Neuronal apoptosis inhibitory protein (NAIP)-like immunoreactivity in brains of adult patients with Down syndrome

In Down syndrome (DS), enhanced apoptosis (programmed cell death) may play a role in the pathogenesis of characteristic early mental retardation and precocious neurodegeneration of Alzheimer-type. The human IAP (inhibitor of apoptosis proteins) genes (NAIP, c-IAP-2/HIAP-1, c-IAP-1/Hiap-2, XIAP, survivin) are an evolutionary conserved family of proteins which prevent cell death across species, implying that they act at a central, highly conserved point in the cell death cascade. Evidence for downregulation of NAIP-mRNA in fetal DS (23rd week of gestation), as found by subtractive hybridization technique challenged studies at the protein level in adult DS brain specimen. NAIP-like immunoreactivity was determined in four different regions of cerebral cortex and cerebellum in 9 adult DS patients with Alzheimer-like neuropathologic lesions, 9 Alzheimer disease (AD) patients as compared to 9 controls. For the first time, NAIP-IR could be demonstrated in different cortical regions of the human brain. Compared to control subjects, western blotting demonstrated significantly decreased levels in parietal and occipital cortex in DS and in frontal and occipital cortex in AD. While the mode of NAIP action is unknown, inhibition of certain caspases has already been demonstrated for other IAP-family members (c-IAP1, c-IAP2 and XIAP). Although decreased NAIP-IR of certain brain regions in DS and AD awaits further confirmation, the results suggest that alterations of apoptosis regulatory (inhibitory) proteins may be another feature of neurodegeneration in DS and AD.

Heat-shock protein 70 levels in brain of patients with Down syndrome and Alzheimer's disease

Heat-shock proteins are proteins serving as molecular chaperones, involved in the protection of cells from various forms of stress. Since the expression of these proteins is closely related to that of amyloid precursor protein (APP), heat-shock protein has been studied in brain of patients with Alzheimer's disease (AD) and furthermore, brain Hsp70 mRNA levels were related to the agonal state. The aim of our study was to demonstrate the presence of Hsp70--immunoreactive protein in brain of controls, patients with AD and Down Syndrome (DS) in individual brain regions. The rationale for the study was to test the hypothesis that expression of Hsp70, a protein involved in apoptosis would be altered in brain of these patients with neurodegenerative disorders where (neuronal) apoptosis is a hallmark of the disease. Brain immunoreactive-Hsp70--protein (Hsp70) was determined by Western blotting using specific monoclonal antibody in five different brain regions (frontal, parietal, occipital, temporal cortex and cerebellum) from controls, DS and AD patients. Hsp70 expression was significantly increased in temporal cortex of patients with AD (arbitrary units: means +/- SD; 0.35 +/- 0.49 for controls, 0.97 +/- 0.70 for DS patients, 1.16 +/- 0.56 for AD patients). In frontal and parietal cortex from DS patients, there was a strong correlation between Hsp70 levels and the length of post-mortem interval (r = 0.95, P < 0.01 and r = 0.82, P < 0.021).

Overexpression of DNAse I in brain of patients with Down syndrome

Human DNAse I (EC 3.1.21.1) is an enzyme most probably involved in apoptotic processes. Splicing of the DNAse I primary transcript in normal and apoptotic cells into up to 20 splicing forms and the recent description of a different family of caspase-activated DNAses, hampered studies on the role of DNAse I in apoptosis research. Performing gene hunting in fetal brain of patients with DS we found a sequence with 100% homology to DNAse I and this formed the Rationale for studies in adult DS brain. It was therefore the aim of the study to evaluate DNAse I-mRNA steady state levels in DS brain using adult brain without brain pathologies and Alzheimer's Disease (AD) brain as control, in order to rule out that DNAse I--overexpression may not be specific for DS but rather reflecting apoptosis per se, a hallmark of both disorders. Determination of DNAse I-mRNA steady state levels was carried out by a blotting method in frontal, parietal, temporal occipital lobe and cerebellum. We found significantly increased DNAse I transcripts in brain of DS and AD both, when normalized versus the house-keeping gene beta actin or total RNA. We demonstrate the significant increase of DNAse I--transcript in the pathogenesis of DS and AD suggesting a role for this enzyme in the apoptotic process known to occur in both disorders. We are now going to carry out protein and enzyme activity levels in our laboratory to confirm our findings at the transcriptional level.

Neuronal nicotinic receptors in dementia with Lewy bodies and schizophrenia: alpha-bungarotoxin and nicotine binding in the thalamus

Neuronal nicotinic receptors have been implicated in schizophrenia on the basis of the high incidence of tobacco smoking in patients, abnormalities in cytisine and alpha-bungarotoxin (alphaBGT) binding in the hippocampus, and linkage between auditory P50 deficits and the region of chromosome 15 coding the alpha7 subunit. In another disease associated with psychosis, dementia with Lewy bodies (DLB), in which visual hallucinations predominate, reductions in nicotine binding have been identified in various cortical and subcortical regions. We investigated both alphaBGT and nicotine binding autoradiographically in different thalamic nuclei in autopsy brain tissue from patients with schizophrenia and DLB. AlphaBGT binding in the reticular nucleus was moderately reduced (25%) in schizophrenia and more extensively reduced (50%) in DLB. There were no significant alterations in nicotine binding in schizophrenia, and in DLB, a trend towards moderate reductions in most nuclei reached significance in the lateral dorsal nucleus. It is concluded that widespread abnormalities of thalamic nicotine are not implicated in schizophrenia or DLB, but that reticular alphaBGT binding may be involved to a lesser and greater extent in the pathophysiology or psychopathology of both disorders.

Enrichment of human brain proteins by heparin chromatography

Detection of low-abundance proteins is essential for the identification of novel drug targets by differential protein expression studies. We studied the enrichment of human fetal brain proteins by heparin chromatography. Total soluble brain proteins were fractionated on Heparin-Actigel and the fractions collected were analyzed by two-dimensional electrophoresis. The proteins were identified by matrix-assisted laser desorption ionization mass spectrometry. Approximately 300 protein spots were analyzed, representing 70 different polypeptides, 50 of which were bound to the heparin matrix. Eighteen brain proteins were identified for the first time. The proteins enriched by heparin chromatography include both minor and major components of the brain protein extract. The enriched proteins belong to several classes, including proteasome components, dihydropirimidinase-related proteins, T-complex protein 1 components and enzymes with various catalytic activities. The results include a two-dimensional map of the soluble brain proteins and a list of the proteins enriched by heparin chromatography. These may be useful in the design of protein purification protocols and in studies of neurological disorders.

Psychiatric morbidity in dementia with Lewy bodies: a prospective clinical and neuropathological comparative study with Alzheimer's disease

OBJECTIVE

The literature reports considerable variation in the rates of psychiatric morbidity for patients with dementia with Lewy bodies. The authors intended to clarify the frequency of psychiatric morbidity in dementia with Lewy bodies and how it differs from probable Alzheimer's disease.

