902 research outputs found
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Regional Cerebral Blood Flow in Mood Disorders. II. Comparison of Major Depression and Alzheimer's Disease
We contrasted regional cerebral blood flow in matched groups of 30 patients with major depression,30 patients with Alzheimer's disease and 30 normal controls using the 133Xe inhalation technique. Whereas both the depressed and AIzheimer's disease groups had markedly reduced global cortical blood flow, the Scaled Subproflle Model,developed to identify abnormalities in regional networks, indicated that they had distinct topographic profiles. Previous findings of an abnormal regional network in major depression were unaltered by the inclusion of Alzheimer's disease patients in the analysis. Alzheimer's disease was associated with a distinct parietotemporal deficit and the degree of this abnormality strongly covaried with cognitive impairment. Alzheimer's disease patients also had abnormal manifestation of three other regional networks. We illustrate a method for distinguishing when a disease imposes a new pattern of interactions among brain regions and when a disease alters the expression of regional patterns characteristic of normal functioning
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The Columbia University Scale for Psychopathology in Alzheimer's Disease
The Columbia University Scale for Psychopathology in Alzheimer's disease is a new screening instrument developed for use by clinicians or trained lay interviewers. Interrater reliability was established between a psychiatrist and a lay interviewer in 20 patients. In an independent sample of 91 outpatients with very mild to moderate probable Alzheimer's disease, caregiver informants reported that depressed mood was common (46.2%) but rarely persistent (2.2%), and that sleep disturbance occurred frequently (41.8%) but was never severe (0%). There were significant but weak associations between the presence of specific subtypes of delusions and severity of dementia. Although a variety of delusional symptoms were reported, they were frequently transient and patients often accepted the truth if corrected by the caregiver. As a result, few patients met broad or narrow operational criteria used to define delusions. Prior studies may have overestimated the prevalence of psychotic features in Alzheimer's disease by not employing standard definitional criteria. The findings also indicate that new methodology such as that employed in this instrument needs to be evaluated more widely
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Depressed Mood and the Incidence of Alzheimer's Disease in the Elderly Living in the Community
BACKGROUND: It remains unclear whether depression increases the risk for dementia in the elderly. We evaluated the relationship between depressed mood at baseline and the incidence of dementia, particularly Alzheimer's disease, in the elderly living in the community. METHODS: A total of 1070 elderly individuals, aged 60 years or older, were identified as part of a registry for dementia in the Washington Heights community of North Manhattan, NY. In a prospective, longitudinal design with follow-up for 1 to 5 years, annual physician evaluation and neuropsychological testing were used to assess levels of cognitive impairment and to diagnose dementia. Depressive symptoms were evaluated with the 17-item Hamilton Rating Scale for Depression. Based on clinical considerations and a validity study, a positive score for the depressed mood item was used in statistical analyses. To confirm the results, the total Hamilton Rating Scale for Depression score was also evaluated as the "depression" variable. RESULTS: Of the 1070 subjects, 218 met criteria for dementia at baseline evaluation. In the 852 subjects without dementia, depressed mood was more common in individuals with greater cognitive impairment. In a follow-up study of 478 of these subjects without dementia (mean +/- SD, 2.54 +/- 1.12 years of follow-up), the effect of baseline depressed mood on the end- point diagnosis of dementia (93% had possible or probable Alzheimer's disease) was evaluated in a Cox proportional hazards model. Depressed mood at baseline was associated with an increased risk of incident dementia (relative risk, 2.94; 95% confidence interval, 1.76 to 4.91; P .001). This effect remained after adjustment for age, gender, education, language of assessment, Blessed Memory Information and Concentration test scores, and Blessed Functional Activity Scale scores (relative risk, 2.05; 95% confidence interval, 1.16 to 3.62; P .02). Similar results were obtained when the total Hamilton Rating Scale for Depression score was used as the depression variable, with the use of the same covariates (relative risk, 1.07 per point interval; 95% confidence interval, 1.02 to 1.11; P .01). CONCLUSIONS: Depressed mood moderately increased the risk of developing dementia, primarily Alzheimer's disease. Whether depressed mood is a very early manifestation of Alzheimer's disease, or increases susceptibility through another mechanism, remains to be determined
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Reproducibility of serum cytokines in an elderly population
Background
It is important to assess the temporal reproducibility of circulating cytokines for their utility in epidemiological studies. However, existing evidence is limited and inconsistent, especially for the elderly population.
