Drug-Eluting Resorbable Scaffold versus Angioplasty for Infrapopliteal Artery Disease.

BACKGROUND: Among patients with chronic limb-threatening ischemia (CLTI) and infrapopliteal artery disease, angioplasty has been associated with frequent reintervention and adverse limb outcomes from restenosis. The effect of the use of drug-eluting resorbable scaffolds on these outcomes remains unknown. METHODS: In this multicenter, randomized, controlled trial, 261 patients with CLTI and infrapopliteal artery disease were randomly assigned in a 2:1 ratio to receive treatment with an everolimus-eluting resorbable scaffold or angioplasty. The primary efficacy end point was freedom from the following events at 1 year: amputation above the ankle of the target limb, occlusion of the target vessel, clinically driven revascularization of the target lesion, and binary restenosis of the target lesion. The primary safety end point was freedom from major adverse limb events at 6 months and from perioperative death. RESULTS: The primary efficacy end point was observed (i.e., no events occurred) in 135 of 173 patients in the scaffold group and 48 of 88 patients in the angioplasty group (Kaplan-Meier estimate, 74% vs. 44%; absolute difference, 30 percentage points; 95% confidence interval [CI], 15 to 46; one-sided P<0.001 for superiority). The primary safety end point was observed in 165 of 170 patients in the scaffold group and 90 of 90 patients in the angioplasty group (absolute difference, -3 percentage points; 95% CI, -6 to 0; one-sided P<0.001 for noninferiority). Serious adverse events related to the index procedure occurred in 2% of the patients in the scaffold group and 3% of those in the angioplasty group. CONCLUSIONS: Among patients with CLTI due to infrapopliteal artery disease, the use of an everolimus-eluting resorbable scaffold was superior to angioplasty with respect to the primary efficacy end point. (Funded by Abbott; LIFE-BTK ClinicalTrials.gov number, NCT04227899.).

Transposon wave remodeled the epigenomic landscape in the rapid evolution of X-Chromosome dosage compensation.

Sex chromosome dosage compensation is a model to understand the coordinated evolution of transcription; however, the advanced age of the sex chromosomes in model systems makes it difficult to study how the complex regulatory mechanisms underlying chromosome-wide dosage compensation can evolve. The sex chromosomes of Poecilia picta have undergone recent and rapid divergence, resulting in widespread gene loss on the male Y, coupled with complete X Chromosome dosage compensation, the first case reported in a fish. The recent de novo origin of dosage compensation presents a unique opportunity to understand the genetic and evolutionary basis of coordinated chromosomal gene regulation. By combining a new chromosome-level assembly of P. picta with whole-genome bisulfite sequencing and RNA-seq data, we determine that the YY1 transcription factor (YY1) DNA binding motif is associated with male-specific hypomethylated regions on the X, but not the autosomes. These YY1 motifs are the result of a recent and rapid repetitive element expansion on the P. picta X Chromosome, which is absent in closely related species that lack dosage compensation. Taken together, our results present compelling support that a disruptive wave of repetitive element insertions carrying YY1 motifs resulted in the remodeling of the X Chromosome epigenomic landscape and the rapid de novo origin of a dosage compensation system.

Prevalence of SARS-CoV-2 Infection among Children and Adults in 15 US Communities, 2021

During January-August 2021, the Community Prevalence of SARS-CoV-2 Study used time/location sampling to recruit a cross-sectional, population-based cohort to estimate SARS-CoV-2 seroprevalence and nasal swab sample PCR positivity across 15 US communities. Survey-weighted estimates of SARS-CoV-2 infection and vaccine willingness among participants at each site were compared within demographic groups by using linear regression models with inverse variance weighting. Among 22,284 persons >2 months of age and older, median prevalence of infection (prior, active, or both) was 12.9% across sites and similar across age groups. Within each site, average prevalence of infection was 3 percentage points higher for Black than White persons and average vaccine willingness was 10 percentage points lower for Black than White persons and 7 percentage points lower for Black persons than for persons in other racial groups. The higher prevalence of SARS-CoV-2 infection among groups with lower vaccine willingness highlights the disparate effect of COVID-19 and its complications.

