Search

• Design of a radiobiology facility based on a laser-driven ion beam source. • Geant4 based simulation tool (BDSIM) verified the beam optics design. • BDSIM determined the energy deposition profile in the end station. • Simulations confirmed 15 MeV as optimal beam energy. The Centre for the Clinical Application of Particles' Laser-hybrid Accelerator for Radiobiological Applications (LhARA) facility is being studied and requires simulation of novel accelerator components (such as the Gabor lens capture system), detector simulation and simulation of the ion beam interaction with cells. The first stage of LhARA will provide protons up to 15 MeV for in vitro studies. The second stage of LhARA will use a fixed-field accelerator to increase the energy of the particles to allow in vivo studies with protons and in vitro studies with heavier ions. BDSIM, a Geant4 based accelerator simulation tool, has been used to perform particle tracking simulations to verify the beam optics design done by BeamOptics and these show good agreement. Design parameters were defined based on an EPOCH simulation of the laser source and a series of mono-energetic input beams were generated from this by BDSIM. The tracking results show the large angular spread of the input beam (0.2 rad) can be transported with a transmission of almost 100% whilst keeping divergence at the end station very low (<0.1 mrad). The legacy of LhARA will be the demonstration of technologies that could drive a step-change in the provision of proton and light ion therapy (i.e. a laser source coupled to a Gabor lens capture and a fixed-field accelerator), and a system capable of delivering a comprehensive set of experimental data that can be used to enhance the clinical application of proton and light ion therapy. [ABSTRACT FROM AUTHOR]

Nonketotic hyperglycinemia is a disorder of amino acid metabolism in which a defect in the glycine cleavage system leads to an accumulation of glycine in the brain and other body compartments. In the classical form it presents as neonatal apnea, intractable seizures, and hypotonia, followed by significant psychomotor retardation. An important subset of children with nonketotic hyperglycinemia are atypical variants who present in a heterogeneous manner. This report describes a patient with mild language delay and mental retardation, who was found to have nonketotic hyperglycinemia following her presentation with acute encephalopathy and chorea shortly after initiation of valproate therapy. [Copyright &y& Elsevier]

Mutations in the voltage-gated sodium channel gene SCN1A are a major cause of severe myoclonic epilepsy of infancy (Dravet syndrome) and generalized epilepsy with febrile seizures plus. This study reports the identification of six de novo SCN1A mutations in patients with severe myoclonic epilepsy of infancy, including a tetranucleotide deletion in exon 26. The same deletion was previously observed in two unrelated patients and appears to result from slipped-strand mispairing of a direct repeat during deoxyribonucleic acid replication. Review of the literature indicates that recurrent mutations account for 25% of SCN1A mutations in severe myoclonic epilepsy of infancy, including six sites of deamination at CpG dinucleotides. [Copyright &y& Elsevier]

Discusses a study that examined psychopathology in a sample of complex partial seizures (CPS), primary generalized epilepsy and nonepileptic children using the Child Behavior Checklist (CBCL) and the Schedule for Affective Disorders and Schizophrenia (K-SADS). Demographics and seizure characteristics of the children; CBCL scores and K-SADS diagnoses; Clinical implications.