scholarly journals Novel Trends in Electrochemical Biosensors for Early Diagnosis of Alzheimer’s Disease

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Pavla Valkova ◽  
Miroslav Pohanka

Background. Alzheimer’s disease (AD) is a multifactorial progressive and irreversible neurodegenerative disorder affecting mainly the population over 65 years of age. It is becoming a global health and socioeconomic problem, and the current number of patients reaching 30–50 million people will be three times higher over the next thirty years. Objective. Late diagnosis caused by decades of the asymptomatic phase and invasive and cost-demanding diagnosis are problems that make the whole situation worse. Electrochemical biosensors could be the right tool for less invasive and inexpensive early diagnosis helping to reduce spend sources— both money and time. Method. This review is a survey of the latest advances in the design of electrochemical biosensors for the early diagnosis of Alzheimer’s disease. Biosensors are divided according to target biomarkers. Conclusion. Standard laboratory methodology could be improved by analyzing a combination of currently estimated markers along with neurotransmitters and genetic markers from blood samples, which make the test for AD diagnosis available to the wide public.

2013 ◽  
Vol 3 (2) ◽  
pp. 20120072 ◽  
Author(s):  
Kari Antila ◽  
Jyrki Lötjönen ◽  
Lennart Thurfjell ◽  
Jarmo Laine ◽  
Marcello Massimini ◽  
...  

Alzheimer's disease (AD) is the most common cause of dementia affecting 36 million people worldwide. As the demographic transition in the developed countries progresses towards older population, the worsening ratio of workers per retirees and the growing number of patients with age-related illnesses such as AD will challenge the current healthcare systems and national economies. For these reasons AD has been identified as a health priority, and various methods for diagnosis and many candidates for therapies are under intense research. Even though there is currently no cure for AD, its effects can be managed. Today the significance of early and precise diagnosis of AD is emphasized in order to minimize its irreversible effects on the nervous system. When new drugs and therapies enter the market it is also vital to effectively identify the right candidates to benefit from these. The main objective of the PredictAD project was to find and integrate efficient biomarkers from heterogeneous patient data to make early diagnosis and to monitor the progress of AD in a more efficient, reliable and objective manner. The project focused on discovering biomarkers from biomolecular data, electrophysiological measurements of the brain and structural, functional and molecular brain images. We also designed and built a statistical model and a framework for exploiting these biomarkers with other available patient history and background data. We were able to discover several potential novel biomarker candidates and implement the framework in software. The results are currently used in several research projects, licensed to commercial use and being tested for clinical use in several trials.


2008 ◽  
Vol 21 (6) ◽  
pp. 755-771
Author(s):  
O. Schillaci ◽  
L. Travascio ◽  
C. Bruni ◽  
G. Bazzocchi ◽  
A. Testa ◽  
...  

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is the most common cause of dementia in the elderly. Magnetic resonance (MR) or computed tomography (CT) imaging is recommended for routine evaluation of dementias. The development of molecular imaging agents and the new techniques of MR for AD are critically important for early diagnosis, neuropathogenesis studies and assessing treatment efficacy in AD. Neuroimaging using nuclear medicine techniques such as SPECT, PET and MR spectroscopy has the potential to characterize the biomarkers for Alzheimer's disease. The present review summarizes the results of radionuclide imaging and MR imaging in AD.


2021 ◽  
Vol 5 (2) ◽  
pp. 14
Author(s):  
Giovanni Frisoni ◽  
Jean-Marie Annoni ◽  
Stefanie Becker ◽  
Tim Brockmann ◽  
Markus Buerge ◽  
...  

The present document represents the position of Swiss health-care associations, clinical and research centers, research-supporting foundations, and the association Alzheimer Switzerland regarding the care of persons with dementia and Alzheimer’s disease. We claim that dementia is not part of normal aging but a disease developing more frequently in old age; early diagnosis and treatment of dementia is paramount; all patients with dementia have the right to receive state-of-the-art treatments; more intense information, education, and counseling on dementia are necessary; media should provide balanced and fair reporting of scientific discoveries on Alzheimer’s and dementia; all patients with dementia have the right to be treated; anti-dementia drugs should be used and accompanied by listening, compassion, and understanding.


