Publications by authors named "Samuel Pleasure"

Background And Objectives: Neutropenia is described as a rare adverse event associated with B cell-depleting therapy (BCDT) use in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). However, little is known about longitudinal clinical outcomes. We estimated the real-world incidence of neutropenia among patients with neuroinflammatory disease treated with BCDT and characterized the clinical course.

View Article and Find Full Text PDF

Delirium is a neurologic syndrome characterized by inattention and cognitive impairment frequently encountered in the medically ill. Peripheral inflammation is a key trigger of delirium, but the patient-specific immune responses associated with delirium development and resolution are unknown. This retrospective cohort study of prospectively collected biospecimens examines RNA sequencing from peripheral blood mononuclear cells of adults hospitalized for COVID-19 to better understand patient-specific factors associated with delirium (n = 64).

View Article and Find Full Text PDF

Mutations in Sonic Hedgehog (SHH) signaling pathway genes, for example, (SUFU), drive granule neuron precursors (GNP) to form medulloblastomas (MB). However, how different molecular lesions in the Shh pathway drive transformation is frequently unclear, and mutations in the cerebellum seem distinct. In this study, we show that fibroblast growth factor 5 (FGF5) signaling is integral for many infantile MB cases and that expression is uniquely upregulated in infantile MB tumors.

View Article and Find Full Text PDF

N-methyl-d-aspartate (NMDA) receptor-mediated autoimmune encephalitis (NMDAR-AE) frequently results in persistent sensory-motor deficits, especially in children, yet the underlying mechanisms remain unclear. This study investigated the long-term effects of exposure to a patient-derived GluN1-specific mAb during a critical developmental period (from postnatal day 3 to day 12) in mice. We observed long-lasting sensory-motor deficits characteristic of NMDAR-AE, along with permanent changes in callosal axons within the primary somatosensory cortex (S1) in adulthood, including increased terminal branch complexity.

View Article and Find Full Text PDF

Ataxia with anti-regulator of G-protein signaling 8 autoantibodies (RGS8-Abs) is an autoimmune disease recently described in four patients. The present study aimed to identify other patients with RGS8-Abs, describe their clinical features, including the link between RGS8-related autoimmune cerebellar ataxia (ACA) and cancer. Patients with RGS8-Abs were identified retrospectively in the biological collections of the French Reference Center for Paraneoplastic Neurological Syndrome and the University of California San Francisco Center for Encephalitis and Meningitis.

View Article and Find Full Text PDF
Article Synopsis
  • Vitamin B12 is essential for blood cell formation and nerve insulation, and its deficiency can lead to neurological issues despite normal blood levels, as seen in a patient with symptoms like tremor and cognitive decline.
  • Researchers discovered an autoantibody against the transcobalamin receptor (CD320) that hinders vitamin B12 uptake in the brain, resulting in low levels found in cerebrospinal fluid even when blood levels appear normal.
  • The study suggests this autoimmune condition can be treated with immunosuppressive therapy and high-dose vitamin B12, and highlights the importance of recognizing how B12 transport differs in various tissues, which could improve diagnosis and treatment strategies for similar neurological disorders.
View Article and Find Full Text PDF

Ca/calmodulin (CaM)-dependent kinase II (CaMKII) plays a critical role in long-term potentiation (LTP), a well-established model for learning and memory through the enhancement of synaptic transmission. Biochemical studies indicate that CaMKII catalyzes a phosphotransferase (kinase) reaction of both itself (autophosphorylation) and of multiple downstream target proteins. However, whether either type of phosphorylation plays any role in the synaptic enhancing action of CaMKII remains hotly contested.

View Article and Find Full Text PDF

Epileptic seizures induce aberrant neurogenesis from resident neural stem cells (NSCs) in the dentate gyrus of the adult mouse hippocampus, which has been implicated in depletion of the NSC pool and impairment of hippocampal function. However, the mechanisms regulating neurogenesis after seizures remain unknown. Here, we demonstrate that Sonic hedgehog (Shh) from mossy cells is a major source of Shh signaling activity after seizures, by which mossy cells contribute to seizure-induced neurogenesis and maintenance of the NSC pool.

View Article and Find Full Text PDF

The timing and specificity of oligodendrocyte myelination during development, as well as remyelination after injury or immune attack, remain poorly understood. Recent work has shown that oligodendrocyte progenitors receive synapses from neurons, providing a potential mechanism for neuronal-glial communication. In this study, we investigated the importance of these neuroglial connections in myelination during development and during neuronal plasticity in the mouse hippocampus.

View Article and Find Full Text PDF

CaMKII plays a critical role in long-term potentiation (LTP), a well-established model for learning and memory through the enhancement of synaptic transmission. Biochemical studies indicate that CaMKII catalyzes a phosphotransferase (kinase) reaction of both itself (autophosphorylation) and of multiple downstream target proteins. However, whether either type of phosphorylation plays any role in the synaptic enhancing action of CaMKII remains hotly contested.

