Journal of Alzheimer's Disease - Volume 15, issue 3

Authors: Tenovuo, Olli | Kemppainen, Nina | Aalto, Sargo | Någren, Kjell | Rinne, Juha O.

Article Type: Research Article

Abstract: Posterior cortical atrophy (PCA) is a rare form of degenerative dementia, which is characterized by progressive atrophy of occipital and parietal cortical areas. It usually manifests as increasing difficulties of visuoperceptive abilities. Later on, memory and other cognitive functions are involved. Various pathologies have been associated with clinical PCA presentation, but most of the patients with autopsy have had Alzheimer-type pathology. Thus, PCA has been considered to be a rare form of Alzheimer-type dementia with unusual pathological distribution. Here we describe a patient who had a typical clinical course for this syndrome and who showed a positive accumulation of amyloid-β …in posterior areas studied with positron emission tomography. Show more

Keywords: Alzheimer's disease, amyloid-β, PET imaging, posterior cortical atrophy

DOI: 10.3233/JAD-2008-15301

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 351-355, 2008

Authors: Moretti, Davide Vito | Pievani, Michela | Fracassi, Claudia | Geroldi, Cristina | Calabria, Marco | De Carli, Charles S. | Rossini, Paolo Maria | Frisoni, Giovanni Battista

Article Type: Research Article

Abstract: We evaluated changes of brain rhythmicity correlating with the cerebrovascular damage of long-range (capsular tract) and short-range (medial and perisylvian tracts) cholinergic pathways in subjects with mild cognitive impairment (MCI). Ninety-four MCI subjects underwent electroencephalographic (EEG) recordings and magnetic resonance imaging (MRI). The EEG relative power spectrum was computed in delta, theta, alpha1, alpha2, alpah3, beta1, beta2, gamma frequency bands. White matter hyperintensities along each cholinergic tract was segmented on MRI. Three MCI subgroups were identified based on increasing damage. A significant increase of delta and theta power band was found in patients with the highest total cholinergic burden as …well as in patients with highest capsular pathway damage; total load of cholinergic damage was also associated with decreased gamma power band. Alpha frequency was differentially affected: decrease of alpha3 power band was associated with the greatest damage of the capsular pathway whereas increase of alpha3 power band was associated with the greatest damage of the perisylvian pathway. Multiple regression linear analysis showed independent association of cholinergic damage with delta, theta and gamma frequency, not with alpha frequency. In conclusion, the damage of long-range and short range cholinergic tracts has possible different implications for cognitive functions in MCI subjects. Show more

Keywords: Brain rhythms, electroencephalography, mild cognitive impairment, vascular cholinergic pathways impairment

DOI: 10.3233/JAD-2008-15302

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 357-372, 2008

Authors: Ashford, J. Wesson

Article Type: Article Commentary

DOI: 10.3233/JAD-2008-15303

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 373-374, 2008

Authors: Papasozomenos, Sozos Ch. | Papasozomenos, Harry

Article Type: Research Article

Abstract: One hundred and fifteen rats were ovariectomized, given daily injections of 10 μg of 17β-estradiol 3-benzoate (EB), 250 μg of testosterone propionate (TP), or 10 μg of EB + 250 μg of TP in sesame oil (SO) or SO alone for 1, 1.5 and 2 mo, and heat shocked at 42°C for 15 min. Immediately after heat shock, the increase in inducibly hyperphosphorylated heat shock transcription factor 1 (pHSF1) was highest in TP-treated and least in EB-treated rats. Heat shock transcription factor 1 (HSF1) also accumulated in the nuclei of neurons in TP-treated and exit the nuclei in EB-treated rats. …While the subnuclear distribution of HSF1 was uniform and similar in control and heat-shocked EB-treated rats, it localized predominantly on euchromatin in heat-shocked TP-treated rats. An antibody, which preferentially recognized pHSF1, stained almost exclusively cell nuclei and demonstrated irregularly-shaped and round neuronal nuclei of heat-shocked TP- and EB-treated rats, respectively. Concomitantly, synthesis of the inducible heat shock protein Hsp70 was lowest in EB- and highest in TP-treated rats. In this model, testosterone prevents the heat shock-induced hyperphosphorylation of tau. Because HSF1 delays aging, its enhanced activation by testosterone strengthens the argument for a therapeutic role of androgens in Alzheimer's disease. Show more

Keywords: Estrogen, heat shock, heat shock transcription factor 1, rat, testosterone

DOI: 10.3233/JAD-2008-15304

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 375-390, 2008

Authors: Macreadie, Ian | Lotfi-Miri, Mehrnoush | Mohotti, Sameera | Shapira, Deborah | Bennett, Louise | Varghese, Joseph

