Publications by authors named "Courtney R Johnson"

Nitric oxide (NO) release from -nitrosothiol-modified mesoporous silica nanoparticles imbedded in the diffusion limiting layer of a glucose sensor has been demonstrated as an effective strategy for mitigating the foreign body response common to sensor implantation, resulting in improved analytical performance. With respect to potential clinical translation of this approach, the effects of sterilization on NO-releasing biosensors require careful evaluation, as NO donor chemistry is sensitive to temperature and environment. Herein, we evaluated the influence of multiple sterilization methods on 1) sterilization success; 2) NO payload; and 3) sensor performance to establish the commercialization potential of NO-releasing glucose sensors.

View Article and Find Full Text PDF

Intracellular proteins function in a complex milieu wherein small molecules influence protein folding and act as essential cofactors for enzymatic reactions. Thus protein function depends not only on amino acid sequence but also on the concentrations of such molecules, which are subject to wide variation between organisms, metabolic states, and environmental conditions. We previously found evidence that exogenous guanidine reverses the phenotypes of specific budding yeast septin mutants by binding to a WT septin at the former site of an Arg side chain that was lost during fungal evolution.

View Article and Find Full Text PDF

Septin proteins evolved from ancestral GTPases and co-assemble into hetero-oligomers and cytoskeletal filaments. In , five septins comprise two species of hetero-octamers, Cdc11/Shs1-Cdc12-Cdc3-Cdc10-Cdc10-Cdc3-Cdc12-Cdc11/Shs1. Slow GTPase activity by Cdc12 directs the choice of incorporation of Cdc11 vs Shs1, but many septins, including Cdc3, lack GTPase activity.

View Article and Find Full Text PDF

Septin hetero-oligomers polymerize into cytoskeletal filaments with essential functions in many eukaryotic cell types. Mutations within the oligomerization interface that encompasses the GTP-binding pocket of a septin (its "G interface") cause thermoinstability of yeast septin hetero-oligomer assembly, and human disease. When coexpressed with its wild-type counterpart, a G interface mutant is excluded from septin filaments, even at moderate temperatures.

View Article and Find Full Text PDF

Septin proteins bind GTP and heterooligomerize into filaments with conserved functions across a wide range of eukaryotes. Most septins hydrolyze GTP, altering the oligomerization interfaces; yet mutations designed to abolish nucleotide binding or hydrolysis by yeast septins perturb function only at high temperatures. Here, we apply an unbiased mutational approach to this problem.

View Article and Find Full Text PDF

Angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon, benign disorder that presents as solitary or multiple nodules in the dermis or subcutaneous tissue. Orbital ALHE has been reported on occasion. We report a case of orbital ALHE which was refractory to systemic steroids but effectively treated with low-dose subcutaneous methotrexate.

View Article and Find Full Text PDF

Needle phobia--fear of medical devices--is a significant problem in pediatric and adult chemotherapy patients. Stress-reducing medical devices is a new, effective cognitive therapy for needle phobia. Twenty-five pediatric and 25 adult chemotherapy patients were randomly exposed to conventional or stress-reducing decorated butterfly needles and syringes.

View Article and Find Full Text PDF

Objective: To determine the incidence and prevalence of neuropsychiatric systemic lupus erythematosus (NPSLE) and glomerulonephritis in ethnically diverse pediatric onset SLE inpatient and outpatient populations.

Methods: Seventy-five pediatric onset patients with SLE including Native American, Asian, Black, Spanish-American, and Caucasian subjects were evaluated prospectively and cross sectionally. During the 6 year study, 55 patients became inpatients.

View Article and Find Full Text PDF