Alzheimer Disease: Juhász A

Kálmán J, Juhász A, Rimanóczy A, Palotás A, Palotás M, Szabó Z, Boda K, Márki-Zay J, Janka Z. · Department of Psychiatry, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, Faculty of Medicine, University of Szeged, Semmelweis u.6, H-6725 Szeged, Hungary. · Dement Geriatr Cogn Disord. · Pubmed #12714797 No free full text.

Abstract: The objective of our study was to investigate whether an interaction exists between apolipoprotein E (APOE) genotype and the response of patients with Alzheimer's disease (AD) to selegiline treatment, and whether APOE genotype independently affects the rate of AD progression. A 48-week multicenter double-blind trial was undertaken on 43 patients with mild to moderate AD. Primary efficacy measures were the AD Assessment Scale (ADAS), an 11-item cognitive subscale of ADAS (ADAS-Cog/11) and the Mini Mental State Examination. Secondary outcome measures were Clinical Global Impression of severity and CGI of change scales. The therapeutic response to selegiline was not affected by APOE genotype. Our results revealed that the APOE4 allele carrier AD probands did not respond better to selegiline treatment than the APOE2-3 patients, i.e. APOE status did not influence the therapeutic outcome of selegiline treatment.

Mórocz M, Kálmán J, Juhász A, Sinkó I, McGlynn AP, Downes CS, Janka Z, Raskó I. · Biological Research Centre of Hungarian Academy of Sciences, Institute of Genetics, POB 521, H-6701, Szeged, Hungary. · Neurobiol Aging. · Pubmed #11755018 No free full text.

Abstract: Previous studies have provided evidence of the involvement of oxidative damage in the pathogenesis of Alzheimer's disease (AD). Although the role of oxidative stress in the aetiology of the disease is still not clear, the detection of an increased damage status in the cells of patients could have important therapeutic implications. The level of oxidative damage and repair capacity in peripheral lymphocytes of AD patients and of age-matched controls was determined by the Comet assay applied to freshly isolated blood samples with oxidative lesion-specific DNA repair endonucleases. This is less prone to errors arising from oxidative artifacts than chemical analytical methods; and is therefore a relatively reliable, as well as rapid method for assay of oxidative DNA damage in cells. Statistically significant elevations (P < 0.05) of oxidized purines were observed in nuclear DNA of peripheral lymphocytes from AD patients, compared to age matched control subjects, both at basal level and after oxidative stress induced by H(2)O(2.) AD patients also showed a diminished repair of H(2)O(2) -induced oxidized purines.

Kálmán J, Kudchodkar BJ, Murray K, McConathy WJ, Juhász A, Janka Z, Lacko AG. · Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107-2644, USA. · Dement Geriatr Cogn Disord. · Pubmed #10559565 No free full text.

Abstract: There is now sufficient evidence to suggest that cardiovascular pathology and altered lipid metabolism contribute to the development of late-onset Alzheimer's disease (AD). In the present study, 24 AD patients and 15 controls were assessed for cardiovascular risk based on serum lipid and lipid oxidation parameters. The AD patients appeared to have a more favorable cardiovascular risk profile than the controls based on high-density lipoprotein cholesterol (HDL-C) values. The levels of thiobarbituric-acid-reactive substances and the activity of the enzyme paraoxonase (PON) following copper oxidation indicate that female patients may have better protection against serum and perhaps tissue oxidants than males with AD. While the higher HDL-C values indicate lower cardiovascular risk, additional data on oxidized lipid parameters suggest a lower level of protection against serum oxidants in male AD probands. CopyrightCopyright 1999S.KargerAG,Basel

Hartai Z, Juhász A, Rimanóczy A, Janáky T, Donkó T, Dux L, Penke B, Tóth GK, Janka Z, Kálmán J. · Department of Psychiatry, University of Szeged, Szeged, Hungary. · Neurochem Int. · Pubmed #17023091 No free full text.

