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Biomedical subjects

A Jouvet

Publications and source records attributed to A Jouvet.

At least 73 records · Page 4Linked to original sources
PubMed1996

Dopamine-beta-hydroxylase and tyrosine hydroxylase immunoreactive neurons in the human brainstem.

Immunohistochemistry of dopamine-beta-hydroxylase in the human hind brain indicates that neuronal cell bodies containing the antigen form prominent populations in the nucleus tractus solitarius and nearby medial and dorsal edge of the medial vestibular nucleus. They are frequent in and around the periphery of the dorsal motor nucleus of the vagus and in an oblique band extending from that region to the ventrolateral aspect of the reticular formation, where they are most numerous at the mid medullary levels. Dopamine-beta-hydroxylase immunoreactive neurons are also closely packed in the nuclei coeruleus and subcoeruleus. Concomitant immunohistochemistry for tyrosine hydroxylase demonstrates small numbers of neuronal cell bodies that are reactive only for this antigen, and which do not contain detectable dopamine-beta-hydroxylase. Such neurons are present in the nucleus tractus solitarius, the pontine lateral parabrachial nucleus and within the core of the rostral pontine reticular formation. Some medullary and pontine axon bundles similarly stain for tyrosine hydroxylase but not for dopamine-beta-hydroxylase. These differential staining patterns suggest, among other possibilities, that in humans some neurons of the caudal brainstem are dopamine (if they contain the second step catecholamine synthesizing enzyme, aromatic L-aminoacid decarboxylase) rather than noradrenaline or adrenaline containing catecholamine neurotransmitters.

Aged↗
PubMed1996

Nycthemeral expression of tryptophan hydroxylase mRNAs in the rat pineal gland.

The expression of mRNAs coding for tryptophan hydroxylase (TPOH), the first enzyme involved in melatonin synthesis, has been studied in the rat adult pineal gland at four different circadian time points by in-situ hybridization using an oligonucleotide probe. TPOH mRNAs were detected at all chosen time-points. The lowest level was seen at 13:00 h. Quantification of the hybridization signals demonstrated a significant increase in expression (+16.5%) between 13:00 h and 19:30 h, with the values at 23:30 h and 09:00 h being similar to that of 19:30 h. These results coincide with the nycthemeral rhythm of TPOH activity. Day/night rhythms in the rat pineal gland are controlled by noradrenaline release at lights-off, which results in an increase in cAMP levels and in gene activation. This study suggests that the TPOH gene might be one such gene whose activation is stimulated in this way.

Animals↗
PubMed1995

CT-guided needle biopsy of intracranial tumours: results in 118 consecutive patients.

The purpose of this paper is to evaluate the efficacy and safety of CT-guided needle biopsies and to determine the optimal indications for this technique. The case histories of 118 patients who underwent a CT-guided biopsy for brain lesions during a six-year period, from November 1986 to September 1992, were reviewed. During a preliminary CT-scan, the entry site was determined and localized using a radio opaque marker and the safest route to the lesion was chosen. One hundred and thirty four procedures were performed in 118 patients. A positive diagnosis of tumour was obtained in 106 patients (89.8%). Repeat procedures were required in 18 patients. High-grade gliomas were the more common lesions (55.1%). Morbidity and mortality was assessed over the 30-day period after the procedure. Nine patients died during this time. Eight patients from day 3 to day 30 in the expected course of their disease and one within 48 first hours from neurological deterioration following the procedure. We found that CT-scan guided biopsies are a safe and accurate way to obtain brain tissue specimens for pathological diagnosis in selected cases. For superficial and large tumours it is a simple, fast and effective procedure.

Adolescent↗
PubMed1995

Developmental expression of tryptophan hydroxylase mRNAs in the rat pineal gland: an in situ hybridization study.

