Category Archives: Issues in Science

Cancer Treatment Breakpoint: A Discovery of 225Ac – H4py4pa Complex

Posted on April 8, 2022 by billyang | Leave a comment

Like the Earth itself, the world of science never stops turning.

More specifically, the world of cancer research never stops turning; there are always improvements to be made. With this mindset, scientists Lily et al. from the Orvig group wrote and published a paper about the characteristics of a molecule called H4py4pa in early 2021. They studied the molecule at multiple locations, such as the UBC Chemistry Labs, TRIUMF and BC Cancer Research Centre, in hopes of improving the effectiveness of a specific type of cancer treatment called targeted alpha therapy. The paper supports the effectiveness of this new molecule by comparing characteristics, such as stability, with the original molecule used in targeted alpha therapy.

With all that said… What is targeted alpha therapy and how exactly does it work?

What in the Jargon?… A Carefully Defined Mechanism of H4py4pa

Before we get into the meat and potatoes, we need to define some of the terms here.

H4py4pa is a ligand, which is essentially a big molecule, that is able to bind to metal atoms. Ligands binding to metal atoms is a chemical phenomenon known as chelation. The metal atom in this case is Actinium-225 (225Ac). Essentially, chelation of H4py4pa to 225Ac can deliver four net alpha particles, which are a particulate form of concentrated radiation. Radiation is known to destroy cancer cells. In other words, radiation is tumoricidal. This process is known as targeted alpha therapy.

Molecular Structure of H4py4pa and visual summary of the study. Source: Bioconjugate Chemistry

Starting from 2:50, you get a visualization of how the mechanism works. Source: STORYHIVE

The Body is ASTOUNDINGLY Large

We, as humans, are fairly large organisms. So the question becomes: How does the 225Ac-H4py4pa find the tumour site? 225Ac is normally bound to a specific antibody, called Trastuzumab, which is attached to the HER2+ protein. The HER2+ gene most notably contributes to breast cancer. This means that 225Ac already has a natural affinity for certain tumour sites in the body. However, 225Ac is still capable of unintentionally interacting with other areas of the complex body. This is where H4py4pa comes in. H4py4pa is a very big molecule that hugs around the 225Ac and prevents it from binding to anything other than the intended antibody.

A good way to visualize this mechanism is through a 4-component arrow mechanism. The 225Ac is the arrowhead that will do the damage to its target (in this case the tumour) while the shaft and the feathers of the arrow are the directional components that direct the 225Ac arrowhead to the right area of the body.

The issue with solely injecting 225Ac into the body, however, is that it’ll go straight to the bone instead of the cancerous area. As you may have heard, opposites attract, so because 225Ac is positively charged, it’ll be attracted to the bone, which has a lot of negatively-charged phosphate groups.

This is where the H4py4pa comes into play.

The fourth component of the arrow is H4py4pa, which acts as the linker for the arrowhead and shaft, binding to the 225Ac and holding it in place as the directional components of the arrow move the 225Ac arrowhead straight towards its target.

We’ve prepared a video in order to visualize this:

So what are the Discoveries of this Study?

Through many trials and tests, it was found that H4py4pa was very effective in conducting targeted alpha therapy with 225Ac. It was the most stable ligand that was bound to 225Ac relative to previously used ligands. There was much more control inside the body and it was less likely to spontaneously react with molecules other than the intended antibody. Furthermore, 225Ac maintained its radioactivity in the body. With some ligands, 225Ac did not release its alpha particles due to incompatible binding. However, with H4py4pa, 225Ac still had high radioactivity in tumour areas and low radioactivity in non-tumour areas such as the bones and the liver. This reduces the risk of untargeted toxicity in the body.

How Does it Differ from Chemotherapy?

Perhaps you’ve heard of chemotherapy before? It’s a fairly common and well-known treatment for cancer. While it is effective, there are drawbacks to chemotherapy as well; to quote Dr. Orvig:

“…the thing about cancer chemotherapy is just using conventional chemicals is that you basically poison the patient. And because the cancer is a little more susceptible, you’re poisoning the cancer a little bit more.”

Dr. Chris Orvig, March 2022

Essentially, chemotherapy reduces cancer by targeting fast-growing cells in the body. Unfortunately, this includes the entire body, so while the fast-growing cancer cells are affected by chemotherapy, fast-growing healthy cells can be affected too.

