Early molecular events of autosomal-dominant Alzheimer's disease in marmosets with PSEN1 mutations.

INTRODUCTION: Fundamental questions remain about the key mechanisms that initiate Alzheimer's disease (AD) and the factors that promote its progression. Here we report the successful generation of the first genetically engineered marmosets that carry knock-in (KI) point mutations in the presenilin 1 (PSEN1) gene that can be studied from birth throughout lifespan. METHODS: CRISPR/Cas9 was used to generate marmosets with C410Y or A426P point mutations in PSEN1. Founders and their germline offspring are comprehensively studied longitudinally using non-invasive measures including behavior, biomarkers, neuroimaging, and multiomics signatures. RESULTS: Prior to adulthood, increases in plasma amyloid beta were observed in PSEN1 mutation carriers relative to non-carriers. Analysis of brain revealed alterations in several enzyme-substrate interactions within the gamma secretase complex prior to adulthood. DISCUSSION: Marmosets carrying KI point mutations in PSEN1 provide the opportunity to study the earliest primate-specific mechanisms that contribute to the molecular and cellular root causes of AD onset and progression. HIGHLIGHTS: We report the successful generation of genetically engineered marmosets harboring knock-in point mutations in the PSEN1 gene. PSEN1 marmosets and their germline offspring recapitulate the early emergence of AD-related biomarkers. Studies as early in life as possible in PSEN1 marmosets will enable the identification of primate-specific mechanisms that drive disease progression.

Improving preclinical to clinical translation of cognitive function for aging-related disorders: the utility of comprehensive touchscreen testing batteries in common marmosets.

Concerns about poor animal to human translation have come increasingly to the fore, in particular with regards to cognitive improvements in rodent models, which have failed to translate to meaningful clinical benefit in humans. This problem has been widely acknowledged, most recently in the field of Alzheimer's disease, although this issue pervades the spectrum of central nervous system (CNS) disorders, including neurodevelopmental, neuropsychiatric, and neurodegenerative diseases. Consequently, recent efforts have focused on improving preclinical to clinical translation by incorporating more clinically analogous outcome measures of cognition, such as touchscreen-based assays, which can be employed across species, and have great potential to minimize the translational gap. For aging-related research, it also is important to incorporate model systems that facilitate the study of the long prodromal phase in which cognitive decline begins to emerge and which is a major limitation of short-lived species, such as laboratory rodents. We posit that to improve translation of cognitive function and dysfunction, nonhuman primate models, which have conserved anatomical and functional organization of the primate brain, are necessary to move the field of translational research forward and to bridge the translational gaps. The present studies describe the establishment of a comprehensive battery of touchscreen-based tasks that capture a spectrum of domains sensitive to detecting aging-related cognitive decline, which will provide the greatest benefit through longitudinal evaluation throughout the prolonged lifespan of the marmoset.

Structure-Activity Relationships and Discovery of (S)-6-Isopropyl-2-methoxy-3-(3-methoxypropoxy)-10-oxo-5,10-dihydro-6H-pyrido[1,2-h][1,7]naphthyridine-9-carboxylic Acid (AB-452), a Novel Orally Available HBV RNA Destabilizer.

Approved therapies for hepatitis B virus (HBV) treatment include nucleos(t)ides and interferon alpha (IFN-α) which effectively suppress viral replication, but they rarely lead to cure. Expression of viral proteins, especially surface antigen of the hepatitis B virus (HBsAg) from covalently closed circular DNA (cccDNA) and the integrated genome, is believed to contribute to the persistence of HBV. This work focuses on therapies that target the expression of HBV proteins, in particular HBsAg, which differs from current treatments. Here we describe the identification of AB-452, a dihydroquinolizinone (DHQ) analogue. AB-452 is a potent HBV RNA destabilizer by inhibiting PAPD5/7 proteins in vitro with good in vivo efficacy in a chronic HBV mouse model. AB-452 showed acceptable tolerability in 28-day rat and dog toxicity studies, and a high degree of oral exposure in multiple species. Based on its in vitro and in vivo profiles, AB-452 was identified as a clinical development candidate.

Clients in Uganda accessing preferred differentiated antiretroviral therapy models achieve higher viral suppression and are less likely to miss appointments: a cross-sectional analysis.