Sex chromosome heteromorphism and the Fast-X effect in poeciliids.

Fast-X evolution has been observed in a range of heteromorphic sex chromosomes. However, it remains unclear how early in the process of sex chromosome differentiation the Fast-X effect becomes detectible. Recently, we uncovered an extreme variation in sex chromosome heteromorphism across poeciliid fish species. The common guppy, Poecilia reticulata, Endler's guppy, P. wingei, swamp guppy, P. picta and para guppy, P. parae, appear to share the same XY system and exhibit a remarkable range of heteromorphism. Species outside this group lack this sex chromosome system. We combined analyses of sequence divergence and polymorphism data across poeciliids to investigate X chromosome evolution as a function of hemizygosity and reveal the causes for Fast-X effects. Consistent with the extent of Y degeneration in each species, we detect higher rates of divergence on the X relative to autosomes, a signal of Fast-X evolution, in P. picta and P. parae, species with high levels of X hemizygosity in males. In P. reticulata, which exhibits largely homomorphic sex chromosomes and little evidence of hemizygosity, we observe no change in the rate of evolution of X-linked relative to autosomal genes. In P. wingei, the species with intermediate sex chromosome differentiation, we see an increase in the rate of nonsynonymous substitutions on the older stratum of divergence only. We also use our comparative approach to test for the time of origin of the sex chromosomes in this clade. Taken together, our study reveals an important role of hemizygosity in Fast-X evolution.

Causes and risk factors of death among people who inject drugs in Indonesia, Ukraine and Vietnam: findings from HPTN 074 randomized trial.

INTRODUCTION: The HIV Prevention Trials Network (HPTN) 074 study demonstrated a positive effect of an integrated systems navigation and psychosocial counseling intervention on HIV treatment initiation, viral suppression, medication assisted treatment (MAT) enrollment, and risk of death among people who inject drugs (PWID). In this sub-study, we analyzed the incidence, causes, and predictors of death among HIV-infected and uninfected participants. METHODS: The HPTN 074 randomized clinical trial was conducted in Indonesia, Ukraine, and Vietnam. HIV-infected PWID with unsuppressed viral load (indexes) were recruited together with at least one of their HIV-negative injection partners. Indexes were randomized in a 1:3 ratio to the intervention or standard of care. RESULTS: The trial enrolled 502 index and 806 partner participants. Overall, 13% (66/502) of indexes and 3% (19/806) of partners died during follow-up (crude mortality rates 10.4 [95% CI 8.1-13.3] and 2.1 [1.3-3.3], respectively). These mortality rates were for indexes nearly 30 times and for partners 6 times higher than expected in a population of the same country, age, and gender (standardized mortality ratios 30.7 [23.7-39.0] and 5.8 [3.5-9.1], respectively). HIV-related causes, including a recent CD4 < 200 cells/µL, accounted for 50% of deaths among indexes. Among partners, medical conditions were the most common cause of death (47%). In the multivariable Cox model, the mortality among indexes was associated with sex (male versus female aHR = 4.2 [1.5-17.9]), CD4 count (≥ 200 versus < 200 cells/µL aHR = 0.3 [0.2-0.5]), depression (moderate-to-severe versus no/mild aHR = 2.6 [1.2-5.0]) and study arm (intervention versus control aHR = 0.4 [0.2-0.9]). Among partners, the study arm of the index remained the only significant predictor (intervention versus control aHR = 0.2 [0.0-0.9]) while controlling for the effect of MAT (never versus ever receiving MAT aHR = 2.4 [0.9-7.4]). CONCLUSIONS: The results confirm that both HIV-infected and uninfected PWID remain at a starkly elevated risk of death compared to general population. Mortality related to HIV and other causes can be significantly reduced by scaling-up ART and MAT. Access to these life-saving treatments can be effectively improved by flexible integrated interventions, such as the one developed and tested in HPTN 074.

Clinic screening for adverse childhood experiences in people living with HIV to Improve Care Delivery.

