Bcl-2 and Bax expression in thyroid tumours. An immunohistochemical and western blot analysis.

Bcl-2 and Bax proteins, which are involved in repressing and promoting programmed cell death, respectively, have been investigated immunohistochemically and by Western blot analysis in a series of thyroid tumours. Three immunostaining patterns were identified. Benign lesions and well-differentiated thyroid carcinomas displayed a profile similar to that of normal follicular epithelium, in which Bcl-2 immunostaining was predominant. Thyroid carcinomas associated with an aggressive behaviour, such as the tall-cell variant of papillary carcinoma and the poorly differentiated carcinomas, co-expressed both proteins. Finally, anaplastic carcinomas expressed only the Bax protein. Western blot analyses revealed that the anti-Bcl-2 antibody recognized two bands, of molecular weights 21 kDa and 25 kDa. This was only seen in the tall-cell papillary carcinomas and in the anaplastic carcinomas.

Ultrastructural characterization of oligodendroglial-like cells in central nervous system tumors.

Cells with uniform, small-round nucleus and clear cytoplasm (oligodendroglial-like cell, OLC) are commonly observed in central nervous system (CNS) neoplasm of glial and neuronal lineage, such as oligodendroglioma, clear-cell ependymoma, and central neurocytoma. Immunohistochemistry does not always contribute to the characterization of OLC because of (1) loss of antigen expression; (2) lack of specific markers for oligodendrogliomas; and (3) occasional coexpression of neuronal and glial antigens. An ultrastructural analysis associated with an immunohistochemical study of 20 cases of CNS tumors largely constituted by OLCs has been performed. Neurocytomas (12 cases), medullocytomas (2 cases), cerebral neuroblastoma (1 case), and ganglioglioma (1 case) showed OLCs with ultrastructural features of neuronal differentiation (neuritic processes, dense-core granules, synaptic structures). Oligodendroglioma (3 cases) OLCs were characterized by mitochondrial-rich cytoplasm, and ependymoma (1 case) OLCs showed microrosettes and scattered cilia. The electron microscopic analysis can provide a more precise diagnosis of these OLC-containing tumors despite their uniform morphological appearance.

Medullocytoma (lipidized medulloblastoma). A cerebellar neoplasm of adults with favorable prognosis.

This study describes three cases of neuroectodermal cerebellar neoplasms occurring in adults, characterized by a monomorphic population of round cells with scanty cytoplasm and focal areas of lipid accumulation. Astrocytic and neuronal differentiation was confirmed in these cells by glial fibrillary acidic protein and synaptophysin immunoreactivity. Electron microscopy performed in two cases showed neuritic processes, synapses, and dense-core granules. Patients included two men and one woman, and the age at diagnosis was 36, 37, and 57 years, respectively. Two patients refused any postoperative treatment. One of these had two surgically removed recurrences after 10 and 11 years and died postoperatively from intracranial hemorrhage. The second had two recurrences after 10 and 15 years and is alive and in good health at the last follow-up. The third patient received postoperative radiotherapy and is alive and well after 2 years. Review of the literature revealed seven cases of cerebellar neoplasms with histological features similar to those observed in our series. These lesions have been considered a variant of medulloblastomas. The age of patients ranged from 42 to 77 years (mean age, 51 years); four were women, 3 men. Follow-up information available in two cases indicates a 5-year survival with surgery alone. These data indicate that these cerebellar neuroectodermal neoplasms have morphologically unique features and indolent biologic behavior that distinguish them from the highly aggressive medulloblastoma; the term medullocytoma for this form is suggested.

Regional distribution of protease-resistant prion protein in fatal familial insomnia.