The expression of messenger RNAs encoding for tryptophan hydroxylase (TPOH), the first enzyme involved in serotonin and melatonin synthesis, has been investigated by in situ hybridization during the development of the rat pineal gland. TPOH mRNAs were detected as early as the twentieth day of gestation (E20) in the rat embryo before any nerve ending was observed in the pineal gland. After birth, their expression increased strongly, and attained a plateau during the second week. This coincides with the setting up of sympathetic innervation. From day 17 (D17), the TPOH mRNA expression diminished. These results indicate that noradrenergic innervation is not involved in the initiation of rat pinealocyte differentiation, but might modulate cell maturation. This study showed the existence of three types of cells arranged in patches in the young rat pineal gland (D6): regions in which cells expressed TPOH mRNAs, regions in which cells expressed vimentin, an intermediate filament protein present in the cytoskeleton of immature cells, and regions in which both TPOH mRNAs and vimentin are expressed. In older rat pineal gland (D20), almost all cells express TPOH mRNAs, and some cells still express vimentin. This suggests that all cells do not reach the same level of differentiation at the same time in the rat pineal gland.

Animals↗
PubMed1994

Structural and ultrastructural characteristics of human pineal gland, and pineal parenchymal tumors.

We have studied 20 pineal parenchymal tumors (PPT) and 4 normal or cystic pineal glands both by light and electron microscopy and immunohistochemistry with antibodies against glial markers [glial fibrillary acidic protein (GFAP) and protein S-100] or neural/neuroendocrine markers [neurofilaments (NF), synaptophysin and chromogranin A]. Light microscopy revealed the cellular organization of pinealocytes in the normal gland and in different morphological types of pineal tumors (typical pineocytomas, PPT with intermediate differentiation, mixed PPT exhibiting elements of both pineocytoma and pineoblastoma and pineoblastomas). Immunohistochemistry showed the presence of GFAP and protein S-100 in interstitial cells in non-neoplastic pineal gland. Cell processes were labeled with anti-synaptophysin and anti-NF antibodies. No immunoreactivity was found for chromogranin A in non-neoplastic pineal gland. In pineocytomas, GFAP and protein S-100 were observed in interstitial cells. Synaptophysin and NF were present in the large rosettes of pineocytomas. Synaptophysin, NF and chromogranin A were present in pineocytomas with a lobular arrangement of cells. Anti-chromogranin A immunoreactivity was also seen in lobular areas of some PPT with intermediate differentiation. Analysis of normal human pineal gland by electron microscopy showed the presence of vesicle-crowned rodlets (VCR or synaptic ribbons), fibrous filaments (F), paired twisted filaments but few dense-core vesicles (DCV) in normal pinealocytes. Tumoral pineal cells appeared to differentiate either towards a neurosensory pathway characterized by the presence of sensory cells elements (VCR and F), or towards a neuroendocrine pathway, with the occurrence of many DCV. Immunogold labeling demonstrated the presence of chromogranin A in neurosecretory granules.

Adolescent↗
PubMed1994

Tectal plate gliomas. Part I: Microsurgery of the tectal plate gliomas.

A series of 12 patients with tectal plate gliomas, is presented treated by direct surgery. Mean age was 19 years. All patients presented with signs of raised intracranial pressure and supratentorial hydrocephalus on CT scan. Diplopia was the most common local sign. CT scan and MR imaging showed 4 intrinsic, 6 exophytic, and 2 ventrally infiltrating tectal tumours. The histological diagnosis was low-grade astrocytoma in 7, high-grade astrocytoma in 2, oligodendroglioma in one, oligo-astrocytoma in one, and ependymoma in one case. The suboccipital supra- and transtentorial approach was used in every cases. Tumour resection was generous at the level of the superior colliculi, but on the contrary, resection was limited at the level of inferior colliculi due to the auditory risk. Tumour removal was total (macroscopically) in 9 cases and partial in 3 cases. There were 4 surgical complications and one death related to surgery. Parinaud's syndrome was the most-common postoperative sequelae. Auditory hallucinations and the acoustic neglect syndrome were seen once. In three cases additional radiotherapy and chemotherapy were given once with severe sequelae. The treatment of tectal plate gliomas is controversial. The role of different therapeutic options remains open. We consider the tectal plate as a relatively safer territory for surgery than the ventral part of the midbrain. The brain stem auditory evoked potentials (BAEPs) and middle latency potentials (MLPs) monitoring can help to determine the appropriate limit of surgery.

