475 results match your criteria: "Johns Hopkins Medical School[Affiliation]"

Objective: Benign epilepsy with centrotemporal spikes (BECTS) is the most common childhood idiopathic localization-related epilepsy syndrome. BECTS presents normal routine magnetic resonance imaging (MRI); however, quantitative analytic techniques have captured subtle cortical and subcortical magnetic resonance anomalies. Network science, including graph theory (GT) analyses, facilitates understanding of brain covariance patterns, potentially informing in important ways how this common self-limiting epilepsy syndrome may impact normal patterns of brain and cognitive development.

View Article and Find Full Text PDF

Internal fixation is a common orthopedic procedure in which a rigid screw is used to fix fragments of a fractured bone together and expedite the healing process. However, the rigidity of the screw, geometry of the fractured anatomy (e.g.

View Article and Find Full Text PDF

Dysregulated Glial Differentiation in Schizophrenia May Be Relieved by Suppression of SMAD4- and REST-Dependent Signaling.

Cell Rep

June 2019

Center for Translational Neuromedicine and Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA; Center for Neuroscience, University of Copenhagen Faculty of Health and Medical Sciences, 2200 Copenhagen N, Denmark; Neuroscience Center, Rigshospitalet, Copenhagen, Denmark. Electronic address:

Astrocytic differentiation is developmentally impaired in patients with childhood-onset schizophrenia (SCZ). To determine why, we used genetic gain- and loss-of-function studies to establish the contributions of differentially expressed transcriptional regulators to the defective differentiation of glial progenitor cells (GPCs) produced from SCZ patient-derived induced pluripotent cells (iPSCs). Negative regulators of the bone morphogenetic protein (BMP) pathway were upregulated in SCZ GPCs, including BAMBI, FST, and GREM1, whose overexpression retained SCZ GPCs at the progenitor stage.

View Article and Find Full Text PDF

BACE1 is the rate-limiting enzyme for amyloid-β peptides (Aβ) generation, a key event in the pathogenesis of Alzheimer's disease (AD). By an unknown mechanism, levels of and a mRNA-stabilizing antisense RNA () are elevated in the brains of AD patients, implicating that dysregulation of expression plays an important role in AD pathogenesis. We found that nuclear factor erythroid-derived 2-related factor 2 (NRF2/NFE2L2) represses the expression of and through binding to antioxidant response elements (AREs) in their promoters of mouse and human.

View Article and Find Full Text PDF

Dissociating task acquisition from expression during learning reveals latent knowledge.

Nat Commun

May 2019

Departments of Otolaryngology, Neuroscience and Physiology, Skirball Institute, Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA.

Performance on cognitive tasks during learning is used to measure knowledge, yet it remains controversial since such testing is susceptible to contextual factors. To what extent does performance during learning depend on the testing context, rather than underlying knowledge? We trained mice, rats and ferrets on a range of tasks to examine how testing context impacts the acquisition of knowledge versus its expression. We interleaved reinforced trials with probe trials in which we omitted reinforcement.

View Article and Find Full Text PDF

Intraoperative ultrasonography (ioUS) characteristics of focal cortical dysplasia (FCD) type II b.

Seizure

July 2019

Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy; Department of Neurological Surgery, Johns Hopkins Medical School, Baltimore, MD, USA.

Purpose: Focal cortical dysplasia (FCD) is one of the major causes of drug-resistant epilepsy. Surgery has proved to be the treatment of choice, however up to a third of patients experience only partial resection. Ill-defined borders and lesions embedded in eloquent areas are two of the main drawbacks of FCD surgery.

View Article and Find Full Text PDF

Our preliminary study investigates an automated, vibrating fiber optic tip for dusting of kidney stones during thulium fiber laser (TFL) lithotripsy. A (0.75-mm diameter and 5-mm length) magnetic bead was attached to the fiber jacket, centered 2 cm from distal fiber tip.

View Article and Find Full Text PDF

Cost- and time-effective markers of Alzheimer's disease (AD), reliable and feasible at the population level are urgently needed. Soluble amyloid-β protein precursor β (sAβPPβ) in plasma has attracted scientific attention as a potential AD biomarker candidate. Here we report that plasma sAβPPβ levels in patients with AD dementia and typical for AD cerebrospinal fluid (CSF) biomarker profiles (N = 33) are significantly lower (p < 0.

