No abstract

Neuroglobin (NGB), a newly discovered member of the globin superfamily, may regulate neuronal survival under hypoxia or oxidative stress. Although NGB is greatly expressed in retinal neurons, the biological functions of NGB in retinal diseases remain largely unknown. We investigated the role of NGB in an experimental model of glaucoma, a neurodegenerative disorder that usually involves elevation of intraocular pressure (IOP). Elevated IOP is thought to induce oxidative stress in retinal ganglion cells (RGCs), thereby causing RGC death and, eventually, blindness. We found that NGB plays a critical role in increasing RGC resistance to ocular hypertension and glaucomatous damage. Neuroglobin (NGB) is a novel member of the globin superfamily that is distantly related to hemoglobin and myoglobin. 1 A highly conserved protein in evolution, human and mouse Ngb, both comprised of 151 amino acids, are 94% identical. 2,3 In mammals, expression of NGB is found in the brain, retina, and other nerve tissues, predominantly in neurons but absent from glial cells. 4 -7 Distribution of NGB protein in the normal human retina is very similar to what has been described in mice: NGB is detected primarily in the plexiform layers and photoreceptor inner segments, which are rich in mitochondria and synapses and consume high amounts of oxygen. 8,9 NGB has been shown to act as an endogenous neuroprotective molecule that enhances neuronal survival under hypoxic-ischemic insults in the brain 10 -12 ; however, its physiological functions and molecular mode of actions are not fully understood. Of note, NGB is present at a 100-fold greater concentration in the retina than in the brain, 8,[13][14][15] suggesting that the retina may be its most important site of function; however, among the many unknown roles of NGB, functional significance of NGB expression in the retina has been largely unexplored.

HKM is a dynamic and spatiotemporally regulated process in the developing retina. Epigenetic regulation of gene transcription by Ezh2- and G9a-mediated HKM plays crucial roles in retinal neuron survival and may represent novel epigenetic targets to enhance viability in retinal neurodegenerative diseases such as glaucoma.

Objectives We describe an approach for analyzing failures in diagnostic processes in a small, enriched cohort of general medicine patients who expired during hospitalization and experienced medical error. Our objective was to delineate a systematic strategy for identifying frequent and significant failures in the diagnostic process to inform strategies for preventing adverse events due to diagnostic error. Methods Two clinicians independently reviewed detailed records of purposively sampled cases identified from established institutional case review forums and assessed the likelihood of diagnostic error using the Safer Dx instrument. Each reviewer used the modified Diagnostic Error Evaluation and Research (DEER) taxonomy, revised for acute care (41 possible failure points across six process dimensions), to characterize the frequency of failure points (FPs) and significant FPs in the diagnostic process. Results Of 166 cases with medical error, 16 were sampled: 13 (81.3%) had one or more diagnostic error(s), and a total of 113 FPs and 30 significant FPs were identified. A majority of significant FPs (63.3%) occurred in “Diagnostic Information and Patient Follow-up” and “Patient and Provider Encounter and Initial Assessment” process dimensions. Fourteen (87.5%) cases had a significant FP in at least one of these dimensions. Conclusions Failures in the diagnostic process occurred across multiple dimensions in our purposively sampled cohort. A systematic analytic approach incorporating the modified DEER taxonomy, revised for acute care, offered critical insights into key failures in the diagnostic process that could serve as potential targets for preventative interventions.

Objective: To identify clinical and demographic features associated with the severity and recovery from acute optic neuritis (AON) episodes in patients with multiple sclerosis (MS).Methods: Adult (n 5 253) and pediatric (n 5 38) patients whose first symptom was AON were identified from our MS database. Severity measured by loss of visual acuity (mild attack #20/40, moderate attack 20/50-20/190, and severe attack $20/200) and recovery in visual acuity at 1 year after the attack (complete recovery #20/20, fair recovery 20/40, and poor recovery $20/50) were recorded. Demographic and clinical features associated with attack severity and recovery were identified using proportional odds logistic regression. For another group of patients, blood samples were available within 6 months of an AON attack. In this group, the impact of vitamin D level on the severity/recovery was also assessed.Results: Men (adjusted odds ratio [OR] 5 2.28, p 5 0.03) and subjects with severe attacks (adjusted OR 5 5.24, p , 0.001) had worse recovery. AON severity was similar between the pediatric and adult subjects, but recovery was significantly better in pediatric subjects in the unadjusted analysis Acute optic neuritis (AON) is an inflammatory disorder of the optic nerve and the initial presenting symptom of multiple sclerosis (MS) in approximately 15% to 20% of patients.1,2 There is wide variability in the severity and recovery from AON among patients with MS, and clinical predictors of AON severity or recovery are not well understood. Previous work has demonstrated that severity and recovery from the initial relapse are associated with severity and recovery for subsequent relapses, but factors specifically affecting AON attacks have not been sufficiently studied.

