Search results for "CARTILAGE"

Changes in collagen cross-linking of articular cartilage are revealed by spectral reflectance imaging

2012

Excessive cross-linking of collagen during aging may contribute to degeneration of articular cartilage. Traditionally, the amount of cross-links is derived by using destructive high-performance liquid chromatography (HPLC). However, a sensitive, non-destructive method could help to evaluate tissue integrity, including cross-links. We increased collagen cross-linking in bovine articular cartilage by controlled threose incubation. During the incubation, optical spectral reflectance images of the samples were captured and related to HPLC results using regression analysis. Significant correlations with reflectance and cross-links were observed. When further developed the optical method may enab…

Zebrafish Fins as a Model System for Skeletal Human Studies

2007

Recent studies on the morphogenesis of the fins ofDanio rerio(zebrafish) during development and regeneration suggest that a number of inductive signals involved in the process are similar to some of those that affect bone and cartilage differentiation in mammals and humans. Akimenko et al. (2002) has shown that bone morphogenetic protein-2b (BMP2b) is involved in the induction of dermal bone differentiation during fin regeneration. Many other groups have also shown that molecules from the transforming growth factor-beta superfamily (TGFβ), including BMP2, are effective in promoting chondrogenesis and osteogenesisin vivoin higher vertebrates, including humans. In the present study, we review…

Multipotential nestin and Isl-1 positive mesenchymal stem cells isolated from human pancreatic islets.

2006

Mesenchymal cells in the developing pancreas express the neural stem cell marker nestin and the transcription factor islet-1 (Isl-1). Using defined culture conditions we isolated on a single cell basis nestin producing cells from human pancreatic islets. These cells were immortalized with lentiviral vectors coding for telomerase and mBmi. They are positive for Isl-1 and nestin and have the potential to adopt a pancreatic endocrine phenotype with expression of critical transcription factors including Ipf-1, Isl-1, Ngn-3, Pax4, Pax6, Nkx2.2, and Nkx6.1 as well as the islet hormones insulin, glucagon, and somatostatin. In addition, they can be differentiated into human albumin producing cells …

Mechanobiological computational model for the development and formation of synovial joints

2019

El desarrollo de las articulaciones sinoviales se debe a diferentes factores genéticos, bioquímicos y mecánicos. Comienza en el brote de las extremidades, que tienen una masa ininterrumpida de células mesenquimales dentro de su núcleo, el blastema esquelético. La mayoría de estas células blastemales se diferencian en condrocitos; sin embargo, algunas de estas células permanecen, sin diferenciar, en el sitio de la futura articulación (interzona). La separación de los rudimentos ocurre con el proceso de cavitación dentro de la interzona. Después de la cavitación, se produce la morfogénesis articular y el hueso toma su forma final. Una vez finalizado el período embrionario, la articulación sin…

Parathyroid Hormone Related Protein (PTHrP)-Associated Molecular Signatures in Tissue Differentiation and Non-Tumoral Diseases

2023

Formulation of Different Chitosan Hydrogels for Cartilage Tissue Repair

2014

Different formulations of Chitosan/sulphate and Chitosan/PEGDE were produced by physical and chemical reticulation to obtain hydrogels with better physiochemical properties. The hydrogels were analyzed – in terms of their non-toxicity, proliferative, differentiative, inflammatory and immunology responses. Commercial grade Chitosan (Sigma) was solubilized and purified by progressive filtrations. Then, the polymer was freeze-dried in a water soluble cationic form. A physical hydrogel was prepared by mixing a 3 % w/w water solution of the a.m. polymer with different stoichiometric ratios of (SO4=) 1/0.5;1/0.75;1/1 respectively. The hydrogels were cross-linked in multiwells. The chemical hydrog…

Artificial cartilage bio-matrix formed of hyaluronic acid and Mg2+-polyphosphate.

2016

Here we show that inorganic polyphosphate (polyP), a polyanionic metabolic regulator consisting of multiple phosphate residues linked by energy-rich phosphoanhydride bonds, is present in the synovial fluid. In a biomimetic approach, to enhance cartilage synthesis and regeneration, we prepared amorphous polyP microparticles with Mg2+ as counterions. The particles were characterised by X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and Fourier transformed infrared spectroscopic (FTIR) analyses. Similar particles were obtained after addition of Mg2+ ions to a solution containing hyaluronic acid, as a major component of the synovial fluid, and soluble Na-polyP. The viscous paste-like ma…

Cartilage Regeneration and Tissue Engineering

2019

Abstract Articular cartilage in synovial joints is a hyaline cartilage highly hydrated with a rigorous order of cells and fibers and a specific content of proteoglycans and glycoproteins. It provides a low-friction surface, participates in the lubrication of the synovial joints, and distributes the forces to the underlying bone. It is an avascular and aneural tissue where small metabolites diffuse to and from cells. Unlike hyaline cartilage in other locations, articular cartilage lacks perichondrium, a layer of fibrous tissue around it that serves as the source of new cartilage cells. Thus, although extracellular matrix undergoes continuous remodeling throughout life, the ability to repair …

Autogreffe chondrocostale pour lésion latérale ostéochondrale de la tête métacarpienne

2020

Abstract Osteochondral injuries of the metacarpal head require anatomical restoration to prevent limitations in range of motion and osteoarthritis. Osteochondral bone grafting is a viable option, especially in younger patients. Central injuries allow for different types of grafting, but when the injured area is on the lateral portion of the metacarpal head, the graft must include both a cortical and a cartilaginous portion. We present here the pearls and pitfalls in the surgical technique of chondrocostal grating from the 6th rib and an example of its use within a case of comminuted fracture of the metacarpal head. This technique provides a graft with cortical bone that allows for a stable …

Indirekte MR-Arthrographie zur Verlaufskontrolle nach autologer osteochondraler Transplantation

2003

Purpose: To evaluate the spectrum of findings in indirect MR-arthrography following autologous osteochondral transplantation. Patients and Methods: 10 patients with autogenous osteochondral homografts underwent indirect MR-arthrography at three, 6 and 12 months postoperatively. The MR protocol at 1.5 T comprised unenhanced imagings with PD- and T 2 -weighted TSE-sequences with and without fat-suppression as well as T 1 -weighted fat-suppressed SE-sequences before and after iv. contrast ad ministration and after active joint exercise. Image analysis was done by two radiologists in conference and comprised the evaluation of signal intensity (Sl) and integrity of the osseous plug and the carti…