Synaptotagmin 7 (SYT7) has emerged as a key regulator of presynaptic function, but its localization and precise role in the synaptic vesicle cycle remain the subject of debate. Here, we used iGluSnFR to optically interrogate glutamate release, at the single-bouton level, in SYT7KO-dissociated mouse hippocampal neurons. We analyzed asynchronous release, paired-pulse facilitation, and synaptic vesicle replenishment and found that SYT7 contributes to each of these processes to different degrees. ‘Zap-and-freeze’ electron microscopy revealed that a loss of SYT7 diminishes docking of synaptic vesicles after a stimulus and inhibits the recovery of depleted synaptic vesicles after a stimulus train. SYT7 supports these functions from the axonal plasma membrane, where its localization and stability require both γ-secretase-mediated cleavage and palmitoylation. In summary, SYT7 is a peripheral membrane protein that controls multiple modes of synaptic vesicle (SV) exocytosis and plasticity, in part, through enhancing activity-dependent docking of SVs.
31 October 2018 in American Journal of Medical Genetics Part A
The 22q11.2 Deletion Syndrome (22q11.2DS) occurs in ~1:3,000–6,000 individuals. Features less typically associated with 22q11.2DS, such as orthopedic manifestations, may be overlooked or may not lead to appropriate diagnostic testing. Club foot has a general population prevalence of ~1:1,000 and has been occasionally described in association with 22q11.2DS. Our hypothesis is that the prevalence of club foot is higher in patients with 22q11.2DS. We performed a retrospective review in two specialized 22q11.2DS centers to determine the prevalence of club foot. “True club foot” requires treatment (either conservative or surgical), therefore we only included those patients with proof of treatment. We investigated whether congenital heart disease (CHD) and/or cleft palate were associated with the presence of club foot within 22q11.2DS. The records of 1,466 patients were reviewed. Of these, 48 (3.3%) had confirmation of club foot (95% Confidence Interval: 2.4–4.3): 22 (46%) had a bilateral, 12 (25%) left, and 14 (29%) right club foot. Within our study, neither a CHD and/or a cleft palate were associated with a club foot. The prevalence of club foot in 22q11.2DS is 30 times higher than that observed in the general population. This suggests the diagnosis of club foot, especially in the face of other typically associated abnormalities of 22q11.2DS, should provoke consideration of 22q11.2DS as an underlying diagnosis, particularly in the neonatal setting.
Epstein–Barr virus (EBV) is strongly associated with the development of post-transplant lymphoproliferative disorder (PTLD) in pediatric liver transplant recipients. PTLD is one of the most common malignancies following liver transplantation and is associated with significant morbidity and mortality. Factors such as EBV–serostatus mismatch and prolonged or high levels of immunosuppression impact a patient’s risk of developing PTLD. While pre-transplant EBV serological screening and post-transplant monitoring of EBV-DNA levels are strongly recommended, universal guidelines for its prevention and management are lacking. Due to a lack of robust prospective studies, current clinical practices vary widely. The treatment of PTLD typically involves reducing immunosuppression and using targeted therapies such as rituximab, or chemotherapy for refractory cases. This review aims to address our current understanding of EBV’s relationship with PTLD, evaluate the available treatment modalities, and highlight evolving strategies for using EBV as a biomarker for PTLD screening and prevention.
17 February 2025 in Journal of the National Medical Association
Purpose: This study evaluated the implementation of a patient- and family-centered rounds (PFCR) educational intervention and a standardized assessment form developed to assess changes in medical students’ PFCR performance over time.Methods: From October 2023 to October 2024, medical students at Johns Hopkins School of Medicine attended a 1-hour PFCR simulation workshop during the Core Clerkship in Pediatrics. Students rotating at the main campus were assessed during rounds with a formative standardized form; all students received summative oral presentation and family rapport scores regardless of site. Performance was compared between students rotating in the first half (H1) and second half (H2) of the clerkship using Wilcoxon rank-sum tests with Holm correction for multiple comparisons. Linear mixed-effects models with student-level random intercepts were used to estimate changes across serial assessments.Results: Among the 74 students rotating at the main campus, assessment forms were completed for 61% of students, with a median of 3 completed forms per student. H1 and H2 students had similar scores on both the formative assessment form and summative evaluations. Both groups improved significantly in inviting patient and family concerns across serial assessments. Summative scores did not differ between students evaluated before and after the educational intervention or between students at the main campus and those at community hospitals.Conclusion: A structured PFCR educational session paired with a standardized assessment form was feasible to implement in a pediatric clerkship. Observed student-level median scores were at or above “meets expectations” across 6 PFCR domains, and no significant performance decline was observed among students rotating later in the clerkship. Further controlled studies are needed to determine whether this intervention improves PFCR skills compared with usual training.