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Biomedical subjects

J Poirier

Publications and source records attributed to J Poirier.

At least 181 records · Page 10Linked to original sources

Erythrocyte antioxidant activity in human patients with Parkinson's disease.

Three groups have reported defective antioxidant mechanisms in substantia nigra of patients with Parkinson's disease, namely a decreased catalase and peroxidase activity, a reduction of glutathione and, more recently, a diminished nigral glutathione peroxidase activity. We decided to investigate these mechanisms in erythrocytes to determine whether these brain defects represent generalized or genetic aberrations, in which case they should also be present in blood cells. The glutathione cycle has been investigated (reduced and oxidized glutathione, glutathione reductase and peroxidase) plus the activities of catalase and superoxide dismutase. The basal malonaldehyde content of erythrocytes was used as an index of endogenous lipid peroxidation. None of the above-mentioned parameters were found altered in erythrocytes of parkinsonians, suggesting that no genetic or generalized biochemical abnormalities underly the deficiencies detected in substantia nigra.

Erythrocytes↗

Post-operative intracranial foreign body granuloma: a case report.

The authors report and discuss some clinical, radiological, histological and ultrastructural aspects of an intracranial foreign body granuloma. This granuloma, which simulated a cavernoma, was due to a surgical swab forgotten during a previous neurosurgical evacuation of an intracerebral hematoma.

Adult↗

Leucoencephalopathy with multinucleated giant cells containing human immune deficiency virus-like particles and multiple opportunistic cerebral infections in one patient with AIDS.

A 29-year-old homosexual male with AIDS presented with progressive encephalopathy and cytomegalovirus (CMV) pneumonia. Neuropathological examination revealed toxoplasma abscesses in corpus callosum, basal ganglia and cerebellar white matter; demyelinating foci in the parietal white matter, with microscopic changes typical of progressive multifocal leucoencephalopathy and intranuclear papovavirus inclusions in oligodendrocytes; and lesions of subacute encephalitis in the periventricular regions with large cells positive by immunostaining for CMV. Diffuse myelin loss was observed in the cerebral white matter. Multinucleated giant cells were numerous in the demyelinated areas, they were also observed in close relationship with papova, CMV and Toxoplasma lesions. Immunostaining of these cells was positive for histiocyte markers and negative with the leucocyte common antigen monoclonal antibody. Some of them contained virus-like particles measuring around 100 nm similar to human immune deficiency virus (HIV) as observed in human brain.

Acquired Immunodeficiency Syndrome↗

Vertebral hemangiomas presenting with neurologic symptoms.

Six cases of spinal hemangiomas with neurologic symptoms are reported. In three of them the diagnosis was obtained before surgery using plain x-rays and spinal computed tomography scan or biopsy. In the other cases the diagnosis was not done before surgery. In two cases preoperative embolization had minimized blood loss during surgery. Laminectomy was performed in three cases. Large removal and/or vertebrectomy was carried out in the other cases. Our results and a review of the literature about the investigations and treatment of vertebral hemangiomas led us to propose a stereotypical management of spinal hemangiomas with neurologic symptoms.

Adolescent↗

Symptomatic xanthogranuloma of the choroid plexus of the third ventricle. A new case with ultrastructural study.

The clinicopathological findings in a new case of a surgically removed, symptomatic xanthogranuloma of the third ventricle are reported. Ultrastructural study showed that the lining epithelium of the tumor was composed of typical leptomeningeal cells, and that transitional forms from leptomeningeal cells into xanthomatous cells were present in the underlying fibrous capsule. These findings support the hypothesis of a leptomeningeal origin of the foamy cells in the present case. The ten cases reported previously of symptomatic xanthogranuloma of the third ventricle are reviewed. We suggest that xanthogranulomas of the choroid plexus might represent a heterogenous entity arising from xanthomatous changes involving various types of cells.

Brain Diseases↗

Aspergillosis of ethmoid sinus and optic nerve, with arteritis and rupture of the internal carotid artery.

A 54-year-old woman had been treated 26 years previously for Hodgkin's disease. Eight months before presentation, the disease had recurred and the patient had received cytotoxic drugs and steroids. She presented with loss of vision of the right eye and died 5 months later from extensive subarachnoid hemorrhage. Postmortem examination revealed an aspergillus abscess of the ethmoid sinus, extending to the right frontal lobe and optic nerve, and to the wall of the right internal carotid artery (ICA). Death was due to rupture of the ICA. Such a presentation of aspergillosis is unusual. Three cases of aspergillus arteritis causing rupture of the ICA have been reported previously.

Arteritis↗

Posterior callosal infarction. Clinicopathological correlations.

Clinicoanatomical observations on a patient with partial interhemispheric disconnection associated with complete ischaemic destruction of the splenium and of the posterior part of the body of the corpus callosum are presented. Neuropathological examination of the areas containing degenerated white matter indicated that the lesions affected the transcallosal fibres that link the cortex of the occipital lobes and the superior parietal lobules (SPL). The white matter situated in the temporal lobes was intact. This suggests that in man, and contrary to what has been described in the monkey, the callosal pathway followed by the temporal fibres is rostral to the one followed by the parietal or at least by the SPL fibres. The most prominent disconnection syndrome elements were left tactile anomia (in spite of a rather good tactile-motor integration between the hemispheres), left visual anomia, agraphia of the left hand and 'diagnostic' apraxia. The fact that the anterior part of the corpus callosum was intact accounts for the preservation of interhemispheric transfer of somatic sensory information and for the absence of left extinction during the dichotic listening test. An attempt is made to give a more detailed explanation of the results obtained during the different tests.

