Ariel - Volume 11 Number 3

Executive Editors Ellen Feldman Leonardo S. Nasca, Jr. Business Managers Barbara L. Davies Martin B. Getzow News Editor Hugh A. Gelabert Features Editor Aaron D. Bleznak CAHS Editor Joan M. Greco Editorial Page Editor Samuel Markind Photography Editor Todd Demmy Sports Editor Paul F. Mansfiel

Stress dynamically regulates behavior and glutamatergic gene expression in hippocampus by opening a window of epigenetic plasticity

Excitatory amino acids play a key role in both adaptive and deleterious effects of stressors on the brain, and dysregulated glutamate homeostasis has been associated with psychiatric and neurological disorders. Here, we elucidate mechanisms of epigenetic plasticity in the hippocampus in the interactions between a history of chronic stress and familiar and novel acute stressors that alter expression of anxiety- and depressive-like behaviors. We demonstrate that acute restraint and acute forced swim stressors induce differential effects on these behaviors in naive mice and in mice with a history of chronic-restraint stress (CRS). They reveal a key role for epigenetic up- and down-regulation of the putative presynaptic type 2 metabotropic glutamate (mGlu2) receptors and the postsynaptic NR1/NMDA receptors in the hippocampus and particularly in the dentate gyrus (DG), a region of active neurogenesis and a target of antidepressant treatment. We show changes in DG long-term potentiation (LTP) that parallel behavioral responses, with habituation to the same acute restraint stressor and sensitization to a novel forced-swim stressor. In WT mice after CRS and in unstressed mice with a BDNF loss-of-function allele (BDNF Val66Met), we show that the epigenetic activator of histone acetylation, P300, plays a pivotal role in the dynamic up- and down-regulation of mGlu2 in hippocampus via histone-3-lysine-27-acetylation (H3K27Ac) when acute stressors are applied. These hippocampal responses reveal a window of epigenetic plasticity that may be useful for treatment of disorders in which glutamatergic transmission is dysregulated

Menopausal hormone use and ovarian cancer risk: individual participant meta-analysis of 52 epidemiological studies

Background Half the epidemiological studies with information about menopausal hormone therapy and ovarian cancer risk remain unpublished, and some retrospective studies could have been biased by selective participation or recall. We aimed to assess with minimal bias the effects of hormone therapy on ovarian cancer risk. Methods Individual participant datasets from 52 epidemiological studies were analysed centrally. The principal analyses involved the prospective studies (with last hormone therapy use extrapolated forwards for up to 4 years). Sensitivity analyses included the retrospective studies. Adjusted Poisson regressions yielded relative risks (RRs) versus never-use. Findings During prospective follow-up, 12 110 postmenopausal women, 55% (6601) of whom had used hormone therapy, developed ovarian cancer. Among women last recorded as current users, risk was increased even with <5 years of use (RR 1·43, 95% CI 1·31–1·56; p<0·0001). Combining current-or-recent use (any duration, but stopped <5 years before diagnosis) resulted in an RR of 1·37 (95% CI 1·29–1·46; p<0·0001); this risk was similar in European and American prospective studies and for oestrogen-only and oestrogen-progestagen preparations, but differed across the four main tumour types (heterogeneity p<0·0001), being definitely increased only for the two most common types, serous (RR 1·53, 95% CI 1·40–1·66; p<0·0001) and endometrioid (1·42, 1·20–1·67; p<0·0001). Risk declined the longer ago use had ceased, although about 10 years after stopping long-duration hormone therapy use there was still an excess of serous or endometrioid tumours (RR 1·25, 95% CI 1·07–1·46, p=0·005). Interpretation The increased risk may well be largely or wholly causal; if it is, women who use hormone therapy for 5 years from around age 50 years have about one extra ovarian cancer per 1000 users and, if its prognosis is typical, about one extra ovarian cancer death per 1700 users

Better data for teachers, better data for learners, better patient care: college-wide assessment at Michigan State University's College of Human Medicine

