Identification of broad, potent antibodies to functionally constrained regions of SARS-CoV-2 spike following a breakthrough infection.

The antiviral benefit of antibodies can be compromised by viral escape especially for rapidly evolving viruses. Therefore, durable, effective antibodies must be both broad and potent to counter newly emerging, diverse strains. Discovery of such antibodies is critically important for SARS-CoV-2 as the global emergence of new variants of concern (VOC) has compromised the efficacy of therapeutic antibodies and vaccines. We describe a collection of broad and potent neutralizing monoclonal antibodies (mAbs) isolated from an individual who experienced a breakthrough infection with the Delta VOC. Four mAbs potently neutralize the Wuhan-Hu-1 vaccine strain, the Delta VOC, and also retain potency against the Omicron VOCs through BA.4/BA.5 in both pseudovirus-based and authentic virus assays. Three mAbs also retain potency to recently circulating VOCs XBB.1.5 and BQ.1.1 and one also potently neutralizes SARS-CoV-1. The potency of these mAbs was greater against Omicron VOCs than all but one of the mAbs that had been approved for therapeutic applications. The mAbs target distinct epitopes on the spike glycoprotein, three in the receptor-binding domain (RBD) and one in an invariant region downstream of the RBD in subdomain 1 (SD1). The escape pathways we defined at single amino acid resolution with deep mutational scanning show they target conserved, functionally constrained regions of the glycoprotein, suggesting escape could incur a fitness cost. Overall, these mAbs are unique in their breadth across VOCs, their epitope specificity, and include a highly potent mAb targeting a rare epitope outside of the RBD in SD1.

Mitochondrial sequencing identifies long noncoding RNA features that promote binding to PNPase.

Extranuclear localization of long noncoding RNAs (lncRNAs) is poorly understood. Based on machine learning evaluations, we propose a lncRNA-mitochondrial interaction pathway where polynucleotide phosphorylase (PNPase), through domains that provide specificity for primary sequence and secondary structure, binds nuclear-encoded lncRNAs to facilitate mitochondrial import. Using FVB/NJ mouse and human cardiac tissues, RNA from isolated subcellular compartments (cytoplasmic and mitochondrial) and cross-linked immunoprecipitate (CLIP) with PNPase within the mitochondrion were sequenced on the Illumina HiSeq and MiSeq, respectively. lncRNA sequence and structure were evaluated through supervised [classification and regression trees (CART) and support vector machines (SVM)] machine learning algorithms. In HL-1 cells, quantitative PCR of PNPase CLIP knockout mutants (KH and S1) was performed. In vitro fluorescence assays assessed PNPase RNA binding capacity and verified with PNPase CLIP. One hundred twelve (mouse) and 1,548 (human) lncRNAs were identified in the mitochondrion with Malat1 being the most abundant. Most noncoding RNAs binding PNPase were lncRNAs, including Malat1. lncRNA fragments bound to PNPase compared against randomly generated sequences of similar length showed stratification with SVM and CART algorithms. The lncRNAs bound to PNPase were used to create a criterion for binding, with experimental validation revealing increased binding affinity of RNA designed to bind PNPase compared to control RNA. The binding of lncRNAs to PNPase was decreased through the knockout of RNA binding domains KH and S1. In conclusion, sequence and secondary structural features identified by machine learning enhance the likelihood of nuclear-encoded lncRNAs binding to PNPase and undergoing import into the mitochondrion.NEW & NOTEWORTHY Long noncoding RNAs (lncRNAs) are relatively novel RNAs with increasingly prominent roles in regulating genetic expression, mainly in the nucleus but more recently in regions such as the mitochondrion. This study explores how lncRNAs interact with polynucleotide phosphorylase (PNPase), a protein that regulates RNA import into the mitochondrion. Machine learning identified several RNA structural features that improved lncRNA binding to PNPase, which may be useful in targeting RNA therapeutics to the mitochondrion.

Math talk by mothers, fathers, and toddlers: Differences across materials and associations with children's math understanding.

