Echigo-1: a panencephalopathic strain of Creutzfeldt-Jakob disease: ultrastructural studies of the optic nerve.

The Echigo-1 strain of CJD was isolated by Mori and colleagues (1989) from a case of 33-year-old female with a panencephalopathic type of CJD. An incubation period following intracerebral inoculation of hamsters with 10% cleared suspension of the Echigo-1-affected brain was approximately six months. We report here ultrastructural changes which are comparable with those in the white matter of another panencephalopathic type of CJD, the Fujisaki strain of CJD (GSS) passaged in mice.

Molecular analysis of PRNP gene in Polish population and in Creutzfeldt-Jakob disease.

In our study we have examined allelic variation of codon 129 among the Polish population as well as Polish and Dutch CJD cases. The open reading frame of the PrP gene was amplified using the polymerase chain reaction (PCR). PCR product was digested with Nsp I and Mae II endonucleases and separated by 2% agarose gel electrophoresis and, finally, sequenced by the Sanger dideoxy-mediated chain-termination method.

Deposition of the prion protein (PrP) during the evolution of experimental Creutzfeldt-Jakob disease.

We studied the immunocytochemical distribution of the prion or proteinase-resistant protein (PrP) during the evolution of experimental Creutzfeldt-Jakob disease (CJD) in mice. Fifty-one brains were collected up to 22 weeks following intracerebral inoculation with the Fujisaki strain of the CJD agent. Slides were also immunostained for apolipoprotein E (apoE) and glial fibrillary acidic protein.

The ultrastructural study of primary intracranial germ tumors.

We describe here ultrastructural and clinicopathological features of five primary intracranial germinomas. By electron microscopy, two major tumor components were defined as large, well differentiated tumor cells and non-neoplastic cells such as macrophages, astrocytes and lymphocytes. Nuclei of tumor cells were round to oval, often presented irregularly contoured nuclear membranes with oval indentations and, occasionally, cytoplasmic invagination.

Dysembryoplastic neuroepithelial tumor (DNT): an ultrastructural study of six cases.

We report six cases od DNT with a detailed ultrastructural characteristics. The patient age ranged from 7 to 16 years (mean 12), the location was temporal in three cases and frontal, temporooccipital and parietooccipital in each of one remaining cases. The predominant clinical feature in each case was history of episodes of intractable seizures.

Clinicopathological analysis of pilocytic astrocytomas and gangliogliomas in children.

We present here a clinico-pathological analysis of 58 pilocytic astrocytomas (PA) and 11 gangliogliomas (GG) based on an analysis of neuronal markers (GFAP, SYN, NFP) in these two groups of neoplasms. During the retrospective review of 58 cases recognized primarily as PA, 11 verified neoplasms demonstrated strong reaction for SYN or NFP or for both antibodies. These cases were reclassified as gangliogliomas.

Proton magnetic resonance spectroscopy of primary pediatric brain tumors: neuropathological correlation.

Forty-five children with primary brain tumors were evaluated by in vivo proton magnetic resonance spectroscopy (MRS) with the aim of detecting correlations between the obtained spectra and tumor malignancy and histology. All investigations were performed using a 1.5 T MR scanner (Picker) with point-resolved spectroscopic (PRESS) sequence (TR 1600 ms, TE 270 ms, NEX 256).

Electron microscopy in diagnosis of tumors of the nervous system.

An abbreviated catalogue of major categories of brain tumors and ultrastructural findings regarding these neoplasms are presented in short review.

Proliferation of mesaxons in the optic nerve of hamsters infected with the Echigo-l strain of Creutzfeldt-Jakob disease.

The Echigo-l strain of CJD was isolated by Mori and colleagues from a case of 33-years-old female with a panencephalopathic type of CJD. An incubation period following intracerebral inoculation of hamsters with l0 % cleared suspension of the Echigo-1-affected brain was approximately six months. We report here ultrastructural changes in the optic nerves.

The ultrastructural study of primary intracranial germ cell tumours.

