1,720,960 research outputs found
Intraductal oncocytic papillary neoplasm (IOPN): two case reports and review of the literature
Full text linkBackground: Intraductal oncocytic papillary neoplasms (IOPNs) place at the oncocytic extreme of the intraductal pancreatic neoplasm spectrum and display typical morphological features. Their identification in 1996 by Adsay et al. has been followed by a growing number of cases, paving the way for a deeper understanding of this underestimated entity. Contrarily to intraductal papillary mucinous neoplasms (IPMNs), most IOPNs run an indolent course and surgery is usually curative. Pancreatic IOPNs tend to develop from the main pancreatic duct (MPD) and their diagnosis is either incidental or subsequent to mass-related symptoms. Up to 30% of cases show concomitant areas of minimal stromal invasion and loco-regional or systemic spread are confined to a minority of cases. Biological hallmarks of IOPNs are being identified, including recurrent kinase gene rearrangements. Morphological and biological traits of IOPNs seem to overlap with those of other malignancies. A deeper understanding of these entities is needed in order to shed light upon the nature of pancreato-biliary oncocytic neoplasms. This case report describes two patients with a diagnosis of IOPN-one of them accounting for the largest IOPN ever described-and provides a brief review of recent discoveries on the subject. Case description: We describe two cases of IOPN occurring in adult male patients, respectively in their 60s and 70s. Both patients had unremarkable clinical history. In case 1 the diagnosis was coincidental to a right renal colic; case 2 complained a right lumbar pain radiating to the homolateral groin. In both cases imaging analyses revealed a voluminous pancreatic mass, posing the indication to laparoscopic pancreatectomy. Gross and histological features were consistent with the diagnosis of IOPN. Surgical margin were free from disease and the patient did not undergo further treatment. After a 10- and 7-month follow-up respectively, patients did not experience relapse. Conclusions: Recent immunohistochemical (IHC) and molecular data reveal unique characteristics of IOPNs, highlighting the substantial differences from IPMNs. Further research is needed in order to identify novel prognostic and predictive markers applicable to oncocytic neoplasms of the pancreato-biliary tract
Metastasis of renal cell carcinoma to the parathyroid gland 16 years after radical nephrectomy: A case report
No full textRenal cell carcinoma (RCC) has a high metastatic potential, and most commonly metastasizes via the bloodstream, although lymphatic metastases also occur. RCC is well-known for its propensity to metastasize to unusual sites, and late metastasis, even after a number of years, is common. The occurrence of RCC metastasis to the head and neck region is uncommon, and occurs primarily in the thyroid gland and in patients with widespread dissemination. Involvement of the parathyroid gland in metastatic carcinoma is extremely rare. In the present report, a case of metastasis confined to the parathyroid gland is described, likely with intrathyroidal localization, arising from a RCC that occurred 16 years after nephrectomy. A 66-year-old man was referred to the Department of Surgery of the University Hospital of Pisa (Pisa, Italy) with a preoperative fineneedle aspiration diagnosis of a follicular lesion in the context of nodular goiter of the thyroid gland. The previous medical history of the patient included a right nephrectomy for the treatment of clear cell RCC in February 1997. No other distant metastases were identified as of the latest followup in March 2014. At the time of thyroid surgery, the thyroid and parathyroid function tests were normal. The gross appearance of the surgical specimen was a multinodular goiter with a solid nodule measuring 33 mm on the left lobe of the thyroid gland. Microscopic examination revealed a completely encapsulated lesion consisting of clear cells arranged in a solid pattern and intermixed with fragments of parathyroid tissue. Following immunohistochemical examination, the clear cell lesion was negative for thyroid transcription factor-1 and thyroglobulin and strongly positive for epithelial membrane antigen, cluster of differentiation 10 and vimentin. To the best of our knowledge,this is the second case of metastasis to the parathyroid gland from a RCC reported in the literature
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
Caratterizzazione biopatologica dei carcinomi polmonari non a piccole cellule
No full textI diversi tipi istologici di carcinoma polmonare non a piccole cellule differiscono fra loro non solo per le caratteristiche patologiche, ma anche per le diverse implicazioni molecolari, epidemiologiche, cliniche e prognostiche. In particolare, mentre l’incidenza del carcinoma a cellule squamose è diminuita negli ultimi anni, quella dell’adenocarcinoma è aumentata significativamente così che quest’ultimo è divenuto la forma di neoplasia polmonare più frequente in entrambi i sessi.
