The Rehabilitation of Princess Caraboo

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

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?

The February 2009 issue of Popular Science magazine has listed a suite of 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

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

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

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?

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.