1,720,980 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
Hobnail Variant of Papillary Thyroid Carcinoma: Case Series with Fine-Needle Aspiration Cytology and Cell-Blocks
No full texthobnail features (HPTC) is a rare, but very aggressive variant of PTC. The cytological features of HPTCs on fine needle aspiration smears have never been described.
Design: We examined smears and cell blocks of 5 cases of HPTC to define their diagnostic cytological features. B-RAF mutation was studied in all cases by pyrosequencing. Histopathological and immunohistochemical data were further obtained from surgical specimens. Follow up information were obtained from medical
record review.
Results: The patients (3 females and 2 males) age ranged from 27 to 86 (mean 65) years. Tumor size ranged from 2 to 9 cm (mean 4,2 cm). All aspirates were highly cellular with a bloody background and scant colloid. The cells were arranged in papillary clusters or in micropapillary groups. The proportion of isolated cells versus clusters varied from case to case. The cell population consisted of small to medium-size cells with tear-drop cytoplasm, apically placed occasionally grooved nuclei that produced a surface bulge leading to a hobnail appearance and high N/C ratio. At higher magnification, the nuclei showed variable degrees of atypia with occasional pink intranuclear holes. Nuclear stratification and atypical mitotic figures were present. B-RAF mutation was present in 3/5 cases. All cases showed positivity for Thyroglobulin, Thyroid transcription factor-1 (TTF-1), partial loss of E-cadherin expression and over-expressioin of p53 protein on
histological sections. Four patients were alive without diseases and 1 patient showed a locoregional recurrence at 8.5 months (range: 2 to 24 months) of follow-up.
Conclusions: A combination of papillary/micropapillary and hobnail cyto-architectural patterns of growth, single tear-drop cells, high N/C ratio, severe crowding could be the most useful criteria for diagnosing HPTC on cytological smear
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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