Posts tagged research

Does the vascularity resulting from cardiovascular exercise increase the risk for metastasis of cancer? — Asked by Anonymous

While there are dozens of types of cancer, and I obviously am not a cancer doctor, all of the research I’ve come across says no, it doesn’t, and during remission, it appears to help stave off recurrence, at least in breast cancers.

Angiogenesis related to aerobic exercise is induced by FGF-1, and is primarily of interest when it comes to treatment and prevention of cardiovascular disease.

Cancerous tumor angiogenesis is most often induced by bFGF and VEGF, both of which are, as far as we know, unaffected by cardiovascular exertion or regular exercise.

How do you know if a website or source is legitimate? Can you list some that are? — Asked by Anonymous

I’m actually working on a side-page of my own regarding this, but for now, it’s kind of a pain to write good guidelines as to what a “good” site is, and in the end some sites can be both good and bad…just like some journals, and some magazines, and some institutions.

Knowing what is true and what isn’t isn’t a one-time trip. You have to be prepared to be surprised, and you have to keep an open mind to the fact that you might be wrong. But don’t think that just because someone says you’re wrong, you are - you have to approach a topic skeptically. Sometimes science proves former “truths” to be incorrect, and former fallacies to be true - but it’s extremely rare (and these days almost unheard of) that someone is “the next persecuted Galileo” like so many claim to be.

A simple list to how to find a good site can be found here.

For more in-depth and life lessons on skeptical thinking and finding the truth in the world, I highly recommend Carl Sagan’s "Demon Haunted World: Science as a Candle in the Dark”, which you can get at most book stores or Amazon, and read in part here.

Hair! Cross-section diagrams and representations of human scalp hair.

Top diagram: Lengthwise cross-section of human scalp hair follicle (or “bulb”), displaying point of growth
Bottom diagram: Cross-section of human scalp hair, taken from follicle region. Visible hair does not contain the medullary region or fibrous tissue sheath.
Charles Darwin: Androgenic hair [beard] and male-pattern baldness of scalp hair.
Female photographs: Types of scalp hair.

Human scalp hair, as shown here, is two separate structures - a collection of dead filamentous cells, divided into roughly three regions, that extends beyond the epidermis of the scalp, and the “root”, or “bulb”, which can be seen when the hair is pulled out. This is also known as the hair follicle, and is where the hair is created.

There are multiple types of hair on the human, each with its own cellular makeup, but all following basically the same construction pattern. The three primary layers are the cuticle (a few layers of smooth, flat, thin cells, layered like roof shingles), cortex (the roughly rod-shaped keratin cell bundles, just under the cuticle), and the medulla (the innermost disorganized layer that is an open region in the center of the hair - this region is not present in all hair types).

Hair growth:

Have you ever noticed that your hair doesn’t all grow at exactly the same rate, and sometimes doesn’t get longer than a certain length? It probably has to do with the length of your growth cycle! Hair growth for each strand on your head can last for 2-7 years, and each stage of growth is happening simultaneously - that is, not every strand is shedding, growing, or resting at the same time. If that were to happen, we’d moult all at once, like birds, and go completely bald every time our hair finished its growth cycle!

Anagen phase: This is the “growth” phase, beginning in the hair follicle, and lasts between two and six years, as determined by genetics. During this phase, the cells in the follicle divide, die, and get pushed out into the visible strand. At any one time, between 80-85% of the follicles on the head are in the anagen phase.

Catagen phase: Catagen is the shortest phase of hair growth; it rarely takes longer than three weeks to complete. This is a transitional phase. When chemical signals from the body signify that it’s time to move past the anagen phase, the follicle begins to shrink and cut the hair shaft off from its blood flow. When the follicle reaches about 1/6 its original size, it is “replenished”, as its generative cells are replaced and it’s not actively creating new hair.

Telogen phase: The resting phase - the hair and follicle remain dormant for between 1 and 4 months, while the follicle regenerates. When the follicle is ready to produce hair again, it pushes the dead hair out of the scalp with the new strand, in the process known as “shedding”.

Sources:

[Wikipedia]

A Treatise on the Diseases of the Skin. Dr. Henry W. Stelwagon, 1923

Images:

A Treatise on the Diseases of the Skin. Dr. Henry W. Stelwagon, 1923

[Young woman modeling: Head, framed in flowing hair]

Charles Darwin by John Collier, 1883.

Ėti︠u︡d golovki by Sergei Mikhailovich Prokudin-Gorskii, c.1905-1915

fuckyeahmedicalstuff:

