this, to Kara O'Neil for sending me these particularly pretty specimens of Macrobdella decora from her pond, and to Sara Watson for the photos.

How to ratchet up the hit rate...

2008-07-09T12:58:00.000-07:00

It seems our friends over at the Dechronization blog have discovered that the internet was made for porn.

I will not be outdone. Herewith, a pair of Chtonobdella (c.f.) bilineata in-copulo! (Credit to Ralph Davis of Sydney, Australia).

Leeches are hermaphrodites, and most of these terrestrial jungle leeches have their male and female gonopores separated by 5 or fewer annuli. The male gonopore from which the penis is pushed out, is anterior to the female gonopore and the vagina; hence the head-to-tail (69) copulation technique. In fact, internal fertilization, though also a characteristic of aquatic medicinal leeches, seems to have originated in their terrestrial ancestors as a way to avoid sperm dessication.

So there... "porn", "penis", "vagina", "69", "sperm" and "copulation" all in one post.

Myth Busters: Leech Anaesthetic

2008-07-07T08:20:00.000-07:00

   Perhaps the most common misconception about leech bites, and one that I keep hearing, is that leeches have an anaesthetic in their salivary secretions. The idea seems to have started with Sawyer's Leech Biology and Behaviour, and has even been repeated in normally reputable journals and academic websites frequented by the public for information on various animals.
   The theory goes that leeches, being stealthy, inject an anaesthetic so as to avoid detection. Most notable was an NPR Science Friday story from August 26, 2005 in which a homeopath (Woodson Merrell, of Beth Israel Hospital) and a neurobiologist (George Stefano, Director of the Neuroscience Research Institute, SUNY at Old Westbury) promogulating the story that leeches inject a morphine-like substance to "numb" host tissue.
   Of course, the real story is that leech 'morphine-like' substances are in the neural tissues not in salivary tissue as had been known five years earlier (Laurent et al., 2000. Morphine-like substance in leech ganglia. Evidence and immune modulation. Eur J Biochem. 267:2354-61).
   It should come as little surprise that the myth of a salivary anaesthetic would be further repeated by BioPharm, Leeches USA, Niagara Medical Leeches, and Ricarimpex, (all purveyors of medicinal leeches). After all, patients might resist leech therapy if it is going to hurt.
   In my experience, the bites do hurt. Usually just a little, sometimes rather acutely (especially if your skin is not numbed from having been in cool water for half an hour), and in at least one case, intensely enough to cause one of us to nearly kick the dashboard off a rental car.
   More importantly, there is not a single refereed article in the scientific literature that in any way points to an anaesthetic in leech salivary gland secretions. Twenty years ago, Meir Rigbi and colleagues showed rather convincingly that it does not exist ( Rigbi et al., 1987. The saliva of the medicinal leech Hirudo medicinalis - II. Inhibition of platelet aggregation and of leukocyte activity and examination of reputed anaesthetic effects. Comp. Biochem. Physiol. 83C, 95).

BUSTED

If PBS Doesn't Do It, Who Will?

2008-07-02T13:27:00.000-07:00

Be sure to watch NOVA Science Now on your local public television station,Wednesday, July 23 at 9pm in which one of the segments is all about leeches!
A web dispatch (different from the July 23rd televised program) is available as a podcast from our time in the field doing the shoot last October.

Leech Pre-Meeting

2008-07-02T13:16:00.000-07:00

A meeting of leech biologists is planned for November 14th, 2008 in Washington D.C. in advance of the 2008 Neurobiology meetings. The meeting is NOT restricted to neurobiology. Please contact Dr. Otto Friesen (wof) at University of Virginia (virginia.edu) to express interest.

American Society of Parasitologists Award for Leech Research

2008-07-02T10:34:00.000-07:00

The best student paper presentation at the 87th Annual American Society of Parasitologists went to Anna J. Phillips for her present entitled "Hirudinidae³: Towards a Revision of the World's Medicinal Leeches". Here's the abstract...

Hirudindae contains the most notorious of the bloodfeeding leeches, the medicinal leeches. These worms gained in popularity with physicians practicing bloodletting, or phlebotomy, due to anticoagulants in the saliva that causes the bite to bleed freely, even after the leech has left. This treatment was performed worldwide, for centuries, with a member of the Hirudinidae native to the area. While a higher-level analysis of the Arhynchobdellidae, by Borda and Siddall (2003), found that the Hirudinidae is surprisingly comprised of two groups, this more intensely focused preliminary analysis shows that the Hirudinidae is actually split among three groups. A morphological analysis of twenty-two morphological characters, based on jaw dentition, sexual anatomy, and external morphology, failed to provide a resolution for most of the relationships in the family. DNA sequence data from nuclear 18S rDNA, nuclear 28S rDNA, mitochondrial 12S rDNA, and mitochondrial cytochrome c oxidase subunit I, were examined separately, and in combination, in a parsimony analysis. This analysis of representative species of the Hirudiniformes indicates that the world’s medicinal leeches comprise multiple independent groups. Clade membership is only partially indicated by continental origin. The African Hirudinidae are split between two clades, with the unexpected results of the North African and Eastern European taxa being sister to select genera of Central and South America, one of which is a new genus with a unique morphology among leeches. These results suggest that, what was previously considered the family Hirudinidae, is actually 3 families: the Macrobdellidae Richardson, constituted by most New World taxa; the “true” Hirudinidae, with the type species (Hirudo medicinalis); and a new family, including the subset of African species grouped with Limnatis nilotica and associated New World taxa.

Latest Therapy for Celebrities

2008-07-02T10:24:00.000-07:00

Watch as Demi Moore waxes poetic on Letterman about leeches on her navel.

Atlantic Monthly

2008-07-02T09:59:00.001-07:00

Leech therapy made it into Atlantic monthly's The 11 1/2 Biggest Ideas of the Year in this month's issue (Volume 301 No. 6 : July/August 2008).

Alas, not as a main article but one of their call-out boxes regarding best-new-old ideas.

Start Up

2008-07-02T09:47:00.000-07:00

I felt the time had come to start up a Hirudinology Blog and toyed with various names. HirudoBlogy didn't really strike the right tone... so BdellaNea it is (roughly, "leech news").

It's my intent, here to keep the community of leech scientists, aficionados and dilettantes alike, abreast of all things leechy as I find them or are informed of them.

With any luck, too, it will keep me abreast of the field somewhat better than I have been at times.

Welcome!