A facilitatory role of astrocytes in axonal regeneration after acute and chronic spinal cord injury.

Neuroscience dogma avers that astrocytic "scars" inhibit axonal regeneration after spinal cord injury (SCI). A recent report suggested however that astrocytes form "borders" around lesions that are permissive rather than inhibitory to axonal growth. We now provide further evidence supporting a facilitatory role of astrocytes in axonal regeneration after SCI. First, even 6months after SCI, injured axons are retained within regions of densely reactive astrocytes, in direct contact with astrocyte processes without being repelled. Second, 6 month-delayed implants of neural stem cells extend axons into reactive astrocyte borders surrounding lesions, densely contacting astrocyte surfaces. Third, bioengineered hydrogels implanted into sites of SCI re-orient reactive astrocytic processes to align along the rostral-to-caudal spinal cord axis resulting in successful regeneration into the lesion/scaffold in close association with astrocytic processes. Fourth, corticospinal axons regenerate into neural progenitor cells implanted six months after injury in close association with host astrocytic processes. Thus, astrocytes do not appear to inhibit axonal regeneration, and the close association of newly growing axons with astrocytic processes suggests a facilitatory role in axonal regeneration.

Adaptation of a cervical bilateral contusive spinal cord injury for study of skilled forelimb function.

We present an updated, clinically relevant model of moderately severe bilateral cervical level 6 contusive spinal cord injury (SCI) in the rat. This model is more clinically relevant than previous models due it its severity, yet animals readily survive the lesion. The C6 bilateral lesion is administered to Fischer 344 rats using the Infinite Horizons impactor adjusted to a 200 kdyne force with a 3.5 mm impactor head. The lesion results in loss of 60 ± 10% of the spinal cord area, including virtually the entire dorsal half of the spinal cord and complete interruption of the main corticospinal tract. Skilled forelimb performance declines by 60 ± 10% compared to the pre-operative baseline and deficits are sustained over time. This model is a substantial step closer to mimicking the most common level (cervical) and more severe form of SCI in humans and should provide a superior tool for assessing the likelihood that experimental interventions may promote motor recovery after SCI in humans.

BDNF guides neural stem cell-derived axons to ventral interneurons and motor neurons after spinal cord injury.

Neural stem cells (NSCs) implanted into sites of spinal cord injury (SCI) extend very large numbers of new axons over very long distances caudal to the lesion site, and support partial functional recovery. Newly extending graft axons distribute throughout host gray and white matter caudal to the injury. We hypothesized that provision of trophic gradients caudal to the injury would provide neurotrophic guidance to newly extending graft-derived axons to specific intermediate and ventral host gray matter regions, thereby potentially further improving neural relay formation. Immunodeficient rats underwent C5 lateral hemisection lesions, following by implants of human NSC grafts two weeks later. After an additional two weeks, animals received injections of AAV2-BDNF expressing vectors three spinal segments (9 mm) caudal to the lesion in host ventral and intermediate gray matter. After 2 months additional survival, we found a striking, 5.5-fold increase in the density of human axons innervating host ventral gray matter (P < 0.05) and 2.7-fold increase in intermediate gray matter (P < 0.01). Moreover, stem cell-derived axons formed a substantially greater number of putative synaptic connections with host motor neurons (P < 0.01). Thus, trophic guidance is an effective means of enhancing and guiding neural stem cell axon growth after SCI and will be used in future experiments to determine whether neural relay formation and functional outcomes can be improved.

Rehabilitation combined with neural progenitor cell grafts enables functional recovery in chronic spinal cord injury.

We reported previously that neural progenitor cell (NPC) grafts form neural relays across sites of subacute spinal cord injury (SCI) and support functional recovery. Here, we examine whether NPC grafts after chronic delays also support recovery and whether intensive rehabilitation further enhances recovery. One month after severe bilateral cervical contusion, rats received daily intensive rehabilitation, NPC grafts, or both rehabilitation and grafts. Notably, only the combination of rehabilitation and grafting significantly improved functional recovery. Moreover, improved functional outcomes were associated with a rehabilitation-induced increase in host corticospinal axon regeneration into grafts. These findings identify a critical and synergistic role of rehabilitation and neural stem cell therapy in driving neural plasticity to support functional recovery after chronic and severe SCI.

