Nanoencapsulation of MDM2 Inhibitor RG7388 and Class-I HDAC Inhibitor Entinostat Enhances their Therapeutic Potential Through Synergistic Antitumor Effects and Reduction of Systemic Toxicity.

Inhibitors of the p53-MDM2 interaction such as RG7388 have been developed to exploit latent tumor suppressive properties in p53 in 50% of tumors in which p53 is wild-type. However, these agents for the most part activate cell cycle arrest rather than death, and high doses in patients elicit on-target dose-limiting neutropenia. Recent work from our group indicates that combination of p53-MDM2 inhibitors with the class-I HDAC inhibitor Entinostat (which itself has dose-limiting toxicity issues) has the potential to significantly augment cell death in p53 wild-type colorectal cancer cells. We investigated whether coencapsulation of RG7388 and Entinostat within polymeric nanoparticles (NPs) could overcome efficacy and toxicity limitations of this drug combination. Combinations of RG7388 and Entinostat across a range of different molar ratios resulted in synergistic increases in cell death when delivered in both free drug and nanoencapsulated formats in all colorectal cell lines tested. Importantly, we also explored the in vivo impact of the drug combination on murine blood leukocytes, showing that the leukopenia induced by the free drugs could be significantly mitigated by nanoencapsulation. Taken together, this study demonstrates that formulating these agents within a single nanoparticle delivery platform may provide clinical utility beyond use as nonencapsulated agents.

The role of texture summary statistics in material recognition from drawings and photographs.

Material depictions in artwork are useful tools for revealing image features that support material categorization. For example, artistic recipes for drawing specific materials make explicit the critical information leading to recognizable material properties (Di Cicco, Wjintjes, & Pont, 2020) and investigating the recognizability of material renderings as a function of their visual features supports conclusions about the vocabulary of material perception. Here, we examined how the recognition of materials from photographs and drawings was affected by the application of the Portilla-Simoncelli texture synthesis model. This manipulation allowed us to examine how categorization may be affected differently across materials and image formats when only summary statistic information about appearance was retained. Further, we compared human performance to the categorization accuracy obtained from a pretrained deep convolutional neural network to determine if observers' performance was reflected in the network. Although we found some similarities between human and network performance for photographic images, the results obtained from drawings differed substantially. Our results demonstrate that texture statistics play a variable role in material categorization across rendering formats and material categories and that the human perception of material drawings is not effectively captured by deep convolutional neural networks trained for object recognition.

Dynamic Electrode-to-Image (DETI) mapping reveals the human brain's spatiotemporal code of visual information.

A number of neuroimaging techniques have been employed to understand how visual information is transformed along the visual pathway. Although each technique has spatial and temporal limitations, they can each provide important insights into the visual code. While the BOLD signal of fMRI can be quite informative, the visual code is not static and this can be obscured by fMRI's poor temporal resolution. In this study, we leveraged the high temporal resolution of EEG to develop an encoding technique based on the distribution of responses generated by a population of real-world scenes. This approach maps neural signals to each pixel within a given image and reveals location-specific transformations of the visual code, providing a spatiotemporal signature for the image at each electrode. Our analyses of the mapping results revealed that scenes undergo a series of nonuniform transformations that prioritize different spatial frequencies at different regions of scenes over time. This mapping technique offers a potential avenue for future studies to explore how dynamic feedforward and recurrent processes inform and refine high-level representations of our visual world.

Neurodevelopmental Outcome in Very Low Birth Weight Infants Exposed to Donor Milk.

