Why is Pepto-Bismol pink? (McGill OSS)

3 minute read

It’s minty, chalky, unpleasantly viscous, and useful for a wide range of stomach ailments, but why is Pepto-Bismol so vibrantly pink?

The active ingredient in Pepto is bismuth subsalicylate. Once in the stomach, bismuth subsalicylate breaks down into two products—bismuth and salicylic acid—the latter of which is rapidly absorbed into the bloodstream. Salicylic acid is the active ingredient in many anti-acne and wart products and is closely related to acetylsalicylic acid, better known as Aspirin. Bismuth is a metal with somewhat unique properties, including notably its low melting point of just 271.5 ˚C. As such, it finds use as a lead replacement in various contexts. One important one is in lead bullets, the use of which has been highly discouraged, or even outlawed in some places, due to its toxicity. If you have a free day, a bottle of bismuth subsalicylate and some laboratory equipment, you can even extract the bismuth from Pepto-Bismol—it’s iridescent and quite pretty!

Bismuth in the stomach is very poorly absorbed and combines with other compounds present to form various bismuth salts. These salts have antimicrobial activity and prevent bacteria from binding and growing on the mucosal cells of the stomach, as well as increasing fluid reabsorption and decreasing intestinal secretions and inflammation. In these ways, bismuth subsalicylate can help with a wide range of digestive issues, including nausea, diarrhea, stomach ulcers, heartburn, and even cholera.

Contrary to what you may be thinking, it is not bismuth subsalicylate that gives Pepto-Bismol its carnation colouring. That compound is beige. It turns out that Pepto is pink simply because Procter and Gamble dye it pink!

According to Pepto-Bismol, the doctor who developed their pink medicine in the early 20^th century chose pink, but no one really knows why. They keep it pink because you don’t mess with success, and who can blame them? The practically neon hue of their product is instantly recognizable, even when their products are in chewable tablet or pill form. Even generic preparations of bismuth subsalicylate tend to stick to the pink colour palette.

In 1992, a Procter and Gamble spokesperson told the LA Times that the doctor chose pink to appeal to children, but as Pepto-Bismol is not recommended for kids under 12, that seems questionable. This recommendation is due to concerns that bismuth subsalicylate could contribute to a rare condition called Reyes syndrome in children. It’s for this exact reason that Aspirin (acetylsalicylic acid) is not approved for children under 12.

You shouldn’t worry about Pepto-Bismol turning you pink, but there is a slight chance it could turn your tongue, or your poop, dark black. This happens due to a reaction between the bismuth metal and sulfur in your mouth or digestive tract, producing bismuth sulfide. This might happen if you’ve recently eaten a lot of sulfur-rich foods—like cruciferous vegetables (broccoli, cabbage, kale etc.) or alliums (onions, garlic, leeks, etc.)—taken a high dose of a sulfur-containing medication (like sulfonamide antibiotics) or live somewhere with high sulfur concentrations in the water. Don’t panic; it’s only temporary and totally benign.

While the doctor who developed Pepto-Bismol and chose its hot pink shade probably didn’t know, the colour of a medication may have surprising impacts on how patients perceive its effects or rate its effectiveness. A couple of studies have found that patients are more likely to perceive warmly coloured medications (red/orange/pink/etc.) as stimulants or antidepressant drugs versus an association with tranquillizers or depressants for cool-coloured (blue/purple/green) meds.

When studied, the marketing of medications echoes this colour coding, implying a feedback loop between buying medications of a particular colour and associating that colour with that type of medication. Interestingly, studies have also shown that the colour of a drug can influence how bitter patients think it will taste and how strong they believe it is. Specifically for children, there’s a belief that red or pink medications make them look sweeter or more palatable to kids. So maybe the inventor of Pepto-Bismol was trying to invoke the idea of a strawberry milkshake!

This article was written for the McGill Office of Science and Society. View the original here: https://www.mcgill.ca/oss/article/you-asked/why-pepto-bismol-pink

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Menopausal Hair Loss: Why It Happens and What We Can Do About It (The Midlife)

8 minute read

Losing your hair might not be the most medically concerning symptom on its own, but its effects on mental health, social well-being, and personal identity can’t be understated. As Dr. Barbra Hanna, FACOG, NCMP, put it, “negative body image, poorer self-esteem, and feeling less control over their life” compound with other “menopause symptoms that can […]

Losing your hair might not be the most medically concerning symptom on its own, but its effects on mental health, social well-being, and personal identity can’t be understated. As Dr. Barbra Hanna, FACOG, NCMP, put it, “negative body image, poorer self-esteem, and feeling less control over their life” compound with other “menopause symptoms that can make one feel as if an alien has invaded their body” to make the time around menopause extremely difficult for many women. Many women suffer for years with thinning hair and widening parts before seeking help, sometimes only to have their concerns dismissed.

