Structural basis of bulk lipid transfer by bridge-like lipid transfer protein LPD-3.

Bridge-like lipid transport proteins (BLTPs) are an evolutionarily conserved family of proteins that localize to membrane contact sites and are thought to mediate the bulk transfer of lipids from a donor membrane, typically the endoplasmic reticulum (ER), to an acceptor membrane, such as a that of the cell or an organelle 1 . Despite the fundamental importance of BLTPs for cellular function, the architecture, composition, and lipid transfer mechanisms remain poorly characterized. Here, we present the subunit composition and the cryo-electron microscopy structure of the native LPD-3 BLTP complex isolated from transgenic C. elegans . LPD-3 folds into an elongated, rod-shaped tunnel whose interior is filled with ordered lipid molecules that are coordinated by a track of ionizable residues that line one side of the tunnel. LPD-3 forms a complex with two previously uncharacterized proteins, here named "Intake" and "Spigot", both of which interact with the N-terminal end of LPD-3 where lipids enter the tunnel. Intake has three transmembrane helices, one of which borders the entrance to the tunnel; Spigot has one transmembrane helix and extends 80 Å along the cytosolic surface of LPD-3. Experiments in multiple model systems indicate that Spigot plays a conserved role in ER-PM contact site formation. Our LPD-3 complex structural data, together with molecular dynamics simulations of the transmembrane region in a lipid bilayer, reveal protein-lipid interactions that suggest a model for how the native LPD-3-complex mediates bulk lipid transport and provide a foundation for mechanistic studies of BLTPs.

Evaluation of Ten Alternative Treatments for the Management of Harlequin Bug (Murgantia histrionica) on Brassica Crops.

Harlequin bug (Murgantia histrionica) poses a significant threat to cruciferous vegetable crops, leading to economic losses and challenges in sustainable agriculture. This 2-year field study evaluated the efficacy of exclusion netting and selected biopesticides in controlling harlequin bug populations in a field-grown broccoli crop. Treatments included an untreated control, industry standards Azera and Entrust, and ProtekNet mesh netting. Additionally, three commercial essential oil treatments including Essentria IC-3, Nature-Cide, and Zero Tolerance were tested along with two bokashi fermented composting products BrewKashi and Oriental Herbal Nutrient (OHN). During both the first and second year of the study, none of the commercially produced essential oil products or bokashi products were effective in controlling harlequin bug or preventing leaf scars. Conversely, ProtekNet consistently provided the highest level of protection against harlequin bugs of all stages as well as leaf damage scars; it also provided the largest broccoli head width and highest yield. Entrust showed similar results compared to ProtekNet, both with the control of harlequin bug life stages and with leaf scars. These findings indicate that both ProtekNet and Entrust are effective organic alternatives for managing harlequin bug on broccoli, while the selected essential oil and bokashi products do not appear to be effective.

Regional and cellular organization of the autism-associated protein UBE3A/E6AP and its antisense transcript in the brain of the developing rhesus monkey.

Angelman syndrome (AS) is a neurogenetic disorder caused by mutations or deletions in the maternally-inherited UBE3A allele, leading to a loss of UBE3A protein expression in neurons. The paternally-inherited UBE3A allele is epigenetically silenced in neurons during development by a noncoding transcript (UBE3A-ATS). The absence of neuronal UBE3A results in severe neurological symptoms, including speech and language impairments, intellectual disability, and seizures. While no cure exists, therapies aiming to restore UBE3A function-either by gene addition or by targeting UBE3A-ATS-are under development. Progress in developing these treatments relies heavily on inferences drawn from mouse studies about the function of UBE3A in the human brain. To aid translational efforts and to gain an understanding of UBE3A and UBE3A-ATS biology with greater relevance to human neurodevelopmental contexts, we investigated UBE3A and UBE3A-ATS expression in the developing brain of the rhesus macaque, a species that exhibits complex social behaviors, resembling aspects of human behavior to a greater degree than mice. Combining immunohistochemistry and in situ hybridization, we mapped UBE3A and UBE3A-ATS regional and cellular expression in normal prenatal, neonatal, and adolescent rhesus macaque brains. We show that key hallmarks of UBE3A biology, well-known in rodents, are also present in macaques, and suggest paternal UBE3A silencing in neurons-but not glial cells-in the macaque brain, with onset between gestational day 48 and 100. These findings support proposals that early-life, perhaps even prenatal, intervention is optimal for overcoming the maternal allele loss of UBE3A linked to AS.

