Quantifying refractive error in companion dogs with and without nuclear sclerosis: 229 eyes from 118 dogs.

OBJECTIVE: To evaluate the relationship between nuclear sclerosis (NS) and refractive error in companion dogs. ANIMALS STUDIED: One hundred and eighteen companion dogs. PROCEDURES: Dogs were examined and found to be free of significant ocular abnormalities aside from NS. NS was graded from 0 (absent) to 3 (severe) using a scale developed by the investigators. Manual refraction was performed. The effect of NS grade on refractive error was measured using a linear mixed effects analysis adjusted for age. The proportion of eyes with >1.5 D myopia in each NS grade was evaluated using a chi-square test. Visual impairment score (VIS) was obtained for a subset of dogs and compared against age, refractive error, and NS grade. RESULTS: Age was strongly correlated with NS grade (p < .0001). Age-adjusted analysis of NS grade relative to refraction showed a mild but not statistically significant increase in myopia with increasing NS grade, with eyes with grade 3 NS averaging 0.58-0.88 D greater myopia than eyes without NS. However, the myopia of >1.5 D was documented in 4/58 (6.9%) eyes with grade 0 NS, 12/91 (13.2%) eyes with grade 1 NS, 13/57 (22.8%) eyes with grade 2 NS, and 7/23 (30.4%) eyes with grade 3 NS. Risk of myopia >1.5 D was significantly associated with increasing NS grade (p = .02). VIS was associated weakly with refractive error, moderately with age, and significantly with NS grade. CONCLUSIONS: NS is associated with visual deficits in some dogs but is only weakly associated with myopia. More work is needed to characterize vision in aging dogs.

Micromolded honeycomb scaffold design to support the generation of a bilayered RPE and photoreceptor cell construct.

Age-related macular degeneration (AMD) causes blindness due to loss of retinal pigment epithelium (RPE) and photoreceptors (PRs), which comprise the two outermost layers of the retina. Given the small size of the macula and the importance of direct contact between RPE and PRs, the use of scaffolds for targeted reconstruction of the outer retina in later stage AMD and other macular dystrophies is particularly attractive. We developed microfabricated, honeycomb-patterned, biodegradable poly(glycerol sebacate) (PGS) scaffolds to deliver organized, adjacent layers of RPE and PRs to the subretinal space. Furthermore, an optimized process was developed to photocure PGS, shortening scaffold production time from days to minutes. The resulting scaffolds robustly supported the seeding of human pluripotent stem cell-derived RPE and PRs, either separately or as a dual cell-layered construct. These advanced, economical, and versatile scaffolds can accelerate retinal cell transplantation efforts and benefit patients with AMD and other retinal degenerative diseases.

Re-formation of synaptic connectivity in dissociated human stem cell-derived retinal organoid cultures.

Human pluripotent stem cell (hPSC)-derived retinal organoids (ROs) can efficiently and reproducibly generate retinal neurons that have potential for use in cell replacement strategies [Capowski et al., Development 146, dev171686 (2019)]. The ability of these lab-grown retinal neurons to form new synaptic connections after dissociation from ROs is key to building confidence in their capacity to restore visual function. However, direct evidence of reestablishment of retinal neuron connectivity via synaptic tracing has not been reported to date. The present study employs an in vitro, rabies virus-based, monosynaptic retrograde tracing assay [Wickersham et al., Neuron 53, 639-647 (2007); Sun et al., Mol. Neurodegener. 14, 8 (2019)] to identify de novo synaptic connections among early retinal cell types following RO dissociation. A reproducible, high-throughput approach for labeling and quantifying traced retinal cell types was developed. Photoreceptors and retinal ganglion cells-the primary neurons of interest for retinal cell replacement-were the two major contributing populations among the traced presynaptic cells. This system provides a platform for assessing synaptic connections in cultured retinal neurons and sets the stage for future cell replacement studies aimed at characterizing or enhancing synaptogenesis. Used in this manner, in vitro synaptic tracing is envisioned to complement traditional preclinical animal model testing, which is limited by evolutionary incompatibilities in synaptic machinery inherent to human xenografts.

