LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 122

Search options

  1. Article ; Online: Brain injury-induced dysfunction of the blood brain barrier as a risk for dementia.

    Abrahamson, Eric E / Ikonomovic, Milos D

    Experimental neurology

    2020  Volume 328, Page(s) 113257

    Abstract: The blood-brain barrier (BBB) is a complex and dynamic physiological interface between brain parenchyma and cerebral vasculature. It is composed of closely interacting cells and signaling molecules that regulate movement of solutes, ions, nutrients, ... ...

    Abstract The blood-brain barrier (BBB) is a complex and dynamic physiological interface between brain parenchyma and cerebral vasculature. It is composed of closely interacting cells and signaling molecules that regulate movement of solutes, ions, nutrients, macromolecules, and immune cells into the brain and removal of products of normal and abnormal brain cell metabolism. Dysfunction of multiple components of the BBB occurs in aging, inflammatory diseases, traumatic brain injury (TBI, severe or mild repetitive), and in chronic degenerative dementing disorders for which aging, inflammation, and TBI are considered risk factors. BBB permeability changes after TBI result in leakage of serum proteins, influx of immune cells, perivascular inflammation, as well as impairment of efflux transporter systems and accumulation of aggregation-prone molecules involved in hallmark pathologies of neurodegenerative diseases with dementia. In addition, cerebral vascular dysfunction with persistent alterations in cerebral blood flow and neurovascular coupling contribute to brain ischemia, neuronal degeneration, and synaptic dysfunction. While the idea of TBI as a risk factor for dementia is supported by many shared pathological features, it remains a hypothesis that needs further testing in experimental models and in human studies. The current review focusses on pathological mechanisms shared between TBI and neurodegenerative disorders characterized by accumulation of pathological protein aggregates, such as Alzheimer's disease and chronic traumatic encephalopathy. We discuss critical knowledge gaps in the field that need to be explored to clarify the relationship between TBI and risk for dementia and emphasize the need for longitudinal in vivo studies using imaging and biomarkers of BBB dysfunction in people with single or multiple TBI.
    MeSH term(s) Animals ; Blood-Brain Barrier/pathology ; Blood-Brain Barrier/physiopathology ; Brain Injuries, Traumatic/complications ; Brain Injuries, Traumatic/pathology ; Brain Injuries, Traumatic/physiopathology ; Dementia/etiology ; Dementia/pathology ; Dementia/physiopathology ; Humans ; Neurovascular Coupling/physiology ; Risk Factors
    Language English
    Publishing date 2020-02-21
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S. ; Review
    ZDB-ID 207148-4
    ISSN 1090-2430 ; 0014-4886
    ISSN (online) 1090-2430
    ISSN 0014-4886
    DOI 10.1016/j.expneurol.2020.113257
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Chronic effects of blast injury on the microvasculature in a transgenic mouse model of Alzheimer's disease related Aβ amyloidosis.

    Clark, Alexander T / Abrahamson, Eric E / Harper, Matthew M / Ikonomovic, Milos D

    Fluids and barriers of the CNS

    2022  Volume 19, Issue 1, Page(s) 5

    Abstract: Background: Altered cerebrovascular function and accumulation of amyloid-β (Aβ) after traumatic brain injury (TBI) can contribute to chronic neuropathology and increase the risk for Alzheimer's disease (AD). TBI due to a blast-induced shock wave (bTBI) ... ...

