https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:12711 Wed 24 Jul 2013 22:24:45 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36190 measured during nighttime ambulatory BP monitoring (ABPM) and basal MAP estimated using a standardized protocol. Materials and methods: For a cohort of 137 consecutive patients, aged ≥40 years, who recently underwent ABPM, a blinded investigator estimated basal MAP from up to five most recent clinic BP measurements. Both basal MAP values, measured and estimated, were compared pairwise for each participant. Results: We traced a median of 4 [interquartile range 3-5] previous BP measurements per patient over a median period of 132 [interquartile range 55-277] days up until the ABPM test. The estimated basal MAP (mean 88 ± 8 mmHg) was linearly related (Pearson's r = 0.41, p = 0.0001) to the measured basal MAP (mean 88 ± 12 mmHg). Bland-Altman plot revealed a mean bias of 0.3 mmHg with agreement limits of ±22 mmHg. Conclusions: The mean bias between estimated and measured values for basal MAP was insignificant and modest. When a recent nighttime ABPM is unavailable, a protocol based on recent clinic BP readings can be used to estimate patient's basal MAP. Study registration: Australian New Zealand Clinical Trials Registry ACTRN12613001382763.]]> Thu 27 Feb 2020 09:35:33 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:12207 Sat 24 Mar 2018 08:08:25 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:17327 Sat 24 Mar 2018 08:01:44 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:18980 i = 10 µM at 100 nM Ca²⁺) that was similar to RyR2 from rat and sheep obtained under the same experimental conditions. However, in the presence of 0.1 mM Ca²⁺, RyR2s from human were 3.5-fold less sensitive to cytoplasmic Mg²⁺ inhibition than those from sheep and rat. The Kₐ values for luminal Ca²⁺ activation were similar in the three species (35 µM for human, 12 µM for sheep, and 10 µM for rat). From the relationship between open probability and luminal [Ca²⁺], the peak open probability for the human RyR2 was approximately the same as that for sheep, and both were ~10-fold greater than that for rat RyR2. Human RyR2 also showed the same sensitivity to luminal Mg²⁺ as that from sheep, whereas rat RyR2 was 10-fold more sensitive. In all species, modulation of RyR2 gating by luminal Ca²⁺ and Mg²⁺ only occurred when cytoplasmic [Ca²⁺] was <3 µM. The activation response of RyR2 to luminal and cytoplasmic Ca²⁺ was strongly dependent on the Mg²⁺ concentration. Addition of physiological levels (1 mM) of Mg²⁺ raised the Kₐ for cytoplasmic Ca²⁺ to 30 µM (human and sheep) or 90 µM (rat) and raised the Kₐ for luminal Ca²⁺ to ~1 mM in all species. This is the first report of the regulation by Ca²⁺ and Mg²⁺ of native RyR2 receptor activity from healthy human hearts.]]> Sat 24 Mar 2018 07:58:52 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46976 Mon 12 Dec 2022 16:54:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:12405 br), Q_br conductance (C_br), bronchial hemicircumference (CIRC_br), and bronchial wall thickness (WALL TH_br) in recovered, standing, awake sheep. Methacholine (MCh; 0.125–2.0 μg/kg iv), at the highest dose, caused a 233% rise in Qbr (P < 0.05) and a 286% rise in C_br (P < 0.05). CIRC_br fell to 90% (P < 0.05); WALL TH_br did not change. In contrast, nebulized MCh (1–32 mg/ml), inhaled through a mask at the highest dose, caused a rise in ventilation and a rise in Qbr proportional to aortic pressure without change in C_br. CIRC_br fell to 91% (P < 0.01), and WALL TH_br did not change. Thus inhaled MCh has access to cholinoceptors of bronchial circumferential smooth muscle to cause airway lumen narrowing but effectively not to those of the systemic bronchovascular circulation. It is speculated that the mechanism is selective neuroparacrine inhibition of muscarinic acetylcholine receptors (M3 bronchovascular cholinoceptors) by prostanoids released by intense MCh activation of epithelial and mucosal cells lining the airway.]]> Fri 30 Aug 2024 11:39:04 AEST ]]>