Tau gene mutation in familial progressive subcortical gliosis.

Familial forms of frontotemporal dementias are associated with mutations in the tau gene. A kindred affected by progressive subcortical gliosis (PSG), a rare form of presenile dementia, has genetic linkage to chromosome 17q21-22. This kindred (PSG-1) is included in the 'frontotemporal dementias and Parkinsonism linked to chromosome 17' group along with kindreds affected by apparently different forms of atypical dementias. Some of these kindreds have mutations in the tau gene. We report here that PSG-1 has a tau mutation at position +16 of the intron after exon 10. The mutation destabilizes a predicted stem-loop structure and leads to an over-representation of the soluble four-repeat tau isoforms, which assemble into wide, twisted, ribbon-like filaments and ultimately result in abundant neuronal and glial tau pathology. The mutations associated with PSG and other atypical dementias can be subdivided into three groups according to their tau gene locations and effects on tau. The existence of tau mutations with distinct pathogenetic mechanisms may explain the phenotypic heterogeneity of atypical dementias that previously led to their classification into separate disease entities.

Family history and adaptation among centenarians and octogenarians.

BACKGROUND: The purpose of this study was to analyze various 'family history' variables (i.e. childhood health, financial situation while growing up, living with grandparents before age 17, and number of children) among participants of the Georgia Centenarian Study. OBJECTIVE: To determine whether family history variables predict critical outcome areas such as cognitive functioning, activities of daily living, mental health, and economic dependence. METHODS: A total of 318 older adults (236 centenarians and 82 octogenarians) were assessed with regard to their mental status, ADL (activities of daily living) functioning, depression, family history, loneliness, and perceived economic status. RESULTS: Analyses indicated that the number of children significantly predicted the ability to engage in activities of daily living and loneliness. In essence, the more children, the higher the activities of the daily living score and the lower the loneliness scores. In addition, childhood health significantly predicted loneliness. The poorer one's health in childhood, the higher the loneliness scores. CONCLUSION: The results of this study confirm the importance of distal family history variables on present-day functioning.

Predicting happiness among centenarians.

BACKGROUND: Happiness is believed to evolve from the comparison of current circumstances relative to past achievement. However, gerontological literature on happiness in extreme old age has been limited. OBJECTIVE: The purpose of this study was to determine how perceptions of health, social provisions, and economics link past satisfaction with life to current feelings of happiness among persons living to 100 years of age and beyond. METHODS: A total of 158 centenarians from the Georgia Centenarian Study were included to conduct the investigation. Items reflecting congruence and happiness from the Life Satisfaction Index were used to evaluate a model of happiness. Pathways between congruence, perceived economic security, subjective health, perceived social provisions, and happiness were analyzed using structural equation modeling. RESULTS: Congruence emerged as a key predictor of happiness. Furthermore, congruence predicted perceived economic security and subjective health, whereas perceived economic security had a strong influence on subjective health status. CONCLUSION: It appears that past satisfaction with life influences how centenarians frame subjective evaluations of health status and economic security. Furthermore, past satisfaction with life is directly associated with present happiness. This presents implications relative to understanding how perception of resources may enhance quality of life among persons who live exceptionally long lives.

Depression among centenarians and the oldest old: contributions of cognition and personality.

BACKGROUND: An estimated 20% of adults over the age of 55 experience clinical mental disorders such as depression and anxiety. For older adults, mental health concerns are often undetected, concomitant with physical challenges, and ultimately go untreated. These realities have significant implications for older adults' day-to-day functioning, particularly among the oldest old. OBJECTIVE: The present study examined the ability of cognition and personality in explaining depression within a sample of octogenarians and centenarians. METHODS: Participants were assessed during the most recent cross-sectional data collection of the Georgia Centenarian Study. The final eligible sample included 76 octogenarians (mean: 84.25 years, SD: 2.82; range: 81-90) and 158 centenarians and near centenarians (mean: 99.82 years, SD: 1.72; range: 98-109). RESULTS: Hierarchical regression analyses were conducted to examine the relation between key variables and depressive symptoms in the two age groups. Blocks entered into the analyses included: demographics (i.e. age group, residential status, sex, and ethnicity) and functioning, memory and problem-solving ability, and personality (i.e. extraversion and neuroticism). Models differed for octogenarians and centenarians. Decreased problem-solving ability was related to greater depressive symptoms among octogenarians. For centenarians, institutional residence and increased neurotic tendencies were related to greater depressive symptoms. CONCLUSION: Study findings demonstrate the need to examine a variety of factors which influence mental health in later life and to consider the unique contexts and differential experiences of octogenarians and centenarians.

