Biomedical subjects

H Budka

Publications and source records attributed to H Budka.

At least 37 records · Page 2Linked to original sources

PubMed2001

Expression of hypoxia-inducible factor-1 alpha in oligodendrogliomas: its impact on prognosis and on neoangiogenesis.

BACKGROUND: Hypoxia-inducible factor (HIF)1 alpha is considered to play a key role in the adaptation of cells to hypoxia by stimulating angiogenesis via regulation of vascular endothelial growth factor and by metabolic adaptation to O(2) deprivation. METHODS: Expression of HIF-1 alpha protein and p53 was investigated by immunohistochemistry in 51 specimens of supratentorial pure oligodendrogliomas. Microvessels density (MVD) was determined by anti-CD34 immunostaining. The influence of HIF-1 alpha expression on survival was investigated using univariate and multivariate analysis. RESULTS: Strong expression of HIF-1 alpha was observed in 12 (23.5%) specimens, moderate in 21 (41.2%) specimens, and weak in 8 (15.7%) cases, and no expression was found in 10 samples (19.6%). There was no correlation of HIF-1 alpha expression with histologic grading (P = 0.428, Mann-Whitney test). Hypoxia-inducible factor-1 alpha expression and MVD showed a strong correlation (P < 0.001, r = 0.735, Spearman coefficient of correlation). Overexpression of p53 was observed in only two cases. Patients with strong or moderate expression of HIF-1 alpha had a significantly shorter overall survival rate compared with those with low or no expression in univariate (P = 0.0434; log-rank test) and multivariate analysis (P = 0.0187). CONCLUSIONS: Overexpression of HIF-1 alpha indicates a diminished prognosis in oligodendrogliomas, independent of p53 status. This finding may be explained by the strong vascularization of these tumors that prevents hypoxia and allows O(2) diffusion and henceforth tumor progression.

Adult↗

PubMed2001

Serotonergic nuclei of the raphe are not affected in human ageing.

Sleep disorders increase with ageing. The serotonergic system has been linked with sleep regulation. In fatal familial insomnia, a prion disease with insomnia as one major clinical feature, we recently observed a disturbance in the serotonergic system as likely substrate of typical symptoms. Using immunohistochemistry for the serotonin synthesizing enzyme, tryptophan hydroxylase, we investigated the serotonergic median raphe nuclei (dorsal raphe nucleus, superior central nucleus, and raphe obscurus nucleus) in brains of an older (n = 12; age range 62-84 years) and a younger group (n = 10; age range 5-29 years). We found no significant difference between age groups in the percentage of neurons able to synthesize serotonin. Other changes might relate to sleep disturbances in the elderly.

Adolescent↗

PubMed2001

Prominent stress response of Purkinje cells in Creutzfeldt-Jakob disease.

To examine the role of stress-related 70-kDa heat shock proteins (Hsp-s) in Creutzfeldt-Jakob disease (CJD), we performed immunocytochemistry to detect Hsp-72 and Hsp-73, together with the abnormal (PrP(Sc)) and the presumed cellular form (PrP(C)) of the prion protein, and TUNEL method to measure cellular vulnerability in different brain regions in CJD and control cases. While Hsp-73 showed uniform distribution in all the examined samples, an increase in the number of Purkinje cells with prominent accumulation of Hsp-72 in the CJD group was observed. These neurons also showed intense PrP(C) staining, but TUNEL-positive nuclei were only detected in the granular (Hsp-72-negative) cell layer. Fewer cells of the inferior olivary nucleus were immunoreactive for Hsp-72 in CJD than in control cases, and regions showing severe spongiform change and gliosis exhibited fewer Hsp-72-immunoreactive neurons. Our results indicate that accumulation of the inducible Hsp-72 in certain cell types may be part of a cytoprotective mechanism, which includes preservation of proteins like PrP(C).

Adult↗

PubMed2001

Autoradiography with [3H]PK11195 of spinal tract degeneration in amyotrophic lateral sclerosis.

The diagnostic hallmarks of amyotrophic lateral sclerosis (ALS) are degeneration of upper and lower motor neurons and of corticospinal tracts. Here, we demonstrate the suitability of the gliosis marker [3H]PK11195 for quantitative evaluation of tract degeneration in ALS in vitro. Binding of [3H]PK11195 was increased in lateral and ventral white matter of ALS spinal cords but not in the anterior horn, in spite of a dramatic loss in muscarinic binding sites and a high level of oxidatively modified protein. Labeling of activated microglia with [11C]PK11195 may also allow tract degeneration in ALS to be visualized in vivo.

