Category Archives: Biological Sciences

Searching for disease-unlocking keys

Ryan Centko, molecular connoisseur

Have you ever heard of a molecular connoisseur? Like wine connoisseurs, they are able to pick up on minute details and identify differences that an untrained person cannot. Only they are identifying molecular structure-scale details and differences, not fruity legs and woody undertones. My friend Ryan Centko is a self-described molecular connoisseur in training. And as part of research that was just published in Organic Letters, he recently helped discover 4 previously unknown molecular compounds in a fungus called Penicillium purpurogenum. While the 4 compounds found are structurally very similar, they may differ from one another in one or two very subtle ways. The structures that Ryan helped to uncover could prove to be the keys that unlock, or cure, diseases that do not yet have effective cures.

Ryan is part of a group of scientists working in a lab at UBC scouring previously unidentified or unexamined organisms for new compounds. He recently spoke with me about his work on Penicillium purpurogenum, the purplish fungus found on Averrhoa Bilimbi, or what can be better described as cucumber trees, in Sri Lanka.

Averrhoa Bilimbi, the cucumber fruit tree. de Silva photo.

Penicillium purpurogenum in a petri dish. de Silva photo.

I found out that the fungus was brought over to UBC researcher Raymond J. Anderson’s lab by a Sri Lankan scientist named Dilip de Silva. Ryan, a PhD candidate working under Anderson, got to take part in the analysis of this exciting organism. To begin the search for unique molecular compounds, the fungus was first prepared for examination. This involved growing it in petri dishes in the lab. Once the fungus grew into a large enough amount, it was mixed with a solvent such as ethanol. Finally, the whole mixture was dried into a sort of paste – the optimal substance for the identification of new compounds.

The four new compounds found within the Sri Lankan Penicillium purpurogenum have been named Dhilirolides A, B, C, and D. Ryan and the rest of the team have sent out the Dhilirolides A – D compounds to researchers around the world who are going to be taking these “keys” and seeing whether they have antibiotic potential (seeing whether they can find the appropriate disease “locks”). In the meanwhile, Ryan and the rest of the team are looking for more unique compounds within Penicillium purpurogenun – Dhilirolides E – Z, perhaps? As Ryan says, the more unique structures they find, the better chance they have of finding something that could work as an antibiotic.

Read Ryan’s Organic Letters paper here!

The Keys to Longevity

Longevity is a goal most of us strive for, and in most of our minds the keys to accomplishing this consists of being happy, eating healthy, and not stressing too much. However, it appears that these common assumptions made by people are in fact wrong. In a recent article published by Science Daily (which can be found here), they reported the findings of a twenty year study about longevity and the results are not what we would expect.

Image from: http://ngm.nationalgeographic.com/ngm/0511/feature1/index.html

The study, which is called “The Longevity Project”, was conducted by a group of scientists at the University of California, Riverside (UCR). These scientists examined, and refined previously collected data by Stanford University. The data which was initiated back in 1921, documented the lives of over 1500 children as they grew, starting from the age of ten. The children were studied throughout their lives, and information regarding family histories, relationships, hobbies, pet ownership, job success, education levels, military service, and numerous other details were collected. The scientists at UCR discovered many similarities in the data and they concluded that personality characteristics and social relations from childhood can predict one’s risk of dying decades later.

On average, it was discovered that test subjects who were the most cheerful and had the best sense of humor as kids lived shorter lives. While, individuals that were most prudent and persistent stayed the healthiest and lived the longest. This is definitely counterintuitive to what most people think. It appears that the subjects that were cheerful as kids tended to take more risks with their health across the years, hence risky or dangerous activities shortened the lives of many. Those that were prudence and persistence on the other hand, often developed many important and beneficial habits throughout their lives. The scientists found out that happiness is not a cause of good health, but instead happiness and health are related because they have common roots.

Image from: http://www.forbes.com/2002/08/07/0807sport_8.html

Furthermore, some of these intriguing key findings include that marriage may be good for men’s health, but it does not really matter for women. Men who remained in long term marriages generally lived longer than single or divorced men. As well continually productive men and women lived much longer than their more laid-back counterparts. Lastly, people who felt loved and cared for reported a better sense of well-being, but surprisingly it did not help them live longer. The clearest health benefit of social relationships comes from being involved with and helping others. The groups you associate with often determine the type of person you become, healthy or unhealthy.

These results are definitely interesting, and hence we should keep them in mind when we are trying to extend our longevity. In fact, it would probably be beneficial if we started to incorporate some of these findings in to our daily lives. For instance, we should all be more productive, and we should all be more involved. Hopefully in the future, the average life expectancy of people can exceed 100 years old.