INTRODUCTION: The Uganda Ministry of Health recommends facility- and community-based differentiated antiretroviral therapy (DART) models to support person-centred care for eligible clients receiving antiretroviral therapy (ART). Healthcare workers assess client eligibility for one of six DART models upon initial enrolment; however, client circumstances evolve, and their preferences are not routinely adjusted. We developed a tool to understand the proportion of clients accessing preferred DART models and compared the outcomes of clients accessing preferred DART models to the outcomes of clients not receiving preferred DART models. METHODS: We conducted a cross-sectional study. A sample of 6376 clients was selected from 113 referrals, general hospitals and health centres purposely selected from 74 districts. Clients receiving ART accessing care from the sampled sites were eligible for inclusion. Healthcare workers interviewed clients (caretakers of clients under 18), over a 2-week period between January and February 2022 using a client preference tool to elicit whether clients were receiving DART services through their preferred model. Treatment outcomes of viral load test, viral load suppression and missed appointment date were extracted from clients' medical files before or immediately after the interview and de-identified. The descriptive analysis determined the interaction between client preferences and predefined treatment outcomes by comparing outcomes of clients whose care aligned with their preferences to outcomes of clients whose care misaligned with their preferences. RESULTS: Of 25% (1573/6376) of clients not accessing their preferred DART model, 56% were on facility-based individual management and 35% preferred fast-track drug refills model. Viral load coverage was 87% for clients accessing preferred DART models compared to 68% among clients not accessing their preferred model. Viral load suppression was higher among clients who accessed the preferred DART model (85%) compared to (68%) clients who did not access their preferred DART model. Missed appointments were lower at 29% for clients who accessed preferred DART models compared to 40% among clients not enrolled in the DART model of their choice. CONCLUSIONS: Clients who accessed their preferred DART model have better clinical outcomes. Preferences should be integrated throughout health systems, improvement interventions, policies and research efforts to ensure client-centred care and client autonomy.

Factors that influence the satisfaction of people living with HIV with differentiated antiretroviral therapy delivery models in east Central Uganda: a cross-sectional study.

BACKGROUND: The World Health Organization (WHO) and the Uganda Ministry of Health recommend differentiated service delivery models (DSDMs) as patient-centered antiretroviral therapy (ART) mechanisms for people living with HIV/AIDS (PLHIV) with undetectable viral loads. We studied patient satisfaction with ART services, and its associated factors amongst PLHIV enrolled in DSDMs in Uganda. METHODS: This cross-sectional study involved a random sample of PLHIV accessing DSDM-related ART at nine facilities in East Central Uganda. Eligible patients were adult PLHIV (≥18 years), on ART, and enrolled for at least 12 months in one of three DSDMs: Community Client-Led ART Delivery (CCLAD), Community Drug Distribution Points (CDDP), or Fast-Track Drug Refill (FTDR). We collected data from June to July 2019. A validated tool measured satisfaction. General Estimating Equations with modified Poisson regression and exchangeable correlation structures accounted for clustering at health facilities and identified DSDM-related satisfaction factors. RESULTS: Of 842 participants enrolled, 530 (63.5%) accessed HIV care through CDDP, 166 (20.1%) through CCLAD, and 146 (16.3%) through FTDR; 541 (64.2%) were satisfied with DSDM services: 78.7% in CDDP, 42.8% in CCLAD, and 36.3% in FTDR. The delivery and treatment factors positively associated with satisfaction included: being enrolled on CDDP [adjusted prevalence ratio (aPR) = 1.51, 95% CI:1.47-1.56] or FTDR [aPR = 1.47, 95% CI:1.26-1.71] relative to CCLAD and being enrolled in a DSDM for more than 3 years [aPR = 1.28, 95% CI:1.11-1.48]. Poor ART adherence [aPR = 0.33, 95% CI:0.19-0.56] and having a baseline WHO HIV stage of 3 or 4 [aPR = 0.36, 95% CI:0.20-0.64] relative to stages 1 and 2 were negatively associated. Among socioeconomic factors, having lower transport costs (< $1.35) per clinic visit [aPR = 1.34, 95% CI:1.17-1.53], being employed [aPR = 1.61, 95% CI:1.38-1.87], and being single [aPR = 1.10, 95% CI:1.08-1.13] were positively associated with satisfaction; drinking alcohol at least once a week [aPR = 0.77, 95% CI:0.63-0.93] was negatively associated with patient satisfaction. CONCLUSIONS: Results showed that 64.2% of patients were satisfied with DSDM services. HIV service delivery and treatment factors (DSDM type, time in DSDM, WHO stage, ART adherence), plus social factors (employment and marital status, transport costs, alcohol consumption), were associated with patient satisfaction. DSDM implementers should tailor services to address these factors to improve patient satisfaction.

