Alzheimer Disease: Kálmán J

Kálmán J. · No affiliation provided · Neuropsychopharmacol Hung. · Pubmed #17073211 No free full text.

This publication has no abstract.

Kálmán J, Kálmán S, Pákáski M. · Szegedi Tudományegyetem, Pszichiátriai Klinika, Alzheimer-kór Kutatócsoport, Szeged. · Neuropsychopharmacol Hung. · Pubmed #19213202 No free full text.

Abstract: The prevalence of the behavioral and psychological symptoms of dementia (BPSD) varies between 20-90%, depending on the care settings and severity of the dementia syndrome. BPSD is the major reason for referrals to secondary care. It exacerbates the dementia-associated morbidity and mortality rates. Furthermore, while BPSD is not a properly defined syndrome, it frequently induces psychic and somatic complaints in caregivers. The social and economic impacts of the BPSD far outweigh the importance of the cognitive symptoms of dementia. The aim of this review is to present the most recent findings regarding the recognition, differential diagnosis, aetiology, and pathomechanism of BPSD with a special focus on the local therapeutic possibilities with the atypical antipsychotics. Of utmost importance is the process of identifying the complex bio-psycho-social aetiological factors in parallel with defining the treatment strategies. Only after the correct recognition of the potential aetiology, non-pharmacological interventions are recommended to start with as first choice treatment in mild and mild-to-moderate BPSD, while in moderate and severe cases pharmacotherapeutic approaches are recommended from the start. Recent findings of neuropathological, neurochemical and neuroimaging studies yielded unequivocal evidence that the BPSD symptoms are not a consequence of a single neurotransmitter imbalance, but rather of disproportionate level changes in biogenic amines, excitatory and inhibitory transmitters in the central nervous system. Consequently, the available pharmacotherapy should target the balancing of the dopaminergic, serotoninergic, noradrenergic, excitatory and GABAergic neurotransmission by using antipsychotics, antidepressants, phase-prophylactic agents, and benzodiazepines. Several clinical studies have proven the efficacy of atypical antipsychotics that target multiple neurotransmitter systems in treating BPSD. The first results of the CATIE-AD study also confirm these findings and indicate that the atypical antipsychotics are effective in controlling anger, aggression and delusions in Alzheimer's disease, while cognitive symptoms, quality of life and care needs are not improved.

Kálmán J. · Szegedi Tudományegyetem, Pszichiátriai Klinika, 6725 Szeged. · Ideggyogy Sz. · Pubmed #18763482 No free full text.

This publication has no abstract.

Pákáski M, Kálmán J. · Alzheimer's Disease Research Centre, Department of Psychiatry, University of Szeged, Semmelweis 6, Szeged H-6725, Hungary. · Neurochem Int. · Pubmed #18602955 No free full text.

Abstract: Alzheimer's disease (AD) is a progressive, neurodegenerative disease characterized by memory and cognitive loss, the formation of senile plaques containing amyloid-beta (Abeta) peptide, degeneration of the cholinergic neurons and the development of neurofibrillary tangles. The build-up of Abeta is considered to be a central feature in the pathogenesis of AD. However, other critical molecular and neurochemical alterations too occur, such as a cholinergic dysfunction. As concerns the pathomechanism of the disease, both the amyloid cascade hypothesis and the cholinergic hypothesis of AD are widely accepted. This review surveys recent in vitro and in vivo experimental evidence relating to these two hypotheses. Bidirectional pathways linking them as regards the cholinergic neurotoxicity of Abeta and the regulatory mechanisms of cholinergic receptor activation or enzyme inhibition in the processing of the amyloid precursor protein are also discussed. Further work is warranted to elucidate the exact effects in the interactions between the cholinergic and amyloid hypotheses of the candidate drugs used in AD therapy.

Zana M, Janka Z, Kálmán J. · Department of Psychiatry, Faculty of Medicine, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, University of Szeged, 6 Semmelweis St, Szeged H-6725, Hungary. · Neurobiol Aging. · Pubmed #16624449 No free full text.

