الفهرس 
SUMMARY
Literature surveyOnly 14 pages are availabe for public view
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Abstract
The two key features of change in the brains of patients: plaques and tangles. What causes these plaques and tangles has been linked to a variety of processes including the accumulation of proteins. Then the risk factors for AD as it develops as a result of multiple factors such a single cause. Types of AD are early and late onset. The biomarkers showing the level of Aβ accumulation in the brain. The strategies for treatment of AD: pharmacological and non-pharmacological. The survey also covers the role of D-galactose (DG) and some heavy metals in AD and then the literature survey for the methods used for determination of beta amyloid (Aβ). The instrumentation used in this thesis viz. voltammetry: square wave voltammetry, cyclic voltammetry, UV-Vis spectrophotometry, high performance liquid chromatography (HPLC) and gas chromatography (GC). The second chapter is for the experimental part including the animals used, the experimental design, brains and blood processing, material and preparation of solutions for each methodology. The third chapter is divided into four parts: The first part is about the determination of Aβ using HPLC. Method development and optimization, instrumentation parameters, method validation were assessed. Successful applicability is achieved of the proposed method for the determination of the Aβ in experimental rats’ brain and in plasma as a cost-effective and non-invasive diagnostic tool that serves as a prognostic blood based biomarker. It also includes the quantitation of Aβ1-38 through its copper (Cu) complex since it enhances the sensitivity ten times its absence. At the end of this part we have concluded that Aβ can be used as biomarker for AD and that our proposed method is valid for determination of Aβ in both brain and blood samples by HPLC. UV-Vis has been also used for the determination of Aβ1-38 giving rise to easy and cheap method of analysis. We also confirmed the increase of Aβ in AD rat’s brain samples than control brain samples by GC/MS. Fragmentation of Aβ to its base units of amino acids was assessed by GC/MS. The second part of chapter three is concerned with the development of highly selective label-free electrochemical biosensor for ex-vivo monitoring of AD biomarker;in this part an electrochemical biosensor was designed and developed for detection of Aβ biomarker in-vitro as well as in ex-vivo. The prepared electrode is gold nanoparticles loaded on Indium tin oxide (AuNPs/ITO) electrode. The third part of chapter three is aboutthe possible complex formation reaction that may be occurred between Al(III), Cu(II) or Pb(II) and Aβ by UV- Vis Spectrometry. The binding constants were calculated to be 35.282x108K/M-1, 2.9396x108K/M-1 and 1.031x108K/M-1 for Al, Cu and Pb respectively. The effect of curcumin on Aβ was studied by UV-Vis and TEM techniques. It is found that there was blue shift in Aβ absorbance peak in the presence of curcumin indicating that there may be a kind of interaction probably a charge transfer complex formation between Aβ and curcumin. By investigating the control brain samples and the Alzheimer’s induced one and that treated with curcumin at different time intervals using TEM, we found that there is a sheet formation and then it degrades quickly in the presence of curcumin. The shape of these samples are very similar to that of the control one indicating that curcumin may be used as a promising drug for AD.