    Abstract Background: Altered cerebrovascular function and accumulation of amyloid-β (Aβ) after traumatic brain injury (TBI) can contribute to chronic neuropathology and increase the risk for Alzheimer's disease (AD). TBI due to a blast-induced shock wave (bTBI) adversely affects the neurovascular unit (NVU) during the acute period after injury. However, the chronic effects of bTBI and Aβ on cellular components of the NVU and capillary network are not well understood.
    Methods: We exposed young adult (age range: 76-106 days) female transgenic (Tg) APP/PS1 mice, a model of AD-like Aβ amyloidosis, and wild type (Wt) mice to a single bTBI (~ 138 kPa or ~ 20 psi) or to a Sham procedure. At 3-months or 12-months survival after exposure, we quantified neocortical Aβ load in Tg mice, and percent contact area between aquaporin-4 (AQP4)-immunoreactive astrocytic end-feet and brain capillaries, numbers of PDGFRβ-immunoreactive pericytes, and capillary densities in both genotypes.
    Results: The astroglia AQP4-capillary contact area in the Tg-bTBI group was significantly lower than in the Tg-Sham group at 3-months survival. No significant changes in the AQP4-capillary contact area were observed in the Tg-bTBI group at 12-months survival or in the Wt groups. Capillary density in the Tg-bTBI group at 12-months survival was significantly higher compared to the Tg-Sham control and to the Tg-bTBI 3-months survival group. The Wt-bTBI group had significantly lower capillary density and pericyte numbers at 12-months survival compared to 3-months survival. When pericytes were quantified relative to capillary density, no significant differences were detected among the experimental groups, for both genotypes.
    Conclusion: In conditions of high brain concentrations of human Aβ, bTBI exposure results in reduced AQP4 expression at the astroglia-microvascular interface, and in chronic capillary proliferation like what has been reported in AD. Long term microvascular changes after bTBI may contribute to the risk for developing chronic neurodegenerative disease later in life.
    MeSH term(s) Alzheimer Disease/etiology ; Alzheimer Disease/metabolism ; Alzheimer Disease/physiopathology ; Amyloid beta-Peptides/metabolism ; Animals ; Blast Injuries/complications ; Blast Injuries/metabolism ; Blast Injuries/physiopathology ; Brain Injuries, Traumatic/complications ; Brain Injuries, Traumatic/metabolism ; Brain Injuries, Traumatic/physiopathology ; Disease Models, Animal ; Female ; Humans ; Mice ; Mice, Transgenic ; Microvessels/metabolism ; Microvessels/physiopathology
    Chemical Substances Amyloid beta-Peptides
    Language English
    Publishing date 2022-01-10
    Publishing country England
    Document type Journal Article
    ZDB-ID 2595406-4
    ISSN 2045-8118 ; 2045-8118
    ISSN (online) 2045-8118
    ISSN 2045-8118
    DOI 10.1186/s12987-021-00301-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article: Application of robust regression in translational neuroscience studies with non-Gaussian outcome data.

    Malek-Ahmadi, Michael / Ginsberg, Stephen D / Alldred, Melissa J / Counts, Scott E / Ikonomovic, Milos D / Abrahamson, Eric E / Perez, Sylvia E / Mufson, Elliott J

    Frontiers in aging neuroscience

    2024  Volume 15, Page(s) 1299451

    Abstract: Linear regression is one of the most used statistical techniques in neuroscience, including the study of the neuropathology of Alzheimer's disease (AD) dementia. However, the practical utility of this approach is often limited because dependent variables ...

    Abstract Linear regression is one of the most used statistical techniques in neuroscience, including the study of the neuropathology of Alzheimer's disease (AD) dementia. However, the practical utility of this approach is often limited because dependent variables are often highly skewed and fail to meet the assumption of normality. Applying linear regression analyses to highly skewed datasets can generate imprecise results, which lead to erroneous estimates derived from statistical models. Furthermore, the presence of outliers can introduce unwanted bias, which affect estimates derived from linear regression models. Although a variety of data transformations can be utilized to mitigate these problems, these approaches are also associated with various caveats. By contrast, a robust regression approach does not impose distributional assumptions on data allowing for results to be interpreted in a similar manner to that derived using a linear regression analysis. Here, we demonstrate the utility of applying robust regression to the analysis of data derived from studies of human brain neurodegeneration where the error distribution of a dependent variable does not meet the assumption of normality. We show that the application of a robust regression approach to two independent published human clinical neuropathologic data sets provides reliable estimates of associations. We also demonstrate that results from a linear regression analysis can be biased if the dependent variable is significantly skewed, further indicating robust regression as a suitable alternate approach.
    Language English
    Publishing date 2024-01-24
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2558898-9
    ISSN 1663-4365
    ISSN 1663-4365
    DOI 10.3389/fnagi.2023.1299451
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Novel ultrasensitive immunoassay for the selective quantification of tau oligomers and related soluble aggregates.

