Nel corso dellanno scolastico abbiamo più volte analizzato articoli di giornale in lingua inglese. I temi trattati sono stati di vario genere e anche i giornali utilizzati erano diversi tra loro.
L8 gennaio del 2007 è uscito sulla rivista scientifica Nature Biotechnology la notizia di una nuova scoperta in merito alla ricerca sulle staminali: il ritrovamento di cellule staminali simili a quelle embrionali nel liquido amniotico. Ho voluto riprendere questa notizia in lingua inglese dal sito della BBC (la tv di stato Inglese), che si riferisce allarticolo uscito su Nature Biotechnology, firmato anche dallitaliano Paolo de Coppi.
‘New stem cell source’ discovered
US scientists say they have discovered a new source of stem cells that could one day repair damaged human organs.
Researchers successfully extracted the cells from the fluid that fills the womb in pregnancy and then grew them in lab experiments.
The types of stem cell with potentially the most use have so far been derived from specially grown human embryos.
But this has created ethical concerns because the embryos are destroyed in the process.
Opponents say this is tantamount to cannibalism.
Supporters say stem cells offer real hope in treating illnesses like diabetes, Parkinson’s and Alzheimer’s.
Implanted in mice
Writing in Nature Biotechnology, the scientists said it should be possible to harness the cells’ ability to grow into different tissue to treat disease.
It shouldn’t be seen as a race between embryonic stem cells and other sources
Prof Colin McGuckin
However, UK experts had doubts about the feasibility of the technique.
They said gathering amniotic fluid from large numbers of women might be difficult.
Amniotic fluid contains a large number of cells, many of which come from the developing foetus.
The team from Wake Forest University School of Medicine, in North Carolina, extracted these from fluid samples taken as part of unrelated diagnostic tests during pregnancy, then encouraged them to grow in the laboratory.
They found that they had the potential to turn into a wide variety of different cells – the hallmark of potentially useful stem cells.
They then transplanted them into mice, and carried out further tests to look at how they performed in a living creature.
Again, the results were encouraging, with the stem cells spreading and starting to produce key body chemicals in both brain and liver.
Bone stem cells introduced onto an artificial ‘scaffold’ then implanted into mice also appeared to behave in a similar way to normal bone cells, forming bone even months later.
The conclusion of the researchers was that the amniotic cells were ‘pluripotent’ – capable of becoming many different cell types, and that they held the potential for treatment – particularly on the child from whose mother they were taken, for whom they are an exact tissue match.
Dr Paolo De Coppi, now of Great Ormond Street Hospital, who worked on the study, said the amniotic stem cells were similar to, but not identical to, embryonic stem cells.
He said: “Our research suggests that for some clinical applications they may work better than embryonic stem cells.
“For example, embryonic stem cells injected into muscle can form teratomas – amniotic stem cells do not do this.
“However, the range of applications for these stem cells may be more narrow than for embryonic stem cells.”
Dr De Coppi it might be possible to take amniotic stem cells from a child diagnosed before birth with a problem, and use them to grow new tissue in the laboratory, which would be ready to use to treat the child when it was born.
In theory, it might also be possible to genetically modify a foetus’ own stem cells and inject them back into the amnioitc fluid to correct gene disorders.
Professor Colin McGuckin, from Newcastle University, is researching the use of similar cells taken from the umbilical cord at birth.
He welcomed the report, saying that it was ‘thorough’ and demonstrated the potential of amniotic stem cells.
“The best thing is to have a variety of stem cell sources to provide the best stem cell for patients. Unless researchers do work to demonstrate there are alternatives to embryonic stem cells, the wider public won’t understand that.
“It shouldn’t be seen as a race between embryonic stem cells and other sources.”
However, he said that harvesting amniotic fluid presented particular difficulties in many cases.
“If it is a natural birth, the waters break and they are all over the floor, and you’ve lost them. In this country, the majority of women give birth naturally, which means that fluid could not be collected.
“You could conceivably gather amniotic fluid during a caesarean section, but that process could interfere with the experience of giving birth.”
Story from BBC NEWS:
Published: 2007/01/08 08:58:41 GMT
© BBC MMVII
FAQ: Fluid option
What is amniotic fluid?
The liquid that envelops a developing baby – it allows movement of the foetus while protecting it from injury. It contains a small amount of nutrients and cell material.
Is extracting the fluid safe?
Amniocentesis involves inserting a needle to extract amniotic fluid, usually to test for genetic abnormalities in the baby. It is straightforward but complications can arise if pathogens are introduced by the needle or the wound does not heal properly.
How can the cells be used?
If they prove useful the stem cells could be stored in a cell bank and cloned indefinitely for research or to provide therapies such as growing tissue that is genetically matched to damaged tissue in a patient.
(ultima parte di un articolo uscito su The Guardian il giorno 01/08/2007)
The first part the article announces that on 08th January 2007 a team of Wake Forest Univerity School of Medicine (North Carolina) published an article were they said that they have found stem cells in the amniotic fluid. These cells are very special because they are similar to embryonic stem cells. If it is true it would be the end of ethical concerns about the embryos.
The team extracted these cells from fluid samples taken as part of diagnostic tests during pregnancy. Then they encouraged them to grow in the laboratory and they saw that the cells turn into a wide variety of different cells. Then they transplanted some derived cells into mice and they saw that they are included by the body.
The conclusion of the study was that amniotic cells are pluripotent, and Dr Paolo de Coppi, one of the researchers, said that these cells were similar, but not identical to, embryonic stem cells. He said that on one hand they are better, because if they are injected into a living creature, there is less possibility that they form teratomas. On the other hand they are worse because the range of applications may be more narrow.
The last part of the article mentions possible limitations of this research. This kind of study shouldnt be seen in contrast with the results of the research on embryonic stem cells as many scientists affirm. In fact they are different and one research doesnt exclude the implications deriving from the other. Finally there is the problem of harvesting amniotic fluid, that may compromise the health of the foetus.
Sample = campione
Encourage = incoraggiare
Transplant = trapiantare
Include = includere, inglobare
Inject = iniettare
Teratomas = Teratomi (un tipo di tumori)
Narrow = ristretto
Range of applications = campo di applicazione
To harvest = raccogliere
Torna all’indice della tesina La scoperta delle cellule staminali: Aspetti scientifici e filosofici di Cristiano Parisi