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1.
Int J Mol Sci ; 21(1)2019 Dec 20.
Article in English | MEDLINE | ID: mdl-31861865

ABSTRACT

The protein Major Facilitator Superfamily Domain containing 2A (MFSD2a) was recently described as the primary carrier for docosahexaenoic acid (DHA) into the brain. Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by lower DHA levels in blood lipids. The aim of this study was to investigate the expression of MFSD2a in the whole blood and brain as a potential biomarker of AD. Three groups were established: 38 healthy controls, 48 subjects with moderate AD (GDS4), and 47 with severe AD (GDS6). We analyzed postmortem brain samples from the hippocampus of 11 healthy controls and 11 severe AD patients. Fatty acid (FA) was determined in serum and brain by gas chromatography. Blood and brain MFSD2a protein expression was analyzed by Western blotting. We found a significant and progressive decline of MFSD2a levels in blood of AD patients (Control 0.83 ± 0.13, GDS4 0.72 ± 0.09, GDS6 0.48 ± 0.05*, p ˂ 0.01). We also corroborated a significant reduction of DHA and other n-3 long-chain polyunsaturated FA in serum of AD. No differences were found in MFSD2a expression or FA levels in brain of controls and AD subjects. MFSD2A carrier was analyzed in AD patients for the first time and the level of MFSD2a in the whole blood could be a potential biomarker of this disease.


Subject(s)
Alzheimer Disease/blood , Symporters/blood , Aged , Alzheimer Disease/pathology , Biomarkers/analysis , Biomarkers/blood , Brain/pathology , Fatty Acids/blood , Female , Humans , Male , Symporters/analysis
2.
Stem Cells ; 30(6): 1277-85, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22415951

ABSTRACT

The objective of this article is to assess the safety of intraspinal infusion of autologous bone marrow mononuclear cells (BMNCs) and, ultimately, to look for histopathological signs of cellular neurotrophism in amyotrophic lateral sclerosis (ALS) patients. We conducted an open single arm phase I trial. After 6 months observation, autologous BMNCs were infused into the posterior spinal cord funiculus. Safety was the primary endpoint and was defined as the absence of serious transplant-related adverse events. In addition, forced vital capacity (FVC), ALS-functional rating scale (ALS-FRS), Medical Research Council scale for assessment of muscle power (MRC), and Norris scales were assessed 6 and 3 months prior to the transplant and quarterly afterward for 1 year. Pathological studies were performed in case of death. Eleven patients were included. We did not observe any severe transplant-related adverse event, but there were 43 nonsevere events. Twenty-two (51%) resolved in ≤2 weeks and only four were still present at the end of follow-up. All were common terminology criteria for adverse events grade ≤2. No acceleration in the rate of decline of FVC, ALS-FRS, Norris, or MRC scales was observed. Four patients died on days 359, 378, 808, and 1,058 post-transplant for reasons unrelated to the procedure. Spinal cord pathological analysis showed a greater number of motoneurons in the treated segments compared with the untreated segments (4.2 ± 0.8 motoneurons per section [mns per sect] and 0.9 ± 0.3 mns per sect, respectively). In the treated segments, motoneurons were surrounded by CD90+ cells and did not show degenerative ubiquitin deposits. This clinical trial confirms not only the safety of intraspinal infusion of autologous BMNC in ALS patients but also provides evidence strongly suggesting their neurotrophic activity.


Subject(s)
Amyotrophic Lateral Sclerosis/pathology , Amyotrophic Lateral Sclerosis/surgery , Bone Marrow Cells/pathology , Bone Marrow Transplantation/methods , Nerve Degeneration/pathology , Spinal Cord/pathology , Adult , Female , Humans , Male , Middle Aged , Motor Neurons/pathology , Pilot Projects , Spinal Cord/surgery
3.
Nat Genet ; 54(4): 412-436, 2022 04.
Article in English | MEDLINE | ID: mdl-35379992

ABSTRACT

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Cognitive Dysfunction/psychology , Genome-Wide Association Study , Humans , tau Proteins/genetics
4.
Dement Geriatr Cogn Disord ; 31(4): 268-75, 2011.
Article in English | MEDLINE | ID: mdl-21508641