Bernardo Alberto Houssay was born in Buenos Aires, Argentina, on April 10, 1887.He was the first Argentine and Latin American scientist awarded the Nobel Prize. The National Academy of Sciences of Sweden awarded him in Physiology and Medicine for his discovery of the role of the hypophysis gland in carbohydrate metabolism and in diabetes. He entered the School of Pharmacy of the University of Buenos Aires at the exceptionally early age of 14, graduating in 1904. He had already begun studying medicine and, in 1907, before completing his studies, he took up a post in the Department of Physiology. He began here his research on the hypophysis which resulted in his M.D.-thesis (1911), a thesis which earned him a University prize. In 1910 he was appointed Professor of Physiology in the University’s School of Veterinary Medicine. During this time he had been doing hospital practice and, in 1913, became Chief Physician at the Alvear Hospital. In addition to this he was also in charge of the Laboratory of Experimental Physiology and Pathology in the National Department of Hygiene from 1915 to 1919. In 1919 he became Professor of Physiology in the Medical School at Buenos Aires University. He also organized the Institute of Physiology at the Medical School, making it a centre with an international reputation. He remained Professor and Director of the Institute until 1943. In this year the Government then in power deprived him of his post, as a result of his voicing his opinion that there should be effective democracy in the country. Although receiving many invitations from abroad, he continued his work in an institute which he organized with the support of funds contributed by the Sauberan Foundation and other bodies. This was the Instituto de Biología y Medicina Experimental, where he still remains as Director. In 1955 a new Government reinstated him in the University. He has worked in almost every field of physiology, having a special interest in the endocrine glands. He has made a lifelong study of the hypophysis and his most important discovery concerns the role of the anterior lobe of the hypophysis in carbohydrate metabolism and the onset of diabetes. He has worked on many other topics in physiology and pharmacology, including the physiology of circulation and respiration, the processes of immunity, the nervous system, digestion, and snake and spider venoms. Apart from his research, he has been active in promoting the advancement of university and medical education, and of scientific research, in Argentina. Dr. Houssay is the author of over 500 papers and of several books. He has won many prizes ranging in time from that of the National Academy of Sciences, Buenos Aires, in 1923, to the Dale Medal of the Society of Endocrinology (London) in 1960.
He was a key figure in the development of science in Argentina. The result of his tireless efforts is the creation of numerous research institutes and training of several generations of scientists. Medical graduate with honors from the University of Buenos Aires, he was, along with others, behind the creation of the National Scientific and Technical Research (CONICET), which he chaired until his death on September 21, 1971. He also created the Institute of Experimental Biology and Medicine, and co-founded the Argentina Association for the Advancement of Science.  He holds honorary degrees of twenty-five universities and is a member of the Argentine National Academy of Medicine, the Academy of Letters, the National Academy of Sciences of Buenos Aires, the Academy of Moral and Political Sciences of Buenos Aires, and of the Pontifical Academy of Sciences. He is honorary professor of 15 universities, foreign associate of 11 academies or learned societies, member (honorary or correspondent) of 38 Academies, 16 Societies of Biology, 11 of Endocrinology, 7 of Physiology and 5 of Cardiology. He has been decorated by the governments of several countries.

fuckyeahmedicalstuff:

Bernardo Alberto Houssay was born in Buenos Aires, Argentina, on April 10, 1887.

He was the first Argentine and Latin American scientist awarded the Nobel Prize. The National Academy of Sciences of Sweden awarded him in Physiology and Medicine for his discovery of the role of the hypophysis gland in carbohydrate metabolism and in diabetes. 


He entered the School of Pharmacy of the University of Buenos Aires at the exceptionally early age of 14, graduating in 1904. He had already begun studying medicine and, in 1907, before completing his studies, he took up a post in the Department of Physiology. He began here his research on the hypophysis which resulted in his M.D.-thesis (1911), a thesis which earned him a University prize.

In 1910 he was appointed Professor of Physiology in the University’s School of Veterinary Medicine. During this time he had been doing hospital practice and, in 1913, became Chief Physician at the Alvear Hospital. In addition to this he was also in charge of the Laboratory of Experimental Physiology and Pathology in the National Department of Hygiene from 1915 to 1919. In 1919 he became Professor of Physiology in the Medical School at Buenos Aires University. He also organized the Institute of Physiology at the Medical School, making it a centre with an international reputation. He remained Professor and Director of the Institute until 1943. In this year the Government then in power deprived him of his post, as a result of his voicing his opinion that there should be effective democracy in the country. Although receiving many invitations from abroad, he continued his work in an institute which he organized with the support of funds contributed by the Sauberan Foundation and other bodies. This was the Instituto de Biología y Medicina Experimental, where he still remains as Director. In 1955 a new Government reinstated him in the University.

He has worked in almost every field of physiology, having a special interest in the endocrine glands. He has made a lifelong study of the hypophysis and his most important discovery concerns the role of the anterior lobe of the hypophysis in carbohydrate metabolism and the onset of diabetes. He has worked on many other topics in physiology and pharmacology, including the physiology of circulation and respiration, the processes of immunity, the nervous system, digestion, and snake and spider venoms.

Apart from his research, he has been active in promoting the advancement of university and medical education, and of scientific research, in Argentina.

Dr. Houssay is the author of over 500 papers and of several books. He has won many prizes ranging in time from that of the National Academy of Sciences, Buenos Aires, in 1923, to the Dale Medal of the Society of Endocrinology (London) in 1960.

He was a key figure in the development of science in Argentina. The result of his tireless efforts is the creation of numerous research institutes and training of several generations of scientists. Medical graduate with honors from the University of Buenos Aires, he was, along with others, behind the creation of the National Scientific and Technical Research (CONICET), which he chaired until his death on September 21, 1971. He also created the Institute of Experimental Biology and Medicine, and co-founded the Argentina Association for the Advancement of Science.

He holds honorary degrees of twenty-five universities and is a member of the Argentine National Academy of Medicine, the Academy of Letters, the National Academy of Sciences of Buenos Aires, the Academy of Moral and Political Sciences of Buenos Aires, and of the Pontifical Academy of Sciences. He is honorary professor of 15 universities, foreign associate of 11 academies or learned societies, member (honorary or correspondent) of 38 Academies, 16 Societies of Biology, 11 of Endocrinology, 7 of Physiology and 5 of Cardiology. He has been decorated by the governments of several countries.

You are my only refuge right now all search engines have failed me. Do you know of any articles that supposes or assumes the mouth as a sexual organ. — Asked by imperatorclass

There are a few that you can find on Google Scholar that explicitly mention the mouth as a sexual organ, but they are largely based upon the works of Freud or some earlier, more…”interesting”, points of view.

I don’t know what resources you have available to you, but if you’re on a high school or college campus, you probably have access to a lot of different journals - I just don’t know which ones you can access.

Beyond Freudian stuff, there are two broad approaches to seeing the mouth as a sexual organ; it can either be viewed as a site of physical stimulation or chemical stimulation (the body responding to a partner’s MHC profile/hormonal profile and *possibly* [not very likely] responding to the pheromone signals via the human vomeronasal organ).

If you’re looking at it as a site of physical stimulation, try looking up the works of Kinsey, and the follow-up research done in the 1990s that heavily references Kinsey. Chemical stimulation articles can be found in the Chemical Senses journal, among others, by searching for “MHC human sexuality”, “human vomeronasal organ”, and similar terms.