Is repeated mistake-making an effective treatment strategy for perfectionism? Findings from a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Perfectionism has been linked to self-criticism, procrastination, and psychological disorders. In a previous study, an exposure-based treatment for perfectionism (ETP), which included exposures targeted at concern over mistakes, showed positive outcomes when compared to waitlist. The aim of this study was to further investigate ETP by comparing it to a stress-management condition and assessing durability of treatment effects by conducting a one-month follow-up assessment. METHODS: Eighty-five individuals with elevated perfectionism were randomly assigned to receive ETP (n = 43) or a stress management treatment (n = 42). ETP involved repeatedly practicing mistake-making by completing computerized tasks engineered to cause individuals to make mistakes. The stress management condition included listening to videos and answering questions about healthy habits, such as diet, exercise, and sleep, as well as viewing calming videos. Participants completed eight treatment sessions as well as baseline, post-test, and one month follow-up self-report questionnaires. RESULTS: Contrary to predictions, compared to ETP, stress management led to significantly lower overall perfectionism, depression, generalized anxiety, and social anxiety at post and significantly lower depression, generalized anxiety, and social anxiety at follow-up. Further, individuals who completed ETP did not habituate to the exposure tasks, but distress increased from the first to the last treatment session. LIMITATIONS: The duration of treatment was relatively brief. CONCLUSIONS: This study highlights the importance of using active psychological control conditions in treatment outcome studies and the need to test various components of treatments for perfectionism to observe what may be effective or even potentially iatrogenic.

Heme sequestration by hemophilin from Haemophilus haemolyticus reduces respiratory tract colonization and infection with non-typeable Haemophilus influenzae.

Iron acquisition is a key feature dictating the success of pathogen colonization and infection. Pathogens scavenging iron from the host must contend with other members of the microbiome similarly competing for the limited pool of bioavailable iron, often in the form of heme. In this study, we identify a beneficial role for the heme-binding protein hemophilin (Hpl) produced by the non-pathogenic bacterium Haemophilus haemolyticus against its close relative, the opportunistic respiratory tract pathogen non-typeable Haemophilus influenzae (NTHi). Using a mouse model, we found that pre-exposure to H. haemolyticus significantly reduced NTHi colonization of the upper airway and impaired NTHi infection of the lungs in an Hpl-dependent manner. Further, treatment with recombinant Hpl was sufficient to decrease airway burdens of NTHi without exacerbating lung immunopathology or systemic inflammation. Instead, mucosal production of the neutrophil chemokine CXCL2, lung myeloperoxidase, and serum pro-inflammatory cytokines IL-6 and TNFα were lower in Hpl-treated mice. Mechanistically, H. haemolyticus suppressed NTHi growth and adherence to human respiratory tract epithelial cells through the expression of Hpl, and recombinant Hpl could recapitulate these effects. Together, these findings indicate that heme sequestration by non-pathogenic, Hpl-producing H. haemolyticus is protective against NTHi colonization and infection. IMPORTANCE: The microbiome provides a critical layer of protection against infection with bacterial pathogens. This protection is accomplished through a variety of mechanisms, including interference with pathogen growth and adherence to host cells. In terms of immune defense, another way to prevent pathogens from establishing infections is by limiting the availability of nutrients, referred to as nutritional immunity. Restricting pathogen access to iron is a central component of this approach. Here, we uncovered an example where these two strategies intersect to impede infection with the respiratory tract bacterial pathogen Haemophilus influenzae. Specifically, we find that a non-pathogenic (commensal) bacterium closely related to H. influenzae called Haemophilus haemolyticus improves protection against H. influenzae by limiting the ability of this pathogen to access iron. These findings suggest that beneficial members of the microbiome improve protection against pathogen infection by effectively contributing to host nutritional immunity.