Distal and proximal resource influences on economic dependency among the oldest old.

BACKGROUND: As exceptional survivors, centenarians may have characteristics that reduce their dependency on family and community support systems despite the expectation that their extreme age creates a burden on those systems. The Georgia Centenarian Study obtained information about assistance for income, medical care, and caregiving of all types for a sample of centenarians and octogenarians. Previous studies have not established which characteristics may contribute to economic dependency among the oldest old. OBJECTIVE: To identify distal and proximal resource influences on economic dependency, considering past lifestyle, proximal health, economic resources, personality, and coping behavior. METHODS: Analysis sample sizes ranged from 109 to 138 octogenarians and centenarians. Blockwise multiple regressions predicted whether they received income assistance, number of medical care events, number of caregiving types, and total caregiving hours. RESULTS: Past life style, gender, ethnicity, socioeconomic status, functional health, and coping were not related to economic dependency. With the exception of the number of types of care, centenarians were not more dependent than octogenarians. Cognitive ability had the strongest effects for medical care and caregiving services. 'Extraversion', 'ideas', 'neuroticism', and 'competence' personality factors had significant effects for caregiving types and total hours of care received. CONCLUSION: Monitoring and intervention to maintain cognitive ability are critical practices for autonomy and reduced economic dependency among the oldest old. Psychological resources are more important influences on social support than functional health and other proximal economic resources.

Social resources and longevity: findings from the Georgia centenarian study.

BACKGROUND: As the proportion of adults aged 85 and older increases, investigations of resources essential for adapting to the challenges of aging are required. OBJECTIVE: To comprehensively investigate the social resources of cognitively intact centenarians participating in the Georgia Centenarian Study and the association between these resources and residence status. METHODS: Two widely used measures of social resources were investigated among participants living in private homes, personal care facilities, and nursing homes. Logistic regression was used to determine significant predictors of nursing home residence. RESULTS: Differences in levels of social resources were found between centenarians and octogenarians, and among centenarians in different living situations. Analyses revealed differential findings between self- and proxy reports. Controlling for education, activities of daily living, and financial ability to meet needs, only one of the two social resources measures significantly reduced the odds of nursing home residence. CONCLUSION: The findings of this study add to the existing literature on one of the basic adaptive resources (social resources) for centenarians. Whether a more specific assessment of network contact is employed, or a more global assessment is used, differences in these constructs exist between centenarians and octogenarians, among centenarians in differing living conditions, and across types of informants. Researchers examining the different resources that may contribute to extraordinary longevity and positive adaptation may find it essential to differentiate between the oldest old and centenarians, and to account for differences based upon measure, reporter type, and centenarian residence status.

Human fetal cerebellar cortex: organization and maturation of cells in vitro.

Human fetal cerebellar cortex was maintained up to 5 months in vitro. Important features included early migration of granule neurons followed by maturation of Purkinje and granule neurons. Unique areas of organization developed in which a rim of leptomeningeal cells surrounded an explant and its outgrowth zone; these areas subsequently grew as well-defined units.

Clinical features of mild cognitive impairment differ in the research and tertiary clinic settings.