On the other hand, targeted alpha therapy is able to directly target the tumorous areas of the body by binding to the antibody of the tumourous cell. This means that the 225Ac is able to directly destroy the cancerous cells without doing as much damage to the surrounding healthy cells.

Who were the people behind this all?

Well, the initial propagator of the idea behind H4py4pa was Dr. Lily Li who, at the time of the study, was a Ph.D. student with Dr. Orvig. After hearing about that idea, Dr. Chris Orvig, a UBC Chemistry Professor and an associate member of the faculty of Pharmaceutical Sciences, initiated the study. He also gathered the funding and the people for the study and helped conduct it as well.

For a bit more detail behind the history of this study and Dr.Orvig, we have a podcast prepared:

Now, that was all about the past, but what does this mean for our future?

Why is this so important?

Significance of H4py4pa and Targeted Alpha Therapy

H4py4pa and targeted alpha therapy could lead to many advancements in cancer treatment research.

As mentioned before, targeted alpha therapy is able to directly target tumours with less damage to the patient’s healthy cells; this could potentially reduce the fatigue most chemotherapy patients experience throughout their entire body. However, it does has limitations.

Before H4py4pa, the molecule used for target alpha therapy tended to bind to Actinium slower than preferred in its surrounding temperatures, which can lead it to be less effective.

This is why H4py4pa is so important.

Not only is it able to bind quicker to Actinium, but it’s also more stable than the previous molecules, all while remaining just as effective against cancer

In the future, this means that different companies can use Actinium and H4py4pa against different types of cancers. In reference to the arrow metaphor, they could adjust the directional components of the arrow (the shaft and the feathers) and direct the Actinium to different areas of the body.

“… I think it’s quite possible that we will see in the future Actinium used in different chemical constructs to treat a number of different cancers. And the hope would be that you give a patient one or two or three shots of this over a two or three-month period, and that we could drive many different cancers into remission. “

Dr. Chris Orvig, March 2022

[Group 5: Bill Yang, Evelyn Zhong & Christine Sun]

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Posted in Biological Sciences, Issues in Science, Public Engagement, Science Communication, Science in the News

Tagged cancer therapy, chelation, chemistry, organometallic chemistry, Pharmaceutical sciences

The ABCs of TNOs

Posted on April 8, 2022 by shilpa shrestha | Leave a comment

Most people have heard about the theory that our solar system started with a big bang, but nobody talks about the leftover residues from it. Trans-Neptunian objects , also known as TNOs, are minor planets with material that were not able to be used to make other planets in our solar system. Furthermore, these objects reside just beyond Neptune and form a ring around the solar system called the Kuiper belt. Scientists say that learning more about TNOs can help us further understand the formation of our solar system.

Barnett,2021 – photo of the Kuiper Belt| source:https://solarsystem.nasa.gov/system/internal_resources/details/original/3267_KBO-Paths_LegacyMissions2.jpg

Classical, Resonant , or Non-resonant?

Trans-Neptunian objects can be classified as either classical, resonant, or non-resonant. Non-resonant TNOs have a nearly constant free inclination, which when calculated can determine whether the object is hot or cold. If a TNO is considered hot, it tells us that they were formed close to the sun and then migrated to the Kuiper belt. Whereas, cold objects haven’t had any real location changes.

Video focusing on the distinction between the hot and cold populations:

Methods

In, “Free Inclinations for Trans-Neptunian Objects in the Main Kuiper Belt” Yukun Huang and his colleagues downloaded samples of 2018 TNOs in the Kuiper belt. They manually classified them into the standard three categories and developed a method of accurately calculating the free inclination of those objects. This was formulated by considering the acceleration, eccentricity, inclination, and precession rate of the objects. The main findings that came from this paper were that the innermost boundary of the cold population is at 42 astronomical units, free inclination values are helpful in studying the structure of the Kuiper belt, and the cold and hot populations of TNOs are well separated.

Yukun explaining his research approach:

In conclusion, Trans-Neptunian objects are said to have important information about our solar system’s past, such as the migration and formation of giant planets. However, it is still unsure how much of the Kuiper belt we’ve explored so far, since there are different models, and it’s such a vast area. In addition, this topic is not a priority in astrophysics which suggests that it will take some time before any mysteries regarding the Kuiper belt and TNOs can be solved.

