1,721,001 research outputs found
L'istogenesi del tumore papillare cistico del pancreas: contributo della microscopia elettronica
No full textDuctal Adenocarcinoma of the Pancreas
No full textPancreatic ductal adenocarcinoma (PDAC) and its variants comprise between 80% and 90% of all tumors of the exocrine pancreas. Because of its silent course, late clinical manifestation, and rapid growth, it is considered a silent killer. Only 10% to 15% of cases are resectable and the 5-year survival rate remains lower than 5%. The differential diagnosis between PDAC and chronic pancreatitis is a challenge for pathologists. This article provides a guide for pathologic evaluation of PDAC specimens with the macroscopic and microscopic features of common PDAC and its variants and discusses the differential diagnosis and morphologic and immunophenotypical prognostic parameters
Doppler ultrasound and contrast-enhanced magnetic resonance angiography in assessing carotid artery stenosis.
No full textPURPOSE:This study prospectively compares Doppler ultrasound (Doppler US) and contrast-enhanced magnetic resonance angiography digital subtraction angiography (DSA) and endarterectomy findings to determine the accuracy in assessing carotid artery stenosis.MATERIALS AND METHODS:Thirty-two patients underwent carotid endarterectomy, 21 studied with Doppler US, CE-MRA and DSA and 11 with Doppler US and CE-MRA. In 41 carotid arteries, the degree of stenosis was analysed with Doppler US and CE-MRA and compared with DSA by using the Spearman rank correlation coefficient. Nine out of 32 endarterectomies were done using the eversion technique, and it was possible to compare Doppler US, CE-MRA and DSA with the specimen measurement. Twenty-three out of 32 endarterectomies were done using the standard technique, and the presence of ulcers was documented.RESULTS:There was a significant Doppler US/DSA (Rs=0.86; p<0.001) and CE-MRA/DSA (Rs=0.81; p<0.001) correlation for the degree of stenosis. The diagnostic accuracy of the three methods was the same (89%). Ulcers were most frequently seen at CE-MRA, with a diagnostic accuracy of 85%.CONCLUSIONS:These data suggest that endarterectomy on the basis of Doppler US and CE-MRA can be considered appropriate. CEMRA was the best noninvasive imaging modality to detect plaque ulceration
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
High-affinity monomeric 67-kD laminin receptors and prognosis in pancreatic endocrine tumours
No full textCell-surface high-affinity monomeric 67-kD laminin receptors have been proposed to promote the invasion and metastasis of a variety of tumours, but there are, as yet, no data regarding the expression of these molecules in pancreatic endocrine tumours (PETs). The prognosis of these very rare tumours is problematic and the only irrefutable evidence of their malignancy still continues to be the occurrence of local invasion and metastases. In this retrospective investigation, 34 functioning and 48 non-functioning sporadic PETs were evaluated for the expression of the MLuC5 monoclonal antibody, which specifically recognizes the 67-kD laminin receptors. Laminin receptors were found in 42/82 cases (51 per cent) and their expression was associated with metastatic disease (P lt 0.001), high proliferative activity expressed by a Ki-67 index above 5.0 per cent (P lt 0.001), absence of progesterone receptors (P=0.013), immunoreactivity for hormones other than insulin (P lt 0.001), a tumour diameter more than 3.0 cm (P=0.001), and a fatal clinical outcome (P lt 0.001). Laminin receptors were also expressed by most metastatic foci and all intravascular emboli of tumour cells. Positivity for receptors was associated with shorter survival in functioning (P=0.026) and non-functioning (P=0.042) turnouts, as well as in the whole series of pancreatic endocrine turnouts (P lt 0.001). On multivariate analysis, laminin receptor expression was not an independent prognostic factor, while a Ki-67 index above 5.0 per cent was the most powerful predictor of survival. However, the association of laminin receptor expression and Ki-67 index could identify a group of malignant PETs with low proliferative activity characterized by sill intermediate prognosis. In conclusion, these data suggest that monomeric laminin receptors may play a role in the invasion and metastasis of PETs and that their expression may be an additional prognostic factor, along with proliferative activity
Molecular pathogenesis of sporadic duodenal cancer
No full textWhether duodenal adenocarcinoma should be considered as a gastrointestinal or as a peripancreatic cancer is a matter of debate, as is the opportunity and type of treatment. We investigated 12 such cancers for the genetic anomalies involved in the pathogenesis of gastrointestinal malignancies, including (a) those occurring in common-type cancers - allelic losses at chromosomes 3p, 5q, 17p and 18q, and Ki-ras and p53 alterations; and (b) those characteristic of mutator-phenotype cancers - microsatellite instability and TGF-betaRII gene mutations. We found Ki-ras and p53 mutations in five (42%) and eight cancers (67%), respectively; chromosome 3p, 5q, 17p and 18q allelic losses in two of nine (22%), six of ten (60%), six of nine (67%) and three of ten (30%) informative cancers, respectively. Finally, three cancers (25%) showed widespread microsatellite instability and two of them had a TGF-betaRII gene mutation. Our data suggest that duodenal cancers may arise from either of the two known pathogenetic molecular pathways of gastric and colorectal cancers. The majority of our cases were highly aggressive cancers with frequent chromosomal changes and p53 mutations as observed in the common-type gastrointestinal malignancies, while widespread subtle alterations characteristic of mutator-phenotype cancers occurred in a minority, which also showed a favourable long-term outcome
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
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