Sandra Hatcher

Donor cell survival in a fresh osteochondral allograft at twenty-nine years. A case report.

Fresh osteochondral allografting is a nonvascularized organ transplantation with a clinical use dating back to the early twentieth century. The procedure, in its current form, involves transplantation of a small segment of bone as a carrier with its overlying cartilage. As the bone is remodeled and revascularized by the recipient, the donor cartilage continues to function mechanically, produces matrix, and receives nutrition from the synovial fluid. The cartilage has traditionally been considered a so-called immunoprivileged tissue, avoiding the immune surveillance of the host presumably because of its paucity of vascular channels and its hypo-cellular matrix1. These qualities make fresh osteochondral allografting unique in the field of transplantation and preclude the need for systemic immunosuppression after this procedure. Although histologically normal articular cartilage has been reported in retrieved fresh osteochondral allografts, we know of no report that has definitively confirmed the specific survival of the donor cells for any length of time. Furthermore, the source of cells in retrieved transplants has not been confirmed as being from the donor or the recipient. The patient was informed that data concerning his case would be submitted for publication. Atwenty-two-year-old man with a large defect on the articular surface of the lateral femoral condyle of the knee underwent fresh osteochondral allografting from a female donor. He recovered well from the allograft procedure and had a relatively pain-free knee for the next twenty-five years. He presented to us with knee pain on the lateral side and tricompartmental arthritis predominantly in the lateral compartment (Fig. 1). A magnetic resonance imaging scan was acquired, and it demonstrated a tear of the posterior horn of the lateral meniscus with loss of the articular cartilage thickness along the posterior aspect of the lateral femoral condyle (Fig. 2). He ultimately requested total knee …

Chondrogenic potential and homogeneity of cell populations of donor and recipient cells in a fresh osteochondral allograft: a case report.

Fresh osteochondral allografts have been widely used to treat cartilage lesions for more than 100 years1. Transplantation of cartilage and bone in the form of an allograft allows osseous healing while maintaining the articular cartilage architecture. This composite tissue transplant remains intact in vivo for extensive periods of time with a favorable mechanical and biological environment. The chondrocytes of the graft are thought to actively remodel the extracellular matrix environment, and thus contribute to the tissue integrity. We recently reported that allograft cells could survive up to twenty-nine years after transplantation without the need for systemic immunosuppression2. Although mosaic cell populations have been demonstrated in other forms of transplantation, these have always been under the umbrella of long-term systemic immunosuppression3,4. In a classic study, Langer and Gross5 showed that intact articular cartilage surfaces obtained by removing the subchondral bone of rat femoral heads and filling of the osseous segments with acrylic cement exhibited essentially no humoral immune response in contrast to that seen with minced cartilage or isolated chondrocyte transplants. This finding has been attributed to the so-called “immunoprivileged” status of articular cartilage, which protects the chondrocytes from the immune system of the host. The extent to which allograft chondrocytes retain their gene expression profiles and chondrogenic capacities remains unknown. Our goal was to compare gene expression, proliferation rate, and chondrogenic potential between host and allograft chondrocytes isolated three years after an unsuccessful fresh osteochondral allograft transplant in the knee. The patient was informed that data concerning her case would be submitted for publication, and she provided consent. The study was performed in full compliance with our institutional review board (IRB). Our IRB at University of California Davis Medical Center does not consider case reports to be research and does not …

Biphenotypic sarcoma with characteristics of both a Ewing sarcoma and a desmoplastic small round cell tumor.

BACKGROUND The EWS gene, a transcription factor of unknown function, is involved in chromosomal translocations associated with a wide variety of tumors, particularly small round blue cell tumors such as Ewing sarcoma. It has previously been reported that desmoplastic small round blue cell tumor (DSRBCT) frequently has an associated t(11;22) abnormality resulting from fusion of the EWS and WT-1 genes. PROCEDURE We report a case of a small round blue cell tumor with characteristics of both Ewing sarcoma and DSRBCT with a t(11;22) translocation leading to fusion of the EWS and FLI1genes. RESULTS The translocation point and fusion products were confirmed by polymerase chain reaction amplification and restriction fragment mapping of the products. CONCLUSIONS The biphenotypic nature of this case and the apparent promiscuity of the EWS gene in tumor-associated translocations coupled with other reports of biphenotypic childhood sarcomas has potential implications for the relationship between small round blue cell tumors and the mechanism of EWS/FLI1 oncogenesis.

Sequential Flow Cytometry and Single Gene Analysis by Enzymatic Amplification and Allele Specific Oligonucleotide Hybridization of Urothelial Cells

In this report, we show that fresh urothelial cells first subjected to propidium iodide staining and flow cytometric quantitative DNA analysis can then be used for DNA analysis using the PCR and hybridization with oligonucleotide probes for the detection of specific B-globin alleles