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Biomedical subjects

J Poirier

Publications and source records attributed to J Poirier.

At least 163 records · Page 9Linked to original sources
PubMed1989

Diffuse "encephalitic" cerebral toxoplasmosis in AIDS. Report of four cases.

Four patients with AIDS presented with a rapidly fatal global neurological illness. CT did not show any focal lesion and gross post mortem examination of the brain was normal in three of the four cases. Microscopic examination revealed numerous widespread microglial nodules in the brain parenchyma, most containing central toxoplama cysts or free tachyzoites. Such diffuse, non-necrotic, "encephalitic" forms of cerebral toxoplasmosis appear unique to AIDS and, to our knowledge, have not been documented previously. They represent a treatable, often misdiagnosed cause of diffuse neurological involvement in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Altered gene expression in Alzheimer's disease brain tissue.

We review the evidence for altered gene expression in Alzheimer's disease brain and identify alternative molecular approaches for isolating additional novel markers. One marker, pADHC-9, was isolated from a human hippocampal cDNA library by differential screening with AD and control cDNA probes. This clone hybridizes to a 2 Kb RNA which is increased 2 fold in AD hippocampus. The deduced amino acid sequence of pADHC-9 codes for a 52 kDAL protein similar to a testicular sulfated glycoprotein secreted by rat Sertoli cells. The normal function of this protein in brain and whether that function is altered in Alzheimer's disease is unknown.

Alzheimer Disease↗
PubMed1989

Acute myeloradiculitis due to cytomegalovirus as the initial manifestation of AIDS.

A 26 year old male intravenous drug abuser presented with rapidly progressive paraplegia and total incontinence. CSF examination showed elevated protein level and pleocytosis. HIV testing was positive. Anti CMV titres were mildly elevated in serum and CSF. Death occurred 26 days after the onset of neurological signs. Necrotic and inflammatory lesions with numerous inclusion bodies characteristic of CMV were found in the roots of the cauda equina, conus terminalis and lumbar segments of the spinal cord. CMV subependymal encephalitis and HIV encephalitis were also present.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Sacral lipoma of the filum terminale with dural arteriovenous fistula. Case report.

A patient presenting with progressive paraparesis was found to have a dural sacral arteriovenous (AV) fistula. His condition deteriorated abruptly after thoracolumbar angiography. Embolization of the fistula improved the patient's status so that he was able to walk with crutches. One year later his neurological condition worsened. He was treated via an enlarged laminectomy because of uncertainty concerning a lipoma noted on the initial computerized tomography scan. The lesion consisted of an intradural filum terminale lipoma associated with an AV fistula, both of which were excised. The patient's condition was unchanged 6 months later. The different types of spinal lipomas and spinal AV malformations are reviewed, and mechanisms are proposed to explain the clinical deterioration in this patient. Venous hypertension seems to be the most likely possibility. The lipoma may have produced local hypervascularization of the dura mater with a subsequently acquired AV fistula.

Arteriovenous Fistula↗
PubMed1989

Anatomy-computerized tomography correlations in transtentorial brain 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 plane 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.

Autopsy↗
PubMed1989

Immunomodulating and antitumor activities of a synthetic lauroyltripeptide (RP 56 142).

Lauroyltripeptide (RP 56 142) (N2-[N-(N-lauroyl-L-alanyl)-gamma-D-glutamyl]-L,L-2,6-diaminopimelami c acid) was shown in murine models to activate several immune mechanisms involved in host defense against tumors. RP 56 142 induced macrophage activation and enhanced cytotoxicity of natural killer cells in spleen, blood, and liver. These activities correlated with prophylactic and therapeutic effects of RP 56 142 on artificial liver metastases of M5076 histiocytosarcoma. RP 56 142 alone did not inhibit spontaneous liver metastases of M5076 sarcoma; however, in combination with surgery or suboptimal doses of cisplatin, the compound exerted synergistic antimetastatic effects in the same model. These findings suggest that RP 56 142 could be used in cancer patients as an immunotherapeutic agent in combination with surgery, radiotherapy and/or conventional chemotherapy.

