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Biomedical subjects

K Majtényi

Publications and source records attributed to K Majtényi.

12 recordsLinked to original sources
PubMed2005

Increased incidence of genetic human prion disease in Hungary.

The authors performed analysis of the prion protein gene (PRNP) in 27 out of 109 confirmed prion disease patients between 1994 and 2004. E200K mutation was found in 17 cases. Another 10 patients, lacking PRNP analysis, showed positive family history. The mean annual incidence (0.27/million) and proportion (25.6%) of genetic prion disease is unusually high in Hungary and might be related to the migration of ancestors from the Slovakian focus.

Adult↗
PubMed2003

Autopsy verifies demyelination and lack of vascular damage in partially reversible radiation myelopathy.

STUDY DESIGN: Case report of recovering radiation myelopathy. OBJECTIVE: To present autopsy and functional imaging findings on a unique case of slowly recovering radiation myelopathy with the aim of the clarification of the underlying mechanism. PATIENT: The cervical spinal cord and the distal part of the medulla oblongata of a 36-year-old thyroid cancer patient had been incorrectly irradiated with a total dose of 61 Gy and a fraction size of 3.4 Gy (J Neurol Sci 1999; 163:39-43), resulting in incomplete cervical transection with a 5-month latency period following the termination of radiotherapy. This was followed by a 9.5-year spontaneous improvement until her demise, during which the check-ups were supplemented by positron emission tomography (PET) investigations; these indicated increased [18F]deoxyglucose and [15O]butanol uptakes, but a diminished [11C]methionine accumulation by the irradiated spinal cord segment. RESULTS: Autopsy revealed demyelination (with axonal loss) and neuronal damage in the cervical spinal cord and the distal part of the medulla oblongata. In the same region, only minimal vascular injury (thickening of some of the capillary walls) was detected, but not cell proliferation or chronic inflammation. Bilateral, secondary pyramidal tract degeneration caudal to the irradiated segment was observed. The PET and autopsy findings, although separated by 2 years, are consistent. CONCLUSIONS: The pathological state of the spinal cord revealed by the autopsy is concordant with the incomplete cervical transection, implying that the functional recovery is supported by a process that probably differs from the restoration of the mechanism destroyed by the radiotherapy. For the restoration of the function, we suggest an altered conduction mechanism of the action potential, involving an increased number of sodium channels along the demyelinated segments of the injured axons, which is fully congruent with the PET findings.

Adult↗
PubMed2001

Key factors in Alzheimer's disease: beta-amyloid precursor protein processing, metabolism and intraneuronal transport.

During the last years it has become evident that the beta-amyloid (Abeta) component of senile plaques may be the key molecule in the pathology of Alzheimer's disease (AD). The source and place of the neurotoxic action of Abeta, however, is still a matter of controversy. The precursor of the beta-amyloid peptide is the predominantly neuronal beta-amyloid precursor protein. We, and others, hypothesize that intraneuronal misregulation of APP leads to an accumulation of Abeta peptides in intracellular compartments. This accumulation impairs APP trafficking, which starts a cascade of pathological changes and causes the pyramidal neurons to degenerate. Enhanced Abeta secretion as a function of stressed neurons and remnants of degenerated neurons provide seeds for extracellular Abeta aggregates, which induce secondary degenerative events involving neighboring cells such as neurons, astroglia and macrophages/microglia. Beta-amyloid precursor protein has a pivotal role in Alzheimer's disease.

Alzheimer Disease↗
PubMed2000

Can intravascular lymphomatosis mimic sinus thrombosis? A case report with 8 months' follow-up and fatal outcome.

We report a case of intravascular lymphomatosis of the brain with 8 months' follow-up and fatal outcome. Several MRI investigations revealed variegated, rapidly changing infarct-like lesions and invasion of the walls of the superior sagittal sinus and deep veins. When disturbances of the venous outflow are detected with multifocal infarct-like lesions, intravascular lymphomatosis should be considered in the differential diagnosis. Brain biopsy may ensure the proper diagnosis ante mortem, but failure of biopsy is frequent, as in our case.