METHOD

The study incorporated two groups--a clinical case register cohort (98 with dementia with Lewy bodies; 92 with Alzheimer's disease) and 80 (40 with dementia with Lewy bodies: 40 with Alzheimer's disease) prospectively studied, neuropathologically confirmed cases. Diagnoses were made by using the McKeith et al. consensus criteria for dementia with Lewy bodies and the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association criteria for Alzheimer's disease. Neuropathological diagnoses were made by using the consensus criteria for dementia with Lewy bodies and the Mirra et al. protocol for Alzheimer's disease.

RESULTS

The occurrence of psychiatric symptoms was reported over 1 month. Hallucinations, depression, delusions, and delusional misidentification were all significantly higher for patients with dementia with Lewy bodies. The differences in frequency between dementia with Lewy bodies and Alzheimer's disease for auditory and visual hallucinations were especially pronounced for patients with mild cognitive impairment. The presence of psychiatric symptoms at presentation was a better discriminator between dementia with Lewy bodies and Alzheimer's disease than occurrence over the course of dementia.

CONCLUSIONS

Delusional misidentification and hallucinations in the early stages of dementia may improve differentiation between patients with dementia with Lewy bodies and those with Alzheimer's disease and have important treatment implications.

Increased steady state mRNA levels of DNA-repair genes XRCC1, ERCC2 and ERCC3 in brain of patients with Down syndrome

Although deficient DNA-repair was proposed for neurodegenerative disorders including Down Syndrome (DS), repair genes for nucleotide excision repair or X-ray repair have not been studied in brain yet. As one of the hypotheses for the pathogenesis of brain damage in DS is oxidative stress and cells of patients with DS are more susceptible to ionizing irradiation, we decided to study ERCC2, ERCC3 and XRCC1, representatives of repair genes known to be involved in the repair of oxidative DNA-damage. mRNA steady state levels of ERCC2, ERCC3, XRCC1, a transcription activator (TAF-DBP) and an elongation factor (EF1A) were determined and normalized versus the housekeeping gene beta-actin in five individual brain regions of nine controls and nine DS patients. Although different in the individual regions, DNA-repair genes were consistently higher in temporal, parietal and occipital lobes of patients with DS accompanied by comparable changes of TFA-DBP and EF1A. Our results are the first to describe DNA-repair gene patterns in human brain regions providing the basis for further studies in this area. We showed that DNA-repair genes ERCC2 and ERCC3 (excision-repair-cross-complementing-) for nucleotide excision repair and XRCC1 (X-ray-repair-cross-complementing-) for X-ray-repair, were increased at the transcriptional level with the possible biological meaning that this increase may be compatible with permanent (oxidative?) DNA damage.

Thyroid stimulating hormone-receptor overexpression in brain of patients with Down syndrome and Alzheimer's disease

Thyroid hormone abnormalities are strongly associated with Down Syndrome (DS) with elevated thyroid stimulating hormone (TSH) levels as the most consistent finding. Using subtractive hybridization for gene hunting we found significant overexpression of mRNA levels for the TSH-receptor (TSH-R) in brain of a fetus with DS. Based upon this observation we determined TSH-R protein levels in five brain regions of patients with DS (n=8), Alzheimer disease (AD, n=8) and controls (C, n=8). Western blots revealed significantly elevated immunoreactive TSH-R protein(s) 40 kD and 61 kD in temporal and frontal cortex of patients with DS and, unexpectedly, in AD. Levels for the 40 kD protein in temporal cortex were 1.00+/-0.036 (arbitrary units+/-SD) in C, 1.35+/-0.143 in DS, 1.52+/-0.128 in AD; in frontal cortex: 1.00+/-0.046 in C, 1.10+/-0.03 in DS, 1.10+/-0.038 in AD. Levels for the 61 kD protein in temporal cortex were 1.01+/-0.015 in C, 1.47+/-0.013 in DS, 1.623+/-0.026 in AD; in frontal cortex: 1.02+/-0.020 in C, 1.18 +/-0.123 in DS, 1.48+/-0.020 in AD. These results show that elevated brain immunoreactive TSH-R is not specific for DS and maybe reflecting apoptosis, a hallmark of both neurodegenerative disorders, as it is well-documented that the thyroid hormone system is involved in the control of programmed cell death.

Decreased levels of synaptosomal associated protein 25 in the brain of patients with Down syndrome and Alzheimer's disease

Synaptosomal associated protein 25 kDa (snap-25) is a widely distributed membrane-associated protein in the brain, mainly localized in nerve terminals. In nerve terminals, snap-25 participates in docking and/or fusion of synaptic vesicles with the plasmalemma, a process essential for synaptic vesicle exocytosis. Recent work suggests a role in brain development, forming presynaptic sites by regulating axonal outgrowth and nerve growth-induced neurite elongation. In Down syndrome (DS) brain, it is abnormally developed from early life, and brain pathology becomes even more pronounced when Alzheimer's disease (AD) develops in the fourth decade. This information led us to examine snap-25 in the brain of patients with DS and AD. We studied snap-25 and glial fibrillary acidic protein (GFAP) brain levels in five individual brain areas of 9 aged patients with DS, 9 patients with AD and 9 controls, applying two-dimensional gel electrophoresis. Decreased snap-25 levels were found in the five brain regions of the patients with DS and AD. Increased expression levels of GFAP were found in the frontal, parietal, temporal and occipital cortex regions of the DS and AD patients. Decreased snap-25 protein levels in the brain of DS and AD may reflect impaired synaptogenesis or represent neuronal loss. Findings of increased GFAP, a marker for neuronal loss, along with data from literature would support the notion of decreased snap-25 secondary to neuronal decay in both neurodegenerative disorders.

Two-dimensional map of human brain proteins

Samples of human brain from the parietal cortex lobe were analyzed by two-dimensional gel electrophoresis, using immobilized pH gradient strips covering the various pH regions. The protein spots were visualized with colloidal Coomassie blue stain and identified by matrix-assisted laser desorption/ionization mass spectrometry. Approximately 400 spots were identified, corresponding to 180 different brain proteins. The list of identified proteins includes a large number of structural proteins and of enzymes or enzyme subunits with various catalytic activities. The majority of proteins are localized in the cytoplasma and in mitochondria. The two-dimensional map may be useful as a reference database to study changes in the protein level caused by various disorders, such as Alzheimer's disease, major depression and schizophrenia.