OBJECTIVE: This study was aimed to evaluate the impact of donor milk (DM) received in the first 28 days of life (DOL) on neurodevelopmental (ND) outcome at 20-months corrected age (CA) in very low birth weight (VLBW) infants. STUDY DESIGN: A total of 84 infants born in 2011 to 2012 who received only mother's own milk (MOM) and/or preterm formula (PF) was compared with 69 infants born in 2013 to 2014 who received MOM and/or DM. Daily enteral intake of MOM, DM, and PF was collected through 28 DOL. ND outcomes were assessed with the Bayley-III. Multiple regression analyses adjusted for the effect of social and neonatal risk factors alongside era of birth on ND outcome. RESULTS: Infants exposed to DM were born to older mothers (p < 0.01) and had higher incidence of severe brain injury (p = 0.013). Although DM group infants received first feed at earlier DOL (p < 0.001), there were no differences in MOM intake at DOL 14 or 28 between the two groups. In regression analyses, DM group did not predict 20-month ND outcome. CONCLUSION: There were no differences in ND outcome between infants born before and after the introduction of DM. This may have been due to the similar percent of MOM at DOL 14 and 28 in the two eras. KEY POINTS: · Donor milk use is increasing in VLBW infant. The impact of donor milk on neurodevelopment is unclear.. · Provision of mother's own milk was high at days of life 14 and 28 for both groups of infants.. · Donor milk was not associated with improved neurodevelopmental outcome..

Disentangling the Independent Contributions of Visual and Conceptual Features to the Spatiotemporal Dynamics of Scene Categorization.

Human scene categorization is characterized by its remarkable speed. While many visual and conceptual features have been linked to this ability, significant correlations exist between feature spaces, impeding our ability to determine their relative contributions to scene categorization. Here, we used a whitening transformation to decorrelate a variety of visual and conceptual features and assess the time course of their unique contributions to scene categorization. Participants (both sexes) viewed 2250 full-color scene images drawn from 30 different scene categories while having their brain activity measured through 256-channel EEG. We examined the variance explained at each electrode and time point of visual event-related potential (vERP) data from nine different whitened encoding models. These ranged from low-level features obtained from filter outputs to high-level conceptual features requiring human annotation. The amount of category information in the vERPs was assessed through multivariate decoding methods. Behavioral similarity measures were obtained in separate crowdsourced experiments. We found that all nine models together contributed 78% of the variance of human scene similarity assessments and were within the noise ceiling of the vERP data. Low-level models explained earlier vERP variability (88 ms after image onset), whereas high-level models explained later variance (169 ms). Critically, only high-level models shared vERP variability with behavior. Together, these results suggest that scene categorization is primarily a high-level process, but reliant on previously extracted low-level features.SIGNIFICANCE STATEMENT In a single fixation, we glean enough information to describe a general scene category. Many types of features are associated with scene categories, ranging from low-level properties, such as colors and contours, to high-level properties, such as objects and attributes. Because these properties are correlated, it is difficult to understand each property's unique contributions to scene categorization. This work uses a whitening transformation to remove the correlations between features and examines the extent to which each feature contributes to visual event-related potentials over time. We found that low-level visual features contributed first but were not correlated with categorization behavior. High-level features followed 80 ms later, providing key insights into how the brain makes sense of a complex visual world.

Controlled coupling of an ultrapotent auristatin warhead to cetuximab yields a next-generation antibody-drug conjugate for EGFR-targeted therapy of KRAS mutant pancreatic cancer.

BACKGROUND: Antibody-drug conjugate (ADC) construction poses numerous challenges that limit clinical progress. In particular, common bioconjugation methods afford minimal control over the site of drug coupling to antibodies. Here, such difficulties are overcome through re-bridging of the inter-chain disulfides of cetuximab (CTX) with auristatin-bearing pyridazinediones, to yield a highly refined anti-epidermal growth factor receptor (EGFR) ADC. METHODS: In vitro and in vivo assessment of ADC activity was performed in KRAS mutant pancreatic cancer (PaCa) models with known resistance to CTX therapy. Computational modelling was employed for quantitative prediction of tumour response to various ADC dosing regimens. RESULTS: Site-selective coupling of an auristatin to CTX yielded an ADC with an average drug:antibody ratio (DAR) of 3.9, which elicited concentration- and EGFR-dependent cytotoxicity at sub-nanomolar potency in vitro. In human xenografts, the ADC inhibited tumour growth and prolonged survival, with no overt signs of toxicity. Key insights into factors governing ADC efficacy were obtained through a robust mathematical framework, including target-mediated dispositional effects relating to antigen density on tumour cells. CONCLUSIONS: Together, our findings offer renewed hope for CTX in PaCa therapy, demonstrating that it may be reformatted as a next-generation ADC and combined with a predictive modelling tool to guide successful translation.

