[Pierre Rayer and pathological anatomy].
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France↗
Biomedical subjects
J Poirier
Publications and source records attributed to J Poirier.
[Historical note: Désiré Bourneville (1840-1909)].
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France↗
[Pseudo-oligodendrogliomatous meningioma. Report of 2 cases and review of the literature].
We report two cases of oligodendroglioma-like meningioma revealed by symptoms of increased intracranial pressure, progressive hemiparesia and partial epileptic seizures. Brain CT-scan or scintigraphy and carotid arteriography were suggestive of a convexity meningioma. One patient had received radiation treatment for scalp tinea capitis 25 years previously. In spite of complete surgical removal, the tumor recurred in both cases respectively 17 years and 18 months later. The two patients were operated again, and one underwent a complementary radiotherapy. Pathologic diagnosis was particularly difficult in the first case where the pattern at conventional histologic technics was that of oligodendroglioma. On the occasion of recurrence, immuno-histochemistry and ultrastructural studies were performed. The tumor was positive for epithelial membrane antigen (E.M.A) and cytokeratin, but was negative for glial fibrillary acidic (G.F.A.) protein, S 100 protein (S 100), neuron-specific enolase (N.S.E.), vimentin, anti-LEU-7 (N.H.K.1), and neurofilaments (N.F.). Electron microscopy showed closely adjacent cells with tonofilaments and numerous desmosomes. These findings permitted to establish the diagnosis of oligodendroglioma-like meningioma instead of oligodendroglioma. In the second case, the histologic pattern was also reminiscent of oligodendroglioma, but presence of few cellular whorls in some part of the tumor permitted the correct diagnosis. The pathogenesis of this atypical form of meningioma, its tendency for recurrence, and usefulness of radiotherapy are discussed and literature is reviewed.
Adult↗
[Neuropathologic study of 135 adult cases of acquired immunodeficiency syndrome (AIDS)].
The central nervous system was examined in 135 adult AIDS patients who died between August 1982 and December 1990. Twenty two brains showed non-diagnostic changes including microglial nodules, discrete myelin pallor with reactive astrocytosis, mineralization of blood vessels and granular ependymitis. In 105 brains with specific changes, toxoplasmosis was the most frequent finding (55 cases) manifested by multifocal necrotic lesions or diffuse pseudo-encephalitic process. Other opportunists included cytomegalovirus (21 case), progressive multifocal leukoencephalopathy (1 cases), cryptococcosis (6 cases), mycobacterium avium intracellulaire (2 cases), varicella-zoster virus (2 cases), aspergillosis (1 case) and multiple bacterial microabscesses (1 case). Multinucleated giant cells were found in 52 cases. In 40 cases, they were widely disseminated throughout the brain and in 39 cases, they were associated with diffuse or multifocal white matter changes. Fifteen cases had a cerebral lymphoma, 9 hepatic encephalopathy, 1 centropontine myelinolysis and 1 focal pontine leukoencephalopathy. Three cases had a cerebral haemorrhage due to disseminated intravascular coagulation, antithrombin therapy and amyloid angiopathy. Spinal changes in 13 cases included vacuolar myelopathy (7 cases), HIV myelitis (1 case) and ganglio-radiculitis (1 cases), cytomegalovirus myelo-radiculitis (1 case) secondary spread from a lymphoma (1 case) and spinal infarcts due to disseminated intravascular coagulation (1 case). These lesions were frequently atypical and various combinations of all these pathologies were encountered in the same brain, sometimes in the same area and occasionally in the same cell. Chronological variations in the incidence of some complications could be related to changes in treatment.
Acquired Immunodeficiency Syndrome↗
Role for the mitochondrial inner membrane in the maturation of the precursor to ornithine carbamyl transferase.
The precursor to ornithine carbamyl transferase (pOCT) is cleaved at two N-terminal sites when imported into intact mitochondria but only at the N-proximal site when incubated with a membrane-free mitochondrial lysate or matrix fraction. Disruption of the mitochondrial membrane system by sonication, freeze-thaw, or lysis with non-ionic detergents blocks the processing of pOCT to its mature form. Mitoplasts prepared from protease-inactivated, import-incompetent mitochondria recover full processing activity; disruption of the inner membrane impairs the maturation process i.e. causes the loss of the mitoplasts' ability to transform pOCT into OCT. The data reveal a dependency of a maturation event on a "specific" interaction between a precursor protein and the mitochondrial inner membrane probably to position and/or to expose the correct N-distal cleavage site of the presequence.
Animals↗
Expression of the mammalian mitochondrial genome. Role for membrane potential in the production of mature translation products.