Determination of the protooncogene ets-2 gene transcript in human brain at the atto-gram-level by the use of competitive RT/PCR

Protooncogenes (PO) play a crucial role for brain biology and pathology. Only the concerted action of protooncogenes enables normal brain development. The reliable and sensitive quantification of brain PO is still holding centre stage in neurobiological research. The aim of our study was therefore the determination of PO in minute amounts of brain areas. For this purpose we decided to apply the most sensitive detection principle of competitive reverse transcriptase polymerase chain reaction using capillary electrophoresis and laser-induced fluorescence detection. We selected the PO ets-2 for our studies as this transcription factor was shown to be involved in neurodegenerative disease. As little as 10 ng of total RNA each were extracted from 5 different regions of human postmortem brain and used in the assay system. Our results revealed that the ets-2 gene transcript was detectable at the atto-gram level in the brain (54.5 +/- 17.7 ag/ 10 ng RNA in the occipital lobe, 34.2 +/- 7.5 in temporal lobe, 40.2 +/- 15.6 in the frontal lobe, 31.4 +/- 15.7 in the cerebellum, and undetectably low in the parietal lobe). This is the first report at this sensitivity level providing neurobiology with a powerful analytical tool.

Increased phosphoglycerate kinase in the brains of patients with Down's syndrome but not with Alzheimer's disease

Impaired glucose metabolism in Down's syndrome (DS) has been well-documented in vivo, although information on the underlying biochemical defect is limited and no biochemical studies on glucose handling enzymes have been carried out in the brain. Through gene hunting in fetal DS brain we found an overexpressed sequence homologous to the phosphoglycerate kinase (PGK) gene. This finding was studied further by investigating the activity levels of this key enzyme of carbohydrate metabolism in the brains of patients with DS. PGK activity was determined in five brain regions of nine patients with DS, nine patients with Alzheimer's disease and 14 controls. PGK activity was significantly elevated in the frontal, occipital and temporal lobe and in the cerebellum of patients with DS. PGK activity in corresponding brain regions of patients with Alzheimer's disease was comparable with controls. We conclude that our findings complement previously published data on impaired brain glucose metabolism in DS evaluated by positron emission tomography in clinical studies. Furthermore, we show that in DS, impaired glucose metabolism, represented by increased PGK activity, is a specific finding rather than a secondary phenomenon simply due to neurodegeneration or atrophy. These observations are also supported by data from subtractive hybridization, showing overexpressed PGK in DS brains at the transcriptional level early in life.

Increased glyceraldehyde 3-phosphate dehydrogenase levels in the brain of patients with Down's syndrome

Impaired glucose metabolism in Down's syndrome (DS) has been well-documented in vivo, although information on the underlying biochemical defect is limited and no biochemical studies on glucose handling enzymes have been carried out in the brain. In a previous study, we found by gene hunting in DS brain an overexpressed sequence homologous to the glyceraldehyde 3-phosphate dehydrogenase (G3PD) gene. Here we studied G3PD activity and expression levels, using two-dimensional gel analysis, in five brain regions of patients with DS and Alzheimer's disease (AD). The protein expression levels in four brain areas were approximately 1.5-fold higher in patients with DS in comparison with the controls. G3PD activity was significantly elevated in the frontal, parietal, occipital and temporal lobe of DS as well, but not in the corresponding AD brain regions. We conclude that our biochemical findings complement previously published data of impaired brain glucose metabolism in DS evaluated by positron emission tomography in clinical studies.

Apoptosis-associated proteins p53 and APO-1/Fas (CD95) in brains of adult patients with Down syndrome

In Down syndrome (DS), enhanced apoptosis (programmed cell death) may play a role in the pathogenesis of characteristic mental retardation and precocious dementia of Alzheimer-type. Upregulation of p53 and APO-1/Fas (CD95) precedes apoptosis in many cell types, and a potential role for these molecules has already been demonstrated in Alzheimer's disease (AD) and several other neurodegenerative diseases. We measured p53 and APO-1/Fas (CD95) protein in four different regions of cerebral cortex and cerebellum in nine adult DS patients with Alzheimer-like neuropathologic lesions compared to nine controls. Quantitative ELISA demonstrated higher frontal lobe (mean+/-SD: 0.10+0.035 vs. 0.041+/-0.016 ng/mg protein), temporal lobe (0.062+/-0.021 vs. 0.032+/-0.019 ng/mg protein) and cerebellar levels (0.078+/-0.030 vs. 0.039+/-0.032 ng/mg protein) of p53 protein, and higher temporal lobe (mean+/-SD: 12.3+/-4.3 vs. 5.3+/-2.0 U/mg protein) and cerebellar levels (5.9+/-1.4 vs. 2.9+/-1.1 U/mg protein) of APO-1/Fas (CD95) protein. The results suggest that p53- or APO-1/Fas (CD95)-associated apoptosis may be an important feature of neurodegeneration in DS.

c-fos expression in brains of patients with Down syndrome

c-fos is a protooncogene serving in multiple physiological processes in brain from signalling to proliferation and synaptic plasticity. We therefore decided to determine this transcription factor in control and Down Syndrome (DS) brain with the Rationale that c-fos may be linked to brain damage in DS. We determined mRNA steady state levels in frontal, parietal, occipital, temporal cortex and cerebellum of 9 patients with DS and 9 controls using RT-PCT. Significantly increased levels of mRNA c-fos normalized versus the housekeeping gene beta-actin mRNA were found in frontal, parietal and temporal cortex of DS brain. c-fox mRNA levels comparable to controls were found in occipital cortex and cerebellum. Deteriorated c-fos expression in the individual brain regions may be linked to increased apoptosis and neurodegeneration, overexcitation by excitatory amino acids of reactive oxygen species.

Altered gene expression in fetal Down syndrome brain as revealed by the gene hunting technique of subtractive hybridization

Information on gene expression in brain of patients with Down Syndrome (DS, trisomy 21) is limited and molecular biological research is focussing on mapping and sequencing chromosome 21. The information on gene expression in DS available follows the current concept of a gene dosage effect due to a third copy of chromosome 21 claiming overexpression of genes encoded on this chromosome. Based upon the availability of fetal brain and recent technology of gene hunting, we decided to use subtractive hybridization to evaluate differences in gene expression between DS and control brains. Subtractive hybridization was applied on two fetal brains with DS and two age and sex matched controls, 23rd week of gestation, and mRNA steady state levels were evaluated generating a subtractive library. Subtracted sequences were identified by gene bank and assigned by alignments to individual genes. We found a series of up- and downregulated sequences consisting of chromosomal transcripts, enzymes of intermediary metabolism, hormones, transporters/channels and transcription factors (TFs). We show that trisomy 21 or aneuploidy leads to the deterioration of gene expression and the derangement of transcripts describes the impairment of transport, carriers, channels, signaling, known metabolic and hormone imbalances. The dys-coordinated expression of transcription factors including homeobox genes, POU-domain TFs, helix-loop-helix-motifs, LIM domain containing TFs, leucine zippers, forkhead genes, maybe of pathophysiological significance for abnormal brain development and wiring found in patients with DS. This is the first description of the concomitant expression of a large series of sequences indicating disruption of the concerted action of genes in this disorder.