ABSTRACT

BACKGROUND: Mild cognitive impairment (MCI) is an intermediate state between normal aging and early dementia. Some MCI patients show white matter hyperintensities in magnetic resonance imaging, revealing subcortical vascular damage (SVD). This study aimed to evaluate potential attention deficits not previously described in these patients. Specifically, we evaluated attention network functioning in MCI on the basis of Posner's cognitive neuroscience model, which considers attention as a set of networks: alerting, orienting and executive control. METHODS: Three groups of participants were tested: 19 MCI patients with SVD (svMCI), 15 MCI patients free from SVD (nvMCI) and 19 healthy controls (HC). We used a task in which the three attention networks and their interactions can be assessed simultaneously, the Attention Network Test (ANT). RESULTS: The svMCI group showed smaller orienting effect compared with the nvMCI and HC groups. In contrast to the HC and nvMCI groups, svMCI patients did not show improvement in the executive network from the valid visual cue. CONCLUSIONS: svMCI patients show a deficit in orienting attention networks. This deficit could be related to an effect of SVD on the cholinergic system because acetylcholine is implicated in the modulation of covert orienting responses of attention.


Subject(s)
Attention Deficit Disorder with Hyperactivity/pathology , Attention Deficit Disorder with Hyperactivity/physiopathology , Cognition Disorders/pathology , Cognition Disorders/physiopathology , Dementia, Vascular/pathology , Dementia, Vascular/physiopathology , Acetylcholine/physiology , Aged , Aged, 80 and over , Atrophy , Attention/physiology , Executive Function/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Severity of Illness Index
5.
Alzheimers Dement ; 7(4): e124-9, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21784344

ABSTRACT

Complement receptor 1 gene polymorphism rs3818361 was recently shown to increase the risk of Alzheimer's disease (AD). We performed an independent replication study of this genetic variant in 2,470 individuals from Spain. By applying an allelic model, we observed a trend toward an association between this marker and late-onset AD susceptibility in our case-control study (odds ratio = 1.114, 95% confidence interval: 0.958-1.296, P = .16). Meta-analysis of available studies (n = 31,771 individuals), including previous studies and public genome-wide association study resources (Alzheimer's Disease Neuroimaging Initiative, Translational Genomics Research Institute, and Multi-site Collaborative Study for Genotype-Phenotype Associations in Alzheimer's Disease), strongly supports the effect of rs3818361 (odds ratio = 1.180, 95% confidence interval: 1.113-1.252, P < 2.99E-8) and suggests the existence of between-study heterogeneity (P < .05). We concluded that the complement receptor 1 gene may contribute to AD risk, although its effect size could be smaller than previously estimated.


Subject(s)
Alzheimer Disease/genetics , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide/genetics , Receptors, Complement/genetics , Female , Gene Frequency , Genetic Association Studies , Genotype , Humans , Male , Odds Ratio , Spain
6.
Nat Commun ; 12(1): 3417, 2021 06 07.
Article in English | MEDLINE | ID: mdl-34099642

ABSTRACT

Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease.


Subject(s)
Alzheimer Disease/genetics , Multifactorial Inheritance , Age of Onset , Aged , Aged, 80 and over , Alzheimer Disease/epidemiology , Alzheimer Disease/pathology , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Apolipoproteins E/genetics , Case-Control Studies , Cohort Studies , Datasets as Topic , Female , Follow-Up Studies , Genetic Predisposition to Disease , Genome-Wide Association Study , Heterozygote , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Risk Assessment/methods , Risk Factors
7.
Transl Psychiatry ; 11(1): 142, 2021 02 24.
Article in English | MEDLINE | ID: mdl-33627629

