By Mae Grewal Writer It’s now officially possible to grow a rat arm. Let that sink in for a moment: science and technology have progressed far enough that there is a way to induce cells to grow into the infinitesimally intricate, fully functioning, dismembered limb of a rodent. The project was undertaken by Harold Ott at Massachusetts General Hospital in Boston, and makes use of a process called decel-recel. In the decellularization step, the limb of a dead donor is treated with chemicals that strip away soft tissue, but leave the inert architectural protein matrix intact. This preserves the vastly complex structure of bones, blood vessels, muscles, and tendons that make up a functioning limb. Then, in recellularization, this scaffold is seeded with the appropriate cells from the eventual recipient of the biolimb. Because the new limb only contains cells from the recipient and not from a foreign source, the limb is much less likely to be rejected by the recipient.. Once Ott and his team grew the muscles of the new limb, they tested whether these muscles actually worked by electrically stimulating them. They found they could make the biolimb clench and unclench its paw, demonstrating successful muscle function. Furthermore, they tested the circulatory system by attaching biolimbs to anesthetized rats and observing whether or not the blood flowed adequately through the new vessels. This groundbreaking research puts medicine one step closer to providing amputees with another—possibly better—option in terms of regaining some of the functions of their lost limb. Current options include advanced prosthetics that allow for almost full range of motion but little to no sensory reception, and hand transplants, which run the risk of being rejected. If regrowing limbs from the amputees’ own cells proves viable, then having to choose between no touch or possible infection will become a thing of the past. Of course, there is still a ways to go in developing this technology for human use. The hand is one of the most complex parts of the body with its sensory and motor nerves and 1-cell-thick network of capillaries. While decel-recel regeneration has seen varying degrees of success with other organs such as the lungs, voice box, and kidneys, the increased complexity of the hand creates new challenges that need to be overcome. Most significantly, it remains to be seen whether a recipient’s nervous system will be able to grow into their new limb, and whether the new tiny capillaries will be able to maintain their structure to allow for blood flow without collapsing and creating clots. Ott himself says that it will be at least a decade before the first biolimbs are ready for human tests, but he, and many others, remain hopeful that technology will continue to progress to this eventual goal. In ten years, who knows? Forget rats, we could be growing human limbs in mass production for the benefit of trauma victims everywhere.
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By Sheela Ranganathan Writer Facebook, Instagram, Twitter, Yik Yak, Snapchat… Social media increasingly controls the lives of teenagers as these apps incessantly gain popularity and the convenient means to network progressively expand. Simultaneously, anxiety has become the greatest mental illness that affects college students in modern American society. I used to roll my eyes at my parents when they told me to limit my time on my phone and to share less posts to my ambiguous, large social media audience. However, researchers from the University of Scotland state that social media is directly linked to depression, anxiety, and poor sleep quality. In particular, those who logged on to these websites at later times in the night demonstrated greater likelihood of risks in mental health. In addition, receiving more or less likes on posts results in beneficial or adverse effects respectively. Extensive studies at the Freie Universität in Berlin demonstrated that receiving likes or tags on Facebook boosted the reward center in the brain. In addition to demonstrating the neurological effects of attention on the brain, this study also provided a basis for how posting on social media can become a compulsive addiction. So, the obsessive quest for compliments on pictures and posts is linked to patterns in the reward and pleasure pathways of the brain. Conversely, the lack of likes to one’s pictures results in feeling undesired or unnoticed. In addition, especially with respect to high school and college students, the concept of pictorial perfection leads to depression as people feel that their own lives are not as exciting or meaningful as the lives of others. Therefore, there is a direct correlation between the length of time spent on social media and the intensity of depression. To scroll or not to scroll? Despite these harms, social media definitely has many perks. However, if viewing the posts on your network makes you feel less confident or happy about yourself, it may be time to hit delete on these apps. Works Cited