    Islam, Tohidul / Kvartsberg, Hlin / Sehrawat, Anuradha / Kac, Przemysław R / Becker, Bruno / Olsson, Maria / Abrahamson, Eric E / Zetterberg, Henrik / Ikonomovic, Milos D / Blennow, Kaj / Karikari, Thomas K

    Alzheimer's & dementia : the journal of the Alzheimer's Association

    2024  Volume 20, Issue 4, Page(s) 2894–2905

    Abstract: Introduction: Tau aggregation into paired helical filaments and neurofibrillary tangles is characteristic of Alzheimer's disease (AD) and related disorders. However, biochemical assays for the quantification of soluble, earlier-stage tau aggregates are ... ...

    Abstract Introduction: Tau aggregation into paired helical filaments and neurofibrillary tangles is characteristic of Alzheimer's disease (AD) and related disorders. However, biochemical assays for the quantification of soluble, earlier-stage tau aggregates are lacking. We describe an immunoassay that is selective for tau oligomers and related soluble aggregates over monomers.
    Methods: A homogeneous (single-antibody) immunoassay was developed using a novel anti-tau monoclonal antibody and validated with recombinant and brain tissue-derived tau.
    Results: The assay signals were concentration dependent for recombinant tau aggregates in solution but not monomers, and recognized peptides within, but not outside, the aggregation-prone microtubule binding region. The signals in inferior and middle frontal cortical tissue homogenates increased with neuropathologically determined Braak staging, and were higher in insoluble than soluble homogenized brain fractions. Autopsy-verified AD gave stronger signals than other neurodegenerative diseases.
    Discussion: The quantitative oligomer/soluble aggregate-specific assay can identify soluble tau aggregates, including oligomers, from monomers in human and in vitro biospecimens.
    Highlights: The aggregation of tau to form fibrils and neurofibrillary tangles is a key feature of Alzheimer's disease. However, biochemical assays for the quantification of oligomers/soluble aggregated forms of tau are lacking. We developed a new assay that preferentially binds to soluble tau aggregates, including oligomers and fibrils, versus monomers. The assay signal increased corresponding to the total protein content, Braak staging, and insolubility of the sequentially homogenized brain tissue fractions in an autopsy-verified cohort. The assay recognized tau peptides containing the microtubule binding region but not those covering the N- or C-terminal regions only.
    MeSH term(s) Humans ; Alzheimer Disease/diagnosis ; Alzheimer Disease/metabolism ; tau Proteins/metabolism ; Neurofibrillary Tangles ; Immunoassay ; Peptides/metabolism
    Chemical Substances tau Proteins ; Peptides
    Language English
    Publishing date 2024-03-23
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2211627-8
    ISSN 1552-5279 ; 1552-5260
    ISSN (online) 1552-5279
    ISSN 1552-5260
    DOI 10.1002/alz.13711
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: The flutemetamol analogue cyano-flutemetamol detects myocardial AL and ATTR amyloid deposits: a post-mortem histofluorescence analysis.

    Abrahamson, Eric E / Padera, Robert F / Davies, Julie / Farrar, Gill / Villemagne, Victor L / Dorbala, Sharmila / Ikonomovic, Milos D

    Amyloid : the international journal of experimental and clinical investigation : the official journal of the International Society of Amyloidosis

    2022  Volume 30, Issue 2, Page(s) 169–187

    Abstract: Background: [: Methods: Myocardial tissue was obtained post-mortem from 29 subjects with cardiac amyloidosis including transthyretin wild-type (ATTRwt), hereditary/variant transthyretin (ATTRv) and immunoglobulin light-chain (AL) types, and from 10 ... ...