ABSTRACT

Long runs of homozygosity (ROH) are contiguous stretches of homozygous genotypes, which are a footprint of inbreeding and recessive inheritance. The presence of recessive loci is suggested for Alzheimer's disease (AD); however, their search has been poorly assessed to date. To investigate homozygosity in AD, here we performed a fine-scale ROH analysis using 10 independent cohorts of European ancestry (11,919 AD cases and 9181 controls.) We detected an increase of homozygosity in AD cases compared to controls [ßAVROH (CI 95%) = 0.070 (0.037-0.104); P = 3.91 × 10-5; ßFROH (CI95%) = 0.043 (0.009-0.076); P = 0.013]. ROHs increasing the risk of AD (OR > 1) were significantly overrepresented compared to ROHs increasing protection (p < 2.20 × 10-16). A significant ROH association with AD risk was detected upstream the HS3ST1 locus (chr4:11,189,482‒11,305,456), (ß (CI 95%) = 1.09 (0.48 ‒ 1.48), p value = 9.03 × 10-4), previously related to AD. Next, to search for recessive candidate variants in ROHs, we constructed a homozygosity map of inbred AD cases extracted from an outbred population and explored ROH regions in whole-exome sequencing data (N = 1449). We detected a candidate marker, rs117458494, mapped in the SPON1 locus, which has been previously associated with amyloid metabolism. Here, we provide a research framework to look for recessive variants in AD using outbred populations. Our results showed that AD cases have enriched homozygosity, suggesting that recessive effects may explain a proportion of AD heritability.


Subject(s)
Alzheimer Disease , Alzheimer Disease/genetics , Homozygote , Humans , Polymorphism, Single Nucleotide
8.
Dement Geriatr Cogn Disord ; 29(2): 139-45, 2010.
Article in English | MEDLINE | ID: mdl-20145400

ABSTRACT

BACKGROUND: Attention deficits are at the core of the defects in neuropsychological performance which define both dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Most studies have used separate tasks to test different attention abilities in patients with these diagnoses, precluding the assessment of any interaction among the different attention components. METHODS: We used a version of the Attention Network Test in which the alerting, orienting and executive attention networks, along with their interactions, could be assessed with a single task. Three groups of participants were tested: DLB patients (n = 13), AD patients (n = 18) and healthy controls (n = 18). RESULTS: The alerting signal improved orienting attention and increased the conflict effect in the healthy controls, but they had no effect on these networks in the AD patients. The DLB patients only showed preserved orienting and conflict effects when the alerting signal was present, indicating that there was regulation of the orienting and executive attention networks by the alerting signal. CONCLUSIONS: The most important differences among the 3 groups were observed in the attention network interactions, where alerting played a more relevant role in the DLB than in the AD patients. Under alerting states, the DLB patients showed evidence of certain regulation in the orienting and executive attention networks.


Subject(s)
Alzheimer Disease/physiopathology , Alzheimer Disease/psychology , Attention/physiology , Lewy Body Disease/physiopathology , Lewy Body Disease/psychology , Nerve Net/physiology , Acoustic Stimulation , Aged , Cues , Education , Female , Humans , Male , Neuropsychological Tests , Psychomotor Performance/physiology , Reaction Time , Socioeconomic Factors
9.
JAMA ; 303(18): 1832-40, 2010 May 12.
Article in English | MEDLINE | ID: mdl-20460622

