Dynamic Opportunities for Medical Students to Assume the Roles of "Medical Teacher".

The traditional undergraduate medical education curriculum focuses on bolstering knowledge for practice and building clinical skills. However, as future clinicians, medical students will be tasked with teaching throughout their careers, first as residents and then as attendings. Here, we describe teaching opportunities for students that foster their development as future teachers and potential clinician educators. These offerings are diverse in their focus and duration and are offered across various levels of the curriculum - including course-based learning, longitudinal electives, and extra-curricular opportunities for medical students who have a passion for teaching.

Mentors and Role Models: the Role Female Medical Educators Serve for Female Medical Students.

Discussion of diversity, equity, and inclusion (DEI) has moved to the forefront in medical education, and in particular, efforts toward gender equity have emphasized the need for more women faculty and physicians. Gender parity was recently achieved for medical students matriculating into US allopathic schools during the 2017-2018 academic year1. However, this documented increase in women attending medical school as students is not matched by an increase in women teaching in the undergraduate medical education (UME) curriculum. In 2020, the faculty employed by medical schools across the USA (totaling 186,311) includes 43% women; this percentage drops significantly when considering the rank of full professor, of which only 26% are women [1]. For faculty representing graduate programs in science, technology, engineering, and math (STEM), many of which teach in the pre-clerkship phase of UME, less than 25% are women [2], according to the 2019 AAMC statement of gender equity. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-023-01776-1.

Impact of Experiential Learning of Nutrition Therapy on Medical Students.

Despite the recognition that nutrition is a critical component of health and disease, many medical schools struggle to incorporate nutrition education into their dense curriculum. We designed this study to determine whether a brief, experiential learning project would be an effective option for teaching this content. Medical students voluntarily enrolled in the study, agreeing to (1) attempt a 2-week "medically prescribed" diet and (2) participate in small group lunch discussions related to their diet experience. Data on student perception of nutrition in medicine was collected through validated surveys. Custom surveys were designed to capture student confidence in using nutrition counseling, while qualitative analysis of lunch discussions revealed themes of experiential learning. Participants reported an overall positive sentiment and named the most impactful learning component as actively attempting the diet. Student participants showed a variety of adherence to their assigned diet, yet as a cohort demonstrated increased confidence over their non-participant peers in the use of nutrition counseling in a clinical setting. In addition, diet participants demonstrated an increased perception of the importance of physician efficacy and the physician-patient relationship in the broader landscape of nutrition in patient care (compared to the control group). This study demonstrates the educational value of a short, immersive, extracurricular opportunity in bolstering an already demanding undergraduate medical education curriculum.

Pharmacogenomics: A Practical Primer for Senior Care Pharmacists.

Pharmacogenomics (PGx), the study of how an individual's genetic makeup affects his or her response to drugs, is a fast-growing field that gives health care providers a valuable tool to help safely and effectively manage medication. However, few providers have experience in applying the results of PGx tests to their practices, and this can lead to disregarding the data or unnecessarily modifying medication regimens. Pharmacists are uniquely positioned to become wellversed in the interpretation of PGx data, critically evaluating the "green-yellow-red" result categories that seemingly signal "go, caution, stop" regarding the use of a particular medication. Pharmacists also can evaluate genotype and phenotype information, commonly included in PGx laboratory reports, to optimize therapy. Using a case-based approach, this primer is intended to provide consultant pharmacists with practical direction to aid in PGx interpretation that will provide contextappropriate recommendations that contributes to positive patient outcomes.

Optimized Agrobacterium-mediated sorghum transformation protocol and molecular data of transgenic sorghum plants.