Menopause-related hair loss is normal. That being said, it is absolutely worth consulting a physician if it concerns you. It can sometimes be prevented or treated, and while an emotional subject, it should not be a cause of embarrassment.

Androgenetic Alopecia, or Pattern Hair Loss

Depending on the study, the prevalence of alopecia in women has been found to be between 20 and 40%. It seems to affect white women more than those of Asian or Black descent. And while it can occur at any point in life, it overwhelmingly occurs following menopause or 12 months of amenorrhea (absence of menstruation).

This article was written for The Midlife. View the entire original for free here: https://themidlife.com/menopausal-hair-loss-why-it-happens-and-what-we-can-do-about-it/

What Does Snake Venom Do to the Human Body? (McGill OSS)

2 minute read

There are more than 3000 species of snakes on Earth, ranging from the Barbados threadsnake at roughly 10 cm long (about the same as a deck of cards) to the reticulated python at around 6 m in length (almost as tall as an adult male giraffe!). Luckily, only about 600 are venomous, and only around 200 are venomous enough to seriously harm or kill a human.

Despite the existence of hundreds of venoms, nearly all snake venoms fall into one of three categories, depending on how they affect us: neurotoxins, cytotoxins or myotoxins.

Neurotoxins are common to the Elapidae family of snakes, which include cobras, mambas, coral snakes, and copperheads. They work on the nervous system by disrupting the electrical impulses that our nerves and muscles use to function.

Neurotoxins can mess with our neurons in a few different ways. Imagine your neurons like a lamp plugged into an electrical socket. For the lamp to function normally, it should be able to turn on and off at different times. With α-neurotoxins, it’s as if someone put a babyproof cover on the socket, preventing us from plugging our lamp in at all. The result? No light. On the other hand, with dendrotoxins, the lamp is plugged in, but no electricity flows from the socket to our lamp. Again, no light. But with fasciculins, it’s like the lamp’s plug is stuck in the wall. Constantly activated with no off switch, even though we want to go to bed.

Vipers favour the use of cytotoxins—venoms that directly damage cells. Some common types include phospholipases, which disrupt cell walls, and hemotoxins, which affect the circulatory system. Some hemotoxins trigger the destruction of red blood cells, while others affect the clotting factor of blood—either by making blood too clotted and thick to flow or too thin to ever clot and stop external bleeding.

Myotoxins are less common in serpent physiology but are found in certain species of rattlesnakes. They contain basic peptides (chains of amino acids too short to be considered proteins) that directly disrupt the flow of charged molecules our muscles rely on to contract.

With such a wide range of venom types and mechanisms of action, it’s no surprise that nearly every snake species needs a tailor-made antivenom. Luckily, Canada only has four native species of venomous snakes.

Nonetheless, it can be pretty tricky to identify snakes reliably in the wild. So, if you’re ever on the receiving end of a snake bite, seek medical attention immediately! Do not try to catch the snake to bring with you—some help for your doctors in identifying your attacker is not worth a second (or third, or fourth) bite.

This article was written for the McGill Office of Science and Society. View the original here: https://www.mcgill.ca/oss/article/environment-you-asked/how-does-snake-venom-kill-human

When the Cows Come Home to Radioactive Ranches (McGill OSS)

5 minute read

A magnitude 9.1 earthquake occurred just off the northeast coast of Japan on March 11^th, 2011, at 14:46 local time. The Fukushima Daiichi Nuclear Power Plant, like all nuclear power plants in Japan, features several safety mechanisms meant to mitigate damage to its reactors in such an event. It was built on top of solid bedrock to increase its stability, and all of its reactors featured systems that would automatically shut down—or SCRAM—the fission reactions in response to an earthquake. Luckily, only reactors 1, 2 and 3, out of six total, were in operation on that day and were successfully SCRAMed.

Even with fission stopped, however, the nuclear fuel rods continued to emit decay heat and required cooling to avoid a catastrophe. With connections to the main electrical grid cut off due to earthquake damage, the plant’s emergency backup diesel-run generators kicked in to power the cooling pumps.

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Almost exactly one hour after the earthquake, the resulting tsunami struck Fukushima Daiichi with waves 14 metres (46 feet) high. All but one of the diesel generators were disabled by the seawater, and by 19:30, the water level in reactor one had drained below the fuel rod. By the same time, two days later, reactors 1, 2 and 3 had all totally melted down.