ABSTRACT

CONTEXT: Genome-wide association studies (GWAS) have recently identified CLU, PICALM, and CR1 as novel genes for late-onset Alzheimer disease (AD). OBJECTIVES: To identify and strengthen additional loci associated with AD and confirm these in an independent sample and to examine the contribution of recently identified genes to AD risk prediction in a 3-stage analysis of new and previously published GWAS on more than 35,000 persons (8371 AD cases). DESIGN, SETTING, AND PARTICIPANTS: In stage 1, we identified strong genetic associations (P < 10(-3)) in a sample of 3006 AD cases and 14,642 controls by combining new data from the population-based Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (1367 AD cases [973 incident]) with previously reported results from the Translational Genomics Research Institute and the Mayo AD GWAS. We identified 2708 single-nucleotide polymorphisms (SNPs) with P < 10(-3). In stage 2, we pooled results for these SNPs with the European AD Initiative (2032 cases and 5328 controls) to identify 38 SNPs (10 loci) with P < 10(-5). In stage 3, we combined data for these 10 loci with data from the Genetic and Environmental Risk in AD consortium (3333 cases and 6995 controls) to identify 4 SNPs with P < 1.7x10(-8). These 4 SNPs were replicated in an independent Spanish sample (1140 AD cases and 1209 controls). Genome-wide association analyses were completed in 2007-2008 and the meta-analyses and replication in 2009. MAIN OUTCOME MEASURE: Presence of Alzheimer disease. RESULTS: Two loci were identified to have genome-wide significance for the first time: rs744373 near BIN1 (odds ratio [OR],1.13; 95% confidence interval [CI],1.06-1.21 per copy of the minor allele; P = 1.59x10(-11)) and rs597668 near EXOC3L2/BLOC1S3/MARK4 (OR, 1.18; 95% CI, 1.07-1.29; P = 6.45x10(-9)). Associations of these 2 loci plus the previously identified loci CLU and PICALM with AD were confirmed in the Spanish sample (P < .05). However, although CLU and PICALM were confirmed to be associated with AD in this independent sample, they did not improve the ability of a model that included age, sex, and APOE to predict incident AD (improvement in area under the receiver operating characteristic curve from 0.847 to 0.849 in the Rotterdam Study and 0.702 to 0.705 in the Cardiovascular Health Study). CONCLUSIONS: Two genetic loci for AD were found for the first time to reach genome-wide statistical significance. These findings were replicated in an independent population. Two recently reported associations were also confirmed. These loci did not improve AD risk prediction. While not clinically useful, they may implicate biological pathways useful for future research.


Subject(s)
Alzheimer Disease/genetics , Genetic Loci , Genetic Predisposition to Disease , Genome-Wide Association Study , Age of Onset , Aged , Case-Control Studies , Humans , Odds Ratio , Polymorphism, Single Nucleotide
10.
Oncotarget ; 9(37): 24590-24600, 2018 May 15.
Article in English | MEDLINE | ID: mdl-29872490

ABSTRACT

The apolipoprotein E (APOE) gene on chromosome 19q13.32, was the first, and remains the strongest, genetic risk factor for Alzheimer's disease (AD). Additional signals associated with AD have been located in chromosome 19, including ABCA7 (19p13.3) and CD33 (19q13.41). The ABCA7 gene has been replicated in most populations. However, the contribution to AD of other signals close to APOE gene remains controversial. Possible explanations for inconsistency between reports include long range linkage disequilibrium (LRLD). We analysed the contribution of ABCA7 and CD33 loci to AD risk and explore LRLD patterns across APOE region. To evaluate AD risk conferred by ABCA7 rs4147929:G>A and CD33 rs3865444:C>A, we used a large Spanish population (1796 AD cases, 2642 controls). The ABCA7 rs4147929:G>A SNP effect was nominally replicated in the Spanish cohort and reached genome-wide significance after meta-analysis (odds ratio (OR)=1.15, 95% confidence interval (95% CI)=1.12-1.19; P = 1.60 x 10-19). CD33 rs3865444:C>A was not associated with AD in the dataset. The meta-analysis was also negative (OR=0.98, 95% CI=0.93-1.04; P=0.48). After exploring LRLD patterns between APOE and CD33 in several datasets, we found significant LD (D' >0.20; P <0.030) between APOE-Ɛ2 and CD33 rs3865444C>A in two of five datasets, suggesting the presence of a non-universal long range interaction between these loci affecting to some populations. In conclusion, we provide here evidence of genetic association of the ABCA7 locus in the Spanish population and also propose a plausible explanation for the controversy on the contribution of CD33 to AD susceptibility.