Repeated dosing with cocaine produces strain-dependent effects on responding for conditioned reinforcement in Collaborative Cross mice.

RATIONALE: Cocaine use disorder (CUD) is a highly heritable form of substance use disorder, with genetic variation accounting for a substantial proportion of the risk for transitioning from recreational use to a clinically impairing addiction. With repeated exposures to cocaine, psychomotor and incentive sensitization are observed in rodents. These phenomena are thought to model behavioral changes elicited by the drug that contribute to the progression into addiction, but little is known about how genetic variation may moderate these consequences. OBJECTIVES: Here, we describe the use of two Collaborative Cross (CC) recombinant inbred mouse strains that either exhibit high (CC018/UncJ) or no (CC027/GeniUncJ) psychomotor sensitization in response to cocaine to measure phenotypes related to incentive sensitization after repeated cocaine exposures; given the relationship of incentive motivation to nucleus accumbens core (NAc) dopamine release and reuptake, we also assessed these neurochemical mechanisms. METHODS: Adult male and female CC018/UncJ and CC027/GeniUncJ mice underwent Pavlovian conditioning to associate a visual cue with presentation of a palatable food reward, then received five, every-other-day injections of cocaine or vehicle. Following Pavlovian re-training, they underwent testing acquisition of a new operant response for the visual cue, now serving as a conditioned reinforcer. Subsequently, electrically evoked dopamine release was assessed using fast-scan cyclic voltammetry from acute brain slices containing the NAc. RESULTS: While both strains acquired the Pavlovian association, only CC018/UncJ mice showed conditioned reinforcement and incentive sensitization in response to cocaine, while CC027/GeniUncJ mice did not. Voltammetry data revealed that CC018/UncJ, compared to CC027/GeniUnc, mice exhibited higher baseline dopamine release and uptake. Moreover, chronic cocaine exposure blunted tonic and phasic dopamine release in CC018/UncJ, but not CC027/GeniUncJ, mice. CONCLUSIONS: Genetic background is a moderator of cocaine-induced neuroadaptations in mesolimbic dopamine signaling, which may contribute to both psychomotor and incentive sensitization and indicate a shared biological mechanism of variation.

Predictive Analytics Using Machine Learning to Identify ART Clients at Health System Level at Greatest Risk of Treatment Interruption in Mozambique and Nigeria.

BACKGROUND: A core objective of HIV/AIDS programming is keeping clients on treatment to improve their health outcomes and to limit spread. Machine learning and artificial intelligence can combine client, temporal, and locational attributes to identify which clients are at greatest risk of loss to follow-up (LTFU) and enable health providers to direct support interventions accordingly. SETTING: The analysis was part of a project funded by U.S. President's Emergency Plan for AIDS Relief and United States Agency for International Development, Data for Implementation, and applied to data from publicly available sources (health facility data, geospatial data, and satellite imagery) and de-identified electronic medical record data on antiretroviral therapy clients in Nigeria and Mozambique. METHODS: The project applied binary classification techniques using temporal cross-validation to predict the risk that patients would be LTFU. Classifiers included logistic regression, neural networks, and tree-based models. RESULTS: Models showed strong predictive power in both settings. In Mozambique, the best-performing model, a Random Forest, achieved an area under the precision-recall curve of 0.65 compared against an underlying LTFU rate of 23%. In Nigeria, the best-performing model, a boosted tree, achieved an area under the precision-recall curve of 0.52 compared against an underlying LTFU rate of 27%. CONCLUSIONS: Machine-learned models outperformed current classification techniques and showed potential to better direct health worker resources toward patients at greatest risk of LTFU. Moreover, models performed equally across sex and age groups, supporting the model's generalizability and wider application.