View Article and Find Full Text PDF

Epileptic seizures induce aberrant neurogenesis from resident neural stem cells (NSCs) in the dentate gyrus of the adult mouse hippocampus, which has been implicated in depletion of the NSC pool and impairment of hippocampal function. However, the mechanisms regulating neurogenesis after seizures remain unknown. Here we demonstrate that Shh from mossy cells is a major source of Shh signaling activity after seizures, by which mossy cells contribute to seizure-induced neurogenesis and maintenance of the NSC pool.

View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on the detection of anti-TRIM9 and TRIM67 autoantibodies (TRIM9/67-IgG) in patients with paraneoplastic cerebellar syndrome, aiming to determine their diagnostic value and the most effective detection methods.
  • A retrospective analysis across multiple centers found that cell-based assays (CBA) were the most sensitive method for confirming the presence of TRIM9/67-IgG, identifying it in all tested cases (100%).
  • The findings indicate that a significant majority of patients with TRIM9/67-IgG had subacute cerebellar syndrome and were often associated with underlying cancers, reinforcing the idea of these auto
View Article and Find Full Text PDF

The BRAIN Foundation (Pleasanton, CA, USA) hosted Synchrony 2022, a translational medicine conference focused on research into treatments for individuals with neurodevelopmental disorders (NDD), including those with autism spectrum disorders (ASD) [...

View Article and Find Full Text PDF

Neuroinvasive infection is the most common cause of meningoencephalitis in people living with human immunodeficiency virus (HIV), but autoimmune etiologies have been reported. We present the case of a 51-year-old man living with HIV infection with steroid-responsive meningoencephalitis whose comprehensive pathogen testing was non-diagnostic. Subsequent tissue-based immunofluorescence with acute-phase cerebrospinal fluid revealed anti-neural antibodies localizing to the axon initial segment (AIS), the node of Ranvier (NoR), and the subpial space.

View Article and Find Full Text PDF

The developmental functions of primary cilia and the downstream signaling pathways have been widely studied; however, the roles of primary cilia in the developing neurovascular system are not clearly understood. In this study, we found that ablation of genes encoding ciliary transport proteins such as intraflagellar transport homolog 88 (Ift88) and kinesin family member 3a (Kif3a) in cortical radial progenitors led to periventricular heterotopia during late mouse embryogenesis. Conditional mutation of primary cilia unexpectedly caused breakdown of both the neuroepithelial lining and the blood-choroid plexus barrier.

View Article and Find Full Text PDF

Growing evidence suggests that the corticotropin-releasing hormone (CRH) signaling pathway, mainly known as a critical initiator of humoral stress responses, has a role in normal neuronal physiology. However, despite the evidence of CRH receptor (CRHR) expression in the embryonic ventricular zone, the exact functions of CRH signaling in embryonic brain development have not yet been fully determined. In this study, we show that CRHR1 is required for the maintenance of neural stem cell properties, as assessed by in vitro neurosphere assays and cell distribution in the embryonic cortical layers following in utero electroporation.

View Article and Find Full Text PDF

Objective: To identify the autoantigen in 2 individuals with possible seronegative paraneoplastic neuropathy.

Methods: Serum and CSF were screened by tissue-based assay and panned for candidate autoantibodies by phage display immunoprecipitation sequencing (PhIP-Seq). The candidate antigen was validated by immunostaining knockout tissue and HEK 293T cell-based assay.

View Article and Find Full Text PDF

Objective: Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD), is a severe pediatric disorder of uncertain etiology resulting in hypothalamic dysfunction and frequent sudden death. Frequent co-occurrence of neuroblastic tumors have fueled suspicion of an autoimmune paraneoplastic neurological syndrome (PNS); however, specific anti-neural autoantibodies, a hallmark of PNS, have not been identified. Our objective is to determine if an autoimmune paraneoplastic etiology underlies ROHHAD.

View Article and Find Full Text PDF

Cognitive post-acute sequelae of SARS-CoV-2 (PASC) can occur after mild COVID-19. Detailed clinical characterizations may inform pathogenesis. We evaluated 22 adults reporting cognitive PASC and 10 not reporting cognitive symptoms after mild SARS-CoV-2 infection through structured interviews, neuropsychological testing, and optional cerebrospinal fluid (CSF) evaluations (53%).

View Article and Find Full Text PDF

Long-term potentiation (LTP) is arguably the most compelling cellular model for learning and memory. While the mechanisms underlying the induction of LTP ('learning') are well understood, the maintenance of LTP ('memory') has remained contentious over the last 20 years. Here, we find that Ca-calmodulin-dependent kinase II (CaMKII) contributes to synaptic transmission and is required LTP maintenance.

View Article and Find Full Text PDF