The structure of the Caenorhabditis elegans TMC-2 complex suggests roles of lipid-mediated subunit contacts in mechanosensory transduction.

Mechanotransduction is the process by which a mechanical force, such as touch, is converted into an electrical signal. Transmembrane channel-like (TMC) proteins are an evolutionarily conserved family of membrane proteins whose function has been linked to a variety of mechanosensory processes, including hearing and balance sensation in vertebrates and locomotion in Drosophila. TMC1 and TMC2 are components of ion channel complexes, but the molecular features that tune these complexes to diverse mechanical stimuli are unknown. Caenorhabditis elegans express two TMC homologs, TMC-1 and TMC-2, both of which are the likely pore-forming subunits of mechanosensitive ion channels but differ in their expression pattern and functional role in the worm. Here, we present the single-particle cryo-electron microscopy structure of the native TMC-2 complex isolated from C. elegans. The complex is composed of two copies of the pore-forming TMC-2 subunit, the calcium and integrin binding protein CALM-1 and the transmembrane inner ear protein TMIE. Comparison of the TMC-2 complex to the recently published cryo-EM structure of the C. elegans TMC-1 complex highlights conserved protein-lipid interactions, as well as a π-helical structural motif in the pore-forming helices, that together suggest a mechanism for TMC-mediated mechanosensory transduction.

Association between dental visits during pregnancy and setting for prenatal care.

OBJECTIVES: Federally Qualified Health Centers (FQHCs) may be well positioned to facilitate dental visits during pregnancy for low-income women. We sought to compare receipt of dental visits during pregnancy for women who received prenatal care at an FQHC versus a non-FQHC setting. METHODS: We analyzed Michigan Medicaid administrative data for all live birth deliveries between April 2018 and December 2020. We used billing data to categorize the predominant setting for prenatal care as occurring at a FQHC or a non-FQHC and claims data to identify dental visits during pregnancy (in the 9 months prior to delivery). We employed bivariate and multivariate analyses to explore the relationship between setting for prenatal care and dental visits during pregnancy. RESULTS: Women who received prenatal care at an FQHC versus non-FQHC had a higher proportion of dental visits during pregnancy (31.85% vs. 19.37%, p < 0.0001). In multivariate analyses, the strongest predictors of having a dental visit during pregnancy were FQHC prenatal care setting, having a dental emergency visit, having ≥3 prenatal visits, and having Medicaid coverage throughout pregnancy. Hispanic or Black race/ethnicity and 2020 delivery year were predictors of a lower likelihood of a dental visit. These predictors were consistent for the overall population and for the subset who had no dental visits pre-pregnancy. CONCLUSION: Medicaid-enrolled women who receive prenatal care at an FQHC are more likely to have a dental visit during pregnancy than their counterparts who receive prenatal care in a non-FQHC setting.

Benefits of a health advocacy intervention intended to improve self-efficacy for self-care in residents of a homeless shelter.

Despite a great need for healthcare, unhoused individuals encounter significant barriers to utilizing public healthcare systems. Given the inequities in access to healthcare, accompanied by disabilities and health risks associated with homelessness, self-efficacy for self-care is particularly critical. As a primary purpose of this article, we describe a self-care intervention (Health Advocacy Behavioral Activation), which was implemented within a long-standing participatory community action research project for homeless shelters, and report evidence of the intervention's effectiveness in enhancing self-efficacy for self-care. Participants included 62 residents of the St. Vincent de Paul Gateway Shelter for Men (Dayton, Ohio). Shelter residents with disabilities and those without disability benefited approximately equally from the intervention and both showed statistically significant pre- to post-intervention improvements in self-efficacy for self-care. Recommendations for future research examining the effectiveness of the intervention are provided. As a secondary (supplementary) purpose, we report preliminary evidence of psychometric validation for a new instrument (Scale of Self-Efficacy for Self-Care), which was developed in service of our primary purpose (i.e., to examine the effects of intervention on self-efficacy for self-care) because a literature search did not identify an appropriate measure. Because this new instrument fills a void in the literature, we anticipate that it will be useful in practice and research, and so we delineate research recommendations for additional psychometric validation of this measure. Because of the barriers that unhoused people encounter with regard to access to healthcare in the community, self-care interventions provided (and evaluated) on-site (e.g., in homeless shelters) are necessary.