Methods
Sixty-five elderly (mean age = 77.89 ± 6.14 years) subjects were randomly selected from an existing prospective cohort study. Levels of 41 cytokines in 195 serum samples, collected at three separate visits that were up to 15.26 years apart, were measured by the Luminex technology. The temporal reproducibility of cytokines was estimated by the intraclass correlation coefficient (ICC) calculated using a mixed-effects model. In addition, data analyses were stratified by the median (4.49 years) of time intervals across sample collection. Sensitivity analyses were performed when excluding subjects with undetectable samples.
Results
A total of 23 cytokines were detectable in more than 60% of samples. Fair to good (ICC = 0.40 to 0.75) and excellent (ICC > 0.75) reproducibility was found in 10 (Eotaxin, VEGF, FGF-2, G-CSF, MDC, GM-CSF, TGFα, IP-10, MIP-1β, IL-1RA) and 5 (GRO, IFNγ, IL-17, PDGF-AA, IL-4) cytokines, respectively. The results were not changed dramatically in the stratification and sensitivity analyses.
Conclusions
Serum levels of the selected 15 cytokines measured with Luminex technology displayed fair to excellent within-person temporal reproducibility among elderly population
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A Preliminary Study of Apolipoprotein E Genotype and Psychiatric Manifestations of Alzheimer's Disease
We evaluated the frequency of depression and psychosis in 46 patients with AD and 135 control subjects with the apolipoprotein (APO) E3/3 or E3/4 genotype. Patients with AD and the APOE3/4 genotype had a more than threefold increase in the signs of depression and psychosis when compared with either patients with the APOE3/3 genotype or to control subjects. Our preliminary study suggests that the phenotype of AD associated with the epsilon 4 allele is more likely to include psychiatric manifestations
Characterization of cytosolic proliferating cell nuclear antigen (PCNA) in neutrophils: antiapoptotic role of the monomer.
We have shown previously that PCNA, a nuclear factor involved in DNA replication and repair in proliferating cells, is localized exclusively in the cytoplasm of neutrophils, where it regulates their survival. Nuclear PCNA functions are tightly linked to its ring-shaped structure, which allows PCNA to bind to numerous partner proteins to orchestrate DNA-related processes. We have shown that only monomeric PCNA can expose its NES to be relocalized from nucleus to cytosol during granulocyte differentiation. This study tested the hypothesis that monomeric PCNA could have a biological role in neutrophils. With the use of a combination of cross-linking and gel-filtration experiments, trimeric and monomeric PCNAs were detected in neutrophil cytosol. The promyelocytic cell line PLB985 was next stably transfected to express the monomeric PCNAY114A mutant to examine its function compared with the WT trimeric PCNA. Monomeric PCNAY114A mutant potentiated DMF-induced differentiation, as evidenced by an increased percentage of CD11b- and gp91phox-positive PLB985PCNAY114A cells and by an increased, opsonized zymosan-triggered NADPH oxidase activity compared with PLB985PCNA or PLB985 cells overexpressing WT PCNA or the empty plasmid, respectively. Regarding antiapoptotic activity, DMF-differentiated PLB985 cells overexpressing WT or the monomeric PCNAY114A mutant displayed a similar antiapoptotic activity following treatment with gliotoxin or TRAIL compared with PLB985. The molecular basis through which cytoplasmic PCNA exerts its antiapoptotic activity in mature neutrophils may, at least in part, be independent of the trimeric conformation
Both common variations and rare non-synonymous substitutions and small insertion/deletions in CLU are associated with increased Alzheimer risk.
BACKGROUND: We have followed-up on the recent genome-wide association (GWA) of the clusterin gene (CLU) with increased risk for Alzheimer disease (AD), by performing an unbiased resequencing of all CLU coding exons and regulatory regions in an extended Flanders-Belgian cohort of Caucasian AD patients and control individuals (n = 1930). Moreover, we have replicated genetic findings by targeted resequencing in independent Caucasian cohorts of French (n = 2182) and Canadian (n = 573) origin and by performing meta-analysis combining our data with previous genetic CLU screenings. RESULTS: In the Flanders-Belgian cohort, we identified significant clustering in exons 5-8 of rare genetic variations leading to non-synonymous substitutions and a 9-bp insertion/deletion affecting the CLU β-chain (p = 0.02). Replicating this observation by targeted resequencing of CLU exons 5-8 in 2 independent Caucasian cohorts of French and Canadian origin identified identical as well as novel non-synonymous substitutions and small insertion/deletions. A meta-analysis, combining the datasets of the 3 cohorts with published CLU sequencing data, confirmed that rare coding variations in the CLU β-chain were significantly enriched in AD patients (OR(MH) = 1.96 [95% CI = 1.18-3.25]; p = 0.009). Single nucleotide polymorphisms (SNPs) association analysis indicated the common AD risk association (GWA SNP rs11136000, p = 0.013) in the 3 combined datasets could not be explained by the presence of the rare coding variations we identified. Further, high-density SNP mapping in the CLU locus mapped the common association signal to a more 5' CLU region. CONCLUSIONS: We identified a new genetic risk association of AD with rare coding CLU variations that is independent of the 5' common association signal identified in the GWA studies. At this stage the role of these coding variations and their likely effect on the β-chain domain and CLU protein functioning remains unclear and requires further studies.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Nucleic acid extraction from formalin-fixed paraffin-embedded cancer cell line samples: a trade off between quantity and quality?