Bartonellosis in Dogs and Cats, an Update.

The unique virulence factors of Bartonella spp make them stealth pathogens that evade the immune system and cause persistent infections that are often difficult to diagnose and treat. Understanding these pathogenic mechanisms allows clinicians to recognize when to pursue diagnostics, how to optimize diagnostic testing and treatment, and ultimately can lead to improved outcomes.

Human retinal organoids harboring IMPG2 mutations exhibit a photoreceptor outer segment phenotype that models advanced retinitis pigmentosa.

Interphotoreceptor matrix proteoglycan 2 (IMPG2) mutations cause a severe form of early-onset retinitis pigmentosa (RP) with macular involvement. IMPG2 is expressed by photoreceptors and incorporated into the matrix that surrounds the inner and outer segments (OS) of rods and cones, but the mechanism of IMPG2-RP remains unclear. Loss of Impg2 function in mice produces a mild, late-onset photoreceptor phenotype without the characteristic OS loss that occurs in human patients. We generated retinal organoids (ROs) from patient-derived induced pluripotent stem (iPS) cells and gene-edited embryonic stem cells to model human IMPG2-RP in vitro. All ROs harboring IMPG2 mutations lacked an OS layer, in contrast to isogenic controls. Subsequent protein analyses revealed that this phenotype arises due to a loss of IMPG2 expression or its inability to undergo normal post-translational modifications. We hypothesized that loss of IMPG2 function destabilizes the interphotoreceptor matrix and renders the OS vulnerable to physical stressors, which is accentuated in the tissue culture environment. In support of this mechanism, transplantation of IMPG2 mutant ROs into the protected subretinal space of immunocompromised rodents restored OS production. Beyond providing a robust platform to study IMPG2-RP, this human RO model system may serve a broader role in honing strategies to treat advanced photoreceptor-based diseases.

Systemic immunosuppression promotes survival and integration of subretinally implanted human ESC-derived photoreceptor precursors in dogs.

Regenerative therapies aimed at replacing photoreceptors are a promising approach for the treatment of otherwise incurable causes of blindness. However, such therapies still face significant hurdles, including the need to improve subretinal delivery and long-term survival rate of transplanted cells, and promote sufficient integration into the host retina. Here, we successfully delivered in vitro-derived human photoreceptor precursor cells (PRPCs; also known as immature photoreceptors) to the subretinal space of seven normal and three rcd1/PDE6B mutant dogs with advanced inherited retinal degeneration. Notably, while these xenografts were rejected in dogs that were not immunosuppressed, transplants in most dogs receiving systemic immunosuppression survived up to 3-5 months postinjection. Moreover, differentiation of donor PRPCs into photoreceptors with synaptic pedicle-like structures that established contact with second-order neurons was enhanced in rcd1/PDE6B mutant dogs. Together, our findings set the stage for evaluating functional vision restoration following photoreceptor replacement in canine models of inherited retinal degeneration.

Human photoreceptors switch from autonomous axon extension to cell-mediated process pulling during synaptic marker redistribution.

Photoreceptors (PRs) are the primary visual sensory cells, and their loss leads to blindness that is currently incurable. Although cell replacement therapy holds promise, success is hindered by our limited understanding of PR axon growth during development and regeneration. Here, we generate retinal organoids from human pluripotent stem cells to study the mechanisms of PR process extension. We find that early-born PRs exhibit autonomous axon extension from dynamic terminals. However, as PRs age from 40 to 80 days of differentiation, they lose dynamic terminals on 2D substrata and in 3D retinal organoids. Interestingly, PRs without motile terminals are still capable of extending axons but only by process stretching via attachment to motile non-PR cells. Immobile PR terminals of late-born PRs have fewer and less organized actin filaments but more synaptic proteins compared with early-born PR terminals. These findings may help inform the development of PR transplantation therapies.

