Biomedical subjects
Publications and source records attributed to F Giangaspero.
Cytogenetic studies on a supratentorial ependymoma from a 1-year-old boy showed a t(11;17)(q13;q21). This is the second ependymoma reported with a rearrangement at 11q13; to our knowledge the 11q13 is the first recurring breakpoint reported in ependymoma.
The frequent cytogenetic abnormality--isochromosome 17q [i(17)q]--observed in medulloblastomas (MB) may result in altered expression of the oncosuppressor gene p53 that is located on 17p. p53 expression was therefore evaluated in five MBs and in one MB cell line derived from one of these tumors. Expression levels of p53 utilizing serially diluted unfractionated RNA from tumors and the cell line were assessed both by dot-blot and by reverse transcription (RT) followed by the polymerase chain reaction (PCR). The quality of RNA, efficiency of reaction, and transcript quantitation were determined by simultaneous transcription and amplification of a similarly sized fragment of the alpha-tubulin gene. All MBs showed low levels of expression of p53 compared to those found in normal tissues. p53 messenger RNA (mRNA) was significantly increased (two- to threefold) in the MB cell line compared to its tumor of origin and to the other MBs. Immunoperoxidase studies performed with monoclonal antibodies to the p53 protein product showed focal nuclear expression in one of five of the original tumors while most cells grown in vitro and in the xenograft were positive.(ABSTRACT TRUNCATED AT 250 WORDS)
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We present four cases of infantile cerebellar neoplasms composed of cells with large vesicular nuclei with prominent nucleoli. All four cases were strongly immunoreactive for synaptophysin, and one case showed immunoreactivity for neurofilaments. Filter hybridization for N-myc and c-myc oncogenes showed a 27-fold c-myc amplification in one case. The cytogenetic analysis in this case showed Double-Minutes and isochromosome 17q. An intracerebral xenograft in nude mice obtained from one such tumor showed a similar morphology to that of the original tumor as well as strong immunoreactivity for synaptophysin and neurofilaments. All the neoplasms were characterized by highly aggressive behavior leading to early cerebrospinal fluid dissemination despite radiotherapy and chemotherapy. We conclude that large-cell medulloblastoma represents a distinct and more aggressive variant of medulloblastoma that requires more aggressive therapy.
Five cases of central neurocytomas are described. The tumors occurred in relatively young patients (range 14 to 43 years; mean age, 27) with no predilection for sex. All the lesions were located in the anterior portion of the lateral ventricles or in the third ventricle, involving the septum pellicidum or the fornix. Histologically, they were composed of uniform cells with round nuclei and clear cytoplasm resembling oligodendrogliomas or, to a lesser extent, ependymomas. In 4 tumors, protein cell nuclear antigen immunostaining showed a low cell proliferation rate. All cases were positive for neuron-specific enolase. Four of the 5 cases were strongly immunoreactive for synaptophysin. The immunohistochemical data were consistent with neuronal differentiation. Resection was subtotal in 4 cases and total in one. Postoperative radiotherapy was given in only one case. The follow-up revealed a good prognosis: 4 patients were alive and had a long survival (from 2 to 8 years). Only one patient died after 14 months for causes unrelated to the neoplasm. The authors emphasize the importance of immunohistochemistry to recognize this benign intraventricular tumor.
A permanent cell line, BO-101, was derived from a classic vermian medulloblastoma in a 9-year-old child. This line grew in vitro in adherent cultures and grew in athymic mice as serially transplantable intracranial and subcutaneous xenografts. Intracranial neoplasms grew as masses of small cells, which focally showed large cells with intense immunoreactivity for desmin, myoglobin and alpha-striated actin. The rhabdomyoblastic nature of these cells was confirmed ultrastructurally. The primary neoplasm showed immunoreactivity for synaptophysin, neuron-specific enolase and vimentin. A large panel of monoclonal antibodies and antisera against neuronal and glial antigens failed to show glial and neuronal immunoreactivity in the cell culture and xenografts. Despite the marked genotypic and phenotypic differences, the original neoplasm and the cell line share a common chromosomal marker del (12) (p 13.1). The BO-101 line differs phenotypically and genotypically from previously established medulloblastoma cell lines and further supports the heterogeneous biologic properties of the cell populations that constitute these neoplasms.