Tim Gunther, n.d.:Orbital plane the the rotation of free inclinations| source: https://media.nationalgeographic.org/assets/photos/000/285/28546.jpg

– By Jack Wu, Shilpa Shrestha, Hanna McDonnell, and Chenyang Luo

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Posted in Issues in Science, Outreach Project, Public Engagement, Science in the News

Tagged astronomy, Neptune, solar system

Paper vs. Plastic: Which Bag is More Sustainable?

Posted on March 28, 2022 by shilpa shrestha | 2 comments

Most of the world has reverted to using paper bags as an eco-friendlier alternative to plastic bags. Recently, many places have either banned the use of plastic bags or added a tax to their usage; It’s interesting because plastic bags were initially created in 1965 to save the planet from the usage of paper bags. The initial reasoning behind this was that plastic bags are more reusable, and they don’t require deforestation. It seems we as a society rotates through periods of using whichever we think are the lesser of two evils.

Myth: Paper Bags Are Greener Than Plastic. Source: https://ecomyths.org/myth-paper-bags-are-greener-than-plastic/

Paper bags

The biggest selling point for paper bags is that they are biodegradable and break down easily. This is great for the environment because it won’t harm wildlife or remain in landfills. However, there is a lot of environmental turmoil in the making of paper bags. Producing paper bags requires four times as much energy and uses chemicals and fertilizers. In addition, lots of water is needed in its production. Analysts suggest that paper is liable for 70 times more air pollution and 50 times more water pollution than plastic bags. Moreover, paper bags are the product of millions of trees being cut which is not great for the environment. It is also reported that one would need to reuse a paper bag 3-43 times to neutralize the environmental impact it took to create the bag. However, this is not plausible for most cases because paper bags break down so easily. Therefore, paper bags are often single-use.

Source: https://www.eastmojo.com/world/2021/07/12/world-paper-bag-day-2021-its-never-too-late-to-switch-from-plastic-to-paper/

Plastic bags

Plastic bags are created from high-density polyethylene which is made from petroleum. It’s the same material that is used to make shampoo bottles, milk jugs, etc. It was initially thought of to be more sustainable than paper bags because it’s sturdier and can be used multiple times. Furthermore, it requires fewer carbon emissions. Plastic bags are also recyclable they often fly away or get stuck in machines, so they rarely do get recycled. The idea of plastic saving the planet didn’t come to fruition though. As they are very hard to break down and stay in landfills and oceans. This is problematic for wildlife. In addition, these bags break down into micro-plastics and spread out. However, the effects of micro-plastics are still not known.

What can be done?

It’s not quite clear whether plastic bags or paper bags are better for the environment because they both have their advantages and disadvantages. The biggest difference consumers can do to help the environment is to reuse bags as much as they can. Re-using bags found at home is the key to reducing the impact. As for the future, I predict that we will transition back to using plastic bags because people will say that paper bags cause deforestation. However, I do think that re-usable cloth bags will be more common because it’s more advertised. Perhaps, someone might even come up with a new type of bag as an alternative.

– Shilpa Shrestha

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Posted in Issues in Science, Public Engagement, Science in the News

Tagged Environment, sustainability

The future of male birth control is within reach!

Posted on March 28, 2022 by Parham Asli | 3 comments

Now here’s something you may not know… condoms are over 5000 years old! That’s right, some of the first forms of birth control date back to thousands of years ago, and while the condom has made huge strides in the millennia that have passed since then, the only other option that exists for men in birth control is a vasectomy that may be hard and often costly to reverse. Well, that is until recently! A new scientific breakthrough has allowed scientists in The United States to design a male contraceptive pill that is 99% effective in preventing pregnancies in mice and is awaiting human trials!

there is a significant discrepancy in the contraceptive options available to women as opposed to men, signaling the need for more balance. Getty Images/Peter Dazeley

How does it work?

The male body needs a certain nutrient called retinoic acid, a form of vitamin A, for fertility, sperm formation and sexual drive. The male contraceptive pill, which was first unveiled at the 2022 American Chemical Society’s spring meeting a few days ago, is equipped with certain compounds that block crucial proteins from binding to retinoic acid receptors (RAR), hence allowing for reliable and reversible sterility in male subjects. The compound was administered orally to mice for a 4-week period. Not only did the compound result in a dramatic decrease in the mice’s sperm count, it also had no observable side effects. Better yet, once they stopped administering the drug, the mice regained the ability to give birth in 4-6 weeks!

