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A scientific satellite needs only 250 watts of power, the equivelant used by two hour light bulbs, to operate. |
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The immortal remains of Henrietta Lacks
Posted on Thursday, December 22, 2005 (CST) by Thoth
 When human body cells are removed and put into a cell culture, they weaken and die quickly, usually within about 50 divisions. Without the rest of the support structure—a heart, blood circulating, a digestive system and so-on—body cells can't survive.
Body cells also age, so even if you were to simulate the body's environment in a test tube or petri dish, the cells would eventually perish anyway. The basic mortality of the cells reflect the basic mortality of the organism they comprise, which is why there's no fountain of youth or medicinal procedure that'll give you biological immortality.
There is, however, one human being who is biologically immortal on a technicality, and her name is Henrietta Lacks. In 1951 she showed up at John Hopkins Hospital in Baltimore, complaining of blood spotting in her underwear. Samples were taken of her cervical tissue and sent to a lab for analysis, which came back with a diagnosis of cervical cancer.
The cancer
was caused by the Human papillomavirus, which is a sexually transmitted
disease. Most variants of this virus are harmless, but some are known
to cause cervical cancer, as in Henrietta's case. After her diagnosis
and before attempts to treat the disease with radium, another sample
from the tumor was sent to George Gey, who was the head of tissue
culture research at Hopkins. Gey discovered that the cells from
Henrietta's tumor would not only survive and multiply outside of her
body, but they didn't age either. These cells were basically immortal.
And they're still alive,
even though Henrietta herself died of the cancer on October 4th, 1951.
Now, HeLa cells are about as common in biological research as the lab
rat and the petri dish, and are still being grown in an unbroken
lineage from the cells originally harvested from Mrs. Lacks in 1951.
They're used in cancer research because a scientist can perform
experiments on them that otherwise couldn't be done on a living human
being. They were also used in the development of the Polio vaccine,
making Henrietta somewhat of a posthumous hero to millions.
But say you're a scientist
looking at HeLa cells under a microscope. They live independently of
the body they came from. They reproduce (faster even than other
cancerous cells). They consume, excrete, and do everything an
independent living organism usually does. A thousand years from now
there will still be HeLa cells multiplying and living, even some of the
original cells sampled from Mrs. Lacks, even though Henrietta Lacks
herself has long since passed away. Is this a new species?
In 1991 the scientific
community decided it was, and blessed HeLa cells with its own genus and
species: Helacyton gartleri, named by Van Valen & Maiorana.
That would make Helacyton
gartleri an example of speciation, which is when a new species is
observed developing from another. In this case, the development is from
a chordate (homo sapien) to something that's more like an ameoba (a
cross-phylum mutation), giving us an animal with a mostly human
genotype, but which does not develop into a human-like phenotype. Since
this event occurred in nature when the papillomavirus transformed
Henrietta's cells, and not in the laboratory, it's a strong piece of
evidence supporting Evolution (although not one that suggests you could
go from an ameoba to a chordate, which would probably take more than
one mutation).
Article Source
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Re: The immortal remains of Henrietta Lacks
by mensa517 on Friday, December 23, 2005 (CST)
(User Info | Send a Message) http://www.thothweb.com | | :-) This is something commonly taught in you basic biology class...we know that cnacerous cells continue to multiply long after the body is dead...they continue to spread but can be killed off by high doses of radiation...as far as evolution is concerned: would not such a cell have been killed off due to the high levels of radiation in early formation of the planet? In effect this is not a new species...just a diseased cell with the capacity to multiply although I do believe scientists have been looking into the possibility of regenerating parts of the human body by trying to decode the way the cell continues on..... |
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Re: The immortal remains of Henrietta Lacks
by gaias-child on Tuesday, December 27, 2005 (CST)
(User Info | Send a Message) | | I heard of this in my biology classes way back in the 70s. However, HeLa referred to a woman called Helen Lane. |
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