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Abstract Background Tau abnormal hyperphosphorylation and the formation of neurofibrillary tangles in AD brain is the result of upregulation of tau kinases and downregulation of tau phosphatases. Methods In a group of 729 Spanish late-onset Alzheimer's disease (AD) patients and 670 healthy controls, we examined variations into a set of candidate genes (PPP2CA, PPP2R2A, ANP32A, LCMT1, PPME1 and PIN1) in the tau protein phosphatase-2A (PP2A) pathway, to address hypotheses of genetic variation that might influence AD risk. Results There were no differences in the genotypic, allelic or haplotypic distributions between cases and controls in the overall analysis or after stratification by age, gender or APOE ε4 allele. Conclusion Our negative findings in the Spanish population argue against the hypothesis that genetic variation in the tau protein phosphatase-2A (PP2A) pathway is causally related to AD risk

Abstract Background Mild cognitive impairment (MCI) is a heterogeneous clinical entity that comprises the prodromal phase of Alzheimer's disease (Pr-AD). New biomarkers are useful in detecting Pr-AD, but they are not universally available. We aimed to investigate baseline clinical and neuropsychological variables that might predict progression from MCI to AD dementia. Methods All patients underwent a complete clinical and neuropsychological evaluation at baseline and every 6 months during a two-year follow-up period, with 54 out of 109 MCI patients progressing to dementia (50 of them progressed to AD dementia), and 55 remaining as stable MCI (S-MCI). Results A combination of MMSE and California Verbal Learning Test Long Delayed Total Recall (CVLT-LDTR) constituted the best predictive model: subjects scoring above 26/30 on MMSE and 4/16 on CVLT-LDTR had a negative predictive value of 93.93% at 2 years, whereas those subjects scoring below both of these cut-off scores had a positive predictive value of 80.95%. Conclusions Pr-AD might be distinguished from S-MCI at baseline using the combination of MMSE and CVLT-LDTR. These two neuropsychological predictors are relatively brief and may be readily completed in non-specialist clinical settings.

Abstract Background Interleukin (IL)-1β is a potent proinflammatory cytokine markedly overexpressed in the brains of patients with Alzheimer's disease (AD), and also involved in development of atherosclerosis and coronary artery disease. Caspase-1 (CASP1), formerly called IL-1β converting enzyme (ICE), mediates the cleavage of the inactive precursor of IL-1β into the biologically active form. CASP1 genetic variation (G+7/in6A, rs501192) has been associated with susceptibility to myocardial infarction and cardiovascular death risk. We examined the contribution of this gene to the susceptibility for AD. Methods We examined genetic variations of CASP1 by genotyping haplotype tagging SNPs (htSNPs) (rs501192, rs556205 and rs530537) in a group of 628 Spanish AD cases and 722 controls. Results There were no differences in the genotypic, allelic or haplotypic distributions between cases and controls in the overall analysis or after stratification by age, gender or APOE ε4 allele. Conclusion Our negative findings in the Spanish population argue against the hypothesis that CASP1 genetic variations are causally related to AD risk.

Abstract Background As dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) has been implicated in the abnormal hyperphosphorylation of tau in Alzheimer's disease (AD) brain, and the development of neurofibrillary tangles, we examined the contribution of this gene to the susceptibility for AD. Methods We examined genetic variations of DYRK1A by genotyping haplotype tagging SNPs (htSNPs) (rs11701483, rs2835740, rs1137600, rs2835761, rs2835762, rs2154545 and rs8132976) in a group of 634 Spanish AD cases and 733 controls. Results There were no differences in the genotypic, allelic or haplotypic distributions between cases and controls in the overall analysis or after stratification by APOE ε4 allele. Conclusion Our negative findings in the Spanish population argue against the hypothesis that DYRK1A genetic variations are causally related to AD risk. Still, additional studies using different sets of patients and control subjects deserve further attention, since supporting evidence for association between DYRK1A gene and AD risk in the Japanese population exists.

