Date: Mon, 06 Jan 2003 01:58:08 -0000

Subject: [StemCells] Pregnancy Hormone Triggers Growth of Brain Cells

Thought this one was interesting...

Pregnancy hormone triggers growth of brain cells
Last Updated Fri, 03 Jan 2003 12:41:05
CALGARY - When mice mate, the smell centres in their brains are
triggered to develop new neurons, Canadian researchers have found.
They hope the finding could lead to a way to repair brain cells
damaged by disease.


INDEPTH: Stem Cells

For a decade, researchers at the University of Calgary have been
working on what was once thought to be impossible: growing new brain
cells. They think they've found a way.

Samuel Weiss 

"We propose a naturally occurring hormone that can be introduced into
the bloodstream and increase brain cell numbers. It may be an
interesting therapeutic molecule," said neurology researcher Prof.
Samuel Weiss of the University of Calgary's faculty of medicine.

In animals, including humans, the hormone prolactin surges after sex,
and during pregnancy and breastfeeding.

When Weiss and his colleagues injected mice with prolactin, they
found cells in the brain's smell centre produced new neurons.

Mammals and insects need their sense of smell to recognize their mate
and offspring. Researchers have found transgenic mice that are
deficient in prolactin receptors tend to ignore their young.

"If prolactin is administered, you initiate the neuro stem cell
proliferation equally well in both sexes in mice," said Weiss's
Calgary colleague, Dr. Jay Cross of the genes and development
research group.

"So it has a much broader potential sort of application, the use of
this hormone, and that's quite exciting."

Stem cells have the ability to turn into any type of cell.

The researchers plan to mimic stroke in mice to test the effects of
prolactin. They hope to see that new neurons can be sent to other
parts of the brain. If it works in mice and eventually in humans, it
may be a way to repair injuries from stroke, or other diseases such
as Parkinson's or Alzheimer's.

"If we can identify the natural stimulators to make brain cells that
are missing, then we may be able to get them to redirect towards
areas that are injured in other diseases, other than stroke," said
Weiss.

An earlier study published last year in the journal Nature found stem
cells in rats redirected neurons toward an injured site. But there
were too few to repair the damage.

The Calgary study appears in Friday's issue of the journal Science.

It was funded by the Canadian Institutes of Health Research, the
Canadian Stroke Network, the Alberta Heritage Foundation for Medical
Research, the Multiple Sclerosis Society of Canada and the Stem Cell
Network of the Network of Centres of Excellence.

Date: Mon, 06 Jan 2003 01:42:17 -0000

Subject: [StemCells] Dolly Creator Denounces Sect's Clone Claims

Note the problems with clones and the extrapolate to the problems
identifying what could be wrong - which is why I always say they
would make poor candidates for any therapy.


Dolly Creator Denounces Sect's Clone Claims

LONDON (Reuters) - Human clones are likely to be unhealthy and such
experiments should be banned, the head of the institute that created
Dolly the sheep said on Saturday, hours after a cult said it had
produced the second cloned baby.

Harry Griffin of the Roslin Institute in Scotland, which made history
by cloning Dolly from an adult sheep in 1996, told Reuters the claims
by Clonaid, a group linked to the UFO-obsessed Raelian religious
sect, were probably bogus.

"Clonaid have made claims of two births, but of yet provided no
evidence that either baby exists, no evidence from DNA tests, and as
yet, therefore, there is no reason to believe this is anything other
than a long, drawn out publicity stunt."

But if cloned babies have been produced, the experiments should be
stopped, Griffin said.

"I think its entirely unacceptable for groups like Clonaid to be
gambling with the health of children," he said.

Griffin said Clonaid's claim of a high success rate in its human
cloning experiment flew in the face of years of research into cloning
in other species.

"There is a lot about this story that doesn't ring true. Success
rates in every other species that have been cloned have been low,
with lots of problems for the fetus and newborn clone," he said.

"Attempts to clone monkeys have been entirely unsuccessful and the
sort of successes claimed by Clonaid are totally at odds with all
past history of cloning other species."

Dolly the sheep is still alive but suffers from severe arthritis.
Griffin said scientists are unsure whether her health problems are a
result of her being a clone, but countless other experiments have
shown that clones are often unhealthy.

"There is a whole raft of serious physiological deformities reported < BR> in clones, and even in entirely healthy animals its not entirely
clear they are normal," he said.

The process of cloning involves taking the genes of an adult -- the
instructions for life that make every organism unique -- and
transferring them into an embryo, turning it into a genetic twin of
the original.

But Griffin said that although the clone has the same genes as the
adult, there can be differences between the way genes behave, which
often means the embryos of clones cannot grow to term, die shortly
after birth or live crippled by disease.

"You've got to persuade the 40,000 genes in that cell to stop
behaving as if they are in a mammary gland cell, or a skin cell or
whatever, and start behaving as if they are in an embryo," he said.

"We don't know how this reprogramming takes place. One, several or
more of the genes can be inappropriately expressed."

Often cloned embryos do not survive to produce a live birth.
Sometimes clones die shortly after birth, and other times they
develop serious health problems later in life, he said.

"All these things have been reported in the clones of cattle, sheep,
pigs, goats, mice, rabbits. And there's no reason to believe that
similar problems will not arise in the cloning of a child," he said.