References of "Vaira, Dolorès"
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See detailHépatite à virus G: mythe ou réalité? VHG/GBV-C: diagnostic, épidémiologie, risque transfusionnel et pathogénicité
Gerard, Christiane ULg; Vaira, Dolorès ULg; Delwaide, Jean ULg et al

in Revue Médicale de Liège (1998), 53(9), 524-528

The recently discovered G virus (also called either GBV-C or HGV) is transmitted by blood transfusion as well as by sexual intercourse. The global prevalence of GBV-C is high, not only in those groups ... [more ▼]

The recently discovered G virus (also called either GBV-C or HGV) is transmitted by blood transfusion as well as by sexual intercourse. The global prevalence of GBV-C is high, not only in those groups classically known to be exposed to parenteral risks (i.v. drug users, polytransfused patients), but also in the blood donors population. The diagnosis of active infection lies on the search of GBV-C RNA by Polymerase Chain Reaction whereas that of resolved (past) infection lies on the presence of specific antibodies. Till now, it has not been possible to correlate convincingly the presence of GBV-C RNA with any acute or chronic hepatopathy. On the contrary, a lot of arguments tend to suggest that the GBV-C is not pathogenic for the liver, although some modes of transmission are common with those of other (known and probably not known) hepatotropic viruses. According to the actual knowledge of the consequences of GBV-C infection, it appears as non relevant to instaure a systematic screening of this new virus in blood donors. [less ▲]

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See detailTransmission du virus de l'hépatite C par examens médicaux invasifs
DELWAIDE, Jean ULg; Gerard, Christiane ULg; Vaira, Dolorès ULg et al

in Gastroentérologie Clinique et Biologique (1998), 22(2), 172

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See detailHIV-1 promoter activation following an oxidative stress mediated by singlet oxygen
Legrand, Sylvie ULg; Hoebeke, Maryse ULg; Vaira, Dolorès ULg et al

in Journal of Photochemistry and Photobiology B : Biology (1993), 17(3), 229-237

Various biological processes, such as photosensitization or inflammatory reactions, can generate singlet oxygen (O-1(2)) as one of the major oxidative species. Because this oxidant can be generated either ... [more ▼]

Various biological processes, such as photosensitization or inflammatory reactions, can generate singlet oxygen (O-1(2)) as one of the major oxidative species. Because this oxidant can be generated either extracellularly or intracellularly, it can cause severe damage to various biological macromolecules, even to those deeply embedded inside the cells such as DNA. Sublethal biological modifications induced by different DNA-damaging agents can promote various cellular responses initiated by the activation of various cellular genes and certain heterologous viruses. Since O-1(2) fulfils essential prerequisites for a genotoxic substance, we have examined the effects of an oxidative stress, mediated by this species, on cells harbouring a heterologous promoter-leader sequence derived from the human immunodeficiency virus type 1 (HIV-1). Our results demonstrate that HIV-1 long terminal repeat (LTR), integrated into the cellular I)NA of epithelial cells, can be transactivated following an oxidative stress mediated by O-1(2). In addition, using HIV-1 latently infected promonocytes or lymphocytes, it can be shown that virus reactivation can be induced through a sublethal dose of O-1(2) generated intracellularly. An extracellular generation of O-1(2) can promote a substantial lethal effect without HIV-1 reactivation. These data may be relevant to the understanding of the events converting a latent infection into a productive one and to the appearance of the acquired immune deficiency syndrome. [less ▲]

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See detailHIV-1 reactivation after an oxidative stress
Legrand, Sylvie ULg; Vaira, Dolorès ULg; Rentier, Bernard ULg et al

in LinkVIII International Conference on AIDS/III STD World Congress, Amsterdam, the Netherlands 19-24 July 1992 (1992)

OBJECTIVES: A common denominator shared by several HIV-1 reactivation agents such as certain cytokines, UV irradiation and heat shock is their ability to cause stress response. Consequently, we have ... [more ▼]

