BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: medicalresearch

Is There a Limit to How Old Humans Will Get?

In the 1900s, the life expectancy for humans in the United States was approximately 50 years. Since then, the age to which humans can live has only grown. In 1997, a woman by the name of Jeanne Calment died at the age of 122- an astounding increase from the life expectancy less than a hundred years ago. A new study written about in the New York Times explains that Dr. Vijg, an expert on aging at the Albert Einstein College of Medicine, feels that we have now reached our “ceiling. From now on, this is it: Humans will never get older than 115.” Dr. Vijg and his graduate students published their pessimistic study in the journal Nature, presenting the evidence for their claim.

For their study, Dr. Vijg and his colleagues looked at how many people of varying ages were alive in a given year. Then they compared the figures from year to year, in order to calculate how fast the population grew at each age. For a while, it looked as though the fastest-growing group was constantly becoming older; “By the 1990s, the fastest growing group of Frenchwomen was the 102-year-olds. If that trend had continued, the fastest-growing group today might well be the 110-year-olds.” (NY Times Article). Instead, the increases slowed and eventually stopped, leading Dr. Vijg and his colleagues to conclude that humans have finally hit an upper limit to their longevity. Further research into the International Database of Longevity seemed to validate their findings; No one, except in rare cases like Ms. Calment, had lived beyond the age of 115. It appears as though human beings have hit the ceiling of longevity.

There was a varied mix of responses to the study. Some, like Leonard P. Guarente, a biology professor at MIT, praised it, saying “it confirms an intuition he has developed over decades of research on aging.” Others, like James W. Vaupel, the director of the Max-Planck Odense Center on the Biodemography of Aging, called the new study a travesty and said, “It is disheartening how many times the same mistake can be made in science and published in respectable journals.”

This study is by no means conclusive. It is simply one more piece of research in the ongoing debate over whether human beings will continue to live longer, and will continue to be debated by many experts in the field.

However, one must wonder whether living longer should be the goal. After all, as Dr. Vijg pointed out, “aging is the accumulation of damage to DNA and other molecules. Our bodies can slow the process by repairing some of this damage. But in the end, it’s too much to fix. At some point, everything goes wrong, and you collapse.” While morbid, he makes a valid observation: Humans can only go so long until necessary bodily functions begin to break down. Rather than worrying about whether we will live to an extraordinary age such as Ms. Calment, I concur with Dr. Vijg; the focus should be on living the most amount of healthy years and taking care of our bodies. While it may seem like a great idea to live to the age of 125, what good would that do if you aren’t able to continue with the activities you enjoy because your body is breaking down?

 

Other Relevant Articles:

In Depth Explanation of Longevity: https://en.wikipedia.org/wiki/Longevity

A brief summary of Dr. Vijg’s findings (a bit shorter than the NY Times article): http://www.newser.com/story/232121/human-lifespan-has-likely-maxed-out.html

An interesting article about an entrepreneur’s quest to make people live even longer: https://www.theguardian.com/science/2015/jan/11/-sp-live-forever-extend-life-calico-google-longevity

 

Could There be Good Gene Mutations?

Is there an epic battle occurring within our bodies right now? The classic battle royale between good and bad? I suppose in the body’s case the fight between good and bad genes.  There is a new field in medical research in which researchers are on the quest to find good gene mutations that fight against the disease causing mutations.  One individual, Doug Whitney, sparked the interest of a few doctors because he has fought his genetic odds to be health at 65 years old.  Whitney has a gene mutation, presenilin, that causes early onset Alzheimer’s disease in those who has inherited it. Whitney’s mother and 9 out of his 13 siblings were killed by this mutation and so Whitney’s fate seemed to be sealed.  However when Whitney reached his 40s and 50s having no symptoms he assumed he did not have the gene.  At 62 years old, Whitney, decided he would get a gene test.  He did have the gene.  This was an anomaly, He was doomed to have early onset Alzheimer’s Disease but had absolutely no symptoms. Although Whitney still have changes of getting Alzhiemers but the effects of his bad gene have been greatly delayed by another gene in Whitney’s DNA.  Whitney joined a study at Washington University in St. Louis led by Doctor Randall Bateman which recruited people with the early onset Alzheimer’s disease gene. This attracted the attention of Doctor Eric E. Schadt and Doctor Stephen H. Friend.  Doctor Schadt said that searching for good genes that protect against bad gene mutations is completely turning genetic research on its head.  Researchers have found gene mutations that partially protect diseases like osteoporosis, Type 2 diabetes, heart disease, and Alzheimer’s.  These good gene mutation’s partial protect have help to develop drugs to help fight certain diseases. Finding good gene mutations are substantially more difficult to find than bad genes, but the search has gotten a little easier with fast and inexpensive methods of sequencing DNA. Doctor Schadt and Doctor Friend decided to start the Resilience Project and search for good gene mutations that counteract bad gene mutations to help develop new break though treatments and drugs. They have contacted the researchers at Washington University, the research that Whitney is currently participating in.

For more information:

Article from NYT

Prokaryotic positive genetic influences

Genetics used for intrusion protection

About genetic testing

 

We All Owe Mice a “thank you”

Recently in our AP Biology class, we read about advances in stem cell research. Important developments began with experiments involving mice. The scientists were able to generate induced pluripotent stem cells from mouse fibroblasts and were later able to generate iPS cells from human fibroblasts . The research as been extremely helpful and scientists were able to learn a lot through the mice cells. It turns out mice are useful for many other avenues of medical research.

Mice have become a critical tool in the quest for new drugs and medical treatments because their genes are remarkably similar to a person’s”. Mice affected with various human ailments, such as “obesity, diabetes, cancer and countless other conditions are being used to study both the illnesses themselves and potential treatments”.

photo from WikimediaCommons

 

 

 

 

 

 

 

 

The latest “mouse sacrifice” for society involves cigarette smoke. We know that cigarette smoke heavily damages the lungs but scientists and doctors have long wondered what it does to the brain. There is an established, but “murky”, relationship between cigarette smoking and Alzheimer’s. A recent study with mice inhaling cigarette smoke significantly strengthened the suggested relationship.

Scientists led by Claudio Soto of the University of Texas Medical School at Houston exposed mice to cigarette smoke for four months. These exposed mice all showed signs of Alzheimer’s. Additionally, mice were bred with Alzheimer’s and then later exposed to cigarette smoke. These mice exhibited significantly worsened Alzheimer’s symptoms.

This sort of research proves extremely beneficial to humans and will most likely continue to become even more popular. Already, there are as many as 25 million mice used for medical research each year.

It seems as though we will have many mice to thank in the future.

 

Main Article:

http://www.sciencenews.org/view/generic/id/348321/description/News_in_Brief_Smoking_damages_mouse_brains

Additional Articles:

http://www.nbcnews.com/id/11700807/#.US1BO81RLzd

http://images.cell.com/images/Edimages/Cell/IEPs/3661.pdf

Picture Link:

http://commons.wikimedia.org/wiki/File:Spiny_Mice.jpg

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