The mouth is also seen as a sexual organ owing to its aural stimulation abilities when producing sounds during intercourse or even in non-sexual interactions. However, this is not a widely-researched view.

Medicine in History: Ancient Egypt - Basics of Life

biomedicalephemera:

The Insinger papyrus, from the Ptolemaic period, states:

A man spends ten years as a child before he understands death and life,

He spends another ten years acquiring the instruction by which he will be able to live.

He spends another ten years earning and gaining possessions by which to live.

He spends another ten years up to old age, when his heart becomes his counselor.

There remain sixty years of the whole life, which Thoth has assigned to the man of god.

From the age of 40 to the expected 100, a man could enjoy the best years of his life, using the fruits of his labor and knowledge.

Of course, most people did not live to be 100, but by the Ptolemaic period, the average age of those whose ages were noted (meaning they likely had a burial of at least middle-class status) was 54 years for men, and 58 for women. The long lifespan has been attributed to a generally healthy lifestyle, a diet with adequate grains and proteins, and a society that generally revered their elders and cared for them, even when they were not able to physically contribute to society.

When You Lived a Long Life…

The workers on the pyramids (and within the royal court) also had pensions, which is the first time in history that this concept was recorded. They received grain rations that, while smaller than what the workers got, was more than enough to sustain an elderly citizen.

It was also expected that the children (especially the oldest son) or nieces and nephews would help attend to the needs of the elderly. Of course, this did not always happen, and there have been wills and manifests found expressly disinheriting children for being disrespectful or not caring for their parents in their frail dotage.

Of Course, Lots of People Still Died Young:

The lifespan was, of course, not always nearly 60 years. From the Old Kingdom onward, the lifespan slowly increased, from a starting point of around an average of 22-30 years of age. 

Analysis of over 3000 Egyptian mummies and medical papyri have left behind information about many different diseases that people suffered and died from.

During the spring and summer (the dry season), the much smaller amount of water available led to concentrations of people in a very narrow region along the banks. This created ideal conditions for infectious diseases, like dysentery, smallpox, typhoid, and relapsing fever.

When the rainy season came, malaria was, of course, very prevalent, thanks to standing water in the flooded fields, which served as ideal mosquito breeding grounds.

A few of the other diseases and ailments found in mummies included:

  • Atherosclerosis: A hardening of the arteries, prevalent especially in non-clergy Egyptians. Their healthy lifestyle and diet led researchers to hypothesize that the atherosclerosis originated from the repeated inflammation due to parasitic diseases. There is also the possibility that salt-preserved foods contributed to unhealthy arteries.
  • Dental caries: The corn in Egypt was very coarsely ground, and to more finely grind it, sand would be added. This, combined with lots of other coarse foods, would lead to fairly rapid decay of teeth, exposure of the dentin and pulp, and chronic infections. These infections would be routinely drained by physicians, using a thin hollow reed.
  • Bone trauma: There was a LOT of this. I mean, they hauled around huge blocks of stone, what would you expect? Broken arms were very common. Unsurprisingly, physicians were fairly good at setting broken bones, and if the skin wasn’t broken (allowing in infection), the splinted limbs had a decent recovery rate.

Ways to Die: Poisonous Plants

Humans have been out to get each other since before we were even Homo sapiens sapiens. For the strong and the brash, there was always outright physical violence; a club to the head or a knife to the throat was a simple way to destroy an unsuspecting rival.

But humanity had more than just violence at its disposal. Those inclined to plan and use their brains over their brawn found that there was an easier way to kill, one that would not risk their own body in an attack, or let others know who killed their rival, or even if the rival was killed by another person in the first place.

Enter: POISONS. Historically largely derived from plants, humans have murdered each other, and at times themselves, using various species of plants. There is an expansive list of plants that can potentially kill a human, but a few have gained reputations over the millenia as premier agents of death…

  • Aconitum spp. - Wolfsbane or Monkshood: A genus of over 250 beautifully flowering plants, closely related to the buttercup. Grows throughout Eurasia, cultivated worldwide.

    Aconitum sp.
    was used by the Ainu of Japan to hunt bears, and A. napellus is used by the Minaro of Ladakhi to hunt ibex. A probable culprit in multiple Borgia murders. Large doses are almost instantaneously fatal. Causes poisoning similar to that of pufferfish - tetrodotoxin-sensitive channels are open, and flaccid paralysis will quickly ensue following exposure.

  • Cicuta maculata - Spotted Water Hemlock, Snakeweed, or Spotted Cowbane: The most deadly plant in North America, due to its roots occasionally being mistaken for wild parsnip.
    Ageratina altissima
    killed Abraham Lincoln’s mother, due to its ingestion by a cow whose milk she drank. A relative of C. maculata, Conium maculatum (poison hemlock) was used in the death sentence of Socrates.

  • Datura stramonium - Jimsonweed, Thorn Apple, or Locoweed: A member of the nightshade (Solanaceae) family. Found mostly in North America, but other species of Datura exist in the rest of the Americas. Contains atropine, hyoscyamine, and scopolamine, which lead to a complete inability to differentiate reality and fantasy (delirium - not hallucination as many people allege), tachycardia, hyperthermia, and bizarre/violent behavior patterns.

    Tea made from Datura plants is sometimes alleged by quacks to be medicinally beneficial. It is not. Multiple people have come very close to death, and two (known) people have died in the United States because they thought it would have some positive hallucinogenic or medicinal effect upon them. The very unpleasant taste of the beans leads to few accidental deaths due to ingestion.

  • Strychnos nux-vomica - Strychnine Tree: Ahh, strychnine. Used as a poison in India from ancient times, and the source of a most unpleasant and violent death (or near-death episode). Strychnine causes prolonged grand mal seizures, due to the entire motor ganglia of the spinal cord being stimulated at one time, once the toxin makes it to the bloodstream.

    Currently still used as a rodent poison in many parts of the world, but illegal in the United States. One of the most common agents of domestic murder in India and Pakistan today. Easily detected by mass spectroscopy, but despite several dozen murders in the US and Indoasian countries, specific testing for the agent is still not routine in those suspected to be poisoned.