Adaptation and Acceptability of a Digitally Delivered Intervention for Parents of Very Low Birth Weight Infants.

BACKGROUND: Very low birth weight (VLBW) infants are at elevated risk for behavioral problems as early as the second year of life. The purpose of this feasibility study was to evaluate the adaptation and acceptability of an existing digitally delivered behavioral parent training program-the ezParent program, with the addition of weekly coaching calls-for parents of former VLBW infants in their second year of life. OBJECTIVES: To assess the adaptation of ezParent for this population, we assessed parent access and use of ezParent and coaching calls, parent learning of strategies from ezParent, and changes in parenting practices or child behavior after using ezParent plus coaching calls. For acceptability, we assessed if parents viewed ezParent content as applicable to their experiences of parenting a former VLBW infant and how parents viewed coaching calls. METHODS: Ten parents of VLBW infants (20 months of age adjusted for prematurity) were recruited from a neonatal intensive care follow-up clinic. Parents completed the six modules of ezParent plus weekly coaching calls over 10-week intervention period. ezParent usage data were electronically uploaded to secure servers. Completion and timing of coaching calls were monitored using a tracking log. Parents completed child behavior and parenting belief and practice questionnaires pre- and postintervention. Calls were recorded and transcribed to assess for learning of parenting strategies, acceptability with the VLBW population, and acceptability of coaching calls. RESULTS: On average, parents completed 85% of the ezParent modules and 89% of the scheduled coaching calls, respectively. Parents spontaneously introduced 44% of the ezParent strategies during their coaching calls. Modest within-group effect sizes were detected for improvement in parenting self-efficacy and child externalizing behavior. Parents felt the ezParent content applied to their experiences parenting a preterm infant and had high satisfaction with coaching calls as a method of reinforcing program content and assessing knowledge and supporting accountability for program participation. DISCUSSION: ezParent with coaching calls is a feasible method of delivering behavioral parent training to parents of former VLBW infants in their second year of life. Coaching calls have high potential to be a low-cost, time-efficient component of digitally delivered programs that would allow for rapid integration into clinical practice.

Towards a state-space geometry of neural responses to natural scenes: A steady-state approach.

Our understanding of information processing by the mammalian visual system has come through a variety of techniques ranging from psychophysics and fMRI to single unit recording and EEG. Each technique provides unique insights into the processing framework of the early visual system. Here, we focus on the nature of the information that is carried by steady state visual evoked potentials (SSVEPs). To study the information provided by SSVEPs, we presented human participants with a population of natural scenes and measured the relative SSVEP response. Rather than focus on particular features of this signal, we focused on the full state-space of possible responses and investigated how the evoked responses are mapped onto this space. Our results show that it is possible to map the relatively high-dimensional signal carried by SSVEPs onto a 2-dimensional space with little loss. We also show that a simple biologically plausible model can account for a high proportion of the explainable variance (~73%) in that space. Finally, we describe a technique for measuring the mutual information that is available about images from SSVEPs. The techniques introduced here represent a new approach to understanding the nature of the information carried by SSVEPs. Crucially, this approach is general and can provide a means of comparing results across different neural recording methods. Altogether, our study sheds light on the encoding principles of early vision and provides a much needed reference point for understanding subsequent transformations of the early visual response space to deeper knowledge structures that link different visual environments.

Shared spatiotemporal category representations in biological and artificial deep neural networks.

Visual scene category representations emerge very rapidly, yet the computational transformations that enable such invariant categorizations remain elusive. Deep convolutional neural networks (CNNs) perform visual categorization at near human-level accuracy using a feedforward architecture, providing neuroscientists with the opportunity to assess one successful series of representational transformations that enable categorization in silico. The goal of the current study is to assess the extent to which sequential scene category representations built by a CNN map onto those built in the human brain as assessed by high-density, time-resolved event-related potentials (ERPs). We found correspondence both over time and across the scalp: earlier (0-200 ms) ERP activity was best explained by early CNN layers at all electrodes. Although later activity at most electrode sites corresponded to earlier CNN layers, activity in right occipito-temporal electrodes was best explained by the later, fully-connected layers of the CNN around 225 ms post-stimulus, along with similar patterns in frontal electrodes. Taken together, these results suggest that the emergence of scene category representations develop through a dynamic interplay between early activity over occipital electrodes as well as later activity over temporal and frontal electrodes.