OBJECTIVE: Comparative analysis of subjects with mild cognitive impairment (MCI) diagnosed in a primary research setting and those seen in a tertiary care memory disorders clinic. METHODS: Subjects who received a diagnosis of MCI between July 1, 2005, and December 31, 2006, in a longitudinal research study of normal cognition (n = 48) and patients diagnosed in a tertiary care referral clinic (n = 34) were evaluated using similar methodologies. Comparative analyses of detailed medical, neurological and neuropsychological data are presented. RESULTS: The diagnosis of MCI was not accepted by 13 of 48 subjects (27%) classified as MCI in the primary research setting. Nondegenerative, potentially treatable causes of cognitive decline were found in 3 of 34 subjects (9%) seen in the tertiary referral clinic and in 11 of 35 subjects (31%) identified as MCI in the primary research setting (p = 0.02, Fisher's exact test). MCI subjects identified in the primary research setting were older than those referred to the memory clinic (mean +/- SD, 79.7 +/- 7.0 vs. 71.5 +/- 9.0 years, p < 0.0001, t test) and had more years of education (16.0 +/- 3.2 vs. 13.6 +/- 4.2 years, p < 0.01, t test). MCI subjects in the primary research setting appeared to be in a milder stage of disease, characterized by higher Mini-Mental State Examination scores (28.2 +/- 1.8 vs. 25.7 +/- 1.8, p < 0.0001), and a tendency towards single domain involvement, predominantly memory (mean number of domains involved, 1.0 vs. 2.5, p < 0.0001). More advanced stages of MCI, seen in the tertiary referral population, had additional involvement of attention (p < 0.0001, Fisher's exact test) and visuospatial domains (p < 0.0002, Fisher's exact test). Semiquantitative grading of hippocampal and medial temporal lobe atrophy did not differ between groups (p = 0.81, Mann-Whitney U test). CONCLUSIONS: The diagnosis of MCI may be unwelcome in naïve persons. Remedial causes of MCI should be actively investigated. Demographic and clinical characteristics of MCI differ between research subjects and patients referred to a tertiary care clinic.

Improved predictive model for pre-symptomatic mild cognitive impairment and Alzheimer's disease.

OBJECTIVE: Delineation of gray matter (GM) structures on brain MRI scans is termed segmentation. Accuracy of segmentation is a key factor in the valid comparison of GM density and volume between individuals and groups. Previously, it was demonstrated that a group of normal subjects who later developed mild cognitive impairment (MCI) had decreased GM volume in the medial temporal lobe compared to other normal subjects who remained normal an average 5.4 years after the scan. The objective of this study was to show whether accuracy of this predictive model was increased using an advanced segmentation technique. METHODS: Structural MRI was performed on 74 longitudinally examined normal aged subjects. All subjects were cognitively normal at the time of their scan, but 18 later developed MCI, and six of these 18 went on from MCI to an AD diagnosis. We independently delineated GM using both a standard segmentation technique and a local Gaussian active contour (LGAC) technique. We compared the contribution of extracted volumes from each technique to a model predicting subjects who will eventually develop MCI. RESULTS: Accuracy of the standard technique to distinguish pre-MCI from normal using imaging alone was 79% (sensitivity 78% and specificity 73%). Using LGAC, accuracy rose to 84% (sensitivity 78% and specificity 84%). DISCUSSION: Structural brain changes precede MCI in longitudinally followed normal subjects. The LGAC technique improves the accuracy of a predictive model incorporating these structural changes by improving GM segmentation and the specificity of the model.

Altered expression of zinc transporters-4 and -6 in mild cognitive impairment, early and late Alzheimer's disease brain.

Accumulating evidence suggests that a disruption of zinc (Zn) homeostasis may play a role in the pathogenesis of Alzheimer's disease. Although several Zn transporter proteins responsible for the regulation of Zn balance are present in the brain, there has been little study of these proteins in Alzheimer's disease. To determine if alterations of Zn transporter proteins exist, levels of Zn transporter-4, which functions to remove Zn from the cytoplasm to endosomal/lysosomal compartments, and Zn transporter-6, which allocates cytoplasmic Zn to the trans-Golgi network, were measured in the hippocampus/parahippocampal gyrus, superior and middle temporal gyrus, and cerebellum of subjects with mild cognitive impairment, early Alzheimer's disease, late stage Alzheimer's disease, and age-matched controls using Western blot analysis and protein specific antibodies. Our results show that Zn transporter-4 and Zn transporter-6 are significantly (P<0.05) increased in hippocampus/parahippocampal gyrus of early Alzheimer's disease and Alzheimer's disease subjects. Zn transporter-6 is also increased (P<0.1) in the superior and middle temporal gyrus of Alzheimer's disease brain.

General immunocompetence of rats bearing avian sarcoma virus-induced intracranial tumors.

The mitogenic responsiveness of spleen cells obtained from avian sarcoma virus-inoculated Fischer 344 rats was studied. Sixty % of the rats had astrocytomas, 13% had sarcomas, 7% had mixed gliosarcomas, and 20% had no evidence of tumors. Only spleen cells from rats bearing astrocytomas had significantly diminished responses to phytohemagglutinin and concanavalin A (Con A) when compared to control responses. The decreased responsiveness observed with phytohemagglutinin was limited to the optimal concentration range (10 and 20 microgram) while a broader concentration of Con A (0.01 to 50 microgram) induced significant suppression. Moreover, a more profound immunosuppression was observed with Con A. The results also demonstrated that spleen cells from rats with the largest astrocytomas exhibited the greatest suppression. From the results of this study, it appears the avian sarcoma virus-induced astrocytoma in rats is an immunological parallel of the human disease based on the loss of general immunological competence as assessed by responsiveness of lymphocytes to phytohemagglutinin and Con A.

