Research in virology最新文献

{"title":"Biological and clinical responses of West African sheep to Crimean-Congo haemorrhagic fever virus experimental infection","authors":"J.-P. Gonzalez , J.-L. Camicas , J.-P. Cornet , M.L. Wilson","doi":"10.1016/S0923-2516(99)80013-2","DOIUrl":"10.1016/S0923-2516(99)80013-2","url":null,"abstract":"<div><p>West African sheep appear to play a central role as virus hosts in the maintenance cycle of Crimean-Congo haemorrhagic fever (CCHF) virus in endemic areas and also because of their role as a principal host of the CCHF virus tick vector. In an effort to clarify CCHF epidemiological significance in sheep, we studied the biological and clinical aspects of sheep experimentally infected with CCHF virus. West Africansheep breeds were infected either by intraperitoneal inoculation or by infestation with experimentally CCHF-virus-infected ticks (<em>Hyalomma truncatum</em>). A total of 17 sheep including controls as well as S lambs from their progeny were monitored. A moderate but constant fever was observed (39.7°C ± +10.3) which correlates with the viraemia. Virus was reisolated from blood samples taken from day 3 to day 9 postinfection (p.i.) at a mean titre of 3.3 log LD<sub>50</sub>/ml. The virus was detected for a period of time of 7 days in non-immune sheep ana for less than 4 days in previously immunized sheep. In non-immune sheep, antibody detected by ELISA showed an IgM response on day 7 p.i., followed by an IgG response one day later. Five infected sheep, surveyed for liver and kidney biological markers, showed hepatic dysfunction with a moderate serum aspartate transferase rise to 210 U/l. Out of four sheep tested for blood markers, two showed an abnormal blood cell count, with marked neutrophilia of up to 63% lasting for two weeks. Infected pregnant ewes produced antibodies in their milk at a significant titre (1:1,000), and antibodies were recovered in the sera of nursing lambs from their first meal to 50 days after birth. These findings are discussed; they demonstrate that, in spite of a high turnover of local sheep herds (median age of 3 years) and long-term CCHF antibody persistence (> 3 years), sheep can be infected and efficiently transmit the virus at least once in a lifetime.</p></div><div><p>Dans l'épidémiologie de la fièvre hémorragique de Crimée-Congo (FHCC) en Afrique de l'Ouest, le mouton est l'hôte domestique essentiel qui favorise en zone d'endémie le passage du virus à l'homme par l'intermédiaire du vecteur acarien qui l'infeste. Afin de clarifier le rôle du mouton dans l'épidémiologie de la FHCC, nous avons étudié de façon expérimentale son infection par le virus.</p><p>Des moutons de races locales ont été infectés par le virus de la FHCC par injection intrapéritonéale ou par morsure de tiques (<em>Hyalomma truncatum</em>) expérimentalement infectées ; 17 moutons y compris les témoins et cinq agneaux ont été suivis du point de vue clinique et aussi biologique. Les données cliniques ont montré, avec l'apparition de la virémie, une élévation modérée de la température (39,7 °C ± 0.3). Le virus a été réisolé (titre moyen de 3,3 log DI<sub>50</sub>/ml), à partir d'échantillons de sang prélevés entre le 3<sup>e</sup> et le 9<sup>e</sup> jour post-inoculation (p.i.). La virémie a été mise en évidence pour une période de ","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 445-455"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80013-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20829056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"S. Michelson","doi":"10.1016/S0923-2516(99)80016-8","DOIUrl":"10.1016/S0923-2516(99)80016-8","url":null,"abstract":"","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Page 465"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80016-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56192739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic evolution of the hypervariable region 1 in hepatitis C virus carriers with normal aminotransferase activities","authors":"A. Ravaggi ,&nbsp;A. Rossini ,&nbsp;G. Fiordalisi ,&nbsp;A. Albertini ,&nbsp;E. Cariani","doi":"10.1016/S0923-2516(99)80012-0","DOIUrl":"10.1016/S0923-2516(99)80012-0","url":null,"abstract":"<div><p>L'évolution de séquence de la région hypervariable 1 (RHV1) du virus de l'hépatite C pendant un an d'observation a été analysée chez 10 porteurs chroniques avec transaminases normales, dont 5 étaient infectés par le génotype 1 et 5 par le génotype 2. Pendant la période d'observation, les sujets infectés par le génotype 1 ont eu des plus larges fluctuations des niveaux d'ARN par rapport à ceux infectés par le génotype 2. Les degrés d'hétérogénéité et d'évolution de séquence sont plus élevés chez les sujets infectés par le génotype 2. L'ensemble des résultats est compatible avec une pression immunitaire majeure sur la RVH1 du génotype 2, indépendemment des valeurs de transaminases.