Abstract: Kynurenine aminotransferases (KAT I and KAT II) are responsible for the transamination of kynurenine (KYN) to form kynurenic acid (KYNA), an excitatory amino acid receptor antagonist. Since these members of the kynurenine pathway (KP) are proposed to be involved in the pathogenesis of Alzheimer's dementia (AD), the activities of these enzymes and the levels of these metabolites were measured in the plasma and red blood cells (RBCs) of AD and control subjects together with the inheritance of the apolipoprotein (APOE) epsilon4 allele. KYNA levels were significantly decreased both in the plasma and in the RBCs in AD, but the levels of KYN and the activities of KAT I and KAT II remained unchanged. No association has been found with the possession of the epsilon4 allele. These findings indicate an altered peripheral KP in AD regardless of the APOE status of the probands.

Bjelik A, Pákáski M, Bereczki E, Gonda S, Juhász A, Rimanóczy A, Zana M, Janka Z, Sántha M, Kálmán J. · Alzheimer's Disease Research Centre, Department of Psychiatry, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, University of Szeged, 6 Semmelweis u., Szeged H-6725, Hungary. · Neurochem Int. · Pubmed #16962684 No free full text.

Abstract: Many of the risk factors for cerebrovascular disease and atherosclerosis also increase the risk of Alzheimer's disease, characterized by the cerebral deposition of beta-amyloid plaques resulting from the abnormal processing of the transmembrane amyloid precursor protein (APP). The initiating event of cholesterol-induced atherosclerosis is the retention and accumulation of atherogenic apolipoprotein B (apoB) together with low-density lipoproteins in the vascular intima. Biglycan, a member of the small leucine-rich protein family, was suspected of contributing to this process. The individual and combined overexpressions of biglycan and apoB-100 were therefore examined on the cortical APP mRNA levels of transgenic mice by means of semiquantitative PCR. As compared with the control littermates, transgenic biglycan mice had significantly increased cortical APP695 (122%) and APP770 (157%) mRNA levels, while the double transgenic (apoB(+/-)xbiglycan(+/-)) mice did not exhibit any changes. These results provide the first experimental evidence that the atherogenic risk factor biglycan alters APP splicing and may participate in the pathogenesis of both Alzheimer and vascular dementias.

Zana M, Szécsényi A, Czibula A, Bjelik A, Juhász A, Rimanóczy A, Szabó K, Vetró A, Szucs P, Várkonyi A, Pákáski M, Boda K, Raskó I, Janka Z, Kálmán J. · Department of Psychiatry, Alzheimer's Disease Research Center, Faculty of Medicine, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, University of Szeged, 6 Semmelweis St., Szeged, H-6725, Hungary. · Biochem Biophys Res Commun. · Pubmed #16696946 No free full text.

Abstract: The aim of the present study was to investigate the oxidative status of lymphocytes from children (n=7) and adults (n=18) with Down's syndrome (DS). The basal oxidative condition, the vulnerability to in vitro hydrogen peroxide exposure, and the repair capacity were measured by means of the damage-specific alkaline comet assay. Significantly and age-independently elevated numbers of single strand breaks and oxidized bases (pyrimidines and purines) were found in the nuclear DNA of the lymphocytes in the DS group in the basal condition. These results may support the role of an increased level of endogenous oxidative stress in DS and are similar to those previously demonstrated in Alzheimer's disease. In the in vitro oxidative stress-induced state, a markedly higher extent of DNA damage was observed in DS children as compared with age- and gender-matched healthy controls, suggesting that young trisomic lymphocytes are more sensitive to oxidative stress than normal ones. However, the repair ability itself was not found to be deteriorated in either DS children or DS adults.

Juhász A, Rimanóczy A, Boda K, Vincze G, Szlávik G, Zana M, Bjelik A, Pákáski M, Bódi N, Palotás A, Janka Z, Kálmán J. · Department of Psychiatry, Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, Szeged, Hungary. · Neurochem Res. · Pubmed #16258842 No free full text.

