Faculty Bibliography

It is a commonplace that evolution proceeds by selection of the fittest with elimination of organisms less well adapted to the environment. Along with this, the appearance of novel form arises from preliminary stages in growth, not as additions to the endpoints of prior specialization. The mechanisms of evolutionary change, from earlier form-building layers and specification by elimination, have been described in morphogenesis as prolongation of pre-terminal stages in development and winnowing of redundancy to achieve specific-ity. In earlier writings, these trends in evolutionary and developmental growth were the basis of an account of the nature of the symptom (error) with focal brain lesion. This paper extends the argument from pathology to subjective experience, namely that patterns in evolutionary and fetal growth that are carried over into adult cognition can explain the emergence of intrapersonal phenomena in human mind conceived as a kind of organism, with activity in the mental (mind/brain) state interpreted as a dynamic process of growth.

Neurons are highly polarized cells organized into functionally and molecularly distinct domains. A key question is whether the multiprotein complexes that comprise these domains are preassembled, transported, and inserted as a complex or whether their components are transported independently and assemble locally. Here, we have dynamically imaged, in pairwise combinations, the vesicular transport of fluorescently tagged components of the nodes of Ranvier and other myelinated axonal domains in sensory neurons cultured alone or together with Schwann cells at the onset of myelination. In general, most proteins are transported independently in the anterograde direction. In contrast, there is substantial cotransport of proteins from distinct domains in the retrograde direction likely due to coendocytosis along the axon. Early myelination did not substantially change these patterns of transport, although it increased the overall numbers of axonal transport vesicles. Our results indicate domain components are transported in separate vesicles for local assembly, not as preformed complexes, and implicate endocytosis along axons as a mechanism of clearance.

BACKGROUND AND PURPOSE/OBJECTIVE:The Neuroform Atlas is a new microstent to assist coil embolization of intracranial aneurysms that recently gained FDA approval. We present a postmarket multicenter analysis of the Neuroform Atlas stent. MATERIALS AND METHODS/METHODS:On the basis of retrospective chart review from 11 academic centers, we analyzed patients treated with the Neuroform Atlas after FDA exemption from January 2018 to June 2019. Clinical and radiologic parameters included patient demographics, aneurysm characteristics, stent parameters, complications, and outcomes at discharge and last follow-up. RESULTS:= .03). CONCLUSIONS:This multicenter analysis provides a real-world safety and efficacy profile for the treatment of intracranial aneurysms with the Neuroform Atlas stent.

Cell death is prevalent throughout life; however, the coordinated interactions and roles of phagocytes during corpse removal in the live brain are poorly understood. We developed photochemical and viral methodologies to induce death in single cells and combined this with intravital optical imaging. This approach allowed us to track multicellular phagocytic interactions with precise spatiotemporal resolution. Astrocytes and microglia engaged with dying neurons in an orchestrated and synchronized fashion. Each glial cell played specialized roles: Astrocyte processes rapidly polarized and engulfed numerous small dendritic apoptotic bodies, while microglia migrated and engulfed the soma and apical dendrites. The relative involvement and phagocytic specialization of each glial cell was plastic and controlled by the receptor tyrosine kinase Mertk. In aging, there was a marked delay in apoptotic cell removal. Thus, a precisely orchestrated response and cross-talk between glial cells during corpse removal may be critical for maintaining brain homeostasis.