Agrobacterium-mediated sorghum transformation frequency has been enhanced significantly via medium optimization using immature embryos from sorghum variety TX430 as the target tissue. The new transformation protocol includes the addition of elevated copper sulfate and 6-benzylaminopurine in the resting and selection media. Using Agrobacterium strain LBA4404, the transformation frequency reached over 10% using either of two different selection marker genes, moPAT or PMI, and any of three different vectors in large-scale transformation experiments. With Agrobacterium strain AGL1, the transformation frequencies were as high as 33%. Using quantitative PCR analyses of 1,182 T0 transgenic plants representing 675 independent transgenic events, data was collected for T-DNA copy number, intact or truncated T-DNA integration, and vector backbone integration into the sorghum genome. A comparison of the transformation frequencies and molecular data characterizing T-DNA integration patterns in the transgenic plants derived from LBA4404 versus AGL1 transformation revealed that twice as many transgenic high-quality events were generated when AGL1 was used compared to LBA4404. This is the first report providing molecular data for T-DNA integration patterns in a large number of independent transgenic plants in sorghum.

Completely humanizing prolactin rescues infertility in prolactin knockout mice and leads to human prolactin expression in extrapituitary mouse tissues.

A variety of fundamental differences have evolved in the physiology of the human and rodent prolactin (PRL) systems. The PRL gene in humans and other primates contains an alternative promoter, 5.8 kbp upstream of the pituitary transcription start site, which drives expression of PRL in "extrapituitary" tissues, where PRL is believed to exert local, or paracrine, actions. Several of these extrapituitary PRL tissues serve a reproductive function (eg, mammary gland, decidua, prostate, etc), consistent with the hypothesis that local PRL production may be involved in, and required for, normal reproductive physiology in primates. Rodent research models have generated significant findings regarding the role of PRL in reproduction. Specifically, disruption (knockout) of either the PRL gene or its receptor causes profound female reproductive defects at several levels (ovaries, preimplantation endometrium, mammary glands). However, the rodent PRL gene differs significantly from the human, most notably lacking the alternative promoter. Understanding of the physiological regulation and function of extrapituitary PRL has been limited by the absence of a readily accessible experimental model, because the rodent PRL gene does not contain the alternative promoter. To overcome these limitations, we have generated mice that have been "humanized" with regard to the structural gene and tissue expression of PRL. Here, we present the characterization of these animals, demonstrating that the human PRL transgene is responsive to known physiological regulators both in vitro and in vivo. More importantly, the expression of the human PRL transgene is able to rescue the reproductive defects observed in mouse PRL knockout (mPRL(-)) females, validating their usefulness in studying the function or regulation of this hormone in a manner that is relevant to human physiology.

Utility of a writing station in the multiple mini-interview.

The multiple mini-interview (MMI) is a reliable and valid method of selecting applicants for admission to health professional schools on the basis of non-cognitive traits. Because the MMI is a series of short interview stations that applicants rotate through in coordinated sequence, it can potentially be resource intensive. However, the MMI design has room for innovation and efficiency. At the University of Manitoba Faculty of Medicine, a 10-minute unsupervised writing station (WS) was incorporated into the MMI to obtain a writing sample from each applicant, to increase the number of independent scores per applicant, and to increase the number of applicants interviewed per circuit without increasing interviewer numbers. One assessor evaluated all the writing samples and assigned a score ranging from 1 to 7. With the inclusion of a WS into an 11-station MMI, the faculty's capacity to interview applicants increased by 9% (from 297 to 324) without substantially increasing interviewer hours needed per day. For 1,257 applicants interviewed in 2008-2011, the mean WS score was 4.03 (SD=1.36), whereas applicants' mean of 10 oral station (OS) scores was 4.62 (SD=0.69). Correlations between WS score and mean OS score ranged from .16 to .27 (p<.01) over the four years. Because inter-station correlations for OS ranged from .01 to .37, the correlation of .21 between WS and mean OS scores for all four years combined appears reasonable. Institutions that want to effectively increase the capacity of their MMI process might consider adding a WS.

Multiple mini-interview scores of medical school applicants with and without rural attributes.