Adverse childhood experiences (ACEs) are associated with negative health outcomes; however, screening for ACEs is not routinely performed among people living with HIV (PLWH). We conducted a single-center, cross-sectional pilot study to define the (1) prevalence of ACEs in PLWH and (2) acceptability of ACEs screening in routine out-patient clinical care. One hundred participants completed screening: median age of participants was 49 years (interquartile range: 38.5-59.5), 73% male, 66% Non-Hispanic Black/African American, and 47% gay/lesbian. Clinically significant ACEs score, defined as ≥4, was reported in 51%. High ACEs score was more common among participants <50 years old (64.7% vs. 36.7%; p < 0.01), but the prevalence of ACEs ≥4 did not differ by gender, race, ethnicity, or sexual orientation. Among participants with ≥4 ACEs, 44.4% screened negative on both PHQ-9 and PC-PTSD screens. The majority of participants (89%) reported a positive experience with ACEs screening. The prevalence of clinically significant ACEs in this clinic population of PLWH was more than twice that reported in the general population. Routine ACEs screening can improve delivery of trauma-informed care in the HIV primary care setting.

Mental Health, Social Influences, and HIV Pre-exposure Prophylaxis (PrEP) Utilization Among Men and Transgender Individuals Screening for HIV Prevention Trials.

The effects of mental health comorbidities and social support on the HIV pre-exposure prophylaxis (PrEP) care continuum are unknown. We conducted a cross-sectional study of men and transgender individuals, ≥ 18 years-old, with ≥ 2 male or transgender partners, or recent condomless anal intercourse. Surveys assessed demographics, mental health treatment, depressive symptomatology, social support, and PrEP-related social contacts. Logistic regression assessed associations between these factors and PrEP uptake and persistence. Participants (n = 247) were 89% cis-male and 46% African-American. Median age was 27 (IQR:23-33). Thirty-seven percent had ever used PrEP, of whom 18% discontinued use. High depressive symptomology was identified in 11% and 9% were receiving mental health treatment. There were no significant associations between depressive symptoms or mental health treatment on the odds of PrEP uptake or discontinuation. Each additional PrEP contact conferred a greater odds of uptake (aOR:1.24, 95% CI: 1.09-1.42). Network-level targets may produce fruitful interventions to increase PrEP uptake.

HIV Infection and Depression Among Opiate Users in a US Epicenter of the Opioid Epidemic.

Using a mobile research facility, we enrolled 141 opioid users from a neighborhood of Philadelphia, an urban epicenter of the opioid epidemic. Nearly all (95.6%) met DSM-5 criteria for severe opioid use disorder. The prevalence of HIV infection (8.5%) was more than seven times that found in the general population of the city. Eight of the HIV-positive participants (67.0%) reported receiving antiretroviral treatment but almost all of them had unsuppressed virus (87.5%). The majority of participants (57.4%) reported symptoms consistent with major depressive disorder. Severe economic distress (60.3%) and homelessness were common (57%). Polysubstance use was nearly universal, 72.1% had experienced multiple overdoses and prior medication for opioid use disorder (MOUD) treatment episodes (79.9%), but few currently engaged in addiction care. The prevalence, multiplicity and severity of chronic health and socioeconomic problems highlight consequences of the current opioid epidemic and underscore the urgent need to develop integrated models of treatment.

RESUMEN: Utilizando un Centro de Investigación Móvil, inscribimos a 141 usuarios de opioides del vecindario de Filadelfia, un epicentro urbano de la epidemia de opioides. Casi todos (95,6%) cumplieron con los criterios del DSM-5 para el trastorno del uso severo del consumo de opioides. La prevalencia de la infección de VIH (8,5%) fue másﹶ de 7 veces superior a las encontrada en la población general de la ciudad. Ocho de los participantes con VIH positivo (67,0%) reportaron haber recibido tratamiento antirretroviral pero casi todos tuvieron virus no suprimido (87,5%). La mayoría de los participantes (57,4%) informaron síntomas compatibles con el Desorden Depresivo Mayor. La angustia severa por lo económico (60,3%) y las personas sin hogar fueron comunes (57%). El uso de múltiples sustancias fue casi universal, el 721% había experimentado múltiples sobredosis y previos medicamentos para el tratamiento del trastorno por consumo de opioides (MOUD) (79,9%), pero muy pocos estaban comprometidos con la atención a las adicciones. La prevalencia, la multiplicidad y la seriedad de los problemas de salud crónica y los problemas socioeconómicos destacan las consecuencias de la actual epidemia de opioides y subrayan la urgente necesidad de desarrollar nuevos modelos de tratamiento integrados.

