by Bill Schutt
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*47The ban on consuming blood appears elsewhere in the Bible, such as Leviticus 7:26–27: “Moreover, you shall eat no blood whatever, whether of fowl or of animal, in any of your dwellings. Whoever eats any blood, that person shall be cut off from his people.”
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*48We know now, of course, that in many instances it is the presence or absence of pathogens (i.e., disease-causing organisms) in the blood and elsewhere that determine one’s health.
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*49Commodus was portrayed by actor Joaquin Phoenix in Ridley Scott’s film Gladiator.
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†50 One function of the liver was thought to be the conversion of tiny particles of food into blood.
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*51Black bile was supposedly produced by the spleen and was thought to be responsible, among other things, for the dark coloration of bodily substances, like blood and feces. Differing levels of black bile were also used to explain why some people had darker skin than others.
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†52 In 1462, a bloodletting calendar was the second medical text to be mass-produced using Johann Gutenberg’s revolutionary printing press. This was some eight years after the first Gutenberg Bible.
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‡53 Less well known is the fact that the Arab physician Ibn al-Nafis (1213–1288) had described much of this dual-circuit pump four hundred years earlier.
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*54Besides connective and nervous tissue, there are two additional tissue types: epithelial tissue, which covers surfaces and lines hollow structures, and muscle tissue, unique for its ability to store chemical energy, then convert it into the energy of motion as the tissue contracts in size.
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†55 The flexibility of cartilage, another type of connective tissue, comes from a gel-like matrix, which is basically bone matrix containing bendable protein fibers instead of calcium and mineral salts. Tendons and ligaments, which connect muscle to bone and bone to bone, respectively, are also structures composed of connective tissue, and they get their strength from the tough, wirelike fibers found embedded within their matrices.
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*56Like other pressure measurements (e.g., barometric pressure), blood pressure is measured in millimeters of mercury, so that a systolic pressure of 110 represents a force applied to the blood vessels’ inner walls equivalent to one that could raise a thin column of mercury 110 millimeters in height (were that column of mercury sitting at sea level in a U-shaped glass tube).
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*57Oxygen (which is actually carried around inside red blood cells) and nutrients diffusing in this manner are said to be following a concentration gradient, moving from areas where they’re in a higher concentration (the blood) to areas where they’re less concentrated (e.g., oxygen-and nutrient-starved tissues and cells).
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*58Like vertebrate blood, hemolymph does carry nutrients, hormones, and metabolic waste. It also functions in clotting and the immune response.
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*59Hemoglobin’s high affinity for carbon monoxide, coupled with the fact that the gas is odorless, are two major reasons why several carbon monoxide detectors are an absolute must for every home. In fact, if you’re reading this and don’t have a CO detector, put this book down and go buy one (or order it online). It’s that important.
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*60Blood can be separated into its three major components by spinning it in a centrifuge. A band of erythrocytes (making up 44 percent of the blood volume) will settle to the bottom of a centrifuge tube, with a thin band (1 percent) of leukocytes and blood platelets (known as the buffy coat) sitting above that. The yellow-colored plasma rests on top, making up the greatest portion (55 percent) of the blood volume. By measuring the hematocrit, the proportion of the spun blood composed of red blood cells, doctors can test for conditions like anemia (a decrease in red blood cells) or polycythemia (an increase in red blood cells). For those of you who may be wondering, the blood is prevented from clotting during this procedure by spinning it in heparinized tubes.
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*61For documentary footage of a large, alien macrophage, I recommend watching the 1958 film The Blob (starring Steve McQueen). By doing so, you can get a pretty good idea of how phagocytosis works.
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*62This is pretty much why you don’t catch the same strain of flu twice and also why you need a new flu shot every year: new viral strains evolve new surface proteins (antigens) that go unrecognized by memory cells or circulating antibodies.
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*63Back then, people ascribed to the concept of vitalism, in which all creatures possessed an inner force responsible for their specific traits (like bravery in lions or a lust for gold in those working in the insurance industry).
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*64Mauroy’s dark-colored urine probably resulted from the chemically altered hemoglobin, released by transfused red blood cells blasted apart by the man’s immune system. Perhaps owing more to luck than anything else, Mauroy began to recover and Denis reported that on the very first day his patient was able to go to confession, he began urinating normally.
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*65Strangely, blood was not the liquid of choice during other early attempts at transfusion. According to the American Red Cross, ale, wine, and milk were used. As late as the mid-nineteenth century, physicians injected patients with milk to treat cholera, believing that the “white corpuscles of milk” would convert into the red corpuscles of blood. This wasn’t as strange an idea as it might sound, since there are many similarities between the two liquids.
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†66 Landsteiner won the Nobel Prize for his work in 1930.
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*67In his book Blood: An Epic History of Medicine and Commerce, Douglas Starr hypothesized that early transfusion recipient Antoine Mauroy actually suffered from an advanced stage of syphilis (which is caused by the bacterium Traponema pallidum ). Starr suggested that Mauroy’s early positive results might have occurred after a transfusion-induced fever killed off the heat-sensitive pathogens for a while.
