1,721,011 research outputs found
Correlation between tumour antigens and malignancy in BKV-transformed hamster cells.
No full textHamster kidney cells transformed by BK virus (HKBK cells) were studied in order to correlate the membrane tumour antigens to the metastatic capability. The presence of the tumour associated surface antigen (TASA) on the surface of HKBK cells was detected by the immunofluorescence test on live cell suspensions. The metastatic ability was investigated by inoculating HKBK cells subcutaneously (s.c.) into newborn hamsters, s.c., intraperitoneally (i.p.) and in the foot pads into adult hamsters, and s.c. into adult hamsters previously immunized with surface antigens extracted from HKBK cells. The results indicate that there is a correlation between the appearance of tumour antigens on the cell surface and the metastatic ability: HKBK cells at low passage (about 30 subcultures after transformation) showed the capping of TASA in the cell membrane and low metastatic ability, whereas HKBK cells at high passage (about 130 subcultures after transformation) exhibited a diffuse appearance of TASA in the cell surface and were highly metastatic
MORPHOLOGICAL-STUDY OF INDUCED-TUMORS IN THE NUDE-MOUSE WITH TRANSFORMED CRICETUS CELLS OF BK VIRUS
No full textNostra esperienza sulla caratterizzazione biologica "in vitro" degli adenocarcinomi renali stadio pT1
No full textIsolation and characterization of cell lines derived from hamster kidney cells transformed by BK virus, and transforming activity of their DNA.
No full textEight cell lines obtained from BK virus-transformed hamster kidney cells were characterized by some biological parameters as presence of BKV T antigen, growth properties and tumourigenicity. The transforming ability of their DNA on primary foetal rat fibroblasts was then studied, and transformed rat cells were characterized by the same biological parameters as above. Transformed hamster cells showed no correlation among presence of virus, growth properties and tumourigenicity; DNA from normal hamster kidney cells and from two BKV-transformed cell lines induced transformation on rat fibroblasts, but presence of BKV T antigen was detected only in one DNA-transformed rat cell line. The role of cellular and viral genes on neoplastic transformation is discussed
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
Effects of the HIV-1 tat protein in BK virus tat transgenic mouse
No full textEffects of the HIV-1 tat protein in BK virus tat transgenic mous
EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS IN HUMAN BLADDER CANCER CELL LINES AND CORRELATION WITH TUMORIGENICITY AND MALIGNANCY
No full textPeroxisome proliferator-activated receptor (PPAR) immunocytochemical expression was analyzed in seven human bladder tumor cell lines (TCCSUP, RT112, VMCUB1, 639V, T24, RT4, SG65), which were also injected in nude mice to assess their tumorigenicity and metastatic ability. PPARα expression was moderate (1.84-5.38% of positive cells) in all cell lines, except for SG65 (11.53%). PPARβ/δ expression was weak (1.50-3.18%) in RT112, TCCSUP, T24, 639V, and greater (5.90-7.77%) in VMCUB1, RT4, SG65. PPARγ expression was low (2.19-3.61%) in not tumorigenic cells (TCCSUP, RT112); it was the highest (10.06- 14.54%) in cells causing tumors resembling human papillary superficial bladder cancers (639V, VMCUB1); it was high (5.80-7.99%) in cells causing tumors resembling human papillary invasive bladder cancers (RT4, T24); it was the lowest (0.73%) in SG65 cells, inducing tumors resembling human solid invasive bladder cancers. These results, confirmed by western blotting, indicate a negative association between PPARγ expression and malignancy in bladder cancer cells. To evaluate the significance of this negative association, the in vitro apoptotic effect of 15-deoxy-∆12,14-prostaglandin J2 (15d-PGJ2), a natural PPARγligand, and of ciglitazone (CGT), a synthetic PPARγ ligand, on four human bladder tumor cell lines (TCCSUP, 639V, T24, SG65), exhibiting different levels of PPARγ expression and representative of different in vivo behaviors, was investigated. While the apoptotic effect of CGT became evident after 48 h and was higher in not tumorigenic (TCCSUP) than in tumorigenic (639V, T24, SG65) cells, the apoptotic effect of 15d-PGJ2 appeared earlier, after 24 h, and was higher in high PPARγ expressing cells causing well differentiated papillary tumors (639V, T24) and lower in low PPARγ expressing cells either not tumorigenic (TCCSUP) or causing undifferentiated malignant cancers (SG65). Since 15d-PGJ2 is abundantly present in human urine, its apoptotic effect could explain the low malignancy and the slow progression of most papillary bladder cancers expressing high levels of PPARγ
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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