In order to minimize potential side effects, the chemicals within the drug were designed such that they would specifically bind to RAR. This way, surrounding tissues will not be affected. But more importantly, the chemists and pharmacologists responsible for developing this drug at The University of Minnesota, attribute its success to the fact that it is completely non-hormonal!

The pill targets Vitamin A and has been shown to cause sterility in male mice. Getty Images/Canopy

what makes a non-hormonal pill better?

Up until now, there have been numerous attempts to create a male contraceptive pill, but any compound that has thus far reached the clinical trial stage, exclusively targets the male sex hormone testosterone. Unfortunately, this may be accompanied with a slew of side effects including increased cholesterol levels, weight gain, depression, and increased risk of cardiovascular disease. This is why current efforts have been targeted towards the non-hormonal pathway to developing a male contraceptive pill.

When can the world expect to see the pill?

Clinical trials are set to begin by the end of 2022. The researchers behind the pill have teamed up with a private company, YourChoice Therapeutics, to achieve this goal. While there is actually no guarantee that the pill will replicate the same results in humans, there is a high level of optimism that the pill can be marketed to the general public in 5 years or under. Jesse Mills, director of the men’s clinic at UCLA jokes “It’s hard to ask a mouse about moodiness or fatigue or other side effects that may manifest in human studies”. Nonetheless, the current pill offers more promise than previous options.

Research associates at The University of Minnesota announce that the pill is ready to begin clinical trials in 2022. CTV News

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Posted in Biological Sciences, Issues in Science, Science Communication, Science in the News

Tagged animal studies, birth control, contraception, fertility, hormones, Pharmaceutical sciences, pharmacology, pregnancy, reproduction, sex

How to Synthesize 40,000 Biochemical Weapons in Six Hours!

Posted on March 21, 2022 by billyang | 1 comment

In the media, we constantly hear about Artificial Intelligence (AI) advancing for the benefit of society. It is assumed that this advancement will aid us in fields such as healthcare and drug development by simplifying complex human tasks. However, what if it did not? What if this AI was abused to potentially harm society?

Collaborations Pharmaceuticals, Inc. had designed a molecule generator called MegaSyn, which discovers new potential drugs that can target and prevent human diseases through machine learning model predictions. This functions as the AI of the story. Essentially, the model depicts all of the predicted target drugs that are synthesizable, while deleting all of the molecules that are considered toxic to humans. The company proposed the idea that they could synthesize toxic molecules by simply inverting this program. Due to the universal abundance of possibilities, they used VX, which is one of the most toxic biochemical nerve agents developed, as a model to focus the results. In less than six hours, the program produced a model that generated 40,000 molecules that were within the same calibre of toxicity as VX.

A few grains of VX (6-10 mg) are enough to kill a person. Source: Periodic Videos

The Potential Misuse of AI Programs

Although the company did not synthesize any of the molecules in their model, this experiment raises serious concerns over the consequences of AI misuse. There are hundreds of commercial companies with technologies that are able to replicate MegaSyn. Furthermore, another AI program that can make this risk more severe is retrosynthesis software, which can computationally break down a molecule into the steps from which it is synthesizable. Although this model was based on VX-like compounds, it would be simple to look for other toxic molecules through minimal adjustments to the program. The abuse of AI should be alarming because all you need is the ability to code in order to greatly lower the technical skills required to synthesize potentially dangerous biochemical weapons.

Quantitative Structure-Activity Relationship is an example of a similar program that is used for Drug Discovery. You can substitute VX as the molecule to apply to this study. Source: Data Professor

Rapid Synthesis Using Combinatorial Chemistry

Complimenting the advancements on the technological side, there have also been significant advancements on the chemical side in the last century. The development of combinatorial chemistry allows for the synthesis of mass numbers (perhaps millions) of similar compounds within a single process. Essentially, there is a large array of structurally diverse compounds, also known as the chemical library, which interacts with biological targets of interest to simultaneously synthesize thousands of peptides. With the AI-generated model acting as the chemical library with its toxic-focused molecule (such as VX), the process of combinatorial chemistry becomes much more easily accessible.

Combining different structures together using biological target interactions to synthesize multiple compounds. Source: Wikimedia Commons

So, Is This Technology Beneficial Or Not?

