A systematic view of JCV papers to discern the distinct set of core researchers, institutional affiliations and corresponding countries helps us to gain a deeper understanding of approaches to JCV. As shown in our bibliometric analysis, the document type of JCV was original articles (1307/1785) and many data (209/1785) had been communicated in meeting activities. The review part occupies 6.9% (123/1785). The results indicated that JCV research was very active and interesting many investigators, and some scientists had begun to summary the achievement of JCV. Among 33 core authors, 19 persons come from Temple University, University of Tokyo, and National Institute of Neurological Disorder and Stroke, which ranked the top in the highly-produced institutes. Additionally, 14 (66.7%) core institutes of USA also focused on the investigation of JCV and USA was the first top producer of JCV papers until now. JVC was discovered in 1971 by American Padgett and named after the two initials of a patient with progressive multifocal leukoencephalopathy (PML). It was suggested that the JCV investigation originated from USA, which consequently became the top source information for JCV. It is rational and helpful for the scientists to tack the core authors and institutes to grasp the frontier of this field, open new projects and submit their distinguished work.
The list of top-cited articles about JCV identified the authors, articles and topics that reflected history and development of this specialty. Among highly-cited authors, Padgett is the discoverer for JCV in PML and published the first article in Lancet. The paper has been cited for 366 times and ranks the top in the highly-cited ones. His outstanding was also due to another article in Journal of Infectious disease, which described the detection of the antibody against JCV in PML. Therefore, it is explanatory for Padgett BL to be the most highly cited. These top-cited articles produced valuable information for readers, but also tell us some historical achievement in some field. According to these highly-cited papers, the research about JCV was chronologically separated into beginning and developing stages including discovery and isolation of JCV in PML disease, and clarification of JCV genomic DNA sequence and its relationship with diseases by polymerase chain reaction (PCR) respectively.
Most of highly-cited journals almost come from Virology, Neurology, and comprehensive journals, indicating JCV paper mainly absorbs frontier knowledge from these fields. Oncogene, Journal of Biological Chemistry, and International Journal of Cancer also become the highly-cited journal (data not shown), indicating the attempts of JCV study to combine with Molecular Biology and Oncology. This data also demonstrate the close link of JCV with these specialties. In the overall references of JCV papers, most highly-cited articles were published in Proceeding of National Academy and Science, USA and New England Journal of Medicine, indicating that these famous-brand journals highlight the investigation of JCV and emphasized the scientific achievement of JCV. Therefore, investigators of JCV not only read the journals of Virology, but also emphasized the novel findings of JCV published in other journals with high impact factor.
Methodologically, the cluster techniques include text segmentation, summary extraction, feature selection, term association, cluster generation, topic identification, and information mapping . Clustering algorithms prominently used in co-citation analysis has proved very useful in revealing research streams in some discipline [20–23]. Here, we carried out empirical co-citation analysis to map the network of highly-cited papers about JCV. Our data indicated that these top highly-cited articles were grouped into such 4 aspects as the correlation between JC virus and tumors, causal correlation of JCV with PML, polyoma virus infection and its related diseases in renal-allograft recipients, detection of JCV antibody, oncogene and its encoding protein, and genetics and molecular biology of JCV. These findings might not only enrich the knowledge of students and specialists about the development's history of JCV research, but also open new bursts of scientific investigation.
Co-occurrence has been considered as carriers of meaning across different domains in studies of science. Based on this principle, we performed co-occurrence cluster analysis using Pubmed MeSH/subheading words to construct a new tie between two words depending on the co-existing frequencies . Consequently, most of the top highly-frequent MeSH/subheading words are mainly classified into C02 subcategory of MeSH (Viral Disease) and B04 subcategory (Viruses). The analytic data showed that the contents of published papers about JCV included JCV isolation and detection, as well as JCV and virus infectious diseases like PML or tumors. It was suggested that JCV investigation centered on its isolation, its pathogenicity of PML and its genetics at early time. Recently, the causal relationship between JCV and tumors has been emphasized by the scientists. It was demonstrated that JCV investigation like isolation and detection mainly aimed to clarify the molecular mechanism of its relevant diseases including PML and tumors.
As well known, JCV infection experiences two outcomes as other viruses. In un-permissive condition, JCV infection initiates binding to the JCV-sensitive cell surface and JCV capsids undergo endocytosis and are transported to the nucleus where the viral DNA is uncoated and the early and late region begins to be transcripted. Subsequently, JCV genomic DNA is assembled with caspid protein to undergo the lytic viral release, finally to cause demyelinating disease, PML. Under permissive infection, viral DNA can replicate, resulting in lytic infection with viral amplification and non-permissive cells don't allow the viral replication, leading to an abortive infection or cell transformation [6–9]. The evidence provided enough reasons for the following data: (1) The core and highly-cited journals mainly contained the field of virology, neurology and oncology; (2) The highly-cited articles and highly-frequent MeSH/subheading also mentioned the research contents of JCV, PML and tumors.
Recently, the further clarification of JCV genetics promoted the scientists to detect its genomic existence in tumors or make the transgenic mice to study the oncogenic role of JCV. Our group had examined the JCV targeting T antigen using nested-PCR, real-time PCR, in situ PCR, in situ hybridization, and immunohistochemistry [6–9]. It was found that positive rate and copies of JCV were higher in gastric, lung and tongue carcinomas than corresponding normal tissues, indicating its oncogenic role in epithelial carcinogenesis. Furthermore, JCV T antigen can serve as helicase, and polymerase, orchestrate the assembly and function of cellular proteins, disrupt the signal pathways of p53, Rb and Wnt signaling pathway, and should be considered as a viral oncogene [2–4]. Therefore, we are establishing a transgenic model of gastric neoplasia induced by JCV T antigen, which will help to verify the oncogenic role of JCV in gastric carcinoma and provide a novel tool to investigate gastric carcinomas. It was hypothesized that application of JCV T antigen in tumor transgenic animal model would be a novel and hot project in the future.