Protease-resistant prion protein, total prion protein, and glial fibrillary acidic protein were measured in various brain regions from 9 subjects with fatal familial insomnia. Six were homozygotes methionine/methionine at codon 129 (mean duration, 10.7 +/- 4 months) and 3 were heterozygotes methionine/valine (mean duration, 23 +/- 11 months). In all subjects, protease-resistant prion protein was detected in gray matter but not in white matter and peripheral organs. Its distribution was more widespread than that of the histopathological lesions, which were observed only in the presence of a critical amount of the abnormal protein. In the mediodorsal thalamic nucleus, however, a severe neuronal loss and astrogliosis were associated with relatively moderate amounts of protease-resistant prion protein, suggesting a higher vulnerability. There was no overall correlation between amount of protease-resistant prion protein and either glial fibrillary acidic protein or total prion protein. While protease-resistant prion protein was virtually limited to subcortical areas and showed a selective pattern of distribution in the subjects with disease of the shortest duration, it was more widespread in the subjects with a longer clinical course, indicating that with time the disease process spreads within the brain. The kinetics of the accumulation of protease-resistant prion protein varied among different brain regions: While in the neocortex and to a lesser extent in the limbic lobe and in the caudate nucleus, the amount increased with disease duration, in the mediodorsal thalamic nucleus and in the brainstem it was present in comparable amounts in all subjects regardless of the disease duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Familial progressive subcortical gliosis: presence of prions and linkage to chromosome 17.

Progressive subcortical gliosis (PSG) is a sporadic and familial dementing disease characterized pathologically by astrogliosis at the cortex-white matter junction, a feature present in some prion diseases. With immunocytochemical and Western blot analyses, we investigated the presence of deposits of the prion protein (PrP) and of the protease-resistant PrP isoform, the hallmarks of prion diseases, in six affected members of two large kindreds with PSG. The coding region of the PrP gene was sequenced and chromosomal linkage determined. We demonstrated "diffuse" PrP plaques in the cerebral cortex of two subjects from one kindred and protease-resistant PrP fragments in four of the five subjects examined. We found no mutation in the coding region of the PrP gene. Moreover, the disease was linked to chromosome 17 and not to chromosome 20, where the PrP gene resides. The familial form of PSG is the first human genetic disease characterized by the presence of protease-resistant PrP that lacks a mutation in the coding region of the PrP gene. The linkage to chromosome 17 suggests that other genes are involved in the PrP metabolism. Whether the protease-resistant PrP plays a primary or secondary role in the pathogenesis of this form of PSG remains to be determined.

Primary T-cell lymphoma of the central nervous system.

A series of 6 patients with primary T-cell lymphomas of the central nervous system (PTCLCNS) is presented. The clinical, histological and immunohistological findings are shown. The lesions were infratentorial in the 34% and sopratentorial in the 66% of the cases. Of the 5 cases with an available follow-up only one died in the first year after diagnosis and one is alive and well after 42 months. These data agree with those of others series of PTCLCNS in the literature. In conclusion our data and those of the literature suggest that immunophenotyping should routinely be carried in primary non-Hodgkin's lymphomas of the CNS (PNHLCNS), because the T-cell forms run a more favourable course than the B-cell varieties.

Non-Hodgkin lymphomas of the central nervous system. Clinico-pathologic and immunohistochemical study of 147 cases.

We report on data gathered from five European centres regarding 147 primary non-Hodgkin Lymphomas (NHLs) of the Central Nervous System (CNS) in HIV-negative patients. The results lead us to make the following considerations: i) there has been a significant and progressive increase in the frequency of observation of this pathology during the course of the last two decades; ii) the pathology lacks specific characteristic symptoms; iii) the radiological profile, as observed by CAT and/or MNR, most frequently corresponds to an isodense or slightly hyperdense lesion which has clear margins and is capable of assuming the contrast medium homogeneously; iv) the tumour most often has a single supratentorial localisation; v) high grade B-cell lymphomas account for 66% of the observations, low grade B-cell varieties being relatively rare and cases of T-cell derivation exceptional (6/147); vi) immunohistochemistry allows the differential diagnoses with respect to primitive or secondary non-lymphoid tumours, and provides confirmation of the histogenetic assessment made on morphological grounds; vii) the course of the disease is not significantly influenced by the histotype, the phenotype, the number of lesions present or the chemotherapy regimen, but rather by the employment of combined surgery and radio- or radiochemotherapy. This study represents the largest series of CNS NHLs so far reported, and as such, provides precise clinico-pathological indications which were only partially obtainable from the relatively small previously published series. Some concluding remarks are made as to the genesis of CNS NHLs, along with some practical suggestions for reaching a better understanding of their complex biology.

