Category Archives: Biological Sciences

The Americanization of Gut Bacteria in Immigrants

Posted on November 5, 2018 by | 3 comments

When immigrating to America everything becomes westernized, including the bacteria in your gut.

The green highlights the large intestines where the majority of the gut bacteria lies. Image credit: Mikael Haggstrom

Previous studies showed that living in the United states increase the risk of obesity and chronic disease among immigrants to the US relative to those who stayed in their country of birth. Researchers from the University of Minnesota, Dan Knights and Pajau Vangay, thinks that this increase in obesity and chronic diseases may be caused by the decrease in biodiversity in the gut of immigrants.

People in developing countries have more diverse microbiomes, while people living in industrialized countries like the United States have lower microbiome diversity. However the study found that when moving from a developing country to an industrialized nation would actually cause the biodiversity of the gut bacteria to decrease.

The Effect of Immigration on Gut Bacteria

The study focused on the Hmong and the Karen who are the most at risk for Obesity in Asian populations in Minnesota. The study studied the immigrants of different residency length and second generation immigrants and compared the biodiversity of the gut bacteria in these populations.

When immigrants move to the United States, their gut microbiome rapidly Americanizes within 6 to 9 months and becomes less diverse. The gut is invaded by with a rise in the population of bacteria of the genus Bacteroides which is associated with an American diet, while replacing the hey began to replace those of the genus Prevotella from the immigrants home countries diet.

When studying immigrants who have been in the US for years, they found the bacteria in the gut has become less diverse also the American genus Bacteroides have become more prevalent. The change of Bacteria is a long process and it starts immediately but it continues for many decades after and  those who have immigrated longer much more at risk for obesity and other chronic diseases.

As Immigrants reside in the US longer, the chances of obesity increases. Image Credit: Pharos

Bacteria Diversity Change with Long Term effects

The researchers also observed the second generation immigrant who have very similar diet as their parents with ten times the amount of rice as the average American. However even with a different diet the diversity of gut microbiome in these second generation immigrants very closely resemble the average American. Meaning the decrease in gut bacteria diversity does not only compound over time but across generations.

Know this decrease in gut bacteria diversity increases obesity and chronic illnesses, maybe it is worthwhile to find how to maintain or increase gut bacteria diversity to maybe help fight obesity and chronic illnesses.

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How much do you know about Spina Bifida? A Neurodevelopment Disorder

Posted on October 15, 2018 by | 4 comments

What is Spina Bifida?

I believe some of you may have heard about neurodevelopment disorder like hydrocephaly. What about the disorder strong related to hydrocephaly – Spina Bifida. Literally speaking, Spina Bifida means the spine split into two. It happens within the first four weeks the fetus in the uterus. Due to the spinal column is not fully closed, the spinal cord inside is not covered and even exposed and protruded out of the spinal column. There are about 120 children born with Spina Bifida each year in Canada, and 90% of them can survive and become adults.

Image result for spina bifida

Image Credit: Mayo Clinic

 

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Video Credit: The Spina Bifida Resource Network

 

Spina Bifida has more than one type. What do they look like?

There are two main types of SB, Spina Bifida Occulta (SBO) and Spina Bifida Myelomeningocele (SBM).

SBO is the mildest case which does not show any symptoms of the condition. The defect is hidden under the skin, and the spinal nerves are not involved in the defect. This type of defect may be noticed early in life if there is an abnormal tuft or clump of hair, or small dimple or birthmark on the skin at the site where the spine is not formed correctly.

However, SBM, also known as open SB, is the most severe form which needs to be treated with surgical treatment as early as possible. The membrane and spinal nerves push through the opening between spinal column gap at birth, forming a sac on the baby’s back. In this situation, the spinal cord is exposed, causing partial or complete paralysis of the body.

Image result for spina bifida

Image Credit: familydoctor.org

Causes & Risk Factors

The specific reason for spina bifida is still not clear nowadays. It shows to result from a combination of genetic and environmental risk factors, such as family history of neural tube defects and folate deficiency during pregnancy.

Then how should we prevent this disorder? Scientists find out that folate plays a significant role in SB prevention. Low levels of the vitamin folic acid during pregnancy are linked to  SB.

Related image

Image Credit: Babyment

how to treat the disorder?

Treatments for SB also depends on the type of SB. Children with SBO typically do not have any symptoms or complications, only routine pediatric care is needed. However, the child with SBM needs to be treated with surgery. The research finds out that fetal surgery can be an effective management strategy for SBM patients, resulting in a significant benefit to these patients, typically in improving motor function.

