Tag Archives: chemistry

Chemistry for Cancer: New Radioactive Tracers for Cancer Diagnosis

Cutting-edge chemistry may be the key to fast and efficient cancer diagnoses. In early 2020, Antonio Wong and his research team at the University of British Columbia (UBC) in Vancouver, BC, developed a new way to synthesize radioactive tracers for positron emission tomography (PET) scan cancer diagnosis. Recently, I interviewed Antonio to discuss his research.

The Problem 

Imaging technologies like the CT scan, ultrasound, X-ray, MRI, and PET scans allow doctors to identify cancerous masses in patients. Although PET scans are a common way to diagnose cancer, researchers want to find ways to make tracers more efficiently. So, Antonio and his team aimed to develop a new kind of tracer and to make the synthetic process more efficient.

PET scan and technician, Source: http://www.bccancer.bc.ca

The Science 

Since cancer cells divide quickly and uncontrollably, they require many more cellular “building blocks” compared to regular cells. Taking advantage of this, researchers have previously developed “tagged” versions of  these building blocks, called tracers, which accumulate inside cancer cells. This allows doctors to see tumors in PET scan images. When I spoke to Antonio, he explained that the “golden standard” for PET imaging uses a sugar molecule called glucose tagged with a radioactive fluoride atom (called FDG) which is responsible for the glow on medical images. To see how tracers work, check out this video below.

Combining innovation and creativity, Antonio’s team developed a more efficient way to make these tiny building blocks by using a careful mixture of chemicals. They used a molecule called thymidine which is required for cell division, tagged it with a radioactive atom (18F), and injected into mice with cancer. The mice were then put into a PET scan to see if the building blocks were “building up” inside the tumors, which would glow on the PET scan images.

Tracer synthesis, Source: Antonio’s Paper

The Impact 

When Antonio ran this study, he was an undergraduate student at UBC. As a result, his story has caught the attention of students on campus. After my interview with Antonio, my colleague Parwaz, a UBC student who runs a podcast called “Thinkin’ a Latte”, chatted with two other UBC undergraduates about the interview. Check out their podcast below.

Although the study’s findings are promising, using thymidine-based tracers for PET tumor imaging requires much more research before it can be used in clinics. 

“I think the significance of this paper is not like ‘look this is the next blockbuster drug that we’re trying to use’, this is more like a proof of concept”

– Antonio Wong

Nonetheless, cancer is a prevalent disease that has touched the lives of almost everyone and research like Antonio’s is bringing much needed innovation and creativity to the field.

– Maya Bird 

Co-authors: Parwaz, Samin, and Teaya 

Need to Sober Up? Just Breathe Out the Booze!

With regards to alcohol, many of us have previously reached the so-called point of no return: a moment where the pleasant buzz is replaced by a throbbing headache (and massive amounts of regret). If only there was a simple way to quickly sober up…

Alcohol! Source: awee_19, Flickr

A simple overview of ethanol breakdown

First, let’s dive into how our bodies break down alcohol. Once ethanol arrives at the stomach and intestines, it is absorbed into the bloodstream. From there, most of the alcohol ends up in the liver. The liver is responsible for detoxifying 90% of the ethanol that we consume; the remaining 10% is eliminated through sweat, urine, and breath.

However, the rate at which the liver breaks down ethanol is zeroth-order: meaning that the breakdown rate is always constant, no matter how much ethanol is in your system. This explains why we haven’t been able to develop techniques to speed up the rate of ethanol breakdown in our livers.

Naturally, the next step would be to see whether we can speed up the elimination of the remaining 10% of ethanol in our bloodstreams. Turns out, we can! Remember how we said that some ethanol is breathed out? This works the same way that we exhale carbon dioxide: diffusion! Since the ethanol concentration in our bloodstream is higher than in the air that we breathe in, some ethanol diffuses into our lungs and we breathe it out!

Diffusion Explained.
Source: Free Animated Education, YouTube

A breathalyzer uses the fact that we breathe out ethanol to determine our blood alcohol concentration (BAC). Source: Dave Shea, Flickr

So can I just hyperventilate until I start to feel sober?

In theory, you could… but you really shouldn’t. Hyperventilating will reduce your ethanol levels, sure, but it will also decrease your CO2 levels: causing your brain’s blood vessels to narrow, and ultimately depriving your brain of oxygen. Thankfully, a recent study has found a simple and effective solution, utilizing isocapnic hyperpnea.

Isocapnic hyperpnea: what is it?

To put it simply, isocapnic hyperpnea (IH) is when you deeply (sometimes rapidly) breathe in air that has an equal concentration of carbon dioxide as in your bloodstream. This lets you breathe out all the nasty ethanol, while your CO2 levels stay steady. In the study, participants drank vodka, then were connected to a device which supplied air which had a CO2 concentration similar to what would be found in normal blood vessels. The results of the study showed that the participants who underwent IH were able to get ethanol out of their system more than three times faster than participants who breathed regular air!

A demonstration of the IH apparatus. Source: UHN

This technology could be widely available in the near future, since IH has already been approved as a treatment for clearing our bodies of other chemicals. IH could help paramedics in clearing the alcohol out of a patient’s system in a timely manner, which could ultimately save their lives. Remember to always drink responsibly!

 

– Sam Jung

Need to Sober Up? Just Breathe Out the Booze!