BACKGROUND:Early childhood is a dynamic period of physical, psychosocial and cognitive development, where age appropriate intervention during the preschool years influences psychosocial, behavioural and academic achievement of children. This study evaluated the impact of a comprehensive preschool intervention on psychosocial, cognitive and behavioural school preparedness among children in Addis Ababa, Ethiopia. METHODS:Employing a cluster-sampling design, 150 preschool children who received the basic preschool curriculum (non-intervention) were compared with 100 randomly selected children who received a comprehensive preschool curriculum (intervention) using the Early Development Instrument (EDI) in five domains. Sample t-tests compared means of domain scores. Binary logistic regression analysed proportions of vulnerability in domains and overall. RESULT/RESULTS:There were no group differences in gender, age, special need status or child's first language. Intervention children had higher domain scores on social competence (mean difference 0.67 (SE=0.26)), emotional maturity (mean difference 0.77 (SE=0.29)), language and cognitive development (mean difference 0.67 (SE=0.40)), communication and general knowledge (mean difference 0.82 (SE=0.34)). Accounting for confounding variables, intervention children had a lower chance of overall vulnerability to domain problems (adjusted OR (AOR)=0.38; 95% CI 0.13 to 1.15), language and cognitive development (AOR=0.21; 95% CI 0.03 to 1.64), and social competence (AOR=0.20; 95% CI 0.08 to 0.45). CONCLUSION/CONCLUSIONS:The comprehensive intervention was associated with better outcomes on early childhood development across four domains. It is recommended to extend this programme to other areas of Ethiopia, where children do not have appropriate school preparation, to reduce risk of school dropout, negative personal and societal outcomes.

BACKGROUND:Alpha-1 antitrypsin (AAT) is a potent anti-protease enzyme which may play a role in arterial wall stability. A variant of its encoding gene has been recently linked to ischemic stroke due to large artery atherosclerosis (LAA). We sought to explore potential relationships between ischemic stroke mechanisms, atherosclerosis burden and serum AAT levels. METHODS:We performed a prospective observational study of consecutive patients with acute ischemic stroke who were admitted to an academic comprehensive stroke center over a three-month period. Blood samples were collected within 24 h of hospital admission, and stroke subtype classification was determined based on modified TOAST criteria. Modified Woodcock scoring system was used to quantify calcification of major cervico-cranial arteries as a surrogate for atherosclerosis burden. Linear regression analysis was used to assess the association between serum AAT levels and calcification scores, both as continuous variables. RESULTS:Among eighteen patients met our inclusion criteria and were enrolled in our study, 10 patients (56%) were men; mean age was 66 (SD 12.5); median NIH stroke scale was 4 (IQR 9.5); 8 patients (44%) had stroke due to LAA. The median serum level of AAT was 140 mg/dl (IQR 41.7) for patients with LAA-related stroke, and 148.5 mg/dl (IQR 37.7) for patients with other stroke mechanisms (p = 0.26). Higher serum AAT levels was associated with lower modified Woodcock calcification scores. (p-value = 0.038) CONCLUSIONS: Measurement of AAT levels in patients with acute stroke is feasible, and there may be associations between AAT levels and stroke mechanism that warrant further study in larger samples.

INTRODUCTION/BACKGROUND:Hereditary (variant) transthyretin amyloidosis (ATTRv) with polyneuropathy (ATTR-PN) is a rare genetic disorder that causes progressive autonomic and sensorimotor neuropathy, severe disability, and death within 10 years of onset. Previous studies have primarily focused on how baseline cardiac characteristics affect mortality, but the impact of non-cardiac baseline characteristics is less defined. METHODS:We systematically searched PubMed/Medline (1990-2019) to identify studies that assessed the impact of baseline ATTR-PN characteristics on survival. Outcomes were first summarized descriptively. Extracted survival data were then disaggregated, and parametric mixture models were used to assess survival differences among patient groups defined by factors known to affect survival. RESULTS:The search yielded 1193 records, of which 35 were retained for analysis. Median survival ranged from 0.5 to > 25 years. The largest survival differences were between cohorts who underwent liver transplantation (LTx) versus those who did not. Among LTx cohorts, pre-LTx ATTR-PN disease duration ≥ 7 years, poor nutritional status, and late disease onset reduced median survival by 13, 12, and 10 years, respectively. Other prognostic survival factors included non-Val30Met genotype and baseline presence of urinary incontinence, erectile dysfunction, or muscle weakness. CONCLUSION/CONCLUSIONS:Survival in patients with ATTR-PN is highly variable and affected by non-cardiac baseline characteristics, such as autonomic dysfunction, large fiber involvement, late-onset disease, and non-Val30Met mutation. Careful interpretation of these findings is warranted given that this synthesis did not control for differences between studies. Survival in patients with ATTR-PN remains poor among those who are untreated or with delayed diagnosis.