Another study investigates the neurodevelopment outcomes of preschool children with SBM treated with myelomeningocele closure. They found children who have undergone fetal myelomeningocele closure have average preschool neurodevelopment scores.

– Elaine Yuling Chen

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One small fragment to bind a protein, one leap for celiacs!

Posted on October 8, 2018 by | 1 comment

In cities such as our own, gluten-free products are becoming increasingly available throughout grocery stores and restaurants. With exception of the health-conscious members of society, who is the primary consumer of these products? One such group is the portion of the population affected by the disorder known as celiac disease.

Rather eating gluten-free for health benefits, celiacs depend on these foods daily to avoid painful illness. In the United States, researchers estimated a prevalence of 1 in 141 peoples affected by celiac disease. Among the people affected many had been undiagnosed leading the researchers to conclude that celiac disease is not as rare as believed in previous years.

What is celiac disease?

What is celiac disease? Celiac disease is a disorder that inhibits those affected from consuming foods with gluten-containing ingredients such as wheat, barley, and rye. Celiac disease harms the small intestine making it incapable of absorbing nutrients during the digestion process which leads to illness. Celiac disease means an abnormal self-defence response is triggered within the body when gluten is consumed causing damage to the small intestine. If celiac disease is left undetected or untreated, common adverse health effects associated include anaemia (iron deficiency caused by iron loss) and osteoporosis (reduced density of bone material that increases chance of fracture). For example, anaemia as an adverse health effect from celiac disease can result because anaemia can be caused by a Vitamin B12 and iron deficiency. Because Vitamin B12 and iron are absorbed in the small intestine, this poses a problem for celiacs whose small intestines are damaged, leading to anaemia that will cause fatigue, weakness, and additional categorical anaemic symptoms.

Figure 1. Image outlining the causes of celiac disease. Source: Kim Moss Electronic Publishing Services Inc. 

Figure 2. Simplified diagram outlining the pathway of inflammation (swelling) for celiac disease caused by gluten antigens (foreign substance that induces a reaction). Source: Nature Genetics

https://youtu.be/nXzBApAx5lY

Video: Celiac disease – causes, symptoms, diagnosis, treatment and pathology. Osmosis YouTube channel.

Why is gluten triggering this disease and how is this discovery a leap forward for the celiac community?

Why is gluten causing these symptoms in people around North America? Gluten is composed of proteins called prolamins that are storage proteins (store key survival components for cells such as amino acids or metals). Prolamins are found in wheat, rye, barley, and corn which are common food ingredients. In a recent study conducted in Austria, a research team has discovered a method that provides the possibility of future treatments for celiac patients. The researchers utilized antibodies (proteins that neutralize invaders such as bacteria) to create fragments that bind and neutralize prolamins. Celiac disease currently requires a gluten-free diet that is expectedly followed religiously. The fragments created bind grains containing prolamin in everyday ingredients and has provided future studies the potential to revolutionize clinical treatments that improve quality of life. Discovered treatments can eventually be used to mask the prolamin, preventing it from being displayed to immune cells so an autoimmune response (self-immune response) is not triggered.

Before believing that you are affected by celiac disease, please be aware that irritable bowel syndrome (IBS) and intolerances to foods such as dairy are similar in symptoms. No need to panic yet, but always be sure to check with a physician if you are experiencing symptoms! With the prevalence of celiac disease in the United States being 1 in 141 people, a treatment to reduce gluten sensitivity or inhibit it completely would improve many lives. The production of the antibody fragment that targets prolamin is a leap for the celiac community.

– Vanessa Niedzielski

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Stress Not…

Posted on October 6, 2018 by | 1 comment

Nowadays, it is very common to hear phrases like “I’m stressed out ” or “I don’t know if I can handle the stress”. However, the prevalence of stress in our society should not be accepted due to the negative impact that stress can have on people’s health.

Stress  is an organism’s response to any environmental or physical factor that is perceived as threatening harm ,

Pathway for Cortisol release in response to stress. Source: Top 10 Home Remedies

where the body experiences biochemical changes such as the release of hormones to prepare the system to confront danger or avoid it . Although, some amount of stress can be expected in any healthy individual, prolonged  stress has become a damaging condition in modern environment.  

According to Statistics Canada, in 2014 about 73% of adults between 20 and 64-years-old suffer from some level of stress. These findings, are indicative of increasing stress levels that could have long-term consequences on people’s health.

Source: Canadian Community Health Survey, 2014.
In 2014, 23% of Canadians reported that most days were “quite a bit” or “extremely stressful”. Additionally, females were more likely to report that most days were “quite a bit” or “extremely stressful”

According to the review Human behaviour: A cooperative instinct , stress in small doses enables people to adapt faster to unexpected changes in environmental conditions. Likewise, the presence of danger triggers a response called “fight-or-flight” where the body defenses increases: adrenalin secretion increases, blood flow to the brain and muscles increases. Nevertheless, the experience of being overwhelmed and in constant stress causes damage to health, decrease in productivity and life quality. 