Learning words for numbers, shapes, spatial relations, and magnitudes-"math talk"-relies on input from caregivers. Language interactions between caregivers and children are situated in activity contexts and likely affected by available materials. Here, we examined how play materials influence the math talk directed to and produced by young children. We video-recorded parents (mothers and fathers; English- and/or Spanish-speaking) and their 24- to 36-month-olds during play with four sets of materials, transcribed and coded types of parent and toddler math words/phrases, and assessed toddlers' understanding of number, shape, and spatial relations terms. Categories of math words varied by materials. Numeracy talk (e.g., "one," "two," "first," "second") was more frequent during interactions with a picture book and toy grocery shopping set than with a shape sorter or magnet board; the reverse held for spatial talk (e.g., "out," "bottom," "up," "circle"). Parent math talk predicted toddler math talk, and both parent and toddler math talk predicted toddlers' understanding of spatial and number words. Different materials provide unique opportunities for toddlers to learn abstract math words during interactions with caregivers, and such interactions support early math cognition.

The Variation of Withdrawal of Life Sustaining Therapy in Older Adults With Traumatic Brain Injury.

INTRODUCTION: The decision to withdraw life sustaining treatment (WDLST) in older adults with traumatic brain injury is subject to wide variability leading to nonbeneficial interventions and unnecessary use of hospital resources. We hypothesized that patient and hospital factors are associated with WDLST and WDLST timing. METHODS: All traumatic brain injury patients ≥65 with Glasgow coma scores (GCS) of 4-11 from 2018 to 2019 at level I and II centers were selected from the National Trauma Data Bank. Patients with head abbreviated injury scores 5-6 or death within 24 h were excluded. Bayesian additive regression tree analysis was performed to identify the cumulative incidence function (CIF) and the relative risks (RR) over time for withdrawal of care, discharge to hospice (DH), and death. Death alone (no WDLST or DH) served as the comparator group for all analyses. A subanalysis of the composite outcome WDLST/DH (defined as end-of-life-care), with death (no WDLST or DH) as a comparator cohort was performed. RESULTS: We included 2126 patients, of whom 1957 (57%) underwent WDLST, 402 (19%) died, and 469 (22%) were DH. 60% of patients were male, and the mean age was 80 y. The majority of patients were injured by fall (76%, n = 1644). Patients who were DH were more often female (51% DH versus 39% WDLST), had a past medical history of dementia (45% DH versus 18% WDLST), and had lower admission injury severity score (14 DH versus 18.6 WDLST) (P < 0.001). Compared to those who DH, those who underwent WDLST had a lower GCS (9.8 versus 8.4, P < 0.001). CIF of WDSLT and DH increased with age, stabilizing by day 3. At day 3, patients ≥90 y had an increased RR of DH compared to WDLST (RR 2.5 versus 1.4). As GCS increased, CIF and RR of WDLST decreased, while CIF and RR of DH increased (RR on day 3 for GCS 12: WDLST 0.42 versus DH 1.31).Patients at nonprofit institutions were more likely to undergo WDLST (RR 1.15) compared to DH (0.68). Compared to patients of White race, patients of Black race had a lower RR of WDLST at all timepoints. CONCLUSIONS: Patient and hospital factors influence the practice of end-of-life-care (WDLST, DH, and death), highlighting the need to better understand variability to target palliative care interventions and standardize care across populations and trauma centers.

Socioeconomic deprivation status predicts both the incidence and nature of Achilles tendon rupture.

