1,720,974 research outputs found
Cloning, restriction endonuclease mapping and partial sequence analysis of the genome of human herpesvirus 7 strain JI
No full textHuman herpesvirus 7 (HHV-7) is a recently isolated herpesvirus that has been shown to be related to human cytomegalovirus and human herpesvirus 6 and to be a member of the betaherpesvirus subgroup. Here we report the cloning, restriction endonuclease mapping and partial sequence analysis of HHV-7 strain JI DNA. Virus particles were obtained from the supernatant of infected SupT1 cells, the DNA isolated by proteinase K treatment-phenol extraction, and full-length viral DNA was purified and isolated on a pulsed-field gel. Aliquots of this highly purified material were treated in the following ways: (i) sonicated and end-repaired to create short randomly sheared fragments for cloning into M13mp 18-Smal vector DNA; (ii) cut with EcoRI for cloning into EcoRI-cut lambda ZAPII or lambda DASHII vectors; (iii) cut with BamHI for cloning into BamHI-cut lambda ZAP-Express or lambda DASHII vectors. Partial nucleotide sequencing of the M13 clones followed by detection of open reading frames and their translation allowed the identification of homologues through FASTA searches of the database. Relevant M13 clones were used as probes to isolate corresponding lambda phage clones, which could tentatively be mapped to the genome on the basis of presumed genetic collinearity between HHV-7 and HHV-6. Genomic "walking' between EcoRI and BamHI lambda genomic libraries enabled overlapping neighbouring clones to be identified and mapped. Each of these clones was analysed to map BamHI, EcoRI, Sa/l, Smal and Xhol restriction endonuclease sites to provide complete endonuclease maps for the entire genome
Identification of envelope glycoproteins h and b homologues of human herpesvirus 7
No full textThe genes encoding the envelope glycoprotein H (gH) and gB homologues were identified by sequencing genomic clones of human herpesvirus-7 (HHV-7), strain JI. A gB cDNA clone from HHV-7 strain AL was also identified. The deduced primary translation products of the gH and gB genes are a protein of 690 amino acids, with a predicted mass of 80.4 kD, and a protein of 822 amino acids, with a predicted mass of 93.3 kD, respectively. Both the predicted proteins have the characteristics of transmembrane glycoproteins, containing signal and transmembrane sequence motifs and characterized by the presence of 10 (gH) and 11 (gB) potential motifs for N-glycosylation. Comparison of amino acid sequence of HHV-7 gH and gB with the homologous sequences of the other human herpesviruses reveals closest homology with HHV-6 (38.8% identity for gH, 56.2% identity for the gB). In addition, significant sequence similarity was also observed between the gH and gB of HHV-7 and the homologs encoded by human cytomegalovirus (21.6% identity for gH, 37.6% identity for gB). No significant differences existed between the gB sequence of the two different HHV-7 strains analyzed. The products of the HHV-7 gH and gB expressed transiently in eukaryotic cells were specifically recognized by an HHV-7-reactive human serum in immunofluorescence assays
Absence of a directly causative role for human herpesvirus 7 in human lymphoma and a review of human herpesvirus 6 in human malignancy
No full textIn search of a (new) viral etiological agent, we screened 64 lymph node samples from Hodgkin's disease (HD) and 43 samples (32 lymph node and 11 skin biopsies) from non-Hodgkin's lymphoma (NHL) for human herpesvirus 7 (HHV-7). Twenty-nine control samples were tested as well, including 17 with benign lymphadenopathy. None of the samples tested positive by Southern blot hybridization using HHV-7-specific probes, We conclude that there is no major HHV-7 load in human lymphoma and that HHV-7 is not likely to be directly involved in its etiology. This is in contrast to a small minority of human lymphoproliferative diseases in which HHV-6 can be found at high copy number, but in which an etiological role is still uncertain
CD4 is a critical component of the receptor for human herpesvirus 7: interference with human immunodeficiency virus.
No full textIdentification of human telomeric repeat motifs at the genome termini of human herpesvirus 7: structural analysis and heterogeneity
No full textHuman herpesvirus 6 (HHV-6) and HHV-7 are closely related T-lymphotropic betaherpesviruses which share a common genomic organization and are composed of a single unique component (U) that is bounded by direct repeats (DRL and DRR). In HHV-6, a sequences have been identified at each end of the DR motifs, resulting in the arrangement aDRLa-U-aDRRa. In order to determine whether determine whether HHV-7 contains similar a sequences, we have sequenced the DRL-U and U-DRR junctions of HHV-7 strain JI, together with the DRR.DRL junction from the head-to-tail concatamer that is generated during productive virus infection. In addition, we have sequenced the genomic termini of an independent isolate of HHV-7. As in HHV-6, a (GGGTTA)n motif identical to the human telomeric repeat sequence (TRS) was identified adjacent to, but not at, the genome termini of HHV-7. The left genome terminus and the U-DRR junction contained a homolog of the consensus herpesvirus packaging signal, pac-1, followed by short tandem arrays of TRSs separated by single copies of a second 6-bp repeat. This organization is similar to the arrangement found at U-DRR in HHV-6 but differs from it in that the TRS arrays are considerably shorter in HHV-7. The right genome terminus and the DRL-U junction contained a homolog of the consensus herpesvirus packaging signal, pac-2, followed by longer tandem arrays of TRSs separated by single copies of either a 6-bp or a 14-bp repeat. This arrangement is considerably more complex than the simple tandem array of TRSs that is present at the corresponding genomic location in HHV-6 and corresponds to a site of both inter- and intrastrain heterogeneity in HHV-7. The presence of TRSs in lymphotropic herpesviruses from humans (HHV-6 and HHV-7), horse (equine herpesvirus 2), and birds (Marek's disease virus) is striking and suggests that these sequences may have functional or structural significance
Fourth International Workshop on Haploidentical Transplants, Naples, Italy, July 8-10, 2004
No full textMany patients with high-risk hematological malignancies or with incurable inborn errors do not have an HLA-matched sibling and cannot find an HLA-matched donor for an allogeneic hematopoietic stem cell transplantation (SCT). Transplantation strategies using mismatched haploidentical family donors have been an important development. Although the procedure has saved patients from certain death, it is still beset by major problems like life-threatening infections--due to profound immunodeficiency following T-cell depletion and to disease relapse. At every International Workshop on Haploidentical Transplants, new data are presented, showing how scientists are attempting to improve the outcomes of mismatched transplants while reducing the severity of complications.The fourth Workshop continues in this tradition of presenting ground-breaking research. It opened with presentations of the current results with unrelated volunteer and umbilical cord blood transplants and proceeded to a session with the results of haploidentical transplants in the world with series of patients with high-risk acute leukemia, ranging in number from well over 100 in Perugia, Italy, and 80 in Haifa, Israel, to smaller groups in Europe and the United States. The session on graft engineering presented the latest results in the search for the optimal graft. The graft-vs.-leukemia effect in the haploidentical transplant was discussed in depth. Subsequently, attention focussed on one of the major problems in haploidentical transplant, that is, the delay in immunological recovery. The Workshop closed with presentations on tolerance induction that was followed by the results of ongoing registration studies being performed by the Italian GIMEMA group and the European Bone Marrow Transplant group
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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