Background: The optimal cut-off for Alzheimer's disease (AD) CSF biomarkers remains controversial. Objective: To analyze the performance of cut-off points standardized by three methods: one that optimized the agreement between 11C-Pittsburgh compound B PET (a-PET) and CSF biomarkers (Aβ1–42, pTau, tTau, and Aβ1–42/Aβ1–40 ratio) in our population, called PET-driven; an unbiased cut-off using data from a healthy research cohort, called data-driven, and that provided by the manufacturer. We also compare changes in ATN classification. Methods: CSF biomarkers measured by the LUMIPULSE G600II platform and qualitative visualization of amyloid positron emission tomography (a-PET) were performed in all the patients. We established a cut-off for each single biomarker and Aβ1–42/Aβ1–40 ratio that optimized their agreement with a-PET using ROC curves. Sensitivity, Specificity, and Overall Percent of Agreement are assessed using a-PET or clinical diagnosis as gold standard for every cut-off. Also, we established a data-driven cut-off from our cognitively unimpaired cohort. We then analyzed changes in ATN classification. Results: One hundred and ten patients were recruited. Sixty-six (60%) were a-PET positive. PET-driven cut-offs were: pTau > 57, tTau > 362.62, Aβ1–42/Aβ1–40 < 0.069. For a single biomarker, pTau showed the highest accuracy (AUC 0.926). New PET-driven cut-offs classified patients similarly to manufacturer cut-offs (only two patients changed). However, 20 patients (18%) changed when data-driven cut-offs were used. Conclusions: We established our sample's best CSF biomarkers cut-offs using a-PET as the gold standard. These cut-offs categorize better symptomatic subjects than data-driven in ATN classification, but they are very similar to the manufacturer's. [ABSTRACT FROM AUTHOR]

Background: Several plasma biomarkers have shown good correlation with brain amyloidosis measured by CSF biomarkers and PET, but their utility to identify subjects with Alzheimer's disease(AD) brain pathology at the community level is not well known. Neuropsychological tests might be a more accessible alternative. Method: Our aims were to assess the utility of plasma p‐tau231, plasma GFAP, and plasma NFL to identify individuals with preclinical AD, and to compare it with the utility of current neuropsychological tests for early AD detection: Preclinical Alzheimer's Cognitive Composite 5(PACC5), Spanish version of Face‐Name Memory Exam(S‐FNAME), Logical Memory Test (LMT‐WMSIII), and Free and Cued Selective Reminding Test(FCSRT). Our study population was a community‐based cohort that enrolls individuals older than 55 living in Cantabria, a region in northern Spain. Exclusion criteria include a diagnosis of dementia or other cognitive disorders. AD+ status was defined by abnormal levels of both CSF amyloid‐β1‐42/1‐40 ratio and CSF p‐tau181. General linear models were used to compare biomarker and cognitive results between AD+ subjects and the rest of the population, with age and sex as covariates. ROC curves were built to compare the utility of each test to identify AD+ cases. Result: The total sample included 156 individuals, 30 of them AD+. AD+ subjects showed significantly higher levels of GFAP (mean difference 78.04, p<0.00001) and p‐tau231 (mean difference 5.53, p 0.00040), but not NFL (mean difference 1.16, p 0.63), compared to non‐AD (table 1). After adjusting by age, sex, APOE4 carrier status, and AD status, age and sex were still independent predictors of GFAP levels, but not of p‐tau231 (table 2). FCSRT delayed recall and LMT‐WMSIII total score were significantly lower in AD+ than in non‐AD cases, but not S‐FNAME nor PACC5 (table 1). Both plasma GFAP and p‐tau231 showed an AUC of 0.75 to identify AD+ individuals (table 3, figure 1). Neuropsychological tests obtained non‐significantly smaller AUC than plasma biomarkers. Conclusion: In our community‐based population, plasma GFAP and p‐tau231 were useful to identify individuals with preclinical AD, but not plasma NFL. Although probably with a lower performance, early detection cognitive tests may also be helpful to identify AD cases in the community. [ABSTRACT FROM AUTHOR]

A 52-year-old male patient with a background of adaptive personality disorder was admitted for mitral valve repair and cardiac ablation for atrial fibrillation. He suffered intraoperative complications with severe mitral insufficiency that suffered ischemia.. Post-operatively, he demonstrated acute loss of retrograde autobiographical memory, prosopagnosia and a loss of public semantic memory. His CT scan was normal and MRI was not possible due to intra-cardiac leads. An initial diagnosis of hypoxic-ischemic encephalopathy was considered. A neuropsychological examination undertaken 20 days after his surgery showed a severe alteration of retrograde autobiographical memory, marked alteration of semantic knowledge and prosopagnosia. He demonstrated an average performance in tasks measuring constructional praxis, visuospatial ability, and executive functions. 34 days after surgery, and after a short nap, the patient "returns" to the day before admission and consequently recovers his memory. Repeat neuropsychological assessment demonstrated performance within the normal range across all previously tested domains. This sudden recovery of memory, together with a normal MRI, led to a rethinking of the diagnosis of dissociative amnesia. This case illustrates the long-standing discussion about the organic or functional origin of some memory disorders, in which, despite advances in neuroimaging techniques, it is still difficult to know their etiology [ABSTRACT FROM AUTHOR]

