Source: brainnurse.com

Source: buzzle.com

Source: stemcellbenefits.info

What is stem cell research?Stem cell research is a relatively new technology from the 19th century that takes primitive human cells that have the potential to develop into most any of the 220 varieties of cells in the human body, including blood cells and brain cells.

It has the ability to uncover treatments and possibly even cures for some of the worst diseases including heart disease, diabetes, and neurodegenerative diseases like Alzheimer's and Parkinson's. Dead cells of almost any kind, no matter the type of injury or disease, can be replaced with new healthy cells thanks to the amazing flexibility of stem cells. As a result, billions of dollars are being poured into this new field.

What is a stem cell?A stem cell is essentially a “blank” cell, capable of becoming another more differentiated cell type in the body.

They are the foundation for every cell, tissue and organ in our body. They help our bodies to replenish themselves by continually growing and dividing. Stem cells act as an internal repair system and in certain organs such as our digestive tract or bone marrow, they can fix and replace worn out tissue.

Source: topnews.in

The 2 main types of stem cells

Embryonic stem cells are derived from very early embryos and can in theory give rise to all cell types in the body. However, coaxing these cells to become a particular cell type in the laboratory is not trivial. Furthermore, embryonic stem cells carry the risk of transforming into cancerous tissue after transplantation. While these cells are already helping us better understand diseases and hold enormous promise for future therapies, there are currently no treatments using embryonic stem cells accepted by the medical community.

Adult Stem Cells

Adult tissues contain stem cells that can replace cells that die or restore tissue after injury.

Skin, muscle, intestine and bone marrow, for example, each contain their own stem cells. In the bone marrow, billions of new blood cells are made every day from blood-forming stem cells.

Adult stem cells are tissue-specific, meaning they are found in a given tissue in our bodies and generate the mature cell types within that particular tissue or organ. It is not clear whether all organs, such as the heart, contain stem cells. The term ‘adult stem cells’ is often used very broadly and may include fetal and cord blood stem cells.

Source: gotecotech.com

Embryonic Stem Cells

The history of stem cell research: From the 19th century to now

1860 - 1920"Stem cells" inferred from analysis of embryo development and microscopy of bone marrow

1958-1959Experiments on animals

1961The existence and properties of transplantable stem cells in mouse bone marrow are established and the first colony methodology for counting them is introduced

1969First application of cell separation technology to dissect marrow stem cell hierarchy

1978Transplantable stem cells are discovered in human cord blood

1981Embryonic stem cells are first derived from the inner cell mass of mouse blastocysts (UK, USA)

1982 - 1986First methodology developed for targeted genetic modification in embryonic stem cells

1994First separation of cancer stem cells from the majority of cells in a cancer Patients with damaged corneas are successfully treated with corneal stem cells

1996First cloning of a mammal: Dolly the sheep is born (Scotland)1998First human embryonic stem cell line derived

2002The International Society for Stem Cell Research is formed

2004First derivation of dopaminergic cells from human embryonic stem cells, a hope for Parkinson's disease treatment

2010Isolation of multipotent human blood stem cells capable of forming all cells in the blood system

Source: groups.nbp.northwestern.edu

Potential uses of stem cellStudies of human embryonic stem cells will yield information about the complex events that occur during human development. A primary goal of this work is to identify how undifferentiated stem cells become the differentiated cells that form the tissues and organs. Human stem cells could also be used to test new drugs.

Source: prlog.org

Stem cell treatments

Bone Marrow TransplantA bone marrow transplant is when stem cells that are normally found in the bone marrow are taken out, filtered, and given back either to the same person (in future if the person contracts diseases such as leukaemia and aplastic amenia) or to another person.

Why is it done?Bone marrow produces stem cells. These stem cells eventually develop into blood cells. Bone marrow is a critical part of the body because it is the body's main blood cell "factory." If something is wrong with the marrow, a person can become very ill, even die.

How is it done?Two Types of Bone Marrow Transplants

• Autologous bone marrow transplant The donor is the person him/herself.

• Allogenic bone marrow transplant The donor is another person whose tissue has the same genetic type as the person needing the transplant (recipient). Because tissue types are inherited, similar to hair or eye colour, it is more likely that the recipient will find a suitable donor in a brother or sister. This, however, happens only 25 to 30 percent of the time.

