Tag: stem cells and applications

The technique in which the stem cells are transplanted from donor into the patient for production of the new cells is known as the stem cell therapy. This technique was performed by James E. Till and Ernest A. Mc Culloch. These scientists were performing experiments on the bone marrow of the mice using radiations. They discovered the existence of the stem cells in the bone marrow.

Hematopoietic stem cells are obtained from the bone marrow and used for transplantation. There are different types of transplantations in which the donor from which the stem cells are received differs. In the case of the autologous stem cell transplantation, the stem cells are obtained from the same individual. In an allogeneic system, the stem cells can be obtained from any related or non-related person who is compatible with the patient. In the syngeneic stem cell transplantation, the stem cells are obtained from the identical twin.

Stem cells are the cells which can form different cells which can differentiate and perform different functions. The pluripotent stem cells are the cells which can generate all the cells in the body of an organism. The multipotent stem cells are cells which can form more than one type of cell. The totipotent cells are the cells which can differentiate to form all the type of cells in the body as well as the extraembryonic structures like the placenta. 

The inner cells present in the blastocyst are the embryonic stem cells. When the embryonic culture is performed for obtaining the stem cells, the embryo is cultured till the blastocyst stage. The cells present as the inner cell mass are removed which act as a source of pluripotent stem cells which can differentiate into cells of the complete body.

The cells, tissues, semen and embryo can be preserved for longer periods at lower temperatures using cryopreservation. When the cells are frozen, there is formation of ice crystals in the cells which will rupture the cells. The cryoprotectants like DMSO (dimethylsulphoxide) prevents the formation of these crystals when the cells are stored in liquid nitrogen. 

Stem cells are found in all organisms and are capable of dividing to form new cells which can be differentiated into various types of specialised cells. The progenitor cells have the capability to differentiate into one type of cell. Due to this property, they are also known as unipotent stem cells. The pancreatic progenitor cells can from the cells in the pancreas. 

Many mechanisms are used to obtain the stem cells. The somatic cells or the reproductive cells can be induced to form the stem cells using genetic reprogramming method. Reprogramming can be performed using the factors or proteins which induce the normal body cells to be stimulated to form stem cells. Pluripotent stem cells are generally formed with the help of the induction mechanism. 

Autologous adult stem cells can be harvested from both adipose tissue (fat) and bone marrow. Therefore, both A and C are valid sources.

The amniotic fluid is present in the amniotic cavity in which the embryo develops. The amniotic fluid contains the stem cells. These cells can be checked by karyotyping for the presence of any chromosomal disorder. These stem cells are present till the childbirth because after birth, the structures are expelled out. 

The pericytes are the stem cells which are found in the adult tissues. These cells are generally found in the outer layer of the blood vessels. These cells can be used for transplantation in the individual who suffers from muscular dystrophy. Muscular dystrophy is a genetic disorder which results in weakening and wasting of the muscle tissues. The pericytes are the stem cells which can help in the production of the new muscle tissues.