Tag: medicine

Posted in Psychology & Medicine

Typhoid Mary

Posted on by Jinavie

New York City, 1901 – an upper-class family presented with fevers and diarrhoea, diagnosed with the infection typhoid fever. This was unusual as typhoid fever was classically associated with poor hygiene, overcrowding and lower socioeconomic status households. It was atypical to see typhoid fever in upper-class households. Within a year, a lawyer and his household fell ill to the same disease – 7 out of 8 people contracted typhoid. Another case emerged 5 years later in Long Island, New York – an area where typhoid fever was very uncommon. This time, 10 out of 11 family members were hospitalised with typhoid. Countless families fell victim to typhoid fever within this year and people started becoming curious as to the cause of this epidemic.

In 1906, typhoid researcher George Soper began investigating the epidemic and found a common link between all of the families who became sick. They had all at some point employed a cook by the name of Mary Mallon. Soper noticed that Mallon had worked for each of these families roughly three weeks before each of them fell victim to the illness, upon which she would leave the job for another family. Soper approached Mallon to obtain urine and stool samples to prove this, but Mallon adamantly refused and denied any responsibility in her possible role in spreading typhoid as she “was not sick”.

Eventually, the New York City Health Department appointed Dr Sara Josephine Baker to handle the situation. Mallon still refused to comply with the investigation and had to be taken into custody by the police. She was forced to be tested while in prison, which proved that she was an asymptomatic carrier of typhoid fever. Doctors discovered that she had a significant growth of typhoid bacteria in her gallbladder. It was determined that Mallon has infected the families through preparing and serving food (she was famous for her ice cream) with poor hand hygiene.

Due to her non-compliance to the order of restricting her from being a cook, Mallon was quarantined for the rest of her life until she died from a stroke in 1938. Mallon – or as the media called her, “Typhoid Mary” – was the source of at least 51 confirmed typhoid fever cases, three of which were fatal. Some estimates say she could have been responsible for as many as 50 deaths as she had worked under many aliases. All because she did not wash her hands properly.

Posted in Psychology & Medicine

Genuine Smile

Posted on by Jinavie

Guillaume Duchenne, the famous French neurologist of the 19th century, conducted many experiments to study facial expressions. Part of his research involved determining how certain expressions are produced – such as stimulating different muscles with electricity to see what muscle produced what expression. During this research, Duchenne identified that a smile could be divided into two distinct groups.

The first – what he called the “Duchenne smile” – involves a muscle called zygomatic major, which raises the corners of the mouth, and also orbicularis oculi, which raises the cheeks and wrinkles the corners of the eyes. The second (“non-Duchenne smile”) type of smile involves less muscles; more specifically it only uses the zygomatic major muscle.

To better visualise this, think of what a natural, genuine smile looks like – a wide grin on the mouth, lifting of the cheeks and slanting of the eyes. This is a Duchenne smile, as opposed to the forced, non-Duchenne smile you see often in photographs. Duchenne concluded that a Duchenne smile only showed when the person was genuinely experiencing a positive emotion. Non-Duchenne smiles were more associated with polite social behaviour when people were pretending to have a good time.

The easiest way to distinguish the two is to look at the eyes, for a real smile is when the eyes are smiling as well. This is a useful physiological trick to remember when you want to figure out whether someone is smiling because they are genuinely happy, or because they are just trying to be polite. Also, knowing how to smile with your eyes to fake a “genuine” smile can be a handy social skill.

Posted in Psychology & Medicine

Dark Circles

Posted on by Jinavie

One of the most tell-tale signs that someone is extremely tired or sleep deprived is having dark circles around the eyes. The skin beneath the eyelids are very thin – almost a quarter of the thickness of skin elsewhere on the body.

During times of exhaustion, the skin becomes paler due to a number of factors. The paleness makes it easier to see the blood vessels running under the skin, which shows as a greyish-blue tint. The more vessels that can be seen and the paler the skin, the darker the circle appears.

Dark circles appear to be an inherited trait, most likely related to the thickness and transparency of your skin. It is also more common in people with hay fever, anaemia and liver problems. The only real treatment for dark circles is rest.