Behavioral phenotypes revealed during reversal learning are linked with novel genetic loci in diversity outbred mice.

Impulsive behavior and impulsivity are heritable phenotypes that are strongly associated with risk for substance use disorders. Identifying the neurogenetic mechanisms that influence impulsivity may also reveal novel biological insights into addiction vulnerability. Our past studies using the BXD and Collaborative Cross (CC) recombinant inbred mouse panels have revealed that behavioral indicators of impulsivity measured in a reversal-learning task are heritable and are genetically correlated with aspects of intravenous cocaine self-administration. Genome-wide linkage studies in the BXD panel revealed a quantitative trait locus (QTL) on chromosome 10, but we expect to identify additional QTL by testing in a population with more genetic diversity. To this end, we turned to Diversity Outbred (DO) mice; 392 DO mice (156 males, 236 females) were phenotyped using the same reversal learning test utilized previously. Our primary indicator of impulsive responding, a measure that isolates the relative difficulty mice have with reaching performance criteria under reversal conditions, revealed a genome-wide significant QTL on chromosome 7 (max LOD score = 8.73, genome-wide corrected p<0.05). A measure of premature responding akin to that implemented in the 5-choice serial reaction time task yielded a suggestive QTL on chromosome 17 (max LOD score = 9.14, genome-wide corrected <0.1). Candidate genes were prioritized (2900076A07Rik, Wdr73 and Zscan2) based upon expression QTL data we collected in DO and CC mice and analyses using publicly available gene expression and phenotype databases. These findings may advance understanding of the genetics that drive impulsive behavior and enhance risk for substance use disorders.

Electroformation of Particulate Emulsions Using Lamellar and Nonlamellar Lipid Self-Assemblies.

We report on the development of an electroformation technique for the preparation of particulate (particle-based) emulsions. These oil-in-water (here, lipid phase acts as an "oil") emulsions were prepared using nonlamellar lipid phases. Such emulsion particles offer high hydrophobic volumes compared to conventional lipid particles based on lamellar phases (vesicles/liposomes). In addition, the tortuous internal nanostructure contributes through greater surface area per volume of lipid particles allowing an enhanced loading of payloads. The electroformation method makes use of a capacitor formed from two indium tin oxide coated conductive glass surfaces separated by a dielectric aqueous medium. This capacitor setup is enclosed in a custom-designed 3D-printed unit. Lipid molecules, deposited on conductive surfaces, self-assemble into a nanostructure in the presence of an aqueous medium, which when subjected to an alternating current electric field forms nano- and/or microparticles. Optical microscopy, dynamic light scattering, and small-angle X-ray scattering techniques were employed for micro- and nanostructural analyses of electroformed particles. With this method, it is possible to produce particulate emulsions at a very low (e.g., 0.0005 wt % or 0.5 mg/mL) lipid concentration. We demonstrate an applicability of the electroformation method for drug delivery by preparing lipid particles with curcumin, which is a highly important but water-insoluble medicinal compound. As the method employs gentle conditions, it is potentially noninvasive for the delivery of delicate biomolecules and certain drugs, which are prone to decomposition or denaturation due to the high thermomechanical energy input and/or nonaqueous solvents required for existing methods.

Patterned Feeding of a Hyper-Palatable Food (Oreo Cookies) Reduces Alcohol Drinking in Rats.

While a bidirectional positive link between palatable food intake and alcohol drinking has been suggested, several rodents studies report reduced alcohol drinking following palatable diets exposure. These studies utilized purified rodents' diets high in sugar/fat; however, the effects of hyper-palatable food (HPF) rich in fat and sugar on alcohol drinking remain unclear. Furthermore, neural substrates involved in HPF-mediated changes in alcohol consumption are poorly understood. Therefore, the present study evaluated the effects of patterned feeding of a hyper-palatable food (Oreo cookies) on alcohol drinking as well as dopamine (DA) and serotonin (5-HT) content in rat's mesocorticolimbic (medial-prefrontal cortex, orbitofrontal cortex, amygdala, and nucleus accumbens) circuitry. Male Long Evans rats received 8-weeks of intermittent (Mon, Tue, Wed) Oreo cookies access, which induced a patterned feeding, in which rats in the Oreo group overconsumed calories on HPF days whereas underconsumption was observed on chow only (Thu, Fri) days. Following HPF exposure, alcohol consumption was evaluated while patterned feeding continued. Alcohol intake in the Oreo group was significantly lower as compared to the chow controls. However, alcohol intake in the Oreo group increased to the levels seen in the group receiving chow following the suspension of patterned HPF feeding. Finally, DA levels in the nucleus accumbens were significantly greater, whereas its metabolite (DOPAC) levels were lower in the Oreo group compared to the chow controls. Surprisingly, 5-HT levels remained unaltered in all tested brain areas. Together, these data suggest that HPF-associated increased DA availability and reduced DA turnover within mesocorticolimbic circuitry may regulate alcohol drinking following patterned HPF feeding.