Aged↗

High-grade malignant cutaneous plasmacytoma metastatic to the central nervous system. A case report with electron microscopy, immunohistological, and neuropathological studies.

A case of high-grade malignant extramedullary plasmacytoma (EMP), unusual in its initial cutaneous localization and major involvement in the central nervous system rapidly resulting in death, is reported. Light- and electron-microscopic studies of a skin nodule revealed a high proportion of immature and mature plasmacytes. Immunohistological study revealed that both cells synthesized different amounts of a monotypic cytoplasmic kappa light chain. Neuropathological study revealed extensive infiltration of the leptomeninges and perivascular spaces as far as the deep parenchyma. In several places, effraction of vessels resulted in parenchymatous, tumor-like, plasmacytic infiltration. The findings of this case were compared with those of the few previously reported cases of EMP with initial cutaneous or intracranial localization, and with those of immunoblastic sarcoma occurring in some cases of myeloma.

Brain Neoplasms↗

Pigmentary type of orthochromatic leukodystrophy (OLD): a new case with ultrastructural and biochemical study.

A 34-year-old woman with no family history of orthochromatic leukodystrophy (OLD) developed progressive intellectual deterioration, a frontal syndrome and spastic tetraparesis. She died four years after the onset of the clinical illness. Neuropathological studies included light and electron microscopy of cerebral and nerve biopsies, and a complete postmortem examination. Light microscopy demonstrated OLD with pigmented macrophages and glial cells. Electron microscopy showed electron-dense, membrane-bound intracytoplasmic lamellar inclusions with curved or straight parallel arrangement, or fingerprint pattern, in white matter macrophages, astrocytes and oligodendrocytes. Cortical cells contained lipofuscin which was normal in type and amount. This suggests that the material in white matter glial cells and macrophages is ceroid pigment, however, the distribution is not that seen in ceroid-lipofuscinosis. Similar inclusions have been found in oligodendrocytes in other forms of OLD. Biochemical study did not show evidence of demyelination. Galactolipids were normal. Polyunsaturated fatty acids were decreased. The most striking feature was an increase in plasmalogens.

Adult↗

Chronic localised encephalitis (Rasmussen's) in an adult with epilepsia partialis continua.

A 29 year old male presented with epileptic fits, progressive left sided focal seizures and epilepsia partialis continua, increasing left hemiparesis and mental slowing. Death occurred 2 years after the onset of the illness. Lesions were limited to the right cerebral hemisphere. Hypertrophic astrocytosis was diffuse throughout the gray and white matter but was more severe in the deep cortical layers and U fibres, where it was associated with vacuolar changes and capillary proliferation. Sparse perivascular lymphocytic cuffs, rod shaped microglia and microglial nodules were present. No inclusion bodies were found. These clinico-pathologic features were similar to the cases described by Rasmussen. Only five necropsy cases of this rare disease have been reported previously, all in children. The aetiology is unknown.

Adult↗

MPTP potentiates iron-induced lipid peroxidation without the involvement of free radicals derived from oxygen.

We demonstrate here that MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) potentiates iron-catalyzed lipid peroxidation in intact erythrocytes, whereas it does not mediate hydrogen peroxide catalysed lipid peroxidation. The malonaldehyde formation which results from this lipid peroxidation is generated in the absence of superoxides, hydroxyl radicals, hydrogen peroxide or singlet oxygen. The MPTP reaction is blocked by addition of iron +2 chelator but not by iron +3 chelator. These results suggest that an iron-MPTP complex promotes the formation of lipid peroxidation by interacting directly with membrane polyunsaturated lipids.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

[Beneficial effects of the combination of antibiotics and immunomodulating lipopeptides].

Although antibiotics are efficient therapeutic weapons, their actions is limited in immunocompromised patients. The efficacy of immunomodulators which restore the immune system could be improved if they were associated to infra-active doses of antibiotics which prepare the bacteria to the immune system attack. Thus it seems possible to obtain a therapeutic gain with such an association and, consequently, to avoid the emergence of antibiotic-resistant germs.

Adjuvants, Immunologic↗

Diffuse subependymal periventricular metastases. Report of three cases.

Three clinicopathologic cases with a remarkable pattern of extensive diffuse subependymal periventricular spread of cerebral metastases from solid systemic cancer are reported. Two patients had a small cell carcinoma of the lung. In the third case, the histologic features of the brain metastases were consistent with a neuron-specific enolase-positive, small cell anaplastic carcinoma. Involvement of the choroid plexus and leptomeninges was moderate or absent. Intraparenchymatous nodular metastases were not found except in one case in which rare nodular superficial cortical metastases were present. The clinical data were nonspecific except for orthostatic hypotension, in one patient, which was probably due to the infiltration of the floor of the third and fourth ventricles. Results of the cerebrospinal fluid examination, available in two cases, were normal. The only diagnostic investigation was contrast-enhanced computed tomography scanning.

Carcinoma↗