A dedicated hypothalamic oxytocin circuit controls aversive social learning.

To survive in a complex social group, one needs to know who to approach and, more importantly, who to avoid. In mice, a single defeat causes the losing mouse to stay away from the winner for weeks1. Here through a series of functional manipulation and recording experiments, we identify oxytocin neurons in the retrochiasmatic supraoptic nucleus (SOROXT) and oxytocin-receptor-expressing cells in the anterior subdivision of the ventromedial hypothalamus, ventrolateral part (aVMHvlOXTR) as a key circuit motif for defeat-induced social avoidance. Before defeat, aVMHvlOXTR cells minimally respond to aggressor cues. During defeat, aVMHvlOXTR cells are highly activated and, with the help of an exclusive oxytocin supply from the SOR, potentiate their responses to aggressor cues. After defeat, strong aggressor-induced aVMHvlOXTR cell activation drives the animal to avoid the aggressor and minimizes future defeat. Our study uncovers a neural process that supports rapid social learning caused by defeat and highlights the importance of the brain oxytocin system in social plasticity.

Changes in adenomyosis following elagolix vs leuprolide treatment in a patient with pelvic pain and infertility: A case report.

Adenomyosis is a uterine form of endometriosis that poses unique challenges in the management of infertility. Severe pelvic pain and menorrhagia associated with these conditions are commonly managed with intramuscular injections of a gonadotropin-releasing hormone agonist (leuprolide acetate). Since receiving approval by the US Food and Drug Administration in 2018, a novel oral gonadotropin-releasing hormone antagonist, elagolix, has also been increasingly used to manage endometriosis-associated pain. However, the efficacy of elagolix in the treatment of adenomyosis and infertility remains uncertain. In this clinical case of an infertile patient with endometriosis and diminished ovarian reserve, treatment with elagolix effectively controlled her severe endometriosis-related pelvic pain but, surprisingly, failed to prevent concurrent progression of adenomyosis. Subsequently, elagolix was changed to treatment with leuprolide acetate, which led to improvement of adenomyosis in preparation for an embryo transfer during an in vitro fertilization cycle. Women's health providers should be aware that elagolix may not as effectively suppress adenomyosis as leuprolide acetate, particularly in infertility patients undergoing treatment with assisted reproductive technologies.

Using augmented reality to cue obstacles for people with low vision.

Detecting and avoiding obstacles while navigating can pose a challenge for people with low vision, but augmented reality (AR) has the potential to assist by enhancing obstacle visibility. Perceptual and user experience research is needed to understand how to craft effective AR visuals for this purpose. We developed a prototype AR application capable of displaying multiple kinds of visual cues for obstacles on an optical see-through head-mounted display. We assessed the usability of these cues via a study in which participants with low vision navigated an obstacle course. The results suggest that 3D world-locked AR cues were superior to directional heads-up cues for most participants during this activity.

UPF1 mutants with intact ATPase but deficient helicase activities promote efficient nonsense-mediated mRNA decay.

The conserved RNA helicase UPF1 coordinates nonsense-mediated mRNA decay (NMD) by engaging with mRNAs, RNA decay machinery and the terminating ribosome. UPF1 ATPase activity is implicated in mRNA target discrimination and completion of decay, but the mechanisms through which UPF1 enzymatic activities such as helicase, translocase, RNP remodeling, and ATPase-stimulated dissociation influence NMD remain poorly defined. Using high-throughput biochemical assays to quantify UPF1 enzymatic activities, we show that UPF1 is only moderately processive (<200 nt) in physiological contexts and undergoes ATPase-stimulated dissociation from RNA. We combine an in silico screen with these assays to identify and characterize known and novel UPF1 mutants with altered helicase, ATPase, and RNA binding properties. We find that UPF1 mutants with substantially impaired processivity (E797R, G619K/A546H), faster (G619K) or slower (K547P, E797R, G619K/A546H) unwinding rates, and/or reduced mechanochemical coupling (i.e. the ability to harness ATP hydrolysis for work; K547P, R549S, G619K, G619K/A546H) can still support efficient NMD of well-characterized targets in human cells. These data are consistent with a central role for UPF1 ATPase activity in driving cycles of RNA binding and dissociation to ensure accurate NMD target selection.

