Traumatic Cervical Spinal Cord Injury and Income and Employment Status.

Importance: Spinal cord injury (SCI) causes drastic changes to an individual's physical health that may be associated with the ability to work. Objective: To estimate the association of SCI with individual earnings and employment status using national administrative health databases linked to income tax data. Design, Setting, and Participants: This was a retrospective, national, population-based cohort study of adults who were hospitalized with cervical SCI in Canada between January 2005 and December 2017. All acute care hospitalizations for SCI of adults ages 18 to 64 years were included. A comparison group was constructed by sampling from individuals in the injured cohort. Fiscal information from their preinjury years was used for comparison. The injured cohort was matched with the comparison group based on age, sex, marital status, province of residence, self-employment status, earnings, and employment status in the year prior to injury. Data were analyzed from August 2022 to January 2023. Main outcomes and Measures: The first outcome was the change in individual annual earnings up to 5 years after injury. The change in mean yearly earnings was assessed using a linear mixed-effects differences-in-differences regression. Income values are reported in 2022 Canadian dollars (CAD $1.00 = US $0.73). The second outcome was the change in employment status up to 5 years after injury. A multivariable probit regression model was used to compare proportions of individuals employed among those who had experienced SCI and the paired comparison group of participants. Results: A total of 1630 patients with SCI (mean [SD] age, 47 [13] years; 1304 male [80.0%]) were matched to patients in a preinjury comparison group (resampled from the same 1630 patients in the SCI group). The mean (SD) of preinjury wage earnings was CAD $46 000 ($48 252). The annual decline in individual earnings was CAD $20 275 (95% CI, -$24 455 to -$16 095) in the first year after injury and CAD $20 348 (95% CI, -$24 710 to -$15 985) in the fifth year after injury. At 5 years after injury, 52% of individuals who had an injury were working compared with 79% individuals in the preinjury comparison group. SCI survivors had a decrease in employment of 17.1 percentage points (95% CI, 14.5 to 19.7 percentage points) in the first year after injury and 17.8 percentage points (14.5 to 21.1 percentage points) in the fifth year after injury. Conclusions and Relevance: In this study, SCI was associated with a decline in earnings and employment up to 5 years after injury for adults aged 18 to 64 years in Canada.

Allosteric Cholesterol Site in Glycine Receptors Characterized through Molecular Simulations.

Glycine receptors are pentameric ligand-gated ion channels that conduct chloride ions across postsynaptic membranes to facilitate fast inhibitory neurotransmission. In addition to gating by the glycine agonist, interactions with lipids and other compounds in the surrounding membrane environment modulate their function, but molecular details of these interactions remain unclear, in particular, for cholesterol. Here, we report coarse-grained simulations in a model neuronal membrane for three zebrafish glycine receptor structures representing apparent resting, open, and desensitized states. We then converted the systems to all-atom models to examine detailed lipid interactions. Cholesterol bound to the receptor at an outer-leaflet intersubunit site, with a preference for the open and desensitized versus resting states, indicating that it can bias receptor function. Finally, we used short atomistic simulations and iterative amino acid perturbations to identify residues that may mediate allosteric gating transitions. Frequent cholesterol contacts in atomistic simulations clustered with residues identified by perturbation analysis and overlapped with mutations influencing channel function and pathology. Cholesterol binding at this site was also observed in a recently reported pig heteromeric glycine receptor. These results indicate state-dependent lipid interactions relevant to allosteric transitions of glycine receptors, including specific amino acid contacts applicable to biophysical modeling and pharmaceutical design.

Functional and structural insights into activation of TRPV2 by weak acids.

Transient receptor potential (TRP) ion channels are involved in the surveillance or regulation of the acid-base balance. Here, we demonstrate that weak carbonic acids, including acetic acid, lactic acid, and CO2 activate and sensitize TRPV2 through a mechanism requiring permeation through the cell membrane. TRPV2 channels in cell-free inside-out patches maintain weak acid-sensitivity, but protons applied on either side of the membrane do not induce channel activation or sensitization. The involvement of proton modulation sites for weak acid-sensitivity was supported by the identification of titratable extracellular (Glu495, Glu561) and intracellular (His521) residues on a cryo-EM structure of rat TRPV2 (rTRPV2) treated with acetic acid. Molecular dynamics simulations as well as patch clamp experiments on mutant rTRPV2 constructs confirmed that these residues are critical for weak acid-sensitivity. We also demonstrate that the pore residue Glu609 dictates an inhibition of weak acid-induced currents by extracellular calcium. Finally, TRPV2-expression in HEK293 cells is associated with an increased weak acid-induced cytotoxicity. Together, our data provide new insights into weak acids as endogenous modulators of TRPV2.

