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4 posts from April 2011

April 27, 2011

Integrating stem cell technologies into health care: It’s time to get our priorities straight

by Ubaka Ogbogu

While preparing a consulting report on ethical issues associated with priority setting (a.k.a. resource allocation, rationing) in the stem cell research context, I was surprised to find that there are no published Canadian studies of priority-setting matters pertaining specifically to stem cell research or stem cell-based technologies. A search of the Canadian Institutes of Health Research grants database produced 47 research projects (concluded and ongoing) on priority-setting issues, but none focused on the (potential) integration of stem cell technologies into health care (Note: see update at bottom). Emerging biotechnologies are not well represented either; I found only a 2004 study of priority setting for genetic services led by Fiona Miller and Rosanna Weksberg and a 2003 study on a similar topic by Mita Giacomini.

Experts generally agree that new and cutting edge health care technologies give rise to acute issues of priority setting. This is because such technologies often emerge at high cost (in a bid to recoup research and development expenses), and corresponding high public demand places significant constraints on the resources needed to integrate them into health care. Stem cell therapies will likely follow this trend, and considering the interplay of revolutionary promise and persistent controversy attending the field, may even generate novel priority-setting challenges for health care decision makers.

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April 19, 2011

Pre-emptive stem cell banking in high-risk individuals: Should Japan’s nuclear workers have their stem cells stored?

by David Kent

A few weeks back, The Guardian reported on a proposal by Japanese doctors and scientists that would see the blood cells of Japanese nuclear clean-up workers banked as a precaution against possible exposure to radiation during the clean-up of the Fukishima power plant. The idea would be to harvest and store their blood cells[1] and, should the worker require a transplant in the future due to the development of a blood cancer or bone marrow failure, to then re-infuse the patient’s own blood cells from the pre-exposure state. This would avoid complications like graft-versus-host disease and finding a donor match.  Furthermore, many businesses and hospitals have pledged their help both inside Japan and internationally.

Sounds pretty amazing right? 

Well yes, but there has been substantial dissent, and this dissent has moved the Japanese government to not support the initiative, despite the support of the Japan Society for Hematopoietic Cell Transplantation. The debate of how useful these transplants would be is well-summarised by Alice Park and appears to boil down to two main arguments: 1) Blood cells are only one tissue type that bear the effects of radiation and blood cell therapies would not help with gastrointestinal or lung damage; and 2) Workers may have an extra (unwarranted) sense of security and take unnecessary risks.

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April 12, 2011

Reconstructing tissues using fat stem cells and the thin line between clinical and cosmetic needs

by Michelle Ly

Reconstructive surgery plays an important role in recovery from disease and injury by attempting to restore function or appearance to the body. While the use of synthetic materials is commonplace, the ability to replace or reconstruct using the same tissues from elsewhere in the body is desirable because it would eliminate many issues that occur with synthetic materials, such as higher infection rates and foreign body reactions.   

One new technique being investigated in the field of reconstructive medicine uses an adherent, multipotent population of cells called adipose-derived stem cells (ASCs). ASCs are isolated from subcutaneous body fat by taking minced tissue fragments, digesting it with an enzyme called collagenase, and then spinning out the resultant mixture to separate the stem cell containing layer. As a type of stem cell, ASCs can theoretically differentiate into any of the adipose cell lineages, making them an extremely useful tool in regenerative medicine. However, the extent of differentiation in ASCs has been questioned, especially in comparison to standards set by other stem cell populations. 

While the supporting technologies in this emerging field are still undergoing development and refinement, some clinical progress has already been achieved. California-based Cytori Therapeutics reported success with a clinical trial to reconstruct breast tissue following breast cancer surgery using what they call “adipose-derived stem and regenerative cells” (ADRCs). The study was conducted across several European health centers and was led by co-principal investigators Dr. Weiler-Mithoff and Dr. Rosa Pérez Cano at the Hospital Universitario Gregorio Marañón in Madrid, Spain. The procedure takes fat from the patient by liposuction and then harvests and processes the ADRCs for inclusion in “cell enriched fat grafts” which are used to reconstruct the breast.

These early successes have not been achieved without criticism however, and some researchers are urging caution in patients and researchers interested in ASC based therapies. In addition to questions about the level of cell differentiation, a recent review pointed to unresolved issues in large-scale engineering and differences in stem cell purity depending on tissue source. Other researchers warn that some studies do not adequately account for the heterogeneity of the ASC population and how that may affect clinical treatments.

With the growing attention to stem cell procedures in recent years and the accompanying rise of marketed stem cell treatments, both clinical and cosmetic, it is more important than ever for patients and their doctors to focus on well-researched studies and trials. As such, future studies in ASC-based treatments will need to address concerns about isolation, purification and differentiation in order to continue with progress in academia and industry.

April 05, 2011

Using stem cells in developmental disorder research

Every two hours, someone is born with Rett Syndrome (RTT), a developmental disorder seen almost always in girls, but occasionally in boys. Those with the disease usually develop normally until they reach 12-18 months, at which point development stops and oftentimes is reversed, causing previously developed skills to deteriorate.

RTT is typically placed under the autism spectrum of disorders (although some have questioned this classification), and is the only autism-spectrum disorder with a known cause: A mutation in the MECP2 gene located on the X chromosome. With the cause known, researchers have a ‘starting point’ to look at for possible ways to combat the disorder, and that’s exactly what they’ve done.

One well-known researcher in the field is Dr. In-Hyun Park from the Yale Stem Cell Center, who presented his work at the Ottawa Hospital Research Institute’s Sprott Centre for Stem Cell Research in late March.

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