  • Ricinus communis - Castor oil Plant: Indigenous to the Mediterranean, East Africa, and India. The attractive flowers have made this tree a popular installation in gardens throughout all tropical regions. This is where the toxic agent ricin comes from. This causes an extremely painful death, with convulsions, and intense conscious pain, vomiting, diarrhea, and spasms.

    While its use in Africa as a “trial-by-fire" agent (if one did not die from ingesting the beans, they were innocent) has been around for centuries, its emergence in the West is relatively recent. In 1971, Bulgarian dissident Georgi Markov was shot in the leg with a pellet of concentrated ricin from a weapon concealed inside an umbrella, and died four days later. Since then, over a dozen in the Western world have been convicted of murdering others with crushed castor beans, and several dozen other incidents are suspected.

Sources:

Wicked Plants by Amy Stewart

A Modern Herbal. Mrs. M. Grieve, 1931.

Plants and Civilization. Maintained by Prof. Arthur C. Gibson, from 1985 textbook.

Classification of Chemical Agents

There are four primary classes of Lethal Agents that are produced as weapons. There are also two classes of Non-Lethal Harassing Agents.

Lethal Agents
Lethal agents are classified by the affect that they have on the body, as all have the capacity to cause death.

  • Blood Agents: Phosgene, Hydrogen Cyanide, Arsine - Prevent the exchange of carbon dioxide and oxygen in the body tissues. Causes a painful death involving violent seizures and ending in respiratory failure. Sodium cyanide and other solid cyanide crystals are also considered blood agents, but are not used in warfare.

  • Blister Agents: Sulfur Mustards (Mustard Gas), Lewisite - Also known as vesicants. Cause severe pain and irritation to the eyes, skin, and mucous membranes. Chemical burns from these agents create large water blisters on the skin that can become infected when not properly treated. Eye and airway damage often causes temporary blindness and respiratory distress.

  • Pulmonary Agents: Phosgene, Chlorine, Chloropicrin  - Also known as choking agents. Cause a build-up of fluid in the lungs that prevents breathing, leading to death by respiratory failure. Also causes corrosive damage to eyes, throat, and skin, leading to chemical burn symptoms, blurred vision, vomiting, and severe headache.

  • Nerve Agents: G-Series Agents [Sarin - GB], V-Series Agents [VX], Novichok Agents - Phosphorus-containing organic chemicals which disrupt nerve signals to muscles. Initial symptoms include pupil constriction, nausea, and a tight chest. This progresses to involuntary salivation, lachrymation (tears), urination, defecation, vomiting, and intense abdominal pain. The final stage includes myoclonic jerks and continual status epilepticus, followed by death due to paralyzed respiratory muscles. Survivors will almost always have long-term effects to their nervous system and neuromuscular junctions.

    Note: Mostly produced post-WWII, only intentionally used against civilians in 1988 in Halabja, Iraq, and in 1995 in the Aum Shinrikyu attack in Tokyo. G-Series agents developed in Germany in WWII but never utilized on the field.

Harassing Agents
Harassing agents are less developed, as the line between incapacitation and lethality is often difficult to control with gaseous weapons, and incapacitation was seen as having little use in warfare for most of history.

The categories of chemicals  are also unrefined, and the difference is only how used they are - “Incapacitators" are currently only in very rare experimental situations, and have not had good effects or publicity in any of the known situations they were in.  "Riot Control" chemicals are considered non-lethal lachrymatory or vomit agents, and are intended for use against civilians or civilian groups seen as belligerent.

  • Incapacitators: A diverse group of chemicals still under development for military use. Both mental and physical incapacitation being researched. Intended to incapacitate hostiles for a much longer period than riot control agents can, to facilitate less-lethal warfare and to provide other domestic and foreign scenarios without need for lethal force.

  • Riot Control: Tear Gas, Pepper Spray, Mace - Less-than-lethal anti-belligerent compounds, used by police and citizenry. Investigated for use in both WWI and WWII, but never utilized. These are lachrymatory agents that stimulate the corneal nerves and induce extreme tearing, blepharospasm, pain, and mild-to-moderate respiratory distress upon prolonged exposure.

Early Chemical Warfare in Europe and the New World

After the decline of the Roman Empire, there was very little usage of chemical weaponry, despite the accusations of many against minority groups. The Plague and the Church controlled the hearts and minds of the populace, and neither were conducive to new innovations in weaponry.

That’s not to say interest was completely lost in the tactic, though. During the Medieval Era and Renaissance, there were multiple proposed usages of chemical warfare, such as Leonardo da Vinci’s suggestion of lobbing mangonels filled with "…poison in the form of powder…chalk, fine sulfide of arsenic, and powdered verdegris…” against naval combatants, so as to asphyxiate the enemy. However, there is no evidence that this suggestion was utilized at any point. 

The Invasion of Hispaniola 

Of the weapons that were known to have actually been used, the Taíno’s 15th-century use of powdered hot peppers against invading Spaniards is one of the more unique. The peppers were ground together with fine ashes, and kept in brittle gourds. When the Spaniards approached, the gourds were thrown from above, and caused them both choking and temporary blindness. The refinement of the tribe’s tactic and subsequent attack while the enemy was incapacitated (but after the ash had settled) suggests that the Taíno may have used these weapons previously, likely against their rival Caribs. Unfortunately, the successful stalling and incapacitation of the newcomers did not save the natives.

Renaissance of Culture, Science, and Chemical Warfare

Back in Europe and Central Asia, the primary chemical tactic used was to simply add noxious agents, such as sulfur, saltpeter, or antimony, to incendiary weapons or structural fires. The immediate irritation to the lungs and eyes often made it so that the people who may have otherwise been able to escape the area would be halted by coughing and disorientation, and eventually killed by smoke inhalation. 

