Detecting the Major Degradation Products of Phosphorothioate Oligonucleotides by Chemical Derivatization and Weak Anion Exchange Chromatography.

Novel polar cysteine analogues have been synthesized for the derivatization of oligonucleotide depurination impurities that may be formed under acidic conditions. Depurination impurities belong to a group that includes deamination and phosphate diester impurities, which are similar in chemical structure to each other and the parent oligonucleotide, and thus coelute by most chromatographic separation methods. The polar cysteine analogues react with depurination impurities and enable their complete separation from the parent oligonucleotide by weak anion exchange (WAX) chromatography.

Activation thresholds, not quitting thresholds, account for the low prevalence effect in dynamic search.

The low-prevalence effect (LPE) is the finding that target detection rates decline as targets become less frequent in a visual search task. A major source of this effect is thought to be that fewer targets result in lower quitting thresholds, i.e.

Isolating the impact of a visual search template's color and form information on search guidance and verification times.

Visual search can be guided by biasing one's attention towards features associated with a target. Prior work has shown that high-fidelity, picture-based cues are more beneficial to search than text-based cues. However, typically picture cues provide both detailed form information and color information that is absent from text-based cues.

The Role of Immunotherapy in the Treatment of Rare Central Nervous System Tumors.

Establishing novel therapies for rare central nervous system (CNS) tumors is arduous due to challenges in conducting clinical trials in rare tumors. Immunotherapy treatment has been a rapidly developing field and has demonstrated improvements in outcomes for multiple types of solid malignancies. In rare CNS tumors, the role of immunotherapy is being explored.

A novel strategy to optimize critical information on over the counter labels for older adults.

Background And Aims: Labels designed to communicate critical information are paramount for the safe and effective use of over-the-counter medications; in recognition of this, the content and formatting of over the counter (OTC) labels sold in interstate commerce has been regulated for decades. Yet, available studies suggest that consumers frequently rely on limited information during decision making, failing to access the information required in the Drug Facts Label. This is particularly important for older consumers, who are at greater risk for adverse reactions to medicines.

A role for worm cutl-24 in background- and parent-of-origin-dependent ER stress resistance.

Background: Organisms in the wild can acquire disease- and stress-resistance traits that outstrip the programs endogenous to humans. Finding the molecular basis of such natural resistance characters is a key goal of evolutionary genetics. Standard statistical-genetic methods toward this end can perform poorly in organismal systems that lack high rates of meiotic recombination, like Caenorhabditis worms.

Quitting thresholds in visual search are impacted by target present detection times but not their variability.

Models of visual search posit that target absent responses occur when the quitting threshold for the trial is reached before a target is detected, and that feedback about missed targets allows the quitting threshold to be adaptively set to the difficulty of the search task. While these models may effectively capture processes in lab-based tasks, in real-world searches feedback is often impossible to provide. Instead, observers have little information about their errors, and may only be aware of when they successfully detect the target.

Cellular NADH and NADPH Conformation as a Real-Time Fluorescence-Based Metabolic Indicator under Pressurized Conditions.

Cellular conformation of reduced pyridine nucleotides NADH and NADPH sensed using autofluorescence spectroscopy is presented as a real-time metabolic indicator under pressurized conditions. The approach provides information on the role of pressure in energy metabolism and antioxidant defense with applications in agriculture and food technologies. Here, we use spectral phasor analysis on UV-excited autofluorescence from (baker's yeast) to assess the involvement of one or multiple NADH- or NADPH-linked pathways based on the presence of two-component spectral behavior during a metabolic response.

Determination of individual oligonucleotide impurities by small amine ion pair-RP HPLC MS and MS/MS: n - 1 impurities.

Ion pair-reversed phase (IP-RP) HPLC is one of the most widely used methods for the analysis of oligonucleotide impurities. The method is compatible with mass spectrometry and has been used to guide the development of improved synthesis and purification approaches. The ability to detect and characterize impurities depends on the reagents and the IP buffer system employed, as each can directly affect the degree of chromatographic separation and the sensitivity of detection by MS.

Severity of misophonia symptoms is associated with worse cognitive control when exposed to misophonia trigger sounds.

The present study aimed to investigate the extent to which the severity of misophonia symptoms is linked with cognitive control under misophonia symptom-provocation circumstances in the general population sample. Participants (N = 79) completed a measure of cognitive control-a Stroop color naming task, which consists of congruent and incongruent stimuli, and requires inhibition of a prepotent response (reading a word) in the service of a less predominant response (naming a color), while listening to misophonia symptom-provocation or universally unpleasant sounds. Participants' misophonia sound sensitivity, and emotional behaviors towards trigger sounds were assessed using the Misophonia Questionnaire.

Impurity Qualification Toxicology Study for a 2'-O-Methoxyethyl-Modified Antisense Inhibitor in Mice.