Adjuvants, Immunologic↗
PubMed1988

Structural identity between the NH2-terminal domain of the rat and human ornithine carbamyltransferase "targeting" sequences.

Analysis of the secondary structure of human and rat ornithine carbamyltransferase's targeting sequence revealed the presence of a highly homologous domain with the following key features: an hydrophobic patch opposite to an hydrophilic surface characterized by the disposition of basic residues at potentially strategic positions. The functional role of this domain was established using a synthetic peptide corresponding to amino acids 1-19 of the rat ornithine carbamyltransferase precursor (pOCT 1-19). When added to an in vitro import assay system, pOCT (1-19) blocked the import of pOCT specifically: it did not impede the entry and processing of the precursor to subunit 2 of the F1-ATPase (p beta). This finding suggests that at least two distinct precursor(s)-specific pathways are required for the import of mitochondrial inner membrane and matrix proteins.

Amino Acid Sequence↗
PubMed1988

Pathological findings in three non-Japanese patients with the POEMS syndrome.

The pathological features of three European patients with plasma cell dyscrasia, osteosclerosis and a multisystem disorder, most frequent in Japan, that includes polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes (POEMS syndrome), are reported. The material was obtained from biopsies (peroneal nerve, lymph node) and general autopsy, including hypophysis, in one case. The most salient findings were: peripheral nerve lesions, including both segmental demyelination and axonal degeneration, with so-called uncompacted myelin lamellae (UML); angiofollicular lymph node hyperplasia (AFLNH); and non inflammatory vascular changes. Though not specific, it appears that UML and AFLNH may be contributive findings in atypical cases of POEMS syndrome (incomplete forms, lack of underlying malignant plasma cell dyscrasia or circulating monoclonal immunoglobulin). Among the various autopsy findings we emphasize the skin thickening which was secondary to a hyaline sclerosis of the papillary dermis, and the presence in adenohypophysis of numerous cells showing positive reactions with the anti-alpha MSH antibody. Though immunological, vascular and hormonal disturbances have been implicated at the origin of several manifestations of the disorder, the pathogenesis of the POEMS syndrome remains obscure.

Adult↗
PubMed1988

The normal vascularization of the intradural filum terminale in man.

The arterial and venous blood-supply of the intradural filum terminale was studied microscopically in 18 fresh cadavers after removing the dorsolumbar spinal cord in one piece, with the roots and the filum in their dural sheath. The arteries were examined after manual injection of the artery of the lumbar enlargement, while study of the veins was made without injection since their bluish-black color made them easily identifiable. After gross examination, each specimen was fixed and then sectioned at 12 different levels from the medullary conus to the bottom of the dural sac for histologic study. The distribution of the vascularization of the filum terminale appeared constant. A single artery, the artery of the filum, arises from the termination of the anterior spinal axis, either by trifurcation or from the proximal part of one of the 2 branches of the anastomotic ansa of the conus. The artery travels in front of the filum, with rapidly diminishing caliber; rarely, it can be followed into the sacral canal. The vein of the filum travels in front of that structure but behind the artery, as in the cord; its caliber is uniform but varies from subject to subject. It traverses the dura below and is continuous with the anterior spinal vein above. No vessels were found on the dorsal aspect of the filum. While the artery of the filum is of a caliber proportional to that of the filum and appears to be a nutrient vessel, the vein has a caliber unrelated to that of the filum and appears rather as an intradural drainage route continuous with the anterior spinal vein.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1988

Immunopotentiating activities of a low molecular weight lipopeptide, RP 56 142--studies in infectious models.

