53 research outputs found
The diagnostic accuracy of US, CT, MRI and 1H-MRS for the evaluation of hepatic steatosis compared with liver biopsy: a meta-analysis
OBJECTIVE: To meta-analyse the diagnostic accuracy of US, CT, MRI and (1)H-MRS for the evaluation of hepatic steatosis. METHODS: From a comprehensive literature search in MEDLINE, EMBASE, CINAHL and Cochrane (up to November 2009), articles were selected that investigated the diagnostic performance imaging techniques for evaluating hepatic steatosis with histopathology as the reference standard. Cut-off values for the presence of steatosis on liver biopsy were subdivided into four groups: (1) >0, >2 and >5% steatosis; (2) >10, >15 and >20%; (3) >25, >30 and >33%; (4) >50, >60 and >66%. Per group, summary estimates for sensitivity and specificity were calculated. The natural-logarithm of the diagnostic odds ratio (lnDOR) was used as a single indicator of test performance. RESULTS: 46 articles were included. Mean sensitivity estimates for subgroups were 73.3-90.5% (US), 46.1-72.0% (CT), 82.0-97.4% (MRI) and 72.7-88.5% ((1)H-MRS). Mean specificity ranges were 69.6-85.2% (US), 88.1-94.6% (CT), 76.1-95.3% (MRI) and 92.0-95.7% ((1)H-MRS). Overall performance (lnDOR) of MRI and (1)H-MRS was better than that for US and CT for all subgroups, with significant differences in groups 1 and 2. CONCLUSION: MRI and (1)H-MRS can be considered techniques of choice for accurate evaluation of hepatic steatosi
Interaction between valence of empathy and familiarity: is it difficult to empathize with the positive events of a stranger?
Background: Empathy in humans is thought to have evolved via social interactions caused by the formation of social groups. Considering the role of empathy within a social group, there might be a difference between emotional empathy for strangers and familiar others belonging to the same social group. In this study, we used the global field power (GFP) index to investigate empathic brain activity during observation of a cue indicating either a negative or positive image viewed by a stranger or close friend. Methods: Sixteen healthy participants observed a partner performing an emotional gambling task displayed on a monitor. After the partner\u27s choice-response, a frowning or smiling face symbol was simultaneously presented to the participant\u27s monitor while a negative or positive emotional image was presented to the partner\u27s monitor. All participants observed a control condition (CT) showing a computer trial, a stranger-observation condition (SO) showing the trial of a stranger, and a friend-observation condition (FO) to observe the trial of a close friend. During these observations, participants\u27 event-related potentials (ERPs) were recorded to calculate GFP, and after the task, a subjective assessment of their feelings was measured. Results: Positive emotion was significantly larger under the FO compared to the CT and the SO. Significantly larger negative emotion was found under the SO and FO compared to the CT. In response to a positive cue, significantly larger GFP during 300 to 600 ms was observed under the FO compared to the CT and SO. In response to a negative cue, significantly larger GFP was observed under the FO and SO compared to the CT. A significantly larger GFP under the SO was found in response to only a negative cue. Topographic map analysis suggested that these differences were related to frontal-occipital dynamics. GFP was significantly correlated with empathic trait. Conclusion: These results revealed that familiarity with another person has different effects depending on the valence of empathy. Negative empathy, including the danger perception function, might easily occur even among strangers, whereas positive empathy related to nursing and supporting an inner group does not happen easily with strangers
Male recombination in Brazilian populations of Drosophila ananassae
With few exceptions, spontaneous crossing over does not normally occur in male Drosophila. Drosophila ananassae males show considerable amounts of crossing over. In wild males of D. ananassae from Asian (2008) and Brazilian populations (1986 and 2007) variable frequencies of meiotic crossing over, estimated from chiasmata counts, suggested the existence of factors controlling male crossing over in these populations. To corroborate for such prediction, we present data on spontaneous recombination in F1 males of D. ananassae heterozygous for chromosomes of the same Brazilian populations (1986) and marker chromosomes using three testers stocks. Mean recombination value was low although high variability existed between individual frequencies. Recombination frequencies between lines in each tester stock were not significantly different, excepting when the 3ple-px and 3ple-cy testers were compared (pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
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