Addressing drug effects on cut point determination for an anti-drug antibody assay.

The effect of trough levels of a monoclonal antibody drug (drugB) on screening cut point (CP) determination for an anti-drug antibody (ADA) assay was scrutinized and the conclusions substantiated by data from a phase 3 cancer clinical study. The ADA assay utilized an acid dissociation step and either 0 or 100 μg/ml drugB was added to the samples prior to obtaining the signals used for CP calculations. Serum samples from three different drug-naive populations were tested (healthy individuals, cancer patients enrolled in the drugB clinical trial and cancer patients whose serum samples were available commercially).

Validation and life-cycle management of a quantitative ligand-binding assay for the measurement of Nulojix(®), a CTLA-4-Fc fusion protein, in renal and liver transplant patients.

Background: Nulojix(®) is a fusion protein composed of the Fc portion of a human IgG1 linked to the extracellular modified domain of CTLA-4. Nulojix differs from another Bristol Myers Squibb product, Orencia(®) by two amino acids and was approved by the FDA on 15 June 2011 for the prophylaxis of organ rejection in adult patients receiving kidney transplant.

Results: A sandwich ELISA utilizing two monoclonal antibodies against CTLA-4 was employed for Nulojix quantification and pharmacokinetic analysis.

How hair cells hear: the molecular basis of hair-cell mechanotransduction.

Purpose Of Review: This review aims to summarize our current knowledge regarding mechanotransduction by hair cells and to highlight unresolved questions.

Recent Findings: Despite over a quarter of a century of electrophysiological data describing hair-cell mechanotransduction, the molecular basis of this process is just now being revealed. Recent work has begun to identify candidate transduction complex molecules, and current work is aimed at confirming these hypotheses and identifying other proteins important for hair-cell function.

In situ binding assay to detect Myosin-1c interactions with hair-cell proteins.

Myosin-1c is an unconventional myosin involved in hair-cell mechanotransduction, a process that underlies our senses of hearing and balance. To study the interaction of myosin-1c with other components of the hair-cell transduction complex, we have developed an in situ binding assay that permits visualization of myosin-1c binding to hair-cell proteins. In this chapter we describe in detail the methods needed for the expression and purification of recombinant myosin-1c fragments and their use in the in situ binding assay.

Stereociliary myosin-1c receptors are sensitive to calcium chelation and absent from cadherin 23 mutant mice.

The identities of some of the constituents of the hair-cell transduction apparatus have been elucidated only recently. The molecular motor myosin-1c (Myo1c) functions in adaptation of the hair-cell response to sustained mechanical stimuli and is therefore an integral part of the transduction complex. Recent data indicate that Myo1c interacts in vitro with two other molecules proposed to be important for transduction: cadherin 23 (Cdh23), a candidate for the stereociliary tip link, and phosphatidylinositol 4,5-bisphosphate (PIP2), which is abundant in the membranes of hair-cell stereocilia.