Biomedical subjects

A Jouvet

Publications and source records attributed to A Jouvet.

At least 55 records · Page 3Linked to original sources

PubMed1998

Prognostic factors in pediatric spinal cord astrocytoma.

BACKGROUND: Factors that could optimize the management of pediatric spinal cord astrocytoma remain unclear and controversial. METHODS: To determine the factors that influence the prognosis of pediatric patients with spinal cord astrocytomas, a series of 73 consecutive patients at 13 French treatment centers with histologically proven spinal cord astrocytomas was retrospectively reviewed. Hospital records, operative records, and results of radiologic investigations were available in all cases. Follow-up was achieved in 94% of cases. RESULTS: Seventy percent of the patients had low grade (1 or 2) tumors. Total or subtotal surgical resection was achieved in 43%. Thirty-six patients were irradiated following surgery. Fifty-one patients were alive at a median follow-up of 54 months. Twenty-three patients relapsed. Univariate analysis showed that good outcome was correlated with male gender, age younger than 7 years, duration of presenting symptoms longer than 2 months, the presence of spinal deformities, and low grade histology, whereas sensory loss was associated with decreased survival. Multivariate analysis using the Cox proportional hazards model confirmed that histology (relative risk [RR] = 7.69) and the interval between first symptoms and diagnosis (RR = 4.93) were significant independent prognostic factors. The extent of surgery or radiotherapy had no clear influence on survival. CONCLUSIONS: This review sheds light on the prognoses of pediatric patients with spinal cord astrocytomas and may help to determine therapeutic strategies based on patients' clinical, radiologic, and pathologic features.

Adolescent↗

PubMed1998

Dopamine synthesizing enzymes in paraventricular hypothalamic neurons of the human and monkey (Macaca fuscata).

Using immunohistochemistry, we demonstrated that paraventricular hypothalamic neurons immunoreactive for tyrosine hydroxylase (TH) were not immunopositive for the second step catecholamine synthesizing enzyme L-amino acid decarboxylase (AADC) in the human and monkey Macaca fuscata. In the latter species, they were not immunoreactive for dopamine. It is most likely that primate paraventricular TH-containing neurons do not synthesize dopamine.

Adult↗

PubMed1998

A dopamine-synthesizing cell group demonstrated in the human basal forebrain by dual labeling immunohistochemical technique of tyrosine hydroxylase and aromatic L-amino acid decarboxylase.

The human basal forebrain has been known to contain many neurons immunoreactive (ir) to tyrosine hydroxylase (TH; the first dopamine-synthesizing enzyme). We examined whether these neurons might contain aromatic L-amino acid decarboxylase (AADC; the second step dopamine-synthesizing enzyme) by dual labeling immunohistochemistry and confocal laser-scanning microscopy. Neurons dually-labeled for TH and AADC were found in the anterior olfactory nucleus, olfactory tubercle and the ventral margin of the rostral nucleus accumbens. The examination in the basal forebrain of the macaque monkey also gave substantially the same results. These neurons appear to constitute an independent dopaminergic cell group in the primate basal forebrain.

Adult↗

PubMed1998

Immunohistochemical, ultrastructural, biochemical and in vitro studies of a pineocytoma.

Using both tumor specimen and cultured tumor cells, we have studied the differentiation of a pineocytoma by light and electron microscopy (EM) and immunohistochemical demonstration of glial, neuronal and neuroendocrine markers. Only interstitial cells were labeled with anti-glial fibrillary acidic protein and anti-S100 protein antibodies. Synaptophysin, neurofilaments and tau labeling was found in cells forming the pineocytomatous rosettes. Some cells also bound the anti-tryptophan hydroxylase antibody (TPOH), but no staining was seen after application of anti-chromogranin A or S-antigen antibodies. EM provided evidence for neurosensory differentiation demonstrating the presence of vesicle-crowned rodlets, cilia (9+0) and fibrous filaments. In culture, tumor cells proliferated slowly and showed positive immunolabeling for vimentin and TPOH. Expression of mRNA coding for TPOH, serotonin N-acetyltransferase, hydroxyindole-O-methyl-transferase and c-myc was found in the tumor using reverse transcriptase-polymerase chain reaction. These results demonstrate neuronal differentiation of this pineocytoma and suggest that the neoplastic pineal cells are capable of synthesizing serotonin and melatonin.