Posted in Psychology & Medicine

Ebola

Posted on by Jinavie

In 1976, an outbreak of a viral illness was identified in Sudan. Patients would present with symptoms of high fever, headache, vomiting, diarrhoea and a spotted rash, but would rapidly deteriorate in health. Within days, patients showed signs of decreased blood clotting, such as bleeding from intravenous line sites, having blood in their vomit and stool, or bleeding from essentially any bodily orifice. If untreated, patients would die within two weeks of shock (very low blood pressure), kidney failure or bleeding into the brain. The outbreak killed 151 people before it disappeared.

Later in the year, a headmaster at a school in Zaire developed a similar disease after travelling to the Ebola River. He died two weeks later. Soon after, people he came in contact with after his trip died of similar symptoms. The World Health Organisation investigated this epidemic and realised that the disease was caused by a new type of virus, which was named ebola virus. Due to its symptoms, the disease caused by the virus is named ebola haemorrhagic fever.

Since the discovery of the disease, occasional ebola outbreaks were seen in various parts of Africa, mainly around Congo and Uganda. Each time, the disease would rapidly claim the lives of hundreds of people and then vanish. This is because ebola virus was so effective in killing people (with a death rate of 90% in one outbreak), that it would kill the infected person before they spread the disease further.

The virus can be spread through any bodily fluid, including blood, tears, semen and sweat. Because of this, once an infected patient is brought into hospital, the disease can spread rapidly throughout the building and infect many patients and hospital staff if proper precautions are not taken. Fortunately, the virus is not known to spread when the patient is in the incubation period (when they are infected but have not shown symptoms yet).

The origin of the virus has been traced back to fruit bats (like many other serious viruses). Fruit bats have extremely powerful immune systems to protect their cells from the harmful metabolites produced by flying, allowing bats to harbour deadly viruses without succumbing to them. These viruses have also evolved to withstand the high temperatures produced by flying (which involves significant muscle work), meaning they can easily survive the high fevers they cause in humans. The transmission from bats to human in modern times is likely attributed to deforestation and humans encroaching into the bats’ native territory.

The current epidemic that originated from West Africa is the biggest ebola outbreak so far, having infected over 9000 people and claiming the lives of over 4500 people (October 14, 2014). However, this is likely a grossly underestimated number. The epidemic is focussed mainly in Guinea, Sierra Leone, Liberia and surrounding countries, but has infected foreign workers and volunteers who have been repatriated to be treated in their home country.

Despite a robust effort from the WHO to try and curb this epidemic, the infection rate continues to climb due to various factors, such as traditional funeral rites involving touching the deceased person’s body, which is still infective after death. There are currently no effective vaccines or treatments and the only thing that can be done is supportive treatment in an intensive care unit where the patient can be adequately hydrated and monitored. Like with most communicable diseases, the most effective treatment is preventing the disease from spreading through education, rigorous infection control protocols and improved healthcare systems in the affected countries.

Posted in Science & Nature

Silver

Posted on by Jinavie

Historically, silver has been associated with cleansing, healing, the moon and warding off evil. For example, it is said that some monsters such as werewolves would only die if it is shot by a silver bullet. The Greek goddess of hunting and the moon, Artemis, carries a silver bow. Although it is always seconded to gold when it comes to precious metals, silver is a fascinating metal.

It is the most reflective metal on Earth and has the highest conductivity for heat and electricity. It is ductile and malleable, making it a good choice of metal for making coins, jewellery and silverware (hence the name). Because of how reflective it is, it is also used in solar panels and special mirrors, such as those in telescopes.

Another useful characteristic of silver is its chemical reactivity. Thanks to this property, silver forms many different compounds with varying applications. Silver halides are photosensitive and turn dark when they are exposed to light. This is the basis of film photography, where the light shone on a film coated with silver halides leaves a photographic imprint. Silver oxides are sometimes used in batteries and silver/mercury alloys are used for dental fillings.