Development and Validation of a Model to Predict Postdischarge Opioid Use After Cesarean Birth.

OBJECTIVE: To develop and validate a prediction model for postdischarge opioid use in patients undergoing cesarean birth. METHODS: We conducted a prospective cohort study of patients undergoing cesarean birth. Patients were enrolled postoperatively, and they completed pain and opioid use questionnaires 14 days after cesarean birth. Clinical data were abstracted from the electronic health record (EHR). Participants were prescribed 30 tablets of hydrocodone 5 mg-acetaminophen 325 mg at discharge and were queried about postdischarge opioid use. The primary outcome was total morphine milligram equivalents used. We constructed three proportional odds predictive models of postdischarge opioid use: a full model with 34 predictors available before hospital discharge, an EHR model that excluded questionnaire data, and a reduced model. The reduced model used forward selection to sequentially add predictors until 90% of the full model performance was achieved. Predictors were ranked a priori based on data from the literature and prior research. Predictive accuracy was estimated using discrimination (concordance index). RESULTS: Between 2019 and 2020, 459 participants were enrolled and 279 filled the standardized study prescription. Of the 398 with outcome measurements, participants used a median of eight tablets (interquartile range 1-18 tablets) after discharge, 23.5% used no opioids, and 23.0% used all opioids. Each of the models demonstrated high accuracy predicting postdischarge opioid use (concordance index range 0.74-0.76 for all models). We selected the reduced model as our final model given its similar model performance with the fewest number of predictors, all obtained from the EHR (inpatient opioid use, tobacco use, and depression or anxiety). CONCLUSION: A model with three predictors readily found in the EHR-inpatient opioid use, tobacco use, and depression or anxiety-accurately estimated postdischarge opioid use. This represents an opportunity for individualizing opioid prescriptions after cesarean birth.

An alternative UPF1 isoform drives conditional remodeling of nonsense-mediated mRNA decay.

The nonsense-mediated mRNA decay (NMD) pathway monitors translation termination in order to degrade transcripts with premature stop codons and regulate thousands of human genes. Here, we show that an alternative mammalian-specific isoform of the core NMD factor UPF1, termed UPF1LL , enables condition-dependent remodeling of NMD specificity. Previous studies indicate that the extension of a conserved regulatory loop in the UPF1LL helicase core confers a decreased propensity to dissociate from RNA upon ATP hydrolysis relative to UPF1SL , the major UPF1 isoform. Using biochemical and transcriptome-wide approaches, we find that UPF1LL can circumvent the protective RNA binding proteins PTBP1 and hnRNP L to preferentially bind and down-regulate transcripts with long 3'UTRs normally shielded from NMD. Unexpectedly, UPF1LL supports induction of NMD on new populations of substrate mRNAs in response to activation of the integrated stress response and impaired translation efficiency. Thus, while canonical NMD is abolished by moderate translational repression, UPF1LL activity is enhanced, offering the possibility to rapidly rewire NMD specificity in response to cellular stress.

Longitudinal uptake of the human papillomavirus vaccine among gay, bisexual and other men who have sex with men in British Columbia, Canada 2012-2019.