Electron spin resonance, hematological, and deformability studies of erythrocytes from patients with Huntington's disease.

Electron spin resonance, hematologic, and deformability studies of erythrocytes from patients with Huntington's disease have been performed A decreased deformability of Huntington's disease erythrocytes compared to normal controls was demonstrated. No difference in erythrocyte hematologic indices, osmotic fragility, reticulocyte counts, or intracellular Na+ concentration was found. Huntington's disease serum had no demonstrable effect on electron spin resonance parameters of a protein-specific spin label attached to membrane proteins in control erythrocytes compared to the effect of control serum. This finding suggests that under the conditions employed no serum component or circulating factor is responsible for the changes in the physical state of membrane proteins in Huntington's disease erythrocytes (Butterfield, D.A., Oeswein, J.Q. and Markesbery, W.R. (1977) Nature 267, 453--455). No alteration in lipid fluidity of Huntington's disease erythrocyte membranes could be discerned suggesting that the underlying molecular defect in Huntington's disease involves a membrane protein. The results of the present studies on erythrocytes strongly support the concept that Huntington's disease is associated with a generalized membrane abnormality.

Alterations in zinc transporter protein-1 (ZnT-1) in the brain of subjects with mild cognitive impairment, early, and late-stage Alzheimer's disease.

Several studies show increased levels of zinc (Zn) in the Alzheimer's disease (AD) brain. More recently, alterations in synaptic Zn and Zn transporter proteins (ZnT) have been implicated in the accumulation of amyloid plaques in an animal model of AD. To determine if alterations in ZnT proteins are present in AD brain, we measured levels of ZnT-1, the protein responsible for export of Zn to the extracellular space in the amygdala (AMY), hippocampus/parahippocampal gyrus (HPG), superior and middle temporal gyrus (SMTG), inferior parietal lobule (IPL), and cerebellum (CER) of 19 AD and 14 age-matched control subjects. To determine if alterations of ZnT-1 occur early in the progression of AD, we analyzed protein levels in the HPG, SMTG and CER of 5 subjects with mild cognitive impairment (MCI), 5 subjects with early AD (EAD) and 4 appropriately age-matched controls. Western blot and dot-blot analysis showed statistically significant (p 0.05) elevations of ZnT-1 in AD AMY, HPG, and IPL and significantly depleted ZnT-1 in AD SMTG compared to age-matched control subjects. We also observed statistically significant elevations of ZnT-1 in the HPG of EAD subjects compared with controls. In contrast to late-stage AD subjects, ZnT-1 levels were significantly decreased in HPG of subjects with MCI and were significantly elevated in the SMTG of both MCI and EAD subjects compared with age-matched controls. Correlation analysis of ZnT-1 levels and senile plaque (SP) and neurofibrillary tangle (NFT) counts in the AMY and CA1 and subiculum of AD HPG showed a significant (p 0.05) positive correlation with SP counts and a trend towards a significant (p = 0.12) positive correlation with NFT counts in AMY. Overall, our results show alterations in one of the key proteins responsible for maintenance of Zn homeostasis early in the progression of AD suggesting that alterations in Zn balance could be involved in the pathogenesis of neuron degeneration and amyloid deposition in AD.

Expression of p53, bcl-2, E-cadherin, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinases-1 in paired primary tumors and brain metastasis.