With regard to alcohol, many of us have previously reached the so-called point of no return: a moment where the pleasant buzz is replaced by a throbbing headache (and massive amounts of regret). If only there was a simple way to quickly sober up…

Alcohol! Source: awee_19, Flickr

A simple overview of ethanol breakdown

First, let’s dive into the details as to how our bodies break down alcohol. Once ethanol arrives at the stomach and small intestine, it is absorbed into the bloodstream. From there, it can travel to various organs in your body, or end up in the liver. The liver is responsible for detoxifying 90% of the ethanol that we consume; the remaining 10% is eliminated through sweat, urine, and breath.

However, the rate at which the liver breaks down ethanol is zeroth-order: meaning that the breakdown rate is always constant, no matter how much ethanol is in your system. This explains why we haven’t been able to develop techniques to speed up the rate of ethanol breakdown in our livers.

The next natural step would be to see whether we can speed up the elimination of the remaining 10% of ethanol in our bloodstreams. Turns out, we can! Remember how we said earlier that some ethanol is removed via breathing? This works the same way that we breathe out carbon dioxide: because the concentration of ethanol in our bloodstream is higher than in the air that we breathe in, some ethanol diffuses into our lungs and we breathe it out!

A breathalyzer uses the fact that we breathe out ethanol to determine our blood alcohol concentration (BAC). Source: Dave Shea, Flickr

So can I just hyperventilate until I start to feel sober?

In theory, you could… but you really shouldn’t. Hyperventilating will reduce your ethanol levels, sure, but it will decrease your CO2 levels as well: causing your brain’s blood vessels to narrow, and ultimately depriving your brain of oxygen. Thankfully, a recent study published just last year has found a simple and effective solution, utilizing isocapnic hyperpnea.

Isocapnic hyperpnea: what is it?

To put it simply, isocapnic hyperpnea (IH) is when you deeply (and sometimes rapidly) breathe in air that has an equal concentration of carbon dioxide as present in your bloodstream. In the study, participants consumed diluted vodka, then were connected to an apparatus which supplied air of CO2 concentration similar to levels found in normal blood vessels. This allowed the subjects to breathe out ethanol at a higher rate while maintaining steady CO2 levels in their blood. The results of the study showed that the participants who underwent IH showed an ethanol elimination rate which was more than three times greater than participants who breathed regularly!

A demonstration of the IH apparatus. Source: UHN

Deaths caused by alcohol poisoning are far too common. In the future, IH could help paramedics in clearing the alcohol out of a patient’s system in a timely manner, which could ultimately save their lives. Remember to always drink responsibly!

 

– Sam Jung

A Promising Treatment in the Fight Against Microplastics

Over the past few years, there has been a global effort by scientists to develop a treatment that is able to limit the pollution of microplastics into marine environments. Fortunately, Marthe Kiendrebeogo and her research team may have found a solution. They discovered that they were able to effectively break down a sample of microplastics through anodic oxidation. 

Now you may ask, what are microplastics?

Microplastics are pieces of plastic less than 5 mm in length. The three main sources of microplastics are the breakdown of larger plastics, cosmetics and laundry washes. All three of these sources have contaminated marine environments all over the Earth. To put this into perspective, a recent study has suggested that there are approximately 12-125 trillion microplastics floating in the oceans today. 

A collection of mainly plastic material that washed ashore. Plastics, such as a water bottle, can be degraded and become a source of microplastics.

Credit: unsplash.com/john_cameron

The Effect of Microplastics on Life:

The buildup of microplastics in aquatic life through ingestion can lead to toxic (harmful) effects. These effects were studied by a different research team led by Dr. Kogel where they found the toxic effects included infertility, decreased growth rate, shorter lifespans, and internal damage. Furthermore, microplastics are known to travel up the food chain and eventually reach humans. There is currently a lack of information regarding the effects of microplastics in humans, but several studies are in progress.

YouTube Preview ImageFor those interested, Drs. Sarah Dudas and Peter Ross show the presence of microplastics in aquatic life in this video.

And now to the study:

With the background information out of the way, I’m going to explain how Marthe Kiendrebeogo and her team created a potential solution to tackle the rising issue of microplastics.

This research team found that the process of anodic oxidation breaks down microplastics efficiently. Anodic oxidation involves a lot of chemistry, but the main thing to know is that it creates hydroxyl radicals (OH-) without adding extra chemicals into the water. These hydroxyl radicals are very good at attacking and breaking down microplastics. The full mechanism is in the article for those interested. This study found that with their proposed mechanism, 58 ± 21% of microplastics broke down in 1 hour which reached approximately 80% in 3 hours. 

I think that the most significant result in this study is that 58 ± 21% of polystyrene was degraded in 1 hour because an hour is close to the time of a normal laundry cycle. A laundry cycle puts a lot of stress on clothing fabrics which leads to the release of microplastics. In fact, a recent study has estimated that 35% of microplastics in oceans can be contributed to laundry. Thus, this mechanism would be very effective at decreasing the amount of microplastic production if it was implemented into laundry machines.

The addition of this treatment into laundry machines can limit the number of microplastics released at the initial source.

Credit: unsplash.com/scottsweb

Based on the results of this study, the future of treatments for microplastics sounds more promising. Nevertheless, there still is a lot of work to be done. The next step for this promising treatment would be to test the effectiveness of the proposed mechanism on samples consisting of other microplastics. 

-Karnvir Dhillon