Noninvasive Autopsy-Validated Tumor Probability Maps Identify Glioma Invasion Beyond Contrast Enhancement.

BACKGROUND AND OBJECTIVES: This study identified a clinically significant subset of patients with glioma with tumor outside of contrast enhancement present at autopsy and subsequently developed a method for detecting nonenhancing tumor using radio-pathomic mapping. We tested the hypothesis that autopsy-based radio-pathomic tumor probability maps would be able to noninvasively identify areas of infiltrative tumor beyond traditional imaging signatures. METHODS: A total of 159 tissue samples from 65 subjects were aligned to MRI acquired nearest to death for this retrospective study. Demographic and survival characteristics for patients with and without tumor beyond the contrast-enhancing margin were computed. An ensemble algorithm was used to predict pixelwise tumor presence from pathological annotations using segmented cellularity (Cell), extracellular fluid, and cytoplasm density as input (6 train/3 test subjects). A second level of ensemble algorithms was used to predict voxelwise Cell, extracellular fluid, and cytoplasm on the full data set (43 train/22 test subjects) using 5-by-5 voxel tiles from T1, T1 + C, fluid-attenuated inversion recovery, and apparent diffusion coefficient as input. The models were then combined to generate noninvasive whole brain maps of tumor probability. RESULTS: Tumor outside of contrast was identified in 41.5% of patients, who showed worse survival outcomes (hazard ratio = 3.90, P < .001). Tumor probability maps reliably tracked nonenhancing tumor on a range of local and external unseen data, identifying tumor outside of contrast in 69% of presurgical cases that also showed reduced survival outcomes (hazard ratio = 1.67, P = .027). CONCLUSION: This study developed a multistage model for mapping gliomas using autopsy tissue samples as ground truth, which was able to identify regions of tumor beyond traditional imaging signatures.

Cystic Brain Metastasis Outcomes After Gamma Knife Radiation Therapy.

Purpose: The response of cystic brain metastases (BMets) to radiation therapy is poorly understood, with conflicting results regarding local control, overall survival, and treatment-related toxicity. This study aims to examine the role of Gamma Knife (GK) in managing cystic BMets. Methods and Materials: Volumetric analysis was conducted to measure tumor and edema volume at the time of GK and follow-up magnetic resonance imaging studies. Survival was described using the Kaplan-Meier method, and the cumulative incidence of progression was described using the Aalen-Johansen estimator. We evaluated the association of 4 variables with survival using Cox regression analysis. Results: Between 2016 and 2021, 54 patients with 83 cystic BMets were treated with GK at our institution. Lung cancer was the most common pathology (51.9%), followed by breast cancer (13.0%). The mean target volume was 2.7 cm3 (range, 0.1-39.0 cm3), and the mean edema volume was 13.9 cm3 (range, 0-165.5 cm3). The median prescription dose of single-fraction and fractionated GK was 20 Gy (range, 14-27.5 Gy). With a median follow-up of 8.9 months, the median survival time (MST) was 11.1 months, and the 1-year local control rate was 75.9%. Gamma Knife was associated with decreased tumor and edema volumes over time, although 68.5% of patients required steroids after GK. Patients whose tumors grew beyond baseline after GK received significantly more whole-brain radiation therapy (WBRT) before GK than those whose tumors declined after GK. Higher age at diagnosis of BMets and pre-GK systemic therapy were associated with worse survival, with an MST of 7.8 months in patients who received it compared with 23.3 months in those who did not. Conclusions: Pre-GK WBRT may select for BMets with increased radioresistance. This study highlights the ability of GK to control cystic BMets with the cost of high posttreatment steroid use.

Symptomatic radionecrosis after postoperative but not preoperative stereotactic radiosurgery in a single patient: illustrative case.