Outer Retinal Cell Replacement: Putting the Pieces Together.

Retinal degenerative diseases (RDDs) affecting photoreceptors (PRs) are one of the most prevalent sources of incurable blindness worldwide. Due to a lack of endogenous repair mechanisms, functional cell replacement of PRs and/or retinal pigmented epithelium (RPE) cells are among the most anticipated approaches for restoring vision in advanced RDD. Human pluripotent stem cell (hPSC) technologies have accelerated development of outer retinal cell therapies as they provide a theoretically unlimited source of donor cells. Human PSC-RPE replacement therapies have progressed rapidly, with several completed and ongoing clinical trials. Although potentially more promising, hPSC-PR replacement therapies are still in their infancy. A first-in-human trial of hPSC-derived neuroretinal transplantation has recently begun, but a number of questions regarding survival, reproducibility, functional integration, and mechanism of action remain. The discovery of biomaterial transfer between donor and PR cells has highlighted the need for rigorous safety and efficacy studies of PR replacement. In this review, we briefly discuss the history of neuroretinal and PR cell transplantation to identify remaining challenges and outline a stepwise approach to address specific pieces of the outer retinal cell replacement puzzle.

Moving Medical Students into Shared Housing During the COVID-19 Pandemic.

A new academic year began in the midst of the COVID-19 pandemic. In order to allow for in-person learning, a fundamental part of medical education, some medical schools grappled with how to safely move students into shared on-campus housing. The authors describe a behavior-based strategy to safely move students from all parts of the United States to the Albert Einstein College of Medicine in the Bronx, New York. This strategy included a school-organized phased move-in that included 14-day quarantines for students coming from states with high COVID prevalence; requiring students to sign a COVID-agreement; the use of a phone-based daily COVID risk assessment; and facilitation of safe in-person social activities with peer monitoring of adherence to behavior guidelines. This strategy resulted in no known transmission of SARS-CoV-2 in student housing between July and October of the 2020 to 2021 academic year. The authors share this strategy in the hope that colleagues at other medical schools will find it useful in utilizing similar behavior-based strategies to keep students safe in shared housing.

Ultrathin micromolded 3D scaffolds for high-density photoreceptor layer reconstruction.

Polymeric scaffolds are revolutionizing therapeutics for blinding disorders affecting the outer retina, a region anatomically and functionally defined by light-sensitive photoreceptors. Recent engineering advances have produced planar scaffolds optimized for retinal pigment epithelium monolayer delivery, which are being tested in early-stage clinical trials. We previously described a three-dimensional scaffold supporting a polarized photoreceptor monolayer, but photoreceptor somata typically occupy multiple densely packed strata to maximize light detection. Thus, patients with severe photoreceptor degeneration are expected to extract greater benefits from higher-density photoreceptor delivery. Here, we describe the microfabrication of a biodegradable scaffold patterned for high-density photoreceptor replacement. The "ice cube tray" structure optimizes mechanical properties and cell-to-biomaterial load, enabling production of a multicellular photoreceptor layer designed for outer retinal reconstruction. Our approach may also be useful in the production of a multitude of micro- and nanoscale structures for multilayered cell delivery in other tissues.

Development of a Positive Psychology Program (LAVENDER) for Preserving Medical Student Well-being: A Single-Arm Pilot Study.