Evaluation of a novel mesh-covered stent for treatment of carotid stenosis in patients at high risk for endarterectomy: 1-year results of the SCAFFOLD trial.

OBJECTIVE: The SCAFFOLD trial evaluated the GORE® Carotid Stent (GCS), a novel, mesh-covered device and evaluated outcomes at 1 year. BACKGROUND: SCAFFOLD was a prospective, multicenter, single-arm clinical trial in patients with severe carotid artery stenosis (angiographically defined as symptomatic ≥50% or asymptomatic ≥80%) at increased risk for adverse events from carotid endarterectomy. Interim 30-day analysis demonstrated low rates of death/stroke/myocardial infarction (DSMI; 3.0%) and stroke (1.1%) in a high surgical risk population. METHODS: The rate of DSMI within 30 days plus ipsilateral stroke between 31 days and 1 year (primary endpoint) was compared to a predetermined performance goal. Secondary outcomes of freedom from clinically driven target lesion revascularization (CD-TLR; diameter stenosis ≥80% by core lab angiography, or ≥50% with clinical symptoms) and restenosis (≥80% diameter stenosis by core lab angiography) are reported as Kaplan-Meier (KM) estimates. RESULTS: Of the 312 patients enrolled and treated, 264 were eligible per protocol and evaluable for major adverse events at 30 days, and 244 (92%) of these were evaluable at 1 year. The proportion of patients with DSMI at 1 year was 4.5% and was significantly lower than the prespecified performance goal of 16.9% (p < .00001). The proportion with ipsilateral stroke from 31 to 365 days was 1.2%. The KM estimates of 1-year event probability were 1.6% for CD-TLR and 1.2% for restenosis. CONCLUSIONS: Use of the mesh-covered GCS in the SCAFFOLD trial demonstrated 100% technical success and low rates of both periprocedural and late stroke, with durable patency at 1 year. ClinicalTrials.gov Identifier: NCT01901874 (redacted).

Adherence among HIV-positive injection drug users undergoing methadone treatment in Taiwan.

AIMS: The study aims were to investigate adherence to methadone maintenance treatment (MMT) and to identify associated clinical factors in patients who inject drugs diagnosed with human immunodeficiency virus (HIV) infection in Taiwan. METHODS: Data were from the National Health Surveillance System on HIV and the National Drug Treatment System on MMT. HIV-positive people who inject drugs (HIVPWID) were defined as the study population. Information obtained included age, sex, education, marital status, employment, methadone dose, and date of diagnosis of HIV infection. Adherence was defined as taking methadone for the past 90, 180 and 365 days, then categorized as high (> 90%), moderate (51 to 90%), or low (<=50%) adherent respectively. RESULTS: Of 1641 HIVPWID registered in the datasets from 2007 to 2012, 961 (58.56%) had received MMT. For HIVPWID evaluated at 90 days (n = 951), 271 (28.5%), 382 (40.2%), and 298 (31.3%) were classified as high, moderate, and low adherent respectively. For HIVPWID evaluated at 180 days (n = 936), 190 (20.3%), 349 (37.3%), and 397 (42.4%) were classified as high, moderate, and low adherent respectively. For HIVPWID evaluated at 365 days (n = 919), 133 (14.5%), 271 (29.5%), and 515 (56.0%) were classified as high, moderate, and low adherent respectively. After controlling for sociodemographics, results showed that methadone dose, location of MMT clinic, and date of HIV diagnosis were significantly associated with MMT adherence. CONCLUSIONS: Study findings underscore the importance to MMT adherence of methadone dosage, early diagnosis of patient's HIV infection, and area of patient residence.