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*68In this technique, a glass cup was inverted over a flame, heating the air within. The cup was then placed flush against the patient’s skin, and when the air within it cooled, a vacuum formed, which was believed to draw out toxins from the body.
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*69Mechanoreceptors are specialized sensory structures that are stimulated by physical contact (just like chemoreceptors are stimulated by chemicals).
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*70To put the diversity of the Hirudinea and its 650 members into perspective, there are roughly five thousand species in the class Mammalia and about thirty thousand species of bony fishes in the class Osteichthyes. Whenever we vertebrate biologists get too pumped up over the vast number of animals we have to study, it’s often sobering to check out the invertebrate class Insecta. This group wins the Animal Diversity Contest hands-down, with estimates of well over one million living species, including over three hundred thousand species of beetles!
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*71One Trinidadian genus (Lumbricobdella) has reverted to the burrowing lifestyle of its ancestors. Not surprisingly, this leech has lost its caudal sucker and moves through the soft ground much as an earthworm does.
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*72Those readers interested in learning more about leeches (a lot more, actually) should consult Roy T. Sawyer’s 1986 three-volume magnum opus Leech Biology and Behavior.
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*73According to American Museum of Natural History leech expert Mark Siddall, the leeches being cultivated today at places like Leeches USA aren’t really Hirudo medicinalis but Hirudo verbana (a species that isn’t protected by the Convention
on International Trade in Endangered Species or approved for use as a medical instrument by the U.S. Food and Drug Administration). Just as important, it appears that wild leeches, from across Europe, comprise three separate species, creating at least the potential for three times as many anticlotting compounds. Rudy Rosenberg said that if the new classification is accepted he will petition to extend its approval to Hirudo verbana.
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*74Like many freshwater leeches, Hirudo is most active in cold water (around 42–45°F, or 5–7°C). Presumably, this is when their aquatic prey are sluggish or inactive and therefore easily attacked. Many leech species become stressed out in warm water, probably owing to a decrease in dissolved oxygen. In some freshwater species that prey on fish, a rapid increase in water temperature coincides with a detachment from their prey, whereupon the leeches reproduce and die.
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*75Whalebone is the layman’s term for baleen, which isn’t bone at all. Baleen is composed of the waterproof protein keratin and grows in plates in the mouths of filter-feeding whales (like the blue whale, Balaenoptera musculus ). Biochemically identical to hair, baleen tends to curl or frizz in humid air, while straightening out in dry air. This property may or may not explain why Merryweather used it in his contraption—since the definitive function of this substance remains uncertain from the somewhat vague descriptions.
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†76 This behavior is similar to that reported in a study of juvenile blacktipped sharks (Carcharhinus limbatus), schools of which were reported to respond to barometric pressure changes associated with approaching tropical storms by moving to deeper water. Darrin Lunde, of the American Museum of Natural History, suggested that the vertical migration of Merryweather’s leeches might be explained by the fact that aquatic leeches move out of the water and onto land only when conditions are humid and wet—as they generally are after significant drops in barometric pressure.
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*77Byron was long rumored to have been the true author of The Vampyre, a work credited to his former friend, the physician John Polidori. Evidently, Byron came up with the tale during the laudanum-fueled summer of 1816 as he and his friends (including Mary Wollstonecraft Shelley) spun tales of horror during their stay at Lake Geneva. After Byron discarded the idea, Polidori expanded it into a short story whose leading character, the aristocratic Lord Ruthven, would become an inspiration for Bram Stoker’s Count Dracula.
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†78 Stalin had recently initiated a purge of physicians (including his own) after claiming that they were part of a sinister Jewish plot to destroy the Russian people. The traitorous doctors, Stalin claimed, were murdering Russian statesmen. According to rumors, mass deportation of Jews to Siberia was to begin on March 5, 1953.
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*79I wondered if any such contrivances had prevented the “wedding night” leeches described by Brantôme from bailing out when attacked by what must have seemed like a blind but energetic relative.
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*80Leech teeth are more accurately referred to as denticles since they don’t share an evolutionary origin with vertebrate teeth.
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†81 This necessitates a dorsally located anus.
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*82In a 1994 study, Norwegians Anders Baerheim and Hogne Sandvik proved that medicinal leeches took twice as long to bite after they had been briefly submerged in Guinness stout (187 seconds to 92 seconds for the water control). According to the authors, “After exposure to beer some of the leeches changed behaviour, swaying their forebodies, losing grip, or falling on their backs.” Presumably after the leeches sobered up, they were used to test an old wives’ tale that a little soured cream applied to the skin would encourage leeches to feed more readily. The results of their study did not support the claim. Finally, Baerheim and Sandvik applied the leeches to arms that had been smeared with garlic. The researchers reported that the leeches “started to wriggle and crawl without assuming the sucking position” and “did not manage to coordinate the process” of biting. The experiment was halted after two leeches dropped dead within two and a half hours of exposure to the garlic-swabbed limb. Lest the reader question the seriousness and scientific relevance of this study, the authors, in their acknowledgments, thanked a local brewery “for supplying sufficient amounts of their precious liquid to satisfy the needs of all participants of the study.” They also thanked the leeches for their enthusiasm, assuring readers that the worms were “by all accounts grateful to Hogne Sandvik for supplying his own precious liquid.”