Component-specific clusters for diagnosis and prediction of allergic airway diseases.

BACKGROUND: Previous studies which applied machine learning on multiplex component-resolved diagnostics arrays identified clusters of allergen components which are biologically plausible and reflect the sources of allergenic proteins and their structural homogeneity. Sensitization to different clusters is associated with different clinical outcomes. OBJECTIVE: To investigate whether within different allergen component sensitization clusters, the internal within-cluster sensitization structure, including the number of c-sIgE responses and their distinct patterns, alters the risk of clinical expression of symptoms. METHODS: In a previous analysis in a population-based birth cohort, by clustering component-specific (c-s)IgEs, we derived allergen component clusters from infancy to adolescence. In the current analysis, we defined each subject's within-cluster sensitization structure which captured the total number of c-sIgE responses in each cluster and intra-cluster sensitization patterns. Associations between within-cluster sensitization patterns and clinical outcomes (asthma and rhinitis) in early-school age and adolescence were examined using logistic regression and binomial generalized additive models. RESULTS: Intra-cluster sensitization patterns revealed specific associations with asthma and rhinitis (both contemporaneously and longitudinally) that were previously unseen using binary sensitization to clusters. A more detailed description of the subjects' within-cluster c-sIgE responses in terms of the number of positive c-sIgEs and unique sensitization patterns added new information relevant to allergic diseases, both for diagnostic and prognostic purposes. For example, the increase in the number of within-cluster positive c-sIgEs at age 5 years was correlated with the increase in prevalence of asthma at ages 5 and 16 years, with the correlations being stronger in the prediction context (e.g. for the largest 'Broad' component cluster, contemporaneous: r = .28, p = .012; r = .22, p = .043; longitudinal: r = .36, p = .004; r = .27, p = .04). CONCLUSION: Among sensitized individuals, a more detailed description of within-cluster c-sIgE responses in terms of the number of positive c-sIgE responses and distinct sensitization patterns, adds potentially important information relevant to allergic diseases.

Quantitative and qualitative survey feedback of pharmacists regarding current and prospective licensure models.

BACKGROUND: Despite variation in licensure requirements and models for pharmacy practice nationwide, there is little published data within the United States regarding pharmacist perspectives. OBJECTIVES: The purpose of this study was to identify the demographics, awareness, and perceptions about current pharmacist licensure models. METHODS: A fifteen-question mixed-methods survey was created and distributed via Qualtrics-XM Survey to all Utah licensed pharmacists (n = 4154). Data collection was August 22-September 22, 2022. Before survey distribution, pilot feedback was sought from the Utah Board of Pharmacy and pharmacists at the 118th National Association of Boards of Pharmacy (NABP) national conference. Exempt status was granted by Roseman University Institutional Review Board. Quantitative and qualitative data analysis allowed for descriptive statistics and thematic content identification. RESULTS: The survey collected 972 responses for a response rate of 23% and a completion rate of 94%. Respondents self-identified 36 practice areas. Distribution of years in practice was well dispersed between the predefined ranges. Primary state of licensure was Utah (80%), with additional representation from all 50 states and Guam. The survey showed a variation in awareness regarding other healthcare professional licensing models with 40.83% "aware," 40.62% "unaware," and 18.55% "unsure". A majority showed awareness of the NABP Verify program (55.8%), but unawareness of the Electronic Licensure Transfer Program program (56.14%). Respondents agreed with increased license portability for medically underserved and rural areas (71.79%) and preference for having a law exam (56.72%). Pharmacists (n = 405) noted concerns regarding multistate renewal requirements, fees, and continuing education. CONCLUSION: This study provided baseline data on a topic that is missing in existing literature. Results illustrated a high completion rate, a diversity of demographics including well dispersed age ranges, years in practice, and qualitative responses. The quantitative data shed light on a variety of pharmacist perspectives and varied awareness about NABP licensure programs and compacts.

Interactive computational and experimental approaches improve the sensitivity of periplasmic binding protein-based nicotine biosensors for measurements in biofluids.