The molecule-generating AI program is concerning due to its applications in biochemical warfare. If the program is misused, it can easily be employed in war and cause the loss of thousands of lives, not to mention the environmental impacts of such chemicals. However, this program could just as easily be used for the benefit of mankind. The key is transparency. Collaborations Pharmaceuticals decided to be transparent with their findings and inform the public about the power of their program. Therefore, there is peace of mind that they will use this program for the benefit of drug discovery.

~ Bill Yang

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Posted in Biological Sciences, Issues in Science, Public Engagement, Science Communication, Science in the News

Tagged Artificial Intelligence, Biochemical Weapons, Biotechnology, Chemical Synthesis, chemistry, Drug Development, Nerve Agents, Pharmaceuticals

New Treatment for HIV

Posted on March 20, 2022 by jack wu | 1 comment

HIV and its Implications

The HIV global pandemic was once a major killer in the 20th century. HIV causes mental panic, social apprehension mortality when left untreated and miseducated. Due to the fact that diseases transmitted from sexual contact or drug usage cause social stigma, the HIV global pandemic became a fight not only against the virus itself but the perception of that from the general public. Though no form of illness should be conceptualized from that of a negative connotation, HIV long has had a conception coming from promiscuity, drug addiction, and carelessness. Treatment for HIV and better education continues to be a global battle.

HIV is described as a virus with no cure but treatable. Proper treatment of HIV can allow an infected individual to live a normal lifespan. Source: HIV.gov

How HIV is Transmitted

HIV is transmitted through sexual contact, needle sharing, contaminated blood transfusion as well as birth. HIV is a virus that attacks the body’s immune system. The latent stage of HIV is AIDS when the CD4 cell count in the body lowers to rates that cause infections to be prone.

HIV is transmitted through four major ways: sex, blood transfusion, needle sharing and mother to baby. Source: avert.org

Treatment History

HIV treatment first began with Zidovudine, which became available in 1987. Zidovudine causes side effects such as low blood cell count, liver damage. More importantly, Zidovudine stops working as the virus mutates. In 1996, antiretrovirals became available for public use. The combination of antiretrovirals made it difficult for enzymes in HIV to replicate. In 2007, Raltegravir became available as an HIV integrase inhibitor. In 2010, Truvada became an available option for pre-exposure prophylaxis for the public.

New Injection Treatment

Treatment for those infected with HIV requires a daily oral pill. Until 2021, one of the oral pills had to be taken by someone HIV positive. A daily pill makes it difficult to adhere to treatment. Moreover, oral pills are difficult for those with swallowing difficulties, poor drug absorption, and gastrointestinal problems. Cabotegravir and rilpivirine are taken as integrase inhibitors and non-nucleoside reverse transcriptase inhibitors. These two medications are taken in injection form once every one or two months. The result is that injection forms require much less dedication to HIV treatment, as these forms don’t require a daily treatment plan. The key to HIV treatment to allow those living with the virus to lower transmission and keep the virus under control is to have an undetectable viral load. An undetectable viral load allows an infected person to live a normal lifespan and be HIV non-transmissible. Injection treatment works equally as well as the oral pill.

HIV injection Treatment Description

New Treatment Plan

In the UK, injection treatment for HIV will begin in 2022. Other European countries are soon to follow this plan. Another treatment plan for HIV is a solution and alternative to approach a virus in modern society.

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Posted in Biological Sciences, Issues in Science, Science in the News, Uncategorized

Tagged HIV/AIDS

Image

Caribou habitat restoration

Motivation

Caribou are critical indicator of forest heath, and they play important role in many places: they are important resource for indigenous people, prey species for many carnivores. However, recent years, there has been a decline in Caribou population.

I want to explore the effectiveness of habitat restoration as a caribou conservation strategy. Habitat restoration has been studied previously, but generally, I am still unsure of how impactful it really is because it is a long-term solution. Therefore, it is important to research this topic and discover whether or not habitat restoration is a strategy government should continue to use.

What is habitat restoration?