Feel less depressed but be more likely to die

Life is not always kind. People lose their jobs, experience the death of family members, break up with lovers and friends, and become victim to other losses. At some point in life, people are bound to get their share of remorse and sorrow and they may end up down in the dumps because of it. To go through such times, it may be tempting to rely on prescription drugs to alleviate emotional pain; however, antidepressants may be a double-edged sword. Although antidepressants do interfere with the nervous system to uplift people’s moods, according to some studies, some or all known antidepressants may increase the rate of suicidal thoughts.

A number of studies show a strong link between antidepressant use and subsequent suicidal behaviour. In one experiment in 2007, young patients aged 10 to 18 with mood disorders were either treated with selective serotonin reuptake inhibitors (SSRIs), the most common class of antidepressants for children, or given a placebo. Afterwards, the experimenters found that, as a group, the patients who took the SSRIs had about twice the number of self-reported suicidal thoughts than the control group which had the placebo.

However, the relationship between suicide risk and antidepressant use is not concrete. There are some studies which found no correlation between the two in other studies with depressed children and young adults. For adults, antidepressants do not seem to increase suicide rate. Moreover, the reasons for why antidepressant use increases suicidal behaviour is unknown.

The dangers antidepressants pose to adolescents is an issue that needs to be brought to public attention. Antidepressants have increased in use since the 1990s and the public may be getting the wrong impression that antidepressants do not pose any more danger than other common prescribed medicine such as antibiotics. More research is needed to determine why antidepressants seem to increase the risk of suicide and assess other possible side-effects the drugs may have.

Arsenic – Venomous or Vital for Life?

Arsenic. Just the thought of the compound sickens many due it its infamous toxic properties.  Who would’ve thought that a compound this hazardous to most organisms could be one of the building blocks of life for another?

A recent discovery of microorganisms in Mono Lake, California shocked geneticists and scientists all over the world. This past December, NASA proclaimed that they had discovered the first known organism on Earth that utilizes arsenic as one of its chemical means of life and survival. Though some bacteria are known to obtain their energy by oxidizing arsenic as a fuel, Prior to this discovery, every known organism on Earth had used carbon, nitrogen, phosphorous, oxygen, sulphur, and hydrogen as the six fundamental elements of life. This organism discovered has been found to replace the phosphorous in the classic combination, with arsenic – using it as a staple backbone in its hereditary units and as an energy-carrying molecule.

Some researchers believe that due to the harsh conditions within Mono Lake, (high levels of saline, alkanes, and arsenic – fun fact, the lake actually has a layer of dead flies floating around the circumference of its surface) the organism may have evolved to adapt to the depleting levels of nutrients and utilize other chemicals present – a process that could have taken who knows how long.

It’s mind-boggling to believe that the discovery of one miniscule, seemingly insignificant organism has completely changed the way scientists viewed the way life has survived. This ‘seventh’ core element can only lead those to wonder what other microorganisms are waiting to be discovered that could potentially utilize fluorine as a main structural component, or harness radio waves as energy.

What about life beyond the planet Earth? Could this discovery just prove that complex species may be thriving in the inhuman conditions of the other planets?

Alzheimer’s Disease

A recent clinical trial on the hit show “Grey’s Anatomy” that was being conducted to find the cure to Alzheimer’s inspired me to write this blog post because I really don’t know much about this disease other than the fact that patients diagnosed with Alzheimer’s suffer from dementia and therefore, wanted to know more about the causes of this disease.

Alzheimer’s is a “progressive and degenerative disease” and is the most common form of dementia. The name for this disease comes from the doctor who first identified the disease: Dr. Alois Alzheimer. According to his research there are two main features to this disease: Plaques and Tangles

Plaques are made of a protein already consisting within the brain called A-beta. A patient with Alzheimer’s generally has more of this protein that accumulates in the brain. They accumulate in such high numbers that it makes it difficult for the enzymes in the brain whose job is to get rid of this protein overwhelming the whole system. Over time as they accumulate they condense into plaques that are toxic.  Researchers believe that these A-beta proteins somehow change the genetic code of the tau protein thereby promoting development of “Tangles”.

Tangles as mentioned before are made of tau protein. These are located in the nerve cells and perform key duties such as self-repair of the nervous system as well as maintaining a transport system within the nerve cells. However after these are modified by the A-beta protein they tend to pile up and create tangles. By creating these tangles the transport system of the cells is disrupted and therefore the cell dies.

The toxic plaques along with the tangles leads to the slow degeneration of cells in the brain, thereby causing the brain to shrink as seen in the following picture.

"Normal Aged brain vs Alzheimer's patient"

I hope to look into more research that has been done on the purpose of the A-beta protein as well as other further research into how doctors might proceed to deal with this disease in the future. Until then I will direct you to the following link that has more information on Alzheimer’s Disease.

http://www.alzheimer.ca/english/