Search

Background and purpose: We analyzed the association of neuropsychological outcomes after epilepsy surgery with the intracranial electrode type (stereo electroencephalography [SEEG] and subdural electrodes [SDE]), and electrical stimulation mapping (ESM) of speech/language. Methods: Drug‐resistant epilepsy patients who underwent comprehensive neuropsychological evaluation before and 1 year after epilepsy surgery were included. SEEG and SDE subgroups were matched by age, handedness, operated hemisphere, and seizure freedom. Postsurgical neuropsychological outcomes (adjusted for presurgical scores) and reliable change indices were analyzed as functions of electrode type and ESM. Results: Ninety‐nine patients aged 6–29 years were included with similar surgical resection/ablation volumes in the SEEG and SDE subgroups. Most of the neuropsychological outcomes were comparable between SEEG and SDE subgroups; however, Working Memory and Processing Speed were significantly improved in the SEEG subgroup. Undergoing language ESM was associated with significant improvements in Spelling, Letter–Word Identification, Vocabulary, Verbal Comprehension, Verbal Learning, and Story Memory scores, but a decline in Calculation scores. Conclusions: Intracranial evaluations with SEEG and SDE are comparable in terms of long‐term postsurgical neuropsychological outcomes. Our data suggest that SEEG may be associated with improvements in working memory and processing speed, representing cognitive domains served by spatially distributed networks. Our study also supports wider use of language ESM before epilepsy surgery, preferably using other language tasks in addition to visual naming. Rather than the type of electrode, postsurgical neuropsychological outcomes are driven by whether language ESM was performed or not, with beneficial effects of language mapping. [ABSTRACT FROM AUTHOR]

Objective: Seizures are common in critically ill children and neonates, and these patients would benefit from intravenous (IV) antiseizure medications with few adverse effects. We aimed to assess the safety profile of IV lacosamide (LCM) among children and neonates. Methods: This retrospective multicenter cohort study examined the safety of IV LCM use in 686 children and 28 neonates who received care between January 2009 and February 2020. Results: Adverse events (AEs) were attributed to LCM in only 1.5% (10 of 686) of children, including rash (n = 3,.4%), somnolence (n = 2,.3%), and bradycardia, prolonged QT interval, pancreatitis, vomiting, and nystagmus (n = 1,.1% each). There were no AEs attributed to LCM in the neonates. Across all 714 pediatric patients, treatment‐emergent AEs occurring in >1% of patients included rash, bradycardia, somnolence, tachycardia, vomiting, feeling agitated, cardiac arrest, tachyarrhythmia, low blood pressure, hypertension, decreased appetite, diarrhea, delirium, and gait disturbance. There were no reports of PR interval prolongation or severe cutaneous adverse reactions. When comparing children who received a recommended versus a higher than recommended initial dose of IV LCM, there was a twofold increase in the risk of rash in the higher dose cohort (adjusted incidence rate ratio = 2.11, 95% confidence interval = 1.02–4.38). Significance: This large observational study provides novel evidence demonstrating the tolerability of IV LCM in children and neonates. [ABSTRACT FROM AUTHOR]

Objective: Electrical stimulation mapping (ESM) is the clinical standard for functional localization with subdural electrodes (SDE). As stereoelectroencephalography (SEEG) has emerged as an alternative option, we compared functional responses, afterdischarges (ADs), and unwanted ESM‐induced seizures (EISs) between the two electrode types. Methods: Incidence and current thresholds for functional responses (sensory, motor, speech/language), ADs, and EISs were compared between SDE and SEEG using mixed models incorporating relevant covariates. Results: We identified 67 SEEG ESM and 106 SDE ESM patients (7207 and 4980 stimulated contacts, respectively). We found similar incidence of language and motor responses between electrode types; however, more SEEG patients reported sensory responses. ADs and EISs occurred less commonly with SEEG than SDE. Current thresholds for language, face motor, and upper extremity (UE) motor responses and EIS significantly decreased with age. However, they were not affected by electrode type, premedication, or dominant hemispheric stimulation. AD thresholds were higher with SEEG than with SDE. For SEEG ESM, language thresholds remained below AD thresholds up to 26 years of age, whereas this relationship was inverse for SDE. Also, face and UE motor thresholds fell below AD thresholds at earlier ages for SEEG than SDE. AD and EIS thresholds were not affected by premedication. Significance: SEEG and SDE have clinically relevant differences for functional brain mapping with electrical stimulation. Although evaluation of language and motor regions is comparable between SEEG and SDE, SEEG offers a higher likelihood of identifying sensory areas. A lower incidence of ADs and EISs, and a favorable relationship between functional and AD thresholds suggest superior safety and neurophysiologic validity for SEEG ESM than SDE ESM. [ABSTRACT FROM AUTHOR]