Habitat restoration is the renewing and repairing of damaged or degraded habitats back to a more stable state. This involves physically going to sites of habitat destruction and manipulating the environment. An example would be positioning trees and branches to create barriers to reduce the sightlines of linear features.
The main goal of habitat restoration is to reduce predator use of linear features like seismic lines and roads in hopes of reestablishing the predator-prey dynamics that caribou and wolves shared prior to human industrialization and exploration. As a result, the caribou population should be better conserved. (graph from MLR images Flickr)

Caribou population declines

During my research, we find that the primary cause of caribou population decline is the unstable predation of caribou which is caused by human-mediated changes to predator-prey dynamics. For example, Industrial exploration which is human-caused destruction impacts predation that impacts the caribou population.

source from Daniel images

Methods to insist caribou population

Wildlife cameras planted in restored and unrestored areas; comparing the use of these linear features for caribou, bears, wolves, moose
Overall prediction: less likely to use restored vs unrestored, increased response with increased treatment intensity
GPS Collars to quantify individual animal use of restored vs unrestored lines
Overall prediction: Restored areas used more than unrestored, effect increases with treatment intensity

Solution

After analyzing the cause of the decline, there are two main goals for habitat restoration reverse the effects that clear cut logging and pipeline Another goal is to promote a sustainable environment for caribous to live in without human intervention. These two ways will benefit to caribous population. But We need a large area and time scale to observe the response of caribous population levels to understand how changes in habitat use after habitat restoration treatment translate into increased survival rates of caribou.

Conclusion

Human activities have caused the destruction of many organisms. What we can do is stimulate the action of habitat restoration. However, the complexity of the ecosystem will cause limitations for habitat restoration. The near local communities opposed habitat restoration because of the impact on their daily life. In addition, high economic costs can be perceived as having a negative impact on the restoration process. Overall, there are pros and cons to habitat restoration but it is necessary for us to consider the best solution to address the consequences of human destruction.

——Chenyang Luo

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Posted on February 7, 2022 by chenyang luo in Biological Sciences, Issues in Science

Tagged animal conservation, Biology, habitat, UBCresearch, 不列颠哥伦比亚大学

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Two is Better than One: A Study of Conjoined Twins

If anyone has siblings, or even a twin, could you imagine being physically joined together with them? And no, I don’t mean metaphorically. Could you imagine being conjoined and having to share the same body with them? Conjoined Twins, or sometimes known as Siamese Twins, may have been something you’ve seen on TV, like in Grey’s Anatomy or American Horror Story.

What are Conjoined Twins?

Conjoined twins are twins that are born with physically connected bodies. Every case of conjoined twins are different, as they could be joined at different parts of the body. For instance, they could share only a small amount of tissue, and each pair could have their own set of organs and structures they need to essentially stay alive if they are able to be separated.
Others, the connection can become quite complex. The twins could share a vital organ, like the heart, or digestive, genital, and urinary systems. They could also share a huge portion of the body, like sharing the entire lower half of the body, or be conjoined at the head where they share parts of the brain and skull.

Approximately 75% of conjoined twins are joined at least partially in the chest, or share organs.

The Success Rate

The progression of advances in imaging studies, surgical techniques, and anesthesia, the rate of successful separation of conjoined twins have increased more now than in the past.

However, at birth, ~40% of conjoined twins are not alive.

~35% die within a day after birth because their organs are not able to support them both.

Schematic diagram showing the various types of conjoined twins

Source: Research Gate

The succession of separating conjoined twins depends on so many factors:

Where the twins are connected
Which structures they share

and this can get quite complicated

This could result in both twins surviving, but because of a serious birth defect, there is a risk of one or both twins dying.

In the cases the structures and organs they share may be too high of a risk, or not able to perform the separation. Lots of conjoined twins live happy and healthy lives by remaining connected.

Causes of Conjoined Twins

Identical twins are called monozygotic twins, and this occurs when a single fertilized egg splits and develops into two individuals. 8-12 days after conception, the embryonic layers split, forming into specific organs and structures.

When the embryo splits later than that time period; usually between 13-15 days after conception, the separation stops before the process is completed, and the twins result in conjoinment.

An alternate theory is that two separate embryos somehow fuse together in early development, but what might cause either of those theories is unknown.

A Case of a Successful Separation

Conjoined Rital and Ritag Gaboura Source: NewScientist

Rital and Ritag Gaboura were joined at the head – and it took a team of more than 15 surgeons and doctors at Great Ormond Street Hospital in London to completely separate the conjoined twins.

Magnetic resonance imaging (MRI) and X-ray computed tomography (CT) was done to show how their skulls were fused. The Gaboura twins turned out to be craniopagus twins – meaning they shared a skull but not a brain. This is extremely rare, and occurs once out of every 2.5 million births.