BACKGROUND: Standard of care for brain metastases involves stereotactic radiosurgery (SRS). For cases that also require surgery because of lesion size, edema, or neurological symptoms, whether to provide pre- or postoperative SRS has become a prevalent debate. OBSERVATIONS: Herein, the unique case of a patient with brain metastases of the same pathology and similar size in two different brain locations at two different times is described. The patient underwent surgery with preoperative SRS for the first lesion and surgery with postoperative SRS for the second lesion. Although both treatments resulted in successful local control, the location that received postoperative SRS developed symptomatic and rapidly progressive radiation necrosis (RN) requiring a third craniotomy. LESSONS: Large randomized controlled trials are ongoing to compare pre- versus postoperative SRS for the treatment of symptomatic brain metastases (e.g., study NRG-BN012). Recent interest in preoperative SRS has emerged from its theoretical potential to decrease rates of postoperative RN and leptomeningeal disease. This valuable case in which both therapies were applied in a single patient with a single pathology and similar lesions provides evidence supportive of preoperative SRS.

Early versus late endoscopic treatment of pancreatic necrotic collections: A systematic review and meta-analysis.

Background and study aims Recently studies have compared early (<4 weeks) vs. late or standard (>4 weeks) endoscopic treatment of pancreatic necrotic collections (PNC) and have reported favorable results for early treatment. In this meta-analysis, we compared the efficacy and safety of early vs. late endoscopic treatment of PNC. Patients and methods We reviewed several databases from inception to September 30, 2021 to identify studies that compared early with late endoscopic treatment of PNC. Our outcomes of interest were adverse events (AEs), resolution of PNC, performance of direct endoscopic necrosectomy, need for further interventions, and mean number of endoscopic necrosectomy sessions. We calculated pooled risk ratios (RRs) with 95% confidence intervals (CIs) for categorical variables and mean differences (MDs) with 95% CIs for continuous variables. Data were analyzed by random effect model. Heterogeneity was assessed by I 2 statistic. Results We included four studies with 427 patients. We found no significant difference in rates of AEs, RR (95% CI) 1.70 (range, 0.56-5.20), resolution of necrotic or fluid collections, RR (95% CI) 0.89 (range, 0.71-1.11), need for further interventions, RR (95% CI) 1.47 (range, 0.70-3.08), direct necrosectomy, RR (95% CI) 1.39 (range, 0.22-8.80), mortality, RR (95% CI) 2.37 (range, 0.26-21.72) and mean number of endoscopic necrosectomy sessions, MD (95% CI) 1.58 (range,-0.20-3.36) between groups. Conclusions Early endoscopic treatment of PNC can be considered for indications such as infected necrosis or sterile necrosis with symptoms or complications; however, future large multicenter studies are required to further evaluate its safety.

Phase separation of protein mixtures is driven by the interplay of homotypic and heterotypic interactions.

Prion-like low-complexity domains (PLCDs) are involved in the formation and regulation of distinct biomolecular condensates that form via phase separation coupled to percolation. Intracellular condensates often encompass numerous distinct proteins with PLCDs. Here, we combine simulations and experiments to study mixtures of PLCDs from two RNA-binding proteins, hnRNPA1 and FUS. Using simulations and experiments, we find that 1:1 mixtures of A1-LCD and FUS-LCD undergo phase separation more readily than either of the PLCDs on their own due to complementary electrostatic interactions. Tie line analysis reveals that stoichiometric ratios of different components and their sequence-encoded interactions contribute jointly to the driving forces for condensate formation. Simulations also show that the spatial organization of PLCDs within condensates is governed by relative strengths of homotypic versus heterotypic interactions. We uncover rules for how interaction strengths and sequence lengths modulate conformational preferences of molecules at interfaces of condensates formed by mixtures of proteins.

Sequence-specific interactions determine viscoelasticity and aging dynamics of protein condensates.

