Embryonic Stem Cells

Question 1

What are six types of stem cells?

Answer 1

1. Embryonic stem cells
2. Fetal stem cells (embryonic germ cells)
3. Embryo carcinoma cells
4. Umbilical cord stem cells
5. Placenta derived stem cells
6. Adult stem cells

Question 2

How are embryonic stem cells harvested?

Answer 2

From inner cell mass of blastocyst seven to ten days after fertilization.

Question 3

How are fetal stem cells harvested?

Answer 3

From germline tissues that would make up the gonads of aborted fetuses.

Question 4

From what are embryo carcinoma stem cells derived?

Answer 4

Derived from tetarocarcinomas.

Question 5

Between embryonic stem cells and embryo carcinoma cells, which have more restricted developmental potential?

Answer 5

Embryo carcinoma cells.

Question 6

Umbilical cord stem cells have cells similar to those found in what anatomical structure?

Answer 6

Bone marrow.

Question 7

How many more stem cells from the placenta can be harvested than from cord blood?

Answer 7

~ ten times as much.

Question 8

Totipotent cells can be harvested by embryos how old?

Answer 8

1-3 days.

Question 9

Pluripotent cells can be harvested by embryos how old?

Answer 9

5-14 days.

Question 10

Multipotent cells can be harvested from what three things?

Answer 10

1. Fetal tissue
2. Cord blood
3. Adult stem cells

Question 11

How many cell types in the human body can pluripotent cells develop into?

Answer 11

Over 200.

Question 12

When was the first historical usage of stem cells and how were they used?

Answer 12

1968 first bone marrow transplant treated severe combined immunodeficiency.

Question 13

Bone marrow stem cells have been used primarily to treat what two things?

Answer 13

1. Immunodeficiencies

2. Leukemias

Question 14

Explain who, when, and how the first human embryonic stem cell lines were developed.

Answer 14

1. 1998
2. James Thomas
3. Isolated cells from inner cell mass.

Question 15

Explain who, when, and how the first human embryonic germ cells were derived.

Answer 15

1. 1998
2. John Gearhart
3. Derived from from fetal gonadal tissue.

Question 16

In 1998, what kind of stem cell “line” was developed from both experiments?

Answer 16

Pluripotent.

Question 17

What are three less-controversial strategies for stem cell research?

Answer 17

1. Use adult stem cells.
2. Use parthenogenetic cells.
3. Use cord blood stem cells.

Question 18

What are two cons to using parthenogenetic stem cells for research?

Answer 18

1. They probably don’t colonize all lineages.

2. Imprinting problems.

Question 19

What are five laws Canada has in place to govern the derivation and use of stem cells?

Answer 19

1. No combining human and non-human stem cells.
2. Embryos used must be less than 14 days post-fertilization.
3. Donors must give free and informed consent.
4. No commercial transaction or financial incentives.
5. Imported stem cells must have conformed with CIHR guidelines.

Question 20

What did the Bush administration put into effect in 2001 regarding stem cell research?

Answer 20

Only research on embryonic stem cell lines approved by them could be performed using federal funding.

Question 21

What order did the Obama administration issue in 2009 regarding stem cell research and why?

Answer 21

“Removing Barrier to Responsible Scientific Research Involving Human Stem Cells” to change how the NIH support stem cell research.

Question 22

How many embryonic stem cell lineages have been used worldwide and how many in the NIH registry?

Answer 22

~300 and 240, respectively.

Question 23

What are three important “unknowns” regarding human stem cell and cloning research?

Answer 23

1. Not sure of the totipotency of human embryonic stem cells cultured in vitro.
2. Unknown if in vitro stem cells will perform properly when injected into the human body (one experiment with insulin-producing cells wound up making tumors when injected into mice).
3. Unknown if embryonic stem cells will continue to proliferate for the lifetime of the organism or if they will eventually fail/malfunction/stop/etc.

Question 24

When was the first cloned human embryo, who did it, and to what stage did it survive?

Answer 24

1. 2001
2. Advanced Cell Technology
3. 6-cell stage

Question 25

What are three steps to deriving an embryonic stem cell line in a lab?

Answer 25

1. Isolate inner cell mass.
2. Culture cells on monolayer of irradiated mouse fibroblast cells (called the feeder layer) to prevent differentiation.
3. Coax different cell lines to form different kinds of cells.

Question 26

In the first report of embryonic stem cell lines derived from human blastocysts, were fresh, frozen, or both embryos donated/used?

Answer 26

Both.

Question 27

In the first report of embryonic stem cell lines derived from human blastocysts, how many cell lines were produced (that meet Thomson’s criteria for human embryonic cell lines)?

Answer 27

Five.

Question 28

How long are human embryos cultured in order to isolate the inner cell mass for stem cell research and why?

Answer 28

Until day 6-7 to allow hatching.

Question 29

If human embryos for stem cell research don’t hatch by day 7, what do researchers do?

Answer 29

Treat it with acid Tyrode’s or prunes to remove the zona pellucida.

Question 30

After the embryo hatches for stem cell research, what do the lab technicians expose it to and why?

Answer 30

A trophoblast antibody followed by a complement in order to obtain just the inner cell mass (this process is called immunosurgery).

Question 31

What are three alternatives now available to using mouse fibroblast layer in stem cell growing?

Answer 31

1. Human bone marrow
2. Endometrium cells
3. Forgoing the feeder layer entirely.

Question 32

What are three culture condition differences between human embryonic stem cell research and mouse embryonic stem cell research?

Answer 32

1. Human cells are LIG independent.
2. Humans are more delicate (trauma triggers differentiation).
3. Human cells must be sub-cultured as a layer of cells.