N-myc and c-myc amplification was investigated in 27 medulloblastomas. DNA was extracted from 19 formalin fixed and paraffin embedded tumors and from fresh frozen tumor tissue in 8 other cases. The results showed no evidence of amplification of N-myc oncogene and only 1 case had a 27 fold amplification of c-myc. Cytogenetically, this neoplasm presented numerous double minute chromosomes (DMs). Moreover, it had an unusual rapidly aggressive course with massive cerebrospinal fluid dissemination unresponsive to intrathecal chemotherapy. Our results indicate a low incidence of N-myc and c-myc gene amplification in medulloblastomas, suggesting that the oncogenic mechanism in these neoplasms is not closely related to DNA gene amplification. C-myc amplification, although not frequently observed, may however provide a growth advantage for medulloblastoma cells in vivo, favoring their rapid dissemination. Medulloblastomas with c-myc activation may represent a subgroup of tumors with a more aggressive behavior.
Precise data on the incidence of transforming ras oncogenes in pediatric tumors and the correlations with the histopathological properties of the tumors are very limited. Additionally the presence of ras activation in medulloblastomas has not been investigated so far. Using a combination of techniques including in vitro gene amplification by polymerase chain reaction (PCR) and detection of single base mutations by sequence-specific oligonucleotides we studied N-ras activation (mutations at codon 12, 13, and 61) in 32 medulloblastomas. DNA was isolated from 20 microns sections of formalin-fixed paraffin-embedded tissue. Mutations were found in 3 out of 32 examined medulloblastomas. In all cases only mutations of codon 61 were found: two of three mutations were C to A mutations at position 1 of the codon 61 (leading to a substitution of a glutamine residue for a lysine) and one was A to T mutation at position 3 in the same codon (glutamine-histidine). Our results indicate 10% incidence N-ras mutation in medulloblastoma, higher than in other CNS tumors studied so far. The main advantages of the procedure described are its greatly improved sensitivity, the increased speed with which tumor samples can be analyzed, and the possibility of using paraffin-embedded sections to analyze various rare tumors in retrospect.
A microfluorometric analysis was performed to analyse the DNA content of 42 medulloblastomas (MBs) and to seek correlations, if any existed, between the DNA distribution and ploidy values, neoplasm types (i.e. classic vs desmoplastic), histological features of aggressiveness, and immunocytochemical features indicating glial and/or neuronal differentiation. Thirty-one cases were classified as classic and 11 cases as desmoplastic MBs. Ten of 11 desmoplastic MBs had a near-diploid main mode and the remaining 1 case had a near-tetraploid main mode. Moreover, 10 of 11 (90%) cases showed a "monomodal" DNA distribution diagram. All these cases showed a uniform histology. In contrast, classic MBs represented a heterogeneous group of neoplasms. Twenty-two cases were near-diploid, 5 cases were near-tetraploid and 3 cases were near-triploid. The histogram type distribution showed a similar heterogeneity. Twelve of 31 (39%) cases had a monomodal histogram, 12 (39%) cases had a bimodal diagram and 7 (22%) cases a complex DNA distribution. There was a statistically significant difference (P less than 0.001) in terms of prevalence of DNA monomodal histograms between classic and desmoplastic MBs. Significant correlations were not observed among classic MBs between histological features of aggressiveness, type and degree of differentiation and DNA distribution. The present study indicates that desmoplastic MBs represent a homogeneous group of neoplasms in terms of histology and DNA distribution. In contrast, classic MBs are lesions with different degrees of histologically apparent aggressiveness and a complex DNA distribution.
