The human body, just like all living things, is made up of billions of components. Each year, more and more discoveries are made concerning the field of biology. Microbiology, the branch of science that deals with the study of microscopic organisms, is a vast subject and has been studied for at least a few centuries.
When it comes to studying living beings, we find that cell is one of the most basic elements that are common in almost all living things on Earth. A cell is defined as the building block of life. It is basically composed of natural elements like carbon, oxygen and hydrogen. The human body itself has trillions of cells. There are several different kinds of cells, each kind serving a unique purpose. Some cells are responsible for transporting various chemicals within our bodies, some are needed to aid in digestion, and some cells are required for reproduction.
You may have heard of a particular type of cell, called the stem cell. The stem cell preservation is one of those medical fields that are subject to a large number of researches, nowadays. Stem cells are a kind of undifferentiated cells (baby cells that have yet to choose a specific function) found in the body of multicellular organisms. Also known as root cells, they have the special ability to divide into two new cells through a process called mitosis. The new stem cells developed through mitosis will have the same characteristics as those of their parents. They may continue as stem cells, or be a different type of cell with some other function.
The word ‘stem cell’ was coined by Russian scientist Alexander Maksimov, in 1908. It was in 1981 that scientists extracted stem cells for the first time. These stem cells were obtained by Martin Evans, Matthew Kaufman and Gail R. Martin from the embryo of a mouse. Then, in 1998, the first human stem cells were extracted as well.
Stem cells don’t have any definite shape or structure. They show a great ability to convert from one cell type to some other (a process called differentiation), even after two or three years. There are two kinds of stem cells; embryonic stem cells and adult stem cells. The embryonic cells are developed from blastocysts (embryos in an earlier stage) about 4 – 5 days old after fertilization. They are then grown through a special medium and subjected to various experiments. This manner of growing cells in labs is called cell culture. Apart from this, the embryonic cells can also be taken from the umbilical cord blood just after childbirth. The adult stem cells are found in the grown organs or tissues. They are also called somatic stem cells. The major sources of adult stem cells are fat, blood and bone marrow. Recently, we have also discovered that it is possible to extract stem cells from the teeth.
Since new cells can be derived from stem cells, they have made a significant impact in the field of medicine. With the help of stem cells, theoretically, cures can be developed for all the diseases triggered by the damaging of cells. This is called stem cell therapy. The stem cells work by repairing a damaged part of the body.
It has been proved that stem cell therapy is useful for many diseases, like cancer, lung diseases, liver degeneration, Parkinson’s disease, multiple sclerosis, cerebral haemorrhage, Alzheimer’s disease and diabetes. Based on their use, stem cells can be divided into three main types: totipotent cells, which can turn into any cell type; pluripotent, which can turn into any type except the placenta; and multipotent, which can turn into some specific cell types.
In 2010, some scientists from Wake Forest University, London, grew a liver from stem cells. Two years later, a group of scientists from the Gothenburg University of Sweden, developed a vein as well. British scientist John Gordon and Japanese scientist Shinya Yamanaka shared the 2012 Physiology Nobel Prize for converting normal cells into stem cells.
Just like blood can be donated, stem cells may also be donated. Many hospitals and laboratories have now facilities to store stem cells. As this is a voluntary medical procedure and requires healthy donors, usually only people between 18 and 35 are allowed to donate stem cells.
- Stem cell (Wikipedia)