Development of a Generic Anti-PEG Antibody Assay Using BioScale’s Acoustic Membrane MicroParticle Technology

Immunogenicity testing for PEGylated biotherapeutics should include methods to detect both anti-protein and anti-PEG antibodies (anti-PEG). Although some methods have been published for the detection of anti-PEG antibodies, the information is incomplete and, in some cases, reagents used (such as Tween-20) are known to interfere with detection. This rapid communication describes the use of BioScale’s Acoustic Membrane MicroParticle (AMMP®) technology using the ViBE® Workstation to measure anti-PEG antibodies in human serum samples. Briefly, a sample spiked with monoclonal human IgG anti-PEG antibody is diluted in buffer and incubated with paramagnetic beads coated with linear chain mPEG to capture anti-PEG antibodies. The complex is then captured on an acoustic membrane coated with Protein A. The change in mass on the membrane caused by the binding of the complex to the membrane results in a signal proportional to the mass of anti-PEG antibodies. The data indicate that an assay with a sensitivity of less than 1000 ng/mL for IgG is achievable. This level of sensitivity is better than current published reports on IgG anti-PEG antibody detection.KEY WORDS: acoustic membrane microparticle technology, anti-peg antibodies, emerging technology, immunogenicity assays, pegylated biotherapeutics     

Rate and Predictors of Ineffective HIV Protection in African Men Who Have Sex with Men Taking Pre-Exposure Prophylaxis

AIDS and Behavior - We investigated the rate and predictors of ineffective HIV protection in men who have sex with men (MSM) taking pre-exposure prophylaxis (PrEP) in a prospective cohort study...     

Pseudoephedrine and circadian rhythm interaction on neuromuscular performance

This study analyzed the effects of pseudoephedrine (PSE) provided at different time of day on neuromuscular performance, side effects, and violation of the current doping cut‐off threshold [World Anti‐Doping Agency (WADA)]. Nine resistance‐trained males carried out bench press and full squat exercises against four incremental loads (25%, 50%, 75%, and 90% one repetition maximum [1RM]), in a randomized, double‐blind, cross‐over design. Participants ingested either 180 mg of PSE (supra‐therapeutic dose) or placebo in the morning (7:00 h; AM_PLAC and AM_PSE) and in the afternoon (17:00 h; PM_PLAC and PM_PSE). PSE enhanced muscle contraction velocity against 25% and 50% 1RM loads, only when it was ingested in the mornings, and only in the full squat exercise (4.4–8.7%; P < 0.05). PSE ingestion raised urine and plasma PSE concentrations (P < 0.05) regardless of time of day; however, cathine only increased in the urine samples. PSE ingestion resulted in positive tests occurring in 11% of samples, and it rose some adverse side effects such us tachycardia and heart palpitations. Ingestion of a single dose of 180 mg of PSE results in enhanced lower body muscle contraction velocity against low and moderate loads only in the mornings. These mild performance improvements are accompanied by undesirable side effects and an 11% risk of surpassing the doping threshold.     

Fetal liver cells produce both fetal and adult erythrocytes in semiallogeneic radiation chimeras: possible influence of adult environment

Two kinds of erythrocytes are released in the blood of irradiated adult hybrid mice grafted with parental fetal liver cells: fetal antigen- bearing erythrocytes (Ft+ cells) and adult-type Ft- erythrocytes. Both are of parental origin, as determined by immune lysis using histocompatibility alloantigens. The latter cells make up all the recipient's red blood cells 2 mo after receipt of the graft, Ft+ cells then being no longer detected. The transient duality of erythropoiesis in irradiated adults grafted with fetal liver cells has been confirmed by studying the kinetics of CFU-E populations, as characterized by their ability to give rise to Ft+ or Ft- erythrocytes. The results are discussed in terms of environmental factors that influenc erythroid differentiation.