OBJECTIVES: In 2015, a publicly funded human papillomavirus (HPV) vaccination programme was implemented for gay, bisexual and other men who have sex with men (gbMSM) up to age 26 years in British Columbia, Canada. We assessed trends and correlates of HPV vaccine uptake from 2012 to 2019 in a cohort of gbMSM in Vancouver. METHODS: We recruited sexually active gbMSM aged ≥16 years using respondent-driven sampling from February 2012 to February 2015 and followed them until July 2019. We evaluated self-reported HPV vaccine trends using mixed-effects logistic regression and identified factors associated with uptake using multivariable mixed-effects Poisson regression. RESULTS: A total of 719 participants were recruited and completed the baseline visit, of whom 549 were unvaccinated with at least one follow-up visit. The median age was 33 years and 23% were living with HIV. HPV vaccination increased from 4% in 2012 to 28% in 2019 (p<0.001) among gbMSM >26 years, and from 9% in 2012 to 20% in 2017 (p<0.001) among gbMSM ≤26 years. Vaccination uptake increased after September 2015, following vaccination policy expansion (adjusted rate ratio (aRR)=1.82, 95% CI 1.06 to 3.12). In multivariable models, increased vaccination was associated with age ≤26 years vs ≥45 years (aRR=3.90; 95% CI 1.75 to 8.70), age 27-44 vs ≥45 years (aRR=2.86; 95% CI 1.46 to 5.62), involvement in gay community sports teams (aRR=2.31; 95% CI 1.15 to 4.64) and other groups (aRR=1.71; 95% CI 1.04 to 2.79), awareness of HIV-postexposure prophylaxis (aRR=5.50; 95% CI 1.31 to 23.09), recent sexually transmitted infection testing (aRR=2.72; 95% CI 1.60 to 4.60) and recent sex-work (aRR=2.59; 95% CI 1.08 to 6.19). CONCLUSIONS: Although we observed increases in HPV vaccination uptake from 2012, by 2019 HPV vaccination still remained below 30% among gbMSM in Vancouver, BC. Additional interventions are needed to increase vaccine uptake.

Analysis of meiosis in Pristionchus pacificus reveals plasticity in homolog pairing and synapsis in the nematode lineage.

Meiosis is conserved across eukaryotes yet varies in the details of its execution. Here we describe a new comparative model system for molecular analysis of meiosis, the nematode Pristionchus pacificus, a distant relative of the widely studied model organism Caenorhabditis elegans. P. pacificus shares many anatomical and other features that facilitate analysis of meiosis in C. elegans. However, while C. elegans has lost the meiosis-specific recombinase Dmc1 and evolved a recombination-independent mechanism to synapse its chromosomes, P. pacificus expresses both DMC-1 and RAD-51. We find that SPO-11 and DMC-1 are required for stable homolog pairing, synapsis, and crossover formation, while RAD-51 is dispensable for these key meiotic processes. RAD-51 and DMC-1 localize sequentially to chromosomes during meiotic prophase and show nonoverlapping functions. We also present a new genetic map for P. pacificus that reveals a crossover landscape very similar to that of C. elegans, despite marked divergence in the regulation of synapsis and crossing-over between these lineages.

Optimization of a bacterial three-hybrid assay through in vivo titration of an RNA-DNA adapter protein.

Noncoding RNAs regulate gene expression in every domain of life. In bacteria, small RNAs (sRNAs) regulate gene expression in response to stress and are often assisted by RNA-chaperone proteins, such as Hfq. We have recently developed a bacterial three-hybrid (B3H) assay that detects the strong binding interactions of certain E. coli sRNAs with proteins Hfq and ProQ. Despite the promise of this system, the signal-to-noise has made it challenging to detect weaker interactions. In this work, we use Hfq-sRNA interactions as a model system to optimize the B3H assay, so that weaker RNA-protein interactions can be more reliably detected. We find that the concentration of the RNA-DNA adapter is an important parameter in determining the signal in the system and have modified the plasmid expressing this component to tune its concentration to optimal levels. In addition, we have systematically perturbed the binding affinity of Hfq-RNA interactions to define, for the first time, the relationship between B3H signal and in vitro binding energetics. The new pAdapter construct presented here substantially expands the range of detectable interactions in the B3H assay, broadening its utility. This improved assay will increase the likelihood of identifying novel protein-RNA interactions with the B3H system and will facilitate exploration of the binding mechanisms of these interactions.

The RNA-binding protein PTBP1 promotes ATPase-dependent dissociation of the RNA helicase UPF1 to protect transcripts from nonsense-mediated mRNA decay.