12.
Arch Clin Neuropsychol ; 31(4): 378-88, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27193368

ABSTRACT

OBJECTIVE: Serial cognitive assessments are useful for many purposes, such as monitoring cognitive decline or evaluating the result of an intervention. In order to determine if an observed change is reliable and meaningful, longitudinal reference data from non-clinical samples are needed. Since neuropsychological outcomes are affected by language and cultural background, cognitive tests should be adapted, and country-based norms collected. The lack of cross-sectional normative data for Spanish population has been partially remediated, but there is still a need of reliable change norms. This paper aims to give an initial response to this need by providing several reliable change indices (RCI) for 1-year follow-up in a Spanish sample. METHOD: A longitudinal observational study was designed. A total of 122 healthy subjects over age 50 were evaluated twice (M = 369.5, SD= 10.7 days) with the NEURONORMA battery. Scores changes were analyzed, and simple discrepancy scores, standard deviation indices, RCI, and standardized regression-based scores were calculated. RESULTS: Significant improvements were observed in variables related to memory, both verbal and visual, visuospatial function, and the completion time of complex problems. Reference tables for several RCI are provided for their use in clinical settings. CONCLUSIONS: Our results confirm the existence of heterogeneous practice effects after 1 year, and support the recommendation of using reliable change norms to avoid misdiagnosis in repeated assessments. This study provides with initial, preliminary norms of cognitive change for its use in Spanish elders. Further studies on larger samples and different inter-visit intervals are still needed.


Subject(s)
Aging/physiology , Cognition Disorders/diagnosis , Cognition/physiology , Geriatric Assessment , Neuropsychological Tests , Aged , Aged, 80 and over , Female , Humans , Longitudinal Studies , Male , Middle Aged , Reference Values , Spain
13.
Neurology ; 85(7): 626-33, 2015 Aug 18.
Article in English | MEDLINE | ID: mdl-26180139

ABSTRACT

OBJECTIVE: To investigate CSF markers involved in amyloid precursor protein processing, neuronal damage, and neuroinflammation in the preclinical stages of Alzheimer disease (AD) and participants with suspected non-Alzheimer pathology (SNAP). METHODS: We collected CSF from 266 cognitively normal volunteers participating in a cross-sectional multicenter study (the SIGNAL study) to investigate markers involved in amyloid precursor protein processing (Aß42, sAPPß, ß-secretase activity), neuronal damage (total-tau [t-tau], phospho-tau [p-tau]), and neuroinflammation (YKL-40). We analyzed the relationship among biomarkers, clinical variables, and the APOE genotype, and compared biomarker levels across the preclinical stages of the National Institute on Aging-Alzheimer's Association classification: stage 0, 1, 2, 3, and SNAP. RESULTS: The median age in the whole cohort was 58.8 years (range 39.8-81.6). Participants in stages 2-3 and SNAP had higher levels of YKL-40 than those in stages 0 and 1. Participants with SNAP had higher levels of sAPPß than participants in stage 0 and 1. No differences were found between stages 0, 1, and 2-3 in sAPPß and ß-secretase activity in CSF. Age correlated with t-tau, p-tau, and YKL-40. It also correlated with Aß42, but only in APOE ε4 carriers. Aß42 correlated positively with t-tau, sAPPß, and YKL-40 in participants with normal Aß42. CONCLUSIONS: Our findings suggest that inflammation in the CNS increases in normal aging and is intimately related to markers of neurodegeneration in the preclinical stages of AD and SNAP. sAPPß and ß-secretase activity are not useful diagnostic or staging markers in preclinical AD.


Subject(s)
Adipokines/cerebrospinal fluid , Alzheimer Disease/cerebrospinal fluid , Amyloid Precursor Protein Secretases/cerebrospinal fluid , Amyloid beta-Peptides/cerebrospinal fluid , Amyloid beta-Protein Precursor/cerebrospinal fluid , Lectins/cerebrospinal fluid , Peptide Fragments/cerebrospinal fluid , Prodromal Symptoms , tau Proteins/cerebrospinal fluid , Adult , Age Factors , Aged , Aged, 80 and over , Alzheimer Disease/genetics , Apolipoproteins E/genetics , Biomarkers/cerebrospinal fluid , Chitinase-3-Like Protein 1 , Cross-Sectional Studies , Female , Humans , Male , Middle Aged
14.
J Alzheimers Dis ; 45(4): 1157-73, 2015.
Article in English | MEDLINE | ID: mdl-25649659