Abstract: Multiple genetic and environmental factors regulate the susceptibility to Alzheimer's disease (AD). Recently, several independent studies have reported that a locus on chromosome 14q32.1, where a gene encoding a cholesterol degrading enzyme of the brain, called 24-hydroxylase (CYP46A1) is located, has been linked with AD. The single nucleotide polymorphism (T/C) in intron 2 of CYP46 gene has been found to confer the risk for AD. The water soluble 24(S)-hydroxysterol is the product of the CYP46A1, and elevated plasma and cerebrospinal fluid hydroxysterol concentrations have been found in AD, reflecting increased brain cholesterol turnover or cellular degradation, due to the neurodegenerative process. A case-control study was performed on 125 AD and 102 age- and gender-matched control subjects (CNT) from Hungary, to test the association of CYP46 T/C and apolipoprotein E (ApoE) gene polymorphisms in AD. The frequency of the CYP46 C allele was similar (chi2=0.647, df=1, P=0.421, exact P=0.466, OR=0.845; 95% CI: 0.561-1.274) in both groups (CNT: 27%; 95% CI: 21.3-33.4; AD 30%; 95% CI: 25.0-36.3). The ApoE varepsilon4 allele was significantly over-represented (chi2=11.029, df=2, P=0.004) in the AD population (23.2%; 95% CI: 18.2-29.0) when compared with the CNT (11.3%; 95% CI: 7.4-16.6). The presence or absence of one or two CYP46C alleles together with the ApoE varepsilon4 allele did not increase the risk of AD (OR=3.492; 95% CI: 1.401-8.707; P<0.007 and OR=3.714; 95% CI: 1.549-8.908; P<0.003, respectively). Our results indicate that the intron 2 T/C polymorphism of CYP46 gene (neither alone, nor together with the varepsilon4 allele) does not increase the susceptibility to late-onset sporadic AD in the Hungarian population.

Rakonczay Z, Horváth Z, Juhász A, Kálmán J. · Department of Oral Biology, Alzheimer's Disease Research Centre, University of Szeged, Szeged, Hungary. · Chem Biol Interact. · Pubmed #16243305 No free full text.

Abstract: The most pronounced neurochemical abnormality in Alzheimer's disease (AD) is cholinergic dysfunction in the central nervous system. Peripheral tissues may also be affected, however, including blood. The present study undertook to determine the activity of acetylcholinesterase (AChE) and its molecular forms in erythrocytes, lymphocytes and platelets of normal elderly subjects and probable AD cases. These samples contained dimeric globular (G2), tetrameric globular (G4) and asymmetric (A12) AChE forms, but no globular monomeric (G1) enzyme. In both lymphocytes and platelets, the major AChE molecular form was G2 (approximately 80%), with G4 and A12 forms accounting for nearly equal portions of the remainder. Total AChE activities and measured sedimentation coefficients were similar in the control and AD samples (from patients with mild and moderately severe cognitive deficiency). However, the groups differed significantly in the proportion of certain AChE molecular forms. Thus, as compared with controls, the amount of A12 AChE in the AD samples was increased 148 and 161% in lymphocytes and platelets, respectively. Genotyping for apolipoprotein E (ApoE) and the butyrylcholinesterase K (BCHE-K) variant, carried out using the polymerase chain reaction, showed that AD patients carried the ApoE4 allele at a significantly higher frequency than the controls. On the other hand there were no significant group differences in the occurrence of the BCHE-K variant and no synergism between ApoE alleles and the BCHE-K variant in our Hungarian AD population.

Juhász A, Palotás A, Janka Z, Rimanóczy A, Palotás M, Bódi N, Boda K, Zana M, Vincze G, Kálmán J. · Department of Psychiatry, Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, Semmelweis u 6, H-6721, Szeged, Hungary. · Neurochem Res. · Pubmed #16176061 No free full text.