The objectives of this study were to: (a) characterize the immunohistochemical expression of p53, bcl-2, E-cadherin (EC), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinases-1 (TIMP-1) in brain metastases; (b) compare immunohistochemical (IHC) expression of brain metastases with their primary tumors; and (c) assess the prognostic value of expression of these markers. Tumors from 35 patients with brain metastasis were studied for IHC expression of p53, bcl-2, EC, MMP-9, and TIMP-1. In 17 cases, primary tumors were also available for study. In brain metastases, p53 was positive in 91% of cases and intermediate in 9%, MMP-9 was positive in all cases, TIMP-1 was intermediate in 6% and negative in 94% of cases, EC expression was positive in 86% of cases and intermediate in 14%, and bcl-2 was variable. All primary tumors were positive for p53 and MMP-9, 3% were intermediate for TIMP-1 and 97% were negative, 65% were positive for EC and 35% were intermediate, whereas bcl-2 expression was variable. Neither p53, bcl-2, TIMP-1, or EC staining correlated with overall survival or survival with brain metastases. No assessment of survival differences could be made for MMP-9 because of its overexpression in all tissues. This study found that MMP-9 and p53 were markedly overexpressed in primary tumors and matched brain metastasis, TIMP-1 expression was negative in the majority of specimens, whereas EC expression was maintained in both primary tumors and brain metastases and bcl-2 expression was variable. This study suggests that the functional balance of MMP-9 and TIMP-1 is shifted toward extracellular matrix degradation in brain metastases and that deregulation of cell cycle control by p53 also exists in brain metastases. The high expression of EC may indicate the importance of adherence at late stages of metastasis but requires further study.

Ultrastructural study of the medulloblastoma in tissue culture.

The electron microscopic features of the early phases of growth of the medulloblastoma maintained in vitro are described. The predominant early growth is comprised of small migrating cells with large nucleocytoplasmic ratio, few organelles and prominent neuritic processes containing abundant microtubules. These cells compare favorably with the cells of the primitive external granular layer of the cerebellum and cells cultivated in vitro from the fetal cerebellar cortex previously described. In addition astrocytes containing 70 to 90 A cytoplasmic filaments were commonly found in these cultures. Undifferentiated cells and cells with cilia were present in the explant proper. Cells with processes containing large dense core vesicles were also present in the explant proper suggesting the presence of neuronal differentiation. Our studies support the concept that the medulloblastoma is derived from primitive neuroectodermal cells. In addition it also suggests that astrocytic and neuronal differentiation may occur in this neoplasm in vitro.

Morphometric analysis of microglia in Alzheimer's disease.

HLA-DR-immunoreactive microglia were quantitated in the middle temporal gyrus of five late-stage patients with Alzheimer's disease (AD) and five age-matched control subjects using LN3 immunocytochemistry and computerized morphometric image analysis. The grand mean numerical density of HLA-DR-immunoreactive microglia in AD (403.86/mm2) was significantly larger than in the five control subjects (193.33/mm2) (p < 0.0001). The grand mean cross-sectional area of HLA-DR-immunoreactive microglia in AD subjects (222.90 microns2) was significantly larger than in control subjects (121.59 microns2) (p < 0.0001). The percentage of total microglia that were large activated microglia was much greater in AD (47.9%) than in control subjects (15.2%). The grand mean percent of the cortical area occupied by HLA-DR-immunoreactive microglia in AD (9.02%) was significantly greater than in controls (2.35%) (p < 0.0001). Microglia were present in greater numbers in the outer three cortical laminae in both AD and controls. The striking increase in activated microglia in the neocortex and their role in the inflammatory response and possible secretion of neurotoxins could be important in neuron degeneration in AD.

Neuronal RNA in relation to neuronal loss and neurofibrillary pathology in the hippocampus in Alzheimer's disease.

Topographic analyses were performed on the distribution of neuronal RNA loss in relation to local neuronal loss and neurofibrillary degeneration in the hippocampal region of brains of patients with Alzheimer's disease (AD). Compared to age-matched controls, pyramidal neuronal RNA was depressed (p less than 0.0001) in all areas of the hippocampus examined in AD, viz., the endplate (33%), Rose's H2 field (30%), Rose's H1 field (37%) and the subiculum (46%). Significant neuronal loss was observed in Rose's H1 field and the subiculum but not in the endplate or Rose's H2 field. The frequency of neurofibrillary tangle-bearing neurons was enhanced in all four regions of AD brains, the number of involved neurons being markedly greater in Rose's H1 field and the subiculum than in the endplate and Rose's H2 field. Overall, the data indicate the existence of a generalized disturbance in RNA metabolism within pyramidal neurons in the hippocampus in AD, occurring in regions of minimal (endplate, Rose's H2 field) as well as those of extensive (Rose's H1 field, subiculum) pathological alterations. Although there is focal accentuation of RNA depletion in the latter, the marked RNA depletion in regions of minimal pathologic change suggests that this effect is largely unrelated to local neuronal loss or neurofibrillary degeneration.

