Bone Marrow-Harvesting Technique Influences Functional Heterogeneity of Mesenchymal Stem/Stromal Cells and Cartilage Regeneration.

Background: Connective tissue progenitors (CTPs) from native bone marrow (BM) or their culture-expanded progeny, often referred to as mesenchymal stem/stromal cells, represents a promising strategy for treatment of cartilage injuries. But the cartilage regeneration capacity of these cells remains unpredictable because of cell heterogeneity.

Hypothesis: The harvest technique of BM may highly influence stem cell heterogeneity and, thus, cartilage formation because these cells have distinct spatial localization within BM from the same bone.

Immune Cell Induced Migration of Osteoprogenitor Cells Is Mediated by TGF-β Dependent Upregulation of NOX4 and Activation of Focal Adhesion Kinase.

The cytokines secreted by immune cells have a large impact on the tissue, surrounding a fracture, e.g., by attraction of osteoprogenitor cells.

[Implantation of a Modular Distal Femoral Replacement with Compressive Osseointegration as a Salvage Procedure in a Complex Femoral Posttraumatic Setting].

Background: Large bone defects and losses play a crucial role in both tumour surgery and in complex primary and revision total knee replacement. The established options of cemented or uncemented long intramedullary stems are limited by large bone defects and are at risk from relatively high exposure to aseptic loosening. There is no general valid agreement on implant fixation of the distal femur.

Crucial Role of Vitamin D in the Musculoskeletal System.

Vitamin D is well known to exert multiple functions in bone biology, autoimmune diseases, cell growth, inflammation or neuromuscular and other immune functions. It is a fat-soluble vitamin present in many foods. It can be endogenously produced by ultraviolet rays from sunlight when the skin is exposed to initiate vitamin D synthesis.

Navigated TKA After Osteotomy Versus Primary Navigated TKA: A Matched-Pair Analysis.

This article presents clinical and radiological outcome analysis of navigated total knee arthroplasty (TKA) following osteotomy compared with primary navigated TKA implantation. The study group (29 legs) received navigated TKA (Columbus with deep-dish, cruciate-retaining inlay, Aesculap AG, Tuttlingen, Germany) following distal femoral (6 legs) or high tibial (23 legs) osteotomy, and the control group (29 legs) received a primary navigated TKA. All patients were examined clinically and radiologically in a retrospective matched-pair analysis.

Bone marrow-derived mesenchymal stromal cells differ in their attachment to fibronectin-derived peptides from term placenta-derived mesenchymal stromal cells.

Introduction: Human mesenchymal stromal cells (MSCs) can be isolated from different sources including bone marrow and term placenta. These two populations display distinct patterns of proliferation and differentiation in vitro. Since proliferation and differentiation of cells are modulated by cell-matrix interactions, we investigated the attachment of MSCs to a set of peptide-coated surfaces and explored their interactions with peptides in suspension.

Computer-assisted navigation is beneficial both in primary and revision surgery with modular rotating-hinge knee arthroplasty.

Purpose: The objective of the present study was to explore the effect of navigation on the reconstruction of the mechanical leg axis, implant positioning and the restoration of the joint line in hinged knee arthroplasty in vivo. We present the first 1- to 3-year clinical and radiological results following computer-navigated implantation of the EnduRo modular rotating-hinge knee arthroplasty system (Aesculap AG, Tuttlingen, Germany) as a primary or revision implant.

Methods: Thirty-one patients were analysed retrospectively.

Long-term results using the straight tapered femoral cementless hip stem in total hip arthroplasty: a minimum of twenty-year follow-up.

We report the first long-term results of a prospective cohort study after total hip arthroplasty using the cementless Bicontact hip stem. Between 1987 and 1990, 250 total hip arthroplasties in 236 patients were performed using the cementless Bicontact hip stem. The average follow-up was 22.

Phenotypic and functional heterogeneity of human bone marrow- and amnion-derived MSC subsets.

Bone marrow-derived mesenchymal stromal/stem cells (MSCs) are nonhematopoietic cells that are able to differentiate into osteoblasts, adipocytes, and chondrocytes. In addition, they are known to participate in niche formation for hematopoietic stem cells and to display immunomodulatory properties. Conventionally, these cells are functionally isolated from tissue based on their capacity to adhere to the surface of culture flasks.

Animal serum-free expansion and differentiation of human mesenchymal stromal cells.

Background Aims: Mesenchymal stromal cells (MSC) are attracting increasing interest for possible application in cell therapies. Fetal calf serum (FCS) is widely utilized for cell culture, but its use in the context of clinical applications is associated with too many risks. Therefore we tested FCS-free media for the expansion and differentiation of MSC in compliance with the European good manufacturing practice (GMP) regulations for medicinal products.

The mesenchymal stem cell antigen MSCA-1 is identical to tissue non-specific alkaline phosphatase.

We have recently identified 2 distinct CD271(bright)MSCA-1(dim)CD56(+) and CD271(bright)MSCA-1(bright)CD56(-) MSC subsets in primary femur-derived bone marrow (BM), which differ in their expression pattern and morphology as well as in their clonogenic and differentiation capacity. Here, we show that MSCA-1 is identical to tissue non-specific alkaline phosphatase (TNAP), an ectoenzyme known to be expressed at high levels in liver, bone, and kidney as well as in embryonic stem (ES) cells. SDS-PAGE of WERI-RB-1 cell lysate and supernatant from phosphatidylinositol-specific phospholipase C (PI-PLC)-treated WERI-RB-1 cells resulted in the appearance of a prominent 68-kDa band.

TGF-beta enhances the integrin alpha2beta1-mediated attachment of mesenchymal stem cells to type I collagen.

The heterodimeric integrins are important receptors for the attachment of cells to their extracellular matrix. Here, we studied the attachment of human mesenchymal stem cells (MSCs) to type I collagen (col-1), which is part of the extracellular matrix in bone, skin, and connective tissues. Furthermore, we examined how TGF-beta influences the integrin expression and attachment of MSC.

Phenotypic characterization of distinct human bone marrow-derived MSC subsets.

Very recently, we identified two distinct mesenchymal stem cell (MSC) subsets in primary bone marrow (BM) that differ in their expression pattern (CD271(bright)MSCA-1(dim)CD56(+) and CD271(bright)MSCA-1(bright)CD56(-)) and morphology as well as in their clonogenic and differentiation capacity. Here we analyzed the cell surface antigen expression in these subsets in more detail and compared the profiles with the expression pattern on cultured MSCs. Most of the tested antigens, including CD13, CD15, CD73, CD140b, CD144, CD146, and CD164, are expressed at similar levels in both primary BM populations.

Isolation of functionally distinct mesenchymal stem cell subsets using antibodies against CD56, CD271, and mesenchymal stem cell antigen-1.

Background: Conventionally, mesenchymal stem cells are functionally isolated from primary tissue based on their capacity to adhere to a plastic surface. This isolation procedure is hampered by the unpredictable influence of co-cultured hematopoietic and/or other unrelated cells and/or by the elimination of a late adhering mesenchymal stem cells subset during removal of undesired cells. To circumvent these limitations, several antibodies have been developed to facilitate the prospective isolation of mesenchymal stem cells.