> >> John Wilkins wrote:
> >>> In article <r7EIm.5728$gi1.5...@newsfe19.iad>, Ron Dean
> >>> <rd...@gmail.com> wrote:

> >>>> Dr. Thomas wrote:
> >>>>> Ron Dean wrote:
> >>>>>>> Volvox minor, is made up of
> >>>>>>> cells that are in a cluster which subtly change. Some of
> >>>>>>> the cells on the outside form a kind of shell. These cells
> >>>>>>> divide until they reach about 2000 cells, at which point, the
> >>>>>>> outside cells die and _release_ the original unaltered cells
> >>>>>>> which in turn make a new Volox minor. The cells which
> >>>>>>> made up the shell were called "somatic". These cells
> >>>>>>> were programed to age and die, having been used
> >>>>>>> merely to obtain food and transportation and to
> >>>>>>> facilitate reproduction.
> >>>>>> For Volvox death seems as inevitable as for a mouse or man.
> >>>>>> Once it has offspring the body (somatic cells) are no longer
> >>>>>> needed, and dies: but the immortal germ live on to build to
> >>>>>> build new volvox.
> >>>>>> Weismann, in 18881 delivered a lecture to fellow scientist in
> >>>>>> which he made the astonishing claim that some animal cells
> >>>>>> including human, were could divide only a limited number of
> >>>>>> times, which he called somatic cells. but other cells were
> >>>>>> capable of an infinite number of divisions, which he called
> >>>>>> germ cells. Weizmann was later vindicated, but tragically
> >>>>>> he lived just long enough to see his life's work seemingly
> >>>>>> falsified.

> >>>>>> Nobel prize winner, Alex Carrel placed chicken cells in a
> >>>>>> "liquid cuisine", of nutrients and they began to grow.
> >>>>>> After several months, he reported that the cells showed
> >>>>>> no indication of aging: so Weismann was wrong. His findings
> >>>>>> were later apparently confirmed when cancer cells were taken
> >>>>>> from a woman named Henrietta Lacks was given to a cancer
> >>>>>> researcher, Dr. George Gey. He placed these cells in a an
> >>>>>> artificial environment, which a reporter called a called
> >>>>>> "cancer in a test tube". These cancer cells began an explosive
> >>>>>> growth, dividing far beyond expectations. They are called
> >>>>>> HiLa cells, to protect the identity of the person from whom
> >>>>>> they were taken. Samples of HiLa cells have been sent to
> >>>>>> researchers all over the world and are alive today. Henrieta
> >>>>>> died in 1951.

> >>>>>> One of the great strength of science is that it is self-
> >>>>>> correcting. Lenard Hayflick of the Wistar Institute in
> >>>>>> Philadelphia was trying to get clean human cells for
> >>>>>> the purpose of identifying possible cancer causing
> >>>>>> viruses. But Hayflick was have trouble getting human
> >>>>>> cells to grow in vitro (in glass). He could not match the
> >>>>>> success  Carrel or Gey had in earlier years. His cells
> >>>>>> would divide until they reached about 50 divisions then
> >>>>>> they would stop dividing. He complained about his failure
> >>>>>> and someone jokingly said, "well, Len your cells are just
> >>>>>> growing old". Could it be? How scandalous would that be!
> >>>>>> Hayflick knew that some human cells were clearly immortal-
> >>>>>> HeLa cells were human cells and they were immortal.

> >>>>>> So, in frustration Hayflick requested other scientist
> >>>>>> take samples of his cells and run the experiment. They did
> >>>>>> and had the same results. Hayflick decided on additional
> >>>>>> test, in which he used cells from an old man with the X
> >>>>>> chromosome needed for distinction, and a young woman
> >>>>>> together in the same enviroment during the same testing
> >>>>>> procedure. The old man cells soon ceased dividing, while
> >>>>>> the young female cells continued dividing long afterwards.
> >>>>>> This old man and young woman test was reversed old woman
> >>>>>> mixed with young male cells. The results were the same.
> >>>>>> The old woman cells ceased dividing long before the young
> >>>>>> man cells. So, it was evident that normal human cell did,
> >>>>>> in fact, age. Normal cells, after becoming cancerous somehow
> >>>>>> seems to acquire immortality.

> >>>>>> Hayflick sent a manuscript to the "Journal of Expermental
> >>>>>> Medicine" describing his results.  A Nobel Laureant on the
> >>>>>> staff read the manuscript and said, "The largest fact to
> >>>>>> come out of tissue cultures in the past 50 years is that
> >>>>>> cells are inherently capable of multiplying will do so
> >>>>>> indefinitely if supplied with the right conditions".
> >>>>>> The manuscript was rejected.