We describe here ultrastructural and clinicopathological features of five primary intracranial germinomas. By electron microscopy, two major tumour components were defined as large, well differentiated tumour cells and non-neoplastic cells such as macrophages, astrocytes and lymphocytes. Nuclei of the tumour cells often presented irregularly contoured nuclear membranes with oval indentations and, occasionally, cytoplasmic invagination.

Ultrastructural pathology of a Chilean case of tropical spastic paraparesis/human T-cell lymphotropic type I-associated myelopathy (TSP/HAM).

Human T-cell lymphotropic virus type I (HTLV-I), is the cause of endemic tropical spastic paraparesis (TSP) or HTLV-I-associated myelopathy (HAM). Because TSP/HAM is not a fatal disease, the neuropathology of this disease, albeit relatively well understood, is based on the examination of just a few incidental cases. Previously, we demonstrated peculiar lamellated structures, called "multilamellar bodies" (MLB).

Biologic heterogeneity of angiomatous meningiomas.

Three angiomatous meningiomas, classified histologically as benign, were analyzed cytogenetically and examined for the expression of EGF/PDGF and their receptors by immunohistochemistry. An accumulation of p53 protein and the presence of mutations in exons 5-8 of the p53 gene in neoplastic cells were also determined. In one tumour, chromosome studies revealed near diploid karyotype with the loss of chromosome 22.

Mutations of TP53, amplification of EGFR, MDM2 and CDK4, and deletions of CDKN2A in malignant astrocytomas.

We investigated the frequency and mutual relationship of molecular alterations in 33 malignant astrocytomas (28 glioblastomas and 5 anaplastic astrocytomas). The genetic alterations analyzed were: deletion of CDKN2a/p16 gene, TP53 mutations, and amplification of EGFR, MDM2 and CDK4. The most common genetic alteration was EGFR amplification which was revealed in 15 cases (45%).

Neuroaxonal pathology in Creutzfeldt-Jakob disease.

Neuroaxonal pathology has met little attention in transmissible spongiform encephalopathies. In brains of a series of 39 consecutive Creutzfeldt-Jakob disease (CJD) cases, we detected numerous abnormal neurites that labeled for neurofilament proteins (NFP) by immunocytochemistry. Three types of abnormally NFP-accumulating structures were more prominently observed in CJD brains than in age-matched control brains: 1.

Spinal cord pathology and viral burden in homosexuals and drug users with AIDS.

Unless treated with effective antiretroviral therapy many AIDS patients develop a characteristic vacuolar myelopathy of the spinal cord associated with moderate clinical disability. Opinion is divided as to whether vacuolar myelopathy is causally linked to HIV myelitis. To investigate this further, spinal cord pathology was assessed in 41 drug users, 33 homosexual men and 16 other patients, all with AIDS.

Progressive multifocal leukoencephalopathy (PML) and cerebral toxoplasmosis in an adult patient, with no symptoms of underlying immunosuppressing illness.

We present a case of the coincidence of progressive multifocal leukoencephalopathy (PML) and central nervous system (CNS) toxoplasmosis in an adult patient, without a detectable cause of cell-mediated immunity impairment. The proper diagnosis was made postmortem on the basis of histological changes typical of both pathological processes. PML was characterized by the presence of subcortical focal demyelination, containing enlarged, densely basophilic oligodendrocyte nuclei, often with intranuclear inclusion, and bizarre astrocytes, mimicking neoplastic cells.

Atypical case of sporadic Creutzfeldt-Jakob disease (CJD) in a young adult.

The great concern exists that new variant of CJD (nvCJD) developed as a result of exposure to bovine spongiform encephalopathy (BSE)-infected meat products. Therefore, all cases of CJD in the young, as the one of ours are the matter of interest. The 21-year-old female developed a rapid progression of pyramidal, extrapyramidal and cerebellar signs, visual loss and psychiatric symptoms, leading to death in 16 weeks.

Cytogenetic changes in two cases of subependymal giant-cell astrocytoma.

Cytogenetic analysis of subependymal giant-cell astrocytomas (SEGAs) from two patients presenting the clinical symptoms of tuberous sclerosis complex (TSC) revealed clonal chromosomal changes, resulting in the partial loss of chromosome 22q in both tumors. Immunohistochemically, tumors exhibited features of glial differentiation, while ultrastructural studies identified the characteristic paracrystalline inclusions within the tumor cells. To our knowledge, it is the first cytogenetic description of SEGAs associated with TSC.