Adult↗

PubMed2001

Marked increase of neuronal prion protein immunoreactivity in Alzheimer's disease and human prion diseases.

In neurodegenerative disorders including Alzheimer's disease (AD), free radical damage to lipids, carbohydrates, proteins and DNA has been demonstrated to play a key pathogenetic role. In vitro studies have suggested a function of the cellular prion protein (PrPc) in the defense against oxidative stress. Therefore, we investigated the distribution of PrPc immunoreactivity in hippocampus (sectors CA4-CA1), subiculum (Sub), entorhinal (EC), and temporal cortex (TC) in sections from AD, human transmissible spongiform encephalopathy (TSE) and control brains. Compared to control cases, AD brains revealed an increase in the proportion of PrPc-immunoreactive neurons, which was statistically significant in CA2, Sub, and TC. In TSEs, a statistically significant increase of PrPc-immunoreactive neurons was observed in CA2, CA1, Sub, EC, and TC. In conclusion, our data show a striking up-regulation of PrPc in neurodegeneration and provide additional support for the concept that PrPc may be involved in the defense against oxidative stress.

Adult↗

PubMed2001

Deposition patterns of disease-associated prion protein in captive mule deer brains with chronic wasting disease.

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) in captive and free-ranging cervids in the USA; its origin is obscure. Archival formalin-fixed and paraffin-embedded specimens of 16 captive mule deer brains with CWD were analyzed using immunocytochemistry for the disease-associated prion protein (PrP). The most prominent pattern of PrP deposition were plaque-like structures, a substantial proportion of which were florid plaques surrounded by a rim of spongiform vacuoles. The percentage of florid plaques was highly variable according to region, ranging from 0% to 52.7%. The highest percentage was observed in the medulla and basal ganglia, the lowest in the cerebral cortex. Only three brains contained no florid plaques. There were also punctate synaptic-type and perivascular deposits, particularly in areas of severe spongiform change, and subpial and subependymal plaque-like deposits, whereas cerebellar involvement was mild. Thus, CWD brain pathology prominently features florid PrP plaques, as does variant Creutzfeldt-Jakob disease (vCJD), but differs in other characteristics from vCJD.

Amino Acid Sequence↗

PubMed2001

Immunohistochemical detection of cell growth fraction in formalin-fixed and paraffin-embedded murine tissue.

Monoclonal antibody MIB-1 is a reliable tool for determining proliferating cells in human tissues, but does not react with the homologous mouse antigen and is therefore useless in experimental pathology using mice as model systems. Standard method for assessment of cellular proliferation in formalin-fixed, paraffin-embedded murine tissues is immunohistochemical detection of DNA synthesis using antibodies against exogenously injected 5-bromodeoxyuridine (BrdU), which is a tedious procedure and not useful for routine investigations. We tested monoclonal antibody MIB-5 and monoclonal and polyclonal anti-MCM3 antibodies as immunohistochemical proliferation markers for paraffin-embedded nonneoplastic and neoplastic tissues of wild-type and transgenic mice, compared to anti-BrdU immunostaining. Percentage of proliferating cells was determined with continuously decreasing antibody dilutions. Percentages of MIB-5 and anti-BrdU immunostained cells correlated strongly, as well as percentage of MIB-5-decorated cells and frequency of mitotic figures. Anti-MCM3 antibodies labeled significantly higher percentages of cells than anti-BrdU or MIB-5, and showed a linear decrease with increasing antibody dilutions. We conclude that MIB-5 detects reliably the cell growth fraction in formalin fixed, paraffin-embedded murine tissues, bypassing methodological drawbacks of BrdU. Anti-MCM3 antibodies are less useful for determination of proliferating cells although they might detect the fraction of cells remaining competent for proliferation.

Adenoma↗

PubMed2001

Fibroblasts can express glial fibrillary acidic protein (GFAP) in vivo.