Abstract: Apolipoprotein E gene (Apo(epsilon)) has three common alleles (epsilon2, epsilon3, and epsilon4), of which epsilon4 has been shown to be associated with an increased risk for Alzheimer's disease (AD). Possible additional genetic factors, like the -491A variant of ApoE promoter may modify the development of AD, independently of the ApoE allele status. The objective of this study was to investigate whether A/T allelic polymorphism at site-491 of the ApoE promoter is associated with AD in a Hungarian population. The genomic DNA isolated from peripheral blood lymphocytes of 52 late-onset AD and 53 control individuals was used as a template for the two examined polymorphisms and PCR assay was applied. The epsilon4 allele was significantly over-represented in the AD group (28%) as compared with the control population (7%). No significant differences have been found between the control and the AD populations regarding the occurrence of the promoter A allele frequencies (control: 77%, AD: 70%). However, the AA genotype was more frequent in the AD group (48%) than in the control (10%) when the presence of epsilon4 allele was also considered. It is unlikely therefore that the -491A variant of the ApoE promoter gene is an independent risk factor in the Hungarian AD population, but a linkage disequilibrium exists between the two examined mutations.

Zana M, Juhász A, Rimanóczy A, Bjelik A, Baltás E, Ocsovszki I, Boda K, Penke B, Dobozy A, Kemény L, Janka Z, Kálmán J. · Department of Psychiatry, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, University of Szeged, 6 Semmelweis Street, Szeged H-6725, Hungary. · Neurobiol Aging. · Pubmed #15961188 No free full text.

Abstract: In the present pilot investigation, the susceptibility of T-lymphocytes from Alzheimer's disease (AD) subjects (n=22) and aged-matched, non-demented controls (CNT) (n=12) was examined with ultraviolet (UV) B light-induced apoptosis in vitro. The basal apoptotic ratios were similar in both groups. However, the AD lymphocytes displayed significantly (p<0.0001) lower apoptotic levels than those of the CNT lymphocytes at all of the applied UVB exposure doses (100, 200 and 300 mJ/cm(2)). These observations indicate that AD lymphocytes are more resistant than CNT lymphocytes to UVB irradiation.

Kálmán J, Kitajka K, Pákáski M, Zvara A, Juhász A, Vincze G, Janka Z, Puskás LG. · Department of Psychiatry, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, Faculty of Medicine, University of Szeged, Semmelweis u. 6. H-6725 Szeged, Hungary. · Psychiatr Genet. · Pubmed #15722950 No free full text.

Abstract: Since the function and metabolism of peripheral lymphocytes is known to be altered in Alzheimer's disease (AD), a pilot study was carried out to examine differences in gene expression profiles of these cells in 16 AD patients and aged control probands. Using a cDNA microarray representing 3200 distinct human genes, we identified 20 candidate genes whose expression is altered in AD lymphocytes compared with the control probands. Among these were the alpha2C-adrenoreceptor gene, known to regulate blood pressure and learning, the defensin, histocompability complex enhancer-binding protein, carboxypeptidase M, and the Fc fragment of IgE known to be involved in cellular and humoral immune responses. Others, like human cell death protein, TRAIL, and galectin-4 participate in the regulation of apoptosis. Real-time quantitative reverse transcription-polymerase chain reaction analysis was performed in order to confirm the expression changes in AD lymphocytes, and it could detect down-regulation of defensin and alpha2c-adrenoceptor genes, while other genes seemed unaltered in their expression, including heat-shock protein (hsp90), cholesteryl ester transfer protein, and apolipoprotein B100 (apoB). The altered expression profile of these genes might be connected with the previously reported AD-specific lymphocyte abnormalities. It remains to be elucidated, however, how these genes are related to the pathomechanism of dementia and whether the gene expression differences of AD lymphocytes reflect disease traits or stage processes.

Datki Z, Papp R, Zádori D, Soós K, Fülöp L, Juhász A, Laskay G, Hetényi C, Mihalik E, Zarándi M, Penke B. · Department of Medical Chemistry, University of Szeged, Szeged, Hungary. · Neurobiol Dis. · Pubmed #15571986 No free full text.