ABSTRACT

Accurate blood-based biomarkers of Alzheimer's disease (AD) could constitute simple, inexpensive, and non-invasive tools for the early diagnosis and treatment of this devastating neurodegenerative disease. We sought to develop a robust AD biomarker panel by identifying alterations in plasma metabolites that persist throughout the continuum of AD pathophysiology. Using a multicenter, cross-sectional study design, we based our analysis on metabolites whose levels were altered both in AD patients and in patients with amnestic mild cognitive impairment (aMCI), the earliest identifiable stage of AD. UPLC coupled to mass spectrometry was used to independently compare the levels of 495 plasma metabolites in aMCI (n = 58) and AD (n = 100) patients with those of normal cognition controls (NC, n = 93). Metabolite alterations common to both aMCI and AD patients were used to generate a logistic regression model that accurately distinguished AD from NC patients. The final panel consisted of seven metabolites: three amino acids (glutamic acid, alanine, and aspartic acid), one non-esterified fatty acid (22:6n-3, DHA), one bile acid (deoxycholic acid), one phosphatidylethanolamine [PE(36:4)], and one sphingomyelin [SM(39:1)]. Detailed analysis ruled out the influence of potential confounding variables, including comorbidities and treatments, on each of the seven biomarkers. The final model accurately distinguished AD from NC patients (AUC, 0.918). Importantly, the model also distinguished aMCI from NC patients (AUC, 0.826), indicating its potential diagnostic utility in early disease stages. These findings describe a sensitive biomarker panel that may facilitate the specific detection of early-stage AD through the analysis of plasma samples.


Subject(s)
Alzheimer Disease/blood , Aged , Aged, 80 and over , Algorithms , Alzheimer Disease/diagnosis , Alzheimer Disease/genetics , Apolipoproteins E/genetics , Area Under Curve , Biomarkers/blood , Cognitive Dysfunction/blood , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/genetics , Cross-Sectional Studies , Early Diagnosis , Female , Humans , Logistic Models , Male , Mass Spectrometry , Middle Aged , Multivariate Analysis , Principal Component Analysis , Sensitivity and Specificity
15.
J Alzheimers Dis ; 45(2): 621-9, 2015.
Article in English | MEDLINE | ID: mdl-25613099

ABSTRACT

The objective of this study was to identify genetic variation in genes encoding death receptors and signals that modulate their activity. After conducting a meta-analysis with five previous genome-wide association studies and aggregated data, the most significant signals, (TNF locus: rs2395488, rs2534672, and rs9267445; and FASLG locus: rs730278), were replicated in 1,046 cases and 372 controls. The rs2395488 and rs2534672 markers showed a modest protective effect (OR = 0.849, p = 0.49780;OR= 0.687, p = 0.11335), in contrast to rs730278 marker (OR = 1.146, p = 0.17212), which did not follow the previous effect direction; in any case it reached the significance level. Final meta-analysis, adding the replication sample, confirmed these observations. We concluded that FASLG marker is not etiologically linked to Alzheimer's disease. However, single nucleotide polymorphisms around TNF locus require further analyses in order to explain the association between Alzheimer's disease and human leukocyte antigen.


Subject(s)
Apoptosis/genetics , Cholinesterase Inhibitors/therapeutic use , Pharmacogenetics , Polymorphism, Genetic/genetics , Tumor Necrosis Factor-alpha/genetics , Aged , Aged, 80 and over , Alzheimer Disease/drug therapy , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Analysis of Variance , Apolipoproteins E/genetics , Apoptosis/drug effects , Cytochrome P-450 CYP2D6/genetics , Donepezil , Fas Ligand Protein/genetics , Female , Humans , Indans/therapeutic use , Longitudinal Studies , Male , Mental Status Schedule , Meta-Analysis as Topic , Piperidines/therapeutic use , Predictive Value of Tests , Treatment Outcome
16.
Exp Gerontol ; 49: 35-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24252535

