GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Ovid Technologies (Wolters Kluwer Health) ; 2001
    In:  Circulation Research Vol. 88, No. 5 ( 2001-03-16), p. 499-505
    In: Circulation Research, Ovid Technologies (Wolters Kluwer Health), Vol. 88, No. 5 ( 2001-03-16), p. 499-505
    Abstract: Abstract —Experimental animals placed on a high-cholesterol diet for 2 or more weeks exhibit an inflammatory response in postcapillary venules. The aims of this study were to determine (1) whether superoxide mediates the hypercholesterolemia-induced inflammatory response and (2) whether leukocyte and/or vessel wall NAD(P)H oxidase contributes to this response. Intravital videomicroscopy was used to quantify leukocyte–endothelial cell adhesion in cremasteric postcapillary venules of wild-type (WT) mice, CuZn-superoxide dismutase transgenic (SOD TgN) mice, and mice heterozygous (p47 phox +/−) or homozygous (p47 phox −/−) for NAD(P)H oxidase placed on either a normal diet or high-cholesterol diet (HCD) for 2 weeks. The number of adherent and emigrated leukocytes in postcapillary venules of WT HCD mice was significantly higher than that detected in venules of their normal-diet counterparts. However, the HCD-induced recruitment of adherent and emigrated leukocytes was not observed in SOD TgN mice. Whereas hypercholesterolemic p47 phox +/− and WT mice exhibited similar inflammatory responses, p47 phox −/− mice did not. Bone marrow chimeras were developed to selectively delete p47 phox from either the vessel wall or circulating leukocytes. Whereas WT marrow transplanted into WT mice produced a normal inflammatory response of venules to HCD, chimeric mice with p47 phox deficiency in either the vessel wall or leukocytes exhibited an attenuated inflammatory response to HCD that was comparable with that observed in p47 phox −/− HCD mice. Our findings indicate that enhanced superoxide production is a critical event that initiates the leukocyte–endothelial cell adhesion in postcapillary venules of HCD mice. NAD(P)H oxidase appears to be an important source of this superoxide.
    Type of Medium: Online Resource
    ISSN: 0009-7330 , 1524-4571
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2001
    detail.hit.zdb_id: 80100-8
    detail.hit.zdb_id: 1467838-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Microcirculation, Wiley, Vol. 9, No. 5 ( 2002-10), p. 407-417
    Abstract: Objective : Hypercholesterolemia promotes the adhesion of leukocytes to vascular endothelium in large and microscopic blood vessels. Lymphocytes that can modulate endothelial cell adhesion molecule expression have been implicated in the altered structure and function of large arterial vessels associated with chronic hypercholesterolemia. This study assesses the contribution of CD4 + and CD8 + T‐cells to acute inflammatory responses observed in the microcirculation of hypercholesterolemic mice. Methods : Intravital microscopy was used to quantify baseline leukocyte‐endothelial cell interactions in cremasteric postcapillary venules of wild‐type (WT) and severe combined immunodeficient (SCID) mice placed on a normal (ND) or high‐cholesterol (HC) diet for 2 weeks. A group of SCID‐HC mice received splenocytes from WT‐HC mice (WT→SCID). Separate WT‐HC groups were depleted of neutrophils or CD4 + and/or CD8 + T‐cells. Results : WT‐HC mice, compared with WT‐ND, exhibited exaggerated leukocyte adherence and emigration. These leukocytes were predominantly granulocytes. These responses were absent in neutropenic WT‐HC mice. SCID‐HC mice also showed significantly less leukocyte adherence and emigration than WT‐HC mice. Elevated leukocyte adherence and emigration were restored in WT→SCID mice, despite a continued absence of circulating blood lymphocytes. Selective depletion of either CD4 + or CD8 + cell populations attenuated HC‐induced leukocyte adhesion but not emigration. However, simultaneous depletion of both CD4 + and CD8 + cells attenuated both leukocyte adhesion and emigration to ND levels. Discussion : These findings indicate that both CD4 + and CD8 + T‐cells contribute to granulocyte adhesion and emigration elicited in postcapillary venules by hypercholesterolemia.
