1,720,972 research outputs found
Identification and characterization of human papillomavirus DNA sequences in Italian breast cancer patients by PCR and line probe assay reverse hybridization.
No full textHuman papillomavirus (HPV) infection is known to play a fundamental role in cervical and other ano-genital human cancers. The recent identification of HPVs in human breast tumors and the immortalization of normal breast cancer cells by HPV high risk types 16 and 18 suggest that the virus could be implicated in the pathogenesis of human mammary tumors. In this study, we investigated the presence of high and low risk HPV genotypes in 30 human breast cancers of different histotypes by PCR with specific HPV primers (MY09/MY11 and GP5+/GP6+) and by line probe assay (LiPA) reverse hybridization. Since the only positive case (untypable HPVX+) was a papillary breast carcinoma, a rare tumor variant, we analyzed a further cohort of 32 papillary cancers and found one additional HPV DNA-positive case (HPV66+). Our results suggest that HPV infection is not significant in mammary tumorigenesis, with the exception of particular tumor histotypes, such as papillary cancer
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
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