Neuropathologists use anti-glial fibrillary acidic protein (GFAP) antibodies as specific markers for glial cells, and neurobiologists use GFAP for targeting transgenes to glial cells. Since GFAP has also been detected in non-glial cells, we systematically analyzed GFAP expression in human and murine non-CNS tissues using a panel of anti-GFAP antibodies. In human tissues we confirm previously observed GFAP expression in Schwann cells, myoepithelial cells, and chondrocytes, and show for the first time GFAP expression in fibroblasts of epiglottic and auricular perichondrium, ligamentum flavum, and cardiac valves. In mice we show GFAP expression in Schwann cells, bone marrow stromal cells, chondrocytes, and in fibroblasts of dura mater, skull and spinal perichondrium, and periosteum, connective stroma of oral cavity, dental pulp, and cardiac valves. Anti-GFAP immunoblotting of human non-CNS tissues reveals protein bands with a molecular mass ranging between approximately 35 and approximately 42 kDa. In GFAP-v-src transgenic mice, whose oncogenic v-src transgene transforms GFAP expressing cells, non-CNS tumors originate from fibroblasts. We conclude that human and murine fibroblasts can express GFAP in vivo. The somatic distribution of GFAP expressing fibroblasts indicates origin from the neural crest. Development of non-CNS tumors from fibroblasts in GFAP-v-src mice functionally confirms GFAP expression in these cells.

Animals↗

PubMed2001

Inherited prion disease with A117V mutation of the prion protein gene: a novel Hungarian family.

Three members of a family with inherited prion disease are reported. One additional family member had a progressive neurological disease without details. Two developed symptoms of ataxia, dementia, myoclonus, rigidity, and hemiparesis, and one had a different phenotype with the combination of lower motor neuron deficit, parkinsonism, intellectual decline, and ataxia. In this last patient cell loss of the anterior horn motor neurons and chronic neurogenic muscle atrophy was evident. Immunostaining for the prion protein disclosed unicentric and multicentric plaques, and coarse and fine granular positivity. Genetic analysis of the prion protein gene of the propositus showed a 117 codon alanine to valine mutation and homozygous 129 valine/valine genotype.

Adult↗

PubMed2001

Nail-patella syndrome associated with respiratory chain disorder.

Nail-patella syndrome (NPS) has not been described to be associated with a respiratory chain disorder (RCD) before. In a 42-year-old man with the typical phenotype of an NPS, weakness and wasting of the shoulder girdle muscles, muscle cramps, fatigability, hyperhidrosis, chest pain and creatine kinase elevation were observed. Echocardiography revealed left ventricular hypertrabeculation. Needle electromyography was myopathic, lactate stress testing was abnormal, muscle biopsy showed typical features of an RCD and mtDNA analysis revealed the A3243G MELAS mutation. In conclusion, this case demonstrates that NPS may be randomly associated with RCD. NPS patients should undergo detailed cardiological and neurological investigations, in order not to overlook a double trouble partially mimicking NPS.

Adult↗

PubMed2001

Increased incidence of sporadic Creutzfeldt-Jakob disease on the island of Crete associated with a high rate of PRNP 129-methionine homozygosity in the local population.

Since the spring of 1997, when the Neurology Department of the University Hospital of Crete admitted its first patient, nine cases (eight neuropathologically confirmed and one probable) of sporadic Creutzfeldt-Jakob disease (sCJD) have been recorded. This represents an annual incidence five-fold higher than expected based on the island's population (0.54 million). Molecular analysis of the prion-protein gene (PRNP) showed no mutations in any of the seven CJD cases studied. Five patients (ages 64-88 years) were homozygous for methionine-129 of PRNP and showed the classic sCJD triad (subacute dementia, myoclonus, periodic electroencephalogram). Brains contained type 1 (unglycosylated 21.5 kDa band) protease-resistant prion protein (PrPres). Two patients (ages 56 and 57 years), both homozygous for valine-129, showed cerebellar ataxia and later dementia not associated with periodic electroencephalogram; brain PrPres was type 2. Genotyping of 205 Cretan controls showed that methionine-129 homozygosity, a susceptibility factor for sCJD, was significantly higher in this population than in other Caucasian populations (57.0% n = 205 vs. 41.5% n = 859, p < 0.0001). These data are the first to relate a high regional incidence rate for sCJD to the distribution of PRNP 129 genotypes in the local population; however, additional factors may be operational.

