scholarly journals Imaging biomarkers in neurodegeneration: current and future practices

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Peter N. E. Young ◽  
Mar Estarellas ◽  
Emma Coomans ◽  
Meera Srikrishna ◽  
Helen Beaumont ◽  
...  
Keyword(s):  
Neurodegenerative Disorders ◽  
Imaging Biomarkers ◽  
New Techniques ◽  
Multimodal Analysis ◽  
The Past ◽  
Positron Emission ◽  
University College London ◽  
Magnetic Resonance Imaging Mri ◽  
The University

AbstractThere is an increasing role for biological markers (biomarkers) in the understanding and diagnosis of neurodegenerative disorders. The application of imaging biomarkers specifically for the in vivo investigation of neurodegenerative disorders has increased substantially over the past decades and continues to provide further benefits both to the diagnosis and understanding of these diseases. This review forms part of a series of articles which stem from the University College London/University of Gothenburg course “Biomarkers in neurodegenerative diseases”. In this review, we focus on neuroimaging, specifically positron emission tomography (PET) and magnetic resonance imaging (MRI), giving an overview of the current established practices clinically and in research as well as new techniques being developed. We will also discuss the use of machine learning (ML) techniques within these fields to provide additional insights to early diagnosis and multimodal analysis.

scholarly journals Imaging of microglial activation in MS using PET: Research use and potential future clinical application

2016 ◽  
Vol 23 (4) ◽  
pp. 496-504 ◽  
Author(s):  
Laura Airas ◽  
Eero Rissanen ◽  
Juha Rinne
Keyword(s):  
Complex Disease ◽  
Treatment Options ◽  
Quantitative Information ◽  
Imaging Biomarkers ◽  
In Vivo Evaluation ◽  
Non Invasive ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri

Multiple sclerosis (MS) is a complex disease, where several processes can be selected as a target for positron emission topography (PET) imaging. Unlike magnetic resonance imaging (MRI), PET provides specific and quantitative information, and unlike neuropathology, it can be non-invasively applied to living patients, which enables longitudinal follow-up of the MS pathology. In the study of MS, PET can be useful for in vivo evaluation of specific pathological characteristics at various stages of the disease. Increased understanding of the progressive MS pathology will enhance the treatment options of this undertreated condition. The ultimate goal of developing and expanding PET in the study of MS is to have clinical non-invasive in vivo imaging biomarkers of neuroinflammation that will help to establish prognosis and accurately measure response to therapeutics. This topical review provides an overview of the promises and challenges of the use of PET in MS.

scholarly journals How to Modulate Tumor Hypoxia for Preclinical In Vivo Imaging Research

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Sven De Bruycker ◽  
Christel Vangestel ◽  
Steven Staelens ◽  
Tim Van den Wyngaert ◽  
Sigrid Stroobants
Keyword(s):  
Tumor Hypoxia ◽  
Imaging Biomarkers ◽  
Tumor Aggressiveness ◽  
Poor Clinical Outcome ◽  
The Past ◽  
Positron Emission ◽  
Cancer Models ◽  
Imaging Research

Tumor hypoxia is related with tumor aggressiveness, chemo- and radiotherapy resistance, and thus a poor clinical outcome. Therefore, over the past decades, every effort has been made to develop strategies to battle the negative prognostic influence of tumor hypoxia. For appropriate patient selection and follow-up, noninvasive imaging biomarkers such as positron emission tomography (PET) radiolabeled ligands are unprecedentedly needed. Importantly, before being able to implement these new therapies and potential biomarkers into the clinical setting, preclinical in vivo validation in adequate animal models is indispensable. In this review, we provide an overview of the different attempts that have been made to create differential hypoxic in vivo cancer models with a particular focus on their applicability in PET imaging studies.

The importance of longitudinal cohort studies in understanding risk and protective factors for dementia

2014 ◽  
Vol 26 (4) ◽  
pp. 541-542 ◽  
Author(s):  
John T. O’Brien
Keyword(s):  
Protective Factors ◽  
Risk And Protective Factors ◽  
Functional Brain Imaging ◽  
Imaging Biomarkers ◽  
Resonance Imaging ◽  
Positron Emission ◽  
Β Amyloid ◽  
Magnetic Resonance Imaging Mri ◽  
Clinical Diagnostic Criteria

As readers of this journal will be well aware, the last decade has witnessed a transformation in our understanding of the pathophysiology of dementias, perhaps most especially Alzheimer's disease (AD), as well as a much greater understanding of the undoubtedly complex and multifactorial etiology of the AD process. An increasing number of genetic risk and protective factors have been identified, as well as potentially modifiable risk factors, including vascular factors such as hypertension and exercise, education, lifestyle, and nutrition. In parallel, there has been considerable progress in developing and validating biomarkers for AD and other dementias. These have transformed the landscape for research, allowing in vivo patient stratification according to pathology, and now have fed through to inform our clinical diagnostic criteria. Particular examples include imaging biomarkers such as characteristic atrophy patterns on magnetic resonance imaging (MRI), hypoperfusion/hypometabolism on functional brain imaging, increased cortical amyloid uptake on positron emission tomography (PET), as well as CSF alterations in tau and β-amyloid. Several changes in blood have also been shown, including altered inflammatory markers, which may prove to be important biomarkers in the future.