Protein synthesis was investigated in isolated mitochondria under conditions which either inhibited electron transport or uncoupled oxidative phosphorylation. In a medium containing an exogenous source of ATP and oligomycin, an inhibitor of the ATP synthase complex, incorporation of [35S]methionine into proteins is stimulated in the presence of inhibitors of the electron transport chain; substituting uncouplers of oxidative phosphorylation for the latter leads, in contrast, to a decrease in the rate of incorporation of the labeled amino acid into mitochondrial translation products. Studies on the metabolic stability of mitochondrial translation products revealed that "mature" polypeptides made in isolated mitochondria are stable as indicated by the absence of degradation during a 50 min "chase" period. Under conditions which reduce or dissipate the membrane potential, 50-60% of the newly made polypeptides (pulse) are degraded within 50 min. The kinetics of the degradation process for individual mitochondrial gene products reveal that the largest proportion of polypeptides degraded to an acid-soluble form during the chase period are abnormal proteins, likely the result of premature chain termination. Emerging as a common denominator in these studies is a role for a transmembrane potential across the inner membrane in the production of mature "stable" mitochondrial gene products.
Animals↗
Spinal cord lesions in the acquired immune deficiency syndrome (AIDS).
Spinal cord involvement in AIDS is not uncommon. Different types of lesions corresponding to varying pathogenetic mechanisms have been reported. Vacuolar myelopathy is the most frequently found. The symptoms and pathological changes resemble those of subacute combined degeneration; however, cobalamine or folate levels have always been found normal. Its frequent association with the multi-nucleated giant cells characteristic of HIV encephalitis makes it likely that the virus plays a role in its pathogenesis. Cytomegalovirus may be responsible for acute myeloradiculitis involving the spinal roots of the cauda equina and inferior part of the spinal cord. In cases of Herpes simplex virus myelitis has been reported; they are usually associated with cytomegalovirus infection and are due to herpes simplex virus type II. Secondary spread from systemic lymphomas may involve the subarachnoid space of the cord and the spinal roots. Compression of the spinal cord by epidural lymphomatous masses has also been described. Spinal infarcts may be secondary to acute or chronic vasculitis or to less specific vascular processes such as disseminated intravascular coagulation.
Acquired Immunodeficiency Syndrome↗
Cytomegalovirus (CMV) encephalomyeloradiculitis and human immunodeficiency virus (HIV) encephalitis: presence of HIV and CMV co-infected multinucleated giant cells.
A 25-year-old homosexual male with AIDS presented with a cauda equina syndrome clinically suggestive of cytomegalovirus (CMV) myeloradiculitis. He was treated with ganciclovir with transient improvement of neurological signs and died 4 months after onset of neurological signs. Neuropathological examination revealed human immunodeficiency virus (HIV) encephalitis, CMV subependymal encephalitis and CMV myeloradiculitis. The latter was characterised by myelin loss, Schwann cell proliferation and presence of CMV early antigens in the nuclei of S-100 protein-positive cells in the spinal roots. In the subependymal regions, morphologically characteristic multinucleated giant cells, positive for CD68, contained early CMV antigens (E13) in their nuclei and HIV antigens (gp41 and p24) in their cytoplasm. The observation that HIV and CMV can co-infect the same cell in vivo raises the possibility of a direct synergistic interaction of both viruses at cell level. This suggests that CMV may play a role as a co-factor in the pathogenesis of HIV encephalopathy.
Acquired Immunodeficiency Syndrome↗
Dynamics of gene expression for a hippocampal glycoprotein elevated in Alzheimer's disease and in response to experimental lesions in rat.
A hippocampal poly(A) RNA, pADHC-9, was cloned by differential screening of a human hippocampal cDNA library. By RNA blot analysis, pADHC-9 was elevated 2-fold in Alzheimer's disease hippocampus. In situ analyses identified pADHC-9 expression in pyramidal and non-pyramidal cells of the hippocampus and entorhinal cortex. Nucleotide sequence analysis identified pADHC-9 as a potential human homolog of rat sulfated glycoprotein 2 (SGP-2). SGP-2 expression increased in rat hippocampus following experimental lesions that mimic intrinsic neuronal loss and/or deafferentation. The function of pADHC-9 in brain has not been defined, but in serum, a similar protein inhibits complement-dependent cytolysis. Increased expression of pADHC-9 in Alzheimer's disease hippocampus may be a compensatory response mounted to retard a complement-driven neurodegenerative cascade.
Alzheimer Disease↗
Cerebral amyloid angiopathy and granulomatous angiitis: immunohistochemical study using antibodies to the Alzheimer A4 peptide.
Neuropathologic study of an 82-year-old male who died from massive cerebral hemorrhage showed extensive amyloid angiopathy, with morphologic and immunohistochemical characteristics similar to those observed in Alzheimer's disease, associated with granulomatous angiitis, including the presence of numerous giant cells. Some of the giant cells contained, in their cytoplasm, congophilic material immunoreactive for the Alzheimer A4 peptide, supporting the hypothesis that the granulomatous angiitis may, in part, represent a foreign body reaction to A4 amyloid deposition.
Aged↗
Selective alterations of RNA in rat hippocampus after entorhinal cortex lesioning.
