Multi-disciplinary team approach for pediatric hemimegalencephaly: Insights from a single institutional case series.

Recent genetic studies have revealed that hemimegalencephaly (HME) is a multi-system disorder associated with germline or mosaic variants within the PI3K-mTOR-GATOR1 signaling pathways. Patients with HME typically develop drug-resistant epilepsy necessitating extensive evaluation, hemispherectomy, and long-term management. We describe the role of a multidisciplinary team (MDT) for the diagnosis and management of recent patients with HME at UCLA who underwent hemispherectomy.

HIV and COVID-19: two pandemics with significant (but different) central nervous system complications.

Human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause significant neurologic disease. Central nervous system (CNS) involvement of HIV has been extensively studied, with well-documented invasion of HIV into the brain in the initial stage of infection, while the acute effects of SARS-CoV-2 in the brain are unclear. Neuropathologic features of active HIV infection in the brain are well characterized whereas neuropathologic findings in acute COVID-19 are largely non-specific.

Tau seeding in cases of multiple sclerosis.

Relapsing remitting multiple sclerosis (MS) is an inflammatory demyelinating disorder of the central nervous system that in many cases leads to progressive MS, a neurodegenerative disease. Progressive MS is untreatable and relentless, and its cause is unknown. Prior studies of MS have documented neuronal accumulation of phosphorylated tau protein, which characterizes another heterogeneous group of neurogenerative disorders, the tauopathies.

Seed-competent tau monomer initiates pathology in a tauopathy mouse model.

Tau aggregation into ordered assemblies causes neurodegenerative tauopathies. We previously reported that tau monomer exists in either inert (M) or seed-competent (M) conformational ensembles and that M encodes strains, that is, unique, self-replicating, biologically active assemblies. It is unknown if disease begins with M formation followed by fibril assembly or if M derives from fibrils and is therefore an epiphenomenon.

Cytoplasmic P53 Immunostaining With N-Terminus P53 Antibody And Absence Of Staining With C-Terminus P53 Antibody: A Report Of Two Pediatric Sarcomas With Distal Truncating Mutations Affecting Nuclear Localization Domain.

P53 immunohistochemical staining with antibodies targeted to epitopes at or near the N-terminus are commonly used in diagnostic pathology practice as a surrogate for mutations. The abnormal staining patterns indicating mutations include nuclear overexpression, null, and the recently described cytoplasmic staining. The latter staining pattern occurs with the less common mutations affecting its nuclear localization and/or tetramerization domains that are located toward the C-terminus.

DnaJC7 binds natively folded structural elements in tau to inhibit amyloid formation.

Molecular chaperones, including Hsp70/J-domain protein (JDP) families, play central roles in binding substrates to prevent their aggregation. How JDPs select different conformations of substrates remains poorly understood. Here, we report an interaction between the JDP DnaJC7 and tau that efficiently suppresses tau aggregation in vitro and in cells.

A synthetic heparinoid blocks Tau aggregate cell uptake and amplification.

Tau aggregation underlies neurodegeneration in Alzheimer's disease and related tauopathies. We and others have proposed that transcellular propagation of pathology is mediated by Tau prions, which are ordered protein assemblies that faithfully replicate and cause specific biological effects. The prion model predicts the release of aggregates from a first-order cell and subsequent uptake into a second-order cell.

Site-Specific Hyperphosphorylation Inhibits, Rather than Promotes, Tau Fibrillization, Seeding Capacity, and Its Microtubule Binding.

The consistent observation of phosphorylated tau in the pathology of Alzheimer's disease has contributed to the emergence of a model where hyperphosphorylation triggers both tau disassociation from microtubules and its subsequent aggregation. Herein, we applied a total chemical synthetic approach to site-specifically phosphorylate the microtubule binding repeat domain of tau (K18) at single (pS356) or multiple (pS356/pS262 and pS356/pS262/pS258) residues. We show that hyperphosphorylation of K18 inhibits 1) its aggregation in vitro, 2) its seeding activity in cells, 3) its binding to microtubules, and 4) its ability to promote microtubule polymerization.

Inert and seed-competent tau monomers suggest structural origins of aggregation.

Tauopathies feature progressive accumulation of tau amyloids. Pathology may begin when these amplify from a protein template, or seed, whose structure is unknown. We have purified and characterized distinct forms of tau monomer-inert (M) and seed-competent (M).

Distinct Therapeutic Mechanisms of Tau Antibodies: Promoting Microglial Clearance Versus Blocking Neuronal Uptake.

Tauopathies are neurodegenerative diseases characterized by accumulation of Tau amyloids, and include Alzheimer disease and certain frontotemporal dementias. Trans-neuronal propagation of amyloid mediated by extracellular Tau may underlie disease progression. Consistent with this, active and passive vaccination studies in mouse models reduce pathology, although by unknown mechanisms.

Tau Trimers Are the Minimal Propagation Unit Spontaneously Internalized to Seed Intracellular Aggregation.

Tau amyloid assemblies propagate aggregation from the outside to the inside of a cell, which may mediate progression of the tauopathies. The critical size of Tau assemblies, or "seeds," responsible for this activity is currently unknown, but this could be important for the design of effective therapies. We studied recombinant Tau repeat domain (RD) and Tau assemblies purified from Alzheimer disease (AD) brain composed largely of full-length Tau.

Proteopathic tau seeding predicts tauopathy in vivo.

Transcellular propagation of protein aggregates, or proteopathic seeds, may drive the progression of neurodegenerative diseases in a prion-like manner. In tauopathies such as Alzheimer's disease, this model predicts that tau seeds propagate pathology through the brain via cell-cell transfer in neural networks. The critical role of tau seeding activity is untested, however.

Distinct tau prion strains propagate in cells and mice and define different tauopathies.

Prion-like propagation of tau aggregation might underlie the stereotyped progression of neurodegenerative tauopathies. True prions stably maintain unique conformations ("strains") in vivo that link structure to patterns of pathology. We now find that tau meets this criterion.

Can music lessons increase the performance of preschool children in IQ tests?

The impact of music on human cognition has a distinguished history as a research topic in psychology. The focus of the present study was on investigating the effects of music instruction on the cognitive development of preschool children. From a sample of 154 preschool children of Tehran kindergartens, 60 children aged between 5 and 6 were randomly assigned to two groups, one receiving music lessons and the other (matched for sex, age and mother's educational level) not taking part in any music classes.

The differential effects of OX1R and OX2R selective antagonists on morphine conditioned place preference in naïve versus morphine-dependent mice.

Conditioned place preference (CPP) has been associated with orexinergic (hypocrtinergic) system activation in naïve mice; however, the distinct role of different receptors of orexin in this paradigm has not been characterized yet. Moreover, the relationship between orexins and morphine in dependent mice may not be equal to naïve mice and seems noteworthy to investigate. We investigated the effects of systemic administration of orexin-1-receptor antagonist, SB 334867, and orexin-2 receptor antagonist, TCS-OX2-29 on the acquisition and expression of morphine conditioned place preference (CPP) in both naïve and morphine-dependent mice.

Estrogen pretreatment modulates morphine-induced conditioned place preference in ovariectomized mice.

Estrogen is known to modulate the neurotransmission in the brain. The main aim of this study was to investigate the effects of estrogen on the rewarding properties of morphine using conditioned place preference (CPP) paradigm in adult female mice. The possible rewarding effect of estrogen was also examined in ovariectomized mice.