A scalable, integrated intervention to engage people who inject drugs in HIV care and medication-assisted treatment (HPTN 074): a randomised, controlled phase 3 feasibility and efficacy study.

BACKGROUND: People who inject drugs (PWID) have a high incidence of HIV, little access to antiretroviral therapy (ART) and medication-assisted treatment (MAT), and high mortality. We aimed to assess the feasibility of a future controlled trial based on the incidence of HIV, enrolment, retention, and uptake of the intervention, and the efficacy of an integrated and flexible intervention on ART use, viral suppression, and MAT use. METHODS: This randomised, controlled vanguard study was run in Kyiv, Ukraine (one community site), Thai Nguyen, Vietnam (two district health centre sites), and Jakarta, Indonesia (one hospital site). PWID who were HIV infected (index participants) and non-infected injection partners were recruited as PWID network units and were eligible for screening if they were aged 18-45 years (updated to 18-60 years 8 months into study), and active injection drug users. Further eligibility criteria for index participants included a viral load of 1000 copies per mL or higher, willingness and ability to recruit at least one injection partner who would be willing to participate. Index participants were randomly assigned via a computer generated sequence accessed through a secure web portal (3:1) to standard of care or intervention, stratified by site. Masking of assignment was not possible due to the nature of intervention. The intervention comprised systems navigation, psychosocial counselling, and ART at any CD4 count. Local ART and MAT services were used. Participants were followed up for 12-24 months. The primary objective was to assess the feasibility of a future randomised controlled trial. To achieve this aim we looked at the following endpoints: HIV incidence among injection partners in the standard of care group, and enrolment and retention of HIV-infected PWID and their injection partners and the uptake of the integrated intervention. The study was also designed to assess the feasibility, barriers, and uptake of the integrated intervention. Endpoints were assessed in a modified intention-to-treat popualtion after exclusion of ineligible participants. This trial is registered on ClinicalTrials.gov, NCT02935296, and is active but not recruiting new participants. FINDINGS: Between Feb 5, 2015, and June 3, 2016, 3343 potential index participants were screened, of whom 502 (15%) were eligible and enrolled. 1171 injection partners were referred, and 806 (69%) were eligible and enrolled. Index participants were randomly assigned to intervention (126 [25%]) and standard of care (376 [75%]) groups. At week 52, most living index participants (389 [86%] of 451) and partners (567 [80%] of 710) were retained, and self-reported ART use was higher among index participants in the intervention group than those in the standard of care group (probability ratio [PR] 1·7, 95% CI 1·4-1·9). Viral suppression was also higher in the intervention group than in the standard of care group (PR 1·7, 95% CI 1·3-2·2). Index participants in the intervention group reported more MAT use at 52 weeks than those in the standard of care group (PR 1·7, 95% CI 1·3-2·2). Seven incident HIV infections occurred, and all in injection partners in the standard of care group (intervention incidence 0·0 per 100 person-years, 95% CI 0·0-1·7; standard of care incidence 1·0 per 100 person-years, 95% CI 0·4-2·1; incidence rate difference -1·0 per 100 person-years, 95% CI -2·1 to 1·1). No severe adverse events due to the intervention were recorded. INTERPRETATION: This vanguard study provides evidence that a flexible, scalable intervention increases ART and MAT use and reduces mortality among PWID. The low incidence of HIV in both groups impedes a future randomised, controlled trial, but given the strength of the effect of the intervention, its implementation among HIV-infected PWID should be considered. FUNDING: US National Institutes of Health.

Client and Provider Perspectives on Antiretroviral Treatment Uptake and Adherence Among People Who Inject Drugs in Indonesia, Ukraine and Vietnam: HPTN 074.