Insights into the role of the respiratory tract microbiome in defense against bacterial pneumonia.

The respiratory tract microbiome (RTM) is a microbial ecosystem inhabiting different niches throughout the airway. A critical role for the RTM in dictating lung infection outcomes is underlined by recent efforts to identify community members benefiting respiratory tract health. Obligate anaerobes common in the oropharynx and lung such as Prevotella and Veillonella are associated with improved pneumonia outcomes and activate several immune defense pathways in the lower airway. Colonizers of the nasal cavity, including Corynebacterium and Dolosigranulum, directly impact the growth and virulence of lung pathogens, aligning with robust clinical correlations between their upper airway abundance and reduced respiratory tract infection risk. Here, we highlight recent work identifying respiratory tract bacteria that promote airway health and resilience against disease, with a focus on lung infections and the underlying mechanisms driving RTM-protective benefits.

Neutrophil responsiveness to IL-10 impairs clearance of Streptococcus pneumoniae from the lungs.

The early immune response to bacterial pneumonia requires a careful balance between pathogen clearance and tissue damage. The anti-inflammatory cytokine interleukin (IL)-10 is critical for restraining otherwise lethal pulmonary inflammation. However, pathogen-induced IL-10 is associated with bacterial persistence in the lungs. In this study, we used mice with myeloid cell specific deletion of IL-10R to investigate the cellular targets of IL-10 immune suppression during infection with Streptococcus pneumoniae, the most common bacterial cause of pneumonia. Our findings suggest that IL-10 restricts the neutrophil response to S. pneumoniae, as neutrophil recruitment to the lungs was elevated in myeloid IL-10 receptor (IL-10R)-deficient mice and neutrophils in the lungs of these mice were more effective at killing S. pneumoniae. Improved killing of S. pneumoniae was associated with increased production of reactive oxygen species and serine protease activity in IL-10R-deficient neutrophils. Similarly, IL-10 suppressed the ability of human neutrophils to kill S. pneumoniae. Burdens of S. pneumoniae were lower in myeloid IL-10R-deficient mice compared with wild-type mice, and adoptive transfer of IL-10R-deficient neutrophils into wild-type mice significantly improved pathogen clearance. Despite the potential for neutrophils to contribute to tissue damage, lung pathology scores were similar between genotypes. This contrasts with total IL-10 deficiency, which is associated with increased immunopathology during S. pneumoniae infection. Together, these findings identify neutrophils as a critical target of S. pneumoniae-induced immune suppression and highlight myeloid IL-10R abrogation as a mechanism to selectively reduce pathogen burdens without exacerbating pulmonary damage.

Implementation of Tenecteplase for Acute Ischemic Stroke Treatment.

INTRODUCTION: Acute ischemic stroke is a neurologic emergency, requiring rapid recognition and treatment with intravenous thrombolysis. Since the publication of the 2019 American Heart Association/American Stroke Association Guidelines that recommend tenecteplase as an alternative agent, several centers across the United States are transitioning from alteplase to tenecteplase as the agent of choice for thrombolysis in acute ischemic stroke. METHODS: Our health system transitioned to tenecteplase for the treatment of acute ischemic stroke in 2021 due to increasing evidence for efficacy and potential for improved door-to-needle time. Herein we describe our experience and provide guidance for other institutions to implement this change. CONCLUSION: Emergency nurses are vital to the care of acute ischemic stroke patients. There are several pharmacologic and logistical differences between alteplase and tenecteplase for this indication. This paper outlines these key differences.

Infectious pathogens and risk of esophageal, gastric and duodenal cancers and ulcers in China: A case-cohort study.