Health Care Utilization after NICU Discharge and Neurodevelopmental Outcome in the First 2 Years of Life in Preterm Infants.

OBJECTIVE: The objective of this study was to determine predictors of health care utilization and its association with neurodevelopmental outcome in a recent cohort of preterm infants. STUDY DESIGN: A total of 405 infants (born 2008-2011) seen in neonatal intensive care unit (NICU) follow-up were compared for use of hospitalizations (hosps), emergency room (ER), subspecialties (SS), and results of the Bayley-III. High rate of use was defined as having >1 hosp, ER, or SS. Multiple regression adjusted for the effect of risk factors on high health care use. RESULTS: High hosp rate was associated with public health insurance (PHI; p = 0.021), severely abnormal head ultrasound (SAHUS; p = 0.04) at 1 year, and PHI (p = 0.011), younger gestational age (GA) (p = 0.029) at 2 years. High ER use was associated with PHI, younger GA at 1 year (p = 0.007 and 0.012) and 2 years (p = 0.010 and 0.005). High SS was associated with NICU morbidities including small for GA (p = 0.005), retinopathy of prematurity (p = 0.001), necrotizing enterocolitis (p = 0.03), and SAHUS (p = 0.045). At 20 months, infants with high hosp and SS had higher rates of cerebral palsy and significantly lower mean cognitive, language, and motor scores. CONCLUSION: Health care utilization is high among preterm infants in recent years and significantly associated with worse neurodevelopmental outcome. Further research is needed to determine if health care utilization after NICU discharge is an independent predictor of poor outcome.

Typicality sharpens category representations in object-selective cortex.

The purpose of categorization is to identify generalizable classes of objects whose members can be treated equivalently. Within a category, however, some exemplars are more representative of that concept than others. Despite long-standing behavioral effects, little is known about how typicality influences the neural representation of real-world objects from the same category. Using fMRI, we showed participants 64 subordinate object categories (exemplars) grouped into 8 basic categories. Typicality for each exemplar was assessed behaviorally and we used several multi-voxel pattern analyses to characterize how typicality affects the pattern of responses elicited in early visual and object-selective areas: V1, V2, V3v, hV4, LOC. We found that in LOC, but not in early areas, typical exemplars elicited activity more similar to the central category tendency and created sharper category boundaries than less typical exemplars, suggesting that typicality enhances within-category similarity and between-category dissimilarity. Additionally, we uncovered a brain region (cIPL) where category boundaries favor less typical categories. Our results suggest that typicality may constitute a previously unexplored principle of organization for intra-category neural structure and, furthermore, that this representation is not directly reflected in image features describing natural input, but rather built by the visual system at an intermediate processing stage.

Maternal Education Level Predicts Cognitive, Language, and Motor Outcome in Preterm Infants in the Second Year of Life.

Objective To evaluate the relative impact of maternal education level (MEL) on cognitive, language, and motor outcomes at 20 months' corrected age (CA) in preterm infants. Study Design A total of 177 preterm infants born between 2008 and 2010 were tested at 20 months' CA using the Bayley Scales of Infant and Toddler Development-III. Multiple regression analyses were done to determine the relative impact of MEL on cognitive, language, and motor scores. Results Infants born to mothers with high school MEL were 3.74 times more likely to have a subnormal motor index, while those born to mothers with some college and graduate school MEL had reduced odds (0.36 and 0.12, respectively) of having subnormal language index at 20 months. In linear regression, MEL was the strongest predictor of cognitive, language, and motor scores, and graduate school MEL was associated with increases in cognitive, motor, and language scores of 8.49, 8.23, and 15.74 points, respectively. Conclusions MEL is the most significant predictor of cognitive, language, and motor outcome at 20 months' CA in preterm infants. Further research is needed to evaluate if targeted interventions that focus on early childhood learning and parenting practices can ameliorate the impact of low MEL.

