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Biomedical subjects

D Gambarelli

Publications and source records attributed to D Gambarelli.

At least 37 records · Page 2Linked to original sources
PubMed1995

Development of lymphoid hyperplasia in transgenic mice expressing the HIV tat gene.

During HIV infection, individuals experience multiorgan disorders such as adenopathy, splenomegaly, and lung and brain diseases. There is an increasing body of evidence that the HIV trans-activating tat gene product possesses multiple activities. First, it can activate several cellular genes; second, in its extracellular soluble form, it plays the role of growth factor in some cells such as Kaposi's sarcoma cells. Thus, we introduced the HIV tat gene, under the control of the cellular proteolipoprotein promoter, into the germline of mice and demonstrate that, when expressed, the tat gene product induces lymphoid hyperplasia in spleen, lymph nodes, and lung, as is observed in AIDS patients, but not in the brain or testes. Our findings indicate that HIV, through some of its genes, directly participates in the pathogenesis of AIDS.

Animals↗
PubMed1995

[Progressive severity of left unilateral apraxia in 2 cases of Alzheimer disease].

Two patients presented with progressive left unilateral motor apraxia and progressive visuo-spatial difficulties, including constructional apraxia, dressing apraxia, spatial dysgraphia and dyslexia, spatial acalculia and neglect of the left side, without significant changes in the other cognitive functions. In both patients, radiological tests demonstrated cortical atrophy, more marked in the retrorolandic areas. A diagnosis of Alzheimer's disease was made in the first patient by cortical biopsy and in the second patient by post-mortem examination. The second patient died from an intercurrent neoplastic condition early in the course. Post-mortem examination of her brain showed the atrophy to be predominantly in the superior parietal gyri. In these areas, in addition to neuritic plaques and neurofibrillary tangles, these was also severe gliosis and superficial spongiosis. These two cases were clinically different from cortico-basal degeneration, where the motor difficulties are associated with occulo-motor problems, extrapyramidal signs and involuntary movements of the "alien hand" type. These data confirm the presence of focal forms of Alzheimer's disease. The motor apraxia seen in our patients resembles the kinesthesic apraxia described by Luria.

Alzheimer Disease↗
PubMed1995

[An anatomo-clinical case of dementia in endovascular large-cell lymphoma].

Cerebral angiotropic large cell lymphoma is a rare fatal neurologic disorder characterized by multifocal intravascular proliferation of large pleomorphic cells within vessels of all caliber, predominantly skin and nervous system. Clinical manifestations in previously reported cases were dominated by focal neurologic signs, epilepsia and progressive dementia. We report a case of a 70 year-old man with subacute dementia, epileptic seizures and cerebrovascular events. There was no evidence of a systemic disease outside the nervous system. Cerebrospinal fluid contained 13 leukocytes/mm3 (49% of lymphocytic cells) and more than 100 mg/dl of protein. Cytology was negative. Cranial MRI demonstrated cerebral atrophy and an increased paraventricular signal in T 2 weighted images. A frontal brain biopsy revealed only neuronal dystrophy and astrocytic gliosis. Despite treatment with corticosteroids the patient died 18 months after the onset of the first symptoms. Autopsy was performed and revealed B cell lymphoma.

Aged↗
PubMed1994

The basic domain of the lentiviral Tat protein is responsible for damages in mouse brain: involvement of cytokines.

The HIV and visna lentiviruses induce an inflammatory reaction in the central nervous system (CNS) of the infected hosts leading to dysmyelination, demyelination, and neuronal loss. The basic domain of the transactivating Tat protein has been involved in CNS damage. Infusion of basic containing domain Tat peptides in the lateral ventricle (systemic injection) or in the grey matter, i.e., hippocampus and thalamus (local injection), induced an inflammatory process characterized by the formation of an edema and invasion of macrophage accompanied by reactive astrogliosis. Control peptides originating from either lentiviral proteins or irrelevant protein as ovalbumin did not lead to any inflammatory reaction or cell death. The inflammation led to the loss of ependymal cells in the lateral ventricles and neurons in the grey matter. RNA extracted from the Tat-injected hemisphere reacted with TNF-alpha, IL-1 alpha and beta, and IL-6 probes. The macrophage/microglia inducible nitric oxyde synthase was also expressed. Blockade of TNF-alpha by a pentoxifylline treatment led to the decrease of IL-1 and iNOS expression accompanied by a reduction of the volume of the lesions indicating that the Tat-induced lesions might be mediated by TNF production.