[1] http://www.businessinsider.com/social-media-use-can-contribute-to-anxiety-and-depression-2015-6 [2] http://www.huffingtonpost.com/entry/social-media-college-mentalhealth_55ae6649e4b08f57d5d28845 [3] http://sundial.csun.edu/2015/03/to-like-or-not-to-like-how-social-media-effects-self-esteem/ [4] http://healthland.time.com/2013/08/31/this-is-your-brain-on-facebook/ [5] http://www.health24.com/Lifestyle/Teen/News/Social-media-may-increase-depression-in-teens-20150915 Thinking the Thought and Walking the Walk: How Technology is Helping Paraplegics to Walk Again12/2/2015 By Mae Grewal Writer Most people don’t really think about walking. When we want to get someplace, it just sort of happens—our brain send signals down our spinal cord into our peripheral nervous system to our motor nerves which cause our leg muscles to contract and suddenly we’re moving across the room to get to where we want to go without having to worry about the details, leaving our mind free to think about the essay that’s due in 12 hours or that cute guy at the RHO or the abysmal state of our political candidates for presidency. Unfortunately not everyone is this lucky. Fortunately, technology is evening the gap. Spinal cord injuries can render a person varying degrees of paralyzed, depending on at which vertebrae the injury occurred. Paraplegia is a result of a spinal cord injury that severs the nerves in the spinal cord rendering the bottom half of the body unable to move. Paraplegic patients have little hope of ever walking again without the assistance of expensive robotic limbs the route for the signal between their brain and legs is damaged. New research is looking to bypass that destroyed route entirely, however, by establishing a different way for the brain to relay walking signals to the leg muscles—and the crazy awesome thing? So far it’s working. A 26 year-old man was wheel chair bound for 5 years after his accident, but now he has become the first paraplegic to walk using impulses created from his own brain. He was outfitted with an EEG cap that monitored his brain waves and was able to distinguish between walking, sitting, and standing signals that the man actively thought. The cap then activates a electrical stimulator at his waist to create the muscle contractions to move the right leg forward, then the left, and so on, for an actual walking motion. He doesn’t have to actively think about each individual leg, but rather about the general motion of walking, and the waist monitor translates that into the more complicated individual muscle movements for him. But even this generalized thinking about walking took a lot of practice. While the brain does not lose the capacity to remember how to walk even if the body is paralyzed, his brain needed to be trained to actively voice that motion, which they practiced by hooking his EEG cap up to a computer avatar that he learned to control. Then, he needed to build up the muscles in his legs to support his own weight again, and finally, after 19 weeks, he was able to control his own movement and weight on a 3.5-meter course on the ground. While this alone is a breakthrough in the field of reestablishing function and control in handicapped persons, there is still a ways to go in perfecting this technology and making it accessible to all those who could benefit from it. The various machines that helped this man walk are quite unwieldy, and ideally should be minimized into implanted brain and muscle chips for maximum convenience. Furthermore, researchers are working on improving the precision of the computer system that recognized the will to move, as it currently still confuses walking intent with balancing intent, something our brains and nerves manage simultaneously. The potential is definitely there though to reintroduce the world of walking—and maybe even someday the world of walking without having to concentrate on it—to paraplegic patients. Works Cited
[1] http://www.theguardian.com/science/2015/sep/24/paraplegic-man-walks-with-own-legs-again By Hannah Gerdes Writer The article “HIV/AIDS epidemiology, pathogenesis, prevention, and treatment” (Simon et. al) sheds light on how HIV-1 injects the viral core material into the cytoplasm of host cells, propagates itself, and hides in infected people. However, the transmission of HIV-1 isn’t just a physical issue. In the novel Sizwe’s Test, journalist Jonny Steinberg follows a shop-owner from an overcrowded, black rural slum on the Eastern Cape of South Africa, called Sizwe, in order to get a better understanding of his thoughts and attitudes towards the virus. Firstly, as Steinberg learns about the establishment of the first local HIV-clinic, he realizes that people would be hesitant to go to such a clinic, for fear of being under the eye of watchful neighbors who could use their HIV-positive status against them. Sizwe also demonstrates that people might not want to get treated at a biomedical clinic. While medical doctors offer antiretrovirals, which can only be administered after someone has the disease, and which don’t ever completely rid the patient of HIV/AIDS, many traditional healers promise a complete cure. As Sizwe confidently asserts, “A cure is better.” Without going to clinics, there are obvious individual harms: people may not learn about their own status, and won’t receive treatment, leading to death. The pathology of HIV/AIDS and certain social factors can work together to promote the transmission of the disease, and worsen the negative biological, psychological, and social experiences associated with the disease.
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AuthorsThe authors of these blog posts are staff writers of The Triple Helix at Georgetown University. Archives
November 2016
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