Neuropathology of Rett syndrome

Rett Syndrome is unlike any other pediatric neurologic disease, and its clinical-pathologic correlation can not be defined with standard histology techniques. Based on hypotheses suggested by careful clinical observations, the nervous system of the Rett child has been explored utilizing morphometry, golgi preparations, computerized tomography, magnetic resonance imaging, chemistry, immunocytochemistry, autoradiography, and molecular biologic techniques. From these many perspectives we conclude that Rett syndrome is not a typical degenerative disorder, storage disorder, nor the result of gross malformation, infectious or neoplastic processes. There remain regions of the brain that have not been studied in detail but the available data suggest that the neuropathology of Rett syndrome can be summarized as follows: the Rett brain is small for the age and the height of the patient; it does not become progressively smaller over three to four decades; it has small dendritic trees in pyramidal neurons of layers III and V in selected lobes (frontal, motor, and temporal); it has small neurons with an increased neuronal packing density; it has an immature expression of microtubular protein-2 and cyclooxygenase; it exhibits a changing pattern of neurotransmitter receptors with an apparent reduction in many neurotransmitters, possibly contributing to some symptomatology. A mutation in Mecp2 causes this unique disorder of brain development. Neuronal mosaicism for normal and mutated Mecp2 produces a consistent phenotype in the classic female patient and a small brain with some preserved islands of function, but with an inability to support hand use and speech. This paper summarizes our current observations about neuropathology of Rett syndrome. MRDD Research Reviews 2002;8:72-76.     

Control of saccades in Parkinson's disease

Parkinson's patients (PD) made pro- and antisaccades: In the no-delay condition, the target appeared concurrent with the GO signal. In the delay condition, the target appeared before the signal for movement. Second, we probed spatial working memory in PD. Subjects looked to the remembered locations of sequential targets. In the no-delay prosaccade condition, PD had faster reaction times, made more express saccades, and exhibited hypometria. In the no-delay antisaccade condition, PD had longer reaction times and made more direction errors. In the delay tasks, PD made more direction errors and had more difficulty withholding a movement. PD made more sequencing errors in the spatial working memory task. These findings are consistent with a basal ganglia pathophysiology influencing eye movement processing in the frontal cortex.     

Unique pathways to resilience across cultures

An international mixed methods study of resilience of 14 sites in eleven countries identified seven tensions that youth resolve in culturally specific ways. Resolution of these tensions is foundational to experiences of resilience. This paper reports on the qualitative findings from interviews with 89 youth. Results support a culturally embedded understanding of positive youth development that better accounts for young people's resilience in western and non-western countries. Specifically, the seven tensions identified include: access to material resources, relationships, identity, cohesion, power and control, social justice, and cultural adherence. Findings show that no one pattern in the resolution of these tensions predicts resilience better than another. A case study of a Palestinian boy demonstrates the intersection of the seven tensions and the uniqueness of their resolution. The implications of this work for interventions is discussed.     

Wild robins (Petroica longipes) respond to human gaze

Gaze following and awareness of attentional cues are hallmarks of human and non-human social intelligence. Here, we show that the North Island robin (Petroica longipes), a food-hoarding songbird endemic to New Zealand, responds to human eyes. Robins were presented with six different conditions, in which two human experimenters altered the orientation or visibility of their body, head or eyes in relation to mealworm prey. One experimenter had visual access to the prey, and the second experimenter did not. Robins were then given the opportunity to ‘steal’ one of two mealworms presented by each experimenter. Robins responded by preferentially choosing the mealworm in front of the experimenter who could not see, in all conditions but one. Robins failed to discriminate between experimenters who were facing the mealworm and those who had their head turned 90° to the side. This may suggest that robins do not make decisions using the same eye visibility cues that primates and corvids evince, whether for ecological, experiential or evolutionary reasons.     

The bonding effect of money in the workplace: priming money weakens the negative relationship between ostracism and prosocial behaviour

The feeling of being ostracized in the workplace has been associated with the withdrawal of prosocial and helping behaviours. We propose that reminders of money would moderate (weaken) this relationship. We conducted three studies with working adult participants. Results showed that activating thoughts of money, even unrelated to compensation, reduced the negative relationship between ostracism and prosocial intentions (Studies 1 and 3) and behaviour (Study 2) in the organization. Study 3 furthermore showed that this effect occurs by reinforcing organizational identification. Our research identifies a factor that is already present in the work setting that could buffer the negative psychological and behavioural outcomes associated with ostracism: cues of money. We discuss the implications for research on money, social threats, and organizational behaviour.     

Effects of a Brief Parenting Intervention In Shelters For Mothers And Their Children Experiencing Homelessness

This study was designed to examine the effectiveness of an evidence-based parenting program—Triple P Positive Parenting Program—in shelter settings for families experiencing homelessness. The intervention has not previously been evaluated in a shelter setting, where there is a critical need for evidence-based parenting programs. Using a within-group pre- and post-intervention with 3-month follow-up design, 39 mothers residing in a shelter with a child ages 2–6 years participated. Results of this preliminary study showed positive effects of Triple P Discussion Groups. There were significant improvements in mother-reported parenting practices and child behavior across time, but no change in child maltreatment risk as measured by the Brief Child Abuse Potential Inventory. Mothers rated satisfaction with the program high immediately after the group and again three weeks later. Results showed Triple P Discussion Groups are acceptable and have some positive effects for this vulnerable population in need of parenting support. We discuss implications of findings, limitations of the study (including a 33% attrition rate), and recommendations for further study.

     

Explaining the effects of a decision intervention on mammography intentions: The roles of worry,fear and perceived susceptibility to breast cancer

Objective: This study examines the effects of a mammography decision intervention on perceived susceptibility to breast cancer (PSBC) and emotion and investigates how these outcomes predict mammography intentions.

Design: Randomised between-subjects online experiment. Participants were stratified into two levels of risk. Within each stratum, conditions included a basic information condition and six decision intervention conditions that included personalised risk estimates and varied according to a 2 (amount of information: brief vs. extended) × 3 (format: expository vs. untailored exemplar vs. tailored exemplar) design. Participants included 2465 US women ages 35–49.

Main Outcome Measures: PSBC as a percentage, PSBC as a frequency, worry, fear and mammography intentions.

Results: The intervention resulted in significant reductions in PSBC as a percentage for women in both strata and significant increases in worry and fear for women in the upper risk stratum. Of the possible mediators examined, only PSBC as a percentage was a consistent mediator of the effect of the intervention on mammography intentions.

Conclusion: The results provide insight into the mechanism of action of the intervention by showing that PSBC mediated the effects of the intervention on mammography intentions.