Safety assessment of drug impurities is a routine part of the drug development process. For oligonucleotide-based drugs, impurities can arise from impurities in starting materials, as by-products of the manufacturing process or from degradation, and are generally structurally similar to the parent oligonucleotide. To study the potential impact of impurities, a representative batch of a 2'-O-methoxyethyl (MOE) antisense oligonucleotide (ASO) was compared to batches of drug that were enriched with nine of the common impurities encountered with the chemical class.

MOG-IgG myelitis coexisting with systemic lupus erythematosus in the post-partum setting.

Background: Longitudinally extensive transverse myelitis (LETM) accompanying systemic lupus erythematosus (SLE) is often due to coexisting aquaporin-4-IgG seropositive neuromyelitis optica spectrum disorder but has not been associated with myelin oligodendrocyte glycoprotein-IgG (MOG-IgG).

Objective And Methods: Case report at an academic medical center.

Results: A 32-year-old woman developed severe transverse myelitis (paraplegia) shortly after SLE onset in the post-partum period.

Synthesis of 5'-GalNAc-Conjugated Oligonucleotides: A Comparison of Solid and Solution-Phase Conjugation Strategies.

Antisense oligonucleotides (ASOs) conjugated to triantennary -acetyl galactosamine (GalNAc) ligands represent an emerging approach to antisense therapy. Our current generation of GalNAc-ASO conjugates link the GalNAc to the 5'-terminus of the ASO. The conjugation reaction can be accomplished using solution-phase or solid-phase techniques.

Conversion of adenine to 5-amino-4-pyrimidinylimidazole caused by acetyl capping during solid phase oligonucleotide synthesis.

The acetyl capping reaction used throughout solid phase oligonucleotide synthesis is meant to minimize n-1 deletionmer impurities by terminating sequences that fail to couple to a phosphoramidite. However, the reaction is also responsible for the formation of a number of impurities. One capping-related impurity has an additional mass of 98amu from the parent oligonucleotide.

General qPCR and Plate Reader Methods for Rapid Optimization of Membrane Protein Purification and Crystallization Using Thermostability Assays.

This unit describes rapid and generally applicable methods to identify conditions that stabilize membrane proteins using temperature-based denaturation measurements as a proxy for target time-dependent stability. Recent developments with thiol-reactive dyes sensitive to the unmasking of cysteine residues upon protein unfolding have allowed for routine application of thermostability assays to systematically evaluate the stability of membrane protein preparations after various purification procedures. Test conditions can include different lipid cocktails, lipid-detergent micelles, pH, salts, osmolytes, and potential active-site ligands.

Formation of the N(2)-acetyl-2,6-diaminopurine oligonucleotide impurity caused by acetyl capping.

The acetyl 'capping' reaction routinely employed during phosphorothioate oligonucleotide synthesis has been implicated in the formation of an impurity species with a mass 41 amu greater than the expected oligonucleotide molecule. The impurity has been found to arise by conversion of a protected guanine nucleobase to N(2)-acetyl-2,6-diaminopurine. A two-part mechanism is proposed consisting of transamidation of the protecting group on guanine and substitution of guanine's O(6) atom.

Architecture of a single membrane spanning cytochrome P450 suggests constraints that orient the catalytic domain relative to a bilayer.

Bitopic integral membrane proteins with a single transmembrane helix play diverse roles in catalysis, cell signaling, and morphogenesis. Complete monospanning protein structures are needed to show how interaction between the transmembrane helix and catalytic domain might influence association with the membrane and function. We report crystal structures of full-length Saccharomyces cerevisiae lanosterol 14α-demethylase, a membrane monospanning cytochrome P450 of the CYP51 family that catalyzes the first postcyclization step in ergosterol biosynthesis and is inhibited by triazole drugs.

New Architectures in Hydrogen Bond Catalysis.

New achiral sulfamide, phosphoric triamide, and thiophosphoric triamide compounds have been synthesized. Their activity as hydrogen bond catalysts for the Friedel-Crafts and Baylis-Hillman reactions compares favorably with that of a known and active thiourea catalyst. The new compounds were also studied by X-ray crystallography and their solid state structures are described.

Squeezing ionic liquids through nanopores.

Room temperature ionic liquids (RTILs) are substances composed entirely of ions and are liquids at or below 100 degrees C. Ionic conductivity of RTIL is one of the most important physical properties of these unique substances that determine their potential applications as a new medium for capacitors, fuel and solar cells as well as in separation systems. The quality of performance of these devices relies on the understanding of ionic transport of RTIL on a nanoscale.

Asymmetric bisboranes as bidentate catalysts for carbonyl substrates.

A new class of C(2) symmetric bisoxazaborolidinone compounds is described which exhibits bidentate binding to carbonyl substrates. Using the Diels-Alder reaction as a model system, the catalytic activity of these bis-Lewis acids is probed. Reaction rates and selectivities are observed that are higher than the corresponding mono-Lewis acids.