The protective effect of the blood brain barrier from systemic cytokines in an animal femur fracture model.

Background: Previous studies of head trauma have shown profound release of cytokines in the brain. These changes were not expressed in peripheral tissues. The intent of this study was to take an animal model of femur fracture, monitor the expression of biochemical markers in the periphery, and compare this to their expression in the brain.

Isolation of large numbers of mesenchymal stem cells from the washings of bone marrow collection bags: characterization of fresh mesenchymal stem cells.

Background: Bone marrow (BM) is an excellent source of mesenchymal stem cells (MSC) which can be expanded in vitro for further use. However, large volumes of BM specimens are not routinely available. We hypothesized that the normally discarded BM collection kits might be a convenient source of large numbers of MSC.

Hyaluronic acid of high molecular weight inhibits proliferation and induces cell death in U937 macrophage cells.

Hyaluronic acid (HA), a major glycosaminoglycan component of the extracellular matrix, has regulatory influences on cells and cellular activities. To explore the effects of a high concentration (1 mg/mL) of high molecular weight HA (500-730 kD) on U937 macrophage growth dynamics, three factors that influence overall cellular growth, namely proliferation, apoptosis, and cell death, were examined. Cells were cultured with HA and were analyzed by flow cytometry every 24 hours during a 168-hour period for proliferation and the presence of apoptotic and dead cells.

Hyalgan has a dose-dependent differential effect on macrophage proliferation and cell death.

The intra-articular injection of high molecular weight hyaluronic acid (HA) has been reported to be an effective treatment for pain of osteoarthritis of the knee. However, the mechanism by which HA exerts its effect is unknown. To explore HA's influence on the growth of U937 human macrophages, cells were incubated for 168 h with three concentrations, 1, 0.

Long-term survival of McKee-Farrar total hip prostheses.

Because of the recent resurgence of interest in metal-on-metal bearing components for total hip arthroplasties, the long-term results of 153 consecutive McKee-Farrar total hip arthroplasties done in 129 patients by one surgeon between 1969 and 1973 were evaluated. A retrospective chart review provided patient demographics (age, gender, weight, primary diagnosis), revision dates, indications, and implant survival data. The average age of the patients at implantation surgery was 61 years (range, 28-85 years) and these patients were observed as many as 28 years.

Macrophage exposure to particulate titanium induces phosphorylation of the protein tyrosine kinase lyn and the phospholipases Cgamma-1 and Cgamma-2.

A frequent long-term complication of total joint arthroplasty is aseptic loosening, the end result of wear debris production, synovial macrophage activation, inflammatory mediator release, and osteolysis about the implant-bone or cement-bone interface. To elucidate the mechanisms of particle-induced macrophage activation and mediator production, we studied early signal transduction events using J774A.1 macrophages and 3 microm titanium particles.