If they shared the same brain, the surgery would have been too risky to perform.

The surgeons needed to study the twin’s skull and brain to meticulously strategize the network of delicate arteries and veins that transported blood to and from the brain. Most craniopagus twins do not share arteries that feed the brain, but their veins are tangled together, and some can run from one twin’s brain to the other.

When separating the veins, if one twin ends up with too many veins, it would cause the heart to collapse.

Leaving the other twin with not enough veins, the brain would swell up with blood.

Studying their blood flow was done by injecting dyes into the twins’ arteries and tracing the blood’s in and out pathway of the brain with a series of X-rays.

A media production company was involved, using the images to make a CGI video of the blood rushing in and out of the brain.

The surgery was chosen to be done in stages, so the skull and veins could recover between each operation.

The two major systems of veins drain blood from the brain:

A superficial system woven into outer layers of dura mater (envelope of protective tissue surrounding the brain)
Deep system in internal brain structures

One twin would be given most of the superficial system, and the other most of the deep system, and hopefully the brains would adapt to the loss by expanding small collateral blood vessels that could connect the two systems.

To divide each vein, the surgeons opened a window in the twins’ skulls and operated on the veins in that little window. A craniotome, which is a high speed drill was used to drill through the skull to reach the blood vessels, and essentially it would push the brain out of the way so only the bone would be cut.

The veins were sliced through, and tied off with ligatures and dissolvable sutures.

When it was possible, the shared veins were split at a junction so each twin could receive one part of the brain.

The final hurdle of full separation was that craniopagus twins do not have enough bone and skin between them to form a complete skull and scalp when it was time to sew everything up.

The problem was solved by putting four silicone balloons filled with saline solution under the scalps, between the bone and skin. The balloons would progressively stretch the skin of the scalp.

Inflatable balloons stretch the skin. Source: https://www.bbc.com/news/health-14969823

The skull bone has three main layers:

Tough outer layer
Spongy middle layer
Tough inner layer

By driving chisels between each layer, the surgeons were able to split the bone and lift up a section so it would double the original area of the skull.

Rital and Ritag were able to recover after their separation, and the surgery was deemed a success as they were separated, and each child was getting the blood it needs and draining blood from the brain in the correct ways.

Source: BBCNews

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Posted on January 30, 2022 by ji hee lee in Biological Sciences, Issues in Science, Public Engagement, Science in the News, Uncategorized

Tagged #, #ConjoinedTwins, Neurology

The tiny but mighty solution to antibiotic resistance

Posted on January 29, 2022 by Parham Asli | 2 comments

So picture this… It’s the year 1928 and penicillin has just been discovered. Penicillin revolutionized modern medicine and with other antibiotics to come, it would go on to treat the untreatable and save millions of lives. Now, let’s flash forward to a more grim version of the future. It’s the year 2022. Antibiotics were supposed to be our precious resource but every time we misused them or overused them, we gave bacteria a chance to evolve and become resistant, and at the same time our scientists were unable to bring new antibiotics to the market. The World Health Organization (WHO) is calling antibiotic resistance “one of the biggest threats to global health today” so in recent years scientists have been looking for new multi-dimensional strategies to combat this issue. One of those is the use of light-activated quantum dots.

Over-prescription and patient non-compliance exacerbate the issue of antibiotic resistance. Getty Images/Joe Raedle

What are quantum dots?

Quantum dots are tiny particles made of semiconducting material, meaning they partly conduct electrical current. They are only a few nanometres in size and can be engineered in terms of shape, size, and material. The way these quantum dots kill bacteria is not all that complicated. Basically, when our bodies are infected with bacteria, they naturally produce what scientists call Reactive Oxygen Species (ROS) in our immune cells to kill bacteria, and what light-activated quantum dots do is that they essentially mimic this natural killing process of the body by producing ROS of their own.

How is the killing initiated?

Now you may be thinking, how do we ensure that the cells that are not infected with bacteria, don’t end up getting killed? Well, the answer is quite simple. In application, quantum dots are specifically injected at the site of bacterial infection in the human body, so as to not affect other tissues, and when they receive an input of light of sufficient energy in a process called photoactivation, their electrons (particles with a negative charge of electricity) jump from a region of space with lower energy called the valence band to a region of space with higher energy called the conduction band. The energy difference between these two is referred to as the “bandgap” and when the electrons relax back to their ground level (i.e. the valence band), a photon of light is released that provides the energy needed for producing the killer Reactive Oxygen Species.

