Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner’s dilemma game. We did not find any correlation between the participants’ tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants’ responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status.     

Expression of Toll-Like Receptors 2 and 3 on Esophageal Epithelial Cell Lines and on Eosinophils During Esophagitis

Background  

The chronic disease eosinophilic esophagitis may be mediated by the innate immune system. Activation of toll-like receptors (TLRs) in other tissues is known to initiate eosinophil infiltration, thus TLRs may be a potential mediator of esophageal eosinophilia. Little is known about TLRs in the esophagus.     

IDH2 mutations are frequent in angioimmunoblastic T-cell lymphoma

Mutations in isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2) occur in most grade 2 and 3 gliomas, secondary glioblastomas, and a subset of acute myelogenous leukemias but have not been detected in other tumor types. The mutations occur at specific arginine residues and result in the acquisition of a novel enzymatic activity that converts 2-oxoglutarate to D-2-hydroxyglutarate. This study reports IDH1 and IDH2 genotyping results from a set of lymphomas, which included a large set of peripheral T-cell lymphomas. IDH2 mutations were identified in approximately 20% of angioimmunoblastic T-cell lymphomas (AITLs), but not in other peripheral T-cell lymphoma entities. These results were confirmed in an independent set of AITL patients, where the IDH2 mutation rate was approximately 45%. This is the second common genetic lesion identified in AITL after TET2 and extends the number of neoplastic diseases where IDH1 and IDH2 mutations may play a role.     

Psychiatric disorders and left-handedness in children living in an urban environment

The objective of this study was to conduct an analysis of left-handed children treated in an urban mental health clinic to investigate the frequency and severity of psychiatric disorders compared to right-handed peers. Data on handedness, diagnoses, hospitalizations and severity of mental disorders were collected on 692 consecutive children, 4–18 years old (M = 10.1, SD = 3.2), referred for psychiatric evaluation. Left-handed children were 18.2% of patients in the study, a rate significantly higher than left-hand dominance in the USA (p < .05). Compared to children with right-handedness, logistic regression analysis yielded 31% [odds ratio (OR) = 1.31, 95% confidence interval (CI): 1.15–1.50] higher odds of having more psychiatric diagnosis, 70% (OR = 1.70, 95% CI: 1.10–2.62) increased odds of anxiety, 53% (OR = 1.53, 95% CI: 1.03–2.27) increased odds of depression and 78% (OR = 1.78, 95% CI: 1.21–2.62) increased odds of oppositional defiant disorder for children who were left-handed. Left-handed children had increased odds of being prescribed antipsychotic and anxiolytic medication uses, 53% and 86% increased odds, respectively, and 66% (OR = 1.66, 95% CI: 1.08–2.55) increased odds of psychiatric hospitalizations. Left-handedness was a phenotypic risk factor for psychiatric disorders and increased severity of psychiatric disorders.     

Characterisation of cannabinoid 1 receptor expression in the perikarya, and peripheral and spinal processes of primary sensory neurons

The cannabinoid 1 (CB1) receptor is expressed by a sub-population of primary sensory neurons. However, data on the neurochemical identity of the CB1 receptor-expressing cells, and CB1 receptor expression by the peripheral and central terminals of these neurons are inconsistent and limited. We characterised CB1 receptor expression in dorsal root ganglia (DRG) and spinal cord at the lumbar 4–5 level, as well as in the urinary bladder and glabrous skin of the hindpaw. About 1/3 of DRG neurons exhibited immunopositivity for the CB1 receptor, the majority of which showed positivity for the nociceptive markers calcitonin gene-related peptide (CGRP) or/and Griffonia (bandeiraea) simplicifolia IB4 isolectin-binding. Virtually all CB1 receptor-immunostained fibres showed immunopositivity for CGRP in the skin, while very few did in the urinary bladder. No CB1 receptor-immunopositive nerve fibres were IB4 positive in either peripheral tissue. Spinal laminae I and II-outer showed the highest density of CB1 receptor-immunopositive punctae, the majority of which showed positivity for CGRP or/and IB4 binding. These data indicate that a major sub-population of nociceptive primary sensory neurons expresses CB1 receptors that are transported to both peripheral and central terminals of these cells. Therefore, the present data suggest that manipulation of endogenous CB1 receptor agonist levels in these areas may significantly reduce nociceptive input into the spinal cord.