Tag Archives: biology

The Epigenetic Relationship Between Income and Aging

Posted on March 7, 2016 by | Leave a comment

You are probably familiar with the old nature versus nurture debate if you have ever taken a course in psychology or philosophy. It inquires whether our development is induced by our DNA, individual choices we make or by our environment and circumstance. Twins are often used to demonstrate the effects environmental factors have on phenotype.

In the early 1990’s a scientist by the name of Conrad Waddington found that environmental stress was causing certain phenotypes of the Drosophila fruit fly to assimilate. In other words, these phenotypes that were first induced by the environment were becoming permanent and hereditary! Waddington named this area of research Epigenetics; a now growing field of research that looks at how environmental factors can change our phenotype.

Dr. Courtney Griffin, a member of the Cardiovascular Biology Research Program at Oklahoma Medical Research Foundation discusses the importance of Epigenetics in this TedX video.

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Many studies in recent years have attempted to reveal a connection between low income and risk for diseases such as heart disease and cancer. What all of these studies have looked at is telomere degradation. As cells divide, the length of these chromosome-caps contracts implying aging. As an indicator of aging, telomere degradation remains unreliable and results from these studies have proven inconsistent.

A new study by Ronald Simons et al. has demonstrated a correlation between accelerated aging and income by a new method. The researchers were able to identify certain epigenetic markers that can be linked to aging by way of DNA methylation. This process involves adding methyl groups to DNA. As the methylation level of a gene increases, the expression of the gene decreases (Read more about DNA methylation here).

A sample of 100 middle-aged, American black women were chosen for the study as the population of black men in America had high incarceration rates (forcing the financial burden on the mother of a family) and low family incomes. The study controlled for other influences of socio-economic status (SES)  such as education, and used a new method of structural equation modeling to find that low income was associated with biological aging.

Income inequality is one of the largest problems the United States faces today as 99% of new income is being distributed to merely one percent of the population. This study implies that this problem may be even worse than previously understood. If these biological effects are in fact hereditary, the vast population of low-income wage earners in America can expect their children and grand children to live shorter lives.

-Johnny Lazazzera

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Organisms Inside Us

Posted on February 29, 2016 by | 2 comments

Have you ever wondered how many micro organisms are living inside us? Micro organisms are living organisms that cannot be seen with our naked eyes. They may be multicellular (made out of more than one cell) or unicellular (made out of one cell). Our human body is packed with trillions of microbes (or micro organisms). In fact, our own body cells are out numbered with a ratio of 1:10. So, we are technically 90% germs and 10% human. Microbes are found in all parts of our body in different proportions. Our lung has approximately 1000x less microbes than our mouth and has approximately 1 billion times less microbes than our intestines. Although most microbes are harmless to us, some may cause bacterial infections in humans.

The Human Body = 90% Germs + 10% Human

Top three functions microbes in our body:

  1. Defense mechanism: Microbes in our lungs, intestines and our skin provide the first line of defense against harmful bacteria that enters our body. Good microbes found in these areas play an essential role in preventing the spread of harmful microbes by occupying space so less space are available for harmful microbes to settle down inside us. Thus, preventing us from bacterial infections that may cause fever, diarrhea or other problems. Other than that, researchers have found evidence that microbes that live inside us help promote our immune system cells to grow and replicate.
  2. Keeping us in shape: The trillions of microbe colonies in our intestines help digest fats and carbohydrates, facilitating the absorption of nutrients in cells. Our intestinal microbes also ferment food that we consume. The fermentation process produces chemicals that speeds up our metabolic processes. As a result, the microbes in our gut helps us keep in shape by increasing our metabolism.
  3. Detoxifies us: Microbes living in us are also capable of digesting toxins that we accidently ingest into less harmful substances. Therefore, preventing us from being poisoned. For example, the microbe Lacrobacillus probiotics found in food help the human body detoxify heavy toxic metals such as aluminum.

