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Biomedical subjects

J Le Beau

Publications and source records attributed to J Le Beau.

At least 19 recordsLinked to original sources
PubMed1989

Evolutionary expression of the neuronal form of the src protein in the brain.

The protooncogene src encodes two proteins, designated pp60c-src+ and pp60c-src.pp60c-src+ is expressed only in neurons, whereas pp60c-src is expressed in neuronal and nonneuronal cells. pp60c-src+ differs from pp60c-src in that it contains an insert of 6 amino acids. To study the evolutionary conservation of the 6-amino acid insert, the expression of pp60c-src+ in the brain of animals from different classes was assayed by using pp60c-src+-specific antibodies raised against a synthetic peptide corresponding to the insert. pp60c-src+ was detected only in the brain of mammals, birds, and reptiles, but not amphibians and fish, whereas pp60c-src was present in the brain of all animals tested, including lobster (invertebrate). These findings indicate that pp60c-src+ may play a role in events associated with higher brain function, such as neuronal plasticity.

Amino Acid Sequence↗
PubMed1979

Histoenzymatic and permeability changes in human brain adjacent to meningioma.

Cerebral specimens were removed from ten patients with meningioma. Vascular permeability was tested with sodium fluorescein and a correlative study of the oxidative and hydrolytic enzyme activity was performed. Vascular permeability change was observed in half of the specimens of cortex taken from the region of the tumor. Labeled tracer diffusion was found to be either perivascular or involved microscopic ischemic areas. Fluorescein diffusion of the edematous white matter was observed in only two specimens. Enzyme activity in walls of the blood vessels was modified in the fluorescent specimens. Alkaline phosphatase and oxidoreductase activities were decreased. Experimental results have shown a relationship between increased vascular permeability and metabolic disorder of both vascular walls and cerebral cortex. Our findings agree with Zülch's hypothesis regarding a "hemodynamic" mechanism in the formation of edema by extraneural compression.

Adenosine Triphosphatases↗
PubMed1978

[Myelinopathy due to carbon monoxyde poisoning. A study in ultrastructural neuropathology (author's transl)].

A 24-year-old woman was found comatose after 2 days of cephalalgia and vomiting. An immediate diagnosis of carbon monoxyde poisoning was disclaimed when blood carbon monoxyde was found to be 1.75 ml/100. A diagnosis of acute intracranial hypertension led to trephination with ventricular punction and brain biopsy on the third day. The patient died on the eleventh day. Ultrastructural study of biopsy tissue showed nearly normal cortex, and injured white matter, with disrupted or destroyed myelin and pycnotic oligodendroglia in contrast with nearly normal axons, astrocytes, and capillaries. Autopsy showed a typical semioval center myelinopathy. After discussion of the histotoxic, vascular, and edema theories for myelinopathy pathogenesis, primary oligodendrogial lesion is considered, and correlated with the diphasic evolution often observed in the course of carbon monoxyde myelinopathy.

Adult↗
PubMed1978

The brain surrounding malignant gliomas: an ultrastructural study.

Brain samples were taken in macroscopically oedematous zones during 21 operations for malignant glioma, and studied with the electron microscope. Oedema was found in 17 cases, mostly as serous extracellular fluid. Vascular changes in the oedema region are mostly as serous extracellular fluid. Vascular changes in the oedema region are mostly secondary to oedema: the origin of oedema fluid ought to be found in the tumour proper. Cellular reaction is slight; neuronal lesions may be ascribed mostly to a perturbation of axonal flow. Oedema round malignant gliomas and oedema round other malignant or benign tumours are morphologically distinct.

Astrocytes↗
PubMed1978

[Herpetic meningo-encephalitis : emergency E.E.G. diagnosis and neurosurgical treatment (author's transl)].

Reporting two cases of true herpetic encephalitis, the authors insist on the great diagnostic value of some nearly constant, but transitory, aspects of localised periodic waves in the E.E.G. An emergency cerebral (usually temporal) resection is then advised. Thus focal infection is reduced and intra-cranial hypertension is prevented. Virologic and electron microscopic studies of the cortical specimen establish with certainty the diagnosis of herpetic encephalitis.

