References of "Piette, Jacques"
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See detailRegulation of VZV gene expression by the IE62 protein and mutational dissection of the IE62 protein
Baudoux, Laurence; Defechereux, Patricia; Rentier, Bernard ULg et al

Conference (1994)

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See detailStimulation of glutatione-peroxidase activity decreases HIV type-1 activation after oxidative stress
Sappey, C.; Legrand, Sylvie ULg; Best-Belopmme, M. et al

in AIDS Research and Human Retroviruses (1994), 10(11), 1451-1461

Am important aspect of human immunodeficiency virus (HIV-1) infection is the regulation of its expression by nuclear factor kappa B (NF-kappa B) by redox-controlled signal transduction pathways. In this ... [more ▼]

Am important aspect of human immunodeficiency virus (HIV-1) infection is the regulation of its expression by nuclear factor kappa B (NF-kappa B) by redox-controlled signal transduction pathways. In this study, we demonstrate that selenium supplementation can effectively increase glutathione peroxidase (GPx) activity in latently infected T lymphocytes. The Se-supplemented cells exhibited an important protection against the cytotoxic and reactivating effects of hydrogen peroxide (H2O2). Concomitantly, NF-kappa B activation by H2O2 was also decreased in Se-supplemented cells. Selenium stimulation of GPx activity also induces a protective effect against cell activation by tumor necrosis factor alpha (TNF-alpha) but less significantly by phorbol esters such as PMA. These Se-mediated effects were specific because they were not found when AP-1 DNA-binding activity was studied after H2O2-induced stress. Hyperthermia was also studied because it could promote intracellular electron leakage in electron transport chains. Elevating the temperature to 42 degrees C did not induce NF-kappa B directly. Rather, it sensitized infected cells to subsequent oxidative stress by H2O2, demonstrating the importance of hyperthermia, often associated with opportunistic infections in the development of immunodeficiency. In this case, Se induced partial protection against the sensitizing effect of hyperthermia. [less ▲]

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See detailCausative role of VZV in two fatal disseminated infections
Nikkels, Arjen ULg; Debrus, S.; Sadzot-Delvaux, Catherine ULg et al

Conference (1994)

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See detailCharacterization of an in vivo model of VZV latency in the nervous system
Sadzot-Delvaux, Catherine ULg; Nikkels, Arjen ULg; Debrus, S. et al

Conference (1994)

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See detailCharacterization of the regulatory functions of varicella-zoster virus open reading frame-4 gene-product
Defechereux, Patricia; Melen-Lamalle, Laurence ULg; Baudoux, Laurence et al

in Journal of Virology (1993), 67(7), 4379-4385

Varicella-zoster virus (VZV) open reading frame 4 (ORF4) encodes a protein with a predicted molecular weight of 51,540 presenting amino acid sequence homology with the immediate-early regulatory protein ... [more ▼]

Varicella-zoster virus (VZV) open reading frame 4 (ORF4) encodes a protein with a predicted molecular weight of 51,540 presenting amino acid sequence homology with the immediate-early regulatory protein ICP27 of herpes simplex virus type 1. To investigate the regulatory properties of the ORF4 gene product, we performed a series of transient expression assays in Vero cells, using a plasmid expressing ORF4 as effector and several VZV genes and heterologous genes as targets. The VZV target plasmids contained promoter/regulatory regions from genes belonging to the three putative VZV kinetic classes fused to the chloramphenicol acetyltransferase (CAT) gene. The heterologous target plasmids consisted of promoter/regulatory regions of human cytomegalovirus, Rous sarcoma virus, and human immunodeficiency virus type 1 fused to the reporter gene. These experiments demonstrated that the ORF4 gene product activated expression of ORF62 in a dose-dependent fashion but had no effect on the expression of the three other putative immediate-early genes (ORF4, ORF61, and ORF63). When various amounts of ORF4 were transfected in the presence of early gene promoters, dose-dependent transactivation was evidenced with the thymidine kinase gene (ORF36) and the major DNA-binding protein gene (ORF29) promoters; interestingly, little activity was detected with the promoter of the DNA polymerase gene (ORF28). No activation of late gene expression, represented by the glycoprotein I and glycoprotein II genes, was seen even over a wide range of concentrations of input ORF4 plasmid. Expression of pCMVCAT, pRSVCAT, and pHIVCAT was also stimulated by the ORF4 gene product. CAT mRNA analysis showed that activation of VZV target promoters occurs at the transcriptional and/or posttranscriptional level. [less ▲]