Good microbes that keep us healthy

Where do we get microbes that live in our body? Most of our microbes that inhabit our intestines comes from the food we ingest. Our skin and lung microbes come from the air we are exposed to. Recently, researchers discovered that newborn infants get their microbes from their mother’s breast milk and vagina. Researchers found that the method of delivery may have an effect on the diversity of intestinal microbes in newborns. They discovered that infants born vaginally and infants born by caesarean section have different intestinal microbe composition. This indicates that we start to develop our microbe colonies from the day we were born.

Microbes inside our body

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Benefits of Breastfeeding: Breast Milk Contains Sugars that Contribute to Healthy Infant Growth

Posted on February 22, 2016 by | 3 comments

Were you aware that the thousands of bacteria residing in our gastrointestinal tract (gut) and their interactions with the dietary foods we consume actually have a great impact on human health?

Two 25-milliliter samples of human breast milk. The lefthand sample is first milk produced and the righthand sample is milk produced later during the same pumping.

Two 25-milliliter samples of human breast milk. Source: Wikipedia Commons

Inspired by this discovery, a team of researchers led by Jeffrey Gordon from the Washington University School of Medicine in St.Louis found that the interactions of gut bacteria with the sugars in breast milk promote healthy infant growth.

Why is healthy infant growth a topic of discussion?
Every year, childhood malnutrition causes over 3 million deaths, leads to stunted growth and is associated with impaired cognitive ability.

Branched Oligosaccharide Structure

Branched Oligosaccharide Structure.                  Source: Wikipedia Commons

In Malawai, Africa, almost 50% of children under the age of 5 showed stunted growth. The researchers collected samples of human breast milk from those mothers with healthy babies or stunted babies. They discovered that the amount of oligosaccharides (sugar) in the breast milk containing sialic acid, an essential nutrient for brain development and cognition, were much greater in the mothers with healthy, relative to stunted growth babies.

This finding suggests that the sugars in the breast milk contribute to healthy infant growth. To analyze whether this was the case, the researchers created animal models, ensuring that both the bacteria in the gut and the diet could be manipulated. Gordon and his team began by isolating bacterial strains from fecal matter of the undernourished babies and inserted it into mice or piglets. Then, the researchers fed the mice or the piglets a typical Malawian diet, consisting of legumes, corn, vegetables, and fruit, a diet itself which is insufficient for healthy growth.

Whey

Whey, a by-product of cheesemaking. Source: Wikipedia Commons

With the mice and the piglets mimicking the undernourished Malawian infants, Gordon and his team then began testing effects of the sialic acid-containing sugars. They used cow milk as an alternative because of the difficulty to purify large amounts of sugars from human breast milk. They were able to obtain sialic acid-containing sugars from whey, a by-product of cheesemaking, and fed it to the animals. The mice and piglets showed significant improvements in growth, in both muscle mass and in bone volume. The mice and piglets also showed improved brain development and metabolic activities in the liver.

Because the bacteria in the gut was allowed to be manipulated, the researchers were able to pinpoint which bacterial strains were affected by sialic acid-containing sugars and how the different strains interacted with one another. They found that one strain of bacteria fed on the sialic acid-containing sugars and another strain fed on the digested products of sialic acid-containing sugars. This revealed a possible food web within the bacterial gut community.These two strains of bacteria alone were not sufficient enough to explain healthy growth in the mice and piglets, signifying that more complex interactions among different bacteria in the gut were necessary for growth.

The results of their study were recently published in Cell and serves as the foundation for future studies on the benefits of the components of breast milk on healthy infant growth and its interaction with gut bacteria.

 

Posted on February 22, 2016 By Jenny U

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Nanotechnology: The Cure for Cancer?

Posted on February 20, 2016 by | 2 comments

What is Cancer (disease)?

Cancer is a very well known disease plaguing human society for the last century. It is characterized by abnormally rapid cell division often accompanied by tumor growth; the type of tumor mainly being malignant to be more precise. It is

Cigarette, Source: Wikimedia Commons

Cigarette, Source: Wikimedia Commons

known to sprout from sources known as carcinogen (such as ultraviolet radiation and smoking cigarettes) as well as genetic dispositions.