> >>>>>> Hayflick eventually re-summited his manuscript to another
> >>>>>> journal and it was published. This paper has since been
> >>>>>> one of the most frequently referenced papers in the history
> >>>>>> of medical research.

> >>>>>> There is a terrible genetic disease visited upon unfortunate
> >>>>>> children called progeria. Children with this mutated DNA
> >>>>>> age at an accelerated rate, seem normal until they are about
> >>>>>> ten. Around 12 they have gray hair, wrinkled skin thinning
> >>>>>> bones and they rarely reach 20 years of age. Skin cells
> >>>>>> from these children also show extremely rapid aging. By
> >>>>>> contrast, the Galapagos tortoises, which can live hundreds
> >>>>>> of years, has cells that can divide far beyond the "Hayflick
> >>>>>> limit" of some 50 divisions for human somatic (soma) cells.

> >>>>>> Research has shown that aging is linked to cell division,
> >>>>>> and not to time itself. One of Hayflick lab assistants,
> >>>>>> Woody Wright exchanged the old man's nucleus with a young
> >>>>>> cell and a nuclei of a young cell into an old cell. This
> >>>>>> show that something in the nucleus kept a count down. A
> >>>>>> "clock" in the nucleus kept up with the number of divisions.
> >>>>>> The way this happens, is that at the linear end of chromosomes,
> >>>>>> there is a series of repeats, discovered by and called
> >>>>>> "telomeres" by Hermann Muller. These are  like the ends of
> >>>>>> shoe laces. They serve as the "clock" keeping track of the
> >>>>>> number of repeats.

> >>>>>> Research demonstrated that each time a cell divided, the
> >>>>>> daughter cell inherits the properties of the parent,
> >>>>>> including the DNA repeats (links)at the chromosome's end
> >>>>>> minus one link.
> >>>>>> Each time a cell divides daughters telomere is one link
> >>>>>> less than the parent cell.

> >>>>>> Next to come, immortal cells and how they differ from
> >>>>>> mortal soma cells.

> >>>>> SO far, so good. I'm anxious for your next installment.

> >>>> Since no one seemed interested I saw no reason to pursue this any
> >>>> further.
> >>> I am interested, but not enough to put you to any trouble,

> >> It is the time and trouble of writing Part III.  However, I had
> >> completed approximately 50% of the next part when I felt it
> >> was a waste of time and effort, since no one appeared interested.
> >> Did you read my two previous post on the subject? If so, any
> >> comments?

> > None, other than I am now much better informed about telomeres and the
> > Hayflick limit than I was before I read them. I am in particular
> > interested to hear what you have to say about HeLa.

> I touched on HeLa cells in part II. Here is what I know about this.

> In 1951 Henrietts Lacks  drove from Virginia to The John Hopkins
> Hospital with unsual bleeding. Here she was diagnosed with cancer.
> Without her knowledge a small section of her cancer was taken and
> given to George and Margaret Gey who had wanted to get a cancer
> growing in a lab. (A cancer in a test tube) In this way, they hoped,
> anticancer therapies and drugs could be tested before they were
> given to people. The 1/2 inch piece was sectioned into smaller pieces
> and placed it in glass bottles with a nutritional culture. Within
> a few days the people in Gey's lab witnessed an explosive growth in
> this artificial environment.

> Over the next months it became evident that Dr. Gey had an immortal
> human cell line consisting of human cancer cells that would continue
> to grow indefinitely. Dr. Gey appeared on national TV with a vial of
> Henrietta's cells which he called HiLa cells to hide their origin. He
> boasted. "It is possible that, from fundamental studies such as these,
> we will be able to learn a way in which cancer can be completely
> wiped out".

> These cells were destined to be sent to research cells around the
> world even into space on board of Discoverer XVII satellite. These
> cells continue to live today, almost 60 years after Henrietta died.

> Normal human somatic cells are not immortal, they will repeat
> only about 50 times, aging during this time, then they will die even
> when provided with with the right nutrients and conditions. But
> Henrietta's cells were truly human somatic cells which became
> immortal once they became cancerous. Eventually, they would play
> a role in the quest to discover what mechanisms are involved in
> immortal cells and how they differed from mortal cells.

> I should emphasize, again that immortal does not mean that immortal
> cells cannot be killed by starvation, heat poison etc. It only means
> they are not Programed to age and die.

> I have no more time, but I will get back to this.

> Thanks

> Ron