Article Type: Research Article

Abstract: Previously in the search for chemopreventatives for Alzheimer's disease (AD), microbial cells with amyloid-β (Aβ) protein fusions have been used to screen for compounds that reduce the aggregation, misfolding or oligomerization of Aβ. In the current study, such a system has been used to look at the effect of folate, whose deficiency has been associated with AD. A folate-deficient yeast strain producing Aβ fused to green fluorescent protein (GFP) that spontaneously misfolds/aggregates and suppresses green fluorescence was used to examine the effects of folinic acid on Aβ-GFP fluorescence. At levels that did not affect growth or plasmid stability, increasing levels …of folinic acid led to increasing green fluorescence, suggesting folate can assist with preventing Aβ-misfolding/aggregation. This result supports a protective role for folate and suggests that yeast assays may provide significant new approaches for testing of AD chemopreventatives. Show more

Keywords: Aggregation, Alzheimer's disease chemo preventatives, amyloid-β, flow cytometry, folate, high throughput screening, oligomerization, Saccharomyces cerevisiae, yeast assays

DOI: 10.3233/JAD-2008-15305

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 391-396, 2008

Authors: Zhao, Xu | Rebeck, G. William | Hoe, Hyang-Sook | Andrews, Peter M.

Article Type: Research Article

Abstract: Both epidemiological and clinical trial data have demonstrated the value of some non-steroidal anti-inflammatory drugs (NSAIDs) and NSAID derivatives for lowering the incidence, slowing the progression, and reducing the symptomatic severity of Alzheimer's disease (AD). Tarenflurbil (R-flurbiprofen, MPC-7869, Myriad Pharmaceuticals) is an attractive compound because its usage is not associated with the adverse side effects of NSAIDs. Although tarenflurbil has been reported to be a selective amyloid-β 42 (Aβ42 )-lowering agent, the concentrations of drug that achieved an IC50 for Aβ42 -lowering activity are approximately two orders of magnitude higher than the concentrations found in the brain (i.e., 1–5 μM). …Therefore, the mechanism by which this compound accomplishes behavioral/physiological effects requires further study. The present investigation reports that clinically relevant concentrations of tarenflurbil (i.e., 1–5 μM) protect both cultured human neuroblastoma cell lines and primary neurons from cytotoxicity associated with exposure to Aβ42 or H2 O2 . In concert with this protection, there is an upregulation of neurotrophins [i.e., nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF)]. Furthermore, blocking exogenous NGF or BDNF by binding it to antibody prevents tarenflurbil from protecting human neuronal cells from Aβ42 and H2 O2 cytotoxicity. These findings suggest that up-regulation of neurotrophins might represent an underlying mechanism contributing to the beneficial effects seen with tarenflurbil in AD. Show more

Keywords: Alzheimer's disease, amyloid-β, brain-derived neurotrophic factor, hydrogen peroxide, neurotrophin, nerve growth factor, non-steroidal anti-inflammatory drugs, R-flurbiprofen, tarenflurbil

DOI: 10.3233/JAD-2008-15306

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 397-407, 2008

Authors: Vuletic, Simona | Li, Ge | Peskind, Elaine R. | Kennedy, Hal | Marcovina, Santica M. | Leverenz, James B. | Petrie, Eric C. | Lee, Virginia M-Y. | Galasko, Douglas | Schellenberg, Gerard D. | Albers, John J.

Article Type: Research Article

Abstract: We assessed cerebrospinal fluid (CSF) levels of apolipoprotein E (apoE), phospholipid transfer protein (PLTP) activity, cholesterol, secreted amyloid-β protein precursor α and β (sAβPPα, sAβPPβ), amyloid-β peptides 1–40 (Aβ40 ) and 1–42 (Aβ42 ), total tau and tau phosphorylated at threonine 181 (pTau) in neurologically healthy, cognitively intact adults. ApoE significantly correlated with sAβPPα (r = 0.679), sAβPPβ (r = 0.634), Aβ40 (r = 0.609), total and pTau (r = 0.589 and r = 0.673, respectively, all p < 0.001), PLTP activity (r = 0.242, p = 0.002) and cholesterol (r = 0.194, p < 0.01). PLTP activity significantly …correlated with sAβPPα (r = 0.292), sAβPPβ (r = 0.281), total and pTau (r = 0.265 and 0.258, respectively; all p ⩽ 0.001). Using partial correlations of CSF biomarkers with apoE, PLTP activity, age and gender, apoE remained significantly correlated with sAβPPα, sAβPPβ, Aβ40 , total and pTau (p < 0.001). The presence of apoE ε2 was associated with lower levels of apoE, PLTP activity and Aβ42 , while APOEε4 had no significant impact on any of the measured variables. Our data suggest that there is a significant physiological link between apoE and AβPP, as well as between apoE and tau in neurologically healthy, cognitively intact individuals. Show more

Keywords: Amyloid-β, amyloid-β protein precursor protein, apolipoprotein E, cerebrospinal fluid, phospholipid transfer protein, tau

DOI: 10.3233/JAD-2008-15307

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 409-417, 2008

Authors: Steenland, N. Kyle | Auman, Courtney M. | Patel, Purvi M. | Bartell, Scott M. | Goldstein, Felicia C. | Levey, Allan I. | Lah, James J.

