Sensitivity and Specificity of 2 Autism Screeners Among Referred Children Between 16 and 48 Months of Age.

OBJECTIVE: Autism screening is recommended by the American Academy of Pediatrics and the Centers for Disease Control and Prevention at ages 18 and 24 months. Popular screening tests have been validated for the age range of 16 to 30 months. However, only a minority of children with autism spectrum disorder (ASD) are identified by age 3 years, and many are not identified until after they enter school. Thus, we aimed to measure the sensitivity and specificity of 2 available screening tests for ASDs in children older than 30 months. METHODS: We assessed the sensitivity and specificity of 2 ASD screening tools administered to parents of children who were referred to a developmental clinic between the ages of 16 and 48 months: the Modified Checklist for Autism in Toddlers (M-CHAT) and the Parent's Observations of Social Interactions (POSI), which is a component of a comprehensive screening instrument called, the Survey of Well-being of Young Children. RESULTS: Both the M-CHAT and the POSI had acceptable sensitivity (≥75%) among children across the age range studied. Their specificity was limited by the fact that the study was conducted in a developmental referral clinic. CONCLUSION: Two readily available screening tools, the POSI and the M-CHAT, have acceptable sensitivity in evaluating risk for autism in children at least to age 48 months. Further research should investigate their sensitivity and specificity when used in primary care settings.

Dual Agonist Surrobody Simultaneously Activates Death Receptors DR4 and DR5 to Induce Cancer Cell Death.

Death receptors of the TNF family are found on the surface of most cancer cells and their activation typically kills cancer cells through the stimulation of the extrinsic apoptotic pathway. The endogenous ligand for death receptors 4 and 5 (DR4 and DR5) is TNF-related apoptosis-inducing ligand, TRAIL (Apo2L). As most untransformed cells are not susceptible to TRAIL-induced apoptosis, death receptor activators have emerged as promising cancer therapeutic agents. One strategy to stimulate death receptors in cancer patients is to use soluble human recombinant TRAIL protein, but this agent has limitations of a short half-life and decoy receptor sequestration. Another strategy that attempted to evade decoy receptor sequestration and to provide improved pharmacokinetic properties was to generate DR4 or DR5 agonist antibodies. The resulting monoclonal agonist antibodies overcame the limitations of short half-life and avoided decoy receptor sequestration, but are limited by activating only one of the two death receptors. Here, we describe a DR4 and DR5 dual agonist produced using Surrobody technology that activates both DR4 and DR5 to induce apoptotic death of cancer cells in vitro and in vivo and also avoids decoy receptor sequestration. This fully human anti-DR4/DR5 Surrobody displays superior potency to DR4- and DR5-specific antibodies, even when combined with TRAIL-sensitizing proapoptotic agents. Moreover, cancer cells were less likely to acquire resistance to Surrobody than either anti-DR4 or anti-DR5 monospecific antibodies. Taken together, Surrobody shows promising preclinical proapoptotic activity against cancer cells, meriting further exploration of its potential as a novel cancer therapeutic agent.

ErbB3 inhibitory surrobodies inhibit tumor cell proliferation in vitro and in vivo.

ErbB3 is an important regulator of tumorigenesis and is implicated in development of resistance to several currently used oncology drugs. We have identified ErbB3 inhibitors based on a novel biologic scaffold termed a surrobody. Two of these inhibitors appear to work by a previously unrecognized mechanism of action. As a consequence, they not only inhibited cell proliferation and intracellular signaling driven by stimulation with the ErbB3 ligand neuregulin (NRG), but also inhibited signaling and proliferation that was driven by overexpression of ErbB2 in the absence of ligand stimulation. In addition, the surrobodies inhibited tumor growth in vivo in both ErbB2-overexpressing and nonoverexpressing cells. In ErbB2-overexpressing cells, both of the anti-ErbB3 surrobodies significantly augmented the activities of trastuzumab, lapatinib, and GDC-0941, agents that inhibit cell proliferation by different mechanisms. Moreover, although NRG diminished the efficacy of these agents, when they were combined with anti-ErbB3 surrobodies the affect of NRG was abrogated. In this capacity, the anti-ErbB3 surrobodies were more effective than the ErbB2/ErbB3 dimerization inhibitory antibody pertuzumab. Despite the fact that these surrobodies appear to engage ErbB3 differently than previously described anti-ErbB3 antibodies, they retain all of the beneficial characteristics of this class of agents, including the ability to augment drugs that inhibit EGF receptor. These anti-ErbB3 agents, therefore, show substantial promise for development as single agents or in combination with other ErbB-directed antibodies or small molecules and may provide for a broader range of therapeutic indications than previously described anti-ErbB3 antibodies.

Consistency of a two clinical site sample collection: a proteomics study.