Validity of current clinical criteria for Alzheimer's disease, vascular dementia and dementia with Lewy bodies

BACKGROUND

Following the success of the NINCDS-ADRDA criteria for Alzheimer's disease, groups interested in vascular dementia and dementia with Lewy bodies have now adopted similar criteria.

AIMS

To assess whether the validity of these criteria are influenced by the prevalence of mixed pathologies or by the prevalence rate.

METHOD

A community based post-mortem study.

RESULTS

Mixed pathologies were common (33.8%). The high specificities obtained for the CDLB and NINDS-AIREN criteria (1.00 and 0.95, respectively) were associated with low sensitivities (0.22 and 0.43, respectively). Low prevalence and the presence of mixed pathologies had a deleterious effect on positive predictive values.

CONCLUSIONS

Current clinical diagnostic criteria are good at detecting pathology per se but not at detecting pure pathology. A large proportion of subjects from the general population fulfilling probable CDLB, probable NINCDS-ADRDA or probable NINDS-AIREN will have mixed pathologies.

Brain vasopressin levels in Down syndrome and Alzheimer's disease

Performing gene hunting in Down Syndrome fetal brain we detected an overexpressed sequence highly homologous to the human vasopressin gene. As this neuropeptide may be involved in the pathogenetic mechanism and, moreover, was described to play a role in memory and learning, we decided to study the brain gene product level in Down Syndrome (DS), controls and patients with Alzheimer's disease (AD). Subtractive hybridization was used to study the differential expression between steady state mRNA levels in fetal brain of DS and controls at the 23rd week of gestation. A radioimmunological method was used to determine vasopressin (AVP) in five brain regions of each 9 aged DS brains, 9 brains with AD and 9 control individuals, obtained from brain bank. An overexpressed nucleic acid sequence with 91% homology to the vasopressin gene was detected in both fetal brains with DS. AVP levels in controls were of the order cerebellum>occipital>frontal>parietal>temporal lobe and were significantly higher in temporal lobe and lower in cerebellum of patients with DS. AVP levels in brain of AD patients were also significantly increased in temporal lobe but were not reduced in cerebellum. The biological meaning of increased AVP remain unclear but may be linked to the neurodegenerative processes, proposed to be similar in both disorders. Data from gene hunting in fetal DS brain along with our data on aged DS and AD patients suggest the early involvement of AVP in the pathomechanism accompanying cholinergic, monoaminergic and neuropeptidergic deficits described in DS and AD.

Decreased transcription factor junD in brains of patients with Down syndrome

JunD is a member of the Jun family of transcription factors (TF), recently shown to negatively regulate cell growth and antagonizes transformation by the protooncogene ras: c-jun decreases while junD is accumulating when fibroblasts become quiescent. Furthermore, overexpression of junD resulted in slower growth and an increase in cells in G0/G1. Performing gene hunting on fetal Down syndrome (DS) brain we found a sequence downregulated and homologous to junD. This observation made us examine junD protein levels in adult brain specimens. Western blot experiments were carried out in five brain regions of aged patients with DS (n = 9), controls (n = 9) and patients with Alzheimer's disease (AD, n = 9). We found that junD in AD brains were comparable to controls, whereas junD levels were significantly and remarkably reduced in frontal, temporal lobe and cerebellum of patients with DS. These findings may indicate a specific finding in DS and were not linked to the AD-like-neuropathological changes of plaques and tangles, observed in DS from the fourth decade, which is also suggested by the findings of downregulated junD at the mRNA level revealed by the gene hunting technique (subtractive hybridization) in fetal DS brain. We propose that junD plays a role for the impaired development and wiring of DS brain, maybe already early in life.

Expression of DNA excision-repair-cross-complementing proteins p80 and p89 in brain of patients with Down Syndrome and Alzheimer's disease

Although deficient DNA repair was proposed for neurodegenerative disorders including Down syndrome (DS), repair proteins for nucleotide excision repair have not been studied in brain yet. As one of the hypotheses for the pathogenesis of brain damage in DS and Alzheimer's disease (AD), is oxidative stress, and cells of patients with DS were shown to be more susceptible to ionizing irradiation. We decided to study expression of excision repair-cross-complementing (ERCC) gene products, proteins 80 and 89, representatives of repair genes known to be involved in the repair of different types of DNA damage. ERCC2-protein 80 kDa and ERCC3-protein p89 were determined in five individual brain regions of controls, aged DS and AD patients. Although different in the individual regions, DNA repair proteins were consistently higher in temporal and frontal lobes of patients with DS and higher in all brain regions of patients with AD. Our results are the first to describe DNA repair gene protein patterns in human brain regions providing the basis for further studies in this area. We showed that DNA repair genes ERCC2 and ERCC3 (excision-repair-cross-complementing) for nucleotide excision repair were increased at the protein level with the possible biological meaning that this increase may be compatible with and indicate ongoing (oxidative?) DNA damage.

A labeled guanidine ligand for studying sweet taste

A synthesis of a biotinylated-, coumarin-substituted-N,N'-diarylguanidine 1 is reported. This ligand has structural features conducive to studying sweet taste including a fluorescent tag to facilitate spectroscopic studies of binding to protein-receptors for sweet ligands and an anchor for affinity purification.

Upregulation of the anti-apoptotic protein Bcl-2 may be an early event in neurodegeneration: studies on Parkinson's and incidental Lewy body disease

Apoptosis and oxidative stress have been suggested to be involved in Parkinson's disease (PD). However, whether this is a cause or consequence of neurodegeneration is unknown. Incidental Lewy Body disease (ILBD) appears to be a presymptomatic form of Parkinson's disease where individuals are neurologically normal, but after post-mortem examination pathology similar to Parkinson's disease is present. Thus, ILBD can be used to examine the early stages of the pathological process in PD. We investigated the levels of Bcl-2, an anti-apoptotic protein known to decrease cell death induced by several mechanisms, including oxidative stress. Our data show that Bcl-2 is significantly raised in the basal ganglia regions of PD patients as compared to age-matched controls. A similar trend is also found in ILBD. We propose that Bcl-2 increases in some brain regions as an early event and that these brain regions are under a stress for perhaps many years before any symptomatic changes occur.