Biomolecular condensates are viscoelastic materials. Here, we report results from investigations into molecular-scale determinants of sequence-encoded and age-dependent viscoelasticity of condensates formed by prion-like low-complexity domains (PLCDs). The terminally viscous forms of PLCD condensates are Maxwell fluids. Measured viscoelastic moduli of these condensates are reproducible using a Rouse-Zimm model that accounts for the network-like organization engendered by reversible physical crosslinks among PLCDs in the dense phase. Measurements and computations show that the strengths of aromatic inter-sticker interactions determine the sequence-specific amplitudes of elastic and viscous moduli as well as the timescales over which elastic properties dominate. PLCD condensates also undergo physical aging on sequence-specific timescales. This is driven by mutations to spacer residues that weaken the metastability of terminally viscous phases. The aging of PLCD condensates is accompanied by disorder-to-order transitions, leading to the formation of non-fibrillar, beta-sheet-containing, semi-crystalline, terminally elastic, Kelvin-Voigt solids. Our results suggest that sequence grammars, which refer to the identities of stickers versus spacers in PLCDs, have evolved to afford control over the metastabilities of terminally viscous fluid phases of condensates. This selection can, in some cases, render barriers for conversion from metastable fluids to globally stable solids to be insurmountable on functionally relevant timescales.

Phase Separation in Mixtures of Prion-Like Low Complexity Domains is Driven by the Interplay of Homotypic and Heterotypic Interactions.

Prion-like low-complexity domains (PLCDs) are involved in the formation and regulation of distinct biomolecular condensates that form via coupled associative and segregative phase transitions. We previously deciphered how evolutionarily conserved sequence features drive phase separation of PLCDs through homotypic interactions. However, condensates typically encompass a diverse mixture of proteins with PLCDs. Here, we combine simulations and experiments to study mixtures of PLCDs from two RNA binding proteins namely, hnRNPA1 and FUS. We find that 1:1 mixtures of the A1-LCD and FUS-LCD undergo phase separation more readily than either of the PLCDs on their own. The enhanced driving forces for phase separation of mixtures of A1-LCD and FUS-LCD arise partly from complementary electrostatic interactions between the two proteins. This complex coacervation-like mechanism adds to complementary interactions among aromatic residues. Further, tie line analysis shows that stoichiometric ratios of different components and their sequence-encoded interactions jointly contribute to the driving forces for condensate formation. These results highlight how expression levels might be tuned to regulate the driving forces for condensate formation in vivo . Simulations also show that the organization of PLCDs within condensates deviates from expectations based on random mixture models. Instead, spatial organization within condensates will reflect the relative strengths of homotypic versus heterotypic interactions. We also uncover rules for how interaction strengths and sequence lengths modulate conformational preferences of molecules at interfaces of condensates formed by mixtures of proteins. Overall, our findings emphasize the network-like organization of molecules within multicomponent condensates, and the distinctive, composition-specific conformational features of condensate interfaces. Significance Statement: Biomolecular condensates are mixtures of different protein and nucleic acid molecules that organize biochemical reactions in cells. Much of what we know about how condensates form comes from studies of phase transitions of individual components of condensates. Here, we report results from studies of phase transitions of mixtures of archetypal protein domains that feature in distinct condensates. Our investigations, aided by a blend of computations and experiments, show that the phase transitions of mixtures are governed by a complex interplay of homotypic and heterotypic interactions. The results point to how expression levels of different protein components can be tuned in cells to modulate internal structures, compositions, and interfaces of condensates, thus affording distinct ways to control the functions of condensates.

The Association of Inflammatory Factors With Peripheral Neuropathy: The Study of Women's Health Across the Nation.