HIV-infected people who inject drugs (PWID) have low uptake of HIV services, increasing the risk of transmission to uninfected injection or sexual partners and the likelihood of AIDS-related deaths. HPTN 074 is a vanguard study assessing the feasibility of an integrated intervention to facilitate treatment as prevention to PWID in Indonesia, Ukraine, and Vietnam. We describe barriers to and facilitators of ART uptake and adherence among PWID. We conducted in-depth interviews with 62 participants, including 25 providers and 37 PWID at baseline across all sites. All interviews were recorded, transcribed, translated into English and coded in NVivo for analysis. Matrices were developed to identify emergent themes and patterns. Overall, differences between provider and PWID perspectives were greater than differences in cross-site perspectives. Providers and PWID recognized clinic access, financial barriers, side effects, and lack of information about HIV testing and ART enrollment as barriers to ART. However, providers tended to emphasize individual level barriers to ART, such as lack of motivation due to drug use, whereas PWID highlighted health systems barriers, such as clinic hours and financial burden, fears, and side effects. Providers did not mention stigma as a barrier though their language reflected stereotypes about drug users. The differences between provider and PWID perspectives suggest a gap in providers' understanding of PWID. This misunderstanding has implications for patient-provider interactions that may affect PWID willingness to access care or adhere to ART. Lessons learned from this study will be important as countries with a significant HIV burden among PWID design and implement programs to engage HIV-infected PWID in care and treatment.

Glucocorticoid-immune response to acute stress in women and men living with HIV.

Despite high risk for serious non-AIDS events (SNAEs) and accelerated age-related increases in inflammatory markers relative to HIV+ men, HIV+ women have been understudied, particularly in terms of stress impacts on immune parameters. The purpose of this study was to examine sex differences in glucocorticoid-immune stress response in mid-life HIV+ individuals, as poor glucocorticoid control of stress-induced inflammation may contribute to health risk in HIV+ women. Male and female participants completed a threat of shock laboratory stressor. Serum cortisol and cytokines [interleukin (IL)-6, IL-8, IL-10, IL-1ß, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interferon (IFN)-γ] were assessed at six timepoints prior to and in response to the stressor. Participants included 8 HIV- controls (n = 5 female) and 9 HIV+ (n = 5 female) who were virally suppressed. Repeated measures mixed models revealed a significant sex by HIV status by time interaction for IL-10, IL-1ß, TNF-α, and cortisol. IL-10 response, an anti-inflammatory cytokine, was larger in males than females, regardless of HIV status. TNF-α response was blunted in HIV+ individuals compared with HIV-, and specifically in HIV+ women, IL-1ß and cortisol response were blunted. Individuals living with HIV may have impaired coordination between the immune system and hypothalamic pituitary adrenal (HPA) axis. HIV+ women in particular exhibited dysregulated IL-1ß and cortisol response to acute stress. Future work should focus on relationships among proinflammatory cytokines, stress, and SNAEs in HIV, with attention to sex as a biological variable.

Similarities in temperature-dependent gene expression plasticity across timescales in threespine stickleback (Gasterosteus aculeatus).

Phenotypic plasticity occurs at a variety of timescales, but little is known about the degree to which plastic responses at different timescales are associated with similar underlying molecular processes, which is critical for assessing the effects of plasticity on evolutionary trajectories. To address this issue, we identified differential gene expression in response to developmental temperature in the muscle transcriptome of adult threespine stickleback (Gasterosteus aculeatus) exposed to 12, 18 and 24°C until hatch and then held at 18°C for 9 months and compared these results to differential gene expression in response to adult thermal acclimation in stickleback developed at 18°C and then acclimated to 5 and 25°C as adults. Adult thermal acclimation affected the expression of 7,940 and 7,015 genes in response to cold and warm acclimation, respectively, and 4,851 of these genes responded in both treatments. In contrast, the expression of only 33 and 29 genes was affected by cold and warm development, respectively. The majority of the genes affected by developmental temperature were also affected by adult acclimation temperature. Many genes that were differentially expressed as a result of adult acclimation were associated with previously identified temperature-dependent effects on DNA methylation patterns, suggesting a role of epigenetic mechanisms in regulating gene expression plasticity during acclimation. Taken together, these results demonstrate similarities between the persistent effects of developmental plasticity on gene expression and the effects of adult thermal acclimation, emphasizing the potential for mechanistic links between plasticity acting at these different life stages.