PURPOSE: We investigated the ability to perform a clinical proteomic study using samples collected at different times from two independent clinical sites. EXPERIMENTAL DESIGN: Label-free 2-D-LC-MS proteomic analysis was used to differentially quantify tens of thousands of peptides from human plasma. We have asked whether samples collected from two sites, when analyzed by this type of peptide profiling, reproducibly contain detectable peptide markers that are differentially expressed in the plasma of disease (advanced renal cancer) patients relative to healthy normals. RESULTS: We have demonstrated that plasma proteins enriched in disease patients are indeed detected reproducibly in both clinical collections. Regression analysis, unsupervised hierarchical clustering and PCA detected no systematic bias in the data related to site of sample collection and processing. Using a genetic algorithm, support vector machine classification method, we were able to correctly classify disease samples at 88% sensitivity and 94% specificity using the second site as an independent validation set. CONCLUSIONS AND CLINICAL RELEVANCE: We conclude that multiple site collection, when analyzed by label-free 2-D-LC-MS, generates data that are sufficiently reproducible to guide reliable biomarker discovery.

Surrobodies with functional tails.

Surrobodies(2) are a unique type of binding protein based on the pre-B-cell receptor (pre-BCR). The pre-BCR is transiently expressed during development of the antibody repertoire. Unlike heterotetrameric canonical antibodies that are composed of identical pairs of heavy and light chains, the pre-BCR is a heterohexameric complex composed of identical pairs of heavy chains that are each paired with a two-subunit surrogate light chain (SLC). The SLC contains nonimmunoglobulin-like peptide extensions on each of the two SLC components. This arrangement provides unique opportunities for protein engineering by functional derivatization of these nonimmunoglobulin-like tails. Here we report recombinant fusions to these tails with either a fully active cytokine or with single-chain variable fragment (scFv) domains to generate Surrobodies with unique functions or Surrobodies that are bispecific with respect to targeted binding.

The contribution of axial fiber extensibility to the adhesion of viscous capture threads spun by orb-weaving spiders.

The viscous capture threads produced by over 4000 species of orb-weaving spiders are formed of regularly spaced aqueous droplets supported by a pair of axial fibers. These threads register increased stickiness when spans of increasing lengths contact a surface, indicating that adhesion is recruited from multiple droplets. This study examined threads produced by five species to test the hypothesis that axial fiber extensibility is crucial for this summation of adhesion. It did so by comparing the stickiness of unstretched threads with threads that had been elongated to reduce the extensibility of their axial fibers. As stretching these threads also increased the distance between their droplets, we measured the stickiness of stretched threads with contact plates whose widths were increased in proportion to the degree of thread elongation. We then accounted for the actual thread elongation achieved for each individual's threads and for differences in the five species' absolute thread extensibility. The results showed that in four species thread extensibility contributed positively to adhesion. For three species, thread extensibility and droplet volume together explained the mean per droplet adhesion of threads. Models based on these three species show that, as threads were elongated, increasing amounts of potential adhesion were lost to diminished axial fiber extensibility. These models indicate that approximately one-third of an unstretched viscous thread's stickiness accrues from the adhesive recruitment made possible by axial fiber extensibility.

Functional mapping of Bas2. Identification of activation and Bas1-interaction domains.

The transcriptional activator protein Bas2 is required to express more than 20 genes in pathways for purine nucleotide and histidine biosynthesis, phosphate utilization, and the HO endonuclease by acting with co-regulator proteins Bas1, Pho4, and Swi5. The role that Bas2 plays in transcriptional activation may be to unmask latent activation domains in the co-regulator and to promote ternary complex formation between Bas2, the co-regulator, and DNA. We show that Bas2 also contributes to transcriptional activation by providing an activation domain. We localize this domain in Bas2 to the C-terminal 156 amino acids using deletion analysis and fusion to a heterologous DNA binding domain. Additionally, we show that Bas2 makes direct contacts with Bas1. This interaction is detected by co-immunoprecipitation and by two-hybrid analysis. We localize the interaction region to the central portion of Bas2, from amino acids 112 to 404.

A receptor for the heterodimeric cytokine IL-23 is composed of IL-12Rbeta1 and a novel cytokine receptor subunit, IL-23R.

IL-23 is a heterodimeric cytokine composed of the IL-12p40 "soluble receptor" subunit and a novel cytokine-like subunit related to IL-12p35, termed p19. Human and mouse IL-23 exhibit some activities similar to IL-12, but differ in their capacities to stimulate particular populations of memory T cells. Like IL-12, IL-23 binds to the IL-12R subunit IL-12Rbeta1. However, it does not use IL-12Rbeta2. In this study, we identify a novel member of the hemopoietin receptor family as a subunit of the receptor for IL-23, "IL-23R." IL-23R pairs with IL-12Rbeta1 to confer IL-23 responsiveness on cells expressing both subunits. Human IL-23, but not IL-12, exhibits detectable affinity for human IL-23R. Anti-IL-12Rbeta1 and anti-IL-23R Abs block IL-23 responses of an NK cell line and Ba/F3 cells expressing the two receptor chains. IL-23 activates the same Jak-stat signaling molecules as IL-12: Jak2, Tyk2, and stat1, -3, -4, and -5, but stat4 activation is substantially weaker and different DNA-binding stat complexes form in response to IL-23 compared with IL-12. IL-23R associates constitutively with Jak2 and in a ligand-dependent manner with stat3. The ability of cells to respond to IL-23 or IL-12 correlates with expression of IL-23R or IL-12Rbeta2, respectively. The human IL-23R gene is on human chromosome 1 within 150 kb of IL-12Rbeta2.