</p></div>","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 439-444"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80012-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20829052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inducible expression of herpes simplex virus thymidine kinase from a bicistronic HIV1 vector","authors":"A. Marcello,&nbsp;I. Giaretta","doi":"10.1016/S0923-2516(99)80010-7","DOIUrl":"10.1016/S0923-2516(99)80010-7","url":null,"abstract":"&lt;div&gt;&lt;p&gt;The possibility of protecting human CD4&lt;sup&gt;+&lt;/sup&gt; lymphocytes from human immunodeficiency virus type 1 (HIV1) infection, through a suicide mechanism elicited by the HIV1 transcription apparatus itself, offers a potentially useful approach for gene therapy of the acquired immunodeficiency syndrome. A replication-defective lentiviral HIV1 vector (HYIRES-TK) was designed to carry both the hygromycin (Hy) phosphotransferase gene for positive selection and the thymidine kinase (TK) gene of herpes simplex virus driven by the viral long terminal repeat (LTR). The internal ribosome entry site (1RES) from encephalomyocarditis virus was placed between the two genes for their efficient simultaneous translation. Transient expression of active TK into transfected COS-1 cells was shown to be induced by Tat and Rev over a detectable basal level. By providing the missing viral proteins &lt;em&gt;in trans&lt;/em&gt;, recombinant viruses were generated and used to transduce Jurkat cells. The Hy-resistant population of cells was sensitive to ganciclovir (GCV) and acyclovir (ACV), a result consistent with a basal level of TK expression. Cocultivation of transduced cells with cells chronically infected with HIV in the presence of 10 μM ACV, a concentration non-toxic for the uninfected cells, resulted in increased killing of cells transduced with the HY-IRES-TK vector. These data indicate that two genes can be expressed from the viral LTR in the context of an HIV1 vector, with the aid of an 1RES sequence. The expression is inducible by the HIV proteins Tat and Rev and it is possible to specifically kill infected cells with subtoxic concentrations of drug. To decrease the sensitivity of the transduced cells towards GCV, a variant vector expressing a truncated TK was constructed. The truncated version was expressed at levels similar to those of wild-type TK but induced sensitivity towards GCV in transduced cells that was intermediate between that of untransduced cells and of cells expressing wild-type TK.&lt;/p&gt;&lt;/div&gt;&lt;div&gt;&lt;p&gt;La possibilité de protéger les lymphocytes CD4&lt;sup&gt;+&lt;/sup&gt; humains de l'infection par le VIH1 à travers un mécanisme suicide provoqué par le dispositif même de transcription du VIH1, offre une approche potentiellement utile pour une thérapie génique du SIDA.&lt;/p&gt;&lt;p&gt;Un vecteur VIH1 lentiviral de replication défectueuse, HY-IRES-TK, a été conçu pour porter à la fois le gène de l'hygromycine (HY) phosphotransférase, pour une sélection positive, et le gène de la thymidine kinase (TK) du virus de l'herpès humain entrainés par le LTR (long terminal repeat) lentiviral. L'IRES (internai ribosome entry site) du virus de l'encéphalomyocardite a été placé entre les deux gènes afin que leur translation soit simultanée. L'expression transitoire de TK active dans les cellules COS-1 transfectées a été induite par les protéines Tat et Rev à un niveau supérieur au niveau basique détectable. L'apport en &lt;em&gt;trans&lt;/em&gt; des protéines virales manquantes a permis de générer de","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 419-431"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80010-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20828462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular epidemiology of Malaysian dengue 2 viruses isolated over twenty-five years (1968–1993)","authors":"M.-Y. Fong ,&nbsp;C.-L. Koh ,&nbsp;S.