2021 ◽  
Author(s):  
Hamed Taheri Gorji ◽  
Ramtin Kardan ◽  
Neda Rezagholizadeh

Alzheimer's Disease (AD) is a progressive neurodegenerative disorder and the most commonly diagnosed cause of dementia, and it is the fifth leading cause of death among people aged 65 and older. During the years, the early diagnosis of AD patients has been a significant concern for researchers, in view of the fact that early diagnosis not only can lead to saving lives of the AD patients but also could bring a considerable amount of saving in health and long-term care expenditures for both people and the government. Mild cognitive impairment (MCI), defined as a transitional state between being healthy and having AD, is considered an established risk factor for AD. Hence, an accurate and reliable diagnosis of MCI and, consequently, discrimination between healthy people, MCI individuals, and AD patients can play a crucial role in the early diagnosis of AD. In recent years, analysis of blood gene expression data has been grabbed more attention than the conventional AD diagnosis method because it provides the opportunity to investigate the biochemical pathways, cellular functions, and regulatory mechanisms for finding the key genes associated with MCI and AD. Therefore, in this study, we employed blood gene expression data from Alzheimer's Disease Neuroimaging Initiative (ADNI), two feature selection methods for determining the most prominent genes related to MCI and AD, and three classifiers for the most accurate discrimination between three groups of healthy, MCI and AD. The proposed method yielded the selection of top ten genes from more than 49,000 genes and the best overall classification result between healthy and AD patients with average values of the area under the curve (AUC) of 0.77 +- 0.08. Furthermore, gene ontology (GO) analysis revealed that four genes were enriched with the GO terms of regulation of cell proliferation, negative regulation of cell population proliferation, signaling receptor binding, biological adhesion, and cytokine production.


2021 ◽  
Vol 7 (1) ◽  
pp. 1-16
Author(s):  
Qinyu Peng ◽  
Zhentao Zhang

Alzheimer’s disease (AD) is the most common neurodegenerative disorder. However, it still has no available disease‐modifying therapies. Its pathology cascade begins decades before symptomatic presentation. For these reasons, highly sensitive and highly specific fluid biomarkers should be developed for the early diagnosis of AD. In this study, the well‐established and emerging fluid biomarkers of AD are summarized, and recent advances on their role in early diagnosis and progression monitoring as well as their correlations with AD pathology are highlighted. Future prospects and related research directions are also discussed.


The Analyst ◽  
2017 ◽  
Vol 142 (8) ◽  
pp. 1276-1284 ◽  
Author(s):  
S. Mordechai ◽  
E. Shufan ◽  
B. S. Porat Katz ◽  
A. Salman

A simple blood test for the diagnosis of Alzheimer's disease using FTIR microscopy.


Bioimpacts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 219-225 ◽  
Author(s):  
Elham Mehdizadeh ◽  
Mohammad Khalaj-Kondori ◽  
Zeinab Shaghaghi-Tarakdari ◽  
Saeed Sadigh-Eteghad ◽  
Mahnaz Talebi ◽  
...  

Introduction: Alzheimer’s disease (AD), which is a progressive neurodegenerative disorder, causes structural and functional brain disruption. MS4A6A, TREM2, and CD33 gene polymorphisms loci have been found to be associated with the pathobiology of late-onset AD (LOAD). In the present study, we tested the hypothesis of association of LOAD with rs983392, rs75932628, and rs3865444 polymorphisms in MS4A6A, TREM2, CD33 genes, respectively.Methods: In the present study, 113 LOAD patients and 100 healthy unrelated age- and gender-matched controls were selected. DNA was extracted from blood samples by the salting-out method and the genotyping was performed by RFLP-PCR. Electrophoresis was carried out on agarose gel. Sequencing was thereafter utilized for the confirmation of the results. Results: Only CD33 rs3865444 polymorphism revealed a significant difference in the genotypic frequencies of GG (P = 0.001) and GT (P = 0.001), and allelic frequencies of G (P = 0.033) and T (P = 0.03) between LOAD patients and controls. Conclusion: The evidence from the present study suggests that T allele of CD33 rs3865444 polymorphism is associated with LOAD in the studied Iranian population.