Patterns of bacterial diversity in embryonic capsules of the spotted salamander Ambystoma maculatum: an expanding view of a symbiosis.

The unicellular green alga, Oophila amblystomatis, populates egg capsules of the spotted salamander Ambystoma maculatum. This nutrient-exchange mutualism is widely perceived as a bipartite interaction, but the presence and contributing effects of bacteria to this symbiosis are unknown. We used standard cultivation techniques and amplicon sequencing of the V4/V5 region of 16S rRNA gene to identify and compare diversity of bacterial taxa in embryonic capsules with that in the aquatic breeding habitat. Our sampling regime allowed us to investigate diversity among individual capsules of an egg mass and between two ponds and sampling years. Capsules contain much lower diversity of bacteria than pond water, and spatial and temporal variation in intracapsular and pond bacterial diversity was observed. Despite this variation, sequences corresponding to species in the orders Burkholderiales and Oligoflexales were either prevalent or abundant, or both. Isolates most commonly recovered from capsules were closely related to species in the genus Herbaspirillum (Burkholderiaceae); other isolates were pseudomonads, but in all cases are closely related to known vascular plant-associated species. We conclude that, despite observed variation, there are bacterial taxa whose presence is held in common spatially and temporally among capsules and that the symbiosis between O. amblystomatis and A. maculatum may involve these taxa.

Facile synthesis of antibiotic-functionalized gold nanoparticles for colorimetric bacterial detection.

The development of quick and efficient methods for the detection of pathogenic bacteria is urgently needed for the diagnosis of infectious diseases and the control of microbiological contamination in global waterways, potable water sources and the food industry. This contribution will describe the synthesis of gold nanoparticles and their conjugation to broad spectrum, polypeptide and ß-lactam antibiotics that function as both reducing agents and surface protectants (ATB@AuNP). Nanoparticle colloids examined using transmission electron microscopy are generally spherical in shape and range from 2-50 nm in size. Dynamic light scattering and infrared spectroscopy were also used to confirm encapsulation of the AuNP surface by antibiotic molecules. ATB@AuNP were then used to detect 3 common pathogenic bacterial species: Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The colour of the AuNP colloid was monitored visually and using UV-visible spectroscopy. A red shift of the UV visible absorbance and a visible colour change following introduction of each pathogen is indicative of ATB binding to the bacteria surface, ascribed to AuNP agglomeration. This work demonstrates that ATB@AuNP may be an efficient and high throughput tool for the rapid detection of common bacterial contaminants.

Challenges to assessing professional identity in medical students: a tale of two measures.

Background: Professional identity formation (PIF), a foundational process in becoming a physician, includes establishment of values, moral principles, and self-awareness. The purpose of this report is to examine challenges in establishing the validity of measures of identity fusion as one facet of PIF. Method: Utilizing the modern approach of validity as a unitary concept, the authors generated six hypotheses to examine the evidence for the construct validity of the scores of Physician Professional Identity (PPI) and Identity Integration (IdIn), considering relationships of these measures with each other, year of training and data from a larger survey. Results: Responses from 3473 students at 8 medical schools revealed a weak association between the measures with distributions varying by cohort. PPI had a stronger relationship to cohort and IdIn was moderately associated with students' attitudes relevant to social media use. Responses were independent of response format and evidence supported the interpretation of scores for IdIn as indications of integration of identity. Discussion : Sufficient evidence was found to suggest that these measures assess aspects of PIF. Use of these measures as part of a multidimensional, longitudinal approach to refining understanding of the construct of PIF and developing effective assessment strategies.

Origins of Neural Progenitor Cell-Derived Axons Projecting Caudally after Spinal Cord Injury.