PURPOSE: The aim of this study was to describe the epidemiology of Achilles tendon rupture (ATR) and its relationship with socioeconomic deprivation status (SEDS). The hypothesis was that ATR occurs more frequently in socioeconomically deprived patients. Secondary aims were to determine variations in circumstances of injury between more and less deprived patients. METHODS: A 6-year retrospective review of consecutive patients presenting with ATR was undertaken. The health-board population was defined using governmental population data and SEDS was defined using the Scottish Index of Multiple Deprivation. The primary outcome was an epidemiological description and comparison of incidence in more and less deprived cohorts. Secondary outcomes included reporting of the relationship between SEDS and patient and injury characteristics with univariate and binary logistic regression analyses. RESULTS: There were 783 patients (567 male; 216 female) with ATR. Mean incidence for adults (≥ 18 years) was 18.75/100,000 per year (range 16.56-23.57) and for all ages was 15.26/100,000 per year (range 13.51 to 19.07). Incidence in the least deprived population quintiles (4th and 5th quintiles; 18.07 per 100,000/year) was higher than that in the most deprived quintiles (1st and 2nd; 11.32/100,000 per year; OR 1.60, 95%CI 1.35-1.89; p < 0.001). When adjusting for confounding factors, least deprived patients were more likely to be > 50 years old (OR 1.97; 95%CI 1.24-3.12; p = 0.004), to sustain ATR playing sports (OR 1.72, 95%CI 1.11-2.67; p = 0.02) and in the spring (OR 1.65, 95%CI 1.01-2.70; p = 0.045) and to give a history of preceding tendinitis (OR 4.04, 95%CI 1.49-10.95; p = 0.006). They were less likely to sustain low-energy injuries (OR 0.44, 95%CI 0.23-0.87; p = 0.02) and to be obese (OR 0.25-0.41, 95%CI 0.07-0.90; p ≤ 0.03). CONCLUSIONS: The incidence of ATR was higher in less socioeconomically deprived populations and the hypothesis was therefore rejected. Significant variations in patient and predisposing factors, mechanisms of injury and seasonality were demonstrated between most and least deprived groups, suggesting that circumstances and nature of ATR may vary with SEDS and these are not a homogenous group of injuries. LEVEL OF EVIDENCE: Prognostic Study Level III.

The epidemiology of Achilles tendon re-rupture and associated risk factors: male gender, younger age and traditional immobilising rehabilitation are risk factors.

PURPOSE: The aim of this study was to describe the epidemiology of Achilles tendon re-rupture. Secondary aims were to identify factors predisposing to increased Achilles tendon re-rupture risk, at the time of primary Achilles tendon rupture. METHODS: A retrospective review of all patients with primary Achilles tendon rupture and Achilles tendon re-rupture was undertaken. Two separate databases were compiled: the first included all Achilles tendon re-ruptures presenting during the study period and described epidemiology, mechanisms and nature of the re-rupture; the second was a case-control study analysing differences between patients with primary Achilles tendon rupture during the study period, who did, or did not, go on to develop re-rupture, with minimum review period of 1.5 years. RESULTS: Seven hundred and eighty-three patients (567 males, 216 females) attended with primary Achilles tendon rupture and 48 patients (41 males, 7 females) with Achilles tendon re-rupture. Median time to re-rupture was 98.5 days (IQR 82-122.5), but 8/48 re-ruptures occurred late (range 3 to 50 years) after primary Achilles tendon rupture. Males were affected more commonly (OR = 7.40, 95% CI 0.91-60.15; p = 0.034). Mean Achilles tendon re-rupture incidence was 0.94/100,000/year for all ages and 1.16/100,000/year for adults (≥ 18 years). Age distribution was bimodal for both primary Achilles tendon rupture and re-rupture, peaking in the fifth decade, with secondary peaks in older age. Incidence of re-rupture was higher in less socioeconomically deprived sub-populations (OR = 2.01, 95%CI 1.01-3.97, p = 0.04). The majority of re-ruptures were low-energy injuries. Greater risk of re-rupture was noted for patients with primary rupture aged < 45 years [adjusted odds ratio (aOR) 1.96; p = 0.037] and those treated with traditional cast immobilisation (aOR 2.20; p = 0.050). CONCLUSION: The epidemiology of Achilles tendon re-rupture is described and known trends (e.g. male predilection) are confirmed, while other novel findings are described, including incidence of a small but significant number of late re-ruptures, occurring years after the primary injury and an increased incidence of re-rupture in less socioeconomically deprived patients. Younger age and traditional immobilising cast treatment of primary Achilles tendon rupture were independently associated with Achilles tendon re-rupture. LEVEL OF EVIDENCE: III.