ABSTRACT

In this preliminary study we assessed the functioning of the different attentional networks in mild cognitive impairment (MCI) patients, taking as theoretical framework the Posner's cognitive neuroscience approach. Two groups of participants were tested in a single short experiment: 20 MCI patients (6 amnestic, 6 non-amnestic and 8 multiple-domain) and 18 healthy matched controls (HC). For attentional assessment we used a version of the Attention Network Test (the ANTI-V) that provided not only a score of the orienting, the executive, and the alerting networks and their interactions, but also an independent measure of vigilance (tonic alerting). The results showed that all subtypes of MCI patients exhibited a selective impairment in the tonic component of alerting, as indexed by a decrease in the d' sensitivity index, and their performance in executive network increased up to the HC group level when phasic alerting was provided by a warning tone. Our findings suggest that a core attentional deficit, especially the endogenous component of alerting, may significantly contribute to the behavioral and cognitive deficits associated with MCI.


Subject(s)
Arousal/physiology , Cognitive Dysfunction/psychology , Aged , Attention/physiology , Case-Control Studies , Cognitive Dysfunction/diagnosis , Executive Function/physiology , Female , Humans , Male , Middle Aged , Nerve Net/physiopathology , Neuropsychological Tests , Orientation/physiology , Reaction Time/physiology
17.
Arch Clin Neuropsychol ; 29(1): 60-74, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24217861

ABSTRACT

The application of the Boston Naming Test (BNT) is time-consuming and shortened versions need to be developed for screening purposes. The aims of this study were to develop four equivalent 15-item forms of a Spanish adaptation of the BNT, to test the equivalence of the new versions in a clinical sample, and to provide normative data. The normative sample consisted of 340 subjects. The clinical sample included 172 patients (76 Mild Cognitive Impairment and 96 Alzheimer's disease). An empirical procedure was used to develop the shortened versions. All new versions demonstrated satisfactory internal consistency. Pearson's coefficient analysis showed strong relationships among the four short-form versions as well as between each of them and the 60-item test. The inferential confidence interval method demonstrated the equivalence between the four shortened versions. Age and education affected the score of all short-form versions, but sex was found to be unrelated to the performance. Normative data were calculated for midpoint age groups. This paper proposes four 15-item equivalent versions that could be useful and time-saving tools for screening purposes.


Subject(s)
Alzheimer Disease/diagnosis , Cognitive Dysfunction/diagnosis , Neuropsychological Tests , Age Factors , Aged , Aged, 80 and over , Alzheimer Disease/psychology , Analysis of Variance , Cognitive Dysfunction/psychology , Female , Humans , Male , Mental Status Schedule , Middle Aged , Reference Values , Spain , Statistics as Topic , Translating
18.
J Alzheimers Dis ; 41(3): 887-901, 2014.
Article in English | MEDLINE | ID: mdl-24718100

ABSTRACT

The aim of this study was to characterize the neuropsychological and neuroimaging profiles of mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients, and to study the magnitude of the differences by comparing both outcomes with healthy subjects in a cross-sectional manner. Five hundred and thirty-five subjects (356 cognitively normal adults (CONT), 79 MCI, and 100 AD) were assessed with the NEURONORMA neuropsychological battery. Thirty CONT, 23 MCI, and 23 AD subjects from this sample were included in the neuroimaging substudy. Patients' raw cognitive scores were converted to age and education-adjusted scaled ones (range 2-18) using co-normed reference values. Medians were plotted to examine the cognitive profile. MRIs were processed by means of FreeSurfer. Effect size indices (Cohen's d) were calculated in order to compare the standardized differences between patients and healthy subjects. Graphically, the observed cognitive profiles for MCI and AD groups produced near to parallel lines. Verbal and visual memories were the most impaired domains in both groups, followed by executive functions and linguistic/semantic ones. The largest effect size between AD and cognitively normal subjects was found for the FCSRT (d = 4.05, AD versus CONT), which doubled the value obtained by the best MRI measure, the right hippocampus (d = 1.65, AD versus CONT). Our results support the notion of a continuum in cognitive profile between MCI and AD. Neuropsychological outcomes, in particular the FCSRT, are better than neuroimaging ones at detecting differences among subjects.