Abstract: Besides the genetic, biochemical and neuropathological analogies between Down's syndrome (DS) and Alzheimer's disease (AD), there is ample evidence of the involvement of oxidative stress (OS) in the pathogenesis of both disorders. The present paper reviews the publications on DS and AD in the past 10 years in light of the "gene dosage" and "two-hit" hypotheses, with regard to the alterations caused by OS in both the central nervous system and the periphery, and the main pipeline of antioxidant therapeutic strategies. OS occurs decades prior to the signature pathology and manifests as lipid, protein and DNA oxidation, and mitochondrial abnormalities. In clinical settings, the assessment of OS has traditionally been hampered by the use of assays that suffer from inherent problems related to specificity and/or sensitivity, which explains some of the conflicting results presented in this work. For DS, no scientifically proven diet or drug is yet available, and AD trials have not provided a satisfactory approach for the prevention of and therapy against OS, although most of them still need evidence-based confirmation. In the future, a balanced up-regulation of endogenous antioxidants, together with multiple exogenous antioxidant supplementation, may be expected to be one of the most promising treatment methods.

Palotás A, Kálmán J. · Alzheimer's Disease Research Center, Department of Psychiatry, Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, H-6720 Szeged, Pécsi u. 4, Hungary. · Curr Drug Metab. · Pubmed #16611022 No free full text.

Abstract: Alzheimer's disease (AD) is a genetically complex and heterogenous disorder. In a small proportion of cases, mutations in three determinative (causal) genes are responsible for autosomal dominant early-onset forms of AD. The majority of cases, however, is sporadic, late-onset AD with unknown etiology. The pathology and clinical manifestations of these forms are influenced by multiple genetic and environmental risk factors. Over the past decades, a number of candidate genes have been identified as disease modifiers with conflicting results. This study reviews susceptibility genes that are associated with increased risk of developing AD.

Kálmán J, Janka Z. · Szegedi Tudományegyetem, Pszichiátriai Klinika,Alzheimer-kór Kutatócsoport, Szeged. · Orv Hetil. · Pubmed #16255374 No free full text.

Abstract: Epidemiological, biochemical and pharmacological investigations provide increasing number of evidences that altered cholesterol metabolism contributes to the development of Alzheimer's disease. The objective of the present paper is to review existing information about the links of cholesterol and amyloid metabolism from the clinical and proposed etiological viewpoints of the most frequent dementing disorder in Hungary. Beta-amyloid peptide, the major component of the senile plaques in the Alzheimer's disease brains is the end product of the abnormal post-translational processing of its precursor, called amyloid precursor protein. The compartmentation of the amyloid precursor protein molecule within the cell membrane is regulated by the cholesterol content of the bilayers. The amyloid precursor protein molecule could be present either in-, or outside of the membrane rafts. Any kind of process, which alters the compartmentation preference of the amyloid precursor protein molecule, by transferring it to the membrane rafts, favours beta- and gamma-secretase cleavage, and should be recognised as an amyloidogenic process. If the blood-brain barrier is intact, the brain is not able to take up the lipoprotein particles responsible for the transport of cholesterol. Instead of the active uptake, neurons and glial cells synthetize cholesterol de novo, in a process, where the rate limiting enzyme is 3-hydroxy-3-methylglutaryl coenzyme A. On the other hand, the brain specific CYP46A1 enzyme is responsible for the degradation of cholesterol into a water soluble metabolite, called 24S-OH cholesterol. The decreased CYP46A1 activity in the brain of Alzheimer's disease patients raises membrane cholesterol levels, and as a consequence the amyloid precursor protein is shifted and deposited in the cholesterol rich lipid rafts leading to beta-amyloid peptide specific metabolism. Among the polymorphic variants of the apolipoprotein E gene, the E4 allele is considered as a major risk factor for Alzheimer's disease. The E4 allele carrier Alzheimer's disease probands have increased amyloid burden, decreased beta-amyloid peptide degradation, and less effective neuronal repair mechanisms. Even as early as age 30, patients with Niemann-Pick Type C disease show clinical and neuropathological signs of Alzheimer's disease. The point mutation of the protein responsible for the endosomal transport of cholesterol is considered as a major cause of the beta-amyloid peptide deposition in the brain of Niemann-Pick Type C patients. One of the most exciting recent discovery, that Niemann-Pick Type C disease could be recognised as a disease model for Alzheimer's disease. New, promising cholesterol metabolism related therapeutic approaches are discussed, but it is emphasized that the clinical evidences regarding their efficacy in Alzheimer's disease are still missing.