In response, over the subsequent days, over 150 000 people were relocated from areas within 40 km of Fukushima Daiichi. Farmers were ordered to facilitate euthanasia for livestock from within the Fukushima exclusion zone, which was estimated to contain 3400 cows, 31 500 pigs, and 630 000 chickens.

Of those 3400 cows, the government euthanized 1500. CNN reports that roughly 1400 were released by farmers to free roam and potentially survive on their own. They are all thought to have starved to death. Three hundred of the remaining animals are unaccounted for, but some farmers who defiantly refused to cull their animals, nor chose to set them free, can account for 200 of the bovines.

Instead, these ranchers—made up almost entirely of cattle breeders—committed to travelling for hours every day into the potentially dangerous Exclusion Zone to continue to feed and care for what some of them refer to as the “cows of hope”.

Where dairy and meat livestock farmers tend to operate larger scale, higher throughput operations, cattle breeders often have small herds and are more attached to individual animals (some even have names). As one farmer told Miki Toda, “The cows are my family. How do I dare kill them?” These animals were spared simply because it was the right thing to do.

These cows and bulls will likely never be used for meat or have their milk collected for consumption. But that doesn’t mean they’re purposeless. Researchers from several universities, including Iwate University, University of Tokyo, Osaka International University, Tokai University, University of Georgia, Rikkyo University and Kitasato University, see the saved herds as an auspicious opportunity for knowledge acquisition.

The scientific research on how radiation affects large mammals is exceedingly sparse. According to Kenji Okada, an associate professor of veterinary medicine from Iwate University, “large mammals are different to bugs and small birds, the genes affected by radiation exposure can repair more easily that it’s hard to see the effects of radiation … We really need to know what levels of radiation have a dangerous effect on large mammals and what levels don’t.”

By studying the cattle exposed to radioactive fallout after the Fukushima Daiichi nuclear disaster, we stand not only to gain retrospective insights into the true effects of radiation on large bovine mammals but to be better prepared if such an event happens again.

The euthanasia of tens of thousands of farm animals represents a massive animal welfare challenge and has a drastic impact on the livelihoods of many. Not only farmers but workers from regulatory agencies, veterinary practices, slaughterhouses, processing plants, feed supply factories, exporters, and anyone else involved in any step of the agricultural process. Nonetheless, it is, of course, warranted if necessary for the safety of consumers of animal products. But was it necessary?

Research on the Fukushima Exclusion Zone herds has been ongoing for nearly a decade now, and while it will take more time to fully see the effects of chronic low-dose radiation exposure, scientists have published preliminary findings and are starting to see trends.

So far, the bovines have not shown any increased rates of cancer. The only abnormal health indicators are white spots that some have developed on their hides. A study of Japanese Black cattle residing on a farm 12 km to the west-northwest of the Fukushima Daiichi nuclear power plant in one of the areas the Japanese government has deemed the “difficult-to-return zone” found no significant increases in DNA damage in the cows. A different study found that horses and cattle fed with radiocesium-contaminated feed showed high radiocesium levels in their meat and milk. However, they found that after just eight weeks of “clean feeding” (feeding with non-contaminated food), “no detectable level of radiocesium was noted in the products (meat or milk) of herbivores that received radiocesium-contaminated feed, followed by non-contaminated feed.”

Much like Chornobyl (the Ukrainian spelling) has become a sanctuary for wild animals despite the residual radioactivity, signs are pointing to a natural “rewilding” of the Fukushima Exclusion Zone. With humans, cars and domestic animals gone, wildlife is able to move into empty urban and suburban environments and thrive. A trail cam study of wild animals around the Exclusion Zone has uncovered “no evidence of population-level impacts in mid- to large-sized mammals or [landfowl] birds.” Wild boars are abundant in the Fukushima region and present another good representative mammal to research. A study of 307 wild boars found no elevation in genetic mutation rates and that a certain amount of boar meat could even be safely consumed by humans.

Although nuclear radiation is a frightening threat, in part due to its invisible nature, evidence seems to be pointing to minimal, if any, health effects for animals exposed to the amount released by the Fukushima Daiichi disaster.

According to a study from the University of Bristol, it’s likely that the situation would be the same for humans had they not been evacuated/relocated. Due to the relatively low-dose nature of the event, the stigma and sometimes severe mental distress experienced by those displaced, as well as losses of life associated directly with relocation and indirectly via increases in alcohol-use disorders and suicide rates, the authors conclude that “relocation was unjustified for the 160,000 people relocated after Fukushima.”