We developed fluorescent protein sensors for nicotine with improved sensitivity. For iNicSnFR12 at pH 7.4, the proportionality constant for ∆F/F0vs [nicotine] (δ-slope, 2.7 µM-1) is 6.1-fold higher than the previously reported iNicSnFR3a. The activated state of iNicSnFR12 has a fluorescence quantum yield of at least 0.6. We measured similar dose-response relations for the nicotine-induced absorbance increase and fluorescence increase, suggesting that the absorbance increase leads to the fluorescence increase via the previously described nicotine-induced conformational change, the 'candle snuffer' mechanism. Molecular dynamics (MD) simulations identified a binding pose for nicotine, previously indeterminate from experimental data. MD simulations also showed that Helix 4 of the periplasmic binding protein (PBP) domain appears tilted in iNicSnFR12 relative to iNicSnFR3a, likely altering allosteric network(s) that link the ligand binding site to the fluorophore. In thermal melt experiments, nicotine stabilized the PBP of the tested iNicSnFR variants. iNicSnFR12 resolved nicotine in diluted mouse and human serum at 100 nM, the peak [nicotine] that occurs during smoking or vaping, and possibly at the decreasing levels during intervals between sessions. NicSnFR12 was also partially activated by unidentified endogenous ligand(s) in biofluids. Improved iNicSnFR12 variants could become the molecular sensors in continuous nicotine monitors for animal and human biofluids.

Discovery of lipid binding sites in a ligand-gated ion channel by integrating simulations and cryo-EM.

Ligand-gated ion channels transduce electrochemical signals in neurons and other excitable cells. Aside from canonical ligands, phospholipids are thought to bind specifically to the transmembrane domain of several ion channels. However, structural details of such lipid contacts remain elusive, partly due to limited resolution of these regions in experimental structures. Here, we discovered multiple lipid interactions in the channel GLIC by integrating cryo-electron microscopy and large-scale molecular simulations. We identified 25 bound lipids in the GLIC closed state, a conformation where none, to our knowledge, were previously known. Three lipids were associated with each subunit in the inner leaflet, including a buried interaction disrupted in mutant simulations. In the outer leaflet, two intrasubunit sites were evident in both closed and open states, while a putative intersubunit site was preferred in open-state simulations. This work offers molecular details of GLIC-lipid contacts particularly in the ill-characterized closed state, testable hypotheses for state-dependent binding, and a multidisciplinary strategy for modeling protein-lipid interactions.

Interactive computational and experimental approaches improve the sensitivity of periplasmic binding protein-based nicotine biosensors for measurements in biofluids.

We developed fluorescent protein sensors for nicotine with improved sensitivity. For iNicSnFR12 at pH 7.4, the proportionality constant for ΔF/F0 vs [nicotine] (δ-slope, 2.7 µM-1) is 6.1-fold higher than the previously reported iNicSnFR3a. The activated state of iNicSnFR12 has a fluorescence quantum yield of at least 0.6. We measured similar dose-response relations for the nicotine-induced absorbance increase and fluorescence increase, suggesting that the absorbance increase leads to the fluorescence increase via the previously described nicotine-induced conformational change, the "candle snuffer" mechanism. Molecular dynamics (MD) simulations identified a binding pose for nicotine, previously indeterminate from experimental data. MD simulations also showed that Helix 4 of the periplasmic binding protein (PBP) domain appears tilted in iNicSnFR12 relative to iNicSnFR3a, likely altering allosteric network(s) that link the ligand binding site to the fluorophore. In thermal melt experiments, nicotine stabilized the PBP of the tested iNicSnFR variants. iNicSnFR12 resolved nicotine in diluted mouse and human serum at 100 nM, the peak [nicotine] that occurs during smoking or vaping, and possibly at the decreasing levels during intervals between sessions. NicSnFR12 was also partially activated by unidentified endogenous ligand(s) in biofluids. Improved iNicSnFR12 variants could become the molecular sensors in continuous nicotine monitors for animal and human biofluids.

tRNA shape is an identity element for an archaeal pyrrolysyl-tRNA synthetase from the human gut.