scholarly journals Porphyrin as Diagnostic and Therapeutic Agent

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2669 ◽  
Author(s):  
Ncediwe Tsolekile ◽  
Simphiwe Nelana ◽  
Oluwatobi Samuel Oluwafemi
Keyword(s):  
Therapeutic Agent ◽  
Disease Diagnosis ◽  
Conjugated Systems ◽  
The Past ◽  
Positron Emission ◽  
Preferential Localization ◽  
Pet Ct ◽  
Magnetic Resonance Imaging Mri

The synthesis and application of porphyrins has seen a huge shift towards research in porphyrin bio-molecular based systems in the past decade. The preferential localization of porphyrins in tumors, as well as their ability to generate reactive singlet oxygen and low dark toxicities has resulted in their use in therapeutic applications such as photodynamic therapy. However, their inherent lack of bio-distribution due to water insolubility has shifted research into porphyrin-nanomaterial conjugated systems to address this challenge. This has broadened their bio-applications, viz. bio-sensors, fluorescence tracking, in vivo magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT imaging to photo-immuno-therapy just to highlight a few. This paper reviews the unique theranostic role of porphyrins in disease diagnosis and therapy. The review highlights porphyrin conjugated systems and their applications. The review ends by bringing current challenges and future perspectives of porphyrin based conjugated systems and their respective applications into light.

scholarly journals Perspectives on the Role of Magnetic Resonance Imaging (MRI) for Noninvasive Evaluation of Diabetic Kidney Disease

2021 ◽  
Vol 10 (11) ◽  
pp. 2461
Author(s):  
José María Mora-Gutiérrez ◽  
María A. Fernández-Seara ◽  
Rebeca Echeverria-Chasco ◽  
Nuria Garcia-Fernandez
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Imaging Biomarkers ◽  
Major Advance ◽  
Resonance Imaging ◽  
Diabetic Kidney ◽  
Magnetic Resonance Imaging Mri

Renal magnetic resonance imaging (MRI) techniques are currently in vogue, as they provide in vivo information on renal volume, function, metabolism, perfusion, oxygenation, and microstructural alterations, without the need for exogenous contrast media. New imaging biomarkers can be identified using these tools, which represent a major advance in the understanding and study of the different pathologies affecting the kidney. Diabetic kidney disease (DKD) is one of the most important diseases worldwide due to its high prevalence and impact on public health. However, its multifactorial etiology poses a challenge for both basic and clinical research. Therefore, the use of novel renal MRI techniques is an attractive step forward in the comprehension of DKD, both in its pathogenesis and in its detection and surveillance in the clinical practice. This review article outlines the most promising MRI techniques in the study of DKD, with the purpose of stimulating their clinical translation as possible tools for the diagnosis, follow-up, and monitoring of the clinical impacts of new DKD treatments.

scholarly journals News about the Role of Fluid and Imaging Biomarkers in Neurodegenerative Diseases

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 252
Author(s):  
Jacopo Meldolesi
Keyword(s):  
Neurodegenerative Diseases ◽  
Imaging Techniques ◽  
Imaging Biomarkers ◽  
Positron Emission ◽  
Specific Proteins ◽  
Great Relevance ◽  
The Brain ◽  
Positive Point

Biomarkers are molecules that are variable in their origin, nature, and mechanism of action; they are of great relevance in biology and also in medicine because of their specific connection with a single or several diseases. Biomarkers are of two types, which in some cases are operative with each other. Fluid biomarkers, started around 2000, are generated in fluid from specific proteins/peptides and miRNAs accumulated within two extracellular fluids, either the central spinal fluid or blood plasma. The switch of these proteins/peptides and miRNAs, from free to segregated within extracellular vesicles, has induced certain advantages including higher levels within fluids and lower operative expenses. Imaging biomarkers, started around 2004, are identified in vivo upon their binding by radiolabeled molecules subsequently revealed in the brain by positron emission tomography and/or other imaging techniques. A positive point for the latter approach is the quantitation of results, but expenses are much higher. At present, both types of biomarker are being extensively employed to study Alzheimer’s and other neurodegenerative diseases, investigated from the presymptomatic to mature stages. In conclusion, biomarkers have revolutionized scientific and medical research and practice. Diagnosis, which is often inadequate when based on medical criteria only, has been recently improved by the multiplicity and specificity of biomarkers. Analogous results have been obtained for prognosis. In contrast, improvement of therapy has been limited or fully absent, especially for Alzheimer’s in which progress has been inadequate. An urgent need at hand is therefore the progress of a new drug trial design together with patient management in clinical practice.