Neural progenitor cells (NPCs) transplanted into sites of spinal cord injury (SCI) extend large numbers of axons into the caudal host spinal cord. We determined the precise locations of neurons in the graft that extend axons into the caudal host spinal cord using AAV9-Cre-initiated retrograde tracing into floxed-TdTomato-expressing NPC grafts. 7,640 ± 630 grafted neurons extended axons to a single caudal host spinal cord site located 2 mm beyond the lesion, 5 weeks post injury. While caudally projecting axons arose from neurons located in all regions of the graft, the majority of caudally projecting graft neurons (53%) were located within the caudal one-third of the graft. Numerous host corticospinal axons formed monosynaptic projections onto caudally projecting graft neurons; however, we find that the majority of host axonal neuronal projections formed by neural progenitor cell interneuronal "relays" across sites of SCI are likely polysynaptic in nature.

Biomimetic 3D-printed scaffolds for spinal cord injury repair.

Current methods for bioprinting functional tissue lack appropriate biofabrication techniques to build complex 3D microarchitectures essential for guiding cell growth and promoting tissue maturation1. 3D printing of central nervous system (CNS) structures has not been accomplished, possibly owing to the complexity of CNS architecture. Here, we report the use of a microscale continuous projection printing method (µCPP) to create a complex CNS structure for regenerative medicine applications in the spinal cord. µCPP can print 3D biomimetic hydrogel scaffolds tailored to the dimensions of the rodent spinal cord in 1.6 s and is scalable to human spinal cord sizes and lesion geometries. We tested the ability of µCPP 3D-printed scaffolds loaded with neural progenitor cells (NPCs) to support axon regeneration and form new 'neural relays' across sites of complete spinal cord injury in vivo in rodents1,2. We find that injured host axons regenerate into 3D biomimetic scaffolds and synapse onto NPCs implanted into the device and that implanted NPCs in turn extend axons out of the scaffold and into the host spinal cord below the injury to restore synaptic transmission and significantly improve functional outcomes. Thus, 3D biomimetic scaffolds offer a means of enhancing CNS regeneration through precision medicine.

Generation and post-injury integration of human spinal cord neural stem cells.

Spinal cord neural stem cells (NSCs) have great potential to reconstitute damaged spinal neural circuitry, but they have yet to be generated in vitro. We now report the derivation of spinal cord NSCs from human pluripotent stem cells (hPSCs). Our observations show that these spinal cord NSCs differentiate into a diverse population of spinal cord neurons occupying multiple positions along the dorso-ventral axis, and can be maintained for prolonged time periods. Grafts into injured spinal cords were rich with excitatory neurons, extended large numbers of axons over long distances, innervated their target structures, and enabled robust corticospinal regeneration. The grafts synaptically integrated into multiple host intraspinal and supraspinal systems, including the corticospinal projection, and improved functional outcomes after injury. hPSC-derived spinal cord NSCs could enable a broad range of biomedical applications for in vitro disease modeling and constitute an improved clinically translatable cell source for 'replacement' strategies in several spinal cord disorders.

Rodent Neural Progenitor Cells Support Functional Recovery after Cervical Spinal Cord Contusion.

Previously, we and others have shown that rodent neural progenitor cells (NPCs) can support functional recovery after cervical and thoracic transection injuries. To extend these observations to a more clinically relevant model of spinal cord injury, we performed unilateral midcervical contusion injuries in Fischer 344 rats. Two-weeks later, E14-derived syngeneic spinal cord-derived multi-potent NPCs were implanted into the lesion cavity. Control animals received either no grafts or fibroblast grafts. The NPCs differentiated into all three neural lineages (neurons, astrocytes, oligodendrocytes) and robustly extended axons into the host spinal cord caudal and rostral to the lesion. Graft-derived axons grew into host gray matter and expressed synaptic proteins in juxtaposition with host neurons. Animals that received NPC grafts exhibited significant recovery of forelimb motor function compared with the two control groups (analysis of variance p < 0.05). Thus, NPC grafts improve forelimb motor outcomes after clinically relevant cervical contusion injury. These benefits are observed when grafts are placed two weeks after injury, a time point that is more clinically practical than acute interventions, allowing time for patients to stabilize medically, simplifying enrollment in clinical trials, and enhancing predictability of spontaneous improvement in control groups.

Prolonged human neural stem cell maturation supports recovery in injured rodent CNS.