Rhabdoid tumours of the central nervous system. Report of three cases with immunocytochemical and ultrastructural findings.

Three cases of rhabdoid tumour of the central nervous system arising in a supratentorial location are reported. The patients were 18, 14, and 7 years old. All three tumours showed a common morphology. The neoplastic cells were usually globoid with round nuclei and prominent nucleoli and large acidophilic, cytoplasmic inclusions were present in many of them. These inclusions showed strong immunoreactivity for vimentin, weak immunoreactivity for epithelial membrane antigen and focal immunoreactivity for cytokeratins. Ultrastructurally they were made up of whorls of intermediate filaments, 8-10 nm in thickness. Rhabdoid tumours of the central nervous system, whatever the cell of origin, appear to be an independent entity with identifiable histology and aggressive behaviour.

Spinal cavernous angioma: a rare cause of subarachnoid hemorrhage.

A case of cervical intrathecal extramedullary cavernous angioma is presented. The rarity of this lesion in comparison with the more frequent vertebral cavernous angiomas with secondary extension to the epidural space is emphasized. The special features of this case are noted: the acute clinical onset due to recurrent subarachnoid hemorrhages, the visualization only by means of magnetic resonance imaging, and the unusual cervical level. The most debated characteristics of these lesions and the relevant literature are summarized.

Primary intrasellar germinoma: case report.

Intracranial germinomas arising primarily within the sella turcica are extremely rare. Preoperative diagnosis is difficult to establish even with sophisticated procedures. Diabetes insipidus is the main clinical manifestation. The authors report a case of an apparently primary intrasellar germinoma causing subclinical pituitary apoplexy in a 12-year-old boy. The transsphenoidal approach and appropriate radiotherapeutic management were employed with a good outcome.

Fatal familial insomnia: clinical and pathologic study of five new cases.

In 1986, we reported two anatomoclinical observations of a familial condition that we called "fatal familial insomnia" (FFI). We now present the pedigree as well as the clinical and neuropathologic findings in five new subjects. The pedigree includes 288 members from six generations. Men and women are affected in a pattern consistent with an autosomal dominant inheritance. The age of onset of the disease varies between 37 and 61 years; the course averages 13 months with a range of 7 to 25 months. Progressive insomnia (polygraphically proven in two cases); autonomic disturbances including hyperhidrosis, hyperthermia, tachycardia, and hypertension; and motor abnormalities including ataxia, myoclonus, and pyramidal dysfunction, were present in every case, but with variable severity and time of presentation. Sleep and autonomic disorders were the earliest signs in two subjects, motor abnormalities were dominant in one, and others had intermediate clinical patterns. Pathologically, all the cases had severe atrophy of the anterior ventral and mediodorsal thalamic nuclei. Other thalamic nuclei were less severely and inconsistently affected. In addition, most of the cases had gliosis of the cerebral cortex, a moderate degree of cerebellar atrophy with "torpedoes," and severe atrophy of the inferior olivary nuclei. One case also showed spongy degeneration of the cerebral cortex. We conclude that all the lesions were primary, and that FFI is a multisystem disease in which the different structures are primarily affected with different severity. The insomnia appears to correlate best with the major thalamic pathology. The possibility that FFI belongs to the group identified as prion diseases or diseases transmitted by unconventional agents is examined.

Fatal familial insomnia, a prion disease with a mutation at codon 178 of the prion protein gene.