PURPOSE: Previous work has focused on the role of diabetes in peripheral neuropathy (PN), but PN often occurs before, and independently from, diabetes. This study measures the association of cardiometabolic and inflammatory factor with PN, independent of diabetes. METHODS: Study of Women's Health Across the Nation participants (n = 1910), ages 60 to 73 (mean 65.6) were assessed for PN by symptom questionnaire and monofilament testing at the 15th follow-up visit (V15). Anthropometric measures and biomarkers were measured at study baseline approximately 20 years prior, and C-reactive protein (CRP) and fibrinogen were measured longitudinally. Log-binomial regression was used to model the association between metabolic syndrome (MetS), obesity (≥35 body mass index), CRP, and fibrinogen with PN, adjusting for sociodemographic and health behavior measures. RESULTS: Baseline MetS [prevalence ratio (PR) 1.79, 95% CI (1.45, 2.20)], obesity [PR 2.08 (1.65, 2.61)], median CRP [PR 1.32 per log(mg/dL), (1.20, 1.45)], and mean fibrinogen (PR 1.28 per 100 mg/dL, (1.09, 1.50)] were associated with PN symptoms at V15. After excluding participants with baseline diabetes or obesity, MetS [PR 1.59 (1.17, 2.14)] and CRP [PR 1.19 per log(mg/dL), (1.06, 1.35)] remained statistically significantly associated with PN. There was a negative interaction between MetS and obesity, and the association between these conditions and PN was mediated by CRP. CONCLUSIONS: Cardiometabolic factors and inflammation are significantly associated with PN, independent of diabetes and obesity. CRP mediates the relationship of both obesity and MetS with PN, suggesting an etiological role of inflammation in PN in this sample.

Case report: Fractional brain tumor burden magnetic resonance mapping to assess response to pulsed low-dose-rate radiotherapy in newly-diagnosed glioblastoma.

Background: Pulsed low-dose-rate radiotherapy (pLDR) is a commonly used reirradiation technique for recurrent glioma, but its upfront use with temozolomide (TMZ) following primary resection of glioblastoma is currently under investigation. Because standard magnetic resonance imaging (MRI) has limitations in differentiating treatment effect from tumor progression in such applications, perfusion-weighted MRI (PWI) can be used to create fractional tumor burden (FTB) maps to spatially distinguish active tumor from treatment-related effect. Methods: We performed PWI prior to re-resection in four patients with glioblastoma who had undergone upfront pLDR concurrent with TMZ who had radiographic suspicion for tumor progression at a median of 3 months (0-5 months or 0-143 days) post-pLDR. The pathologic diagnosis was compared to retrospectively-generated FTB maps. Results: The median patient age was 55.5 years (50-60 years). All were male with IDH-wild type (n=4) and O6-methylguanine-DNA methyltransferase (MGMT) hypermethylated (n=1) molecular markers. Pathologic diagnosis revealed treatment effect (n=2), a mixture of viable tumor and treatment effect (n=1), or viable tumor (n=1). In 3 of 4 cases, FTB maps were indicative of lesion volumes being comprised predominantly of treatment effect with enhancing tumor volumes comprised of a median of 6.8% vascular tumor (6.4-16.4%). Conclusion: This case series provides insight into the radiographic response to upfront pLDR and TMZ and the role for FTB mapping to distinguish tumor progression from treatment effect prior to redo-surgery and within 20 weeks post-radiation.

Condensates formed by prion-like low-complexity domains have small-world network structures and interfaces defined by expanded conformations.

Biomolecular condensates form via coupled associative and segregative phase transitions of multivalent associative macromolecules. Phase separation coupled to percolation is one example of such transitions. Here, we characterize molecular and mesoscale structural descriptions of condensates formed by intrinsically disordered prion-like low complexity domains (PLCDs). These systems conform to sticker-and-spacers architectures. Stickers are cohesive motifs that drive associative interactions through reversible crosslinking and spacers affect the cooperativity of crosslinking and overall macromolecular solubility. Our computations reproduce experimentally measured sequence-specific phase behaviors of PLCDs. Within simulated condensates, networks of reversible inter-sticker crosslinks organize PLCDs into small-world topologies. The overall dimensions of PLCDs vary with spatial location, being most expanded at and preferring to be oriented perpendicular to the interface. Our results demonstrate that even simple condensates with one type of macromolecule feature inhomogeneous spatial organizations of molecules and interfacial features that likely prime them for biochemical activity.

