Author Archives: akashaujla

Extra Gene Leads to Long Cancer-free and Fat-free Lives in Mice

Posted on March 19, 2012 | 1 comment

Mouse (Photo by Ernst Vikne on www.flickr.com)

Can you imagine a world in which cancer and obesity can be prevented by a single gene? It may sound too good to be true, but researchers at the Spanish National Cancer Research Center (CNIO) in Spain have found such a gene. In fact, not only does this particular gene prevent cancer and obesity, it also increases longevity!

The gene in question is known as the ‘Pten’ gene, a tumor-suppressing gene that is often lost in humans affected with cancer.

“Tumor suppressors are actually genes that have been used by evolution to protect us from all kinds of abnormalities,” explains Manuel Serrano, a researcher who worked on this study.

With an extra copy of the Pten gene, mice appeared to be immune to cancer. In addition, these mice were also found to have less body fat; in fact, the Pten gene led to slimmer mice despite an increase in appetite.

Difference in liver fat of a mouse with the Pten gene and without. (Source: Researchers' own materials)

The decreased body fat can be explained by the fact that most tumor-suppressing genes increase the activity and production of brown fat. Brown fat is a special type of fat that burns energy rather than storing it. As people age, the amount of brown fat in their tissues tends to decrease and be replaced by the more familiar—and much-disliked—white fat. In the case of the mice with the extra Pten gene, the overactive brown fat led to their burning more calories.

Brown fat can also explain the observed increase in longevity, as it has been shown to have the beneficial effect of protecting against metabolic damage commonly associated with aging. Metabolism refers to the chemical reactions that take place in our body in order to maintain life. Numerous studies exist that show a correlation between the rate at which these metabolic processes occur and the longevity of organisms.

This study may have been performed on mice, but the results are very promising for humans as well. The amazing effects of the Pten gene indicate that it may be possible to develop a drug for humans that offers the same benefits.
References:
http://www.time.com/time/health/article/0,8599,1890175,00.html
http://www.eurekalert.org/pub_releases/2012-03/cp-weg022912.php
http://www.sciencedaily.com/releases/2012/03/120306131252.htm

 

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

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Disrupted Biological Clocks Shown to Cause Neurodegeneration and Early Death

Posted on February 27, 2012 | 3 comments

Researchers at Oregon State University have managed to show that disruptions to the biological clock can directly lead to neurodegeneration— the progressive loss of nerve cells—and early death. These findings are significant, as they represent a step forward in the extensive study of circadian rhythms, which are the basis of our internal clock.

The sleep cycle is affected by the biological clock. (Source: 'marcinbunsch' on flickr.com)

Circadian rhythms coordinate many of our biological processes, from eating and sleeping to molecular processes such as hormonal secretions. Over millions of years, animals’ internal ‘clocks’ have been fine-tuned to align very closely with the 24-hour periodicity of Earth’s rotation—that is, our biological clocks are synced with the length of the 24-hour day that we know. These internal rhythms are what cause us to eat at regular intervals throughout the day, and what cause us to sleep at night and wake in the morning. In other words, our biological clocks are responsible for our internal synchronization.

Many studies have been conducted on the effect these circadian rhythms have on animal health. Disruptions to the biological clock have previously been linked with neurodegeneration; however, it was not apparent whether these disruptions were the cause or the result of the neurodegeneration. The study at Oregon State University is the first to demonstrate that disruptions to the biological clock are, in fact, a cause of neurodegeneration and early death.

Fruit Fly (Drosophila melanogaster). (Source: 'Oregon State University' on flickr.com)

The researchers conducted the study on fruit flies (Drosophila melanogaster), which have been found to share many similarities with humans. The flies used in the study were genetically modified to show signs of neurodegeneration. In order to assess the effect of disruptions to the internal clock, some of these flies were further modified to have interrupted circadian rhythms.

It was found that the flies with disrupted internal clocks had a 32 to 50 percent shorter lifespan than those without the internal disruption. In addition, these flies also exhibited accelerated neurogeneration—as evidenced by signs of holes in the brain—along with decreased climbing ability.

Holes forming in fruit fly brain. (Source: 'Oregon State University' on flickr.com)

These results clearly show the importance of the biological clock in the maintenance of animal health and functioning. Through this study, a greater understanding of circadian rhythms and their effects on organisms has been achieved.

 

 

 

References:

http://www.sciencedaily.com/releases/2012/01/120110140225.htm

http://oregonstate.edu/ua/ncs/archives/2012/jan/disruption-biological-clocks-causes-neurodegeneration-early-death

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

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Scientists Manage to Cloak a Three-dimensional Object

Posted on January 30, 2012 | 1 comment

Researchers at the University of Texas have managed to cloak a three-dimensional object, essentially rendering the object invisible from all angles. This feat represents a major breakthrough in cloaking research, with previous studies having been either limited to two dimensions, or merely theoretical.

So, does this mean that Harry Potter’s invisibility cloak has become a reality? Not quite. This study was limited to working with waves at microwave frequencies, meaning that waves falling within the visible region of the electromagnetic spectrum would still render the object detectable.

Left: Microwaves being blocked and scattered by object. Right: Microwaves being reconstructed by cloak. (Source: http://www.bbc.co.uk/news/science-environment-16726609)

The researchers employed the use of plasmonic metamaterials—manmade materials with special light-bending properties. These metamaterials interact with light in a way that is opposite to that of ordinary materials. Our ability to see an object relies entirely on the process of light waves striking its surface and then reflecting back into our eyes. In the case of plasmonic metamaterials, waves striking their surface are scattered and reflected in a manner such that a “photo negative” is produced. This, in turn, results in the original waves being cancelled out, and it is this cancellation effect that renders the object invisible.

The process is similar to the way in which noise-cancelling headphones work. The headphones reduce outside noises by receiving them through a microphone, inverting them, and then playing the inverted signal back through the headphones. Since the inverted audio waves are completely out of phase with the audio waves coming from the listener’s environment, the two waves cancel each other out, significantly reducing the sound levels heard.

In essence, this study relates to the effectiveness of plasmonic metamaterials in cloaking real, three-dimensional objects in space. Although this study was limited to microwaves, the researchers hope to eventually extend their studies to work with waves in the visible light spectrum.

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

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