This article was written for the McGill Office of Science and Society. View the original here: https://www.mcgill.ca/oss/article/history-environment/when-cows-come-home-radioactive-ranches

Blood Tests for Menopause (The Midlife)

4 minute read

One of the most common questions that we hear is, “How will I know if I am in menopause?” As you likely already know, that is not a simple yes-or-no question.

Menopause is defined clinically as 12 months of amenorrhea or absence of menstruation. That seemingly straightforward definition, however, masks a complex condition affecting millions of people. With an average age of onset of 47 years old, perimenopause—the transition period from fertility to menopause—can only be diagnosed in retrospect by considering a set of wide-ranging, somewhat vague symptoms.

Given the ambiguity and interpretation required in menopause diagnosis, a simple test that could definitively state whether someone has reached menopause or not would be extremely helpful for clinicians and patients alike. Medical practitioners can use some hormone tests to gather information about your reproductive status, but none provide the definitive answer we’d like them to.

This article was written for The Midlife. View the entire original here: https://themidlife.com/blood-tests-for-menopause/

What rhythm does throbbing pain follow? (McGill OSS)

1 minute read

There are many kinds of pain—Piercing, burning, aching, shocking—but the type I want to focus on today is throbbing. Throbbing pain is often associated with toothaches, headaches, migraines, and pain in the extremities but can occur nearly anywhere in the body. Its pulsing nature can be incredibly annoying to those affected, but it also raises an interesting question: when pain throbs, what rhythm is it following?

Contrary to what you might think, throbbing pain is not beating to your heartbeat or pulse. A 2012 study looked at the throbbing rate of 29 dental patients’ pain, as recorded by patients pushing a button every time they felt a painful throb, compared to their arterial pulse measured in their earlobes. The mean arterial pulse rate was 73 beats per minute (bpm), compared to a throbbing pain rate of just 44 bpm. Researchers further analyzed the simultaneous recordings and found that the two rhythms weren’t synchronous in any way.

If throbbing pain isn’t paced against our heartbeat or pulse, then what determines its rhythm? Simply put, we don’t know! The study’s authors theorize that the pacemaker of throbbing pain is contained somewhere within the central nervous system, but we currently do not have any more specific theories. For now, we just have to accept that throbbing pain marches to the beat of its own drum.

This article was written for. the McGill Office for Science and Society. View the original here: https://www.mcgill.ca/oss/article/did-you-know/what-rhythm-does-throbbing-pain-follow

Why do we wake up feeling cold? (McGill OSS)

1 minute read

A few different bodily processes in humans follow a stable, roughly 24-hour cycle. For example, the cortisol and melatonin levels in our blood. Physical parameters like your blood pressure and heart rate too.

Also under a circadian cycle is our core body temperature. We reach our minimum temperature about halfway through our sleep cycle. By the time we wake up, our bodies have warmed up slightly, but often not yet to our typical body temp.

So, we wake up feeling cold because we are cold. From a normal body temperature of 36.4-37.2 °C (97.5-98.9 °F), normal circadian fluctuations can take us up or down about 1 ˚C. It might not feel like a lot, but remember that most doctors consider fevers to start at 38 ˚C.

Interestingly, there seems to be some variation in when we reach our minimum temperature during the night. A 2001 study measured the temperatures of 172 young men and women and sorted them according to their self-declared status of “morning person,” “evening person,” or “neither.” They found that morning people hit their minimum temps after an average of 3.5 hours, compared to 5.02 hours for neither types and 6.01 hours for evening types. Since individuals tend to feel more alert and perform better on cognitive tasks at higher body temperatures, these differences in the circadian rhythm of body temperature may be one reason some of us struggle to wake up and feel alert immediately.

Image source: https://www.mdpi.com/2079-7737/10/1/65

This article was written for the McGill Office for Science and Society. View the original here: https://www.mcgill.ca/oss/article/medical-you-asked/why-do-we-wake-feeling-cold

Does size matter when it comes to needles? (McGill OSS)

5 minute read

Shots, jabs, pricks—whatever you call it, having a needle inserted into your body is not most people’s idea of a fun afternoon activity. Even if you don’t have a specific needle phobia, injection reactions typically range from neutral at best to quite negative at worst. But what if needles didn’t have to hurt? Or, at least, what if they hurt less? It seems intuitively true that decreasing the size of a needle would make it hurt less, but is it really that simple?