Protein translation is orchestrated through tRNA aminoacylation and ribosomal elongation. Among the highly conserved structure of tRNAs, they have distinguishing features which promote interaction with their cognate aminoacyl tRNA synthetase (aaRS). These key features are referred to as identity elements. In our study, we investigated the tRNA:aaRS pair that installs the 22nd amino acid, pyrrolysine (tRNAPyl:PylRS). Pyrrolysyl-tRNA synthetases (PylRSs) are naturally encoded in some archaeal and bacterial genomes to acylate tRNAPyl with pyrrolysine. Their large amino acid binding pocket and poor recognition of the tRNA anticodon have been instrumental in incorporating >200 noncanonical amino acids. PylRS enzymes can be divided into three classes based on their genomic structure. Two classes contain both an N-terminal and C-terminal domain, however the third class (ΔpylSn) lacks the N-terminal domain. In this study we explored the tRNA identity elements for a ΔpylSn tRNAPyl from Candidatus Methanomethylophilus alvus which drives the orthogonality seen with its cognate PylRS (MaPylRS). From aminoacylation and translation assays we identified five key elements in ΔpylSn tRNAPyl necessary for MaPylRS activity. The absence of a base (position 8) and a G-U wobble pair (G28:U42) were found to affect the high-resolution structure of the tRNA, while molecular dynamic simulations led us to acknowledge the rigidity imparted from the G-C base pairs (G3:C70 and G5:C68).

Enzymes known as PylRS offer the remarkable ability to expand the natural genetic code of a living cell with unnatural amino acids. Currently, over 200 unnatural amino acids can be genetically encoded with the help of PylRS and its partner tRNAPyl, enabling us to endow proteins with novel properties, or regulate protein activity using light or inducible cross-linking. One intriguing feature of PylRS enzymes is their ability to avoid cross-reactivity when two PylRS homologs from different organisms-such as those from the archaea Methanosarcina mazei and Methanomethylophilus alvus-are co-expressed in a single cell. This makes it possible to simultaneously encode two unnatural amino acids in a single protein. This study illuminates the elusive mechanism of PylRS specificity by using cryo-electron microscopy, biochemistry and molecular simulations. The interaction of PylRS from M. alvus with its tRNAPyl is best described as two pieces of a jigsaw puzzle; in which PylRS recognizes the unique shape of its cognate tRNA instead of specific nucleotides in the tRNA sequence like other tRNA-binding enzymes. This finding may streamline the rational design of tools for simultaneous genetic incorporation of multiple unnatural amino acids, thereby facilitating the development of valuable proteins for research, medicine, and biotechnology.

Striatal dopamine tone is positively associated with body mass index in humans as determined by PET using dual dopamine type-2 receptor antagonist tracers.

The relationship between adiposity and dopamine type-2 receptor binding potential (D2BP) in the human brain has been repeatedly studied for >20 years with highly discrepant results, likely due to variable methodologies and differing study populations. We conducted a controlled inpatient feeding study to measure D2BP in the striatum using positron emission tomography with both [18F]fallypride and [11C]raclopride in pseudo-random order in 54 young adults with a wide range of body mass index (BMI 20-44 kg/m2). Within-subject D2BP measurements using the two tracers were moderately correlated (r=0.47, p<0.001). D2BP was negatively correlated with BMI as measured by [11C]raclopride (r= -0.51; p<0.0001) but not [18F]fallypride (r=-0.01; p=0.92) and these correlation coefficients were significantly different from each other (p<0.001). Given that [18F]fallypride has greater binding affinity to dopamine type-2 receptors than [11C]raclopride, which is more easily displaced by endogenous dopamine, our results suggest that adiposity is positively associated with increased striatal dopamine tone.

Structure and dynamics of differential ligand binding in the human ρ-type GABAA receptor.

The neurotransmitter γ-aminobutyric acid (GABA) drives critical inhibitory processes in and beyond the nervous system, partly via ionotropic type-A receptors (GABAARs). Pharmacological properties of ρ-type GABAARs are particularly distinctive, yet the structural basis for their specialization remains unclear. Here, we present cryo-EM structures of a lipid-embedded human ρ1 GABAAR, including a partial intracellular domain, under apo, inhibited, and desensitized conditions. An apparent resting state, determined first in the absence of modulators, was recapitulated with the specific inhibitor (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid and blocker picrotoxin and provided a rationale for bicuculline insensitivity. Comparative structures, mutant recordings, and molecular simulations with and without GABA further explained the sensitized but slower activation of ρ1 relative to canonical subtypes. Combining GABA with picrotoxin also captured an apparent uncoupled intermediate state. This work reveals structural mechanisms of gating and modulation with applications to ρ-specific pharmaceutical design and to our biophysical understanding of ligand-gated ion channels.

Structural insights into opposing actions of neurosteroids on GABAA receptors.