Amino Acid Oxidoreductases↗
PubMed1994

Detection of i(17q) chromosome by fluorescent in situ hybridization (FISH) with interphase nuclei in medulloblastoma.

Medulloblastomas are the most frequent primitive neurectodermal tumors in children. An isochromosome for the long arm of 17, i(17q), is found in 30% of medulloblastomas. For some authors, this abnormality is observed in cases with a shorter survival time. In our cytogenetic studies of 30 medulloblastomas, we observed i(17q) in only three cases, a monosomy 17 in two cases, a monosomy 22 in four cases, nonspecific numerical or structural abnormalities in five cases, and normal karyotypes in 12 cases. We compared the results of karyotypic analysis after culture and FISH with a chromosome 17 alpha satellite DNA probe on interphase nuclei in five cases of medulloblastoma. In one case, i(17q) was only observed in four cells in karyotypic analysis, in three cases a normal karyotype was found, and in one case karyotypic analysis was impossible. In all of these cases, i(17q) was observed in a great number of nuclei by FISH on interphase nuclei. Our study shows that the FISH on interphase nuclei permitted us to observe i(17q) in the cases where it was not or could not be completely detected by karyotypic analysis. The association of these two techniques is required to detect i(17q), an abnormality whose prognosis value in medulloblastomas is now recognized.

Adolescent↗
PubMed1994

Platelet-derived growth factor (PDGF) and receptor (PDGFR) expression in human meningiomas: correlations with clinicopathological features and cytogenetic analysis.

PDGFs and their receptors expression were examined in a series of 46 meningiomas by using specific monoclonal antibodies. The immunostaining was quantified by an image analyser and the results correlated with clinical and morphological data (histological type and grade). In addition, since the PDGFB chain is encoded by the c-sis proto-oncogene localized on chromosome 22 and because monosomy 22 has been frequently reported in meningiomas, PDGFs and PDGFRs expression have been correlated with cytogenetic analysis performed in 29 cases. The results demonstrate PDGF A and PDGF B expression in most meningioma specimens and co-expression of these growth factors in numerous cells. PDGF A and B immunoreactivity was related to histological grade. PDGFR beta expression was strong in almost all meningiomas whereas PDGFR alpha was low. PDGFR alpha expression was related to tumour location and grade and PDGFR beta to histological subtype only. The cytogenetic analysis was not related to PDGFB chain expression. Taken together these data further confirm PDGF and PDGFR expression in human meningioma; PDGF may exist as an heterodimer (AB) as well as its receptor. The lack of correlation between cytogenetic analysis and PDGF values, the low level of PDGFB in recurrent meningiomas suggests that it is unlikely that the c-sis proto-oncogene plays an important role in the genesis of meningiomas.

Adult↗
PubMed1994

The maedi-visna virus Tat protein induces multiorgan lymphoid hyperplasia in transgenic mice.

Sheep infected with maedi-visna virus experience immunological disorders leading to progressive chronic diseases involving the brain, lung, spleen, and lymph nodes. To study the biological activity of the viral transactivating Tat protein, we generated transgenic mice carrying the tat gene. Analysis of the transgenic mouse tissues for tat mRNA revealed that while low at the messenger level, the expression of the transgene correlated with dramatic follicular lymphoproliferative disorders involving the lung, spleen, lymph nodes, and skin. This finding suggests that the viral protein possesses a high pathological potency. Our findings show that the maedi-visna virus tat gene product contributes to the pathogenesis of multiorgan proliferative disorders associated with maedi-visna virus infection.

Animals↗
PubMed1994

Choristoma of the intracranial maxillary nerve in a child. Case report.