OBJECTIVES: A common denominator shared by several HIV-1 reactivation agents such as certain cytokines, UV irradiation and heat shock is their ability to cause stress response. Consequently, we have investigated the effects of oxidative stress on HIV-1 reactivation, knowing that HIV-1 latently infected T cells can be exposed in vivo to such a stress when blood phagocytes are stimulated during inflammatory reactions. METHODS: The promonocytic (U1) and lymphocytic (ACH-2) cell lines, both HIV-1 chronically infected, were used to study the reactivation phenomenon. To test wether HIV-1 reactivation is mediated by LTR transactivation, the HeLa HIV-1 CAT cell line, which carries an integrated DNA cartridge containing CAT gene under control of HIV-1 LTR, was also exposed to an oxidative stress. RESULTS: Hydrogen peroxide exposure of U1 cells leads to an increased reverse transcriptase (RT) activity in supernatant fluid. Over the optimal concentrations range (0.5 to 1 mM), a four to fivefold stimulation level is reached. Below these concentrations, stress conditions are not sufficient and above, they induce a too important lethal effect. Immunofluorescence carried out on stressed U1 cells shows that H2O2 leads to HIV-1 gene expression activation and not to a release of viral particles from damaged cells. H2O2 also induces a stimulation of CAT activity in HeLa HIV-1 CAT cells. Intracellular singulet oxygen (1O2) is also able to induce an increase of RT activity in supernatant fluid of U1 and ACH-2 cells and a stimulation of CAT activity in HeLa HIV-1 CAT cells. A dose-response curve can also be demonstrated. In order to transpose these in vitro experiments to situations encountered in vivo, activated phagocytes were cocultivated with HeLa HIV-1 CAT cells. A weak stimulation of CAT activity was detected. CONCLUSIONS: Cellular oxidative damages induce HIV-1 LTR transactivation leading to viral gene expression and consequently to a burst of virus production. DNA damages induced by oxidative stress could be at the onset of HIV-1 reactivation. Experiments are now in progress to elucidate the mechanisms leading to HIV-1 reactivation after an oxidative stress. [less ▲]

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See detailHIV-1 reactivation after an oxidative stress
Legrand, Sylvie ULg; Hoebeke, Maryse ULg; Vaira, Dolorès ULg et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100

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See detailActivation of human immunodeficiency virus type 1 by an oxidative stress
Legrand-Poels, Sylvie ULg; VAIRA, Dolorès ULg; PINCEMAIL, Joël ULg et al

in AIDS Research and Human Retroviruses (1990)

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See detailReactivation of HIV-1 after an oxidative stress
Piette, Jacques ULg; Legrand-Poels, Sylvie; Vaira, Dolorès ULg et al

in Free Radicals in Biology and Medicine (1990), 9(Suppl. A), 5

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See detailDiagnosis by PCR of HIV-1 infection in seronegative individuals at risk
Vaira, Dolorès ULg; François-Gérard, Ch.; Doppagne, A. et al

in AIDS Research and Human Retroviruses (1990), 6(2), 173-174

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See detailMéthodes de détection de l'infection par le virus de l'immunodéficience humaine (HIV)
François-Gérard, Ch.; Warling, Ch.; Vaira, Dolorès ULg et al

in Revue Médicale de Liège (1989), 44(8), 295-305

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See detailDiagnosis of HIV-1 in African couples : comparison of serology and PCR
Vaira, Dolorès ULg; Sondag, Danièle ULg; François-Gérard, C. et al

in Cinquième conférence internationale sur le SIDA : le défi scientifique et social (1989)

OBJECTIVE: Search for the rate of HIV-1 contamination among seronegative sexual partners of seropositive individuals. METHODS: Classical serological methods (EIA, WB) and PCR. SERIES: 36 heterosexual ... [more ▼]

OBJECTIVE: Search for the rate of HIV-1 contamination among seronegative sexual partners of seropositive individuals. METHODS: Classical serological methods (EIA, WB) and PCR. SERIES: 36 heterosexual couples from central Africa, accounting for a total of 73 persons: 13/37 seropositive women, 23/36 seropositive men. All couples were serologically discordant, i.e. one partner was seropositive. CONCLUSIONS: In such a population, particularly at risk of HIV contamination, the rate of false negative serological diagnosis reached 70%. [less ▲]

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See detailAbsence of seroconversion in a PCR positive person 18 months after transfusion of HIV infected blood
Vaira, Dolorès ULg; François-Gérard, C.; Rentier, Bernard ULg et al

in Vox Sanguinis (1989), 57(3), 220-221

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See detailIn vivo model of varicella-zoster virus latency in the nervous system
Sadzot-Delvaux, Catherine ULg; Merville-Louis, Marie Paule; Delrée, P. et al

Conference (1989)

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See detailInterprétation du Western Blot (WB)
François-Gérard, C.; Vaira, Dolorès ULg; Rentier, Bernard ULg et al

Conference (1988)

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See detailResistance to exogenous MMTV infection in a strain of "Swiss" mice is correlated with the presence of an endogenous proviral gene, mtv-3
Hainaut, Pierre; Vaira, Dolorès ULg; Calberg-Bacq, Claire Michèle et al

Poster (1987)

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See detailNatural infection of Swiss mice by the Mouse Mammary Tumor Virus (MMTV). 2. Studies on the pathway of infection
Hainaut, P.; Vaira, Dolorès ULg; Calberg-Bacq, Claire Michelle et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1984), 92(1), 28

Detailed reference viewed: 7 (4 ULg)