Acervuli and fragments of pineal gland obtained from 33 subjects of both sexes and age ranging from 1 to 87 years, (30 autopsy and 3 biopsy specimens) were analyzed by light microscopy, transmission and scanning electron microscopy, X-ray diffraction and X-ray energy dispersive microanalysis. It was found that primary mineralization occurs in an organic matrix formed by pinealocytes and that hydroxyapatite also takes place in mineral deposition. From our analysis, the formation of acervuli appears to be age and sex independent and can be possibly related to the secretory activity of the gland.
Human immunodeficiency virus (HIV) encephalitis in children with AIDS includes a diffuse white matter disease associated with an inflammatory cell infiltrate that features multinucleated giant cells. Cerebral cortex is relatively preserved and only focal loss of Purkinje cells in the cerebellum has been observed. We describe a case of encephalitis in a child with AIDS in which there was massive and diffuse destruction of the cerebral cortex with severe neuronal loss, marked inflammatory perivascular infiltrate with abundant multinucleated cells and large pleomorphic reactive astrocytes. Similar findings were present in the basal ganglia. Moreover, the cerebellum disclosed a complete loss of Purkinje and granule cells. These findings could not be related to an ischemic mechanism or to an associated opportunistic infection. Electron microscopy showed numerous HIV particles. This case illustrates a different pattern of CNS involvement by HIV and emphasizes the destructive capacity of this neurotropic virus for neural tissue.
An immunocytochemical study using a panel of commercially available antisera, has been performed to distinguish on the basis of their immunoreactivity a series of spindle cell sarcomas diagnosed solely on the histologic features: 11 malignant schwannomas (MS), 8 leiomyosarcomas (LMS) and 3 malignant fibrous histiocytomas (MFH). The results have been compared with those obtained in 12 benign and 8 malignant peripheral nerve sheath tumors (MPNST) in which the microscopic diagnosis was supported by their origin in a nerve trunk and/or in von Recklinghausen's (vR) disease. The following antisera were used: anti-S-100 protein, anti-Leu-7, anti-neuron specific enolase (NSE), anti-myelin basic protein (MBP), anti-glial fibrillary acidic protein (GFAP) and anti-actin. S-100 protein was present in 100% of benign and malignant peripheral nerve tumors and in 7/11 (63%) of MS diagnosed on histological basis only and in 3/8 (37%) LMS. MFH were negative. Leu-7 positivity was observed in 8/12 (66%) and 6/8 (75%), respectively, in benign and malignant PNS neoplasms, in 5/11 (45%) MS, 4/8 (50%) LMS and 2/3 (66%) MFH. NSE was present in 7/12 (58%) and 6/8 (75%), respectively, in benign and malignant PNS tumors, in 6/11 (54%) MS and in 1/8 (12%) LMS. MFH were negative. MBP resulted negative in peripheral nerve neoplasms and spindle cell sarcomas. GFAP positivity was observed in 2/12 (16%) and 1/8 (12%), respectively, in benign and malignant PNS neoplasms. All spindle cell sarcomas were negative. All cases of MPNST and spindle cell sarcomas showed actin immunoreactivity. These results indicate that: (1) MBP, Leu-7 and NSE do not represent markers of schwannian differentiation; (2) GFAP, although rarely expressed, may indicate schwannian differentiation, and (3) malignant peripheral nerve neoplasms and LMS share immunoreactivity for S-100, Leu-7, NSE and actin, therefore they cannot be differentiated on immunocytochemical basis using commercially available antisera.
A histochemical and ultrastructural study was carried out on the pineal gland of 2 day- to 86-year-old subjects. Specimens were obtained by stereotaxis in the course of neurosurgery; other specimens were autoptical pineal fragments. Histochemical and ultrastructural analyses showed lipofuscin pigments, frequently localized in the proximity of blood capillaries and of cytoplasmic microacervuli. The brain sand amount does not appear to be age-related because microacervuli are barely present or frequently absent in the oldest subjects. Its involvement in the secretory activity rather than in gland atrophy is also suggested. The close relationship between cytoplasmic microacervuli and intermediate filaments suggests a possible role of the cytoskeleton in the formation of the brain sand.