Acetylserotonin O-Methyltransferase↗

PubMed1998

Aromatic L-amino acid decarboxylase- and tyrosine hydroxylase-immunohistochemistry in the adult human hypothalamus.

The distribution of cell bodies immunoreactive for tyrosine hydroxylase and aromatic L-amino acid decarboxylase was studied in the adult human hypothalamus. Many neurons in the posterior (A11) and caudal dorsal hypothalamic areas (A13) as well as in the arcuate (A12) and periventricular (A14) zone were immunoreactive for the two enzymes, suggesting that they were dopaminergic. Numerous tyrosine hydroxylase-immunoreactive neurons, which were not immunoreactive for aromatic L-amino acid decarboxylase, could be seen in the paraventricular, supraoptic and accessory nuclei (A15) as well as in the rostral dorsal hypothalamic area. These were considered to be non-dopaminergic. Conversely, large numbers of small neurons immunoreactive for aromatic L-amino acid decarboxylase but not for tyrosine hydroxylase, were identified in the premammillary nucleus (D8), zona incerta (D10), lateral hypothalamic area (D11), anterior portion of the dorsomedial nucleus (D12), suprachiasmatic nucleus (D13), medial preoptic area and bed nucleus of the stria terminalis (D14). In the human hypothalamus, besides dopaminergic cell bodies, there exists a large number of tyrosine hydroxylase-only and aromatic L-amino acid decarboxylase-only neurons, whose physiological roles remain to be determined.

Aged↗

PubMed1998

Gliomatosis cerebri: a rare cause of progressive headache.

A 49-year-old right-handed woman was admitted for an 8-month history of unusual headache and transient diplopia. Clinical examination and brain CT scan were normal. Two months later, symptoms of raised intracranial pressure developed and a brain CT scan showed small lateral ventricles and sulci without any abnormal contrast enhancement or tumor mass. Brain MRI with T2-weighted spin echo sequences revealed a hyperintense signal in the right temporoparietal region, whereas only a slight enlargement of this region was noted on T1 spin echo. The patient deteriorated rapidly and died with uncontrollable raised cerebrospinal fluid pressure. The diagnosis of gliomatosis cerebri was made at necropsy. Gliomatosis cerebri is a rare intracranial neoplasm of neuroepithelial origin. Spread of this tumor is particularly fast in the white matter compared with the gray matter and nuclei. Clinical symptoms are not specific. The diagnosis can be suspected by MFU showing an isointense or hypointense signal in the deep white matter on T1-weighted images, and largely a hyperitense signal on T2-weighted sequences. The diagnosis is confirmed by stereotactic biopsy or necropsy. No curative treatment is currently available. Radiotherapy can delay the rapidly fatal outcome. Our case illustrates the possible onset of this rare disease by isolated cephalgia with normal early CT scan.

Brain Neoplasms↗

PubMed1998

Chemotherapy for aggressive or anaplastic high grade oligodendrogliomas and oligoastrocytomas: better than a salvage treatment.

This series reports a pilot study of chemotherapy conducted for newly diagnosed and relapsing patients with oligodendrogliomas and oligoastrocytomas. Twenty-three patients with clinically or histologically aggressive tumours were eligible to receive procarbazine CCNU and vincristine (PCV) chemotherapy followed by radiotherapy in previously non irradiated patients. Sixteen (69%) responded to chemotherapy with complete responses in two patients and partial responses in 14. Previously irradiated patients were as likely to respond to PCV as those previously non irradiated. An over 1-year history of seizures was the main clinical prognostic factor of response. All toxicities were manageable and no treatment related deaths occurred. Chemotherapy is an effective treatment in aggressive oligodendrogliomas. Further studies must assess the role of chemotherapy in the multidisciplinary management of oligodendroglioma.