BACKGROUND: We previously described two members of a family affected by an apparently genetically determined fatal disease characterized clinically by progressive insomnia, dysautonomia, and motor signs and characterized pathologically by severe atrophy of the anterior ventral and mediodorsal thalamic nuclei. Five other family members who died of this disease, which we termed "fatal familial insomnia," had broader neuropathologic changes suggesting that fatal familial insomnia could be a prion disease. METHODS: We used antibodies to prion protein (PrP) to perform dot and Western blot analyses, with and without proteinase K, on brain tissue obtained at autopsy from two patients with fatal familial insomnia, three patients with sporadic Creutzfeldt-Jakob disease, and six control subjects. The coding region of the PrP gene was amplified and sequenced in the samples from the two patients with fatal familial insomnia. Restriction-enzyme analysis was carried out with amplified PrP DNA from 33 members of the kindred. RESULTS: Protease-resistant PrP was found in both patients with fatal familial insomnia, but the size and number of protease-resistant fragments differed from those in Creutzfeldt-Jakob disease. In the family with fatal familial insomnia, all 4 affected members and 11 of the 29 unaffected members had a point mutation in PrP codon 178 that results in the substitution of asparagine for aspartic acid and elimination of the Tth111 I restriction site. Linkage analysis showed a close relation between the point mutation and the disease (maximal lod score, 3.4 when theta was zero). CONCLUSIONS: Fatal familial insomnia is a prion disease with a mutation in codon 178 of the PrP gene, but the disease phenotype seems to differ from that of previously described kindreds with the same point mutation.

Ultrastructural localization of beta-amyloid, tau, and ubiquitin epitopes in extracellular neurofibrillary tangles.

Neurofibrillary tangles (NFTs), a hallmark of Alzheimer disease, are commonly located in perikarya of neurons. In advanced cases of Alzheimer disease, however, NFTs are observed also in the extracellular space. As extracellular NFTs (E-NFTs), and occasionally intracellular NFTs (I-NFTs), are recognized by antibodies to beta-amyloid protein (beta AP), beta AP may be present not only in amyloid deposits but also in paired helical filaments (PHFs), the primary components of NFTs. We compared the antigenic characteristics of I-NFTs and E-NFTs with light- and electron-microscopic immunocytochemistry by using several antibodies to noncontiguous epitopes of the microtubule-associated protein tau and of ubiquitin (Ub) as well as an antiserum to beta AP. At variance with I-NFTs, E-NFTs were made predominantly of straight filaments (SFs), rather than PHFs, that were often separated by astroglial processes and in close association with small beta AP deposits. Occasionally, E-NFTs were made of bundles of amorphous material, which showed no resemblance to SFs, PHFs, or amyloid fibrils. The antigenic changes in E-NFTs suggest that when NFTs become extracellular they lose the N and, possibly, the C termini of tau while maintaining the intermediate region of the molecule; they also lose the N-terminal two-thirds of Ub while the C-terminal conjugation site of Ub is preserved. A small subset of E-NFTs reacted with antibodies to both beta AP and tau. Although in most E-NFTs, the epitopes recognized by tau and Ub antibodies were located in typical PHFs and SFs, the epitopes recognized in this subset of anti-beta AP and anti-tau-positive E-NFTs were located exclusively in the bundles of amorphous material. It is suggested that either beta AP epitopes are present but inaccessible in PHFs and SFs and become exposed after conformational changes occurring in the extracellular space or PHFs and SFs become closely associated with beta AP in the extracellular space.

Malignant peripheral nerve sheath tumor arising in a "de novo" ganglioneuroma. A case report.

A case of a "de novo" ganglioneuroma showing an internal area of malignant nerve sheath tumor is described. The tumor arose in an 18-year-old girl without a history of von Recklinghausen's disease. Immunohistochemically, the ganglioneuromatous component was positive with anti-synaptophysin, anti-S100 protein and anti-vimentin antisera, whereas the malignant part was immunoreactive only with anti-S100 protein and anti-vimentin antisera. The patient is free of disease 4 years after surgery. The clinicopathologic features of this rare case are discussed.

Intracranial squamous cell carcinoma arising in remnant of extirpated epidermoid cyst.

Development of a squamous cell carcinoma in an epidermoid cyst is rare. A case is presented in which such malignant change arose in the capsule remnants of an intracranial epidermoid removed 31 years previously. The limited literature dealing with this late sequela is summarized.

Paretic neurosyphilis and cerebral gumma. Case report.

A rare case of neurosyphilis presenting with dementia paralytica and radiological appearance of cerebral gumma is reported. In accordance with previous comparable reports Authors noticed that diagnosis of this disease actually is still based on serological tests and clinical examination. CT, NMR and Cerebral angiography were not able to provide diagnostic findings, although NMR confirmed its ability to detect lesions not discovered by CT scan. Also findings from stereotactic biopsy only revealed an old not active infection.