Silver also plays a role in medicine. Silver ions have been shown to inactivate bacteria such as E. coli, making silver nanoparticles a useful antiseptic that can be impregnated into different materials such as wound dressings. Silver nitrate sticks are used in emergency departments as applying it to a bleeding vessel in the nose will release nitric acid, which cauterises (burns off) the vessel to stop a nosebleed. In medieval Korea, silver spoons were used to test if a food has been poisoned with arsenic, as arsenic reacts with silver to form a black tarnish. If a person has too much silver build-up in their body, they can develop argyria (silver poisoning), which turns the skin an eerie bluish-grey colour.

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Posted in Science & Nature

Head Bobbing

Posted on by Jinavie

If you take the time to look at how most birds walk, such as a chicken or a pigeon, you will notice that they bob their heads. This seems extremely impractical as if we bobbed our heads like that, we would likely become dizzy and vomit quite soon. So why do birds do it and why does it not make them dizzy?

A major difference between birds and human beings is the way our vision works. In humans, our eyes are constantly moving at a rapid rate (saccade) to collate information and stabilise images. Even when we are walking and our head is moving around, our eyes use various sensory information and reflexes to fix our vision at one point, giving us a clear picture. This is such a powerful reflex that one test to check a person’s brainstem function (for example, when they are in a coma) is to move the head and see if the eyes stay fixed on a point or if they follow the head (doll’s eye test). If the brainstem is intact, the eyes will keep looking at a fixed point despite head movement.

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Birds on the other hand, cannot fix their vision this way. Instead what they do is they keep their head absolutely still in three-dimensional space when their body is moving. If you hold a chicken in the air and move the body around, you will find that the head stays stationary. This means that when they are walking, the bird’s head will stay still while the body takes a step forwards, then it will move to catch up to the body. From a third person’s point of view, this makes it look like they are bobbing their head, although they are just keeping it very still. In 1978, Dr Barrie J. Frost did an experiment where he put pigeons on a treadmill surrounded by a still backdrop and found that the pigeons did not bob their heads because there was nothing to see.

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Posted in Science & Nature

Atrophy

Posted on by Jinavie

With exercise, muscles get bigger and bigger to generate enough power to meet the demand. This is called hypertrophy, where the cells in tissue divide faster to increase their numbers and build mass. When you do not use the muscles as much, the body decides to recycle the precious resources by breaking down the extra muscle. This is called atrophy – also known as wasting.

Muscles are not the only things that atrophy. The less you think deeply and explore your curiosities, the more your intelligence and wisdom atrophies. As you care less, your heart and ability to love atrophies. As you smile and laugh less, your happiness atrophies.

Like much of nature, the human body dislikes the status quo and strives to avoid stagnation. It continuously breaks down old, unnecessary things to make way for new, different things that will help you better adapt to your environment.

Unfortunately for us, that means to maintain the parts of us that we like, we must train and use the relevant “muscles” – whether it be lifting weights, reading books or laughing heartily for no reason.

Posted in Science & Nature

Mandrake

Posted on by Jinavie

The plant Mandragora officinarum, more commonly known as mandrake, is a plant that has interested people in various fields throughout history. Firstly, the root is split into two at the end, giving the uprooted plant the appearance of a human being. Secondly, it belongs to the nightshade family, containing plants such as the infamous deadly nightshade (belladonna), tobacco, Datura, petunia, tomatoes and potatoes. Like its relatives the belladonna and Datura, mandrakes contain alkaloids such as atropine, scopolamine and hyoscyamine. These substances are potent (and toxic) hallucinogenics and sedatives, which is why they have had various uses ranging from witchcraft to anaesthesia to murder through poisonings.

The shape of the mandrake and its hallucinogenic effects have given it notoriety. Legend goes that when a mandrake root is dug up, it shrieks with such terror that anyone who hears it will die – possibly referring to the toxicity of the alkaloids. Historical texts give detailed instructions on digging up mandrakes by tying a hungry dog to the root and making it pull the plant out of the ground when the owner is out of earshot and he lures the dog with food.

Other folklore suggest that mandrake only grow when the ground is inseminated by semen dripping from a hanged man. This folklore is likely fuelled by the mandrake’s human-like appearance. Ancient and medieval literature associates mandrake being used to make fertility agents and love potions(again, likely related to the hallucinatory, sedative effects). Mandrake is a common ingredient in magic rituals of various kinds, such as in Wiccan rituals.