    Type of Medium: Online Resource
    ISSN: 1073-9688 , 1549-8719
    Language: English
    Publisher: Wiley
    Publication Date: 2002
    detail.hit.zdb_id: 1217758-1
    detail.hit.zdb_id: 2008083-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    In: Microcirculation, Wiley, Vol. 9, No. 5 ( 2002-01), p. 407-417
    Type of Medium: Online Resource
    ISSN: 1073-9688 , 1549-8719
    Language: English
    Publisher: Wiley
    Publication Date: 2002
    detail.hit.zdb_id: 1217758-1
    detail.hit.zdb_id: 2008083-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Online Resource
    Online Resource
    Ovid Technologies (Wolters Kluwer Health) ; 2003
    In:  Circulation Vol. 107, No. 16 ( 2003-04-29), p. 2140-2145
    In: Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 107, No. 16 ( 2003-04-29), p. 2140-2145
    Abstract: Background— A T-cell–mediated inflammatory response occurs in the microcirculation during acute hypercholesterolemia. The objective of this study was to define the contribution of T-lymphocyte–derived interferon-γ (IFN-γ) to the leukocyte–endothelial cell adhesion induced by hypercholesterolemia. Methods and Results— Intravital videomicroscopy was used to quantify the adhesion and emigration of leukocytes and oxidant stress (dihydrorhodamine [DHR] oxidation) in cremasteric venules. Wild-type (WT), IFN-γ −/− , and severe combined immunodeficiency (SCID) mice were placed on either a normal (ND) or high-cholesterol (HC) diet for 2 weeks. WT-HC mice exhibited exaggerated adhesion and emigration of leukocytes and enhanced DHR oxidation compared with WT-ND. The exaggerated adhesion responses and increased DHR oxidation were not seen in IFN-γ −/− –HC mice. SCID-HC mice also exhibited attenuated inflammatory responses compared with WT-HC. Reconstitution of either SCID-HC or IFN-γ −/− –HC mice with WT-HC splenocytes restored the inflammatory responses, whereas reconstitution of SCID-HC with IFN-γ −/− –HC splenocytes did not. The HC-induced oxidant stress was restored in IFN-γ −/− –HC mice reconstituted with WT-HC splenocytes. Conclusions— These findings implicate IFN-γ as a cause of the inflammatory phenotype that is assumed by the microvasculature of hypercholesterolemic mice and suggest that T lymphocytes are a major source of this proinflammatory cytokine.
    Type of Medium: Online Resource
    ISSN: 0009-7322 , 1524-4539
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2003
    detail.hit.zdb_id: 1466401-X
    detail.hit.zdb_id: 80099-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Online Resource
    Online Resource
    American Physiological Society ; 2003
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 285, No. 6 ( 2003-12), p. H2623-H2629
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 285, No. 6 ( 2003-12), p. H2623-H2629
    Abstract: We have previously shown that T lymphocytes and interferon-γ are involved in hypercholesterolemia-induced leukocyte adhesion to vascular endothelium. This study assessed the contribution of interleukin 12 (IL-12) to these hypercholesterolemia-induced inflammatory responses. Intravital videomicroscopy was used to quantify leukocyte adhesion and emigration and oxidant stress (dihydrorhodamine oxidation) in unstimulated cremasteric venules (wall shear rate ≥500 s –1 ) of wild-type (WT) C57Bl/6, lymphocyte-deficient [recombinase-activating gene knockout (RAG1 –/– )], and IL-12-deficient (p35 –/– and p40 –/– ; p35 and p40 are the two subunits of active IL-12) mice on either a normal (ND) or high-cholesterol (HC) diet for 2 wk. RAG1 –/– -HC mice received splenocytes from WT-HC (WT → RAG1 –/– ), p35 –/– -HC (p35 –/– → RAG1 –/– ), or p40 –/– -HC (p40 –/– → RAG1 –/– ) mice. Compared with WT-ND mice, WT-HC mice exhibited exaggerated leukocyte adherence and emigration as well as increased dihydrorhodamine oxidation. The