Eicosapentaenoic acid suppression of systemic inflammatory responses and inverse up-regulation of 15-deoxyΔ(12,14) prostaglandin J2 production.

Background And Purpose: Eicosapentaenoic acid (EPA) has been shown to suppress immune cell responses, such as cytokine production and downstream PG production in vitro. Studies in vivo, however, have used EPA as a minor constituent of fish oil with variable results. We investigated the effects of EPA on systemic inflammatory responses as pure EPA has not been evaluated on immune/inflammatory responses in vivo.

Effects of glass ionomer cements on bone tissue.

In vivo biocompatibility of glass ionomer cements (GICs) was evaluated for use in orthopaedic surgery using a rat model and compared with conventional bone cement, Polymethyl methacrylate, PMMA. The unset GICs and PMMA were inserted into the marrow cavities of rat femora and retained in situ for various periods of time. The PMMA bone cement showed complete biocompatibility with no interference with reparative bone.

Time dependence of the mechanical properties of GICs in simulated physiological conditions.

The mechanical properties of glass-ionomer cements (GICs) have been satisfactory for dental applications and have shown their potential in orthopedic surgery. Because the physiological environment in orthopedics is different from dentistry by unavoidable contamination with blood and other fluids such as normal saline used during an operation, the determination of GICs for orthopedic applications should be performed in an appropriate environment. The properties of a novel resin-modified GIC, S430, for orthopedic applications were evaluated in simulated orthopedic conditions by an early exposure to and long-term storage in normal saline.

Comparison of the material properties of PMMA and glass-ionomer based cements for use in orthopaedic surgery.

The intrinsic benefits of low exotherm and bioactivity have generated interest in utilizing glass-ionomer cements (GIC) as a bone cement replacement in orthopaedic surgery. This paper is concerned with evaluating the mechanical properties of compressive strength, flexural strength, and fracture toughness for two traditional GICs, one resin-modified GIC (an experimental bone cement) and two polymethylmethacrylate (PMMA) cement systems. To determine the suitability of a GIC system for use in the clinical orthopaedic setting, the additional characteristics of setting exotherm and setting time have also been evaluated.

Interfacial fracture toughness between bovine cortical bone and cements.

To evaluate the bonding strength of the interfaces within the cemented arthroplasty system, various mechanical tests have been used. Conventional push-out and pull-out tests cannot reveal the actual bonding property of the interface because of the significant influence of surface roughness on the measured adhesion and the failure to account for the mismatch of elastic modulus across the interface. An alternative fracture mechanics approach, which considers the mix of opening and shear modes of the crack tip loading associated with the testing system and the elastic mismatch of materials across the interface, was used to evaluate the bonding ability of various cements.