Abstract: The cell biology of Alzheimer's disease (AD) is characterized mainly by the neurodegeneration caused by the beta-amyloid (Abeta) peptides and by the formation of neurofibrillary tangles. The initial events of neurodegeneration in the brain tissue include synaptic dysfunction and axonopathy. Abeta-induced axonopathy and neurite degeneration were studied in vitro on differentiated human-derived neurotypic SH-SY5Y cells. Different methods were used to investigate the mechanism of action of aggregated Abeta on neuroblastoma cells. Abeta 1-42 aggregated for 1 h induced irreversible changes in the neurite morphology. Change of tau hyperphosphorylation and cell viability (cytoplasmic redox state and active membrane uptake) was irreversible during the first hour after the addition of Abeta 1-42 to the cells. These rapid events indicate that Abeta might induce neurodegeneration even at an early stage of Abeta-cell contact. A novel pentapeptide LPYFD-amide, an analog of Soto's LPFFD, significantly decreased neurite degeneration, tau aggregation, and cell viability reduction induced by Abeta 1-42.

Kálmán J, Juhász A, Janka Z, Rakonczay Z, Abrahám G, Boda K, Farkas T, Penke B. · No affiliation provided · Atherosclerosis. · Pubmed #15177135 No free full text.

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Kálmán J, Juhász A, Rimanóczy A, Palotás A, Palotás M, Boda K, Márki-Zay J, Csibri E, Janka Z. · Department of Psychiatry, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, Faculty of Medicine, University of Szeged, Hungary. · Psychiatr Genet. · Pubmed #14639046 No free full text.

Abstract: An association study was performed between apolipoprotein E (apoE) polymorphism and the common structural polymorphism Glu/Asp at codon 298 of the nitric oxide synthase (NOS3) gene in late-onset sporadic Alzheimer's dementia probands (LOAD), diffuse Lewy body dementia cases (DLBD) and controls in a Hungarian sample. The frequency of individuals who carried the apoE epsilon4 allele was significantly more common in both dementia groups (LOAD, 20%; DLBD, 27%; control, 8%; control versus DLBD, chi2=13.264, degrees of freedom=2, P<0.001; control versus LOAD, chi2=6.628, degrees of freedom=2, P<0.036). However, there were no significant differences in the NOS3 genotype and allele distributions between the LOAD, DLBD and control groups. The apoE status has been found to be independent from the NOS3 codon 298 polymorphism in the examined cohort. Despite the facts that NOS3 is associated with neuritic sprouting, and aberrant neuronal and glial expression of the same molecule has been found in neurodegenerative diseases, it is unlikely that the polymorphism Glu/Asp of the NOS3 gene is involved in the development of LOAD and DLBD.

Palotás A, Kálmán J, Palotás M, Juhász A, Janka Z, Penke B. · Department of Medical Chemistry, University of Szeged, Szeged, Hungary. · Prog Neuropsychopharmacol Biol Psychiatry. · Pubmed #12369273 No free full text.

Abstract: A major neuropathological finding in Alzheimer's disease (AD) is the presence of senile plaques in certain regions in the brain. The plaques contain extracellular deposits of beta-amyloid peptide (beta AP). Destabilization of intracellular calcium homeostasis in neurons, caused by beta AP, plays a central role in AD pathogenesis. In the present study, the authors report ionic alterations of lymphocytes and fibroblasts harvested from sporadic AD patients and from age-matched controls. Intracellular free calcium level ([Ca2+]i) of human cells, labeled with Fura-2AM, was determined by dual wavelength spectrofluorimetry. Basal [Ca2+]i appeared to be higher in AD lymphocytes when compared to control ones. Resting [Ca2+]i of AD fibroblasts, however, has proven to be lower than that seen with control cells. Exposure of cells to beta AP resulted in the elevation of the [Ca2+]i in both control cell types, however, that of AD lymphocytes and fibroblasts did not differ considerably.