Cornelia de Lange syndrome is a rare developmental malformation syndrome characterized by small stature, limb anomalies, distinctive facial features, developmental delays, and behavioral issues. The diagnosis of Cornelia de Lange syndrome is made clinically or on the basis of an identified variant in one of the genes associated with Cornelia de Lange syndrome. SMC1A variants are the cause of 5% of the cases of Cornelia de Lange syndrome. SMC1A is located on the X-chromosome and is thought to escape X-inactivation in some females. Patients with SMC1A variants are being increasingly identified through panel testing or exome sequencing without prior clinical suspicion of Cornelia de Lange syndrome. In general, intractable epilepsy is not considered a prominent feature of Cornelia de Lange syndrome, yet this is found in these patients with SMC1A variants. Here we report on a series of patients with SMC1A variants and intractable epilepsy. In contrast to patients with typical SMC1A -associated Cornelia de Lange syndrome, all of the identified patients were female, and when available, X-inactivation studies were highly skewed with truncating variants. We describe the medical involvement and physical appearance of the participants, compared to the diagnostic criteria used for classical Cornelia de Lange syndrome. We also report on the clinical characteristics of the epilepsy, including age of onset, types of seizures, electroencephalographic (EEG) findings, and response to various antiepileptic medications. These findings allow us to draw conclusions about how this population of patients with SMC1A variants fit into the spectrum of Cornelia de Lange syndrome and the broader spectrum of cohesinopathies and allow generalizations that may impact clinical care and, in particular, epilepsy management. [ABSTRACT FROM AUTHOR]

In pursuit of therapeutics for human polyomaviruses, we identified a peptide derived from the BK polyomavirus (BKV) minor structural proteins VP2/3 that is a potent inhibitor of BKV infection with no observable cellular toxicity. The thirteen-residue peptide binds to major structural protein VP1 with single-digit nanomolar affinity. Alanine-scanning of the peptide identified three key residues, substitution of each of which results in ~1000 fold loss of binding affinity with a concomitant reduction in antiviral activity. Structural studies demonstrate specific binding of the peptide to the pore of pentameric VP1. Cell-based assays demonstrate nanomolar inhibition (EC50) of BKV infection and suggest that the peptide acts early in the viral entry pathway. Homologous peptide exhibits similar binding to JC polyomavirus VP1 and inhibits infection with similar potency to BKV in a model cell line. Lastly, these studies validate targeting the VP1 pore as a novel strategy for the development of anti-polyomavirus agents. [ABSTRACT FROM AUTHOR]

RAS mutations lead to a constitutively active oncogenic protein that signals through multiple effector pathways. In this chemical biology study, we describe a novel coupled biochemical assay that measures activation of the effector BRAF by prenylated KRASG12V in a lipid-dependent manner. Using this assay, we discovered compounds that block biochemical and cellular functions of KRASG12V with low single-digit micromolar potency. We characterized the structural basis for inhibition using NMR methods and showed that the compounds stabilized the inactive conformation of KRASG12V. Determination of the biophysical affinity of binding using biolayer interferometry demonstrated that the potency of inhibition matches the affinity of binding only when KRAS is in its native state, namely post-translationally modified and in a lipid environment. The assays we describe here provide a first-time alignment across biochemical, biophysical, and cellular KRAS assays through incorporation of key physiological factors regulating RAS biology, namely a negatively charged lipid environment and prenylation, into the in vitro assays. These assays and the ligands we discovered are valuable tools for further study of KRAS inhibition and drug discovery. [ABSTRACT FROM AUTHOR]

The article presents a study that determines the potential of cyclin-dependent kinase 9 (CDK9) and MYC/BRD4 in inducing growth arrest and apoptosis of cancer cells.

Further application of the tritiated amino acid suicide selection procedure, designed to select conditional protein synthesis mutants, has yielded over 300 aminoacyl-tRNA synthetase mutants of Chinese hamster ovary cells, representing seven complementation groups. A number of these mutants and their revertants were used to examine the extent of X-chromosome linkage or other functional hemizygosity in CHO cells. Our results indicated that none of the seven different aaRS loci tested was X linked, and the the glnRS locus, unlike the asnRS and leuRS loci, does not appear to be functionally hemizygous in CHO cells. [ABSTRACT FROM AUTHOR]

