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See detailEpithelial-to-Mesenchymal Transition in Hpv-33-Transfected Cervical Keratinocytes Is Associated with Increased Invasiveness and Expression of Gelatinase A
Gilles, Christine ULg; Polette, M.; Piette, Jacques ULg et al

in International Journal of Cancer = Journal International du Cancer (1994), 59(5), 661-6

The invasive potential of a set of HPV-33- and HPV-33 + ras-transfected cervical keratinocytes was investigated. These cell lines were previously separated into 2 groups according to their behavior on ... [more ▼]

The invasive potential of a set of HPV-33- and HPV-33 + ras-transfected cervical keratinocytes was investigated. These cell lines were previously separated into 2 groups according to their behavior on collagen rafts. Cell lines from the first group reconstituted CINIII-like lesions, whereas cell lines from the second group reconstituted epithelia comparable to micro-invasive carcinomas. They were thus postulated to represent distinct stages of cervical carcinogenesis. The present results have shown that lines from group I, which have conserved an epithelial morphology in monolayer, (i) could not invade matrigel when tested in a modified Boyden chamber assay, (ii) produced solely gelatinase B and (iii) were unable to activate exogenous gelatinase A. On the other hand, lines from group II associated epithelial-to-mesenchymal transition (acquisition of elongated morphology, vimentin positivity) with high in vitro invasive potential and with the ability both to produce and to activate gelatinase A. These results strongly support the hypothesis that the epithelial-to-mesenchymal transition and the associated events might be implicated in the progression to the metastatic phenotype. [less ▲]

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See detailVaricelle et zona: Virus VZV, étiologie, complications et traitement
Rentier, Bernard ULg; Piette, Jacques ULg; Nikkels, Arjen ULg

in Patient Care (1994), 17

La varicelle est une affection très fréquente et très contagieuse. Presque toujours bénigne chez l'enfant, elle peut être plus grave chez l'adulte. Quant au zona, il frappe essentiellement les adultes. C ... [more ▼]

La varicelle est une affection très fréquente et très contagieuse. Presque toujours bénigne chez l'enfant, elle peut être plus grave chez l'adulte. Quant au zona, il frappe essentiellement les adultes. C'est le seul et même virus de la varicelle et du zona (Varicella-Zoster Virus, VZV) qui constitue le lien commun entre les 2 maladies. Sa particularité est de fonctionner par disparition-réactivation. Le VZV appartient à la famille des Herpesviridae. Proche des autres Herpès-virus comme les virus de l'Herpes simplex (HSV-1 et HSV-2), le cytomégalovirus (CMV), le virus d'Epstein-Barr (EBV) et les Herpèsvirus humains 6 et 7 (HHV-6 et HHV-7) nouvellement décrits, il possède néanmoins certaines caractéristiques propres. [less ▲]

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See detailViral glycoproteins in herpesviridae granulomas
Nikkels, Arjen ULg; Debrus, S.; Delvenne, Philippe ULg et al

in American Journal of Dermatopathology (1994), 16(6), 588-592

Granulomatous reactions after varicella zoster virus (VZV) and herpes simplex virus (HSV) infections are rare, and their pathogenesis remains unclear. We studied by immunohistochemistry and in situ ... [more ▼]

Granulomatous reactions after varicella zoster virus (VZV) and herpes simplex virus (HSV) infections are rare, and their pathogenesis remains unclear. We studied by immunohistochemistry and in situ hybridization early granulomatous reactions after VZV and HSV infections. In the five cases studied, the VZV glycoproteins gp I and gp II were present in cells abutted to altered vessels, but the corresponding genome sequences were disclosed in similar locations in only one of these cases. In an immunocompromised patient with diffuse HSV eruption, HSV I antigens were present in cells of the reticular dermis, while viral nucleic acids were not evident. Immunophenotyping of the granulomas showed strong Mac 387 and CD68 positive labelings of macrophages/monocytes, without any involvement of Factor XIIIa-positive cells. These findings suggest that the major viral envelope glycoproteins, rather than complete viral particles could trigger granuloma formation following HSV and VZV skin infections. [less ▲]