Neural stem cells (NSCs) differentiate into both neurons and glia, and strategies using human NSCs have the potential to restore function following spinal cord injury (SCI). However, the time period of maturation for human NSCs in adult injured CNS is not well defined, posing fundamental questions about the design and implementation of NSC-based therapies. This work assessed human H9 NSCs that were implanted into sites of SCI in immunodeficient rats over a period of 1.5 years. Notably, grafts showed evidence of continued maturation over the entire assessment period. Markers of neuronal maturity were first expressed 3 months after grafting. However, neurogenesis, neuronal pruning, and neuronal enlargement continued over the next year, while total graft size remained stable over time. Axons emerged early from grafts in very high numbers, and half of these projections persisted by 1.5 years. Mature astrocyte markers first appeared after 6 months, while more mature oligodendrocyte markers were not present until 1 year after grafting. Astrocytes slowly migrated from grafts. Notably, functional recovery began more than 1 year after grafting. Thus, human NSCs retain an intrinsic human rate of maturation, despite implantation into the injured rodent spinal cord, yet they support delayed functional recovery, a finding of great importance in planning human clinical trials.

The relationship between study strategies and academic performance.

OBJECTIVES: To investigate if and to what extent the Learning and Study Strategy Inventory (LASSI) and the Self-Directed Learning Readiness Scale (SDLRS) yield academic performance predictors; To examine if LASSI findings are consistent with previous research. METHODS: Medical school students completed the LASSI and SDLRS before their first and second years (n = 168). Correlational and regression analyses were used to determine the predictive value of the LASSI and the SDLRS. Paired t-tests were used to test if the two measurement points differed. Bivariate correlations and R2s were compared with five other relevant studies. RESULTS: The SDLRS was moderately correlated with all LASSI subscales in both measures (r(152) =.255, p=.001) to (r(152) =.592, p =.000). The first SDLRS, nor the first LASSI, were predictive of academic performance. The second LASSI measure was a significant predictor of academic performance (R2(138) = 0.188, p = .003). Six prior LASSI studies yielded a range of R2s from 10-49%. CONCLUSIONS: The SDLRS is moderately correlated with all LASSI subscales. However, the predictive value of the SDLRS and LASSI differ. The SDLRS does not appear to be directly related to academic performance, but LASSI subscales: Concentration, Motivation, Time Management, and Test Strategies tend to be correlated. The explained LASSI variance ranges from 10% to 49%, indicating a small to substantial effect. Utilizing the LASSI to provide medical school students with information about their strengths and weaknesses and implementing targeted support in specific study strategies may yield positive academic performance outcomes.

Simulated Disaster Day: Benefit From Lessons Learned Through Years of Transformation From Silos to Interprofessional Education.

STATEMENT: Disaster Day is a simulation event that began in the College of Nursing and has increased exponentially in size and popularity for the last 8 years. The evolution has been the direct result of reflective practice and dedicated leadership in the form of students, faculty, and administration. Its development and expansion into a robust interprofessional education activity are noteworthy because it gives health care professions students an opportunity to work in teams to provide care in a disaster setting. The "authentic" learning situation has enhanced student knowledge of roles and responsibilities and seems to increase collaborative efforts with other disciplines. The lessons learned and modifications made in our Disaster Day planning, implementation, and evaluation processes are shared in an effort to facilitate best practices for other institutions interested in a similar activity.

In Situ Confocal Raman Microscopy of Hydrated Early Stages of Bacterial Biofilm Formation on Various Surfaces in a Flow Cell.