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*83Not everyone is enamored with the therapeutic uses of leeches, as was recently illustrated by the development of an artificial leech by researchers at the University of Wisconsin. Basically, the device is a glass vacuum chamber with separate tubes for suction and the introduction of the anticoagulant heparin. Inserted just under the skin, the disk-shaped tip rotates to inhibit blood clotting.
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*84Less than three years after returning to work, my dad had a major stroke that crippled his body and brain for the last thirteen years of his life. William A. Schutt Sr. died in the spring of 1992 at the age of seventy-one. He had survived the poverty of the Great Depression, D-day, a nightmarish boating accident, and a horribly disabling stroke. He was the bravest man I have ever met.
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*85Rudy actually finished the story by reiterating that leech therapy shouldn’t be undertaken at home or without the supervision of a physician.
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*86According to New York City’s Department of Housing Preservation and Development, there were no complaints of bed bugs in fiscal year 2003, 79 complaints in 2004, 928 in 2005, 4,638 in 2006, and 6,889 in 2007.
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*87In the Helmsley case, a Mexican businessman alleged that he’d been mauled by bed bugs during his stay at the hotel. The case was quickly settled out of court. The Mandarin Oriental case, however, did not go away quietly, possibly because the plaintiffs were a prominent New York City celebrity attorney and his wife. As of March 2007, their lawyers had filed a twenty-page five-count complaint alleging that the couple had suffered over a hundred bed bug bites in an assault that continued after they returned home and the bed bugs moved into their Manhattan apartment. The couple was seeking over four million dollars in damages—which works out to around forty thousand dollars a bite.
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*88This muscle is actually what you’re eating when you chow down on the succulent meat inside a lobster, crab, or shrimp.
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*89Ecdysiast was also the term coined by the early-twentieth-century reporter and critic H. L. Mencken (famous for his coverage of the Scopes “Monkey trial” of 1925). Mencken had been contacted by Georgia Southern (“a practitioner of the art of strip-teasing”) who was concerned about negative connotations people had about “stripping.” Ms. Southern asked Mencken to “coin a new and more palatable word to describe this art” and he did. “I sympathize with you in your affliction,” Mencken wrote back to her. “It might be a good idea to relate strip-teasing in some way to the…zoological phenomenon of molting…which is ecdysis. This word produces…ecdysiast.”
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*90Molted arthropod casts and the feces dropped by their former owners are the real allergens that plague those who are hypersensitive to “dust.” Although I’m sure there are a few allergists who have chosen to spare their patients some of the following details, the discarded arthropod outerwear and microscopic excreta come from dust mites, tiny creatures more closely related to spiders than to insects. Fortunately for us, dust mites are not blood feeders (although, as we’ll see later, there are hundreds of mite species that are). Instead, they feed on the approximately twelve grams of skin flakes that humans shed each day. This epidermal debris would accumulate into gigantic snowdrifts
were it not for the hungry mites.
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*91When I was a child, soft-shelled crabs were expensive and available for only a few weeks each summer. What I didn’t know was that they were actually just ordinary blue crabs (Callinectes sapidus) that either didn’t get the good hiding places after a molt or had been tempted to leave them by the irresistible allure of rotting chicken entrails. Nowadays though, farm raised soft-shelled crabs can be purchased year-round since their molts are regulated by human-administered hormones.
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†92 The largest terrestrial arthropod, by far, is the coconut crab (Birgus latro), which can weigh up to 8.8 pounds (four kilograms). Birgus is a hermit crab relative but without the snail shell. It copes with the “soft-shell vs. gravity” problem by molting in the safety of its burrow, where it remains for up to thirty days. Depending on which entomologist you ask, the largest insects are either New Zealand grasshoppers, called wetas, which can weigh as much as 2.5 ounces (seventy grams), or giant beetles belonging to several genera like Goliathus, Titanus, and Megasoma. The world’s largest spider (class Arachnida) is the giant bird-eating tarantula (Theraphosa blondi), which can weigh up to 4.25 ounces (120 grams) and whose legs can span twelve inches (30.5 centimeters). Its venomous fangs can reach one inch (2.54 centimeters) in length. Some centipedes (class Chilopoda), like the Amazonian giant centipede (Scolopendra gigantea), can reach more than twelve inches in length. These predators feed on pretty much anything that moves—including rodents and bats, which are subdued with a venomous bite before being devoured. The heaviest lobster on record is forty-four pounds, six ounces (about 20 kilograms), which is five times heavier than the coconut crab and roughly three hundred times heavier than the largest insect.