An input of light causes electrons of the quantum dots to move around, energy is released, and the killer ROS come to life! Adapted from Redox-Active Therapeutics

What are the consequences?

The killer ROS will break down bacterial biofilms (self-contained bacterial communities), damage the bacterial cell wall and cell membrane and inactivate enzymes needed for bacterial survival. And because the ROS are killing these microbes through all these different non-specific ways, the microbes can no longer develop resistance!

Quantum Dots and their many ways of killing bacteria! Adapted from McCollum et
al. and Imlay

One for the future?

It is abundantly clear that quantum dot technology shows great promise in combating the widespread issue of antibiotic resistance. Although the clinical use of the technology is a long way off, the strategy is an intriguing new approach at a time when the rate of drug development is much slower than the rate of antibiotic development and the pharmaceutical industry is lagging behind.

Student research on the applications of quantum dots at The University of Colorado. Materials Research Society

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Posted in Biological Sciences, Issues in Science, Science Communication, Science in the News

Tagged antibiotics, bacteria, chemistry, multi-drug resistance, nanoparticles, nanotechnology, quantum dots, Quantum Mechanics

Everyday, You Create Infinite Universes

Posted on January 24, 2022 by billyang | 1 comment

Someone approaches you and asks you on a date. You’re nervous, but you answer with a “yes”. Meanwhile, another you says “no”. Regardless, you just created two different universes. Wait, what do I mean by “another you”?

The Many-Worlds Interpretation (MWI) hypothesizes that for every observation of one state or outcome, there exists a separate world, or worlds, in which a different outcome becomes that separate world’s reality. Therefore, whenever an experiment with multiple different outcomes is conducted, we have achieved all possible outcomes. Each of those outcomes creates a new universe. This hypothesis was stated by theoretical physicist Sean Carroll in his 2019 book, Something Deeply Hidden. Note that this is an interpretation, not a comprehensive theory. Consequently, there are multiple interpretations from different individuals (which is both ironic and analogous to the topic). The interpretation I have defined above is what I will be discussing.

A decision/state branches into different quantum outcomes.
Source: Flickr

Why Are There “Infinite” Universes?

We accomplish several tasks during the day. Even the smallest outcomes matter. For example, when we style our hair in the morning, every single hair placement can create another universe. Every step you take or do not take creates universes. Now consider that there are also billions of other people in our world that are, themselves, creating universes with their outcomes. On a smaller scale, even the particles in our world interact differently from one another. The Second Law of Thermodynamics states that entropy, which is a measure of disorder, increases in an isolated system. A relevant example of an isolated system is one universe. Essentially, the natural order is disorder. An example may be two particles colliding together at various possible angles, with each angle forming a universe. Further abstraction can postulate that particles interacting with other particles differently can cause different behaviours that create different universes. An example of this would be matter acting like waves or particles. These outcomes lead to what can only be considered as an infinite number of universes.

Source: Science & Cocktails

So When Can I Meet These Other “Mes”?

Unfortunately, you currently cannot. The new universes that we constantly create cannot intersect with our own, meaning that we only observe the outcome that we see in our world. Assuming these universes physically exist, research conducted by theoretical physicist Alexander Vilenkin suggests that different universes are in their own bubbles. These bubbles never intersect because they continue to expand faster than the speed of light, which is faster than we can travel. This means that the MWI is currently neither observable nor falsifiable. In other words, it cannot be proven nor disproven. Hence, it is an interpretation rather than a concrete theory.

Bubbles That Contain Different Universes
Source: Pixabay

Do Our Decisions Really Matter?

For every decision that we make, no matter how minute it may seem, there exists another us that makes the exact opposite decision. If all outcomes are achieved in the MWI, is there any weight to the decisions that we make? While this is an interesting argument, the MWI is not currently falsifiable. Overall, we should continue making decisions that are unique to us while being open-minded about the possibility that we are creating many universes.

~ Bill Yang

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Posted in Issues in Science, Public Engagement, Science Communication, Science in the News

Tagged Many Worlds Interpretation, Multiverse, Philosophy, Physical Chemistry, physics, Quantum Mechanics, Thermodynamics, Universe

Category Archives: Issues in Science

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