need lots lots of information on emboryanic stem cell?

Question

what is emboryanic stem \cell
what does is the difference between emboryanic and adult cells
what does pluripotent mean
what does totipotent mean
according to scientist which type of stem cell is more useful
where is stem cells found
what is embryo
what is blastocys
what are icm cell?
what happens to the embryo once the stem cells are removed
what are some possible potential uses for stem cless
why are some people opposed to stem cell research
where would stem cells for research come from
what is intro fertillization
what happens to the left over embryos after couple has succesfully had children
what are other sources of stemm cell
are they as useful as embryonic stem cells
what ethical question did president bush have to consider before making his desicion
what is the position of the Senator Hatch on stem cell research
according to pres bush, how many stem cell lines exist?

Answer 1

http://en.wikipedia.org/wiki/Stem_cell
http://en.wikipedia.org/wiki/Stem_cell_controversy
http://en.wikipedia.org/wiki/Inner_cell_mass
go to these web sites you can find answers to all your questions

Answer 2

hey, this is a good site:
http://stemcells.nih.gov/info/basics/defaultpage.asp

Answer 3

What are embryonic stem cells?
Embryonic stem cells, as their name suggests, are derived from embryos. Specifically, embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro—in an in vitro fertilization clinic—and then donated for research purposes with informed consent of the donors. They are not derived from eggs fertilized in a woman's body. The embryos from which human embryonic stem cells are derived are typically four or five days old and are a hollow microscopic ball of cells called the blastocyst. The blastocyst includes three structures: the trophoblast, which is the layer of cells that surrounds the blastocyst; the blastocoel, which is the hollow cavity inside the blastocyst; and the inner cell mass, which is a group of approximately 30 cells at one end of the blastocoel.


Differences between embryonic cells and adult cells
There are two basic types of stem cells, embryonic or pluripotent stem cells, and adult or multipotent stem cells. Unlike embryonic stem cells, which are found in discarded human embryos, adult stem cells are derived from bone marrow, fat, or brain tissue. Embryonic cells can differentiate into any other type of cell, but can sometimes grow uncontrollably and cause unwanted results. Adult cells, however, can also differentiate into other types of cells, yet do not grow uncontrollably, and are already programmed to create cells that serve a specific purpose. Recent research has led many to believe that using adult stem cells instead of embryonic cells could increase the length of a person’s life after a heart attack, reconstruct damaged joints, or even find a cure for Parkinson’s and Lou Gehrig’s disease (Hall 42).

What is pluripotent?
Pluripotent—Ability of a single stem cell to give rise to all of the various cell types that make up the body. Pluripotent cells cannot make so-called "extra-embryonic" tissues such as the amnion, chorion, and other components of the placenta.

What is totipotent?
Totipotent—A totipotent stem cell can give rise to all the cell types that make up the body plus all of the cell types that make up the extraembryonic tissues such as the placenta. (See also Pluripotent and Multipotent).


Which type of stem cell is more useful?
The current thinking in the scientific community is that embryonic stem cells may be more useful than adult stem cells in creating treatments and possible cures for diseases such as Parkinson's, Alzheimer's and spinal cord injuries. From a scientific perspective, however, the downside of totipotent embryonic stem cells is that they are more difficult to control and manipulate in the lab than pluripotent stem cells. Some researchers are exploring ways to increase the pluripotency of non-embryonic stem cells. Some studies are beginning to support the theory that adult stem cells are much more pluripotent than originally thought, and are able to turn into many more types of cells and tissues than previously suspected.

Where are stem cells found?
Stem cells are found in the human body in many different tissues including bone marrow, brain, blood, skeletal muscle, fat, and the skin. Stem cells are also found in placenta tissue and umbilical cord blood after birth. Stem cells called embryonic stem cells develop very early in the human embryo days after fertilization. In fact, embryonic stem cells are the basic building blocks of every other tissue in the human body and during development, the embryo directs certain embryonic stem cells to become bone tissue, others to become nerve tissue, etc. until the embryonic stem cells transform into each of the other kinds of cells and tissues which make up the human body.


What is the embryo?
Embryo—In humans, the developing organism from the time of fertilization until the end of the eighth week of gestation, when it is called a fetus.

What is the blastocyst?
The blastocyst is the structure formed in early mammalian embryogenesis, after the formation of the blastocele, but before implantation. It possesses an inner cell mass, or embryoblast, and an outer cell mass, or trophoblast. The blastocyst is usually comprised of 200 cells.

ICM?
Any of the germinal disk cells of the inner cell mass in the blastocyst that form the embryo.

What happens to embryo once stem cells are removed?
They are killed

Potential uses of stem cells
There are many ways in which human stem cells can be used in basic research and in clinical research. However, there are many technical hurdles between the promise of stem cells and the realization of these uses, which will only be overcome by continued intensive stem cell research.