What is the link between stress and the immune system?

According to the article published by GM Lewitus and M Schwartz, cells from the immune and nervous system interact together during stress episodes to secrete memory cells that will help people cope with stress-situations in the future. In other words, this mechanism is used by your body to protect you from possible danger. 

What are the causes of stress? 

When encountering a stressful situation, cortisol is released, it maintains bodily functions consistent. However, when stress is present for an extended period of time, high levels of cortisol inhibit some immune responses causing more susceptibility to infections and does not control properly inflammatory responses.

What are the effects of stress?

Some of the effects include: problems with the digestive and reproductive systems, increase the risk of heart attack  and stroke. In addition, a review article shows that stress can even rewire the brain, leaving people more vulnerable to anxiety, depression, and other mental health problems.

 The skin condition know as psoriasis appears to be linked to constant stress periods rather than medication or diet reasons. Researchers suggest that psoriasis is caused by the regulation of cortisol becoming dysfunctional leading to poor control of inflammatory responses causing this condition.

Therefore, being aware of the negative consequences that stress has on people’s health, will allow to reduce its prevalence in society.  

Effects of stress on the body Source: Live Love Fruit.

Mariana Paspuel

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Directed Enzyme Evolution: A novel technique to speed up evolution and create specialized proteins

Posted on October 6, 2018 by | 1 comment

What would you think if I told you that it is possible to speed up millions of years of evolution in a test tube on the lab?

Well, this is exactly what three scientists independently achieved. The 2018 chemistry Nobel Prizes developed a crazy and revolutionary process called direct evolution. This process uses evolutionary concepts to produce novel proteins with the desired characteristics to be used in distinct fields such as the pharmaceutical industry, the production of renewable energy among others. The revolutionary idea of directed evolution was developed by Prof. Frances H. Arnold, Prof. George P. Smith, and the emeritus research leader Gregory P. Winter. 

Nobel Prize in Chemistry,2018 Nobel Prizes,Chemistry Nobel prize

                                                    Source: Hindustan Times.                                                            Frances H. Arnold, a professor of chemical engineering, was awarded half the Nobel prize for being the first person to use evolutionary techniques since 1996 to accelerate the production and modification of enzymes. Meanwhile, Prof. George P. Smith and Gregory P. Winter worked on using direct enzyme evolution to improve the synthesis of more efficient enzymes used in the pharmaceutical field.

But what is exactly is Directed Evolution?

                             “Life Evolution”                                Credit: GIPHY

Nature over the years has used evolution to create the diverse environment around us. Over the generations, nature has made sure that only the desired and competent genes pass the filter of natural selection. The individuals with the “strongest” characteristics thrive in the environment, leaving better fit  populations. Similarly, these principles were used by the pioneer scientists to accelerate evolutionary processes and replicate pathways in which enzymes are naturally selected.

“Humans have exploited the concept of Darwinian evolution for thousands of years with selective breeding,” said Stefan Lutz, the chairman of the chemistry department at Emory University. “Directed evolution takes this same principle and applies it to the lab.”

Directed evolution works by inducing repeated mutations on bacteria or viruses, creating mutated populations that give rise to the desired enzymes. In each turn of bred the chosen enzyme is artificially selected allowing it to be more specialized over time. Different methods are used to induce random mutations; methods such as  chemical mutagenesis, UV radiation, and DNA recombination. The novel part is the use of the called error-prone PCR, which induces random mutagenesis in the bacterial strains. This technique is well suited for this job because it allows the scientists to keep track of the number of genetic doubling events occurring. This unique process optimizes the use of mutations for evolving enzymes to an improved version of themselves with a more stable folding, solubility, and binding affinity. With this technique, the scientists have rendered enzymes 256 times more effective than before.

Graphic illustrating the work flow for the directed evolution of enzymes

                                     “Directed Enzyme Evolution Technique”                                       Source: Quanta Magazine

The magic of this technique is that directed evolution can be used  as an alternative pathway to solve questions related to life evolution, as well as to study different research areas related to industrial and pharmaceutical processes. The improvement of proteins is used in industrial processes to manufacture biocatalysts that are resistant to extreme temperatures and very harsh environments. Evolved enzymes can be also used as a sustainable way to accelerate chemical reactions for the production of drugs in a very cost-efficient way, and to maximize the production of  certain drugs. Surprisingly, scientists also hope this new technique will help generate new sources of renewable energy, by using the catalytic power of enzymes.