Evidence against increased oxidative DNA-damage in Down syndrome

In Down syndrome (DS), oxidative DNA-damage may play a role in the pathogenesis of characteristic mental retardation and precocious dementia of Alzheimer type. We measured the oxidized nucleoside, 8-hydroxy-2'-deoxyguanosine (8-OHdG), in nuclear DNA (nDNA) isolated from four different regions of cerebral cortex and cerebellum in 10 adult DS and 10 Alzheimer's disease (AD) patients compared to normal controls. Levels of 8-OHdG in post-mortem brain tissue were investigated by means of high-performance liquid chromatography with electrochemical detection. There was no significant increase in DS and AD compared to controls in any of the brain regions. Highest amounts of 8-OHdG were in temporal cortex in DS (180.0 +/- 9.6 nmol/g wet weight tissue), AD (172.4 +/- 14.6 nmol/g wet weight tissue) and controls (183.4 +/- 12.7 nmol/g). We conclude that the results provide evidence against an increased reactive oxygen species (ROS) induced damage to nDNA in DS and AD.

Oxidative DNA damage in the parkinsonian brain: an apparent selective increase in 8-hydroxyguanine levels in substantia nigra

Oxidative damage has been implicated in the pathology of Parkinson's disease (PD), e.g., rises in the level of the DNA damage product, 8-hydroxy-2'-deoxyguanosine, have been reported. However, many other products result from oxidative DNA damage, and the pattern of products can be diagnostic of the oxidizing species. Gas chromatography/mass spectrometry was used to examine products of oxidation and deamination of all four DNA bases in control and PD brains. Products were detected in all brain regions examined, both normal and PD. Analysis showed that levels of 8-hydroxyguanine (8-OHG) tended to be elevated and levels of 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FAPy guanine) tended to be decreased in PD. The most striking difference was a rise in 8-OHG in PD substantia nigra (p = 0.0002); rises in other base oxidation/deamination products were not evident, showing that elevation in 8-OHG is unlikely to be due to peroxynitrite (ONOO-) or hydroxyl radicals (OH.), or to be a prooxidant effect of treatment with L-Dopa. However, some or all of the rise in 8-OHG could be due to a change in 8-OHG/FAPy guanine ratios rather than to an increase in total oxidative guanine damage.

Evidence against increased glycoxidation in patients with Alzheimer's disease

Neuropathological findings of Alzheimer's disease (AD) are intracellular (neurofibrillary tangles) and extracellular (senile plaques) filamentous protein aggregates. Non-enzymatic glycation has been proposed as a primary factor in this pathogenesis, leading to increased insolubility of tau protein and beta-amyloid. The aim of our study was to test the hypothesis that increased glycoxidation, i.e. increased levels of oxidized products from non-enzymatic glycation could be found in brains of patients with AD and of aged Down syndrome (DS) subjects with abundant AD-like neuropathological lesions. Frontal cortex specimens were assayed for pentosidine (Pent) and N-epsilon-carboxymethyl-lysine (CML) by reversed phase high performance liquid chromatographical methods. Pent and CML levels in AD (n = 10; Pent, 35.5 +/- 4.84 mumol/g wet-weight tissue; CML, 135.2 +/- 5.0 mumol/g wet-weight tissue) were comparable to DS (n = 9; Pent, 36.4 +/- 3.21; CML, 133.5 +/- 4.7) and controls (n = 10; Pent, 35.2 +/- 3.55; CML, 136.9 +/- 3.3). We conclude that the results are not compatible with the concept of increased glycoxidation in AD compared to normal aging.

Similar deficits of central histaminergic system in patients with Down syndrome and Alzheimer disease

In order to study whether Alzheimer-like neuropathological changes involve the central histaminergic system we measured the concentration of histamine, its precursor histidine as well as the activity of histidine decarboxylase (HDC) and histamine-N-methyl-transferase (HMT) in frontal cortex of aging Down syndrome (DS) patients, Alzheimer patients and control individuals. The study populations were also investigated for choline acetyltransferase (ChAT) activity, since reduced ChAT activity is an established biochemical hallmark in DS and Alzheimer disease (AD). HDC and ChAT activity were reduced in brains of both DS and Alzheimer patients versus control patients. Additionally, we observed a significant decrease of histamine levels in the DS group. Histamine levels in AD brains tended to be decreased. Histidine concentrations and HMT activities were comparable between the three groups. Thus, our results for the first time show histaminergic deficits in brains of patients with DS resembling the neurochemical pattern in AD. Neuropathological changes may be responsible for similar neurochemical alterations of the histaminergic system in both dementing disorders.

Excitatory amino acids and monoamines in parahippocampal gyrus and frontal cortical pole of adults with Down syndrome

Aspartate (ASP), glutamate (GLU), noradrenaline (NA), dopamine (DA) and its acidic metabolites DOPAC and HVA, serotonin (5-HT) and its metabolite 5-HIAA were simultaneously investigated in post-mortem tissue samples from right parahippocampal gyrus (temporal cortex) and frontal cortical pole (frontal cortex) of adults with Down syndrome (DS), and of neurologically healthy controls by use of high performance liquid chromatography (HPLC). In parahippocampal gyrus, ASP, GLU, NA, DOPAC and 5-HT levels were significantly decreased in patients with DS, compared to levels found in control subjects (approximately 50%). No significant changes were observed in frontal pole. ASP and GLU levels were significantly lower in parahippocampal gyrus than in frontal pole of DS, a regional distribution that could not be observed in control subjects. In conclusion, the results of this study suggest that the temporal cortex would be more affected than the frontal cortex in adult patients with DS, a finding in line with reports showing a marked hypometabolism and extensive cell loss in temporal cortex of DS, and with those showing that parahippocampal gyrus abnormality may correlate with the extent of mental retardation affecting this type of patients.

Decreased cyclin dependent kinase in brain of patients with Down syndrome

In order to study whether phosphokinases might be involved in the neuropathology of Down Syndrome (DS) and Alzheimer disease (AD), cyclin dependent kinase (CDK) activity and protein, phosphokinase C (PKC) and phosphokinase A (PKA) activities have been determined in frontal lobes of DS, AD and control brains. An enzyme linked immunosorbent assay (ELISA) technique for CDK protein, and commercially available enzyme assays for CDK, PKC and PKA activities have been used. The major finding of our study was the remarkable and significant decrease of CDK protein and activity in DS brains in comparison to AD and controls. PKC and PKA were unaffected in both, AD and DS. As CDK controls cell division and differentiation, lowered CDK levels could reflect impaired proliferation and differentiation in DS.

