
Scientists develop very early stage human stem cell lines - salmonet
https://www.cam.ac.uk/research/news/scientists-develop-very-early-stage-human-stem-cell-lines-for-first-time
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jawns
Kudos to the author for pointing out the distinction between stem cells
derived from the destruction of an embryo and stem cells derived from adult
tissue, and for explaining which type of stem cells this research involves
(embryonic). Too often, even reputable news sites don't properly explain the
difference, or even say which of the two they're talking about.

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jessriedel
Related facts that were new to me:

The cells of the placenta correspond genetically to the fetus, not the mother
(although it meshes with maternal cells, so that the physical organ contains a
layer of maternal cells that intermingle with fetal cells).

[http://www.nsta.org/publications/news/story.aspx?id=53497](http://www.nsta.org/publications/news/story.aspx?id=53497)

The division between placental and non-placental cells is, rather sensibly,
the first step of specialization in the developing fetus.

[https://en.wikipedia.org/wiki/Cell_potency](https://en.wikipedia.org/wiki/Cell_potency)

The chain of increasing specializatio can be broken up like this:

> _Totipotent_ (a.k.a. omnipotent) stem cells can differentiate into embryonic
> and extraembryonic cell types. Such cells can construct a complete, viable
> organism.[4] These cells are produced from the fusion of an egg and sperm
> cell. Cells produced by the first few divisions of the fertilized egg are
> also totipotent.[5]

> _Pluripotent_ stem cells are the descendants of totipotent cells and can
> differentiate into nearly all cells,[4] i.e. cells derived from any of the
> three germ layers.[6]

> _Multipotent_ stem cells can differentiate into a number of cell types, but
> only those of a closely related family of cells.[4]

> _Oligopotent_ stem cells can differentiate into only a few cell types, such
> as lymphoid or myeloid stem cells.[4]

> _Unipotent_ cells can produce only one cell type, their own,[4] but have the
> property of self-renewal, which distinguishes them from non-stem cells (e.g.
> progenitor cells, muscle stem cells).

[https://en.wikipedia.org/wiki/Stem_cell#Potency_definition](https://en.wikipedia.org/wiki/Stem_cell#Potency_definition)

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fourstar
Glad to see more focus on breakthroughs in health care.

We are living in exciting times, but I just wish that more research
authorities would be willing to share clinical trial data with one another or
even work together.

I suspect most of them are unwilling to do so due to the refusal of patent-
sharing (and initial funding costs).

How come there isn't a YC for more health related startups/companies (or is
there and I just haven't heard of it yet)?

