Search

Your search keyword '"McDougall, J.J."' showing total 32 results
Start Over Author "McDougall, J.J."
32 results on '"McDougall, J.J."'

9. Central neural activation of hyperdynamic circulation in portal hypertensive rats depends on vagal afferent nerves

Author

Liu, H., Schuelert, N., McDougall, J.J., and Lee, S.S.

Subjects
Afferent pathways -- Genetic aspects, Afferent pathways -- Research, Afferent pathways -- Physiological aspects, Portal hypertension -- Development and progression, Portal hypertension -- Genetic aspects, Portal hypertension -- Research, Gene expression -- Research, Peripheral circulation -- Physiological aspects, Peripheral circulation -- Research, Health
Published
2008

31. Paradoxical effects of the cannabinoid CB2 receptor agonist GW405833 on rat osteoarthritic knee joint pain.

Author

Schuelert, N., Zhang, C., Mogg, A.J., Broad, L.M., Hepburn, D.L., Nisenbaum, E.S., Johnson, M.P., and McDougall, J.J.

Abstract

Summary: Objective: The present study examined whether local administration of the cannabinoid-2 (CB2) receptor agonist GW405833 could modulate joint nociception in control rat knee joints and in an animal model of osteoarthritis (OA). Method: OA was induced in male Wistar rats by intra-articular injection of sodium monoiodo-acetate with a recovery period of 14 days. Immunohistochemistry was used to evaluate the expression of CB2 and transient receptor potential vanilloid channel-1 (TRPV1) receptors in the dorsal root ganglion (DRG) and synovial membrane of sham- and sodium mono-iodoacetate (MIA)-treated animals. Electrophysiological recordings were made from knee joint primary afferents in response to rotation of the joint both before and following close intra-arterial injection of different doses of GW405833. The effect of intra-articular GW405833 on joint pain perception was determined by hindlimb incapacitance. An in vitro neuronal release assay was used to see if GW405833 caused release of an inflammatory neuropeptide (calcitonin gene-related peptide – CGRP). Results: CB2 and TRPV1 receptors were co-localized in DRG neurons and synoviocytes in both sham- and MIA-treated animals. Local application of the GW405833 significantly reduced joint afferent firing rate by up to 31% in control knees. In OA knee joints, however, GW405833 had a pronounced sensitising effect on joint mechanoreceptors. Co-administration of GW405833 with the CB2 receptor antagonist AM630 or pre-administration of the TRPV1 ion channel antagonist SB366791 attenuated the sensitising effect of GW405833. In the pain studies, intra-articular injection of GW405833 into OA knees augmented hindlimb incapacitance, but had no effect on pain behaviour in saline-injected control joints. GW405833 evoked increased CGRP release via a TRPV1 channel-dependent mechanism. Conclusion: These data indicate that GW405833 reduces the mechanosensitivity of afferent nerve fibres in control joints but causes nociceptive responses in OA joints. The observed pro-nociceptive effect of GW405833 appears to involve TRPV1 receptors. [Copyright &y& Elsevier]

Published
2010
Full Text
View/download PDF

32. Catface copper-molybdenum porphyry, west-central Vancouver Island, British Columbia: an update.

Author

Enns S.G., McDougall J.J., Enns S.G., and McDougall J.J.

Abstract

The calc-alkalic deposit has a partially defined resource of 124 000 000 tonnes grading 0.46% Cu in the Cliff zone, with a higher grade, smaller mineralised zone known as the Irishman Creek zone. Mineralisation is related to a small, mid-Eocene porphyritic quartz diorite to granodiorite stock that intruded quartz monzonite and basalts. Disseminated and fracture-controlled chalcopyrite, bornite and minor molybdenite are present, with the best Cu grades being directly related to high fracture density. Potassic alteration, as secondary biotite, is associated with Cu mineralisation. Results from an airborne magnetic survey show a direct response to the intrusion beneath the Cliff zone and also indicate the presence of a buried stock in the upper Irishman Creek basin. Metallurgical work has shown that the best Cu grades lie beneath partially oxidised low-grade material, which causes variable Cu recoveries. An environmental base-line study has shown that mining would be unlikely to generate acid mine water., The calc-alkalic deposit has a partially defined resource of 124 000 000 tonnes grading 0.46% Cu in the Cliff zone, with a higher grade, smaller mineralised zone known as the Irishman Creek zone. Mineralisation is related to a small, mid-Eocene porphyritic quartz diorite to granodiorite stock that intruded quartz monzonite and basalts. Disseminated and fracture-controlled chalcopyrite, bornite and minor molybdenite are present, with the best Cu grades being directly related to high fracture density. Potassic alteration, as secondary biotite, is associated with Cu mineralisation. Results from an airborne magnetic survey show a direct response to the intrusion beneath the Cliff zone and also indicate the presence of a buried stock in the upper Irishman Creek basin. Metallurgical work has shown that the best Cu grades lie beneath partially oxidised low-grade material, which causes variable Cu recoveries. An environmental base-line study has shown that mining would be unlikely to generate acid mine water.

Catalog

Books, media, physical & digital resources
See catalog results