Background: Neurodegenerative diseases might affect social cognition in various ways depending on their components (theory of mind, emotional processing, attribution bias, and social perception) and the subtype of dementia they cause. This review aims to explore this difference in cognitive function among individuals with different aetiologies of dementia. Methods: The following databases were explored: MEDLINE via PubMed, Cochrane Library, Lilacs, Web of Science, and PsycINFO. We selected studies examining social cognition in individuals with neurodegenerative diseases in which dementia was the primary symptom that was studied. The neurodegenerative diseases included Alzheimer's disease, Lewy body disease and frontotemporal lobar degeneration. The search yielded 2,803 articles. Results: One hundred twenty-two articles were included in the present review. The summarised results indicate that people with neurodegenerative diseases indeed have deficits in social cognitive performance. Both in populations with Alzheimer's disease and in populations with frontotemporal dementia, we found that emotional processing was strongly affected. However, although theory of mind impairment could also be observed in the initial stages of frontotemporal dementia, in Alzheimer's disease it was only appreciated when performing highly complex task or in advanced stages of the disease. Conclusions: Each type of dementia has a differential profile of social cognition deterioration. This review could provide a useful reference for clinicians to improve detection and diagnosis, which would undoubtedly guarantee better interventions. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display%5frecord.php?ID=CRD42020152562, PROSPERO, identifier: CRD42020152562. [ABSTRACT FROM AUTHOR]

There is increasing evidence of the relationship between sleep and neurodegeneration, but this knowledge is not incorporated into clinical practice yet. We aimed to test whether a basic sleep parameter, as total sleep estimated by actigraphy for 1 week, was a valid predictor of CSF Alzheimer's Disease core biomarkers (amyloid-β-42 and –40, phosphorylated-tau-181, and total-tau) in elderly individuals, considering possible confounders and effect modifiers, particularly the APOE ε 4 allele. One hundred and twenty-seven cognitively unimpaired volunteers enrolled in the Valdecilla Study for Memory and Brain Aging participated in this study. Seventy percent of the participants were women with a mean age of 65.5 years. After adjustment for covariates, reduced sleep time significantly predicted higher t-tau and p-tau. This association was mainly due to the APOE ε4 carriers. Our findings suggest that total sleep time, estimated by an actigraphy watch, is an early biomarker of tau pathology and that APOE modulates this relationship. The main limitation of this study is the limited validation of the actigraphy technology used. Sleep monitoring with wearables may be a useful and inexpensive screening test to detect early neurodegenerative changes. [ABSTRACT FROM AUTHOR]

Oculomotor behavior can provide insight into the integrity of widespread cortical networks, which may contribute to the differential diagnosis between Alzheimer's disease and frontotemporal dementia. Three groups of patients with Alzheimer's disease, behavioral variant of frontotemporal dementia (bvFTD) and semantic variant of primary progressive aphasia (svPPA) and a sample of cognitively unimpaired elders underwent an eye-tracking evaluation. All participants in the discovery sample, including controls, had a biomarker-supported diagnosis. Oculomotor correlates of neuropsychology and brain metabolism evaluated with 18F-FDG PET were explored. Machine-learning classification algorithms were trained for the differentiation between Alzheimer's disease, bvFTD and controls. A total of 93 subjects (33 Alzheimer's disease, 24 bvFTD, seven svPPA, and 29 controls) were included in the study. Alzheimer's disease was the most impaired group in all tests and displayed specific abnormalities in some visually-guided saccade parameters, as pursuit error and horizontal prosaccade latency, which are theoretically closely linked to posterior brain regions. BvFTD patients showed deficits especially in the most cognitively demanding tasks, the antisaccade and memory saccade tests, which require a fine control from frontal lobe regions. SvPPA patients performed similarly to controls in most parameters except for a lower number of correct memory saccades. Pursuit error was significantly correlated with cognitive measures of constructional praxis and executive function and metabolism in right posterior middle temporal gyrus. The classification algorithms yielded an area under the curve of 97.5% for the differentiation of Alzheimer's disease vs. controls, 96.7% for bvFTD vs. controls, and 92.5% for Alzheimer's disease vs. bvFTD. In conclusion, patients with Alzheimer's disease, bvFTD and svPPA exhibit differentiating oculomotor patterns which reflect the characteristic neuroanatomical distribution of pathology of each disease, and therefore its assessment can be useful in their diagnostic work-up. Machine learning approaches can facilitate the applicability of eye-tracking in clinical practice. [ABSTRACT FROM AUTHOR]