RP 56 142, N2-[N-(N-lauroyl-L-alanyl)-gamma-D glutamyl] L,L-2,6-diaminopimelamic acid belongs to a family of immunomodulating lipopeptides. Its structure is directly derived from that of lauroyltetrapeptide RP 40 639 which is a mixture of two stereoisomers, one of which (with D,D-2,6 diaminopimelamic acid) is totally devoid of in vivo activity. RP 56 142 displayed potent protective activities against bacterial infections such as K. pneumoniae, L. monocytogenes or S. typhimurium (at doses ranging between 0.03 and 100 mg/kg s.c., i.p., i.v.). In combined treatment protocols, suboptimal doses of RP 56 142 given preventively (day-1) or curatively (day 0 + 4h) significantly protected mice receiving antibiotics at doses which were ineffective when administered by themselves. Given s.c. 1 or 2 days before infectious challenge, RP 56 142 was able to normalize and even enhance significantly the resistance of mice previously immunocompromised by lomustine, 5-fluorouracile or hydrocortisone. These results correlated with the stimulation of the clearance of a virulent Salmonella typhimurium strain and with an important production of colony-stimulating factor in RP 56 142-treated mice.

Adjuvants, Immunologic↗
PubMed1988

Adult polyglucosan body disease (APBD).

Three patients aged 63, 63 and 74 years had various combinations of progressive lower and upper motor neuron dysfunction, sensory loss, urinary incontinence and dementia. Postmortem examinations in two cases showed moderate cerebral and spinal atrophy, ill-defined areas of incomplete myelin loss in white matter and small necrotic foci in the white matter of gyri, around the basal ganglia and near the dentate nuclei. The main microscopic abnormality was a massive accumulation of PAS-positive polyglucosan bodies (PB) of various sizes and shapes in the cerebral hemispheres, brainstem, cerebellum, spinal cord, nerve roots and nerves. These PB were found in the processes of nerve cells and astrocytes, but not in their perikarya. Similar PB were present in peripheral nerves and in the lungs, heart, liver and kidneys. In the third case, a nerve biopsy revealed several, unusually large, PB in the axons of myelinated fibers. These clinicopathologic features are consistent with adult polyglucosan body disease (APBD) and are distinctive from other conditions in which PB may accumulate. Twelve similar cases have been reported previously. The diagnosis can be made by nerve biopsy. The pathogenesis of APBD is not known, but it may be a polysaccharide storage disease.

Aged↗
PubMed1988

[Pigmentary orthochromatic leukodystrophy. Van Bogaert and Nyssen disease].

A 43 year old woman with a strong likelihood of familial history, developed progressively a spastic tetraparesis associated with intellectual deterioration and terminal epileptic fits. She died 11 years after onset of the clinical disorders. Neuropathological study revealed an orthochromatic leukodystrophy. Macrophages and glial cells of the white matter contained a brown-yellow, autofluorescent pigment which stained positively with PAS, Perls stain for iron and Masson-Fontana. 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 oligodentrocytes in other forms of orthochromatic leucodystrophy. Ten similar cases of pigmentary type of orthochromatic leucodystrophy have been reported previously; only one had had an ultrastructural study.

Adult↗
PubMed1988

[Neuropathologic study of 15 cases of multinucleated giant cell encephalitis in acquired immunodeficiency syndrome (AIDS)].

The central nervous system (CNS) of 40 patients who died of acquired immune deficiency syndrome (AIDS) between August 1982 and August 1987 was examined. In 15 cases, multinucleated giant cells (MGC) characteristic of Human Immunodeficiency Virus (HIV) infection were observed. In 3 cases ultrastructural examination disclosed HIV-like viral particles in the cytoplasm of some MGC. All cases with MGC showed, in addition, predominant white matter lesion: diffuse myelin pallor, multiple small, usually subcortical, necrotic foci, vacuolar myelopathy, proliferation of rod-shade microglia and microglial nodules, reactive astrocytosis, mineralization of the vessel walls. These changes, typical of HIV encephalitis, were isolated in 3 cases. In the other cases, they were associated with other AIDS-related CNS lesions, i.e., cerebral toxoplasmosis (9 cases), cytomegalovirus infection (5 cases), progressive multifocal leukoencephalitis (1 case), cryptococcosis (1 case) and cerebral lymphoma (1 case). The involvement of MGC with these lesions was remarkable.

Acquired Immunodeficiency Syndrome↗