| |
 | Posted by admin |
|
|
|
Japanese researchers have succeeded for the first time in mice the production of a pituitary gland from embryonic stem cells. The paper detailing this operation, which involved complex juxtaposition of different types of tissue, appears this week in the latest issue of the journal Nature .
(Enlargement of the pituitary tissue created from embryonic stem cells. Image: Yoshiki Sasai)
The adenohypophysis or anterior pituitary functions as an important center of production of hormones. At present, no type of stem cell culture is capable of generating this type of tissue in humans, but Japanese scientists have just successfully in mice and intend to create a human pituitary in the next three years.
One of the authors of the study, Yoshiki Sasai, the group of Neurogenesis and Organogenesis of the Riken Center for Developmental Biology (Kobe, Japan) has explained to SINC that “as an extension of this success, we plan to apply our technology to human stem cells from the ES (embryonic) and IPS (induced pluripotent). We hope to develop an efficient method for producing human pituitary in the coming years. “
The mouse embryonic stem cells were stimulated in a culture that mimicked three-dimensional tissue interactions, to thereby produce the five hormones generated by different cell types present in the pituitary. The corticotrophic, for example, showed they were capable of secreting the hormone adenocorticotrópica in response to corticotropin-releasing hormone.
Click to continue »
| |
| Posted by admin |
|
|
|
Many patients suffering from chronic liver diseases are receiving inadequate treatment due to lack of donor organs for transplantation. However, hepatocytes derived from induced pluripotent stem (iPS) could provide an alternative for the future.
Scientists at the Max Planck Institute for Molecular Genetics in Berlin compared the hepatocytes of the embryonic stem cells with hepatocytes iPS cells, and found that gene expression is very similar. However, compared to hepatocytes “real”, just under half of the genes showed different gene expression. Therefore, gene expression of hepatocytes derived from iPS cells still requires an adjustment before the cells can be used in the treatment of liver diseases.
Induced pluripotent stem cells can be obtained from different cell types. Hepatocytes derived from iPS cells are an ideal starting point for future regenerative therapies.
Click to continue »
| |
| Posted by admin |
|
|
|
Not without debate , Brazil , countries with strong Catholic tradition, has allowed research on stem cells, while framing it in a rather strict . This research, which are now subject to support from authorities , the institutional and financial results are beginning to get recognized by the scientific community
1 . A recent legal framework governing research on stem cells
1.1. A 2005 law allowing research on embryonic stem cells
The use and research on stem cells is regulated by the Biosafety Law ( Law 11,105 of March 24, 2005 ) . This Act repeals the provisions of the Biosecurity Act 1995 which prohibits research on embryos .
The 2005 law, which also regulates GMOs , allows ” for research and therapy , the use of embryonic stem cells derived from human embryos produced by in vitro fertilization , under certain conditions . These conditions laid down in Article 5 are fulfilled:
- The embryos must be frozen or non – viable for at least three years ,
- Clinics and hospitals must keep a register of all embryos available with their date of freezing ,
- The parents must give their consent .
This text is a brief reference to adult stem cells , on which can be searchable and have applications in the medical field . In addition, the sale of medical equipment thereto is qualified by the law of crime .
Click to continue »
| |
| Posted by admin |
|
|
|
An international scientific team led by Columbia University Medical Center (New York) has restored vision in mice suffering from retinitis pigmentosa, replacing diseased retinal cells from embryonic stem cells. This technique could lead to the development of a new treatment of retinitis pigmentosa or macular degeneration associated with age (AMD). The study is published in the journal “Transplantation”.
Retinitis pigmentosa are genetic diseases of the eye caused by abnormalities in the photoreceptor cells and pigment epithelium, responsible for vision. They are one cause of blindness, and affects between 3000 to 4000 U.S. and 1.5 million people worldwide.
Click to continue »
| |
| Posted by admin |
|
|
|
A new technical development is able to avoid situations like that startled the medical community when researchers discovered virtually all lines of human embryonic stem cells that were being used in 2005 were contaminated. Certain animal used in some operations to prepare plates Petri had left traces in human cells. If these cells had been implanted in a human body, would probably have been rejected by the patient’s immune system.
Even today, with new stem cell lines approved for use in medical research, there is a risk that these contaminating cells in the same way. Most laboratories research still use “layers” based on animal products because it is still the cheapest and most reliable way to make cells mother multiply.
Some materials scientists at the University of Washington, have now created an alternative. They built a scaffold three-dimensional from a natural material that mimics the points junction of stem cells, allowing you to play in a biodegradable and clean structure. The latest results show that in that structure human embryonic stem cells grow and multiply easily and smoothly.
Click to continue »
| |
| Posted by admin |
|
|
|
Regulatory proteins common to all eukaryotic cells and may have additional functions unique to embryonic stem cells. This suggests a new study shows the possibility of making targets of these proteins in therapeutic treatments against tumors.
The study, conducted by Thomas and Barbara Panning Fazzio, researchers at the University of California (USA), showed that two chromatin regulatory proteins essential for the survival of embryonic stem cells (SMC2 and Smc4), join to form core condensita complexes, which promote the assembly and chromosome segregation in eukaryotic cells.
The key is that if it is shown that the tumor-forming cells (which operate in a manner similar to stem cells) depend on these regulatory proteins in the same way, it may be possible to turn them into targets for therapeutic treatments without damaging healthy neighboring cells.
Click to continue »
(Enlargement of the pituitary tissue created from embryonic stem cells. Image: Yoshiki Sasai)
1 . A recent legal framework governing research on stem cells