Cognitive appraisal in fish: stressor predictability modulates the physiological and neurobehavioural stress response in sea bass.

The role of cognitive factors in triggering the stress response is well established in humans and mammals (aka cognitive appraisal theory) but very seldom studied in other vertebrate taxa. Predictability is a key factor of the cognitive evaluation of stimuli. In this study, we tested the effects of stressor predictability on behavioral, physiological and neuromolecular responses in the European sea bass (Dicentrarchus labrax). Groups of four fish were exposed to a predictable (signalled) or unpredictable (unsignalled) stressor. Stressor predictability elicited a lower behavioural response and reduced cortisol levels. Using the expression of immediate early genes (c-fos, egr-1, bdnf and npas4) as markers of neuronal activity, we monitored the activity of three sea bass brain regions known to be implicated in stressor appraisal: the dorsomedian telencephalon, Dm (putative homologue of the pallial amygdala); and the dorsal (Dld) and ventral (Dlv) subareas of the dorsolateral telencephalon (putative homologue of the hippocampus). The activity of both the Dm and Dlv significantly responded to stressor predictability, suggesting an evolutionarily conserved role of these two brain regions in information processing related to stressor appraisal. These results indicate that stressor predictability plays a key role in the activation of the stress response in a teleost fish, hence highlighting the role of cognitive processes in fish stress.

Comparative analysis of lung and blood transcriptomes in mice exposed to multi-walled carbon nanotubes.

Pulmonary exposure to multi-walled carbon nanotubes (MWCNT) causes inflammation, fibroproliferation, immunotoxicity, and systemic responses in rodents. However, the search for representative biomarkers of exposure is an ongoing endeavor. Whole blood gene expression profiling is a promising new approach for the identification of novel disease biomarkers. We asked if the whole blood transcriptome reflects pathology-specific changes in lung gene expression caused by MWCNT. To answer this question, we performed mRNA sequencing analysis of the whole blood and lung in mice administered MWCNT or vehicle solution via pharyngeal aspiration and sacrificed 56 days later. The pattern of lung mRNA expression as determined using Ingenuity Pathway Analysis (IPA) was indicative of continued inflammation, immune cell trafficking, phagocytosis, and adaptive immune responses. Simultaneously, innate immunity-related transcripts (Plunc, Bpifb1, Reg3g) and cancer-related pathways were downregulated. IPA analysis of the differentially expressed genes in the whole blood suggested increased hematopoiesis, predicted activation of cancer/tumor development pathways, and atopy. There were several common upregulated genes between whole blood and lungs, important for adaptive immune responses: Cxcr1, Cd72, Sharpin, and Slc11a1. Trim24, important for TH2 cell effector function, was downregulated in both datasets. Hla-dqa1 mRNA was upregulated in the lungs and downregulated in the blood, as was Lilrb4, which controls the reactivity of immune response. "Cancer" disease category had opposing activation status in the two datasets, while the only commonality was "Hypersensitivity". Transcriptome changes occurring in the lungs did not produce a completely replicable pattern in whole blood; however, specific systemic responses may be shared between transcriptomic profiles.

Hippocampal and parahippocampal volumes vary by sex and traumatic life events in children

