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Biomedical subjects

R Vazeux

Publications and source records attributed to R Vazeux.

29 records · Page 2Linked to original sources

Severe encephalitis resulting from coinfections with HIV and JC virus.

We observed 3 cases of progressive multifocal leukoencephalopathy (PML) among frozen CNS samples obtained at autopsy from 102 adult AIDS patients. In 2 patients, PML was associated with severe HIV encephalitis. In those 2 cases, the areas of extensive JC-induced demyelination were massively infiltrated by HIV infected macrophages/microglial cells with evidence for localized increase of HIV encephalitis in PML lesions. Using immunohistochemistry and in situ hybridization, we demonstrated that each virus infects, in a latent or productive fashion, different CNS cell populations. Therefore, the extension of HIV encephalitis could not be related to an intracellular transactivation of 1 virus by the other. However, the results are consistent with dissemination of viral infection by the recruitment of HIV-infected macrophages to damaged areas of the brain. This phenomenon might be generalized to other pathogens that are frequently associated with HIV CNS infection. Early detection and treatment of opportunistic CNS lesions could be important to prevent extension of HIV encephalitis.

AIDS Dementia Complex↗

MRI pattern of progressive multifocal leukoencephalopathy (PML) in AIDS. Pathological correlations.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease which occurs in immunodepressed subjects and is particularly frequent in AIDS. Some authors having drawn attention to the protean aspect of the disease and claimed that AIDS may lose its basic characteristics and affect the grey matter as well as the white matter, we reviewed a series of 8 patients who had been biopsied and/or autopsied and had been examined at least once by MRI. In this series, contrary to what is regularly observed in toxoplasmic abscesses we did not find any lesion of the grey matter or any mass effect. On the other hand, we confirmed that PLM is not multifocal in all cases and that it course may be interrupted by prolonged remissions. The MRI criteria for PML therefore are reliable, provided multiple T2-weighted slices in coronal plane are performed, clearly showing the anatomy of the white fibres affected. However, it must be borne in mind that HIV-infected patients often have other associated brain pathologies, especially when the immune deficiency increases.

Acquired Immunodeficiency Syndrome↗

The rev gene product of the human immunodeficiency virus affects envelope-specific RNA localization.

By in situ hybridization analysis and immunoprecipitations following transfection of COS cells, we show that the Rev protein of the human immunodeficiency virus is necessary for envelope protein expression, which is correlated with the appearance in the cytoplasm of envelope-specific RNA. In the absence of cotransfection with a plasmid expressing Rev, envelope-specific RNA is retained in the nucleus. Several cis-acting sites in the envelope are involved, one of which is between nucleotides 7330 and 7735 and is required for the response to Rev. Other sequences (nucleotides 5797-7330 and 7735-7989) are involved in the apparent retention of the envelope-specific RNA in the nucleus in the absence of Rev and its response element. Because Rev affects the localization of envelope RNA both in the presence and in the absence of the normal splice sites on the RNA, the mechanism of Rev action is independent of splicing.

Cell Compartmentation↗

HIV-associated endometritis.

Using immunohistochemical staining, in situ hybridization and a combination of both, we demonstrate here the replication of HIV in the endometrial stroma. Infected cells do not belong to the T-lymphocyte lineage but rather to a monocyte-macrophage cell type. This report suggests a possible relationship between HIV infection and endometritis. Moreover, HIV replication in endometrial tissues could play a role in heterosexual and materno-fetal transmission.

Acquired Immunodeficiency Syndrome↗

HIV-2 in rhesus monkeys: serological, virological and clinical results.

Diseases induced by animal retroviruses are not considered to be good models for the human acquired immunodeficiency syndrome (AIDS) at present. The lack of an animal model for the human immunodeficiency virus (HIV) infection presents a main problem in the complete understanding of the pathogenesis of HIV-mediated diseases. Because of the homologies between simian immunodeficiency virus (SIV) and HIV-2, we inoculated rhesus monkeys with HIV-2 and HIV-2 adapted in vitro to monkey cells. One of the ten animals inoculated developed clinical symptoms that might be related to the infection with HIV-2.

Acquired Immunodeficiency Syndrome↗

[Neuropathological study of 31 cases of acquired immunodeficiency syndrome].

