Identifying and Responding to Lead in Drinking Water in a University Setting.

Lead is an established neurotoxicant, and it has known associations with adverse neurodevelopmental and reproductive outcomes. Exposure to lead at any level is unsafe, and the United States (US) has enacted various federal and state legislations to regulate lead levels in drinking water in K-12 schools and childcare facilities; however, no regulations exist for higher education settings. Upon the discovery of lead in drinking water fixtures in the University of North Carolina at Chapel Hill (UNC-CH) campus, a cross-campus water testing network and sampling plan was developed and deployed. The campaign was based on the US Environmental Protection Agency's (EPA) 3Ts (Training, Testing, and Taking Action) guidance. The seven-month campaign involved 5954 tests on 3825 drinking water fixtures across 265 buildings. A total of 502 (8.43%) tests showed lead above the limit of detection (1 part per billion, ppb), which represented 422 (11.03%) fixtures. Fewer than 1.5% of the tests were above the EPA action level for public water systems (15 ppb). In conclusion, systematic testing of all the fixtures across campus was required to identify localized contamination, and each entity in the cross-campus network undertook necessary roles to generate a successful testing campaign. UNC-CH established preventative measures to test drinking water fixtures every three years, which provide a framework for other higher education institutions in responding to lead contamination.

Oxidative cyclization reagents reveal tryptophan cation-π interactions.

Methods for selective covalent modification of amino acids on proteins can enable a diverse array of applications, spanning probes and modulators of protein function to proteomics1-3. Owing to their high nucleophilicity, cysteine and lysine residues are the most common points of attachment for protein bioconjugation chemistry through acid-base reactivity3,4. Here we report a redox-based strategy for bioconjugation of tryptophan, the rarest amino acid, using oxaziridine reagents that mimic oxidative cyclization reactions in indole-based alkaloid biosynthetic pathways to achieve highly efficient and specific tryptophan labelling. We establish the broad use of this method, termed tryptophan chemical ligation by cyclization (Trp-CLiC), for selectively appending payloads to tryptophan residues on peptides and proteins with reaction rates that rival traditional click reactions and enabling global profiling of hyper-reactive tryptophan sites across whole proteomes. Notably, these reagents reveal a systematic map of tryptophan residues that participate in cation-π interactions, including functional sites that can regulate protein-mediated phase-separation processes.

Light-sensitive phosphorylation regulates retinal IMPDH1 activity and filament assembly.

Inosine monophosphate dehydrogenase (IMPDH) is the rate-limiting enzyme in guanosine triphosphate (GTP) synthesis and assembles into filaments in cells, which desensitizes the enzyme to feedback inhibition and boosts nucleotide production. The vertebrate retina expresses two splice variants IMPDH1(546) and IMPDH1(595). In bovine retinas, residue S477 is preferentially phosphorylated in the dark, but the effects on IMPDH1 activity and regulation are unclear. Here, we generated phosphomimetic mutants to investigate structural and functional consequences of S477 phosphorylation. The S477D mutation resensitized both variants to GTP inhibition but only blocked assembly of IMPDH1(595) filaments. Cryo-EM structures of both variants showed that S477D specifically blocks assembly of a high-activity assembly interface, still allowing assembly of low-activity IMPDH1(546) filaments. Finally, we discovered that S477D exerts a dominant-negative effect in cells, preventing endogenous IMPDH filament assembly. By modulating the structure and higher-order assembly of IMPDH, S477 phosphorylation acts as a mechanism for downregulating retinal GTP synthesis in the dark when nucleotide turnover is decreased.

A female woolly mammoth's lifetime movements end in an ancient Alaskan hunter-gatherer camp.

Woolly mammoths in mainland Alaska overlapped with the region's first people for at least a millennium. However, it is unclear how mammoths used the space shared with people. Here, we use detailed isotopic analyses of a female mammoth tusk found in a 14,000-year-old archaeological site to show that she moved ~1000 kilometers from northwestern Canada to inhabit an area with the highest density of early archaeological sites in interior Alaska until her death. DNA from the tusk and other local contemporaneous archaeological mammoth remains revealed that multiple mammoth herds congregated in this region. Early Alaskans seem to have structured their settlements partly based on mammoth prevalence and made use of mammoths for raw materials and likely food.