INTRODUCTION: Students from rural areas are under-represented in medical schools. Concerns have been raised about rural applicants' qualifications relative to those of their urban counterparts, and the impact such potential differences in competitiveness may have on their under-representation. Although studies have reported no differences in Grade Point Average (GPA) and Medical College Admission Test (MCAT) scores between applicants with and without rural attributes, to date no study has assessed if performance on the multiple mini-interview (MMI) varies between the two groups. METHODS: The MMI scores of 1257 interviewees for admission to the MD program at the Faculty of Medicine, University of Manitoba, in years 2008 to 2011, were studied for an association with graduation from a rural high school and attributes in the following three domains: rural connections, employment in rural areas, and rural community service. RESULTS: There were 205 (16.3%) rural high school graduates among interviewed applicants. Rural high school graduates scored significantly lower (mean of 4.4 on a scale of 1 to 7; p < 0.05) than urban high school graduates (4.6). Among rural-attribute domains, those with rural community service alone had the highest MMI scores (4.9) while those with rural connections alone had the lowest scores (4.3; p = 0.016). After adjusting for demographics, GPA, and MCAT scores in a multiple linear regression model, rural-attribute domains were not significant predictors of an applicant's MMI score. However, graduation from a rural high school was significantly associated with decreased MMI scores (a 0.122 decrease in predicted MMI scores on a scale of 1 to 7). CONCLUSION: Despite graduates from rural and urban high schools having comparable GPA, there exists a rural-urban divide in MMI scores that could exacerbate the under-representation of rural students in medical schools. Aboriginal applicants can also potentially be disproportionately affected, as they were more often from rural high schools than from urban high schools. Future studies need to determine systematic and institutional reasons, if any, for the differential in MMI scoring that can affect admission decisions for some rural applicants. It is also to be noted that the magnitude of difference is small enough that it may ultimately be irrelevant for future physician performance and practitioner outcomes.

Use of Z-scores to rank applicants to professional degree programs.

Criteria for assessing suitability of applicants for professional degree programs such as veterinary medicine are usually treated as distinct components of a composite scoring procedure that determines applicant ranking. Some components are valued more than others, which is reflected in the relative weights assigned to each component. However, the patterns of dispersal of individual components have the potential to alter the assigned relative weights. Components with larger variances can have greater influences on composite scores than intended. Such unintended altered weighting can be avoided through standardization. Yet non-standardized approaches continue to be used for admissions ranking in several programs. In this study, we documented the potential for differential selection of applicants when non-standardized scoring approaches are applied to admissions assessment components. At our medical school, applicants' component scores with differing variances are standardized by determining Z-scores with a mean of 0 and standard deviation of 1 before mathematically combining to calculate composite scores and admissions ranking. We retrospectively and hypothetically ranked one applicant cohort using non-standardized methods and identified differences in ranking between the standardized and non-standardized approaches. Most differences were observed for applicants in the second, third, and fourth quintiles of the admissions rank list, that is, those for whom admissions cut-off decisions make a marked difference. Observations were supported by lower Spearman's rank correlation coefficients in these quintiles. Although standardization of component scores is not a novel topic, we document the implications of using non-standardized scoring approaches for applicant ranking and underscore the importance of standardization of component scores.

Raw and test-thaw semen parameters after cryopreservation among men with newly diagnosed cancer.

OBJECTIVE: To characterize sperm parameters from thawed semen samples of men with different cancers who cryopreserved semen before oncologic therapy. DESIGN: Retrospective cohort study. SETTING: Tertiary academic medical center. PATIENT(S): 1,010 semen samples collected between 1994 to 2010. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Mean total motile count (TMC), change in percentage motility and percentage survival (100 * [postthaw % motility/raw % motility]) for each cancer compared with data from samples of men without cancer (the "procreative management" group), and proportion of postthaw samples with TMC >5 × 10(6). RESULT(S): The procreative management group had the best raw and postthaw semen quality. The best raw and postthaw semen quality for cancer patients occurred in those with prostate cancer (TMC of 155.1 and 53.2 × 10(6), respectively) and the worst in those with leukemias. Lymphoid leukemias demonstrated the worst raw TMC (26.8 × 10(6)), but myeloid leukemias displayed the worst postthaw TMC (6.9 × 10(6)). The testicular cancer group was the only group with a statistically significantly lower chance of having TMC >5 × 10(6). CONCLUSION(S): Men with testicular cancer were most commonly referred for sperm cryopreservation and were the only group that was statistically significantly less likely to have TMC >5 × 10(6) on postthaw semen analysis. The most severe reduction in TMC was seen in the myeloid leukemia group, suggesting that these patients along with men with testis cancer and those with lymphoid leukemia should be counseled to provide increased numbers of specimens for fertility preservation.