Some adult-onset disorders may be linked to dysregulated embryonic development, yet the mechanisms underlying this association remain poorly understood. Congenital retinal degenerative diseases are blinding disorders characterized by postnatal degeneration of photoreceptors, and affect nearly 2 million individuals worldwide, but ∼50% do not have a known mutation, implicating contributions of epigenetic factors. We found that embryonic deletion of the histone methyltransferase (HMT) Ezh2 from all retinal progenitors resulted in progressive photoreceptor degeneration throughout postnatal life, via derepression of fetal expression of Six1 and its targets. Forced expression of Six1 in the postnatal retina was sufficient to induce photoreceptor degeneration. Ezh2, although enriched in the embryonic retina, was not present in the mature retina; these data reveal an Ezh2-mediated feed-forward pathway that is required for maintaining photoreceptor homeostasis in the adult and suggest novel targets for retinal degeneration therapy.

ObjectiveA rare variant Miller Fisher Syndrome overlap with Guillain Barre Syndrome is described in an adult patient with SARS-COV-2 infection.Case PresentationThe clinical course of a 45-year-old immunosuppressed man is summarized as a patient who developed ataxia, ophthalmoplegia, and areflexia after upper respiratory infection symptoms began. A nasopharyngeal swab was positive for COVID-19 polymerase chain reaction. He progressed to acute hypoxemic and hypercapnic respiratory failure requiring intubation and rapidly developed tetraparesis. Magnetic resonance imaging of the spine was consistent with Guillain Barre Syndrome. However, the clinical symptoms, along with positive anti-GQ1B antibodies, were consistent with Miller Fisher Syndrome and Guillain Barre Syndrome overlap. The patient required tracheostomy and had limited improvement in his significant neurological symptoms after several months.ConclusionsThe case demonstrates the severe neurological implications, prolonged recovery and implications in the concomitant respiratory failure of COVID-19 patients with neurological symptoms on the spectrum of disorders of Guillain Barre Syndrome.

Objectives To test a structured electronic health record (EHR) case review process to identify diagnostic errors (DE) and diagnostic process failures (DPFs) in acute care. Methods We adapted validated tools (Safer Dx, Diagnostic Error Evaluation Research [DEER] Taxonomy) to assess the diagnostic process during the hospital encounter and categorized 13 postulated e-triggers. We created two test cohorts of all preventable cases (n=28) and an equal number of randomly sampled non-preventable cases (n=28) from 365 adult general medicine patients who expired and underwent our institution’s mortality case review process. After excluding patients with a length of stay of more than one month, each case was reviewed by two blinded clinicians trained in our process and by an expert panel. Inter-rater reliability was assessed. We compared the frequency of DE contributing to death in both cohorts, as well as mean DPFs and e-triggers for DE positive and negative cases within each cohort. Results Twenty-seven (96.4%) preventable and 24 (85.7%) non-preventable cases underwent our review process. Inter-rater reliability was moderate between individual reviewers (Cohen’s kappa 0.41) and substantial with the expert panel (Cohen’s kappa 0.74). The frequency of DE contributing to death was significantly higher for the preventable compared to the non-preventable cohort (56% vs. 17%, OR 6.25 [1.68, 23.27], p<0.01). Mean DPFs and e-triggers were significantly and non-significantly higher for DE positive compared to DE negative cases in each cohort, respectively. Conclusions We observed substantial agreement among final consensus and expert panel reviews using our structured EHR case review process. DEs contributing to death associated with DPFs were identified in institutionally designated preventable and non-preventable cases. While e-triggers may be useful for discriminating DE positive from DE negative cases, larger studies are required for validation. Our approach has potential to augment institutional mortality case review processes with respect to DE surveillance.