Adolescent↗
PubMed1994

Tectal plate gliomas. Part II: CT scans and MR imaging of tectal gliomas.

CT scans and MR images were analyzed in 12 patients with histologically proved tectal plate gliomas. In an attempt to identify the nature of these lesions, their radiological characteristics were correlated with the histological results. In four of our patients CT scan failed to show the tumour. MR imaging demonstrated the tectal distortion in all cases. Contrast enhancement, calcification, cystic portions, exophytic nature were observed in both high and low-grade gliomas. We conclude that in the case of intrinsic tectal tumours, the most probable diagnosis is that of low-grade astrocytoma while in the case of exophytic tectal tumours, the differential diagnosis from pineal region tumour is required and a histological verification is necessary.

Adolescent↗
PubMed1993

Successful treatment for a metastatic supratentorial malignant rhabdoid tumor.

The case of a boy with a familial history of Rendu-Osler disease, who successively developed a cerebellar pilocytic astrocytoma (at 3 years of age) and a metastatic supratentorial malignant rhabdoid tumor (at the age of 12 years) is reported. After a complete surgical removal, the CSF was cleared by 4 courses of chemotherapy, and the child received a craniospinal irradiation. He is currently alive and well 19 months after completion of the treatment. The authors discuss the ethiopathogeny of such intracranial tumors and argue for aggressive treatment.

Astrocytoma↗
PubMed1993

A new point mutation in the prion protein gene at codon 210 in Creutzfeldt-Jakob disease.

We screened 16 cases of sporadic Creutzfeldt-Jakob disease (CJD) and 28 healthy control subjects to detect possible polymorphisms in their prion protein gene (PRNP). The molecular analysis of the PRNP coding sequence was performed using denaturing gradient gel electrophoresis of polymerase chain reaction products and direct sequencing. We identified (1) a silent mutation at codon 177 in a healthy individual, (2) a codon 200 glutamate-to-lysine substitution in a 48-year-old CJD-affected Libyan Jew, and (3) a G-to-A point substitution at codon 210, leading a valine-to-isoleucine change, in a 63-year-old French CJD patient. This new mutation occurs in a highly conserved part of the PRNP coding sequence, close to the known CJD-associated codon 200 mutation, and might be linked to a symptomatologic and neuropathologic pattern of typical sporadic CJD. This mutation was also present in a sister of the patient who died at the age of 67 without neurologic symptomatology.

Aged↗
PubMed1993

[Association of amyotrophic lateral sclerosis and multiple sclerosis].

A twenty-five year old woman developed a progressive right hemiparesis which remitted within three months, without treatment. The diagnosis was a first relapse of multiple sclerosis. After a 10 year fully asymptomatic period, the patient developed weakness of the legs with falls and swallowing difficulties. Fasciculations and amyotrophy were present in the limbs and the tongue. There were no sensory abnormalities. The electromyogram confirmed the peripheral neurogenic degeneration with signs of anterior horn involvement. Motor and sensory nerve conductions were normal. Muscle weakness and atrophy increased in the limbs and the bulbar territory and the patient died nine months later. The autopsy showed characteristic "old" plaques of multiple sclerosis in the cerebrum with anterior horn cell and pyramidal tracts degeneration, typical of amyotrophic lateral sclerosis, in the spinal cord. Although exceptional, this association of amyotrophic lateral sclerosis and multiple sclerosis leads to the discussion of an etiological immunological dysregulation common to these two diseases.

Adult↗
PubMed1992

Encephalitis in cat scratch disease with persistent dementia.

Encephalitis in cat scratch disease is uncommon and usually reversible. The patient with cognitive impairment and severe memory disorder did not improve after a 30 month follow up. MRI revealed disseminated lesions in the white matter of the cerebral hemispheres.

