1,720,963 research outputs found
Microembedding in thyroid cytology.
No full textFine needle aspiration (FNA) of the thyroid, which is a
rapid and cost-effective procedure, has gained wide acceptance
as a valuable method for distinguishing neoplastic
from non-neoplastic nodules and identifying those patients
requiring surgery 1-4. At the present time, the thyroid gland
is the most frequently aspirated organ for triage/diagnostic
purposes.
Clinically-relevant thyroid nodules occur in 5-10% of the general
population in Italy and approximately 5% of the patients
have malignant lesions. The goal of thyroid FNA is to identify
the nodules that require surgery and decrease the number of
thyroidectomy for patients with benign disease. Overall, the
technique has a high sensitivity and specificity for the detection
of thyroid neoplasm 5-7.
Cell blocks (CBs) are often prepared on FNAs from several
organ sites as an adjunct to smears in the diagnosis of potential
lesions. However, the literature contains few reports
on their utility with regard to specific organ sites. The main
advantage of the CB is the potential to produce several sections
for special stains and other ancillary, in particular immunoistochemical,
studies 8-10. At our institution, CBs are
made routinely on thyroid FNAs since twenty years and we
have been performing about eight-hundred thyroid FNAs each
year. As a result, we have been collecting a high number of
CB of thyroid lesions, of great value for investigative and
retrospective studies.
The aspirates were procured by experienced cytopathologists,
clinicians, or radiologists. The majority of the aspirates were
performed by the radiologist or clinicians under ultrasound
guidance and each aspirate had an immediate in situ assessment
for adequacy by the cytopathologist. FNAs were performed
using a 23- or 25-gauge needle attached to a 10-ml
disposable syringe mounted to a metallic Cameco syringe
pistol (Morton Medical Ltd., London, United Kingdom). One
to 4 aspirates were performed per case. After each sampling,
air-dried Hematoxylin & Eosin-stained slides were made for
immediate assessment and alcohol-fixed slides for subsequent
Papanicolaou (Pap) staining. The residual material and the
needles were rinsed immediately in a 50% Ethanol solution
(s.c. Lysis Buffer) containing Ammonia Chloride, Potassium
Bicarbonate and EDTA, which proved effective for fixing
cells and lysing erythrocytes. Material collected by centrifugation
was embedded in paraffin.presence
of cellular fragments.
CB has greatly improved the pre-surgical diagnosis of thyroid
nodules, since small tissue specimens representative of the lesion
were detected in the great majority of cases. These “micro-biopsies”
provided morphologically-relevant data. Besides, sections
were employed for immunoistochemical and molecular tests.
Expression of galectin-3 is routinely tested on thyroid follicular
lesions (cytological cell-blocks) obtained preoperatively
by ultrasound-guided fine-needle aspiration of thyroid
nodules 11.
Moreover, CB procedure provides the basis for new molecular
and immunoistochemical studies to determine the definition
of thyroid neoplasm of indeterminate malignant behavior
(Thy3). Recently, we focused on the immunohistochemistry
of Emerin, a protein of the nuclear membrane (NM)
whose decoration best demarcates the nuclear shape of the
thyrocytes 12 and we performed this stain on a series of 82
cytological CB thyroid specimens. Emerin revealed a uniform
arrangement of the NM in non-neoplastic lesions (thyroiditis,
microfollicular goiter, follicular adenoma) and normal thyroid
as well as in follicular carcinoma. In contrast, irregular folding
of the membrane and presence of curling and invaginations,
eventually leading to the formation of nuclear pseudoinclusions,
was observed in PTC and VFPTC cells.
In conclusions, the integration of CB method with conventional
cytomorphological and clinical diagnostic procedures
represents a sensitive and reliable diagnostic approach for
preoperative identification of thyroid carcinomas. This procedure
improves the diagnostic accuracy of conventional cytology.