Studies of human embryonic stem cells may yield information about the complex events that occur during human development. A primary goal of this work is to identify how undifferentiated stem cells become differentiated. Scientists know that turning genes on and off is central to this process. Some of the most serious medical conditions, such as cancer and birth defects, are due to abnormal cell division and differentiation. A better understanding of the genetic and molecular controls of these processes may yield information about how such diseases arise and suggest new strategies for therapy. A significant hurdle to this use and most uses of stem cells is that scientists do not yet fully understand the signals that turn specific genes on and off to influence the differentiation of the stem cell.

Human stem cells could also be used to test new drugs. For example, new medications could be tested for safety on differentiated cells generated from human pluripotent cell lines. Other kinds of cell lines are already used in this way. Cancer cell lines, for example, are used to screen potential anti-tumor drugs. But, the availability of pluripotent stem cells would allow drug testing in a wider range of cell types. However, to screen drugs effectively, the conditions must be identical when comparing different drugs. Therefore, scientists will have to be able to precisely control the differentiation of stem cells into the specific cell type on which drugs will be tested. Current knowledge of the signals controlling differentiation fall well short of being able to mimic these conditions precisely to consistently have identical differentiated cells for each drug being tested.

Perhaps the most important potential application of human stem cells is the generation of cells and tissues that could be used for cell-based therapies. Today, donated organs and tissues are often used to replace ailing or destroyed tissue, but the need for transplantable tissues and organs far outweighs the available supply. Stem cells, directed to differentiate into specific cell types, offer the possibility of a renewable source of replacement cells and tissues to treat diseases including Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis.

Why are some people opposed to stem cell research?
Research is opposed by many pro-lifers, mainly Roman Catholics and conservative Protestants. They feel that the embryos from which the stem cells are often extracted are human persons. Many believe that the embryos have a soul. Since the embryos are killed when the stem cells are removed, pro-lifers view the extraction procedure as murder and a type of Nazi-like medical experimentation on human beings. They generally have no objection to adult stem cells that are extracted from an umbilical cord, a child's body or an adult's body, if the appropriate consent is obtained.

There are two main problems associated with embryonic stem cells. Both remain very hot political matters:

The first involves harvesting of stem cells from surplus embryos prepared for in-vitro fertilization procedures in fertility clinics. A few hundred thousand of these are stored in clinics. The debate centers in whether they can ethically be killed in order to harvest their stem cells.
A second ethical problem is whether stem cells lines which had already been created in the past from embryos, should be used in research today. Here, the embryos have already been killed. The only real matter to decide is whether federal funding should continue so that the resultant stem cells, which are already growing in laboratories, can be used.


Where does stem cells for research come from?
Stem cells can also be obtained from sources like the umbilical cord of a newborn baby. This is an accessible source of stem cells, compared to adult tissues like the brain and bone marrow. Although scientists can grow these cells in culture dishes, they can do so only for a limited time. Recently, scientists have discovered the existence of stem cells in baby teeth and in amniotic fluid-the "water bath" that surrounds an unborn baby- and these cells may also have the potential to form multiple cell types. Research to characterize and study these cells is very promising but at a very early stage.


Invitro fertilization?
To gain a better understanding of the procedure, though, you may want to read our more detailed descriptions of each stage of the IVF procedure, including retrieval, embryo culture, and transfering of the embryo. Our Timetable & Embryo Grading guide will help you understand just how your embryo develops before it is transfered back to you. Embryo Development will give you a detailed look at how a fertilized egg divides before being trasnfered.

It is important to note that there are two types of transfers that can occur in an IVF procedure: the standard 3-day transfer or a blastocyst transfer. Both types of transfer have advantages and disadvantages, as outlined in 3 Day Transfer vs. Blastocyst Transfers.
While your embryos are still in the lab, there are a number of techniques that IVF specialists can perform to improve the health your embryos. One such technique is assisted hatching, which may improve your embryos ability to implant in your uterus. Some couples also ask that their embryos receive a preimplantation genetic diagnosis before being transfered. This diagnositic test allows specialists to transfer only those embryos which are healthiest.
Since many eggs are retrieved and fertilized during IVF, you may be wondering what happen to those embryos that are not transfered back to you. A common procedure for numerous couples is to have the extra embryos cryo-preserved so that they can be used in future IVF cycles if necessary. This is known as frozen embryo transfer.
For couples who aren't sure that IVF is the right form of ART for them, there are alternatives. Some other types of ART include GIFT, ZIFT, and TET.