Background: Major surgery has been associated with perioperative neurocognitive disorders (PND), but the contributing factors and long-term prognosis are uncertain. We hypothesize that preclinical Alzheimer's disease (AD) might predispose to cognitive deterioration after surgery.Objective: To analyze the effect of amyloid-β on the cognitive trajectory after orthopedic surgery in a sample of non-demented subjects.Methods: Non-demented individuals older than 65 years that were on the waiting list for orthopedic surgery with spinal anesthesia underwent a neuropsychological assessment before and after surgery. During surgery, cerebrospinal fluid samples were obtained to determine AD biomarkers.Results: Cumulative incidence of PND was 55.2%during a mean follow-up of nine months. The most affected cognitive domains were executive function and constructional praxis. The presence of abnormal levels of amyloid-β was associated to a postoperative impairment in verbal and visual memory tests. According to their AD biomarker profile, participants were categorized as either Amyloid Positive (A+) or Amyloid Negative (A-). The incidence of PND did not differ between both groups. The A- group showed a tendency similar to the global sample, worsening in executive function tests and improving on memory scales due to practice effects. In contrast, the A + group showed a notable worsening on memory performance.Conclusion: Our findings support the hypothesis that surgery may promote or accelerate memory decline in cognitively asymptomatic subjects with brain amyloid-β deposits. [ABSTRACT FROM AUTHOR]

Objective: To assess and compare the involvement of choroidal thickness (CT) in patients with mild cognitive impairment (MCI) and dementia due to Alzheimer's disease (AD) defined by amyloid PET and healthy controls (HC). Methods: Sixty-three eyes from 34 AD patients [12 eyes (19.0%) with dementia and 51 eyes (80.9%) with MCI], positive to 11C-labelled Pittsburgh Compound-B with positron emission tomography (11C-PiB PET/CT), and the same number of sex- and age-paired HC were recruited. All participants underwent enhanced depth imaging optical coherence tomography (EDI-OCT) assessing CT at 14 measurements from 2 B-scans. Paired Student t-test was used to compare CT measurements between MCI, dementia and sex- and age-paired HC. A univariate generalized estimating equations model (GEE) test was performed to compare MCI and dementia individually with all HC included. Results: Compared with HC, eyes from patients with positive 11C-PiB PET/CT showed a significant CT thinning in 5 selected locations (in foveal thickness in vertical scan, in temporal scan at 1500μm, in superior scan at 500μm and in inferior scan at 1000μm and 1500μm, p = 0.020–0.045) whilst few significant CT reduction data was reported in MCI or dementia individually versus HC. However, the GEE test identified significant CT thinning in AD compared with all HC included (p = 0.015–0.046). Conclusions: To our knowledge, the present study is the first measuring CT in eyes from MCI and dementia eyes positive to 11C-PiB PET/CT reporting a significant trend towards CT thinning in MCI patients which became more pronounced in dementia stage. We support further investigation involving larger and prospective OCT studies in AD population characterized with available biomarkers to describe whether choroidal vascular damage occurs specifically in prodromal stages of AD. [ABSTRACT FROM AUTHOR]

Introduction : In recent years, the study of the benefits that physical exercise has on brain health has acquired special relevance. In order to implement exercise as an intervention to protect the brain, it is important to have a more clear idea of its effect in the young population. However, few studies have been carried out on these ages. Objective : The main objective of our study was to evaluate the association between physical activity (PA) with memory and executive function, in university students, analyzing the modulatory effect of sex. Methodology : We collected socio-demographic and life habit information, as well as data on the PA that was carried out during the previous week using the international PAquestionnaire short version (IPAQ-SF) questionnaire in 206 university students (mean age 19.55 ± 2.39; 67.5% women). Memory and executive function were assessed using a comprehensive battery of validate cognitive tests. Univariate and multivariate analyses were performed to correlate PA with cognitive tests scores and to evaluate the potential synergistic role of sex. Results : The main finding was that the total amount of PA correlated positively with several tests that evaluated aspects of executive function, specifically Stroop Colors (Pearson's r = 0.17; p = 0.01) and the Stroop Test Color–Word (Pearson's r = 0.15. p = 0.03). These results were adjusted by a large number of possible confounders and modifying variables in a multivariate analysis, like age, sex, academic record, day of the week, and time at which the test was performed. Additionally, we found out that sex had a synergistic effect with PA on the executive test Trail making test-A (TMTA), and in women, this association was stronger than in men. The more PA women reported, the better they performed, that is to say that they took less time to finalize the TMT-A (interaction term between PA and sex: b = −0.0009; p = 0.014). Conclusion : Our study adds evidence of the benefit of PA in cognition in the young population, specifically in the executive inhibitory control, and more significantly in women. [ABSTRACT FROM AUTHOR]