Moreover, the CB is useful for immunoistochemical and
molecular study of thyroid neoplas
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
Progetto BIOSEL - Nuovi processi di valorizzazione dei sottoprodotti della coltivazione della patata al selenio per applicazioni ad alto valore aggiunto
No full textByproducts of selenium enriched “Selenella” potatoes, typical Emilia Romagna’s product, have many potential unexploited application for its nutritional value due to the presence of selenium, a very important micronutrient for human diet. Bioliquefaction by means of enzymatic catalysts allows to recover the mix of bioactive molecules of this agri-food biomass and then re-use it in novel applications in cosmetic and food sector
Histological sectioning of brush bristles allows improved diagnosis of biliary tract
No full textIntroduction. Biliary tract brush cytology is increasingly
being recognized as a favoured method for evaluating abnormalities
of the pancreatic and biliary tract.
In order to increase the diagnostic potential of endoscopic
brushing of the biliary tract, we devised a novel technique
finalized to the complete and ideal cytologic examination of
the collected material through an original new brush processing
method.
Material and methods. 112 consecutive pancreato-biliary
brush cytology specimens (67M; 45F) collected at Molinette
Hospital, University of Turin, between January 2002 and
August 2006 were included in our study. All patients had
a definite final benign or malignant diagnosis based either
on independent histological or cytological sampling, or on
clinical follow-up data (follow-up was median 21 months).
Immediately following brushing, the brush is immersed
into methanol; then, in order to induce formation of a glue
surrounding the brush, in the pathological laboratory it is
immersed into egg albumen (a mixture 1:1 of egg albumen
and glycerol), and finally returned to methanol. For paraffin
embedding, the metal handling is cut away and the remaining
brush is introduced into a cassette: paraffin-embedded sections
parallel to the long axis of brush are cut until the metal
wire is almost reached, then the block is rotated and new sections
are obtained from the opposite side. Small fragments of
the mucosa, of inflammatory cell aggregates or of carcinomas
(stained in Haematoxylin & Eosin and Alcyan blue mucine)
were observed in our series, and displayed an optimal fixation
allowing a definite diagnosis which proved mandatory for
proper therapy in the almost totality of cases.
Results. The results obtained on 112 consecutive cases using
such technique showed a satisfactory sensibility when
compared to final histological diagnosis, this method showed:
87% sensitivity, 100% specificity, 100% positive predictive
value (PPV), and 91% negative predictive value (NPV).
Moreover when compared this method to the patient clinical
diagnosis, after at least 6 months follow-up, it showed: 88%
sensitivity, 100% specificity, 100% positive predictive value
(PPV), and 96% negative predictive value (NPV).
Conclusion. Finally such novel technique proved to be highly
sensitive and specific, limiting the un-satisfactory cytological
diagnoses to less than 1% and providing a 88% concordance
(K value) with the final histology at surgery and a 91% concordance
(K value) with patient follow-up
On-site cytopathological evaluation of endoscopic ultrasound-guided fine needle aspiration of pancreatic neuroendocrine tumors
No full textObjectives. Endoscopic ultrasound-guided fine needle aspiration
(EUS-FNA) is increasingly used in diagnosis of pancreatic
tumors. Our study aims to identify cytological characteristics of on-site evaluation helpful for recognizing pancreatic
neuroendocrine tumors (NETs).
Methods. Our study comprises 5 cases of pancreatic tumors
with cytological features suggestive of neuroendocrine origin,
obtained by EUS-FNA which diagnosis was confirmed
by surgical excision. For each case we analized: cytological
smears, cell block sections and immunocytochemical stains.
Results. All cases show similar and peculiar cytological characteristics
of on-site evaluation: smears were richly cellular
with poorly cohesive small cells; they display a monotonous
basophilic appearance with scanty cytoplasm and small eccentric
nucleus with speckled or dusty chromatin pattern conferring
a plasmocytoid appearance. Immunocytochemical stains
(Chromogranin A, Synaptophysin), performed on cell-block,
confirmed neuroendocrine differentiation.
Conclusion. EUS-FNA is a useful method of identification
of pancreatic NETs. Recognizing cytopathological features
of neuroendocrine origin improves the diagnostic yield of the
procedure, allowing a three-tiered approach in planning the
handling of FNA specimens
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