Category Archives: Biological Sciences

Last resort: It’s better to be overweight!

Posted on November 12, 2018 by | Leave a comment

Being obese is a serious health risk especially because obesity is a risk factor which causes cancer. This is because the excess fat cells secrete extra hormones and growth factors that stimulate cells to multiply. Which then, there is an increased chance of cancer cell also reproducing in vast numbers.

How does being overweight cause cancer?
https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/obesity-weight-and-cancer/does-obesity-cause-cancer

The fact that obesity is a major risk factor for malignancies has been proven many times, but the relationship between obesity and the immune response is not very well understood. Ironically, a recently published scientific study has shown that obese patients had a greater survival outcome to targeted therapy to treat Metastatic Melanoma. This suggests that obesity has some kind of factor that helps these patients respond better to treatments.

Metastatic Melanoma is an advanced skin cancer where the cancer cells spread to other parts of the body, such as the lungs, liver and brain. Patients at this stage of cancer are treated with targeted therapy, checkpoint inhibitor immunotherapies and chemotherapy. Dr. McQuade and her colleagues followed 2046 patients with metastatic melanoma that were actively receiving one or more of these treatments from Aug. 8, 2006, to Jan. 15, 2016. Each patient was classified as normal, overweight or obese according to the body-mass index (BMI). The results show that compared to patients with normal BMI, obese patients had improved overall survival. Obese patients lived about 27 months with advanced melanoma cancer while normal BMI patients lived to only about to 17 months, near doubling in survival.

PD-1 protein inhibiting T-cells & Immune Response
https://www.arigobio.com/news/new-spd-1-elisa-kit

It is suspected that the treatment works very well for obese patients because of the amplified results from the treatment. Advanced Melanoma treatment works by blocking activation of a protein, PD-1. Tumours stimulate the release of these proteins because they reduce the amount of immune response towards cancerous cells. In obese patients, there are greater amounts of PD-1 than in normal BMI patients and also a greater amount of leptin, a hormone created by fat cells which trigger a pathway that increases PD-1. So as soon as the treatment is in effect, the PD-1 is removed and the immune response is increased. With abundant nutrient available in obese patients, the immune response works better to attach the cancer cells.

Unfortunately, this study also showed these results were only applicable to men and there was no association between obesity and survival rates in women. Also, treating metastatic melanoma patients with a high-fat diet to mimic the effects of obesity can cause harm to patients so further research is needed before clinically used.

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Does Sleep Affect Your Hydration?

Posted on November 5, 2018 by | 2 comments

We have been consistently educated about drinking enough water being vital to our health. We have been told to drink about two litres of water per day to keep hydrated, but what about sleep? A new study from Pennsylvania State University examined how a good night’s sleep is associated with hydration.

Source: Flickr By: Navy_NADAP

The study looked urine samples from over 20,000 U.S. and Chinese adults, and each participant was surveyed regarding their sleeping habits. From these urine samples, researchers were able to analyze the level of hydration in each participant. It was found that across both country’s populations, participants who were sleeping six hours at night were 16-59% more likely to be dehydrated and had significantly more concentrated urine than participants who slept eight hours on a regular basis.

To understand this phenomenon, researchers linked the association to a hormone called vasopressin. Vasopressin is released in our bodies to help regulate hydration status in the body. While vasopressin is released throughout the day and night, it is released more quickly and later on in the sleep cycle. Therefore, waking up earlier can decrease the amount of this hormone being released and lead to dehydration.

Source: Youtube By: TED-ed

 

It is important to stay properly hydrated so our bodies can perform its everyday functions. The brain, heart, and muscles all require enough fluids or else it can negatively affect your mood, physical performance, and cognition. If the dehydration continues for a long period of time, it can lead to more serious consequences such as higher susceptibility to certain infections and kidney stones.

Since the study only includes observational data from a particular population, the results are an association and cannot be viewed as causal. However, it provides an interesting insight as to how sleeping patterns may affect our hydration levels.

Written by: Anna Han

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Posted in Biological Sciences

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Sun Sneezing: “Cross Wiring” in Our Nerves?

Posted on October 8, 2018 by | 3 comments

Your nose starts to twitch just as you step out of a dark room and into the sun. The mild tingle inside the nasal cavity soon turns into an uncomfortable itch.

“ACHOO!”

What you just experienced is the Photic Sneeze Reflex, otherwise known as ACHOO (Autosomal Compelling Helio-Ophthalmic Outburst) syndrome or “sun sneezing”. It is estimated to occur in 18 to 35 percent of the population. The condition tends to be most intense after one has spent a considerable length of time in a dark environment. Yet, due to its seemingly harmless nature, there has been surprisingly scarce study on the subject.

In his Book of Problems, Aristotle was one of the first to ponder about this curious phenomenon in 350 BCE.  He speculated it may have been due to the heat of the sun on the nose, which led to sweating inside the nose, prompting a sneeze to remove the moisture. Nearly 2000 years later, English philosopher Francis Bacon tested Aristotle’s idea by walking into the sun with his eyes closed. The sneeze was no longer there, despite the presence of the heat. He then hypothesized that the heat causes the eyes to water, which then seeps down to the nose, triggering a sneeze. Amusing as his idea may seem, it was considered plausible until our modern understanding of physiology made it clear that the rate of which our eyes water,and the speed of fluid travelling through tear ducts is much, much slower compared to how quickly the sneeze occurs.

Nowadays, most scientists agree that “cross wiring” in the brain are most likely behind the Photic Sneeze Reflex. It was first hypothesized in 1964 that the reflex was a cause by the nervous system, perhaps a confusion of nerve signals. The theory states that the trigeminal nerve, which triggers sneezes and is responsible for facial sensation and motor control, lies closely to the optic nerve, which would sense a sudden flood of light entering the retina. Some of the signal within the optic nerve is picked up by the trigeminal nerve, mistaken by the brain as irritation in the nose, leading to a sneeze. Further studies suggested a genetic basis for the symptoms, revealing that the trait is autosomal-dominant, meaning if one parent exhibits the trait, about half of his or her children will too. But as of now the genetic culprit has yet to be identified.