Structural, Functional, and Molecular Neuroimaging Biomarkers for Alzheimer’s Disease

2013 ◽  
pp. 821-825
Author(s):  
James B. Brewer ◽  
Jorge Sepulcre ◽  
Keith A. Johnson
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Cognitive Impairment ◽  
Neurodegenerative Disorders ◽  
Brain Dysfunction ◽  
Imaging Biomarkers ◽  
Neurocognitive Evaluation ◽  
Neuroimaging Biomarkers

Advances in quantitative structural, functional, and molecular neuroimaging have provided new tools for objective, in vivo, assessment of critical aspects of Alzheimer’s disease and other neurodegenerative disorders. Measures of brain atrophy or brain dysfunction, coupled with measures of disease-linked pathology, might complement the history, physical and neurocognitive evaluation of patients and thereby improve predictive prognosis, especially at early stages of cognitive impairment where neurodegenerative etiology is less certain. Such imaging biomarkers are currently used in nearly all clinical trials of therapeutic agents for Alzheimer’s disease and are increasingly incorporated into clinical practice. In this chapter, imaging biomarkers are introduced and discussed to familiarize the reader with their potential research and clinical uses.

scholarly journals Pharmaceutical Applications of Molecular Tweezers, Clefts and Clips

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1803 ◽  
Author(s):  
Amira Mbarek ◽  
Ghina Moussa ◽  
Jeanne Leblond Chain
Keyword(s):  
Cardiovascular Disease ◽  
Neurodegenerative Disorders ◽  
Therapeutic Agents ◽  
Mechanistic Studies ◽  
Molecular Tweezers ◽  
The Past ◽  
Pharmaceutical Applications ◽  
Controlled Motion

Synthetic acyclic receptors, composed of two arms connected with a spacer enabling molecular recognition, have been intensively explored in host-guest chemistry in the past decades. They fall into the categories of molecular tweezers, clefts and clips, depending on the geometry allowing the recognition of various guests. The advances in synthesis and mechanistic studies have pushed them forward to pharmaceutical applications, such as neurodegenerative disorders, infectious diseases, cancer, cardiovascular disease, diabetes, etc. In this review, we provide a summary of the synthetic molecular tweezers, clefts and clips that have been reported for pharmaceutical applications. Their structures, mechanism of action as well as in vitro and in vivo results are described. Such receptors were found to selectively bind biological guests, namely, nucleic acids, sugars, amino acids and proteins enabling their use as biosensors or therapeutics. Particularly interesting are dynamic molecular tweezers which are capable of controlled motion in response to an external stimulus. They proved their utility as imaging agents or in the design of controlled release systems. Despite some issues, such as stability, cytotoxicity or biocompatibility that still need to be addressed, it is obvious that molecular tweezers, clefts and clips are promising candidates for several incurable diseases as therapeutic agents, diagnostic or delivery tools.

scholarly journals Metabolic Impairment in Human Amnesia: A PET Study of Memory Networks

1992 ◽  
Vol 12 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Ferruccio Fazio ◽  
Daniela Perani ◽  
Maria Carla Gilardi ◽  
Fabio Colombo ◽  
Stefano F. Cappa ◽  
...  
Keyword(s):  
Hippocampal Formation ◽  
Cerebral Metabolism ◽  
Human Memory ◽  
Clinical Syndrome ◽  
Long Term Memory ◽  
Positron Emission ◽  
New Information ◽  
Magnetic Resonance Imaging Mri

Human amnesia is a clinical syndrome exhibiting the failure to recall past events and to learn new information. Its “pure” form, characterized by a selective impairment of long-term memory without any disorder of general intelligence or other cognitive functions, has been associated with lesions localized within Papez's circuit and some connected areas. Thus, amnesia could be due to a functional disconnection between components of this or other neural structures involved in long-term learning and retention. To test this hypothesis, we measured regional cerebral metabolism with 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG) and positron emission tomography (PET) in 11 patients with “pure” amnesia. A significant bilateral reduction in metabolism in a number of interconnected cerebral regions (hippocampal formation, thalamus, cingulate gyrus, and frontal basal cortex) was found in the amnesic patients in comparison with normal controls. The metabolic impairment did not correspond to alterations in structural anatomy as assessed by magnetic resonance imaging (MRI). These results are the first in vivo evidence for the role of a functional network as a basis of human memory.

Enhanced magnetic resonance imaging in multiple sclerosis

2000 ◽  
Vol 6 (5) ◽  
pp. 320-326 ◽  
Author(s):  
M Filippi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Tissue Loss ◽  
Resonance Imaging ◽  
The Past ◽  
Magnetic Resonance Imaging Mri ◽  
The One ◽  
The Relationship

Gadolinium-enhanced magnetic resonance imaging (MRI) is very sensitive in the detection of active lesions of multiple sclerosis (MS) and has become a valuable tool to monitor the evolution of the disease either natural or modified by treatment. In the past few years, several studies, on the one hand, have assessed several ways to increase the sensitivity of enhanced MRI to disease activity and, on the other, have investigated in vivo the nature and evolution of enhancing lesions using different non-conventional MR techniques to better define the relationship between enhancement and tissue loss in MS. The present review is a summary of these studies whose results are discussed in the context of MS clinical trial planning and monitoring.

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