City-wide wastewater genomic surveillance through the successive emergence of SARS-CoV-2 Alpha and Delta variants.

Genomic surveillance of SARS-CoV-2 has provided a critical evidence base for public health decisions throughout the pandemic. Sequencing data from clinical cases has helped to understand disease transmission and the spread of novel variants. Genomic wastewater surveillance can offer important, complementary information by providing frequency estimates of all variants circulating in a population without sampling biases. Here we show that genomic SARS-CoV-2 wastewater surveillance can detect fine-scale differences within urban centres, specifically within the city of Liverpool, UK, during the emergence of Alpha and Delta variants between November 2020 and June 2021. Furthermore, wastewater and clinical sequencing match well in the estimated timing of new variant rises and the first detection of a new variant in a given area may occur in either clinical or wastewater samples. The study's main limitation was sample quality when infection prevalence was low in spring 2021, resulting in a lower resolution of the rise of the Delta variant compared to the rise of the Alpha variant in the previous winter. The correspondence between wastewater and clinical variant frequencies demonstrates the reliability of wastewater surveillance. However, discrepancies in the first detection of the Alpha variant between the two approaches highlight that wastewater monitoring can also capture missing information, possibly resulting from asymptomatic cases or communities less engaged with testing programmes, as found by a simultaneous surge testing effort across the city.

Quantifying Coexistence Concentrations in Multi-Component Phase-Separating Systems Using Analytical HPLC.

Over the last decade, evidence has accumulated to suggest that numerous instances of cellular compartmentalization can be explained by the phenomenon of phase separation. This is a process by which a macromolecular solution separates spontaneously into dense and dilute coexisting phases. Semi-quantitative, in vitro approaches for measuring phase boundaries have proven very useful in determining some key features of biomolecular condensates, but these methods often lack the precision necessary for generating quantitative models. Therefore, there is a clear need for techniques that allow quantitation of coexisting dilute and dense phase concentrations of phase-separating biomolecules, especially in systems with more than one type of macromolecule. Here, we report the design and deployment of analytical High-Performance Liquid Chromatography (HPLC) for in vitro separation and quantification of distinct biomolecules that allows us to measure dilute and dense phase concentrations needed to reconstruct coexistence curves in multicomponent mixtures. This approach is label-free, detects lower amounts of material than is accessible with classic UV-spectrophotometers, is applicable to a broad range of macromolecules of interest, is a semi-high-throughput technique, and if needed, the macromolecules can be recovered for further use. The approach promises to provide quantitative insights into the balance of homotypic and heterotypic interactions in multicomponent phase-separating systems.

KNEMIDOKOPTES MITES AND THEIR EFFECTS ON THE GRIPPING POSITION OF THE FEET OF STELLER'S JAYS (CYANOCITTA STELLERI).

Steller's Jays (Cyanocitta stelleri) with swollen legs and feet resembling the signs of scaly leg have been commonly seen around Arcata, California, US. The clinical signs are thought to be caused by knemidokoptic mites, a group of parasites specialized on avian hosts. Between February 2019 and March 2020, we analyzed the long-term database of Steller's Jays collected by Humboldt State University for trends in the prevalence of signs of scaly leg, compared the gripping position in the feet of Steller's Jays with variable signs of this condition as an index of their ability to perch, identified the mites using a partial sequence of the cytochrome oxidase subunit I gene, and examined genetic distances between mites collected from different host species both sequenced in this study and from GenBank. Overall, 27% of jays recorded in the long-term database had shown signs of scaly leg. Jays with signs captured in this study had greater variability in and a reduced degree of contraction in the gripping position of their feet compared to jays without signs, suggesting that infestation may have an impact on the host's ability to perch. The cytochrome oxidase subunit I sequence (578 base pairs) from mites collected from Steller's Jays was compared to sequences from Knemidokoptes jamaicensis, Knemidokoptes derooi, and to unidentified Knemidokoptes spp. collected from different hosts. The mites from Steller's Jays were most closely related to Knemidokoptes jamaicensis but had a relatively high sequence divergence, 7.8%, supporting the possibility that the form infesting these jays may be an undescribed species.

