Effects of cell banking manipulations on ex vivo amplification of umbilical cord blood

The small volume of placental/umbilical cord blood (PUCB) collectable restricts the use of these stem cells to pediatric transplantation. To extend the use of PUCB to adult recipients, many laboratories are investigating the feasibility of ex vivo PUCB expansion. The present study analyses the effects that PUCB banking cell manipulations (cell sedimentation, cryopreservation and thawing, mononuclear and CD34+ cell isolation) have on the number, viability and ex vivo expansion potential of PUCB cells. The results presented indicate the necessity of an open discussion on whether procedures used for handling the cells in PUCB banks can be extrapolated or not as such to the clinical use of ex vivo expanded PUCB.     

Marked bleeding diathesis in patients with platelet dysfunction due to a novel mutation in RASGRP2, encoding CalDAG-GEFI (p.Gly305Asp)

Congenital platelet function disorders are often the result of defects in critical signal transduction pathways required for platelet adhesion and clot formation. Mutations affecting RASGRP2, the gene encoding the Rap GTPase activator, CalDAG-GEFI, give rise to a novel, and rare, group of platelet signal transduction abnormalities. We here report platelet function studies for two brothers (P1 and P2) expressing a novel variant of RASGRP2, CalDAG-GEFI(p.Gly305Asp). P1 and P2 have a lifelong history of bleeding with severe epistaxis successfully treated with platelet transfusions or rFVIIa. Other bleedings include extended hemorrhage from minor wounds. Platelet counts and plasma coagulation were normal, as was αIIbβ3 and GPIb expression on the platelet surface. Aggregation of patients’ platelets was significantly impaired in response to select agonists including ADP, epinephrine, collagen, and calcium ionophore A23187. Integrin αIIbβ3 activation and granule release were also impaired. CalDAG-GEFI protein expression was markedly reduced but not absent. Homology modeling places the Gly305Asp substitution at the GEF-Rap1 interface, suggesting that the mutant protein has very limited catalytic activity. In summary, we here describe a novel mutation in RASGRP2 that affects both expression and function of CalDAG-GEFI and that causes impaired platelet adhesive function and significant bleeding in humans.     

Long‐term oral administration of melatonin improves spatial learning and memory and protects against cholinergic degeneration in middle‐aged Ts65Dn mice,a model of Down syndrome

Ts65Dn mice (TS), the most commonly used model of Down syndrome (DS), exhibit phenotypic characteristics of this condition. Both TS mice and DS individuals present cognitive disturbances, age‐related cholinergic degeneration, and increased brain expression of β‐amyloid precursor protein (AβPP). These neurodegenerative processes may contribute to the progressive cognitive decline observed in DS. Melatonin is a pineal indoleamine that has been reported to reduce neurodegenerative processes and improve cognitive deficits in various animal models. In this study, we evaluated the potentially beneficial effects of long‐term melatonin treatment on the cognitive deficits, cholinergic degeneration, and enhanced AβPP and β‐amyloid levels of TS mice. Melatonin was administered for 5 months to 5‐ to 6‐month‐old TS and control (CO) mice. Melatonin treatment improved spatial learning and memory and increased the number of choline acetyltransferase (ChAT)‐positive cells in the medial septum of both TS and CO mice. However, melatonin treatment did not significantly reduce AβPP or β‐amyloid levels in the cortex or the hippocampus of TS mice. Melatonin administration did reduce anxiety in TS mice without inducing sensorimotor alterations, indicating that prolonged treatment with this indoleamine is devoid of noncognitive behavioral side effects (e.g., motor coordination, sensorimotor abilities, or spontaneous activity). Our results suggest that melatonin administration might improve the cognitive abilities of both TS and CO mice, at least partially, by reducing the age‐related degeneration of basal forebrain cholinergic neurons. Thus, chronic melatonin supplementation may be an effective treatment for delaying the age‐related progression of cognitive deterioration found in DS.     

Evaluating how electronic charting affects resident productivity

Electronic medical records (EMRs) are becoming standard to improve the communication of information and longevity of patient records. Using an EMR in the emergency department (ED) could potentially slow residents evaluating patients. We evaluated how introducing an EMR affected resident productivity in an academic ED. We retrospectively studied first year emergency medicine residents from a large, academic, tertiary care center before-and-after the institution of an EMR on July 1st, 2010. No residents from the 2009–2010 class used the EMR, while all of the 2010–2011 residents used the EMR. We performed univariate and multivariate analyses using productivity, measured in patients per hour (pt/hr), as the primary outcome. A mixed-model multivariate regression, stratified by acuity zone, was created incorporating EMR and other possible confounders: admissions, signouts, daily ED volume, and days after July 1st for each shift. The study was granted IRB waiver of informed. We reviewed 2,405 shifts: 1,259 shifts before and 1,146 shifts after EMR implementation. When using the EMR, the univariate analysis estimated a 0.084 pt/hr increase in the high acuity zone (p = 0.1317) and 0.029 pt/hr decrease (p = 0.7085) in the low acuity zone. The multivariate regression estimated a 0.038 pt/hr increase (p = 0.3413) in the high acuity zone and a 0.009 pt/hr increase (p = 0.9049) in the low acuity zone with the EMR. Despite the expectation that electronic charting is detrimental to resident productivity, our analyses do not suggest a significant relationship between resident productivity and using the EMR.