1,720,955 research outputs found
PCNA--a cell proliferation marker in vocal cord cancer. Part II: Recurrence in malignant laryngeal lesions
No full textLaryngeal squamous cell carcinoma constitutes the most frequent carcinoma found in the head and neck region. A precise prediction for recurrence potential cannot be done on site, treatment and histologic grading. Since Proliferating Cell Nuclear Antigen (PCNA) and DNA-cytometry have shown a good correlation between premalignant lesions and their progressive potential towards full-fledged carcinoma in the larynx as described in part I of this work, we have analyzed the PCNA index and DNA cytometry in specimen taken from vocal chord carcinomas with a 5-year follow-up, in order to assess its relationship with the presence or absence of tumour progression. 42 cases with (21) and without (21) recurrence have been examined. The DNA-index ranged from 1.01 to 1.43 (mean 1.10) in the group without and from 1.02 to 1.59 (mean 1.38) in the group with recurrent carcinoma (p = 0.002). The PCNA-index ranged from 0.00% to 18.90% (mean 6.97%) in the non-recurrent group and from 0.00 to 3g.50% (mean 16.35%) in the patients with recurrence (p = 0.001). Both indices also correlated in a highly significant way. From these data emerges a highly significant correlation between the cytometric indices of cell proliferation and PCNA immunostaining. Furthermore the high correlation between PCNA and DNA-index is of special interest for single case assessment. High DNA aberration and PCNA-index in vocal chord carcinoma may indicate a higher cellular aggressiveness of the tumour, resulting in a greater overall risk of metastases and local recurrences. Our results support the thesis that the indices of cellular proliferation within some cancers can define subsets of patients of high risk and help in isolating a population in which a more aggressive clinical protocol may be proposed
Exercise rhinomanometric test in the diagnosis of vasomotor rhinopathy
No full textThe Authors examined 55 patients divided into two groups, one of 30 vasomotor rhinopatic patients and the other of 25 normal subjects. The aim of the study was to set up an objective diagnostic rhinomanometer test through observation and evaluation of reaction brought about by physical exertion following an exertion test of 5 minutes which employed a computerized climb simulator. Nasal resistance was measure before and immediately after exertion and then at intervals of 10, 20 and 50 minutes. Our data reveal a noteworthy decrease in nasal resistance brought about by the sympathetic nervous system in normal and rhinopathic subjects. Return to pre-exertion values, however occurred difference in the two groups: in the control group nasal resistance returned to pre-exertion values slowly, while in the rhinopathic group, it decreased rapidly and a rebound effect was observed. In vasomotor rhinopathy the orthosympathetic system is overcome by the para sympathetic system with regard to nasal vascularization control and, therefore, in rhinopatic patients exertion stimulates efficacions activation of the orthosympathetic system a phenomenon which does not occur in healthy subject. On the basis of our results an intensive stimulus such as physical exertion seems to have a different effect on the two groups suggesting that the vessels of nasal mucosa do not always respond in the same way, and that in vasomotor patients there is an alternate reactivity of neural control of nasal mucosa. The rhinomanometric exercise test seems to be useful in revealing this phenomenon and to be diagnostically reliable. The method is easily reproducible, non-invasive and can be usefully applied in clinical practice associated with the normal rhinomanometric challenge test
PCNA--a cell proliferation marker in vocal chord cancer. Part I: Premalignant laryngeal lesions
No full textLaryngeal hyperkeratotic lesions can progress to fully developed malignant carcinoma in some cases. These premalignant lesions are proliferative disorders whose potential for further tumour progression is perhaps difficult to assess by mere histology. Immunostaining with PCNA, a protein correlated with cell proliferation, has been used to study tissue behavior in 30 cases of premalignant laryngeal vocal chord lesions treated by epithelial stripping in microlaryngoscopy, 15 of whom had no progression and 15 had recurrence and final development of full malignancy. The results showed a statistically significantly higher PCNA-index in the cases which underwent further tumour progression towards malignancy. PCNA testing may thus be suggested as a marker for tumour progression potential and help in determining clinical treatment choices
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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