View Article and Find Full Text PDF

The Pancreas Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition aims to promote awareness of pediatric pancreatic diseases, support clinical and basic science research in the field, educate pediatric gastroenterologists, and advocate on behalf of pediatric patients with pancreatic disorders. At the 2017 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the Pancreas Committee held a full day symposium on pediatric pancreatic diseases, entitled, "Frontiers in Pediatric Pancreatology." The symposium served as a timely and novel academic meeting that brought together individuals with a vested interest in the care of children with pancreatic disorders.

View Article and Find Full Text PDF

On the Use of a Continuum Manipulator and a Bendable Medical Screw for Minimally Invasive Interventions in Orthopedic Surgery.

IEEE Trans Med Robot Bionics

February 2019

Laboratory for Computational Sensing and Robotics, The Johns Hopkins University, Baltimore, MD 21218 USA, and also with the Applied Physics Laboratory, The Johns Hopkins University, Laurel, MD 20723 USA.

Accurate placement and stable fixation are the main goals of internal fixation of bone fractures using the traditional medical screws. These goals are necessary to expedite and avoid improper fracture healing due to misalignment of the bone fragments. However, the rigidity of the screw, geometry of the fractured anatomy (e.

View Article and Find Full Text PDF

Objectives: The experimental Thulium fiber laser (TFL) is currently being studied as a potential alternative to the gold standard Holmium:YAG laser for lithotripsy. Recent advances in both Holmium and TFL technology allow operation at similar laser parameters for direct comparison. The use of a "dusting" mode with low pulse energy (0.

View Article and Find Full Text PDF

Recent advances in infrared laser lithotripsy [Invited].

Biomed Opt Express

September 2018

Department of Physics and Optical Science, University of North Carolina at Charlotte, NC 28223, USA.

The flashlamp-pumped, solid-state, pulsed, mid-infrared, holmium:YAG laser (λ = 2120 nm) has been the clinical gold standard laser for lithotripsy for over the past two decades. However, while the holmium laser is the dominant laser technology in ureteroscopy because it efficiently ablates all urinary stone types, this mature laser technology has several fundamental limitations. Alternative, mid-IR laser technologies, including a thulium fiber laser (λ = 1908 and 1940 nm), a thulium:YAG laser (λ = 2010 nm), and an erbium:YAG laser (λ = 2940 nm) have also been explored for lithotripsy.

View Article and Find Full Text PDF

Neural Interactions Underlying Visuomotor Associations in the Human Brain.

Cereb Cortex

December 2019

Departments of Ophthalmology and Neurosurgery, Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, US.

Rapid and flexible learning during behavioral choices is critical to our daily endeavors and constitutes a hallmark of dynamic reasoning. An important paradigm to examine flexible behavior involves learning new arbitrary associations mapping visual inputs to motor outputs. We conjectured that visuomotor rules are instantiated by translating visual signals into actions through dynamic interactions between visual, frontal and motor cortex.

View Article and Find Full Text PDF

Advanced Ultrasound Imaging in Glioma Surgery: Beyond Gray-Scale B-mode.

Front Oncol

December 2018

Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.

Glioma surgery is aimed at obtaining maximal safe tumor resection while preserving or improving patient's neurological status. For this reason, there is growing interest for intra-operative imaging in neuro-oncological surgery. Intra-operative ultrasound (ioUS) provides the surgeon with real-time, anatomical and functional information.

View Article and Find Full Text PDF

Intraoperative Strain Elastosonography in Brain Tumor Surgery.

Oper Neurosurg (Hagerstown)

August 2019

Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.

Background: Sonoelastography is an ultrasound imaging technique able to assess mechanical properties of tissues. Strain elastography (SE) is a qualitative sonoelastographic modality with a wide range of clinical applications, but its use in brain tumor surgery has been so far very limited.

Objective: To describe the first large-scale implementation of SE in oncological neurosurgery for lesions discrimination and characterization.

View Article and Find Full Text PDF

Peripheral Vertigo.

Emerg Med Clin North Am

February 2019

Department of Emergency Medicine, Johns Hopkins Medical School, Johns Hopkins University School of Medicine, 733 North Broadway, Baltimore, MD 21205, USA. Electronic address:

This article summarizes the systematic assessment of the dizzy patient who presents with peripheral vertigo. It demonstrates the steps and tests necessary using the Triage-Timing-Trigger-Test (Triage + TiTraTe) method to accurately diagnose the underlying most probable cause while ruling out life-threatening causes. Using video support and just-in-time infographics, it demonstrates the Dix-Hallpike, Semont, Epley, and HINTS maneuvers.