When our school organized the curriculum around a core set of medical student competencies in 2004, it was clear that more numerous and more varied student assessments were needed. To oversee a systematic approach to the assessment of medical student competencies, the Office of College-wide Assessment was established, led by the Associate Dean of College-wide Assessment. The mission of the Office is to ‘facilitate the development of a seamless assessment system that drives a nimble, competency-based curriculum across the spectrum of our educational enterprise.’ The Associate Dean coordinates educational initiatives, developing partnerships to solve common problems, and enhancing synergy within the College. The Office also works to establish data collection and feedback loops to guide rational intervention and continuous curricular improvement. Aside from feedback, implementing a systems approach to assessment provides a means for identifying performance gaps, promotes continuity from undergraduate medical education to practice, and offers a rationale for some assessments to be located outside of courses and clerkships. Assessment system design, data analysis, and feedback require leadership, a cooperative faculty team with medical education expertise, and institutional support. The guiding principle is ‘Better Data for Teachers, Better Data for Learners, Better Patient Care.’ Better data empowers faculty to become change agents, learners to create evidence-based improvement plans and increases accountability to our most important stakeholders, our patients

Mitochondrial leukoencephalopathy and complex II deficiency associated with a recessive SDHB mutation with reduced penetrance

Mitochondrial disease involving complex II is rare among respiratory chain deficiencies and its genetic cause remains often unknown. Two main clinical presentations are associated with this biochemical defect: mitochondrial encephalomyopathy and susceptibility to tumors. Only one homozygous SDHBmutation has been described in a patient with mitochondrial disorder. We report here two sisters, who presented highly different phenotypes (neurological impairmentwith leukoencephalopathy vs. asymptomatic status) and harbored the same homozygous SDHB mutation, suggesting reduced penetrance

Functionally pathogenic EARS2 variants in vitro may not manifest a phenotype in vivo

OBJECTIVE: To investigate the genetic etiology of a patient diagnosed with leukoencephalopathy, brain calcifications, and cysts (LCC). METHODS: Whole-exome sequencing was performed on a patient with LCC and his unaffected family members. The variants were subject to in silico and in vitro functional testing to determine pathogenicity. RESULTS: Whole-exome sequencing uncovered compound heterozygous mutations in EARS2, c.328G>A (p.G110S), and c.1045G>A (p.E349K). This gene has previously been implicated in the autosomal recessive leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL). The p.G110S mutation has been found in multiple patients with LTBL. In silico analysis supported pathogenicity in the second variant. In vitro functional testing showed a significant mitochondrial dysfunction demonstrated by an ∼11% decrease in the oxygen consumption rate and ∼43% decrease in the maximum respiratory rate in the patient's skin fibroblasts compared with the control. EARS2 protein levels were reduced to 30% of normal controls in the patient's fibroblasts. These deficiencies were corrected by the expression of the wild-type EARS2 protein. However, a further unrelated genetic investigation of our patient revealed the presence of biallelic variants in a small nucleolar RNA (SNORD118) responsible for LCC. CONCLUSIONS: Here, we report seemingly pathogenic EARS2 mutations in a single patient with LCC with no biochemical or neuroimaging presentations of LTBL. This patient illustrates that variants with demonstrated impact on protein function should not necessarily be considered clinically relevant.Funding provided by the Baylor Scott & White Healthcare Foundation

Clinical-genetic features and peculiar muscle histopathology in infantile DNM1L-related mitochondrial epileptic encephalopathy

Mitochondria are highly dynamic organelles, undergoing continuous fission and fusion. The DNM1L gene encodes for the DRP1 protein, an evolutionary conserved member of the dynamin family, responsible for fission of mitochondria, and having a role in the division of peroxisomes, as well. DRP1 impairment is implicated in several neurological disorders and associated with either de novo dominant or compound heterozygous mutations. In five patients presenting with severe epileptic encephalopathy we identified 5 de novo dominant DNM1L variants, the pathogenicity of which was validated in a yeast model. Fluorescence microscopy revealed abnormally elongated mitochondria and aberrant peroxisomes in mutant fibroblasts, indicating impaired fission of these organelles. Moreover, a very peculiar finding in our cohort of patients was the presence, in muscle biopsy, of core like areas with oxidative enzyme alterations, suggesting an abnormal distribution of mitochondria in the muscle tissue

Not only dominant, not only optic atrophy: expanding the clinical spectrum associated with OPA1 mutations

