Generating High Purity Embryonic Stem Cell-derived Cell Populations for Transplantation Following Spinal Cord Injury

Embryonic stem cells hold great potential for cell replacement strategies in the central nervous system. Pre-differentiation into various neural cell types can help generate tissue-specific cell populations that can replace cells and tissue lost due to do injury or disease. A small number of undifferentiated pluripotent stem cells persist in most transplant populations even after pre-differentiation. Given the right environment, i.e. biomaterial scaffolds, these cells can lead to tumor formation thereby eliminating any potential therapeutic benefit. This dissertation focused on the development of high purity embryonic stem cell-derived cell populations devoid of pluripotent stem cells for transplantation into the central nervous system, in particular the injured spinal cord. In the first study, transgenic expression of the puromycin resistance enzyme, puromycin N-acetyltransferase, is driven by the gene regulatory elements of the progenitor motor neuron associated transcription factor Olig2. Selection by puromycin exposure resulted in an enriched population of progenitor motor neurons, as well as recent progeny of progenitor motor neurons. Furthermore, undifferentiated stem cells were removed by puromycin selection. The efficacy of these enriched populations was evaluated in tissue engineered fibrin scaffolds containing a heparin-based delivery system for controlled delivery of two growth factor combinations. Greater differentiation into oligodendrocytes in vitro was observed in selected cell groups compared to unselected controls in fibrin scaffolds delivery neurotrophin-3 and glial derived neurotrophic factor. Enriched progenitor motor neurons survived and differentiated into oligodendrocytes, astrocytes and motoneurons in a two week sub-acute dorsal hemisection model of spinal cord injury. Encapsulating the transplant population in the tissue engineered fibrin scaffold with growth factors did not enhance proliferation or survival suggesting that tumorgenic cell populations were not present. In the final study, high purity mature cholinergic motoneurons were generated by driving puromycin resistance under control of two highly conserved enhancers for the motoneuron transcription factor Hb9. Puromycin selection resulted in a uniform group of post-mitotic immature motoneurons. Purity was observed through maturation and no proliferating glia were observed at any time point. Selected motoneurons maintained appropriate electrophysiological characteristics. Through this work, antibiotic selection appears to be a suitable method for generating high purity ES-cell derived neural populations

Student level II fieldwork failure: strategies for intervention.

OBJECTIVE: This report describes how common student communicative and behavioral characteristics that appear to predict the existence of potential problems during Level II fieldwork were identified in order to develop and implement preventative interventions during the academic curriculum at New York University (NYU). RECORD REVIEW: A record review of NYU professional-level occupational therapy students from 1986 to 1995 was completed to identify common factors among students who performed well academically but failed clinical fieldwork. Eight communicative and behavioral characteristics were identified: (a) rigidity of thinking, (b) discomfort with the ambiguity that accompanies clinical reasoning, (c) lack of psychological insight, (d) difficulty interpreting feedback, (e) externalization of responsibility, (f) difficulty learning from mistakes, (g) discomfort with the physical handling of patients, and (h) dependence on external measures for self-esteem. INTERVENTION: On the basis of the identified characteristics, five intervention strategies were adopted: (a) academic seminars that address professional behavior and interpersonal skills, (b) faculty feedback to students regarding problematic behaviors, (c) clinician and senior student counseling with identified students, (d) student remediation programs consisting of community service, and (e) student learning contracts based on specific behavioral objectives. These strategies were administered before Level II fieldwork to 10 students in the 1996 class who exhibited the characteristics indicative of potential fieldwork failure. OUTCOME: Of the 10 students in the 1996 class, 7 passed fieldwork without further difficulty, two failed fieldwork midterm assessments but went on to achieve passing final evaluations, and one failed the final fieldwork assessment but passed an additional third fieldwork experience. The class of 1996, which was the first to receive formal intervention designed to decrease fieldwork failure, demonstrated lower fieldwork failure rates than did all other classes in the past 10 years

Using Healthcare Data in Embedded Pragmatic Clinical Trials among People Living with Dementia and Their Caregivers: State of the Art

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/156003/1/jgs16617_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156003/2/jgs16617.pd

Reducing neuroinflammation by delivery of IL‐10 encoding lentivirus from multiple‐channel bridges

