Medicine & Health

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Now showing 1 - 10 of 10
  • (2007) Bertrand, P. P
    Conference Paper
    Background/Aims: Enterochromaffin (EC) cells are sensors in the intestinal lumen that detect chemical or mechanical stimuli and respond with the release of serotonin (5-HT). 5-HT can activate local reflexes but whether local activation of enteric neural circuits also evoke 5-HT release is unclear. Methods: Recordings were made from full-thickness preparations of guinea pig ileum using electrochemical techniques with carbon fibre electrodes placed in the mucosa to measure local concentrations of 5-HT. The tension in the circular muscle (CM) was recorded with a force transducer. Amplitude and time course of local 5-HT release events and muscle contractions were measured and compared using paired Student’s t-test with Bonferroni’s correction for multiple comparisons. Results: Stretch of the CM caused 5-HT release and reflex contraction of the CM. Focal electrical stimulation of the intestine near to the carbon fibre electrode evoked 5-HT release and caused a local contraction in the ring of CM where the recording site was located. Paralysis of the smooth muscle with papaverine (100 mm; n55), sodium nitroprusside (100 mm; n55) or isoproterenol (1 mm; n55) significantly reduced (o25% of control) the stretch-evoked release of 5-HT. Similarly, isoproterenol (1 mm; n54) or sodium nitroprusside (100 mm; n53), abolished (o10% of control) the electrically evoked release of 5-HT. Atropine (1 mm; n53), which would be expected to block muscarinic input to the EC cell, did not reduce stretch-evoked 5-HT release. Conclusion: The present study provides direct evidence that activated enteric nerves are not responsible for the 5-HT release seen during local reflexes. There was little residual 5-HT release in response to stretch or electrical stimulation of the nerves in paralysed preparations and atropine did not reduce reflex-evoked 5-HT release. Together, these data suggest that mechnical, and not neural, stimuli provide an important excitatory input to the EC cells.

  • (2007) Gattellari, Melina; Worthington, John; Zwar, N; Middleton, S
    Conference Paper
    Background: Optimising the management of NVAF is proving difficult and the potential to reduce stroke risk is yet to be fully realised. Barriers to using anticoagulants need to be addressed. Aims: To describe GP management of NVAF and barriers to the use of warfarin. Methods: Representative survey of Australian GPs. b: Of the 593 GP participants (response = 64.3%), 46.2% reported the experience of an ischaemic stroke in their NVAF patients without anticoagulation. When asked to select treatment for a hypothetical NVAF patient at 'high' risk of stroke, 71.0% appropriately selected warfarin. In the presence of a minor falls risk, 45.4% of GPs selected warfarin. Only 28.8% would anticoagulate the patient at high risk of stroke with a history of recurrent nosebleeds and 16.9% would anti-coagulate such a patient with a treated peptic ulcer bleed. 37.9% agreed that 'it is hard to decide whether the benefits of warfarin outweigh the risks', while only 54.3% agreed they fully understood their patients' views on both the benefits and risks of warfarin. Conclusion: Any strategy to improve the evidence based management of NVAF must address the excessive concerns clinicians have about anticoagulation. We need to reduce anxiety about 'acts of commission' in the management of NVAF.

  • (2007) Wei, Aiqun; Chung, Sylvia; Tao, Helen; Brisby, Helena; Lin, Zhen; Ma, David; Diwan, Ashish
    Conference Paper

  • (2007) Prestage, C; Zablotska, I; Frankland, A; Imrie, John; Grulich, Andrew
    Conference Paper

  • (2007) Zablotska, I; Frankland, A; Prestage, Garrett; Grulich, Andrew; Imrie, John
    Conference Paper

  • (2007) Mao, Limin; Imrie, John; Prestage, Garrett; Grulich, Andrew; Donovan, Basil; Kaldor, John; Kippax, Susan
    Conference Paper

  • (2007) Templeton, David; Fin, F; Prestage, Garrett; Donovan, Basil; Imrie, John; Kippax, Susan; Kaldor, John; Grulich, Andrew
    Conference Paper

  • (2007) Templeton, David; Jin, F; Prestage, Garrett; Donovan, Basil; Kippax, Susan; Imrie, John; Kaldor, John; Grulich, Andrew
    Conference Paper

  • (2007) Zablotska, I; Prestage, Garrett; Grulich, Andrew; Imrie, John; Kippax, Susan
    Conference Paper

  • (2007) Jin, Feng Yi; Prestage, Garrett; Imrie, John; Kippax, Susan; Pell, Catherine; Donovan, Basil; Templeton, David; Cunningham, Philip; Cunningham, Amy; Mindel, Adrian; Kaldor, John; Grulich, Andrew
    Conference Paper