enhanced leukocyte recruitment was absent in the RAG1 –/– -ND, p35 –/– -ND, and p40 –/– -ND groups. Hypercholesterolemia-induced leukocyte adherence and emigration were attenuated in RAG1 –/– -HC vs. WT-HC mice but were similar to ND mice. Furthermore, compared with WT-HC animals, p35 –/– -HC and p40 –/– -HC mice showed significantly lower leukocyte adhesion and tissue oxidant stress responses, but these values were comparable to ND mice. Leukocyte adherence and emigration in WT → RAG1 –/– mice were similar to responses of WT-HC mice. However, p35 –/– → RAG1 –/– mice had lower levels of adherence and emigration vs. the WT → RAG1 –/– and WT-HC groups. Elevated levels of leukocyte adherence and emigration were restored by ∼50% toward WT-HC levels in p40 –/– → RAG1 –/– mice. These findings implicate IL-12 in the inflammatory responses observed in the venules of hypercholesterolemic mice.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2003
    detail.hit.zdb_id: 603838-4
    detail.hit.zdb_id: 1477308-9
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    In: Brain, Oxford University Press (OUP), Vol. 147, No. 5 ( 2024-05-03), p. 1680-1695
    Abstract: Insulin, insulin-like growth factors (IGF) and their receptors are highly expressed in the adult hippocampus. Thus, disturbances in the insulin-IGF signalling pathway may account for the selective vulnerability of the hippocampus to nascent Alzheimer's disease (AD) pathology. In the present study, we examined the predominant IGF-binding protein in the CSF, IGFBP2. CSF was collected from 109 asymptomatic members of the parental history-positive PREVENT-AD cohort. CSF levels of IGFBP2, core AD and synaptic biomarkers were measured using proximity extension assay, ELISA and mass spectrometry. Cortical amyloid-beta (Aβ) and tau deposition were examined using 18F-NAV4694 and flortaucipir. Cognitive assessments were performed during up to 8 years of follow-up, using the Repeatable Battery for the Assessment of Neuropsychological Status. T1-weighted structural MRI scans were acquired, and neuroimaging analyses were performed on pre-specified temporal and parietal brain regions. Next, in an independent cohort, we allocated 241 dementia-free ADNI-1 participants into four stages of AD progression based on the biomarkers CSF Aβ42 and total-tau (t-tau). In this analysis, differences in CSF and plasma IGFBP2 levels were examined across the pathological stages. Finally, IGFBP2 mRNA and protein levels were examined in the frontal cortex of 55 autopsy-confirmed AD and 31 control brains from the Quebec Founder Population (QFP) cohort, a unique population isolated from Eastern Canada. CSF IGFBP2 progressively increased over 5 years in asymptomatic PREVENT-AD participants. Baseline CSF IGFBP2 was positively correlated with CSF AD biomarkers and synaptic biomarkers, and negatively correlated with longitudinal changes in delayed memory (P = 0.024) and visuospatial abilities (P = 0.019). CSF IGFBP2 was negatively correlated at a trend-level with entorhinal cortex volume (P = 0.082) and cortical thickness in the piriform (P = 0.039), inferior temporal (P = 0.008), middle temporal (P = 0.014) and precuneus (P = 0.033) regions. In ADNI-1, CSF (P = 0.009) and plasma (P = 0.001) IGFBP2 were significantly elevated in Stage 2 [CSF Aβ(+)/t-tau(+)]. In survival analyses in ADNI-1, elevated plasma IGFBP2 was associated with a greater rate of AD conversion (hazard ratio = 1.62, P = 0.021). In the QFP cohort, IGFBP2 mRNA was reduced (P = 0.049); however, IGFBP2 protein levels did not differ in the frontal cortex of autopsy-confirmed AD brains (P = 0.462). Nascent AD pathology may induce an upregulation in IGFBP2 in asymptomatic individuals. CSF and plasma IGFBP2 may be valuable markers for identifying CSF Aβ(+)/t-tau(+) individuals and those with a greater risk of AD conversion.