γ-Aminobutyric acid type A (GABAA) receptors mediate fast inhibitory signaling in the brain and are targets of numerous drugs and endogenous neurosteroids. A subset of neurosteroids are GABAA receptor positive allosteric modulators; one of these, allopregnanolone, is the only drug approved specifically for treating postpartum depression. There is a consensus emerging from structural, physiological and photolabeling studies as to where positive modulators bind, but how they potentiate GABA activation remains unclear. Other neurosteroids are negative modulators of GABAA receptors, but their binding sites remain debated. Here we present structures of a synaptic GABAA receptor bound to allopregnanolone and two inhibitory sulfated neurosteroids. Allopregnanolone binds at the receptor-bilayer interface, in the consensus potentiator site. In contrast, inhibitory neurosteroids bind in the pore. MD simulations and electrophysiology support a mechanism by which allopregnanolone potentiates channel activity and suggest the dominant mechanism for sulfated neurosteroid inhibition is through pore block.

A cost-utility analysis of thrombopoietin receptor agonists for treating pediatric immune thrombocytopenia purpura after failure of first-line therapies.

BACKGROUND: Thrombopoietin receptor agonists (TPO-RAs) have emerged as a recommended treatment for children with persistent and/or chronic immune thrombocytopenic purpura (ITP). The purpose of this study was to evaluate the cost-effectiveness of TPO-RAs relative to treatment without TPO-RAs (non-TPO-RAs/usual care) for ITP in children who do not respond to first-line therapy and in whom splenectomy is not recommended in Ontario, Canada, from a hospital payer perspective. PROCEDURE: A 2-year Markov model with an embedded decision tree was used. Data on medications used, dose, response rate, bleeding, and emergency treatment events were collected from the Hospital for Sick Children in Toronto. The health outcomes were described in quality-adjusted life-years (QALYs). Health-state utilities were derived from the peer-reviewed literature. Scenario analyses, deterministic, and probabilistic sensitivity analyses were conducted. Economic costs were measured in 2021 Canadian dollars ($1.00 = US$0.80) RESULTS: TPO-RAs are estimated to result in an increased cost of $27,118 and a QALY gain of 0.21 compared to non-TPO-RAs over a 2-year horizon, resulting in an incremental cost-effectiveness ratio (ICER) of $129,133. In a 5-year scenario analysis, the ICER fell to $76,403. In the probabilistic sensitivity analysis, TPO-RAs exhibit a 40.0% probability of being cost-effective at a conventional ($100,000) willingness-to-pay threshold per QALY gained. CONCLUSIONS: Further assessment of the long-term efficacy of TPO-RAs is warranted to obtain more precise long-term estimates. As the costs of TPO-RAs decline with the introduction of generic formulations, TPO-RAs may be increasingly cost-effective.

Automated simulation-based membrane protein refinement into cryo-EM data.

The resolution revolution has increasingly enabled single-particle cryogenic electron microscopy (cryo-EM) reconstructions of previously inaccessible systems, including membrane proteins-a category that constitutes a disproportionate share of drug targets. We present a protocol for using density-guided molecular dynamics simulations to automatically refine atomistic models into membrane protein cryo-EM maps. Using adaptive force density-guided simulations as implemented in the GROMACS molecular dynamics package, we show how automated model refinement of a membrane protein is achieved without the need to manually tune the fitting force ad hoc. We also present selection criteria to choose the best-fit model that balances stereochemistry and goodness of fit. The proposed protocol was used to refine models into a new cryo-EM density of the membrane protein maltoporin, either in a lipid bilayer or detergent micelle, and we found that results do not substantially differ from fitting in solution. Fitted structures satisfied classical model-quality metrics and improved the quality and the model-to-map correlation of the x-ray starting structure. Additionally, the density-guided fitting in combination with generalized orientation-dependent all-atom potential was used to correct the pixel-size estimation of the experimental cryo-EM density map. This work demonstrates the applicability of a straightforward automated approach to fitting membrane protein cryo-EM densities. Such computational approaches promise to facilitate rapid refinement of proteins under different conditions or with various ligands present, including targets in the highly relevant superfamily of membrane proteins.

MDverse: Shedding Light on the Dark Matter of Molecular Dynamics Simulations.

