1,720,957 research outputs found
AGGRESSIVE (DESMOID) FIBROMATOSIS IN PEDIATRIC AGE: ITALIAN EXPERIENCE
Med.Pediatr Oncol - XXXII SIOP Meetin
Renal angiomyolipoma in children: Diagnostic difficulty in 3 patients
PURPOSE: Because angiomyolipoma is less common in children than in adults, its diagnosis can be difficult. We present 3 cases of pediatric angiomyolipoma in which diagnostic problems resulted due to the presenting characteristics.
MATERIALS AND METHODS: We report on 3 children with unilateral renal angiomyolipoma. Computerized tomography (CT) and ultrasonography revealed 3 large renal masses, 20, 7 and 8 cm. in diameter, respectively. A correct diagnosis was not made preoperatively in any case by CT, ultrasound or fine needle biopsy. Wilms tumor was suspected in the first patient who received preoperative chemotherapy. Imaging was inconclusive in the other 2 cases.
RESULTS: All patients underwent surgical exploration and subsequent nephrectomy due to the large size of the tumor. At followup 33, 23 and 13 months postoperatively all children were well without signs of recurrence.
CONCLUSIONS: It has been reported that the demonstration of fat on renal ultrasound and CT can diagnose angiomyolipoma in 95% of the cases. Most radiologists rely solely on CT demonstration of lipid density in the renal mass to diagnose angiomyolipoma but the identification at imaging of lipid tissue may be difficult in small tumors. In our cases the fat content of the tumors was less than 10% despite the large size. This low fat content results in misdiagnosis, since fatty tissue is also present in other renal tumors, such as lipoma, liposarcoma, teratoma and Wilms tumors. We recommend conservative surgery when tumor size permits in pediatric patients with angiomyolipoma to avoid chemotherapy
Jatrogenic vascular lesions in extremly low bird weith and low birth weith neonates
PURPOSE:
Aggressive treatment has improved the long-term outcome of extremely low birth weight (ELBW) and low birth weight (LBW) neonates, but it has also increased the risk of iatrogenic lesions. The aim of this paper is to evaluate the incidence of vascular injuries observed in the neonatal intensive care unit of our hospital.
METHODS:
From 1987 to 1994, 2898 neonates were admitted to the neonatal intensive care unit; 335 of them were either LBW or ELBW (11.5%). A review of the charts of these neonates disclosed nine neonates (four male, five female) with vascular lesions (2.6%); the mean gestational age of these patients was 28.7 weeks (range, 24 to 33 weeks), the mean weight at birth was 880 g (range, 590 to 1450 g), and the mean weight at diagnosis was 1825 g (range, 1230 to 2700 g). In the same period, 10 neonates with vascular injuries were reported in the 2563 neonates who weighed more than 1500 g (0.3%). The injuries observed in LBW and ELBW group were arteriovenous fistulas (two bilateral) at the femoral level (six neonates), carotid lesion (one neonate), and limb ischemia (two neonates). Injury was associated with venipuncture in seven neonates, and with umbilical catheter in one; the case of carotid lesion was related to surgical error. No general symptoms were observed.
RESULTS:
The carotid lesion and five arteriovenous fistulas were repaired by microsurgical techniques; one case of limb ischemia was resolved with thrombolytic drugs, whereas an amputation at the knee level was required in the other after 10 days of medical treatment. One neonate with an arteriovenous fistula was just observed according to the parents' wishes. At clinical and echo-color Doppler follow-up, seven of nine neonates had normal vascular function without sequelae.
CONCLUSIONS:
In our experience, LBW and ELBW neonates are at greater risk than older neonates of the development of iatrogenic vascular lesions. We advocate aggressive microsurgery, medical treatment, or both to obtain good results and prevent late sequelae
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
We 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
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