    Type of Medium: Online Resource
    ISSN: 0006-8950 , 1460-2156
    RVK:
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2024
    detail.hit.zdb_id: 1474117-9
    detail.hit.zdb_id: 80072-7
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    In: Brain, Oxford University Press (OUP), Vol. 146, No. 9 ( 2023-09-01), p. 3719-3734
    Abstract: Mechanisms of resilience against tau pathology in individuals across the Alzheimer’s disease spectrum are insufficiently understood. Longitudinal data are necessary to reveal which factors relate to preserved cognition (i.e. cognitive resilience) and brain structure (i.e. brain resilience) despite abundant tau pathology, and to clarify whether these associations are cross-sectional or longitudinal. We used a longitudinal study design to investigate the role of several demographic, biological and brain structural factors in yielding cognitive and brain resilience to tau pathology as measured with PET. In this multicentre study, we included 366 amyloid-β-positive individuals with mild cognitive impairment or Alzheimer’s disease dementia with baseline 18F-flortaucipir-PET and longitudinal cognitive assessments. A subset (n = 200) additionally underwent longitudinal structural MRI. We used linear mixed-effects models with global cognition and cortical thickness as dependent variables to investigate determinants of cognitive resilience and brain resilience, respectively. Models assessed whether age, sex, years of education, APOE-ε4 status, intracranial volume (and cortical thickness for cognitive resilience models) modified the association of tau pathology with cognitive decline or cortical thinning. We found that the association between higher baseline tau-PET levels (quantified in a temporal meta-region of interest) and rate of cognitive decline (measured with repeated Mini-Mental State Examination) was adversely modified by older age (Stβinteraction = −0.062, P = 0.032), higher education level (Stβinteraction = −0.072, P = 0.011) and higher intracranial volume (Stβinteraction = −0.07, P = 0.016). Younger age, higher education and greater cortical thickness were associated with better cognitive performance at baseline. Greater cortical thickness was furthermore associated with slower cognitive decline independent of tau burden. Higher education also modified the negative impact of tau-PET on cortical thinning, while older age was associated with higher baseline cortical thickness and slower rate of cortical thinning independent of tau. Our analyses revealed no (cross-sectional or longitudinal) associations for sex and APOE-ε4 status on cognition and cortical thickness. In this longitudinal study of clinically impaired individuals with underlying Alzheimer’s disease neuropathological changes, we identified education as the most robust determinant of both cognitive and brain resilience against tau pathology. The observed interaction with tau burden on cognitive decline suggests that education may be protective against cognitive decline and brain atrophy at lower levels of tau pathology, with a potential depletion of resilience resources with advancing pathology. Finally, we did not find major contributions of sex to brain nor cognitive resilience, suggesting that previous links between sex and resilience might be mainly driven by cross-sectional differences.
    Type of Medium: Online Resource
    ISSN: 0006-8950 , 1460-2156
    RVK:
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2023
    detail.hit.zdb_id: 1474117-9
    detail.hit.zdb_id: 80072-7
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    In: Brain, Oxford University Press (OUP), Vol. 147, No. 4 ( 2024-04-04), p. 1497-1510
    Abstract: Females are disproportionately affected by dementia due to Alzheimer's disease. Despite a similar amyloid-β (Aβ) load, a higher load of neurofibrillary tangles (NFTs) is seen in females than males. Previous literature has proposed that Aβ and phosphorylated-tau (p-tau) synergism accelerates tau tangle formation, yet the effect of biological sex in this process has been overlooked. In this observational study, we examined longitudinal neuroimaging data from the TRIAD and ADNI cohorts from Canada and USA, respectively. We assessed 457 participants across the clinical spectrum of Alzheimer's disease. All participants underwent baseline multimodal imaging assessment, including MRI and PET, with radioligands targeting Aβ plaques and tau tangles, respectively. CSF data were also collected. Follow-up imaging assessments were conducted at 1- and 2-year intervals for the TRIAD cohort and 1-, 2- and 4-year intervals for the ADNI cohort. The upstream pathological events contributing to faster tau progression in females were investigated—specifically, whether the contribution of Aβ and p-tau synergism to accelerated tau tangle formation is modulated by biological sex. We hypothesized that cortical Aβ predisposes tau phosphorylation and tangle accumulation in a sex-specific manner. Findings revealed that Aβ-positive females presented higher CSF p-tau181 concentrations compared with Aβ-positive males in both the TRIAD (P = 0.04, Cohen's d = 0.51) and ADNI (P = 0.027, Cohen's d = 0.41) cohorts. In addition, Aβ-positive females presented faster NFT accumulation compared with their male counterparts (TRIAD: P = 0.026, Cohen's d = 0.52; ADNI: P = 0.049, Cohen's d = 1.14). Finally, the triple interaction between female sex, Aβ and CSF p-tau181 was revealed as a significant predictor of accelerated tau accumulation at the 2-year follow-up visit (Braak I: P = 0.0067, t = 2.81; Braak III: P = 0.017, t = 2.45; Braak IV: P = 0.002, t = 3.17; Braak V: P = 0.006, t = 2.88; Braak VI: P = 0.0049, t = 2.93). Overall, we report sex-specific modulation of cortical Aβ in tau phosphorylation, consequently facilitating faster NFT progression in female individuals over time. This presents important clinical implications and suggests that early intervention that targets Aβ plaques and tau phosphorylation may be a promising therapeutic strategy in females to prevent the further accumulation and spread of tau aggregates.