Conformational buffering underlies functional selection in intrinsically disordered protein regions.

Many disordered proteins conserve essential functions in the face of extensive sequence variation, making it challenging to identify the mechanisms responsible for functional selection. Here we identify the molecular mechanism of functional selection for the disordered adenovirus early gene 1A (E1A) protein. E1A competes with host factors to bind the retinoblastoma (Rb) protein, subverting cell cycle regulation. We show that two binding motifs tethered by a hypervariable disordered linker drive picomolar affinity Rb binding and host factor displacement. Compensatory changes in amino acid sequence composition and sequence length lead to conservation of optimal tethering across a large family of E1A linkers. We refer to this compensatory mechanism as conformational buffering. We also detect coevolution of the motifs and linker, which can preserve or eliminate the tethering mechanism. Conformational buffering and motif-linker coevolution explain robust functional encoding within hypervariable disordered linkers and could underlie functional selection of many disordered protein regions.

Prediction of Naming Outcome With fMRI Language Lateralization in Left Temporal Epilepsy Surgery.

BACKGROUND AND OBJECTIVES: Naming decline after left temporal lobe epilepsy (TLE) surgery is common and difficult to predict. Preoperative language fMRI may predict naming decline, but this application is still lacking evidence. We performed a large multicenter cohort study of the effectiveness of fMRI in predicting naming deficits after left TLE surgery. METHODS: At 10 US epilepsy centers, 81 patients with left TLE were prospectively recruited and given the Boston Naming Test (BNT) before and ≈7 months after anterior temporal lobectomy. An fMRI language laterality index (LI) was measured with an auditory semantic decision-tone decision task contrast. Correlations and a multiple regression model were built with a priori chosen predictors. RESULTS: Naming decline occurred in 56% of patients and correlated with fMRI LI (r = -0.41, p < 0.001), age at epilepsy onset (r = -0.30, p = 0.006), age at surgery (r = -0.23, p = 0.039), and years of education (r = 0.24, p = 0.032). Preoperative BNT score and duration of epilepsy were not correlated with naming decline. The regression model explained 31% of the variance, with fMRI contributing 14%, with a 96% sensitivity and 44% specificity for predicting meaningful naming decline. Cross-validation resulted in an average prediction error of 6 points. DISCUSSION: An fMRI-based regression model predicted naming outcome after left TLE surgery in a large, prospective multicenter sample, with fMRI as the strongest predictor. These results provide evidence supporting the use of preoperative language fMRI to predict language outcome in patients undergoing left TLE surgery. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that fMRI language lateralization can help in predicting naming decline after left TLE surgery.

Comparison of the Respiratory Resistomes and Microbiota in Children Receiving Short versus Standard Course Treatment for Community-Acquired Pneumonia.