A solution to Nature's haemoglobin knockout: a plasma-accessible carbonic anhydrase catalyses CO2 excretion in Antarctic icefish gills.

In all vertebrates studied to date, CO2 excretion depends on the enzyme carbonic anhydrase (CA) that catalyses the rapid conversion of HCO3- to CO2 at the gas-exchange organs. The largest pool of CA is present within red blood cells (RBCs) and, in some vertebrates, plasma-accessible CA (paCA) isoforms participate in CO2 excretion. However, teleost fishes typically do not have paCA at the gills and CO2 excretion is reliant entirely on RBC CA - a strategy that is not possible in icefishes. As the result of a natural knockout, Antarctic icefishes (Channichthyidae) are the only known vertebrates that do not express haemoglobin (Hb) as adults, and largely lack RBCs in the circulation (haematocrit <1%). Previous work has indicated the presence of high levels of membrane-bound CA activity in the gills of icefishes, but without determining its cellular orientation. Thus, we hypothesised that icefishes express a membrane-bound CA isoform at the gill that is accessible to the blood plasma. The CA distribution was compared in the gills of two closely related notothenioid species, one with Hb and RBCs (Notothenia rossii) and one without (Champsocephalus gunnari). Molecular, biochemical and immunohistochemical markers indicate high levels of a Ca4 isoform in the gills of the icefish (but not the red-blooded N. rossii), in a plasma-accessible location that is consistent with a role in CO2 excretion. Thus, in the absence of RBC CA, the icefish gill could exclusively provide the catalytic activity necessary for CO2 excretion - a pathway that is unlike that of any other vertebrate.

Persistent and plastic effects of temperature on DNA methylation across the genome of threespine stickleback (Gasterosteus aculeatus).

Epigenetic mechanisms such as changes in DNA methylation have the potential to affect the resilience of species to climate change, but little is known about the response of the methylome to changes in environmental temperature in animals. Using reduced representation bisulfite sequencing, we assessed the effects of development temperature and adult acclimation temperature on DNA methylation levels in threespine stickleback (Gasterosteus aculeatus). Across all treatments, we identified 2130 differentially methylated cytosines distributed across the genome. Both increases and decreases in temperature during development and with thermal acclimation in adults increased global DNA methylation levels. Approximately 25% of the differentially methylated regions (DMRs) responded to both developmental temperature and adult thermal acclimation, and 50 DMRs were common to all treatments, demonstrating a core response of the epigenome to thermal change at multiple time scales. We also identified differentially methylated loci that were specific to a particular developmental or adult thermal response, which could facilitate the accumulation of epigenetic variation between natural populations that experience different thermal regimes. These data demonstrate that thermal history can have long-lasting effects on the epigenome, highlighting the role of epigenetic modifications in the response to temperature change across multiple time scales.

Gene expression plasticity in response to salinity acclimation in threespine stickleback ecotypes from different salinity habitats.

Phenotypic plasticity is thought to facilitate the colonization of novel environments and shape the direction of evolution in colonizing populations. However, the relative prevalence of various predicted patterns of changes in phenotypic plasticity following colonization remains unclear. Here, we use a whole-transcriptome approach to characterize patterns of gene expression plasticity in the gills of a freshwater-adapted and a saltwater-adapted ecotype of threespine stickleback (Gasterosteus aculeatus) exposed to a range of salinities. The response of the gill transcriptome to environmental salinity had a large shared component common to both ecotypes (2159 genes) with significant enrichment of genes involved in transmembrane ion transport and the restructuring of the gill epithelium. This transcriptional response to freshwater acclimation is induced at salinities below two parts per thousand. There was also differentiation in gene expression patterns between ecotypes (2515 genes), particularly in processes important for changes in the gill structure and permeability. Only 508 genes that differed between ecotypes also responded to salinity and no specific processes were enriched among this gene set, and an even smaller number (87 genes) showed evidence of changes in the extent of the response to salinity acclimation between ecotypes. No pattern of relative expression dominated among these genes, suggesting that neither gains nor losses of plasticity dominated the changes in expression patterns between the ecotypes. These data demonstrate that multiple patterns of changes in gene expression plasticity can occur following colonization of novel habitats.