Adult↗
PubMed1978

[Glial histoenzymatic study in human cerebral edema (collateral edema in glial tumors)].

Histoenzymatic study was performed on neurosurgical specimens. Two patterns of reactive astrocytes were found. Normal shape cells with perivascular processes were observed in subcortical white matter and in moderate edematous changes. Hypertrophic cells without processes were seen in severe edematous changes. The role of glia in the selective vulnerability of the white matter is discussed.

Astrocytes↗
PubMed1977

[Division of the pituitary stalk (mischotomy) for malignant exophthalmos after treatment of Basedow's disease with I 131].

The authors report a case of malignant exophthalmia occuring after treatment of Grave's disease with I 131. The exophthalmia was resistant to corticosteroids, thyroxin in large doses, reserpine, and the patient was treated by mischotomy (division of the pituitary stalk with interposition of polyethylene strips). There was progressive marked regression of the exophthalmia with return to work and normal social life.

Female↗
PubMed1977

[Curable ECHO 5 virus encephalitis. Clinical, electroencephalographic, virologic and ultrastructural study].

A 10 1/2 years old boy fell brutally ill with a fit followed by confusion, and then by deep coma, with 40 degrees C fever and morbilliform rash. Consciousnesse came back within ten days, with transient Parkinson-like tremor. Myoclonus persisted for about six months. Complete recovery was followed up for six years. A diagnosis of encephalitis was considered on early EEG evidence (stereotyped repetitive sharp wave bursts) and was confirmed by isolation of ECHO 5 virus from brain specimen, and ultrastructural observation of characteristic cytopathic effect (disappearance of organelles, proliferation of smooth membranes) and of probable viral particules in astrocytes, without any inflammatory process.

Cerebral Cortex↗
PubMed1976

[Cerebral cortex in normal pressure hydrocephalus: an electron microscopy study (author's transl)].

A cortical biopsy was taken at the time when ventricular pressure was measured, or a ventriculo-atrial shunt placed, in 11 patients with Normal Pressure Hydrocephalus (N.P.H.), and was studied with the electron microscope. In 9 cases, a rather typical electron microscopic picture with marked increase of extracellular space in an otherwise normal cortical neuropil was observed. 2 patients did not exhibit this pattern and, coincendentally, did not benefit from the placing of the shunt. As a control, about 600 cortical biopsies that had been taken for other reasons were reviewed. In the group, there were only 3 cortices that had a pattern of increased extracellular space similar to the described in N.P.H. On review of the clinico-pathologic data of these cases, it was felt that all 3 probably represented cases of normal pressure hydrocephalus. It is concluded that the ultrastructure of the cerebral cortex is of at least nosological interest in the study of N.P.H.

Cerebral Cortex↗
PubMed1975

[The neurosurgical forms of Hurst's acute hemorrhagic leukoencephalitis].

Within the group of acute encephalitis, H.A.H.L. is individualized mostly by its post mortem pathology. But several cases of recovery were recently published, the diagnostic being based on biopsy material. In 4 of our 8 cases, a comparison between the biopsy and post mortem examinations was possible : in/the diagnostic of H.A.H.L. was unequivocally confirmed, in 2 H.A.H.L. is nearly certain, in 1 it is doubtful. These considerations do not contradict the necessity of an emergency brain decompression in many instances of acute encephalitic states.

Acute Disease↗
PubMed1975

[Histochemical correlations of vascular permeability and enzyme activity in the choroid plexus in man].

The choroid plexuses are characterized by the absence of alcaline phosphatase activity as well as the absence of any vascular barrier for proteins as revealed by fluorescein tracer observation. This correlation is interpreted as supporting the hypothesis of enzymatic control, via alcaline phosphatase, of the blood-brain barrier. Adenosine mono and triphosphatase activity, on the contrary, is identical in choroid plexus vessels and in vessels where the blood-brain barrier phenomena may be demonstrated.

Adenosine Triphosphatases↗