Dural involvement in central nervous system langerhans cells histiocytosis (LCH) on FDG PET/CT: Case report and review of CNS manifestations of LCH on PET/CT.

We report a case of multisystem Langerhans cell histiocytosis in a pediatric patient with central nervous system involvement, highlighting F-18(FDG) uptake characteristics of dural sites of disease. We also highlight the advantages of functional data offered by FDG-PET as a useful follow-up tool to assess viability and, therefore, treatment response of previously known central nervous system lesions. The utility of recognizing characteristic patterns of FDG uptake in dural disease is also applicable in cases of diagnostic uncertainty, such as when evaluating isolated dural lesions or when distinguishing between Langerhans cell histiocytosis and similar appearing lesions such as meningiomas.

Variability in the diagnostic and management practices of post-hemorrhagic ventricular dilatation in very preterm infants across Canadian centers and comparison with European practices.

Objectives: To investigate the variability in diagnostic and therapeutic approaches to posthemorrhagic ventricular dilatation (PHVD) among Canadian neonatal centers, and secondary exploration of differences in approaches between Canadian and European practices.

Methods: We conducted a survey among Canadian tertiary neonatal centers on their local practices for managing very preterm infants with PHVD. The survey covered questions on the diagnostic criteria, timing and type of interventions and resources utilization (transfer to neurosurgical sites and neurodevelopmental follow-up).

Increased intracranial pressure in a patient with Congenital Heart Defect and Ectodermal Dysplasia (CHDED): Extension of phenotype and review of literature.

Congenital heart defect (CHD) is a birth defect that affects the structure of the heart. Although CHD is often multifactorial, it can also be inherited as part of a Mendelian disorder such as in congenital heart defect and ectodermal dysplasia (CHDED). This disorder is caused by de novo variants in PRKD1.

Mechanical feedback and robustness of apical constrictions in Drosophila embryo ventral furrow formation.

Formation of the ventral furrow in the Drosophila embryo relies on the apical constriction of cells in the ventral region to produce bending forces that drive tissue invagination. In our recent paper we observed that apical constrictions during the initial phase of ventral furrow formation produce elongated patterns of cellular constriction chains prior to invagination and argued that these are indicative of tensile stress feedback. Here, we quantitatively analyze the constriction patterns preceding ventral furrow formation and find that they are consistent with the predictions of our active-granular-fluid model of a monolayer of mechanically coupled stress-sensitive constricting particles.

Validation of 3D fluoroscopy for image-guidance registration in depth electrode implantation for medically refractory epilepsy.

Background: Frame registration is a critical step to ensure accurate electrode placement in stereotactic procedures such as stereoelectroencephalography (SEEG) and is routinely done by merging a computed tomography (CT) scan with the preoperative magnetic resonance (MR) examination. Three-dimensional fluoroscopy (XT) has emerged as a method for intraoperative electrode verification following electrode implantation and more recently has been proposed as a registration method with several advantages.

Methods: We compared the accuracy of SEEG electrode placement by frame registration with CT and XT imaging by analyzing the Euclidean distance between planned and post-implantation trajectories of the SEEG electrodes to calculate the error in both the entry (EP) and target (TP) points.

Nuclear Imaging of Neuroendocrine Tumors.

Consensus guidelines acknowledge the role of gallium Ga-68 (Ga) 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic (DOTA) somatostatin receptor (SSTR) positron emission tomography/computed tomography (PET/CT) in management of neuroendocrine tumor (NET) patients. Ga-DOTA-SSTR PET/CT demonstrates superior performance to conventional imaging in initial detection, staging, detection of recurrent tumor, and detection of unknown primary in known metastatic disease. Ga-DOTA-SSTR PET/CT is low yield for NET detection in the setting of symptoms or elevated biomarkers when conventional imaging is negative, but may still guide management.

Charge exchange recombination spectroscopy at Wendelstein 7-X.

The Charge Exchange Recombination Spectroscopy (CXRS) diagnostic has become a routine diagnostic on almost all major high temperature fusion experimental devices. For the optimized stellarator Wendelstein 7-X (W7-X), a highly flexible and extensive CXRS diagnostic has been built to provide high-resolution local measurements of several important plasma parameters using the recently commissioned neutral beam heating. This paper outlines the design specifics of the W7-X CXRS system and gives examples of the initial results obtained, including typical ion temperature profiles for several common heating scenarios, toroidal flow and radial electric field derived from velocity measurements, beam attenuation via beam emission spectra, and normalized impurity density profiles under some typical plasma conditions.

