Growth factors for clinical-scale expansion of human articular chondrocytes: relevance for automated bioreactor systems.

The expansion of chondrocytes in automated bioreactors for clinical use requires that a relevant number of cells be generated, starting from variable initial seeding densities in one passage and using autologous serum. We investigated whether the growth factor combination transforming growth factor beta 1/fibroblast growth factor 2/platelet-derived growth factor BB (TFP), recently shown to enhance the proliferation capacity of human articular chondrocytes (HACs), allows the efficiency of chondrocyte use to be increased at different seeding densities and percentages of human serum (HS). HACs were seeded at 1,000, 5,000, and 10,000 cells/cm2 in medium containing 10% fetal bovine serum or 10,000 cells/cm2 with 1%, 5%, or 10%HS.

Gene expression during redifferentiation of human articular chondrocytes.

Objective: The aim of the present study was to investigate gene expression during the in vitro redifferentiation process of human articular chondrocytes isolated from clinical samples from patient undergoing an autologous chondrocyte transplantation therapy (ACT).

Method: Monolayer (ML) expanded human articular chondrocytes from four donors were cultured in a 3D pellet model and the redifferentiation was investigated by biochemistry, histology, immunohistochemistry and microarray analysis.

Results: The culture expanded chondrocytes redifferentiated in the pellet model as seen by an increase in collagen type II immunoreactivity between day 7 and 14.

In situ compressive stiffness, biochemical composition, and structural integrity of articular cartilage of the human knee joint.

Objective: Reduction of compressive stiffness of articular cartilage has been reported as one of the first signs of cartilage degeneration. For the measurement of in situ compressive stiffness, a hand-held indentation probe has recently been developed and baseline data for macroscopically normal knee joint cartilage were provided. However, the histological stage of degeneration of the measured cartilage was not known.

Hematopoietic stem cell transplantation (HSCT) with a conditioning regimen of busulfan, cyclophosphamide, and etoposide for children with acute myelogenous leukemia (AML): a phase I study of the Pediatric Blood and Marrow Transplant Consortium.

Background: Hematopoietic stem cell transplantation (HSCT) is an important treatment modality for children with AML. The optimal conditioning regimen is unknown. The aim of this study was to determine the appropriate dosing of etoposide in combination with busulfan and cyclophosphamide in this setting.

Cartilage fibrils of mammals are biochemically heterogeneous: differential distribution of decorin and collagen IX.

Cartilage fibrils contain collagen II as the major constituent, but the presence of additional components, minor collagens, and noncollagenous glycoproteins is thought to be crucial for modulating several fibril properties. We have examined the distribution of two fibril constituents-decorin and collagen IX-in samples of fibril fragments obtained after bovine cartilage homogenization. Decorin was preferentially associated with a population of thicker fibril fragments from adult articular cartilage, but was not present on the thinnest fibrils.