The sequence-specific RNA-binding proteins PTBP1 (polypyrimidine tract-binding protein 1) and HNRNP L (heterogeneous nuclear ribonucleoprotein L) protect mRNAs from nonsense-mediated decay (NMD) by preventing the UPF1 RNA helicase from associating with potential decay targets. Here, by analyzing in vitro helicase activity, dissociation of UPF1 from purified mRNPs, and transcriptome-wide UPF1 RNA binding, we present the mechanistic basis for inhibition of NMD by PTBP1. Unlike mechanisms of RNA stabilization that depend on direct competition for binding sites among protective RNA-binding proteins and decay factors, PTBP1 promotes displacement of UPF1 already bound to potential substrates. Our results show that PTBP1 directly exploits the tendency of UPF1 to release RNA upon ATP binding and hydrolysis. We further find that UPF1 sensitivity to PTBP1 is coordinated by a regulatory loop in domain 1B of UPF1. We propose that the UPF1 regulatory loop and protective proteins control kinetic proofreading of potential NMD substrates, presenting a new model for RNA helicase regulation and target selection in the NMD pathway.

Genetic identification of the functional surface for RNA binding by Escherichia coli ProQ.

The FinO-domain-protein ProQ is an RNA-binding protein that has been known to play a role in osmoregulation in proteobacteria. Recently, ProQ has been shown to act as a global RNA-binding protein in Salmonella and Escherichia coli, binding to dozens of small RNAs (sRNAs) and messenger RNAs (mRNAs) to regulate mRNA-expression levels through interactions with both 5' and 3' untranslated regions (UTRs). Despite excitement around ProQ as a novel global RNA-binding protein, and its potential to serve as a matchmaking RNA chaperone, significant gaps remain in our understanding of the molecular mechanisms ProQ uses to interact with RNA. In order to apply the tools of molecular genetics to this question, we have adapted a bacterial three-hybrid (B3H) assay to detect ProQ's interactions with target RNAs. Using domain truncations, site-directed mutagenesis and an unbiased forward genetic screen, we have identified a group of highly conserved residues on ProQ's NTD as the primary face for in vivo recognition of two RNAs, and propose that the NTD structure serves as an electrostatic scaffold to recognize the shape of an RNA duplex.

Community awareness of, use of and attitudes towards HIV pre-exposure prophylaxis (PrEP) among men who have sex with men in Vancouver, Canada: preparing health promotion for a publicly funded PrEP program.

Background HIV rates are persistently disproportionate among men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) is an effective HIV prevention method, now publicly funded in British Columbia. This study assessed PrEP-related attitudes, sexual behaviour and self-reported use before public funding. METHODS: Adult MSM were recruited from January to June 2017 through a local community-based organisation's PrEP campaign website (www.getpreped.ca). Participants self-completed an anonymous online questionnaire, and were stratified into three groups: (i) HIV-positive participants; (ii) HIV-negative participants not using PrEP; and (iii) HIV-negative participants using PrEP. Descriptive, bivariate and univariate regression analyses were conducted. RESULTS: Of 249 participants, 191 (77%) were HIV-negative not using PrEP, 41 (17%) were HIV-negative using PrEP and 17 (7%) were HIV-positive. Among PrEP users, 90% used PrEP daily and all reported having recommended medical follow-up care. Among HIV-negative, non-PrEP-users, 44% said they would reduce condom use if they used PrEP and 28% were uncomfortable asking their doctor for PrEP. Interest in PrEP among non-users was associated with higher objective risk scores (i.e. HIV Incidence Risk Index for MSM), higher self-perceived risk, greater perceived PrEP effectiveness, no prescription medications insurance, open or single relationship status (vs closed) and not always using condoms (vs always). Among HIV-positive participants, 53% agreed PrEP reduced stigma for people living with HIV. All study groups perceived a greater percentage of MSM on PrEP (10%, 15%, 18%) than in their own social networks (5%, 4%, 6%). CONCLUSIONS: PrEP health promotion must consider comprehensive PrEP education; accuracy of self-perceived HIV risk and PrEP social norms; and barriers to culturally safe primary care for MSM.

Tertiary Care Multidisciplinary Teams Associated with Improved Survival in Rectal Cancer Patients: A Comparative Study.