    Type of Medium: Online Resource
    ISSN: 0006-8950 , 1460-2156
    RVK:
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2024
    detail.hit.zdb_id: 1474117-9
    detail.hit.zdb_id: 80072-7
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    In: Journal of the Royal Statistical Society Series B: Statistical Methodology, Oxford University Press (OUP), ( 2024-03-22)
    Abstract: We introduce a novel framework for the classification of functional data supported on nonlinear, and possibly random, manifold domains. The motivating application is the identification of subjects with Alzheimer’s disease from their cortical surface geometry and associated cortical thickness map. The proposed model is based upon a reformulation of the classification problem as a regularized multivariate functional linear regression model. This allows us to adopt a direct approach to the estimation of the most discriminant direction while controlling for its complexity with appropriate differential regularization. Our approach does not require prior estimation of the covariance structure of the functional predictors, which is computationally prohibitive in our application setting. We provide a theoretical analysis of the out-of-sample prediction error of the proposed model and explore the finite sample performance in a simulation setting. We apply the proposed method to a pooled dataset from Alzheimer’s Disease Neuroimaging Initiative and Parkinson’s Progression Markers Initiative. Through this application, we identify discriminant directions that capture both cortical geometric and thickness predictive features of Alzheimer’s disease that are consistent with the existing neuroscience literature.
    Type of Medium: Online Resource
    ISSN: 1369-7412 , 1467-9868
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2024
    detail.hit.zdb_id: 204795-0
    detail.hit.zdb_id: 1490719-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    In: Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 120, No. 2 ( 2023-01-10)
    Abstract: The gap between chronological age (CA) and biological brain age, as estimated from magnetic resonance images (MRIs), reflects how individual patterns of neuroanatomic aging deviate from their typical trajectories. MRI-derived brain age (BA) estimates are often obtained using deep learning models that may perform relatively poorly on new data or that lack neuroanatomic interpretability. This study introduces a convolutional neural network (CNN) to estimate BA after training on the MRIs of 4,681 cognitively normal (CN) participants and testing on 1,170 CN participants from an independent sample. BA estimation errors are notably lower than those of previous studies. At both individual and cohort levels, the CNN provides detailed anatomic maps of brain aging patterns that reveal sex dimorphisms and neurocognitive trajectories in adults with mild cognitive impairment (MCI, N  = 351) and Alzheimer’s disease (AD, N  = 359). In individuals with MCI (54% of whom were diagnosed with dementia within 10.9 y from MRI acquisition), BA is significantly better than CA in capturing dementia symptom severity, functional disability, and executive function. Profiles of sex dimorphism and lateralization in brain aging also map onto patterns of neuroanatomic change that reflect cognitive decline. Significant associations between BA and neurocognitive measures suggest that the proposed framework can map, systematically, the relationship between aging-related neuroanatomy changes in CN individuals and in participants with MCI or AD. Early identification of such neuroanatomy changes can help to screen individuals according to their AD risk.
    Type of Medium: Online Resource
    ISSN: 0027-8424 , 1091-6490
    RVK:
    RVK:
    Language: English
    Publisher: Proceedings of the National Academy of Sciences
    Publication Date: 2023
    detail.hit.zdb_id: 209104-5
    detail.hit.zdb_id: 1461794-8
    SSG: 11
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...