Chronic Venous Insufficiency Causing a Diagnostic Conundrum on Tc-99m Bone Scan Done for Osteosarcoma Surveillance: Awareness is the Key!

Bone scans are the most commonly used imaging technique to rule out local recurrence or metastasis during surveillance of malignant bone tumors after treatment. Although bone scans are very sensitive in detecting recurrence or metastasis, they are less specific. There are many nonmalignant conditions which can mimic either recurrence or metastasis on a Tc-99m bone scan.

Alterations in ALK/ROS1/NTRK/MET drive a group of infantile hemispheric gliomas.

Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups.

Cerebellar mutism after posterior fossa tumor resection in children: a multicenter international retrospective study to determine possible modifiable factors.

Purpose: A preliminary survey of pediatric neurosurgeons working at different centers around the world suggested differences in clinical practice resulting in variation in the risk of pediatric cerebellar mutism (CM) and cerebellar mutism syndrome (CMS) after posterior fossa (PF) tumor resection. The purposes of this study were (1) to determine the incidence and severity of CM and CMS after midline PF tumor resection in children treated at these centers and (2) to identify potentially modifiable factors related to surgical management (rather than tumor biology) that correlate with the incidence of CM/CMS.

Methods: Attending pediatric neurosurgeons at British Columbia's Children's Hospital (BCCH) and neurosurgeons who completed a pediatric neurosurgery fellowship at BCCH were invited to provide data from the center where they currently practiced.

Endoscopic Retrieval of Flanged Ventricular Catheters.

Flanged ventricular catheters are now used infrequently. Many patients with longstanding hydrocephalus still harbor these catheters, either as their current ventricular catheter, or as a retained catheter from a prior implant. The removal of flanged ventricular catheters is sometimes necessary, and may be challenging due to intraventricular adhesions.

Posterior Reversible Encephalopathy Syndrome on 18F-FDG PET/CT in a Pediatric Patient With Burkitt's Lymphoma.

We present a case of posterior reversible encephalopathy syndrome (PRES) in a pediatric patient with Burkitt's lymphoma predominantly involving the bone marrow. F-FDG PET/CT scan obtained after the first cycle of chemotherapy, complicated by acute kidney injury, hypertension, tumor lysis syndrome, and lethargy with focal neurological symptoms, showed a favorable marrow and lymph node response but increased FDG uptake in the bilateral frontal and occipital cortical/subcortical regions. Brain MRI was consistent with PRES.

Safety and accuracy of Ga-DOTATOC PET/CT in children and young adults with solid tumors.

Ga-DOTA-tyr3-Octreotide (Ga-DOTATOC) PET/CT has been shown to have high accuracy in adults with neuroendocrine tumors, however has not been studied in pediatric patients. This study evaluated the safety and accuracy of Ga-DOTATOC PET/CT in children and young adults with solid tumors that express somatostatin receptor type 2. A series of three prospective, IRB approved, clinical trials evaluating safety and efficacy of Ga-DOTATOC PET/CT were conducted for subjects aged 6 months to 90 years.

AR Binding Kinetics in the Ligand Depletion Regime.

Ligand binding plays a fundamental role in stimulating the downstream signaling of membrane receptors. Here, ligand-binding kinetics of the full-length human adenosine A receptor (AR) reconstituted in detergent micelles were measured using a fluorescently labeled ligand via fluorescence anisotropy. Importantly, to optimize the signal-to-noise ratio, these experiments were conducted in the ligand depletion regime.

Impact of purification conditions and history on A2A adenosine receptor activity: The role of CHAPS and lipids.

The adenosine A2A receptor (A2AR) is a much-studied class A G protein-coupled receptor (GPCR). For biophysical studies, A2AR is commonly purified in a detergent mixture of dodecylmaltoside (DDM), 3-(3-cholamidopropyl) dimethylammoniopropane sulfonate (CHAPS), and cholesteryl hemisuccinate (CHS). Here we studied the effects of CHAPS on the ligand binding activity and stability of wild type, full-length human A2AR.

Pediatric thalamic tumors in the MRI era: a Canadian perspective.

Background: Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system.