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The Sun Sneeze Gene by Veritasium (Youtube)

Are there any risks? Although sneezing itself is merely an annoyance and usually does not present any risk of injury, concerns have been raised regarding the combined threat of sudden increase in light intensity, an induced sneeze, and subsequent eyelid closure, which could be dangerous for some occupations, such as vehicle operation at high speeds.

Despite the phenomenon still being poorly understood, scientists are taking an increasing interest in trying to solve the mystery. Nonetheless, if you are one of the many of us affected, perhaps consider shielding your eyes with hats or sunglasses more often.

James Wang

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DNA Vaccine: A New Universal Vaccine Platform

Posted on October 8, 2018 by | Leave a comment

With the sudden drop in temperature as autumn comes to an end, the inevitable flu season is once again underway. For many of us, this means another visit to the doctor for a flu vaccine to last us through the winter. We have become so reliant on vaccines to protect us from disease-causing pathogens and now there is a new radical platform using DNA that will make vaccines much more accessible and cheaper.

The researchers at The University of Texas Medical Branch at Galveston (UTMB) have discovered a method of using DNA for vaccine production that is much inexpensive with longer shelf-life (80% increase) and the same effectiveness as those that are manufactured in cell culture. This new approach promises not only the treatment of common flus at the universal level, it can also treat patients with weakened or impaired immune systems including those infected with HIV.

The Current Procedure

Currently, the most common way of supplying vaccine has been through cell culture in factories where large amounts of cells are cultivated in a dish. This method of vaccine production is ineffective because vaccines are prone to contamination when not refrigerated in their optimal temperature range. Maintaining a cold enough temperature while they are delivered from factories to hospitals and clinics can cost up to 80% of the original cost of vaccine in warmer regions.

Illustration of Zika virus in blood

Illustration of Zika virus in blood by Kateryna Kon

The New Platform

To eliminate the problem of storage and cost of vaccines, the researchers of UTMB were able to design a vaccine against a type of virus spread through mosquitoes called Zika in the form of DNA. DNA vaccine contains nucleotides that encode the region of a virus that contain the pathogens. When the DNA construct is taken up in the host cell, the viral gene is expressed into the corresponding antibodies. In the research by UTMB, a single-dose immunization of the Zika vaccine was shown to protect mice of the virus infection, as well as maternal-to-fetal transmission during pregnancy and testis damage in males.

Image result for dna vaccine

Schematic flow chart of DNA vaccine by Margaret Scuderi

Thanks to this new approach, vaccines no longer need to be manufactured in cell culture. Also with DNA molecules being much less temperature-dependent, they can now last for years without the risk of contamination, consequently making vaccines accessible worldwide no matter the climate at the cheapest cost. Adapting to this new platform will increase vaccine availability and ensure future prospects of immunization, taking us one step closer to creating a world free of disease, ensuring health and wellness to not only the privileged but to the overarching public.

Ellena Yoon

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A DNA Tool to Predict the Future

Posted on October 7, 2018 by | 1 comment

A common fear among parents is the risk of their children being diagnosed with serious illnesses such as heart disease and cancer. Fortunately, a DNA tool created by Michigan State University has been shown to accurately predict people’s height and bone density. This tool could also potentially assess people’s risk for illnesses such as heart disease and cancer.

Figure1. A new tool, created by Michigan State University, capable of predicting height. Used with permission, © 2018 Science Daily.

The Potential:

This amazing tool uses an algorithm to predict human traits including height, bone density and even the level of education an individual might achieve, entirely based on one’s genome. Lead investigator of the study Stephen Hsu mentions, “This is only the beginning.” There are plans in motion to apply this tool to predict more relevant matters like heart disease, diabetes and breast cancer. These are major diseases that impact a large amount of people. Heart disease, for instance, is the second leading cause of death in Canada. About 1 in 12 Canadian adults live with diagnosed heart disease alone! Hence, this tool could greatly impact and advance healthcare. Doctors would be able to step in during the early stages of illnesses to prevent or delay them!

Creating and Testing:

Stephen Hsu and his team’s research used machine learning, where a computer learns from data, to analyze the entire genome of around 500 thousand adults in the United Kingdom. The genome’s obtained from the United Kingdom Biobank, an international resource for health information, were used to put the algorithm to work. The algorithm evaluated each individual’s DNA and taught the computer to identify unique differences. “The algorithm looks at the genetic makeup and height of each person, learns from each person, and ultimately produces a predictor that can determine how tall they are from their genome alone,” said Hsu.

The computer was able to accurately predict everyone’s height within about an inch. However, predictions for bone density and educational achievement were not as accurate. Nevertheless, they were accurate enough to identify outliers in the population who were at risk of having problems in school and low bone density, which is associated with osteoporosis.

Future Plans:

Hsu’s team plans to continue to improve the algorithm by obtaining larger, more diverse data sets for the computer to learn. This would increase the algorithm’s capability to understand and interpret the combination of genes responsible for risks against specific diseases.

With increasing technology, the bright future of healthcare is considerably closer than originally believed. “What was once thought to be 5 to 10 years out, is now a lot closer when it comes to this type of work,” Hsu mentioned.

Figure 2. Collecting DNA using mouth swabs. Used with permission, © 2015 InfoLaw.

It is quite possible in the near future that a simple swab of the cheek could save families millions of dollars in treatment costs and more importantly, the lives of their children through early interventions of genetically based diseases.

Trevor Shen

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