Adolescent↗

PubMed1997

Tryptophan hydroxylase mRNAs analysis by RT-PCR: preliminary report on the effect of noradrenaline in the neonatal rat pineal gland.

The levels of mRNAs coding for tryptophan hydroxylase (TPOH), the first enzyme in melatonin synthesis, have been investigated by quantitative reverse transcription of RNA, followed by polymerase chain reaction (RT-PCR), after stimulation of neonatal pineal organ cultures with Noradrenaline (NA). TPOH mRNAs were specifically amplified from various adult tissues, namely the pineal gland, raphe, retina, and kidney, but not the lung. PCR signals for TPOH were detected in the neonatal pineal gland in the absence of stimulation. Stimulation of neonatal pineal organ culture with 0.1 microM NA resulted in a significant increase (x2.5) in expression of TPOH mRNAs, whereas higher doses (1 and 10 microM) had no effect. All concentrations of NA enhanced melatonin secretion. Our results suggest that the level of TPOH mRNAs can be controlled by NA and that this effect might be implicated in the gene level regulation of the daily enzyme rhythm in the rat pineal gland.

Animals↗

PubMed1997

Demonstration of L-dopa decarboxylating neurons specific to human striatum.

In the human striatum, we immunohistochemically demonstrated many neurons that were immunoreactive for aromatic L-amino acid decarboxylase (AADC; the second step dopamine-synthesizing enzyme) but not for tyrosine hydroxylase (TH; the first step dopamine-synthesizing enzyme). The number of AADC-positive neurons was especially large in the ventral striatum including the nucleus accumbens. The significance of AADC-positive neurons are discussed in relation to the acting sites of L-dopa and antipsychotic drugs.

Adult↗

PubMed1997

Brain metastases in children with solid tumors.

BACKGROUND: Brain metastases are uncommon among children with solid tumors. However, improvements in survival have increased the period of time during which children are at risk for developing these metastases. The authors reviewed brain metastases in children with solid tumors treated at the Centre Léon Bérard during the 9 years between 1987 and 1995. METHODS: Among 486 patients with solid tumors, 162 eventually developed distant metastases in their disease process, including 12 brain metastases detected by imaging. The tumor type, clinical setting, imaging characteristics, treatment modalities, and outcome were assessed for each patient. RESULTS: The most common tumors causing brain metastases were Ewing's sarcoma (in three patients), neuroblastoma (in three patients), and osteogenic sarcoma (in three patients). At the time of initial diagnosis, 9 of the 12 patients had metastatic disease. All but one patient initially received intensive multiagent chemotherapy, including high dose chemotherapy with bone marrow rescue in six patients. The median time from initial diagnosis to the detection of brain metastases was 15 months. These metastases were clinically detectable in 10 patients and subclinical in 2 patients. Brain metastases were present at the time of first relapse in five patients. In two patients, the brain was the only site of relapse. All other patients had extensive systemic disease. Seven patients had multiple brain metastases. Two children underwent surgical resection of solitary metastases, and eight were irradiated. One child achieved complete remission following chemotherapy and irradiation. All other children died, mostly of their systemic disease, within a median period of 3 months. CONCLUSIONS: The introduction of effective systemic chemotherapy has changed the patterns of brain metastases in children. The increasing incidence of these metastases in patients with sarcoma and neuroblastoma suggests that the brain is a pharmacologically protected site in patients initially diagnosed with metastatic disease.

Adolescent↗

PubMed1997

Spinal cord compression by secondary epi- and intradural metastases in childhood.

Over a 9-year period, 35 out of 614 children with malignant tumours who were treated at the Centre Léon Bérard developed spinal metastases. Of these, 18 with known malignancies before the development of spinal cord compression are reviewed. The most common tumours causing spinal metastases were Ewing's sarcoma, neuroblastoma and renal tumours. Cord compression occurred 5-88 months after the diagnosis of systemic cancer. The median interval from first symptoms to the diagnosis of compression was 17 days. There were 16 patients with neurological deficit, including 5 with paraplegia. Specific imaging procedures were performed in 16 patients. Treatment included operation in 8 patients, followed by chemotherapy (6 patients) and/or radiotherapy (4 patients); 9 of the 10 non-operated patients received radiotherapy. Only 6 patients had a significant neurological improvement. All patients but 1 died within a median time of 2 months. Early diagnosis might prevent permanent disability in these children with a short survival expectancy.