BACKGROUND: Mental health tends to worsen over the course of medical school, with steep declines in well-being in students' clerkship year (M3). Positive emotion promotes adaptive coping to stress and may help preserve medical student well-being. OBJECTIVE: This study describes the development of LAVENDER (Leveraging Affect and Valuing Empathy for Nurturing Doctors' Emotional Resilience), a program aimed at increasing positive emotion to preserve well-being in medical students. METHODS: We conducted a single-arm pilot of LAVENDER, a positive psychology intervention developed for medical students delivered in an interactive classroom format to a cohort of 157 third-year medical students at the Albert Einstein College of Medicine. Our primary outcome was the acceptability of LAVENDER. We also examined preliminary efficacy using measures of emotion, stress and burnout collected at each intervention session. RESULTS: LAVENDER showed good acceptability: 76% of participants agreed that the LAVENDER skills were useful and 72% agreed that they would recommend the LAVENDER program to others. Qualitative feedback suggested that medical students enjoyed the program and found the skills to be useful for coping with stress, but also reported the following barriers to engagement: lack of time to practice the skills, resistance to the mandatory nature of the wellness sessions, and difficulty integrating the skills in daily life. We did not find support for the preliminary efficacy of LAVENDER for improving medical student well-being in students' clerkship year. Participants showed decreases in positive emotion and increases in symptoms of burnout over the intervention period (ps < .01). CONCLUSION: The current paper describes the development and a single-arm pilot test of LAVENDER, a positive psychology program tailored for medical students. Although we found preliminary evidence for the acceptability of LAVENDER, we did not find support for the preliminary efficacy. Lessons learned and next steps for the program are discussed.

Imaging Transplanted Photoreceptors in Living Nonhuman Primates with Single-Cell Resolution.

Stem cell-based transplantation therapies offer hope for currently untreatable retinal degenerations; however, preclinical progress has been largely confined to rodent models. Here, we describe an experimental platform for accelerating photoreceptor replacement therapy in the nonhuman primate, which has a visual system much more similar to the human. We deployed fluorescence adaptive optics scanning light ophthalmoscopy (FAOSLO) to noninvasively track transplanted photoreceptor precursors over time at cellular resolution in the living macaque. Fluorescently labeled photoreceptors generated from a CRX+/tdTomato human embryonic stem cell (hESC) reporter line were delivered subretinally to macaques with normal retinas and following selective ablation of host photoreceptors using an ultrafast laser. The fluorescent reporter together with FAOSLO allowed transplanted photoreceptor precursor survival, migration, and neurite formation to be monitored over time in vivo. Histological examination suggested migration of photoreceptor precursors to the outer plexiform layer and potential synapse formation in ablated areas in the macaque eye.

3D Microstructured Scaffolds to Support Photoreceptor Polarization and Maturation.

Blinding disorders of the outer retina involve dysfunction and degeneration of photoreceptors. One potential approach to treat these forms of blindness is to repopulate the outer retina via a simple bolus injection of donor photoreceptors. However, this may not be ideal due to the highly polarized organization of photoreceptors that include apical light sensing photopigments and basal axon terminals. Furthermore, bolus injections create uncertainty with regard to the area, density, and retention of donor cells. Here, a novel and robust microfabrication process is developed to create 3D, micrometer-sized complex structures in ultrathin and biocompatible elastomer films (nonbiodegradable polydimethylsiloxane and biodegradable poly(glycerol-sebacate)) that can serve as polarizable photoreceptor delivery scaffolds, consisting of an array of cup-shaped photoreceptor capture wells that funnel into a microchannel. This "wine glass" scaffold design promotes efficient capture of human pluripotent stem-cell-derived photoreceptor cell bodies and guidance of basal axon extensions, ultimately achieving a uniform level of organization and polarization that is not possible with bolus injections or previously described scaffolds. In addition to future therapeutic applications, our scaffold design and materials provide a platform to generate reproducible and scalable in vitro models of photoreceptor-based diseases.

Group observed structured encounter (GOSCE) for third-year medical students improves self-assessment of clinical communication.