Galariotis V, Bódi N, Janka Z, Kálmán J. · University of Szeged, Department of Psychiatry, Szeged. · Ideggyogy Sz. · Pubmed #16173270 No free full text.

Abstract: This is a comprehensive paper in three parts covering history, prevalence, clinical forms, differential diagnosis, genetics, molecular pathomechanism, pathology, clinical diagnosis and treatment of frontotemporal dementia (FTD). The second part focuses on the differential diagnosis, genetics, molecular pathomechanism and pathology. The clinical diagnosis of frontotemporal dementia is based on the presence of a prominent disturbance of the executive function and of frontal lobe syndrome or a progressive aphasic syndrome without severe global cognitive impairment. Of other dementias, it is primarily Alzheimer's disease that it should be differentiated from, but other psychiatric disorders must also be ruled out. The disease has familial and sporadic forms. Recent identification of mutations in the gene encoding the microtubule-associated tau protein in the inherited frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) has demonstrated that various tau dysfunctions can lead to neurodegeneration. Tau gene mutations have varied effects on the biology and function of the protein. This heterogeneous pathomechanism explains the wide range of clinical and neuropathological features observed in the FTDP-17. Tau and ubiquitin antibodies can be detected by sensitive immunohistochemical methods. The diagnosis of FTD should be based on neuropathological examination, and this is also the only method by which it can be definitely differentiated from other types of dementias.

Galariotis V, Bódi N, Janka Z, Kálmán J. · University of Szeged, Department of Psychiatry, Szeged. · Ideggyogy Sz. · Pubmed #16021963 No free full text.

Abstract: The authors report a comprehensive publication consisting of three parts going into the details of history, prevalence, clinical forms, differential diagnosis, genetics, molecular pathomechanism, pathology, clinical diagnosis and treatment of frontotemporal dementia (FTD). The first part of the present review deals with history, prevalence and clinical forms of FTD. The prototypical FTD with circumscribed atrophy was first described by Arnold Pick; Alois Alzheimer found the intraneural inclusions in the patients' brain. Later it was recognised that many patients had neither the atrophy nor the cellular changes, but genetic mutations have been identified. Frontotemporal dementia is a degenerative condition with unknown etiology in the frontal and anterior temporal lobes of the brain. It is a progressive neurobehavioral syndrome characterized by early decline in social interpersonal conduct, early impairment in the regulation of personal conduct, early emotional blunting, and early loss of insight. There are no reliable epidemiological studies on the prevalence of FTD, but it is well-accepted that FTD is a common cause for dementia before the age of 65 (it constitutes approximately five percent of all irreversible dementias). The nomenclature of the FTD has been confusing and continues to be. Three major clinical syndromes can be identified: 1 frontal variant FTD (dementia of frontal type) in which changes in social behavior and personality predominate, 2. in semantic dementia (progressive fluent aphasia) there is a breakdown in the conceptual database which underlies language production and comprehension, 3. in progressive nonfluent aphasia the phonologic and syntactic components of language are affected. The authors report two cases, which can point to clinical symptoms and forms, and mention the problems of the differential diagnosis and therapy.

Kálmán J, Palotás A, Bódi N, Kincses TZ, Benedek G, Janka Z, Antal A. · Department of Psychiatry, Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, H-6721 Szeged, Semmelweis u. 6, Hungary. · Brain Res Bull. · Pubmed #15862926 No free full text.

