About sun burn, sun caused skin changes, and chronic skin damage

Accute sunburn or sun damage

The sun contains ultraviolet rays. Those reys deliver energy to molecules in the cells of the skin and in the substance between the cells. This impact break chemical bonds and causes new bonds to be formed.

Also llfe-vital molecules in the cells are damaged this way and cells in the skin will die. The dead cells will break and release a lot o substances in the surrounding of the cells.

The released substance causes an accute inflammatory reaction in the skin. Histamine and other tissue hormones are released, causing blood vessels to delate. Other reactions are caused to tidy up the damaged area and to repair the damage. These accute reactions cause redness, iching and other accute symptoms.

If enough cells are destroyed, the layer of the skin will die and must be repaired from beneath. This will cause the outermost layer of the skin to flake off when a new vital layer has been created just under the dead layer.

Sometimes the reaction triggered in the immune system will last longer than neccessary to tidy up the damage. In that case on have a condition called sun eczema.

Chronic sun damage or changes

Not all damaged cells will die. Some cells will live further with a damged genetic structure. These cells will however not function well, and furter changes in the gens can cause cancer.

The substcnces between the cells will also change structures. Elastic proteins in the cells, especially collagen, will bind together to less elastic complexes. These changes will make the skin less elastic and cause wrincles and miscoloration.

To protect iteslf, the skin will produce more color and cells will proliferate to make the skin thicker. These changes are not bad in the first place, and can actually make the skin more beautiul. But if the changes get uneven and too heavy, the skin can get ugly instead.



About stem cells and how they can be used to treat diseases and for rejuvenation

What are stem cells

Stem cells are present in all multi-cellular organisms. Stem cellc can divide and remain stem cells after each mitotic division. When the need is present stem cells can also divide and develop into more mature cells or normal tissue cells specific of the actual organ. Stem cells are broadly divided in embryonic stem cells, that is stem cells present in a fetus and adult stem cells.

Stem cell science developed from findings by the Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s.

In a developing embryo, stem cells differentiate into all of the specialized embryonic tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing specialized cells after serious injury. In some tissues they also perform the normalcell regeneration, such as blood, skin or intestinal tissues.

As stem cells can be grown and transformed into specialized tissue cells cells , use of stem cells in some medical therapies are widely used, and many new treatments using stem cells are proposed and investigated. Types of stem cells of greatest interst are: Embryonic cell lines, autologous embryonic stem cells generated through therapeutic cloning, and highly plastic adult stem cells from the umbilical cord blood or bone marrow.

Types and potency of stem cells

Totipotent stem cells are produced from the fusion of an egg and sperm cell. Cells produced by the first few divisions of the fertilized egg are also totipotent. These cells can differentiate into embryonic and extraembryonic cell types through a series of divisions and transformations. During these transformations steadily more specialized stem cells and mature cells are produced.

Pluripotent stem cells are the descendants of totipotent cells and can differentiate into cells derived from any of the three germ layers. The embryo develope in its first faces a simple anatomy with three cell layers, so called germ layers - the outer layer or ectoderm, the inner layer or entoderm and the middel layer or mesoderm.

The ectodermal cells give rise to the cells in the outer skin layers, the glands in the skin, the epitel in the blood vessels, the nerve cells, and some blood cells.

The mesoderm give rize to the muscle, connective tissue, scheletal tissues and some blood cells.

The cells in the entoderm give rise to the epitel in the inner organs and the inner glandular tissues.

Multipotent stem cells produce only cells of a closely related family of cells (e.g. hematopoietic stem cells differentiate into red blood cells, white blood cells, platelets, etc.).

Unipotent cells produce only one cell type, but have the property of self-renewal which distinguishes them from non-stem cells (e.g. muscle stem cells).

Treatment using stem cells

There are two main methods of treatment by stem cells. On method consist of furnishing new stem cells to tissues. The other method is to stimulate the activation of existing stem cells or newly furnished stem cells to divide and differentiate.

Stem cells are allready used a lot in research and in treatment of certain diseases. For over 30 years, bone marrow and more recently umbilical cord blood stem cells have been used to treat cancer patients with conditions such as leukemia and lymphoma. During chemotherapy, most growing cells are killed by the cytotoxic agents. These agents not only kill the leukemia or neoplastic cells, but also those which release the stem cells from the bone marrow. It is this unfortunate side effect of the chemotherapy that the Stem Cell Transplant attempts to reverse; by introducing new stem cells into the body. Usually the stem cells are introduced into the blood stream and they find their way to the bone masrrow themselves.

In many cases it is possible to take out bone marrow or blood from the patient himself and rinse the healthy stem cells out of the sample. These rinsed stem cells are then reintroduced into the patient's body after the treatment. Stem cells from cord blood taken when the patient was born, can also be used.

It is also possible to use stem cells from a healthy doner that have compatible tissue markers. Stem cells from foreign persons' cord blood is probably better than bone marrow stem cells, sinse fewer markers have to be taken into account.

Recently cord blood is taken from new-born babys and stored for a fee into the future, if the partents of the baby wishes to. Then this cord blood can be used for harvesting stem cells when needed.

New areas where stem cell use are investigated with great promicss are:

- Treatment of diabetes by replacing damaged insuline producing cells from stem cells.

- Replacing damaged nerve and brain cells with new cells in nerve tissues, for example by parkinsons disease, stroke and multiple sclerosis.

- Stem cells use can be a method of curing altzheimer's disease and mechanical brain injury.

- The brain has stem cells that can grow new nerve cells and repair damage. These stem cells can probably be evoked by stimulating chemicals and commanded to divide and mature into new nerve cells. Conventional knowledge was for a long time that the brain had no capcity of replacing damaged nerve cells, but only capacity to repair injured cells that still were allive and to use existing cells for new purposes. By now it is an established fact that the brain can grow new nerve cells, but does so little effectively. But research seem to show that this capasity can be stimulated. It also seems probable that it is possible to grow new nerve cells from new stem-cells introduced into the brain.

- Cure for heart disease where heart tissues have been destroyed by groeing new tissue from stem cells.

Replacing old cells with new from stem cells can eventually become an important tool in totally preventing and curing age changes and to drastically prolong a persons life. This is something experts do not talk very much about, because of the great implications it has for the society as a whole. Genrally experts try to hide how great the potetial of stem cells for this use really is.

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