Katie Atalla's List: Stem Cell Research

• creates a new life without a father, and reduces a mother to the provider of an almost emptied egg.

• hope that one day therapeutic cloning can be used to generate   tissues and organs for transplants.

• In theory, the cloned organ could then   be transplanted into the patient without the risk of tissue rejection.   If organs could be generated from cloned human embryos, the need for organ   donation could be significantly reduced.  
• Many challenges must be overcome before "cloned organ" transplants   become reality. More effective technologies for creating human embryos,   harvesting stem cells, and producing organs from stem cells would have   to be developed.
• The team of researchers created a cloned cow embryo   by removing the DNA from an egg cell and then injecting the DNA from the   skin cell of the donor cow's ear.
• Since little is known about manipulating   embryonic stem cells from cows, the scientists let the cloned embryos   develop into fetuses. The scientists then harvested fetal tissue from   the clones and transplanted it into the donor cow
• More than 90% of cloning attempts fail to produce viable offspring
• More than 100 nuclear transfer procedures could be required to produce one viable clone
• Due to the inefficiency of animal cloning (only about 1 or 2 viable offspring   for every 100 experiments) and the lack of understanding about reproductive   cloning,
• Not only do most attempts to   clone mammals fail, about 30% of clones born alive are affected with "large-offspring syndrome" and other debilitating conditions. Several cloned   animals have died prematurely from infections and other complications.
• scientists   do not know how cloning could impact mental development.

8 more annotations...

• Cloning is the process of creating a new organism by copying genetic information from a single “parent” organism.
• it took 277
• only about 50 percent of the implanted animal embryos resulted in pregnancies, he said, and only one or two out of every 10 embryos were successfully carried to term.
• The published research indicates that 25 to 30 percent of the animals that came to term suffered abnormalities, Lanza said.

• Lanza said cloned offspring have evidenced dozens of health problems, including obesity, seizures, tumors, severe cardiovascular problems, thymus problems and joint problems.

  Many of the problems are not apparent at birth, and there’s not enough of a track record to determine the full array of maladies that could arise during a clone’s life.

  Scientists suspect that the problems are linked to abnormalities in gene expression that arise during the cloning process. Some researchers have reported that the cells of cloned animals appear to have shorter telomeres — snippets of DNA at the ends of chromosomes that have been linked to the cellular aging process. They suggest that the telomeres may play a key role in the cloned animals’ health problems, but other researchers aren’t so sure.
• Clonaid says Eve’s mother is a 31-year-old American woman who went through the cloning process because her husband is infertile. The organization says other clients are trying to have babies who will genetically match children they have lost. The Raelians, meanwhile, believe that humans could achieve a kind of immortality by cloning themselves, then somehow transferring their consciousness from one generation to the next.

4 more annotations...

• In most cases, isolated genes or cells are duplicated for scientific study, and no new animal results.
• duplicates of biological material.
• somatic cell nuclear transfer

  • Adult cell nuclear transfer????
• cloning of Dolly the sheep in 1997
• lthough delayed in time
• two potential applications: 1) for reproductive purposes, i.e., to produce a child, or 2) for producing a source of ES cells for research.
• Unlike sexual reproduction, during which a new organism is formed when the genetic material of the egg and sperm fuse, in nuclear transplantation cloning there is a single genetic "parent." This technique also differs from previous cloning techniques because it does not involve an existing embryo. Dolly is different because she is not genetically unique; when born she was genetically identical to an existing six-year-old ewe.
• n fact, the procedure has not been perfected and it is not yet clear whether Dolly will remain healthy or whether she is already experiencing subtle problems that might lead to serious diseases. Thus, the prospect of applying this technique in humans is troubling for scientific and safety reasons in addition to a variety of ethical reasons related to our ideas about the natural ordering of family and successive generations.
• ypically, very few cloning attempts are successful.

• Many cloned animals die in utero, even at late stages or soon after birth, and those that survive frequently exhibit severe birth defects. In addition, female animals carrying cloned fetuses may face serious risks, including death from cloning-related complications.

   

• An additional concern focuses on whether cellular aging will affect the ability of somatic cell nuclei to program normal development. As somatic cells divide they progressively age, and there is normally a defined number of cell divisions that can occur before senescence. Thus, the health effects for the resulting liveborn, having been created with an "aged" nucleus, are unknown. Recently it was reported that Dolly has arthritis, although it is not yet clear whether the five-and-a-half-year-old sheep is suffering from the condition as a result of the cloning process. And, scientists in Tokyo have shown that cloned mice die significantly earlier than those that are naturally conceived, raising an additional concern that the mutations that accumulate in somatic cells might affect nuclear transfer efficiency and lead to cancer and other diseases in offspring. Researchers working with clones of a Holstein cow say genetic programming errors may explain why so many cloned animals die, either as fetuses or newborns.

   

9 more annotations...

• they are capable of dividing and renewing themselves for long periods; they are unspecialized; and they can give rise to specialized cell types.
• While differentiating, the cell usually goes through several stages, becoming more specialized at each step.

• Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth.

  • good intro..
• In addition, in many tissues they serve as a sort of internal repair system, dividing essentially without limit to replenish other cells as long as the person or animal is still alive.
• First, they are unspecialized cells capable of renewing themselves through cell division, sometimes after long periods of inactivity. Second, under certain physiologic or experimental conditions, they can be induced to become tissue- or organ-specific cells with special functions. In some organs, such as the gut and bone marrow, stem cells regularly divide to repair and replace worn out or damaged tissues. In other organs, however, such as the pancreas and the heart, stem cells only divide under special conditions.

  • Differ cuz of said characteristics ^^
• embryonic stem cells and non-embryonic "somatic" or "adult" stem cells. The functions and characteristics of these cells will be explained in this document.
• embryonic stem cells from early mouse embryos nearly 30 years ago, in 1981.
• In 2006, 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.
• Given their unique regenerative abilities, stem cells offer new potentials for treating diseases such as diabetes, and heart disease.

5 more annotations...