The rise of open science and the absence of a global dedicated data repository for molecular dynamics (MD) simulations has led to the accumulation of MD files in generalist data repositories, constituting the dark matter of MD - data that is technically accessible, but neither indexed, curated, or easily searchable. Leveraging an original search strategy, we found and indexed about 250,000 files and 2,000 datasets from Zenodo, Figshare and Open Science Framework. With a focus on files produced by the Gromacs MD software, we illustrate the potential offered by the mining of publicly available MD data. We identified systems with specific molecular composition and were able to characterize essential parameters of MD simulation, such as temperature and simulation length, and identify model resolution, such as all-atom and coarse-grain. Based on this analysis, we inferred metadata to propose a search engine prototype to explore collected MD data. To continue in this direction, we call on the community to pursue the effort of sharing MD data, and increase populating and standardizing metadata to reuse this valuable matter.

Reliability of the NACC Telephone-administered Neuropsychological Battery (T-cog) and Montreal Cognitive Assessment for participants in the USC ADRC.

Introduction: Restrictions during the COVID-19 pandemic necessitated remote administration of neuropsychological testing. We assessed the test-retest reliability for a telephone-administered cognitive battery, recommended for use in the National Institute on Aging Alzheimer's Disease Research Center (ADRC). Methods: 64 participants in the University of Southern California ADRC clinical core underwent repeat telephone evaluation using the T-cog Neuropsychological Battery. Reliability was measured by intraclass correlation coefficient (ICC) for continuous variables and weighted Kappa coefficient for categorical variables. Mean scores for Montreal Cognitive Assessment (MoCA) total and Craft Story 21 Immediate and Delayed Recall were compared using paired t tests. Results: Mean age was 74.8 (8.3 standard deviation); 73.4% were female. ICCs ranged from 0.52 to 0.84, indicating moderate test-retest reliability except for number span backward, which showed poor reliability. Weighted Kappa for MoCA items ranged from -0.016 to 0.734; however, relatively good observed agreement was seen across all items (70.3% to 98.4%). Although MoCA total scores did not significantly change, Craft Story 21 Immediate and Delayed Recall mean scores increased between first and second administrations (P < 0.0001). Discussion: Test-retest reliability for the T-cog Neuropsychological Battery is adequate. The variation seen in testing is similar to results seen from face-to-face testing, with Craft Story 21 recall showing modest and expected practice effects. Highlights: Moderate test-retest reliability is seen in most measures of the National Alzheimer's Coordinating Center Neuropsychological Test Battery and the Montreal Cognitive Assessment (MoCA).Intraclass correlation coefficients ranged from 0.52 to 0.84, except for number Span backward.Weighted Kappa for MoCA items varied, but good observed agreement was seen.MoCA total mean score did not change significantly between administrations.Craft Story 21 Immediate and Delayed Recall means increased on repeat testing (P < 0.0001).

Amino acid substitutions in human growth hormone affect secondary structure and receptor binding.

The interaction between human Growth Hormone (hGH) and hGH Receptor (hGHR) has basic relevance to cancer and growth disorders, and hGH is the scaffold for Pegvisomant, an anti-acromegaly therapeutic. For the latter reason, hGH has been extensively engineered by early workers to improve binding and other properties. We are particularly interested in E174 which belongs to the hGH zinc-binding triad; the substitution E174A is known to significantly increase binding, but to now no explanation has been offered. We generated this and several computationally-selected single-residue substitutions at the hGHR-binding site of hGH. We find that, while many successfully slow down dissociation of the hGH-hGHR complex once bound, they also slow down the association of hGH to hGHR. The E174A substitution induces a change in the Circular Dichroism spectrum that suggests the appearance of coiled-coiling. Here we show that E174A increases affinity of hGH against hGHR because the off-rate is slowed down more than the on-rate. For E174Y (and certain mutations at other sites) the slowdown in on-rate was greater than that of the off-rate, leading to decreased affinity. The results point to a link between structure, zinc binding, and hGHR-binding affinity in hGH.

Eliminating hepatitis C in Australia: a novel model of hepatitis C testing and treatment for people who inject drugs at a medically supervised injecting facility.