 

Current Treatment

Current treatments are quite limited and do not have an 100% success rate since there are so many mutations and varieties in cancer. Treatments such as chemotherapy often have lasting side effects. Additionally, there is a likelihood that cancerous cells are not completely eradicated and may resurface in years to come.

The following is the background behind chemotherapy and the effects it has on the human body provided by Dnews on YouTube.

What the Future Holds?

What scientists are trying to obtain is a sustainable as well as safe method of treating cancer. Scientists are looking into stem cell research, protein inhibition (protein Kinase inhibition) and artificial intelligence as potential methods. But, perhaps one of the most promising of the potential treatments is nanotechnology.

*Credit to Inquisitr.com for providing these different potential treatment methods.*

Nanotechnology and Cancer Treatment

Nanoparticles are as small as cell organelles with great flexibility when it

Mesoporous silica, Source: Wikimedia Commons

Mesoporous silica, Source: Wikimedia Commons

comes to shape, size and composition. Research by scientists have found a mesoporous silicon nano particle that is able to encase azobenzene molecules within its membrane pores as well as carry different sized substrates inside the particle itself.  It is important to note the fact that azobenzene switches its orientation/ configuration (cis/trans) when exposed to light and its size changes when going from cis to trans. This  means that the permeability of the silica nanoparticle can be regulated by the azobenzene molecular configuration.  Small pellets of anti-cancer drugs can be inserted into the silica nanoparticles and injected into the human body. With controlled light exposure and intensity, the size of azobenzene changes releasing the substrate into the cancer cell targeting either just the cancerous components or the entire cell.  The following video uploaded by FGRGAnimation made by Frank Gu from the University of Waterloo outlines the process of osmosis and cell substrate concentration in regulating and controlling transport in a nanoparticle.

This process will be safe due to the high control levels in the real (in vivo) environment. We are able to selectively insert the amount of substrate into the nanoparticles to control concentration and light intensity. Thus, the correct dosage is always applied. Interestingly, the treatment  process can be both selective or general meaning scientists are able to use substrate specifically targeting cancerous components in a cell or the entire cancer cell.

Although the focus was on nanoparticles and nanotechnology, any of the the aforementioned 4 methods can be an important breakthrough in cancer treatments if proven experimentally successful.

Posted by Ming Lun (Allan) Zhu

 

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Martian Life a Possibility

Posted on February 8, 2016 by | 4 comments

Last September, NASA scientists, using image spectroscopy on the Mars Reconnaissance Orbiter, had published new evidence in support of the hypothesis that present day water flows on the surface of Mars. It is often said that where there is water, there is usually life; but what kind of life can exist in such an extreme environment?

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A recently published study by a group of European Researchers has shown that certain fungi and lichens on Earth have the ability to survive in conditions similar to Mars for an extended period of time. The study is ongoing and will involve several more Fungi and Lichen species as part of the Lichens and Fungi Experiment (LIFE).

"Lichen" by Brittany. From Flickr. Licensed under CC 2.0.

“Lichen” by Brittany. From Flickr. Licensed under CC 2.0.

The two types of fungi collected come from the cryptoendolithic family: the Cryomyces antarcticus and Cryomyces minteri. The organisms were taken from within cracks of rocks found in the McMurdo Dry Valleys in Antarctica. Strong winds, cold temperatures and no precipitation characterize this region. The samples were placed in cells and attached to the ISS via the EXPOSE-E platform.

EXPOSE-E Platform Installation. From Astronomy Magazine.

EXPOSE-E Platform Installation. From Astronomy Magazine.

For a year and a half, half the fungi were subject to Mars-like conditions while the others were exposed to regular conditions in space. The results show that not only did 60% of cells remain unharmed but many were able to resume and even increase cellular activity.

If these lifeforms can survive on the surface of Mars, it may be possible that Martian life already exists. The challenge now for NASA, the European Space Agency and other scientists is to send humans to Mars without contaminating the region.

