Difficult removal of fully covered Self Expandable Metal Stents (SEMS) for benign biliary strictures: The “SEMS in SEMS” technique

BackgroundRemoval of biliary Fully Covered Self Expandable Metal Stents can fail due to stent migration and/or hyperplastic ingrowth/overgrowth.MethodsA case series of 5 patients with benign biliary strictures (2 post-cholecystectomy, 2 following liver transplantation and 1 related to chronic pancreatitis) is reported. The biliary stricture was treated by temporary insertion of Fully Covered Self Expandable Metal Stents. Stent removal failed due to proximal stent migration and/or overgrowth. Metal stent removal was attempted a few weeks after the insertion of another Fully Covered Metal Stent into the first one.ResultsThe inner Fully Covered Self Expandable Metal Stent compressed the hyperplastic tissue, leading to the extraction of both the stents in all cases. Two complications were reported as a result of the attempt to stents removal (mild pancreatitis and self-limited haemobilia).ConclusionIn the present series, the “SEMS in SEMS” technique revealed to be effective when difficulties are encountered during Fully Covered Self Expandable Metal Stents removal.     

Opioidergic modulation of ethanol self-administration in the ventral pallidum

Background: Striatopallidal medium spiny neurons have been viewed as a final common path for drug reward and the ventral pallidum as an essential convergent point for hedonic and motivational signaling in the brain. The medium spiny neurons are GABAergic, but they colocalize enkephalin. Purpose of this study was to investigate the role of the opioidergic mechanisms of the ventral pallidum in ethanol self‐administration behavior. Methods: Effects of bilateral microinjections of μ‐, δ‐, and κ‐opioid receptor agonists and antagonists into the ventral pallidum on voluntary ethanol consumption were monitored in alcohol‐preferring Alko Alcohol (AA) rats using the 90‐minute limited access paradigm. Results: Stimulation of μ‐opioid receptors with DAMGO (0.01 to 0.1 μg) or morphine (1 to 10 μg) in the ventral pallidum decreased ethanol intake dose‐dependently. Conversely, blocking μ‐receptors with CTOP (0.3 to 3 μg) increased ethanol intake significantly. Unlike CTOP, DAMGO also increased locomotor activity. Consumption of ethanol was not modified significantly by a broad‐spectrum opioid receptor antagonist naltrexone, by δ‐opioid receptor agonist DPDPE or antagonist naltrindole, or by a κ‐opioid receptor agonist U50,488H or antagonist nor‐BNI. Conclusions: The study provides evidence for μ‐ but not δ‐ or κ‐opioid receptors in the ventral pallidum playing a role in the regulation of voluntary ethanol consumption. Furthermore, present findings give support to earlier work, suggesting an essential role of pallidal opioidergic transmission in drug reward.     

Oxytocin increases empathy to pain when adopting the other- but not the self-perspective

There is growing evidence that the neuropeptide oxytocin (OT) facilitates various forms of sensitivity to others, but the mechanism by which OT enhances empathy in humans is unclear. In this study, we examined whether OT increases empathy by the way of blurring the distinction between self and other, or by enhancing the difference between self and other. In this double-blind, placebo-controlled, within-subject crossover design, empathic responses of healthy participants were compared when imagining oneself (i.e., self-perspective empathy) versus when imagining the other (i.e., other-perspective empathy) in painful and nonpainful situations. Under OT treatment, participants expressed more empathy when imagining others than when imagining oneself in pain. This was in contrast to the placebo condition where there were no differences between the empathic responses during the self- and the other-perspective. We propose that the modulatory effect of OT on empathy when taking the other-perspective may be mediated by its role in self- and other-distinctiveness and corollary by its role in increasing salience to social agents and cues.     

Differential dorsal and ventral medial prefrontal representations of the implicit self modulated by individualism and collectivism: An fMRI study

Individualism and collectivism, or self-construal style, refer to cultural values that influence how people think about themselves and their relation to the social and physical environment. Recent neuroimaging evidence suggests that cultural values of individualism and collectivism dynamically modulate neural response within cortical midline structures, such as the medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC), during explicit self-evaluation. However, it remains unknown whether cultural priming modulates neural response during self-evaluation due to explicit task demands. Here we investigated how cultural priming of self-construal style affects neural activity within cortical midline structures during implicit self-evaluation in bicultural individuals. Results indicate that ventral MPFC showed relatively less deactivation during implicit evaluation of both self- and father-relevant information as compared to control condition (e.g., information of an unfamiliar person), irrespective of cultural priming. By contrast, dorsal MPFC showed relatively less deactivation during implicit evaluation of father-relevant information, but not self-relevant information, as compared to control condition, only when they were primed with individualism. Furthermore, dorsal MPFC showed relatively less deactivation during implicit evaluation of father-relevant information as compared to self-relevant condition only when they were primed with individualism. Hence, our results indicate that cultural priming modulates neural response within dorsal, but not ventral, portions of MPFC in a stimulus-driven rather than task-driven manner. More broadly, these findings suggest that cultural values dynamically shape neural representations during the evaluation, rather than the detection, of self-relevant information.