                              ” 3D Enzyme Structure”                                   Source: GIPHY

The discoveries from three inspiring scientists models paved the way for future scientists to use this technique to solve urgent global problems  such as the development of renewable energy sources.

Daniela Yanez

 

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Should I change my diet for the sake of the world?

My first impression about meatless Mondays 

It is hard to give up meat! Source: GIPHY

They were just normal Mondays at the Open Kitchen, the cafeteria of Orchard Commons Residence at UBC, but for me, they were the most unsatisfactory days during my first year at university. Mondays were the busiest days in my schedule and I used to get so hungry that all I wanted was a big hamburger. However, I got annoyed after reading a poster about the “meatless” Monday at Orchard Commons and found no hamburger or any meat-containing dish at all! Apparently, it was an alternative implemented to reduce meat consumption.

Should I go vegetarian?

Is it challenging to give up meat? Answer the questions in this flowchart to know if you can become a vegetarian! Source: Dining Out

Why should I care about meat?

Food security is a matter that concerns everybody. We are almost 7.4 billion people on Earth right now, but we will be 9 billion in 2050. According to a well-known paper in Science, the food supply will need to increase by 70% to 100% to feed this population.  The solution is not as simple as increasing the land for agriculture. The truth is that humans do not use the 100% of agricultural land exclusively to feed people, but roughly 36% of the total production is destined to feed livestock. Otherwise, this land would serve to feed 3.5 billion people more. Also, we gain fewer calories from the meat and milk we consumed than the number of calories we waste on feeding animals. We only get 3 calories from beef for every 100 calories of grain we feed on cattle.

Picture of corn piling up outside full silos in Brazil

“A bumper crop of corn piles up outside full silos in Brazil’s Mato Grosso state, which sends much of its grain to China and South Korea to feed their pigs and chickens. The demand for more crops to feed livestock is one reason experts say we’ll need to double crop production by 2050.” Source: National Geographic, May 2014 Issue

Is meat consumption increasing?

Meat consumption is increasing at an accelerated rate. The preference for pork and chicken has increased 4.5 times since the last 50 years, and an overall of 1.5-fold increase for all kind of meat. It is because of the change in the number of people who will eat meat. Economic prosperity has been observed to contribute the shifting from vegetables to meat. People with better income in countries such as China and India, that have a high rate of vegetarian population, will choose a richer diet, boosting the demand for cattle, pigs, and chicken.

The relative area of land occupied by agriculture and other human activities compared with the total Earth surface. Source: National Geographic, May 2014 Issue

Should I give up meat then?

If only Americans shift to a plant-based diet, 91 million cropland acres can be saved and 278 million metric ton of CO₂ would not end up in the atmosphere. Should I change my diet then? It is hard to give up beef. However, little steps can make the way we eat more sustainable. It is as simple as reducing the number of days you eat meat or buying chicken instead of beef. Why? Check this video or go to this link!

(Video: Why meat is the best worst thing in the world? We love meat, but we should make agriculture more sustainable.)

Mirkka Puente

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Posted on October 6, 2018 by in Biological Sciences, Issues in Science, Science in the News

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Zombie Amoebas: Your Brain is at Risk

Posted on October 1, 2018 by | Leave a comment

What would you say if I told you that there are brain-eating amoebas lurking in warm bodies of water, capable of entering your body through your nose? Would you ask what an amoeba is? Would you ask why it wants to eat your brain? Would you decide to boycott outdoor water parks for the rest of your life?

Naegleria fowleri
Credit: Wikimedia Commons. This image is part of the public domain.

Not to worry, these amoebas do not intentionally set out to eat your brain. However, they are capable of causing a fatal infection upon entering a human body, so it is important to be aware of their existence as well as practices that can help prevent disease.

First, some background information. An amoeba is a single-celled organism that is capable of moving around by projecting pseudopodia or “false feet”. It can use its cell membrane to engulf food particles through a process called phagocytosis.

More specifically, the “zombie amoeba” itself is a species called Naegleria fowleri. It was first discovered in Australia in 1965.

Naegleria fowleri thrives in warm waters – it can survive in temperatures of 45 degrees Celsius! Areas in which the organism is commonly found include warm lakes or ponds, mud puddles, slowly moving rivers, pools or spas that are not chemically treated, hot springs, aquariums and soil. Some good news, however: Naegleria fowleri cannot survive in salt water or in swimming pools that are correctly chemically treated, so you don’t have to stop frequenting your local swimming pools or the beach.