    Abstract Background: [
    Methods: Myocardial tissue was obtained post-mortem from 29 subjects with cardiac amyloidosis including transthyretin wild-type (ATTRwt), hereditary/variant transthyretin (ATTRv) and immunoglobulin light-chain (AL) types, and from 10 cardiac amyloid-free controls. Most subjects had antemortem electrocardiography, echocardiography, SPECT and cardiac MRI. Cyano-flutemetamol labeling patterns and integrated density values were evaluated relative to fluorescent derivatives of Congo red (X-34) and Pittsburgh compound-B (cyano-PiB).
    Results: Cyano-flutemetamol labeling was not detectable in control subjects. In subjects with cardiac amyloidosis, cyano-flutemetamol labeling matched X-34- and cyano-PiB-labeled, and transthyretin- or lambda light chain-immunoreactive, amyloid deposits and was prevented by formic acid pre-treatment of myocardial sections. Cyano-flutemetamol mean fluorescence intensity, when adjusted for X-34 signal, was higher in the ATTRwt than the AL group. Cyano-flutemetamol integrated density correlated strongly with echocardiography measures of ventricular septal thickness and posterior wall thickness, and with heart mass.
    Conclusion: The high selectivity of cyano-flutemetamol binding to myocardial amyloid supports the diagnostic utility of [
    MeSH term(s) Humans ; Plaque, Amyloid/pathology ; Prealbumin/genetics ; Prealbumin/metabolism ; Myocardium/pathology ; Benzothiazoles/metabolism ; Amyloidosis/metabolism ; Amyloid/metabolism ; Amyloidogenic Proteins/metabolism
    Chemical Substances flutemetamol (0F3M7032P5) ; Prealbumin ; 1,4-bis(3-carboxy-4-hydroxyphenylethenyl)-benzene ; Benzothiazoles ; Amyloid ; Amyloidogenic Proteins
    Language English
    Publishing date 2022-11-21
    Publishing country England
    Document type Journal Article
    ZDB-ID 1205246-2
    ISSN 1744-2818 ; 1350-6129
    ISSN (online) 1744-2818
    ISSN 1350-6129
    DOI 10.1080/13506129.2022.2141623
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Vesicular Glutamate Transporter Changes in the Cortical Default Mode Network During the Clinical and Pathological Progression of Alzheimer's Disease.

    Mi, Zhiping / Abrahamson, Eric E / Ryu, Angela Y / Malek-Ahmadi, Michael / Kofler, Julia K / Fish, Kenneth N / Sweet, Robert A / Villemagne, Victor L / Schneider, Julie A / Mufson, Elliott J / Ikonomovic, Milos D

    Journal of Alzheimer's disease : JAD

    2023  Volume 94, Issue 1, Page(s) 227–246

    Abstract: Background: Altered glutamatergic neurotransmission may contribute to impaired default mode network (DMN) function in Alzheimer's disease (AD). Among the DMN hub regions, frontal cortex (FC) was suggested to undergo a glutamatergic plasticity response ... ...

