In other organs, however, such as the pancreas and the heart, stem cells only divide under special conditions. Until recently, scientists primarily worked with two kinds of stem cells from animals and humans: The functions and characteristics of these cells will be explained in this document. Scientists discovered ways to derive embryonic stem cells from early mouse embryos more than 30 years ago, in The detailed study of the biology of mouse stem cells led to the discovery, in , of a method to derive stem cells from human embryos and grow the cells in the laboratory.
These cells are called human embryonic stem cells. The embryos used in these studies were created for reproductive purposes through in vitro fertilization procedures. When they were no longer needed for that purpose, they were donated for research with the informed consent of the donor. In , researchers made another breakthrough by identifying conditions that would allow some specialized adult cells to be "reprogrammed" genetically to assume a stem cell-like state.
This new type of stem cell, called induced pluripotent stem cells iPSCs , will be discussed in a later section of this document. Stem cells are important for living organisms for many reasons. In the 3- to 5-day-old embryo, called a blastocyst , the inner cells give rise to the entire body of the organism, including all of the many specialized cell types and organs such as the heart, lungs, skin, sperm, eggs and other tissues.
In some adult tissues, such as bone marrow, muscle, and brain, discrete populations of adult stem cells generate replacements for cells that are lost through normal wear and tear, injury, or disease. Given their unique regenerative abilities, stem cells offer new potentials for treating diseases such as diabetes, and heart disease. However, much work remains to be done in the laboratory and the clinic to understand how to use these cells for cell-based therapies to treat disease, which is also referred to as regenerative or reparative medicine.
Scientists are already using stem cells in the laboratory to screen new drugs and to develop model systems to study normal growth and identify the causes of birth defects. Research on stem cells continues to advance knowledge about how an organism develops from a single cell and how healthy cells replace damaged cells in adult organisms.
The donation and storage process is similar to blood banking. Donation of umbilical cells is highly encouraged. Compared to adult cells and embryonic cells, the umbilical cord is by far the richest source of stem cells, and cells can be stored up in advance so they are available when needed.
Further, even where there is not an exact DNA match between donor and recipient, scientists have developed methods to increase transferability and reduce risk. Pros and Cons of Stem Cell Research - Embryonic Cells The pros and cons of stem cell research come to the surface when we examine the third source of stem cells - embryonic cells.
Embryonic stem cells are extracted directly from an embryo before the embryo's cells begin to differentiate. At this stage the embryo is referred to as a "blastocyst. A replicating set of stem cells from a single blastocyst is called a "stem cell line" because the genetic material all comes from the same fertilized human egg that started it. President Bush authorized federal funding for research on the 15 stem cell lines available in August Other stem cell lines are also available for research but without the coveted assistance of federal funding.
So what is the controversy all about? Those who value human life from the point of conception, oppose embryonic stem cell research because the extraction of stem cells from this type of an embryo requires its destruction. In other words, it requires that a human life be killed. Some believe this to be the same as murder. Against this, embryonic research advocates argue that the tiny blastocyst has no human features.
Further, new stem cell lines already exist due to the common practice of in vitro fertilization. Research advocates conclude that many fertilized human cells have already been banked, but are not being made available for research.
Advocates of embryonic stem cell research claim new human lives will not be created for the sole purpose of experimentation. Others argue against such research on medical grounds. March 25, , New England Journal of Medicine, p.
God , the Father, sent His only Son to satisfy that judgment for those who believe in Him. Jesus , the creator and eternal Son of God, who lived a sinless life, loves us so much that He died for our sins, taking the punishment that we deserve, was buried , and rose from the dead according to the Bible. If you truly believe and trust this in your heart, receiving Jesus alone as your Savior , declaring, " Jesus is Lord ," you will be saved from judgment and spend eternity with God in heaven.
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Stem cell timeline: The history of a medical sensation. Stem cells are the cellular putty from which all tissues of the body are made. Ever since human embryonic stem cells were first grown in the lab, researchers have dreamed of using them to repair damaged tissue or create new organs, but such medical uses have also attracted controversy.
History of Stem Cell Research QUESTION: What is the history of stem cell research? ANSWER: The history of stem cell research had a benign, embryonic beginning in the mid 's with the discovery that some cells could generate other cells.
History of Stem Cell Research — A TimelineWrights/Giemsa stained human embryonic stem cell (hESC) colony on murine embryonic fibroblast feeder cells. The colony contains roughly individual hESCs. Photo courtesy of M. William Lensch, PhD. The information used to compile this Stem Cell Research Timeline comes from many different sources, including the National Institutes of Health.A useful list of links to other stem cell research timelines from around the Web can be found at the bottom of this page.
From early fetal tissue research to the first successful human treatments, this timeline documents the progress in stem cell science, and the policies that have impeded or promoted it. The stories of research involving human embryonic stem cells and the policy governing that work are intertwined and stretch back into the mids. The history of research on adult stem cells began more than 60 years ago. In the s, researchers discovered that the bone marrow contains at least two kinds of stem cells. Hematopoietic stem cells form all the types of blood cells in the body.