Age Factors↗

PubMed2000

Analysis of EEG and CSF 14-3-3 proteins as aids to the diagnosis of Creutzfeldt-Jakob disease.

OBJECTIVE: To improve diagnostic criteria for sporadic Creutzfeldt-Jakob disease (CJD). METHODS: Pooled data on initial and final diagnostic classification of suspected CJD patients were accumulated, including results of investigations derived from a coordinated multinational study of CJD. Prospective analysis for a comparison of clinical and neuropathologic diagnoses and evaluation of the sensitivity and specificity of EEG and 14-3-3 CSF immunoassay were conducted. RESULTS: Data on 1,003 patients with suspected CJD were collected using a standard questionnaire. After follow-up was carried out, complete clinical data and neuropathologic diagnoses were available in 805 cases. In these patients, the sensitivity of the detection of periodic sharp wave complexes in the EEG was 66%, with a specificity of 74%. The detection of 14-3-3 proteins in the CSF correlated with the clinical diagnosis in 94% (sensitivity). The specificity (84%) was higher than that of EEG. A combination of both investigations further increased the sensitivity but decreased the specificity. CONCLUSIONS: Incorporation of CSF 14-3-3 analysis in the diagnostic criteria for CJD significantly increases the sensitivity of case definition. Amended diagnostic criteria for CJD are proposed.

14-3-3 Proteins↗

PubMed2000

An autosomal dominant early adult-onset distal muscular dystrophy.

In this study we describe an autosomal dominant distal muscular dystrophy in a small Austrian family. The myopathy started in early adulthood with a slowly progressive weakness of the muscles of the anterior tibial compartment, followed by the long finger extensors and sternocleidomastoids in some family members. Other muscles were spared. Histopathology showed fiber size variation and autophagic vacuoles. This disease pattern is similar to Laing distal myopathy, which has been described previously in only one other family.

Adult↗

PubMed2000

Evidence for oxidative stress in experimental prion disease.

Oxidative stress has been shown to be important in several neurodegenerative disorders. Previous in vitro studies have already demonstrated the ability of a prion protein fragment to induce oxidative stress in cultured cells. By immunohistochemistry for nitrotyrosine (NT) and heme oxygenase-1 as markers for oxidative stress, we found widespread neuronal labeling for NT in scrapie-infected mouse brains, in agreement with peroxynitrite mediated neuronal degeneration. Damage by free radicals is a likely cause for neurodegeneration in prion disease, and antioxidants are a potential therapy of these disorders.

Animals↗

PubMed2000

Histopathology and immunohistochemistry of human transmissible spongiform encephalopathies (TSEs).

Neuropathological examination has remained the most important tool to give a definite diagnosis of human transmissible spongiform encephalopathies (TSEs). In recent years, immunohistochemistry (IHC) for the disease-associated prion protein (PrP) has emerged as an indispensable adjunct to the neuropathological confirmation of TSEs, especially in cases with equivocal histopathological changes. The clinico-pathological phenotype including histopathology and IHC for PrP depends upon PrPres fragment size and codon 129 genotype in the PrP gene, PRNP. However, some TSEs have little or no spongiform change or detectable PrP, such as fatal familial insomnia (FFI). IHC for PrP requires appropriate technique, has some pitfalls and thus should be interpreted by experienced observers. The amount and distribution of PrP deposits do not always correlate with type and severity of local tissue damage. PrP deposition occurs only where neuronal parenchyma is present; in pre-existing tissue lesions such as scarred infarctions with prominent gliosis, PrP does not accumulate. Most recently, new patterns of granular ganglionic and tiny adaxonal PrP deposits were described in the peripheral nervous system in rare human TSE cases and experimental scrapie. There is early, severe and selective loss of a peculiar parvalbumin-expressing subset of inhibitory GABAergic neurons both in human and experimental TSEs.

Brain↗

PubMed2000

Cyclooxygenase-2 is induced in microglia during chronic cerebral ischemia in humans.