Click on the video below for more information about Naegleria fowleri: 

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Credit: Centers for Disease Control and Prevention, Wikimedia Commons. This work is in the public domain.

As stated previously, the term “zombie amoeba” is actually slightly misleading, as the organism does not actively seek out human brains as a food source. According to the Centers for Disease Control and Prevention, Naegleria fowleri normally feeds on bacteria. The organism may enter the nose during activities such as swimming and diving. Once it has entered, the amoeba travels to the brain where it feeds on brain tissue, causing swelling and ultimately, death.

These infections occur most frequently in the southern United States during warmer months. The name of the infection itself is primary amebic meningoencephalitis (PAM), the symptoms of which are: headache, fever, nausea, vomiting, neck stiffness, confusion, balance problems and seizures or hallucinations. Rapid progression of the disease can lead to death within an average of 5 days.

Changes observed in body tissue as a result of PAM. Source: Wikimedia Commons. This Image is part of the public domain.

However, according to the CDC:

“Naegleria fowleri infections are rare. In the 10 years from 2008 to 2017, 34 infections were reported in the U.S. Of those cases, 30 people were infected by recreational water, 3 people were infected after performing nasal irrigation using contaminated tap water, and 1 person was infected by contaminated tap water used on a backyard slip-n-slide.”

To prevent infection, the CDC recommends focusing on keeping water from entering your nose by abstaining from diving headfirst into water or submerging your head. As well, it is a good idea to avoid stagnant bodies of water. There is no effective treatment for PAM at the moment, so more research needs to be done so that this disease can be stopped from claiming more lives.

Maya Liepert

 

 

 

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Echolocation: How Two Seemingly Polar-Opposite Creatures Developed the Same Highly Specialized Skill

Posted on October 1, 2018 by | Leave a comment

Have you ever been walking through your house in the middle of the night with all the lights off, searching for a glass of water, but you feel an intense pain running through your body as you stub your toe on the counter? This would never happen if humans had echolocation: the ability to map out the area ahead of you by using reflections from high-pitched sonar signals.

Animal Echolocation
Credit: WikiMedia

Echolocation is an ability that is primarily used by dolphins and bats. This raises the question, why is it that dolphins: hairless mammals which live in the ocean, happen to have the same specialized ability as bats: which are furry, nocturnal, and flying critters?

Dolphins utilise a unique organ called the melon to send out high frequency clicks. They have a large depression in their skull to make space for this organ, allowing them to produce bisonar for orientation. Beyond this, echolocation gives dolphins an idea on the object’s shape and size, although it is not quite understood by scientists exactly how this happens.

Bisonar by cetaceans
Credit: Wikimedia

Bats dominantly use a method of echolocation called laryngeal echolocation, which is characterized by the production of very short wavelength sounds from their larynx. The connection between their stylohyal bone and tympanic bone enables the bat to neurally register and separate outgoing and incoming ultrasonic waves. They have evolved to differentiate between the pulses they produce and the echoes that they receive back.

Ventral view of the Florida Freetail bat, highlighting the tympanic and stylohal bones. Credit: Pacific Lutheran University Natural History 

This skill could potentially be relevant for humans today, as researchers are using this skill to test human echolocation in blind people. It has been revealed that some blind people were able to independently develop a type of echolocation, by utilising sound, they are able to map out the space they are in and develop an image of it for themselves. Some researchers are studying this ability, attempting to make it accessible for all who might need it.

So how is it that dolphins and bats have developed these extremely similar skills? Clearly, there is the fact that because dolphins hunt in murky ocean waters, and bats hunt late at night in the dark. Thus they both had to have evolved some method to cope with the darkness, but why was it that they developed the same method of echolocation independently? A team of scientists were trying to answer this question, and a paper in Science Advances announced that there exist genetic characteristics that could have helped dolphins and bats both develop this skill.

This international group of scientists searched through the genomes of each animal, searching side by side for any similarities in amino acid sequences. They found that bats and dolphins share amino acids linked to proteins involved in the development of a very specific set of fast-twitch muscles. These were the muscles that drive the “terminal buzz”, or the rapid high frequency calls that bats and dolphins both make when hunting.

Figure showing sudden increase in high frequency calls in a bat
Credit: The Gall Lab

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Sound clip of terminal buzz – the terminal buzz is the last pulses of an echolocation call sequence: and will speed up at the end because the bat is getting closer to the object it is interested in.
Credit: The Gall Lab

This similarity in amino acid sequence may be a part of what helped these two very different animals develop the same skill, but there is still plenty to uncover about the specifics of how dolphins and bats developed echolocation independently. However, we are much closer to uncovering this mystery than in the past.

Jin Kyu Lee

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