The spinal cord is unable to regenerate after injury largely due to growth‐inhibition by an inflammatory response to the injury that fails to resolve, resulting in secondary damage and cell death. An approach that prevents inhibition by attenuating the inflammatory response and promoting its resolution through the transition of macrophages to anti‐inflammatory phenotypes is essential for the creation of a growth permissive microenvironment. Viral gene delivery to induce the expression of anti‐inflammatory factors provides the potential to provide localized delivery to alter the host inflammatory response. Initially, we investigated the effect of the biomaterial and viral components of the delivery system to influence the extent of cell infiltration and the phenotype of these cells. Bridge implantation reduces antigen‐presenting cell infiltration at day 7, and lentivirus addition to the bridge induces a transient increase in neutrophils in the spinal cord at day 7 and macrophages at day 14. Delivery of a lentivirus encoding IL‐10, an anti‐inflammatory factor that inhibits immune cell activation and polarizes the macrophage population towards anti‐inflammatory phenotypes, reduced neutrophil infiltration at both day 7 and day 28. Though IL‐10 lentivirus did not affect macrophages number, it skewed the macrophage population toward an anti‐inflammatory M2 phenotype and altered macrophage morphology. Additionally, IL‐10 delivery resulted in improved motor function, suggesting reduced secondary damage and increased sparing. Taken together, these results indicate that localized expression of anti‐inflammatory factors, such as IL‐10, can modulate the inflammatory response following spinal cord injury, and may be a key component of a combinatorial approach that targets the multiple barriers to regeneration and functional recovery.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134909/1/btm210018.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134909/2/btm210018_am.pd

Black Girls Speak STEM: Counterstories of Informal and Formal Learning Experiences

This study presents the interpretations and perceptions of Black girls who participated in I AM STEM – a community-based informal science, technology, engineering, and mathematics (STEM) program. Using narrative inquiry, participants generated detailed accounts of their informal and formal STEM learning experiences. Critical race methodology informed this research to portray the dynamic and complex experiences of girls of color, whose stories have historically been silenced and misrepresented. The data sources for this qualitative study included individual interviews, student reflection journals, samples of student work, and researcher memos, which were triangulated to produce six robust counterstories. Excerpts of the counterstories are presented in this article. The major findings of this research revealed that I AM STEM ignited an interest in STEM learning through field trips and direct engagement in scientific phenomena that allowed the girls to become agentic in continuing their engagement in STEM activities throughout the year. This call to awaken the voices of Black girls to speak casts light on their experiences and challenges as STEM learners ⎯ from their perspectives. The findings confirm that when credence and counterspaces are given to Black girls, they are poised to reveal their luster toward STEM learning. This study provided a space for Black girls to reflect on their STEM learning experiences, formulate new understandings, and make connections between the informal and formal learning environments within the context of their everyday lives, thus offering a more holistic approach to STEM learning that occurs across settings and over a lifetime

Rhabdovirus Matrix Protein Structures Reveal a Novel Mode of Self-Association

The matrix (M) proteins of rhabdoviruses are multifunctional proteins essential for virus maturation and budding that also regulate the expression of viral and host proteins. We have solved the structures of M from the vesicular stomatitis virus serotype New Jersey (genus: Vesiculovirus) and from Lagos bat virus (genus: Lyssavirus), revealing that both share a common fold despite sharing no identifiable sequence homology. Strikingly, in both structures a stretch of residues from the otherwise-disordered N terminus of a crystallographically adjacent molecule is observed binding to a hydrophobic cavity on the surface of the protein, thereby forming non-covalent linear polymers of M in the crystals. While the overall topology of the interaction is conserved between the two structures, the molecular details of the interactions are completely different. The observed interactions provide a compelling model for the flexible self-assembly of the matrix protein during virion morphogenesis and may also modulate interactions with host proteins

Extreme events are more likely to affect the breeding success of lesser kestrels than average climate change

Climate change is predicted to severely impact interactions between prey, predators and habitats. In Southern Europe, within the Mediterranean climate, herbaceous vegetation achieves its maximum growth in middle spring followed by a three-month dry summer, limiting prey availability for insectivorous birds. Lesser kestrels (Falco naumanni) breed in a time-window that matches the nestling-rearing period with the peak abundance of grasshoppers and forecasted climate change may impact reproductive success through changes in prey availability and abundance. We used Normalised Difference Vegetation Index (NDVI) as a surrogate of habitat quality and prey availability to investigate the impacts of forecasted climate change and extreme climatic events on lesser kestrel breeding performance. First, using 14 years of data from 15 colonies in Southwestern Iberia, we linked fledging success and climatic variables with NDVI, and secondly, based on these relationships and according to climatic scenarios for 2050 and 2070, forecasted NDVI and fledging success. Finally, we evaluated how fledging success was influenced by drought events since 2004. Despite predicting a decrease in vegetation greenness in lesser kestrel foraging areas during spring, we found no impacts of predicted gradual rise in temperature and decline in precipitation on their fledging success. Notwithstanding, we found a decrease of 12% in offspring survival associated with drought events, suggesting that a higher frequency of droughts might, in the future, jeopardize the recent recovery of the European population. Here, we show that extreme events, such as droughts, can have more significant impacts on species than gradual climatic changes, especially in regions like the Mediterranean Basin, a biodiversity and climate change hotspotinfo:eu-repo/semantics/publishedVersio