Background: Childhood trauma is reliably associated with smaller hippocampal volume in adults; however, this finding has not been shown in children, and even less is known about how sex and trauma interact to affect limbic structural development in children. Methods: Typically developing children aged 9 to 15 years who completed a trauma history questionnaire and structural T1-weighted MRI were included in this study (n = 172; 85 female, 87 male). All children who reported 4 or more traumas (n = 36) composed the high trauma group, and all children who reported 3 or fewer traumas (n = 136) composed the low trauma group. Using multivariate analysis of covariance, we compared FreeSurfer-derived structural MRI volumes (normalized by total intracranial volume) of the amygdalar, hippocampal and parahippocampal regions by sex and trauma level, controlling for age and study site. Results: We found a significant sex × trauma interaction, such that girls with high trauma had greater volumes than boys with high trauma. Follow-up analyses indicated significantly increased volumes for girls and generally decreased volumes for boys, specifically in the hippocampal and parahippocampalregions for the high trauma group; we observed no sex differences in the low trauma group. We noted no interaction effect for the amygdalae. Limitations: We assessed a community sample and did not include a clinical sample. We did not collect data about the ages at which children experienced trauma. Conclusion: Results revealed that psychological trauma affects brain development differently in girls and boys. These findings need to be followed longitudinally to elucidate how structural differences progress and contribute to well-known sex disparities in psychopathology.

Attention bias variability and posttraumatic stress symptoms: the mediating role of emotion regulation difficulties.

Growing literature has linked attention bias variability (ABV) to the experience and treatment of posttraumatic stress disorder (PTSD). Unlike assessments of attention bias in only one direction, ABV captures dynamic fluctuations in attention toward and away from threat. While mechanisms underlying the ABV-PTSD relations are unclear, some research implicates emotion regulation difficulties. The current study examined in community women with varying PTSD symptom severity, the amount of variance in the association between ABV and PTSD accounted for by emotion regulation difficulties. The full sample (N = 74) was comprised of 59% community women with PTSD due to domestic and/or sexual violence, and 41% community women without PTSD. All participants completed self-report questionnaires including the Difficulties in Emotion Regulation Scale-16, which assessed emotion regulation. ABV was calculated following a computerised dot probe task. The indirect effect of ABV on PTSD symptom severity through emotion regulation difficulties was statistically significant, while the direct effect between ABV and PTSD symptom severity was not significant. Findings replicated after controlling for total trauma exposure. Clinical implications and literature suggesting how ABV may perpetuate emotion regulation difficulties associated with PTSD symptomology are discussed.

The developmental trajectory of sensorimotor cortical oscillations.

Numerous studies of motor control have confirmed beta and gamma oscillations in the primary motor cortices during basic movements. These responses include a robust beta decrease that precedes and extends through movement onset, a transient gamma response that coincides with the movement, and a post-movement beta rebound (PMBR) response that occurs after movement offset. While the existence of these responses has been confirmed by many studies, very few studies have examined their developmental trajectory. In the current study, we utilized magnetoencephalography (MEG) to investigate age-related changes in sensorimotor cortical oscillations in a large cross-section of children and adolescents (n = 94; age range = 9 -15 years-old). All participants performed a stimulus detection task with their right finger and the resulting MEG data were examined using oscillatory analysis methods and imaged using a beamformer. Consistent with adult studies, these youth participants exhibited characteristic beta (16-24 Hz) decreases prior to and during movement, as well as PMBR responses following movement offset, and a transient gamma (74-84 Hz) response during movement execution. Our primary findings were that the strength of the PMBR increased with age, while the strength of the gamma synchronization decreased with chronological age. In addition, the strength of each motor-related oscillatory response was significantly correlated with the power of spontaneous activity in the same frequency range and same voxel. This was the case for all three oscillatory responses. In conclusion, we investigated motor-related oscillatory activity in the largest cohort of children and adolescents reported to date, and our results indicated that beta and gamma cortical oscillations continue to develop as children transition into adolescents, and that these responses may not be fully matured until young to middle adulthood.

Neural dynamics of verbal working memory processing in children and adolescents.