Estrogen regulation of the dopamine-activated GIRK channel in pituitary lactotrophs: implications for regulation of prolactin release during the estrous cycle.

Prolactin (PRL), synthesized and secreted from lactotrophs of the anterior pituitary gland, is tonically inhibited by hypothalamic dopamine (DA) throughout the female reproductive (estrous) cycle. Our laboratory has shown that DA hyperpolarizes these cells by activating G protein-coupled inwardly rectifying K(+) (GIRK) channels; however, this response is only observed on proestrus. While the cellular mechanisms that allow for functional expression of this unique DA-signaling pathway are unclear, we hypothesized that activation of the DA-GIRK effector pathway is due to the rise in circulating estrogen (E2) during the preceding day of diestrus. Thus, we examined the effects of E2 on primary lactotrophs isolated from female rats. Treatment with a physiological concentration of E2 (40-80 pg/ml, in vivo or in vitro) induced a proestrous phenotype in diestrous lactotrophs. These cells exhibited a DA-induced membrane hyperpolarization, as well as a secretory rebound of PRL following DA withdrawal (characteristic of proestrous cells). Internal dialysis of GTPγS demonstrated that E2 exposure enabled functional expression of GIRK channels, and this regulation by E2 did not involve the D2R. The effect of E2 was blocked by the receptor antagonist, ICI 182,780, and by the protein synthesis inhibitor, cycloheximide. Single-cell analysis revealed increased mRNA expression of GIRK channel subunits in E2-treated lactotrophs. While E2 is known to have multiple actions on the lactotroph, the present findings illuminate a novel action of E2 in lactotrophs-regulation of the expression of a DA effector, the GIRK channel.

A highly toxic cellular prion protein induces a novel, nonapoptotic form of neuronal death.

Several different deletions within the N-terminal tail of the prion protein (PrP) induce massive neuronal death when expressed in transgenic mice. This toxicity is dose-dependently suppressed by coexpression of full-length PrP, suggesting that it results from subversion of a normal physiological activity of cellular PrP. We performed a combined biochemical and morphological analysis of Tg(DeltaCR) mice, which express PrP carrying a 21-aa deletion (residues 105-125) within a highly conserved region of the protein. Death of cerebellar granule neurons in Tg(DeltaCR) mice is not accompanied by activation of either caspase-3 or caspase-8 or by increased levels of the autophagy marker, LC3-II. In electron micrographs, degenerating granule neurons displayed a unique morphology characterized by heterogeneous condensation of the nuclear matrix without formation of discrete chromatin masses typical of neuronal apoptosis. Our data demonstrate that perturbations in PrP functional activity induce a novel, nonapoptotic, nonautophagic form of neuronal death whose morphological features are reminiscent of those associated with excitotoxic stress.

Optimal promoter usage for lentiviral vector-mediated transduction of cultured central nervous system cells.

Lentiviral vectors transduce both dividing and non-dividing cells and can support sustained expression of transgenes. These properties make them attractive for the transduction of neurons and other neural cell types in vitro and in vivo. Lentiviral vectors can be targeted to specific cell types by using different promoters in the lentiviral shuttle vector. Even with identical constructs, however, levels of expression can vary significantly in different types of neurons and different culture preparations; expression levels in the same neuronal subtypes can be very different in primary cell culture and in vivo. We systematically assessed the ability of different promoters to direct expression of foreign transgenes in primary murine neocortical neurons, cerebellar granule cells and in undifferentiated and differentiated neuroblastoma cells. In primary cortical neurons, constructs using the ubiquitin C promoter directed the highest level of transgene expression; the phosphoglycerate kinase (PGK) promoter also directed robust transgene expression, while the cytomegalovirus (CMV) and MND (a synthetic promoter that contains the U3 region of a modified MoMuLV LTR with myeloproliferative sarcoma virus enhancer) promoters resulted in the expression of the transgenes in only limited number of neurons. In contrast, in cerebellar granule cells and in differentiated SH-SY5Y neuroblastoma cultures, the CMV promoter directed the most robust transgene expression. There was similar variability in transgene expression directed by these promoters in primary cultures of oligodendrocytes and astrocytes. These findings may prove useful in the design of lentiviral vectors for use in cell culture models of the nervous system.