OBJECTIVES: This study assesses the effectiveness of a GOSCE in teaching medical students clinical communication, as well as group collaboration and peer feedback. METHODS: The GOSCE was administered during the Internal Medicine clerkship. Groups consisted of 4-6 students and one faculty member. Students completed pre- and post-GOSCE surveys to assess confidence in clinical communication and a GOSCE evaluation to rate the overall experience. Pre- and post-GOSCE program survey scores were compared, and the mean score and standard deviation of the GOSCE evaluation was calculated. RESULTS: Students perceived improvement in their general (Mean 4.49-4.57, p < .0001), case-specific (3.61-3.84, p < .0001) and group clinical communication (3.75-4.09, p < .0001) skills. Students agreed or strongly agreed that the GOSCE taught them something new (91.20%), made them more comfortable in giving (64.31%) and receiving (66.57%) feedback and working with a group (64.22%). Students found the GOSCE to be as effective as an OSCE (70.97%). CONCLUSIONS: A GOSCE is a valuable resource for use in formative assessment of clinical communication, and it offers the benefit of group collaboration and peer feedback. These findings support the broader use of GOSCEs in undergraduate medical education.

Four-Station Group Observed Structured Clinical Encounter for Formative Assessment of Communication Skills for Internal Medicine Clerks.

INTRODUCTION: Communication with patients and among colleagues is critical to effective clinical care. A group observed structured clinical encounter (GOSCE) is an effective and resource-saving tool for teaching communication skills to medical students. While objective structured clinical exams (OSCEs) are a well-established assessment tool for communication skills, a GOSCE allows for formal observation of communication skills while also providing an opportunity for peer observation and feedback. Additionally, a GOSCE costs less and requires fewer faculty per learner than a traditional OSCE. METHODS: This is a four-station GOSCE to teach advanced communication skills to medical students. The stations are smoking cessation, difficult doctor-patient encounter, shared decision making, and delivering bad news. A group is made up of four to six students and one faculty member. At each station, one student takes the lead in the patient interview, followed by a group interview and ending with feedback by all participants. RESULTS: In the pilot phase, a total of 44 students were administered the GOSCE and were surveyed about their experience. Students felt the GOSCE was an enjoyable and educational experience. The GOSCE has subsequently been administered to more than 600 students, and 25 internal medicine faculty have participated. DISCUSSION: Our work demonstrates that the GOSCE is a feasible curricular enhancement for formative assessment of communication skills during the internal medicine clerkship. It is easy to implement and has been well received by all participants, with minimal impact on limited medical school and faculty resources.

Depression and stress amongst undergraduate medical students.

BACKGROUND: The demands placed on medical trainees pose a challenge to personal wellbeing, leading to burnout and erosion of empathy. However, it is unclear at what point in medical education this decline begins. Although many schools have begun to design and implement wellness programs for their students, the medical education community's experience in evaluating their impact is limited. METHODS: The authors designed a wellness needs assessment of all medical students at the Albert Einstein College of Medicine in order to assess students' health behaviors, stress and depressive symptoms. The online survey was administered to all medical students from the classes of 2014 and 2015 at the beginning of their first year of medical school and again at the end of their third year. Chi-square and T-tests were run comparing the survey responses of the two classes. RESULTS: There was a significant increase in perceived stress from an average of 5.51 in the first year to 6.49 in the third year (p = .0001). The number of students at risk for depression, defined as a CES-D score greater than 16, was 94 (28.4%) in the first year and 131 (39.0%) in their third year (p = .004). CONCLUSIONS: This study demonstrates a significant increase in the proportion of students at risk for depression in their third year as compared to the first year as well as an increase in perceived stress. In response to these findings, the authors took a multi-disciplinary approach in the development of a comprehensive program to address student wellness, including efforts to address issues specific to the clinical clerkships. This program is unique in that its design, inception and ongoing evaluation have taken the needs of an entire medical school class into account.

Comparison of two- and three-times-daily topical ophthalmic application of 0.005% latanoprost solution in clinically normal dogs.