Screening for Youth Firearm Violence Exposure in Primary Care.

Introduction: The aim of this study was to assess a modified gun violence exposure tool at a pediatric clinic on the West Side of Chicago to identify youth at high risk of future gun violence. Methods: A modified version of the SaFETy gun violence exposure tool, studied in a community pediatric primary care setting, was implemented from June to August 2021. Patients and pediatric clinicians were surveyed after pilot. Results: Of 508 eligible patients, 341 youth (67.1%) completed the SaFETy tool. None had a SaFETy score ≥6, the threshold for immediate referral. Over a quarter (26.4%) of youth had scores of 1-5, and of those, 7.8% were referred at the clinician's discretion. Youth (n=84) participants randomly selected to complete an anonymous survey provided feedback about the SaFETY tool, reporting that the questions were easy to understand (92%). All 6 pediatric clinicians surveyed agreed that the tool helped to identify youth exposed to gun violence. Conclusions: Screening for gun violence exposure among youth is logistically feasible in the pediatric outpatient setting. A more sensitive validated tool to stratify low-/medium-risk patients in the primary care setting is needed.

Light-sensitive phosphorylation regulates enzyme activity and filament assembly of human IMPDH1 retinal splice variants.

Inosine monophosphate dehydrogenase (IMPDH) is the rate-limiting enzyme in de novo guanosine triphosphate (GTP) synthesis and is controlled by feedback inhibition and allosteric regulation. IMPDH assembles into micron-scale filaments in cells, which desensitizes the enzyme to feedback inhibition by GTP and boosts nucleotide production. The vertebrate retina expresses two tissue-specific splice variants IMPDH1(546) and IMPDH1(595). IMPDH1(546) filaments adopt high and low activity conformations, while IMPDH1(595) filaments maintain high activity. In bovine retinas, residue S477 is preferentially phosphorylated in the dark, but the effects on IMPDH1 activity and regulation are unclear. Here, we generated phosphomimetic mutants to investigate structural and functional consequences of phosphorylation in IMPDH1 variants. The S477D mutation re-sensitized both variants to GTP inhibition, but only blocked assembly of IMPDH1(595) filaments and not IMPDH1(546) filaments. Cryo-EM structures of both variants showed that S477D specifically blocks assembly of the high activity assembly interface, still allowing assembly of low activity IMPDH1(546) filaments. Finally, we discovered that S477D exerts a dominant-negative effect in cells, preventing endogenous IMPDH filament assembly. By modulating the structure and higher-order assembly of IMPDH, phosphorylation at S477 acts as a mechanism for downregulating retinal GTP synthesis in the dark, when nucleotide turnover is decreased. Like IMPDH1, many other metabolic enzymes dynamically assemble filamentous polymers that allosterically regulate activity. Our work suggests that posttranslational modifications may be yet another layer of regulatory control to finely tune activity by modulating filament assembly in response to changing metabolic demands.

Neurodevelopmental disorder mutations in the purine biosynthetic enzyme IMPDH2 disrupt its allosteric regulation.

Inosine 5' monophosphate dehydrogenase (IMPDH) is a critical regulatory enzyme in purine nucleotide biosynthesis that is inhibited by the downstream product GTP. Multiple point mutations in the human isoform IMPDH2 have recently been associated with dystonia and other neurodevelopmental disorders, but the effect of the mutations on enzyme function has not been described. Here, we report the identification of two additional missense variants in IMPDH2 from affected individuals and show that all of the disease-associated mutations disrupt GTP regulation. Cryo-EM structures of one IMPDH2 mutant suggest this regulatory defect arises from a shift in the conformational equilibrium toward a more active state. This structural and functional analysis provides insight into IMPDH2-associated disease mechanisms that point to potential therapeutic approaches and raises new questions about fundamental aspects of IMPDH regulation.

Caregiver Concerns About Child Development During the COVID-19 Pandemic among those with Missed Appointments: Preliminary Results.