Palotás A, Kálmán J, Palotás M, Juhász A, Janka Z, Penke B. · Department of Medical Chemistry, University of Szeged, Szeged, Hungary. · Brain Res Bull. · Pubmed #12127018 No free full text.

Abstract: Senile plaques containing beta-amyloid peptide (betaAP) comprise the major neuropathological lesions in Alzheimer's disease (AD). In line with ongoing studies investigating alterations of various biochemical processes of cells of peripheral tissues, the authors demonstrate differences in resting intracellular free calcium levels of lymphocytes harvested from sporadic Alzheimer patients and from age-matched controls. Resting intracellular calcium concentration was measured in Fura-2AM-loaded human lymphocytes by dual wavelength spectrofluorimetry. Resting calcium level appeared to be higher in Alzheimer cells when compared to control lymphocytes. After incubating cells in 10(-7)M of beta-amyloid, the resting calcium concentration of the control cells elevated, while that of Alzheimer lymphocytes did not differ considerably.

Palotás A, Kálmán J, Laskay G, Juhász A, Janka Z, Penke B. · Szegedi Tudományegyetem, Orvosi Vegytani Intézet, 6721 Szeged. · Ideggyogy Sz. · Pubmed #12122875 No free full text.

Abstract: RATIONALE: beta-amyloid peptides, comprising the major neuropathological lesions of Alzheimer's disease, have been found to form depositions in various peripheral tissues, including the skin. Neurons in the disorder succumb to the altered ionic homeostasis and some other factors caused by this toxic peptide. In line with these findings, our study aimed to find differences in biochemical processes of cultured cutaneous fibroblasts derived from sporadic Alzheimer patients and from age-matched control individuals that may mirror changes in the central nervous system. METHODS: Intracellular ionic homeostasis of Alzheimer and control fibroblasts was measured in Fura-2AM-loaded human fibroblasts by dual wavelength spectrofluorimetry. RESULTS: Cells derived from Alzheimer patients exhibited lower intracellular free calcium levels as compared to the control cultures. Exposure of fibroblasts to beta-amyloid resulted in increased calcium concentrations of the control cells, but not of Alzheimer ones. CONCLUSION: Our findings indicate that Alzheimer's disease is a systemic disorder that, among others, affects the calcium homeostasis of fibroblasts. Even though it is unknown whether the diminished ionic response of Alzheimer fibroblasts is a disease or actual status marker, it could prove to be a useful model for the analysis of Alzheimer specific changes.

Janka Z, Juhász A, Rimanóczy A, Boda K, Márki-Zay J, Palotás M, Kuk I, Zöllei M, Jakab K, Kálmán J. · Department of Psychiatry, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, Faculty of Medicine, University of Szeged, Szeged, Hungary. · Psychiatr Genet. · Pubmed #11901360 No free full text.

Abstract: Several lines of biochemical evidence support a role of alpha2-macroglobulin (A2M) in the pathogenesis of Alzheimer's dementia (AD). A2M participates in the general defence mechanism against proteinases and it is supposed to be involved in the degradation of beta-amyloid peptide (betaAP). Furthermore, A2M has been shown to reduce betaAP fibril formation, and it is upregulated in the acute-phase inflammatory response like the process occurring in the AD brain. The exon 18 splice acceptor deletion polymorphism and the exon 24 (Val-1000-Ile) GG genotype were reported to be associated with AD, but the results are contradictory. Since the Hungarian population is genetically distinct from the other European ethnic groups, we examined whether the risk for developing AD is increased in the A2M GG carriers. The interaction of apolipoprotein E (apoE) and A2M polymorphisms was also examined. The distribution of A2M genotypes and alleles in the entire data set was consistent with the previous negative observations in which A and G allelic frequencies were comparable in both groups (72% and 28% in the AD population, and 72% and 28% in the control population, respectively). The GG genotype was over-represented (14%) only in the apoE epsilon4 non-carrier subgroup of AD probands (7% in the control group), but the difference was not significant. Our data suggest that, although A2M has an important role in the AD-specific neurodegenerative process, its exon 24 Val-1000-Ile polymorphism is not likely to be associated with late-onset sporadic AD in the Hungarian population.