A deleted prion protein that is neurotoxic in vivo is localized normally in cultured cells.

The prion protein (PrP) possesses sequence-specific domains that endow the molecule with neuroprotective and neurotoxic activities, and that may contribute to the pathogenesis of prion diseases. To further define critical neurotoxic determinants within PrP, we previously generated Tg(DeltaCR) mice that express a form of PrP harboring a deletion of 21 amino acids within the central domain of the protein [Li et al., EMBO J. 26 (2007), 548]. These animals exhibit a neonatal lethal phenotype that is dose-dependently rescued by co-expression of wild-type PrP. In this study, we examined the localization and cell biological properties of the PrP(DeltaCR) protein in cultured cells to further understand the mechanism of PrP(DeltaCR) neurotoxicity. We found that the distribution of PrP(DeltaCR) was identical to that of wild-type PrP in multiple cell lines of both neuronal and non-neuronal origin, and that co-expression of the two proteins did not alter the localization of either one. Both proteins were found in lipid rafts, and both were localized to the apical surface in polarized epithelial cells. Taken together, our results suggest that PrP(DeltaCR) toxicity is not a result of mislocalization or aggregation of the protein, and more likely stems from altered binding interactions leading to the activation of deleterious signaling pathways.

Prion protein lacks robust cytoprotective activity in cultured cells.

BACKGROUND: The physiological function of the cellular prion protein (PrPC) remains unknown. However, PrPC has been reported to possess a cytoprotective activity that prevents death of neurons and other cells after a toxic stimulus. To explore this effect further, we attempted to reproduce several of the assays in which a protective activity of PrP had been previously demonstrated in mammalian cells. RESULTS: In the first set of experiments, we found that PrP over-expression had a minimal effect on the death of MCF-7 breast carcinoma cells treated with TNF-alpha and Prn-p0/0 immortalized hippocampal neurons (HpL3-4 cells) subjected to serum deprivation. In the second set of assays, we observed only a small difference in viability between cerebellar granule neurons cultured from PrP-null and control mice in response to activation of endogenous or exogenous Bax. CONCLUSION: Taken together, our results suggest either that cytoprotection is not a physiologically relevant activity of PrPC, or that PrPC-dependent protective pathways operative in vivo are not adequately modeled by these cell culture systems. We suggest that cell systems capable of mimicking the neurotoxic effects produced in transgenic mice by N-terminally deleted forms of PrP or Doppel may represent more useful tools for analyzing the cytoprotective function of PrPC.

Non-infectious aggregates of the prion protein react with several PrPSc-directed antibodies.

The key event in the pathogenesis of prion diseases is the conformational conversion of the normal prion protein (PrP) (PrP(C)) into an infectious, aggregated isoform (PrP(Sc)) that has a high content of beta-sheet. Historically, a great deal of effort has been devoted to developing antibodies that specifically recognize PrP(Sc) but not PrP(C), as such antibodies would have enormous diagnostic and experimental value. A mouse monoclonal IgM antibody (designated 15B3) and three PrP motif-grafted monoclonal antibodies (referred to as IgG 19-33, 89-112, and 136-158) have been previously reported to react specifically with infectious PrP(Sc) but not PrP(C). In this study, we extend the characterization of these four antibodies by testing their ability to immunoprecipitate and immunostain infectious and non-infectious aggregates of wild-type, mutant, and recombinant PrP. We find that 15B3 as well as the motif-grafted antibodies recognize multiple types of aggregated PrP, both infectious and non-infectious, including forms found in brain, in transfected cells, and induced in vitro from purified recombinant protein. These antibodies are exquisitely selective for aggregated PrP, and do not react with soluble PrP even when present in vast excess. Our results suggest that 15B3 and the motif-grafted antibodies recognize structural features common to both infectious and non-infectious aggregates of PrP. Our study extends the utility of these antibodies for diagnostic and experimental purposes, and it provides new insight into the structural changes that accompany PrP oligomerization and prion propagation.

