Citations

BACKGROUNDUmbilical cord blood (UCB) units collected from African Americans (AAs) have lower total nucleated cell (TNC) and CD34+ cell counts and are more likely to disqualify for banking compared to other ethnic groups. Furthermore, AAs have higher prevalence of 25‐hydroxyvitamin D (25(OH)D) deficiency. Given the importance of 25(OH)D in hematopoiesis, we examined the racial differences in UCB unit 25(OH)D content and its correlation with UCB cellular characteristics.STUDY DESIGN AND METHODSA total of 119 UCB units that did not meet the TNC count banking criteria were analyzed. Fifty‐one UCB units were collected from AA mothers and 68 from Caucasian mothers. We analyzed UCB volume, hematocrit (Hct), TNCs, mononuclear cells (MNCs), CD34+ cells, plasma 25(OH)D concentration, and progenitor clonogenic capacity measured by colony‐forming cell (CFC) assay.RESULTSCompared to Caucasians, AAs had significantly lower UCB 25(OH)D levels (p < 0.0001), TNCs (p = 0.002), MNCs (p = 0.026), and CD34+ cells (p = 0.026). Severe deficiency (25(OH)D < 10 ng/mL) was only detected in AAs. No difference in median CFC count/10,000 MNCs was detected between AAs and Caucasians. Independent of race, a significant association was detected between 25(OH)D level and TNCs (r = 0.193 p = 0.035) and Hct (r = 0.196 p = 0.033).CONCLUSIONThese results indicate the importance of 25(OH)D level as a racially independent predictor of UCB cellular characteristics and support further investigation of bioactive vitamin D and other predictors of hematopoiesis on cord blood quality.

ABSTRACT Background: Sleep deprivation and fatigue have been associated with medical errors, clinical performance decrements, and reduced quality of life for both practicing physicians and medical students. Greater understanding of the impact of sleep quantity on clinical reasoning could improve patient care. The purpose of our pilot study was to examine relationships between clinical reasoning (assessed by functional magnetic resonance imaging) and sleep time (measured in different ways by actigraphy) while answering multiple-choice questions (MCQs) from licensing agencies. Methods: Residents and faculty were administered a clinical reasoning exercise (MCQs from licensing bodies) during functional magnetic resonance imaging. Usual sleep patterns were sampled with actigraphy. Covariate analysis was used to examine the relationship between sleep duration (mean sleep, minimum sleep, maximum sleep) and brain activity during clinical reasoning (solving MCQs from licensing bodies). Results: The mean sleep time over the duration of monitoring for the group was 7.19 hours (SD 0.66) with a range of 6.1 to 8.1 hours (internal medicine faculty 7.1 hours, SD 0.41; internal medicine residents 7.27 hours, SD 0.92). There was a negative relationship between activation in the prefrontal cortex and minimum sleep time while reflecting on MCQs. Conclusion: Our findings provide evidence that the quantity of sleep can modulate brain activity while completing a clinically meaningful task that should be confirmed in larger studies. Our findings suggest that the construct of sleepiness may be more complex than appreciated by many and that the most important of these sleep measures in terms of outcomes remains to be determined.

AbstractIntroductionUnderstanding clinical reasoning is essential for patient care and medical education. Dual‐processing theory suggests that nonanalytic reasoning is an essential aspect of expertise; however, assessing nonanalytic reasoning is challenging because it is believed to occur on the subconscious level. This assumption makes concurrent verbal protocols less reliable assessment tools.MethodsFunctional magnetic resonance imaging was used to explore the neural basis of nonanalytic reasoning in internal medicine interns (novices) and board‐certified staff internists (experts) while completing United States Medical Licensing Examination and American Board of Internal Medicine multiple‐choice questions.ResultsThe results demonstrated that novices and experts share a common neural network in addition to nonoverlapping neural resources. However, experts manifested greater neural processing efficiency in regions such as the prefrontal cortex during nonanalytical reasoning.ConclusionsThese findings reveal a multinetwork system that supports the dual‐process mode of expert clinical reasoning during medical evaluation.

AbstractBackgroundLate‐onset Alzheimer's disease (AD) is heritable with 20 genes showing genome‐wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease, we extended these genetic data in a pathway analysis.MethodsThe ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain.ResultsALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (P = 3.27 × 10−12 after multiple testing correction for pathways), regulation of endocytosis (P = 1.31 × 10−11), cholesterol transport (P = 2.96 × 10−9), and proteasome‐ubiquitin activity (P = 1.34 × 10−6). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected P = .002–.05).ConclusionsThe immune response, regulation of endocytosis, cholesterol transport, and protein ubiquitination represent prime targets for AD therapeutics.