The effects of pressure on chondrocyte tumour necrosis factor receptor expression.

This work was performed to determine whether one aspect of load, pressure, could alter tumour necrosis factor (TNF) receptor type I (RI) expression on chondrocytes. Encapsulated tsT/AC62, osteoarthritic (OA) or non-arthritic (NA) chondrocytes were centrifuged at speeds representing 5 or 20 MPa, incubated for specific periods, released from alginate and TNFRI and II (TNFRII) expression determined by flow cytometry. Significant (p<0.

Susceptibility to physiological concentrations of IL-1beta varies in cartilage at different anatomical locations on human osteoarthritic knee joints.

Objectives: To determine whether cartilage biopsies from specific regions of osteoarthritic knee joints differ in susceptibility to the degradative effects of the amounts of interleukin-1 beta (IL-1 beta; 1-10 pg/ml) found in osteoarthritic joints. To establish whether biopsies are sensitive to the effects of either IL-1 beta or TNFalpha or both catabolic cytokines.

Methods: Cartilage from specified regions of 22 osteoarthritic knee joints was examined.

Identification of novel single nucleotide polymorphisms in intron 1B and exon 1C of the human interleukin-1 receptor type I (IL-1RI) gene.

We have identified two novel single nucleotide polymorphisms in the 5' region of the human IL-1RI gene: (1) A-->G at position 52 in intron 1B (GenBank accession number AF146426), which creates an Mspl restriction endonuclease site. Allele frequencies in a Caucasian population were 0.1 (A allele) and 0.

Tumor necrosis factor alpha can contribute to focal loss of cartilage in osteoarthritis.

Unlabelled: OBJECTIVE; To evaluate the potential for tumor necrosis factor alpha (TNFalpha)-induced focal loss of cartilage in osteoarthritic (OA) knee joints.

Design: Fresh cartilage from specified regions of OA joints was immunostained for TNF-receptor (R) bearing chondrocytes. Cartilage explants from the same regions were cultured with or without small amounts of TNFalpha and cumulative GAG release into supernatants measured.