Introduction: To examine caregiver's perception of their child falling behind on developmental milestones after canceled or delayed appointments in metropolitan Chicago during stay-at-home orders, from March 21-May 7, 2020. Methods: We fielded a web-based caregiver survey to understand the impact of the early weeks of the COVID-19 pandemic on children's health care experiences characterizing proportions of caregiver perceptions of children falling behind in developmental milestones by canceled or delayed appointment types. Multivariable logistic regression was used to estimate the likelihood of falling behind in milestones . Results: Overall, 229 (7.5%) caregivers reported children with canceled or delayed appointments falling behind in developmental milestones. Approximately 25.4% of caregivers reported children falling behind on milestones in the Missed Therapeutic group, compared with the Other Missed group (2.9%) (p<0.001). Children in the Missed Therapeutic group (adjusted odds ratio (aOR) 10.3, 95% confidence interval (CI) 7.60-14.0)) and caregivers who experienced job loss (aOR 1.59, CI 1.11-2.28) or reduced hours or pay (aOR 1.90, CI 1.28-2.82) had higher odds of falling behind on developmental milestones. Conclusions: Implementation of new strategies to address the social needs of families should be develop when disruptions in developmental or therapeutic services among children occurs, particularly among children living in households with job insecurity.

Point mutations in IMPDH2 which cause early-onset neurodevelopmental disorders disrupt enzyme regulation and filament structure.

Inosine 5' monophosphate dehydrogenase (IMPDH) is a critical regulatory enzyme in purine nucleotide biosynthesis that is inhibited by the downstream product GTP. Multiple point mutations in the human isoform IMPDH2 have recently been associated with dystonia and other neurodevelopmental disorders, but the effect of the mutations on enzyme function has not been described. Here, we report identification of two additional affected individuals with missense variants in IMPDH2 and show that all of the disease-associated mutations disrupt GTP regulation. Cryo-EM structures of one IMPDH2 mutant suggest this regulatory defect arises from a shift in the conformational equilibrium toward a more active state. This structural and functional analysis provides insight into IMPDH2-associated disease mechanisms that point to potential therapeutic approaches and raises new questions about fundamental aspects of IMPDH regulation.

A Pilot Graduate Student-Led Near-Peer Mentorship Program for Transfer Students Provides a Supportive Network at an R1 Institution.

The undergraduate transfer process has well-documented challenges, especially for those who identify with groups historically excluded from science, technology, engineering, and mathematics (STEM) programs. Because transfer students gain later access to university networking and research opportunities than first-time-in-college students, transfer students interested in pursuing postbaccalaureate degrees in chemistry have a significantly shortened timeline in which to conduct research, a crucial component in graduate school applications. Mentorship programs have previously been instituted as effective platforms for the transfer of community cultural wealth within large institutions. We report here the design, institution, and assessment of a near-peer mentorship program for transfer students, the Transfer Student Mentorship Program (TSMP). Founded in 2020 by graduate students, the TSMP pairs incoming undergraduate transfer students with current graduate students for personalized mentorship and conducts discussion-based seminars to foster peer relationships. The transfer student participants have access to a fast-tracked networking method during their first transfer semester that can serve as a route for acquiring undergraduate research positions. Program efficacy was assessed via surveys investigating the rates of research participation and sense of belonging of transfer students. We observed that respondents that participated in the program experienced an overall improvement in these measures compared to respondents who did not. Having been entirely designed, instituted, and led by graduate students, we anticipate that this program will be highly tractable to other universities looking for actionable methods to improve their students' persistence in pursuing STEM degrees.

An Activity-Based Oxaziridine Platform for Identifying and Developing Covalent Ligands for Functional Allosteric Methionine Sites: Redox-Dependent Inhibition of Cyclin-Dependent Kinase 4.