However, that wasn’t all that was used. There is evidence that in 1672, the Bishop of Münster, Bernhard von Galen, attempted to overtake the city of Groningen using explosives and incendiary devices that had both dried and fresh Belladonna (Deadly Nightshade) incorporated into them.  There is no evidence that there was any additional affect to the citizens of Groningen due to the added plants, but the intent was no doubt to induce the delirium and confusion that belladonna poisoning was known for. 

Early Chemical Warfare: Antiquity

Though chemical weapons became well-known and feared during the First World War, evidence of their use goes back almost 15,000 years, to the South African San tribes, which utilized poison from scorpions and snakes on their arrow tips used for hunting.

However, unlike the Mesoamerican peoples who were shown to have used curare vine and dart frog poison on their weapons several thousand years later, there is a lack of evidence that the San actively used these tactics against other humans. That’s not to say that they didn’t, but there is as yet no solid evidence of it that has been found.

Chemicals in Early Warfare

Despite the efficacy of poison-tipped arrows and weapons in killing individuals, to utilize chemical weaponry in warfare required being able to disperse a substance over a significant area, so as to incapacitate or kill large numbers of enemies. Aside from large-scale water and foodstore poisonings, gaseous compounds have been used against enemies and revolting subjects alike, since before the days of Sun-Tzu in the East, and the Peloponnesian War in the West.

Thucidydes wrote in 500 BCE, in History of the Peloponnesian War, of Spartans burning wood, pitch, and sulfur under the walls of Athens, hoping to incapacitate the enemy before the direct assault. Unfortunately, a thunderstorm rolled in shortly after the incendiaries were ignited, and the tactic failed. There were recorded incidents of burning sulfur in several wars in the following millennium, however, and it functioned as a moderate choking agent when it dispersed correctly.

Recent Findings

Recent excavations of Dura-Europos, in modern-day Syria, proved that burning sulfur could be extremely effective in closed quarters, especially when combined with other compounds. In 256 CE, the city launched a counter-attack against Roman forces tunneling under the battlements. The Persians heard the tunneling, and formed a smaller tunnel that connected to the Romans. At the bottom of their tunnel, they lit a fire of pitch, sulfur, and bitumen. The smoke from this fire traveled up a small chimney and into the larger Roman tunnel.

Almost 17 centuries later, excavators in the 1930s would find a pile of twenty men within the large tunnel, with Roman armor, and no apparently mortal wounds to their bones, unlike those found from the same era and area. Though ancient texts proposed chemical and incendiary tactics, proof of their use had never before been found in this area. However, in 2008, a team of archaeologists from the University of Leicester tested the tunnels, remains, and findings within the tunnels, and their findings demonstrated the earliest archaeological proof of chemical warfare.

Ways to Die: Pellagra

Pellagra (formerly “Asturian leprosy”) is one of the five pandemic deficiency diseases that have occurred in humans, and is caused by a lack of available niacin (vitamin B3) in the diet. Since niacin is a precursor to the NAD+/NADH molecules, which provide cellular energy throughout the body, many systems become disordered. Primary symptoms include weakness, insomnia,  diarrhea, constant headache, sensitivity to sunlight (causing photo-dermatitis when exposed, as shown here on the face and hands), aggression, and eventually dementia. Death often follows within 4-5 years, if untreated. 

One of the historical causes of pellagra was the widespread cultivation of corn, and the eventual usage of corn as a staple food, especially among the poor. While the corn plant does have niacin, it’s chemically bound and indigestible. The traditional Mesoamerican preparation of corn (now known as nixtamalization) by soaking it in limewater exposes the compound to a high pH (11+), which unbinds the niacin, and the human body is then able to absorb it. This practice is known to go back thousands of years, and is the reason that despite a maize-based diet, Native American peoples did not regularly suffer from pellagra.

Unfortunately, Europeans never really understood why the limewater was needed - indeed, we didn’t even understand what pellagra actually was until the 1930s. Up to that point, pellagra was known to be endemic to areas that were highly dependent upon corn, but it was believed to be either a germ or a maize-based toxin. It wasn’t until 1937 that Conrad Elvehjem identified the molecule in fresh meat and yeast called niacin, and its direct link to the condition was established.

Today, pellagra is very rare in the majority of the developed world, surfacing primarily in patients with chronic alcoholism or eating disorders. We now know that nuts, leafy greens, and whole-grain products also provide sufficient amounts of niacin, and the human body does not necessarily require meat or yeast as a source. However, in displaced populations requiring food aid, availability of niacin-providing nutriment is extremely limited, as many countries that provide aid still provide only oil and a basic cornmeal substance for food. Because of several outbreaks of pellagra and other deficiency diseases in refugee camps in the 1970s and 1980s, the United States and Western European food aid programmes now prepare their cornmeal with vitamin and mineral sprays to provide the necessary nutrients.

Want to know more? Read on:

The Mastery of Pellagra (1916 account of the ongoing pellagra epidemic)

How Vitamin B3 Works

Conrad Elvehjem: Further Studies on the Concentration of the Antipellagra Factor

Politics and Pellagra: The epidemic of pellagra in the U.S. in the early 20th century.

[Image Source: Tropical Diseases. Sir Patrick Manson, 1914]

Medical Eponyms: Legacy of the Anatomists

An eponym is a word derived from the name of a person, real or fictional. They can be found in every discipline of academia, but are particularly prevalent in medicine and physiology.

There are signs, reflexes, diseases, syndromes, medical instruments, and almost everything else you can think of, named after the discoverer, inventor, or someone else significant in the term’s development. Often the names become so associated with what they refer to that the historical figure is completely forgotten, even among those who use the term every day.

In light of that, let’s check out a few of the real people who have their legacy preserved in the parts of the body associated with their name -

Anatomical Eponyms -

Eustachian tube: Named after Bartolomeo Eustachi, a 16th-century Italian anatomist. Though very little is known about his life in general, he was physician to nobility and religious figures, and was unusually open (for the age) to new “innovative” ideas about anatomy not put forth by Galen, something his contemporaries actively fought. The Eustachian tube is a 3-4 cm canal that connects the middle ear to the nose, which maintains equal atmospheric pressure on either side of the eardrum. Admirer of Eustachi Antonio Maria Valsalva  first coined the term “Eustachian tube” around 100 years after Eustachi’s death.

