Archive for October, 2009
Scientists Map First Complete Human Epigenome, The Driver Of Gene Expression
From medicalnewstoday.com
When scientists mapped the DNA sequence of 3 billion bases in the human genome they uncovered the master blueprint of what makes a human being; now a team in the US has produced a high resolution map of the first complete human epigenome, the driver of gene expression that regulates how all the options offered in the genome are put together to make the unique person that grows in a particular environment. Understanding the epigenome is the key to understanding how genes affect health and disease under the influence of factors like lifestyle, diet and environment.
The work is described in a paper published in the 14 October online issue of Nature.
Click link above for complete article
Surgeons ‘Grow’ New Cheekbones for 15-Year-Old Born With Rare Condition
From Foxnews.com
A 15-year-old boy born without cheekbones has a new lease on life after surgeons at Cincinnati Children’s Hospital used a first-of-its-kind procedure to reconstruct the teen’s face.
They did it by using a combination of donor bone, growth hormone and the teenager’s own stem cells, The Cincinnati Enquirer reported.
Brad Guilkey was born with Treacher Collins Syndrome, which is a rare genetic condition that affects the development of bones and other tissues in the face. It’s passed down through families and is estimated to occur in 1 in 50,000 people, according to the National Institutes of Health.
Brad was born without zygomatic bones, which is the arch of bone beneath the eye that forms the prominence of the cheek. Because of the lack of this bone, the teenager was left with a “sunken-cheek” look.
In order to fix this, Dr. Jesse Taylor, the surgeon in the division of craniofacial and pediatric plastic surgery, first carved a model of the missing bones from cadaver bone.
Next, Taylor and his team injected the cadaver bone with stem cells harvested from Brad’s stomach fat and a type of growth hormone, called Bone Morphogenic Protein-2, which signals stem cells to turn into bone cells.
The team then wrapped the whole construct in a piece of periosteum — the thick membrane covering the entire surface of a bone – which was harvested from Brad’s thigh. Finally, they placed the bone constructs in Brad’s skull.
A few months after the surgery, doctors received the news they were hoping for: CT scans showed new living bone had grown in place in Brad’s skull.
Taylor said this technique gives doctors a new option for treating children and adults who have lost bone to disease or traumatic injury.
Jaw bone created from stem cells
From news.bbc.co.uk
Scientists have created part of the jaw joint in the lab using human adult stem cells.
They say it is the first time a complex, anatomically-sized bone has been accurately created in this way.
It is hoped the technique could be used not only to treat disorders of the specific joint, but more widely to correct problems with other bones too.
The Columbia University study appears in Proceedings of the National Academy of Sciences.
The bone which has been created in the lab is known as the temporomandibular joint (TMJ).
Problems with the joint can be the result of birth defects, arthritis or injury.
Although they are widespread, treatment can be difficult.
The joint has a complex structure which makes it difficult to repair by using grafts from bones elsewhere in the body.
The latest study used human stem cells taken from bone marrow.
These were seeded into a tissue scaffold, formed into the precise shape of the human jaw bone by using digital images from a patient.
The cells were then cultured using a specially-designed bioreactor which was able to infuse the growing tissue with exactly the level of nutrients found during natural bone development.
Big potential
Lead researcher Dr Gordana Vunjak-Novakovic said: “The availability of personalised bone grafts engineered from the patient’s own stem cells would revolutionise the way we currently treat these defects.”
Dr Vunjak-Novakovic said the new technique could also be applied to other bones in the head and neck, including skull bones and cheek bones, which are similarly difficult to graft.
The option to engineer anatomically pieces of human bone in this way could potentially transform the ability to carry out reconstruction work, for instance following serious injury or cancer treatment.
She said: “We thought the jawbone would be the most rigorous test of our technique; if you can make this, you can make any shape.”
She stressed that the joint created in the lab was bone only, and did not include other tissue, such as cartilage. However, the Columbia team is working on a new method for engineering hybrid grafts including bone and cartilage.
Another major challenge for scientists will be to find a way to engineer bone with a blood supply that can be easily connected to the blood supply of the host.
Professor Anthony Hollander, a tissue engineering expert from the University of Bristol who helped produce an artificial windpipe last year, said there was still a lot of work to be done before the new bone could be used on patients.
But he said: “One of the major problems facing scientists in this field is how to engineer a piece of bone with the right dimensions – that is critical for some of these bone defects.
“This is a lovely piece of tissue engineering which has produced bone with a high degree of accuracy in terms of shape.”
International Stem Cell Corporation and Absorption Systems Announce Potential Stem Cell Alternative to Live Animal Testing for Corneal Damage
OCEANSIDE, Calif. & EXTON, Pa.–(BUSINESS WIRE)–International Stem Cell Corporation (OTCBB:ISCO)), the first company to perfect a method of creating human “parthenogenetic” stem cells from unfertilized eggs, announces positive results of its collaboration with Absorption Systems to study ISCO’s stem-cell-derived human corneal tissue as an alternative to live animals for drug testing. Initial results using non-animal or “in vitro” tests indicate an excellent correlation between the rates at which drugs pass through ISCO’s lab-grown corneal tissue and rabbit corneal tissue. The results offer great promise for reducing the use of living animals for eye safety testing. ISCO’s human corneal tissue is created from parthenogenetic stem cells in the laboratories of Lifeline Cell Technology (Walkersville, MD), ISCO’s wholly-owned subsidiary.
See Intlstemcell.blogspot.com for complete article.