OBJECTIVE: To evaluate the feasibility of testing and treating people who inject drugs at a supervised injecting facility for hepatitis C virus (HCV) infection. DESIGN: Retrospective cohort study. SETTING, PARTICIPANTS: People who inject drugs who attended the Melbourne supervised injecting facility, 30 June 2018 - 30 June 2020. MAIN OUTCOME MEASURES: Proportion of people tested for hepatitis C; proportions of people positive for anti-HCV antibody and HCV RNA, and of eligible people prescribed direct-acting antiviral (DAA) treatment; sustained virological response twelve weeks or more after treatment completion. RESULTS: Of 4649 people who attended the supervised injecting facility during 2018-20, 321 were tested for hepatitis C (7%); 279 were anti-HCV antibody-positive (87%), of whom 143 (51%) were also HCV RNA-positive. Sixty-four of 321 had previously been treated for hepatitis C (20%), 21 had clinically identified cirrhosis (7%), eight had hepatitis B infections (2%), and four had human immunodeficiency virus infections (1%). In multivariate analyses, people tested for hepatitis C were more likely than untested clients to report psychiatric illness (adjusted odds ratio [aOR], 9.65; 95% confidence interval [CI], 7.26-12.8), not have a fixed address (aOR, 1.59; 95% CI, 1.18-2.14), and to report significant alcohol use (aOR, 1.57; 95% CI, 1.06-2.32). The median number of injecting facility visits was larger for those tested for hepatitis C (101; interquartile range [IQR], 31-236) than for those not tested (20; IQR, 3-90). DAA treatment was prescribed for 126 of 143 HCV RNA-positive clients (88%); 41 of 54 with complete follow-up data were cured (76%). CONCLUSIONS: People who attend supervised injecting facilities can be tested and treated for hepatitis C on site. Models that provide streamlined, convenient hepatitis C care promote engagement with treatment in a group in which the prevalence of hepatitis C is high.

The Impact of Dental Care Programs on Individuals and Their Families: A Scoping Review.

BACKGROUND: Despite significant global improvements in oral health, inequities persist. Targeted dental care programs are perceived as a viable approach to both improving oral health and to address inequities. However, the impacts of dental care programs on individual and family oral health outcomes remain unclear. OBJECTIVES: The purpose of this scoping review is to map the evidence on impacts of existing dental programs, specifically on individual and family level outcomes. METHODS: We systematically searched four scientific databases, MEDLINE, EMBASE, CINAHL, and Sociological Abstracts for studies published in the English language between December 1999 and November 2021. Search terms were kept broad to capture a range of programs. Four reviewers (AG, VD, AE, and KKP) independently screened the abstracts and reviewed full-text articles and extracted the data. Cohen's kappa inter-rater reliability score was 0.875, indicating excellent agreement between the reviewers. Data were summarized according to the PRISMA statement. RESULTS: The search yielded 65,887 studies, of which 76 were included in the data synthesis. All but one study assessed various individual-level outcomes (n = 75) and only five investigated family outcomes. The most common program interventions are diagnostic and preventive (n = 35, 46%) care, targeted children (n = 42, 55%), and delivered in school-based settings (n = 28, 37%). The majority of studies (n = 43, 57%) reported a significant improvement in one or more of their reported outcomes; the most assessed outcome was change in dental decay (n = 35). CONCLUSIONS: Dental care programs demonstrated effectiveness in addressing individual oral health outcomes. However, evidence to show the impact on family-related outcomes remains limited and requires attention in future research.

Structural Elucidation of Ivermectin Binding to α7nAChR and the Induced Channel Desensitization.

The α7 nicotinic acetylcholine receptor (α7nAChR) mediates signaling in the central nervous system and cholinergic anti-inflammatory pathways. Ivermectin is a positive allosteric modulator of a full-length α7nAChR and an agonist of the α7nAChR construct containing transmembrane (TMD) and intracellular (ICD) domains, but structural insights of the binding have not previously been determined. Here, combining nuclear magnetic resonance as a primary experimental tool with Rosetta comparative modeling and molecular dynamics simulations, we have revealed details of ivermectin binding to the α7nAChR TMD + ICD and corresponding structural changes in an ivermectin-induced desensitized state. Ivermectin binding was stabilized predominantly by hydrophobic interactions from interfacial residues between adjacent subunits near the extracellular end of the TMD, where the inter-subunit gap was substantially expanded in comparison to the apo structure. The ion-permeation pathway showed a profile distinctly different from the resting-state profile but similar to profiles of desensitized α7nAChR. The ICD also exhibited structural changes, including reorientation of the MX and h3 helices relative to the channel axis. The resulting structures of the α7nAChR TMD + ICD in complex with ivermectin provide opportunities for discovering new modulators of therapeutic potential and exploring the structural basis of cytoplasmic signaling under different α7nAChR functional states.