Image analysis of neuropil threads in Alzheimer's, Pick's, diffuse Lewy body disease and in progressive supranuclear palsy.

Neuropil threads (NT) in the middle temporal gyrus (MTG) were quantitated by computerized image analysis from five patients each with Alzheimer's disease (AD), Pick's disease (PD), and diffuse Lewy body disease (DLBD), four patients with progressive supranuclear palsy (PSP), and five cognitively normal control subjects (24 patients total). All disease groups met clinical and pathological criteria for their respective diseases. The DLBD subjects did not have pathological features of AD. Using the Gallyas silver method, the percentage of cortical area occupied by NT was calculated for each case examined and compiled for each group. Intergroup comparison revealed the percentage of cortical area occupied by NT as follows: AD, 6.87%; PSP, 1.12%; PD, 0.37%; DLBD, 0.04%; control 0.02%. The evaluation disclosed a significance level of p < 0.0001 when AD was compared to control, PD and DLBD cases and a p < 0.001 when compared to PSP. There was no statistically significant difference between control-DLBD, control-PD, control-PSP, DLBD-PSP, PD-PSP, or PD-DLBD cases (p > 0.05). These data indicate the density of neocortical threads is much greater in AD than in other dementing disorders. It also suggests that NT are not related to the intellectual decline in PD, DLBD, and PSP.

Expression and activities of aldo-keto oxidoreductases in Alzheimer disease.

A reactive intermediate generated by lipid peroxidation, 4-hydroxy-2-nonenal (HNE), has received considerable attention as a potential effector of oxidative damage and Abeta peptide-mediated neurotoxicity in Alzheimer disease (AD). However, little is known about aldo-keto oxidoreductases, a group of enzymes that constitute a major detoxifying pathway for HNE and related reactive aldehydes in human brain. We have determined the regional, cellular, and class distribution in human brain of the 4 major aldo-keto oxidoreductases that detoxify HNE: aldehyde dehydrogenase (ALDH): aldose reductase; aldehyde reductase: and alcohol dehydrogenase (ADH). Of these 4 enzymes, only ALDH and aldose reductase were expressed in cerebral cortex. hippocampus, basal ganglia, and midbrain: all 4 enzymes were present in cerebellum. In cerebrum and hippocampus, aldose reductase was localized to pyramidal neurons and mitochondrial class 2 ALDH was localized to glia and senile plaques. ALDH, but not aldose reductase, activity was significantly increased in temporal cortex from patients with AD compared to age-matched controls. These results suggest that in brain regions involved in AD, neurons and glia utilize different mechanisms to detoxify HNE, and that increased ALDH activity is a protective response of cerebral cortex to AD.

4-hydroxy-2-nonenal pyrrole adducts in human neurodegenerative disease.

Increasing age and inheritance of the epsilon 4 allele of apolipoprotein E (APOE4) are significant risk factors for sporadic and late onset familial Alzheimer disease (AD); however, the mechanisms by which either leads to AD are unknown. Numerous studies have associated advancing age with increased indices of oxidative challenge to brain, and with still further increased oxidative damage to relevant brain regions in AD patients. A major consequence of oxidative damage to brain is lipid peroxidation with production of the neurotoxic metabolite 4-hydroxy-2-nonenal (HNE). HNE reacts with protein to yield several adducts, including a pyrrole adduct that forms irreversibly in biological systems. Previously, we have shown in a small number of AD and control patients that HNE pyrrole adduct antiserum is immunoreactive with neurofibrillary tangles (NFT), and that this reactivity was significantly associated with inheritance of APOE4. Others have confirmed this pattern of immunoreactivity in AD brain but did not observe an association with APOE4. Herein, we have expanded the study group to 19 AD patients homozygous for APOE4 or APOE3, as well as 30 patients with other neurodegenerative diseases, including diffuse Lewy body disease, Pick's disease, progressive supranuclear palsy, Parkinson's disease, and human immunodeficiency virus-1 encephalitis. HNE pyrrole adduct immunoreactivity on NFT in AD patients was strongly associated with APOE4 homozygosity. With the exception of rare immunoreactive Pick bodies in one case of Pick's disease, no other structure was recognized by HNE pyrrole adduct antiserum in this series of patients. We propose that there is a significant difference between the interaction of apoE3 and apoE4 with lipid peroxidation in the brains of AD patients.