    Abstract Background: Altered glutamatergic neurotransmission may contribute to impaired default mode network (DMN) function in Alzheimer's disease (AD). Among the DMN hub regions, frontal cortex (FC) was suggested to undergo a glutamatergic plasticity response in prodromal AD, while the status of glutamatergic synapses in the precuneus (PreC) during clinical-neuropathological AD progression is not known.
    Objective: To quantify vesicular glutamate transporter VGluT1- and VGluT2-containing synaptic terminals in PreC and FC across clinical stages of AD.
    Methods: Unbiased sampling and quantitative confocal immunofluorescence of cortical VGluT1- and VGluT2-immunoreactive profiles and spinophilin-labeled dendritic spines were performed in cases with no cognitive impairment (NCI), mild cognitive impairment (MCI), mild-moderate AD (mAD), or moderate-severe AD (sAD).
    Results: In both regions, loss of VGluT1-positive profile density was seen in sAD compared to NCI, MCI, and mAD. VGluT1-positive profile intensity in PreC did not differ across groups, while in FC it was greater in MCI, mAD, and sAD compared to NCI. VGluT2 measures were stable in PreC while FC had greater VGluT2-positive profile density in MCI compared to sAD, but not NCI or mAD. Spinophilin measures in PreC were lower in mAD and sAD compared to NCI, while in FC they were stable across groups. Lower VGluT1 and spinophilin measures in PreC, but not FC, correlated with greater neuropathology.
    Conclusion: Frank loss of VGluT1 in advanced AD relative to NCI occurs in both DMN regions. In FC, an upregulation of VGluT1 protein content in remaining glutamatergic terminals may contribute to this region's plasticity response in AD.
    MeSH term(s) Humans ; Alzheimer Disease/pathology ; Vesicular Glutamate Transport Proteins/metabolism ; Default Mode Network ; Vesicular Glutamate Transport Protein 2/metabolism ; Presynaptic Terminals/metabolism ; Vesicular Glutamate Transport Protein 1/metabolism
    Chemical Substances Vesicular Glutamate Transport Proteins ; Vesicular Glutamate Transport Protein 2 ; Vesicular Glutamate Transport Protein 1
    Language English
    Publishing date 2023-05-19
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1440127-7
    ISSN 1875-8908 ; 1387-2877
    ISSN (online) 1875-8908
    ISSN 1387-2877
    DOI 10.3233/JAD-221063
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article: Postmortem Neocortical

    Pivtoraiko, Violetta N / Racic, Tamara / Abrahamson, Eric E / Villemagne, Victor L / Handen, Benjamin L / Lott, Ira T / Head, Elizabeth / Ikonomovic, Milos D

    Frontiers in aging neuroscience

    2021  Volume 13, Page(s) 728739

    Abstract: Individuals with Down syndrome (DS) have a genetic predisposition for amyloid-β (Aβ) overproduction and earlier onset of Aβ deposits compared to patients with sporadic late-onset Alzheimer's disease (AD). Positron emission tomography (PET) with ... ...

    Abstract Individuals with Down syndrome (DS) have a genetic predisposition for amyloid-β (Aβ) overproduction and earlier onset of Aβ deposits compared to patients with sporadic late-onset Alzheimer's disease (AD). Positron emission tomography (PET) with Pittsburgh Compound-B (PiB) detects fibrillar Aβ pathology in living people with DS and AD, but its relationship with heterogeneous Aβ forms aggregated within amyloid deposits is not well understood. We performed quantitative
    Language English
    Publishing date 2021-08-13
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2558898-9
    ISSN 1663-4365
    ISSN 1663-4365
    DOI 10.3389/fnagi.2021.728739
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Heart and brain tissue banks for research on co-occurring cardiovascular and neurological/psychiatric disorders.

    Ikonomovic, Milos D

    Cardiovascular psychiatry and neurology

    2009  Volume 2009, Page(s) 427840

    Abstract: Epidemiological studies point to a strong and possibly causal association of psychiatric and neurological disorders with cardiovascular disease (CVD). Mechanistic links between these co-occurring illnesses are not well understood. Better insight into ... ...

