4,223 research outputs found
Systemic Amyloidosis – Insights by Cardiovascular Magnetic Resonance
No full textSystemic amyloidosis is the exemplar infiltrative, extracellular disease. Although it is a multi-organ disorder, cardiac involvement drives prognosis. Survival is worst in the AL amyloidosis subtype. It can affect any age and any race. There is no direct test for amyloid burden and there is no treatment for amyloidosis, there is only treatment for the underlying condition. Earlier diagnosis permits prompt treatment and improves survival. A number of imaging modalities exist to non-invasively detect cardiac disease but all have limitations. Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging provides the highest sensitivity for early detection. However, this also has its shortcomings. There is currently no non-invasive method of directly measuring amyloid burden in the extracellular space. New therapies are pending – but their development needs new surrogate endpoints and new tests are therefore desperately needed. T1 mapping permits tissue abnormalities to be directly visualised in a simple scan – the colour changes being instantly recognisable, either before contrast (pre contrast or native T1 mapping) or after, when the myocardial extracellular volume (ECV) can be measured. In a collaboration between the National Amyloidosis Centre and the Heart Hospital, I explored the possibility and potential that T1 mapping might measure cardiac (and other organ) involvement in systemic amyloidosis using EQ-MRI. In early clinical exploration in systemic AL amyloid, I showed that native myocardial T1 was elevated in cardiac amyloidosis and tracked disease, particularly early disease. Mean pre contrast myocardial T1 as measured by ShMOLLI was higher in patients at 1086 ± 90msec, compared to healthy volunteers of 958 ± 20msec (P 0.9 for both the FLASH IR and ShMOLLI techniques of T1 mapping and good agreement of ECV derived from both techniques. In pilot studies, I also demonstrated by serial scanning that changes (including regression) over time could be measured. In other organs, I showed that the amyloid burden could be measured and was higher in amyloidosis compared to healthy volunteer: ECV 0.32 vs 0.29 (P<0.001) for liver, 0.39 vs 0.34 (P<0.001) for spleen and 0.16 vs 0.09 (P<0.001) for skeletal muscle. These ECVs also tracked current conventional measures of disease severity by nuclear scintigraphy. These results demonstrate that the interstitial volume in patients with systemic AL amyloidosis can be measured non invasively in the heart, liver, spleen and skeletal muscle and that this correlates with existing markers of disease and survival. Pre contrast myocardial T1 was a good alternative measure for the heart. In conclusion, the work in this thesis has enabled a deeper understanding of cardiac amyloidosis, disease processes and stages. It has pioneered a new prognostic marker that is also able to identify some patients with cardiac involvement that were previously unrecognised. Novel subtypes are now recognised (e.g. cardiac amyloidosis with no LVH) and it has also allowed direct quantification of the liver and spleen. ECV is a new and powerful biomarker that has already been adopted by industry allowing development of new therapies and providing hope that an end to the scourge of this disease is near
Single breath-hold Vd(m) calculation as good as multi breath-hold technique in Equilibrium Contrast
No full textAssessemnt of the Interstitial Volume in Healthy Volunteers. An Equilibrium Contrast CMR study
No full textCardiac involvement in cardiac AL Amyloidosis as measured by Equilibrium Contrast Magnetic Resonance.
No full textYeast metabolism in fresh and frozen dough : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Palmerston North, New Zealand
No full textAuthor also known as SM LovedayFresh bakery products have a very short shelf life, which limits the extent to which manufacturing can be centralised. Frozen doughs are relatively stable and can be manufactured in large volumes, distributed and baked on-demand at the point of sale or consumption. With appropriate formulation and processing a shelf life of several months can be achieved.Shelf life is limited by a decline in proofing rate after thawing, which is attributed to a) the dough losing its ability to retain gas and b) insufficient gas production, i.e. yeast activity. The loss of shelf life is accelerated by delays between mixing and freezing, which allow yeast cells the chance to ferment carbohydrates.This work examined the reasons for insufficient gas production after thawing frozen dough and the effect of pre-freezing fermentation on shelf life. Literature data on yeast metabolite dynamics in fermenting dough were incomplete. In particular there were few data on the accumulation of ethanol, a major fermentation end product which can be injurious to yeast.Doughs were prepared in a domestic breadmaker using compressed yeast from a local manufacturer and analysed for glucose, fructose, sucrose, maltose and ethanol. Gas production after thawing declined within 48 hours of frozen storage. This was accelerated by 30 or 90 minutes of fermentation at 30;C prior to freezing.Sucrose was rapidly hydrolysed and yeast consumed glucose in preference to fructose. Maltose was not consumed while other sugars remained. Ethanol, accumulated from consumption of glucose and fructose, was produced in approximately equal amounts to CO2, indicating that yeast cells metabolised reductively.Glucose uptake in fermenting dough followed simple hyperbolic kinetics and fructose uptake was competitively inhibited by glucose. Mathematical modelling indicated that diffusion of sugars and ethanol in dough occurred quickly enough to eliminate solute gradients brought about by yeast metabolism
T1 mapping for ECV measurement: is the bolus technique good enough? A 123 patient study with gold standard of histological validatation and EQ-CMR
No full textConverting SrI <sub>2</sub> :Eu <sup>2+</sup> into a near infrared scintillator by Sm <sup>2+</sup> co-doping
No full text The luminescence and scintillation properties of SrI 2 single crystals doped with 5% Eu 2+ and 0.05%, 0.2% and 0.5% Sm 2+ are evaluated. X-ray excited and photoluminescence measurements show energy transfer from excited Eu 2+ ions to Sm 2+ ions. At a concentration of 0.5% Sm 2+ , the luminescence consists almost entirely of 740 nm emission from Sm 2+ 5d-4f transitions. Co-doping SrI 2 :5% Eu 2+ with Sm 2+ provides a novel method to bypass the self-absorption problem encountered in large SrI 2 :Eu 2+ crystals and, at the same time, provides a unique near-infrared emitting scintillator with a light yield of approximately 40,000 photons/MeV. Accepted Author ManuscriptRST/Fundamental Aspects of Materials and EnergyRST/Luminescence Material
'Laws 'Needefull in Later to be Abrogated': Intersex and the Sources of Christian Theology
No full textThis is the author accepted manuscript. The final version is available from Palgrave Macmillan via the DOI in this record
Introduction: Troubling Bodies?
No full textThis is the author accepted manuscript. The final version is available from Palgrave Macmillan via the DOI in this record
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