[Evaluation of the Effectiveness of a Neck Fixation Device for Improving Image Quality in Diffusion-weighted Whole-body Imaging with Background Suppression].

The effectiveness of a neck fixation device to improve the image quality of DWIBS was investigated. Healthy volunteers were examined while chewing with and without a neck fixation device using a 3-T MRI system. Distance of mandibular movement was measured using true-fast imaging of steady-state precession (true FISP).

Pharmacological characteristics of the inhibitory effects of docosahexaenoic acid on vascular contractions studied in rat mesenteric artery.

Background/aims: Effects of docosahexaenoic acid (DHA) on blood vessel contractions to various constrictors were investigated in rat mesenteric artery and compared with those of eicosapentaenoic acid (EPA) and linoleic acid (LA).

Methods: Tension changes in mesenteric ring segments were isometrically recorded.

Results: On sustained contractions induced by a thromboxane A₂ mimetic (U46619), DHA exerted a strong inhibitory effect.

Pharmacological evidence showing significant roles for potassium channels and CYP epoxygenase metabolites in the relaxant effects of docosahexaenoic acid on the rat aorta contracted with U46619.

Docosahexaenoic acid (DHA) shows more pronounced relaxation when blood vessel is contracted with prostanoid receptor agonists than other stimulants. The present study was carried out to obtain information on the mechanisms underlying prostanoid receptor-selective relaxant action of DHA, particularly focusing on the possible roles for K(+) channels and its CYP epoxygenase (EOX) metabolites. In endothelium-denuded rat thoracic aorta, DHA (10(-5) M) almost completely relaxed U46619 (a thromboxane A2 (TP) receptor agonist)-contracted muscle without substantially affecting noradrenaline (NA)-induced contraction.