The diameter of a needle (how big it is across) is measured in a unit called a gauge. Because the concept of a gauge pre-dates the 18^th century and has been defined in many different, inconsistent ways, it’s worth specifying that needle width is measured in the Birmingham gauge. The bigger the gauge, the smaller the needle. For example, the width of a 7-gauge needle is roughly 4.6 mm (0.18 inch), while the width of a 30-gauge needle is about 0.31 mm (0.012 inch). To give you some context, a typical spaghetti noodle is roughly 14-gauge, and a regular stud earring is about 19-gauge.

There are a few factors that determine what size of needle a practitioner needs to use, including the body size of the patient and the body part being pricked, but a critical factor is the amount of fluid being injected or drawn out of the patient. If you try to inject a large amount of fluid through a very thin needle, it will both take longer and hurt more due to the high pressure.

Image source: https://www.nms.ac.uk/explore-our-collections/stories/science-and-technology/syringes/

For blood collection, which is typically a few millilitres of blood, clinicians use needles of 21-22 gauge. Vaccines are often <1 mL and accordingly use needles that are slightly smaller, around 22-25 gauge. Delivering insulin to diabetic patients requires even less fluid and can use needles as small as 29-31 gauge.

Even with the limitations imposed by volume, there is some wiggle room in the gauge of needle used for a certain procedure. Medical practitioners can often use their own judgment, experience, and clinical guidelines to change the size of needle they use. Much like how artists may favour a certain size brush, some clinicians have personal preferences in the tools of their trade.

Luckily, it is actually relatively simple to study whether decreasing needle diameter decreases pain. Just find some volunteers who are willing to be stabbed for science (or who are already being treated with a needle-involved method), stick them with at least 2 needles of different gauges without telling them which is which, and ask them how much it hurt on a numeric scale. There are dozens of studies that take this form.

Regarding simple injections in the body, this study compared a 30-gauge needle with a 26-gauge one and found no significant difference in the reported pain. As did this study, which compared 27-gauge vs 23-gauge vs 21-gauge. For injecting Botox around patients’ eyes, this study found no difference in pain scores between a 32-gauge and a 30-gauge needle. These are by no means all of the studies on needle size and pain, but they are representative of the scientific literature on this topic. Again and again, trial participants seem to find no significant difference in their pain when comparing needle gauges.

For many people, the anesthetic injection is the worst part of any dentist visit. While it would be lovely to tell you that a quick swap to a thinner needle is all you need to decrease the pain of dental injections, there is a wealth of evidence to the contrary. For anesthetic injections in the mouth, smaller-width needles were not only ineffective at reducing pain; in one study, they actually increased it!

To continue reading, for free, click here- https://www.mcgill.ca/oss/article/medical/does-size-matter-when-it-comes-needles

Why is poop brown? (McGill OSS)

1 minute read

A certain amount of the muddy colour can be attributed to the different colours of food we eat. Like mixing all the paint colours together, the result is a dull brown. But, much bigger factors for humans’ brown poop are bilirubin and bile. Bilirubin is a yellow substance found in the liver, the product of the breakdown of old red blood cells. Bile is dark brown or green and is produced by the liver to help digest fats. Both of these substances are secreted into the small intestine during digestion, and slowly make their way into poop, bringing with them a dark brown hue.

Bird poop, on the other hand, is not brown but white. That is because—unlike mammals—birds don’t pee!

To read the entire article, click here: https://www.mcgill.ca/oss/article/health-and-nutrition-did-you-know/why-poop-brown

Do We Actually Need To Eat More Calories When Menstruating? (Skeptical Inquirer)

4 minute read

Shark week, moon time, the crimson tide, a visit from Auntie Flo: whatever you call it menstruation is the roughly monthly interval during which the uterus sheds its lining. For the uterus owner, it is not generally a super fun time; cramping, bloating, headaches, and fatigue are just a few of the symptoms associated with “that time of the month.”

The symptom I want to focus on today, though, is hunger. Whether for chocolate, pizza, or any food really, an increased hunger is a commonly reported phenomenon during, or right before, menstruation. Although we know that periodic (get it?) changes in appetite can be influenced by fluctuations in hormones such as estrogen and progesterone, I became curious whether this increase in hunger also correlated with an actual increased need for energy from food. Just like our bodies produce the sensation of thirst when they require more hydration, maybe they produce the sensation of hunger during menstruation in part because of an increased caloric need.

Read the entire article here: https://skepticalinquirer.org/exclusive/do-we-actually-need-to-eat-more-calories-when-menstruating/