Development of cognitive functions and the underlying neurophysiology is evident throughout childhood and adolescence, with higher order processes such as working memory (WM) being some of the last cognitive faculties to fully mature. Previous functional neuroimaging studies of the neurodevelopment of WM have largely focused on overall regional activity levels rather than the temporal dynamics of neural component recruitment. In this study, we used magnetoencephalography (MEG) to examine the neural dynamics of WM in a large cohort of children and adolescents who were performing a high-load, modified verbal Sternberg WM task. Consistent with previous studies in adults, our findings indicated left-lateralized activity throughout the task period, beginning in the occipital cortices and spreading anterior to include temporal and prefrontal cortices during later encoding and into maintenance. During maintenance, the occipital alpha increase that has been widely reported in adults was found to be relatively weak in this developmental sample, suggesting continuing development of this component of neural processing, which was supported by correlational analyses. Intriguingly, we also found sex-specific developmental effects in alpha responses in the right inferior frontal region during encoding and in parietal and occipital cortices during maintenance. These findings suggested a developmental divergence between males and females in the maturation of neural circuitry serving WM during the transition from childhood to adolescence.

tDCS modulates behavioral performance and the neural oscillatory dynamics serving visual selective attention.

Transcranial direct-current stimulation (tDCS) is a noninvasive method for modulating human brain activity. Although there are several hypotheses about the net effects of tDCS on brain function, the field's understanding remains incomplete and this is especially true for neural oscillatory activity during cognitive task performance. In this study, we examined whether different polarities of occipital tDCS differentially alter flanker task performance and the underlying neural dynamics. To this end, 48 healthy adults underwent 20 min of anodal, cathodal, or sham occipital tDCS, and then completed a visual flanker task during high-density magnetoencephalography (MEG). The resulting oscillatory responses were imaged in the time-frequency domain using beamforming, and the effects of tDCS on task-related oscillations and spontaneous neural activity were assessed. The results indicated that anodal tDCS of the occipital cortices inhibited flanker task performance as measured by reaction time, elevated spontaneous activity in the theta (4-7 Hz) and alpha (9-14 Hz) bands in prefrontal and occipital cortices, respectively, and reduced task-related theta oscillatory activity in prefrontal cortices during task performance. Cathodal tDCS of the occipital cortices did not significantly affect behavior or any of these neuronal parameters in any brain region. Lastly, the power of theta oscillations in the prefrontal cortices was inversely correlated with reaction time. In conclusion, anodal tDCS modulated task-related oscillations and spontaneous activity across multiple cortical areas, both near the electrode and in distant sites that were putatively connected to the targeted regions.

Aberrant occipital dynamics differentiate HIV-infected patients with and without cognitive impairment.

Combination antiretroviral therapies have revolutionized the treatment of HIV infection, and many patients now enjoy a lifespan equal to that of the general population. However, HIV-associated neurocognitive disorders (HAND) remain a major health concern, with between 30% and 70% of all HIV-infected patients developing cognitive impairments during their life time. One important feature of HAND is visuo-perceptual deficits, but the systems-level neural dynamics underlying these impairments are poorly understood. In the current study, we use magnetoencephalography and advanced time series analyses to examine these neural dynamics during a visuospatial processing task in a group of HIV-infected patients without HAND (n = 25), patients with HAND (n = 18), and a group of demographically-matched uninfected controls (n = 24). All participants completed a thorough neuropsychological assessment, and underwent magnetoencephalography and structural MRI protocols. In agreement with previous studies, patients with HAND performed significantly worse than HIV-infected patients without HAND and controls on the cognitive task, in terms of increased reaction time and decreased accuracy. Our magnetoencephalography results demonstrated that both spontaneous and neural oscillatory activity within the occipital cortices were affected by HIV infection, and that these patterns predicted behavioural performance (i.e. accuracy) on the task. Specifically, spontaneous neural activity in the alpha (8-16 Hz) and gamma (52-70 Hz) bands during the prestimulus baseline period, as well as oscillatory theta responses (4-8 Hz) during task performance were aberrant in HIV-infected patients, with both spontaneous alpha and oscillatory theta activity significantly predicting accuracy on the task and neuropsychological performance outside of the magnetoencephalography scanner. Importantly, these rhythmic patterns of population-level neural activity also distinguished patients by HAND status, such that spontaneous alpha activity in patients with HAND was elevated relative to HIV-infected patients without HAND and controls. In contrast, HIV-infected patients with and without HAND had increased spontaneous gamma compared to controls. Finally, there was a stepwise decrease in oscillatory theta activity as a function of disease severity, such that the response diminished from controls to patients without HAND to patients with HAND. Interestingly, the strength of the relationship between this theta response and accuracy also dissociated patient groups in a similar manner (controls > HIV with no HAND > HIV with HAND), indicating a reduced coupling between neurophysiology and behaviour in HIV-infected patients. This study provides the first neuroimaging evidence of a dissociation between HIV-infected patients with and without HAND, and these findings shed new light on the neural bases of cognitive impairment in HIV infection.

