https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30612 18F-Florbetaben, was employed to categorise participants as low NAL (standard uptake value ratio; SUVR < 1.35, N = 65) and high NAL or preclinical AD (SUVR ≥ 1.35, N = 35) wherein, linear models were employed to compare FA compositions between the two groups. Increased arachidonic acid (AA, p < 0.05) and decreased docosapentaenoic acid (DPA, p < 0.05) were observed in high NAL. To differentiate low from high NAL, the area under the curve (AUC) generated from a ‘base model’ comprising age, gender, APOEε4 and education (AUC = 0.794) was outperformed by base model + AA:DPA (AUC = 0.836). Our findings suggest that specific alterations in erythrocyte FA composition occur very early in the disease pathogenic trajectory, prior to cognitive impairment. As erythrocyte FA levels are reflective of tissue FA, these alterations may provide insight into the pathogenic mechanism(s) of the disease and may highlight potential early diagnostic markers and therapeutic targets.]]> Wed 11 Apr 2018 11:27:55 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46149 40 and Aβ₄₂ concentrations were measured using the ultrasensitive Single Molecule Array (Simoa) assay in 95 cognitively normal elderly individuals, who have all undergone PET to assess brain Aβ deposition. Based on the standard uptake value ratios (SUVR) obtained from PET imaging, using the tracer ¹⁸F-Florbetaben, plasma Aβ was compared between 32 participants assessed to have low brain Aβ load (Aβ–, SUVR <1.35) and 63 assessed to have high brain Aβ load (Aβ+, SUVR ≥1.35). Results: Plasma Aβ₄₂/Aβ₄₀ ratios were lower in the Aβ+ group compared to the Aβ–group. Plasma Aβ₄₀ and Aβ₄₂ levels were not significantly different between Aβ–and Aβ+ groups, although a trend of higher plasma Aβ₄₀ was observed in the Aβ+ group. Additionally, plasma Aβ₄₂/Aβ₄₀ ratios along with the known AD risk factors, age and APOE ɛ4 status, resulted in Aβ+ participants being distinguished from Aβ–participants based on an area under the receiver operating characteristic curve shown to be 78%. Conclusion: Plasma Aβ ratios in this study are a potential biomarker for brain Aβ deposition and therefore, for preclinical AD. However, this method to measure plasma Aβ needs further development to increase the accuracy of this promising AD blood biomarker.]]> Fri 11 Nov 2022 18:51:47 AEDT ]]>