Evidence against the involvement of reactive oxygen species in the pathogenesis of neuronal death in Down's syndrome and Alzheimer's disease

It has been proposed that the pathogenesis of Down's Syndrome (DS) involves reactive oxygen species (ROS) arising from a gene dosage effect that disproportionately elevates superoxide dismutase (SOD1) activity. It was also suggested that generation of ROS might be responsible for neuronal death in Alzheimer's Disease (AD). Little data on brain ROS in DS and AD exist; therefore, we determined activities of choline acetyltransferase (ChAT) and of the oxidative defense enzymes SOD1 and glutathione peroxidase (GSHPx) in frontal cortex of aged patients with DS and AD. We also measured levels of malondialdehyde, which reflects lipid peroxidation, and o-tyrosine, which represents the hydroxyl radical attack. ChAT was significantly reduced in cortex of patients with DS (-68%) and AD (-66%) as compared to controls. There were no statistically significant differences, however, between controls and both neurodegenerative disorders for SOD1, GSHPx, malondialdehyde and o-tyrosine. Our data contradict the only previous finding on increased SOD1 and ROS in brains of patients with DS: age as well as methodological differences might account for the discrepancy. In conclusion, no evidence for a pathogenetic role of SOD1, GSHPx, lipid peroxidation or hydroxyl radical attack in aged patients with DS and AD could be provided.

Cortical NMDA receptor properties and membrane fluidity are altered in Alzheimer's disease

NMDA receptor density as measured by the specific binding of [3H]MK 801 was significantly decreased (about 20%) in the frontal but not in the parietal cortex of postmortem brain samples of Alzheimer's disease (AD) patients (n = 21), when compared with control brains (n = 20). Membrane fluidity was not altered in the frontal cortex samples, but was slightly reduced in the parietal cortex samples of the AD patients. Since AD-specific histopathological changes (densities of senile plaques and neurofibrillary tangles) were about similar in both areas, it is concluded that the reductions of NMDA receptor densities in the frontal cortex is independent of AD-specific histopathological changes and of changes of membrane fluidity.

Increased kynurenic acid levels and decreased brain kynurenine aminotransferase I in patients with Down syndrome

Excitatory amino acid (EAA) receptors are central to brain physiology and play important roles in learning and memory processes. Kynurenic acid (KYNA), a metabolite of tryptophan in the brain blocks all three classical ionotropic EAA receptors and also serves as an antagonist at the glycine site associated with the N-methyl-D-aspartate receptor (NMDA) complex. We measured the endogenous levels of KYNA and activities of KYNA synthesizing enzymes kynurenine aminotransferase I (KAT I) and kynurenine aminotransferase II (KAT II) in the frontal and temporal cortex of elderly Down syndrome (DS) patients (aged 46-69 years). Compared with control specimens (0.21 +/- 0.06 pmol/mg tissue), the measurement of KYNA content revealed a significant 3-fold increase in frontal cortex of DS patients (0.67 +/- 0.13 pmol/mg tissue; p < or = 0.01). In temporal cortex KYNA levels were increased by 151% (p < or = 0.05) of control (0.41 +/- 0.09 pmol/mg tissue) Using crude cell free homogenate KAT's activities were determined in the presence of the 1 mM 2-oxoacid as a co-substrate at their pH optima of 10.0 for KAT I and 7.4 for KAT II. KATs activities in the presence of 1 mM pyruvate were 2.79 +/- 0.52 and 4.55 +/- 1.98 pmol/mg protein/h for KAT I and 0.98 +/- 0.07 and 1.09 +/- 0.14 pmol/mg protein/h for KAT II in frontal cortex and temporal cortex, respectively. When compared with the brain samples of controls the activity of KAT I was reduced in frontal cortex (9.8 +/- 2.4%; p < or = 0.01) and temporal cortex (25.8 +/- 6.4 %) of DS patients, while KAT II levels were within the normal range. Measurement of the neuronal, cholinergic marker choline acetyltransferase (ChAT) in the frontal cortex, revealed a significant reduction (36.6 +/- 4.3% of control; p < or = 0.01) in DS. Our data demonstrate the involvement of KYNA-metabolism in the cellular mechanisms underlying altered cognitive function in patients with DS. Although the localisation of both, KAT I and KAT II is not stated yet the reduction of KAT I may suggest impairment of KYNA metabolism in neuronal and/or nonneuronal compartments.

Molecular analysis of the presenilin 1 (S182) gene in "sporadic" cases of Alzheimer's disease: identification and characterisation of unusual splice variants

Mutations of the presenilin 1 (PS-1) gene at the Alzheimer's disease (AD) FAD3 locus on chromosome 14q24.3 are responsible for the majority of familial early-onset AD. As genes responsible for familial forms of AD are obvious candidates for further investigation in "sporadic" disease, we performed a molecular analysis of PS-1 transcripts extracted from brain tissues of a series of histologically confirmed cases of "sporadic" AD (n=10) and also from histologically "normal" (non-Alzheimer) age-matched brain controls (n=5). No sequence changes in the PS-1 coding sequence were detected after analysis by reverse transcription-PCR. This suggests that the frequency of mutations in the PS-1 (S182) coding region in "sporadic" Alzheimer's disease in very low. However, we demonstrated that the PS-1 gene is highly variably spliced. One splice variant involves the 5' untranslated region of the PS-1 gene only and hence encodes for normal PS-1. Six further splice variants involve coding regions of the PS-1 gene and result in truncated proteins lacking specific transmembrane domains. Most of these variants do not coincide with recognized sites of introns in the PS-1 gene. One of these variants, resulting in the loss of transmembrane domain TM-VII, was found only in an AD patient.

Polyamines in frontal cortex of patients with Down syndrome and Alzheimer disease

Polyamines may play an important role in brain development, mature brain function and also in neurodegenerative conditions. We investigated polyamine levels in frontal cortex of human post-mortem brain samples of elderly patients with Down syndrome (DS), Alzheimer disease (AD) and normal controls by means of chromatographic separation after dansylation. Spermidine and spermine concentrations were markedly decreased in DS and AD. Polyamine levels were neither related to age and post-mortem interval nor to choline acetyltransferase activity, as indicator of neuronal loss. Our results support the idea that besides other neurotransmitter systems, endogenous polyamine levels are altered in dementing illnesses such as Alzheimer disease and Down syndrome.

Endogenous opioids in frontal cortex of patients with Down syndrome

The main purpose of this study was to investigate differences regarding endogenous opioids in post-mortem frontal cortex of adult patients with Down syndrome (DS), patients with Alzheimer disease (AD) and neurologically healthy persons, respectively, using specific radioimmunoassays. The results of this study show that there is an increase in the levels of leu-enkephalin and dynorphin A in the frontal cortex of patients with DS as compared to the control group. An almost identical increase was also observed when comparing patients with AD to controls. In conclusion, the results of this study suggest a relationship between elevated tissue levels of leuenkephalin and dynorphin A in cerebral cortex and cognitive impairments in patients with DS and AD.

Tissue pH as an indicator of mRNA preservation in human post-mortem brain

The relationship between pH and mRNA preservation in post-mortem human brain was examined using in situ hybridization histochemistry and Northern hybridization with oligonucleotide probes in a large group of human subjects, including control and neuropathological cases. Tissue pH was found to correlate strongly with preservation of four mRNA species in three brain areas. Tissue with low pH, assumed to result from prolonged terminal hypoxia, contained reduced or absent mRNA, while tissue with higher pH was found to contain quantifiable amounts, the values for pathological brain samples being comparable to those for control material of similar pH. Measurement of tissue pH provides a simple means to screen post-mortem brain for mRNA preservation and is suggested as a means to match material in case-control studies of human neurodegenerative disease.