Background: Semantic dementia (SD) is a subtype of frontotemporal dementia (FTD) characterized by semantic memory loss and preserved abilities of other cognitive functions. The clinical manifestations of SD require a differential diagnosis with Alzheimer's disease (AD), especially those with early onset, and behavioral variant FTD (bvFTD).Objective: The present study aimed to compare cognitive performances and neuropsychiatric symptoms in a population of AD, bvFTD, and left and right SD defined with the support of molecular imaging (amyloid and 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography) and assessed the accuracy of different neuropsychological markers in distinguishing these neurodegenerative diseases.Methods: Eighty-seven participants (32 AD, 20 bvFTD, and 35 SD (17 Left-SD and 18 Right-SD) completed a comprehensive neuropsychological battery that included memory, language, attention and executive functions, visuospatial function, visuoconstructional skills, and tasks designed specifically to evaluate prosopagnosia and facial emotions recognition. The Neuropsychiatric Inventory was administered to assess neuropsychiatric symptoms.Results: An episodic memory test that included semantic cues, a visuospatial test (both impaired in AD), a naming test and a prosopagnosia task (both impaired in SD) were the four most valuable cognitive metrics for the differential diagnosis between groups. Several behavioral abnormalities were differentially present, of which aggression, self-care (both more frequent in bvFTD), and eating habits, specifically overeating and altered dietary preference (more frequent in SD), were the most valuable in group discrimination.Conclusion: Our study highlights the value of a comprehensive neuropsychological and neuropsychiatric evaluation for the differential diagnosis between FTD syndromes and AD. [ABSTRACT FROM AUTHOR]

Background: Semantic dementia (SD) is a subtype of frontotemporal lobe degeneration characterized by semantic loss, with other cognitive functions initially preserved. SD requires differential diagnosis with Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD). Semantic knowledge can be evaluated through different tests; however, most of them depend on language.Objective: We describe the development of a brief drawing task that may be helpful for the differential diagnosis of SD.Methods: Seventy-two patients, including 32 AD, 19 bvFTD, and 21 SD were asked to draw 12 items with different age of acquisition and familiarity, belonging to four different semantic categories. We employed the drawings of healthy volunteers to build a scoring scheme.Results: Turtle, strawberry, train, and envelope were the items of each category that best discriminated between groups and were selected for the Brief drawing task. The discriminatory power of the Brief drawing task between SD versus AD and bvFTD patients, estimated through the area under the curve was 0.84 (95% CI = 0.72-0.96, p = 0.000007). In a logistic model, the Brief drawing task (p = 0.003) and VOSP "number location" subtest (p = 0.016) were significant predictors of the diagnosis of SD versus AD and bvFTD after adjustment by the main covariates. The Brief drawing task provided clinically useful qualitative information. SD drawings were characterized by loss of the distinctive features, intrusions, tendency to prototype, and answers like "I don't know what this is".Conclusion: The Brief drawing task appears to reveal deficits in semantic knowledge among patients with SD that may assist in the differential diagnosis with other neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

The clinical utility of amyloid positron emission tomography (PET) has not been fully established. Our aim was to evaluate the effect of amyloid imaging on clinical decision making in a secondary care unit and compare our results with a previous study in a tertiary center following the same methods. We reviewed retrospectively 151 cognitively impaired patients who underwent amyloid (Pittsburgh compound B [PiB]) PET and were evaluated clinically before and after the scan in a secondary care unit. One hundred and fifty concurrently underwent fluorodeoxyglucose (FDG)-PET. We assessed changes between the pre- and post-PET clinical diagnosis and Alzheimer's disease treatment plan. The association between PiB/FDG results and changes in management was evaluated using χ2 and multivariate logistic regression. Concordance between classification based on scan readings and baseline diagnosis was 66% for PiB and 47% for FDG. The primary diagnosis changed after PET in 17.2% of cases. When examined independently, discordant PiB and discordant FDG were both associated with diagnostic change (p < 0.0001). However, when examined together in a multivariate logistic regression, only discordant PiB remained significant (p = 0.0002). Changes in treatment were associated with concordant PiB (p = 0.009) while FDG had no effect on treatment decisions. Based on our regression model, patients with diagnostic dilemmas, a suspected non-amyloid syndrome, and Clinical Dementia Rating <1 were more likely to benefit from amyloid PET due to a higher likelihood of diagnostic change. We found that changes in diagnosis after PET in our secondary center almost doubled those of our previous analysis of a tertiary unit (9% versus 17.2%). Our results offer some clues about the rational use of amyloid PET in a secondary care memory unit stressing its utility in mild cognitive impairment patients. [ABSTRACT FROM AUTHOR]