Infection by certain pathogens is associated with cancer development. We conducted a case-cohort study of ~2500 incident cases of esophageal, gastric and duodenal cancer, and gastric and duodenal ulcer and a randomly selected subcohort of ~2000 individuals within the China Kadoorie Biobank study of >0.5 million adults. We used a bead-based multiplex serology assay to measure antibodies against 19 pathogens (total 43 antigens) in baseline plasma samples. Associations between pathogens and antigen-specific antibodies with risks of site-specific cancers and ulcers were assessed using Cox regression fitted using the Prentice pseudo-partial likelihood. Seroprevalence varied for different pathogens, from 0.7% for Hepatitis C virus (HCV) to 99.8% for Epstein-Barr virus (EBV) in the subcohort. Compared to participants seronegative for the corresponding pathogen, Helicobacter pylori seropositivity was associated with a higher risk of non-cardia (adjusted hazard ratio [HR] 2.73 [95% CI: 2.09-3.58]) and cardia (1.67 [1.18-2.38]) gastric cancer and duodenal ulcer (2.71 [1.79-4.08]). HCV was associated with a higher risk of duodenal cancer (6.23 [1.52-25.62]) and Hepatitis B virus was associated with higher risk of duodenal ulcer (1.46 [1.04-2.05]). There were some associations of antibodies again some herpesviruses and human papillomaviruses with risks of gastrointestinal cancers and ulcers but these should be interpreted with caution. This first study of multiple pathogens with risk of gastrointestinal cancers and ulcers demonstrated that several pathogens are associated with risks of gastrointestinal cancers and ulcers. This will inform future investigations into the role of infection in the etiology of these diseases.

Unique Presentations of Burkholderia gladioli Infections in Several Strains of Immunocompromised Mice.

Four strains of experimentally naïve mice (NOD. Cg-Prkdc scid Il2rg tm1Wjl /SzJ [NSG], NOD. Cg- Rag1 tm1Mom Il2rg tm1Wjl /SzJ [NRG], B6.129S(Cg)-Stat1 tm1Dlv/J [STAT1 -/-], and B6.129S7- Ifngr1 tm1Agt/J[IFNγR -/-] housed in a barrier facility developed unusual and seemingly unrelated clinical signs. Young NSG/NRG mice (n = 49, mean age = 4 ± 0.4 mo) exhibited nonspecific clinical signs of moderate-to-severe lethargy, hunched posture, decreased body condition, and pallor. In contrast to the NSG/NRG mice, the STAT1-/- and IFNγ R-/- mice (n = 5) developed large subcutaneous abscesses on the head and neck. These mice were euthanized, and samples were collected for culture. NSG/NRG mice had moderate-markedly enlarged livers (20 of 49, 40%) and spleens (17 of 49, 35%). The livers contained multiple, variably-sized, tan regions throughout all lobes. Histology revealed necrotizing hepatitis (13 of 17, 77%), splenic and hepatic extramedullary hematopoiesis (17 of 17, 100%), glomerular histiocytosis (6 of 17, 35%), and metritis (6 of 11, 55%) with perivascular inflammation, suggesting hematogenous spread Differentials for these lesions included mouse hepatitis virus, ectromelia virus, Pseudomonas aeruginosa, Salmonella spp., and Clostridium piliforme. Burkholderia gladioli was cultured from liver lesions and subcutaneous abscesses and confirmed with 16S ribosomal RNA sequencing. After completing systematic testing of the environment, failure of the water autoclave cycle was suspected as the cause of the outbreak. To address the situation, individually ventilated racks were sanitized and new breeders were purchased; these actions dramatically reduced B. gladioli infections. The current literature contains few reports of B. gladioli infections in immunocompromised mice, and its typical presentation is torticollis and rolling. B. gladioli infection is a potential differential for subcutaneous abscesses, hepatitis, and splenomegaly in immunocompromised mice. Careful monitoring of sterilization techniques is essential to prevent such infections in a barrier facility.

Relationship between Depression and Anxiety during Pregnancy, Delivery-Related Outcomes, and Healthcare Utilization in Michigan Medicaid, 2012-2021.