This report describes what the authors believe to be the first reported case of choristoma of the intracranial maxillary nerve. This 12-year-old girl presented with a 5-year history of severe isolated left-sided trigeminal neuralgia. Computerized tomography and magnetic resonance imaging revealed a mass below the anterior portion of the left cavernous sinus, enlarging the foramen rotundum. Total resection was achieved via a pterional extradural approach. Histological examination revealed a choristoma composed of smooth-muscle fibers. The histogenesis of these tumors when they develop in a nerve remains unclear. They may represent abnormal migration or proliferation of neuroectodermal tissue in or close to a peripheral nerve. Total removal of these tumors should be attempted at initial diagnosis.

Actin Cytoskeleton↗
PubMed1994

[Stereotaxic biopsies of pineal tumors. Comments on their risk and implication apropos of 370 cases].

370 stereotactic biopsies of pineal region tumors, from 15 neurosurgical centers in France have been reviewed with the goal to evaluate the mortality/morbidity rates and diagnostic yield of this procedure. The impact of neuroradiological means of localisation, the probe trajectory, the type of biopsy instrument, the time of shunting are discussed in order to maximize the diagnostic yield and minimize the mortality/morbidity rates. Stereotactic biopsy contribution, as compared to other diagnostic methods, in pineal region tumors was evaluated. The mortality rate was 1.3 % (5 patients of 370), 3 patients suffered severe neurological complication. In relation to the large number of patients in this study, we can assess that the mortality rate of stereotactic biopsy in this region doesn't significantly exceed that of stereotactic brain tumor biopsies in general.

Adolescent↗
PubMed1993

Central neurocytoma: a synopsis of clinical and histological features.

The central neurocytoma is a supratentorial, often calcified brain tumour affecting young adults and is typically located in the lateral ventricles in the region of the foramen of Monro. Clinically, the tumour causes signs of increased intracranial pressure, visual and mental disturbances and, occasionally, pyramidal or endocrine symptoms. By light microscopy, the tumour is composed of small round cells in a delicate fibrillary matrix. Tumour cells consistently show features of neuronal differentiation by electron microscopy (synapses, dense-core vesicles, presynaptic clear vesicles, specialized synaptic junctions) and immunoreactivity for synaptophysin and other neuronal marker proteins. The tumour can be totally removed in nearly half of the cases. After incomplete surgical resection neurocytomas may recur but because of their low proliferation potential, radio- or chemotherapy are not generally recommended. Postoperative recurrence-free survival times of up to 19 years have been reported. Neurocytomas constitute nearly one half of supratentorial intraventricular tumours in adults but amount to less than 1% of all tumours of the central nervous system and its coverings.

Brain Neoplasms↗
PubMed1993

Walker-Warburg syndrome: a report of 3 cases.

Walker-Warburg syndrome is a congenital malformation syndrome of unknown etiology which is characterized by fatal neurological lesions. It was first described by Walker in 1942 as involving agyria, hydrocephalus and eye malformations. Its etiology has been discussed in all of the articles on the subject in the literature, but the majority of the authors describe it as an autosomal recessive syndrome. Ultrasonography plays a key role in detecting a cephalic anomaly by prenatal diagnosis as in our 2 cases. The aim of this article is to report 3 new cases of Walker-Warburg syndrome in two families. Knowledge of this syndrome emphasizes both the need for ultrasonographic observation and genetic counselling for families at risk.

Abnormalities, Multiple↗
PubMed1993

Correlation between cytogenetic and histopathological findings in 75 human meningiomas.

The correlations between cytogenetic and histopathological findings were analyzed in 75 human meningiomas. The tumors were classified according to increasing degrees of anaplasia into three grades: Grade I, benign; Grade II, atypical; Grade III, anaplastic. In 45 tumors of Grade I (benign), we more often observed a normal karyotype or monosomy 22. In 23 tumors of Grade II (atypical), we observed karyotypes with structural and/or numerical abnormalities with the presence of telomeric associations in 8 of them. These last tumors were fibroblastic. In seven Grade III tumors (anaplastic), we also observed complex abnormalities, and in one case, we observed telomeric associations. Our observations show that complex chromosome abnormalities and telomeric associations are observed in tumors that histologically display a certain degree of anaplasia. It is possible that the result of histopathological and cytogenetic correlations might represent a prognostic factor in meningiomas.