What happens to left over embryos?
Embryo adoption is a phrase that often causes quizzical looks from those who have never heard of it. Embryos are often talked about in terms of their value in medical research, but more and more couples are discovering embryo adoption --not only to save embryos from destruction, but also to help build the families they have always dreamed about.


Other sources of stem cells
-Fat has been identified as one of the richest sources – 150 ccs of fat is supposed to contain 4 million cells
-Olfactory Ensheathing Cells (OEC)
-Amnion
-Cord lining and Wharton’s Jelly
-In addition almost every organ in the body has a small quantity of stem cells.

Bush's position on stem cell research:
"As a result of private research, more than 60 genetically diverse stem cell lines already exist. They were created from embryos that have already been destroyed, and they have the ability to regenerate themselves indefinitely, creating ongoing opportunities for research. I have concluded that we should allow federal funds to be used for research on these existing stem cell lines, where the life and death decision has already been made. I also believe that great scientific progress can be made through aggressive federal funding of research on umbilical cord placenta, adult and animal stem cells which do not involve the same moral dilemma. This year, your government will spend $250 million on this important research."

Senator Hatch's position
Statement of Senator Orrin G. Hatch
“The Human Cloning Ban and Stem Cell Research Protection Act of 2005”


I’m very pleased to be here today with this distinguished, bipartisan group of Senators. I want to thank Senators Feinstein, Specter, Kennedy and Harkin for their support of this important legislation.

We’re here today to announce the reintroduction of a bill, The Human Cloning Ban and Stem Cell Research Protection Act of 2005, that, simply put, could help usher in the next great era of medical treatment. At the same time, it will criminalize the offensive practice of reproductive cloning.

If you think back and remember when Jonas Salk discovered the polio vaccine – and I realize I’m probably one of the few here old enough to remember that – but remember what a revolutionary step that was, to be able to stop ravaging diseases before they hit their victims. It led to a whole new way of practicing medicine and paved the way for the vaccines and treatments that we take for granted today.

I believe we are on the verge of a similar step, a new generation in medical research and treatment, thanks to the incredible potential of stem cells. Stem cell research – particularly, embryonic stem cell research – holds great promise. To quote Nobel Laureate Dr. Harold Varmus, “The development of cell lines that may produce almost every tissue of the human body is an unprecedented scientific breakthrough. It is not too unrealistic to say that this research has the potential to revolutionize the practice of medicine and improve the quality and length of life.”

As Dr. Varmus noted, embryonic stem cells appear to have the amazing potential to transform themselves into any of the more than 200 types of cells that form the human body. These cells could be the key to understanding much about human health and disease and may yield new diagnostic tests, treatments, and cures for diseases such as diabetes, cancer, heart disease, Parkinson’s, autoimmune diseases, and many, many others.

Stem cell research could potentially be the scientific advance that takes the practice of medicine not just to the next level, but to five or ten levels above and beyond. I won’t go into all the details of the science or the bill today, but we have a fact sheet available that explains just what this bill will promote, and ensure that America remains the world leader in.

Senator Feinstein will go into some detail about the urgent need for uniformity in the rules governing stem cell research in America. But let me just stress one aspect of that need: ethics. Without the National Institutes of Health setting the ethical guidelines for stem cell research, we invite a host of problems. Most of us feel strongly that human reproductive cloning is wrong, for example. But where should the lines be drawn with regard to embryonic stem cell research – particularly, somatic cell nuclear transfer and the use of cell lines derived from IVF embryos?

The NIH is the obvious and crucial choice to help set the ethical boundaries. Our bill will ban outright any attempt at bringing to life a cloned human being. It will also prohibit research on any embryo created through somatic cell nuclear transfer beyond 14 days, require informed consent of donors, prohibit profiteering from donated eggs, and mandate separation of the egg collection site from the research laboratory.

The NIH will help determine other suitable ethical guidelines in allowing this critical research to go forward with federal funding and at federally-funded institutions. There is no question in my mind that, when they do, the rest of the world will follow.

Now, the last time we introduced this bill, there was interest in the fact that I, as a strongly pro-life senator, would be the lead sponsor. I think we have put that issue behind us, as more pro-life lawmakers have expressed their support for this research. The fact is, I have never believed that life begins in a Petri dish. And as I travel across my home state of Utah, more and more Utahns, whether they are pro-life or not, come up to me and say, “Orrin, we’re with you on this. You’re doing the right thing.”

That support is building across the country, and we must act. If we do not seize this opportunity, other countries could take the leading role in medicine’s next great advance. We will lose the chance to set ethical guidelines, we will lose doctors to overseas research institutions, and most importantly, we will lose the chance to offer new hope to American and other patients who are waiting in desperation for treatments and cures.

I appreciate the tremendous support for this bill among my colleagues in the Senate, and I look forward to the work ahead. Thank you.