Adolescent↗

PubMed1997

Evidence for tryptophan hydroxylase and hydroxy-indol-O-methyl-transferase mRNAs in human blood platelets.

Human blood platelets were tested for the presence of mRNAs coding for tryptophan hydroxylase (TPOH) and hydroxy-indol-o-methyl-transferase (HIOMT). Total RNA was extracted from platelets (12.9 +/- 3.3 mg RNA/100 ml blood, mean +/- SEM of 6 preparations) and cDNA synthesized by reverse transcription using random hexamers, oligo-dT or TPOH- or HIOMT-specific primers, designed to amplify a 254 bp fragment for TPOH and a 301 bp fragment for HIOMT. Positive controls were performed using RNA extracted from human normal or tumoral pineal glands. The PCR products were analyzed by gel electrophoresis, transferred to a nylon membrane and hybridized with a 32P-labeled internal probe. When random hexamers, oligo-dT or specific primers were used for reverse transcription, amplification products of the predicted sizes were detectable following electrophoresis in the case of pineal glands and following transfer and hybridization in the case of platelets. These results show TPOH and HIOMT mRNAs to be present in human blood and support the hypothesis that serotonin and melatonin may be synthesized in blood and, more particularly, in platelets.

Acetylserotonin O-Methyltransferase↗

PubMed1997

Etoposide and thiotepa followed by ABMT (autologous bone marrow transplantation) in children and young adults with high-grade gliomas.

The addition of conventional chemotherapy to irradiation has improved the outcome of children with malignant gliomas. The application of high-dose chemotherapy has been proposed as a possible way to increase the response rate and thus the survival in children with malignant brain tumours. High-dose etoposide (500 mg/m2/day x 3) and thiotepa (300 mg/m2/day x 3) followed by bone marrow transplantation were given to 22 patients (age range 4-20 years) with newly diagnosed or recurrent high-grade glioma. The response rate in the 14 assessable patients was 29% with one complete and three partial responses. 5 patients had stable disease, and 5 progressive disease. 2 patients died of treatment-related toxicity. Only 3 patients remain alive disease free 54, 60 and 65 months after high-dose therapy. For children with high-grade gliomas, survival using high-dose chemotherapy is no better than that reported with conventional treatments.

Adolescent↗

PubMed1997

Brain glucose metabolism with [18F]-fluorodeoxyglucose and positron emission tomography before and after surgical resection of epileptogenic cavernous angiomas.

Surgery of cavernous angiomas is often proposed due to the epileptogenic and hemorrhagic potential of this lesion. Little information is available on the impact of surgical resection on brain metabolism, locally or at a distance from the lesion. Fifteen patients presenting with a cavernoma and epileptic seizures underwent positron emission tomography examinations before and 1 year after surgical resection. We studied the quantitative cerebral metabolic rate of glucose (CMRGlu) with [18F]-fluorodeoxyglucose. The global brain CMRGlu remained unchanged after surgery. There was a significant decrease of metabolism in the lesion hemisphere, which remained unchanged after surgery. The perilesional regions were less metabolic than the contralateral ones and less metabolic than remote regions within the same hemisphere, before and after surgery. The absence of pre- to postsurgical variations suggests that the metabolic consequences of the lesion are maintained despite the surgical procedure during long-term follow-up studies.

Brain↗

PubMed1997

A large multiple endocrine neoplasia type 1 family with clinical expression suggestive of anticipation.