To evaluate associations between depression and/or anxiety disorders during pregnancy (DAP), delivery-related outcomes, and healthcare utilization among individuals with Michigan Medicaid-funded deliveries. We conducted a retrospective delivery-level analysis comparing delivery-related outcomes and healthcare utilization among individuals with and without DAP between January 2012 and September 2021. We used generalized estimating equation models assessing cesarean and preterm delivery; 30-day readmission after delivery; severe maternal morbidity within 42 days of delivery; and ambulatory, inpatient, emergency department or observation (ED), psychotherapy, or substance use disorders (SUD) visits during pregnancy. We adjusted models for age, race/ethnicity, urbanicity, federal poverty level, and obstetric comorbidities. Among 170,002 Michigan Medicaid enrollees with 218,890 deliveries, 29,665 (13.6%) had diagnoses of DAP. Compared to those without DAP, individuals with DAP were more often White, rural dwelling, had lower income, and had more comorbidities. In adjusted models, deliveries with DAP had higher odds of cesarean and preterm delivery OR = 1.02, 95% CI: [1.00, 1.05] and OR = 1.15, 95% CI: [1.11, 1.19] respectively), readmission within 30 days postpartum (OR = 1.14, 95% CI: [1.07, 1.22]), SMM within 42 days (OR = 1.27, 95% CI: [1.18, 1.38]), and utilization compared to those without DAP diagnoses (ambulatory: OR = 7.75, 95% CI: [6.75, 8.88], inpatient: OR = 1.13, 95% CI: [1.11, 1.15], ED: OR = 1.86, 95% CI: [1.80, 1.92], psychotherapy: OR = 172.8, 95% CI: [160.10, 186.58], and SUD: OR = 5.6, 95% CI: [5.37, 5.85]). Among delivering individuals in Michigan Medicaid, DAP had significant associations with adverse delivery-related outcomes and greater healthcare use. Early detection and intervention to address mental illness during pregnancy may help mitigate burdens of these complex yet treatable disorders.

Structural basis for VLDLR recognition by eastern equine encephalitis virus.

Alphaviruses are arthropod-borne enveloped RNA viruses that include several important human pathogens with outbreak potential. Among them, eastern equine encephalitis virus (EEEV) is the most virulent, and many survivors develop neurological sequelae, including paralysis and intellectual disability. The spike proteins of alphaviruses comprise trimers of heterodimers of their envelope glycoproteins E2 and E1 that mediate binding to cellular receptors and fusion of virus and host cell membranes during entry. We recently identified very-low density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2), two closely related proteins that are expressed in the brain, as cellular receptors for EEEV and a distantly related alphavirus, Semliki forest virus (SFV) 1 . The EEEV and SFV spike glycoproteins have low sequence homology, and how they have evolved to bind the same cellular receptors is unknown. Here, we used single-particle cryo-electron microscopy (cryo-EM) to determine structures of the EEEV and SFV spike glycoproteins bound to the VLDLR ligand-binding domain. The structures reveal that EEEV and SFV use distinct surfaces to bind VLDLR; EEEV uses a cluster of basic residues on the E2 subunit of its spike glycoprotein, while SFV uses two basic residues at a remote site on its E1 glycoprotein. Our studies reveal that different alphaviruses interact with the same cellular receptor through divergent binding modes. They further suggest that the ability of LDLR-related proteins to interact with viral spike proteins through very small footprints with flexible binding modes results in a low evolutionary barrier to the acquisition of LDLR-related proteins as cellular receptors for diverse sets of viruses.

Headache among combat-exposed veterans and service members and its relation to mild traumatic brain injury history and other factors: a LIMBIC-CENC study.

