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Will we be able to live to 1000? Dr. Humberto Mandirola
6/19/2012 1 6/19/2012
Is Human Immortality a Scientific Reality? Shall we live forever?
Genetic structure
• With recent discoveries in biology,
many scientists predict that life
expectancy will be more than 100 years.
• In fact, if they are correct, humans
shouldn't have to die at all in the future.
• Today's scientists are studying inside
the genetic structure of cells and paying
less attention to the role of stress and
diet on life spans.
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just 25 years
• 1750
it doubled to 50
• 1850
80 years
• 1950
Average life expectancy
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?? Years of life spans
• 2050
How do tissues survive?
When a cell gets older, it is under attack by oxides and free-radicals in the body and environment. We survive
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Usually a small portion of the DNA molecule is lost, misaligned and not copied. Since errors are more frequent on the ends of the DNA molecule, this area, the telomere, does not contain any important DNA information and the effect is insignificant.
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as living beings because our cells have the ability to duplicate and replace themselves before being killed by these natural causes. Each time our cells divide, the DNA molecule makes a new copy of itself.
Why do we age and die?
• The cause of what we call "aging" is now being understood.
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• This new understanding may soon move anti-aging
cosmetics and surgery to the ranks of snake oil and
Siberian yogurt as life-extension fads.
• There are a few obstacles that need to be addressed.
Telometers
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• Determine the lifetime of the cells.
• A telomere is a region of repetitive nucleotide sequences at the end of
a chromosome.
• Protects the end of the chromosome from deterioration or from
fusion with neighboring chromosomes.
• Are involved in such important diseases as cancer.
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Hayflick
• Scientists observe that the length of telomere chains becomes
shorter as we grow older.
• Eventually the telomeres become so short that cell replication
produces lethal errors or missing pieces in the DNA sequence,
ending the cell's ability to replace itself.
• This point, when the cell has lost vital DNA code and cannot
reproduce, is called the Hayflick limit. It's the measure of how
many times a cell can copy itself before it dies.
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Perhaps the best analogy is to compare the telomeres to the white margin surrounding an important type written document. In this analogy, the printed text is the vital DNA code while the white space is the "blank" telomeres. Imagine that this paper is repeatedly slapped on a photocopy machine, a copy is made, and then that copy is used to make another copy. Each time the paper is subject to errors of alignment and these errors accumulate. After enough copying, it is probable that the white space will diminish and some of the actual text will not be copied. That's what happens inside our cells and it is the reason we get old and die.
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The Cancer Problem
You might be wondering why biologists don't simply find a way to keep our body's telomeres long. This would prevent replication errors and humans could live indefinitely. The big problem is cancer.
Usually, if a cell makes an error in copying itself, the error will prevent the cell from duplicating itself in the future. So the mistake is limited. But with cancer, cells with errors somehow "turn on" the production of telomerase and make the mutant cell immortal. Now, aberrant cells can reproduce unchecked and outlive normal cells. This is the process that creates tumors. 6/19/2012
Discovery of telomerase Carol Greider
• Greider joined the laboratory of Elizabeth Blackburn in April, 1984, She
find the enzyme that was hypothesized to add extra DNA bases to the
ends of chromosomes.
• On Christmas Day, 1984, Greider first obtained results indicating that she
had found the responsible enzyme. An additional six months of research
led Greider and Blackburn to the conclusion that they had, indeed,
identified the enzyme responsible for telomere addition.
• She won the Nobel Prize in Physiology or Medicine 2009
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Thanks for watching
11
I'll see you in hundred years Dr. Humberto Mandirola
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References
• http://news.bbc.co.uk/2/hi/uk/4003063.stm
• http://www.nature.com/nm/journal/v12/n10/full/nm1006-1133.html
• http://www.viewzone.com/aging.html
• http://www.laskerfoundation.org/awards/pdf/2006_b_blackburn.pdf
• http://en.wikipedia.org/wiki/Telomere
• http://www.youtube.com/watch?v=AJNoTmWsE0s
• http://www.youtube.com/watch?v=DV3XjqW_xgU&feature=related (Michio Kaku)
• http://www.youtube.com/watch?v=PYQnbUwOwB0&feature=related
• http://www.youtube.com/watch?v=2z63vUN9bTk&feature=related (song)
• http://en.wikipedia.org/wiki/Carol_W._Greider
• http://www.nobelprize.org/nobel_prizes/medicine/laureates/2009/press.html
• http://www.youtube.com/watch?v=m3qqUy880dQ&feature=related
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