Adult↗
PubMed2000

Axonal changes in chronic demyelinated cervical spinal cord plaques.

Imaging and pathomorphological studies in multiple sclerosis suggest that axonal injury and axonal loss are playing a crucial role in those with persistent disability and long-standing disease. Although the existence of axonal injury in multiple sclerosis is proven, especially in the zone of active inflammation, the effect of chronic inflammation on the axons remains elusive. The aim of this study was to perform a quantitative morphometrical analysis, estimating axonal loss and evaluating axonal degenerative changes in cervical spinal cord samples of patients suffering from secondary progressive multiple sclerosis. Completely demyelinated plaques, normal appearing white matter (NAWM) and control material from anatomically identical regions of the cord have been compared. Neurofilament immunostaining was used for identification of the axons. We observed a significant reduction of axonal density (number of axons/mm(2)) in multiple sclerosis, both in the plaque and in the NAWM compared with the control cases. Axons under approximately 3.3 microm diameter seemed to be more affected. The intensity of the immunostaining was significantly reduced in the plaque compared with either NAWM or control. Our results on the cervical cord combined with other observations support the concept of slow axonal degeneration rather than acute damage as a cause of chronic disability in multiple sclerosis.

Adult↗
PubMed1996

[Creutzfeldt-Jakob disease].

A most common form of human prion disease, also known as non-conventional slow virus diseases; Creutzfeldt-Jakob's disease is described in detail. The available data on the pathogenesis of the illness have recently changed and constitute a most exciting article of contemporary medicine. 109 cases are introduced that have been verified neuropathologically in Hungary until now; their summed up clinical data, the pathological findings and their epidemiological characteristics are discussed. It must be emphasized that the diagnosis of the illness cannot be inevitably confirmed clinically. Transplantation of organs or tissues of all deceased, who suffered of an illness with dementia, should be strictly avoided accordingly.

Creutzfeldt-Jakob Syndrome↗
PubMed1995

[Non-ketotic hyperglycinemia].

Three children with non-ketotic hyperglycinaemia (NKH) is reported. Two patients had typical neonatal form of NKH, one patients had atypical form of NKH. The clinical symptoms laboratory findings and therapeutical approach are discussed. One of the patients with typical neonatal form of NKH is died, neuropatological examination revealed corpus callosal agenesis and diffuse hypomyelinisation. The two children treated with N-methyl-D-aspartate-antagonist drugs reached a significantly better clinical condition. The authors reviewed the data of the literature, especially focused on the therapeutical possibilities.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

[Wernicke encephalopathy in childhood osteosarcoma].

Two children with osteosarcoma are presented in whom Wernicke encephalopathy with vomiting occurred during the chemotherapy. One of the children died with symptoms of toxic cardiomyopathy. Autopsy revealed Wernicke encephalopathy. The other child had similar symptoms (ocular signs, ataxia, somnolence). Parenteral thiamine had been given and after this therapy the child recovered from the encephalopathy. The authors emphasize the importance of the recognition of this neurological disorder occurring rarely in childhood: it can be cured with parenteral thiamine. Without thiamine treatment this condition is lethal.

Adolescent↗
PubMedDate not supplied

Apolipoprotein E polymorphism in Pick's disease and in Huntington's disease.

The polymorphism of apolipoprotein E (apoE) has been recognized as a genetic risk factor in different neurodegenerative disorders, with or without tau protein- related neuropathology, but few published epidemiological data are available as concerns the association of different apoE alleles with two relatively rare forms of dementia, Pick's disease (PiD) and Huntington's disease (HD). In this study the frequency of the apoE4 allele was examined in 36 persons with histopathologically proven PiD and compared with that of the apoE genotype in 28 HD probands and 79 aged healthy controls. The E4 allele was overrepresented selectively in PiD (42%) as compared with the control population (7%). No such association was found for HD probands (9%). This finding lends further support to the hypothesis that the E4 genotype is not an Alzheimer's disease specific susceptibility factor, and that it could be present in diverse dementing disorders with tau protein related neuropathology, such as PiD.

Aged↗