    Abstract Epidemiological studies point to a strong and possibly causal association of psychiatric and neurological disorders with cardiovascular disease (CVD). Mechanistic links between these co-occurring illnesses are not well understood. Better insight into their relationship could help identify novel diagnostic markers and therapeutic targets. For successful translation of basic biomedical research into clinical practice, analyses of postmortem human tissues are essential. However, current tissue banks dedicated to psychiatric and neurological research collect only brain tissue samples deemed most important to the institution's participating investigators. While this practice is often dictated by budget constraints, restricted tissue storage space and other practical reasons, it limits the ability of the biological research community to access and study multiple organ systems relevant to cardiovascular and neuronal systems dysfunction. This problem is worsened when clinical records pertaining to coexistent systemic pathology are not available. To promote further understanding of co-occurring CVD and psychiatric/neurological disorders, efforts should be made to support tissue banks that harvest heart, coronary arteries, and aorta samples as well as brain tissue, from the same subjects.
    Language English
    Publishing date 2009-04-15
    Publishing country Egypt
    Document type Journal Article
    ZDB-ID 2514153-3
    ISSN 2090-0171 ; 2090-0163
    ISSN (online) 2090-0171
    ISSN 2090-0163
    DOI 10.1155/2009/427840
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Biostatistical Estimation of Tau Threshold Hallmarks (BETTH) Algorithm for Human Tau PET Imaging Studies.

    Gogola, Alexandra / Lopresti, Brian J / Tudorascu, Dana / Snitz, Beth / Minhas, Davneet / Doré, Vincent / Ikonomovic, Milos D / Shaaban, C Elizabeth / Matan, Cristy / Bourgeat, Pierrick / Mason, N Scott / Aizenstein, Howard / Mathis, Chester A / Klunk, William E / Rowe, Christopher C / Lopez, Oscar L / Cohen, Ann D / Villemagne, Victor L

    Journal of nuclear medicine : official publication, Society of Nuclear Medicine

    2023  Volume 64, Issue 11, Page(s) 1798–1805

    Abstract: A methodology for determining tau PET thresholds is needed to confidently detect early tau deposition. We compared multiple threshold-determining methods in participants who underwent ... ...

    Abstract A methodology for determining tau PET thresholds is needed to confidently detect early tau deposition. We compared multiple threshold-determining methods in participants who underwent either
    MeSH term(s) Humans ; Alzheimer Disease/diagnostic imaging ; Amyloid beta-Peptides/metabolism ; Brain/metabolism ; Carbolines ; Cognitive Dysfunction/diagnostic imaging ; Positron-Emission Tomography ; tau Proteins/metabolism ; Middle Aged
    Chemical Substances Amyloid beta-Peptides ; Carbolines ; tau Proteins
    Language English
    Publishing date 2023-09-14
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 80272-4
    ISSN 1535-5667 ; 0097-9058 ; 0161-5505 ; 0022-3123
    ISSN (online) 1535-5667
    ISSN 0097-9058 ; 0161-5505 ; 0022-3123
    DOI 10.2967/jnumed.123.265941
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Infrequent false positive [

    Ikonomovic, Milos D / Fantoni, Enrico R / Farrar, Gill / Salloway, Stephen

    Alzheimer's research & therapy

    2018  Volume 10, Issue 1, Page(s) 60

    Abstract: Background: The performance of [: Main body: This viewpoint article addresses infrequently observed discordance between visual [: Conclusion: [ ...

    Abstract Background: The performance of [
    Main body: This viewpoint article addresses infrequently observed discordance between visual [
    Conclusion: [
    MeSH term(s) Aged ; Aged, 80 and over ; Alzheimer Disease/complications ; Alzheimer Disease/diagnostic imaging ; Aniline Compounds/metabolism ; Benzothiazoles/metabolism ; Dementia/diagnostic imaging ; Dementia/etiology ; Dementia/pathology ; Female ; Humans ; Male ; Plaque, Amyloid/diagnostic imaging ; Positron-Emission Tomography
    Chemical Substances Aniline Compounds ; Benzothiazoles ; flutemetamol (0F3M7032P5)
    Language English
    Publishing date 2018-06-23
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2506521-X
    ISSN 1758-9193 ; 1758-9193
    ISSN (online) 1758-9193
    ISSN 1758-9193
    DOI 10.1186/s13195-018-0387-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top