View Article and Find Full Text PDF

Oncology and cerebrovascular disease constitute two of the most common diseases afflicting the central nervous system. Standard of treatment of these pathologies is based on multidisciplinary approaches encompassing combination of interventional procedures such as open and endovascular surgeries, drugs (chemotherapies, anti-coagulants, anti-platelet therapies, thrombolytics), and radiation therapies. In this context, therapeutic ultrasound could represent a novel diagnostic/therapeutic in the armamentarium of the surgeon to treat these diseases.

View Article and Find Full Text PDF

Tuning Pharmacokinetics to Improve Tumor Accumulation of a Prostate-Specific Membrane Antigen-Targeted Phototheranostic Agent.

Bioconjug Chem

November 2018

Princess Margaret Cancer Centre , University Health Network , 101 College Street, Toronto , Ontario M5G 1L7 , Canada.

We describe a simple and effective bioconjugation strategy to extend the plasma circulation of a low molecular weight targeted phototheranostic agent, which achieves high tumor accumulation (9.74 ± 2.26%ID/g) and high tumor-to-background ratio (10:1).

View Article and Find Full Text PDF

Purpose: Glioblastoma (GBM) is the most common primary brain tumor. The identification of blood biomarkers reflecting the tumor status represents a major unmet need for optimal clinical management of patients with GBM. Their high number in body fluids, their stability, and the presence of many tumor-associated proteins and RNAs make extracellular vesicles potentially optimal biomarkers.

View Article and Find Full Text PDF

Objective: Structural and functional magnetic resonance imaging (MRI) studies have consistently documented cortical and subcortical abnormalities in patients with juvenile myoclonic epilepsy (JME). However, little is known about how these structural abnormalities emerge from the time of epilepsy onset and how network interactions between and within cortical and subcortical regions may diverge in youth with JME compared to typically developing children.

Methods: We examined prospective covariations of volumetric differences derived from high-resolution structural MRI during the first 2 years of epilepsy diagnosis in a group of youth with JME (n = 21) compared to healthy controls (n = 22).

View Article and Find Full Text PDF

Filling the gap between the OR and virtual simulation: a European study on a basic neurosurgical procedure.

Acta Neurochir (Wien)

November 2018

Neurosurgery Department, Fondazione IRCCS Istituto Neurologico Nazionale "C. Besta", via Celoria 11, 20133, Milan, Italy.

Background: Currently available simulators are supposed to allow young neurosurgeons to hone their technical skills in a safe environment, without causing any unnecessary harm to their patients caused by their inexperience. For this training method to be largely accepted in neurosurgery, it is necessary to prove simulation efficacy by means of large-scale clinical validation studies.

Methods: We correlated and analysed the performance at a simulator and the actual operative skills of different neurosurgeons (construct validity).

View Article and Find Full Text PDF

Epigenetic modifications have become an emerging interface that links extrinsic signals to alterations of gene expression that determine cell identity and function. However, direct signaling that regulates epigenetic modifications is unknown. Our previous work demonstrated that phosphorylation of CBP at Ser 436 by atypical protein kinase C (aPKC) regulates age-dependent hippocampal neurogenesis and memory.

View Article and Find Full Text PDF

PDK4 Deficiency Suppresses Hepatic Glucagon Signaling by Decreasing cAMP Levels.

Diabetes

October 2018

Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, South Korea

In fasting or diabetes, gluconeogenic genes are transcriptionally activated by glucagon stimulation of the cAMP-protein kinase A (PKA)-CREB signaling pathway. Previous work showed pyruvate dehydrogenase kinase (PDK) inhibition in skeletal muscle increases pyruvate oxidation, which limits the availability of gluconeogenic substrates in the liver. However, this study found upregulation of hepatic PDK4 promoted glucagon-mediated expression of gluconeogenic genes, whereas knockdown or inhibition of hepatic PDK4 caused the opposite effect on gluconeogenic gene expression and decreased hepatic glucose production.

View Article and Find Full Text PDF

The relevance of the cerebral venous system is often underestimated during neurosurgical procedures. Damage to this draining system can have catastrophic implications for the patient. Surgical decision-making and planning must consider each component of the venous compartment, from the medullary draining vein to the dural sinuses and extracranial veins.

View Article and Find Full Text PDF