Biomedical subjects

Jennifer M Ryan

Publications and source records attributed to Jennifer M Ryan.

3 recordsLinked to original sources

PubMed2005

Mesenchymal stem cells avoid allogeneic rejection.

Adult bone marrow derived mesenchymal stem cells offer the potential to open a new frontier in medicine. Regenerative medicine aims to replace effete cells in a broad range of conditions associated with damaged cartilage, bone, muscle, tendon and ligament. However the normal process of immune rejection of mismatched allogeneic tissue would appear to prevent the realisation of such ambitions. In fact mesenchymal stem cells avoid allogeneic rejection in humans and in animal models. These finding are supported by in vitro co-culture studies. Three broad mechanisms contribute to this effect. Firstly, mesenchymal stem cells are hypoimmunogenic, often lacking MHC-II and costimulatory molecule expression. Secondly, these stem cells prevent T cell responses indirectly through modulation of dendritic cells and directly by disrupting NK as well as CD8+ and CD4+ T cell function. Thirdly, mesenchymal stem cells induce a suppressive local microenvironment through the production of prostaglandins and interleukin-10 as well as by the expression of indoleamine 2,3,-dioxygenase, which depletes the local milieu of tryptophan. Comparison is made to maternal tolerance of the fetal allograft, and contrasted with the immune evasion mechanisms of tumor cells. Mesenchymal stem cells are a highly regulated self-renewing population of cells with potent mechanisms to avoid allogeneic rejection.

Journal Article↗

PubMed2002

SCHIP turns five: taking stock, moving ahead.

This issue brief notes the five-year anniversary of the effective date of Title XXI of the Social Security Act, the State Children's Health Insurance Program (SCHIP). It looks at the successes of the program, as well as some of the obstacles SCHIP will face as it moves from childhood into adolescence and attempts to maintain its effectiveness in providing health coverage to uninsured children and families. The paper explores the critical funding impasse created by the down turns in the economy and the financing structure of the SCHIP statute. It also highlights the emerging issue of program retention and the need to minimize unnecessary disenrollments. Finally, the issue brief considers the prospects for SCHIP's continued success-through bipartisan support in Congress and states' efforts to develop new and improved strategies to maintain and even expand their SCHIP programs in the coming years.

Child↗

PubMed2002

1115 ways to waive Medicaid and SCHIP rules.

This issue brief explores the history and context of the Section 1115 Medicaid waiver authority, discusses the Health Insurance Flexibility and Accountability (HIFA) initiative under way in the Bush administration, and considers some of the potential impacts that HIFA could have on state budgets and access to health care for low-income families. Finally, it considers the future of Section 1115 waivers as a vehicle for modifying Medicaid and the State Children's Health Insurance Program.

Adult↗