Activity-based protein profiling (ABPP) is a versatile strategy for identifying and characterizing functional protein sites and compounds for therapeutic development. However, the vast majority of ABPP methods for covalent drug discovery target highly nucleophilic amino acids such as cysteine or lysine. Here, we report a methionine-directed ABPP platform using Redox-Activated Chemical Tagging (ReACT), which leverages a biomimetic oxidative ligation strategy for selective methionine modification. Application of ReACT to oncoprotein cyclin-dependent kinase 4 (CDK4) as a representative high-value drug target identified three new ligandable methionine sites. We then synthesized a methionine-targeting covalent ligand library bearing a diverse array of heterocyclic, heteroatom, and stereochemically rich substituents. ABPP screening of this focused library identified 1oxF11 as a covalent modifier of CDK4 at an allosteric M169 site. This compound inhibited kinase activity in a dose-dependent manner on purified protein and in breast cancer cells. Further investigation of 1oxF11 found prominent cation-π and H-bonding interactions stabilizing the binding of this fragment at the M169 site. Quantitative mass-spectrometry studies validated 1oxF11 ligation of CDK4 in breast cancer cell lysates. Further biochemical analyses revealed cross-talk between M169 oxidation and T172 phosphorylation, where M169 oxidation prevented phosphorylation of the activating T172 site on CDK4 and blocked cell cycle progression. By identifying a new mechanism for allosteric methionine redox regulation on CDK4 and developing a unique modality for its therapeutic intervention, this work showcases a generalizable platform that provides a starting point for engaging in broader chemoproteomics and protein ligand discovery efforts to find and target previously undruggable methionine sites.

Trends in Suicidal Ideation-Related Emergency Department Visits for Youth in Illinois: 2016-2021.

BACKGROUND AND OBJECTIVES: Increasing suicide rates and emergency department (ED) mental health visits reflect deteriorating mental health among American youth. This population-based study analyzes trends in ED visits for suicidal ideation (SI) before and during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: We analyzed Illinois hospital administrative data for ED visits coded for SI from January 2016 to June 2021 for youth aged 5 to 19 years. We characterized trends in patient sociodemographic and clinical characteristics, comparing three equal 22 month periods and analyzed patient and hospital characteristics associated with the likelihood of hospitalization. RESULTS: There were 81 051 ED visits coded for SI at 205 Illinois hospitals; 24.6% resulted in hospitalization. SI visits accounted for $785 million in charges and 145 160 hospital days over 66 months. ED SI visits increased 59% from 2016 through 2017 to 2019 through 2021, with a corresponding increase from 34.6% to 44.3% of SI principal diagnosis visits (both P < .001). Hospitalizations increased 57% between prepandemic fall 2019 and fall 2020 (P = .003). After controlling for demographic and clinical characteristics, youth were 84% less likely to be hospitalized if SI was their principal diagnosis and were more likely hospitalized if coded for severe mental illness, substance use, anxiety, or depression, or had ED visits to children's or behavioral health hospitals. CONCLUSIONS: This study documents child ED SI visits in Illinois spiked in 2019, with an additional surge in hospitalizations during the pandemic. Rapidly rising hospital use may reflect worsening mental illness and continued difficulty in accessing low cost, high-quality outpatient mental health services.

Enhancing grant-writing expertise in BUILD institutions: Building infrastructure leading to diversity.

BACKGROUND: The lack of race/ethnic and gender diversity in grants funded by the National Institutes of Health (NIH) is a persistent challenge related to career advancement and the quality and relevance of health research. We describe pilot programs at nine institutions supported by the NIH-sponsored Building Infrastructure Leading to Diversity (BUILD) program aimed at increasing diversity in biomedical research. METHODS: We collected data from the 2016-2017 Higher Education Research Institute survey of faculty and NIH progress reports for the first four years of the program (2015-2018). We then conducted descriptive analyses of data from the nine BUILD institutions that had collected data and evaluated which activities were associated with research productivity. We used Poisson regression and rate ratios of the numbers of BUILD pilots funded, students included, abstracts, presentations, publications, and submitted and funded grant proposals. RESULTS: Teaching workshops were associated with more abstracts (RR 4.04, 95% CI 2.21-8.09). Workshops on grant writing were associated with more publications (RR 2.64, 95% CI 1.64-4.34) and marginally with marginally more presentations. Incentives to develop courses were associated with more abstracts published (RR 4.33, 95% CI 2.56-7.75). Workshops on research skills and other incentives were not associated with any positive effects. CONCLUSIONS: Pilot interventions show promise in supporting diversity in NIH-level research. Longitudinal modeling that considers time lags in career development in moving from project development to grants submissions can provide more direction for future diversity pilot interventions.