The ultrastructure of glial tumors of astrocytic lineage: a review.

In order to complete the classical descriptions of astrocytic tumors, I report here ultrastructural findings regarding this group of neoplasms. Fibrillary astrocytomas consisted of a mixture of cell bodies and their processes. Nuclei were indented and contained various types of nuclear bodies or filamentous paracrystalline inclusions.

A comparative study of epidermal growth factor receptor (EGFR) and MDM2 gene amplification and protein immunoreactivity in human glioblastomas.

The gene of epidermal growth factor receptor (EGFR) is often altered in human astrocytomas and its amplification, rearrangement and overexpression occur almost exclusively in high grade tumours (glioblastomas). MDM2 gene is amplified in a small proportion of glioblastomas, and MDM2 immunoreactivity has also been found in this group. However, the relation between gene amplification and protein overexpression depends on several factors.

Severe, early and selective loss of a subpopulation of GABAergic inhibitory neurons in experimental transmissible spongiform encephalopathies.

Little is known about the pathogenetic basis of characteristic symptoms in transmissible spongiform encephalopathies (TSEs) such as myoclonus and characteristic EEG hyperactivity. We investigated the GABAergic system and its subpopulations in mice inoculated with experimental scrapie (ME7, RML, 22A strains) and Creutzfeldt-Jakob disease (CJD; Fujisaki strain), to study damage to inhibitory neurons. Since recent studies have shown electrophysiological changes in prion protein (PrP) knockout mice, we also studied mice lacking or overexpressing the PrP gene.

A case of sporadic Creutzfeldt-Jakob disease with a Gerstmann-Sträussler-Scheinker phenotype but no alterations in the PRNP gene.

We report here an unusual sporadic case of Creutzfeldt-Jakob disease (CJD) characterized by an abundance of prion protein (PrP)-immunopositive kuru and multicentric but not florid plaques. Molecular genetic analysis of the PRNP open reading frame region spanning codons 8-221 was performed. Neither deletion nor insertion mutations were detected in the repeat area of the PRNP.

Coexistence of Alzheimer-type neuropathology in Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) and Alzheimer's disease (AD) share clinical, neuropathological, and pathogenetic features. To investigate eventual mutual influences, we screened prominently affected neocortex from 110 neuropathologically proven CJD patients for Alzheimer-type pathology with anti-beta/A4, Bielschowsky and anti-tau (immuno)stains. The neuropathological classification of Alzheimer-type pathology was made according to the CERAD criteria.

Desmoplastic cerebral astrocytoma of infancy: a case report.

We report a case of desmoplastic cerebral astrocytoma of infancy (DCAI), in a 7-month-old boy. DCAI belongs to a group of recently described central nervous system (CNS) tumors, which also includes desmoplastic infantile ganglioglioma (DIG), pleomorphic xanthoastrocytoma (PXA) and dysembryoplastic neuroepithelial tumor (DNT), all characterized by relatively favorable prognosis and occurring mostly in children and young adults. DCAI is a rare neoplasm arising in the cerebral hemispheres within the first two years of life, and histologically is characterized by dense fibrous desmoplasia.

Differential activation of total and EGF receptor (EGF-R) tyrosine kinase (tyr-k) in the rectal mucosa in patients with adenomatous polyps, ulcerative colitis and colon cancer.

Background/aims: Tyrosine kinase and a number of growth factors, especially EGF and TGF-alpha are known to stimulate proliferation in much of the gastrointestinal tract, including colon. In humans increased colonic mucosal proliferative activity has been observed in numerous premalignant lesions including adenomatous polyps and ulcerative colitis. The aim of the present study was to determine the differences of proliferative patterns in patients with adenomatous polyps, ulcerative colitis and colonic adenocarcinoma as reflected by rectal mucosa tyrosine kinase, EGF receptor tyrosine kinase and PCNA and to evaluate the role of tyr-k in colonic mucosal cell proliferation during carcinogenic process.