Cyclooxygenase-2 (COX-2) is known to be up-regulated in ischemic rodent brains, but only little information is available for the human brain. Using immunohistochemistry for COX-2, we investigated brains from control subjects and from patients with cerebrovascular diseases. COX-2 was markedly up-regulated in the neurons and endothelial cells in acute cerebral infarction, but was detected sparsely at chronic stages in these cellular compartments. In contrast, COX-2 immunoreactivity in glial cells was localized to the perinuclear region even in control brains. This immunolabeling was more intense and occurred also in the glial cytoplasm in the brains with chronic cerebral ischemia such as Binswanger's disease. Double-labeling immunohistochemistry confirmed that COX-2-immunoreactive glia were mostly microglia. These results indicate that prostanoid synthesis is up-regulated in microglia during chronic cerebral ischemia, and that these cells may be involved in tissue repair or inflammation-mediated cell responses.

Aged↗

PubMed2000

Binswanger's encephalopathy: serial sections and morphometry of the cerebral arteries.

To identify arterial changes that are characteristic of Binswanger's encephalopathy (BE), we analyzed cerebral subarachnoid and medullary arteries of seven BE autopsy specimens by reconstruction of stained serial sections. We also noted the frequency of intimal fibrosis with or without atheroma of the subarachnoid arteries, and determined the medial thickness of the subarachnoid and medullary arteries. The results for the BE specimens were compared with those of six hypertensive brain hemorrhage (HH) specimens and six normotensive (NT) specimens from patients without cerebral abnormalities. In medullary arteries of BE in comparison with HH, we observed nonspecific but significantly more widespread intimal fibrosis with or without atheroma, as well as segmental loss of the medial smooth muscle cells (SMCs), which was sometimes associated with intimal plasma exudation or microaneurysm. A few medullary arteries in BE were completely occluded by fibrous connective tissue. Intimal fibrosis of the subarachnoid arteries was significantly more widespread in BE than in HH and NT. The media of the subarachnoid and medullary arteries was significantly thicker in BE and HH than in NT, and tended to be thicker in BE than in HH. In NT specimens the medullary arteries tended to be thinner in medial thickness than the subarachnoid arteries. These findings suggest that dysfunction of blood flow regulation due to increased arterial stiffness caused by hypertension-induced intimal fibrosis and loss of medial SMCs is an essential mechanism resulting in diffuse myelin loss of the cerebral white matter in BE, whereas luminal stenosis or occlusion and adventitial fibrosis are secondary. Moreover, selective and severe involvement of the cerebral medullary arteries compared with the subarachnoid arteries may be explained by the following two factors, (1) that many medullary arteries have normally dilated segments, and (2) that their media is thinner compared with that of the subarachnoid arteries of the corresponding diameter.

Aged↗

PubMed2000

Kynurenic acid metabolism in the brain of HIV-1 infected patients.

Patients who are infected with human immunodeficiency virus type 1 (HIV-1) frequently present with neurological and psychiatric symptoms. Kynurenic acid (KYNA), an intermediate metabolite of L-kynurenine (L-KYN), is a neuroprotectant and a broad-spectrum antagonist at excitatory amino acid (EAA) receptors. The present study examines the biosynthetic machinery of KYNA in the frontal cortex and cerebellum of 25 HIV-1 and 16 control (CO) patients. We measured the contents of L-KYN and KYNA and the activity of enzymes synthesizing KYNA, kynurenine aminotransferases I and II (KAT I and KAT II). The KYNA level was significantly increased in the frontal cortex (209 +/- 38% of CO; p < 0.05) and moderately increased in the cerebellum (164 +/- 31% of CO) of HIV-1 brains as compared with controls. The bioprecursor of KYNA, L-KYN, was increased in frontal cortex (188 +/- 45% of CO) and cerebellum (151 +/- 16% of CO; p < 0.05). The elevated KYNA in frontal cortex correlated with significant increases of KAT I (341 +/- 95% of CO; p < 0.05) and KAT II (141 +/- 8% of CO; p < 0.05). In the cerebellum, a high KYNA content was in the line with increased KAT I (262 +/- 52% of CO; p < 0.05) activity, while KAT II was in a control range (85 +/- 12% of CO). This study demonstrates that HIV-1 infection associates with elevated KYNA synthesis in the brain. In contrast to KAT II, KAT I was prominently increased in both brain regions investigated. Differences in neurochemical parameters of KYNA metabolism between frontal cortex and cerebellum suggests selective tissue damage. Drugs which influence the synthesis of the endogenous neuroprotectant KYNA may become useful in the therapy of neuropsychiatric manifestations of HIV-1 infected patients.

AIDS Dementia Complex↗