Differential changes in the cellular composition of the developing marsupial brain

Throughout development both the body and the brain change at remarkable rates. Specifically, the number of cells in the brain undergoes dramatic nonlinear changes, first exponentially increasing in cell number and then decreasing in cell number. Different cell types, such as neurons and glia, undergo these changes at different stages of development. The current investigation used the isotropic fractionator method to examine the changes in cellular composition at multiple developmental milestones in the short‐tailed opossum, Monodelphis domestica. Here we report several novel findings concerning marsupial brain development and organization. First, during the later stages of neurogenesis (P18), neurons make up most of the cells in the neocortex, although the total number of neurons remains the same throughout the life span. In contrast, in the subcortical regions, the number of neurons decreases dramatically after P18, and a converse relationship is observed for nonneuronal cells. In the cerebellum, the total number of cells gradually increases until P180 and then remains constant, and then the number of neurons is consistent across the developmental ages examined. For the three major structures examined, neuronal density and the percentage of neurons within a structure are highest during neurogenesis and then decrease after this point. Finally, the total number of neurons in the opossum brain is relatively low compared with other small‐brained mammals such as mice. The relatively low number of neurons and correspondingly high number of nonneurons suggests that in the marsupial brain nonneurons may play a significant role in signal processing. J. Comp. Neurol. 521:2602–2620, 2013. © 2013 Wiley Periodicals, Inc.     

A computer-aided telephone system to enable five persons with Alzheimer's disease to make phone calls independently

This study extended the assessment of a computer-aided telephone system to enable five patients with a diagnosis of Alzheimer's disease to make phone calls independently. The patients were divided into two groups and exposed to intervention according to a non-concurrent multiple baseline design across groups. All patients started with baseline in which the technology was not available, and continued with intervention in which the technology was used. The technology involved a net-book computer provided with specific software, a global system for mobile communication modem (GSM), a microswitch, and lists of partners to call with related photos. All the patients learned to use the system and made phone calls independently to a variety of partners, such as family members, friends, and caregivers. A social validation assessment, in which care and health professionals working with persons with dementia were asked to rate the patients’ performance with the technology and with the help of a caregiver, provided generally more positive scores for the technology-assisted performance. The positive implications of the findings for daily programs of patients with Alzheimer's disease are discussed.     

Is the Next Generation of Physicians Adequately Prepared to Diagnose and Treat Eating Disorders in Children and Adolescents?

This study examined medical residents’ comfort with and knowledge of eating disorder assessment and treatment practices for children and adolescents. Since entering medical school, the majority of respondents reported receiving fewer than 5 hours of training in this area. Participants reported feeling more comfortable with the assessment of eating disorders than with their medical management and treatment. Questions testing participants’ knowledge in these domains reflected this finding; participants did well on the assessment questions, but quite poorly on the treatment questions. Intensity of training and self-reported comfort with these skills predicted residents’ knowledge, suggesting that additional training opportunities are warranted.     

Law Student Stress: Relationships Between Academic Demands,Social Isolation,Career Pressure,Study/Life Imbalance and Adjustment Outcomes in Law Students

Although Australian law students report elevated distress compared with community norms and other student groups, few studies have examined the relationships between perceived stress in law school and adjustment in law students. A total of 647 Australian law students completed the purpose-built Law Student Perceived Stress Scale (LSPSS). Analyses indicated that the LSPSS was psychometrically sound and measured four dimensions of law school stress: academic demands, social isolation, career pressure and study/life imbalance. Regression analyses on a subsample (n = 481) indicated that higher scores on each dimension were related to higher depression and anxiety symptoms. Social isolation was related to reduced life satisfaction and psychological well-being across all dimensions. Further analysis indicated that the majority of law students reported Moderate to Extremely Severe symptoms of depression (53%) and anxiety (54%). Practice implications, including the need to promote social connectedness in law schools, are discussed.     

Report from the European Myeloma Network on interphase FISH in multiple myeloma and related disorders

The European Myeloma Network has organized two workshops on fluorescence in situ hybridization in multiple myeloma. The first aimed to identify specific indications and consensus technical approaches of current practice. A second workshop followed a quality control exercise in which 21 laboratories analyzed diagnostic cases of purified plasma cells for recurrent abnormalities. The summary report was discussed at the EHA Myeloma Scientific Working Group Meeting 2010. During the quality control exercise, there was acceptable agreement on more than 1,000 tests. The conclusions from the exercise were that the primary clinical applications for FISH analysis were for newly diagnosed cases of MM or frank relapse cases. A range of technical recommendations included: 1) material should be part of the first draw of the aspirate; 2) samples should be sent at suitable times to allow for the lengthy processing procedure; 3) most importantly, PCs must be purified or specifically identified; 4) positive cut-off levels should be relatively conservative: 10% for fusion or break-apart probes, 20% for numerical abnormalities; 5) informative probes should be combined to best effect; 6) in specialist laboratories, a single experienced analyst is considered adequate; 7) at least 100 PC should be scored; 8) essential abnormalities to test for are t(4;14), t(14;16) and 17p13 deletions; 9) suitable commercial probes should be available for clinically relevant abnormalities; 10) the clinical report should be expressed clearly and must state the percentage of PC involved and the method used for identification; 11) a retrospective European based FISH data bank linked to clinical data should be generated; and 12) prospective analysis should be centralized for upcoming trials based on the recommendations made. The European Myeloma Network aims to build on these recommendations to establish standards for a common European data base to define subgroups with prognostic significance.     

Neural stem and progenitor cells in the aged subependyma are activated by the young niche

Previous studies have demonstrated an age related decline in the size of the neural stem cell (NSC) pool and a decrease in neural progenitor cell proliferation, however, the mechanisms underlying these changes are unclear. In contrast to previous reports, we report that the numbers of NSCs is unchanged in the old age subependyma and the apparent loss is because of reduced proliferative potential in the aged stem cell niche. Transplantation studies reveal that the proliferation kinetics and migratory behavior of neural precursor cells are dependent on the age of the host animal and independent of the age of the donor cells suggesting that young and old age neural precursors are not intrinsically different. Factors from the young stem cell niche rescue the numbers of NSC colonies derived from old age subependyma and enhance progenitor cell proliferation in vivo in old age mice. Finally, we report a loss of Wnt signaling in the old age stem cell niche that underlies the lack of expansion of the NSC pool after stroke.     

Technology-aided Programs to Enable Persons with Multiple Disabilities to Move through Sequences of Occupational Activities Independently

These two studies assessed technology-aided programs for fostering sustained occupational engagement and mobility in persons with multiple disabilities who typically failed to move through sequences of activities. Study I involved two participants with severe intellectual disability and blindness. The program ensured automatic presentation of (a) auditory cues to guide the participants to different workstations with activities, and (b) musical and social (reinforcing) stimulation at the participants’ arrival at each of the workstations. Study II involved one participant with severe to profound intellectual disability and moderate hearing impairment. The program presented combinations of auditory and visual cues to guide the participant to the workstations and positive social consequences as she reached them. The results of both studies were largely positive. The participants’ mean percentages of independent transition moves (i.e., moves to reach the different workstations available and carry out the activities scheduled) increased from zero or below 20 at the beginning of the study (under baseline conditions) to about 95 by the end of the study (with the use of the programs). Practical and technical implications of the results for daily intervention with persons with multiple disabilities are discussed.