-K. Lam","doi":"10.1016/S0923-2516(99)80014-4","DOIUrl":"10.1016/S0923-2516(99)80014-4","url":null,"abstract":"<div><p>The limited sequencing approach was used to study the molecular epidemiology of 24 Malaysian dengue 2 viruses which were isolated between 1968 and 1993. The sequences of a 240-nucleotide-long region across the envelope/non-structural 1 protein (E/NS1) gene junction of the isolates were determined and analysed. Alignment and comparison of the nucleotide and deduced amino acid sequences of the isolates revealed that nucleotide changes occurred mostly at the third position of a particular codon and were of the transition (AG, CU) type. Five nucleotide changes resulted in amino acid substitutions. Pairwise comparisons of the nucleotide sequences gave divergence values ranging from 0 to 9.2%. At the amino acid level, the divergence ranged between 0 and 3.8%. Based on the 6% divergence as the cut-off point for genotypic classification, the isolates were grouped into two genotypes, I and II. Comparison of the nucleotide sequences of the Malaysian dengue isolates with those of the dengue viruses of other regions of the world revealed that members of genotypes I and II were closely related to viruses from the Indian Ocean and Western Pacific regions, respectively.</p></div><div><p>Une approche séquentielle a été utilisée pour l'étude de 24 souches de dengue 2 isolées en Malaisie entre 1968 et 1993. Nous avons déterminé et analysé les séquences d'une région de 240 nucléotides concernant la jonction génique E/NS1 (enveloppe/protéine 1 non structurale) des souches isolées: les modifications nucléotidiques apparaissent surtout en troisième position d'un codon particulier et sont du type (AG, CU) de transition. Cinq modifications nucléotidiques se caractérisent par des substitutions d'acides aminés. Des comparaisons par paires de séquences nucléotidiques révèlent des divergences allant de 0 à 9,2% ; au niveau des acides aminés les divergences vont de 0 à 2,8 % ; sur la base de 6% de divergences, on peut grouper les souches en deux génotypes, I et II. La comparaison des séquences nucléotidiques des souches de dengue isolées en Malaisie et des souches originaires d'autres pays montre que les virus ayant le génotype I ou II sont très apparentés à ceux des régions de l'Océan Indien et du Pacifique ouest, respectivement.</p></div>","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 457-464"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80014-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20829722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and patterns of HGV/GBV-C infection in patients with suspected HCV-related hepatitis","authors":"D. García de Viedma,&nbsp;R. Alonso,&nbsp;M. Rivera,&nbsp;M. Rodríguez-Créixems,&nbsp;E. Bouza","doi":"10.1016/S0923-2516(99)80011-9","DOIUrl":"10.1016/S0923-2516(99)80011-9","url":null,"abstract":"<div><p>Hepatitis G virus (HGV) is a recently described hepatotropic parenterally transmitted flavivirus. The presence of HGV was tested in 61 patients with a request for confirmation of HCV active infection. Thirty-two patients were in haemodialysis and 29 were referred from wards other than nephrology. Active HCV and HGV infections were determined by detection of their viral RNA in serum. Evaluation of previous HGV infection was carried out by detection of antibodies to E2 antigen. HCV prevalence was 62.29% (38/61). HGV-active infection was found in 11.47% (7/61) of the population studied: in 18.7% (6/32) of the haemodiarysed patients and in 3.4% (1/29) of patients belonging to the other group. HGV prevalence increased two-fold when previous infection was also considered. HGV clearance was prospectivery detected in 5 out of the 7 patients with active infection, and at an earlier stage for those patients coinfected with HCV. Anti-E2 seropositivity was associated with HGV clearance in only two patients.</p></div><div><p>La présence de HGV a été étudiée dans le plasma de 61 sujets chez lesquels on soupçonnait une infection par HCV: 32 suivaient des programmes d'hémodialyse et 29 étaient confiés à notre laboratoire en provenance de Services hors Néphrologie. La prévalence de l'infection active par HGV est de 11,47% dans l'ensemble de la population examinée; elle est six fois plus élevée chez les hémodialysés. Quand les cas d'infections anti-E2 positives sont pris en considération, la prévalence double par rapport aux sujets atteints d'infection active, le virus est éliminé 5 fois sur 7 et plus précocément dans les cas de coinfection par HCV. La négativation de HGV associée à la production d'anti-E2 a été observée dans 2 cas seulement.