Since 1924, when ependymomas were first classified as a distinctive glial neoplasm by Bailey, much has been published concerning these tumors, but there are important points of interest that are still not clear. In order to study more fully the clinical and pathologic characteristics of the ependymoma, we identified 62 patients with histologically proven neoplasms. Twenty-two were supratentorial, 21 were infratentorial, and 19 were intramedullary spinal cord tumors. These groups had mean ages of 17, 7, and 41 years, respectively, at the time of first symptoms. The presenting and accompanying symptoms were related to location and included headaches, nausea, visual changes, hemiparesis, and neck, back, and radicular pain. Neurological signs included papilledema, nystagmus, gait disturbance, cranial nerve palsies, altered mental status, paraparesis, and sensory dysfunction. Radiologic modalities of particular importance included computed tomography and myelography. Surgery and radiation therapy were the primary treatment modalities with median survival times from first symptoms being 92, 36, and 117 months for the above groups, respectively. Based on computer-generated survival curves, several characteristics significantly affected survival. These included tumor site, age, and neuraxis metastases. In patients with supratentorial tumors, cranial nerve palsies, microcystic changes, and mitotic figures were important, while in patients with infratentorial tumors, widened sutures, increased head circumference, age, epithelial features, and subependymal features significantly affected survival. Patients who had complete gross resection of a spinal cord tumor had no recurrences or mortality.
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We report a case of a 25-year-old woman affected by the acquired immunodeficiency syndrome in whom the neuropathologic examination disclosed the presence of diffuse axonal swellings in the brain stem and in selected areas of cerebral hemispheres. These lesions, although microscopically similar to those previously described as focal pontine leukoencephalopathy, differ in that their distribution was wider, there was an absence of associated necrosis of the adjacent nervous tissue, and there was a lack of calcification. It is suggested that axonal swellings represent a nonspecific reaction of the central nervous system to infection by opportunistic agents and/or human immunodeficiency virus in patients with the acquired immunodeficiency syndrome.
The DNA content of selected areas of 16 glioblastoma multiforme predominantly composed of small anaplastic cells was investigated. These findings were contrasted with those of five cases of anaplastic astrocytomas. The microfluorometric determination of DNA was performed on mechanically isolated single cells stained by the Feulgen method, obtained from selected areas of the neoplasms in paraffin blocks. Twelve of 16 cases of glioblastoma multiforme had a main population that was diploid-near diploid. Although four of the five anaplastic astrocytomas disclosed a diploid-near diploid main population there was a more complex DNA distribution than in the small cells in glioblastomas. These differences were evident using two numerical DNA indices obtained from the analysis of each tumor histogram which defined, respectively, the extent to which the main tumor cell population deviated from euploid values and the probabilities to have multiple stemlines with abnormal DNA content. The results suggest that small anaplastic cells which appear to represent the most aggressive population in glioblastomas have a DNA content diploid-near diploid, and in malignant gliomas the degree of aneuploidy of the main stemline is not related to the biologic behavior of the neoplasm.
The monoclonal antibody Ki-67, which reacts with cells in the active part of the cell cycle, was used to evaluate immunocytochemically the growth fraction in 22 primary brain neoplasms. The percentage of labelled cells reflected the histological grade of malignancy of each neoplasms. High percentage of Ki-67-positive cells were observed in one choroid plexus carcinoma (60%), one primary melanoma of meninges (40%), three medulloblastomas (40%-50%), one anaplastic astrocytoma and six glioblastomas (10%-40%). One ependymoma had 7% positive cells. Rare positive cells (1%) were present in one pilocytic astrocytoma and one ganglioglioma. Except one negative case, the meningiomas (five cases) had values of positivity ranging from 1% to 6%. Two acoustic schwannomas were negative. These results suggest that immunocytochemical staining with the Ki-67 may be a useful method for measuring the growth fraction in brain neoplasms.