The nature and consequences of cognitive deficits among tobacco smokers with HIV: a comparison to tobacco smokers without HIV.

HIV-infected smokers lose more years of life to tobacco-related disease than HIV. Since neurocognitive deficits are common among those with HIV and are associated with smoking persistence, these deficits may be a unique barrier to smoking cessation among HIV-infected smokers. Documenting unique differences in and correlates of cognition among HIV-infected smokers is a critical step towards developing a population-specific tobacco cessation treatment. We compared neurocognitive function between HIV-infected (n = 103) and HIV-uninfected smokers (n = 70), accounting for demographic and smoking-related variables. We also evaluated whether HIV-related health outcomes (e.g., CD4 count, viral load, depression ratings, quality of life [QoL]) and HAART adherence were associated with cognition. Participants completed neurocognitive tasks (N-back and Continuous Performance Task [CPT]) measuring working memory, attention, and processing speed, and intra-individual variability. Stepwise regression models were conducted and validated with resampling techniques. HIV-infected smokers performed worse than HIV-uninfected smokers on working memory, processing speed, and intra-individual variability (all p < 0.01). ROC analysis for the model including cognitive measures demonstrated 85% area under the curve, which indicates "good prediction" for distinguishing between HIV-infected and HIV-uninfected smokers. This was a significant improvement over the model including demographic and smoking-related variables only (p = 0.0003). Among HIV-infected smokers, neurocognitive performance was negatively associated with QoL and depression ratings. Smoking cessation interventions for HIV-infected smokers should consider cognitive neurorehabilitation as a potential strategy to decrease the likelihood of nicotine relapse and decrease tobacco-related morbidity in this population.

Association Between Depression and Condom Use Differs by Sexual Behavior Group in Patients with HIV.

Identifying a relationship between depression and sexual risk behavior in HIV-infected patients could establish a mechanism to enhance prevention efforts. We conducted a cross-sectional analysis using data from the University of Pennsylvania Center for AIDS Research and used ordinal logistic regression to measure the association between depression and non-condom use. 716 men who have sex with men (MSM), 262 heterosexual men and 277 heterosexual women were included. The association between depression and non-condom use was strongest in heterosexual men with and without HIV-infected regular partners (OR 8.53, 95% CI 1.18-61.89 and OR 2.30, 95% CI 0.99-5.36 respectively), but absent in heterosexual women regardless of partner. Although the OR was low in MSM overall, an association was detected in MSM without HIV-infected regular partners (OR 2.44, 95% CI 1.39-4.31). In conclusion, we demonstrated an association between depression and non-condom use driven by heterosexual men and MSM without HIV-infected regular partners. Sexual risk should be addressed when intervening on depressive symptoms in these subgroups.

Maternal stress has divergent effects on gene expression patterns in the brains of male and female threespine stickleback.

Maternal stress can have long-term effects on neurodevelopment that can influence offspring performance and population evolutionary trajectories. To examine the mechanistic basis for these neurodevelopmental effects of maternal stress, we used RNA-seq to assess differential gene expression across the brain transcriptome of adult male and female threespine stickleback (Gasterosteus aculeatus) from stressed and unstressed mothers. We identified sexually divergent effects of maternal stress on the brain transcriptome. In males, genes that were upregulated by maternal stress were enriched for processes involved in synaptic function and organization and steroid hormone-mediated signalling pathways, whereas in females genes that were upregulated by maternal stress were enriched for processes involved in protein translation and metabolic functions. The expression of several genes involved in the hypothalamic-pituitary-interrenal response to stress and epigenetic processes such as the regulation of DNA methylation patterns and miRNAs increased in males and not in females. These data suggest that maternal stress has markedly different effects on cellular pathways in the brains of male and female offspring of mothers that are exposed to stress, which could have important implications when assessing the long-term ecological and evolutionary impacts of stress across generations.