Background: Heterozygous mutations in OPA1 are a common cause of autosomal dominant optic atrophy, sometimes associated with extra-ocular manifestations. Few cases harboring compound heterozygous OPA1 mutations have been described manifesting complex neurodegenerative disorders in addition to optic atrophy. Results: We report here three patients: one boy showing an early-onset mitochondrial disorder with hypotonia, ataxia and neuropathy that was severely progressive, leading to early death because of multiorgan failure; two unrelated sporadic girls manifesting a spastic ataxic syndrome associated with peripheral neuropathy and, only in one, optic atrophy. Using a targeted resequencing of 132 genes associated with mitochondrial disorders, in two probands we found compound heterozygous mutations in OPA1: in the first a 5 nucleotide deletion, causing a frameshift and insertion of a premature stop codon (p.Ser64Asnfs*7), and a missense change (p.Ile437Met), which has recently been reported to have clinical impact; in the second, a novel missense change (p.Val988Phe) co-occurred with the p.Ile437Met substitution. In the third patient a homozygous mutation, c.1180G > A (p.Ala394Thr) in OPA1 was detected by a trio-based whole exome sequencing approach. One of the patients presented also variants in mitochondrial DNA that may have contributed to the peculiar phenotype. The deleterious effect of the identified missense changes was experimentally validated in yeast model. OPA1 level was reduced in available patients\u2019 biological samples, and a clearly fragmented mitochondrial network was observed in patients\u2019 fibroblasts. Conclusions: This report provides evidence that bi-allelic OPA1 mutations may lead to complex and severe multi-system recessive mitochondrial disorders, where optic atrophy might not represent the main feature

Causes of Death Among US Medical Residents

IMPORTANCE: From 2000 to 2014, the leading causes of medical resident death in the United States were neoplastic diseases and suicide. OBJECTIVE: To examine whether US medical resident rates of death have changed since 2014 and whether causes of resident death differ by specialty. DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study, residents and fellows who were enrolled in Accreditation Council for Graduate Medical Education (ACGME)-accredited training programs and who died from January 2015 to December 2021 were submitted to the National Death Index to obtain causes of death. These decedents were compared with residents and fellows who died between January 2000 and December 2014. Data were analyzed between July 2024 to March 2025. EXPOSURE: Death while actively enrolled in an ACGME-accredited residency and fellowship training program. MAIN OUTCOMES AND MEASURES: The primary outcome was the difference in rates of death for US residents and fellows between 2 time periods, 2000 to 2014 and 2015 to 2021. Poisson regression modeling was used to calculate incidence rate ratios (IRRs) with 95% CIs for this comparison. Rates were also compared across specialties. Secondary outcomes included comparing trainee decedents with age- and gender-matched peers in the general population and querying differences in causes of death by specialty from 2000 through 2021. RESULTS: Between 2015 and 2021, 370 778 residents and fellows participated in 961 755 person-years of training. In that same period, 161 residents (50 [31.1%] female; median [IQR] age, 31 [29-35] years) died during training. Forty-seven residents (29.2%) died by suicide, 28 (17.4%) by neoplastic diseases, 22 (13.7%) from other medical and surgical diseases, 22 (13.7%) from accidents, and 21 (13.0%) from accidental poisoning. The highest number of resident suicides occurred during the first quarter of the first year. The death rate from neoplastic diseases decreased since 2000 to 2014 (IRR, 0.59; 95% CI, 0.38-0.90). Rates of other causes remained unchanged. Resident death rates from 2000 to 2021, including rates of death by suicide, were lower than age- and gender-matched peers across causes. The highest specialty suicide rate was for pathology (19.76 deaths per 100 000 person-years). The highest death rate from neoplastic diseases was psychiatry (9.67 deaths per 100 000 person-years). The highest death rate from accidental poisoning was anesthesiology (15.46 deaths per 100 000 person-years). CONCLUSIONS AND RELEVANCE: In this cross-sectional study comparing rates of US medical resident deaths from 2000 to 2014 with rates observed in 2015 to 2021, the rate of resident deaths from neoplastic diseases decreased, while the rates of death from all other causes remained unchanged. Nevertheless, the number of residents who died by suicide during their very first academic quarter, observed during both study windows, remains concerning. Future efforts to address trainee well-being must focus on the drivers and mitigating factors of distress, particularly during transitions