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Biomedical subjects

R Sciot

Publications and source records attributed to R Sciot.

At least 91 records · Page 5Linked to original sources
PubMed2000

Mutation analysis of P73 and TP53 in Merkel cell carcinoma.

The p73 gene has been mapped to 1p36.33, a region which is frequently deleted in a wide variety of neoplasms including tumours of neuroectodermal origin. The p73 protein shows structural and functional homology to p53. For these reasons, p73 was considered as a positional and functional candidate tumour suppressor gene. Thus far, mutation analysis has provided no evidence for involvement of p73 in oligodendrogliomas, lung carcinoma, oesophageal carcinoma, prostatic carcinoma and hepatocellular carcinoma. In neuroblastoma, two mutations have been observed in a series of 140 tumours. In view of the occurrence of 1p deletions in Merkel cell carcinoma (MCC) and the location of p73 we decided to search for mutations in the p73 gene in five MCC cell lines and ten MCC tumours to test potential tumour suppressor function for this gene in MCC. In view of the possible complementary functions of p73 and TP53 we also examined the status of the TP53 gene. Sequence analysis of the entire coding region of the p73 gene revealed previously reported polymorphisms in four MCCs. In one MCC tumour, a mis-sense mutation located in the NH2-terminal transactivation region of the p73 gene was found. These results show that p73, analogous to neuroblastoma, is infrequently mutated in MCC. This is also the first report in which the role of TP53 in MCC has been investigated by sequencing the entire coding region of TP53. TP53 mis-sense mutations and one non-sense mutation were detected in three of 15 examined MCCs, suggesting that TP53 mutations may play a role in the pathogenesis or progression of a subset of MCCs. Moreover, typical UVB induced C to T mutations were found in one MCC cell line thus providing further evidence for sun-exposure in the aetiology of this rare skin cancer.

Base Sequence↗
PubMed1999

Inflammatory myofibroblastic tumor with HMGIC rearrangement.

Inflammatory pseudotumors or inflammatory myofibroblastic tumors (IMT) are lesions of extreme heterogeneity showing a highly variable mixture of bland-looking spindle cells, inflammatory cells, and collagen fibers. We describe our results of molecular cytogenetic and rapid amplification of cDNA ends (RACE-PCR) studies on an IMT characterized by a translocation involving 12q15. Chromosomal aberrations involving this region are very frequent among other benign tumors, such as lipomas, uterine leiomyomas, or pulmonary chondroid hamartomas. Recently, we have shown that, by these structural chromosomal aberrations, the HMGIC gene is affected. Fluorescence in situ hybridization (FISH) analysis and 3' RACE-PCR on cells of the present case of an inflammatory myofibroblastic tumor indicated an intragenic rearrangement of HMGIC, resulting in an aberrant transcript of that gene. Clonal cytogenetic aberrations have been described in very few cases of IMT. The results presented herein indicate that this case of IMT represents a true benign mesenchymal neoplasm associated with, or due to, a rearrangement of HMGIC.

Adult↗
PubMed1999

Trisomy 7 and trisomy 8 in dividing and non-dividing tumor cells in Dupuytren's disease.

Cytogenetic and molecular cytogenetic analysis is reported in a series of 40 tissue samples from 36 patients with Dupuytren's disease, presenting as palmar and/or finger nodules. No consistent structural chromosome changes could be found. Instead, recurrent clonal numerical abnormalities were demonstrated in 22 of 40 tissue nodules, involving trisomies of chromosome 7 or 8 and loss of the Y chromosome. In addition, we showed that trisomy 7 and trisomy 8 were also present in non-dividing cells.

Adult↗
PubMed1999

Diffusion-weighted MRI in sporadic Creutzfeldt-Jakob disease.

Diffusion-weighted MRI (DWI) was used in three patients with autopsy-proven sporadic Creutzfeldt-Jakob disease (CJD) to provide a rapid noninvasive way to make this sometimes confusing diagnosis. DWI prompted the diagnosis of CJD at an early stage and appears to be particularly useful for monitoring the progression of the disease. We suggest that patients with suspected CJD and no abnormalities on T2- and proton density-weighted images may have cortical involvement on DWI.

Aged↗
PubMed1999

Intramuscular mixed tumour with clonal chromosomal changes.

A case of an entirely intramuscular mixed tumour occurred in an 82-year-old man, who presented with a large mass in the region of the right triceps muscle. A lobulated tumour was seen, with plump, round epithelioid cells embedded in a chondromyxoid stroma. Immunohistochemical examination showed strong S100 protein and pancytokeratin positivity in most of the tumour cells. Cytogenetic analysis revealed complex clonal chromosomal changes: 47, XY, +i(2) (q10), -15, der(17) t(15; 17) (q11; p12), +r. Differential diagnosis against extraskeletal myxoid chondrosarcoma (EMC) may be problematic, particularly in an incisional biopsy. Chromosomal analysis can be very helpful in solving this problem, since EMC shows a specific reciprocal chromosome translocation characterised as t (9;22) (q22-31) (q11-12).