</p></div>","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 433-438"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80011-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20829051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure/antigenicity relationship of cyclic and linear peptides mimicking the V3 loop of HTV2 envelope glycoprotein","authors":"B. Belhadj Jrad ,&nbsp;S. Massou ,&nbsp;J. Czaplicki ,&nbsp;C. Moureau ,&nbsp;M. Moynier ,&nbsp;P. Fourquet ,&nbsp;A. Milon ,&nbsp;J.-C. Mazié ,&nbsp;E. Bahraoui","doi":"10.1016/S0923-2516(99)80004-1","DOIUrl":"10.1016/S0923-2516(99)80004-1","url":null,"abstract":"&lt;div&gt;&lt;p&gt;We report the structure and antigenicrty of the third variable region (V3) of the HIV2 envelope glycoprotein by the use of linear and cyclic peptides. To this end, a peptide mimicking this region was synthesized and purified, both as an iodoacetamidated linear peptide and a disulphide-bridged cyclic peptide. The cross-reactivity of three monoclonal antibodies (mAbs) produced against the envelope glycoprotein gp140 with the linear and cyclic peptides was tested with ELISA. The results showed that the cyclic peptide is a better ligand for the 3 mAbs 125-F, 125-J and 125-K. The avidity of the mAb/peptide interaction was further analysed by determining the concentration of linear or cyclic peptide leading to 50% inhibition of mAb-peptide complex formation (K&lt;sub&gt;0.5&lt;/sub&gt;). The K&lt;sub&gt;0.5&lt;/sub&gt; value of mAb 125-F, which displayed the best reactivity with gp140, was estimated to be 5 times higher for the linear (K&lt;sub&gt;0.5&lt;/sub&gt;=1.5×10&lt;sup&gt;−6&lt;/sup&gt; M) than for the cyclic peptide K&lt;sub&gt;0.5&lt;/sub&gt;=3×10&lt;sup&gt;−7&lt;/sup&gt; M). This indicates a higher affinity of m Ab 125-F for the cyclic peptide. mAb 125-J, which exhibited a lower avidity for the gp140 compared to mAb 125-F, had a similar affinity for the cyclic and the linear peptides (K&lt;sub&gt;0.5&lt;/sub&gt;=3×10&lt;sup&gt;−7&lt;/sup&gt; M). mAb 125-K had the lowest reactivity with gp140 and its binding to adsorbed peptide could not be inhibited by the soluble linear or cyclic peptide used up to 10&lt;sup&gt;−5&lt;/sup&gt; M. These results suggest that cyclic peptides may have a higher propensity for adopting a native-like structure for the peptide/antibody interaction. Nuclear magnetic resonance experiments at 25°C in phosphate buffer pH 5.4, however, showed that neither peptide displayed a well-defined structure.&lt;/p&gt;&lt;/div&gt;&lt;div&gt;&lt;p&gt;Pour l'étude de la relation structure/antigénicité de la troisième région variable (V3) de la glycoprotéine de l'enveloppe du virus de l'immunodéficience humaine VIH2, un peptide mimant cette région a été synthétisé et purifié, à la fois sous sa forme linéaire iodoacétamidée et sous une forme cyclique après formation du pont disulfure. La réactivité croisée de trois anticorps monoclonaux (mAbs) produits contre la glycoprotéine d'enveloppe gp140 a été testée par ELISA contre les formes linéaire et cyclique du peptide. Le peptide cyclique est mieux reconnu par les trois mAbs 125-F, 125-J et 125-K. L'avidité de l'interaction mAb/peptide a été mesurée par la détermination des concentrations des peptides linéaire et cyclique permettant d'inhiber de 50% (K&lt;sub&gt;0.5&lt;/sub&gt;) la formation du complexe mAb-peptide. La valeur du K&lt;sub&gt;0.5&lt;/sub&gt; pour le 125-F, qui montre la meilleure réactivite avec la gp140, a été trouvée cinq fois plus élevée pour le peptide linéaire (K&lt;sub&gt;0.5&lt;/sub&gt;= 1,5×10&lt;sup&gt;−6&lt;/sup&gt; M) que pour le peptide cyclique (K&lt;sub&gt;0.5&lt;/sub&gt;=3×10&lt;sup&gt;−7&lt;/sup&gt; M). La comparaison des K&lt;sub&gt;0.5&lt;/sub&gt; indique une meilleure affinité de 125-F pour le peptide cyclique. L'anticorps 125-J, qui montre une moindre avidit","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 363-373"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80004-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20828457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selection and characterization of two specific monoclonal antibodies directed against the two variants of human herpesvirus-6","authors":"C. Robert ,&nbsp;V. Massonneau ,&nbsp;P. Pothier ,&nbsp;A. Clément ,&nbsp;G. Hejblum ,&nbsp;P. Hubert ,&nbsp;J.