Fallopian tubes: Named after Gabriele Falloppio, one of the most important anatomists of the 16th century, and a contemporary of other notables such as Eustachi and Vesalius. He corrected many of Vesalius’ mistakes in myology, and wrote some of the most detailed works on the inner ear and sexual organs to date. The Fallopian tubes are two fine ciliated tubules in females, leading from the ovaries to the uterus, which carry mature ova away from the ovary during ovulation.

Organ of Corti: Named after Alfonso Giacomo Gaspare Corti, an Italian anatomist who performed some of the first microscopic studies on mammalian hearing in the mid-19th century. His methods of preserving the cochlea were able to effectively allow him to discover some of the tiny mechanisms of hearing that hadn’t been previously understood. The organ of Corti is the organ in the inner ear that has the auditory sensory cells, or “hair cells” - those things your doctor warns you can’t re-grow if you listen to music too loudly!

Cowper’s Glands: Named after William Cowper, the late-17th-century English anatomist, who was the first to describe these glands. Though considered a great surgeon and anatomist in his own right, there was an unfortunate incident where he published several plates of Govard Bidloo’s musculature works under his own name (with no mention of Bidloo), and there was a very heated exchange between the two men and their supporters. The Cowper’s glands are small glands in the male, on either side of the prostate gland, and release pre-seminal fluid. This fluid neutralizes the acidic traces of urine in the urethra, which has the potential to kill the spermatozoa. 

Haversian Canal: Named after 17th-century (I sense a bit of a trend here…) English anatomist Clopton Havers. He was a physician with a keen interest in microscopy and bones, and was the first to document several unique substructures in both compact and spongy bone. The Haversian canals are small hollow canals that run within the longitudinal axis of compact bones, which generally contain one or two capillaries and a nerve. They deliver nutrients to the living bone cells.

Bundle of His: Named after Wilhelm His Jr., the late-19th-century Swiss cardiologist and anatomist. He practiced and taught medicine in Berlin, Germany, and only became a cardiologist later in life. His earlier work on diseases led to his name being  used as one of the eponyms for trench fever, which is a pretty horrendous disease of war. The bundle of His is also known as the atrioventricular (AV) bundle, and is a collection of cardiac muscle cells specialized for electrical conduction, essential for a rhythmic heartbeat.

Islets of Langerhans: Named after Paul Langerhans, a 19th-century German physiologist, pathologist, and biologist. He was the son of a physician and was keenly interested in anatomy from an early age, and many of his most important discoveries were before he turned 30. He was also keen on biology, and did work on the fauna of Syria and the surrounding areas. The islets of Langerhans are the regions of the pancreas that contain the endocrine cells. They’re most well-known for producing insulin.

Circle of Willis: Named after Thomas Willis, a 17th-century English physician and founding member of the Royal Society of London. He also belonged to the circles that the many notable contemporary Oxford scientists comprised. Though he had a very well-off medical practice, his association with the Oxford experimenters led to significant time spent in the dissection room and trading ideas. Willis wrote about rudimentary psychological principles, neurology, and the anatomy of the brain. The Circle of Willis is a circle of arteries at the base of the brain. It creates a level of redundancy for the brain’s blood supply, meaning that if one part of it gets blocked or narrowed, the brain can stay fully oxygenated by getting blood from another artery that connects to the Circle.

Of course, this is only a few of the many medical and anatomical eponyms out there, but they’re some of the ones you tend to hear about a lot but might not know the origin of.

Next time I’ll cover Purkinje fibers, the Node of Ranvier, the Loop of Henle, Malpighian bodies, Meissner's corpuscles, Volkmann’s canals, Sharpey’s fibers, and Herring bodies (which are not fish). 

Sources and Further Reading:

Who Named It?

MedEponyms

What’s in a Name? The Eponymic Route to Immortality.

Bubonic Plague - Yersinia pestis

Yersinia pestis is always a fun little organism to see under the microscope. It’s a Gram-negative, rod-shaped bacteria, but it looks more like a safety-pin than a “rod” because of the natural bi-polar staining pattern of the organism. The species was found to be the causative agent of bubonic plague during an 1894 epidemic in Hong Kong, by Alexandre Yersin. Until 1967, however, it was categorized with the Pasteurella genus, and was known as Pasteurella pestis.

There are several strains of Y. pestis, and three different manifestations of the plague:

  • Bubonic plague - Incubation period of 2-6 days with few symptoms, while bacteria multiply within lymph nodes. Sudden fever and headache at end of incubation period, with complete loss of energy. The characteristic buboes (lymph swellings) appear at this point, as the lymph nodes swell to enormous proportions thanks to the bacteria within them. The inguinal (groin) nodes generally are the first to show signs of infection.

  • Septicemic plague - Same bacteria, different strain of Y. pestis, and way worse. From what we know, primary septicemic plague is generally caused by one unique strain, or by any strain in immuno-compromised patients. When the other manifestations of the disease cause overwhelming sepsis prior to death, this is known as secondary septicemic plague. Primary septicemic plague is characterized by hypotension, shock, hepatosplenomegaly (swollen spleen and liver), and death. Sometimes very few or even no outward symptoms develop before the patient is killed by the bacteria’s internal effects.

  • Pneumonic plague - Caused by direct inhalation of bacteria (often person-to-person), with initial site of infection being the lungs. Different strains have different degrees of ability to transfer in this manner, but it generally requires prolonged contact with infected persons or animals. Causes tracheal and bronchial hemorrhaging, large amounts of alveolar exudate, congestion of the lungs, and pleural edema. Often quickly spreads to other organs, much like bubonic plague.

While all three manifestations of the disease can be deadly, the incidence of death is greatly reduced by IV antibiotics, and thanks to modern sanitation standards, outbreaks in developed countries are unheard of.