Among primary progressive aphasias (PPAs), logopenic variant PPA (lv-PPA) is usually related to Alzheimer's disease. Although it has been widely clinically and pathologically evaluated, the topography in LPA is still controversial. We report a patient presenting with a logopenic syndrome due to a strategic lesion located in the superior and middle temporal gyrus and compare our findings with those of a PiB-PET positive lv-PPA patient matched by age, gender, and education. We consider that our study provides new anatomical clues to better understand the cognitive mechanisms underlying the logopenic syndrome. [ABSTRACT FROM AUTHOR]

Background: MicroRNAs have been postulated as potential biomarkers for Alzheimer's disease (AD). Exosomes are nanovesicles which transport microRNAs, proteins, and other cargos. It has been hypothesized that the exosome traffic might be increased in neurodegenerative disorders.Objective: i) To assess the cerebrospinal fluid (CSF) microRNA profile in a group of AD patients and control subjects and to validate a group of microRNAs previously reported by other authors. ii) To compare microRNA levels in whole CSF and in the exosome-enriched fraction in AD patients.Methods: A panel of 760 microRNAs was analyzed in the CSF of 10 AD patients and 10 healthy subjects. Among microRNAs differently expressed, we selected those that had been previously reported by other authors. Candidates were validated in a larger group by individual qPCR assays. MicroRNA expression was also evaluated in exosome-enriched CSF samples of patients with AD and controls.Results: Fifteen microRNAs were differently expressed in AD. MiR-9-5p, miR-134, and miR-598 were selected as candidates for further analysis. MiR-9-5p and miR-598 were detected in 50 and 75% of control CSF samples, respectively, while they were not detected in any AD CSF samples. We observed an opposite pattern when we evaluated the microRNA expression in the exosome-enriched CSF AD samples. No pattern variations were noted among healthy subjects.Conclusion: These data propose miR-9-5p and miR-598 as potential biomarkers for AD. Further studies in plasma and other body fluids will confirm their potential role as easily accessible biomarkers. In addition, our data suggest that exosome trafficking is different between AD and control subjects raising the need to take this phenomenon into consideration in future studies of AD biomarkers. [ABSTRACT FROM AUTHOR]

Our aim was to evaluate whether or not alcohol consumption in the form of binge drinking is associated with alterations of memory and executive functions in a population of university students. At the same time, we have studied the role of potential modulating factors, such as the APOE genotype or physical exercise.University students enrolled in academic year 2013–2014 at Escuelas Universitarias Gimbernat-Cantabria, affiliated with the University of Cantabria, were invited to participate in the study. We gathered sociodemographic data and details regarding the lifestyle of 206 students (mean age 19.55 ± 2.39; 67.5% women). We evaluated memory and executive functions via a series of validated cognitive tests. Participants were classified as binge drinkers (BD) and non-BD. Using Student's t-distribution we studied the association between cognitive tests and BD patterns. Multivariate analyses were carried out via multiple linear regression. 47.6% of the students were found to be BD. The BD differed significantly from the non-BD in their results in the executive functions test TMT B (43.41 ± 13.30 vs 37.40 ± 9.77; p = 0.0003). Adjusting by age, sex, academic records, age at which they started consuming alcohol, cannabis consumption, level of physical activity and other possible modifying variables, the association was statistically significant (p = 0.009). We noticed a statistically significant inverse correlation (Pearson’s r2 = -0.192; p = 0.007) between TMT B and starting age of alcohol consumption. Differences were observed in another executive functions test, TMT A, but only in the group of women (19.73±6.1 BD vs 17.78±5.4 non-BD p = 0.05). In spite of the young age of our participants, BD was associated with a lower performance in the executive functions test (TMT B). These deficits were related to the age at which they started drinking alcohol, suggesting an accumulative effect. [ABSTRACT FROM AUTHOR]