Background: Advanced genomic techniques such as Next-Generation-Sequencing (NGS) and gene expression profiling, including NanoString, are vital for the development of personalised medicines, as they enable molecular disease classification. This has become increasingly important in the treatment of cancer, aiding patient selection. However, it requires efficient nucleic acid extraction often from formalin-fixed paraffin-embedded tissue (FFPE). Methods: Here we provide a comparison of several commercially available manual and automated methods for DNA and/or RNA extraction from FFPE cancer cell line samples from Qiagen, life Technologies and Promega. Differing extraction geometric mean yields were evaluated across each of the kits tested, assessing dual DNA/RNA extraction vs. specialised single extraction, manual silica column based extraction techniques vs. automated magnetic bead based methods along with a comparison of subsequent nucleic acid purity methods, providing a full evaluation of nucleic acids isolated. Results: Out of the four RNA extraction kits evaluated the RNeasy FFPE kit, from Qiagen, gave superior geometric mean yields, whilst the Maxwell 16 automated method, from Promega, yielded the highest quality RNA by quantitative real time RT-PCR. Of the DNA extraction kits evaluated the PicoPure DNA kit, from Life Technologies, isolated 2–14× more DNA. A miniaturised qPCR assay was developed for DNA quantification and quality assessment. Conclusions: Careful consideration of an extraction kit is necessary dependent on quality or quantity of material required. Here we provide a flow diagram on the factors to consider when choosing an extraction kit as well as how to accurately quantify and QC the extracted material
Clinical and biomarker changes in dominantly inherited Alzheimer\u27s disease
BACKGROUND: The order and magnitude of pathologic processes in Alzheimer\u27s disease are not well understood, partly because the disease develops over many years. Autosomal dominant Alzheimer\u27s disease has a predictable age at onset and provides an opportunity to determine the sequence and magnitude of pathologic changes that culminate in symptomatic disease. METHODS: In this prospective, longitudinal study, we analyzed data from 128 participants who underwent baseline clinical and cognitive assessments, brain imaging, and cerebrospinal fluid (CSF) and blood tests. We used the participant\u27s age at baseline assessment and the parent\u27s age at the onset of symptoms of Alzheimer\u27s disease to calculate the estimated years from expected symptom onset (age of the participant minus parent\u27s age at symptom onset). We conducted cross-sectional analyses of baseline data in relation to estimated years from expected symptom onset in order to determine the relative order and magnitude of pathophysiological changes. RESULTS: Concentrations of amyloid-beta (Aβ) 42 in the CSF appeared to decline 25 years before expected symptom onset. Aβ deposition, as measured by positron-emission tomography with the use of Pittsburgh compound B, was detected 15 years before expected symptom onset. Increased concentrations of tau protein in the CSF and an increase in brain atrophy were detected 15 years before expected symptom onset. Cerebral hypometabolism and impaired episodic memory were observed 10 years before expected symptom onset. Global cognitive impairment, as measured by the Mini-Mental State Examination and the Clinical Dementia Rating scale, was detected 5 years before expected symptom onset, and patients met diagnostic criteria for dementia at an average of 3 years after expected symptom onset. CONCLUSIONS: We found that autosomal dominant Alzheimer\u27s disease was associated with a series of pathophysiological changes over decades in CSF biochemical markers of Alzheimer\u27s disease, brain amyloid deposition, and brain metabolism as well as progressive cognitive impairment. Our results require confirmation with the use of longitudinal data and may not apply to patients with sporadic Alzheimer\u27s disease. (Funded by the National Institute on Aging and others; DIAN ClinicalTrials.gov number, NCT00869817.
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