186,976 research outputs found
SDHB immunohistochemistry: a useful tool in the diagnosis of Carney–Stratakis and Carney triad gastrointestinal stromal tumors
Mutations in the tumor suppressor genes SDHB, SDHC, and SDHD (or collectively SDHx) cause the inherited paraganglioma syndromes, characterized by pheochromocytomas and paragangliomas. However, other tumors have been associated with SDHx mutations, such as gastrointestinal stromal tumors (GISTs) specifically in the context of Carney-Stratakis syndrome. Previously, we have shown that SDHB immunohistochemistry is a reliable technique for the identification of pheochromocytomas and paragangliomas caused by SDHx mutations. We hypothesized that GISTs in patients with SDHx mutations would be negative immunohistochemically for SDHB as well. Four GISTs from patients with Carney-Stratakis syndrome and six from patients with Carney triad were investigated by SDHB immunohistochemistry. Five GISTs with KIT or PDGFRA gene mutations were used as controls. In addition, SDHB immunohistochemistry was performed on 42 apparently sporadic GISTs. In cases in which the SDHB immunohistochemistry was negative, mutational analysis of SDHB, SDHC, and SDHD was performed. All GISTs from patients with Carney-Stratakis syndrome and Carney triad were negative for SDHB immunohistochemically. In one patient with Carney-Stratakis syndrome, a germline SDHB mutation was found (p.Ser92Thr). The five GISTs with a KIT or PDGFRA gene mutation were all immunohistochemically positive for SDHB. Of the 42 sporadic tumors, one GIST was SDHB-negative. Mutational analysis of this tumor did not reveal an SDHx mutation. All SDHB-negative GISTs were located in the stomach, had an epithelioid morphology, and had no KIT or PDGFRA mutations. We show that Carney-Stratakis syndrome-and Carney-triad-associated GISTs are negative by immunohistochemistry for SDHB in contrast to KIT-or PDGFRA-mutated GISTs and a majority of sporadic GISTs. We suggest that GISTs of epithelioid cell morphology are tested for SDHB immunohistochemically. In case of negative SDHB staining in GISTs, Carney-Stratakis syndrome or Carney triad should be considered and appropriate clinical surveillance should be instituted. Modern Pathology (2011) 24, 147-151; doi:10.1038/modpathol.2010.185; published online 1 October 201
SDHB immunohistochemistry: A useful tool in the diagnosis of Carney-Stratakis and Carney triad gastrointestinal stromal tumors
Mutations in the tumor suppressor genes SDHB, SDHC, and SDHD (or collectively SDHx) cause the inherited paraganglioma syndromes, characterized by pheochromocytomas and paragangliomas. However, other tumors have been associated with SDHx mutations, such as gastrointestinal stromal tumors (GISTs) specifically in the context of Carney-Stratakis syndrome. Previously, we have shown that SDHB immunohistochemistry is a reliable technique for the identification of pheochromocytomas and paragangliomas caused by SDHx mutations. We hypothesized that GISTs in patients with SDHx mutations would be negative immunohistochemically for SDHB as well. Four GISTs from patients with Carney-Stratakis syndrome and six from patients with Carney triad were investigated by SDHB immunohistochemistry. Five GISTs with KIT or PDGFRA gene mutations were used as controls. In addition, SDHB immunohistochemistry was performed on 42 apparently sporadic GISTs. In cases in which the SDHB immunohistochemistry was negative, mutational analysis of SDHB, SDHC, and SDHD was performed. All GISTs from patients with Carney-Stratakis syndrome and Carney triad were negative for SDHB immunohistochemically. In one patient with Carney-Stratakis syndrome, a germline SDHB mutation was found (p.Ser92Thr). The five GISTs with a KIT or PDGFRA gene mutation were all immunohistochemically positive for SDHB. Of the 42 sporadic tumors, one GIST was SDHB-negative. Mutational analysis of this tumor did not reveal an SDHx mutation. All SDHB-negative GISTs were located in the stomach, had an epithelioid morphology, and had no KIT or PDGFRA mutations. We show that Carney-Stratakis syndrome- and Carney-triad-associated GISTs are negative by immunohistochemistry for SDHB in contrast to KIT- or PDGFRA-mutated GISTs and a majority of sporadic GISTs. We suggest that GISTs of epithelioid cell morphology are tested for SDHB immunohistochemically. In case of negative SDHB staining in GISTs, Carney-Stratakis syndrome or Carney triad should be considered and appropriate clinical surveillance should be instituted
"Rival Freedoms in terms of Security: The Case of Data Protection and the Criterion of Connexity." CEPS Challenge Paper No. 7, December 2007
The analysis of the present paper is based on two axes: one is that of the rivalry between different freedoms in a liberal regime, as well as the security restrictions to the concept of liberty. The other axis is that of the rivalry between the different forms of governing, governance and government in the EU, as articulated in the connexity criterion – a concept proposed and explored in this paper by Dr. Nicolas Scandamis, Professor of European Law at Athens University and doctoral students F. Sigalas and S. Stratakis. The case study of the data protection regime in the EU demonstrates the tension between the individual right to data protection, economic freedoms and political freedoms and how that right is redefined by security necessities and the ‘principle of availability’. The connexity criterion between governance and government is employed in the analysis of the Passenger Name Record judgement of the European Court of Justice
Author-wise bibliometric analysis based on entropy.
Author-wise bibliometric analysis based on entropy.</p
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
A novel PRKAR1A mutation associated with hepatocellular carcinoma in a young patient and a variable Carney complex phenotype in affected subjects in older generations.
CONTEXT: Carney complex (CNC) is an autosomal dominant multiple endocrine neoplasia syndrome (OMIM 160980). About 70% of cases are familiar; most have mutations of the PRKAR1A gene on chromosome 17q22-24. There is little phenotype-genotype correlation known to date. OBJECTIVE: To study the genotype-phenotype correlation in a family with newly diagnosed CNC and three generations of subjects bearing the same PRKAR1A mutation. The proband was diagnosed with hepatocellular carcinoma, a tumour that appears to be associated with CNC. DESIGN: The study consisted of clinical and genetic analysis of a total of 10 individuals belonging to a large Italian family. PATIENTS: The index case was referred for PRKAR1A gene mutation analysis because he met the diagnostic criteria for a clinical diagnosis of CNC. RESULTS: The PRKAR1A-inactivating mutation c.502 +1G > A in the intron 5 splice-donor site was detected after bidirectional sequencing of germline DNA. The mutation causes a frameshift in the transcribed sequence and a nonsense mRNA that was shown to be degraded; this leads to PRKAR1A haploinsufficiency in all tissues. All available relatives were screened first by DNA testing and, if the latter was positive, by clinical, biochemical and imaging means. CONCLUSIONS: A novel PRKAR1A mutation with an apparently low penetrance and variable expression is reported; the same mutation is also associated with a hepatocellular carcinoma. This is the first time a PRKAR1A mutation is reported in individuals who were diagnosed with CNC after retrospective family screening and following the identification of a proband; the finding has implications for genetic counselling on PRKAR1A and/or CNC
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
Dr. Edward P. Wimberly, ITC, July 2011
This video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
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