Background: Headache (HA) is a common persistent complaint following mild traumatic brain injury (mTBI), but the association with remote mTBI is not well established, and risk factors are understudied. Objective: Determine the relationship of mTBI history and other factors with HA prevalence and impact among combat-exposed current and former service members (SMs). Design: Secondary cross-sectional data analysis from the Long-Term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium prospective longitudinal study. Methods: We examined the association of lifetime mTBI history, demographic, military, medical and psychosocial factors with (1) HA prevalence ("lately, have you experienced headaches?") using logistic regression and (2) HA burden via the Headache Impact Test-6 (HIT-6) using linear regression. Each lifetime mTBI was categorized by mechanism (blast-related or not) and setting (combat deployed or not). Participants with non-credible symptom reporting were excluded, leaving N = 1,685 of whom 81% had positive mTBI histories. Results: At a median 10 years since last mTBI, mTBI positive participants had higher HA prevalence (69% overall, 78% if 3 or more mTBIs) and greater HA burden (67% substantial/severe impact) than non-TBI controls (46% prevalence, 54% substantial/severe impact). In covariate-adjusted analysis, HA prevalence was higher with greater number of blast-related mTBIs (OR 1.81; 95% CI 1.48, 2.23), non-blast mTBIs while deployed (OR 1.42; 95% CI 1.14, 1.79), or non-blast mTBIs when not deployed (OR 1.23; 95% CI 1.02, 1.49). HA impact was only higher with blast-related mTBIs. Female identity, younger age, PTSD symptoms, and subjective sleep quality showed effects in both prevalence and impact models, with the largest mean HIT-6 elevation for PTSD symptoms. Additionally, combat deployment duration and depression symptoms were factors for HA prevalence, and Black race and Hispanic/Latino ethnicity were factors for HA impact. In sensitivity analyses, time since last mTBI and early HA onset were both non-significant. Conclusion: The prevalence of HA symptoms among formerly combat-deployed veterans and SMs is higher with more lifetime mTBIs regardless of how remote. Blast-related mTBI raises the risk the most and is uniquely associated with elevated HA burden. Other demographic and potentially modifiable risk factors were identified that may inform clinical care.

Unique Presentations of Burkholderia gladioli Infections in Several Strains of Immunocompromised Mice.

Four strains of experimentally naïve mice (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ [NSG], NOD.Cg-Rag1tm1Mom Il2rgtm1Wjl/SzJ[NRG], B6.129S(Cg)-Stat1tm1Dlv/J [STAT1-/-], and B6.129S7-Ifngr1tm1Agt/J [IFNγR-/-] housed in a barrier facility developedunusual and seemingly unrelated clinical signs. Young NSG/NRG mice (n = 49, mean age = 4 ± 0.4 mo) exhibited nonspecificclinical signs of moderate-to-severe lethargy, hunched posture, decreased body condition, and pallor. In contrast to the NSG/NRGmice, the STAT1-/- and IFNγR-/-mice (n = 5) developed large subcutaneous abscesses on the head and neck. These micewere euthanized, and samples were collected for culture. NSG/NRG mice had moderate-markedly enlarged livers (20 of49, 40%) and spleens (17 of 49, 35%). The livers contained multiple, variably-sized, tan regions throughout all lobes. Histologyrevealed necrotizing hepatitis (13 of 17, 77%), splenic and hepatic extramedullary hematopoiesis (17 of 17, 100%), glomerularhistiocytosis (6 of 17, 35%), and metritis (6 of 11, 55%) with perivascular inflammation, suggesting hematogenous spreadDifferentials for these lesions included mouse hepatitis virus, ectromelia virus, Pseudomonas aeruginosa, Salmonella spp.,and Clostridium piliforme. Burkholderia gladioli was cultured from liver lesions and subcutaneous abscesses and confirmedwith 16S ribosomal RNA sequencing. After completing systematic testing of the environment, failure of the water autoclavecycle was suspected as the cause of the outbreak. To address the situation, individually ventilated racks were sanitized andnew breeders were purchased; these actions dramatically reduced B. gladioli infections. The current literature contains fewreports of B. gladioli infections in immunocompromised mice, and its typical presentation is torticollis and rolling. B. gladioliinfection is a potential differential for subcutaneous abscesses, hepatitis, and splenomegaly in immunocompromised mice.Careful monitoring of sterilization techniques is essential to prevent such infections in a barrier facility.