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See detailDestruction of Stearic Acid Nitroxyl Radicals Mediated by Photoexcited Merocyanine 540 in Liposomal and Micellar Systems
Hoebeke, Maryse ULg; Seret, Alain ULg; Piette, Jacques ULg et al

in Biochemistry (1993), 32(10), 2730-2736

Fatty acid spin labels have been included into liposomes and micelles, in order to study the photochemical behavior of merocyanine 540 toward nitroxyl radicals situated at various depths in the bilayer or ... [more ▼]

Fatty acid spin labels have been included into liposomes and micelles, in order to study the photochemical behavior of merocyanine 540 toward nitroxyl radicals situated at various depths in the bilayer or the surfactant layer. Visible illumination of the dye, either free in ethanol or bound to liposomes or micelles, leads to the reduction of the electron spin resonance signal of the label. The efficiency of the interaction between merocyanine 540 and spin labels depends on the depth at which the nitroxyl moiety is localized in the micelle or vesicle. Fluorescence measurements indicate that the first excited singlet state of merocyanine 540 is not directly implicated in the reaction mechanism. Flash photolysis experiments conducted in aqueous solutions of hexadecyltrimethylammonium bromide micelles show that the presence of nitroxyl radical decreases the rate constant of triplet decay in a concentration-dependent fashion. The corresponding quenching rate constant (kq) is determined for the different spin labels. The kq values and the reduction rates of ESR signal show the same dependence on the localization of the nitroxyl moiety in the micelles. [less ▲]

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See detailImmortalization of Human Cervical Keratinocytes by Human Papillomavirus Type 33
Gilles, Christine ULg; Piette, Jacques ULg; Rombouts, S. et al

in International Journal of Cancer = Journal International du Cancer (1993), 53(5), 872-9

Ten immortalized cell lines were established by transfection of human cervical keratinocytes (CK) with HPV-33 DNA and some of their characteristics were investigated. The following observations were made ... [more ▼]

Ten immortalized cell lines were established by transfection of human cervical keratinocytes (CK) with HPV-33 DNA and some of their characteristics were investigated. The following observations were made: (a) several cell lines have reached over 100 population doublings in vitro; (b) 3 transcripts were observed, 2 being encoded by the E6/E7 open reading frames (ORFs); (c) cytogenetic analyses showed important genetic modifications such as aneuploidy and isochromosome formation of the q arm of chromosome 8; (d) 2 of the 10 cell lines developed colonies in soft agar but none was able to form tumors when injected s.c. into nude mice; (e) Southern analysis suggested that a single copy of HPV-33 is integrated at a single common site within the genome of the 10 cell lines. These immortalized cell lines should be useful for studying mechanisms involved in proliferation, differentiation and neoplastic transformation of CK by HPV-33. [less ▲]

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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 detailComparative immunohistochemical study of herpes-simplex and varicella-zoster infections
Nikkels, Arjen ULg; Debrus, S.; Sadzot-Delvaux, Catherine ULg et al

in Virchows Archiv. A : Pathological Anatomy and Histopathology (1993), 422(2), 121-126

Herpes simplex (HSV) and varicella-zoster (VZV) skin infections share so many histological similarities that distinguishing between them may prove to be impossible. We developed and characterized a new ... [more ▼]

Herpes simplex (HSV) and varicella-zoster (VZV) skin infections share so many histological similarities that distinguishing between them may prove to be impossible. We developed and characterized a new monoclonal antibody, VL8, IgG kappa isotype, directed to the VZV envelope glycoprotein gpI. Immunohistochemistry with VL8 appeared highly sensitive and specific on formalin-fixed paraffin-embedded biopsies and a clear-cut distinction between HSV and VZV infections was possible. The pattern of VL8 immunolabelling in VZV infections was strikingly different from that found in HSV infections studied with polyclonal antibodies to HSV I and II. Double immunolabelling revealed the VL8 positivity of sebaceous cells, endothelial cells, Mac 387-and CD68-positive monocyte-macrophages, and factor XIIIa-positive perivascular, perineural and interstitial dendrocytes. Intracytoplasmic VL8 labelling of endothelial cells and perivascular dendrocytes was found at the site of leukocytoclastic vasculitis. [less ▲]

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See detailIntracellular damages induced by singlet oxygen are signals for HIV-1 reactivation
Piette, Jacques ULg; Legrand-Poels, Sylvie ULg

in Journal of Free Radicals in Biology & Medicine (1993)