Abstract: Impaired neuronal energy metabolism, oxidative changes and microvascular abnormalities lead to altered lactate levels in Alzheimer's dementia. The aim of the present study was to assess whether intravenous sodium-lactate, a metabolic alternative and vasodilator that is thought to improve cognition, advances the cognitive performance of Alzheimer patients. Semantic categorization paradigm was used to present the electrophysiological correlates of natural scene categorization of Alzheimer patients before and after intravenous saline or sodium-lactate infusion. Mean amplitudes of event-related potentials (ERPs) were measured in two time windows before and after the treatments; two negative components (N1 between 150 and 250 ms and N2 between 400 and 600 ms) and one positive component (P2 between 250 and 400 ms) were identified. The negative components were more negative for the non-animal trials than for the animal trials while the positive component was similar for both categories. After the lactate treatment the amplitudes of the negative components became more negative mainly for the non-animal trials while the amplitude of the positive component turned more positive for the animal trials, however these changes were not significant. No changes have been observed after normal saline infusion. These results suggest that, contrary to its anticipated beneficial effects, sodium-lactate fails to significantly improve semantic categorization processes in Alzheimer's disease and this enhancement can be detected by recording ERPs. The effect of sodium-lactate to slightly improve semantic memory might be based on its positive effect on cardio- and cerebro-vascular function and neuronal metabolism.

Kálmán J, Palotás A, Kis G, Boda K, Túri P, Bari F, Domoki F, Dóda I, Argyelán M, Vincze G, Séra T, Csernay L, Janka Z, Pávics L. · Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, H-6721 Szeged, Semmelweis u. 6, Hungary. · Eur J Neurosci. · Pubmed #15845094 No free full text.

Abstract: Bilateral temporoparietal hypoperfusion is a characteristic single photon emission computed tomography (SPECT) finding in Alzheimer's disease (AD). Lactate is a metabolic vasodilator and is known to provoke increased cerebral blood flow (CBF) in healthy adults. This work investigated whether lactate, which is present in high concentrations in AD cerebrospinal fluid, affects AD-specific perfusion abnormalities. Twenty mild-to-moderately demented AD probands participated in the self-controlled study. The regional CBF was examined utilizing (99m)Tc-HMPAO SPECT after sodium lactate infusion (0.5 M, 5 mL/kg body weight) and 0.9% NaCl infusion, one on each of two separate days. Despite the vasodilatator effects of sodium lactate, AD rCBF patterns did not show increase in temporo-parietal regions after its infusion. AD-specific bi-temporo-parietal reduction in CBF was accompanied by further hypoperfusion in the parieto-occipital areas after the sodium lactate infusion in seven patients, while no CBF changes were observed in the case of the remaining 13 probands. The pattern of the CBF abnormalities was not correlated with the apolipoprotein E genotype. The decreased vascular responsiveness to sodium lactate reflects disturbed vasoregulatory processes in AD and it is unlikely that lactate would have any relevance in the treatment of AD-related cerebral hypoperfusion, but could be used to improve the value of perfusion SPECT in the diagnosis of AD.

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

Pákáski M, Hugyecz M, Sántha P, Jancsó G, Bjelik A, Domokos A, Janka Z, Kálmán J. · Alzheimer's Disease Research Centre, Department of Psychiatry, University of Szeged, 6 Semmelweis, H-6725 Szeged, Hungary. · Neurochem Int. · Pubmed #19428784 No free full text.

Abstract: Besides being an important component of spices used worldwide, capsaicin has wide-ranging therapeutic potential as a hypolipidemic, antioxidant and anti-inflammatory agent. Accordingly, it is very important to investigate the long-term effect of capsaicin in the pathogenesis of Alzheimer's disease. In this study, the effects of capsaicin on the processing of amyloid precursor protein (APP) were investigated in an in vivo model. The APP mRNA and protein levels were examined in the brain cortices of control and capsaicin-treated rats. The protein kinase C (PKC) translocation state in the soluble and membrane-bound fractions and the levels of beta-secretase (BACE) were also evaluated. Capsaicin enhanced the level of membrane-bound APP 1.7-fold. The APP mRNA and PKC and BACE protein levels were unchanged after capsaicin treatment. These in vivo data indicate that capsaicin is able to interfere with the brain APP metabolism by promoting the amyloidogenic route. We suggest that PKC is not involved in the mechanism underlying the effects.

Járdánházy A, Járdánházy T, Kálmán J. · Department of Neurology, University of Szeged, Szeged, Hungary. · Eur J Neurol. · Pubmed #18093154 No free full text.