Heritable variation in locomotion, reward sensitivity and impulsive behaviors in a genetically diverse inbred mouse panel.

Drugs of abuse, including alcohol and stimulants like cocaine, produce effects that are subject to individual variability, and genetic variation accounts for at least a portion of those differences. Notably, research in both animal models and human subjects point toward reward sensitivity and impulsivity as being trait characteristics that predict relatively greater positive subjective responses to stimulant drugs. Here we describe use of the eight collaborative cross (CC) founder strains and 38 (reversal learning) or 10 (all other tests) CC strains to examine the heritability of reward sensitivity and impulsivity traits, as well as genetic correlations between these measures and existing addiction-related phenotypes. Strains were all tested for activity in an open field and reward sensitivity (intake of chocolate BOOST®). Mice were then divided into two counterbalanced groups and underwent reversal learning (impulsive action and waiting impulsivity) or delay discounting (impulsive choice). CC and founder mice show significant heritability for impulsive action, impulsive choice, waiting impulsivity, locomotor activity, and reward sensitivity, with each impulsive phenotype determined to be non-correlating, independent traits. This research was conducted within the broader, inter-laboratory effort of the Center for Systems Neurogenetics of Addiction (CSNA) to characterize CC and DO mice for multiple, cocaine abuse related traits. These data will facilitate the discovery of genetic correlations between predictive traits, which will then guide discovery of genes and genetic variants that contribute to addictive behaviors.

The impact of COVID-19 on multi-month dispensing (MMD) policies for antiretroviral therapy (ART) and MMD uptake in 21 PEPFAR-supported countries: a multi-country analysis.

INTRODUCTION: Increasing access to multi-month dispensing (MMD) of antiretroviral therapy (ART) supports treatment continuity and viral load suppression for people living with HIV (PLHIV) and reduces burden on health facilities. During the COVID-19 response, PEPFAR worked with ministries of health to scale up MMD and expand eligibility to new groups of PLHIV, including children and pregnant/breastfeeding women. We analysed PEPFAR program data to understand the impact of the policy changes on actual practice. METHODS: We conducted a desk review in 21 PEPFAR-supported countries to identify and collect official documentation released between March and June 2020 addressing changes to MMD guidance during the COVID-19 response. MMD coverage, the proportion of all ART clients on MMD, was assessed in the calendar quarters preceding the COVID-19 response (Q4 2019, October-December 2019; and Q1, January-March 2020) and the quarters following the start of the response (Q2 2020, April-June 2020; Q3 2020, July-September, 2020; Q4 2020, October-December 2020). We used the two-proportion Z-test to test for differences in MMD coverage pre-COVID-19 (Q4 2019) and during implementation of COVID-19 policy adaptations (Q2 2020). RESULTS AND DISCUSSION: As of June 2020, 16 of the 21 PEPFAR-supported countries analysed adapted MMD policy or promoted intensified scale-up of MMD in response to COVID-19. MMD coverage for all clients on ART grew from 49% in Q4 2019 pre-COVID-19 to 72% in Q2 2020 during COVID-19; among paediatric clients (< 15), MMD coverage increased from 27% to 51% in the same period. Adaptations to MMD policy were associated with a significantly accelerated growth in the proportion of clients on MMD (p < 0.001) for all populations, irrespective of age and dispensing interval. CONCLUSIONS: Access to MMD markedly expanded during the COVID-19 pandemic, supporting treatment continuity while mitigating exposure to COVID-19 at health facilities. This model is beneficial in public health emergencies and during disruptions to the healthcare system. Outside emergency contexts, expanded MMD eligibility extends client-centred care to previously excluded populations. The success in expanding MMD access during COVID-19 should motivate countries to recommend broader MMD access as a new standard of care.