Neuropathological correlates of psychotic phenomena in confirmed Alzheimer's disease

BACKGROUND

The prevalence of psychotic phenomena in confirmed Alzheimer's disease (AD) and their potential neuropathological correlates have rarely been the subject of prospective investigation.

METHOD

Psychopathological disturbances were recorded prospectively according to the Geriatric Mental State Schedule and the CAMDEX: The frequency of these phenomena and neuropathological changes were examined in 56 patients with definite AD.

RESULTS

Hallucinations had been documented in 13 patients, paranoid delusions in 9 and delusional misidentification (e.g. the Capgras-type and the 'phantom boarder' symptoms) in 14 patients. Misidentifications were associated with lower neurone counts in the area CA1 of the hippocampus. Delusions and hallucinations were observed in patients with less severe cell loss in the parahippocampal gyrus and with lower cell counts in the dorsal raphe nucleus. A decrease of neurones in the locus coeruleus in a subset of depressed patients with AD had been reported earlier. Delusions and delusional misidentification were common in 5 patients with basal ganglia mineralisation, but there was no statistically significant association of these symptoms with the presence of Lewy bodies in the brainstem and neocortex of our patient sample.

CONCLUSIONS

These findings are compatible with the view that morphological changes in certain brain areas may promote the development of psychotic phenomena in AD. AD may offer a model for the understanding of pathomechanisms underlying the development of psychopathological disturbances in other psychoses with more discrete neuropathological changes.

Disproportionate loss of noradrenergic and cholinergic neurons as cause of depression in Alzheimer's disease--a hypothesis

Forty-two patients with neuropathologically confirmed Alzheimer's disease, who had been examined prospectively, had a significant decrease of neuron numbers in the locus coeruleus, substantia nigra, and basal nucleus of Meynert compared to 10 age-matched, non-demented controls. A subgroup of 12 demented patients with a history of depression had significantly lower neuron numbers in the locus coeruleus and slightly higher neuronal density in the basal nucleus of Meynert. We hypothesize that a noradrenergic/cholinergic imbalance may promote the development of depressive features in patients with Alzheimer's disease.

Pathways and patterns of cell loss in verified Alzheimer's disease: a factor and cluster analysis of clinico-pathological subgroups

Thirty-seven patients with neuropathologically verified Alzheimer's disease (AD) have been studied prospectively. A principal components analysis of neuron numbers in cortical and subcortical areas revealed two variables: Variable I with high loadings for the hippocampo-parahippocampo-parietal neuron counts and Variable II with high loadings for coeruleo-frontal cell numbers. Both may reflect functional neuroanatomical connections which may act as pathways of neurodegeneration in AD. A cluster analysis based on these neuron numbers yielded three groups of patients: Cluster A with low hippocampo-parahippocampo-parietal cell counts, Cluster B with well-preserved neuron numbers, and Cluster C with low coeruleo-frontal neuron numbers. Differences in clinical features between these patient groups indicated the potential clinical relevance of these clusters.

Neuropathological correlates of behavioural disturbance in confirmed Alzheimer's disease

Clinico-pathological correlations were examined in 54 patients with neuropathologically verified Alzheimer's disease (AD) who were part of a prospective study. Behavioural disturbance was documented using an expanded version of the Stockton Geriatric Rating Scale (SGRS). The subscores for physical disability (P), apathy (A) and communication failure (C) (summation score PAC) were closely correlated and were high in most patients during the late stages of illness. High PAC scores correlated with an earlier onset and longer duration of illness, lower brain weight, more severe tangle pathology in the parahippocampal gyrus and the frontal and parietal neocortex, and lower neuron counts in the hippocampus and basal nucleus of Meynert. Features of the Klüver-Bucy syndrome (range behaviour and hypermetamorphosis) were significantly associated with lower counts of large neurons in the parahippocampal gyrus and parietal neocortex, but not with more severe plaque or tangle formation or with neuronal loss in the subcortical nuclei. No correction was made for multiple comparisons. These findings may signify decreased cortical inhibition in patients with relatively well preserved subcortical structures who show features suggestive of the Klüver-Bucy syndrome. High PAC scores on the SGRS could reflect more advanced and widespread cerebral pathology in the end stages of AD.

Neuropathological basis for drawing disability (constructional apraxia) in Alzheimer's disease

The performance on four drawing tasks was studied in a sample of patients with verified Alzheimer's disease in order to examine the relationship of 'constructional apraxia' to neuropathological changes in the parietal lobe and in other brain areas. Twenty-three patients were able to attempt to copy pentagons, a spiral and a three-dimensional drawing of a house, 22 patients were able to draw a clock-face spontaneously. The results were rank-ordered by two independent raters. The values obtained in the different drawing tasks were correlated significantly with each other, with global estimates of cognitive performance (CAMCOG, Mini-Mental State), with a shorter duration of illness, higher brain weight (in the subsample of female patients), higher counts of large neurons in the parahippocampal gyrus and hippocampus, but not in the parietal lobe. This suggests that there is no specific relationship between 'constructional apraxia' and neuropathological changes in the parietal lobes of patients with advanced Alzheimer's disease, but that there is a correlation between widespread brain changes and several neuropsychological deficits, one of them being drawing disability.

The Lewy-body variant of Alzheimer's disease. Clinical and pathological findings

At post-mortem, Lewy bodies (LBs) were found in the brainstem and neocortex of eight out of 65 patients who had been collected during a prospective long-term study on clinically diagnosed Alzheimer's disease. All eight patients had accompanying Alzheimer pathology which was less severe than in a sample of eight age- and sex-matched patients from the same study with neuropathologically verified Alzheimer's disease. Parkinsonian features were more common in patients with LBs. There were no particular differences in duration of illness, severity of cognitive impairment, presence of hallucinations, or fluctuations in the course of illness. Frontal cerebral atrophy was more marked in patients with LBs, as was the loss of neurons in the basal nucleus of Meynert and the substantia nigra. Cognitive performance correlated with the number of pigmented neurons in the substantia nigra. We conclude that the differential diagnosis of LB dementia should be considered in patients satisfying NINCDS-ADRDA criteria for Alzheimer-type dementia who show marked Parkinsonian features and a frontal accentuation of cerebral atrophy.