Anti-Bacterial Agents↗
PubMed1992

Cryptic angioma in the trochlear nerve. Excision of the invaded portion and successful repair with an autologous graft: case report.

Cryptic angiomas, which are intrinsic to cranial nerves, are uncommon. Such lesions involving the trochlear nerve have not been previously described. The authors have therefore found it interesting to report a case fortuitously discovered in a patient with trigeminal neuralgia who underwent a fifth nerve microvascular decompression through the supracerebellar space. The angioma was not responsible for the neuralgia, but because of its potential risk of bleeding, the lesion was treated by resection of the trochlear nerve in its invaded portion. Then, the nerve was successfully repaired with an autograft harvested from the distal part of the sural nerve.

Aged↗
PubMed1992

[Bilateral thalamic glioma. A clinicopathological study of 2 cases].

Two cases of bilateral thalamic glioma in a 70 year-old man and a 8 year-old boy, documented by MRI and pathological data are reported. Such tumors are rare. Early symptoms may be misleading, with intellectual impairment or psychiatric disorders together with a normal CT scan. MRI and pathological findings support the view that bilateral thalamic gliomas represent a particular clinico-pathological entity among thalamic tumors.

Aged↗
PubMed1992

Haemorrhagic complications of intracerebral cavernomas: value of MRI.

The authors report a retrospective series of 10 cases of intracerebral haematomas consecutive to cavernomas and studied with MRI. The factors that led to the MRI study were the patients' age and clinical history, the site of the haematoma, the persistence of CT images and a negative arteriography. MRI showed that the haematoma was in contact with the cavernoma in 4 cases and at a distance from it in one case. In 5 cases only the cavernoma was seen at the site of the haematoma. Three patients had multiple cavernomas. In all cases, the diagnosis of cavernoma was confirmed at surgical excision.

Adolescent↗
PubMed1991

Magnetic resonance imaging contribution to the diagnosis of spinal cord compression by a subdural arachnoid cyst.

A case of subdural arachnoid cyst of the thoracic spine was studied by magnetic resonance imaging (MRI), myelography and CT myelography. Myelography and especially CT myelography suggested the diagnosis; MRI established it, showing the communication between the cyst and the subarachnoid space. Final characterization was based on surgical findings and pathological examination.

Arachnoid Cysts↗
PubMed1991

Detection of Epstein-Barr virus sequences in primary brain lymphoma without immunodeficiency.

We searched for Epstein-Barr virus (EBV) sequences by enzymatic DNA amplification in nine primary brain lymphomas from patients without immunodeficiency. We used seven nonlymphoma brain tumors as negative controls, and the Raji cell line as a positive control. We detected EBV DNA, using ethidium bromide-stained-agarose minigel electrophoresis and dot blot hybridization, in the positive control and in only one brain lymphoma tumor; we did not detect EBV DNA in the other tumors. The EBV-positive patient had a second B-cell monoclonal population in the peripheral blood without detectable EBV DNA, suggesting a direct role for EBV in the development of the brain lymphoma.

Brain Neoplasms↗
PubMed1990

[Large-cell intravascular malignant lymphoma].

Neoplastic angioendotheliosis is a rare, severe, disease characterized by neoplastic proliferation of mononuclear cells within the lumen of small blood vessels. The clinical signs are usually dermatological and neurological. We report the case of a 57 year old woman who died after 20 months of subacute dementia. She had had also transient recurrent episodes of right paresthesiae and paresis. CSF proteins were increased. MRI showed areas of high signal in the white matter. Post-mortem showed widespread ischemic lesions, mainly in the subcortical white matter. Microscopically there was marked proliferation of cells in most CNS blood vessels. Similar cells were present in adrenals, liver, uterus, lungs and kidneys. Immunohistochemical studies showed intensive staining for leukocyte common antigen and negative staining for factor VIII-related antigen, a specific endothelial cell marker.

Brain Neoplasms↗