Source: http://rarediseases.about.com/od/rarediseasesb/a/bmt05.htm

Stem cell research and cloning

Dolly the SheepTo clone Dolly, researchers took a cell from the udder of a six year old Finn Dorset sheep, and kept in a nutritional solution. They then deprived the cell of the nutrients which made the cell's DNA go into a 'sleeping' state. The nucleus of a sheep egg cell from another ewe was then removed, and inserted the sleeping cell into the now nucleus-free egg cell. The two combined cells were then given an electric shock, and to the scientist surprise, the combined cells acted like a fertilized egg cell and starting to divide and grow, thus starting the development of Dolly. The egg was then implanted into a third ewe and a few months later, Dolly was born. She was genetically an exact copy of the ewe from which the udder cell was taken.

Source :Wikipedia, the free encyclopaedia

Why clone Dolly?A team of researchers wants to prove the hypothesis that differentiated animal cells could give rise to entire new organism.

Source: Wikipedia, the free encyclopaedia

Advantages of stem cell research It has great potential to treat many diseases that were thought to

be incurable before. It has decreased the dependency on donor organs and the problem

of timely availability of organs It has thrown light on cell development and growth of organs in

humans. It has opened new doors in the field of clinical research as doctors

can study the potential of new drugs without testing them on animals and humans.

It has helped study all the different development stages in a human embryo, study the causes and treatments of birth defects, pregnancy loss and infertility. This can help get rid of fetal anomalies (diseases and abnormalities present during birth) and treat them at an early stage.

Disadvantages of stem cell research This is a new technology and is still undergoing researches.

Scientists are still unaware of the long term effects of this therapy as they are directly playing with nature.

The use of embryonic stem cell has set religious groups and political parties into frenzy. This treatment involves destruction of blastocysts post extraction of stem cells

The technology used is expensive The stem cells derived from embryos stand chances of rejection

as they are not patients own and stand chances of rejection.

Source:nts.wtyl.org

Is cloning ethical and should it be researched most intensively ?

Most people say no. There are many arguments against cloning, especially on humans. Logically there is no better organ donor than one’s own test tube twin. However, would a person or society have the right to decide a clone is less than human and is allowed to be spare parts for ‘real’ people?

Large percentage of cloning efforts on mammals end in failure. It took hundreds of attempts to clone Dolly the sheep. Often clones don't live as long as sexually reproduced animals, possibly because the genes taken from adult cell s are more likely to have undergone mutations. Also, inbreeding animals constantly can result in reduced variations and an increased risk of genetic defects.

However, there are also benefits to cloning. Firstly is the preserving of endangered species. Secondly, cloning of domesticated animals could be important in the future production of transgenic livestock.

Source: http://www.biology.iupui.edu/biocourses/Biol540/12cloningfullCSS.html

Is stem cell research ethical?

Reasons on why stem cell research is not ethical

A human embryo is a human being in the embryonic stage, just as an infant is a human being in the infant stage.

Although an embryo does not currently have the characteristics of a person, it will become a person and should be given the respect and dignity of a person.

Reasons on why stem cell research is ethical

An early embryo that has not yet implanted into the uterus does not have the psychological, emotional or physical properties that we associate with being a person.

The embryo cannot develop into a child without being transferred to a woman’s uterus. It needs external help to develop. Something that could potentially become a person should not be treated as if it actually were a person

When scientists want to obtain embryonic stem cells, they have to “ destroy” a human embryo . However, many people are claiming that this is very inhumane and evil and want it banned. Below are the arguments from both parties on if stem cell research is ethical.

United StatesThe United States is only one of many countries playing an important role in stem cell research. In the last decade, several European and Asian countries have become leading centres for the study of stem cells and their possible therapeutic uses.

AfricaIn 2004, South Africa became the first African nation to create a stem cell bank

Middle EastSaudi Arabia has been active in stem cell research since 2002, when the government decided to make biotechnology "the new oil of Saudi Arabia."

Source: htsa-online.co.uk

Stem cell research around the world

EuropeBelgium bans reproductive cloning but allows therapeutic cloning of embryos. France prohibits reproductive cloning and the creation of embryos for research purposesItaly strictly limits embryonic stem cell researchThe United Kingdom has long been a major player in bioscience and has been heralded as Europe's leader in stem cell research

AsiaChina prohibits human reproductive cloning but allows the creation of human embryos for research and therapeutic purposesIndia has established a booming industry in stem cell banking, which involves storing a patient's stem cells with the aim of possibly using them for future medical treatmentsSingapore has been dubbed "Asia's stem cell centre"

Source: irfl.org

Source: sibin.blogspot.com

Tan Yan Yuh1O2 22

2012 Term 3 Science ACE