Article Type: Research Article

Abstract: Mild cognitive impairment (MCI) often presages development of Alzheimer's disease (AD). We recently completed a cross-sectional study to test the hypothesis that a combination of a brief cognitive screening instrument (Mini-Cog) with a functional scale (Functional Activities Questionnaire; FAQ) would accurately identify individuals with MCI and undiagnosed dementia. The Mini-Cog consists of a clock drawing task and 3-item recall, and takes less than 5 minutes to administer. The FAQ is a 30-item questionnaire completed by an informant. In addition to the Mini-Cog and FAQ, a traditional cognitive test battery was administered, and two neurologists and a neuropsychologist determined a consensus …diagnosis of Normal, MCI, or Dementia. A classification tree algorithm was used to pick optimal cutpoints, and, using these cutpoints, the combined Mini-Cog and FAQ (MC-FAQ) predicted the consensus diagnosis with an accuracy of 83% and a weighted kappa of 0.81. When the population was divided into Normal and Abnormal, the sensitivity, specificity and positive predictive value were 89%, 90%, and 95%, respectively. The MC-FAQ discriminates individuals with MCI from cognitively normal individuals and those with dementia, and its ease of administration makes it an attractive screening instrument to aid detection of cognitive impairment in the elderly. Show more

Keywords: Cognitive screening, dementia, Functional Activities Questionnaire, mild cognitive impairment, Mini-Cog

DOI: 10.3233/JAD-2008-15308

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 419-427, 2008

Authors: Joseph, James A. | Neuman, Anna | Bielinski, Donna F. | Fisher, Derek R.

Article Type: Research Article

Abstract: Research indicates that muscarinic receptors (MAChRs) may show selective declines in sensitivity during aging and Alzheimer's disease (AD), and these decrements may be related to oxidative stress sensitivity. M1AChR – transfected COS-7 cells exhibit greater decrements in Ca2+ buffering following oxotremorine-induced depolarization than M3 cells. This loss, induced via dopamine (DA) or amyloid-β (Aβ), is similar to those reported in many studies with respect to aging and AD, but were antagonized by blueberry (BB) treatment. However, they may be exacerbated by ceramide which shows considerable increases in AD and aging. Thus, the effects of DA, Aβ42 and/or BB …were assessed on calcium parameters (e.g., calcium buffering) in the presence or absence of ceramide in M1 and M3 transfected cells. Results indicated that while ceramide did not produce profound deficits in calcium buffering, in either M1- or M3-transfected COS-7 cells, decrements were seen in the ability of M1- and M3-transfected cells to initially respond to oxotremorine, regardless of DA or Aβ42 exposure. BB pre-treatment (prior to ceramide) antagonized the ceramide treatment in M1-transfected cells but not M3-transfected cells, where ceramide suppressed BB effects. Results are discussed in terms of the effects on lipid induced changes in plasma membranes. Show more

Keywords: Aging, blueberry polyphenols, ceramide, muscarinic receptors, oxidative stress

DOI: 10.3233/JAD-2008-15309

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 429-441, 2008

Authors: Dong, Jiang | Robertson, J. David | Markesbery, William R. | Lovell, Mark A.

Article Type: Research Article

Abstract: Previous studies show significantly decreased levels of zinc transporter 1 (ZnT-1) in the brain of subjects with mild cognitive impairment (MCI) but significantly increased ZnT-1 in late stage AD (LAD). However, the reason for the apparent dichotomy is unclear. Based on in vivo studies that show animals provided a zinc (Zn) deficient diet demonstrate decreased brain ZnT-1, we used inductively coupled plasma-mass spectrometry (ICP-MS) to quantify serum Zn levels from 18 living mild to moderate AD patients (9 men, 9 women), 19 MCI patients (9 men, 10 women) and 16 age-matched normal control (NC) subjects (9 men, 7 women). Zinc …levels for all subjects were not significantly different among any of the three subject groups. However, there was a statistically significant decrease of serum Zn (11.7 ± 0.5 μM) in men with MCI compared to women with MCI (13.7 ± 0.6 μM) and NC men (13.9 ± 0.6 μM). Serum Zn levels in probable AD patients were comparable to those in NC subjects. Overall, these data suggest a significant decrease of serum Zn in men with MCI, may explain the loss of ZnT-1 observed in previous studies and suggest there may be more pronounced sex differences in MCI than were previously recognized. Show more

Keywords: Alzheimer's disease, mild cognitive impairment, serum, zinc, zinc transporters

DOI: 10.3233/JAD-2008-15310

Citation: Journal of Alzheimer's Disease, vol. 15, no. 3, pp. 443-450, 2008