Effective signaling of surface boundaries by L-vertices reflect the consistency of their contrast in natural images.

An L-vertex, the point at which two contours coterminate, provides highly reliable evidence that a surface terminates at that vertex, thus providing the strongest constraint on the extraction of shape from images (Guzman, 1968). Such vertices are pervasive in our visual world but the importance of a statistical regularity about them has been underappreciated: The contours defining the vertex are (almost) always of the same direction of contrast with respect to the background (i.e., both darker or both lighter). Here we show that when the two contours are of different directions of contrast, the capacity of the L-vertex to signal the termination of a surface, as reflected in object recognition, is markedly reduced. Although image statistics have been implicated in determining the connectivity in the earliest cortical visual stage (V1) and in grouping during visual search, this finding provides evidence that such statistics are involved in later stages where object representations are derived from two-dimensional images.

Basic level category structure emerges gradually across human ventral visual cortex.

Objects can be simultaneously categorized at multiple levels of specificity ranging from very broad ("natural object") to very distinct ("Mr. Woof"), with a mid-level of generality (basic level: "dog") often providing the most cognitively useful distinction between categories. It is unknown, however, how this hierarchical representation is achieved in the brain. Using multivoxel pattern analyses, we examined how well each taxonomic level (superordinate, basic, and subordinate) of real-world object categories is represented across occipitotemporal cortex. We found that, although in early visual cortex objects are best represented at the subordinate level (an effect mostly driven by low-level feature overlap between objects in the same category), this advantage diminishes compared to the basic level as we move up the visual hierarchy, disappearing in object-selective regions of occipitotemporal cortex. This pattern stems from a combined increase in within-category similarity (category cohesion) and between-category dissimilarity (category distinctiveness) of neural activity patterns at the basic level, relative to both subordinate and superordinate levels, suggesting that successive visual areas may be optimizing basic level representations.

A novel RCE1 isoform is required for H-Ras plasma membrane localization and is regulated by USP17.

Processing of the 'CaaX' motif found on the C-termini of many proteins, including the proto-oncogene Ras, requires the ER (endoplasmic reticulum)-resident protease RCE1 (Ras-converting enzyme 1) and is necessary for the proper localization and function of many of these 'CaaX' proteins. In the present paper, we report that several mammalian species have a novel isoform (isoform 2) of RCE1 resulting from an alternate splice site and producing an N-terminally truncated protein. We demonstrate that both RCE1 isoform 1 and the newly identified isoform 2 are required to reinstate proper H-Ras processing and thus plasma membrane localization in RCE1-null cells. In addition, we show that the deubiquitinating enzyme USP17 (ubiquitin-specific protease 17), previously shown to modulate RCE1 activity, can regulate the abundance and localization of isoform 2. Furthermore, we show that isoform 2 is ubiquitinated on Lys43 and deubiquitinated by USP17. Collectively, the findings of the present study indicate that RCE1 isoform 2 is required for proper 'CaaX' processing and that USP17 can regulate this via its modulation of RCE1 isoform 2 ubiquitination.

Maternal psychological distress and visitation to the neonatal intensive care unit.

AIM: To examine associations between maternal neonatal intensive care unit (NICU) visitation rates, maternal psychological distress ('distress') and preterm infant outcome post-NICU discharge in a contemporary cohort of very low birthweight (VLBW) infants. METHODS: This was a prospective study of 69 mothers and their VLBW infants. Distress was assessed 1-month postbirth, 2 weeks prior to NICU discharge and after NICU discharge at 4-month corrected age (CA). Maternal NICU visitation rates were calculated for the first 2 weeks and 1-month postbirth as well as for the entire NICU hospitalization. Regression analyses adjusted for the impact of (i) maternal and infant characteristics and distress on maternal visitation rates and (ii) the impact of visitation on long-term maternal distress and rates of infant clinic attendance and rehospitalization. RESULTS: Greater number of children in the home, maternal exposure to a greater number of potentially traumatic events prior to childbirth and lower maternal anxiety consistently predicted lower visitation rate. Lower maternal visitation rate predicted higher maternal depression scores at infants' 4-month CA visit. Maternal NICU visitation rate did not predict post-NICU discharge infant clinic attendance or rehospitalization. CONCLUSION: Distress is an important predictor of visitation. In turn, visitation is associated with long-term maternal distress.