Adolescent↗
PubMed1992

Ectopic intrapelvic medulloepithelioma: case report.

A primary extraspinal medulloepithelioma with lung metastases is reported. The tumour was located in the presacral area. Microscopically, it showed typical features of medulloepithelioma with focal ependymal differentiation. Medulloepitheliomas are malignant tumours of primitive neuro-epithelium usually involving the cerebral hemispheres. This report demonstrates their possible extraspinal presacral occurrence. By immunohistochemistry, neuron-specific-enolase, S100 protein, vimentin, cytokeratin and glial fibrillary acidic protein were found in some tumour cells. Electron microscopy demonstrated poorly differentiated cells forming stratified epithelium resting on a basal lamina and short junctional complexes at the apical pole. Ultrastructural evidence of ependymal differentiation was observed. Presacral medulloepithelioma may arise from undifferentiated embryonic cells forming the presacral remnants of the neurenteric canal.

Adolescent↗
PubMed1992

Epilepsy and focal gyral anomalies detected by MRI: electroclinico-morphological correlations and follow-up.

The authors studied 10 patients (mean age 15 years 6 months) with localized developmental gyral disorder detected by MRI. There were two groups of major malformations. Seven patients (group 1) had unilateral 'macrogyric-like' insulo-opercular changes, one of whom died early in life and had extensive microgyria. The six others had mental retardation and epilepsy, three of whom had focal neurological signs. Age at onset of epilepsy varied greatly. Clinical and EEG data suggested a wider cerebral involvement than recognized on MRI. The remaining three patients (group 2) had abnormal gyri of variable topography and extension, with bulging grey matter and ventricular deformity. One had mental retardation, another had neurological signs. All had intractable complex partial seizures and focal EEG anomalies correlating with the MRI lesion site, pointing to a well-defined epileptogenic zone. No clinical or EEG evidence of significant malformation in the remaining brain tissue was observed. Ablative surgery was beneficial for one patient; focal cortical dysplasia was the pathological substrate.

Adolescent↗
PubMed1992

Sleep electroencephalogram at the early stage of Creutzfeldt-Jakob disease.

We describe sleep EEG studies in three patients at the early stage of Creutzfeldt-Jakob disease. Little work has been devoted to the study of the sleep EEG in the course of the CJ disease: disorganized sleep architecture was noted, associated with a decrease in stage 4 and an almost complete disappearance of the REM stage. Our patients were considered to have normal stage 2; yet spindles and K complexes were rare at this stage. No evolution towards stage 4 was noted. The percentage of rapid eye movement sleep was significantly low in two cases and normal in one case. Sleep disturbances in the other dementing disorders are reported.

Aged↗
PubMed1992

[Expression of adhesion molecules N.CAM, L1 and HNK1 epitope by medulloblastoma].

Twelve medulloblastomas were screened for their expression of adhesion molecules L1, N.CAM isoforms and HNK1 epitope by Western blotting and immunohistochemistry. Highly sialylated N.CAM isoforms were distinguished from total N.CAMs by using a monoclonal antibody (anti-MenB) specifically recognizing high polymers of 2-8 linked neuraminic acid. All tumors expressed HNK1 epitope, N.CAM and its highly sialylated isoforms on their surface membrane. L1 adhesion molecule was detected by immunohistochemistry in only one medulloblastoma. This spectrum of expression of cell surface adhesion molecules distinguishes medulloblastomas from other primitive neuroectodermal tumors. Medulloblastomas share some immunological features with post-mitotic cells forming the external granular layer of the cerebellum. Western blotting analysis of cerebrospinal fluid (CSF) samples with anti-MenB antibody enabled us to detect highly sialylated N.CAM in some samples. The presence of this antigen in CSF appears to correlate with meningeal spreading of medulloblastomas and could help monitoring chemotherapeutic treatment.

Antibodies, Monoclonal↗