Ketamine as a prophylactic resilience-enhancing agent.

Stress exposure is one of the greatest risk factors for psychiatric illnesses, including major depressive disorder (MDD) and posttraumatic stress disorder (PTSD). Enhancing stress resilience could potentially protect against the development of stress-induced psychiatric disorders, yet no resilience-enhancing pharmaceuticals have been developed to date. This review serves to consider the existing evidence for a potential pro-resilience effect of ketamine in rodents as well as the preliminary evidence of ketamine as a prophylactic treatment for postpartum depression (PPD) in humans. Several animal studies have demonstrated that ketamine administered 1 week prior to a stressor (e.g., chronic social defeat and learned helplessness) may protect against depressive-like behavior. A similar protective effect has been demonstrated against PTSD-like behavior following Contextual Fear Conditioning (CFC). Recent work has sought to explore if the administration of ketamine prevented the development of postpartum depression (PPD) in humans. Researchers administered ketamine immediately following caesarian-section and found a significantly reduced prevalence of PPD in the ketamine-treated groups compared to the control groups. Utilizing ketamine as a resilience-enhancing treatment may have unique applications, including leading to a deeper understanding of the neurobiological mechanism underlying resilience. Future trials aiming to translate and replicate these findings with humans are warranted.

COVID-Net CXR-2: An Enhanced Deep Convolutional Neural Network Design for Detection of COVID-19 Cases From Chest X-ray Images.

As the COVID-19 pandemic devastates globally, the use of chest X-ray (CXR) imaging as a complimentary screening strategy to RT-PCR testing continues to grow given its routine clinical use for respiratory complaint. As part of the COVID-Net open source initiative, we introduce COVID-Net CXR-2, an enhanced deep convolutional neural network design for COVID-19 detection from CXR images built using a greater quantity and diversity of patients than the original COVID-Net. We also introduce a new benchmark dataset composed of 19,203 CXR images from a multinational cohort of 16,656 patients from at least 51 countries, making it the largest, most diverse COVID-19 CXR dataset in open access form. The COVID-Net CXR-2 network achieves sensitivity and positive predictive value of 95.5 and 97.0%, respectively, and was audited in a transparent and responsible manner. Explainability-driven performance validation was used during auditing to gain deeper insights in its decision-making behavior and to ensure clinically relevant factors are leveraged for improving trust in its usage. Radiologist validation was also conducted, where select cases were reviewed and reported on by two board-certified radiologists with over 10 and 19 years of experience, respectively, and showed that the critical factors leveraged by COVID-Net CXR-2 are consistent with radiologist interpretations.

Success of implementation of a systemwide point-of-care ultrasound privileging program for emergency medicine faculty.

Objectives: Point-of-care ultrasound (POCUS) is widely used in the emergency department (ED). Not all practicing emergency physicians received POCUS training during residency, leaving a training gap that is reflected in POCUS privileging. The purpose of this study was to evaluate the success of meeting privileging criteria as well as associated factors, following implementation of a basic POCUS training and privileging program within a large emergency medicine department. Methods: We implemented a POCUS training and privileging program, based on national guidelines, for faculty physicians who worked at one of the following EDs staffed by the same emergency medicine department: a pediatric tertiary site, two tertiary academic sites, and seven community sites. POCUS examinations included aorta, cardiac, first-trimester obstetrics (OB), and extended focused assessment with sonography in trauma. Pediatric emergency medicine faculty were taught soft tissue and thoracic US instead of aorta and OB. Completion of the program required 16 h of didactics, ≥25 quality-assured US examinations by examination type, and passing a series of knowledge-based examinations. Descriptive statistics were calculated. Associations between physician characteristics and successfully becoming privileged in POCUS were modeled using Firth's logistic regression. Results: A total of 176 faculty physicians were eligible. A total of 145 (82.4%) achieved basic POCUS privileging during the study period. Different pathways were used including 86 (48.9%) practice-based, nine (5.1%) fellowship-based, and 82 (46.9%) residency-based. POCUS privileging was lower for those working in a community versus academic setting (odds ratio 0.3, 95% confidence interval 0.1-0.9). A greater number of scans completed prior to the privileging program was associated with greater success. Conclusions: Implementation of a POCUS training and privileging program can be successful in a large emergency medicine department that staffs hospitals in a large-scale health care system composed of both academic and community sites. Faculty physicians with at least some prior exposure to POCUS were more successful.