Visual categorization is automatic and obligatory: evidence from Stroop-like paradigm.

Human observers categorize visual stimuli with remarkable efficiency--a result that has led to the suggestion that object and scene categorization may be automatic processes. We tested this hypothesis by presenting observers with a modified Stroop paradigm in which object or scene words were presented over images of objects or scenes. Terms were either congruent or incongruent with the images. Observers classified the words as being object or scene terms while ignoring images. Classifying a word on an incongruent image came at a cost for both objects and scenes. Furthermore, automatic processing was observed for entry-level scene categories, but not superordinate-level categories, suggesting that not all rapid categorizations are automatic. Taken together, we have demonstrated that entry-level visual categorization is an automatic and obligatory process.

Impact of the COVID-19 pandemic on early intervention utilization and need for referral after NICU discharge in VLBW infants.

OBJECTIVE: To examine the impact of COVID-19 pandemic on early intervention (EI) services in VLBW infants. STUDY DESIGN: 208 VLBW infants seen in NICU follow-up (FU) pre-COVID-19 were compared to 132 infants seen during COVID-19 at 4, 8 and 20 months corrected age (CA) in terms of enrollment in Child and Family Connections (CFC; intake agency for EI), EI therapies, need for CFC referral and Bayley scores. RESULTS: Infants seen during COVID-19 at 4, 8 and 20 months CA were 3.4 (OR, 95% CI 1.64, 6.98), 4.0 (1.77, 8.95) and 4.8 (2.10, 11.08) times more likely to need CFC referral at FU based on severity of developmental delay. Infants followed during COVID-19 had significantly lower mean Bayley cognitive and language scores at 20 months CA. CONCLUSIONS: VLBW infants seen during COVID-19 had significantly higher odds of needing EI and significantly lower cognitive and language scores at 20 months CA.

Dual-Hit Strategy for Therapeutic Targeting of Pancreatic Cancer in Patient-Derived Xenograft Tumors.

PURPOSE: Paracrine activation of pro-fibrotic hedgehog (HH) signaling in pancreatic ductal adenocarcinoma (PDAC) results in stromal amplification that compromises tumor drug delivery, efficacy, and patient survival. Interdiction of HH-mediated tumor-stroma crosstalk with smoothened (SMO) inhibitors (SHHi) "primes" PDAC patient-derived xenograft (PDX) tumors for increased drug delivery by transiently increasing vascular patency/permeability, and thereby macromolecule delivery. However, patient tumor isolates vary in their responsiveness, and responders show co-induction of epithelial-mesenchymal transition (EMT). We aimed to identify the signal derangements responsible for EMT induction and reverse them and devise approaches to stratify SHHi-responsive tumors noninvasively based on clinically-quantifiable parameters. EXPERIMENTAL DESIGN: Animals underwent diffusion-weighted magnetic resonance (DW-MR) imaging for measurement of intratumor diffusivity. In parallel, tissue-level deposition of nanoparticle probes was quantified as a marker of vascular permeability/perfusion. Transcriptomic and bioinformatic analysis was employed to investigate SHHi-induced gene reprogramming and identify key "nodes" responsible for EMT induction. RESULTS: Multiple patient tumor isolates responded to short-term SHH inhibitor exposure with increased vascular patency and permeability, with proportionate increases in tumor diffusivity. Nonresponding PDXs did not. SHHi-treated tumors showed elevated FGF drive and distinctly higher nuclear localization of fibroblast growth factor receptor (FGFR1) in EMT-polarized tumor cells. Pan-FGFR inhibitor NVP-BGJ398 (Infigratinib) reversed the SHHi-induced EMT marker expression and nuclear FGFR1 accumulation without compromising the enhanced permeability effect. CONCLUSIONS: This dual-hit strategy of SMO and FGFR inhibition provides a clinically-translatable approach to compromise the profound impermeability of PDAC tumors. Furthermore, clinical deployment of DW-MR imaging could fulfill the essential clinical-translational requirement for patient stratification.