Nella maggior parte dei casi l’adenocarcinoma si sviluppa in fumatori o in ex-fumatori, ma più frequentemente di altri tipi istologici, si sviluppa in soggetti che non hanno mai fumato, dimostrando un’associazione relativamente più debole con il fumo di tabacco. Soprattutto quindi in questo distinto tipo istologico di carcinoma non a piccole cellule altri fattori eziologici sembrano essere coinvolti nella iniziazione e progressione tumorale.
Il recettore per gli estrogeni beta (ERβ) sembra essere il sottotipo recettoriale predominante a livello del polmone ed è espresso sia nel tessuto polmonare normale che in quello tumorale.
In questo studio è stata valutata l’espressione di ERβ nei vari tipi istologici di carcinoma polmonare non a piccole cellule, con particolare attenzione ai distinti sottotipi istologici dell’adenocarcinoma, e il suo significato patogenetico e prognostico.
L’espressione di ERβ è stata anche correlata alla presenza di mutazioni nei geni del recettore di crescita epidermico (EGFR) e del gene K-ras. Recentemente sono state, infatti, descritte interazioni funzionali tra il pathway di EGFR e quello di ERβ e questo potrebbe avere importanti implicazioni cliniche e terapeutiche, soprattutto alla luce del fatto che alcuni tumori polmonari, caratterizzati dalla presenza di alterazioni mutazionali del gene EGFR, mostrano una maggiore suscettibilità terapeutica agli inibitori delle tirosino-chinasi, famiglia recettoriale a cui EGFR appartiene.
WWOX (WW domain containing oxidoreductase) è un gene oncosoppressore che sembra essere coinvolto nel metabolismo e nella trasduzione del segnale degli ormoni estrogenici e dati recenti della letteratura indicano come la perdita di espressione di WWOX sia differente in distinti tipi istologici di carcinoma polmonare. Questi dati costituiscono il razionale per lo studio delle interazioni tra lo stato di ERβ e l’espressione di WWOX.
L’espressione di ERβ è stata valutata con l’immunoistochimica in due distinte casistiche: la prima retrospettiva composta da 73 casi di carcinomi polmonari non a piccole cellule, la seconda prospettica comprendente 112 casi di adenocarcinoma polmonare, sia “sottotipo singolo”, sia “sottotipo misto”.
Nella casistica retrospettiva l’espressione di ERβ è stata correlata alle caratteristiche clinico-patologiche dei campioni, all’espressione di WWOX e ai dati di follow-up clinico (intervallo libero da malattia e sopravvivenza globale). L’espressione di ERβ è risultata essere fortemente correlata all’istotipo, con una maggiore espressione nell’adenocarcinoma rispetto al carcinoma a cellule squamose. Una correlazione è stata inoltre trovata tra ERβ e espressione di WWOX: la perdita dell’espressione di WWOX è più frequente nei tumori che esprimono bassi livelli di ERβ.
Nella casistica prospettica ERβ è stato correlato alle caratteristiche clinico-patologiche e allo stato mutazionale dei geni che codificano per EGFR e per K-Ras. E’ stata osservata un’associazione statisticamente significativa tra l’espressione di ERβ e i diversi patterns istologici dell’adenocarcinoma. Infatti, un’alta espressione di ERβ è stata riscontrata nel 76.5% dei sottotipi “bronchioloalveolare non mucinoso”, nel 69.4% dei sottotipi “acinare” e nel 61.2% dei sottotipi “papillare”, ma solo nel 31.8% dei sottotipi “solido”, dimostrando in quest’ ultimo sottotipo un trend di espressione opposto. In questa casistica inoltre, l’espressione di ERβ è risultata essere anche fortemente correlata con il grado istologico delle neoplasie polmonari, infatti ERβ è maggiormente espresso ad alti livelli nei tumori moderatamente e ben differenziati, mentre dimostra bassi livelli di espressione nei carcinomi scarsamente differenziati (P = 0.0014). Nessuna associazione statisticamente significativa è stata invece trovata fra espressione di ERβ e stato mutazionale dei geni EGFR e K-Ras.
In conclusione l’espressione di ERβ è risultata essere significativamente più alta nell’adenocarcinoma, con forti differenze di espressione nei diversi sottotipi istologici, e questo suggerisce che ERβ abbia un ruolo specifico nella patogenesi dei differenti patterns di questo tipo di neoplasia. Inoltre la bassa espressione di ERβ nei tumori poco differenziati potrebbe indicare che la perdita di questo recettore rappresenti un momento fondamentale nel processo di differenziazione dell’adenocarcinoma polmonare
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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