The word quarantine stems from the Latin quadraginta and the Italian quaranta, both meaning “40” and traces back to the Black Death.

The Black Death of the 14th century killed half the population of Europe and millions more in Asia and Africa. The likely cause of the Black Death was plague; a bacterial (Yersina pestis) infection carried by rats and transmitted by flea bites (bubonic plague).

In an attempt to protect coastal cities from the plague epidemic, ships arriving from infected ports were required to sit at anchor for 40 days before landing. This practice was known as quarantine.

It remains unclear why the 40-day stipulation was enforced. It is possible that the arbitrary number coincided with biblical references like Jesus’ fast in the desert, Moses’ time on Mount Sinai, and the Christian observation of Lent.

Quarantine stations for maritime travellers were called lazarettos, a direct biblical reference to the parable of Lazarus the beggar (and patron saint of lepers in Catholicism). Leprosy, of course, has a long history of social isolation.

A true human tail (persistent vestigial tail) is rare. It consists of a central core of mature fatty tissue, small blood vessels, bundles of muscle fibres, and nerve fibres. It may be as long as 13 cm and can move and contract. The true tail is the distal remnant of the embryologic tail, which is present between the fourth and seventh or eighth weeks of fetal development [1]. For most of us, our tailbone (coccyx) is the vestigial representation of the tail. The word coccyx is via Latin from the Greek word kokkux (cuckoo) because the shape of the human tailbone resembles the cuckoo’s bill.

 

1. Singh, D., Kumar, B., Sinha, V. and Bagaria, H. (2008). The human tail: rare lesion with occult spinal dysraphism—a case report. Journal of Pediatric Surgery, 43(9), pp.e41-e43.

I came across this late-night-stoner theory on the internet: “Maybe plants are really farming us, giving us oxygen until we eventually expire and turn into mulch which they can consume.” There is something to be said for the idea that humans did not domesticate plants; plants domesticated humans.

In Yuval Noah Harari’s book: “Sapiens: A Brief History of Humankind”, he uses wheat as an example:

“[Humans] had been living a fairly comfortable life hunting and gathering until about 10,000 years ago, but then began to invest more and more effort in cultivating wheat. Within a couple of millennia, humans in many parts of the world were doing little from dawn to dusk other than taking care of wheat plants. It wasn’t easy. Wheat demanded a lot of them. Wheat didn’t like rocks and pebbles, so Sapiens broke their backs clearing fields. Wheat didn’t like sharing its space, water, and nutrients with other plants, so men and women labored long days weeding under the scorching sun. Wheat got sick, so Sapiens had to keep a watch out for worms and blight. Wheat was defenseless against other organisms that liked to eat it, from rabbits to locust swarms, so the farmers had to guard and protect it. Wheat was thirsty, so humans lugged water from springs and streams to water it. Its hunger even impelled Sapiens to collect animal feces to nourish the ground in which wheat grew.

“The body of Homo sapiens had not evolved for such tasks. It was adapted to climbing apple trees and running after gazelles, not to clearing rocks and carrying water buckets. Human spines, knees, necks, and arches paid the price. Studies of ancient skeletons indicate that the transition to agriculture brought about a plethora of ailments, such as slipped disks, arthritis, and hernias. Moreover, the new agricultural tasks demanded so much time that people were forced to settle permanently next to their wheat fields. This completely changed their way of life. We did not domesticate wheat. It domesticated us. The word “domesticate” comes from the Latin domus, which means “house.” Who’s the one living in a house? Not the wheat. It’s the Sapiens.

If a human gets infected with a tapeworm that has cancer, can the tapeworm’s cancer spread to the human host? Well, we know that certain cancers develop from infections (mostly viruses but the bacterium Helicobacter pylori and parasite Schistosoma also immediately spring to mind). However, the mechanism of carcinogenesis is not via the direct invasion of host tissue by microbial neoplasms. Is it possible? According to this case report (https://www.ncbi.nlm.nih.gov/pubmed/26535513), it is not improbable.

Newborns can have one or more erupted teeth at birth (usually the lower incisors), called natal teeth. This familial tendency (autosomal dominant trait) occurs in 1 in 2000 neonates. Teeth may also erupt in the 4 weeks after birth; they are called neonatal teeth. Natal teeth are often extracted because they cause discomfort during breastfeeding and may lacerate the baby’s tongue.

A lot is going on in this joke. Marijuana users know that increased appetite (or munchies) results from THC stimulating CB1 receptors in the brain. CBD has some opposing pharmacological effects to THC and so may attenuate these effects to some extent. Smart alecks will point out that a drug which blocks those CB1 receptors might induce the anti-munchies and make people skinny. Well, an anti-cannabinoid drug was, in fact, available in some parts of the world, but most North Americans would never have heard of it. Rimonabant was never approved in the US or Canada but promised to be an effective weight loss pill. It helped smokers quit, improved cholesterol levels, showed promise in treating diabetes, and helped people lose weight (4-5 kg on average). So why was it withdrawn from the European market? It was also really good at causing depression and increasing suicidal thinking. Following these severe psychiatric side effects, the company who made rimonabant withdrew it from the market.

Many doctors refer to a fracture of the fourth or fifth metacarpal bones as a boxer’s fracture. Why is that term considered a misnomer?

A fracture of the fifth metacarpal neck is, more correctly, called a “brawler’s fracture or a streetfighter’s fracture”. This distinction exists because professional boxers rarely break the fifth metacarpal. They are far more likely to fracture the second or third metacarpal bones (such injuries used to be called the boxer’s fracture). Amateurs and people who hit solid objects like walls are the victims of fourth or fifth metacarpal fractures. Because doctors like to disagree and medical students struggle to remember facts, nowadays the term boxer’s fracture is thrown around like a sloppy punch to refer to any metacarpal fracture. We seem to agree that the term should describe the most common cause of the injury—hitting an object with a clenched fist—instead of the technical ability of the slugger.

And too much alcohol can make your arm fall asleep. Have you heard of ‘Saturday night palsy’? Following alcohol intoxication, an unconscious drunk with his arm draped over the back of a chair can compress his radial nerve causing his arm to fall asleep. This syndrome is also called honeymooner’s palsy because it can happen when somebody sleeps with their head rested on another person’s arm. The radial nerve paralysis appears as a wrist drop deformity; the appearance of which resembles the hand and wrist position when dipping into a depleted bowl of bar peanuts.

The plant responsible for more human suicides than any other is aptly named “Suicide Tree”. This hardwood tree, endemic to India and southeast Asia, is also known as Pong-Pong Tree or Cerbera odollam. It accounts for 10% of the total poisonings in Kerala, India. In the centre of its fruit lies a kernel with high concentrations of a cardiotoxin. The toxin, called cerberin, has a range of biochemical effects on heart muscle cells. Similar to Foxglove plants, it slows the heart and influences contractility.

There is no laboratory test available to detect cerberin, leaving doctors to rely on the patient’s history and an index of suspicion. For this reason, Pong-Pong seeds may also be responsible for an unknown number of homicides. The taste of the poison is masked easily with spicy food, and many toxicology centres cannot test for cerberin.

A few suicide cases have also been reported in North America after Pong-Pong seeds were purchased online.