In vitro translation products from RNA of rat hippocampus after deafferentation by entorhinal cortex lesions were analyzed by two-dimensional gel electrophoresis. Although hippocampal total RNA yield was not affected 14 days after the lesion, analysis of the gels showed reproducible changes in the steady-state level of several transcripts. Glial fibrillary acidic protein RNA increased 2-fold over control hippocampi RNA. Moreover, seven other transcripts of unknown identity had increased prevalence in the denervated hippocampus. The changes, which ranged from 2- to 20-fold, involved mRNA encoding small slightly acidic polypeptides: 12 kDa (pI 5.6), 13 kDa (pI 6.1), 20 kDa (pI 5.8), 31 kDa (pI 5.7), 33 kDa (pI 5.7), 35 kDa (pI 5.6), and 53 kDa (pI 5.4). These results suggest new molecular markers for analyzing the complex mechanisms of synaptic reorganization in the dentate gyrus after deafferentation.
Actins↗
HIV encephalitis-like multinucleated giant cells in a nodal lymphoma in AIDS.
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AIDS Dementia Complex↗
Giant gangliocytic paraganglioma of the filum terminale. Case report.
The clinical and pathological features of a giant cauda equina paraganglioma arising from the intradural filum terminale is described. Scattered mature large neurons characterized the tumor as a gangliocytic paraganglioma. Histologically, these neoplasms have considerable similarity with ependymoma and the diagnosis can be easily missed unless special techniques are employed.
Adult↗
[The iconography of "Popular medicine", a weekly illustrated journal (1880-1884)].
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Folklore↗
[Theories of demographic transition: toward a certain convergence?].
"The aim of this paper is to present, in their points of convergence and opposition, the main theoretical currents which have arisen around the concept of demographic transition in its application to Third World countries. Four currents are identified: structural functionalism, culturalism, Marxism and feminism. The authors identify two main trends in recent debates surrounding the question of transition in demography: on the one hand, convergence of macro-structural approaches and, on the other, greater opposition between the latter and those which favor cultural factors." (SUMMARY IN ENG AND SPA)
Communism↗
[Correlations between anatomy and computerized tomography findings in transtentorial cerebral herniation].
The diagnosis of transtentorial brain herniation has long relied on encephalography, then arteriography. Computerized tomography (CT) is a safer method which permits a more precise and earlier visualization of temporal and central herniations and herniation of the culmen cerebelli, which are the three varieties of transtentorial herniation. In an attempt to evaluate the reliability of CT images of herniation, the authors have conducted a study of anatomy-CT correlations, using autopsy specimens of brains with these three types of transtentorial herniation. Temporal herniation was well studied, irrespective of the CT reference plane. Direct visualization of temporal uncus herniation and filling of the homolateral perimesencephalic cistern was regularly obtained. Central herniation was better visualized when the occipito-temporal was used as reference. The disappearance of perimesencephalic cisterns on CT sections through the widest part of the tentorial incisura is the best element of diagnosis. Herniation of the culmen is easily studied on the conventional orbito-meatal plane. Provided CT scans are performed with the technique they recommend, the authors consider that this examination is reliable for the diagnosis of transtentorial herniation. Some variations in the anatomy of the incisura may explain why the clinical consequences of herniation are varied. CT perfectly shows the configuration of this notch and therefore may be helpful in predicting the prognosis.
Brain↗
Expression of the mammalian mitochondrial genome. Stability of mitochondrial translation products as a function of membrane potential.
Polypeptide decay has been measured as a function of membrane potential. Mitochondrial translation products were pulse-labeled in vitro with [35S]methionine using isolated rat heart mitochondria in the presence of an energy-generating system. The relative rate of protein degradation was estimated from the specific activity (counts/min/mg of protein) of the labeled translation products following the addition of unlabeled methionine (chase). To modulate membrane potential, inhibitors of oxidative phosphorylation were used singly or in combination; their effect was monitored by following uptake of the nonmetabolizable lipophilic cation triphenylmethylphosphonium. When the potential was dissipated, the rate of polypeptide decay increased and vice versa. These results suggest that the stability of mitochondrial translation products is linked to a process(es) that is dependent upon delta psi; likely candidates include synthesis and/or assembly of mitochondrial gene products.
Animals↗
Studies on the biogenesis of the mammalian ATP synthase complex: isolation and characterization of a full-length cDNA encoding the rat F1-beta-subunit.
Screening a rat cDNA library with a fragment of the gene encoding the corresponding bovine protein, we have isolated cDNA clones encoding the complete precursor to the rat F1-beta-subunit. Comparison with other mammalian beta-subunit sequences reveals a 5' untranslated sequence of 27 bp, a targeting sequence of 48 amino acid residues, a 480 amino acid long mature polypeptide and a 3' untranslated region of approximately 150 bp. In vitro translation of F1-beta mRNA reveals the synthesis of multiple fragments of the protein. Preliminary characterization of intron-containing cDNA isolates indicates that the gene encoding the rat F1-beta subunit contains at least two introns.
Amino Acid Sequence↗