-T. Aubin ,&nbsp;H. Agut","doi":"10.1016/S0923-2516(99)80008-9","DOIUrl":"10.1016/S0923-2516(99)80008-9","url":null,"abstract":"<div><p>Monoclonal antibodies (mAbs) specific for human herpesvirus-6 (HHV6) proteins were derived from the splenocytes of mice immunized with HHV6 TAN isolate-infected peripheral blood mononuclear cells. The two mAbs 8C8 and 7C7 reacted by means of immunofluorescence and immunoperoxidase assays with both variant A and variant B isolates giving two different staining patterns. In infected cells, cytoplasmic diffuse staining was observed with mAb 8C8, whereas intense nuclear staining was obtained with mAb 7C7. These different locations of viral target proteins were confirmed by confocal microscopy. The mAb 8C8 reacted with a family of six glycoproteins designated as the gp72 complex in the case of variant A strains and gp63 complex in the case of variant B strains. The endoglycosidases H and F reduced those glycoproteins to a putative precursor molecule of 58 kDa. The mAb 7C7 reacted with 116 and 109 kDa proteins with the two HHV6 variants. These two mAbs did not neutralize virion infectivity in the absence of complement. No cross-reactivity was observed when these mAbs were used in immunoperoxidase assay and immunoblotting against the proteins of human cytomegalovirus or other human herpesviruses. Thus, the two mAbs 8C8 and 7C7 may be valuable tools for the diagnosis and biological investigation of HHV6 infections.</p></div><div><p>Des anticorps monoclonaux ont été obtenus après immunisation de souris avec des lymphocytes sanguins périphériques infectés par un variant A de FHHV6 (human herpesvirus type 6), l'isolat TAN. Deux anticorps sélectionnés, 8C8 et 7C7, reconnaissent indifféremment les deux variants, A et B, en immunofluorescence et en immunoperoxydase sur cellules infectées. Deux aspects caractéristiques ont été observés en fluorescence, un marquage cytoplasmique diffus obtenu avec l'anticorps 8C8 et un marquage nucléaire intense obtenu avec l'anticorps 7C7. La microscopic confocale a permis de confirmer cette localisation intracellulaire des protéines reconnues par les deux anticorps. L'anticorps 8C8 réagit en ≪Werstern-blot≫ avec une famille de glycoprotéines, le complexe gp72 dans le cas des variants A, et le complexe gp63 dans le cas des variants B. L'anticorps 7C7 reconnaît deux protéines de 116 et 109 kDa de façon identique pour les deux variants. Aucune activité neutralisante de ces anticorps n'a été démontrée. Aucune réactivité croisée n'a été observée, en immunoperoxidase et en Werstern-blot, avec des protéines du cytomégalovirus ou celles d'autres virus herpétiques humains.</p></div>","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 403-411"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80008-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20828460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence that single-stranded DNA wrapped around the tubulofilamentous particles termed “nemaviruses” is the genome of the scrapie agent","authors":"H.K. Narang","doi":"10.1016/S0923-2516(99)80005-3","DOIUrl":"10.1016/S0923-2516(99)80005-3","url":null,"abstract":"<div><p>Homogenized brain tissue from scrapie-infected hamsters and uninfected hamsters was subjected to subcellular fractionation to isolate unique tubulofilamentous particles termed “nemaviruses”. Nucleic acid was purified from the concentrate by the phenol/chloroform extraction procedure and by alkaline gel electrophoresis; a single band of ssDNA corresponding to about 1.2 kb was visualized. The gel-purified ssDNA was mixed before inoculation with (a) MgCl₂, (b) lipofectin, (c) ssDNA-binding protein and (d) normal brain homogenate. Hamsters in group b, c and d injected with a mixture of ssDNA developed the clinical disease. Brain pathology revealed generalized vacuolation, while animals injected with ssDNA mixed with MgCl₂ and controls remained healthy. These results suggest that ssDNA is the genome of the scrapie agent.</p></div><div><p>Le tissu cérébral homogénéisé de hamsters infectés par la tremblante du mouton et non infectés a été soumis à des fractionnements subcellulaires en vue d'isoler les particules tubulofilamenteuses appelées ≪némavirus≫. À partir de l'extrait concentré, l'acide nucléique a été purifié par extraction phénol-chloroforme et par électrophorèse alcaline en gel ; une seule bande d'ADN simple brin correspondant à 1,2 kb a été visualisée. Avant inoculation cet ADN purifié sur gel a été mélangé à (a) MgCl₂, (b) la lipofectine, (c) la protéine fixant l'ADN et (d) l'homogénat de cerveau normal. Les hamsters des groupes b, c et d qui ont reçu les mélanges d'ADN ont présenté une maladie clinique. L'examen anatomopathologique du cerveau révèle une vacuolisation généralisée, mais les hamsters inoculés avec le mélange ADN + MgCl₂ de même que les témoins n'ont pas été atteints. Ces résultats suggèrent que l'ADN simple brin est le génome de l'agent de la tremblante.