• Primary hub was significantly closer to the stereotactic EEG-defined seizure onset zone compared to the center of ECD cluster. • Both ECD cluster and network analyses suggested that spatially restricted region correlate with better seizure outcomes. • Our findings suggest that magnetoencephalography network analysis could be a valuable complement to the conventional ECD method. To clinically validate the connectivity-based magnetoencephalography (MEG) analyses to identify seizure onset zone (SOZ) with comparing to equivalent current dipole (ECD). The ECD cluster was quantitatively analyzed by calculating the centroid of the cluster and maximum distance (the largest distance between all dipoles). The "primary hub" was determined by the highest eigencentrality. The distribution of nodes in the top 5% of eigenvector centrality values was quantified by generating the convex hull between each node. Thirty-one patients who underwent MEG, stereotactic-EEG, and focal surgery were included. The primary hub was significantly closer to the sEEG-defined SOZ compared to ECD (p = 0.009). The seizure freedom positive and negative predictive values of complete ECD cluster and primary hub resections did not significantly differ, although complete resection of the primary hub showed slightly better negative predictive value (ECD: 50.0% NPV, hub: 64.7% NPV). Both quantitative ECD and functional connectivity analyses suggested that spatially restricted dipole distributions and higher connectivity in a smaller region correlate with better seizure outcomes. Our findings suggest that MEG network analysis could be a valuable complement to the ECD methods. The results of this study are an important step towards using non-invasive neurophysiologic recordings to accurately define the epileptic network. [ABSTRACT FROM AUTHOR]

CDK9 is the kinase subunit of positive transcription elongation factor b (P-TEFb) that enables RNA polymerase (Pol) II's transition from promoter-proximal pausing to productive elongation. Although considerable interest exists in CDK9 as a therapeutic target, little progress has been made due to lack of highly selective inhibitors. Here, we describe the development of i-CDK9 as such an inhibitor that potently suppresses CDK9 phosphorylation of substrates and causes genome-wide Pol II pausing. While most genes experience reduced expression, MYC and other primary response genes increase expression upon sustained i-CDK9 treatment. Essential for this increase, the bromodomain protein BRD4 captures P-TEFb from 7SK snRNP to deliver to target genes and also enhances CDK9's activity and resistance to inhibition. Because the i-CDK9-induced MYC expression and binding to P-TEFb compensate for P-TEFb's loss of activity, only simultaneously inhibiting CDK9 and MYC/BRD4 can efficiently induce growth arrest and apoptosis of cancer cells, suggesting the potential of a combinatorial treatment strategy.

Utilizing structure-based drug design, a novel dihydropyridopyrimidinone series which exhibited potent Hsp90 inhibition, good pharmacokinetics upon oral administration, and an excellent pharmacokinetic/pharmacodynamic relationship in vivo was developed from a commercial hit. The exploration of this series led to the selection of NVP-HSP990 as a development candidate.

A series of arylaminobenzimidazoles was designed and synthesized as Raf kinase inhibitors. Exploration of the structure-activity relationship resulted in compounds that are potent in vitro and show desirable in vivo properties.

Deacetylation of uridyldiphospho-3-O-(R-hydroxydecanoyl)-N-acetylglucosamine by LpxC is the first committed step in the Pseudomonas aeruginosa biosynthetic pathway to lipid A; homologous enzymes are found widely among Gram-negative bacteria. As an essential enzyme for which no inhibitors have yet been reported, the P. aeruginosa LpxC represents a highly attractive target for a novel antibacterial drug. We synthesized several focused small-molecule libraries, each composed of a variable aromatic ring, one of four heterocyclic/spacer moieties, and a hydroxamic acid and evaluated the LpxC inhibition of these compounds against purified P. aeruginosa enzyme. To ensure that the in vitro assay would be as physiologically relevant as possible, we synthesized a tritiated form of the specific P. aeruginosa glycolipid substrate and measured directly the enzymatically released acetate. Several of our novel compounds, predominantly those having fluorinated substituents on the aromatic ring and an oxazoline as the heterocyclic moiety, demonstrated in vitro IC(50) values less than 1 microM. We now report the synthesis and in vitro evaluation of these P. aeruginosa LpxC inhibitors.

The urokinase receptor is a multi-functional protein that plays a central role in cell surface plasminogen activation, cell migration, and cell adhesion. We previously demonstrated that high affinity peptide ligands for the urokinase receptor, which are urokinase competitors, can be obtained from a 15mer peptide library (Goodson et al., 1994). In order to probe for additional urokinase receptor binding sites we affinity selected the same bacteriophage library on complexes of soluble urokinase receptor (suPAR) and the receptor binding domain of urokinase, residues 1-48 (uPA1-48). Bacteriophage were isolated which bound to suPAR and suPAR:uPA1-48 complexes with high yield. The peptide sequences encoded by these bacteriophage were distinct from those obtained previously on urokinase receptor expressing cells, and comprise two groups based upon effects on su-PAR:1-anilino-8-napthalene sulfonate (ANS) fluorescence, and vitronectin binding competition. Alanine scanning mutagensis of the soluble peptides was used to define minimal regions and key residues for suPAR binding by competition with the parent bacteriophage. A comparison of these results with sequences of domains of both vitronectin and integrin alpha-chains, which have been reported to be important for urokinase receptor binding, suggests that the homology with the peptide sequences selected is functionally significant.