Serotonin transporter binding of [123I]ADAM in bulimic women, their healthy twin sisters, and healthy women: a SPET study

<p>Abstract</p> <p>Background</p> <p>Bulimia Nervosa (BN) is believed to be caused by an interaction of genetic and environmental factors. Previous studies support the existence of a bulimia-related endophenotype as well as disturbances in serotonin (5-HT) transmission. We studied serotonin transporter (SERT) binding in BN, and to investigate the possibility of a SERT-related endophenotype for BN, did this in a sample of female twins. We hypothesized clearly reduced SERT binding in BN women as opposed to healthy women, and intermediate SERT binding in unaffected co-twins.</p> <p>Methods</p> <p>We studied 13 female twins with BN (9 with purging and 4 with non-purging BN) and 25 healthy women, including 6 healthy twin sisters of BN patients and 19 women from 10 healthy twin pairs. [¹²³I]ADAM, a selective SERT radioligand for single photon emission tomography (SPET) imaging, was used to assess SERT availability in the midbrain and the thalamus.</p> <p>Results</p> <p>No differences in SERT binding were evident when comparing the BN women, their unaffected co-twins and the healthy controls (p = 0.14). The healthy sisters of the BN patients and the healthy control women had similar SERT binding in both brain regions. In a <it>post hoc </it>subgroup analysis, the purging bulimics had higher SERT binding than the healthy women in the midbrain (p = 0.03), but not in the thalamus.</p> <p>Conclusion</p> <p>Our finding of increased SERT binding in the midbrain in the purging BN women raises the possibility that this subgroup of bulimics might differ in serotonergic function from the non-purging ones. The similarity of the unaffected co-twins and the healthy controls doesn't support our initial assumption of a SERT-related endophenotype for BN. Due to the small sample size, our results need to be interpreted with caution and verified in a larger sample.</p

Pay for performance in emerging markets: Insights from China

With the rapid increase in the application of Western HR practices in emerging markets, it is crucial to investigate how non-Western employees react to Western HR practices such as pay for performance (PFP). We investigate employee reactions to PFP in emerging markets using China as a case. Our multilevel analyses, based on data from 574 engineers in 22 domestic firms and eight foreign firms in China, demonstrated that PFP was positively associated with conscientiousness at the individual level. In contrast, PFP was negatively related to employees` organizational commitment and interpersonal helping at the organization level. This study suggests that the impact of "culture distance" associated with Western HR practices may be more likely to manifest itself in the collective entity than at the individual level. Employees of domestic firms reported significantly higher levels of performance appraisal satisfaction and justice perceptions than employees of foreign firms, which might explain why PFP was more widely implemented in domestic firms in China. The present results demonstrated that, in addition to the culture distance, the "context distance" between domestic and foreign firms may play a critical role in accruing benefits from PFP, indicating that PFP can be more beneficial to domestic firms than to foreign firms. The present findings provide practical implications for foreign firms operating in emerging markets. Journal of International Business Studies (2010), 41, 671-689. doi:10.1057/jibs.2009.40