</p></div>","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 6","pages":"Pages 375-382"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)80005-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20828456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term lymphoblastoid interferon-α therapy for non-cirrhotic chronic hepatitis C: an Italian multicentre study on dose and duration of IFNα treatment","authors":"F. Piccinino,&nbsp;F.M. Felaco,&nbsp;E. Sagnelli,&nbsp;L. Aprea,&nbsp;V. Messina,&nbsp;G. Pasquale,&nbsp;P. Filippini,&nbsp;C. Scolastico","doi":"10.1016/S0923-2516(99)89007-4","DOIUrl":"10.1016/S0923-2516(99)89007-4","url":null,"abstract":"&lt;div&gt;&lt;p&gt;The aims of the study were to evaluate the long-term efficacy and tolerability of different doses of interferon-α (IFNα) and different durations of treatment in chronic hepatitis C by comparing 3 or 6 mega units (MUs) three times weekly given for either 12 or 24 months, and the possibility of obtaining a response in non-responder patients by increasing the dose or by administering IFN daily. A total of 504 patients with non-cirrhotic chronic hepatitis C enrolled in a multicentre study were consecutively assigned to receive either 3 (255 patients) or 6 MU (249 patients) of lymphoblastoid IFNα 3 times a week (tiw). At the 12th month of therapy, patients with normal aminotransferase (AMT) in both groups were either given IFN for an additional 12 months with an unmodified or halved dose, or else discontinued therapy. For patients with unmodified AMT levels after 6 months of therapy, the IFN dose was doubled in the 3-MU group, while it was administered at 3 MU daily in the 6-MU group. When no improvement was achieved, therapy was discontinued; otherwise it was prolonged until the 18th month. Patients were followed up for 12 months after discontinuing IFN. Of the 255 patients enrolled at 3 MU, therapy was stopped during the first 6 months in 36 patients (14.1%) because of side effects, and in 24 (9.4%) because of lack of cooperation. Of the remaining 195 patients at the 6th month of therapy, 119 (61%) had normal and 76 (39%) unmodified AMT levels; 14 of the 76 normalized AMT after doubling the dose of IFN, but only 5 (6.6%) had a sustained response. Of the 119 patients with normal AMT, 40 discontinued IFN at the 12th month (schedule A), 39 remained at 3 MU tiw (schedule B) and 40 were given a dose of 1.5 ML) tiw (schedule C) for an additional 12 months. At the end of follow-up, 23/40 (57.5%) patients in schedule A, 31/39 (79.5%) on schedule B and 29/40 (72.5%) on schedule C still had normal AMT (A vs. B p = 0.04). In an intention-to-treat analysis, the sustained response rate for patients enrolled at 3 MUs, including the 5 initial non-responders, was 34.5%. Of the 249 patients enrolled at 6 MU, therapy was discontinued during the first 6 months for 39 (15.7%) because of side effects, and for 27 (10.8%) because of lack of cooperation. Of the remaining 183 patients at the 6th month of therapy, 110 (60%) had normal and 73 (40%) unmodified AMT levels. Of the 73 patients, 55 accepted the daily regimen and 8 of them (14.5%) showed a sustained response. Of the 110 patients with normal AMT, 32 (29.1%), despite normalization of AMT, spontaneously discontinued IFN or reduced the dose because of a poor quality of life, while 78 continued with 6 MU until the 12th month, when therapy was discontinued for 28 (schedule A1); 24 patients were given an unmodified dose (schedule B1) and 26 a halved dose (schedule C1) for an additional 12 months. At the end of follow-up, 18/28 (64.3%) patients on schedule A1, 19/24 (79.2%) on schedule B1 and 19/26 (73.1%) on C1 st","PeriodicalId":77352,"journal":{"name":"Research in virology","volume":"149 5","pages":"Pages 283-291"},"PeriodicalIF":0.0,"publicationDate":"1998-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0923-2516(99)89007-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20787830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}