Host Poly(A) Polymerases PAPD5 and PAPD7 Provide Two Layers of Protection That Ensure the Integrity and Stability of Hepatitis B Virus RNA.

Noncanonical poly(A) polymerases PAPD5 and PAPD7 (PAPD5/7) stabilize hepatitis B virus (HBV) RNA via the interaction with the viral posttranscriptional regulatory element (PRE), representing new antiviral targets to control HBV RNA metabolism, hepatitis B surface antigen (HBsAg) production, and viral replication. Inhibitors targeting these proteins are being developed as antiviral therapies; therefore, it is important to understand how PAPD5/7 coordinate to stabilize HBV RNA. Here, we utilized a potent small-molecule AB-452 as a chemical probe, along with genetic analyses to dissect the individual roles of PAPD5/7 in HBV RNA stability. AB-452 inhibits PAPD5/7 enzymatic activities and reduces HBsAg both in vitro (50% effective concentration [EC50] ranged from 1.4 to 6.8 nM) and in vivo by 0.94 log10. Our genetic studies demonstrate that the stem-loop alpha sequence within PRE is essential for both maintaining HBV poly(A) tail integrity and determining sensitivity toward the inhibitory effect of AB-452. Although neither single knockout (KO) of PAPD5 nor PAPD7 reduces HBsAg RNA and protein production, PAPD5 KO does impair poly(A) tail integrity and confers partial resistance to AB-452. In contrast, PAPD7 KO did not result in any measurable changes within the HBV poly(A) tails, but cells with both PAPD5 and PAPD7 KO show reduced HBsAg production and conferred complete resistance to AB-452 treatment. Our results indicate that PAPD5 plays a dominant role in stabilizing viral RNA by protecting the integrity of its poly(A) tail, while PAPD7 serves as a second line of protection. These findings inform PAPD5-targeted therapeutic strategies and open avenues for further investigating PAPD5/7 in HBV replication. IMPORTANCE Chronic hepatitis B affects more than 250 million patients and is a major public health concern worldwide. HBsAg plays a central role in maintaining HBV persistence, and as such, therapies that aim at reducing HBsAg through destabilizing or degrading HBV RNA have been extensively investigated. Besides directly degrading HBV transcripts through antisense oligonucleotides or RNA silencing technologies, small-molecule compounds targeting host factors such as the noncanonical poly(A) polymerase PAPD5 and PAPD7 have been reported to interfere with HBV RNA metabolism. Herein, our antiviral and genetic studies using relevant HBV infection and replication models further characterize the interplays between the cis element within the viral sequence and the trans elements from the host factors. PAPD5/7-targeting inhibitors, with oral bioavailability, thus represent an opportunity to reduce HBsAg through destabilizing HBV RNA.

Panuveitis in patient on ipilimumab/nivolumab combination for small-cell lung cancer treated with an intravitreal dexamethasone implant.

BACKGROUND: Immunotherapy with checkpoint inhibitors has demonstrated durable responses and remarkable antitumor effects in a variety of cancers. Although these agents are generally well-tolerated, patients can experience immune-related adverse events (irAEs) that require prompt recognition by healthcare providers. Immune-related ocular toxicities are rare, but serious adverse events have been reported with the use of checkpoint inhibitors.Case presentation: Here, we describe a rare case of panuveitis during Nivolumab and Ipilimumab combination treatment in a patient being treated for recurrent Small Cell Lung Cancer (SCLC). The patient was managed with an injection of Ozurdex (Allergan, Madison, NJ), a dexamethasone intravitreal implant. The patient had a resolution of inflammation and an improvement in her vision and was able to resume nivolumab monotherapy without recurrence of the panuveitis. CONCLUSION: This case highlights the importance of early recognition of ocular irAEs by ocular oncologists and the successful approach to treatment of immunotherapy-induced panuveitis in order to avoid permanent cessation of therapy.

Characterization of genetically complex Collaborative Cross mouse strains that model divergent locomotor activating and reinforcing properties of cocaine.