Do you think that within the century we will discover the first examples of extraterrestrial life?

-Johnny Lazazzera

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Type 1 Diabetes: A Potential Cure?

Posted on February 1, 2016 by | 5 comments

Type 1 Diabetes, also known as diabetes mellitus type 1, is a condition characterized by the impaired ability of one’s pancreas to produce insulin. In an individual with type 1 diabetes, the immune system malfunctions and attacks the beta cells of the pancreas, which are responsible for producing insulin. This classifies type 1 diabetes as an autoimmune disease, which is where the immune system attacks the body, thus it is currently incurable. The current treatment for this condition involves daily injections of insulin to allow the individual to regulate their blood sugar levels. Unfortunately, insulin therapy has side effects, such as hypoglycemia (low blood glucose levels) or hyperglycemia (high blood glucose levels) from incorrect dosages, and some individuals may be allergic to the preservatives added to insulin medication. Furthermore, insulin therapy involves precise control of blood sugar levels, and this is very difficult to achieve, often causing patients to face long-term medical problems as a result.

Diagram of the pancreas and beta cells. Via Wikimedia Commons.

Diagram of the pancreas and beta cells. Via Wikimedia Commons.

So what is this new potential cure? It began in 2014, when a team of Harvard University researchers used human stem cells, unspecialized cells that can become cells with a specific function, to create new beta cells in large quantities, as published in Cell. This new technique of creating insulin producing cells from human embryonic stem cells was a big step in diabetes research. In further experiments, these beta cells were transplanted into diabetic mice, as an attempt to replace the destroyed beta cells. Unfortunately, the immune system in the mice destroyed these new beta cells as well.

The experiments were first done on lab mice. Via Wikimedia Commons.

The experiments were first done on lab mice. Via Wikimedia Commons.

A team of researchers from MIT and several other institutions have devised an “invisibility cloak” for the beta cells, so they can hide from the faulty immune system. The cloak is composed of modified alginate, which is a material isolated from brown algae. After testing 800 various derivatives of this alginate capsule, they chose the best capsule from the tests, known as triazole-thiomorpholine dioxide (TMTD). This research was shown in a recently posted article in the Nature Biotechnology journal.

Brown algae that form the alginate used in "invisibility cloak". Via Wikimedia Commons.

Brown algae that form the alginate used in “invisibility cloak”. Via Wikimedia Commons.

The results were incredible! As a study in Nature Medicine showed, the injected mice were able to produce insulin until the implants were removed 174 days later. This has massive implications for diabetes therapy, as not being dependent on insulin injections is the end goal. If these implants were able to function in humans, then the diabetic individuals would not require insulin injections anymore. The next step of research is to move from trials on mice to trials on primates. If the tests on primates show positive results, the step after would be human trials. Researchers are making large strides towards a cure for type 1 diabetes.

– Kush Khanna

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Eating Turkey Makes You Sleepy: True or False?

Posted on January 31, 2016 by | 4 comments

https://www.youtube.com/watch?v=aa1_CeUAQIc#action=share

Many of us have probably heard or even experienced the famous phenomenon known as food coma. If you have no idea what food coma is, you most probably have experienced it before unknowingly. Food coma is a state of lethargy or sleepiness experienced after consuming a large portion of food. Despite its informal name, it is a medically recognized condition called post-prandial comnolence.

Food coma generally hits harder at the most festive times of the year- the holiday seasons. The thanksgiving turkey is no exception. You stack your plates with turkey, sweet potatoes, dressing, cranberries and all the other old-fashioned foods, then fill your stomach up to the brim. Then, of course, you go for a second, then third round. It’s the holiday seasons after all. Not long after, you start to feel lethargic, energy-less and sleepy. Unknowingly, you have fallen into the food-coma trap.

For many years, urban myths have blamed the turkey for the main cause of the sleepiness. But is the turkey really to be blamed?

