Linkage and physical mapping of X-linked lissencephaly/SBH (XLIS): a gene causing neuronal migration defects in human brain

While disorders of neuronal migration are associated with as much as 25% of recurrent childhood seizures, few of the genes required to establish neuronal position in cerebral cortex are known. Subcortical band heterotopia (SBH) and lissencephaly (LIS), two distinct neuronal migration disorders producing epilepsy and variable cognitive impairment, can be inherited alone or together in a single pedigree. Here we report a new genetic locus, XLIS, mapped by linkage analysis of five families and physical mapping of a balanced X;2 translocation in a girl with LIS. Linkage places the critical region in Xq21-q24, containing the breakpoint that maps to Xq22.3-q23 by high-resolution chromosome analysis. Markers used for somatic cell hybrid and fluorescence in situ hybridization analyses place the XLIS region within a 1 cM interval. These data suggest that SBH and X-linked lissencephaly are caused by mutation of a single gene, XLIS, that the milder SBH phenotype in females results from random X-inactivation (Lyonization), and that cloning of genes from the breakpoint region on X will yield XLIS.      

Maternal postpartum behavior and the emergence of infant-mother and infant-father synchrony in preterm and full-term infants: the role of neonatal vagal tone

Relations between maternal postpartum behavior and the emergence of parent-infant relatedness as a function of infant autonomic maturity were examined in 56 premature infants (birthweight = 1000-1500 g) and 52 full-term infants. Maternal behavior, mother depressive symptoms, and infant cardiac vagal tone were assessed in the neonatal period. Infant-mother and infant-father synchrony, maternal and paternal affectionate touch, and the home environment were observed at 3 months. Premature birth was associated with higher maternal depression, less maternal behaviors, decreased infant alertness, and lower coordination of maternal behavior with infant alertness in the neonatal period. At 3 months, interactions between premature infants with their mothers and fathers were less synchronous. Interaction effects of premature birth and autonomic maturity indicated that preterm infants with low vagal tone received the lowest amounts of maternal behavior in the postpartum and the least maternal touch at 3 months. Infant-mother and infant-father synchrony were each predicted by cardiac vagal tone and maternal postpartum behavior in both the preterm and full-term groups. Among preterm infants, additional predictors of parent-infant synchrony were maternal depression (mother only) and the home environment (mother and father). Findings are consistent with evolutionary perspectives on the higher susceptibility of dysregulated infants to rearing contexts and underscore the compensatory mechanisms required for social-emotional growth under risk conditions for parent-infant bonding.     

Combinatorial screening of cell proliferation on poly(L-lactic acid)/poly(D,L-lactic acid) blends

We have combined automated fluorescence microscopy with a combinatorial approach for creating polymer blend gradients to yield a rapid screening method for characterizing cell proliferation on polymer blends. A gradient in polymer blend composition of poly(L-lactic acid) (PLLA) and poly(D,L-lactic acid) (PDLLA) was created in the form of a strip-shaped film and was annealed to allow PLLA to crystallize. Fourier transform infrared (FTIR) microspectroscopy was used to determine the composition in the gradients and atomic force microscopy was used to characterize surface topography. Osteoblasts were cultured on the gradients and proliferation was assessed by automated counting of cells using fluorescence microscopy. Surface roughness varied with composition, was smooth on PDLLA-rich regions and was rough on the PLLA-rich regions. Cell adhesion was similar on all regions of the gradients while proliferation was faster on the smooth, PDLLA-rich end of the gradients than on the rough, PLLA-rich end of the gradients. These results demonstrate the feasibility of a new, combinatorial approach for evaluating cell proliferation on polymer blends.     

Are you talking to me?! An exploration of the triadic physician–patient–companion communication within memory clinics encounters

Objective

To explore and gain further insight into the nature of the triadic interaction among patients, companions and physicians in first-time diagnostic disclosure encounters of Alzheimer's disease in memory-clinic visits.

Methods

Twenty-five real-time observations of actual triadic encounters by six different physicians were analyzed. The analysis was accomplished through an innovative combination of grounded theory text analysis and graphics to illustrate the communicational exchanges.

Results

The “triadic” communication was actually a series of alternating dyadic exchanges where the third person tries, with inconsistent degrees of success, to become actively involved. During the initial introduction (phase 1) and summation/disclosure (phase 3), the core dyad shifts from physician–patient to physician–companion.

Conclusion

The focus of communication shifts within these encounters: from talking with the patient to talking about him or ignoring him. These shifts may signify an emotionally loaded role transformation from companion to caregiver.

Practice implications

Effective and empathic management of a triadic communication that avoids unnecessary interruptions and frustrations requires specific communication skills (e.g., explaining the rules and order of the conversation). Professionals need to facilitate the emotionally difficult shift from companion to caregiver and the adjustment of companion and demented patient to this shift.     

Emotional and physiological responses to normative and idiographic positive stimuli in bipolar disorder

Background

Few studies have examined differences in emotional responding among distinct types of positive stimuli. This is important to understand both for individuals characterized by extreme positive mood (i.e., bipolar disorder) and healthy adults.

Methods

Using a multi-method within-subjects design, the current study examined physiological, behavioral, and self-reported responses to normative (film) and idiographic (memory) happy stimuli in bipolar (BD; n = 25) and healthy control groups (CTL; n = 23).

Results

For both groups, the happy films were associated with greater self-reported and behavioral displays of positive emotion compared to the happy memory. Furthermore, the BD group displayed greater cardiac vagal tone - a putative marker of positive emotion - across both the film and memory.

Conclusion

Normative stimuli were more potent elicitors of positive emotion compared to idiographic stimuli. The study provided further evidence for cardiac vagal tone as a potential biomarker of extreme positive emotion in BD.