Subject(s)
Alzheimer Disease/pathology , Alzheimer Disease/physiopathology , Brain/pathology , Cognitive Dysfunction/pathology , Cognitive Dysfunction/physiopathology , Aged , Aged, 80 and over , Analysis of Variance , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Neuropsychological Tests , Reference Values , Spain
19.
J Alzheimers Dis ; 35(2): 403-12, 2013.
Article in English | MEDLINE | ID: mdl-23403532

ABSTRACT

The interaction between neurexins and neuroligins promotes the formation of functional synaptic structures. Recently, it has been reported that neurexins and neuroligins are proteolytically processed by presenilins at synapses. Based on this interaction and the role of presenilins in familial Alzheimer's disease (AD), we hypothesized that dysfunction of the neuroligin-neurexin pathway might be associated with AD. To explore this hypothesis, we carried out a meta-analysis of five genome-wide association studies (GWAS) comprising 1, 256 SNPs in the NRXN1, NRXN2, NRXN3, and NLGN1 genes (3,009 cases and 3,006 control individuals). We identified a marker in the NRXN3 gene (rs17757879) that showed a consistent protective effect in all GWAS, however, the statistical significance obtained did not resist multiple testing corrections (OR = 0.851, p = 0.002). Nonetheless, gender analysis revealed that this effect was restricted to males. A combined meta-analysis of the former five GWAS together with a replication Spanish sample consisting of 1,785 cases and 1,634 controls confirmed this observation (rs17757879, OR = 0.742, 95% CI = 0.632-0.872, p = 0.00028, final meta-analysis). We conclude that NRXN3 might have a role in susceptibility to AD in males.


Subject(s)
Alzheimer Disease/genetics , Nerve Tissue Proteins/genetics , Alzheimer Disease/epidemiology , Calcium-Binding Proteins , Cell Adhesion Molecules, Neuronal/genetics , DNA/genetics , DNA/isolation & purification , Databases, Genetic , Genetic Markers , Genome-Wide Association Study , Genotype , Haplotypes , Humans , Linkage Disequilibrium , Neural Cell Adhesion Molecules , Polymorphism, Single Nucleotide/genetics , Sex Characteristics , Spain/epidemiology , White People
20.
Neuropsychology ; 26(4): 483-9, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22545618

ABSTRACT

OBJECTIVE: Previous studies have demonstrated the benefit of the differential outcomes procedure (DOP) in human learning. In the present study we aimed to explore whether the DOP might also help to overcome the face recognition memory deficit commonly observed in Alzheimer's disease (AD) patients. METHOD: A delayed matching-to-sample task was used. Participants were instructed to choose which of the 4 alternative faces (comparison stimuli) matched the previously seen face (sample stimulus). Either short (5 seconds) or long (25 seconds) delays were interposed between the sample and the comparison stimuli. In the differential outcomes condition each sample face was paired with its own outcome. In contrast, in the nondifferential condition, outcomes were randomly arranged. RESULTS: The differential outcomes effect (DOE) was evident in the AD patients with both accuracy and latency data. That is, they showed a significantly better and faster delayed face recognition when differential outcomes were arranged. The analyses also revealed a significant main effect of delay; participants were slower in the 25 seconds condition than in the 5 seconds condition, but the difference was higher in the patients than in the controls. CONCLUSIONS: These findings demonstrate, to our knowledge for the first time, that face recognition memory in patients with Alzheimer is improved when differential outcomes are used and draw attention to the potential of this procedure as a therapeutic technique.


Subject(s)
Alzheimer Disease/complications , Face , Memory Disorders/etiology , Memory Disorders/rehabilitation , Recognition, Psychology/physiology , Aged , Aged, 80 and over , Female , Humans , Male , Neuropsychological Tests , Paired-Associate Learning/physiology , Photic Stimulation/methods , Reaction Time/physiology , Reinforcement, Psychology , Statistics, Nonparametric
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