These type of cells are the ones that are able to divide themself indefinitely without loosing their properties, too they are able to create specialized cells.
The mayority of cells of an adult or completely developed mamal, usually dont multiply themselves, except for some that mantain the skin and blood. The cells of muscles and fats normally dont divide themselves, if we increased our weight this doesnt mean that we have more cells, because in fact we mantain the same number of cell, but that they are increasing their sizes.
To understand better stem cells, we should see the embryonic develpment:
the zygote create by an ovule and a sperm is able to generate a complete new individual, this is about a totipotent cells that are able to create an complete specimen with all its tissues.
Between the 1st and and the 4th day of the embryonic development the original cell starts dividing into several more. Each one of these cells if they are separated they can produced a complete new individual. these cells are too called totipotent cells.
Since the 4th day of this same development the blastocyst is form, this one is form by 2 types of cells and a great internal cavity:
- External layer: form by the placenta and embryonic envelopes.
- Celular mass: will form all tissues from the human body.
The cells of the blastocyst now arent able to be totipotent, well now there is not a single cell that can produce a complete individual.They become pluripotent.
These pluripotent cells (the embryonic stem cells) they have the capacity of producing any tissue.
What are the adult stem cells?
In an adult individual there are tissues in which cells can divide in an active way, but in some dont . Between the ones that can be divided we can found the bone marrow and the skin, in these two parts we cant find their stem cells. These cells can reproduce and generate cells of skin and blood. They have discover that in other tissues the existance of stem cells that are specialized that are able to reproduce and produce specialized tissues but only that tissues. These stem cells are very few and difficult to isolate.
What are the therapeutic uses of stem cells?
- They are use to the treatment of Parkinson in the way that the stem cells are use to generate more and better neurones that can work better by theresolves and with the preexisting ones.
- They are use too for the treatment of severe heart diseases were there are use bone marrow stem cells, these stem cells repare damage areas of the heart by becoming new muscles cells and in new blood cells.
- The stem cells of the umbilical cord are used to the revert the effects of the chemotherapy in patents with cancer, well they will generate all the substance inside the bones that make blood that is damage for the chemicals.
- In babies with genetic deformities that produce them inmunodeficiency will repare them. Well the stem cell of their bone marrow will be removed and developed and finally tey will replace the bad gene.
- The regeneration of some tissues, muscles.
- fertilization
The studies with stem cells mostly continue in development thats way they havent a sure all the solutions they will bring. Some solutions predicted are:
- They will let us experiment new medicines in different tissues before testing in animals or human beings.
- The generation of independant organs will make more accesable transplants for people. The expert think we will able to generated eyes, hearts, kidneys, and more.
- Reparate medular lesions
- Burns
- Diabetes
- Osteoporesis
- Artritis reu matoide
- Change human face
- Calm pain
What are the benefits of stem cells therapies?
- There are many benefits in the use of this therapy maybe the most important one is that the participant of this wont have to use transplant from other people he could use their own stem cells to generate it own tissues.
- The progresses will be indisputable, and evident.
- persons without any hopes will find a hope in stem cells to long term.
- organs will be of easier acquisition and the traffic of orgarns and prices of these ones will decrease.
- finally the value of knowledge that the humanity will get will be the final succes of a scientist society.
What are the risks of stem cell therapies?
The principal risks of the implementation of stem cells in human beings consist in the lack of control in the reproduction of them .Other high facts that make of this practice something dangerous is the immune rejection of this kind of transplant that the patience can develop after the actual procedure .To avoid rejections during the procedures doctors are using some drugs such as Cyclosporin , this drugs are immunosuppressive meaning they avoid the activation of cells against the transplant but also against pathogen microorganism that can appear during the process , this let the patient in a high risk of acquiring diseases such as hepatotoxicity .
Looking at the other mayor reason of risk about this transplants ; the control of their growth , we can said it is divided in to two principal problems .The apparition of tumors and the inappropriate migration of cells. In one hand the apparition of tumors is considered the inminent cause of Cancer because of the exponential way stem cells continued growing and the inappropriate migration of cell can bring inspected and unwanted results, such as the deterioration of the driving properties and neuronal disorders.
Briefly the main risks are:
- Tumor formation.
- Inappropriate stem cells migration.
- Immune rejection of transplanted stem cells.
- Postoperative infections.
http://www.youtube.com/watch?v=8kvPSbf1WQ8&NR=1
Techonology in stem cells
http://www.youtube.com/watch?v=razyWEbRg_o
Does all these have the potencial to hurt anyone?
YES! Basicly what the extraction embryo stem cells propose is to negate the right of life, this because the embryo is not able life even to born in a develop way just to obtain its stem cells to our own benefit. Too what will happen with those one in which the treatments doesnt work? who will response for the amount of money invested, the health damage that can be provocated, and what will happen if all the proyect o stem cells just dont prove a compability in the use of embryonic or just the cirguries are too risky. Or finally hurts the in a way the whole humanity.
Ethical position
Our Ethical position about this controversial theme is the next one:
We are in total agreement with the use of new technology for research about stem cells because this will contributes to the improvement of the human life quality. This project about stem cells has many things in favor and against. In one hand the implementation of this kind of cells would bring many opportunities and hope to people how think they have lost part of their life by losing some sense or the mobility of some part of the body. But by the other side we think is not fair to obtain this cells from fetus, because their right to live is being violated, we think this practice is unethical taking in to account the main responsibility of doctors is to preserve human life.
We find the better solution is to implement the use of adult stem cells and the donation of the umbilical cord, because these options don’t violate the principal right to life. But we are aware that even these options have to go through strict research to avoid having problems such as the risks we mention previously.
How the scienfic community conveys information sbout its work to the wider community in such a way that informed decisions about research can be made?
The way in which the scientist community informs the wider community about decisions about research are many they do by the leaders of nation, important health ngo´s, and through advertisments.
Foundations
Obama´s speech about stem cells
http://www.youtube.com/watch?v=63Uqp9VcCq4
BIBLIOGRAPHY
http://www.ecojoven.com/uno/05/celulasm.html
http://www.podologiaalicante.com/images/CelulaMadre.jpg
http://www.mincyt.gov.ar/documentos/comision_celulas_madre/preguntas_celulas_madre.pdf
www.grg.org/resources/glossary.html
wordnetweb.princeton.edu/perl/webwn
www.bio.org/speeches/pubs/er/glossary_b.asp
http://www.madrimasd.org/cienciaysociedad/ateneo/dossier/celulasmadre/ecojoven_archivos/evolucion.gif
http://www.washingtonpost.com/wp-dyn/content/article/2006/10/22/AR2006102200928.html
http://jme.bmj.com/cgi/content/full/33/3/169
http://www.lukor.com/ciencia/04092701.htm
http://es.wikipedia.org/wiki/C%C3%A9lula_madre#Tratamientos_con_c.C3.A9lulas_madre
BY: Maria Fernanda Tuta
Maria Camila Luna
Laura Santos
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