Clinical and neuropathological correlates of depression in Alzheimer's disease

Depressive symptoms have been reported in patients with mild to moderate Alzheimer's disease (AD). Recent evidence suggests that a noradrenergic deficit originating from neuronal degeneration in brainstem nuclei may represent an organic correlate of these disturbances. We examined the neuropathological changes in the locus coeruleus (LC), substantia nigra (SN), basal nucleus of Meynert and cortex of 52 patients (12 male, 40 female, mean age 83.2 +/- 6.4 years) with pathologically verified AD. Fourteen patients (1 male, 13 female) showed signs of depression. The majority of these patients suffered from severe physical disability or sensory impairment and developed persistent delusions, but had less cognitive impairment. Neuronal counts in the LC were significantly lower than in the 38 patients without depression (36.9 +/- 14.0; 51.4 +/- 28.0 neuromelanin-pigmented cells per section per nucleus; F = 3.4, df = 1, 50, P = 0.04). Neuron counts were higher in the basal nucleus of Meynert in depressed AD patients and there were no differences of the neuron numbers in the SN. Depression (main effect; F = 4.5, P = 0.04) contributed significantly to the variance of neuronal counts in the LC, even when covarying for gender, age of onset, cognitive impairment and cortical Alzheimer pathology. The observed disproportionate loss of noradrenergic and cholinergic neurons in the LC and basal nucleus of Meynert may represent an important organic substrate of depression in AD.

Neurologic signs in Alzheimer's disease. Results of a prospective clinical and neuropathologic study

Neurologic signs and their neuropathologic correlates were examined in a sample of 56 patients with autopsy-proved Alzheimer's disease (13 men, 43 women; mean age at death, 83.1 years; range, 67 to 96 years) from a prospective longitudinal study. Full-range regular rigidity with cog-wheeling was found in 20 patients and was significantly associated with lower neuron counts in the substantia nigra and with the presence of Lewy bodies in the brain stem and neocortex. Twelve patients with myoclonus had a younger age at onset, a lower age at death (mean, 78.6 years), and lower neuron counts in the serotoninergic dorsal raphe nucleus and in the noradrenergic locus coeruleus than did the patients without myoclonus. Generalized motor seizures were reported in six patients, and they had significantly lower counts of pyramidal cells in cortical layers III through IV of the parietal cortex (area 7) and slightly decreased pyramidal cell numbers in the parahippocampal gyrus (area 28). The 19 patients with a positive grasp reflex had an earlier onset of illness and a significantly inferior performance on the Mini-Mental State examination and Cambridge Cognitive Examination tests. They, and 25 patients with a positive snout reflex, had significantly lower counts of large pyramidal cells in layers III through V of the frontal cortex (area 32). These results indicate that different neurologic symptoms in Alzheimer's disease can be related to disproportionate neuronal degeneration in functionally different brain areas.

[Organic correlates of depressive symptoms in Alzheimer's dementia. Results of a prospective study, review of the literature]

The diagnosis of Alzheimer's disease (AD) was verified at post-mortem examination in 46 patients (9 male: 37 female; mean age 83.6 +/- 6.5 years) from a prospective clinical study. Compared to 10 age-matched controls, the total AD group showed a significant neuronal loss in the locus coeruleus, dorsal raphe nucleus, substantia nigra and in the basal nucleus of Meynert. Twelve patients (1 male: 11 female) had experienced symptoms of depression. These patients had significantly lower neuronal counts in the locus coeruleus, but less severe cell loss in the basal nucleus of Meynert compared to the AD patients without depression.

Basal ganglia mineralization in Alzheimer's disease: a comparative study of clinical, neuroradiological and neuropathological findings

Fifty patients from a longitudinal study on 178 cases of Alzheimer's disease were examined at postmortem. The clinical features, CT-scans and neuropathological findings of five patients, with verified Alzheimer's disease, who had bilateral basal ganglia mineralization (BGM; 2 male, 3 female; age 78-91 years) were compared with the data of five age- and sex-matched Alzheimer patients without BGM and of five control subjects. Persecutory and other delusions (4 patients), persistent depression (2), parkinsonism (4), myoclonus (1) and epileptic seizures (1) were observed more frequently in the patients with BGM than was expected. The BGM-group had significantly lower counts of large neurons in the pallidum internum than the demented patients without BGM or the control group. We did not find other differences between the dementia groups regarding the CT-scans, or plaque, tangle and neuron counts in neocortex and brainstem. We suggest that the combined effects of Alzheimer pathology and BGM might lead to an increased manifestation of psychotic and motor disturbances.

Medical disorders in Alzheimer's disease and vascular dementia

The clinical and postmortem findings of 29 patients with Alzheimer's disease were evaluated and compared to the findings of 19 patients with vascular dementia. The patients with Alzheimer's disease had received treatment for an average of 2.0 internal medical disorders, the patients with vascular dementia for 2.1 disorders. The average number of medical diseases found at postmortem was 3.7 in the group with Alzheimer's dementia and 4.1 in vascular dementia. Apart from a marginally increased rate of peripheral occlusive artery disease in vascular dementia, the proportions of the most common disorders of the cardiovascular, genitourinary, gastrointestinal and endocrinological disorders and the most common causes of death did not differ significantly between these groups. Therefore patients with Alzheimer's disease should receive the same internal medical attention as patients with vascular dementia.

[Dementia and internal diseases: incidence of internal diseases in Alzheimer dementia, vascular dementia and other dementing diseases]

The medical histories and postmortems of 30 patients with neuropathologically verified Alzheimer's disease were compared with a group of 20 patients suffering from vascular dementia and a group of 10 patients with other forms of dementia. The total numbers of clinically or pathologically diagnosed medical disorders did not show significant differences between the different forms of dementia. Metabolic, infectious, degenerative, and malignant disorders occurred with similar frequency in all investigated groups. Cardiovascular diseases were only slightly more common in patients with vascular dementia. In contrast to several earlier clinical or epidemiological studies, it has to be concluded that patients with Alzheimer's dementia cannot be considered physically "healthier" than patients with other forms of dementia. Therefore, they need the same medical attention as do other elderly demented patients.

Alzheimer's disease: the relationship between the density of senile plaques, neurofibrillary tangles and A4 protein in human patients

The numerical density of senile plaques (SP) and neurofibrillary tangles (NFT) as revealed by the Glees silver method was compared with SP and NFT revealed by the Gallyas method and with amyloid (A4) deposits in immunostained sections in 6 elderly cases of Alzheimer's disease. The density of NFT was generally greater and A4 lower in tissue from hippocampus compared with the neocortex suggesting that A4 deposition was less important than the degree of paired helical filament (PHF) related damage in the hippocampus. The density of Glees SP was positively correlated Gallyas SP weakly correlated with A4 deposit number. A stepwise multiple regression analysis which included A4 deposit and Gallyas SP density and accounted for 54% of the variation in Glees SP density. Hence, different populations of SP were revealed by the different staining methods. The results suggested that the Glees method may stain a population of SP in a region of cortex where both amyloid deposition and neurofibrillary changes have occurred.