OBJECTIVE: To determine whether 2- or 3-times-daily application of topical ophthalmic 0.005% latanoprost solution is more effective at lowering intraocular pressure (IOP) in clinically normal dogs. ANIMALS: 9 clinically normal dogs. PROCEDURES: For each dog, I drop of latanoprost 0.005% solution was applied to 1 eye every 8 or 12 hours each day for 5 days; the contralateral eye received topical ophthalmic treatment with 1 drop of saline (0.9% NaCl) solution at the times of latanoprost application. Ocular examinations of both eyes were performed every 6 hours starting 48 hours prior to and ending 42 hours after the treatment period. Following a 5-week washout interval, the procedures were repeated but the previously latanoprost-treated eye of each dog received latanoprost application at the alternate frequency. RESULTS: Mean ± SD IOP reduction in the latanoprost-treated eyes was 31 ± 6.9% with 2-times-daily application and 33 ± 8.2% with 3-times-daily application. A 2-way repeated-measures ANOVA revealed significant differences in IOP with contributions by treatment (2 or 3 times daily), time of day (diurnal variation), and individual dog. The maximum mean daily IOP reduction in latanoprost-treated eyes was detected on day 3 of latanoprost treatment in each group. Eyes treated 3 times daily had significantly smaller pupil diameter and greater conjunctival hyperemia than eyes treated 2 times daily. CONCLUSIONS AND CLINICAL RELEVANCE: The clinical importance of the ocular hypotensive effects of 3-times-daily topical ophthalmic application of 0.005% latanoprost solution in dogs with glaucoma warrants investigation.

Smartphone use during inpatient attending rounds: prevalence, patterns and potential for distraction.

BACKGROUND: While there are numerous benefits of smartphone use for physicians, little is known about the negative effects of using these devices in the context of patient care. OBJECTIVE: To assess resident and faculty smartphone use during inpatient attending rounds and its potential as a source of distraction during transfer of clinical information. DESIGN: Cross-sectional survey. SETTING: University-affiliated public teaching hospital. PARTICIPANTS: All housestaff and inpatient faculty in the departments of Medicine and Pediatrics. METHODS: Participants were asked about smartphone ownership, usage patterns during attending rounds, and whether team members had ever missed important data during rounds due to distraction from smartphones. Attendings were asked whether policies should be established for smartphone use during rounds. RESULTS: The overall response rate was 73%. Device ownership was prevalent (89% residents, 98% faculty), as was use of smartphones during inpatient rounds (57% residents, 28% attendings). According to self-reports, smartphones were used during rounds for patient care (85% residents, 48% faculty), reading/responding to personal texts/e-mails (37% residents, 12% faculty), and other non-patient care uses (15% residents, 0% faculty). Nineteen percent of residents and 12% of attendings believed they had missed important information because of distraction from smartphones. Residents and faculty agreed that smartphones "can be a serious distraction during attending rounds," and nearly 80% of faculty believed that smartphone policies should be established. CONCLUSIONS: Smartphone use during attending rounds is prevalent and can distract users during important information transfer. Attendings strongly favored the institution of formal policies governing appropriate smartphone use during inpatient rounds.

Changing patient care orders from paper to computerized provider order entry-based process.

The purpose of this study was to describe the extent of change in patient care orders primarily for six diagnoses, procedures, or conditions in a not-for-profit Midwestern rural referral hospital. A descriptive method was used to analyze changes in the order sets over time for chest pain with acute myocardial infarction, degenerative osteoarthritis with hip joint replacement and degenerative osteoarthritis with knee joint replacement procedures, coronary artery bypass graft procedures, congestive heart failure, and pneumonia. Ten items about service-specific order sets were abstracted during pre- and post-EHR implementation and a year later. We then examined use 5 years later. The findings illustrate how the order sets evolved with multiple nested order sets to facilitate computerized provider order entry with a rate greater than 70% by physicians. The total number of available patient care orders within the order sets increased primarily because of linked nested order sets related to medications and diagnostic tests. Five years later, 50% of the orders were medication orders. In conclusion, this was important to deploy the order sets within smaller critical-access hospital facilities to train providers in adopting order sets internally.