Aged↗
PubMed1999

Clonal chromosomal changes in juxta-articular myxoma.

Cytogenetic analysis of a juxta-articular myxoma revealed two distinct cytogenetically abnormal cell populations: inv(2)(p15q36) and +7, t(8;22)(q11-12; q12-13). These clonal chromosomal changes, the first to be reported in this tumour type, suggest that at least some juxta-articular myxomas are neoplastic rather than reactive in nature.

Chromosome Aberrations↗
PubMed1999

Correlation between clinicopathological features and karyotype in spindle cell sarcomas. A report of 130 cases from the CHAMP study group.

Soft-tissue tumors have proved to be a fruitful area for the identification of reproducible cytogenetic aberrations, especially among pediatric round-cell sarcomas and lipomatous tumors. Thus far, however, data regarding sarcomas of monomorphic spindle cell type have been limited and somewhat disappointing, with the notable exception of synovial sarcoma. As part of an ongoing international collaborative study, 130 karyotyped spindle-cell sarcomas were reviewed and classified histologically, without knowledge of the clinical and karyotypic data, with the aim of identifying objective correlations between morphology, karyotype, and clinical parameters. Clonal chromosomal abnormalities were identified in 82 cases studied (63%), but only in the group of synovial sarcomas was there clear correlation between the cytogenetic findings, in the form of a consistent t(X;18)(p11;q11), and morphology. Among leiomyosarcomas (41 cases) and malignant peripheral nerve sheath tumors (MPNSTs; 27 cases) as well as in individual examples of rarer entities, there was a general tendency for karyotypic complexity associated with frequent loss or rearrangement of chromosome arms 1p, 10p, 11q, 12q, 17p, and 22q. Rearrangements of 17q (the region of the NF1 gene) were seen in 9/27 (33%) of MPNSTs. Among nine cases of solitary fibrous tumor (in which previous cytogenetic data are very limited) no consistent aberrations were identified. We conclude that, with the exception of synovial sarcoma, most spindle-cell sarcomas share with pleomorphic sarcomas the tendency for karyotypic complexity. There was no indication (in most of these lesions) that detectable cytogenetic aberrations could either facilitate their diagnosis or help to determine prognosis. There is a clear need to further study and understand the significance of multiple chromosomal abnormalities in this group of mesenchymal neoplasms with the particular goal of determining their role in the process of tumor development.

Adolescent↗
PubMed1999

Prominent axonopathy in the brain and spinal cord of transgenic mice overexpressing four-repeat human tau protein.

Mutations in the human tau gene cause frontotemporal dementia and parkinsonism linked to chromosome 17. Some mutations, including mutations in intron 10, induce increased levels of the functionally normal four-repeat tau protein isoform, leading to neurodegeneration. We generated transgenic mice that overexpress the four-repeat human tau protein isoform specifically in neurons. The transgenic mice developed axonal degeneration in brain and spinal cord. In the model, axonal dilations with accumulation of neurofilaments, mitochondria, and vesicles were documented. The axonopathy and the accompanying dysfunctional sensorimotor capacities were transgene-dosage related. These findings proved that merely increasing the concentration of the four-repeat tau protein isoform is sufficient to injure neurons in the central nervous system, without formation of intraneuronal neurofibrillary tangles. Evidence for astrogliosis and ubiquitination of accumulated proteins in the dilated part of the axon supported this conclusion. This transgenic model, overexpressing the longest isoform of human tau protein, recapitulates features of known neurodegenerative diseases, including Alzheimer's disease and other tauopathies. The model makes it possible to study the interaction with additional factors, to be incorporated genetically, or with other biological triggers that are implicated in neurodegeneration.

Animals↗
PubMed1999

Embryonal rhabdomyosarcoma with only numerical chromosome changes. Case report and review of the literature.

An embryonal rhabdomyosarcoma, presenting as a retroperitoneal mass in a 15-year-old girl, is reported. The histological and immunohistochemical picture was typical, except for the presence of focal chondroid differentiation. Interestingly, expression of the "muscle markers" desmin and alpha-sarcomeric actin was present in the latter areas. Cytogenetic analysis showed a hyperdiploid karyotype without structural chromosome changes. The pertinent literature on the subject is reviewed. Hyperdiploidy of the clonal type seems to occur frequently, but no characteristic karyotype is so far emerging.

Adolescent↗
PubMed1999

Intravascular lymphomatosis of the brain: a diagnostic problem.

Intravascular lymphomatosis (of B- or T-cell origin) is a rare lymphoproliferative disorder characterised by neoplastic proliferation of lymphoid cells within the lumen of capillaries, small veins and arteries with no or minimal involvement of the parenchyma. Its predilection sites are the skin and the brain. We studied a 44-year-old man who presented with a 2 year history of unexplained LDH elevation followed by a neurological syndrome without systemic involvement. Brain biopsy showed an intravascular lymphoma of the B-cell lineage. This report illustrates the diagnostic challenge of this rare disorder with a grim prognosis.