Pediatric community-acquired pneumonia (CAP) is often treated with 10 days of antibiotics. Shorter treatment strategies may be effective and lead to less resistance. The impact of duration of treatment on the respiratory microbiome is unknown. Data are from children (n = 171), ages 6 to 71 months, enrolled in the SCOUT-CAP trial (NCT02891915). Children with CAP were randomized to a short (5 days) versus standard (10 days) beta-lactam treatment strategy. Throat swabs were collected at enrollment and the end of the study and used for shotgun metagenomic sequencing. The number of beta-lactam and multidrug efflux resistance genes per prokaryotic cell (RGPC) was significantly lower in children receiving the short compared to standard treatment strategy at the end of the study (Wilcoxon rank sum test, P < 0.05 for each). Wilcoxon effect sizes were small for beta-lactam (r: 0.15; 95% confidence interval [CI], 0.01 to 0.29) and medium for multidrug efflux RGPC (r: 0.23; 95% CI, 0.09 to 0.37). Analyses comparing the resistome at the beginning and end of the trial indicated that in contrast to the standard strategy group, the resistome significantly differed in children receiving the short course strategy. Relative abundances of commensals such as Neisseria subflava were higher in children receiving the standard strategy, and Prevotella species and Veillonella parvula were higher in children receiving the short course strategy. We conclude that children receiving 5 days of beta-lactam therapy for CAP had a significantly lower abundance of antibiotic resistance determinants than those receiving standard 10-day treatment. These data provide an additional rationale for reductions in antibiotic use when feasible. IMPORTANCE Antibiotic resistance is a major threat to public health. Treatment strategies involving shorter antibiotic courses have been proposed as a strategy to lower the potential for antibiotic resistance. We examined relationships between the duration of antibiotic treatment and its impact on resistance genes and bacteria in the respiratory microbiome using data from a randomized controlled trial of beta-lactam therapy for pediatric pneumonia. The randomized design provides reliable evidence of the effectiveness of interventions and minimizes the potential for confounding. Children receiving 5 days of therapy for pneumonia had a lower prevalence of two different types of resistance genes than did those receiving the 10-day treatment. Our data also suggest that children receiving longer durations of therapy have a greater abundance of antibiotic resistance genes for a longer period of time than do children receiving shorter durations of therapy. These data provide an additional rationale for reductions in antibiotic use.

Substituent Effects Impact Surface Charge and Aggregation of Thiophenol-Labeled Gold Nanoparticles for SERS Biosensors.

SERS immunoassay biosensors hold immense potential for clinical diagnostics due to their high sensitivity and growing interest in multi-marker panels. However, their development has been hindered by difficulties in designing compatible extrinsic Raman labels. Prior studies have largely focused on spectroscopic characteristics in selecting Raman reporter molecules (RRMs) for multiplexing since the presence of well-differentiated spectra is essential for simultaneous detection. However, these candidates often induce aggregation of the gold nanoparticles used as SERS nanotags despite their similarity to other effective RRMs. Thus, an improved understanding of factors affecting the aggregation of RRM-coated gold nanoparticles is needed. Substituent electronic effects on particle stability were investigated using various para-substituted thiophenols. The inductive and resonant effects of functional group modifications were strongly correlated with nanoparticle surface charge and hence their stability. Treatment with thiophenols diminished the negative surface charge of citrate-stabilized gold nanoparticles, but electron-withdrawing substituents limited the magnitude of this diminishment. It is proposed that this phenomenon arises by affecting the interplay of competing sulfur binding modes. This has wide-reaching implications for the design of biosensors using thiol-modified gold surfaces. A proof-of-concept multiplexed SERS biosensor was designed according to these findings using the two thiophenol compounds with the most electron-withdrawing substitutions: NO2 and CN.

Deciphering how naturally occurring sequence features impact the phase behaviours of disordered prion-like domains.

Prion-like low-complexity domains (PLCDs) have distinctive sequence grammars that determine their driving forces for phase separation. Here we uncover the physicochemical underpinnings of how evolutionarily conserved compositional biases influence the phase behaviour of PLCDs. We interpret our results in the context of the stickers-and-spacers model for the phase separation of associative polymers. We find that tyrosine is a stronger sticker than phenylalanine, whereas arginine is a context-dependent auxiliary sticker. In contrast, lysine weakens sticker-sticker interactions. Increasing the net charge per residue destabilizes phase separation while also weakening the strong coupling between single-chain contraction in dilute phases and multichain interactions that give rise to phase separation. Finally, glycine and serine residues act as non-equivalent spacers, and thus make the glycine versus serine contents an important determinant of the driving forces for phase separation. The totality of our results leads to a set of rules that enable comparative estimates of composition-specific driving forces for PLCD phase separation.