Tau-reactive neurofibrillary tangles in cerebellar cortex from patients with Alzheimer's disease.

In 4 cases of Alzheimer's disease (AD) a tau antiserum immunostained thin, round or flame-shaped profiles disposed around the nuclei of the cerebellar fusiform-type Golgi cells. In adjacent sections either a Bodian silver method or Congo red failed to reveal any abnormal structures. Since normal tau immunoreactivity is located on axons and is absent in formalin-fixed tissue, the tau-reactive profiles are likely to correspond to small masses of abnormal filaments, antigenically similar to those composing neurofibrillary tangles (NFT). This observation indicates that in AD the NFT formation is more diffuse than that showed with conventional histological methods.

Selective presence of ubiquitin in intracellular inclusions.

The authors have shown previously that ubiquitin, a protein involved in the degradation of short-lived and abnormal proteins, is present in several cytoplasmic inclusions of neurons. This study used a library of antibodies to ubiquitin and immunohistochemically examined for the presence of ubiquitin in nonviral intracytoplasmic inclusions that form in different cell types under various pathologic conditions. Membrane-bound lysosomal and nonlysosomal inclusions such as those of storage disease, Russell bodies, alpha-1-antitrypsin and alpha-fetoprotein as well as nonmembrane-bound inclusions were examined. Ubiquitin epitopes were detected in some of the nonmembrane-bound inclusions only. The ubiquitin-containing inclusions were the Rosenthal fibers, Mallory bodies, Crooke bodies, Lafora bodies, amyloid bodies, and the giant axons of giant axonal neuropathy. Nemaline bodies and the inclusions of juvenile digital fibromatosis, both of which contain actin and actinbinding proteins, did not show immunoreaction. These findings, as well as those of the previous study, show that the presence of ubiquitin in cellular inclusions is selective. The ubiquitin-containing inclusions are not membrane bound; they are fibrillary and most contain also intermediate filament-related proteins. The role of ubiquitin in the formation of these inclusions remains to be elucidated.

Ependymoma of the foramen of Monro: ultrastructural characterization.

The characteristics of clear cells of an ependymoma of the foramen of Monro have been studied by electron microscopy to precisely define its organellar composition and to establish the tumor histogenesis. Our data confirm that the once-thought oligodendroglial is, in fact, an ependymal tumor. Both the scarce number of organelles, owing to the low degree of differentiation, and the abundance of hyaloplasmic lipid vacuoles can account for the clear appearance of these tumor cells.

Ubiquitin is present on the cytokeratin intermediate filaments and Mallory bodies of hepatocytes.

To investigate the relationship of cytokeratin intermediate filaments (IFs) and Mallory bodies (MBs) to the regulatory protein ubiquitin, the griseofulvin-fed mouse was examined by double-label immunocytochemistry. In controls, immunofluorescence of hepatocytes showed that an antiserum specific to ubiquitin stained the cell border and the cytoplasm as well as the nuclear rim. In griseofulvin-fed liver cells, the MBs induced by this treatment were stained in an identical pattern by the antiserum to ubiquitin and a monoclonal antibody specific to cytokeratin (TROMA 1). Upon examination of the immunoreaction at the ultrastructural level, the ubiquitin antiserum decorated the cytokeratin filaments as well as MB filaments. Particularly striking was the coincidence of localization of TROMA 1 and ubiquitin epitopes, many IF surrounding MBs being either intensely decorated or alternatively nonimmunoreactive. These results suggest that normal cytokeratin IFs are lightly ubiquitinated, whereas MBs are heavily ubiquitinated. Immunoblot analysis of extracted cytoskeletal proteins separated by gel electrophoresis showed that extensive ubiquitination of peptides was present in the livers of the griseofulvin-fed mice. Further, the lack of ubiquitin and TROMA 1 epitopes in some liver IF suggest that loss of the TROMA 1 epitope may lead to concomitant loss of the ability to bind ubiquitin. Although the role ubiquitin plays in Mallory body formation remains to be elucidated, we suggest that its significance here may be related to its normal association with cytokeratin.