For anyone interested in Stem cell research........ (reject, blood, diseases)

[michel]

Research on stem cells is advancing knowledge about how a complex organism develops from a single cell as well as how healthy cells replace damaged cells in an adult organism. It is an incredibly promising area of research, leading scientists to investigate the possibility of stem cell-based therapies to treat disease, commonly referred to as regenerative or “reversive" medicine.

The two main characteristics that distinguish stem cells from other types of cells are their lack of specialization, allowing them to renew themselves for long periods of time through cell division; further, under certain physical conditions, they can be induced to become specialized cells, like the insulin-producing cells of the pancreas, for example. Scientists primarily work with two types of stem cells: embryonic stem cells and adult stem cells. Embryos used in the stem cell research were created using in-vitro fertilization at fertility clinics and donated for research, with the informed consent of the donor, once they were no longer needed.

Stem cells are vital to a human organism for their formative and regenerative functions. In five-day old embryos, stem cells in developing tissues give rise to multiple specialized cell types that make up the heart, lungs, skin, and other tissues. In some adult tissues, such as bone marrow, muscle, and brain, populations of adult stem cells generate replacements for cells that are lost through normal wear and tear, injury, or disease. It is due to these properties that many in the medical and scientific communities believe that stem cell-based therapies would become the mainstream method of treating degenerative – and, in many cases, previously incurable – diseases such as Parkinson's disease, cancer, heart disease, diabetes, and many others.

Despite the potential of stem cells, there are numerous technical difficulties that must be overcome before the technology is realized into applicable medical therapies. These difficulties can be overcome only through continuous, intensive research. It is vital, for example, to determine at which point and under what conditions the undifferentiated and unspecialized embryonic stem cells become differentiated and specialized. Scientists have determined that turning genes on and off is central to this process, but no exact understanding exists concerning the types of signals that turn specific genes on and off to stimulate specific cell differentiation. 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 promises to yield information about what gives rise to such diseases and suggest new strategies for therapy.

Human stem cells also can be used to test new drugs. For example, new medications can be tested for safety on differentiated cells generated from human pluripotent cell lines. Other kinds of cell lines are already being used in this way. Cancer cell lines, for example, are used to screen potential anti-tumor drugs. 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. For this, scientists must be able to exercise precise control over the cell differentiation process to make sure identical cell types are created on which to test various drugs. Current knowledge of the signals controlling differentiation falls far short of being able to mimic these conditions precisely.

Perhaps the most important potential application of human stem cells is the generation of cells and tissues that can be used for cell-based therapies. Today, donated organs and tissues are often used to replace ailing or destroyed tissues, but demand for such transplantable material by far outnumbers the available supply. Stem cells, directed to differentiate into specialized cell types, offer the possibility of a renewable source of replacement cells and tissues to treat, among others, Parkinson's and Alzheimer's diseases, strokes, burns, spinal cord injuries, heart disease, diabetes, and various types of arthritis. Animal testing conducted to date already indicates the ability of stem cells to generate new blood vessels and vascular tissues to repopulate damaged heart muscles, so the potential of stem cell-based therapies is tangible.

To realize the full promise of cell-based therapies, scientists must be able to manipulate stem cells to a high degree of ease, effectiveness, and precision to ensure that that the cells possess the necessary characteristics for potential differentiation, transplantation, and engraftment. To be useful for transplant purposes, stem cells must be reproducibly made to:

• proliferate extensively and generate sufficient quantities of tissue;

• differentiate into the desired cell types;

• survive in the recipient after transplant;

• integrate into the surrounding tissue after transplant;

• function appropriately for the duration of the recipient's life;

• avoid harming the recipient in any way.



Also, to avoid the problem of immune rejection, scientists are experimenting with different research strategies to generate tissues that will not be rejected.

For more information on the available research from our wholly owned subsidiary Novo Life Scientific please visit the website of the Institute of Molecular Biology .

From:- http://www.newlifesci.com/pages/home.aspx