Automated food intake tracking requires depth-refined semantic segmentation to rectify visual-volume discordance in long-term care homes.

Malnutrition is a multidomain problem affecting 54% of older adults in long-term care (LTC). Monitoring nutritional intake in LTC is laborious and subjective, limiting clinical inference capabilities. Recent advances in automatic image-based food estimation have not yet been evaluated in LTC settings. Here, we describe a fully automatic imaging system for quantifying food intake. We propose a novel deep convolutional encoder-decoder food network with depth-refinement (EDFN-D) using an RGB-D camera for quantifying a plate's remaining food volume relative to reference portions in whole and modified texture foods. We trained and validated the network on the pre-labelled UNIMIB2016 food dataset and tested on our two novel LTC-inspired plate datasets (689 plate images, 36 unique foods). EDFN-D performed comparably to depth-refined graph cut on IOU (0.879 vs. 0.887), with intake errors well below typical 50% (mean percent intake error: [Formula: see text]%). We identify how standard segmentation metrics are insufficient due to visual-volume discordance, and include volume disparity analysis to facilitate system trust. This system provides improved transparency, approximates human assessors with enhanced objectivity, accuracy, and precision while avoiding hefty semi-automatic method time requirements. This may help address short-comings currently limiting utility of automated early malnutrition detection in resource-constrained LTC and hospital settings.

Teaching Seasoned Doctors New Technology: An Intervention to Reduce Barriers and Improve Comfort With Clinical Ultrasound.

Introduction Although clinical ultrasound (CUS) is a core skill that is a requirement for emergency medicine (EM) residency graduation, only a fraction of EM practitioners who trained prior to this requirement are certified in CUS. The objective of the study was to implement a CUS workshop for practicing EM physicians, identify barriers to utilization, and assess comfort with the machine, obtaining and interpreting images, and incorporating CUS into clinical practice. Methods This was a prospective descriptive cohort study of EM physician faculty who participated in an interactive 5-hour CUS workshop intervention that introduced four core CUS modalities via didactics and hands-on scanning stations. Pre- and post-surveys were administered to identify barriers to utilization and assess perceived comfort with CUS using a 5-point Likert scale. Results were analyzed using Fisher's exact and paired t-tests. Results Thirty-five EM physicians participated with a 100% survey response rate. Only five of the physicians were ultrasound certified at the time of the workshop. On average, physicians were 16 years post-residency. Prior to the workshop, 29% had minimal ultrasound experience and 43% had not performed more than 50 ultrasounds. In the pre-course survey, every physician expressed at least one barrier to CUS utilization. Post-workshop, physicians felt significantly more comfortable using the ultrasound machine (p=0.0008), obtaining and interpreting images (p=0.0009 and p=0.0004), and incorporating CUS into clinical practice (p=0.002). Conclusion This workshop is an effective tool to expose practicing physicians to core concepts of CUS, improve their comfort level, and reduce barriers to ultrasound utilization.

Racial/Ethnic Differences in Food Allergy.

Immunoglobulin E-mediated food allergy is an increasingly prevalent public health concern globally. In North America, particularly in the United States, racial and ethnic differences in food allergy prevalence and rates of sensitization have become apparent. Black and Hispanic children in the United States have been estimated to have the highest rates of food allergy. Beyond rates of prevalence, food allergy outcomes, such as health care utilization, psychosocial outcomes, and economic burden, also vary considerably by race and ethnicity. It is important to consider socioeconomic status in conjunction with race and ethnicity in studying differences in food allergy outcomes.