RATIONALE: Few effective treatments exist for cocaine use disorders due to gaps in knowledge about its complex etiology. Genetically defined animal models provide a useful tool for advancing our understanding of the biological and genetic underpinnings of addiction-related behavior and evaluating potential treatments. However, many attempts at developing mouse models of behavioral disorders were based on overly simplified single gene perturbations, often leading to inconsistent and misleading results in pre-clinical pharmacology studies. A genetically complex mouse model may better reflect disease-related behaviors. OBJECTIVES: Screening defined, yet genetically complex, intercrosses of the Collaborative Cross (CC) mice revealed two lines, RIX04/17 and RIX41/51, with extreme high and low behavioral responses to cocaine. We characterized these lines as well as their CC parents, CC004/TauUnc and CC041/TauUnc, to evaluate their utility as novel model systems for studying the biological and genetic mechanisms underlying behavioral responses to cocaine. METHODS: Behavioral responses to acute (initial locomotor sensitivity) and repeated (behavioral sensitization, conditioned place preference, intravenous self-administration) exposures to cocaine were assessed. We also examined the monoaminergic system (striatal tissue content and in vivo fast scan cyclic voltammetry), HPA axis reactivity, and circadian rhythms as potential mechanisms for the divergent phenotypic behaviors observed in the two strains, as these systems have a previously known role in mediating addiction-related behaviors. RESULTS: RIX04/17 and 41/51 show strikingly divergent initial locomotor sensitivity to cocaine with RIX04/17 exhibiting very high and RIX41/51 almost no response. The lines also differ in the emergence of behavioral sensitization with RIX41/51 requiring more exposures to exhibit a sensitized response. Both lines show conditioned place preference for cocaine. We determined that the cocaine sensitivity phenotype in each RIX line was largely driven by the genetic influence of one CC parental strain, CC004/TauUnc and CC041/TauUnc. CC004 demonstrates active operant cocaine self-administration and CC041 is unable to acquire under the same testing conditions, a deficit which is specific to cocaine as both strains show operant response for a natural food reward. Examination of potential mechanisms driving differential responses to cocaine show strain differences in molecular and behavioral circadian rhythms. Additionally, while there is no difference in striatal dopamine tissue content or dynamics, there are selective differences in striatal norepinephrine and serotonergic tissue content. CONCLUSIONS: These CC strains offer a complex polygenic model system to study underlying mechanisms of cocaine response. We propose that CC041/TauUnc and CC004/TauUnc will be useful for studying genetic and biological mechanisms underlying resistance or vulnerability to the stimulatory and reinforcing effects of cocaine.

Damp mouldy housing and early childhood hospital admissions for acute respiratory infection: a case control study.

INTRODUCTION: A gap exists in the literature regarding dose-response associations of objectively assessed housing quality measures, particularly dampness and mould, with hospitalisation for acute respiratory infection (ARI) among children. METHODS: A prospective, unmatched case-control study was conducted in two paediatric wards and five general practice clinics in Wellington, New Zealand, over winter/spring 2011-2013. Children aged <2 years who were hospitalised for ARI (cases), and either seen in general practice with ARI not requiring admission or for routine immunisation (controls) were included in the study. Objective housing quality was assessed by independent building assessors, with the assessors blinded to outcome status, using the Respiratory Hazard Index (RHI), a 13-item scale of household quality factors, including an 8-item damp-mould subscale. The main outcome was case-control status. Adjusted ORs (aORs) of the association of housing quality measures with case-control status were estimated, along with the population attributable risk of eliminating dampness-mould on hospitalisation for ARI among New Zealand children. RESULTS: 188 cases and 454 controls were studied. Higher levels of RHI were associated with elevated odds of hospitalisation (OR 1.11/unit increase (95% CI 1.01 to 1.21)), which weakened after adjustment for season, housing tenure, socioeconomic status and crowding (aOR 1.04/unit increase (95% CI 0.94 to 1.15)). The damp-mould index had a significant, adjusted dose-response relationship with ARI admission (aOR 1.15/unit increase (95% CI 1.02 to 1.30)). By addressing these harmful housing exposures, the rate of admission for ARI would be reduced by 19% or 1700 fewer admissions annually. CONCLUSIONS: A dose-response relationship exists between housing quality measures, particularly dampness-mould, and young children's ARI hospitalisation rates. Initiatives to improve housing quality and to reduce dampness-mould would have a large impact on ARI hospitalisation.