Still, Yersinia pestis isn’t, and probably never will be, completely exterminated. Wild animals such as rodents, prairie dogs, and some marsupials and primates are known to both be affected by and serve as reservoirs for the bacteria. This means that even if humans somehow stopped acquiring the plague for a while, the bacteria itself would still be around, and we would still be able to contract it.

Interestingly, a 2011 study in the journal Nature showed that the strain of Y. pestis which caused the Black Death in both the 1st century C.E. and the early Middle Ages may no longer be extant. The genome of the bacteria analyzed from victims of those plagues showed a more ancient form of Y. pestis that lacked a number of the mutations that exist in current-day strains, which are known to have caused all epidemics beyond the Renaissance.

Have I gone on about the plague enough? If not, check out way more information than you’ll ever use about the pathogen at CIDRAP Bioterrorism and PLoS Pathogens!

Images:

  • Bacillus of Bubonic Plague - Elementary Bacteriology and Protozoology, for the use of Nurses. Herbert Fox, 1919.
  • Swelling of inguinal bubo in U.S. soldier - From the U.S. Centers for Disease Control and Prevention, ca. 1970.
  • Plague victims being blessed by priest - Omne Bonum. James le Palmer, 1360.
  • Mass grave of plague victims- From Martiques, France, dated to the last pandemic of plague in Europe, between 1720 and 1722.
  • Plague Riot of Moscow - Depicts the rioting during and after the 1770s Moscow epidemic.
Differentiation of Filarial Endoparasites
Filaria! These nematodes cause (and carry) some of the most disfiguring, debilitating, and widespread parasitic diseases. Transmitted by Diptera, Culicinae, and a few other blood-sucking arthropods throughout the equatorial belt, the infestation of humans by these roundworms has been largely ignored since the end of colonization and abandonment of the majority of the impoverished areas where they’re endemic.
Currently, several organizations are working together to eradicate the filaria who have humans as their sole reservoir, but there’s still a long way to go. The fact that some of these parasites leave patients with life-long disabilities requiring support makes allocating resources purely for eradication much more difficult.
In this image you can see four separate nematodes, each causing a very different type of infection:
 Mf. Bancrofti = Wuchereria bancrofti. Causes elephantiasis [note: it’s NOT elephantitis, which literally means “swollen elephant”. Elephantiasis means, misleadingly, “caused by an elephant”, after its elephantine appearance.] Transmitted by several species of mosquito. Originally endemic to the equatorial regions of the Old World, brought to the New World by the slave trade. 120 million people infected worldwide.
Mf. perstans = Mansonella perstans. Causes serous cavity filariasis, which is relatively minor compared to other filarial infestation. However, the infestation can cause a general malaise (decreasing work ability) and is very difficult to treat, as other anti-filarial drugs are ineffective. Around 114 million people in Sub-Saharan Africa and South America are known to be infected, but the non-specificity of symptoms and infection make exact figures impossible.
Mf. loa = Loa loa. Causes loa loa. This is the one with “that worm that crawls across your eye”. Loa loa also causes Calabar swellings, which are dense, goose-egg sized, non-specific swellings, just below the surface of the skin. This parasite is co-endemic with Onchocerca volvus (the cause of river blindness, also a filarial worm), causing problems during eradication attempts of the latter: Loa loa can cause encephalitis when it’s killed off by ivermectin, which is the primary way to eliminate O. volvus.
Mf. demarquaii = Mansonella ozzardi. Causes serous cavity filariasis, but is restricted to the New World. Mexico and Argentina are the primary areas where one would contract this worm.
Significant species not included in this image are Onchocerca volvus, which causes river blindness, Brugia malayi and Brugia timori, which cause lymphatic filariasis, and Mansonia streptocerca, which causes subcutaneous filariasis. Dracunculus medinensis (Guinea worm)is also not included, but that nematode has a significantly different life cycle and infectious mechanism than the others.
[Source: A Treatise on Tropical Diseases: A Manual of the Diseases of Warm Climates. Sir Patrick Manson, 1919.]

Differentiation of Filarial Endoparasites

Filaria! These nematodes cause (and carry) some of the most disfiguring, debilitating, and widespread parasitic diseases. Transmitted by Diptera, Culicinae, and a few other blood-sucking arthropods throughout the equatorial belt, the infestation of humans by these roundworms has been largely ignored since the end of colonization and abandonment of the majority of the impoverished areas where they’re endemic.

Currently, several organizations are working together to eradicate the filaria who have humans as their sole reservoir, but there’s still a long way to go. The fact that some of these parasites leave patients with life-long disabilities requiring support makes allocating resources purely for eradication much more difficult.

In this image you can see four separate nematodes, each causing a very different type of infection:

  1. Mf. Bancrofti = Wuchereria bancrofti. Causes elephantiasis [note: it’s NOT elephantitis, which literally means “swollen elephant”. Elephantiasis means, misleadingly, “caused by an elephant”, after its elephantine appearance.] Transmitted by several species of mosquito. Originally endemic to the equatorial regions of the Old World, brought to the New World by the slave trade. 120 million people infected worldwide.
  2. Mf. perstans = Mansonella perstans. Causes serous cavity filariasis, which is relatively minor compared to other filarial infestation. However, the infestation can cause a general malaise (decreasing work ability) and is very difficult to treat, as other anti-filarial drugs are ineffective. Around 114 million people in Sub-Saharan Africa and South America are known to be infected, but the non-specificity of symptoms and infection make exact figures impossible.
  3. Mf. loa = Loa loa. Causes loa loa. This is the one with “that worm that crawls across your eye”. Loa loa also causes Calabar swellings, which are dense, goose-egg sized, non-specific swellings, just below the surface of the skin. This parasite is co-endemic with Onchocerca volvus (the cause of river blindness, also a filarial worm), causing problems during eradication attempts of the latter: Loa loa can cause encephalitis when it’s killed off by ivermectin, which is the primary way to eliminate O. volvus.
  4. Mf. demarquaii = Mansonella ozzardi. Causes serous cavity filariasis, but is restricted to the New World. Mexico and Argentina are the primary areas where one would contract this worm.