Janka Z, Juhász A, Rimanóczy A A, Boda K, Márki-Zay J, Kálmán J. · Department of Psychiatry, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, Faculty of Medicine, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary. · Mol Psychiatry. · Pubmed #11803456 links to  free full text

Abstract: The gene of an esterase enzyme, called paraoxonase (PON, EC.3.1.8.1.) is a member of a multigene family that comprises three related genes PON1, PON2, and PON3 with structural homology clustering on the chromosome 7.(1,2) The PON1 activity and the polymorphism of the PON1 and PON2 genes have been found to be associated with risk of cardiovascular diseases such as hypercholesterolaemia, non-insulin-dependent diabetes, coronary heart disease (CHD) and myocardial infaction.(3-8) The importance of cardiovascular risk factors in the pathomechanism of Alzheimer's disease (AD) and vascular dementia (VD)(9-13) prompted us to examine the genetic effect of PON2 gene codon 311 (Cys-->Ser; PON2*S) polymorphism and the relationship between the PON2*S allele and the other dementia risk factor, the apoE polymorphism in these dementias. The PON2*C and PON2*S allele frequencies were similar in both AD (25% and 75%) and VD groups (23% and 77%), respectively, compared with the controls (27% and 73%). The ratio of the PON2*S carriers was significantly higher among the apoE4 allele carrier AD (27%) and VD (25%) groups than in the control (12%). Our results indicate that the PON2*S and apoE4 alleles have interactive effect on the development of the two most common forms of dementias AD and VD, and further support the hypothesis that cardiovascular factors contribute to the development of AD.

Palotás A, Kálmán J, Laskay G, Juhász A, Janka Z, Penke B. · Department of Medical Chemistry, University of Szeged, Hungary. · Neurochem Res. · Pubmed #11565613 No free full text.

Abstract: The accumulation of the beta-amyloid peptide (betaAP) in the brain, produced from the ubiquitously expressed amyloid precursor protein (APP) is a defining feature of Alzheimer's disease (AD). Consistent with studies demonstrating the importance of skin biopsy in the diagnosis of neurodegenerative disorders, we investigated whether differences in intracellular free calcium levels ([Ca2+]i) of cultured cutaneous fibroblasts derived from sporadic AD patients and from age-matched control individuals might be present. [Ca2+]i was measured in Fura-2AM-loaded human fibroblasts by dual wavelength spectrofluorimetry. AD cells exhibited lower [Ca2+]i as compared to the control cultures. Exposure of fibroblasts to betaAP resulted in increased [Ca2+]i of the control cells, but not of AD fibroblasts. Our test could prove useful in supporting the diagnosis of (sporadic) AD in patients suspected of suffering from the disease.

Kálmán J, Márki-Zay J, Juhász A, Sántha A, Dux L, Janka Z. · Department of Psychiatry, Szent-Györgyi University Medical School, Szeged, Hungary. · Acta Neurol Scand. · Pubmed #10770527 No free full text.

Abstract: INTRODUCTION: Cystatin C, a cysteine protease inhibitor, has been implicated in the neurodegenerative and repair processes of the nervous system, and the deposition of the same protein together with beta amyloid peptide was found as cerebral amyloid angiopathy (CAA) in different types of dementias. OBJECTIVE AND METHODS: Because of the differential diagnostic importance, serum and cerebrospinal fluid (CSF) cystatin C levels of 24 late onset Alzheimer's demented (AD) and 16 ischemic type of vascular demented (VD) probands were compared with 17 aged control (AC) persons. RESULTS: The serum and CSF cystatin levels were found in the normal range in all groups. The ischemic VD probands had the tendency to have higher cystatin C levels than the AD. No correlation has been found with the severity and duration of dementia and with the other measured parameters. CONCLUSION: These results indicate that lower than normal CSF cystatin C level is not a diagnostic marker in ischemic VD and CAA related to AD.