Matrix-Induced Autologous Chondrocyte Implantation (MACI) Using a Cell-Seeded Collagen Membrane Improves Cartilage Healing in the Equine Model.

Background: Autologous chondrocyte implantation (ACI) using a collagen scaffold (matrix-induced ACI; MACI) is a next-generation approach to traditional ACI that provides the benefit of autologous cells and guided tissue regeneration using a biocompatible collagen scaffold. The MACI implant also has inherent advantages including surgical implantation via arthroscopy or miniarthrotomy, the elimination of periosteal harvest, and the use of tissue adhesive in lieu of sutures. This study evaluated the efficacy of the MACI implant in an equine full-thickness cartilage defect model at 1 year.

RNA Interference Mediated Interleukin-1β Silencing in Inflamed Chondrocytes Decreases Target and Downstream Catabolic Responses.

Posttraumatic activation of the catabolic cascade plays a major role in degradation of cartilage. Interleukin-1β (IL-1β), a primary instigator in the catabolic axis, is upregulated in chondrocytes following injury. IL-1β activates key degradative enzymes, including MMPs and aggrecanases, and other proinflammatory mediators such as PGE2 which contribute to ECM breakdown.

Gene therapy in musculoskeletal repair.

Local and regional gene therapy has improved healing in preclinical trials of articular and other muculoskeletal conditions. Combinations of cell supplementation and cells overexpressing growth factor genes have shown promising results for improving cartilage repair, enhancing delayed union of fractures, and driving organized tendon repair. Proof of concept has been developed using viral vectors, predominantly adenovirus, to deliver growth factor genes, such as BMP-2, TGF-beta1, and IGF-I.

Effects of gpx4 haploid insufficiency on GPx4 activity, selenium concentration, and paraquat-induced protein oxidation in murine tissues.

Selenium-dependent glutathione peroxidase-4 (GPx4) catalyzes the reduction of phospholipid hydroperoxides. Because a full gpx4 knockout is embryonic lethal, we examined the effect of deletion of one copy of gpx4 on the activities of three selenoperoxidases (GPx1, GPx3, and GPx4), selenium concentrations, and pro-oxidant-induced protein oxidation in various tissues of mice. A total of 32 gpx4 hemizygous (GPx4+/-) and wild-type (WT) mice (8- to 10-weeks old; 16 males and 16 females) were fed a selenium-adequate diet and given an intraperitoneal injection of paraquat (PQ; 24 mg/kg body wt) or phosphate-buffered saline (PBS).

Discordant 16S and 23S rRNA gene phylogenies for the genus Helicobacter: implications for phylogenetic inference and systematics.

Analysis of 16S rRNA gene sequences has become the primary method for determining prokaryotic phylogeny. Phylogeny is currently the basis for prokaryotic systematics. Therefore, the validity of 16S rRNA gene-based phylogenetic analyses is of fundamental importance for prokaryotic systematics.

Absence of photoreceptor rescue with D-cis-diltiazem in the rd mouse.

Purpose: Because of a previous report suggesting that D-cis-diltiazem slows retinal degeneration in rd mice, this study was undertaken to examine the effect of D-cis-diltiazem on photoreceptor structure and function in this line of mice.

Methods: Mice were randomly assigned to daily intraperitoneal injections of D-cis-diltiazem or saline between postnatal days 9 and 24. On postnatal day 26 or 27, retinal function was assessed by recording dark-adapted bright-flash ERGs in all animals.