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See detailDifferentiation Ability and Oncogenic Potential of Hpv-33- and Hpv-33 + Ras-Transfected Keratinocytes
Gilles, Christine ULg; Piette, Jacques ULg; Peter, W. et al

in International Journal of Cancer = Journal International du Cancer (1994), 58(6), 847-54

Five HPV-33-immortalized and 5 HPV-33 + ras-transfected cell lines were characterized in terms of growth in soft agar, tumorigenic potential in nude mice, p21 expression, morphology and expression of ... [more ▼]

Five HPV-33-immortalized and 5 HPV-33 + ras-transfected cell lines were characterized in terms of growth in soft agar, tumorigenic potential in nude mice, p21 expression, morphology and expression of differentiation markers in organotypic cultures. No striking differences were observed between the HPV-33-immortalized cell lines and their corresponding ras-transfected counterparts as regards their tumorigenicity in nude mice (only one cell line was able to develop tumors in nude mice) or their behavior on lifted collagen gels. However, all the ras-transfected cell lines gave rise to colonies in soft agar while only 2 HPV-33-transfected lines (CK1 and CK4) displayed this property. The 10 cell lines could be divided into 2 groups with respect to their phenotype in monolayer and in organotypic cultures. Lines from group I (CK2, 3, 5 and their ras-transfected homologous lines) shared a typical epithelial phenotype in monolayer and the ability (a) to form an epithelium similar to a CIN-III lesion and (b) to strongly express keratins K1-K10 and involucrin in organotypic cultures. On the other hand, for the lines from group II (CK1, CK4, CK1EJ7 and CK4EJ5), there was a correlation between an elongated phenotype in monolayer and the property (a) to form a structure similar to a microinvasive carcinoma and (b) to express vimentin and keratins K8-K18. These cell lines, exhibiting various transformation-associated alterations, can be considered as an in vitro model representing various stages of HPV-33-associated cervical carcinogenesis. [less ▲]

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See detailRegulation of Varicella-Zoster virus 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 detailMeningoradiculoneuritis due to acyclovir-resistant varicella zoster virus in an acquired immune deficiency syndrome patient
Snoeck, R.; Gérard, M.; Sadzot-Delvaux, Catherine ULg et al

in Journal of Medical Virology (1994), 42(4), 338-347

Varicella zoster virus (VZV) is recognized as one of the major viral pathogens reactivated in patients with the acquired immune deficiency syndrome (AIDS). We report the case of meningoradiculoneuritis in ... [more ▼]

Varicella zoster virus (VZV) is recognized as one of the major viral pathogens reactivated in patients with the acquired immune deficiency syndrome (AIDS). We report the case of meningoradiculoneuritis in an AIDS patient, associated with the isolation in the cerebrospinal fluid (CSF) of a thymidine kinase (TK)-deficient, acyclovir (ACV)-resistant strain of VZV. Although the virus was sensitive in vitro to phosphonoformate (PFA), the patient did not improve during PFA therapy and finally died. Several VZV strains isolated from this patient (including two isolates from the patient's CSF) were analyzed for their TK activity and subsequently the viral TK gene was sequenced showing a major deletion leading to a truncated protein. Their susceptibility to several antiviral agents including ACV, PFA, (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU), 9-beta-D-arabinofuranosyladenine (vidarabine), (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl) cytosine (HPMPC), and (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA) was evaluated. All the virus strains isolated from this patient remained sensitive to HPMPA and HPMPC, pointing to the potential usefulness of these acyclic nucleoside phosphonates for the treatment of ACV-resistant VZV infections in immunocompromised patients. (C) 1994 Wiley-Liss, Inc. [less ▲]

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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 detailVaricelle et zona: virus VZV, étiologie, complications et traitement
Rentier, Bernard ULg; Piette, Jacques ULg; Nikkels, Arjen ULg

in Patient Care (1994), (17), 35-47

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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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