2021 ◽  
Vol 22 (4) ◽  
pp. 2110
Author(s):  
Wieke M. van Oostveen ◽  
Elizabeth C. M. de Lange

Background. Alzheimer’s disease (AD) is a progressive neurodegenerative disorder affecting many individuals worldwide with no effective treatment to date. AD is characterized by the formation of senile plaques and neurofibrillary tangles, followed by neurodegeneration, which leads to cognitive decline and eventually death. Introduction. In AD, pathological changes occur many years before disease onset. Since disease-modifying therapies may be the most beneficial in the early stages of AD, biomarkers for the early diagnosis and longitudinal monitoring of disease progression are essential. Multiple imaging techniques with associated biomarkers are used to identify and monitor AD. Aim. In this review, we discuss the contemporary early diagnosis and longitudinal monitoring of AD with imaging techniques regarding their diagnostic utility, benefits and limitations. Additionally, novel techniques, applications and biomarkers for AD research are assessed. Findings. Reduced hippocampal volume is a biomarker for neurodegeneration, but atrophy is not an AD-specific measure. Hypometabolism in temporoparietal regions is seen as a biomarker for AD. However, glucose uptake reflects astrocyte function rather than neuronal function. Amyloid-β (Aβ) is the earliest hallmark of AD and can be measured with positron emission tomography (PET), but Aβ accumulation stagnates as disease progresses. Therefore, Aβ may not be a suitable biomarker for monitoring disease progression. The measurement of tau accumulation with PET radiotracers exhibited promising results in both early diagnosis and longitudinal monitoring, but large-scale validation of these radiotracers is required. The implementation of new processing techniques, applications of other imaging techniques and novel biomarkers can contribute to understanding AD and finding a cure. Conclusions. Several biomarkers are proposed for the early diagnosis and longitudinal monitoring of AD with imaging techniques, but all these biomarkers have their limitations regarding specificity, reliability and sensitivity. Future perspectives. Future research should focus on expanding the employment of imaging techniques and identifying novel biomarkers that reflect AD pathology in the earliest stages.


2020 ◽  
Vol 16 (12) ◽  
pp. 1132-1142 ◽  
Author(s):  
Fantian Zeng ◽  
Yuyan Li ◽  
Yungen Xu ◽  
Jian Yang ◽  
Zhengshi Liu ◽  
...  

Background: Alzheimer’s Disease (AD) is the most common neurodegenerative disorder, and it is still incurable. Early diagnosis and intervention are crucial for delaying the onset and progression of the disease. Mounting evidence indicates that the neurotoxic effects might be attributed to Soluble β-Amyloid Oligomers (SAβO). The SAβO are believed to be neurotoxic peptides more predominant than Aβ plaques in the early stage, and their key role in AD is self-evident. Unfortunately, identification of SAβO proves to be difficult due to their heterogeneous and transient nature. In spite of many obstacles, multiple techniques have recently been developed to target SAβO effectively. This review focuses on the recent progress in the approaches towards SAβO detection in order to shed some light on the future development of SAβO assays. Methods : Literatures were obtained from the following libraries: Web of Science, PubMed, EPO, SIPO, USPTO. Articles were critically reviewed based on their titles, abstracts, and contents. Results: A total of 85 papers are referenced in the review. Results are divided into three categories based on the types of detection methods: small molecule fluorescence probes, oligomer-specific antibodies and electrochemical biosensors. Finally, the improvements and challenges of these approaches applied in the early diagnosis of AD were discussed. Conclusion: This review article covers three kinds of strategies that could be translated into clinic practice and lead to earlier diagnosis and therapeutic interventions of AD.


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