Abstract: Bilateral temporo-parietal hypoperfusion and decreased glucose metabolism are characteristic in vivo findings in Alzheimer's disease (AD). Lactate is a metabolic vasodilator and is known to induce increased cerebral blood flow in healthy adults. The present study addresses the issue whether sodium lactate infusion affects functional state and resulting electroencephalographic patterns of AD patients. Twelve late-onset sporadic AD probands participated in this self-control study. The relative power and synchronization likelihood (SL) values of the electroencephalographic samples were calculated and compared off-line before and after sodium lactate infusion (0.5 M, 5 ml/kg body weight). Based on the reactivity to sodium lactate the scalp could be divided into three parts; no significant changes were seen in the seriously damaged (P3-P4) areas. The moderately affected regions in the close neighborhood showed a paradoxic inactivation with electroencephalographic slowing, a likely consequence of the metabolic-like steal effect of the near-normal areas outside. These results indicate a diminished vascular and/or metabolic reserve capacity to sodium lactate challenge in AD and confirm the formerly described electroencephalographic abnormalities.

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.

Kálmán J, Palotás M, Pákáski M, Hugyecz M, Janka Z, Palotás A. · University of Szeged, Department of Psychiatry, Hungary. · Eur J Anaesthesiol. · Pubmed #16884554 No free full text.

Abstract: BACKGROUND AND OBJECTIVE: Recent studies emphasize a positive correlation between (cardiac) surgical interventions and increased risk for developing Alzheimer's disease in the late postoperative period. Since amyloid precursor protein and its neurotoxic derivatives play key roles in the development of Alzheimer's dementia, the impact of several agents used in the intra- and perioperative period is examined. METHOD: Amyloid precursor protein concentrations were assessed by semi-quantitative Western-immunoblot in brains of rats following intraperitoneal treatment with diazepam and midazolam. RESULTS: There were no significant changes in the amyloid precursor protein concentrations. CONCLUSION: Both diazepam and midazolam are considered to be relatively safe with respect to amyloid precursor protein metabolism.

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.

Palotás M, Palotás A, Bjelik A, Pákáski M, Hugyecz M, Janka Z, Kálmán J. · Department of Psychiatry, Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, H-6721, Szeged, Semmelweis u. 6, Hungary. · Neurochem Res. · Pubmed #16258851 No free full text.

Abstract: The incidence of Alzheimer's disease is elevated after exposure to surgical interventions. Since amyloid precursor protein (APP) and its neurotoxic derivatives play key roles in the development of Alzheimer dementia, the role of general anesthesia is controversial in the development of cognitive decline. As such, the effect of anesthetics on APP protein and mRNA levels was assessed utilizing semiquantitative Western-immunoblot and reverse transcription polymerase chain reaction (RT-PCR) in brains of rats following intraperitoneal treatment with propofol and thiopental. The anesthetics did not change cortical APP protein and mRNA concentration considerably. These results indicate that both propofol and thiopental are considered to be relatively safe with respect to APP metabolism.

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.

Bari F, Tóth-Szuki V, Domoki F, Kálmán J. · Department of Physiology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Dóm tér 10, Hungary. · Microvasc Res. · Pubmed #16229865 No free full text.

Abstract: Oscillations in laser Doppler signals derived from the forehead and forearm skin were analyzed in 77 healthy probands from 4 various age groups (ranging between 15 and 77 years) and 22 late-onset sporadic Alzheimer's disease (AD) patients. A characteristic pattern of oscillations in the microcirculatory blood flux ( approximately 8 cycles/min, 0.13 Hz) was observed in the forehead skin, the occurrence of which correlated inversely with age (r = 0.80). The occurrence of forehead vasomotion pattern was 100% in the teenagers, whereas it was significantly less in the elderly control subjects (32%) and in the AD patients (18%). Forearm reactive hyperemia was provoked by 1-min occlusion of the brachial artery, and the vascular reactivity was calculated. This phenomenon also proved to be age-dependent, but the process was not related to AD. Our results indicate that the lack of forehead vasomotion reflects aging better than does the forearm vasomotion. Both of these functions are preserved in AD.

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.