Bacterial biofilms are precursors to biofouling by other microorganisms. Understanding their initiation may allow us to design better ways to inhibit them, and thus to inhibit subsequent biofouling. In this study, the ability of confocal Raman microscopy to follow the initiation of biofouling by a marine bacterium, Pseudoalteromonas sp. NCIMB 2021 (NCIMB 2021), in a flow cell, using optical and confocal Raman microscopy, was investigated. The base of the flow cell comprised a cover glass. The cell was inoculated and the bacteria attached to, and grew on, the cover glass. Bright field images and Raman spectra were collected directly from the hydrated biofilms over several days. Although macroscopically the laser had no effect on the biofilm, within the first 24 h cells migrated away from the position of the laser beam. In the absence of flow, a buildup of extracellular substances occurred at the base of the biofilm. When different coatings were applied to cover glasses before they were assembled into the flow cells, the growth rate, structure, and composition of the resulting biofilm was affected. In particular, the ratio of Resonance Raman peaks from cytochrome c (CC) in the extracellular polymeric substances, to the Raman phenylalanine (Phe) peak from protein in the bacteria, depended on both the nature of the surface and the age of the biofilm. The ratios were highest for 24 h colonies on a hydrophobic surface. Absorption of a surfactant with an ethyleneoxy chain into the hydrophobic coating created a surface similar to that given with a simple PEG coating, where bacteria grew in colonies away from the surface rather than along the surface, and CC:Phe ratios were initially low but increased at least fivefold in the first 48 h.

Implementation of interprofessional education (IPE) in 16 U.S. medical schools: Common practices, barriers and facilitators.

BACKGROUND: Enhanced patient outcomes and accreditation criteria have led schools to integrate interprofessional education (IPE). While several studies describe IPE curricula at individual institutions, few examine practices across multiple institutions. PURPOSE: To examine the IPE integration at different institutions and determine gaps where there is potential for improvement. METHOD: In this mixed methods study, we obtained survey results from 16 U.S. medical schools, 14 of which reported IPE activities. RESULTS: The most common collaboration was between medical and nursing schools (93%). The prevalent format was shared curriculum, often including integrated modules (57%). Small group activities represented the majority (64%) of event settings, and simulation-based learning, games and role-play (71%) were the most utilized learning methods. Thirteen schools (81.3%) reported teaching IPE competencies, but significant variation existed. Gaps and barriers in the study include limitations of using a convenience sample, limited qualitative analysis, and survey by self-report. CONCLUSIONS: Most IPE activities focused on the physician role. Implementation challenges included scheduling, logistics and financial support. A need for effective faculty development as well as measures to examine the link between IPE learning outcomes and patient outcomes were identified.

Bone Marrow Stromal Cell Intraspinal Transplants Fail to Improve Motor Outcomes in a Severe Model of Spinal Cord Injury.

Bone marrow stromal cells (BMSCs) have been reported to exert potential neuroprotective properties in models of neurotrauma, although precise mechanisms underlying their benefits are poorly understood. Despite this lack of knowledge, several clinical trials have been initiated using these cells. To determine whether local mechanisms mediate BMSC neuroprotective actions, we grafted allogeneic BMSCs to sites of severe, compressive spinal cord injury (SCI) in Sprague-Dawley rats. Cells were administered 48 h after the original injury. Additional animals received allogeneic MSCs that were genetically modified to secrete brain-derived neurotrophic factor (BDNF) to further determine whether a locally administered neurotrophic factor provides or extends neuroprotection. When assessed 2 months post-injury in a clinically relevant model of severe SCI, BMSC grafts with or without BDNF secretion failed to improve motor outcomes. Thus, allogeneic grafts of BMSCs do not appear to act through local mechanisms, and future clinical trials that acutely deliver BMSCs to actual sites of injury within days are unlikely to be beneficial. Additional studies should address whether systemic administration of BMSCs alter outcomes from neurotrauma.

Conceptualizing Interprofessional Teams as Multi-Team Systems-Implications for Assessment and Training.