Alkaloids extracted from mandrake have been used in medicine since the Middle Ages, where extracts were used to anaesthetise patients before surgery, as it has a sedating, hypnotic effect. Eye drops made from mandrake extract were used for hallucinations and mandrake syrups were used to aide sleep. In modern medicine, scopolamine is used in motion sickness patches and atropine is used to speed up the heart rate when it slows too much.

The extensive list of supposed and actual properties of mandrake has made it a popular plant in fiction as well and it can be found in countless works throughout time, such as works of Shakespeare, Sir Arthur Conan Doyle and J.K. Rowling.

Posted in Psychology & Medicine

Stampede

Posted on by Jinavie

In the movie The Lion King, Simba’s father Mufasa is killed when he is trampled by a wildebeest stampede. Stampedes are a common behaviour in herd animals such as cattle, horses, wildebeests and elephants. When one animal is startled by something, it shows a fear response which then startles the animals around it. This startle propagates rapidly through the herd and the entire herd begins running away from whatever caused the first startle. They run with no clear reason or direction – it is a mindless rush of fear. Because of this, anything in the path of a stampede is crushed to death as the herd blindly rushes forward with impressive power and energy.

The destructive nature of a stampede not only affects whatever is in the path of the herd, but the herd itself. Native Americans are well-known for their buffalo jump style of hunting, where they would herd wild bison then trigger a stampede. They would direct the stampede towards a cliff and the frightened bison would blindly jump off the cliff to their deaths.

As deadly as a bison or wildebeest stampede may be, there is a species that causes far greater damage to humans when they stampede: us. Human stampedes are a well-known phenomenon documented throughout history, from crowds rushing away from a city being bombed to religious pilgrimages to sports games. Just like animals, when there is a large enough crowd of people, a simple spark of fear can cause mass panic.

This is described as the “falsely shouting fire in a crowded theatre” effect. In 1941, 4000 people were killed when the Japanese army bombed the Chinese city of Chongqing, causing a mass panic at an air raid shelter. More famously, 96 people were killed in the Hillsborough stadium crush in England, 1989, when crowds of people attending a soccer match squeezed into a tunnel blocked at the other end. There have been several incidents during the pilgrimage to Mecca where hundreds of people were killed during stampedes.

In human stampedes, death is not usually caused by trampling but by compressive asphyxiation. The sheer force of people pressing on each other limits chest expansion, making breathing impossible. The force of a panicked crowd can be great enough to bend steel bars. This phenomenon is also called crowd crush.

Posted in Science & Nature

Chocolate Overdose

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It is common knowledge that you should not feed dogs and cats chocolate as it is poisonous to them. This is because chocolate contains a substance called theobromine. The name theobromine comes from the Greek words theo (“god”) and broma (“food”), thus meaning “food of the gods”.

Cats and dogs metabolise this chemical very slowly, so they can easily overdose on it. Theobromine poisoning causes vomiting and diarrhoea initially, then progresses to cause hyperactivity, cardiac arrhythmias (irregular heartbeats), seizures, internal bleeding, cardiac arrest, respiratory failure and eventually death. Although cats and dogs have the same metabolism rate of theobromine, there are far less cases of cats overdosing on it as they do not have sweet taste receptors and do not particularly like the taste of chocolate.

Luckily for us, the human body can metabolise theobromine much more efficiently and we are much less likely to get theobromine poisoning (although it is still possible if you eat too much of it). Although it is weaker, theobromine behaves similarly to caffeine in the human body. It stimulates the heart to beat faster, relaxes the blood vessels, reduces blood pressure and stimulates your nervous system to decrease your tiredness and give you a “buzz”.

The effects are potent enough that there is some evidence that eating dark chocolate (which has a higher theobromine content) regularly can reduce your risk of heart disease. However, this is counterbalanced by the negative health effects of sugar and fat found in chocolate. That being said, a small amount of chocolate every now and then not only has a positive effect on your heart, but is a great medicine for your exhausted mind and soul.