tDCS Modulates Visual Gamma Oscillations and Basal Alpha Activity in Occipital Cortices: Evidence from MEG.

Transcranial direct-current stimulation (tDCS) is now a widely used method for modulating the human brain, but the resulting physiological effects are not understood. Recent studies have combined magnetoencephalography (MEG) with simultaneous tDCS to evaluate online changes in occipital alpha and gamma oscillations, but no study to date has quantified the offline (i.e., after tDCS) alterations in these responses. Thirty-five healthy adults received active or sham anodal tDCS to the occipital cortices, and then completed a visual stimulation paradigm during MEG that is known to elicit robust gamma and alpha oscillations. The resulting MEG data were imaged and peak voxel time series were extracted to evaluate tDCS effects. We found that tDCS to the occipital increased the amplitude of local gamma oscillations, and basal alpha levels during the baseline. tDCS was also associated with network-level effects, including increased gamma oscillations in the prefrontal cortex, parietal, and other visual attention regions. Finally, although tDCS did not modulate peak gamma frequency, this variable was inversely correlated with gamma amplitude, which is consistent with a GABA-gamma link. In conclusion, tDCS alters gamma oscillations and basal alpha levels. The net offline effects on gamma activity are consistent with the view that anodal tDCS decreases local GABA.

Evaluating growth failure with diffusion tensor imaging in pediatric survivors of high-risk neuroblastoma treated with high-dose cis-retinoic acid.

BACKGROUND: The survival of patients with high-risk neuroblastoma has increased with multimodal therapy, but most survivors demonstrate growth failure. OBJECTIVE: To assess physeal abnormalities in children with high-risk neuroblastoma in comparison to normal controls by using diffusion tensor imaging (DTI) of the distal femoral physis and adjacent metaphysis. MATERIALS AND METHODS: We prospectively obtained physeal DTI at 3.0 T in 20 subjects (mean age: 12.4 years, 7 females) with high-risk neuroblastoma treated with high-dose cis-retinoic acid, and 20 age- and gender-matched controls. We compared fractional anisotropy (FA), normalized tract volume (cm3/cm2) and tract concentration (tracts/cm2) between the groups, in relation to height Z-score and response to growth hormone therapy. Tractography images were evaluated qualitatively. RESULTS: DTI parameters were significantly lower in high-risk neuroblastoma survivors compared to controls (P<0.01), particularly if the patients were exposed to both cis-retinoic acid and total body irradiation (P<0.05). For survivors and controls, DTI values were respectively [mean ± standard deviation]: tract concentration (tracts/cm2), 23.2±14.7 and 36.7±10.5; normalized tract volume (cm3/cm2), 0.44±0.27 and 0.70±0.21, and FA, 0.22±0.05 and 0.26±0.02. High-risk neuroblastoma survivors responding to growth hormone compared to non-responders had higher FA (0.25±0.04 and 0.18±0.03, respectively, P=0.02), and tract concentration (tracts/cm2) (31.4±13.7 and 14.8±7.9, respectively, P<0.05). FA, normalized tract volume and tract concentration were linearly related to height Z-score (R2>0.31; P<0.001). Qualitatively, tracts were nearly absent in all non-responders to growth hormone and abundant in all responders (P=0.02). CONCLUSION: DTI shows physeal abnormalities that correlate with short stature in high-risk neuroblastoma survivors and demonstrates response to growth hormone treatment.