Frontal fibrosing alopecia: survey of severity assessment methods in routine clinical practice and validation of the International Frontal Fibrosing Alopecia Cooperative Group measurement guidance.

BACKGROUND: The lack of validated and responsive outcome measures in the management of frontal fibrosing alopecia (FFA) significantly limits assessment of disease progression and treatment response over time. AIM: To understand how FFA extent and progression is currently assessed in UK specialist centres, to validate components of the International FFA Cooperative Group (IFFACG) statement on FFA assessment, and to identify pragmatic advice to improve FFA management in clinic. METHODS: Consultant dermatologists with a specialist interest in hair loss (n = 17) were invited to take part. Preferred FFA assessment methods were explored using questionnaires and clinical scenarios. Participants were asked to identify and mark the current hairline in 10 frontal and 10 temporal hairline images (Questionnaire 1), with assessment repeated 3 months later to assess intraindividual variability (Questionnaire 2) and 12 months later to test whether interindividual accuracy could be improved with simple instruction (Questionnaire 3). RESULTS: All 17 clinicians (100%) completed the questionnaire at each time interval. We identified a wide variation in assessment techniques used by our experts. Measurements were perceived as the most accurate method of assessing frontal recession whereas photography was preferred for temporal recession. Inter-rater reliability between clinicians measuring the frontal hairline scenarios indicated a moderate strength of agreement [intraclass coefficient (ICC) = 0.61; 95% CI 0.40-0.85], yet intrarater reliability was found to be poor with wide limits of agreement (-8.71 mm to 9.92 mm) on follow-up. Importantly, when clear guidance was provided on how the hairline should be identified (Questionnaire 3), inter-rater reliability improved significantly, with ICC = 0.70, suggesting moderate agreement (95% CI 0.51-0.89; P < 0.001). A similar pattern was seen with temporal hairline measurements, which again improved in accuracy with instruction. CONCLUSION: We found that accuracy of measurements in FFA can be improved with simple instruction and we have validated components of the IFFACG measurement recommendations.

Innovation in regulatory approaches for endocrine disrupting chemicals: The journey to risk assessment modernization in Canada.

Globally, regulatory authorities grapple with the challenge of assessing the hazards and risks to human and ecosystem health that may result from exposure to chemicals that disrupt the normal functioning of endocrine systems. Rapidly increasing number of chemicals in commerce, coupled with the reliance on traditional, costly animal experiments for hazard characterization - often with limited sensitivity to many important mechanisms of endocrine disruption -, presents ongoing challenges for chemical regulation. The consequence is a limited number of chemicals for which there is sufficient data to assess if there is endocrine toxicity and hence few chemicals with thorough hazard characterization. To address this challenge, regulatory assessment of endocrine disrupting chemicals (EDCs) is benefiting from a revolution in toxicology that focuses on New Approach Methodologies (NAMs) to more rapidly identify, prioritize, and assess the potential risks from exposure to chemicals using novel, more efficient, and more mechanistically driven methodologies and tools. Incorporated into Integrated Approaches to Testing and Assessment (IATA) and guided by conceptual frameworks such as Adverse Outcome Pathways (AOPs), emerging approaches focus initially on molecular interactions between the test chemical and potentially vulnerable biological systems instead of the need for animal toxicity data. These new toxicity testing methods can be complemented with in silico and computational toxicology approaches, including those that predict chemical kinetics. Coupled with exposure data, these will inform risk-based decision-making approaches. Canada is part of a global network collaborating on building confidence in the use of NAMs for regulatory assessment of EDCs. Herein, we review the current approaches to EDC regulation globally (mainly from the perspective of human health), and provide a perspective on how the advances for regulatory testing and assessment can be applied and discuss the promises and challenges faced in adopting these novel approaches to minimize risks due to EDC exposure in Canada, and our world.