For stage II/III rectal cancer patients, comprehensive multidisciplinary care (MDC) affects outcomes. Randomized trials have shown the effectiveness of adjuvant and neoadjuvant therapy in treatment of these patients. However, the effectiveness of collaboration within MDC is undetermined. It is possible that regional variation in survival outcomes may be tied to treatment facility. We retrospectively reviewed a prospectively collected database of patients with stage II/III rectal cancer who received MDC at any location and underwent oncologic colorectal resection at a tertiary care center (TCC) between 2005 and 2011. Of the 571 rectal cancer patients, 391 had a stage II/III rectal cancer and received surgery at a TCC. After exclusion criteria, we observed that 120 patients received neoadjuvant therapy and 119 patients received adjuvant therapy. For neoadjuvant patients, no difference in overall survival was observed between treatment received at a TCC versus an outside facility. However, a significant improvement in survival was observed in patients who received adjuvant therapy at a TCC (P = 0.01). Thus, the location of postoperative adjuvant therapy shows improvement in 10-year survival at a TCC versus elsewhere. Thus, standardization of care can impact outcomes for invasive rectal cancer patients. The limitations of this study are its retrospective nature and relatively small sample size.

Critical dynamics in population vaccinating behavior.

Vaccine refusal can lead to renewed outbreaks of previously eliminated diseases and even delay global eradication. Vaccinating decisions exemplify a complex, coupled system where vaccinating behavior and disease dynamics influence one another. Such systems often exhibit critical phenomena-special dynamics close to a tipping point leading to a new dynamical regime. For instance, critical slowing down (declining rate of recovery from small perturbations) may emerge as a tipping point is approached. Here, we collected and geocoded tweets about measles-mumps-rubella vaccine and classified their sentiment using machine-learning algorithms. We also extracted data on measles-related Google searches. We find critical slowing down in the data at the level of California and the United States in the years before and after the 2014-2015 Disneyland, California measles outbreak. Critical slowing down starts growing appreciably several years before the Disneyland outbreak as vaccine uptake declines and the population approaches the tipping point. However, due to the adaptive nature of coupled behavior-disease systems, the population responds to the outbreak by moving away from the tipping point, causing "critical speeding up" whereby resilience to perturbations increases. A mathematical model of measles transmission and vaccine sentiment predicts the same qualitative patterns in the neighborhood of a tipping point to greatly reduced vaccine uptake and large epidemics. These results support the hypothesis that population vaccinating behavior near the disease elimination threshold is a critical phenomenon. Developing new analytical tools to detect these patterns in digital social data might help us identify populations at heightened risk of widespread vaccine refusal.

Functional Human and Murine Tissue-Engineered Liver Is Generated from Adult Stem/Progenitor Cells.

Liver disease affects large numbers of patients, yet there are limited treatments available to replace absent or ineffective cellular function of this crucial organ. Donor scarcity and the necessity for immunosuppression limit one effective therapy, orthotopic liver transplantation. But in some conditions such as inborn errors of metabolism or transient states of liver insufficiency, patients may be salvaged by providing partial quantities of functional liver tissue. After transplanting multicellular liver organoid units composed of a heterogeneous cellular population that includes adult stem and progenitor cells, both mouse and human tissue-engineered liver (TELi) form in vivo. TELi contains normal liver components such as hepatocytes with albumin expression, CK19-expressing bile ducts and vascular structures with α-smooth muscle actin expression, desmin-expressing stellate cells, and CD31-expressing endothelial cells. At 4 weeks, TELi contains proliferating albumin-expressing cells and identification of ß2-microglobulin-expressing cells demonstrates that the majority of human TELi is composed of transplanted human cells. Human albumin is detected in the host mouse serum, indicating in vivo secretory function. Liquid chromatography/mass spectrometric analysis of mouse serum after debrisoquine administration is followed by a significant increase in the level of the human metabolite, 4-OH-debrisoquine, which supports the metabolic and xenobiotic capability of human TELi in vivo. Implanted TELi grew in a mouse model of inducible liver failure. Stem Cells Translational Medicine 2017;6:238-248.