Unexpected synergistic and antagonistic antibiotic activity against Staphylococcus biofilms.

Objectives: To evaluate putative anti-staphylococcal biofilm antibiotic combinations used in the management of periprosthetic joint infections (PJIs). Methods: Using the dissolvable bead biofilm assay, the minimum biofilm eradication concentration (MBEC) was determined for the most commonly used antimicrobial agents and combination regimens against staphylococcal PJIs. The established fractional inhibitory concentration (FIC) index was modified to create the fractional biofilm eradication concentration (FBEC) index to evaluate synergism or antagonism between antibiotics. Results: Only gentamicin (MBEC 64 mg/L) and daptomycin (MBEC 64 mg/L) were observed to be effective antistaphylococcal agents at clinically achievable concentrations. Supplementation of gentamicin with daptomycin, vancomycin or ciprofloxacin resulted in a similar or lower MBEC than gentamicin alone (FBEC index 0.25-2). Conversely, when rifampicin, clindamycin or linezolid was added to gentamicin, there was an increase in the MBEC of gentamicin relative to its use as a monotherapy (FBEC index 8-32). Conclusions: This study found that gentamicin and daptomycin were the only effective single-agent antibiotics against established Staphylococcus biofilms. Interestingly the addition of a bacteriostatic antibiotic was found to antagonize the ability of gentamicin to eradicate Staphylococcus biofilms.

Chemoenzymatic Synthesis of Galectin Binding Glycopolymers.

Chemoenzymatic synthesis is an important strategy for the formation of glycopolymers. The use of a smaller number of traditional chemical steps and enzyme catalyzed reactions increases the yield of glycopolymer that can be produced by reducing the overall number of synthetic steps. In addition, chemoenzymatic routes are likely to be more accessible to those without a background in carbohydrate synthesis, making glycopolymers more available for studies across a broader range of scientists. Here, the enzymatic addition of galactose to N-acetylglucosamine functionalized glycodendrimers reduced the requisite number of synthetic steps for the full chemical synthesis of N-acetyl lactosamine (Lac NAc) functionalized dendrimers to four steps. Unpurified cell lysate was used in the enzyme catalyzed glycosylation, and product glycodendrimers were readily purified by dialysis after enzymatic degradation of all protein components of the lysate in the crude reaction mixture. Lac NAc functionalized dendrimers were used very effectively in homotypic cancer cellular aggregation assays and were found to either inhibit or enhance galectin-3 mediated cancer cellular aggregation, with differences in outcomes dependent on the generation of Lac NAc functionalized dendrimers that were used.

Maternal veterinary occupation and adverse birth outcomes in Washington State, 1992-2014: a population-based retrospective cohort study.

OBJECTIVE: Women in veterinary occupations are routinely exposed to potential reproductive hazards, yet research into their birth outcomes is limited. We conducted a population-based retrospective cohort study of the association between maternal veterinary occupation and adverse birth outcomes. METHODS: Using Washington State birth certificate, fetal death certificate and hospital discharge data from 1992 to 2014, we compared birth outcomes of mothers in veterinary professions (n=2662) with those in mothers in dental professions (n=10 653) and other employed mothers (n=8082). Relative risks (RRs) and 95% CIs were estimated using log binomial regression. Outcomes studied were premature birth (<37 weeks), small for gestational age (SGA), malformations and fetal death (death at ≥20 weeks gestation). Subgroup analyses evaluated risk of these outcomes among veterinarians and veterinary support staff separately. RESULTS: While no statistically significant associations were found, we noted a trend for SGA births in all veterinary mothers compared with dental mothers (RR=1.16, 95% CI 0.99 to 1.36) and in veterinarians compared with other employed mothers (RR=1.37, 95% CI 0.96 to 1.96). Positive but non-significant association was found for malformations among children of veterinary support staff. CONCLUSIONS: These results support the need for further study of the association between veterinary occupation and adverse birth outcomes.