Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease: Presentation and outcomes of adults at a single center.

BACKGROUND/INTRODUCTION: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a chronic demyelinating disorder that has been increasingly recognized since the serum antibody became commercially available in 2017. The most common clinical presentation is optic neuritis, and first line acute treatment is intravenous (IV) steroids. However, there are many questions that remain unanswered. For clinicians and patients, the primary question is whether relapses will occur and whether to treat with chronic therapy. METHODS: This retrospective chart review examined characteristics of thirty-three known adult MOGAD cases at a single institute. Data was collected on patient demographics, clinical presentation, objective diagnosis with MRI and serum antibody levels, acute and chronic treatment and disease outcomes. RESULTS: Our MOGAD cases revealed a slight female to male predominance of 1.5:1. No racial groups were affected disproportionately, and age of symptom onset spanned a large range with a median of 40 years. The most common clinical and radiologic presentation was optic neuritis followed by transverse myelitis and brainstem symptoms/lesions. IV methylprednisolone was used in the vast majority of cases for acute treatment. 83.3% of our patients were treated with chronic therapy at some point during their disease course. Therapies include rituximab, IVIG, ocrelizumab, mycophenolate mofetil and ofatumumab. The majority of our patients were treated with rituximab and we did not see a significant benefit of yearly relapse reduction for rituximab versus other therapies. Our cohort had a higher-than- expected percentage of cases with relapsing disease (56.3%) compared to monophasic (43.8%). DISCUSSION/CONCLUSION: Our study confirms prior data regarding the demographics, clinical presentation and radiologic presentation of MOGAD. There is no consensus on whether maintenance therapy should be started for MOGAD cases with a single clinical event. Our cohort showed a higher relapse rate than has been reported previously and all known relapses occurred within one year of diagnosis. More data is necessary to confirm risk of relapse in the years following diagnosis. In addition, further data on biomarkers are needed to predict the disease course could help guide management.

Outcomes of reciprocal invasions between genetically diverse and genetically uniform populations of Daphnia obtusa (Kurz).

Ecological theory predicts that genetic variation produced by sexual reproduction results in niche diversification and provides a competitive advantage both to facilitate invasion into genetically uniform asexual populations and to withstand invasion by asexual competitors. We tested the hypothesis that a large group of diverse clones of Daphnia obtusa has greater competitive advantage when invading into genetically uniform populations of this species than a smaller group with inherently less genetic diversity. We compared competitive outcomes to those of genetically uniform groups of small and large size invading into genetically diverse populations. Genetically diverse invaders of initially large group size increased their representation by more than those of initially small size; in contrast, genetically uniform invaders of initially large group size diminished on average by more than those of initially small size. These results demonstrate an advantage to the genetic variation produced by sexual reproduction, both in invasion and resisting invasion, which we attribute to competitive release experienced by individuals in genetically diverse populations.

Time symmetry: an application to shaped pulse excitation of spin-1 systems.

The role of time symmetry in the design of amplitude-modulated (shaped) pulses for spin-1 excitation is examined. The quaternion calculus is used to calculate the quaternion elements (Euler-Rodrigues parameters) of each shaped pulse. In this manner, it is shown how the simplicity and compactness of the Euler-Rodrigues parametrization can be used to significantly expedite a computer search for optimal time-symmetric shaped pulses. Theoretical and experimental tests of a new class of symmetric quadrupole-shaped (SQUASH) pulses identified by this procedure show a significant improvement in both excitation bandwidth and efficiency in comparison to the time-asymmetric QUASH shaped pulse previously identified.