Post-mortem study of every patient who died from AIDS in Pitié-Salpêtrire Hospital from June 1984 to November 1985 was performed without regard to the presence of neurological signs and symptoms. Autopsy were performed in 31/48 cases. Patients had been hospitalized in the Departments of Parasitology-Infectious Disease (24 cases) Internal Medicine (4 cases) and Neurology (3 cases). In every case, formalin-fixed material from the brain and the spinal cord were embedded in paraffin (20 samples), stained with hematoxylin-eosin, PAS, Alcian blue, Giemsa, Grocott and Ziehl techniques and Bodian's silver impregnation along with Luxol fast blue, and, in celloïdin (8 samples), stained with hematoxylin-eosin and Loyez' impregnation. There were 30 men (27 caucasian, 1 egyptian, 1 haïtian, 1 senegalese) and one woman (congolese). Twenty eight (28) patients were homosexuals. AIDS was transfusion-associated in two cases. Neurologic complications revealed the disease in 2 cases. Eighteen (18) patients had neurological signs or symptoms before death. Age range at death was 22-58 (mean 38). Brain weight in AIDS (from 1150 gms to 1750 gms-mean 1428 gms) was not statistically different from the mean weight of 100 male patients in the same age range autopsied in the same laboratory during the identical period (mean 1427 gms, standard deviation: 23). Microscopic abnormalities were present in every brain examined. These included non-Hodgkin lymphoma (3 cases), opportunistic infections (21 cases: 13 toxoplasmosis, 4 cytomegalovirus encephalitis, 3 cryptococcal meningitis, 1 infection by mycobacterium avium-intracellulare), and subacute encephalitis (17 cases, 9 isolated, 8 associated with other disorders). The characteristic changes consisted of lympho-monocytic focal infiltrates (so-called microglial nodules) and mild lympho-monocytic perivascular cuffs in 10 cases. Typical giant cells were seen only in one case. Mild demyelinating changes were also seen in only one case. No spinal cord spongiosis, nor Progressive Multifocal Leukoencephalopathy was found. HIV localization was performed on frozen sections utilizing in situ hybridization techniques (2 cases) and immunohistologic techniques (5 cases). HIV, RNA and proteins, was detected in 2 cases with subacute encephalitis. Infected cells were labeled with macrophage markers, and rarely with T4 lymphocyte markers. Infected astrocytes (identified by anti-GFAP serum) or neurons (identified by anti-NSE serum) were never observed. No giant cells were seen in these two cases.

Acquired Immunodeficiency Syndrome↗

AIDS subacute encephalitis. Identification of HIV-infected cells.

Human immunodeficiency virus (HIV) RNA and proteins were detected in the brains of several AIDS patients with subacute encephalitis, by in situ hybridization and immunohistology. The majority of infected cells were mononucleated and bore processes. Using single and double immunohistologic procedures, the authors identified these cells as macrophages. The majority of them had the phenotype of microglial cells (Leu-M3-, CD4-), others were labeled with markers of circulating macrophages (Leu-M3+, CD4+/-). The presence of HIV RNA and proteins in CD4- cells could be explained by depressed CD4 antigen expression, as a result of infection or macrophage tissue differentiation.

Acquired Immunodeficiency Syndrome↗

Positive Coombs test in acute leukaemia.

We present the results of the immunohaematological tests performed in an unselected group of patients with acute leukaemia at the time of diagnosis, and when possible the follow-up in remission and/or in relapse. Thirteen out of the 112 patients tested had a positive Coombs test at the time of diagnosis and, in six patients, the Coombs test became positive during remission. All the 19 positive Coombs test were of the complement type with, in 11 cases, an anti-I antibody eluted from the patient's RBC. There was no relationship between the FAB morphologic subtype, the presence of other immune abnormalities, the course of the leukaemia and the immunohaematological abnormalities. Several hypotheses on the possible relationships between the acute leukaemias and the immunohaematological abnormalities are discussed.

Adult↗

[AIDS dementia].

Human immunodeficiency virus type I (HIV), the etiology of AIDS is also the cause of a primary infection of the central nervous system. The AIDS Dementia Complex is a common and important cause of morbidity in patients in advanced stages of infection. Subacute encephalitis demonstrating, the neuropathogenicity of HIV 1 constitute an human model for slow virus encephalitis.

AIDS Dementia Complex↗