Tau abnormal hyperphosphorylation and the formation of neurofibrillary tangles in the Alzheimer's disease (AD) brain is the result of upregulation of tau kinases. In a group of 729 Spanish late-onset AD patients and 670 healthy controls, we examined variations into a set of 20 candidate genes of kinases involved in tau phosphorylation at AD-related sites (PRKACB; CAMK2A; MARK1, 2, 3 and 4; CSNK1D; CDC2; RPS6KB1 and 2; p38α and β; IB1; JNK1, 2 and 3; MEK1 and 2; ERK1 and 2), to address hypotheses of genetic variation that might influence both AD risk and age at disease onset. There was an increased frequency of RPS6KB2 (intron 2, rs917570) minor allele in patients (50%) versus controls (39%) (OR = 1.52; 95% CI 1.30-1.77; p = 1.24 × 10-5 Bonferroni corrected), and the presence of this minor allele was significantly (p = 4.2 × 10-5) associated with a 3-years later onset of AD (mean age 74.1 years) when compared to age at onset of non-minor allele carriers (mean age 71.1 years). In APOE non-ℇ4 allele carriers, the combined effect of AD-associated risk alleles from the genes of CDC2, RPS6KB1 and 2, p38α, JNK (1, 2 and 3), MEK2, and ERK2 was significantly (p = 0.002) associated with a late-onset (>76 years) of AD. The CDC2 AGC haplotype derived from SNPs in introns 3 (rs2448347), 5 (rs2456772), and 7 (rs1871447) showed a protective effect against AD in APOE non-ℇ4 allele carriers (permutation p = 1.0 × 10-4) with a frequency of 9% in cases and 15% in controls. Common genetic variation in the tau kinases pathway does underlie individual differences not only in susceptibility to AD but also in disease phenotype (age at disease onset). [ABSTRACT FROM AUTHOR]

Background: Mild cognitive impairment (MCI) is a heterogeneous clinical entity that comprises the prodromal phase of Alzheimer's disease (Pr-AD). New biomarkers are useful in detecting Pr-AD, but they are not universally available. We aimed to investigate baseline clinical and neuropsychological variables that might predict progression from MCI to AD dementia. Methods: All patients underwent a complete clinical and neuropsychological evaluation at baseline and every 6 months during a two-year follow-up period, with 54 out of 109 MCI patients progressing to dementia (50 of them progressed to AD dementia), and 55 remaining as stable MCI (S-MCI). Results: A combination of MMSE and California Verbal Learning Test Long Delayed Total Recall (CVLT-LDTR) constituted the best predictive model: subjects scoring above 26/30 on MMSE and 4/16 on CVLT-LDTR had a negative predictive value of 93.93% at 2 years, whereas those subjects scoring below both of these cut-off scores had a positive predictive value of 80.95%. Conclusions: Pr-AD might be distinguished from S-MCI at baseline using the combination of MMSE and CVLTLDTR. These two neuropsychological predictors are relatively brief and may be readily completed in non-specialist clinical settings. [ABSTRACT FROM AUTHOR]

Aberrant cholesterol metabolism has been implicated in Alzheimer's disease (AD). Recent findings have suggested an interaction of Niemann-Pick C1 (NPC1) and ATP-binding cassette transporter A1 (ABCA1) proteins in intracellular cholesterol transport and in maintaining cell cholesterol balance. Underexpression of NPC1 in concert with under-expression of ABCA1 would result in increased cholesterol accumulation and increased AD risk. We examined a functional polymorphism in the ABCA1 promoter region (-477, rs2422493), and four NPC1 polymorphisms in exon 6 (rs18050810), intron 20 (rs4800488), intron 22 (rs2236707), and intron 24 (rs2510344) capturing 85% of genetic variability in the Hap Map Caucasian (CEU) population, in a group of 631 Spanish AD patients and 731 controls. Subjects carrying both the ABCA1 (-477) TT genotype and the NPC1 (exon 6) GG genotype (OR=1.89; 95% CI 1.04–3.41), NPC1 (intron 20) AA genotype (OR=2.05; 95% CI 1.26–3.33), NPC1 (intron 22) AA genotype (OR=2.05; 95% or NPC1 (intron 24) GG genotype (OR=1.89; 95% higher risk of developing AD than subjects without these risk genotypes. Testing for epistatic interaction between genes in the pathway of cholesterol metabolism might be useful for predicting AD risk. [ABSTRACT FROM AUTHOR]

