STEM CELL

Stem Cell

Abstract

A stem cell is a cell that has the ability to self-renew by divisions mitotic or continue the differentiation pathway for which is scheduled and, therefore, produce cells of one or more tissues mature and fully functional differentiated according to their degree of multi-potentiality. This paper is a brief overview of the stem cell, its types and the current controversies surrounding stem cell research.

Stem Cell

Introduction

Stem cells are present in all animal life forms. In humans, they possess two important properties that differentiate them from most other cells in the human body:

They are unspecialized but under the right conditions can develop into many of the almost 200 different types of specialized cells in the body (such as brain cells or red blood cells), and

They are able to divide and renew themselves for long periods of time.

Over the past decade, research in this area has been the subject of considerable political controversy in the United States. The controversy has often drawn public attention through media coverage, generally reflecting communication efforts by stakeholders on all sides of this issue. This paper discusses stem cell and related controversies in a holistic context.

Discussion and Analysis

Stem cells have the ability to divide without losing their properties and can differentiate into other cells. Most tissues of an adult have a very specific population of stem cells that allow periodic renewal or regeneration when tissue damage occurs. Some adult stem cells are capable of differentiating into more than one cell type as mesenchymal stem cells and stem cells hematopoietic , while others are direct precursors of tissue cells which are, like stem cells Skin stem cells or gonadal (germline stem cells). It is common in specialized documents to be called true stem cells, which means stem trunk, most often referred to as stem cells (Herold, 2006).

Types of Stem Cells:

There are four types of stem cells:

Toti-potent stem cells can grow and form a complete organism, both embryonic components (for example, the three germ layers, the germ line and tissues that give rise to yolk sac) and the extra-embryonic (such as the placenta). That is, can form all cell types.

Pluri-potent stem cells cannot form a complete organism, but any other cell type for the three embryonic lineages (endoderm, ectoderm and mesoderm) and the germinal and yolk sac. They can therefore form cell lineages.

Multi-potent stem cells are those that can only generate cells of the same layer or lineage of embryonic origin (e.g., a mesenchymal stem cell from bone marrow, having mesodermal nature, will give rise to cells of that layer as myocytes, adipocytes or osteocytes, etc).

Uni-potent stem cells can form only a particular cell type.

It is possible to stimulate stem cells, in the laboratory, to provoke them into developing into many of the various specialized cells that develop naturally in the body. Most national governments have passed legislation constraining the use of human embryos in research and the ethical aspects of taking this stem-cell culture technique forwards will have to be ...