It’s worth the wait: optimizing questioning methods for effective intraoperative teaching

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138426/1/ans14046_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138426/2/ans14046.pd

Synthetic hydrogels for human intestinal organoid generation and colonic wound repair

In vitro differentiation of human intestinal organoids (HIOs) from pluripotent stem cells is an unparalleled system for creating complex, multicellular three-dimensional structures capable of giving rise to tissue analogous to native human tissue. Current methods for generating HIOs rely on growth in an undefined tumour-derived extracellular matrix (ECM), which severely limits the use of organoid technologies for regenerative and translational medicine. Here, we developed a fully defined, synthetic hydrogel based on a four-armed, maleimide-terminated poly(ethylene glycol) macromer that supports robust and highly reproducible in vitro growth and expansion of HIOs, such that three-dimensional structures are never embedded in tumour-derived ECM. We also demonstrate that the hydrogel serves as an injection vehicle that can be delivered into injured intestinal mucosa resulting in HIO engraftment and improved colonic wound repair. Together, these studies show proof-of-concept that HIOs may be used therapeutically to treat intestinal injury

Regeneration Of Fat Cells From Myofibroblasts During Wound Healing

Although regeneration through the reprogramming of one cell lineage to another occurs in fish and amphibians, it has not been observed in mammals. We discovered in the mouse that during wound healing, adipocytes regenerate from myofibroblasts, a cell type thought to be differentiated and nonadipogenic. Myofibroblast reprogramming required neogenic hair follicles, which triggered bone morphogenetic protein (BMP) signaling and then activation of adipocyte transcription factors expressed during development. Overexpression of the BMP antagonist Noggin in hair follicles or deletion of the BMP receptor in myofibroblasts prevented adipocyte formation. Adipocytes formed from human keloid fibroblasts either when treated with BMP or when placed with human hair follicles in vitro.Thus, we identify the myofibroblast as a plastic cell type that may be manipulated to treat scars in humans

Choosing a specialty: how faculty and residents may influence medical students career choices

Medical students’ specialty selection is strongly influenced by highly rated faculty, resident educators and mentors. Income, lifestyle, personality attributes, and intellectual content are particularly important factors. However, the reactions of faculty and residents medical students interact with during clerkship have not yet been explored. The study sought to understand the effect of faculty and resident feedback to medical students upon disclosure of their specialty selection. A validated 41-item survey was developed to gather medical student experiences with faculty and resident feedback regarding specialty selection. The survey was distributed in March 2021 via Qualtrics. There were 329 surveys included in the analysis. A total of 41% of students felt uncomfortable sharing their specialty selection with faculty and residents. Fear of judgments, grades, and retaliation were reported as reasons medical students were not comfortable with sharing their decision. It was reported that 26.8% of medical students changed their specialty selection following negative feedback from faculty or residents. Family medicine applicants reported the highest proportion of negative feedback from different specialty faculty (20%) and residents (24%). Surgical specialties received the most positive feedback regardless of the faculty or resident specialty. The findings show many medical students report discomfort about sharing their intended specialty with faculty and residents. For medical student who do share their career trajectory, faculty and resident feedback plays an important role.http://deepblue.lib.umich.edu/bitstream/2027.42/176210/1/HPE Day.pdfDescription of HPE Day.pdf : PosterSEL

A 3D adrenocortical carcinoma tumor platform for preclinical modeling of drug response and matrix metalloproteinase activity

Abstract Adrenocortical carcinoma (ACC) has a poor prognosis, and no new drugs have been identified in decades. The absence of drug development can partly be attributed to a lack of preclinical models. Both animal models and 2D cell cultures of ACC fail to accurately mimic the disease, as animal physiology is inherently different than humans, and 2D cultures fail to represent the crucial 3D architecture. Organoids and other small 3D in vitro models of tissues or tumors can model certain complexities of human in vivo biology; however, this technology has largely yet to be applied to ACC. In this study, we describe the generation of 3D tumor constructs from an established ACC cell line, NCI-H295R. NCI-H295R cells were encapsulated to generate 3D ACC constructs. Tumor constructs were assessed for biomarker expression, viability, proliferation, and cortisol production. In addition, matrix metalloproteinase (MMP) functionality was assessed directly using fluorogenic MMP-sensitive biosensors and through infusion of NCI-H295R cells into a metastasis-on-a-chip microfluidic device platform. ACC tumor constructs showed expression of biomarkers associated with ACC, including SF-1, Melan A, and inhibin α. Treatment of ACC tumor constructs with chemotherapeutics demonstrated decreased drug sensitivity compared to 2D cell culture. Since most tumor cells migrate through tissue using MMPs to break down extracellular matrix, we validated the utility of ACC tumor constructs by integrating fluorogenic MMP-sensitive peptide biosensors within the tumor constructs. Lastly, in our metastasis-on-a-chip device, NCI-H295R cells successfully engrafted in a downstream lung cell line-based construct, but invasion distance into the lung construct was decreased by MMP inhibition. These studies, which would not be possible using 2D cell cultures, demonstrated that NCI-H295R cells secreted active MMPs that are used for invasion in 3D. This work represents the first evidence of a 3D tumor constructs platform for ACC that can be deployed for future mechanistic studies as well as development of new targets for intervention and therapies

Single-cell analysis reveals fibroblast heterogeneity and myeloid-derived adipocyte progenitors in murine skin wounds.

During wound healing in adult mouse skin, hair follicles and then adipocytes regenerate. Adipocytes regenerate from myofibroblasts, a specialized contractile wound fibroblast. Here we study wound fibroblast diversity using single-cell RNA-sequencing. On analysis, wound fibroblasts group into twelve clusters. Pseudotime and RNA velocity analyses reveal that some clusters likely represent consecutive differentiation states toward a contractile phenotype, while others appear to represent distinct fibroblast lineages. One subset of fibroblasts expresses hematopoietic markers, suggesting their myeloid origin. We validate this finding using single-cell western blot and single-cell RNA-sequencing on genetically labeled myofibroblasts. Using bone marrow transplantation and Cre recombinase-based lineage tracing experiments, we rule out cell fusion events and confirm that hematopoietic lineage cells give rise to a subset of myofibroblasts and rare regenerated adipocytes. In conclusion, our study reveals that wounding induces a high degree of heterogeneity among fibroblasts and recruits highly plastic myeloid cells that contribute to adipocyte regeneration