Cryo-EM structures reveal native GABAA receptor assemblies and pharmacology.

Type A γ-aminobutyric acid receptors (GABAARs) are the principal inhibitory receptors in the brain and the target of a wide range of clinical agents, including anaesthetics, sedatives, hypnotics and antidepressants1-3. However, our understanding of GABAAR pharmacology has been hindered by the vast number of pentameric assemblies that can be derived from 19 different subunits4 and the lack of structural knowledge of clinically relevant receptors. Here, we isolate native murine GABAAR assemblies containing the widely expressed α1 subunit and elucidate their structures in complex with drugs used to treat insomnia (zolpidem (ZOL) and flurazepam) and postpartum depression (the neurosteroid allopregnanolone (APG)). Using cryo-electron microscopy (cryo-EM) analysis and single-molecule photobleaching experiments, we uncover three major structural populations in the brain: the canonical α1ß2γ2 receptor containing two α1 subunits, and two assemblies containing one α1 and either an α2 or α3 subunit, in which the single α1-containing receptors feature a more compact arrangement between the transmembrane and extracellular domains. Interestingly, APG is bound at the transmembrane α/ß subunit interface, even when not added to the sample, revealing an important role for endogenous neurosteroids in modulating native GABAARs. Together with structurally engaged lipids, neurosteroids produce global conformational changes throughout the receptor that modify the ion channel pore and the binding sites for GABA and insomnia medications. Our data reveal the major α1-containing GABAAR assemblies, bound with endogenous neurosteroid, thus defining a structural landscape from which subtype-specific drugs can be developed.

Structure of C. elegans TMC-2 complex suggests roles of lipid-mediated subunit contacts in mechanosensory transduction.

Mechanotransduction is the process by which a mechanical force, such as touch, is converted into an electrical signal. Transmembrane channel-like (TMC) proteins are an evolutionarily-conserved family of ion channels whose function has been linked to a variety of mechanosensory processes, including hearing and balance sensation in vertebrates and locomotion in Drosophila. The molecular features that tune homologous TMC ion channel complexes to diverse mechanical stimuli are unknown. Caenorhabditis elegans express two TMC homologs, TMC-1 and TMC-2, both of which are the likely pore-forming subunits of mechanosensitive ion channels but differ in their expression pattern and functional role in the worm. Here we present the single particle cryo-electron microscopy structure of the native TMC-2 complex isolated from C. elegans. The complex is composed of two copies each of the pore-forming TMC-2 subunit, the calcium and integrin binding protein CALM-1 and the transmembrane inner ear protein TMIE. Comparison of the TMC-2 complex to the recently published cryo-EM structure of the C. elegans TMC-1 complex reveals differences in subunit composition and highlights conserved protein-lipid interactions, as well as other structural features, that together suggest a mechanism for TMC-mediated mechanosensory transduction.

Size and site specific transcriptomic responses of blue mussel (Mytilus edulis) to acute hypoxia.

The Prince Edward Island (PEI) mussel aquaculture industry is being challenged by climate change induced environmental stressors including hypoxic/anoxic episodes, that can impact mussel health and survival. Physiological responses of mussels to hypoxia/anoxia have been studied; however, less is known about how transcriptomic response leads to physiology. The present study examined the transcriptomic response of acute (4 h) hypoxia in blue mussels (Mytilus edulis) from two sites and size classes in PEI, Canada. Overall, major changes in whole-mussel transcriptomics associated with metabolism, cellular organelles/processes and environmental sensing were observed in the first hours of hypoxia exposure. Differences in differentially expressed transcripts were observed between each site and size, indicating that responses to acute hypoxia exposure are highly complex. A size related pattern was observed, with seed size mussels having differential expression of transcripts associated with development, muscle function, and byssal attachment compared to the adults. Adult mussels had higher HSP 90 expression, while HSPs were predominately under-expressed in seed mussels. Seed mussels had significant under-expression of several classes of byssal thread attachment transcripts, indicating a decline in the production of byssal thread or detachment, both which have negative consequences for mussel aquaculture.