replace damaged cell organs. introduce some new words the function and the prospect stem cell the...
TRANSCRIPT
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Replace Damaged Cell
Organs
Introduce some new words
The function and the prospect
Stem cell
The procedure
Some question
Immunologic rejection 免疫反应Organ transplant 器官移植Recipient 接收者 donor 供给者Blood-forming bone marrow tissue 造血骨髓组织Hematopoietic stem cells(HSCs) 造血干细胞Embryonic stem cells (ESCs) 胚胎干细胞
Somatic cell 体细胞 oocyte 卵母细胞 liver cell 肝细胞 Fertilized egg 受精卵 ovary 卵巢Proliferate 增殖 Differentiate 分化 specialize 特化
The function and prospect
When a person loose his heart or liver …… when a person have a serious damage on his organ,…
….. When a person suffer a cancer disease, leukaemia( 白
血病) , malignant tumor( 恶性肿瘤 ) ,Parkinson’s disease …….
is one of the great successes of modern medicine !!
However……….
where are the enough donors’organ ?…..
Although , there are enough ……
there is a high risk of immunologic rejection !!
So…..w e imagine ……..
Whether exist a kind of cells , we can grow the cells and organ in the laboratory .
If it exist ……then we can ……
What’s the Stem Cells?
undifferentiated cells
Can self-renewal(production of cells like themselves)
Can differentiate into two or more mature cell types
Some types of importantstem cells
Hematopoietic stem cells (HSCc) Cells that are normally responsible for replacing t
he red and white blood cells that age and die every day in our bodies.(it was well used to treat the leukae
mia and other blood disease)
Neural stem cells like HSCc , can proliferate in a laboratory culture dish and can be k
ept undifferentiated or induced to differentiate into specialize cell types(have a great contribute to treat Parkinson’s disease)
Show a normal human brain
A person with parkinson’disease ,but ,on one side ,it received the nerve cells ten years ago !
Embryonic stem cells (ESc) 胚胎干细胞 Cells that are isolate from very young mammalian( 哺乳动物 ),
which are capable of differentiating into every type of cell in the body ,either in culture or within a host embryo.
Adult stem cells have a lower differentiation and proliferation capacity comp
ared with the Esc , but they can be isolate from the individual who is being treated and ,thus,will not face immunologic refection when used in subsequent cell replacement .
The procedure
remove somatic cells from the recipient,pick up the nucleus
Transfer the nucleus to the donor oocyte whose own nucleus had been removed
Allow to develop into an early embryo and form many ES cells
Grow ES cells in culture and induce to differentiate into the required cells(eg.blood cells, liver cells ,nerve cells)
Transplant the differentiated cells back into patient to restore organ function
Some questions
ethical issues
Human ES cells are derived from embryos !!!
Should we destroy human embryos ??
Can we take the adult stem cells instead of the ES cells??
What are the differences between the Esc and the adult stem cells??
technical obstacles
How to exactly induce the cells to differentiate into
the required organ ? ?
technical obstacles
Firstly ,.these cells can be obtained only from very early embryos and, although several human ES-cell lines have been made, they will not be immunologically compatible with most patients who require cell transplants. So researchers will need either to derive many more ES-cell lines or to customize ES cells on a patient-by-patient basis by 'therapeutic cloning'.
technical obstacles
Second, undifferentiated ES cells form teratomas ( — 畸瘤) benign tumours containing a mixture of tissue types — after being transplanted. Thus ES cells must be reliably differentiated into the appropriate cell type in culture before transplantation.( 即先要进行纯化和克隆成体干细胞 )
technical obstacles
Moreover, until now it had not been proved that specialized cells derived from cultured ES cells can actually function within tissues after transplantation
Any how
Replacing damaged cell and organs is
full of challenge as well as it has a
great and broad prospect !!! I believe one day we can crack the hard nut ! by then it must have a tremendous
contribute to human being !!!!