Indoor allergen exposure in primary school classrooms in New Zealand.

AIM: Indoor allergens exposure is a risk factor for respiratory symptoms in sensitised children. There is limited data on indoor allergen exposures in New Zealand schools. METHODS: Vacuumed floor dust samples were collected from 136 classrooms in 12 primary schools and analysed for allergens from the house dust mite Dermatophagoides pteronyssinus (Der p 1), cat dander (Fel d 1), cockroach (Bla g 2), cow dander (Bos d 2), horse dander (Equ c 4) and peanut (Ara h 2) by ELISA. RESULTS: House dust mite, cat, cockroach, cow and horse allergens were detected in 96.4%, 100%, 2.2%, 27.0% and 59.9% respectively in the classrooms dust samples. Thirty-one (22.6%) classrooms had Fel d 1 levels of >8.0µg/g while none had Der p 1 levels of >10.0µg/g. Only one classroom had detectable levels of peanut allergen. CONCLUSIONS: House dust mite allergen levels were low in New Zealand classrooms while about a quarter of classrooms had cat allergen levels that may be associated with respiratory symptoms.

An experimental test of the allotonic frequency hypothesis to isolate the effects of light pollution on bat prey selection.

Artificial lights may be altering interactions between bats and moth prey. According to the allotonic frequency hypothesis (AFH), eared moths are generally unavailable as prey for syntonic bats (i.e., bats that use echolocation frequencies between 20 and 50 kHz within the hearing range of eared moths) due to the moths' ability to detect syntonic bat echolocation. Syntonic bats therefore feed mainly on beetles, flies, true bugs, and non-eared moths. The AFH is expected to be violated around lights where eared moths are susceptible to exploitation by syntonic bats because moths' evasive strategies become less effective. The hypothesis has been tested to date almost exclusively in areas with permanent lighting, where the effects of lights on bat diets are confounded with other aspects of human habitat alteration. We undertook diet analysis in areas with short-term, localized artificial lighting to isolate the effects of artificial lighting and determine if syntonic and allotonic bats (i.e., bats that use echolocation frequencies outside the hearing range of eared moths) consumed more moths under conditions of artificial lights than in natural darkness. We found that syntonic bats increased their consumption of moth prey under experimentally lit conditions, likely owing to a reduction in the ability of eared moths to evade the bats. Eared moths may increase in diets of generalist syntonic bats foraging around artificial light sources, as opposed to allotonic species and syntonic species with a more specialized diet.

Environmental heterogeneity mediates scale-dependent declines in kelp diversity on intertidal rocky shores.

Biodiversity loss is driven by interacting factors operating at different spatial scales. Yet, there remains uncertainty as to how fine-scale environmental conditions mediate biological responses to broad-scale stressors. We surveyed intertidal rocky shore kelp beds situated across a local gradient of wave action and evaluated changes in kelp diversity and abundance after more than two decades of broad scale stressors, most notably the 2013-2016 heat wave. Across all sites, species were less abundant on average in 2017 and 2018 than during 1993-1995 but changes in kelp diversity were dependent on wave exposure, with wave exposed habitats remaining stable and wave sheltered habitats experiencing near complete losses of kelp diversity. In this way, wave exposed sites have acted as refugia, maintaining regional kelp diversity despite widespread local declines. Fucoids, seagrasses and two stress-tolerant kelp species (Saccharina sessilis, Egregia menziesii) did not decline as observed in other kelps, and the invasive species Sargassum muticum increased significantly at wave sheltered sites. Long-term monitoring data from a centrally-located moderate site suggest that kelp communities were negatively impacted by the recent heatwave which may have driven observed losses throughout the region. Wave-sheltered shores, which saw the largest declines, are a very common habitat type in the Northeast Pacific and may be especially sensitive to losses in kelp diversity and abundance, with potential consequences for coastal productivity. Our findings highlight the importance of fine-scale environmental heterogeneity in mediating biological responses and demonstrate how incorporating differences between habitat patches can be essential to capturing scale-dependent biodiversity loss across the landscape.