Cloning and characterization of two glutathione peroxidase cDNAs from southern bluefin tuna (Thunnus maccoyii).

Glutathione peroxidases (GPXs; EC 1.11.19) are key enzymes in the antioxidant defence systems of living organisms, including fish.

Purification and properties of a glutathione peroxidase from Southern bluefin tuna (Thunnus maccoyii) liver.

A glutathione peroxidase (GPX) protein was purified approximately 1000-fold from Southern bluefin tuna (Thunnus maccoyii) liver to a final specific activity of 256 micromol NADPH oxidised min(-1) mg(-1) protein. Gel filtration chromatography and denaturing protein gel electrophoresis of the purified preparation indicated that the protein has a native molecular mass of 85 kDa and is most likely a homotetramer with subunits of approximately 24 kDa. The Km values of the purified enzyme for hydrogen peroxide, cumene hydroperoxide, t-butyl hydroperoxide and glutathione were 12, 90, 90 and 5900 microM, respectively.

Microdialysis of the lateral and medial temporal lobe during temporal lobe epilepsy surgery.

Background: This study was undertaken to establish whether, in temporal lobe epilepsy (TLE), there are relative differences between the lateral and ipsilateral medial temporal lobe in the extracellular levels of 3 of the human brain's major neuroactive amino acids.

Methods: Seven generally anesthetized patients with TLE undergoing anatomically standardized resective surgery had at operation microdialysis catheters inserted within the middle temporal gyrus (ie, lateral temporal lobe) and anterior hippocampus (ie, medial temporal lobe). Surface electrocorticography (ECoG) recordings were also obtained.

Development and validation of a radioimmunoassay for fish insulin-like growth factor I (IGF-I) and the effect of aquaculture related stressors on circulating IGF-I levels.

This paper describes the development and validation of a commercially available radioimmunoassay (RIA) for the detection of fish insulin-like growth factor-I (IGF-I). The assay was developed using recombinant barramundi IGF-I as antigen and recombinant tuna IGF-I as radiolabelled tracer and standard. Assay sensitivity was 0.