Significant species not included in this image are Onchocerca volvus, which causes river blindness, Brugia malayi and Brugia timori, which cause lymphatic filariasis, and Mansonia streptocerca, which causes subcutaneous filariasis. Dracunculus medinensis (Guinea worm)is also not included, but that nematode has a significantly different life cycle and infectious mechanism than the others.

[Source: A Treatise on Tropical Diseases: A Manual of the Diseases of Warm Climates. Sir Patrick Manson, 1919.]

Scientific Terminology: Taxonomy and Nomenclature 101

The origins of medical terms are interesting enough, but Greek and Latin roots are used throughout the sciences, and around here, you’ll see them a lot when it comes to species names. There are some interesting ones out there, with some bizarre (and sometimes humorous) meanings…

But first! Some taxonomy basics:

Setting aside phylogeny-specific nomenclature and cladistics for now, Linnaean taxonomy is the system of naming species that has been used since, well, Carl Linnaeus. A “taxon" (plural taxa) is simply a grouping of one or more organisms, judged to belong to the same unit based on any number of qualifications. 

Though current “Linnaean taxonomy" (which is what’s commonly used in schools and in general literature) differs significantly from Linnaeus’ original three-kingdom, five-level, ranked classifications, it’s still known by that name and takes many of the concepts from it, such as hierarchical classification. Thanks to the popularity of Linnaeus’ 1735 work, Systema Naturae, a solid foundation for modern taxonomy was put in place, with an organized system, and short, understandable, scientific names.

Taxonomy today:

Currently, animal species are organized according to rules set down by the International Code of Zoological Nomenclature, to ensure uniformity across the zoological community. Plants and bacteria follow different naming codes, but those are less relevant here.

This is a basic schematic demonstrating the hierarchical system that’s used when we classify a species:

According to the ICZN, the basic rank is that of species. The next most important rank is that of genus: when an organism is given a species name it is assigned to a genus, and the genus name is part of the species name. Species and genus were both seen by Linnaeus as “God-given”/”natural”. Anything above genus was considered a construct made by man to more easily classify the world around him.

The third-most important rank, although it was not used by Linnaeus, is that of family. Even though family is important in understanding the classification of an animal, it is not used in the “scientific name”, nor are any of the higher levels in its classification.

So what’s a “scientific name?”

The italicized names that you see in scientific literature (and around here) refer to the specific species of a creature, and are called the binomen; that is, “two names”. Those two names are the genus (first, and capitalized) and the species (second, never capitalized, even when named after a proper noun). An example of a binomen would be Choloepus hoffmanni - the genus is Choloepus, the two-toed sloths, and the species is Choloepus hoffmanni, Hoffmann’s two-toed sloth.

Sometimes there are three names, or the trinomen of a creature. These tell you, first, the genus, second, the species, and third, the subspecies. Take the trinomen Choloepus hoffmanni pallescens. The genus is Choloepus, the species is Choloepus hoffmanni, and the subspecies is Choloepus hoffmanni pallescens, the Peruvian two-toed sloth.

Though you only are told the two (or three) most specific taxonomic groupings for a creature, you can use those (and a phylogenetic tree) to figure out all of the less-specific (Linnaean) taxa it belongs to, such as its Family, Order, Class, and Phylum.

What does the scientific name actually mean, though?

Often, the scientific name describes notable or distinguishing characteristics about a species, that you can decode (scientific terminology time!). Let’s take the species Cyclopes didactylus. The first name given tells us that this creature belongs to the genus Cyclopes - “Circle-foot”. Within that genus, the species name is Cyclopes didactylus (abbreviated C. didactylus after the first use), and yes, you do repeat the genus name in the species name, by ICZN guidelines. On its own, “didactylus" can be broken down to the roots of di-, dactyl, -(o)us. “Having two fingers.” So the binominal can be deciphered as “Circle-foot having two fingers.”

Circle-foot two-fingers! (aka the Silky or Pygmy Anteater)

This descriptive-type species name is not the only way scientists assign taxa, though.

For everything above genus, the taxa are fairly regulated/already-determined, are not easy to add and subtract from, and have strict naming guidelines. From genus on down, though, so long as what you’ve discovered is verified as a new species (or group of species falling together as a genus), congratulations! You have the honor of naming it. Well, assuming it’s not patently offensive, vulgar, or unpronounceable. The ICZN approval board or the equivalent for your field has final say on whether or not a species can be given a submitted name.

Still, there are many ways to name a new species. You can name it in reference to physical characteristics, location found, a specific person or group, or even an ironic joke or pun. Look at the name Linnaeus gave the Blue Whale:

Balaenoptera musculis. Balaenoptera = “Baleen-winged”, ok, they have huge fins and baleen, so that makes sense.  Musculis = "little mouse". Har har har.

Musculis" can also refer to "muscle," but given that Linnaeus was given to puns and double-meanings, he was well aware of the "little mouse" definition.

Notes:

**Though the specific epithet for a species can be used in more than one genus, genus names must remain absolutely unique, in accordance with ICZN rules. Ex. Since you can have more than one species with the didactylus epithet, Cyclopes didactylus and Inimicus didactylus are both valid names - though you really don’t want to mix up the silky anteater with the "devil stinger"/lumpfish.

**When the specific species is not known, the abbreviation “sp.” is used after the genus name. Ex. Lutra sp. refers to either Lutra lutra OR Lutra sumatrana, but it’s unknown as to which one. When multiple species within a genus are being referred to (or the specific species is unimportant), the abbreviation “spp.” is used after the genus name. Ex. Lutra spp. refers to BOTH Lutra lutra AND Lutra sumatrana.

Additional resources:

Armadillo Online’s Taxonomy

Tree of Life Web Project

Nomenclator Zoologicus

Etymology Online

Integrated Taxonomic Information System

International Code of Zoological Nomenclature