The cellular prion protein (PrP(C)): its physiological function and role in disease.

Prion diseases are caused by conversion of a normal cell-surface glycoprotein (PrP(C)) into a conformationally altered isoform (PrP(Sc)) that is infectious in the absence of nucleic acid. Although a great deal has been learned about PrP(Sc) and its role in prion propagation, much less is known about the physiological function of PrP(C). In this review, we will summarize some of the major proposed functions for PrP(C), including protection against apoptotic and oxidative stress, cellular uptake or binding of copper ions, transmembrane signaling, formation and maintenance of synapses, and adhesion to the extracellular matrix. We will also outline how loss or subversion of the cytoprotective or neuronal survival activities of PrP(C) might contribute to the pathogenesis of prion diseases, and how similar mechanisms are probably operative in other neurodegenerative disorders.

Neonatal lethality in transgenic mice expressing prion protein with a deletion of residues 105-125.

To identify sequence domains important for the neurotoxic and neuroprotective activities of the prion protein (PrP), we have engineered transgenic mice that express a form of murine PrP deleted for a conserved block of 21 amino acids (residues 105-125) in the unstructured, N-terminal tail of the protein. These mice spontaneously developed a severe neurodegenerative illness that was lethal within 1 week of birth in the absence of endogenous PrP. This phenotype was reversed in a dose-dependent fashion by coexpression of wild-type PrP, with five-fold overexpression delaying death beyond 1 year. The phenotype of Tg(PrPDelta105-125) mice is reminiscent of, but much more severe than, those described in mice that express PrP harboring larger deletions of the N-terminus, and in mice that ectopically express Doppel, a PrP paralog, in the CNS. The dramatically increased toxicity of PrPDelta105-125 is most consistent with a model in which this protein has greatly enhanced affinity for a hypothetical receptor that serves to transduce the toxic signal. We speculate that altered binding interactions involving the 105-125 region of PrP may also play a role in generating neurotoxic signals during prion infection.

Histone deacetylase-dependent establishment and maintenance of broad low-level histone acetylation within a tissue-specific chromatin domain.

The murine beta-globin locus in adult erythroid cells is characterized by a broad pattern of erythroid-specific histone acetylation. The embryonic beta-globin genes Ey and betaH1 are located in a approximately 30 kb central subdomain characterized by low-level histone acetylation, while the fetal/adult genes betamajor and betaminor and the upstream locus control region reside in hyperacetylated chromatin. Histone deacetylase (HDAC) inhibitors induce H4 acetylation at the Ey promoter [Forsberg, E. C., Downs, K. M., Christensen, H. M., Im, H., Nuzzi, P. A., and Bresnick, E. H. (2000) Proc. Natl. Acad. Sci. U.S.A. 97, 14494-14499], indicating that HDACs maintain low-level H4 acetylation at this site. Since little is known about the establishment of broad histone modification patterns, we asked whether this mechanism applies only to the promoter or to the entire subdomain. We show that the HDAC inhibitor trichostatin A induces H4 hyperacetylation at multiple sites within the subdomain in erythroid cells. The hematopoietic factors p45/NF-E2, GATA-1, and erythroid kruppel-like factor (EKLF), which function through cis elements of the beta-globin locus, were not required for induction of H4 hyperacetylation. Analysis of chromatin structure within the subdomain revealed low accessibility to restriction endonucleases and nearly complete CpG dinucleotide methylation. Induction of H4 hyperacetylation did not restore hallmark features of transcriptionally active chromatin. We propose that an HDAC-dependent surveillance mechanism counteracts constitutive histone acetyltransferase (HAT) access, thereby maintaining low-level H4 acetylation throughout the subdomain.