UNLABELLED: SGEA 2015 CONFERENCE ABSTRACT (EDITED). Evaluating Interprofessional Teamwork During a Large-Scale Simulation. Courtney West, Karen Landry, Anna Graham, and Lori Graham. CONSTRUCT: This study investigated the multidimensional measurement of interprofessional (IPE) teamwork as part of large-scale simulation training. BACKGROUND: Healthcare team function has a direct impact on patient safety and quality of care. However, IPE team training has not been the norm. Recognizing the importance of developing team-based collaborative care, our College of Nursing implemented an IPE simulation activity called Disaster Day and invited other professions to participate. The exercise consists of two sessions: one in the morning and another in the afternoon. The disaster scenario is announced just prior to each session, which consists of team building, a 90-minute simulation, and debriefing. Approximately 300 Nursing, Medicine, Pharmacy, Emergency Medical Technicians, and Radiology students and over 500 standardized and volunteer patients participated in the Disaster Day event. To improve student learning outcomes, we created 3 competency-based instruments to evaluate collaborative practice in multidimensional fashion during this exercise. APPROACH: A 20-item IPE Team Observation Instrument designed to assess interprofessional team's attainment of Interprofessional Education Collaborative (IPEC) competencies was completed by 20 faculty and staff observing the Disaster Day simulation. One hundred sixty-six standardized patients completed a 10-item Standardized Patient IPE Team Evaluation Instrument developed from the IPEC competencies and adapted items from the 2014 Henry et al. PIVOT Questionnaire. This instrument assessed the standardized or volunteer patient's perception of the team's collaborative performance. A 29-item IPE Team's Perception of Collaborative Care Questionnaire, also created from the IPEC competencies and divided into 5 categories of Values/Ethics, Roles and Responsibilities, Communication, Teamwork, and Self-Evaluation, was completed by 188 students including 99 from Nursing, 43 from Medicine, 6 from Pharmacy, and 40 participants who belonged to more than one component, were students at another institution, or did not indicate their institution. The team instrument was designed to assess each team member's perception of how well the team and him- or herself met the competencies. Five of the items on the team perceptions questionnaire mirrored items on the standardized patient evaluation: demonstrated leadership practices that led to effective teamwork, discussed care and decisions about that care with patient, described roles and responsibilities clearly, worked well together to coordinate care, and good/effective communication. RESULTS: Internal consistency reliability of the IPE Team Observation Instrument was 0.80. In 18 of the 20 items, more than 50% of observers indicated the item was demonstrated. Of those, 6 of the items were observed by 50% to 75% of the observers, and the remaining 12 were observed by more than 80% of the observers. Internal consistency reliability of the IPE Team's Perception of Collaborative Care Instrument was 0.95. The mean response score-1 (strongly disagree) to 4 (strongly agree)-was calculated for each section of the instrument. The overall mean score was 3.57 (SD = .11). Internal consistency reliability of the Standardized Patient IPE Team Evaluation Instrument was 0.87. The overall mean score was 3.28 (SD = .17). The ratings for the 5 items shared by the standardized patient and team perception instruments were compared using independent sample t tests. Statistically significant differences (p < .05) were present in each case, with the students rating themselves higher on average than the standardized patients did (mean differences between 0.2 and 0.6 on a scale of 1-4). CONCLUSIONS: Multidimensional, competency-based instruments appear to provide a robust view of IPE teamwork; however, challenges remain. Due to the large scale of the simulation exercise, observation-based assessment did not function as well as self- and standardized patient-based assessment. To promote greater variation in observer assessments during future Disaster Day simulations, we plan to adjust the rating scale from "not observed," "observed," and "not applicable" to a 4-point scale and reexamine interrater reliability.

Tools to investigate how interprofessional education activities link to competencies.

Integrating interprofessional education (IPE) activities and curricular components in health professions education has been emphasized recently by the inclusion of accreditation standards across disciplines. The Interprofessional Education Collaborative (IPEC) established IPE competencies in 2009, but evaluating how activities link to competencies has not been investigated in depth. The purpose of this project is to investigate how well two IPE activities align with IPEC competencies. To evaluate how our IPE activities met IPEC competencies, we developed a checklist and an observation instrument. A brief description of each is included as well as the outcomes. We analyzed Disaster Day, a simulation exercise that includes participants from Nursing, Medicine, and Pharmacy, and Interprofessional Healthcare Ethics (IPHCE), a course that introduced medical, nursing, and pharmacy students to ethical issues using didactic sessions and case discussions. While both activities appeared to facilitate the development of IPE competencies, Disaster Day aligned more with IPEC competencies than the IPHCE course and appears to be a more comprehensive way of addressing IPEC competencies. However, offering one IPE activity or curricular element is not sufficient. Having several IPE options available, utilizing the tools we developed to map the IPE curriculum and evaluating competency coverage is recommended.