1,720,978 research outputs found
Adjuvant chemotherapy in colorectal cancer patients with microsatellite instability - Response
No full textInresponse: The major criticism raised by Watanabe in his
letter about our recently published article (1) concerns the
number of patients with stage II and III MSI-Hcolorectal
cancer (CRC) who received chemotherapy, that ‘‘should be
around 20 at most’’ and thus ‘‘seems too small to draw any
conclusions.’’
The assumption of Watanabe on the small number of
patients in our study is based on his interpretation that among
those 65 MSI-Hwho received chemotherapy, 31 were in stage
IV. This assumption is not correct. In fact, we considered as
patients receiving adjuvant chemotherapy only those who
underwent surgical intervention with curative intent (i.e.,
radical surgery), thus excluding most of stage IV patients who
received only palliative chemotherapy. We apologize for the
fact that this explanation was not present in the text leading to
the misinterpretation of the data. On this basis, among the 65
MSI-Hpatients considered as treated with adjuvant chemotherapy,
only 2 were in stage IV whereas 25 were in stage II and
the remaining 38 were in stage III, which is almost double of
what was hypothesized.
Furthermore, Watanabe states that the results of our study
‘‘could potentially bias the significance of MSI-Has predictor of
survival in adjuvant-treated colon cancer patients’’ as shown by
the results of his study (2), which compared the survival of
MSI-Hand MSS patients in stage II and III who received
chemotherapy.
We think that our results are not completely comparable
with those of Watanabe, mainly for the reason that our study
had a different design. In his work, Watanabe compared,
among patients who received chemotherapy, those affected by
MSI-HCRC versus those with stable tumors and found a
survival advantage in the first group; this study design could
not clearly establish whether this prognostic advantage is
conferred by the better sensitivity of MSI-HCRC to chemotherapeutic
agents or is due to the presence of instability by
itself.
On the contrary, our study was designed to investigate the
sensitivity of MSI-HCRC to chemotherapy. For this reason, we
compared among MSI-HCRC patients the outcome of those
who underwent 5-fluorouracil-based chemotherapy versus
those who were not treated. The results showed that chemotherapy
did not confer any survival advantage in MSI-HCRC
patients, confirming the report of another study with larger
sample size (3). In addition, the results of multivariate analysis
in stage II and III CRC cases showed the presence of MSI-H as an independent prognostic factor: this means that even in our
study, in accordance with Watanabe’s study, among patients
who received chemotherapy, MSI-Hpatients have a better
outcome than MSS patients.
Finally, another difference between the two studies involved
the definition of MSI. To define MSI, in our study, we used the
reference marker panel, as established in Bethesda guidelines.
Watanabe used eight dinucleotide and two polyadenine
markers in most cases, or two mononucleotide markers in
those cases without normal DNA available. This could have
important implications leading to heterogeneity in the population
defined as MSI in the two investigations
Genetic transmission of colorectal cancer: Exploratory data analysis from a population based registry
No full textClassical segregation analysis was conducted on 605 families of probands with colorectal carcinoma ascertained through the Cancer Registry of the Province of Modena in Italy. The families were classified as 28 suspected hereditary non-polyposis colorectal cancer (HNPCC) syndromes and 577 presumed non-HNPCC. In 11 of these, both parents had colorectal carcinoma, in 130 one parent was affected, and in 436 both parents were normal. In the suspected HNPCC families, segregation was compatible with dominant transmission of susceptibility to carcinoma. In families with one parent affected, the segregation frequency was almost exactly equal to the frequency of segregation in families where both parents were normal. The model of dominant transmission of susceptibility through a major gene with greatly reduced penetrance in heterozygotes fitted the data acceptably
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
Lymphatic vessel density and its prognostic value in stage I colorectal carcinoma.
No full textAIMS:The assessment of lymphatic vessel density (LVD) has been suggested as a tool to determine the metastatic risk of neoplasias. On this premise, the authors aimed to verify whether progression risk of stage I colorectal cancer may be related to LVD. The authors also evaluated and correlated vascular endothelial growth factor (VEGF)-A expression with LVD revealed in the same cases in order to investigate its potential lymphangiogenic role in the early stage colorectal cancer.METHODS:LVD and VEGF immunoexpression were analysed and compared in series of 29 stage I surgically resected colorectal carcinomas obtained from patients showing disease progression and in a cohort of 23 stage I colorectal cancers from patients with no evidence of disease progression. The prognostic value of LVD and of VEGF expression on the progression-free survival to colorectal cancer was investigated.RESULTS:A high density of peritumoural lymphatics (P-LVD) was significantly associated with high VEGF expression and disease progression. Moreover, high P-LVD and high VEGF expression were significant negative prognostic parameters associated with a shorter disease-free interval in stage I colorectal cancer.CONCLUSIONS:If our findings are further confirmed in other studies, the assessment of P-LVD on surgical specimens might be used as a tool to identify patients with stage I colorectal cancer at higher risk of progression in order to submit them to adjuvant therapies. Since P-LVD seems to show a VEGF-A mediated regulation in stage I colorectal cancer, therapies targeting this factor might be exploited to reduce lymphangiogenesis and the progression risk of this neoplasia
Outsiders within? A Bioarchaeological Perspective of Prone Burials in Roman Populations from Italy and Switzerland (1st-3rd c. AD)
No full textIrregular burials (i.e. burials showing features deviating from the majority of others in their geographic and chronological context), have traditionally puzzled researchers attempting to disentangle their possible social meanings. Studies of irregular burials are often methodologically biased by their discussion as archaeological curiosities, rather than as the expression of complex underlying funerary practices, and by interpretative generalizations largely based on unsupported ethnographic parallels. Here, we discuss a specifi c type of Roman irregular burial (prone burials) from Italy (Bononia, modern-day Bologna, 1st c. AD) and Switzerland (Aventicum, modern-day Avenches, 1st-3rd c. AD) by means of an alternative, multidisciplinary approach (multivariate analysis of bioarchaeological data, paleopathological analysis, biochemical study of diet and mobility). The following research questions are addressed: 1) Is there a link between this specifi c funerary treatment and differential patterns of health, ethnicity, or social differentiation at each site? Especially, is it possible that pathological conditions (e.g. residual rickets, endocranial lesions, auditory exostoses) observed primarily in these individuals may have infl uenced their differential funerary treatment? 2) Can we distinguish the signals of independent cultural traditions (vs. state-sanctioned homogeneity) in the performance of the same irregular funerary practice in Bologna and Aventicum? Generating a synthetic analysis of diverse datasets we establish important parameters to be taken in account for a more holistic approach to the interpretation of irregular burials.
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