Abnormal tau hyperphosphorylation is one of the central events in the development of neurofibrillary tangles (NFTs) in Alzheimer’s disease (AD), and phosphorylation of tau is accelerated by the increase in the level of neuronal cholesterol. Apolipoprotein E (APOE) promotes the neuronal uptake of cholesterol via APOE receptors such as the low-density lipoprotein receptor-related protein 1 (LRP1), and the APOE ε4 allele is associated with an increase in NFT burden in AD brain. In a case-control study in 246 AD patients and 237 healthy controls, we examined whether the combined gene effects between tau (intron 9, rs2471738) polymorphism and LRP1 (exon 3, rs1799986) polymorphism might be responsible for susceptibility to AD, independently or in concert with the APOE ε4 allele. Subjects carrying both the tau (intron 9, rs2471738) T allele (CT and TT genotypes) and the LRP1 (exon 3, rs1799986) T allele (CT and TT genotypes) had a 6 times higher risk of developing AD than subjects without these risk genotypes (odds ration = 6.20, 95% confidence interval = 1.74–22.05, p = 0.005), and this genetic interaction was observed in either the presence or the absence of the APOE ε4 allele. These data suggest that the synergistic effects (epistasis) between tau and LRP1 might modify the risk of AD in an APOE ε4 allele-independent fashion. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: MicroRNAs have been postulated as potential biomarkers for Alzheimer's disease (AD). Exosomes are nanovesicles which transport microRNAs, proteins, and other cargos. It has been hypothesized that the exosome traffic might be increased in neurodegenerative disorders., Objective: i) To assess the cerebrospinal fluid (CSF) microRNA profile in a group of AD patients and control subjects and to validate a group of microRNAs previously reported by other authors. ii) To compare microRNA levels in whole CSF and in the exosome-enriched fraction in AD patients., Methods: A panel of 760 microRNAs was analyzed in the CSF of 10 AD patients and 10 healthy subjects. Among microRNAs differently expressed, we selected those that had been previously reported by other authors. Candidates were validated in a larger group by individual qPCR assays. MicroRNA expression was also evaluated in exosome-enriched CSF samples of patients with AD and controls., Results: Fifteen microRNAs were differently expressed in AD. MiR-9-5p, miR-134, and miR-598 were selected as candidates for further analysis. MiR-9-5p and miR-598 were detected in 50 and 75% of control CSF samples, respectively, while they were not detected in any AD CSF samples. We observed an opposite pattern when we evaluated the microRNA expression in the exosome-enriched CSF AD samples. No pattern variations were noted among healthy subjects., Conclusion: These data propose miR-9-5p and miR-598 as potential biomarkers for AD. Further studies in plasma and other body fluids will confirm their potential role as easily accessible biomarkers. In addition, our data suggest that exosome trafficking is different between AD and control subjects raising the need to take this phenomenon into consideration in future studies of AD biomarkers.

Background: Tau abnormal hyperphosphorylation and the formation of neurofibrillary tangles in AD brain is the result of upregulation of tau kinases and downregulation of tau phosphatases., Methods: In a group of 729 Spanish late-onset Alzheimer's disease (AD) patients and 670 healthy controls, we examined variations into a set of candidate genes (PPP2CA, PPP2R2A, ANP32A, LCMT1, PPME1 and PIN1) in the tau protein phosphatase-2A (PP2A) pathway, to address hypotheses of genetic variation that might influence AD risk., Results: There were no differences in the genotypic, allelic or haplotypic distributions between cases and controls in the overall analysis or after stratification by age, gender or APOE ε4 allele., Conclusion: Our negative findings in the Spanish population argue against the hypothesis that genetic variation in the tau protein phosphatase-2A (PP2A) pathway is causally related to AD risk.

Background: Interleukin (IL)-1beta is a potent proinflammatory cytokine markedly overexpressed in the brains of patients with Alzheimer's disease (AD), and also involved in development of atherosclerosis and coronary artery disease. Caspase-1 (CASP1), formerly called IL-1beta converting enzyme (ICE), mediates the cleavage of the inactive precursor of IL-1beta into the biologically active form. CASP1 genetic variation (G+7/in6A, rs501192) has been associated with susceptibility to myocardial infarction and cardiovascular death risk. We examined the contribution of this gene to the susceptibility for AD., Methods: We examined genetic variations of CASP1 by genotyping haplotype tagging SNPs (htSNPs) (rs501192, rs556205 and rs530537) in a group of 628 Spanish AD cases and 722 controls., Results: There were no differences in the genotypic, allelic or haplotypic distributions between cases and controls in the overall analysis or after stratification by age, gender or APOE epsilon4 allele., Conclusion: Our negative findings in the Spanish population argue against the hypothesis that CASP1 genetic variations are causally related to AD risk.

Background: As dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) has been implicated in the abnormal hyperphosphorylation of tau in Alzheimer's disease (AD) brain, and the development of neurofibrillary tangles, we examined the contribution of this gene to the susceptibility for AD., Methods: We examined genetic variations of DYRK1A by genotyping haplotype tagging SNPs (htSNPs) (rs11701483, rs2835740, rs1137600, rs2835761, rs2835762, rs2154545 and rs8132976) in a group of 634 Spanish AD cases and 733 controls., Results: There were no differences in the genotypic, allelic or haplotypic distributions between cases and controls in the overall analysis or after stratification by APOE epsilon4 allele., Conclusion: Our negative findings in the Spanish population argue against the hypothesis that DYRK1A genetic variations are causally related to AD risk. Still, additional studies using different sets of patients and control subjects deserve further attention, since supporting evidence for association between DYRK1A gene and AD risk in the Japanese population exists.