We describe a large multigenerational multiple endocrine neoplasia Type 1 (MEN1) family with clinical expression suggestive of anticipation. In the second and third generations, two deceased obligate gene carriers died at the ages of 85 and 76 without the history of MEN1, whereas two other living gene carriers above the age of 65 have had no clinical evidence of MEN1 to date. In the fourth generation, eight members were affected, with four having severe MEN1-related and atypical malignancies: a case of metastatic endocrine pancreatic tumor, two cases of metastatic thymic carcinoids, and a case of spinal ependymoma. In the fifth generation, all five patients were below the age of 22 when the disease was detected. MEN1 was confirmed in the family by linkage analysis using MEN1-linked microsatellite markers and by identification of a nonsense mutation in the MEN1/menin gene. Alleotyping showed loss of heterozygosity (LOH) involving the wild-type alleles in seven tumors in the family including the ependymoma, which is the first MEN1-related case that shows genetic abnormality in chromosome 11q13, suggesting that MEN1 gene might be involved in the tumorigenesis of a subset of ependymomas. In relation to clinical anticipation, repeated expansion studies were carried out but failed to detect any expansion. We conclude that this is a unique MEN1 family and that an unknown genetic mechanism might be contributing to the anticipation phenomenon. We demonstrate in this family that all gene carriers, including the very young members, will need close and careful follow-up.

Adult↗

PubMed1997

Percutaneous biopsy of cavernous sinus tumors through the foramen ovale.

OBJECTIVE: We present a new application to the widely used Hartel percutaneous route through the foramen ovale to the parasellar region to obtain aspiration biopsies of lesions arising from or invading the posterolateral part of the cavernous sinus. METHODS: Thirteen patients with cavernous sinus lesions that were diagnosed using imaging underwent aspiration biopsy by this route. Nine of them were subsequently operated on, and two will undergo surgery in the near future. For the remaining two, surgical removal of the tumor was not indicated. One of these two patients had a meningioma without any related symptoms and no growth revealed by repeated computed tomographic scans, and the other was diagnosed as having a nasopharyngeal carcinoma and consequently received radiotherapy. RESULTS: The accuracy of diagnosis with this technique was 84%. There was no complication related to the procedure. Having knowledge of the pathological diagnosis before determining the correct treatment helped to define the most appropriate strategy. CONCLUSION: We suggest that aspiration biopsy procedures through the foramen ovale be performed in cavernous sinus tumors before making any decision to indicate open surgical, radiosurgical, and/or radiotherapeutic treatments.

Adult↗

PubMed1997

[Assessment of procarbazine, vincristine and lomustine association (PCV protocol) in oligodendroglioma and mixed glioma].

Effective chemotherapy using PCV (procarbazine, lomustine and vincristine) has been documented in anaplastic oligodendrogliomas and oligoastrocytomas. A pilot study using PCV was conducted for relapsing patients with anaplastic oligodendrogliomas and oligoastrocytomas. Preliminary results are reported. Fourteen patients were enrolled. All received at least two courses of PCV and were evaluable for response. Eleven patients (78%) responded to chemotherapy with complete responses in 2 patients. Response was more obvious regarding contrast enhanced areas than volumes changes (11 responses versus 7). A story of seizure was the main clinical prognostic factor for response. All toxicities were manageable and no treatment related death occurred. Chemotherapy is an effective treatment in aggressive oligodendrogliomas. Further studies must assess the role of chemotherapy in the multidisciplinary management of oligodendroglioma.

Adolescent↗

PubMed1996

Cerebral oligodendrogliomas in children: an analysis of 15 cases.

The cases of 15 children operated on for cerebral pure oligodendroglioma were studied. Two groups of children were distinguished. Group I children presented with epilepsy (7 cases); their tumor was histologically benign in all cases. These children are all alive after a median follow-up of 72 months: however, 2 of them presented with a local recurrence, which was operated on, and are actually disease-free. Group 2 children presented with intracranial hypertension (8 cases); the tumor was anaplastic in 7 cases. Despite postoperative radiotherapy and chemotherapy 6 children died; their median survival time was 17 months. The present series shows the existence of a clear correlation between clinical presentation, histological grading and survival in childhood cerebral oligodendrogliomas.

Adolescent↗