Where did the myth come from?  Many of you might have heard about the amino acid called tryptophan. Tryptophan is one of the components of the hormone serotonin. Serotonin is converted to the sleep-inducing hormone melatonin. Without melatonin, we will all be always wide awake. This chemical is essential in our body to give us enough rest at night for proper bodily functions. Hence, yes, tryptophan is an essential chemical in our body. However, our body does not produce tryptophan. Tryptophan is obtained by our body from the food we eat.

The tryptophan we ingest competes with other amino acids in our body to enter our brain through the blood-brain barrier. The blood-brain barrier is an interface that separates the brain from the rest of the body. It protects the brain from harmful chemicals that enters the body by filtering them. The blood-brain barrier will only allow certain chemicals to enter the brain. Only a portion of the tryptophan we ingest successfully enters our brain. Most of them are broken down in our liver. The myth that turkeys make us sleepy began when tryptophan were found in turkey meat.

So, do turkeys make us sleepy? The answer to this question is- yes and no. Turkey meat contains tryptophan-yes. However, according to Standford neuroimmunologist Lawrence Steinman, MD, the levels of tryptophan  in turkey “is not higher than in most other muscle tissue from other animals, more commonly known as meats”. It is not the turkey that makes us sleepy but it is the enormous amounts of carbohydrates and often alcohol consumed on the holiday seasons.

Carbohydrates such as the dressing or mashed potatoes induces the release of insulin into the bloodstream compared to other amino acids present. As a result, higher levels of tryptophan are concentrated at the brain-blood barrier.

In conclusion, it is not the turkey that makes you sleepy after Thanksgiving. So, take a quick nap on Thanksgiving, but be sure to wake up in time for the dishes!

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Do Chimpanzees Trust Their Friends?

Posted on January 17, 2016 by | Leave a comment

Have you ever played a game of “trust fall”? Perhaps you were nervous as those behind you may not have been close friends. Trust is the cornerstone of a civilized society; one in which we can confidently rely on others to uphold their duties in maintaining mutually beneficial relationships.

Conversely,  self interest may cause individuals to disregard their moral obligations to others and use trust as a tool to get ahead. For this reason humans tend to put their trust in friends before strangers as to minimize their risk of danger – but what about animals?

Researchers from the Max Planck Institute for Evolutionary Anthropology in Germany wanted to know if Chimpanzees operated on the same principles. In their previous study, the researchers had acknowledged certain behaviors among the chimpanzees that were similar to human friendships.

If they could show that chimpanzees are selective with their trust, it may imply that trust, and other complex psychological behaviours have evolved from our common ancestors!

To put their theory to the test, Esther Hermann and Jan Engelmann conducted a study, observing closely fifteen chimpanzees from the Sweetwaters Sanctuary in Kenya, where most of them have been living for nearly twenty five years. They began by monitoring the interactions of smaller groups and even pairs of chimps during feeding and grooming times to determine which could be considered friends.

The experiment was set up in a way that would observe whether a chimpanzee would chose a low risk and relatively small reward option over a higher risk and greater reward option. Specifically, the experiment, which was replicated 12 times with both the chimp’s close ally and a stranger, looked like the following:

Two chimpanzees, A and B, are placed in separate rooms joined by a feeding mechanism that includes two ropes: a non-trust rope and a trust rope. The non-trust rope, if pulled, provides the chimpanzee that pulls it with an immediate but not preferred food. The trust rope, if pulled by chimpanzee A, will give chimpanzee B access to a more preferred food first who must then pull the same rope to send the food back to chimpanzee A. Chimpanzee A, in pulling the trust rope, must trust that chimpanzee B will send the food back in order for the event to be mutually beneficial.

The results of the test showed that the chimpanzees preferred the riskier option significantly more when the receiving chimp was a friend. These findings show that the trusting behaviors of humans towards their friends are not solely demonstrated by our species and had perhaps evolved from our predecessors!

The door is open for scientists to explore whether other human psychological behaviours are also being demonstrated in the animal kingdom.

Post by:  Johnny Lazazzera

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