Adult↗
PubMed1999

A retrospective study of Creutzfeldt-Jakob disease in Belgium.

Using data from Belgian neuropathological archives, completed with the results of a comprehensive study of available medical records, we found 100 patients who fulfilled diagnostic criteria for probable or definite Creutzfeldt-Jakob d1551isease (CJD). Mean age at death was 63 years. The median disease duration was 9 months. Progressive mental deterioration was present in all cases, whereas signs of cerebellar dysfunction and myoclonus were found in approximately 80% of the patients. In 50% of the population, the EEG revealed characteristic abnormalities. Ninety-six patients suffered from the sporadic type of CJD, while 4 suffered from a hereditary form. In our series, we could find no evidence for the new variant, neither for an iatrogenic cause.

Adult↗
PubMed1999

Primary malignant peripheral nerve sheath tumour of the heart.

AIMS: Malignant peripheral nerve sheath tumour (MPNST) is an unusual sarcoma of the heart and should be differentiated from other spindle cell sarcomas. METHODS AND RESULTS: We combined morphological, immunohistochemical and cytogenetic techniques in the differential diagnosis, particularly from monophasic synovial sarcoma. The tumour consisted of dense fascicles, alternating with hypocellular, myxoid zones. There was a marked herniation of tumour cells into the vascular lumen. Immunohistochemically, the tumour cells expressed vimentin and focally S100 protein. There was no expression of cytokeratin or epithelial membrane antigen (EMA). Although we found a complex karyotype, the finding of involvement of 17q11. the loss of chromosome 22, and the absence of a t(X:18)(p11.2:q11.2), which characterizes synovial sarcoma allowed us to the final diagnosis of malignant peripheral nerve sheath tumour. CONCLUSION: MPNST of the heart can be diagnosed by combining morphological and immunohistochemical data. Cytogenetics can be useful in reaching a correct diagnosis, also by helping to rule out monophasic synovial sarcoma.

Aged↗
PubMed1999

Is calcifying fibrous pseudotumor a late sclerosing stage of inflammatory myofibroblastic tumor?

Calcifying fibrous pseudotumor is a recently described distinctive lesion, characterized by the presence of abundant hyalinized collagen with psammomatous or dystrophic calcifications and a lymphoplasmacytic infiltrate. The cause and pathogenesis are unclear, but a possible relationship with other pseudotumors, like nodular fasciitis or inflammatory myofibroblastic tumor, has been proposed by some authors. However, cases with overlapping histologic features have not been reported. A 17-year-old girl with multiple peritoneal calcifying fibrous pseudotumors and inflammatory myofibroblastic tumors (inflammatory pseudotumors) is described. Some multinodular lesions showed calcifying fibrous pseudotumors next to inflammatory myofibroblastic tumors. Transitional stages between calcifying fibrous pseudotumor and inflammatory myofibroblastic tumor were also present. This case clearly illustrates a histogenetic relationship between calcifying fibrous pseudotumor and inflammatory myofibroblastic tumor, and it suggests that calcifying fibrous pseudotumor is a late sclerosing stage of inflammatory myofibroblastic tumor, at least in some cases.

Adolescent↗
PubMed1999

Cutaneous sclerosing perineurioma with cryptic NF2 gene deletion.

Sclerosing perineurioma is a recently described variant of perineurioma that characteristically occurs in the fingers and palms of young adults. We report a cutaneous sclerosing perineurioma with preservation of the axons and Schwann cells in the center of the whorls of perineurial cells, a feature that previously was reported to be typically absent in these lesions. Additionally, clonal chromosomal abnormalities of chromosome 10 and a cryptic deletion of the 5'BCR and NF2 loci on chromosome 22 were present. These findings further support the hypothesis that a gene on chromosome 22 may play a role in the pathogenesis of perineurioma. The NF2 gene is a logical candidate because of its involvement in other nerve sheath tumors.

Adolescent↗
PubMed1999

Resistance of young gelatinase B-deficient mice to experimental autoimmune encephalomyelitis and necrotizing tail lesions.

Regulated expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) plays a role in various physiological processes. To determine in vivo how unbalanced expression of these factors can promote or affect the course of pathologies, we knocked out the mouse gelatinase B gene by replacing the catalytic and zinc-binding domains with an antisense-oriented neomycin resistance gene. Adult gelatinase B-deficient mice and wild-type controls could be induced to develop experimental autoimmune encephalomyelitis (EAE) with similar scores for neurologic disease, blood-brain barrier permeability, and central nervous system histopathology. However, whereas diseased control animals showed necrotizing tail lesions with hyperplasia of osteocartilaginous tissue, adult gelatinase B-deficient mice were resistant to this tail pathology. Gelatinase B-deficient mice younger than 4 weeks of age were significantly less susceptible to the development of EAE than were age matched controls and, even as they aged, they remained resistant to tail lesions. These data illustrate that gelatinase B expression plays a role in the development of the immune system and that, in ontogenesis, the propensity to develop autoimmunity is altered by the absence of this MMP.

Age Factors↗