1,720,962 research outputs found
RESULTS OF LAPAROSCOPIC ADRENALECTOMY FOR LARGE AND POTENTIALLY MALIGNANT TUMORS
No full textEndoscopic adrenalectomy is the procedure of choice for patients with small functioning adrenal tumors. For most surgeons invasive adrenal carcinoma is an absolute contraindication for laparoscopic adrenalectomy (LA). Whether LA should be proposed for large (> 6 cm), potentially malignant tumors is questionable. The aim of this study was to evaluate the risks and outcome of LA performed in our department in patients with tumors > 6 cm and potentially malignant. We performed a retrospective study of 216 patients who underwent 233 LAs in our department from 1994 to 2000. We selected 19 patients with a tumor > 6 cm and potentially malignant: 8 nonfunctional tumors, 4 cortisol-secreting tumors, 1 virilizing tumor, and 6 pheochromocytomas. In none of these patients did preoperative investigations demonstrated invasive carcinoma. The median tumor size was 70 mm. LA was performed by a transperitoneal flank approach. Conversion to open adrenalectomy was performed in two patients owing to intraoperative evidence of invasive carcinoma. The median operating time was 150 minutes (range 95-240 minutes). Capsular disruption occurred during the dissection of two pheochromocytomas. There was no postoperative morbidity. Six patients had an adrenocortical carcinoma on pathologic diagnosis: three of the eight nonfunctional tumors, one of the four cortisol-secreting tumors, and one virilizing tumor. One patient presented with liver metastases 6 months after surgery and died. The five other patients are disease-free with a follow-up ranging from 8 to 83 months. The 13 patients with benign lesions (6 cortical adenomas, 1 ganglioneuroma, 6 pheochromocytomas) are disease-free with a median follow-up of 47 months (range 10-81 months). In experienced hands LA can be proposed for large, potentially malignant tumors. Conversion to open adrenalectomy should be performed if local invasion is observed during surgery. At present the risk of intraabdominal recurrence is unknown
Results of surgical treatment of sporadic medullary thyroid carcinoma following routine measurement of serum calcitonin.
No full textAIM: The aim of this study was to evaluate the results of the surgical management of medullary thyroid carcinoma (MTC), following the introduction of systematic calcitonin measurement in patients referred for thyroid diseases.
METHOD: We included all the patients with elevated calcitonin and MTC from January 1993 to March 2001.
RESULTS: Among 8497 patients, MTC was diagnosed in 52 with a mean age of 56.1 years. Thirty-two fine needle biopsies led to diagnose MTC in 19 cases. The median basal pre-operative calcitonin level was 245 pg/ml. Elevated calcitonin serum was the only indicator of MTC in 31 patients. Fifty-one patients underwent total thyroidectomies, with lymphadenectomy in 45. Thirteen patients had lymph node involvement. Post-operatively, 40 (77%) had normal basal and pentagastrin (Pg) stimulated calcitonin serum levels, and remained normal at a mean follow-up of 5.16 years (1.8-8).
CONCLUSION: Routine pre-operative measurement of calcitonin should be performed because it is often the only indicator of MTC at an early stage. This could lead to an improved MTC cure rate
INDICATIONS AND RESULTS OF VIDEOASSISTED PARATHYROIDECTOMY BY LATERAL APPROACH IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM
No full textAbstract: Background. Different minimally invasive techniques of parathyroidectomy have been described. We performed a retrospective study to evaluate the indications and results of video-assisted parathyroidectomy by lateral approach (VAPLA) in the management of our patients with primary hyperparathyroidism (PHPT).
Methods. From December 1997 to December 2000, we operated on 293 patients with PHPT. VAPLA was proposed for patients with sporadic PHPT a single adenoma was localized by means of sonography or sestamibi scanning, or both. VAPLA was performed on the anterior border of the sternosonography muscle. A quick parathormone (PTH) assay was used during the surgical procedures.
Results. Of the 293 patients, 127 (43.3 %) were not eligible for VAPLA: ipsilateral previous neck surgery (28 cases), associated nodular goiter (59 cases), suspicion of multiglandular disease (15 cases), no preoperative localization (17 cases), and miscellaneous causes (8 cases). VAPLA was performed in 166 patients (56.7 %). Conversion to conventional parathyroidectomy was required in 26 patients (15.6 %). Morbidity included 2 local hematomas, 1 definitive recurrent nerve palsy, and 4 capsular fractures. All of the 166 patients were normocalcemic, with follow-up ranging from 3 to 33 months.
Conclusions. VAPLA is safe and effective. It should be reserved for patients with sporadic PHPT, with a small single adenoma clearly localized preoperatively
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
- …