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See detailMeningoradiculoneuritis due to acyclovir-resistant varicella-zoster virus in a patient with aids
Snoeck, R.; Gerard, M.; Sadzot-Delvaux, Catherine ULg et al

in Journal of Infectious Diseases (1993), 168(5), 1330-1331

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See detailSinglet Oxygen Quantum Yield of Sulfur and Selenium Analogs of Psoralen
Seret, Alain ULg; Piette, Jacques ULg; Jakobs, Andréas et al

in Photochemistry and Photobiology (1992), 56(3), 409-412

The quantum yield of singlet oxygen production by eight newly synthesized sulfur and selenium analogs of psoralen irradiated with UV-A (366 nm) has been determined in CCl4 with the help of the steady ... [more ▼]

The quantum yield of singlet oxygen production by eight newly synthesized sulfur and selenium analogs of psoralen irradiated with UV-A (366 nm) has been determined in CCl4 with the help of the steady state luminescence technique. The new psoralen derivatives are generally better singlet oxygen producers than psoralen itself. In particular, the replacement of selenophene for furan and/or of thiopyrone for pyrone induces an important enhancement of the singlet oxygen quantum yield. [less ▲]

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See detailFlow cytometric method for the detection of gpI antigens of varicella zoster virus and evaluation of anti-VZV agents
Snoeck, R.; Schols, D.; Sadzot-Delvaux, Catherine ULg et al

in Journal of Virological Methods (1992), 38(2), 243-254

Varicella zoster virus (VZV) is responsible for a primary infection (varicella.) and, upon reactivation, zoster, which in immunocompromised patients, may both lead to life-threatening disseminated disease ... [more ▼]

Varicella zoster virus (VZV) is responsible for a primary infection (varicella.) and, upon reactivation, zoster, which in immunocompromised patients, may both lead to life-threatening disseminated disease. There is a great need for antiviral compounds that are effective inhibitors of VZV replication and for rapid and accurate methods for evaluating viral sensitivity to candidate anti-VZV drugs. With the monoclonal antibody (mAb) (VL8), which is directed against the gpI of VZV, and using the fluorescence-activated cell sorter (FACS) we could readily demonstrate expression of the VZV gpI antigen at 3-4 days after VZV infection. (E)-5-(2-Bromovinyl)-2'-deoxyuridine (BVDU), (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA) and (S)-1-(3-hydro-xy-2-phosphonylmethoxypropyl)cytosine (HPMC) were shown to be potent inhibitors of VZV replication by this assay. HPMPA and HPMPC were also active against thymidine kinase-deficient (TK-) VZV whereas BVDU was not. The flow cytometric method based on the use of mAb VL8 may be of considerable help for the early diagnosis of VZV infection and evaluation of viral sensitivity to antiviral drugs. [less ▲]

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See detailHigh-rate of multiple genital HPV infections detected by DNA hybridization
Lauricella-Lefèbvre, M. A.; Piette, Jacques ULg; Lifrange, Eric ULg et al

in Journal of Medical Virology (1992), 36(4), 265-270

Cervical smears collected from 450 patients involved in a clinical follow-up of cervical human papillomaviruses (HPV) infections were screened for the presence of HPV 6b, 11, 16, and 18 DNA by both dot ... [more ▼]

Cervical smears collected from 450 patients involved in a clinical follow-up of cervical human papillomaviruses (HPV) infections were screened for the presence of HPV 6b, 11, 16, and 18 DNA by both dot blot and southern blot hybridization methods. Using very high stringency hybridization assays, the four HPV types could be easily distinguished by dot blotting. After a preliminary clinical sorting, 42.9% of the samples were found to be HPV-positive. Among the samples infected by a single HPV, type 16 was the most frequent (25.4% of the positive samples) followed by 6b (19.7%), 11 (8.3%), and 18 (7.2%). Double or even multiple infections by the different HPV types were detected at a very high rate (39.4% of the positive samples). [less ▲]

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See detailDetection by PCR of varicella zoster virus DNA during primary infection in mice
Plumier, Jean-Christophe ULg; Sadzot-Delvaux, Catherine ULg; Debrus, Serge et al

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

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See detailEtude ultrastructure de l'organisation du nucléoïde du virus de la varicelle et du zona
Schoonbroodt, Sonia; Piette, Jacques ULg; Rentier, Bernard ULg

in Bulletin de la Société Royale des Sciences de Liège (1992), 60(6), 373-383

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See detailHuman papillomavirus type 33 upstream regulatory elements can control gene expression in human cervical keratinocytes
Lauricella-Lefèbvre, M. A.; Rentier, Bernard ULg; Piette, Jacques ULg

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

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